Technical Field

The technical field of the present invention relates to cabl e sheathings, in particular el ectric and optical fiber cabl e sheathing, di splaying, among others, excellent termite resi stant properties.

The invention rel ates to the use of a composition compri sing at least one particular aliphatic polyamide, at least one UV ab sorber and/or UV stabilizer, and at least one antioxidant, to manufacture a mono or multilayer cable sheathing resi stant to termite damage, in particular for el ectric and optical fiber cables. The cable according to the invention di splay besides at least an additional property as di sclo sed further below.

In particular, the invention relates to a composition compri sing at least one particular aliphatic polyamide, at least one UV ab sorber 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 cabl e, copper cable) and/or optical fiber cable, from damages of termites and eventually damages from light, heat, wind, water air, humidity, soil s, 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 chemical s in the soil s may harm non-target organi sms and are dangerous to handle.

Second, cable sheathing layer material s have been chosen to b e used as anti termite barrier layers, such as for example metal or hard plastics.

In AU201 125371 8, it was found that polyethylene terephtalate (PET) was useful as anti termite barrier tape to protect cable from termite attacks. However, thi s material i s improper to be extruded onto the core of a cable due to its high melting temperature (260°C) and low melt vi scosity, and thus, requires thermopl astic polymer termite barrier manufacturers who usually use tub e 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 PA 12 or PA 1 1 based grades to make anti termite cable sheathings.

However, these material s are very expensive and had to face recently production shortage.

Contents of Invention

Therefore, there i s now a need to find new cabl e sheating compositions which can be extruded into tubes, are environment friendly, non toxic to human health, and which lead to cable sheathing di splaying 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 di splays one or several properties to face outdoor conditi ons especially in tropical and subtropical regions where live most of the termite. For example, mention may be made of light and water resi stance after long term exposition, low moi sture uptake, mechanical resi stance, chemical resi stance, resi stance to other insects attacks, bending resi stance. . . .

When cables are exposed to external environment in particular wind, sun and water (rain, humidity), such as outdoor and overhead cables, cable sheathings shall resi st 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 cabl e sheathing resi stant to UV ageing, resi stant 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 chemical s during the installation (oil s, grease, j elly . . .) 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 al so preferably resi stant to hydrolysi s and have low moisture uptake.

Moreover, it is searched a cable sheathing that di splay sufficient mechanical strength and heat resi stance 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 i s preferably dimension stable, meaning its dimension should not vary over time. Thi s enables to avoid looseness of the sheathing, water penetration in the underneath layers, surface defects or wrinkles.

It is al so preferred cable sheathing which outer surface i s smooth and glossy . Indeed without being limited to the theory, it i s thought that any defect surface i s a potential point of attack by termites. Therefore, a glossy surface might contribute to the resi stance to termite attacks .

To get such aspect, the cable sheathing should be at least resi stant to bli stering. Bli stering may occur for example when the material is moisture sensitive in particular when the material has high moi sture uptake .

Surpri singly, it has now been found that by using a composition comprising at least one particular aliphatic polyamide, at least one UV ab sorber and/or UV stabilizer, and at least one, it was possible to get an antitermite cable sheathing, in particular for electric and optical fib er cabl es, 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 compri sing :

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 i s stri ctly superior to 1 8,

(hereafter PA X. Y)

b) at least one UV ab sorber 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 ab sorber(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 i s the use of a composition compri sing :

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 i s strictly superior to 1 8,

b) at least one UV ab sorber and/or UV stabilizer,

c) at least one antioxidant,

to manufacture a mono or multilayer cable sheathing resi stant to termite damage . In particular, it was ob served that the mono or multilayer cable sheathing according to the invention presents from good to excellent results as regards :

- termite resi stance,

- thermal ageing resi stance,

- ultraviolet (UV) ageing resi stance,

- processability (extrusion or coextrusion),

- moi sture uptake,

- gloss, and

- chemical resi stance (against lewi s 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 ob served 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/m ² , l nm 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 stabl e extruded products .

The cable sheathing according to the invention have preferably a low moi sture 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 resi stant to hydrolysi s (ISO 62) .

It has preferably a smoothy and glo ssy outer surface. Glo ss can be measured by detecting the intensity of the refl ected 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 resi stant to chemicals such as formic acid, as characterized by AS 1 049-2008.2 appendix M.

When composition of the invention compri ses a colorant or pigment, colorfastness may b e characterized by AS 1 049-2008.2.

The cable sheathing according to the invention i s preferably flexible enough to resi st to bending as characterized by AS 1049-2008 appendix J, Indeed, it has been ob served 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 al so rel ates to a process to manufacture a cable sheathing according to the invention by extrusion or coextrusion.

The invention al so 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, soil s, oil, grease, j elly, other insects and/or kinking.

Other characteri stics, 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 poly condensation 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 H ₂ N-(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), tetradecanedi amine (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, 2, 4 -tri methyl- 1 , 6-hexanediamine (X=9), 2,4,4-trimethyl- l ,6-hexanedi amine (X=9), 2-methyl- l , 8- octanediamine (X=9) . Preferably, the branched and aliphatic di amine 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 (C i ₈ ) and oleic acid (C i ₈ )), as described especially in document EP 0 471 566.

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 to form the polyamide used according to the invention from a biobased raw material as characterized in ASTM D6866. By way of exampl e, mention may be made of 1 , 10-decanediamine, linear and aliphatic diamines and di acides as above-mentioned .

Advantageously, the polyamide used in the composition according to 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 Y is 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, PAIO.IO, PA10.12, PA10.14, PA12.12 and mixture thereof, in particular from PAIO.IO, PA10.12, PA12.12 and mixture thereof, and more preferably the polyamide is PAIO.IO, PA10.12 or PA12.12.

Advantageously, the polyamide used according to the invention presents a melting point of less than 210°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 ab sorber used according to the invention provides UV protection through effective ab sorption 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 ab sorber i s chosen from among black colored UV ab sorbers (hereafter referred as L I ) . The term black colored UV absorber includes UV ab sorber di splaying a black color or capable to color the composition of the invention in black when present in effective amount (for exampl e in an amount of less than or equal to 0, 1 % by weight (wt%)) . In particular, these black colored UV ab sorbers ab sorb any incident rays of light of any wavelength (including UV rays), leading thus to a black colored component.

Preferably, the black colored UV ab sorb er (L I ) that i s used in the composition according to the invention may be chosen from among mineral black colored UV ab sorbers such as black pigments such as carbon black, iron oxide black, manganese bl ack (Mn02), cobalt black (Co203 ), antimony black, and mixture thereof. More preferably, carbon black i s used .

Carbon black may b e available under the brand Vulcan® P sold by Cabot Corporation.

Advantageously, the average particle size of the mineral black colored UV ab sorber is less than 25 nm . Average particle size may b e determined in accordance with ASTM D3849.

Advantageously, the mineral black colored UV ab sorb er may be homogenously di spersed in the polyamide matrix of the composition, in accordance with standard ISO 1 8553 .

Preferably, the mineral black colored UV ab sorber is present in the composition in an amount of at l east 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/NZ S 1660.2.4 : 1998 Standards. In thi s 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 b e made of mineral copper b ased 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 b e 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 compositi on of the invention ranges preferably from 0. 1 wt% 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 l wt% relative to the total weight of the composition.

In a second embodiment of the invention, the UV absorber i s chosen from organic and/or mineral UV ab sorbers (L2) . These UV ab sorbers are different from those of first embodiment. In particul ar, the UV ab sorb er used according to second embodiment is not black colored.

As example of organic or mineral UV ab sorbers (L2) that may be used in the composition of the invention, mention may be made of benzophenone UV ab sorbers; b enzotriazole UV ab sorbers such as 2- (2H-benzotriazol-2-yl)-4,6-bi s( l - methyl - 1 -phenyl ethyl) phenol (Tinuvin® 234), N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)- ethanediamide (TINUVIN® 3 12) and 2-(2'-hydroxy-3 ', 5 '-di-tert- butylphenyl)benzotriazole (TINUVIN® 320); and Ti02 eventually coated by rutile . More preferably, it may be chosen from benzotriazol e UV ab sorbers .

The UV ab sorber (L2) may b e 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 thi s second embodiment, the composition according to the invention does not compri se component that may give a black color to the composition. In particul ar, the composition does not compri se black colorant and black pigment such as the above mentioned bl ack colored UV ab sorber (L I ) .

The composition according to the invention may comprise at least one colorant or pigment, different from black colorant or black pigment. S ai d 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 vi sible light. Preferably, the composition according to the invention does not compri se metallic salts or complex such as copper and potassium halogen salts or complex. Indeed, those metalli c salts and complexes may interfer and darken the color given by the non black colorant or pigment.

When present (i. e. when the composition compri ses more than 0wt% relative to the total weight of the composition), the colorant or pigment is preferably chosen in an effective amount to vi sibly 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 thi s second embodiment, preferably the composition according to the invention i s 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; bi s-(l-octyloxy-2, 2,6,6- tetramethyl-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- tetramethyl-l,3,8-triazaspiro(4,5)decane-2, 4-dione; poly methylpropy 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 alpha- methyl 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, b eta, b eta', 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-tetramethyl-4- piperidinylidene)-(HALS 7); oligomer of 7-oxa-3,20- diazadispiro[5, 1, 1 l,2]-heneicosan-21-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- pentamethyl-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,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 N- butyl-2,2,6,6-tetramethyl-4-piperidinamine (CHIMASSORB® 2020) ; l,5-dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(2, 2,6,6- tetramethyl-4-peridinyl)ester (CYASORB® UV-500); 1,5- dioxaspiro(5,5)undecane 3,3-dicarboxylic acid, bis(l,2,2,6,6- pentamethyl-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(r ^, ,2",2",6",6"- pentamethyl-4"-piperidinyl(butyl)amino)- ,3',5'-triazine-6'-yl]- 1,5,8, 12-tetraazadodecane; HALS PB-41 (CLARIANT ® S.A.); Ν,Ν'- 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-methyl- piperazinone) (GOOD-RITE® 3034); 1 , 1 Ί "-(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-pentamet hyl-4- piperidinyl) (CHIMASSORB® 119); 1 ,6-hexanediamine, Ν,Ν'- 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 N- butyl-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)pro pionate] (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,alpha- dimethylbenzyl)diphenylamine) (NAUGARD® 445); 4-{[4,6- bis(octylsulfanyl)-l,3,5-triazin-2-yl]amino}-2,6-di-tert-but ylphenol, (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-ditert- butylphenyl)phosphite (IRGAFOS® 168), tetrakis(2,4-di-tert- butylphenyl)[l,l-biphenyl]-4,4-glybisphosphate (IRGAFOS® P-EPQ), di-phenyl isodecyl phosphite (IRGAFOS® DDPP), , bis(2,4-ditert- butylphenyl)pentaerytritol diphosphite (IRGAFOS® 126), bis(2,6-di- tert-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[triethyl- tris[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(tert- butyl)-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-prop anediyl] ester (ADK STAB® AO 412S), propanoic acid,3,3'-thiobis-, 1,1'- didodecyl ester (IRGANOX® PS 800), propanoic acid,3,3'-thiobis-, Ι,Ι'-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-methyl- phenol (IRGANOX® 415), 2,2'-thiobis[6-(l, 1 -dimethylethyl)-4- methyl-phenol (IRGANOX® 1081), 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 compri se 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 b enzene sulphonamide (BB SA), ethyl toluene sulphonamide or N-cyclohexyl toluene sulphonamide; esters of hydroxybenzoic acids, such as 2-ethylhexyl- para-hydroxybenzoate and 2-decylhexyl-para-hydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol, such as oligoethyleneoxytetrahydrofurfuryl alcohol ; and esters of citric aci d or hydroxymalonic acid, such as oligoethyleneoxy malonate. Mention may also be made of decylhexyl-para-hydroxybenzoate and ethylhexyl- para-hydroxybenzoate. One particularly preferred plasti cizer is N- butyl benzene sulphonamide (BB SA) .

As examples of impact modifiers, mention may be made of polyolefins, crosslinked polyolefins, Ethyl ene Propylene Rubber (EPR) el astomer, Ethylene Propylene Diene Monomer (EPDM) elastomer, Styrene-Butadiene- Styrene (SB S) and Styrene-Ethyl ene-Butadiene- Styrene (SEB S) elastomers, it b eing possible for these elastomers to be grafted in order to facilitate their compatibilization with polyami des, copolymers containing polyamide blocks and polyether blocks . These copolymers containing polyamide blocks and polyether blocks are known per se - they are al so known by the name PEBA (polyether- block-amide) . Mention may al so be made of acrylic el astomers, for example those of the Nitrile Butadiene Rubber (NBR) type, Hydrogenated Nitril e 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 1 5wt% 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 consi st s of:

a' ) at least one PA X.Y,

b ' ) at least one black colored UV ab sorber 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,

f ) 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 ab sorber(s) and UV stabilizer(s) being les s than or equal to 0.7, more preferably less than or equal to 0.4 and i s different from zero .

The ingredients a' ) to h' ) are as defined above.

In particular, the composition of the invention consi sts 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 l wt% of at least one metallic antioxidant or heat stabilizer (MA2),

f ) from 0 to 35wt% of at least one additive chosen from among plasticizer and impact modifi er, preferably from 0 to 1 5% 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 emb odiment of the invention, the composition consi sts of:

a") at least one PA X.Y,

b") at least one UV ab sorb er, preferably chosen from among benzotriazole UV ab sorber,

c") at least one UV stabilizer chosen from HALS, preferably HAL S 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 l east one impact modifi er.

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 ingredi ents 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 consi st of; a") the complement to 1 00% of at least of PA X.Y,

b") from 0 to l wt%, preferably from 0. 1 to l wt%, more preferably from 0.2 to 0.5wt%, of at least one UV ab sorber,

c" ) from 0. 1 to 1 .5wt%, preferably from 0.2 to 0.5wt%, of at least one UV stabilizer L I chosen from HAL S,

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 modifi er, preferably from 0 to 1 5% of plasticizer,

preferably the weight ratio of the total amount of antioxidants over the total amount of UV ab sorb er(s) and UV stabilizer(s) being l ess 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 numb er average molecular weight (Mn) of les s than 2000 as determined for polymeric material s 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 alcohol s or polyhydroxy polymers, it leads to cable sheathing di splaying surpri singly lower moi sture 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 compri ses as outer layer a layer constituted of a composition according to the invention.

When the cable sheathing i s 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, chemical s such as oil , grease, j elly . . . ) . When the cable sheathing i s 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 cabl e 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 i s 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 diel ectric 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 i s a process to manufacture a mono or multilayer cable sheathing according to the invention, such as defined above.

Conventional extrusion and coextrusion techniques may b e 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 1 80°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 : TEX30XS ST-45.5BW-5 V available by RC Group .

The composition according to the invention may be extruded into mono or multilayer films or tub es.

The thickness of the monolayer cable sheathing according to the invention may be chosen as those conventionality used for cabl e sheathing, in particular electric or optical fiber cable sheathing.

The present invention al so 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 ab ove is an optical fiber having a diameter from 0.008 mm to 0. 1 mm.

In an advantageous embodiment, the cable defined ab ove 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, j elly, 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-45.5B W-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 adjacent 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 150μιη 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 150μιη 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/m ² , 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>18 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 b est results. No nibbling nor attack marks have been ob served whereas, the comparative compositions V, VI, VII including PAX.Y with X+Y less than or equal to 1 8 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 1 8 lead to extruded samples exhibiting a lower heat ageing resi stance than compositions I, II, III according to the invention including PAX. Y with X+Y> 1 8 over time. Particularly, samples i ssued 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, AS 1049 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. Sampl es from compositions including PAX. Y with X+Y of less than or equal to 1 8 failed thi s test.

Second set of tests : Other physical properties

Thi s 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 formi c 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 ob served 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 u sing the compositions I, II, III of the invention are glos sy without defects on the surface.

Moisture uptake and Blistering resistance: It has been ob served that the samples extruded from compositions I, II and III according to the invention exhibit far lower moisture retention and no bli stering defects on surface compared to other comparative samples.

Chemical resistance : It has b een ob served that the sampl es extruded from compositions I, II and III according to the invention exhibit better resi stance to formic acid compared to other comparative samples, as they retain better their mechanical properties.