FhG ... e.V., et al.
12476W0; description
Resins from unsaturated polyesters and polysilazanes and duroplastic reaction
resin moulding materials produced therefrom
The present invention relates to reaction resins from unsaturated polyesters in
combination with copolymerizable, preferably vinyl group-based silazanes as crosslinking
agents and optionally an additional reactive diluting agent in which the mixture is
provided in dissolved form. Furthermore, the invention relates to reaction resin moulding
materials from said reaction resins. The hardened masses feature better flame
retardancies and satisfactory glass transition temperatures.
Unsaturated polyester resins have been disclosed long ago and are based on an
invention by Ellis & Foster in 1937. Normally, flame-retardant polyester resins are
produced with the addition of flame retardants such as aluminum trihydroxide or
ammonium phosphate, such as disclosed e.g. in EP 848032. Normally, the addition of
these kinds of agents increases the viscosity, thus having a detrimental effect on the
processability of the resins, as well as resulting in lower mechanical load bearing
capacities of components produced from the resins, especially in connection with very
high filling material contents in the range of more than 50 % by weight of filling material
relative to the filled resin.
The object of the invention is to provide unsaturated polyester resins which can be used
to produce moulded materials with better char resistance. Furthermore, the object of the
invention is to provide corresponding moulded materials.
The object is solved by using a mixture as polyester reaction resin which comprises at
least one polyester and at least one silazane containing one or a plurality of C=C double
bonds and which can be polymerized into the product via said double bonds in
connection with the polymerization of the polyester double bonds.
Unsaturated polyesters are the polycondensation product of unsaturated dicarboxylic
acids, optionally in combination with saturated, often aromatic dicarboxylic acids or their
respective anhydrides and diols. a,P-unsaturated dicarboxylic acids such as maleic acid
or maleic acid anhydride or fumaric acid are typically used. However, it is also possible
to use itaconic acid, mesaconic acid or citraconic acid. The distance between the
double bonds is relevant with respect to the future properties of the unsaturated
polyester resin and its reactivity. For this reason, saturated dicarboxylic acids are
additionally used in some cases in order to reduce the double bond density.
Furthermore, saturated dicarboxylic acids are used to control additional properties of the
FhG ... e.V., et al.
12476W0; description
resin parts and the future components. Phthalic acid or phthalic acid anhydride,
isophthalic acid, terephthalic acid or adipinic acid are predominantly used for this
purpose. However, all other saturated dicarboxylic acids can also be used as additive to
reduce the double bond density.
Different types of di- andlor trifunctional alcohols are used as alcohol component,
wherein difunctional alcohols are normally preferred to prevent the branching of the
polyester molecule. Typically, saturated alcohols such as for example 1,2-propanediol,
ethylene glycol, diethylene glycol or dipropylene glycol are used as diol, wherein diols
with a longer chain length andlor a different distance between the chain links can
obviously be used instead. Neopentyl glycol, 1,3-butanediol as well as bis-ethoxylated
and bis-propoxylated bisphenol A are frequently used as special diols to convey special
properties to the polyester molecule. This list is obviously not complete and can be
supplemented with virtually any aliphatic dialcohol. If the presence of trifunctional
alcohols is desired, they are normally used in mixture with diols.
The polycondensation reaction between the acid (anhydride) and alcohol groups may or
may not take place with the use of a catalyst (e.g. Zn or Sn compounds). An inhibitor
such as hydroquinone is often added to the starting material for the unsaturated
polyester or to the polyester itself to prevent premature polymerization. Purely linear
products are generated if exclusively dicarboxylic acids and dialcohols are used as
starting materials, wherein branching may however occur as a result of secondary
reactions.
The unsaturated polyesters are provided in different forms. Depending on the used
components and polycondensation conditions, they can either be viscous and tough or
hard and brittle. They are soluble in different solvents.
Due to the existing double bonds, the unsaturated polyesters are accessible to a radical
polymerization reaction (polyaddition). The latter can be used to cross-link the
polyesters with each other. For this purpose, additives are normally used which are
themselves accessible to a radical polyaddition reaction and which can cross-link the
linear polyester structures during co-polymerization. Since said additives are at the
same time preferably used as solvent for the polyester, they are referred to as "reactive
diluting agents", provided they are capable of performing said task. Depending on the
quantity of reactive diluting agent, the viscosity of the unsaturated polyester resin can
be set lower or higher. Styrene is normally used as reactive diluting agent. Other
FhG ... e.V., et at.
12476W0; description
possible reactive diluting agents include e.g. acrylates such as methyl methacrylate or
styrene derivatives. This list is not complete.
A polymerization inhibitor such as hydroquinone can equally be added to the reactive
5 diluting agent to prevent premature polymerization.
The mixture of polyester and reactive diluting agent is also known as reaction resin or
unsaturated polyester resin (in short: UP resin).
lo A radical initiator is used for hardening (cross-linking) the unsaturated polyester resins.
They are compounds which dissociate into radicals when exposed to heat or radiation,
said radicals subsequently activating the radical copolymerization. Once activated, the
latter can no longer be stopped. Hydroperoxides, peroxides and peresters as well as
other compounds with the necessary properties are normally used for thermohardening.
I5 Methyl ethyl ketone peroxide (MEKP) is commonly used for industrial hardening
purposes. This is often done in connection with an accelerator (e.g. a cobalt,
manganese or iron naphthenate or octanoate, as well as a tertiary amine) to allow
hardening at room temperature. In principle, all known radical initiators can be used.
The appropriate initiator is selected with respect to the desired processing properties of
20 the polyester resins and the chosen hardening temperatures (the addition of accelerator
in combination with MEKP allows cold hardening). However, radiation chemical
methods such as e. g. electron beam or UV hardening are also possible in addition to
thermohardening. A number of initiator systems are available for this purpose.
25 Gelling is the first step of the hardening process; in it, the growing molecule chains are
no longer able to diffuse, the resulting moulding material is no longer flowing and should
therefore have its final shape. Complete hardening follows, which is normally associated
with a certain degree of shrinkage.
30 Unsaturated polyester resins are processed in many different ways. The most common
ones are hand-lay-up 1 spray-lay-up (application or spraying on of the resin onto
reinforcing materials, followed by the manual incorporation of the resins using rollers
and drums), the RTM (resin transfer moulding) method, the SMC (sheet moulding
compound) 1 BMC (bulk moulding compound) method and other processing methods. In
35 principle, all unsaturated polyester resins can be processed in this manner, although a
precise adjustment to match the respective method is often required.
FhG ... e.V., et al.
12476W0; description
The unsaturated polyester resin moulded materials are thermosetting polymers. They
are predominantly used in the ship building, automotive and railway industries. Other
areas of application include case materials for the electronics industry, wind turbine
generator rotor blades and other large and small-scale uses in a variety of technical
5 fields. In the process, they are often used in a fibre-reinforced form. Glass fibres are
commonly used as fibres; carbon fibres are used less commonly.
The silazane mentioned above used for the invention is a monomeric silazane, an
oligosilazane andlor a polysilazane and comprises at least one C=C double bond.
lo Accordingly, in the present invention, the term "silazane" shall comprise monomeric,
oligomeric and polymeric silazanes as well as mixtures of silazanes which can be
monomeric, oligomeric and/or polymeric, unless otherwise provided for the specific
case. According to the invention, "oligosilazanes" and "oligomeric silazanes" means
silazanes having 2 to 10 silicon atoms. "Polysilazanes" and "polymeric silazanes" are
15 silazanes having at least 11 silicon atoms.
Silazanes, especially polysilazanes have gained increasing significance in recent years
for a number of reasons. They have been incorporated into phenolic resins and epoxy
resins and their insertion reaction in isocyanates was examined, wherein poly-urea
20 silazanes are created. The latter are of interest in particular as starting materials for the
production of ceramics.
For the purpose of the present invention, the at least one silazane can be added to the
polyester as single co-monomer; however, it is often used in mixture with a common
25 reactive diluting agent. This is the rule when the silazane is unable to dissolve the
polyester completely or adequately and a reaction in the molten mass is impossible or
not desirable.
FhG ... e.V., et al.
12476W0; description
A vinyl group-based silazane is preferably used as C=C double bond-based silazane.
The latter can comprise a single, two or a plurality of vinyl groups and bring about a
corresponding wider or closer meshed cross-linkage.
The formula of the simplest silazane body is R3Si-NR-SiR3w ith any organic R residues.
In the process, the organic residue bonded to the nitrogen is preferably hydrogen, and
in some cases also an alkyl residue such as methyl (usually containing 1-4 carbon
atoms). For the purpose of the invention, every silazane of said structure shall be
deemed suitable as long as at least one R residue has a C=C double bond and is
preferably a vinyl residue.
is one example. In this illustration, the lines depicting the bonds at the silicon represent
substituents selected from hydrogen and linear-chain, branched or cyclical, substituted
or - preferably - unsubstituted alkyl, aryl, arylalkyl, alkylaryl, alkenylaryl or arylalkenyl,
preferably hydrogen or C1-C4 alkyl. It is particularly preferred that no, only one or at
most two lines depicting bonds are provided for hydrogen. lnstead of the vinyl residue, a
different residue with a C=C double bond could be bonded to the silicon in each of said
cases, e. g. an allyl or styryl residue. lnstead of the hydrogen substituent on the
nitrogen, the nitrogen atom could carry an alkyl residue with preferably 1 to 4 carbon
atoms or a substituted or (preferably) unsubstituted phenyl residue in each of said
cases.
Oligomers and polymeric silazanes contain at least two Si-N groups, which can again
be substituted as described for the silazane above. Because both the silicon atoms as
well as the nitrogen atoms can be substituted differently depending on the starting
materials, a large variety of substances is created which can also be provided as
mixture with different molecule lengths depending on the manufacturing method. In the
process, the mentioned silazanes can be provided as chains; however, they often have
a ring structure.
Generally, the oligomeric and polymeric silazanes to be used according to the invention
can be depicted as a composition comprising one or a plurality of the following required
or optional components:
FhG ... e.V., et al.
12476WO; description
component A (required)
wherein
R2 is an organic residue containing at least one C=C double bond, preferably vinyl, R3
5 can be identical or different in several components A within the same molecule and
means hydrogen or straight-chain, branched or cyclical, substituted or - preferably -
unsubstituted alkyl, alkenyl, aryl, arylalkyl, alkylaryl, alkenylaryl or arylalkenyl, preferably
is hydrogen, phenyl or Cl-C4-alkyl and particularly preferably is hydrogen or methyl, and
R4 can be identical or different in several components A within the same molecule and
lo means hydrogen, C1-C4-alkyl or phenyl, preferably hydrogen or methyl and particularly
preferably hydrogen,
-si(R3)(R5)-N(R4)- component B (optional)
15 wherein
R3 and R4 are defined identical as for component A and R5 can be identical or different
in several components A within the same molecule and in rare cases means hydrogen,
otherwise straight-chain, branched or cyclical, substituted or - preferably -
unsubstituted alkyl, alkenyl, aryl, arylalkyl, alkylaryl, alkenylaryl or arylalkenyl, preferably
20 is Cl-C4-alkyl and particularly preferably is methyl,
-si(R3)(R6)-N(R4)- component C (optional)
wherein
25 R3 and R4 are defined as above and R6 represents a cross-linkage site to any other
component of the components mentioned herein, wherein the cross-linkage to the
silicon atom of the other component is achieved via an alkylene group, in particular an
ethylene group,
30 -si(R3)(R5)-N(R7)- component D (optional)
wherein R3 and R5 are defined as above and R7 represents a cross-linkage site to any
other component of the components mentioned herein, wherein the cross-linkage is
achieved via a direct bond of the nitrogen atom of component D to the silicon atom of
35 the other component,
-s~(R~)(R~)P-s~(R~)(R~)-N(R~)- component E (optional)
FhG ... e.V., et al.
12476W0; description
wherein R3, R4 and R5 are defined as above and R3 and R5 can have an identical or
different meaning within the same component and P is an alkylene group having 1 to 12
carbon atoms, preferably ethylene,
-si(R3)(R5)-N(R~)-~(0)-N(R4)- component F (optional)
wherein R3, R4 and R5 are defined as above and can have an identical or different
meaning within the same component.
Each of the mentioned components can be provided bonded to identical components on
both sides (if the silazanes are ring-shaped, they exclusively contain these types of
components); alternatively, it is provided at the periphery within the molecule. In this
case, either the silicon atom carries an additional residue R3 with the meaning
mentioned above, or the nitrogen atom carries an additional residue R6, with one of the
following meanings:
- R3 is defined as above,
- si(R3)3, wherein the three residues R3 can be identical or different and have the
meaning mentioned above, wherein preferably none of the residues represents a
hydrogen atom, and
- s~(R~)~-x-R~-s~(R~w)~he(roeRin ~th)e~ r-e~si,d ues R3 can be identical or different
and have the meaning mentioned above, while preferably being hydrogen or
alkyl, in particular C1-C4-alkyl, if they are provided bonded to the silicon, and
alkyl, in particular C1-C4-alkyl, if they are provided in the form of an 0R3 group, X
is either 0 or NR4 with the meaning mentioned above, R~ represents a single
bond or a substituted or - preferably - unsubstituted, straight-chain, branched or
cyclical alkylene group and q is 0, 1, 2 or 3.
The number of components and their relative proportion can fluctuate arbitrarily; the
total number is often in the range of up to 500, and if necessary, considerably higher.
The components can be distributed regularly or arranged in blocks; however, they are
preferably provided randomized within the atoms.
Examples include oligomers/polymers having the components hereinafter written in
square brackets, whose relative proportion to each other within the molecule is in each
case indicated behind the square bracket:
FhG ... e.V., et al.
12476W0; description
II
and based on mixtures of polysilazanes of the formula (I) additionally:
FhG ... e.V., et al.
12476W0; description
Some silazanes of the structures mentioned above are available on the market and can
be manufactured based on standard procedures, in particular the ammonolysis of
lo monohalogen silanes, such as described for instance in US 4,395,460 and the literature
cited therein. In the process, silazanes of the formula (I) are created e.g. as a result of
the conversion of a monohalogen silane, wherein the indices n and o are zero, the index
m means 1 and R5 means s~(R')(R')(R'). The organic residues are not removed during
the reaction.
15
Likewise, it is possible to ammonolyze mono-, di- or trisilanes in a pressure apparatus in
liquid ammonia analogous to US 6,329,487 Bl of the Kion Corporation and to obtain
silazanes of the general formula (I) in this fashion.
20 If halogen silanes having at least one Si-H bond are converted alone andlor in
combination with di- or trihalogen silanes in an excess of liquid anhydrous ammonia and
left in sa,id medium for an extended period of time, polymerization products are formed
over time in the environment which became acidic due to the developing ammonium
halide salt or the corresponding acid as a result of the exhaustive reaction of Si-H
25 bonds, in which the indices m, n and o have a higher value andlor a different proportion
than previously, possibly catalysed by the presence of dissolved and ionized ammonium
halide.
As well, it is described in US 6,329,487 B1 that corresponding polymerization products
30 can be obtained with the exposure to sodium dissolved in ammonia.
Furthermore, US 4,621,383 and WO 87105298 describe the possibility to synthesize
polysilanes by means of transition metal-catalysed reactions.
35 The suitable selection of organic substituents on the silicon atom of the silane or a
mixture of corresponding starting silanes allows the creation of a multitude of silazanes
of the formula (I) using said methods, wherein index o is zero, and where a mixture of
linear and chain-shaped polymers often develops.
FhG ... e.V., et at.
12476W0; description
For more information about the reaction mechanism, please refer to the thesis of
Michael Schulz at the Research Centre Karlsruhe, Institute for Materials Research
entitled "Microstructuring of pre-ceramic polymers by means of deep UV and X-ray
5 lithography", November 2003, FZKA 6901. In it, the manufacture of silazanes of the
formula (I) is described as well, wherein the index o is zero and the silicon atoms in the
blocks with the indices m and n carry different substituents.
In it, reference is also made to the manufacture of urea silazanes: if monofunctional
lo isocyanates are added to silazanes, an insertion reaction of the NCO group into N-H
bonds takes place, with the formation of an urea group [see the silazanes of formula (11)
described above]. In addition, please refer to US 6,165,551, US 4,929,704 and US
3,239,489 with respect to the manufacture of urea silazanes and poly(-urea silazanes).
15 The manufacture of compounds of the formula (Ill) (alkoxy-substituted silazanes) is
disclosed in US 6,652,978 82. For the manufacture of said compounds, monomeric or
oligomeric/polymeric silazanes of the formula (I), wherein o is zero, can be converted
with amino or hydroxyl group-based alkoxysilanes, for example 3-aminopropyltriethoxysilane.
20
A manufacturing procedure for compounds of the formula (I) where o is unequal to zero
is presented specifically using the ammonolysis of 1,2-Bis(dichloromethyIsilyl-ethane in
the thesis of G. Motz (G. Motz, thesis, University of Stuttgart, 1995). According to S.
Kokott and G. Motz, "Modification of the polycarbosilazane ABSE using multi-walled
25 carbon nanotubes for the manufacture of spinnable masses", Material Science and
Engineering 2007, 38 (1 I), 894-900, the manufacture of a special representative of said
compounds, ABSE, is achieved by means of hydrolysis and ammonolysis of a mixture
containing MeHSiCI2 and MeViSiC12.
30 In turn, the person skilled at the art is easily able to produce N-alkyl-substituted
silazanes in the same fashion, by bringing the corresponding halogen silanes to react
with alkyl amines, such as described for example in US 4,935,481 and US 4,595,775.
The polysilazane of the formula (IV) is a processed form of a polyvinyl silane of the
35 formula (I), containing differently sized molecules. Low-boiling components are removed
from it by means of distillation. A thermal cross-linkage via the double bonds and the Si-
H groups takes place to a certain degree in the process during the so-called hydrolysis.
Polysilazanes of the formula (V) are formed if conversion in the presence of a fluoride
FhG ... e.V., et al.
12476W0; description
catalyst takes place after the distillation, wherein dehydrocoupling occurs with the new
formation of Si-N-Si groups under the formation of HZ Products of the formula (VI) can
be obtained if said type of fluoride-catalysed reaction is performed using a mixture of
polysilazanes of the formula (I), which contains low-boiling components.
An unsaturated polyester is mixed with a silazane or a silazane mixture as defined
above for the manufacture of polyester resins according the invention. In principle, the
invention is suitable for any type of unsaturated polyester resin. However, it is preferred
that the polyester has a relatively low acid number, because this enhances the
compatibility between the components. In addition, there is a risk associated with very
high acid numbers that the Si-N groups disintegrate under the removal of NH3, which
can result in intense undesirable secondary reactions. Therefore, an acid number of 20
mg1KOH should not be exceeded under any circumstances; preferably, the number is
below 15 mg1KOH and particularly preferably under 10 mg1KOH.
If the silazane is unable to dissolve the polyester, it is additionally preferred to either add
a solvent or a reactive diluting agent. Indeed, the reaction can also take place in the
molten mass, but said conversion is more difficult to control. A reactive diluting agent is
preferable to a solvent, because it can be fully incorporated into the developing network
during the radical polymerization, while the subsequent removal of the solvent from the
network is necessary. The typically often used styrene is a suitable reactive diluting
agent.
In principle, the quantitative proportion of unsaturated polyester to silazane and
optionally to the reactive solvent is not critical, because all mentioned components are
involved in the radical polymerization and are statistically incorporated into the
developing network. Networks with different densities are obtained with the use of
different quantitative relations. Moreover, the properties of the polyester resin moulded
materials can be controlled with the ratios of aliphaticllinear or cross-linked structures
(e.g. with the use of corresponding silazanes) and aromatic structures (e.g. with the use
of styrene as reactive diluting agent), in order to prevent a high network density (with
the consequence of a potentially undesirably low glass transition temperature), as
known to the person skilled at the art. It is e.g. possible to use polyester or polyester +
reactive diluting agent and silazane at a quantitative proportion (weightlweight) of 1 :I00
to 100: 1, preferably of 1 : 10 to 10: 1 and more preferably of 1 :5 to 5: 1. If reactive diluting
agent is present, a quantitative proportion (weightlweight) between polyester and
reactive diluting agent of 1:10 to 10:1, preferably 1:5 to 5:l is advantageous. Mixtures
with a proportion between 4:l and 1:l are often sold commercially.
FhG ... e.V., et al.
12476WO; description
To obtain bubble-free products, the mixture should be degassed prior to processing, for
example at approx. 200 mbar, unless it contains a low-boiling solvent.
5 It can be processed in any fashion, for instance as described above for polyester resins
of the prior art or as casting resin. One essential exemplary embodiment of the
invention relates to fibre-reinforced polyester resin moulded masses. They can be
produced e.g. by means of the known RTM (resin transfer moulding) method. With this
method, a stack of dry fibrous tissue is placed into a tool and shaped by means of a
lo press. Next, it is impregnated with the low-viscosity resin according to the invention,
usually be means of pressure, or - e.g. with the VARTM (vacuum assisted RTM) - by
means of a vacuum in the closed tool and subsequently hardened, which is normally
done with the exposure to heat, thus creating the corresponding component.
1s The reactive resin mixture can be hardened in the known fashion. The use of lowoxidizing
peroxides is advantageous, as it is known to the person skilled at the art.
Favourable results can be achieved with tertiary butyl perbenzoate.
The hardened masses are characterized by a glass temperature of up to 155" C. The
20 char resistance increases considerably (based on the examples, the MAHRE value of
pure resin specimens decreases by approx. 30% compared with similar polyesters
without silazane). It is particularly advantageous if the char residues are considerably
higher (as much as approximately 30-50 percent by mass of material is found after the
moulded materials according to the invention have been charred, while the char residue
25 of common UP moulded materials is as low as approximately 1 percent by mass).
Moreover, the specimens still have a residual strength after being charred. In the case
of fibrous carbon tissue-RTM specimens, it was possible to reduce the MAHRE value to
a value of lower than 100 kw/m2. In addition, an extremely low absolute heat release of
10 M J /w~as~ a chieved. The loss of mass during the charring process is as low as
30 15%.
FhG ... e.V., et al.
12476W0; description
Exemplary embodiments
Example 1
50 parts by weight of a polyester comprising 1 rnol of maleic acid anhydride, 0.5 rnol of
phthalic acid anhydride, 0.84 rnol of propylene glycol and 0.75 rnol of dipropylene glycol
with endcapping of the COOH terminal groups through I-Octanol (isomolar addition at
an acid number of 25 mg KOHlg), with a final acid number of 10 mg KOHIg, dissolved in
40 percent by weight of styrene, were thoroughly mixed using a glass rod with 50 parts
by weight of a silazane having the approximate formula (IV) (manufactured with the
distillation of a mixture of a vinyl silazane which consisted of 20% -Si(CH3)(CH=CH2)-
NH- components and 80% -Si(H)(CH=CH2)-NH- components, wherein thermal crosslinkage
in part occurred via the double bonds and the Si-H groups (so-called
hydrosilylation)) and 0.5 parts by weight of tertiary Butyl perbenzoate, wherein gas
bubbles rose. After mixing it thoroughly, the mixture was deventilated at 200 mbar, until
no visible gas bubbles were present any more. Next, it was poured into a plate mould
and fully hardened at 160-180" C.
The data illustrated in Table 1 were measured.
Example 2
Example 1 was repeated with the change that 66.6 parts by weight of the polyester
resin, 33.3 parts by weight of the silazane and 0.66 parts by weight of tertiary Butyl
perbenzoate were used.
The data illustrated in Table 1 were measured.
Example 3
66.6 parts by weight of an unsaturated polyester comprising 1 rnol of fumaric acid, 0.4
rnol of neopentyl glycol, 0.606 rnol of bispropoxylated bisphenol A and 0.051 rnol of
propylene glycol with endcapping of the COOH terminal groups through I-Octanol
(isomolar addition at an acid number of 25 mg KOHlg) having a final acid number of 4
mg KOHlg dissolved in 50 % by weight of styrene were mixed with 33.3 parts by weight
of the silazane according to example 1 as well as 0.66 parts by weight of tertiary Butyl
perbenzoate and fully dried as described in example 1.
FhG ... e.V., et al.
12476WO; description
A bubble-free pure resin plate was created.
Example 4
5 A mixture was produced analogous to example 3 and processed by means of RTM.
Fibrous carbon tissue was used as reinforcing material. The hardening was carried out
analogous to the conditions in example 1. The characterization supplied the data
illustrated in Table 1.
lo Comparative examples 5 and 6
The resins of examples 1 and 3 were polymerized without the addition of silazane, but
otherwise as described in these examples. The glass transition temperature of the
obtained moulded materials is illustrated in Table 1.
15
Table 1
20 Abbreviations:
TTI = Time of ignition
HRRpeak = Heat release rate peak
MARHE = Maximum average rate of heat emission
THR = Total heat release
25 TSR = Total smoke released
Am indicates the loss of mass in % as a result of the charring, i.e.
100% - Am indicates the mass of the char residue (CR).
Example 1
Example 2
Example 4
Comparative
example 5
Comparative
example 6
Am
[%I
51
66
15
TG [OC]
ca.60-70
90
155
106
170
TTI [s]
45
43
42
THR
[MJ/~']
102
114
10
TSR
[m2/m2]
5200
6400
400
HRRpeak
[kw/m2]
595
732
243
MARHE
[kw/m2]
277
319
95

Fraunhofer-Gesellschaft.. . e.V., et al.
12476WO; claims (clean copy)
PCT/EP20111065890
July 26, 2012 *
Claims:
1. An unsaturated polyester resin, containing
(a) a polyester or a polyester mixture, produced from at least
one unsaturated dicarboxylic acid and
at least one diol
and
(b) at least one silazane, comprising one or a plurality of C=C double bonds and
which is accessible for copolymerization with a C=C double bond of the
dicarboxylic acid.
2. An unsaturated polyester resin according to claim 1, further comprising
(c) a reactive diluting agent.
1s 3. An unsaturated polyester resin according to claim 2, wherein the reactive diluting
agent is an unsubstituted or substituted styrene.
4. An unsaturated polyester resin according to any one of the preceding claims,
further comprising
(d) at least one radical initiator.
5. An unsaturated polyester resin according to any one of the preceding claims,
wherein the polyester has an acid number of less than 12 mg/KOH.
25 6. An unsaturated polyester resin according to any one of the preceding claims,
wherein the silazane which is accessible for copolymerisation with a C=C double
bond of the dicarboxylic acid comprises vinyl groups bound to silicon atoms.
7. An unsaturated polyester resin according to claim 6, wherein at least part of the
mentioned silazane comprises the component -Si(R)(CH=CHz)-NH- where R
equals H or methyl.
8. An unsaturated polyester resin moulding material which can be obtained or is
obtained by cross-linking an unsaturated polyester resin according to any one of
35 claims 1 to 7.
9. An unsaturated polyester resin moulding material according to claim 8, containing
at least one reinforcing material, in particular reinforcing fibres.
Replacement page (Art. 34 PCT)
Fraunhofer-Gesellschaft... e .V., et al.
12476WO; claims (clean copy)
PCT/EP20111065890
July 26, 2012
10. A method for the production of an unsaturated polyester resin according to any
one of claims 1 to 7, characterized by the steps
(a) provision of a polyester from at least one diol and at least one unsaturated
dicarboxylic acid as defined in i n y one of claims 1 to 5,
(b) provision of at least one silazane containing one or a plurality of C=C double
bonds and which is accessible for copolymerization with a C=C double bond
of the dicarboxylic acid as defined in any one of claims 1, 6 and 7,
(c) mixing of the components according to (a) and (b).
11. A method according to claim 10, wherein the polyester and/or the silazane islare
provided dissolved in a solvent or a reactive diluting agent and/or wherein a
polymerization inhibitor is added to the polyester.
12. A method for the production of an unsaturated polyester resin moulding material
according to claim 8, comprising
(a) the provision of an unsaturated polyester resin as defined in any one of
claims 1 to 7 and
(b) the hardening of the unsaturated polyester resin by means of a radical
initiator under the formation of the moulding material.
13. A method for the production of an unsaturated polyester resin moulding material
containing reinforcing fibres according to claim 9, comprising
(a) the provision of an unsaturated polyester resin as defined in any one of
claims 1 to 7,
(b) the incorporation of fibres into the unsaturated polyester resin or the
impregnation or coating of fibres or the filling of a mold containing fibres with
the polyester resin as well as
(c) the hardening of the unsaturated polyester resin by means of a radical
initiator under the formation of the moulding material.
30
14. A method according to claim 12 or 13, wherein the unsaturated polyester resin is
provided with its production according to claim 10 or 11.
15. A method according to any one of claims 12 to 14, wherein the unsaturated
35 polyester resin is degassed before being converted into a form in which it is
hardened.
* * *
-- - - - - - , . -
Dated tl&s Ld4.2013
ATTORNEY FOR THE APPLICANT[S]