ELECTRICALLY CONDUCTIVE COMPOSITIONS AND METHOD OF
MANUFACTURE THEREOF
CROSS-REFERENCE TO RELATED APPLICATION
This application claims benefit to U.S. Provisional Patent Application Serial Number
60/494,678 filed August 12, 2003, which is fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
This disclosure relates to electrically conductive compositions and methods of
manufacture thereof.
Articles made from organic polymers are commonly utilized in material-handling and
electronic devices such as packaging film, chip carriers, computers, printers and
photocopier components where electrostatic dissipation or electromagnetic shielding
are important requirements. Electrostatic dissipation (hereinafter ESD) is defined as
the transfer of electrostatic charge between bodies at different potentials by direct
contact or by an induced electrostatic field. Electromagnetic shielding (hereinafter
EM shielding) effectiveness is defined as the ratio (in decibels) of the proportion of an
electromagnetic field incident upon the shield that is transmitted through it. As
electronic Devices become smaller and faster, their sensitivity to electrostatic charges
is increased and hence it is generally desirable to utilize organic polymers that have
been modified to provide improved electrostatically dissipative properties. In a
similar manner, it is desirable to modify organic polymers so that they can provide
improved electromagnetic shielding while simultaneously retaining some or all of the
advantageotis mechanical properties of the organic polymers.
Conductive fillers such as graphite fibers derived from pitch and polyacrylonitrile
having diameters larger than 2 micrometers are often incorporated into organic
polymers to improve the electrical properties and achieve ESD and EM shielding.
However, because of the large size of these graphite fibers, the incorporation of such
fibers generally causes a decrease in the mechanical properties such as impact. There
accordingly remains a need in the art for conductive polymeric compositions, which
while providing adequate ESD and EM shielding, can retain their mechanical
properties.
BRIEF DESCRIPTION OF THE INVENTION
A method for manufacturing a conductive composition comprises blending a polymer
precursor with a single wall carbon nanotube composition; and polymerizing the
polymer precursor to form an organic polymer.
DETAILED DESCRIPTION OF THE INVENTION
Disclosed herein are compositions comprising organic polymers and a single wall
carbon nanotube (SWNT) composition that are manufactured by adding the SWNTs
to the polymer precursors either prior to or during the process of polymerization of the
polymer precursor. Disclosed herein are compositions comprising organic polymers
and an efficient amount of single wall carbon nanotube (SWNTs). By an efficient
amount of SWNTs is meant that amount which is sufficient for the compositions to
have a bulk volume resistivity less than or equal to about 1012 ohm-cm, while
displaying impact properties greater than or equal to about 5 kilojoules/square meter
and a Class A surface finish. In one embodiment, the composition has a surface
resistivity greater than or equal to about 10s ohm/square (ohm/sq) and a bulk volume
resistivity less than or equal to about 10' ohm-cm while displaying impact properties
greater than or equal to about 5 kilojoules/square meter and a Class A surface finish.
In another embodiment, the composition has a surface resistivity of less than or equal
to about 10K ohm/square (ohm/sq). and a bulk volume resistivity of greater than or
equal to about IOK ohm-cm, while displaying impact properties greater than or equal
to about 5 kilojoules/square meter and a Class A surface finish. In one embodiment,
the composition has impact properties of greater than or equal to about 10
kilojoules/square meler, while in another embodiment, the composition has impact
properties of greater than or equal to about 15 kilojoules/square meter.
In one embodiment, the composition has a bulk volume resistivity of less than or
equal to about 1,01 0 ohm-cm while displaying impact properties greater than or equal
to about 5 kilojoules/square meter and a Class A surface finish. In another
embodiment, the composition has a bulk volume resistivity of less than or equal to
about 108 ohm-cm while displaying impact properties greater than or equal to about 5
kilojoules/square meter and a Class A surface finish. In yet another embodiment, the
composition has a bulk volume resistivity of less than or equal to about 10" ohm-cm
while displaying impact properties greater than or equal to about 5 kilojoules/square
meter and a Class A surface finish.
Such compositions can be advantageously utilized in computers, electronic goods,
semi-conductor components, circuit boards, or the like that need to be protected from
electrostatic charges. They may also be used advantageously in automotive body
panels both for interior and exterior components of automobiles that can be
electrostatically painted if desired.
In one embodiment, the SWNTs are added to the polymer precursors prior to the
process of polymerization. In another embodiment, the SWNTs are added during the
process of polymerization of the polymer precursors. In yet another embodiment, a
proportion of the SWNTs are added to the polymer precursors prior to the process of
polymerization, while another proportion of the SWNTs are added to the polymer
precursors during the process of polymerization. The polymer precursors, as defined
herein, comprise reactive species that are monomeric, oligomeric or polymeric and
which can undergo additional polymerization.
The organic polymers that may be obtained from the polymerization of the polymer
precursors are thermoplastic polymers, blends of thermoplastic polymers, or blends of
thermoplastic polymers with thermosetting polymers. The organic polymers may also
be a blend of polymers, copolymers, terpolymers, interpenetrating network polymers
or combinations comprising at least one of the foregoing organic polymers. Examples
of thermoplastic polymers include polyacetals, polyacrylics, polycarbonates,
polyalkyds, polystyrenes, polyesters, polyamides, polyaramides, polyamideimides,
polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides,
polysulfones. polyimides, polyetherimides, polytetrafluoroethylenes,
polyetherketones, polyether etherketones, polyether ketone ketones,
polybenzoxazoles, polyoxadiazoles, polybenzothiazinophenothiazines,
polybenzothiazoles. polypyrazinoquinoxalines, polypyromellitimides,
polyquinoxa'lines, polybenzimidazoles, polyoxindoles, polyoxoisoindolines,
polydioxoisoindolines, polytriazines, polypyridazines, polypiperazines, polypyridines.
polypiperidines, polytriazoles, polypyrazoles, polycarboranes,
polyoxabicyclononanes, polydibenzofurans. polyphthalides, polyacetals,
polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl
ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates,
polysulfides, polythioesters, polysulfones, polysulfonamides, polyureas,
polyphosphazenes, polysilazanes, or the like, or combinations comprising at least one
of the foregoing organic polymers.
Specific examples of blends of thermoplastic polymers include acrylonitrilebutadiene-
styrene/nylon, polycarbonate/acrylonitrile-butadiene-styrene,
polyphenylene ether/polystyrene, polyphenylene ether/polyamide,
polycarbonate/polyester, polyphenylene ether/polyolefin, and combinations
comprising at least one of the foregoing blends of thermoplastic polymers.
In one embodiment, an organic polymer that may be used in the composition is a
polyarylene ether. The term poly(arylene ether) polymer includes polyphenylene
ether (PPE),,and poly(arylene ether) copolymers; graft copolymers; poly(arylene
ether) ether ionomers; and block copolymers of alkenyl aromatic compounds with
poly(arylene ether)s, vinyl aromatic compounds, and poly(arylene ether), and the like;
and combinations comprising at least one of the foregoing. Poly(arylene ether)
polymers per se, are polymers comprising a plurality of structural units of the formula
(I):
(Figure Removed)
wherein.for each structural unit, each Q1 is independently hydrogen, halogen, primary
or secondary lower alkyl (e.g., alky] containing up to 7 carbon atoms), phenyl,
haloalkyl, aminoalkyl, hydrocarbonoxy, halohydrocarbonoxy wherein at least two
carbon atoms separate the halogen and oxygen atoms, or the like; and each Q is
independently hydrogen, halogen, primary or secondary lower alky], phenyl,
haloalkyl, hydrocarbonoxy, halohydrocarbonoxy wherein at least two carbon atoms
separate the halogen and oxygen atoms, or the like. Preferably, each Q1 is alkyl or
phenyl, especially C1-4 alkyl, and each Q2 is hydrogen.
Both homopolymer and copolymer poly(arylene ether)s are included. The preferred
homopolymers are those containing 2,6-dimethylphenylene ether units. Suitable
copolymers include random copolymers containing, for example, such units in
combination with 2,3,6-trimethyl-l,4-phenylene ether units or copolymers derived
from copolymerization of 2,6-dimethylphenol with 2,3,6-trimethylphenol. Also
included are poly(arylene ether) containing moieties prepared by grafting vinyl
monomers or polymers such as polystyrenes, as well as coupled poly(arylene ether) in
which coupling agents such as low molecular weight polycarbonates, quinones,
heterocycles and formals undergo reaction with the hydroxy groups of two
poly(arylene ether) chains to produce a higher molecular weight polymer.
Poly(arylene ether)s further include combinations comprising at least one of the
above.
The poly(arylene ether) has a number average molecular weight of about 10,000 to
about 30,000 grams/mole (g/mole) and a weight average molecular weight of about
30,000 to about 60,000 g/mole, as determined by gel permeation chromatography.
The poly(arylene ether) may have an intrinsic viscosity of about 0.10 to about 0.60
deciliters per gram (dl/g), as measured in chloroform at 25°C. It is also possible to
utilize a high intrinsic viscosity poly(arylene ether) and a low intrinsic viscosity
poly(arylene ether) in combination. . Determining an exact ratio, when two intrinsic
viscosities are used, will depend somewhat on the exact intrinsic viscosities of the
poly(arylene ether) used and the ultimate physical properties that are desired.
The poly(arylene ether) is typically prepared by the oxidative coupling of at least one
monohydroxyaromatic compound such as 2,6-xylenol or 2,3,6-trimethylphenol.
Catalyst systems are generally employed for such coupling; they typically contain at
least one heavy metal compound such as a copper, manganese or cobalt compound,
usually in combination with various other materials.
Particularly useful poly(arylene ether)s for many purposes are those, which comprise
molecules having at least one aminoalkyl-containing end group. The aminoalkyl
radical is typically located in an ortho position to the hydroxy group. Products
containing such end groups may be obtained by incorporating an appropriate primary
or secondary monoamine such as di-n-butylamine or dimethylamine as one of the
constituents of the oxidative coupling reaction mixture. Also frequently present are 4-
hydroxybiphenyl end groups, typically obtained from reaction mixtures in which a byproduct
diphenoquinone is present, especially in a copper-halide-secondary or tertiary
amine system. A substantial proportion of the polymer molecules, typically
constituting as much as about 90% by weight of the polymer, may contain at least one
of the aminoalkyl-containing and 4-hydroxybiphenyl end groups.
In another embodiment, the organic polymer used in the composition may be a
polycarbonate. Polycarbonates comprising aromatic carbonate chain units include
compositions having structural units of the formula (11):
(Figure Removed)
in which the R1 groups are aromatic, aliphatic or alicyclic radicals. Preferably, R1 is
an aromatic organic radical and, more preferably, a radical of the formula (111):
(Figure Removed)
wherein each of A1 and A2 is a monocyclic divalent aryl radical and Y1 is a bridging
radical having zero, one, or two atoms which separate A1 from A2. In an exemplary
embodiment, one atom separates A1 from A2. Illustrative examples of radicals of this
type are -O-, -S-, -S(O)-, -S(O2)-, -C(O)-, methylene, cyclohexyl-methylene,
2-[2,2,l]-bicycloheptylidene. ethylidene, isopropylidene, neopentylidene,
cyclohexylidene, cyclopentadecylidene, cyclododecylidene, adamantylidene, or the
like. The bridging radical Y1 can be a hydrocarbon group or a saturated hydrocarbon
group such as methylene, cyclphexylidene or isopropylidene.
Polycarbonates may be produced by the Schotten-Bauman interfacial reaction of the
carbonate precursor with dihydroxy compounds. Typically, an aqueous base such as
sodium hydroxide, potassium hydroxide, calcium hydroxide, or the like, is mixed with
an organic, v/ater immiscible solvent such as benzene, toluene, carbon disulfide, or
dichloromethane, which contains the dihydroxy compound. A phase transfer agent is
generally used to facilitate the reaction. Molecular weight regulators may be added
either singly or in admixture to the reactam mixture. Branching agents, described
forthwith may also be added singly or in admixture.
Aromatic dihydroxy compound comonomers that can be employed in the disclosure
comprise those of the general formula (IV):
(Figure Removed)
wherein A'SsSelected from divalent substituted and unsubstituted aromatic radical.
In some embodiments, A2 has the structure of formula (V):
(Figure Removed)
wherein G1 represents an aromatic group, such as phenylene, biphenylene,
naphthylene, etc. E may be an alkylene or alkylidene group such as methylene,
ethylene, etrry,ljdene, propylene, propylidene, isopropylidene, butylene, butylidene,
isobutyliderieyamylene, amylidene, isoamylidene, etc. and may consist of two or more
alkylene or Slkylidene groups connected by a moiety different from alkylene or
alkylidene, sucn as an aromatic linkage; a tertiary amino linkage; an ether linkage; a
carbonyl linkage; a silicon-containing linkage; or a sulfur-containing linkage such as
sulfide, sulsfpxide, .sulfone, etc.; or a phosphorus-containing linkage such as
phosphinyl, phosphonyl, or the like. In addition, E may be a cycloaliphatic group. R1
represents hydrogen or a monovalent hydrocarbon group such as alkyl, aryl, aralky),
alkaryl, or cycloalkyl. Y1 may be an inorganic atom such as halogen (fluorine,
bromine, chlorine, iodine); an inorganic group such as nitro; an organic group such as
alkenyl, allyl, or R1 above, or an oxy group such as OR; it being only necessary that
Y1 be inert to and unaffected by the reactants and reaction conditions used to prepare
the polymer. The letter m represents any integer from and including zero through the
number of positions on G1 available for substitution; p represents an integer from and
including zero through the number of positions on E available for substitution; "t"
represents an integer equal to at least one; "s" is either zero or one; and "u" represents
any integer including zero.
Suitable examples of E include cyclopentylidene, cyclohexylidene, 3,3,5-
trimethylcyclohexylidene, methylcyclohexylidene, 2-[2.2.1]-bicycloheptylidene,
neopentylidene, cyclopentadecylidene, cyclododecylidene, adamantylidene, etc.); a
sulfur-containing linkage, such as sulfide, sulfoxide or sulfone; a phosphoruscontaining
linkage, such as phosphinyl, phosphonyl; an ether linkage; a carbonyl
group; a tertiary nitrogen group; or a silicon-containing linkage such as silane or
siloxy. In the aromatic dihydroxy comonomer compound (III) in which A2 is
represented by formula (IV) above, when more than one Y1 substituent is present,
they may be the same or different. The same holds true for the R1 substituent. Where
s is zero in formula (IV) and u is not zero, the aromatic rings are directly joined with
no intervening alkylidene or other bridge. The positions of the hydroxyl groups and
Y1 on the aromatic nuclear residues G1 can be varied in the ortho, meta, or para
positions and the groupings can be in vicinal, asymmetrical or symmetrical
relationship, where two or more ring carbon atoms of the hydrocarbon residue are
substituted with Y1 and hydroxyl .groups. In some particular embodiments, the
parameters "t", "s", and "u" are each one; both G1 radicals are unsubstituted
phenylene radicals; and E is an alkylidene group such as isopropylidene. In particular
embodiments, both G1 radicals are p-phenylene, although both may be o- or mphenylene
or one o- or m-phenylene and the other p-phenylene.Suitable examples of
aromatic dihydroxy compounds of formula (IV) are illustrated by 2,2-bis(4-
hydroxypheny1)propane (bisphenol A); 2,2-bis(3-chloro-4-hydroxyphenyl)propane;
2,2-bis(3-bromo-4-hydroxyphenyl)propane; 2,2-bis(4-hydroxy-3-
inethylp]ienyl)propane; 2,2-bis(4-hydroxy-3-isopropylphenyl)propane; 2,2-bis(3-tbutyl-
4-hydroxyphenyl)propane; 2,2-bis(3-phenyl-4-hydroxyphenyl)propane; 2,2-
bis(3,5-dichloro-4-hydroxyphenyl)propane: 2,2-bis(3,5-dibromo-4-
hydroxyphenyOpropane; 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane; 2,2-bis(3-
chloro-4-hydroxy-5-methylphenyl)propane; 2,2-bis(3-bromo-4-hydroxy-5-
methylphenyl)propane; 2,2-bis(3-ch)oro-4-hydroxy-5-isopropylphenyl)propane; 2,2-
bis(3-bromo-4-hydroxy-5-isopropylphenyl)propane; 2,2-bis(3-t-butyl-5-chloro-4-
hydroxyphenyl)propane; 2,2-bis(3-bromo-5-t-butyl-4-hydroxyphenyl)propane; 2,2-
bis(3-chloro-5-phenyl-4-hydroxypheny])propane; 2,2-bis(3-bromo-5-phenyl-4-
hydroxyphenyOpropane; 2,2-bis(3,5-disopropyl-4-hydroxyphenyi)propane; 2,2-
bis(3,5-di-t-butyl-4-hydroxyphenyl)propane; 2,2-bis(3,5-diphenyl-4-
hydroxyphenyl)propane; 2,2-bis(4-hydroxy-2,3,5,6-tetrachlorophenyl)propane; 2,2-
bis(4-hydroxy-2,3,5,6-tetrabromophenyl)propane; 2,2-bis(4-hydroxy-2,3,5,6-
tetramethylpheny])propane; 2,2-bis(2,6-dichloro-3,5-dimethyl-4-
hydroxyphenyl)propane: 2,2-bis(2,6-dibromo-3,5-dimethyl-4-
hydroxypheny!)propane; 1,1 -bis(4-hydroxypheny])cyclohexane; 1,) -bis(3-chloro-4-
hydroxyphenyl)cyclohexane; 1,1 -bis(3-bromo-4-hydroxyphenyl)cyclohexane; 1,1-
bis(4-hydroxy-3-methylphehy])cyclohexane; 1,1 -bis(4-hydroxy-3-
isopropylphenyl)cyclohexane; 1,1 -bis(3-t-butyl-4-hydroxyphenyl)cyclohexane; 1,1-
bis(3-phenyl-4-hydroxyphenyl)cyclohexane; . 1,1 -bis(3,5-dichloro-4-
hydroxyphenyl)cyclohexane; l,l-bis(3,5-dibroino-4-hydroxyphenyl)cyclohexane;
1,1 -bis(3,5-dimethy]-4-hydroxyphenyl)cyclohexane; 1,1 -bis(3-chloro-4-hydroxy-5-
methylphenyl)cyclohexane; 1,1 -bis(3-bromo-4-hydroxy-5-
methylphenyl)cyclohexane; ], 1 -bis(3-chloro-4-hydroxy-5-
isopropylphenyl)cyclohexane; 1,1 -bis(3-bromo-4-hydroxy-5-
isopropylphenyl)cyc!ohexane; ], 1 -bis(3-t-butyl-5-chJoro-4-
hydroxyphenyl)cyclohexane; 1,1 -bis(3-bromo-5-t-butyl-4-
hydroxyphenyl)cyclohexane; 1 ,l-bis(3-chloro-5-phenyl-4-
hydroxyphenyl)cyclohexane; 1,1 -bis(3-bromo-5-phenyl-4-
hydroxyphenyl)cyclohexane; l,l-bis(3,5-disopropyl-4-hydroxyphenyl)cyclohexane;
[l.]-bis(3,5-di-t-butyl-4-hydroxyphenyl)cyclohexane:
hydroxyphenyl)cyclohexane;
fetrachlorophenyl)cyclohexane:
tetrabromophenyl)cyclohexane;
l,l-bis(3,5-diphenyl-4-
1,1-bis(4-hydroxy-2,3,5,6-
l,l-bis(4-hydroxy-2,3,5,6-
l,l-bis(4-hydroxy-2,3,5,6-
tetramethylphenyl)cyclohexane; l,l-bis(2,6-dichloro-3,5-dimethyl-4-
hydroxyphenyl)cyclohexane: 1,1 -bis(2,6-dibromo-3,5-dimethyl-4-
hydroxyphenyl)cyclohexane; l,I-bis(4-hydroxyphenyl)-3,3,5-trJmethylcyclohexane:
l,l-bis(3-chloro-4-hydroxyphenyl)-3,3,5-trimethylcyclohexane; l,l-bis(3-bromo-4-
hydroxyphenyl)-3,3,5-trimethylcyclohexane; 1,1 -bis(4-hydroxy-3-methylphenyl)-
3,3,5-trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane:
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane:
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane;
trimethylcyclohexane; 1,
trimethylcyclohexane;
],]-bis(4-hydroxy-3-isopropylpheny])-3,3,5-
. l,l-bis(3-t-butyl-4-hydroxyphenyl)-3,3,5-
l,l-bis(3-phenyl-4-hydroxyphenyl)-3,3,5-
1,1 -bis(3,5-dichloro-4-hydroxyphenyl)-3,3,5-
l,]-bis(3,5-dibromo-4-hydroxyphenyl)-3,3,5-
1,1 -bis(3,5-dimethyl-4-hydroxyphenyI)-3,3,5-
1,1 -bis(3-chloro-4-hydroxy-5-methylphenyl)-3,3,5-
1,1 -bis(3-bromo-4-hydroxy-5-methylphenyl)-3,3,5-
l,l-bis(3-chloro-4-hydroxy-5-isopropylphenyl)-3,3,5-
1,1 -bis(3-bromo-4-hydroxy-5-isopropylphenyl)-3,3,5-
1,1 -bis(3-t-butyl-5-chloro-4-hydroxyphenyl)-3,3,5-
1,1 -bis(3-bromo-5-t-butyl-4-hydroxyphenyl)-3,3,5-
bis(3-chloro-5-phenyl-4-hydroxyphenyl)-3,3,5-
1,1 -bis(3-bromo-5-phenyl-4-hydroxyphenyl)-3,3,5-
l,l-bis(3,5-disopropyl-4-hydroxyphenyl)-3,3,5-
I, I -bis(3,5-di-t-butyl-4-hydroxyphenyl)-3,3,5-
1,1 -bis(3,5-diphenyl-4-hydroxypheny])-3,3,5-
l,l-bis(4-hydroxy-2,3,5,6-tetrachlorophenyl)-3,3,5-
1,1 -bis(4-hydroxy-2,3,5,6-tetrabromophenyl)-3,3,5-
l,l-bis(4-hydroxy-2,3,5,6-tetramethylphenyl)-3,3,5-
1,1 -bis(2,6-dichloro-3,5-dimethyl-4-hydroxyphenyl)-3,3,5-
l,l-bis(2,6-dibromo-3,5-dimethyl-4-hydroxyphenyl)-3,3,5-
trimethylcyclohexane; 4,4'dihydroxy-],l-biphenyl; 4,4'-dihydroxy-3, 3'-dimethyl-
1,1 -biphenyl; 4,4'-dihydroxy-3,3'-dioctyl-1,1 -biphenyl; 4,4'-dihydroxydiphenylether;
4,4'-dihydroxydipheny]thioether; 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene; 1,3-
bis(2-(4-hydroxy-3-methylphenyl)-2-propyl)benzene; .l,4-bis(2-(4-hydroxyphenyl)-2-
propyl)benzene and 1,4-bis(2-(4-hydroxy-3-methylphenyl)-2-propyl)benzene. The
preferred aromatic dihydroxy compound is Bisphenol A (BPA).
Other bisphenol compounds that may be represented by formula (IV) include those
where X is -O-, -S-, -SO- or-SOj- Some examples of such bisphenol compounds are
bis(hydroxyaryl)ethers such as 4,4'-dihydroxy diphenylether, 4,4'-dihydroxy-3,3'-
dimethylphenyl ether, or the like; bis(hydroxy diaryl)sulfides, such as 4,4'-dihydroxy
diphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide, or the like;
bis(hydroxy diaryl) sulfoxides, such as, 4,4'-dihydroxy diphenyl sulfoxides, 4,4'-
dihydroxy-3,3'-dimethyl diphenyl sulfoxides, or the like; bis(hydroxy diaryl)sulfones,
such as 4,4'-dihydroxy diphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyl diphenyl
sulfone, or the like; or combinations comprising at least one of the foregoing
bisphenol compounds.
Other bisphenol compounds that may be utilized in the polycondensation of
polycarbonate are represented by the formula (VI)
(Figure Removed)
wherein, Rf , is a halogen atom of a hydrocarbon group having 1 to 10 carbon atoms or
a halogen substituted hydrocarbon group; n is a value from 0 to 4. When n is at least
2, R1 may be the same or different. Examples of bisphenol compounds that may be
represented by the formula (V), are resorcinol, substituted resorcinol compounds such
as 3-methyl resorcin, 3-ethyl resorcin, 3-propyl resorcin, 3-butyl resorcin, 3-t-butyl
resorcin, 3-phenyl resorcin, 3-cumyl resorcin, 2,3,4,6-tetrafloro resorcin, 2,3,4,6-
tetrabromo resorcin, or the like; catechol, hydroquinone, substituted hydroquinones,
such as 3-methyl hydroquinone, 3-ethyl hydroquinone, 3-propyl hydroquinone, 3-
butyl hydroquinone, 3-t-butyl hydroquinone, 3-phenyl hydroquinone, 3-cumyl
hydroquinone, 2,3,5,6-tetramethyl hydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone,
2,3,5,6-tetrafloro hydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the .like; or
:ombi nations comprising at least one of the foregoing bispheno] compounds.
Bisphenol compounds such as 2,2, 2', 2'- tetrahydro-3, 3, 3', 3'- tetramethyl-1, 1'-
spirobi-[lH-indene]-6, 6'- diol represented by the following formula (VII) may also be
used.
(Figure Removed)
The preferred bisphenol compound is bisphenol A.
Typical carbonate precursors include the carbonyl halides, for example carbonyl
chloride (phosgene), and carbonyl bromide; the bis-haloformates, for example, the
bis-haloformates of dihydric phenols such as bisphenol A, hydroquinone, or the like,
and the bis-haloformates of glycols such as ethylene glycol and neopentyl glycol; and
the diary), carbonates, such as diphenyl carbonate, di(tolyl) carbonate, and
di(naphthyl) carbonate. The preferred carbonate precursor for the interfacial reaction
is carbonyl chloride.
It is also possible to employ polycarbonates resulting from the polymerization of two
or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol
or with a hydroxy- or acid-terminated polyester or with a dibasic acid or with a
hydroxy acid or with an aliphatic diacid in the event a carbonate copolymer rather
than a homopolymer is desired for use. Generally, useful aliphatic diacids have about
2 to about 40 carbons. A preferred aliphatic diacid is dodecanedioic acid.
Branched polycarbonates, as well as blends of linear polycarbonate and a branched
polycarbonate may also be used in the composition. The branched polycarbonates
may be prepared by adding a branching agent during polymerization. These
branching agents may comprise polyfunctional organic compounds containing at least
three functional groups, which may be hydroxyl, carboxyl, carboxylic anhydride,
haloformyl, and combinations comprising at least one of the foregoing branching
agents. Specific examples include trimellitic acid, trimellitic anhydride, trimellitic
trichloride, tris-p-hydroxy phenyl ethane, isatin-bis-phenol, tris-phenol TC (1,3,5-
tris((p-hydroxyphenyl)isopropyl)benzene), tris-phenol PA (4(4(1,l-bis(phydrdxyphenyl)-
ethyl) a,a-dimethyl benzyl)phenol), 4-chloroformyl phthalic
anhydride, trimesic acid, benzophenone tetracarboxylic acid, or the like, or
combinations comprising at least one of the foregoing branching agents. The
branching agents may be added at a level of about 0.05 to about 2.0 .weight percent
(wt%), based upon the total weight of the polycarbonate in a given layer.
In one embodiment, the polycarbonate may be produced by a melt polycondensation
reaction between a dihydroxy compound and a carbonic acid diester. Examples of the
carbonic acid diesters that may be utilized to produce the polycarbonates are diphenyl
carbonate, bis(2,4-dichlorophenyl)carbonate, bis(2,4,6-trichlorophenyl) carbonate,
bis(2-cyanophenyl) carbonate, bis(o-nitrophenyl) carbonate, ditolyl carbonate, mcresyl
carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, bis
(methylsalicyl)carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate,
dicyclohexyl carbonate, or. the like, or combinations comprising at least one of the
foregoing carbonic acid diesters. The preferred carbonic acid diester is diphenyl
carbonate or bis (methylsalicyl)carbonate.
Preferably, the number average molecular weight of the polycarbonate is about 3,000
to about 1,000,000 grams/mole (g/mole). Within this range, it is desirable to have a
number average 'molecular weight of greater than or equal to about 10,000, preferably
greater than or equal to about 20,000, and more preferably greater than or equal to
about 25,000 g/mole. Also desirable is a number average molecular weight of less
than or equal to about 100,000, preferably less than or equal to about 75,000, more
preferably less than or equal to about 50,000, and most preferably less than or equal to
about 35, 000 g/mole.
Cycloaliphatic polyesters are generally prepared by reaction of a diol with a dibasic
acid or derivative. The diols useful in the preparation of the cycloaliphatic polyester
polymers are straight chain, branched, or cycloaliphatic, preferably straight chain or
branched alkane diols, and may contain from 2 to 12 carbon atoms,
Suitable examples of diols include ethylene glycol, propylene glycol, i.e., 1,2- and
1,3-propylene glycol; butane diol, i.e., 1,3- and 1,4-butane diol; diethylene glycol,
2,2-dimethyl-l,3-propane diol, 2-ethyl, 2-methyl, 1,3-propane diol, 1,3- and 1,5-
pentane diol, dipropylene glycol, 2-methyl-1,5-pentane diol, 1,6-hexane diol, 1,4-
cyclohexane dimethanol and particularly its cis- and trans-isomers, triethylene glycol,
1,10-decane diol, and mixtures of any of the foregoing. Particularly preferred is
dimethanol bicyclo octane, dimethanol decalin, a cycloaliphatic diol or chemical
equivalents thereof and particularly 1,4-cyclohexane dimethanol or its chemical
equivalents. If 1,4-cyclohexane dimethanol is to be used as the diol component, it is
generally preferred to use a mixture of cis- to trans-isomers in mole ratios of about 1:4
to about 4:1. Within this range, it is generally desired to use a mole ratio of cis- to
trans-isomers of about ! :3.
The diacids useful in the preparation of the cycloaliphatic polyester polymers are
aliphatic diacids that include carboxylic acids having two carboxyl groups each of
which are attached to a saturated carbon in a saturated ring. Suitable examples of
cycloaliphatic acids include decahydro naphthalene dicarboxylic acid, norbornene
dicarboxylic acids, bicyclo octane dicarboxylic acids. Preferred cycloaliphatic diacids
are 1,4-cyclohexanedicarboxylic acid and trans-1,4-cyclohexanedicarboxylic acids.
Linear aliphatic diacids are also useful when the polyester has at least one monomer
containing a cycloaliphatic ring. Illustrative examples of linear aliphatic diacids are
succinic acid, adipic acid, dimethyl succinic acid, and azelaic acid. Mixtures of diacid
and diols may also be used to make the cycloaliphatic polyesters.
Cyclohexanedicarboxylic acids and their chemical equivalents can be prepared, for
example, by the hydrogenation of cycloaromatic diacids and corresponding
derivatives such as isophthalic acid, terephthalic acid or naphthalenic acid in a
suitable solvent, water or acetic acid at room temperature and at atmospheric pressure
using suitable catalysts such as rhodium supported on a suitable carrier of carbon or
alumina. They may also be prepared by the use of an inert liquid medium wherein an
acid is at least partially soluble under reaction conditions and a catalyst of palladium
or ruthenium in carbon or silica is used.
Typically, during hydrogenation, two or more isomers are obtained wherein the
carboxylic acid groups are in either the cis- or trans-positions. The cis-and transisomers
can be separated by crystallization with or without a solvent, for example, nheptane,
or by distillation. While the cis-isomer tends to blend better, the transisomer
has-'higher melting and crystallization temperature and is generally preferred.
Mixtures of the cis- and trans-isomers may also be used, and preferably when such a
mixture is used, the trans-isomer will preferably comprise at least about 75 wt% and
the cis-isomer will comprise the remainder based on the total weight of cis- and transisomers
combined. When a mixture of isomers or more than one diacid is used, a
copolyester or a mixture of two polyesters may be used as the cycloaliphatic polyester
resin.
Chemical equivalents of these diacids including esters may also be used in the
preparation of the cycloaliphatic polyesters. Suitable examples of the chemical
equivalents of the diacids are alkyl esters, e.g., dialkyl esters, diaryl esters,
anhydrides, acid chlorides, acid bromides, or the like, or combinations comprising at
least one of the foregoing chemical equivalents. The preferred chemical equivalents
comprise the dialkyl esters of the cycloaliphatic diacids, and the most preferred
chemical equivalent comprises the dimethyl ester of the acid, particularly dimethyltrans-
1,4-Q,y,clohexanedicarboxylate.
Dimethyl-1,4-cyclohexanedicarboxylate can be obtained by ring hydrogenation of
dimethylterephthalate, wherein two isomers having the carboxylic acid groups in the
cis- and trans-positions are obtained. The isomers can be separated, the trans-isomer
being especially preferred. Mixtures of the isomers may also be used as detailed
above.
The polyester polymers are generally obtained through the condensation or ester
interchange polymerization of the diol or diol chemical equivalent component with
the diacid or diacid chemical equivalent component and having recurring units of the
formula (VIII):
(Figure Removed)
wherein R represents an aryl, alkyl or cycloalkyl radical which is the residue of a
straight chain, branched, or cycloaliphatic alkane diol or chemical equivalents thereof;
and R4 is an aryl, alkyl or a cycloaliphatic radical which is the decarboxylated residue
derived from a diacid, with the proviso that at least one of R3 or R4 is a cycloalkyl
group. The aryl radicals may be substituted aryl radicals if desired.
A preferred cycloaliphatic polyester is poly(l,4-cyclohexane- dimethanol-1,4-
cyclohexanedicarboxylate) having recurring units of formula (IX)
(Figure Removed)
wherein in the formula (V111), R3 is a cyclohexane ring, and wherein R4 is a
cyclohexane ring derived from cyclohexanedicarboxylate or a chemical equivalent
thereof and is selected from the cis- or trans-isomer or a mixture of cis- and transisomers
thereof. Cycloaliphatic polyester polymers can be generally made in the
presence of a suitable catalyst such as a tetra(2-ethyl hexyl)titanate, in a suitable
amount, typically about 50 to 400 ppm of titanium based upon the total weight of the
final product. Poly( 1,4-cyclohexanedimethanol-l ,4-cyclohexanedicarboxylate)
generally forms a suitable blend with the polycarbonate.
Preferably, the number average molecular weight of the copolyestercarbonates or the
polyesters is about 3,000 to about 1,000,000 g/mole. Within this range, it is desirable
to have a number average molecular weight of greater than or equal to about 10,000,
preferably greater than or equal to about 20,000, and more preferably greater than or
equal to about 25.000 g/mole. Also desirable is a number average molecular weight
of less than or equal to about 100,000, preferably less than or equal to about 75,000,
more preferably less than or equal to about 50,000, and most preferably less than or
equal to about 35, 000 g/mole.
Another preferred polyester is a polyarylate. Polyarylates generally refers to
polyesters of aromatic dicarboxylic acids and bisphenols. Polyarylate copolymers
that include carbonate linkages in addition to the aryl ester linkages, are termed
polyester-carbonates, and may also be advantageously utilized in the mixtures. The
polyarylates can be prepared in solution or by the melt polymerization of aromatic
dicarboxylic acids or their ester forming derivatives with bisphenols or their
derivatives.
In general, it is preferred for the polyarylates to comprise at least one diphenol residue
in combination with at least one aromatic dicarboxylic acid residue. The preferred
diphenol residue, illustrated in formula (X), is derived from a 1,3-dihydroxybenzene
moiety, referred to throughout this specification as resorcinol or resorcinol moiety.
Resorcinol or resorcinol moieties include both unsubstituted 1,3-dihydroxybenzene
and substituted 1,3-dihydroxybenzenes.
In formula-(X), R is at least one of C|.|2 alky] or halogen, and n is 0 to 3. Suitable
dicarboxylic acid residues include aromatic dicarboxylic acid residues derived from
monocyclic -moieties, preferably isophthalic acid, terephthalic acid, or mixtures of
isophthalic' §nd terephthalic acids, or from polycyclic moieties such as diphenyl
dicarboxylie acid, diphenylether dicarboxylic acid, and naphtha!ene-2,6-dicarboxylic
acid, and the like, as well as combinations comprising at least one of the foregoing
polycyclic moieties. The preferred polycyclic moiety is naphthalene-2,6-dicarboxylic
acid.
Preferably, the aromatic dicarboxylic acid residues are derived from mixtures of
isophthalic and/or terephthalic acids as generally illustrated in formula (XI).
Therefore, in one embodiment the polyarylates comprise resorcinol arylate polyesters
as illustrated in formula (XI1)
(Figure Removed)
wherein R is at least one of Ci.i2 alky] or halogen, n is 0 to 3, and m is at least about
8. It is preferred for R to be hydrogen. Preferably, n is zero and m is about 10 and
about 300. The molar ratio of isophthalate to terephthalate is about 0.25:1 to about
4,0:1.
In another embodiment, the polyarylate comprises thermally stable resorcinol arylate
polyesters that have polycyclic aromatic radicals as shown in formula (XIII)
(XIII)
wherein R is at least one of C|.|2 alkyl or halogen, n is 0 to3, and m is at least about 8.
In another embodiment, the polyarylates are copolymerized to form block
copolyestercarbonates, which comprise carbonate and arylate blocks. They include
polymers comprising structural units of the formula (XIV)
(Figure Removed)
wherein each R1 is independently halogen or CM2 alkyl, m is at least 1, p is about 0 to
about 3, each R2 is independently a divalent organic radical, and n is at least about 4.
Preferably n is at least about 10, more preferably at least about 20 and most preferably
about 30 to about 150. Preferably m is at least about 3, more preferably at least about
1.0 and most preferably about 20 to about 200. In an exemplary embodiment m is
present in an amount of about 20 and 50.
It is generally desirable for the weight average molecular weight of the polyarylate to
be about 500 to about 1,000,000 grams/mole (g/mole). In one embodiment, the
polyarylate has a weight average molecular weight of about 10,000 to about 200,000
g/mole. In another embodiment, the polyarylate has a weight average molecular
weight of about 30,000 to about 150,000 g/mole. In yet another embodiment, the
polyarylate has a weight average molecular weight of about 50,000 to about 120,000
g/mole. An exemplary molecular weight for the polyarylate utilized in the cap layer
is 60,000 and 120,000 g/mole.
In one embodiment, the polymer precursor comprises an ethylenically unsaturated
group. The ethylenically unsaturated groups used can be any ethylenically
unsaturated functional group capable of polymerization. Suitable ethylenically
unsaturated functionality includes functionalization that can be polymerized through
radical polymerization or cationic polymerization. Specific examples of suitable
ethylenic unsaturation are groups containing acrylate, methacrylate, vinyl aromatic
polymers such as styrene; vinylether, vinyl ester, N-substituted acrylamide, N-vinyl
amide, maleate esters, fumarate esters, and the like. Preferably, the ethylenic
unsaturation is provided by a group containing acrylate, methacrylate, or styrene
functionality, and most preferably styrene.
The vinyl aromatic resins are preferably derived from polymer precursors that contain
al least 25% by weight of structural units derived from a monomer of the. formula
(Figure Removed)
wherein R5 is hydrogen, lower alkyl or halogen; Z1 is vinyl, halogen or lower alkyl;
and p is from 0 to about 5. These polymers include homopolymers of styrene,
chlorostyrene and vinyltoluene, random copolymers of styrene with one or more
monomers illustrated by acrylonitrile, butadiene, alpha -methylstyrene,
ethylvinylbenzene, divinylbenzene and maleic anhydride, and rubber-modified
polystyrenes comprising blends and grafts, wherein the rubber is a polybutadiene or a
rubbery copolymer of about 98-70% styrene and about 2-30% diene monomer.
Polystyrenes are miscible with polyphenylene ether in all proportions, and any such
blend may contain polystyrene in amounts of about 5-95% and most often about 25-
75%, based on the total weight of the polymers.
In yet another embodiment, polyimides may be used as the organic polymers in the
composition. Useful thermoplastic polyimides have the general formula (XVI)
(Figure Removed)
wherein "a" is greater than or equal to about 1, preferably greater than or equal to
about 10, and more preferably greater than or equal to about 1000; and wherein V is a
tetravalent linker without limitation, as long as the linker does not impede synthesis or
use of the polyimide. Suitable linkers include (a) substituted or unsubstituted,
saturated, unsaturated or aromatic monocyclic and polycyclic groups having about 5
to about 50 carbon atoms, (b) substituted or unsubstituted, linear or branched,
saturated or unsaturated alkyl groups having 1 to about 30 carbon atoms; or
combinations thereof. Suitable substitutions and/or linkers include, but are not
limited to, ethers, epoxides, amides, esters, and combinations thereof. Preferred
linkers include but are not limited to tetravalent aromatic radicals of formula (XV11),
such as
wherein W is a divalent moiety selected from the group consisting of-O-, -S-, -C(O)-,
-SO2-, -SO-, -CyH2y- (y being an integer from 1 to 5), and halogenated derivatives
thereof, including perfluoroalkylene groups, or a group of the formula -O-Z-Owherein
the divalent bonds of the -O- or the -O-Z-O- group are in the 3,3', 3,4', 4,3', or
the 4,4' positions, and wherein Z includes, but is not limited, to divalent radicals of
formula (XVIII).
(Figure Removed)
R in formula (XVI) includes substituted or unsubstituted divalent organic radicals
such as (a) aromatic hydrocarbon radicals having about 6 to about 20 carbon atoms
and halogenated derivatives thereof; (b) straight or branched chain alkylene radicals
having about 2 to about 20 carbon atoms; (c) cycloalkylene radicals having about 3 to
about 20 carbon atoms, or (d) divalent radicals of the general formula (XIX)
wherein Q includes a divalent moiety selected from the group consisting of-O-, -S-, -
C(O)-, -SOr, -SO-, -CyH2y- (y being an integer from 1 to 5), and halogenated
derivatives thereof, including perfluoroalkylene groups.
Preferred classes of polyimides include polyamidimides and polyetherimides,
particularly those polyetherimides that are melt processable.
Preferred polyetherimide polymers comprise more than 1, typically about 10 to about
1000 or more, and more preferably about 10 to about 500 structural units, of the
formula (XX)
(wherein T is -O- or a group of the formula -O-Z-O- wherein the divalent bonds of the
-O- or the -O-Z-O- group are in the 3,3', 3,4', 4,3', or the 4,4' positions, and wherein Z
includes, but is not limited, to divalent radicals of formula (XV1I1) as defined above.
In one embodiment, the polyetherimide may be a copolymer, which, in addition to the
etherimide units described above, further contains polyimide structural units of the
formula (XXI)
(Figure Removed)
wherein R is as previously defined for formula (XVI) and M includes^ but is not
limited to, radicals of formula (XXII).
, and
(Figure Removed)
The polyetherimide can be prepared by any of the methods including the reaction of
an aromatic bis(ether anhydride) of the formula (XX111)
with an organic diamine of the formula (XIV)
H2N-R-NH2 (XXIV)
wherein T and R are defined as described above in formulas (XV]) and (XX).
Illustrative examples of aromatic bis(ether anhydride)s of formula (XX1I1) include
2,2-bis[4-(3"4-dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(3,4-
dicarboxypnejnoxy)diphenyl ether dianhydride; 4,4'-bis(3,4-
dicarboxyphenoxy)diphenyl sulfide dianhydride; 4,4'-bis(3,4-
dicarboxypnenoxy)benzophenone dianhydride; 4,4'-bis(3,4-
dicarboxyph?noxy)diphenyl sulfone dianhydride; 2,2-bis[4-(2,3-
dicarboxyphenoxy)pheny]]propane dianhydride; 4,4'-bis(2,3-
dicarboxyph?,noxy)diphenyl ether dianhydride; 4,4'-bis(2,3-
dicarboxyphen'oxy)dipheny] sulfide dianhydride; 4,4'-bis(2,3-
dicarboxypherioxy)benzophenone dianhydride; 4,4'-bis(2,3-
dicarboxyph.enoxy)diphenyl sulfone dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4-
dicarboxyDhenoxy)diphenyl-2,2-propane dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-
(3,4-dicarb@^'yphenoxy)diphenyl ether dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-
(3,4-dicarbo|yphenoxy)diphenyl sulfide dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-
(3,4-dicarboxyphenoxy)benzophenone dianhydride and 4-(2,3-dicarboxyphenoxy)-4'-
(3,4-dicarb©xyphenoxy)diphenyl sulfone dianhydride, as well as various mixtures
thereof.
The bis(ether;anhydride)s can be prepared by. the hydrolysis, followed by dehydration,
of the reaction product of a nitro substituted phenyl dinitrile with a metal salt of
dihydric phenol compound in the presence of a dipolar, aprotic solvent. A preferred
class of aromatic bis(ether anhydride)s included by formula (XXIII) above includes,
but is not limited to, compounds wherein T is of the formula (XXV)
(Figure Removed)
and the ether linkages, for example, are preferably in the 3,3', 3,4', 4,3', or 4,4'
positions, and mixtures thereof, and where Q is as defined above.
Any diamino compound may be employed in the preparation of the polyimides and/or
polyetherimides. Examples of suitable compounds are ethylenediamine,
propylenediamine, trimethylenediamine, diethylenetriamine, triethylenetertramine,
hexamethylenediamine, heptamethylenediamine, octamethylenediamine,
nonamethylenediamine, decamethylenediamine, 1,12-dodecanediamine, 1,18-
octadecanediamine, 3-methylheptamethylenediamine, 4,4-
dimethylheptamethylenediamine, 4-methylnonamethylenediamine, 5-
methylnonamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,5-
dimethylheptamethylenediamine, 2, 2-dimethylpropylenediamine, N-methyl-bis (3-
aminopropyl) amine, 3-methoxyhexamethylenediamine, 1,2-bis(3-aminopropoxy)
ethane, bis(3-aminopropyl) sulfide, 1,4-cyclohexanediamine, bis-(4-aminocyclohexyl)
methane, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-
diaminotoluene, m-xylylenediamine, p-xylylenediamine, 2-methyl-4,6-diethyl-l,3-
phenylene-diamine, 5-methyI-4,6-diethyl-l,3-phenylene-diamine, benzidine, 3,3'-
dimethylbenzidine, 3,3'-dimethoxybenzidine, 1,5-diaminonaphthalene, bis(4-
aminophenyl) methane, bis(2-chloro-4-amino-3, 5-diethylphenyl) methane, bis(4-
aminophenyl) propane, 2,4-bis(b-amino-t-butyl) toluene, bis(p-b-amino-tbutylphenyl)
ether, bis(p-b-methyl-o-aminophenyl) benzene, bis(p-b-methyl-oaminopentyl)
benzene, 1, 3-diamino-4-isopropylbenzene, bis(4-aminophenyl) sulfide,
bis (4-aminophenyl) sulfone, bis(4-aminophenyl) ether and 1,3-bis(3-aminopropyl)
tetramethyldisiloxane. Mixtures of these compounds may also be present. The
preferred diamino compounds are aromatic diamines, especially m- and pphenylenediamine
and mixtures thereof.
In an exemplary embodiment, the polyetherimide resin comprises structural units
according to -formula (XX) wherein each R is independently p-phenylene or mphenylene
or a mixture thereof and T is a divalent radical of the formula (XXVI)
In general, the reactions can be carried out employing solvents such as odichlorobenzene,
m-cresol/toluene, or the like, to effect a reaction between the
anhydride of formula (XV111) and the diamine of formula (XIX), at temperatures of
about 100°€ to about 250°C. Alternatively, the polyetherimide can be prepared by
melt polymerization of aromatic bis(ether anhydride)s of formula (XV]11) and
diamines of formula (XIX) by heating a mixture of the starting materials to elevated
temperatures with concurrent stirring. Generally, melt polymerizations employ
temperatures of about 200°C to about 400°C. Chain stoppers and branching agents
may also be employed in the reaction. When polyetherimide/polyimide copolymers
are employed, a dianhydride, such as pyromellitic anhydride, is used in combination
with the bis(ether anhydride). The polyetherimide polymers can optionally be
prepared from reaction of an aromatic bis(ether anhydride) with an organic diamine in
which the diamine is present in the reaction mixture at no more than about 0.2 molar
excess, and preferably less than about 0.2 molar excess. Under such conditions the
polyetherimide resin has less than about 15 microequivalents per gram (|aeq/g) acid
titratable groups, and preferably less than about 10 (Jeq/g acid titratable groups, as
shown by titration with chloroform solution with a solution of 33 weight percent
(wt%) hydrobromic acid in glacial acetic acid. Acid-titratable groups are essentially
due to amine end-groups in the polyetherimide resin.
Generally, useful polyetherimides have a melt index of about 0.1 to about 10 grams
per minute (g/min), as measured by American Society for Testing Materials (ASTM)
D1238 at 295°C, using a 6.6 kilogram (kg) weight. In a preferred embodiment, the
polyetherimide resin has a weight average molecular weight (Mw) of about 10,000 to
about 150,000 grams per mole (g/mole), as measured by gel permeation
chromatography, using a polystyrene standard. Such polyetherimide polymers
typically have an intrinsic viscosity greater than about 0.2 deciliters per gram (dl/g),
preferably about 0.35 to about 0.7 dl/g measured in m-cresol at 25°C.
In yet another embodiment, polyamides may be used as the organic polymers in the
composition. Polyamides are generally derived from the polymerization of organic
lactams having from 4 to 12 carbon atoms. Preferred lactams are represented by the
formula (XXVII)
(Figure Removed)
wherein n is about 3 to about 11. A highly preferred lactam is epsilon-caprolactam
havingn equal to 5.
Polyamides may also be synthesized from amino acids having from 4 to 12 carbon
atoms. Preferred amino acids are represented by the formula (XXVIII)
(Figure Removed)
wherein n is about 3 to about 11. A highly preferred amino acid is epsilonaminocaproic
acid with n equal to 5.
Polyamides may also be polymerized from aliphatic dicarboxylic acids having from 4
to 12 carbon atoms and aliphatic diamines having from 2 to 12 carbon atoms.
Suitable and preferred aliphatic dicarboxylic acids are the same as those described
above for the synthesis of polyesters. Preferred aliphatic diamines are represented by
the formula (XXIX)
H2N-(CH2)n NH2 (XX]X)
wherein n is about 2 to about 12. A highly preferred aliphatic diamine is
hexamethylenediamine (H2N(CH2)fiNH2). It is preferred that the molar ratio of the
dicarboxylic acid to the diamine be about 0.66 to about 1.5. Within this range it is
generally desirable to have the molar ratio be greater than or equal to about 0.81,
preferably greater than or equal to about 0.96. Also desirable within this range is an
amount of less than or equal to about 1.22, preferably less than or equal to about 1.04.
The preferred polyamides are nylon 6, nylon 6,6, nylon 4,6, nylon 6, 12, nylon 10, or
ihe like, or combinations comprising at least one of the foregoing nylons.
Synthesis of polyamideesters may also be accomplished from aliphatic lactones
having from 4 to 12 carbon atoms and aliphatic lactams having from 4 to 12 carbon
atoms. The aliphatic lactones are the same as those described above for polyester
synthesis, and the aliphatic lactams are the same as those described above for the
synthesis of polyamides. The ratio of aliphatic lactone to aliphatic lactam may vary
widely depending on the desired composition of the final copolymer, as well as the
relative reactivity of the lactone and the lactam. A presently preferred initial molar
ratio of aliphatic lactam to aliphatic lactone is about 0.5 to about 4. Within this range
a molar ratio of greater than or equal to about 1 is desirable. Also desirable is a molar
ratio of less than or equal to about 2.
The composition may further comprise a catalyst or an initiator. Generally, any
known catalyst or initiator suitable for the corresponding thermal polymerization may
be used. Alternatively, the polymerization may be conducted without a catalyst or
initiator. For example, in the synthesis of polyamides from aliphatic dicarboxylic
acids and aliphatic diamines, no catalyst is required.
For the synthesis of polyamides from lactams, suitable catalysts include water and the
omega-amino acids corresponding to the ring-opened (hydrolyzed) lactam used in the
synthesis. Other suitable catalysts include metallic aluminum alkylates (MAl(OR)sH;
wherein M is an alkali metal or alkaline earth metal, and R is C|-C|2 alkyl), sodium
dihydrobis(2-methoxyethoxy)aluminate, lithium dihydrobis(tert-butoxy)aluminate,
.aluminum alkylates (A1(OR)2R; wherein R is C,-C|2 alkyl), N-sodium caprolactam,
magnesium chloride or bromide salt of epsilon-caprolactam (MgXQ,H|oNO, X=Br or
Cl), dialkoxy aluminum hydride. Suitable initiators include
isophthaloybiscaprolactam, N-acetalcaprolactam, isocyanate epsilon-caprolactam
adducts, alcohols (ROH; wherein R is C|-C|2 alkyl), diols (HO-R-OH; wherein R is R
is C;-C|2 alkylene), omega-aminocaproic acids, and sodium methoxide.
For the synthesis of polyarnideesters from lactones and lactams, suitable catalysts
include metal hydride compounds, such as a lithium aluminum hydride catalysts
(having the formula LiAI(H)x(R')v, where x is about Ito about 4, y is about 0 to about
3, x+y is equal to 4, and R1 is selected from the group consisting of C|-C|2 alky) and
C1-C2 alkoxy; highly preferred catalysts include LiAl(H)(OR2)v wherein R2 is
selected from the group consisting of C|-C« alkyl; an especially preferred catalyst is
LiAl(H)(OC(CH;0:0:t. Other suitable catalysts and initiators include those described
above for the polymerization of poly(epsilon-caprolactam) and poly(epsiloncaprolactone).
A preferred type of polyamide is one obtained by the reaction of a first polyamide and
a polymeric material selected from the group consisting of a second polyamide,
poly(arylene ether), poly(alkenyl aromatic) homopolymer, rubber modified
poly(alkenyl aromatic) resin, acrylonitrile-butadiene-styrene (ABS) graft copolymers,
block copolymer, and combinations comprising two or more of the foregoing. The
first polyamide comprises repeating units having formula (XXX)
(Figure Removed)
wherein R'is a branched or unbranched alkyl group having nine carbons. R1 is
preferably 1,9-nonane and/or 2-methyl-l,8-octane. Polyamide resins are
characterized by the presence of an amide group (-C(O)NH-) which is the
condensation product of a carboxylic acid and an amine. The first polyamide is
typically made by reacting one or more diamines comprising a nine carbon alkyl
moiety with terephthalic acid (1,4-dicarboxy benzene). When employing more than
one diamine the ratio of the diamines can affect some of the physical properties of the
resulting polymer such as the melt temperature. The ratio of diamine to dicarboxylic
acid is typically equimolar although excesses of one or the other may be used to
determine the end group functionality. In addition the reaction can further include
monoamines and monocarboxylic acids which function as chain stoppers and
determine, at least in part, the end group functionality. In some embodiments it is
preferable to have an amine end group content of greater than or equal to about 30
meq/g, and- more preferably greater than or equal to about 40 meq/g.
The secoricfcpolyamide comprises repeating units having formula (XXXI) and/or
formula (XXX11)
(Figure Removed)
wherein R2 js;a branched or unbranched alkyl group having four to seven carbons and
R3 is an arqrnatic group having six carbons or a branched or unbranched alkyl group
having fourto seven carbons. R2 is preferably 1,6-hexane in formula XXXI and 1,5-
pentane in formula XXX11. R3 is preferably 1,4-butane.
The first polyamide has better dimensional stability, temperature resistance, resistance
to moisture^uptake, abrasion resistance and chemical resistance compared to other
polyamides. Hence, compositions comprising the first polyamide exhibit these same
improved properties when compared to comparable compositions containing other
polyamides in place of the first polyamide. In some embodiments the combination of
the first arid'second polyamide improves the compatibility of the polyamide phase
with other phases, such as poly(arylene ether), in multiphasic compositions thereby
improving the impact resistance. Without being bound by theory it is believed that
the second pojyamide increases the amount of available terminal amino groups. The
terminal arinitoo groups can, in some instances, react with components of other phases
or be functiosnalized to react with other phases, thereby improving the compatibility.
The organic polymer is generally present in amounts of about 5 to about 99.999
weight percent (wt%) in the composition. Within this range, it is generally desirable
use the organic polymer or the polymeric blend in an amount of greater than or equal
to about 10 wt%, preferably greater or equal to about 30 wt%, and more preferably
greater than or equal to about 50 wt% of the total weight of the composition. The
organic polymers or polymeric blends are furthermore generally used in amounts less
than or equal to about 99.99 wt%, preferably less than or equal to about 99.5 wt%,
more preferably less than or equal to about 99.3 wt% of the total weight of the
composition
SWNTs used in the composition may be produced by laser-evaporation of graphite,
carbon arc synthesis or the high-pressure carbon monoxide conversion process
(H1PCO) process. These SWNTs generally have a single wall comprising a graphene
sheet with outer diameters of about 0.7 to about 2.4 nanometers (nm). SWNTs having
aspect ratios of greater than or equal to about 5, preferably greater than or equal to
about. 100, more preferably greater than or equal to about 1000 are generally utilized
in the compositions. While the SWNTs are generally closed structures having
hemispherical caps at each end of the respective tubes, it is envisioned that SWNTs
having a single open end or both open ends may also be used. The SWNTs generally
comprise a central portion, which is hollow, but may be filled with amorphous carbon.
In an exemplary embodiment, the purpose of dispersion of the SWNTs in an organic
polymer is to disentangle the SWNTs so as to obtain an effective aspect ratio that is as
close to the aspect ratio of the SWNT as possible. The ratio of the effective aspect
ratio to the aspect ratio is a measure of the effectiveness of dispersion. The effective
aspect ratio is a value that is twice the radius of gyration of a single SWNT divided by
the outer diameter of the respective individual nanotube. It is generally desirable for
the average value of ratio of the effective aspect ratio to the aspect ratio to be greater
than or equal to about 0.5, preferably greater than or equal to about 0.75, and more
preferably greater than or equal to about 0.90, as measured in a electron micrograph at
a magnification of greater than or equal to about 10,000.
In one embodiment, the SWNTs may exist in the form of rope-like-aggregates. These
aggregates are commonly termed "ropes" and are formed as a result of Van der
Waal's forces between the individual SWNTs. The individual nanotubes in the ropes
may slide against one another and rearrange themselves within the rope in order to
minimize the free energy. Ropes generally having between 10 and 105 nanotubes may
be used in the compositions. Within tnis range, n is gcneiany desirable to have ropes
having greater than or equal to about 100, preferably greater than or equal to about
500 nanotubes. Also desirable, are ropes having less than or equal to about 10
nanotubes, preferably less than or equal to about 5,000 nanotubes.
In yet another embodiment, it is desirable for the SWNT ropes to connect each other
in the form of branches after dispersion. This results in a sharing of the ropes
between the branches of the SWNT networks to form a 3-diminsional network in the
organic polymer matrix. A distance of about 10 nm to about 10 micrometers may
separate the branching points in this type of network. It is generally desirable for the
SWNTs to have an inherent thermal conductivity of at least 2000 Watts per meter
Kelvin (W/m-K) and for the SWNT ropes to have an inherent electrical conductivity
of 104 Siemens/centimeter (S/cm). It is also generally desirable for the SWNTs to
have a tensile strength of at least 80 gigapascals (GPa) and a stiffness of at least about
0.5 tarapascals (TPa).
In another embodiment, the SWNTs may comprise a mixture of metallic nanotubes
and semi-conducting nanotubes. Metallic nanotubes are those that display electrical
characteristics similar to metals, while the semi-conducting nanotubes are those,
which are electrically semi-conducting. In general the manner in which the graphene
sheet is rolled up produces nanotubes of various helical structures. Zigzag and
armchair nanotubes constitute two possible confirmations. In order to minimize the
quantity of SWNTs utilized in the composition, it is generally desirable to have the
composition comprise as large a fraction of metallic SWNTs. It is generally desirable
for the SWNTs used in the composition to comprise metallic nanotubes in an amount
of greater than or equal to about 1 wt%, preferably greater than or equal to about 20
wt%, more preferably greater than or equal to about 30 wt%, even more preferably
greater than or equal to about 50 wt%, and most preferably greater than or equal to
about 99.9 wt% of the total weight of the SWNTs. in certain situations, it is generally
desirable for the SWNTs used in the composition to comprise semi-conducting
nanotubes in an amount of greater than or equal to about 1 wt%, preferably greater
than or equal to about 20 wt%, more preferably greater than or equal to about 30 wt%,
even more preferably greater than or equal to about 50 wt%, and most preferably
areater than or equal to about 99.9 wt% of the total weight of the SWNTs.
SWNTs are generally used in amounts of about 0.001 to about 80 wt% of the total
weight of the composition when desirable. Within this range, SWNTs are generally
used in amounts greater than or equal to about 0.25 wt%, preferably greater or equal
to about 0.5 wt%, more preferably greater than or equal to about 1 wt% of the total
weight of the composition. SWNTs are furthermore generally used in amounts less
than or equal to about 30 wt%, preferably less than or equal to about 10 wt%, more
preferably less than or equal to about 5 wt% of the total weight of the composition.
In one embodiment, the SWNTs may contain production related impurities.
Production related impurities present in SWNTs as defined herein are those
impurities, which are produced during processes substantially related to the
production of SWNTs. As stated above, SWNTs are produced in processes such as,
for example, laser ablation, chemical vapor deposition, carbon arc, high-pressure
carbon monoxide conversion processes, or the like. Production related impurities are
those impurities that are either formed naturally or formed deliberately during the
production of SWNTs in the aforementioned processes or similar manufacturing
processes. A suitable example of a production related impurity that is formed
naturally are catalyst particles used in the production of the SWNTs. A suitable
example of a production related impurity that is formed deliberately is a dangling
bond formed on the surface of the SWNT by the deliberate addition of a small amount
of an oxidizing agent during the manufacturing process.
Production related impurities include for example, carbonaceous reaction by-products
such as defective SWNTs, multiwall carbon nanotubes, branched or coiled multiwall
carbon nanotubes, amorphous carbon, soot, nano-onions, nanohorns, coke, or the like;
catalytic residues from the catalysts utilized in the production process such as metals,
metal oxides, metal carbides, metal nitrides or the like, or combinations comprising at
least one of the foregoing reaction byproducts. A process that is substantially related
to the production of SWNTs is one in which the fraction of SWNTs is larger when
compared with any other fraction of production related impurities. In order for a
process to be substantially related to the production of SWNTs, the fraction of
SWNTs would have to be greater than a fraction of any one of the .above listed
reaction byproducts or catalytic residues. For example, the fraction of SWNTs would
have to be greater than the fraction of multiwall nanotubes, or the fraction of soot, or
the fraction of carbon black. .The fraction of SWNTs would not have to be greater
than the sums of the fractions of any combination of production related impurities for
the process to be considered substantially directed to the production of SWNTs.
In general, the SWNTs used in the composition may comprise an amount of about 0.1
to about 80 wt% impurities. Within this range, the SWNTs may have an impurity
content greater than or equal to about 3, preferably greater than or equal to about 7,
and more preferably greater than or equal to about 8 wt%, of the total weight of the
SWNTs. Also desirable within this range, is an impurity content of less than of equal
to about 50, preferably less than or equal to about 45, and more preferably less than or
equal to about 40 wt% of the total weight of the SWNTs.
In one embodiment, the SWNTs used in the composition may comprise an amount of
about 0.1 to about 50 wt% catalytic residues. Within this range, the SWNTs may
have a catalytic residue content greater than or equal to about 3, preferably greater
than or equal to about 7, and more preferably greater than or equal to about 8 wt%, of
the total weight of the SWNTs. Also desirable within this range, is a catalytic residue
content of less than of equal to about 50, preferably less than or equal to about 45, and
more preferably less than or equal to about 40 wt% of the total weight of the SWNTs.
Other carbon nanotubes such as multiwall carbon nanotubes (MWNTs) and VGCF
may also be added to the compositions during the polymerization of the polymeric
precursor. The MWNTs and VGCF that are added to the composition are not
considered impurities since these are not produced during the production of the
SWNTs. MWNTs derived from processes such as laser ablation and carbon arc
synthesis, which is not directed at the production of SWNTs, may also be used in the
compositions. MWNTs have at least two graphene layers bound around an inner
hollow core. Hemispherical caps generally close both ends of the MWNTs, but it
may desirable to use MWNTs having only one hemispherical cap or MWNTs, which
are devoid of both caps. MWNTs generally have diameters of about 2 to about 50
nm. Within this range, it is generally desirable to use MWNTs having diameters less
man or equal to about 40, preferably less than or equal to about 30, and more
preferably less than or equal to about 20 nm. When MWNTs are used, it is preferred
to have an average aspect ratio greater than or equal to about 5, preferably greater
than or equal to about 100, more preferably greater than or equal to about 1000.
MWNTs are generally used in amounts of about 0.001 to about 50 wt% of the total
weight of the composition when desirable. Within this range, MWNTs are generally
used in amounts greater than or equal to about 0.25 wt%, preferably greater or equal
to about 0.5 wt%, more preferably greater than or equal to about 1 wt% of the total
weight of the composition. MWNTs are furthermore generally used in amounts less
than or equal to about 30 wt%, preferably less than or equal to about 10 wt%, more
preferably less than or equal to about 5 wt% of the total weight of the composition.
Other conductive fillers such as vapor grown carbon fibers, carbon black, conductive
metallic fillers, solid non-metallic, conductive fillers, or the like, or combinations
comprising at least one of the foregoing may optionally be used in the compositions.
Vapor grown carbon fibers or small graphitic or partially graphitic carbon fibers, also
referred to as vapor grown carbon fibers (VGCF), having diameters of about 3.5 to
about 2000 nanometers (nm) and an aspect ratio greater than or equal to about 5 may
also be used. When VGCF are used, diameters of about 3.5 to about 500 nm are
preferred, with diameters of about 3.5 to about 100 nm being more preferred, and
diameters of about 3.5 to about 50 nm most preferred. It is also preferable to have
average aspect ratios greater than or equal to about 100 and more preferably greater
than or equal to about 1000.
VGCF are generally used in amounts of about 0.001 to about 50 wt% of the total
weight of the composition when desirable. Within this range, VGCF are generally
used in amounts greater than or equal to about 0.25 wt%, preferably greater or equal
to about 0.5 wt%, more preferably greater than or equal to about 1 wt% of the total
weight of the composition. VGCF are furthermore generally used in amounts less
than or equal to about 30 wt%, preferably less than or equal to about 10 wt%, more
preferably less than or equal to about 5 wt% of the total weight of the composition,
Both the SWNTs and the other carbon nanotubes utilized in the composition may also
be derivatized with functional groups to improve compatibility and facilitate the
mixing with the organic polymer. The SWNTs and the other carbon nanotubes may be
functionalized on either the graphene sheet constituting the sidewall, a hemispherical
cap or on both the side wall as well as the hemispherical endcap. Functionalized
SWNTs and the other carbon nanotubes are those having the formula (XXXIII)
(Figure Removed)
wherein n is an integer, L is a number less than O.ln, m is a number less than 0.5n,
and wherein each of R is the same and is selected from -SO.iH, -NH2, -OH, -C(OH)R',
-CHO, -CN, -C(O)C1, -C(O)SH, -C(O)OR', -SR', -SiR3', -Si(OR')yR'(j.y), -R", -A1R2',
halide, ethylenically unsaturated functionalities, epoxide functionalities, or the like,
wherein y is an integer equal to or less than 3, R' is hydrogen, alkyl, aryl, cycloalkyl,
araalkyl, cycloaryl, poly(alkylether), or the like and R" is fluoroalkyl, fluoroaryl,
fluorocycloalkyl, fluoroaralkyl, cycloaryl, or the like. The carbon atoms, Cn, are
surface carbons of a carbon nanotube. In both, uniformly and non-uniformly
substituted SWNTs and other carbon nanotubes, the surface atoms Cn are reacted.
Non-uniformly substituted SWNTs and other carbon nanotubes may also be used in
the composition. These include compositions of the formula (I) shown above wherein
n, L, m, R and the SWNT itself are as defined above, provided that each of R does not
contain oxygen, or, if each of R is an oxygen-containing group, COOH is not present.
Also included are functionalized SWNTs and other carbon nanotubes having the
formula (XXXIV)
(Figure Removed)
where n, L, m, R' and R have the same meaning as above. Most carbon atoms in the
surface layer of a carbon nanotube are basal plane carbons. Basal plane carbons are
relatively inert to chemical attack. At defect sites, where, for example, the graphitic
_olane fails to extend fully around the carbon nanotube, there are carbon atoms
analogous to the edge carbon atoms of a graphite plane. The edge carbons are
reactive and must contain some heteroatom or group to satisfy carbon valency.
The substituted SWNTs and other carbon nanotubes described above may
advantageously be further functionalized. Such compositions include compositions of
the formula (XXXV)
[Cn HL-J—Am (XXXV)
where n, L and m are as described above, A is selected from -OY, -NHY, -CRVOY, -
C(O)OY, -C(O)NR'Y, -C(O)SY, or -C(O)Y, wherein Y is an appropriate functional
group of a protein, a peptide, an enzyme, an antibody, a nucleotide, an
oligonucleotide, an antigen, or an enzyme substrate, enzyme inhibitor or the transition
state analog of an enzyme substrate or is selected from -R'OH, -R'NFh , -R'SH, -
R'CHO, -R'CN, -R'X, -R'SiR'.-, , -RSi-(OR')y-R'o-y), -R' Si-(0-SiR'2)-OR', -R'-R", -R'-
NCO, (C2H4 O)WY, -(C3H6O)WH, -(C2H4O)WR', -(C.1H6O)WR/ and R", wherein w is an
integer greater than one and less than 200.
The functional SWNTs and other carbon nanotubes of structure (XXXIV) may also be
functionalized to produce compositions having the formula (XXXVI)
(Figure Removed)
where n, L, m, R' and A are as defined above.
The compositions also include SWNTs and other carbon nanotubes upon which
certain cyclic compounds are adsorbed. These include compositions of matter of the
formula (XXXVII)
where n is an integer, L is a number less than O.ln, m is less than 0. 5n, a is zero or a
number less than 10, X is a polynuclear aromatic, polyheteronuclear aromatic or
metallopolyheteronuclear aromatic moiety and R is as recited above. Preferred cyclic
compounds are planar macrocycles such as re porphyrins and phthalocyanines.
The adsorbed cyclic compounds may be functionalized. Such compositions include
compounds of the formula (XXXVIII)
(Figure Removed)
where m, n, L, a, X and A are as defined above and the carbons are on the SWNT or
on other nanotubes such as MWNTs, VGCF, or the like.
Without being bound to a particular theory, the functionalized SWNTs and other
carbon nanotubes are better dispersed into organic polymers because the modified
surface properties may render the carbon nanotube more compatible with the organic
polymer, or, because the modified functional groups (particularly hydroxyl or amine
groups) are bonded directly to the organic polymer as terminal groups. In this way,
organic polymers such as polycarbonates, polyamides, polyesters, polyetherimides, or
the like, bond directly to the carbon nanotubes, thus making the carbon nanotubes
easier to disperse with improved adherence to the organic polymer.
Functional groups may generally be introduced onto the outer surface of the SWNTs
and the other carbon nanotubes by contacting the respective outer surfaces with a
strong oxidizing agent for a period of time sufficient to oxidize the surface of the
SWNTs and other carbon nanotubes and further contacting the respective outer
surfaces with a reactant suitable for adding a functional group to the oxidized surface.
Preferred oxidizing agents are comprised of a solution of an alkali metal chlorate in a
strong acid. Preferred aJkali metal chlorates are sodium chlorate or potassium
.chlorate. A preferred strong acid used is sulfuric acid. Periods of time sufficient for
oxidation are about 0. 5 hours to about 24 hours.
Carbon black may also be optionally used in the compositions. Preferred carbon
blacks are those having average particle sizes less than about 200 nm, preferably less
than about 100 nm, more preferably less than about 50 nm. Preferred conductive
carbon blacks may also have surface areas greater than about 200 square meter per
gram (m2/g), preferably greater than about 400 nr/g, yet more preferably greater than
about 1000 m2/g. Preferred conductive carbon blacks may have a pore volume
dibutyl phthalate absorption) greater than about 40 cubic centimeters per hundred
grams cmVlOOg), preferably greater than about 100 crrvYlOOg, more preferably
greater than about 150 cnrVlOOg. Exemplary carbon blacks include the carbon black
commercially available from Columbian Chemicals under the trade name
Conductex®; the acetylene black available from Chevron Chemical, under the trade
names S.C.F. (Super Conductive Furnace) and E.C.F. (Electric Conductive Furnace);
the carbon blacks available from Cabot Corp. under the trade names Vulcan XC72
and Black Pearls; and the carbon blacks commercially available from Akzo Co. Ltd
under the trade names Ketjen Black EC 300 and EC 600. Preferred conductive
carbon blacks may be used in amounts from about 2 wt% to about 25 wt% based on
the total weight of the composition.
Solid conductive metallic fillers may also optionally be used in the conductive
compositions. These may be electrically conductive metals or alloys that do not melt
under conditions used in incorporating them into the organic polymer, and fabricating
finished articles therefrom. Metals such as aluminum, copper, magnesium,
chromium, tin, nickel, silver, iron, titanium, and mixtures comprising any one of the
foregoing metals can be incorporated into the organic polymer as conductive fillers.
Physical mixtures and true alloys such as stainless steels, bronzes, and the like, may
also serve as conductive filler particles. In addition, a few intermetallic chemical
compounds such as borides, carbides, and the like, of these metals, (e.g., titanium
diboride) may also serve as conductive filler particles. Solid non-metallic, conductive
filler particles such as tin-oxide, indium tin oxide, and the like may also optionally be
added to render the organic polymer conductive. The solid metallic and non-metallic
conductive fillers may exist in the form of powder, drawn wires, strands, fibers, tubes,
nanotubes, flakes, laminates, platelets, ellipsoids, discs, and other commercially
available geometries.
Non-conductive, non-metallic fillers that have been coated over a substantial portion
of their surface with a coherent layer of solid conductive metal may also optionally be
used in the conductive compositions. The non-conductive, non-metallic fillers are
commonly referred to as substrates, and substrates coated with a layer of solid
conductive metal may be referred to as "metal coated fillers". Typical conductive
metals such as aluminum, copper, magnesium, chromium, tin, nickel, silver, iron,
titanium, and mixtures comprising any one of the foregoing metals may be used to
coat the substrates. Examples of substrates include those described in "Plastic
Additives Handbook, 5lh Edition" Hans Zweifel, Ed, Carl Hanser Verlag Publishers,
Munich, 2001. Examples of such substrates include silica powder, such as fused
silica and crystalline silica, boron-nitride powder, boron-silicate powders, alumina,
magnesium oxide (or magnesia), wollastonite, including surface-treated wollastonite,
calcium sulfate (as its anhydride, dihydrate or trihydrate), calcium carbonate,
including chalk, limestone, marble and synthetic, precipitated calcium carbonates,
generally in the form of a ground particulates, talc, including fibrous, modular, needle
shaped, and lamellar talc, glass spheres, both hollow and solid, kaolin, including hard,
soft, calcined kaolin, and kaolin comprising various coatings to facilitate
compatibility with the polymeric matrix polymer, mica, feldspar, silicate spheres, flue
dust, cenospheres, fillite, aluminosilicate (armospheres), natural silica sand, quartz,
quartzite, perlite, tripoli, diatomaceous earth, synthetic silica, and mixtures
comprising any one of the foregoing. All of the above substrates may be coated with a
layer of metallic material for use in the conductive compositions.
Regardless of the exact size, shape and composition of the solid metallic and nonmetallic
conductive filler particles, they may be dispersed into the organic polymer at
loadings of about 0.001 to about 50 wt% of the total weight of the composition when
desired. Within this range it is generally desirable to have the solid metallic and nonmetallic
conductive filler particles in an amount of greater than or equal to about 1
wt%, preferably greater than or equal to about 1.5 wt% and more preferably greater
than or equal to about 2 wt% of the total weight of the composition. The loadings of
the solid metallic and non-metallic conductive filler particles may be less than or
equal to 40 wt%, preferably less than or equal to about 30 wt%, more preferably less
than or equal to about 25 wt% of the total weight of the composition.
In one embodiment, in one method of manufacturing the composition, the polymeric
precursor in the form of a monomer, oligomer, or polymer is added to a reaction
vessel. Suitable examples of reaction vessels are kettles, thin film evaporators, single
or multiple screw extruders, Buss kneaders, Henschel mixers, helicones, Ross mixers,
anbury, roll mills, molding machines such as injection molding machines, vacuum
forming machines, blow molding machine, or then like, or combinations comprising
at least one of the foregoing machines. The conductive composition comprising the
SWNTs and optionally other carbon nanotubes and conductive fillers may then be
added to the reaction vessel during the polymerization of the polymeric precursor.
In one embodiment, the SWNTs may be added to the reaction vessel prior to the
polymerization of the polymer precursor. The polymerization of the polymer
precursor may be conducted in a solvent or in the absence of a solvent, in the melt if
desired. In another embodiment, the SWNTs may be added to the reaction vessel
during the polymerization of the polymer precursor. In yet another embodiment, the
SWNTs may be added to the reaction vessel prior the polymerization of the polymer
precursor, while the other conductive and non-conductive fillers may be added to the
reaction vessel after the polymerization of the organic precursors is substantially
completed. In yet another embodiment, the reaction vessel may contain a high
proportion of the SWNTs and other conductive and non-conductive fillers during the
initial stages of the polymerization process in order to adjust the viscosity in the
reaction to vessel to be effective to facilitate the disentangling of the SWNTs and
other fillers. After agitating the reaction solution for a desired period of time,
additional polymer precursors are added to the reaction vessel to continue the
polymerization process.
In one embodiment, the SWNTs together with other conductive and non-conductive
fillers may be added to the reaction vessel in the form of a masterbatch. In another
embodiment, related to the use of masterbatches, a first masterbatch comprising the
SWNTs may be added to the reaction vessel at a first time, while the second
masterbatch comprising the other non-conductive fillers may be added to the reaction
vessel at a second time during the process of polymerization of the polymer
precursors.
As stated above, the composition may be manufactured in the melt or in a solution
comprising a solvent. Melt reacting of the composition involves the use of shear
fgrce, extensional force, compressive force, ultrasonic energy, electromagnetic
energy, thermal energy or combinations comprising at least one of the foregoing
forces or forms of energy and is conducted in processing equipment wherein the
aforementioned forces are exerted by a single screw, multiple screws, intermeshing
co-rotating or counter rotating screws, non-intermeshing co-rotating or counter
rotating screws, reciprocating screws, screws with pins, screws with screens, barrels
with pins, rolls, rams, helical rotors, baffles, or combinations comprising at least one
of the foregoing.
In one embodiment, ultrasonic energy may be utilized to disperse the SWNTs. The
polymer precursors together with the SWNTs, and other optional conductive or nonconductive
fillers are first sonicated in an ultrasonicator to disperse the SWNTs.
Following the sonication, the polymer precursors are polymerized. The
ultrasonication may be continued during the polymerization process if desired. The
ultrasonic energy may be applied to the different reaction vessels such as kettles,
extruders, and the like, in which the polymerization may be carried out.
Melt reacting involving the aforementioned forces may be conducted in machines
such as, but not limited to single or multiple screw extruders, Buss kneader, Henschel,
helicones, Ross mixer, Banbury, roll mills, molding machines such as injection
molding machines, vacuum forming machines, blow molding machine, or then like,
or combinations comprising at least one of the foregoing machines. Solution reacting
is generally conducted in a vessel such as a kettle.
In one embodiment, the polymer precursor in powder form, pellet form, sheet form, or
the like, may be first dry blended with the SWNTs and other optional fillers if desired
in a Henschel or a roll mill, prior to being fed into a reaction vessel such as an
extruder or Buss kneader. While it is generally desirable for the shear forces in the
reaction vessel to generally cause a dispersion of the SWNTs in the polymer
precursor, it is also desired to preserve the aspect ratio of the SWNTs during the
reaction. In order to do so, it may be desirable to introduce the SWNTs into the
reaction vessel in the form of a masterbatch. In such a process, the masterbatch may
be introduced into the reaction vessel downstream of the polymer precursor.
The masterbatch may comprise either an organic polymer or a polymer precursor with
the SWNTs. When a masterbatch is used, the SWNTs may be present in the
masterbatch in an amount of about 0.01 to about 50 wt%. Within this range, it is
generally desirable to use SWNTs in an amount of greater than or equal to about 0.1
wt%, preferably greater or equal to about 0.2 wt%, more preferably greater than or
equal to about 0.5 wt% of the total weight of the masterbatch. Also desirable are
SWNTs in an amount of less than or equal to about 30 wt%, preferably less than or
equal to about 10 wt%, more preferably less than or equal to about 5 wt% of the total
weight of the masterbatch. In one embodiment pertaining to the use of masterbatches,
while the masterbatch containing the SWNTs may not have a measurable bulk or
surface resistivity either when extruded in the form of a strand or molded into the
form of dogbone, the resulting composition into which the masterbatch is
incorporated has a measurable bulk or surface resistivity, even though the weight
fraction of the SWNTs in the composition is lower than that in the masterbatch. It is
preferable for the organic polymer in such a masterbatch to be semi-crystalline.
Examples of semi-crystalline organic polymers which display these characteristics
and which may be used in masterbatches are polypropylene, polyamides, polyesters,
or the like, or combinations comprising at least on of the foregoing semi-crystalline
organic polymers.
The composition may also be used as a masterbatch if desired. When the composition
is used as a masterbatch, the SWNTs may be present in the masterbatch in an amount
of about 0.01 to about 50 wt%. Within this range, it is generally desirable to use
SWNTs in an amount of greater than or equal to about 0.1 wt%, preferably greater or
equal to about 0.2 wt%, more preferably greater than or equal to about 0.5 wt% of the
total weight of the masterbatch. Also desirable are SWNTs in an amount of less than
or equal to about 30 wt%, preferably less than or equal to about 10 wt%, more
preferably less than or equal to about 5 wt% of the total weight of the masterbatch.
43
In another embodiment relating to the use of masterbatches in the manufacture of a
composition comprising a blend of organic polymers, it is sometimes desirable to
have the masterbatch comprising an organic polymer that is the same as the organic
polymer that is derived from the polymerization of the polymer precursors. This
feature permits the use of substantially smaller proportions of the SWNTs, since only
the continuous phase of the organic polymer carries the SWNTs that provide the
composition with the requisite volume and surface resistivity. In yet another
embodiment relating to the use of masterbatches in polymeric blends, it may be
desirable to have the masterbatch comprising an organic polymer that is different in
chemistry from other the polymeric that are used in the composition. In this case, the
organic polymer of the masterbatch will form the continuous phase in the blend. In
yet another embodiment, it may be desirable to use a separate masterbatch comprising
multiwall nanotubes, vapor grown carbon fibers, carbon black, conductive metallic
fillers, solid non-metallic, conductive fillers, or the like, or combinations comprising
at least one of the foregoing in the composition.
The composition comprising the organic polymer and the SWNTs may be subject to
multiple blending and forming steps if desirable. For example, the composition may
first be extruded and formed into pellets. The pellets may then be fed into a molding
machine where it may be formed into other desirable shapes such as housing for
computers, automotive panels that can be electrostatically painted, or the like.
Alternatively, the composition emanating from a single melt blender may be formed
into sheets or strands and subjected to post-extrusion processes such as annealing,
uniaxial or biaxial orientation.
In one embodiment, the organic polymer precursor may be first mixed with the
SWNT's in a reaction vessel such as a kettle, and subsequently polymerized in a
device where a combination of shear, extension and/or elongational forces are used
during the polymerization. Suitable devices for conducting the polymerization are
those having a single screw, multiple screws, intermeshing co-rotating or counter
rotating screws, non-intermeshing co-rotating or counter rotating screws,
reciprocating screws, screws with pins, screws with screens, barrels with pins, rolls,
rams, helical rotors, baffles, or combinations comprising at least one of the foregoing.
Solution blending may also be used to manufacture the composition. The solution
blending may also use additional energy such as shear, compression, ultrasonic
fdbration, or the like, to promote homogenization of the SWNTs with the organic
polymer. In one embodiment, the polymer precursors may be introduced into an
ultrasonic sonicator along with the SWNTs. The mixture may be solution blended by
sonication for a time period effective to disperse the SWNTs onto the organic
polymer particles prior to or during synthesis of the polymer precursors. The organic
polymer along with the SWNTs may then be dried, extruded and molded if desired.
A fluid such as a solvent may optionally be introduced into the sonicator with the
SWNTs and the organic polymer precursor. The time period for the sonication is
generally an amount effective to promote dispersion and/or encapsulation of the
SWNTs by the organic polymer precursor. After the encapsulation, the organic
polymer precursor is then polymerized to form an organic polymer within which is
dispersed the SWNTs. This method of dispersion of the SWNTs in the organic
polymer promotes the preservation of the aspect ratios of the SWNTs, which therefore
permits the composition to develop electrical conductivity at lower loading of the
SWNTs.
In general, it is desirable to sonicate the mixture of organic polymer, organic polymer
precursor, fluid and/or the SWNTs a period of about 1 minute to about 24 hours.
Within this range, it is desirable to sonicate the mixture for a period of greater than or
equal to about 5 minutes, preferably greater than or equal to about 10 minutes and
more preferably greater than or equal to about 15 minutes. Also desirable within this
range is a time period of less than or equal to about 15 hours, preferably less than or
equal to about 10 hours, and more preferably less than or equal to about 5 hours.
In one embodiment, related to the dispersion of the SWNTs having production related
impurities, the SWNT compositions having a higher fraction of impurities may be
dispersed using less energy than SWNT compositions having a lower fraction of
impurities. Without being limited by theory, it is believed that in certain organic
polymers, the impurities interact to promote a reduction in the Van der.Waal's forces
thereby facilitating an easier dispersion of the nanotubes within the organic polymer.
In another embodiment, related to the dispersion of SWNTs having production related
impurities, the SWNT compositions having a higher fraction of impurities may
Require a larger amount of mixing than those compositions having a lower fraction of
impurities. However, the composition having the SWNTs with the lower fraction of
impurities generally lose electrical conductivity upon additional mixing, while the
composition having the higher fraction of SWNT impurities generally gain in
electrical conductivity as the amount of mixing is increased. These compositions may
be used in applications where there is a need for a superior balance of flow, impact,
and conductivity. They may also be used in applications where conductive materials
are used and wherein the conductive materials possess very small levels of conductive
filler such as in fuel cells, electrostatic painting applications, and the like.
The compositions described above may be used in a wide variety of commercial
applications. They may be advantageously utilized as films for packaging electronic
components such as computers, electronic goods, semi-conductor components, circuit
boards, or the like that need to be protected from electrostatic dissipation. They may
also be used internally inside computers and other electronic goods to provide
electromagnetic shielding to personnel and other electronics located outside the
computer as well as to protect internal computer components from other external
electromagnetic interference. They may also be used advantageously in automotive
body panels both for interior and exterior components of automobiles that can be
electrostatically painted if desired.
The following examples, which are meant to be exemplary, not limiting, illustrate
compositions and methods of manufacturing of some of the various embodiments of
the electrically conductive compositions described herein.
Example 1
Viis example was undertaken to disperse SWNTs in polycarbonate (PC) and to create
a masterbatch of SWNTs in PC. 250 milligrams (mg) of SWNTs obtained from
Carbon NanotechnoJogies Incorporated was first dispersed in 120 milliliter (ml) of 1,2
dichloroethane by using an ultrasonication horn for 30 minutes. The ultrasonic horn
used an ultrasonic processor at 80% amplitude (600 Watts, probe diameter of 13 mm
available from Sonics & Materials Incorporated). 30 gms of
bis(methylsalicyl)carbonate (BMSC) and 20.3467 gms of bisphenol A (BPA) (mol of
BMSC / mol of BPA = 1.02) were added to dispersion and SWNT the reaction
mixture was again sonicated for 30 minutes. The sonicated mass was transferred into
a glass reactor, which was first passivated by soaking the reactor in a bath containing
1 molar aqueous hydrochloric acid solution for 24 hours followed by vigorous rinsing
with deionized water. The solvent was dried by heating the glass reactor to 100°C in
presence of flowing nitrogen at low pressure. Appropriate amount of catalyst solution
was then introduced into the reactor using a syringe. The amount of catalyst consists
of 4.5x 10"° moles of NaOH per mole of BPA and 3.0xlO"" moles of TBPA (tetrabutyl
phosphonium acetate) per mole of BPA (bisphenol A).
The atmosphere inside the reactor was then evacuated using a vacuum source and
purged with nitrogen. This cycle was repeated 3 times after which the contents of the
reactor were heated to melt the monomer mixture (bis(methylsalicyl)carbonate
(BMSC) and bisphenol A (BPA)). When the temperature of the mixture reached
about 180°C, the stirrer in the reactor was turned on and adjusted to about 60
revolutions per minute (rpm) to ensure that the entire solid mass fully melted, a
process that usually took about 15 to about 20 minutes. Next, the reaction mixture
was heated to about 220°C, while the pressure inside the reactor was adjusted slowly
to about 100 millibar using a vacuum source. After stirring the reaction mass at this
condition for about 15 minutes, the reaction temperature was raised to about 280°C
while readjusting the pressure to around 20 millibar. After being maintained at this
condition for about 10 minutes, the temperature of the reaction mixture was raised to
300°C while bringing the pressure down to about 1.5 millibar. After allowing the
reaction to proceed under these conditions for about 2 to about 5 minutes, the pressure
inside the reactor was brought to atmospheric pressure and the reactor was vented to
relieve any excess pressure. Product isolation was accomplished by breaking the
|iass nipple at the bottom of the reactor and collecting the material. The glass reactor
was dismantled and the rest of the polymer was taken our from the reactor tube.
To measure the molecular weight, the resulting polycarbonate was dissolved in
methylene chloride followed by re-precipitation of the polymers from methanol. The
molecular weight of the polymer was determined by gel permeation chromatography
with respect to polystyrene standard. The weight average molecular weight was 55756
g/mole, while the number average molecular weight was 23,938 g/mole and the
polydispersity index was 2.32.
Example 2
This example was undertaken to disperse SWNTs in PCCD (poly(l,4-cyclohexanedimethanol-
l,4-cyclohexanedicarboxylate) polymer and to create a masterbatch of
SWNTs in PCCD. The PCCD polymer was synthesized by melt polycondensation in
presence of SWNTs obtained from Carbon Nanotechnologies Incorporated. A. slurry
of SWNTs (0.24 gm, 1 wt%) was prepared by mixing the SWNTs with 1,4-dimethyl
cyclohexane dicarboxylate (14.01 gm, 0.07 moles) (DMCD), 1,4-cyclohexane
dimethanol (10.09 gm, 0.07 moles) (CHDM) and 1,2-dichloroethane (50 mL) under
high stirring. The slurry was transferred to the glass reactor tube. The reactor tube
was mounted to the melt polycondensation reactor equipped with side arm, a
mechanical stirrer driven by an overhead stirring motor and a side arm with a stopcock.
The side arm is used to purge nitrogen gas as well as for applying vacuum.
Initially, the reactor tube was heated under nitrogen to remove the 1,2-dichloroethane
and cooled to room temperature. The contents in the reactor were evacuated and
purged with nitrogen three times to remove any traces of oxygen. The reactor was
purged with nitrogen and brought to atmospheric pressure and the contents of the
reaction mixture were heated to 200°C with constant stirring (100 rpm). Through the
side arm 400 parts per million (ppm) of titanium (IV) isopropoxide was. added as a
catalyst and the ester interchange reaction proceeded with the distillation of methanol
which was collected through the side arm in the measuring cylinder (receiver). The
temperature of the melt was increased to 250 °C and stirred for 1 hour under nitrogen.
The polycondensation was conducted by reducing the pressure in the reactor in
Itepwise from 900 mm Hg to 700, 500, 300, 100, 50, 25, and 10 mm mercury (Hg).
Finally, a full vacuum of 0.5 to 0.1 mbar was applied to the reactor and the
polymerization was continued for 30 minutes. After completion of the
polymerization, the pressure inside the reactor was brought to atmospheric pressure
by purging with nitrogen and the polymer composite was removed from the reactor
tube. The polymer was dissolved in dichloromethane for molecular weight
determinations using the intrinsic viscosity method. The solution viscosity was
determined in phenol/tetrachloroethane (a volume ratio of 2:3 at 25°C) solution and
was found to be 0.58 deciliter/gram (dL/g), which corresponds to the viscosity
average molecular weight of 50,000 g/mole.
The masterbatches prepared in Examples 1 and 2 were then melt blended with
polymers in a small scale laboratory mixing and molding machine to decrease the
loading or the SWNT. The strands from the molding machine were fractured under
liquid nitrogen and the exposed ends were painted with conductive silver paint to
make the conductivity measurements. The conductivity values are shown in the Table
1 below.
(Table Removed)
As may be seen from the above table, Samples 2 - 4 were manufactured from PC
masterbatcheS of Example 1 (sample #1), while Samples 6-9 were manufactured
from the masterbatches of Example 2 (sample# 5). From the Examples it can be
clearly seen that as the level of the SWNTs is increased, the resistivity is decreased.
Further it can be seen that the masterbatches may be advantageously used to disperse
the SWNT's in the polymer.
Example 3
This example was used to prepared a masterbatch of SWNTs in Nylon 6 during the
polymerization of the polyamide. 24.8 gm of e-caprolactam was taken in a beaker
and heated to 90°C. After compound has melted, 250 milligrams (mg) of SWNTs
.containing about 10 wt% impurities (commercially available from Carbon
Nanotechnologies Incorporated) was added to the e-caprolactam. The mixture was
ultrasonicated at the same temperture for half an hour using an ultrasonic processor at
80% amplitude (600 Watts, probe diameter of 13 mm available from Sonics &
Materials Incorporated). The dispersion of SWNTs in the molten e-caprolactam was
then transferred to a reactor tube and was kept overnight to allow the SWNT ropes to
gel (forming a network). 1.5 gm of aminocaproic acid was then added to the reactor
and caprolactam was polymerized to nylon-6 by ring-opening polymerization, under
nitrogen with slow stirring, for 9 hours at 260°C.
Example 4
This experiment was undertaken to prepare an SWNT composite in PCCD by in-situ
polymerization without using a solvent. In this example, 17.29 gm of 1,4-
cyclohexane dicarboxylate, 24.03 gms of 1,4-cyclohexane dimethanol was mixed and
melted at 80°C in a beaker. 33 mg of SWNT containing about 10 wt% impurities
(commercially available from Carbon Nanotechnologies Incorporated) was added to
the beaker. The mixture was ultrasonicated at the same temperture for half an hour
using an ultrasonic processor at 80% amplitude (600 Watts, probe diameter 13mm,
Sonics & Materials Incorporated, USA). The dispersion of SWNT in the molten
monomer mixture was then transferred to a reactor tube and was kept overnight to
allow the SWNT ropes to gel (forming a network). The monomers were then
polymerized to PCCD using the same procedure as in Example 2.
A portion of the composite prepared above was heated for one hour to 240°C for
"Nylon 6 composite of Example 3 (above the melting point of Nylon 6) and 230°C for
the PCCD composite of Example 4 respectively. The composite was then cooled
slowly to room temperature and the conductivity was measured as shown in Table 2.
Similarly, the composite material from Examples 3 and 4 was melted mixed with
additional polymer and pressed through in a small scale laboratory mixing and
molding machine to form strands which were then used to make conductivity
measurements as detailed in Example 2. These results are also shown in Table 4.
(Table Removed)
"S. D. represents the numbers in the parenthesis, which are the standard deviations.
From the above data it may be seen that the samples that were annealed displayed
superior electrical properties than those samples that were annealed. Annealing
enables the SWNT ropes to rearrange in the polymer matrix and increases the
rejoining/sharing of the SWNT rope-branches, creating an extensive long range
networked morphology, which in turn, leads to higher conductivity of the composites.
While the invention has been described with reference to exemplary embodiments, it
will be understood by those skilled in the art that various changes may be made and
equivalents may be substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to adapt a particular
situation or material to the teachings of the invention without departing from the
essential scope thereof. Therefore, it is intended that the invention not be limited to
the particular embodiment disclosed as the best mode contemplated for carrying out this invention.

CLAIMS:
1. A method for manufacturing a conductive composition comprising:
blending a polymer precursor with an efficient amount of single wall carbon
nanotube composition; and
polymerizing the polymer precursor to form an organic polymer;
wherein the composition has an electrical bulk volume resistivity less than or
equal to about 1012 ohm-cm, and a notched Izod impact strength greater than or equal
to about 5 kilojoules/square meter.
2. The method of Claim 1, wherein the efficient amount of single wall
carbon nanotube composition comprises 1 to about 99 wt% metallic carbon
nanotubes.
3. The method of any of Claims 1 - 3 , wherein the efficient amount of
single wall carbon nanotube composition comprises 1 to about 99 wt% semiconducting
carbon nanotubes.
4. The method of any of Claims 1 - 3, wherein the composition has an
electrical surface resistivity less than or equal to about 1012 ohm/square.
5. The method of any of Claims ] - 4, wherein the composition comprises
a polymer precursor is selected from the group of:
a) a polymer precursor of the structure (I):
(Figure Removed)
wherein for each structural unit, each Q1 is independently hydrogen, halogen, primary
or secondary lower alkyl, phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy,
halohydrocarbonoxy wherein at least two carbon atoms separate the halogen and
oxygen atoms; and each Q2 is independently hydrogen, halogen, primary or secondary
lower alkyl, phenyl, haloalkyl, hydrocarbonoxy, halohydrocarbonoxy wherein at least
two carbon atoms separate the halogen and oxygen atoms;
b) 2,6-dimethylphenol and 2,3,6-trimethylphenol; and
c) an ethylenically unsaturated monomer.
6. The method of any of Claims 1 - 5, wherein the composition comprises
an organic polymer is selected from the group of:
a) a polymerization product of carbonyl compounds and dihydroxy
compounds, wherein the dihydroxy compounds have the general formula (IV)
(Figure Removed)
wherein A has the structure of formula (V):
(Figure Removed)
wherein G1 represents an aromatic group, E represents an alkylene, alkylidene group
or a cycloaliphatic group, R1 represents hydrogen or a monovalent hydrocarbon
group, Y1 is an inorganic atom, m represents any integer from and including zero
through the number of positions on G1 available for substitution; p represents an
integer from and including zero through the number of positions on E available for
substitution; t represents an integer equal to at least one; s is either zero or one; and u
represents any integer including zero;
b) a polyester polymer having recurring units of the formula (VIII):
(Figure Removed)
wherein R5 represents an ary], alkyl or cycloalkyl radical having greater than or equal
to about 2 carbon atoms and which is the residue of a straight chain, branched, or
cycloaliphatic alkane diol; and R4 is an aryl, alky] or a cydoaliphatic radical.
c) a polymerization product of a diol or diol chemical equivalent with a
diacid or diacid chemical equivalent.
d) a poly( 1,4-cyclohexane- dimethanol-l,4-cyclohexanedicarboxylate)
having recurring units of formula (IX)
(Figure Removed)
e) a polymerization product of an aromatic dicarboxylic acid with a
bisphenol.
f) an organic polymer comprising structural units of the formula (XIV)
wherein each R1 is independently halogen or C\.\i alkyl, m is at least 1, p is up to
about 3, each R2 is independently a divalent organic radical, and n is at least about 4.
g) a polymerization product of a polymer precursor of the formula (XV):
(Figure Removed)
wherein R5 is hydrogen, lower alkyl or halogen; Z1 is.vinyl, halogen or lower alkyl;
and p is from 0 to about 5.
h) a copolymer of styrene;
i) a polyimide having the general formula (XVI)
(Figure Removed)
wherein a is greater than or equal to about 1; and wherein V is a tetravalent linker
comprising (a) substituted or unsubstituted, saturated, unsaturated or aromatic
monocyclic and polycyclic groups having about 5 to about 50 carbon atoms, (b)
substituted or unsubstituted, linear or branched, saturated or unsaturated alkyl groups
having 1 to about 30 carbon atoms; or combinations of the foregoing tetravalent
linkers; R is a substituted or unsubstituted divalent aromatic hydrocarbon radical
having about 6 to about 20 carbon atoms, a straight or branched chain alkylene radical
having about 2 to about 20 carbon atoms, a cycloalkylene radical having about 3 to
about 20 carbon atoms, or a divalent radicals of the general formula (XIX)
(Figure Removed)
wherein Q includes a divalent moiety selected from the group consisting of -O-, -S-, -
C(O)-, -SO2-, -SO-, -CyH2y- or its halogenated derivatives an y is about 1 to about 5;
j) a polyamide that is the polymerization product of organic lactams
represented by the formula (XXVII):
(Figure Removed)
wherein n is about 3 to about 11 and amino acids represented by the
formula (XXVIII)
(Figure Removed)
wherein n is about 3 to about 11;
k) a polyamide that is the polymerization product of aliphatic
dicarboxylic acids having from 4 to 12 carbon atoms and aliphatic diamines having
from 2 to 12 carbon atoms;
1) a polyamide that is the polymerization product of a first polyamide
with a second polyamide; wherein the first polyamide comprises repeating units
having formula (XXX)
(Figure Removed)
wherein R'is a branched or unbranched alkyl group having nine carbons; and
wherein the second polyamide comprises repeating units having formula (XXXI)
and/or formula (XXXII)
(Figure Removed)
wherein R2 is a branched or unbranched alkyl group having four to seven
carbons and R3 is an aromatic group having six carbons or a branched or unbranched
alkyl group having four to seven carbons.
7. The method of any of Claims 1 • 6, wherein the composition comprises
an organic polymer that comprises a polyimide having the general formula (XVI) and
wherein the tetravalent linker comprises aromatic radicals of formula (XVII),
(Figure Removed)
wherein W is -0-, -S-, -C(O)-, -SO2-, -SO-, -CyH2y- or halogenated derivatives
thereof, wherein y is from 1 to 5, or a group of the formula -O-Z-O- wherein the
divalent bonds of the -O- or the -O-Z-O- group are in the 3,3', 3,4', 4,3', or the 4,4'
positions, and wherein Z is a divalent radical of formula (XVIII):
8. The method of any of Claims 1 - 7, wherein the composition comprises
an organic polymer, and wherein the organic polymer is a polyacetal, a polyacrylic, a
polyalkyd, a polyacrylate, a polycarbonate, a polystyrene, a polyester, a polyamide, a
polyaramid, a polyamideimide, a polyarylate, a polyarylsulfone, a polyethersulfone, a
polyphenylene sulfide, a polysulfone, a polyimide, . a polyetherimide, a
polytetrafluoroethylene, a polyetherketone, a polyether etherketone, a polyether
ketone ketone, a polybenzoxazole, a polyoxadiazole, a
polybenzothiazinophenothiazine, a polybenzothiazole, a polypyrazinoquinqxaline, a
polypyromellitimide, a polyquinoxaline, a polybenzimidazole, a polyoxindole, a
polyoxoisoindoline, a polydioxoisoindoline, a polytriazine, a polypyridazine, a
polypiperazine, a polypyridine, a polypiperidine, a polytriazole, a polypyrazole, a
polycarborane, a polyoxabicyclononane, a polydibenzofuran, a polyphthalide, a
polyacetal, a polyanhydride, a polyvinyl ether, a polyvinyl thioether, a polyvinyl
alcohol, a polyvinyl ketone, a polyvinyl halide, a polyvinyl nitrile, a polyvinyl ester, a
polysulfonate, a polysulfide, a polythioester, a polysulfone, a polysulfonamide, a
polyurea, a polyphosphazene, a polysilazane, or a combination comprising at least one
of the foregoing thermoplastic polymers.
9. The method of any of Claims 1 - 8, further comprising carbon
nanotubes, wherein the carbon nanotubes are multiwall carbon nanotubes, vapor
grown carbon fibers, or a combination comprising at least one of the foregoing types
of carbon nanotubes.
10. The method of any of Claims 1 - 1 0 , wherein the single wall carbon
nanotubes have an inherent electrical conductivity of about JO4 Siemens/centimeter.
11. The method of any of Claims 1-10, wherein the single wall carbon
nanotube composition comprises single wall carbon nanotubes selected from the
group of:
a) single wall carbon nanotubes in the form of ropes prior to processing
and said single wall carbon nanotubes are in the form of a single wall carbon
nanotube network in three dimensions after processing;
b) metallic carbon nanotubes, semi-conducting carbon nanotubes, or a
combination comprising at least one of the foregoing single wall carbon nanotubes;
c) armchair nanotubes, zigzag nanotubes, or a combination comprising at
least one of the foregoing nanotubes;
d) single wall carbon nanotubes derivatized with functional groups;
e) single wall carbon nanotubes derivatized with functional groups either
on a side-wall or on a hemispherical end;
f) single wall carbon nanotubes having no hemispherical ends attached
thereto or have at least one hemispherical end attached thereto; and
g) a combination comprising at least one of the foregoing nanotubes.
12. The method of any of Claims 1 - 1 1 , wherein the blending is
accomplished through one of the followings:
a) sonicating;
b) in a solution comprising a solvent;
c) in a melt form;
d) using of shear force, extensional force, compressive force, ultrasonic
energy, electromagnetic energy, thermal energy or combinations comprising at least
one of the foregoing forces and energies and is conducted in processing equipment
wherein the aforementioned forces are exerted by a single screw, multiple screws,
intermeshing co-rotating or counter rotating screws, non-intermeshing co-rotating or
counter rotating screws, reciprocating screws, screws with pins, barrels with pins,
screen packs, rolls, rams, helical rotors, baffles, ultrasonicator; and
e) a combination comprising at least one of the foregoing.
13. The method of any of Claims 1 - 12, wherein the composition is
further blended with additional organic polymer.
14. The method of Claim 13, wherein the organic polymer to be further
blended with the composition is semi-crystalline or amorphous and has a molecular
wight of about 1 OOg/mole to about 1,000,000 g/mole. .
15. The method of any of Claims 1 - 14, wherein the blending of the
composition is conducted in a kettle, while the polymerization is conducted in a
device having a single screw, multiple screws, intermeshing co-rotating or counter
rotating screws, non-intermeshing co-rotating or counter rotating screws,
reciprocating screws, screws with pins, screws with screens, barrels with pins, rolls,
rams, helical rotors, baffles, or a combination comprising at least one of the
foregoing.
16. A conductive composition manufactured by the method of any of
Claims 1-15, wherein said composition is used as a masterbatch.
17. An article comprising the composition manufactured by the method of
any of Claims 1 - 16.