Anti termite cable sheathing comprising an aliphatic polyamide X.Y
with X+Y>18, an UV absorber and/or UV stabilizer, and an
antioxidant
Technical Field
The technical field of the present invention relates to cable
sheathings, in particular electric and optical fiber cable sheathing,
displaying, among others, excellent termite resistant properties.
The invention relates to the use of a composition comprising at
least one particular aliphatic polyamide, at least one UV absorber
and/or UV stabilizer, and at least one antioxidant, to manufacture a
mono or multilayer cable sheathing resistant to termite damage, in
particular for electric and optical fiber cables. The cable according to
the invention display besides at least an additional property as
disclosed further below.
In particular, the invention relates to a composition comprising
at least one particular aliphatic polyamide, at least one UV absorber
and/or UV stabilizer, and at least one antioxidant, with a weight ratio
of the total amount of antioxidant over the total amount of UV
protective agent being less than or equal to 0.7.
The invention also relates to a mono or multilayer cable
sheathing constituted of at least one layer of a composition according
to the invention; a process to manufacture a cable sheathing from said
composition according to the invention; and the use of a mono or
multilayer sheathing according to the invention to prevent and/or
protect a cable, in particular an electric cable (such as power cable,
copper cable) and/or optical fiber cable, from damages of termites and
eventually damages from light, heat, wind, water air, humidity, soils,
oil, grease, j elly, other insects, and/or bending.
Background Art
It is known different ways to protect cable from termite
attacks.
First, cable sheathing and soils were impregnated with
insecticide or repellent. However, the difficulty with loading chemical
is to practically load insecticide or repellent enough to deter termites
from further attacks. On the other side, putting chemicals in the soils
may harm non-target organisms and are dangerous to handle.
Second, cable sheathing layer materials have been chosen to be
used as anti termite barrier layers, such as for example metal or hard
plastics.
In AU20112537 18, it was found that polyethylene terephtalate
(PET) was useful as anti termite barrier tape to protect cable from
termite attacks. However, this material is improper to be extruded onto
the core of a cable due to its high melting temperature (260°C) and
low melt viscosity, and thus, requires thermoplastic polymer termite
barrier manufacturers who usually use tube extrusions process to make
additional investment to implementing new installations to produce
cable sheathings.
On the market, it has been known for years to use PA12 or
PA1 1 based grades to make anti termite cable sheathings.
However, these materials are very expensive and had to face recently
production shortage.
Contents of Invention
Therefore, there is now a need to find new cable sheating
compositions which can be extruded into tubes, are environment
friendly, non toxic to human health, and which lead to cable sheathing
displaying a broad range of properties and at least antitermite
properties. In particular, it is searched a composition which can be
used to manufacture antitermite cable sheathing which displays one or
several properties to face outdoor conditions especially in tropical and
subtropical regions where live most of the termite. For example,
mention may be made of light and water resistance after long term
exposition, low moisture uptake, mechanical resistance, chemical
resistance, resistance to other insects attacks, bending resistance. ...
When cables are exposed to external environment in particular
wind, sun and water (rain, humidity), such as outdoor and overhead
cables, cable sheathings shall resist at least to high exposure to
sunlight (ultraviolet rays) and/or rain over long term periods. Water
should not penetrate underneath the sheathing as it will cause damage
to the optical fibers and perturbate the transmitted signal or cause
shortcircuit to electric cable. Therefore, it is searched a cable
sheathing resistant to UV ageing, resistant to hydrolysis and/or having
a low moisture uptake.
When cables are buried, cable sheathings are exposed to
various type of soils more or less acid, different types of chemicals
during the installation (oils, grease, jelly. ..) and to surrounding fauna
rej ects such as formic acid. Therefore, cable sheathings should present
preferably chemical resistance.
Moreover, soils may be humid or exposed to floods. Therefore,
it is searched a cable sheathing that are also preferably resistant to
hydrolysis and have low moisture uptake.
Moreover, it is searched a cable sheathing that display
sufficient mechanical strength and heat resistance so that it will not be
damaged and will not melt under regular use (indoor or outdoor use) of
the electric or optical fiber cables.
It is also searched cable sheathing that is preferably dimension
stable, meaning its dimension should not vary over time. This enables
to avoid looseness of the sheathing, water penetration in the
underneath layers, surface defects or wrinkles.
It is also preferred cable sheathing which outer surface is
smooth and glossy. Indeed without being limited to the theory, it is
thought that any defect surface is a potential point of attack by
termites. Therefore, a glossy surface might contribute to the resistance
to termite attacks.
To get such aspect, the cable sheathing should be at least
resistant to blistering. Blistering may occur for example when the
material is moisture sensitive in particular when the material has high
moisture uptake.
Surprisingly, it has now been found that by using a
composition comprising at least one particular aliphatic polyamide, at
least one UV absorber and/or UV stabilizer, and at least one, it was
possible to get an antitermite cable sheathing, in particular for electric
and optical fiber cables, possessing one or several of the above
mentioned properties, and preferably several of the above mentioned
properties.
Summary of the invention
In order to resolve prior art disadvantage, the present invention
relates to a composition comprising:
a) at least one aliphatic polyamide having at least two units
corresponding to the following general formula:
X.Y
in which:
X.Y represents a unit obtained, preferably directly, by
polycondensation of:
- a diamine containing X carbon atoms and,
- a dicarboxylic acid containing Y carbon atoms,
and such that the sum of X+Y is strictly superior to 18,
(hereafter PA X.Y)
b) at least one UV absorber and/or UV stabilizer,
c) at least one antioxidant,
wherein the weight ratio of the total amount of antioxidant(s) over the
total amount of UV absorber(s) and UV stabilizer(s) (when present)
being less than or equal to 0.7, and preferably less than or equal to
0.4, with a weight ratio greater than zero.
Another obj ect of the invention is the use of a composition
comprising:
a) at least one aliphatic polyamide having at least two units
corresponding to the following general formula:
X.Y
in which:
X.Y represents a unit obtained, preferably directly, by
polycondensation of:
- a diamine containing X carbon atoms and,
- a dicarboxylic acid containing Y carbon atoms,
and such that the sum of X+Y is strictly superior to 18,
b) at least one UV absorber and/or UV stabilizer,
c) at least one antioxidant,
to manufacture a mono or multilayer cable sheathing resistant to
termite damage.
In particular, it was observed that the mono or multilayer cable
sheathing according to the invention presents from good to excellent
results as regards:
- termite resistance,
- thermal ageing resistance,
- ultraviolet (UV) ageing resistance,
- processability (extrusion or coextrusion),
- moisture uptake,
- gloss, and
- chemical resistance (against lewis acid such as formic acid)
colour fastness
- cold bend performance in particular, when used as outer layer or
overlayer of a cable.
Indeed, it was observed that after heat ageing at 100°C for 120
hours in an air circulating oven, the cable sheathing according to the
invention present preferably over 80% retention of elongation at break.
After 1200 hours UV exposure (radiance level of 0.5W/m2, lnm
bandpass at 340nm, optical filter: cut-on 295nm, black panel
temperature of 63°C, relative humidity (RH) = 50%, no water spray),
the cable sheathing according to the invention present preferably over
85% even over 90% retention of elongation at break (over 90% for
coloured cable sheathing).
The composition according to the invention is in particular
easy to process, (easy to extrude) and lead to dimension stable
extruded products.
The cable sheathing according to the invention have preferably
a low moisture uptake after immersion in water or exposure to
saturated humidity at 23°C over one and up to two weeks at (less than
2 .5%) , and are resistant to hydrolysis (ISO 62).
It has preferably a smoothy and glossy outer surface. Gloss can
be measured by detecting the intensity of the reflected light from an
incident beam at a given incidence angle on the tested material surface
(ASTM D 2457).
Preferably the antitermite cable sheathing i s resistant to
chemicals such as formic acid, as characterized by AS1049-2008.2
appendix M.
When composition of the invention comprises a colorant or
pigment, colorfastness may be characterized by AS1049-2008.2.
The cable sheathing according to the invention i s preferably
flexible enough to resist to bending as characterized by AS1049-2008
appendix J, Indeed, it has been observed that the cable sheathing of
the invention do not present any crackings after being bent around a
mandrel for 4 hours at - 15°C.The invention also relates to a process to
manufacture a cable sheathing according to the invention by extrusion
or coextrusion.
The invention also relates to the use of a cable sheathing
according to the invention or manufactured according to a process of
the invention to prevent and/or protect the cable, in particular power
cable, copper cable and optical fiber cable, from damages due to
termites and eventually/or light, heat, wind, water air, humidity, soils,
oil, grease, j elly, other insects and/or kinking.
Other characteristics, aspects, subj ects and advantages of the
present invention will emerge even more clearly on reading the
description and the examples that follow.
Specific Mode for Carrying out the Invention
The composition according to the invention comprises at least one PA X.Y
as defined above.
The diamine used for the polycondensation of PA X.Y may be chosen from
linear or branched aliphatic diamine.
As linear and aliphatic diamine used for the polycondensation of PA X.Y,
mention may be made of those, saturated or unsaturated, corresponding to the
formula H2N-(CH 2)x-NH 2, in which X has the same meaning as above
mentioned. Such linear and aliphatic diamine may be chosen from hexanediamine
(X=6), heptanediamine (X=7), octanediamine (X=8), nonanediamine (X=9),
decanediamine (X=10), undecanediamine (X=l l), dodecanediamine (X=12),
tridecanediamine (X=13), tetradecanediamine (X=14), hexadecanediamine (X=16),
octadecanediamine (X=18), octadecenediamine (X=18), eicosanediamine (X=20),
docosanediamine (X=22) and the diamines obtained from fatty acids.
As branched and aliphatic diamine used for the polycondensation of PA
X.Y, mention may be made of those chosen from linear and aliphatic diamines, such
as those defined above, comprising one or several alkyl group (in particular methyl or
ethyl) pendant to the main chain of the diamine. Such branched and aliphatic diamine
may be saturated or unsaturated. By way of example, it may be chosen from 2-
methyl- 1,5-pentanediamine (X=6), 2, ,4-tri methyl- 1,6-hexanediamine
(X=9), 2,4,4-trimethyl-l ,6-hexanediamine (X=9), 2-methyl- l ,8-
octanediamine (X=9). Preferably, the branched and aliphatic diamine
has from 6 to 12 carbon atoms in its main chain.
The dicarboxylic acid used for the polycondensation of PA X.Y may be
chosen from linear or branched aliphatic dicarboxylic acid.
The linear and aliphatic dicarboxylic acid used for the polycondensation of
PA X.Y may be saturated or unsaturated. By way of example, mention may be made
of adipic acid (Y=6), heptanedioic acid (Y=7), octanedioic acid (Y=8), azelaic acid
(Y=9), sebacic acid (Y=10), undecanedioic acid (Y=l 1), dodecanedioic acid (Y=12),
brassylic acid (Y=13), tetradecanedioic acid (Y=14), pentanedecanedioic acid
(Y=15), hexadecanedioic acid (Y=16), octadecanedioic acid (Y=18), octadecenedioic
acid (Y=18), eicosanedioic acid (Y=20), docosanedioic acid (Y=22) and fatty acid
dimers containing 36 carbon atoms.
The fatty acid dimers mentioned above are dimerized fatty
acids obtained by oligomerization or polymerization of unsaturated
monobasic fatty acids bearing a long hydrocarbon-based chain (such as
linoleic acid (Ci ) and oleic acid (Ci )), as described especially in
document EP 0 47 1 566.
The branched and aliphatic dicarboxylic acid used for the
polycondensation of PA X.Y, may b e saturated or unsaturated.
The diamine and/or dicarboxylic acid used t o form the
polyamide used according t o the invention from a biobased raw
material as characterized in ASTM D6866. By way of example,
mention may be made of 1, 10-decanediamine, linear and aliphatic
diamines and diacides as above-mentioned.
Advantageously, the polyamide used in the composition
according t o the invention does not result from recycling of prior-used
polyamides. In other terms, the polyamide i s directly obtained from
the polycondensation of:
- a diamine containing X carbon atoms and,
- a dicarboxylic acid containing Y carbon atoms,
and such that the sum of X+Y is strictly superior to 18, preferably
superior or equal to 20, and more preferably inferior or equal to 36 .
The diamine and dicarboxylic acid used to form the polyamide
used in the composition according to the invention are chosen so as to
satisfy the condition that the sum of X+Y is strictly greater than 18,
and preferably greater or equal to 20, and more preferably inferior or
equal to 36.
Preferably, X is chosen from 6 to 12 and/or Yis chosen from 10 to 18.
Preferably, the polyamide used in the composition of the
inventionis a homopolymer.
Preferably, the polyamide used in the composition of the
invention may be chosen from among PA6. 14, PA 6 . 18, PAI O. I O,
PA10 . 12, PA10 . 14, PA12. 12 and mixture thereof, in particular from
PAI O. IO, PA10 . 12, PA12. 12 and mixture thereof, and more preferably
the polyamide is PAI O. IO, PA10 .12 or PA12. 12.
Advantageously, the polyamide used according to the invention
presents a melting point of less than 2 10°C, preferably from 180°C to
205°C.
Preferably, the mole proportions of diamine, and of
dicarboxylic acid used to form the polyamide used according to the
invention, are stoichiometric.
The polyamide used according to the invention have a
flexibility of less than or equal to 2000 MPa, preferably ranging from
1000 to 1800MPa (measured according to AS1049. 2-2008, appendix J)
Preferably, the polyamide is used in the composition of the
invention in an amount such that the complement to 100% of the
composition being constituted by said polyamide, said amount being of
at least 50wt%, more preferably at least 60wt% of the total weight of
the composition.
The composition according to the invention comprises at least
one UV absorber and eventually at least one UV stabilizer.
The UV absorber used according to the invention provides UV
protection through effective absorption or reflection of incident UV
rays.
The UV stabilizer used according to the invention functions as
scavenger of harmful molecules that may attack and degrade the
plastic material used in the composition of the invention.
In a first embodiment of the invention, the UV absorber is
chosen from among black colored UV absorbers (hereafter referred as
LI). The term black colored UV absorber includes UV absorber
displaying a black color or capable to color the composition of the
invention in black when present in effective amount (for example in an
amount of less than or equal to 0, 1% by weight (wt%)). In particular,
these black colored UV absorbers absorb any incident rays of light of
any wavelength (including UV rays), leading thus to a black colored
component.
Preferably, the black colored UV absorber (LI) that is used in
the composition according to the invention may be chosen from among
mineral black colored UV absorbers such as black pigments such as
carbon black, iron oxide black, manganese black (Mn02), cobalt black
(Co203), antimony black, and mixture thereof. More preferably,
carbon black is used.
Carbon black may be available under the brand Vulcan® P sold
by Cabot Corporation.
Advantageously, the average particle size of the mineral black
colored UV absorber is less than 25 nm. Average particle size may be
determined in accordance with ASTM D3849.
Advantageously, the mineral black colored UV absorber may be
homogenously dispersed in the polyamide matrix of the composition,
in accordance with standard ISO 18553 .
Preferably, the mineral black colored UV absorber is present in
the composition in an amount of at least 2%wt relative to the total
weight of the composition, and preferably from 2 to 3wt% relative to
the total weight of the composition.
Its content may be determined in accordance with AS/NZS
1660.2.4: 1998 Standards.
In this first embodiment, the composition comprises as
antioxidant at least one metallic antioxidant.
The composition may also comprise at least one heat
stabilizer.
Advantageously, the metallic antioxidant plays the role of
a heat stabilizer. This enables to get cable sheathing with better
thermal ageing resistance.
As example of metallic antioxidants and/or heat stabilizers
which may be used in accordance with the invention, mention may be
made of mineral copper based antioxidants and heat stabilizers, and
more preferably copper salts and complexes such as potassium and
copper halogen blends (KI/CuI) with stearate based or wax binder
lubrifiant.
Such metallic antioxidants and heat stabilizers may be
available under the brand BRUGGOLEN® H3336 sold by
BRUGGEMANN CHEMICAL, or POLYAD® PB 201 IODIDE STAB
sold by POLYAD SERVICES.
The total amount of metallic antioxidant(s) and heat stabilizer
that may be present in the composition of the invention ranges
preferably from 0 .1wt% to 2wt% relative to the total weight of the
composition.
When the metallic antioxidant plays the role of a heat
stabilizer, an vice versa, the total amount of metallic antioxidant(s)
and heat stabilizer(s) that may be present in the composition ranges
preferably from 0.05wt% to lwt% relative to the total weight of the
composition.
In a second embodiment of the invention, the UV absorber is
chosen from organic and/or mineral UV absorbers (L2). These UV
absorbers are different from those of first embodiment. In particular,
the UV absorber used according to second embodiment is not black
colored.
As example of organic or mineral UV absorbers (L2) that may
be used in the composition of the invention, mention may be made of
benzophenone UV absorbers; benzotriazole UV absorbers such as 2-
(2H-benzotriazol-2-yl)-4,6-bis(l -methyl -1-phenyl ethyl) phenol
(Tinuvin® 234), N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-
ethanediamide (TINUVIN® 312) and 2-(2'-hydroxy-3 ',5'-di-tertbutylphenyl)
benzotriazole (TINUVIN® 320); and Ti02 eventually
coated by rutile. More preferably, it may be chosen from benzotriazole
UV absorbers.
The UV absorber (L2) may be present in the composition
according to the invention in an amount ranging from 0 .1 to 1.5wt%
and preferably from 0.2 to 0.5wt% relative to the total weight of the
composition.
In this second embodiment, the composition according to the
invention does not comprise component that may give a black color to
the composition. In particular, the composition does not comprise
black colorant and black pigment such as the above mentioned black
colored UV absorber (L I).
The composition according to the invention may comprise at
least one colorant or pigment, different from black colorant or black
pigment. Said colorant and pigment enable to color the composition in
the desired colored
By way of example, said colorant or pigment may be chosen
from colorant or pigment giving a blue, green, yellow, red or white
colour to the composition or cable sheathing according to the
invention, under visible light. Preferably, the composition according to
the invention does not comprise metallic salts or complex such as
copper and potassium halogen salts or complex. Indeed, those metallic
salts and complexes may interfer and darken the color given by the
non black colorant or pigment.
When present (i.e. when the composition comprises more than
0wt% relative to the total weight of the composition), the colorant or
pigment is preferably chosen in an effective amount to visibly colour
the composition, for example ranging from 1 to 10wt% relative to the
total weight of the composition. For example, the amount of the
colorant or pigment may vary up to 4wt%, up to 6wt% or up to 8w%,
relative to the total weight of the composition.
In this second embodiment, preferably the composition
according to the invention is a halogen free composition.
The composition according to the invention may comprise at
least one UV stabilizer, preferably chosen from among hindered amine
light stabilizers (HALS).
In the composition according to the first embodiment, UV
stabilizer may not be used.
When present in the composition of the invention, HALS may
be chosen from among amine derivatives of 2,2,6,6-
tetramethylpiperidine; amino ether derivatives of 2,2,6,6-
tetramethylpiperidine (hereafter HALS amine and HALS aminoether
respectively); and mixture thereof.
Mention may be made of 2,2,6,6-tetramethyl -4-piperidone;
2,2,6,6-tetramety 1-4-piperidinol; bis-(l ,2, 2,6,6-pentamethylpi perl dyl)-
(3',5'-ditert-butyl-4'-hydroxybenzyl)butylmalonate; di-(2, 2,6,6-
tetramethyl-4-piperidyl)sebacate (TINUVIN® 770); oligomer of N-(2-
hydroxyethyl)-2, 2,6,6-tetramethy 1-4-piperidinol and succinic acid
(TINUVIN® 622); oligomer of cyanuric acid and N,N-di(2, 2,6,6-
tetramethy l -4-piperldyl)-hexamethylenedi amine; bis-(2, 2,6,6-
tetramethy 1-4-piperldinyl) succinate; bis-(l-octyloxy-2, 2,6,6-
tetramethy l -4-piperldinyl)sebacate (TINUVIN® 123); bis-(l ,2,2,6,6-
pentamethyl-4-piperldinyl)sebacate (TINUVIN® 765); ; tetrakis-
(2, 2,6,6-tetramethy 1-4-piperidyl)- 1,2,3 ,4-butane tetracarboxylate;
N,N'-bi s-(2, 2,6,6-tetramethy 1-4-piperidyl)-hexane- 1, 6-di amine
(CHIMASORB® T5); N-butyl-2, 2,6,6-tetramethy 1-4-piperidinamine;
2,2'-[(2,2,6,6-tetramethyl-piperidinyl)-imino]-bis-[ethanol]; polyK6-
morpholine-S-triazine-2,4-diyl) (2, 2,6,6-tetramethy 1-4-piperidinyl)-
iminohexamethy lene-(2,2, 6,6-tetramethy 1-4-piperldinyl)-
imino)(Cyasorb UV 3346); 5-(2, 2,6,6-tetramethy 1-4-piperidinyl)-2-
cyclo-undecyl-oxazole) (HOSTAVIN® N20); 1,1'-(1 ,2-ethane-di-yl)-
bis-(3,3 ',5,5'-tetramethyl-piperazinone); 8-acetyl-3-dothecy 1-7,7,9,9-
tetramethy l - l ,3,8-triazaspiro(4,5)decane-2, 4-dione;
polymethylpropy 1-3-oxy- [4 (2, 2,6,6-tetramethy l)-piperidinyl]siloxane
(UVASIL® 299); 1,2,3,4-butane-tetracarboxylic acid- l ,2,3-tris(l ,2,2,
6,6-pentamethyl-4-piperldinyl)-4-tridecylester; copolymer of alphamethyl
styrene-N-(2, 2,6,6-tetramethy 1-4-piperidinyl) maleimide and
stearyl maleimide; 1,2,3,4-butanetetracarboxylic acid, polymer with
beta,beta,beta',beta'-tetramethyl-2,4,8, 10-tetraoxaspiro[5,5]undecane-
3,9-diethanol, l ,2,2,6,6-pentamethyl-4-piperidinyl ester (MARK®
LA63); 2,4,8, 10-tetraoxaspiro[5,5]undecane-3,9-
diethanol,b eta,beta,beta', beta'-tetramethyl -polymer with 1,2,3,4-
butanetetracarboxylic acid,2,2,6,6-tetramethyl -4-piperidinyl ester
(MARK® LA68); D-glucitol, l ,3,2,4-bis-0-(2,2,6,6-tetramethy l -4-
piperidinylidene)-(HALS 7); oligomer of 7-oxa-3,20-
diazadispiro[5, 1,1l ,2]-heneicosan-2 1-one-2,2,4,4-tetramethyl -20-
(oxiranylmethyl) (HOSTAVIN® N30); propanedioic acid, [(4-
methoxyphenyl)methylene]-bis-(l ,2, 2,6,6-pentamethy 1-4-
piperidinyl)ester (SANDUVOR® PR 31); formamide,N,N'- 1,6-
hexanediylbis [N-(2,2,6,6-tetramethyl-4-piperidinyl (UVINUL®
4050H); l ,3,5-triazine-2,4,6-triamine,N,N"'-[ l ,2-ethanediylbis[[[4,6-
bis [butyl ( 1,2, 2,6,6-pentamethy l-4-piperldinyl)amino]- 1,3, 5-triazine-2-
yl]imino]-3, l -propanediyl]]-bis[N',N"-dibutyl-N',N"-bis(l ,2,2,6,6-
pentamethy l -4-piperidinyl) (CHIMASSORB® 119); poly[[6-[(l ,1,3,3-
tetramethylbutyl)amino] -1,3 ,5-triazine-2,4-diyl] [(2, 2,6,6-tetramethy 1-
4-peperi dinyl)-imino]- l ,6-hexanediyl [(2, 2,6,6-tetramethy 1-4-
piperidinyl)imino]] (CHIMASSORB® 944); 1,6-hexanediamine, N,Nbis(
2,2,6,6-tetramethyl-4-piperidinyl)-, polymer with 2,4,6-trichloro-
1,3,5-triazine, reaction products with N-butyl- 1-butanamine and Nbutyl-
2,2,6,6-tetramethyl-4-piperidinamine (CHIMASSORB® 2020) ;
l ,5-dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(2, 2,6,6-
tetramethy l -4-peridinyl)ester (CYASORB® UV-500); 1,5-
dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(l ,2,2,6,6-
pentamethy l -4-peridinyl)ester (CYASORB® UV-516); N-2,2,6,6-
tetramethyl-4-piperidinyl-N-amino-oxamide; 4-acryloyloxy- 1,2,2,6,6-
pentamethyl-4-piperidine. 1, 5, 8, 12-tetrakis[2', 4,-bis ( ,,2",2",6",6"-
pentamethyl-4"-piperidinyl(butyl)amino )- ,3',5'-triazine-6'-yl]-
1,5,8, 12-tetraazadodecane; HALS PB-4 1 (CLARIANT ® S.A.); N ,N '-
bi s(2, 2,6,6-tetramethy l-4-piperidinyl)- l ,3 -benzenedicarboxamide
(NYLOSTAB® SEED); 3-dodecyl- 1-(2, 2,6,6-tetramethy 1-4-piperidyl)-
pyrrolidin-2,5-dione; 1,3-Propanediamine, N,N" -1,2-ethanediylbis-,
polymer with 2,4,6-trichloro- 1,3 ,5-triazine, reaction products
with N-butyl-2,2,6,6-tetramethyl-4-piperidinamine (UVASORB®
HA88); l , l '-(l ,2-ethane-di-yl)-bis-(3,3 ',5,5'-tetra-methylpiperazinone)
(GOOD-RITE® 3034); 1,1 "-(1 ,3,5-triazine-2,4,6-
triyltris((cyclohexylimino)-2, 1-ethanediy l)tris-(3, 3,5,5 -
tetramethylpiperazinone) (GOOD-RITE® 3150) and; 1,1', 1"-(1 ,3,5-
triazine-2,4,6-triyltris((cyclohexylimino)-2, 1-
ethanediyl)tris-(3 ,3,4,5,5-tetramethylpiperazinone) (GOOD-RITE®
3159); l ,3,5-Triazine-2,4,6-triamine, N2,N2'- l ,2-ethanediylbis[N2-[3-
[[4, 6-bis[butyl( 1,2, 2,6,6 -pentamethyl-4-pi peri dinyl)amino]- 1,3,5 -
triazin-2-yl]amino]propyl]-N4,N6-dibutyl-N4,N6-bis( 1,2, 2,6,6-
pentamethyl-4-piperidinyl)- (SONGLIGHT® 1190).
Preferably, the HALS that may be used in the composition of
the invention is chosen from HALS amines and mixture thereof. By
way of example mention may be made of poly[[6-[(l ,1,3,3-
tetr amethylbutyl)amino] -1,3 ,5-triazine-2,4-diyl] [(2,2,6, 6-tetramethyl-
4-piperidinyl)imino]- 1,6-hexanediyl[(2,2,6,6-tetramethyl-4-
piperidinyl)imino]]) (CHIMASSORB® 944); l ,3,5-triazine-2,4,6-
triamine, N,N"'-[ l ,2-ethanediylbis[[[4,6-bis[butyl( 1,2, 2,6,6-
pentamethyl-4-piperldinyl)amino]- 1,3 ,5-triazine-2-yl]imino]-3, 1-
propanediyl]]-bis[N',N"-dibutyl-N',N"-bis(l ,2,2,6,6-pentamethy l -4-
piperidinyl) (CHIMASSORB® 119); 1,6-hexanediamine, N ,N ' -
bis(2,2,6,6-tetramethyl-4-piperidinyl)-polymer with 2,4,6-trichloro-
1,3,5-triazine, reaction products with N-butyl- 1-butanamine and Nbutyl-
2,2,6,6-tetramethyl-4-piperidinamine (CHIMASSORB® 2020);
N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)- l ,3-benzenedicarboxamide
(NYLOSTAB® SEED).
More preferably, the HALS amine used in the composition of
the invention is poly[[6-[(l , l ,3 ,3-tetramethylbutyl)amino]- l ,3,5-
triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidinyl)imino]- l ,6-
hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]])
(CHIMASSORB® 944).
Preferably, when present in the composition according to the
invention, the UV stabilizer is present in an amount ranging from 0 .1
to lwt% and preferably from 0.2 to 0 .5wt% relative to the total weight
of the composition.
The composition according to the invention comprises at least
one antioxidant, and preferably at least two or at least three
antioxidants.
In the first embodiment of the invention, the composition
comprises at least two antioxidants, at least one being organic (Al )
and advantageously at least one being metallic (MAI) as defined
above.
The organic antioxidant (Al) is different from said at least
metallic antioxidant (MAI) and is preferably chosen from organic
antioxidant.
As organic antioxidant (Al) that may be used in the
composition according to the invention, mention may be made of
sterically hindered phenolic antioxidants; aromatic secondary amines;
and mixture thereof. Preferred organic antioxidant (Al) is chosen from
among sterically hindered phenolic antioxidants.
By way of example of sterically hindered phenolic antioxidant,
mention may be made of N,N'-hexane- l ,6-diylbis(3-(3,5-di-tert-butyl-
4-hydroxyphenylpropionamide)) (IRGANOX® 1098); ethylene-bis
(oxyethylene)-bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]
(IRGANOX® 245); pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-
hydroxyphenyl)propionate) (IRGANOX® 1010); 6,6'-di-tert-butyl-4,4'-
butylidenedi-m-cresol (LOWINOX® 44B25); 3,9-Bis[ l ,1-dimethyl-2-
[p-(3-tert-butyl-4-hydroxy-5-
methylphenyl)propionyloxy]ethyl]2,4,8, 10-tetraoxaspiro[5,5]-
undecane (ADK STAB® AO - 80). By way of example of aromatic
secondary amines that may be used in the composition of the
invention, mention may be made of such as 4,4'-bis(alpha,alphadimethylbenzyl)
diphenylamine) (NAUGARD® 445); 4-{ [4,6-
bis(octylsulfanyl)- l ,3,5-triazin-2-yl]amino}-2,6-di-tert-butylphenol,
(IRGANOX® 565); 1-N,4-N-di(phenyl)benzene- 1,4-diamine
(FLEXAMINE® G); benzenamine,N-phenyl-, reaction products with
2,4,4-trimethylpentene (IRGANOX® 5057).
According to the second embodiment of the invention, the
composition comprises at least one organic antioxidant (Al).
Said organic antioxidant (Al) may be chosen from among those
defined above. Preferred organic antioxidant (Al) is chosen from
among sterically hindered phenolic antioxidants.
The composition according to the invention may comprises at
least one antioxidant (A2) as secondary antioxidant, said antioxidant
(A2) being different from antioxidant (Al ) and preferably chosen from
among organic antioxidant. Organic antioxidant (A2) may be chosen
from among organophosphites, organophosphonites and/or thio
antioxidants. Preferred organic antioxidant (A2) is chosen from among
organophosphites and organophosphonites. As organophosphite or
organophosphinite that may be used in the composition of the
invention, mention may be made of 4,4'-biphenylenediphosphonous
acid tetrakis(2,4-di-tert-butylphenyl) ester(HOSTANOX® P-EPQ),
phosphorous acid triphenyl ester (IRGAFOS® TPP), tris(4-
nonylphenyloxy)phosphine (IRGAFOS® TNPP), tris(2,4-ditertbutylphenyl)
phosphite (IRGAFOS® 168), tetrakis(2,4-di-tertbutylphenyl)[
l , l -biphenyl]-4,4-glybisphosphate (IRGAFOS® P-EPQ),
di-phenyl isodecyl phosphite (IRGAFOS® DDPP), , bis(2,4-ditertbutylphenyl)
pentaerytritol diphosphite (IRGAFOS® 126), bis(2,6-ditert-
butyl-4-methylphenyl)pentaerythritol diphosphite (ADK STAB®
PEP-36), bis(2,4-dicumylphenyl)pentaerythritol diphosphite
(DOVERPHOS® S-9228 sold by DOVER), 2,2'2"-nitrilo[triethyltris[
3,3 ' ,5,5 '-tetra-tert-butyl- l , l '-biphenyl-2,2'-diyl]] phosphite
(IRGAFOS® 12), 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl
phosphite (ADK STAB® HP 10), phenol, 2-(l ,1-dimethylethyl)-6-
methyl-4-[3-[[2,4,8, 10-tetrakis(l , l -
dimethylethyl)dibenzo[d,f] [l ,3,2]dioxaphosphepin-6-yl]oxy]propyl]-
(SUMILIZER® GP sold by SUMIMOTO), calcium bis[3,5-di(tertbutyl)-
4-hydroxybenzyl(ethoxy) phosphinate] (IRGANOX® 1425).
As thio antioxidants that may be used in the composition of the
invention, mention may be made of propanoic acid,3-(dodecylthio)-
, l , l '-[2,2-bis[[3-(dodecylthio)- l -oxopropoxy]methyl]- l ,3-propanediyl]
ester (ADK STAB® AO 412S), propanoic acid,3,3'-thiobis-, 1,1'-
didodecyl ester (IRGANOX® PS 800), propanoic acid,3,3'-thiobis-,
I , I '-dioctadecyl ester (HOSTANOX® SE 4), distearyl disulfide
(HOSTANOX® SE 10), ADK STAB® AO-23 (CAS-Number 66534-05-
2, 71982-66-6), 2-methyl-4,6-bis(octylsulfanylmethyl)phenol
(IRGANOX® 1520), phenol, 2,4-bis[(dodecylthio)methyl]-6-methyl
(IRGANOX® 1726), Benzenepropanoic acid,3,5-bis(l ,1-
dimethylethyl)-4-hydroxy-, 1,1'-(thiodi-2, 1-ethanediyl) ester
(IRGANOX® 1035), 4,4'-thiobis[2-(l , l -dimethylethyl)-5-methylphenol
(IRGANOX® 415), 2,2'-thiobis[6-(l ,1-dimethylethyl)-4-
methyl-phenol (IRGANOX® 108 1), 2-methyl-4,6-
bis[(octylthio)methyl]-phenol (IRGANOX® 1520).
Preferably, the composition according to the invention
comprises a mixture of antioxidant (Al ) and antioxidant (A2), and
more preferably a mixture of sterically hindered phenolic
antioxidant(s) and organophosphite(s) and/or organophosphinite(s).
The organic antioxidant (Al) that may be used in the
composition of the invention may be present in an amount ranging
from 0.05 to 0.4wt% relative to the total weight of the composition.
Preferably, in the composition according to first embodiment of
the invention, the organic antioxidant (Al) is present in an amount
ranging from 0 .1 to 0.3wt% relative to the total weight of the
composition. Preferably, when present, the antioxidant (A2) is present
in the composition according to the invention in an amount ranging
from 0 .1 to 1 wt% and preferably from 0.3 to 0 .5wt% relative to the
total weight of the composition.
Preferably, in the composition according to the second
embodiment of the invention, the antioxidant (Al) is present in an
amount ranging from 0 .1 to 0.2wt% relative to the total weight of the
composition. Preferably, when present, the antioxidant (A2) is present
in the composition according to the invention in an amount ranging
from 0.05 to 0.4 wt% relative to the total weight of the composition,
and preferably from 0 .1 to 0.5wt% relative to the total weight of the
composition. Preferably, the weight amount of the antioxidant(s)
(MAI , Al, A2), UV absorber(s) and UV stabilizer(s) are chosen
independently from each other in the range amount as defined above,
provided that the weight ratio of the total amount of antioxidant(s)
over the total amount of UV absorber(s) and UV stabilizer(s) is less
than or equal to 0.7, and more preferably less than or equal to 0.4, said
weight ratio being different from zero.
The composition according to the invention advantageously
does not produce smoke during (co)extrusion process.
The composition according to the invention may comprise at
least one additive chosen from among plasticizers and impact
modifiers.
As examples of plasticizers, mention may be made of benzene
sulphonamide derivatives, such as N-butyl benzene sulphonamide
(BBSA), ethyl toluene sulphonamide or N-cyclohexyl toluene
sulphonamide; esters of hydroxybenzoic acids, such as 2-ethylhexylpara-
hydroxybenzoate and 2-decylhexyl-para-hydroxybenzoate; esters
or ethers of tetrahydrofurfuryl alcohol, such as
oligoethyleneoxytetrahydrofurfuryl alcohol; and esters of citric acid or
hydroxymalonic acid, such as oligoethyleneoxy malonate. Mention
may also be made of decylhexyl-para-hydroxybenzoate and ethylhexylpara-
hydroxybenzoate. One particularly preferred plasticizer is Nbutyl
benzene sulphonamide (BBSA).
As examples of impact modifiers, mention may be made of
polyolefins, crosslinked polyolefins, Ethylene Propylene Rubber (EPR)
elastomer, Ethylene Propylene Diene Monomer (EPDM) elastomer,
Styrene-Butadiene-Styrene (SBS) and Styrene-Ethylene-Butadiene-
Styrene (SEB S) elastomers, it being possible for these elastomers to be
grafted in order to facilitate their compatibilization with polyamides,
copolymers containing polyamide blocks and polyether blocks. These
copolymers containing polyamide blocks and polyether blocks are
known per se - they are also known by the name PEBA (polyetherblock-
amide). Mention may also be made of acrylic elastomers, for
example those of the Nitrile Butadiene Rubber (NBR) type,
Hydrogenated Nitrile Butadiene Rubber (HNBR) type and
Carboxylated Nitrile Butadiene Rubber (X-NBR) type.
The additive may be present in the composition according to
the invention in an amount up to 35wt% and more preferably up to
15wt% relative to the total weight of the composition.
The nature and quantity of additives that may be present in the
composition should be chosen such as not to impair the advantageous
properties of the composition of the invention.
In a particularly preferred first embodiment of the invention,
the composition consists of:
a') at least one PA X.Y,
b') at least one black colored UV absorber preferably being carbon
black,
c') at least one organic antioxidant (Al), preferably chosen from
among sterically hindered benzophenol,
d') optionally at least one UV stabilizer,
e') optionally at least another organic antioxidant (A2), preferably
chosen from among organophosphite and organophosphinite,
) optionally at least one metallic antioxidant or heat stabilizer
(MA2), preferably chosen from among copper based antioxidant or
heat stabilizer,
g') optionally at least one plasticizer,
h') optionally at least one impact modifier.
preferably the weight ratio of the total amount of antioxidant(s) over
the total amount of UV absorber(s) and UV stabilizer(s) being less
than or equal to 0.7, more preferably less than or equal to 0.4 and is
different from zero.
The ingredients a') to h') are as defined above.
In particular, the composition of the invention consists of:
a') the complement to 100% of at least of PA X.Y,
b') from 2 to 3wt% of carbon black,
c') from 0.05 to 0.4wt%, preferably from 0 .1 to 0.3wt%, of at least one
organic antioxidant (Al),
d') from 0 .1 to 1 wt%, preferably from 0.3 to 0 .5wt% of at least
another organic antioxidant (A2),
e') from 0.05 to lwt% of at least one metallic antioxidant or heat
stabilizer (MA2),
) from 0 to 35wt% of at least one additive chosen from among
plasticizer and impact modifier, preferably from 0 to 15% of
plasticizer,
preferably the weight ratio of the total amount of antioxidant over the
total amount of light stabilizer being less than or equal to 0.7, and
more preferably 0.4, zero being excluded.
In another particularly preferred second embodiment of the
invention, the composition consists of:
a") at least one PA X.Y,
b") at least one UV absorber, preferably chosen from among
benzotriazole UV absorber,
c") at least one UV stabilizer chosen from HALS, preferably HALS
amine,
d") at least one organic antioxidant (Al), preferably chosen from
among sterically hindered benzophenol,
e") optionally at least one organic antioxidant (A2), preferably chosen
from organophosphite and organophosphinite,
f") optionally at least one pigment or colorant being different from
black colorant or black pigment,
g") optionally at least one plasticizer,
h") optionally at least one impact modifier.
preferably the weight ratio of the total amount of antioxidant over the
total amount of light stabilizer being less than or equal to 0.7, more
preferably less than or equal to 0.4, zero being excluded.
The ingredients a") to h") are as defined above.
The ingredients a") to e") and g") to h") shall be chosen so that
they are not likely to modify the colour given to the composition by
ingredient f") if present.
In particular, the composition of the invention may consist of;
a") the complement to 100% of at least of PA X.Y,
b") from 0 to lwt%, preferably from 0 .1 to lwt%, more preferably
from 0.2 to 0 .5wt%, of at least one UV absorber,
c") from 0 .1 to 1.5wt%, preferably from 0.2 to 0.5wt%, of at least one
UV stabilizer LI chosen from HALS,
d") from 0.05 to 0.4wt%, preferably from 0 .1 to 0.2wt%, of at least
one organic antioxidant (Al),
e") from 0.05 to 0.4 wt%, preferably from 0 .1 to 0 .5wt% of at least
another antioxidant (A2),
f") from 0 to 4wt%, or from 0 to 6wt% or from 0 to to 8wt% of at least
one pigment or colorant being different from black colorant or black
pigment, preferably the quantity of said pigment or colorant being
more than zero,
g") from 0 to 35wt% of at least one additive chosen from among
plasticizer and impact modifier, preferably from 0 to 15% of
plasticizer,
preferably the weight ratio of the total amount of antioxidants over the
total amount of UV absorber(s) and UV stabilizer(s) being less than or
equal to 0.7, preferably less than or equal to 0.4, zero being excluded.
Advantageously, the composition according to the invention
does not contain any polyhydric alcohol or polyhydroxy polymer,
having in particular a number average molecular weight (Mn) of less
than 2000 as determined for polymeric materials with gel permeation
chromatography (GPC). As example of polyhydric alcool or
polyhydroxy polymer, mention may be made of polyols such as
pentaerythritol, dipentaerythritol, tripentaerythritol,
ditrimethylolpropane, and saccharides. The terms polyhydric alcohol
and polyhydroxy polymer used in the present application do not cover
sterically hindered phenol antioxidants.
When the composition according to the invention does not
contain such polyhydric alcohols or polyhydroxy polymers, it leads to
cable sheathing displaying surprisingly lower moisture uptake and/or
better water resistance.
The invention also relates to a cable sheathing comprising at
least one layer constituted of any one of the compositions according to
the invention.
Advantageously, the cable sheathing of the invention comprises
as outer layer a layer constituted of a composition according to the
invention.
When the cable sheathing is a monolayer structure, the term
outer layer means the monolayer sheathing and the outer surface of
said sheathing is in contact with the outdoor environment (soil, air,
sunlight, water, termites and other insects, chemicals such as oil,
grease, jelly. ..).
When the cable sheathing is a multilayer structure, the outer
layer means the layer having its external surface in contact with the
outdoor environment.
The other layer constituting the multilayer cable sheathing of
the invention may be chosen from among the conventionally used
layers.
In particular, the cable sheathing according to the invention
may form a composite layer with a polyolefine layer, such as
polyethylene layer, positioned underneath a monolayer cable sheathing
according to the invention (PAX.Y rich monolayer, i.e. >50wt% of PA
X.Y relative to the total weight of the layer composition).
The resulting composite layer is part of the invention and can
be manufactured by conventional coextrusion methods.
For example, the multilayer cable sheathing according to the
invention may comprise from inner to outwards:
at least an insulation layer, made of the same or different
dielectric material(s) over the conductor wire,
optionally at least one intermediate layer chosen from
among thermoplastic polymer based layer and polyolefine
based layer, such as polyethylene based layer,
at least an outer layer constituted from a monolayer
sheathing or composite layer according to the invention.
The term inner layer referring to the layer whose inner surface
is in contact with the conductor wire, in particular the electric wire or
optical fiber.
Another obj ect of the invention is a process to manufacture a
mono or multilayer cable sheathing according to the invention, such as
defined above.
Conventional extrusion and coextrusion techniques may be
performed. For example, a mono or multilayer cable sheathing
according to the invention may be manufactured by performing at least
the following steps:
i) melt blending the different ingredients of the (or each) layer
composition(s), and
ii) extruding (or coextruding) the mixture(s) preferably at an extruder
barrel temperature of the ranging from 180°C to 280°C.
Preferably, the process according to the invention comprise
only one melt blending step or one extrusion (or coextrusion) step: the
polymer is directly extruded without forming pellets prior to
extrusion (or coextrusion) of the cable sheathing.
As example of extruder that may be used, mention may be made
of JSW Model : TEX30XSST-45 .5BW-5V available by RC Group.
The composition according to the invention may be extruded
into mono or multilayer films or tubes.
The thickness of the monolayer cable sheathing according to
the invention may be chosen as those conventionality used for cable
sheathing, in particular electric or optical fiber cable sheathing.
The present invention also relates to a Cable comprising :
a) a conductive Core element having a diameter from 0.008 mm
to 12 mm,
b) at least one insulating layer having a thickness from 0 .5 mm
to 9 mm around the conductive Core element,
c) at least one sheath layer or composite layer according to the
invention having a thickness from 0.20 mm to 1.2 mm around the
insulating layer,
wherein at least one of said sheath layer being the cable outer
sheath.
In an advantageous embodiment, the cable defined above is an
optical fiber having a diameter from 0.008 mm to 0 .1 mm.
In an advantageous embodiment, the cable defined above is an
conductive cable having a diameter from 0.08 mm to 12 mm, in
particular a copper conductive cable.
The present invention further relates to the use of a cable
sheathing according to the invention or manufactured according to the
process of the invention to prevent and/or protect cable, in particular
power cable, copper cable and optical fiber cable, from damages of
termites and eventually light, heat, wind, water, humidity, soils, oil,
grease, jelly, other insects and/or kinking.
Indeed, it has been observed that the cable sheathing according to the
invention is resistant enough against the damage by the Australien
substerranean termite "Mastotermes darwiniensis", which are known as
one of the most destructive termite species in the world. Therefore, the
cable sheathing according to the invention or manufactured according
to the process of the invention, may be advantageously used as outer
layer or overlayer of a cable, such as electric cable or optical fiber
cable, to protect the overall cable.
TINUVIN®, CHIMASSORB®, IRGANOX® and IRGAFOS® materials
are available from BASF; CYASORB® materials are available from
CYTEC TECHNOLOGY CORP;
UVASIL® materials are available from GREAT LAKES CHEMICAL
CORP;
SADUVOR®, HOSTAVIN®, NYLOSTAB® and HOSTANOX®
materials are available from CLARIANT;
UVINUL® materials are available from BASE;
UVASORB® materials are available from PARTECIPAZIONI
INDUSTRIALS
GOOD-RITE® materials are available from B.F.GOODRICH CO;
MARK® materials are available from ASAHI DENKA CO;
SONGLIGHT® materials are available from SONGWON
LOWINOX®, NAUGARD® and FLEXAMINE® materials are available
from CHEMTURA.
ADK STAB® materials are available from PALMAROLE
Other aims and advantages of the present invention will emerge
on reading the following examples, which are given as a guide and
without any limitation.
EXAMPLES:
The following compositions have been prepared by melt
blending the different ingredients and then extruded into films or
tubes depending on the test purpose. Extrusion was performed at a
screw speed of 40 round per minute (rpm) with a barrel temperature
varying from 180°C to 245°C in the extruder. Suitable die is used to
get either a film or a tube.
The quantities in the table below are given in percent by wei
relative to the total weight of the composition.
q .s . 100: quantity sufficient to get 100% relative to the total weight of
the composition
Comparative compositions V, VI, VII corresponding to
compositions I , II, III wherein PAX.Y have been replaced by PA 6.6,
PA6. 10, PA 6 . 12 (which correspond to PAX.Y wherein the sum of
X+Y is less than or equal to 18) were also prepared and extruded into
films or tubes using the same process. Extruder JSW Model :
TEX30XSST-45.5BW-5V has been used to prepare the films and
tubes from the above mentioned compositions (Co-rotation, screw
type: segment, screw LSP-2, Screw diameter: 32 mm, Screw speed
59.5-595rpm, L/D ration: 45 .5 (base diameter 30mm)).
Both samples according to the invention and comparative
samples have been submitted to two set of tests:
First set of test: properties required by AS 1049-2008 for
anti-termite cable sheathing
Termite resistance: The compositions were extruded into tubes which
were cut into 100mm length and were evaluated in the bioassay. The
samples tubes were exposed to Australian subterraneans termite
species. The ends of each tube samples were capped with brass dome
nuts. A single piece of timber was placed adj acent to each test
specimen to both provide food source for termites and encourage them
to contact and explore the surface of the plastic samples. The duration
of the bioassay was 12 weeks.
Thermal resistance: The compositions were extruded into 150mih
thick film. ASTM type IV dumbbells were die-cut along the flow in
this extruded film. The test was performed in accordance with
AS1049. 2-2008 (heat ageing at 100°C for 120 hours in an air
circulating oven, 80% retention of elongation at break required
according to the AS1049 standard).
UV resistance: The compositions were extruded into 150mih thick
film. ASTM type IV dumbbells were die-cut along the flow in this
extruded film. The test was performed in accordance with AS1049.2-
2008 (1200 hours UV exposure (radiance level of 0 .5W/m2, lnm
bandpass at 340nm, optical filter: cut-on 295nm, black panel
temperature of 63°C, relative humidity (RH) = 50%, no water spray)).
Results: The results are as follows:
Termite resistance: It was observed that the tube samples constituted
by compositions I , II, III according to the invention including PAX.Y
with X+Y>1 8 exhibit a superior resistance to the attack of termites.
Particularly, tube samples constituted by compositions II, III including
PAX.Y with X+Y>20 shows the best results. No nibbling nor attack
marks have been observed whereas, the comparative compositions V,
VI, VII including PAX.Y with X+Y less than or equal to 18 showed
clear signs of attacks.
Thermal resistance: Despite their high melting point, compositions V,
VI, VII including PAX.Y with X+Y less than or equal to 18 lead to
extruded samples exhibiting a lower heat ageing resistance than
compositions I , II, III according to the invention including PAX.Y
with X+Y>1 8 over time. Particularly, samples issued from
compositions II, III PAX.Y with X+Y>20 show the best results.
UV resistance: The plastic sheath should remain highly flexible and
not degraded after long outdoor exposures during cables installation.
Therefore, AS1049 standard imposes to retain 85% of elongation at
break after an intense UV exposure. Compositions including PAX.Y
with X+Y>1 8 have been formulated to meet this stringent criterion.
Particularly, compositions including PAX.Y with X+Y>20 lead to the
best results. Samples from compositions including PAX.Y with X+Y of
less than or equal to 18 failed this test.
Second set of tests: Other physical properties
This second set of physical properties enables to check the
quality and efficiency of the sheath of the cable sheathing according to
the invention.
Moisture uptake and Blistering resistance: The samples have been
kept in a 50%RH (relative humidity) oven at 23°C for two weeks.
Retention of tensile properties were assessed according to ISO 527
test.
Chemical resistance: The samples have been immersed in an aqueous
solution of 5.8wt% of formic acid at 40°C for one week. Retention of
tensile properties was assessed according to ISO 527 test.
Properties V VI VII I II III
Processability Medium Medium Medium Good Good Good
into tube
Moisture
8.0% 3.3% 3.0% 2.1% 2.1% 1.4%
uptake
Blistering Bad Bad Bad Medium Good Good
Resistance
Chemical Medium Medium Medium Medium Good Good
Resistance
Processability: It has been observed that the samples extruded from
compositions I , II and III according to the invention are easier to
extrude into tubes compared to other comparative samples. Moreover,
the tubes extruded by using the compositions I , II, III of the invention
are glossy without defects on the surface.
Moisture uptake and Blistering resistance: It has been observed that
the samples extruded from compositions I , II and III according to the
invention exhibit far lower moisture retention and no blistering defects
on surface compared to other comparative samples.
Chemical resistance: It has been observed that the samples extruded
from compositions I , II and III according to the invention exhibit
better resistance to formic acid compared to other comparative
samples, as they retain better their mechanical properties.

CLAIMS
1. Use of a composition comprising:
a) at least one aliphatic polyamide having at least two units
corresponding to the following general formula:
X.Y
in which:
X.Y represents a unit obtained by polycondensation of:
- a diamine containing X carbon atoms and,
- a dicarboxylic acid containing Y carbon atoms,
and such that the sum of X+Y is strictly superior to 18,
b) at least one UV absorber and eventually at least one UV stabilizer,
c) at least one antioxidant ,
to manufacture a mono or multilayer cable sheathing resistant to
termite damage.
2 . Composition comprising:
a) at least one aliphatic polyamide having at least two units
corresponding to the following general formula:
X.Y
in which:
X.Y represents a unit obtained by polycondensation of:
- a diamine containing X carbon atoms and,
- a dicarboxylic acid containing Y carbon atoms,
and such that the sum of X+Y is strictly superior to 18,
b) at least one UV absorber and eventually at least one UV stabilizer
c) at least one antioxidant,
with a weight ratio of the total amount of antioxidant(s) over the total
amount of UV absorber(s) and UV stabilizer(s) is less than or equal to
0.7.
3. Composition according to Claim 2, wherein said composition
does not contain any polyhydric alcohol or polyhydroxy polymer, said
polyhydric alcohol or polyhydroxy polymer being different from
sterically hindered phenols.
4 . Composition according to any one of Claims 2 to 3, wherein
X is chosen from 6 to 12, Y is chosen from 10 to 18, and/or the sum of
X+Y is superior or equal to 20.
5. Composition according to Claim 4, wherein the polyamide i s
chosen from among PA6. 14, PA 6 .18, PA10 .10, PA10 . 12, PA10 . 14,
PA12. 12 and mixture thereof.
6 . Composition according to any one of Claims 2 to 5, wherein
the at least one UV absorber is chosen from among black colored UV
absorbers (L I).
7 . Composition according to Claim 6, wherein the composition
comprises at least one metallic antioxidant or heat stabilizer.
8 . Composition according to Claim 7, wherein the composition
comprises at least one colorant or pigment, said colorant or pigment
being different from black colorant and black pigment.
9 . Composition according to any one of Claims 7 to 8, wherein
the composition comprises at least one UV stabilizer chosen from
among Hindered Amine Light Stabilizers (HALS) amine and HALS
amine ether.
10 . Composition according to Claim 2 or 9, wherein the
composition comprises at least one UV absorber chosen from among
organic and/or mineral UV absorbers (L2) chosen from among
benzophenone UV absorbers, benzotriazole UV absorbers and Ti0 2
eventually coated with rutile, said UV absorber.
11. Composition according to any one of Claims 2 to 10,
wherein the at least one antioxidant is chosen from among sterically
hindered phenolic antioxidants and aromatic secondary amines, and
preferably sterically hindered phenolic antioxidants.
12. Composition according to any one of Claims 2 to 11, where
the composition comprises at least one antioxidant being chosen from
among organophosphites, organophosphonites and/or thio antioxidants.
13. Composition according to any one of Claims 2 to 12,
wherein the composition comprises at least one additive chosen from
among plasticizers and impact modifiers.
14. Cable sheathing comprising at least one layer comprising a
composition as defined in any one of Claims 2 to 13.
15. Cable sheathing as defined in Claim 14, wherein it
comprises as outer layer or overlayer a layer constituted of a
composition as defined in any one of Claims 2 to 13.
16 . Process to manufacture a cable sheathing as defined in
Claim 14 or 15, by performing at least the following steps:
i) melt blending the different ingredients of the (or each) layer
composition(s), and
ii) extruding (or coextruding) the mixture(s) at an extruder barrel
temperature of the ranging from 180°C to 280°C.
17 . Process according to Claim 16, wherein it comprises only
one melt blending step or one extrusion (or coextrusion).
18 . Use of a cable sheathing as defined in any one of Claims 14
to 15 or as manufactured in Claim 16 to 17, to prevent and/or protect
cable, in particular electric cable or optical fiber cable, from damages
of termites and eventually light, heat, wind, water, humidity, soils, oil,
grease, jelly, other insects and/or kinking.