WO2010089902A1 - Use of a peba copolymer, composition, process and skin - Google Patents

Abstract

The present invention relates to the use of a copolymer comprising a polyether block and a polyamide block, for the manufacture of skins having a stable appearance over time and improved resistance to fogging, said copolymer being of at least partially renewable origin. The present invention also relates to a thermoplastic polymer composition and also to a process for the manufacture of such skins, and to the use thereof, in particular in parts of passenger compartments of vehicles, such as dashboards.

Description

DESCRIPTION

USE OF A PEBA COPOLYMER, COMPOSITION, PROCESS AND SKIN

Technical Field

The invention relates to the field of thermoplastic polymer compositions used for the manufacture of skins, in particular by moulding or by powder melt agglomeration of at least one layer of powder.

More particularly, a subject of the present invention is a polyether block amide (PEBA)-based powder composition for use in the manufacture of skins, such as those used both in the leather industry, furniture, decorations, sporting goods, computer material, seats, packaging and in the automobile industry and/or the aeronautics industry.

In the construction of motor vehicles in particular, many parts are increasingly made out of polymer materials. This is especially the case of dashboards (or instrument panels), passenger compartment coverings, interior door trims (door panels), consoles, airbags, etc. Since these parts are a very visible part of the interior architecture of a vehicle, their visible surface should give a pleasant aesthetic appearance which reproduces, for example, the appearance of leather. This visible surface constitutes the skin of the part. For example, a dashboard consists of a base made of a rigid polymer (for example polypropylene), a foam, generally made of polyurethane, and a skin. These skins are conventionally manufactured by the moulding technique in which powder is poured into a hot mould, which technique comprises rotomoulding and/or slush moulding.

The skin, which is bulk-coloured, should have good resistance to scratching and to chemical agents (solvents, cleaning agents, drinks, for example) and also good resistance to heat variations, ranging from extreme cold to prolonged exposure to sunlight in a confined atmosphere. The skin should withstand UV radiation and high temperatures, even in the presence of moisture. Thus, the skin of a car dashboard should be aesthetic and pleasant to the touch and the mechanical and aesthetic properties thereof should remain stable over time. The skin should remain ductile even at extremely low temperatures

(-4O⁰C). Dashboards are often equipped with integrated airbags (also known as invisible airbags), which conventionally have very short opening times. When the airbag opens, the skin of the dashboard should tear without fragmenting, and should not produce any projection of particles in the passenger compartment, in particular at low temperature (-40⁰C). At higher temperatures, for example 80⁰C, this skin should break rapidly without too much distortion, since such distortion can impair the deployment of the airbag. These same problems are encountered for all parts of the passenger compartment in which airbags are inserted, for example the lateral posts, the rear faces of the front passenger seats, the doors, etc. The problem is therefore common to all the parts of the passenger compartment equipped with an integrated airbag (therefore an airbag substantially invisible to the passengers and the driver).

Moreover, today, manufacturers which use thermoplastic polymers are increasingly adopting an ecodesign approach and are searching for plastics with a high added value that are of renewable plant origin.

In markets as competitive as that of sport or motorcars, manufacturers must meet consumer demand for polymer materials which combine technical and environmental performance levels. Now, these performance levels depend both on the starting materials and on the processes used. The aim of the present invention is therefore to provide a thermoplastic composition and a process that is simple and easy to implement for the manufacture of skins which meet these requirements, both in terms of mechanical properties, resistance to chemicals and resistant to ageing, and in terms of ecological and biological ethics. Background Art

The polymers conventionally used for the manufacture of these skins are polyvinyl chloride (PVC), thermoplastic urethane (TPU) or alternatively thermoplastic polyolefins (TPO). These polymers nevertheless have certain limitations.

Among the immediate drawbacks, PVC is formulated with a large amount of plasticizers. The migration of these plasticizers leads to stiffening, detrimental modifications in appearance, windscreen deposits and fogging on the windscreen. In fact, PVC-based skins are, by virtue of their composition, quite highly loaded with volatile materials (in particular the plasticizers of PVC). With use and under the effect of the temperature variations in the passenger compartment of the vehicle, these materials are volatilized and migrate to the cold zones and condense there: this is a well-known phenomenon of the slow opacification of vehicle windscreens, which is particularly bothersome in terms of the driver's view and good control of the vehicle.

PVC also exhibits drawbacks, related to the recycling, at the end of their life, of the materials that are part of the manufacture of motor vehicles. Since polymer materials resulting from crushing used vehicles are currently used (entirely or partly) as fuel in certain types of furnaces, for instance cement kilns, specific end-of life procedure should be followed to ensure proper and safer recycling or elimination of PVC to prevent acidic effluent gases formation.

For this reason, in order to satisfy the dual preoccupation of motor vehicle manufacturers and public authorities, which is first that of protection of the environment (eliminating the harmful effluent gases generated by the burning of polymer material waste and limiting the dumping thereof) and then that of as complete a recycling as possible of the waste (made up of polymer materials) resulting from the destruction of used vehicles by crushing, motor vehicle manufacturers must limit the number of these polymers present in each vehicle.

In order to replace PVC, thermoplastic polyolefin compositions have been proposed, for example in document EP0508801, so as to allow easier recycling at the end of the life of the vehicles. However, according to this document:

- in order to promote the molten- state fluidity of the moulded article and at the same to improve the flexibility thereof, the ethylene- alpha-olefin copolymer rubber is diluted with mineral oils as softening agent at a relatively high level compared with the polyolefinic elastomer. These oils in fact constitute a risk in terms of emission of volatile materials that are polluting for the environment and opacifying for vehicle windscreens, but also a risk in terms of impairment of the appearance of the skin as it ages: the exudation phenomenon is not eliminated; - in order to enable easy demoulding of the skin, external demoulding agents (for example dimethylsiloxane) deposited on the mould or demoulding agents within the composition (for example methylpolysiloxane) are used. These demoulding agents also constitute a risk of direct pollution of the environment of workshops, but especially make it more difficult to carry out the subsequent skin lacquering operation currently necessary to make the skins conform to the specifications of car manufacturers (appearance, level of mattness-sheen, resistance to scratching, to abrasion and chemical agents, including solvents).

Another document, US 5,302,454, also describes a thermoplastic polyolefin (TPO) composition having elastic properties that can be used in the motor vehicle field, which is in pulverulent form. However, it does not appear to be possible to readily use such a composition for preparing skins, without performing a certain modification of said preparation through the addition of particular agents such as polyolefin resins (risk of caking, difficulty in demoulding). Consequently, there remains the problem of the use of compositions for replacing polyvinyl chloride in the preparation of the skins. Moreover, TPOs have a relatively unpleasant feel, and limited performance levels under hot conditions.

Thermoplastic polyurethanes (TPU) are also used. Compared with PVC, they are intrinsically flexible, but have a high density, and limited resistance to UV radiation, unless aliphatic TPUs are used. The thermoplastic copolyesters described in document EP1456052 can be used. However, they have the drawback of being relatively unflexible, and of having a high melting point, which complicates their use.

Moreover, all these thermoplastic elastomers are petroleum-derived. The use of PEBAs for application of this type is described in the prior art. Thus, document WO 2002094610 describes the use of polyether block amide (PEBA) in a plasticized PVC composition for use in dashboards. The PEBA content is between 2% and 30%. The use of 20% of Pebax® (PEBA sold by Arkema) makes it possible to very significantly reduce the cold embrittlement temperature of the skin. Document DE102005012720A1 decribes a dashboard consisting of a solid substrate, a layer of foam and a visible skin composed of thermoplastic elastomer (TPE), it being possible for this TPE to be a styrene block copolymer, a thermoplastic urethane (TPU), a thermoplastic polyetherester (TPEE), a thermoplastic polyether amide (PEBA) or else a thermoplastic polyolefin (TPO). This document does not precisely describe the PEBA-based compositions most suitable for the type of uses of the invention.

Disclosure of Invention Technical Problem The aim of the present invention is therefore to design a new PEBA-based composition for the manufacture of skins that are both of renewable origin and high performance. The dashboard skins should in fact have the following characteristics : low hardness, generally between 65 and 95 Shore A - long-lasting surface feel and appearance resistance to scratching and to abrasion resistance to chemical agents (cleaning agents, drinks, etc) low emission of volatile organic compounds resistance to high temperature (120°C) - resistance to hydrolysis resistance to UV radiation no fragmentation when an airbag is deployed under cold conditions (-40⁰C) adhesion to polyurethane foam easy to use, ready demoulding - resistance to fogging.

The aim of the present invention is also to provide a process for the manufacture of such skins which is simple, easy to implement and rapid (which has as few steps as possible) and which does not require the involvement of laborious chemical or technological manipulations that are costly in terms of energy or polluting, so as to have as low an environmental impact as possible.

Armed with its expertise in the manufacture of high-performance polymers made from renewable resources, the Applicant has now shown that, surprisingly, the use of PEBAs derived at least partially from renewable resources for the manufacture of skins makes it possible to improve the properties of the skins, in particular by preventing the problem of fogging.

For the purpose of the invention, the term "fogging" should be understood to mean a tarnishing of a surface, a clouding, mist, "fog" or condensation effect at the surface of a material. This effect can impair the transparency of windows, such as a windscreen, and the aesthetic appearance and the sheen of the surface of a covering. This fogging is linked to the formation of a layer of fine particles forming a film at the surface of a material. These particles may be the result of various phenomena, in particular: direct exposure to light, to UV radiation, surface exudation and migration of certain components of a material.

The Applicant Company has also designed a novel simpler process for the manufacture of skins which meet the specifications defined above.

Technical Solution

A subject of the present invention is the use of a copolymer comprising a polyether block and a polyamide block, for the manufacture of skins having a stable appearance over time and an improved resistance to fogging, said copolymer being of at least partially renewable origin. More specifically, a subject of the present invention is the use of a thermoplastic polymer composition containing at least 35% by weight of a copolymer as defined above, for the manufacture of skins having a stable appearance over time and an improved resistance to fogging, and preferably for the manufacture of dashboard skins.

Advantageously, said copolymer comprises at least one PA block of at least partially renewable origin and/or at least one PE block of at least partially renewable origin.

Advantageously, said at least one PA block comprises at least one of the following polyamide monomers: 11, 5.4, 5.9, 5.10, 5.12, 5.13, 5.14, 5.16, 5.18, 5.36, 6.4, 6.9, 6.10, 6.12, 6.13, 6.14, 6.16, 6.18, 6.36, 10.4, 10.9, 10.10, 10.12, 10.13, 10.14, 10.16, 10.18, 10.36, 10.T, 12.4, 12.9, 12.10, 12.12, 12.13, 12.14, 12.16, 12.18, 12.36, 12. T, and mixtures or copolymers thereof. Advantageously, said at least one PA block comprises at least one of the following poly amides: PA 6, PA 12, PA 11, PA 10.10, PA 10.12, PA 10.14, PA 10.18, PA 6.10, PA 6.18, PA 6.12, PA 6.14; and/or at least one of the following copolyamides: PA 11/10.10, PA 6/11, PA 6.6/6, PA 11/12, PA 10.10/10.12, PA 10.10/10.14, PA 11/10.36, PA 11/6.36 and/or PA 10.10/10.36.

Advantageously, said at least one PE block comprises at least one polyether of at least partially renewable origin, chosen from: PEG, PPG, PO3G and PTMG, and mixtures thereof in the form of random and/or block copolymers. Advantageously, said copolymer comprises at least PAlI-PTMG, PAlO.10— PTMG, PA10.12-PTMG, PAlO.14-PTMG, PA6.10-PTMG, PA6.12-PTMG, and/or PA6.18-PTMG, preferably PAlI-PTMG. Advantageously, said copolymer comprises at least one PAlI block and at least one PTMG block. Preferably, the PAl 1 block has a molar mass of between 500 and 1500 g/mol, preferably substantially equal to 1000 g/mol, and the PTMG block has a molar mass of between 500 and 1500 g/mol, preferably substantially equal to 1000 g/mol. A subject of the present invention is also a thermoplastic polymer composition for the manufacture of skins having a stable appearance over time and an improved resistance to fogging, containing at least 35% by weight of a copolymer comprising a polyether block and a polyamide block of at least partially renewable origin.

A subject of the present invention is in particular a thermopolastic polymer composition comprising: from 35% to 99% by weight of at least one copolymer comprising a polyether block and a polyamide block, of at least partially renewable origin, from 0 to 39%, preferably from 0.1% to 30% by weight of at least a second polymer compatible with said at least one copolymer, from 0 to 15%, preferably from 0.1% to 10% by weight of at least one colouring agent, from 0.05% to 5%, preferably from 0.1% to 2% by weight of at least one agent for improving castability, - from 0.05% to 6%, preferably from 0.1% to 4% by weight of at least one anti- ageing agent, relative to the total weight of the composition.

Advantageously, said anti-ageing agent comprises an anti-UV agent and/or an antioxidant. Advantageously, said composition comprises at least one additional agent chosen from: colouring agents, fluidizing agents, anti-abrasion agents and/or demoulding agents.

Advantageously, said composition is in the form of a powder, the particles of which have a volume median diameter of less than 600 n m, preferably less than 400 μ m, preferably less than 200 p, m.

Advantageously, the second polymer is chosen from the following polymers: thermoplastic polyurethane; thermoplastic polyetherester; copolymer comprising a polyether block and a polyamide block (hereinafter also called "PEBA" or "polyether block amide") of fossil origin; grafted or ungrafted thermoplastic polyolefin; functionalized or nonfunctionalized ethylene/vinyl monomer polymer; functionalized or nonfunctionalized ethylene/alkyl (meth)acrylate or (meth) acrylic acid polymer; functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymer; ethylene/vinyl monomer/carbonyl terpolymer; ethylene/alkyl (meth)acrylate/carbonyl terpolymer; MBS-type core-shell polymer; SBM block terpolymer; chlorinated or chlorosulphonated polyethylene; PVDF; melt processable elastomer; TPEs, homopolymers and copolymers such as polyolefins; polyamides; polyesters; polyethers; polyimides; polycarbonates; phenolic resins; crosslinked or noncrosslinked polyurethanes, in particular in the form of foam; poly(ethylene/vinyl acetate)s; natural or synthetic elastomers such as polybutadienes, polyisoprenes, (styrene-butadiene-styrene)s (SBSs), (styrene- butadiene-acrylonitrile)s (SBNs), polyacrylonitriles; silicones; fibres of organic polymers, such as fibres of polypropylene, polyethylene, polyesters, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polyamide; glass fibres, carbon fibres; and combinations thereof. Advantageously, the second polymer comprises polyamide 11.

Advantageously, said composition comprises ¹⁴C.

Advantageously, said composition comprises at least 20% by weight of carbon of renewable origin, preferably 50% by weight of carbon of renewable origin. Advantageously, said composition comprises a ¹⁴C/¹²C isotope ratio of at least 0.2xl0 ¹², preferably of at least O.βxlO ¹², and not exceeding 1.2xlO"¹².

A subject of the present invention is also a process for the manufacture of a fogging-resistant skin, said process comprising the following successive steps: producing a powder of particles with a volume median diameter of less than 600 n m, preferably less than 400 μ m, preferably less than

200 li ra, more preferably equal to 150 u va, by cryomilling and/or by microgranulation of PEBA of partially renewable origin in accordance with that defined above; mixing said powder with at least one agent for improving castability and/or at least one anti-ageing agent; heating a mould at a temperature TO above the melting point Mp of the powder; applying an excess of the powder to a surface of said mould, said moulding being at a temperature Tl below TO while at the same time also being above Mp; - leaving a sufficient contact time between the powder and said surface; removing the excess powder, and leaving the powder still in contact with said surface for the amount of time necessary for the powder to form a film; - cooling the mould, and then demoulding the skin.

A subject of the present invention is also the use of a PEBA or of a thermoplastic polymer composition according to the invention, for the manufacture of skins, of synthetic and/or vegetable-tanned leather, of coverings, of passenger compartment elements, of dashboards, of furnishings, of decoration products, of furniture, of seats, of armchairs, of computer material, of bags and/or of shoes.

A subject of the present invention is also a skin having a composition according to the invention. Advantageously, said skin has a thickness within the range of from 0.1 to 3 mm, preferably from 0.3 to 1.5 mm, more preferably from 0.3 to 1.2 mm. A subject of the present invention is also a part of a passenger compartment of a vehicle comprising such a skin. Advantageously, said part of a passenger compartment is chosen from dashboards, door panels and/or airbags.

A subject of the present invention is also a vehicle comprising such a part of a passenger compartment.

Best Mode for Carrying Out the Invention

According to the present invention, at least one copolymer comprising polyether blocks and polyamide blocks (PEBA), of at least partially renewable origin, is used in a composition which is used for the manufacture of skins. Said composition of the invention thus makes it possible to obtain skins which have improved mechanical and aesthetic properties, and in particular better resistance to fogging.

Said at least one copolymer and the composition according to the invention comprise products of natural origin as starting products for the manufacture of skins.

The carbon of a biomaterial originates from plant photosynthesis and therefore from atmospheric CO2- The degradation ("degradation" will also be intended to mean combustion/incineration at the end of lifetime) of these materials to CO2 does not therefore contribute to warming since there is no increase in carbon emitted into the atmosphere. The CO2 balance of biomaterials is therefore much better and contributes to reducing the carbon footprint of the products obtained (only the energy for manufacturing is to be taken into account). Conversely, a material of fossil origin which also degrades to CO2 will contribute to increasing the CO2 level and therefore to global warming. The compounds according to the invention will therefore have a carbon footprint which will be better than that of compounds obtained from a fossil source.

The invention therefore also improves the ecological balance during the manufacture of the skins. The term "biocarbon" indicates that the carbon is of natural renewable origin and comes from a biomaterial, as indicated hereinafter. The content of carbon of renewable origin, the biocarbon content and the biomaterial content are expressions denoting the same value.

A material of renewable origin, also called biomaterial, is an organic material in which the carbon comes from CO2 recently fixed (on the human scale) by photosynthesis from the atmosphere. On land, this CO2 is captured or fixed by plants. In the sea, the CO2 is captured or fixed by bacteria or by plankton performing photosynthesis. A biomaterial (100% carbon of natural origin) has a ¹⁴CA²C isotope ratio of greater than 10"¹², typically of the order of 1.2 x lO"¹², whereas a fossil material has a zero ratio. This is because the ¹⁴C isotope forms in the atmosphere and is subsequently integrated by photosynthesis, according to a timescale of no more than a few tens of years. The half-life of ¹⁴C is 5730 years. Materials derived from photosynthesis, namely plants in general, therefore necessarily have a maximum content of ¹⁴C isotope

The biomaterial content or biocarbon content is determined by applying the standards ASTM D 6866 (ASTM D 6866-06) and ASTM D 7026 (ASTM D 7026-04). The object of standard ASTM D 6866 is "Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis", whereas the object of standard ASTM D 7026 is "Sampling and Reporting of Results for Determination of Biobased Content of Materials via Carbon Isotope Analysis". The second standard refers back, in its first paragraph, to the first.

The first standard describes a test for measuring the ¹⁴CV¹²C ratio of a sample and compares it with the ¹⁴CA²C ratio of a reference sample of 100% renewable origin, so as to give a relative percentage of C of renewable origin in the sample. The standard is based on the same concepts as ¹⁴C dating, but without the application of the dating equations.

The ratio thus calculated is denoted the "pMC" (percent Modern Carbon). If the material to be analyzed is a mixture of biomaterial and of fossil material (without radioactive isotope), then the value of pMC obtained is directly correlated to the amount of biomaterial present in the sample. The reference value used for ¹⁴C dating is a value dating to the 1950s. This year was chosen owing to the existence of nuclear tests in the atmosphere which introduced large amounts of isotopes into the atmosphere after this date. The 1950 reference to a pMC value of 100. Given the thermonuclear tests, the current value to be retained is approximately 107.5 (which corresponds to a correction factor of 0.93). The radioactive carbon signature of a current plant is therefore 107.5. A signature of 54 pMC and a signature of 99 pMC therefore correspond to an amount of biomaterial in the sample of 50% and of 93%, respectively.

Standard ASTM D 6866 proposes three techniques for measuring the ¹⁴C isotope content:

LSC (Liquid Scintillation Counting). This technique consists in counting the "beta" particles derived from the disintegration of ¹⁴C. The beta radiation derived from a sample of known mass (known number of C atoms) is measured for a certain period of time. This "radioactivity" is proportional to the number of ¹⁴C atoms, which can thus be determined. The ¹⁴C present in the sample emits β-radiation, which, in contact with the liquid scintillant (scintillator) gives rise to photons. These photons have different energies (between 0 and 156 keV) and form what is known as a ¹⁴C spectrum. According to two variants of this method, the analysis relates either to the CO2 produced beforehand by the carbonaceous sample in a suitable absorbent solution, or to benzene, after prior conversion of the carbonaceous sample to benzene. Standard ASTM D 6866 therefore provides two methods A and C, based on this LSC method.

AMS/IRMS (Accelerated Mass Spectrometry coupled with Isotope Radio Mass Spectrometry). This technique is based on mass spectrometry. The sample is reduced to graphite or to CO2 gas, and analyzed in a mass spectrometer. This technique uses an accelerator and a mass spectrometer to separate the ¹⁴C ions from the ¹²C ions and therefore to determine the ratio of the two isotopes.

The compositions according to the invention originate at least in part from biomaterial and therefore have a biomaterial content of at least 1%, preferably of at least 20% (which corresponds to a ¹⁴CV¹²C isotope ratio of at least 0.2x10 ^Λ2\ or better still of at least 50% by weight of carbon of renewable origin (which corresponds to a ¹⁴CV¹²C isotope ratio of at least 0.6χl0"¹²). This content is advantageously higher, in particular up to 100% (which corresponds to a ¹⁴CV¹²C isotope ratio not exceeding 1.2xlO ¹²). The compounds according to the invention may therefore comprise 100% of biocarbon or, on the contrary, result from a mixture with a fossil origin.

The thermoplastic compositions according to the invention comprise from 35% to 99% by weight of at least one copolymer comprising polyether blocks and polyamide blocks (abbreviated to PEBA) relative to the total weight of the composition, said copolymer being of at least partially renewable origin. The PEBAs, also called "polyether block amides", belong to the family of thermoplastic elastomer polymers (abbreviated to TPE polymers).

The term "thermoplastic elastomer polymer (TPE)" is intended to mean a block copolymer comprising alternating "hard" or "rigid" blocks or segments (with a rather thermoplastic behaviour) and "soft" or "flexible" blocks or segments (with a rather elastomeric behaviour). The soft blocks are generally based on polyethers (PE). The rigid blocks are generally based on polyamide, on polyurethane, on polyester or on a blend of these polymers.

The expression "copolymer comprising polyether blocks and polyamide blocks, of at least partially renewable origin" is intended to mean any PEBA of which the polyether blocks are of at least partially renewable origin and/or the polyamide blocks are of at least partially renewable origin.

For the purpose of the invention, the term "polyether" (abbreviated to PE) is intended to mean polyalkylene ether polyols, in particular polyalkylene ether diols. The PE blocks of the copolymer of the invention may comprise PEs of renewable origin or of fossil origin, chosen from: poly(ethylene glycol) (PEG), poly (1,2 -propylene glycol) (PPG), poly(l,3-propylene glycol) (PO3G), poly(tetramethylene glycol) (PTMG), polyhexamethylene glycol, poly(3-alkyl tetrahydrofuran)s, in particular poly(3-methyltetrahydrofuran) (poly( 3MeTHF)), and blends thereof in the form of random and/or block copolymers.

In fact, it is also possible to envisage a PE block of block or random "copolyether" type containing a series of at least two types of PE mentioned above.

The polyether blocks may also comprise blocks obtained by oxyethylation of bisphenols, for instance bisphenol A. The latter products are described in patent EP 613 919.

The polyether blocks may also comprise ethoxylated primary amines. These blocks are advantageously also used. By way of example of ethoxylated primary amines, mention may be made of the products of formula: H (OCH₂CH₂)_m — N (CH₂CH₂O)_n-H

in which m and n are between 1 and 20 and x is between 8 and 18. These products are commercially available under the trademark NORAMOX® from the company CECA and under the trademark GENAMIN® from the company CLARIANT.

The PE-block chain ends may be diOH, diNH2, diisocyanate or diacid depending on the process for synthesizing them.

The PE blocks with NEb chain ends can be obtained by cyanoacetylation of aliphatic alpha-omega- dihydroxylated polyoxyalkylene sequences, called polyether diols, such as Jeffamines® D300, D400, D2000, ED-600, ED-900, ED2003, and Elastamines® RP-409, RP-2009, RT- 1000, RE-600, RE-900, RE- 2000, HT-1700 and HE-180 from the company Huntsman. Such blocks are described in patents JP 2004346274, JP 2004352794 and EP1482011.

In addition, the soft PEBA blocks may also comprise blocks of polyester type containing dimerized fatty acids, which can also be obtained (at least partially) from renewable sources. These blocks are terminated at both ends with alcohol or amine functions.

Preferably, the polyether blocks of PEBAs which go to make up the composition of the invention are of at least partially renewable origin. On the other hand, in the case where the PA blocks are not of renewable origin, the PE blocks are of renewable origin, in accordance with the composition of the present invention. Thus, the polyether blocks of the PEBAs according to the invention comprise at least one -0-(CEb)-I- unit, in which the carbons are biocarbons. According to a preferred embodiment of the invention, the PE blocs comprise PTMG of renewable origin, synthesized from tetrahydrofuran, which is itself synthesized from furfural (also called 2-furaldehyde or furfuraldehyde) which is the derivative of various agricultural by-products such as maize, oat bran and wheat, and sawdust.

According to other embodiments, the PE blocks may comprise PO3G produced from 1,3 -propanediol derived from biofermentation of dextrose (for example those of the trademark Cerenol® sold by Dupont) or else PEG of renewable origin or any other type of PE of renewable origin.

For the purpose of the invention, the term "polyamide" (abbreviated to PA) is intended to mean the products of condensation of lactams, of amino acids or of diacids with diamines and, as a general rule, any polymer made up of units linked to one another by amide groups. The expression "polyamide of completely renewable origin" that can go to make up the copolymer according to the invention, is intended to mean : aliphatic polyamides obtained from lactams or from amino acids (for instance PA 11 obtained by polycondensation of 11-amino- undecanoic acid); - the products of condensation of a dicarboxylic acid with a diamine

(for instance PA 10.10, product of the condensation of decanediamine with sebacic acid, or else PA 10.36, product of the condensation of decanediamine with a fatty acid dimer); the copolyamides resulting from the polymerization of various monomers, such as those mentioned above, for instance the following copolyamides: PA 11/10.10, PA 11/10.36, PA 10.10/10.36, the 11-amino-undecanoic/n-heptyl-ll-aminoundecanoic copolyamide, etc. The copolyamides of renewable origin, which comprise at least two monomers, are more particularly described in French patent application No.: 07.53319.

The term "monomer" in the present description of the copolyamides should be taken in the sense of a "repeating unit". In fact, the case where one repeating unit of the PA consists of the association of a diacid with a diamine is particular. It is considered to be the association of a diamine and of a diacid, i.e. the diamine. diacid pair (in equimolar amount), which corresponds to the monomer. This is explained by the fact that, individually, the diacid or the diamine is merely a structural unit, which is not sufficient on its own to polymerize.

By way of examples of amino acids of renewable origin, mention may be made of: 11-aminoundecanoic acid produced from castor oil, for example, 10- aminodecanoic acid produced from decylenic acid obtained by metathesis of oleic acid, for example, and 9-aminononanoic acid produced from oleic acid, for example.

By way of examples of diacids of renewable origin, mention may be made, according to the number x of carbons of the molecule (Cx) of :

- C4: succinic acid from glucose, for example; - C6: adipic acid from glucose, for example;

- C7: heptanedioic acid from castor oil;

- C9: azelaic acid from oleic acid (ozonolysis), for example;

- ClO: sebacic acid from castor oil, for example;

- ClI: undecanedioic acid from castor oil; - C12: dodecanedioic acid from biofermentation of dodecanoic acid = lauric acid (rich oil: palm kernel and coconut oil), for example;

- C 13: brassylic acid from erucic acid (ozonolysis) which is found in rapeseed, for example;

- Cl4:tetradecanedioic acid by biofermentation of myristic acid (rich oil: palm kernel and coconut oil), for example;

- C16: hexadecanedioic acid by biofermentation of palmitic acid (mainly palm oil), for example;

- C18: octadecanedioic acid obtained by biofermentation of stearic acid (a little in all plant oils, but predominantly in animal fats), for example;

- C20: eicosanedioic acid obtained by biofermentation of arachidic acid

(predominantly in rapeseed oil), for example;

- C22: dodosanedioic acid obtained by metathesis of undecylenic acid

(castor oil), for example; - C36: fatty acid dimer derived mainly from oleic acid and linoleic acid.

By way of examples of diamines of renewable origin, mention may be made, as a function of the number x of carbons of the molecule (Cx), of:

- C4: butanediamine obtained by amination of succinic acid, by biofer mentation ;

- C5: pentamethylenediamine (from lysine); and so on for the diamines obtained by amination of the diacids of renewable origin seen above.

The expression "polyamide of partially renewable origin", i.e. derived only in part from renewable materials (referred to in the text as "mixed" polyamide), is intended to mean: - the products of condensation of a dicarboxylic acid with a diamine, and in which only one of the two (the diacid or the diamine) is of renewable origin. This is the case of PA 6.10, for example, since in the 6.10 monomer, only the sebacic acid is of renewable origin, whereas the hexamethylenediamine is derived from petrochemistry; - the copolyamides resulting from the polymerization of various monomers (renewable, nonrenewable or mixed) such as those mentioned above. This is the case, for example, of CoPA 6.6/10.10 in which the "6.6" monomer is of nonrenewable origin, whereas the "10.10" monomer is of renewable origin. This is also the case of PA 11/10. T, for example, which comprises a monomer of renewable origin

("11") and a mixed monomer of partially renewable origin ("10. T") since only the decanediamine is of renewable origin, whereas the terephthalic acid (T) is not.

The expression "polyamide of fossil origin" is intended to mean all the other polyamides on Earth which do not fall into the two categories mentioned above, i.e. which are not produced from renewable organic starting materials.

The copolymers comprising polyether blocks and polyamide blocks result from the polycondensation of polyamide blocks having reactive ends with polyether blocks having reactive ends, such as, inter alia: 1) polyamide blocks having diamine chain ends with polyoxyalkylene blocks having dicarboxylic chain ends; 2) polyamide blocks having dicarboxylic chain ends with polyoxyalkylene blocks having diamine chain ends, obtained by cyanoethylation and hydrogenation of aliphatic alpha,omega-dihydroxylated polyoxyalkylene blocks called polyether diols; 3) polyamide blocks having dicarboxylic chain ends with polyether diols, the products obtained being, in this particular case, polyetheresteramides .

The polyamide blocks having dicarboxylic chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain- limiting dicarboxylic acid.

The polyamide blocks having diamine chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain-limiting diamine. The number- average molar mass Mn of the polyamide blocks is within the range of from 400 to 20 000 g/mol, preferably from 500 to 10 000 g/mol, more preferably from 600 to 6000 g/mol, and more preferably from 600 to 2000g/mol.

The polymers comprising polyamide blocks and polyether blocks may also comprise randomly distributed units.

The polyamide blocks may comprise homopolyamides or copolyamides. Three types of polyamides may go to make up the composition of these PA blocks.

According to a first type, the polyamide blocks come from the condensation of a dicarboxylic acid (aliphatic, cyclo aliphatic or aromatic), in particular those containing from 4 to 36 carbon atoms, preferably those containing from 6 to 18 carbon atoms, and of a diamine (aliphatic, cycloaliphatic or aromatic) chosen in particular from those containing from 2 to 20 atoms, preferably those containing from 6 to 15 carbon atoms.

By way of examples of aliphatic diacids, mention may be made of butanedioic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, myristic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, octadecanedicarboxylic acid and dimerized fatty acids. By way of examples of cycloaliphatic diacids, mention may be made of 1,4- cyclohexyldicarboxylic acid.

By way of examples of aromatic diacids, mention may be made of terephthalic acid (T) and isophthalic acid (I). By way of examples of aliphatic diamines, mention may be made of tetramethylenediamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine.

By way of example of cycloaliphatic diamines, mention may be made of the isomers of bis(4-aminocyclohexyl)methane (BACM or PACM), bis(3-methyl-4- aminocyclohexyl)methane (BMACM or MACM), and 2,2-bis(3-methyl-4- aminocyclohexyl)propane (BMACP), isophoronediamine (IPDA), 2,6- bis(aminomethyl)norbornane (BAMN) and piperazine (Pip).

Advantageously one has PA 4.6, PA 4.9, PA 4.10, PA 4.12, PA 4.14, PA 4.16, PA 4.18, PA 6.6, PA 6.9, PA 6.10, PA 6.12, PA 6.14, PA 6.16, PA 6.18, PA 9.12, PA 10.6, PA 10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA BMACM.6, PA BMACM.9, PA BMACM.10, PA BMACM.12, PA BMACM.14, PA BMACM.16, PA BMACM.18, PA PACM.6, PA PACM.9, PA PACM.10, PA PACM.12, PA PACM.14, PA PACM.16, PA PACM.18, PA Pip.6, PA Pip.9, PA Pip.10, PA Pip.12, PA Pip.14, PA Pip.16, PA Pip.18 blocks. According to a second type, the polyamide blocks result from the condensation of one or more alpha,omega-aminocarboxylic acids and/or of one or more lactams containing from 6 to 12 carbon atoms, in the presence of a dicarboxylic acid containing from 4 to 12 carbon atoms or of a diamine.

By way of examples of lactams, mention may be made of caprolactam, oenantholactam and lauryllactam.

By way of examples of alpha, omega- aminocarboxylic acid, mention may be made of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid.

Advantageously, the polyamide blocks of the second type are of polyamide 11, of polyamide 12 or of polyamide 6.

According to a third type, the polyamide blocks result from the condensation of at least one monomer of the first type with at least one monomer of the second type. In other words, polyamide blocks result from the condensation of at least one alpha,omega-aminocarboxylic acid (or a lactam) with at least one diamine and one dicarboxylic acid. In this case, the PA blocks are prepared by polycondensation: of the linear aliphatic or aromatic diamine(s) containing X carbon atoms; of the dicarboxylic acid(s) containing Y carbon atoms; and of the comonomer(s) {Z}, chosen from lactams and alpha, omega- aminocarboxylic acids containing Z carbon atoms; in the presence of a chain limiter chosen from dicarboxylic acids, or of an excess of diacid or of diamine used as structural unit. Advantageously, the dicarboxylic acid containing Y carbon atoms is used as chain limiter, which is introduced in excess relative to the stoichiometry of the diamine(s).

According to one other variant (the case of copoly amides), the polyamide blocks result from the condensation of at least two different alpha,omega- aminocarboxylic acids or of at least two different lactams containing from 6 to 12 carbon atoms or of a lactam and an aminocarboxylic acid which do not have the same number of carbon atoms, in the optional presence of a chain limiter.

By way of examples of polyamide blocks of the third type, mention may be made of the following :

PA 6.6/6 in which 6.6 denotes a monomer resulting from the condensation of hexamethylenediamine with adipic acid. 6 denotes a monomer resulting from the condensation of caprolactam.

6.6/Pip.lO/12 in which 6.6 denotes a monomer resulting from the condensation of hexamethylenediamine with adipic acid. Pip.10 denotes a monomer resulting from the condensation of piperazine with sebacic acid. 12 denotes a monomer resulting from the condensation of lauryllactam.

6.6/6.10/11/12 in which 6.6 denotes a monomer resulting from the condensation of hexamethylenediamine with adipic acid. 6.10 denotes a monomer resulting from the condensation of hexamethylenediamine with sebacic acid. 11 denotes a monomer resulting from the condensation of aminoundecanoic acid. 12 denotes a monomer resulting from the condensation of lauryllactam.

By way of examples, mention may be made of PA 10.10/11, PA 6.10/11, PA10.12/11, PA 10.10/11/12, PA 6.10/10.10/11, PA 6.10/6.12/11 and PA 6.10/6.12/10.10.

The polyether blocks may represent 5% to 90%, preferably 30% to 90%, and more preferably 50% to 90%, by weight of the copolymer comprising polyamide and polyether blocks. The mass Mn of the polyether blocks is within the range of from 100 to 6000 g/mol, and preferably from 200 to 3000 g/mol, even more preferably from 250 to 2000 g/mol.

The preparation of the copolymers comprising polyamide blocks and polyether blocks according to the invention comprises any means for attaching the polyamide blocks (PA block) and the polyether blocks (PE block) according to the present invention. In practice, two processes, one referred to as a 2-step process, the other as a one-step process, are essentially used.

In the one- step process, the polyamide precursors, the chain limiter and the polyether are mixed. Thus, in the one-step process, polyamide blocks are also produced. The simultaneous polycondensation of the polyether blocks and of the polyamide block precursors is preferably carried out at a temperature of 180 to

300°C. A polymer having essentially polyether blocks, polyamide blocks of variable length, but also the various reactants that have reacted randomly, which are distributed randomly along the polymer chain, is then obtained.

Whether the process is a one-step or two-step process, it is advantageous to carry it out in the presence of a catalyst. The term "catalyst" is intended to mean any product which makes it possible to facilitate the linking of the polyamide blocks and of the polyether blocks by esterification or by amidation. The esterification catalyst is advantageously a derivative of a metal chosen from the group made up of titanium, zirconium and hafnium, or else a strong acid such as phosphoric acid or boric acid. The catalysts described in patents US 4 331 786, US 4 115 475, US 4 195 015, US 4 839 441, US 4 864 014, US 4 230 838 and US 4 332 920, WO 04 037898, EP 1262527, EP 1270211, EP 1136512, EP 1046675, EP 1057870, EP 1155065, EP 506495 and EP 504058 may be used. In the two-step process, the polyamide blocks are first produced and then, in a second step, the polyamide blocks and the polyether blocks are attached. The polyether diol blocks according to the invention are either used as they are and copolycoiidensed with polyamide blocks having carboxylic ends, or they are aminated so as to be converted to polyetherdiamines and condensed with polyamide blocks having carboxylic ends. The general method for the two-step preparation of the PEBA copolymers having ester bonds between the PA blocks and the PE blocks is known and is described, for example, in French patent FR 2 846 332. The general method for the preparation of the PEBA copolymers of the invention having amide bonds between the PA blocks and the PE blocks is known and is described, for example, in European patent EP 1 482 011.

The reaction for forming the PA block is usually carried out between 180 and 300⁰C, preferably from 200 to 290°C, the pressure in the reactor becomes set up between 5 and 30 bar, and is maintained for approximately 2 to 3 hours. The pressure is slowly reduced, placing the reactor at atmospheric pressure, and then the excess water is distilled, for example for one hour or two.

Once the polyamide having carboxylic acid ends has been prepared, the polyether and the catalyst are then added. The polyether may be added in one or two steps, similarly for the catalyst. According to one advantageous embodiment, the polyether is first added, and the reaction of the OH ends of the polyether and of the COOH ends of the polyamide begins, with the formation of ester bonds and elimination of water. The water is removed from the reaction medium as much as possible by distillation, and then the catalyst is introduced so as to finish off the bonding of the polyamide blocks and of the polyether blocks. This second step is carried out with stirring, preferably in a vacuum of at most 100 mbar, preferably of at most 50 mbar, more preferably of at most 20 mbar, even more preferably of at most 10 mbar, at a temperature such that the reactants and the copolymers obtained are in the molten state. By way of example, this temperature may be between 100 and 300⁰C, and most commonly between 200 and 250⁰C. The reaction is followed by measuring the torque exerted by the molten polymer on the stirrer or by measuring the electric power consumed by the stirrer. The end of the reaction is determined by the target torque or power value.

One or more molecules used as an antioxidant, for example Irganox® 1010 or Irganox® 245, may also be added during the synthesis, at the moment judged to be the most opportune. Advantageously, the PEBA copolymers comprise PA blocks comprising at least one of the following polyamides PA 11, PA 10.10, PA 10.12, PA 10.14, PA 10.18, PA 6.10, PA 6.12, PA 6.14, PA 6.18, as predominant components (percentage by mass greater than 50% relative to the total mass of PA) and PE blocks comprising PTMG of renewable origin as predominant component (percentage by mass greater than 50% relative to the total mass of PE), and/or PO3G of renewable origin as other components of the PE blocks of the PEBA of the invention.

For the polyamide block of the copolymer according to the invention, the polyamides chosen from PA 6, PA 12, PA 11, PA 10.10, PA 10.12, PA 10.14, PA 10.18, PA 6.10 and PA 6.18, which are obtained (at least partially) from renewable resources, are preferred. Copolyamide-based polyamide blocks can also be envisaged, and more particularly those chosen from PA 11/10.10, PA 6/11, PA 11/12, PA 10.10/10.12, PA 10.10/10.14, PA 11/10.36, PA 11/6.36 and/or PA 10.10/10.36. These blocks are terminated at both ends with carboxylic acid functions.

For the polyether block of the copolymer according to the invention, PTMG, PEG, PPG and PO3G, and/or blends thereof in the form of random or block copolymers, which may be obtained (at least partially) from renewable resources, are preferred. The use of blocks derived from renewable resources has both an ecological advantage, and in the case of the objective sought by the present invention, technical advantages. Thus, the PAlI-PTMG PEBAs have advantages, compared with PA12-PTMG, regarding cold impact, melting point or alternatively fogging, as illustrated in Table 2 below.

The length of the blocks is adjusted so as to obtain the desired hardness. For the skins used in car interiors (passenger compartment), the PEBA compositions with a low hardness, preferably between 65 and 95 Shore A, are preferred. The hardness may, however, be increased up to 72 Shore D, or even 75 Shore D, by adding reinforcing fillers, for specific parts or applications in other markets mentioned above. The thermoplastic compositions according to the invention also comprise from 0 to 39%, preferably from 0.1 to 30% by weight of at least a second polymer which is compatible with said at least one copolymer and which is of at least partially renewable origin.

The "second polymer which is compatible" is intended to mean all elastomers, in particular thermoplastics, other than the PEBAs of renewable origin, and which can be used in the molten state, i.e. which are melt "processable", with the PEBAs of renewable origin. These other compatible polymers are preferably those of renewable origin.

By way of compatible polymer, mention may be made of the following polymers: polyamide; thermoplastic polyurethane; thermoplastic polyetherester; polyether block amide (PEBA) of fossil origin; thermoplastic polyolefin; functionalized or nonfunctionalized ethylene/vinyl monomer polymer; functionalized or nonfunctionalized ethylene/alkyl (meth)acrylate or (meth) acrylic acid polymer; functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymer; ethylene/vinyl monomer/carbonyl terpolymer; ethylene/alkyl (meth) aery late/carbonyl terpolymer; MBS-type core- shell polymer; SBM block terpolymer; chlorinated or chlorosulphonated polyethylene; PVDF; and any other melt-processable elastomer.

The expression polyamide, as "second compatible polymer" of the composition of the invention" is intended to mean the polyamides already described in the definition of the PEBAs above. They are preferably polyamides of at least partially renewable origin, more preferably those of entirely renewable origin.

The thermoplastic polyurethane (TPU) may in particular contain sequences or blocks which are soft segments. This term "soft segment" is intended to mean, for example, polyether or polyester diol blocks.

Mention may be made of the following TPUs: polyurethane ether, for example comprising blocks of polyether having hydroxyl ends linked to diisocyanates by urethane functions; polyurethane ester, for example comprising blocks of polyester having hydroxyl ends linked to diisocyanates by urethane functions; polyurethane ether ester, for example comprising blocks of polyester and blocks of polyether having hydroxyl ends, these blocks being linked to diisocyanate residues by urethane functions. There may also be polyether- polyester chains having hydroxyl ends linked to diisocyanates by urethane functions. An example of TPU is Estanes® from Goodrich, and also Elastollane® from

BASF and Desmopan® from Bayer.

The thermoplastic polyetherester may, for example, comprise blocks of polyether having hydroxyl ends linked to blocks of polyester having acid ends, it being possible for this structure to also comprise diols (for example, 1,4- butanediol). An example of such a polyetherester is Hytrels® from Dupont.

The PEBAs of fossil origin are the same as the polymers comprising copolyamide blocks and polyether blocks already described above in the description, except for the fact that all their blocks and components are derived from petrochemistry. Mention may, for example, be made of the Pebax® MX1205 grade, or alternatively the Pebax® 6333 grade, sold by Arkema.

The term "polyolefins" is intended to mean polymers which derive by at least 50% by weight from units derived from unsaturated aliphatic hydrocarbons of formula C_nHb_n called olefins, and more particularly α-olefins. By way of example, mention may be made of: - thermoplastic polyolefins, and more particularly the polyethylene

(PE) grades such as HD, LLD, VLD, ULD, UHMW, the various random or nonrandom polypropylene (PP) homopolymers and copolymers, thermoplastic polyolefin (TPO) elastomers which are physical mixtures prepared from polyolefins; those which contain more than 60% of polypropylene and those of which the elastomer phase is predominant (more than 70%), it being possible for the latter to be crosslinked or noncrosslinked, stand out; mention will in particular be made of EPR and EPDM, copolymers containing more than 50% by weight of ethylene, such as copolymers, and especially terpolymers, derived from ethylene and alkyl acetate(s), or from ethylene and alkyl (meth)aerylate(s), and also all the above products grafted with, for example, at least one unsaturated dicarboxylic acid anhydride, such as maleic anhydride, with silanes, compounds comprising epoxy groups, such as glycidyl methacrylate GMA.

The ethylene/vinyl monomer copolymer is based on ethylene and a vinyl monomer of the vinyl acetate family, this monomer representing in general from 5% to 40% by weight of the copolymer.

The ethylene/alkyl (meth)acrylate or (meth)acrylic acid copolymer is based on ethylene and alkyl (meth)acrylate, which represents in general from 5% to 40% by weight of the copolymer.

The alkyl (meth)acrylate monomer may contain up to 24, and preferably, 10 carbon atoms and may be linear, branched or cyclic. By way of illustration of the alkyl (meth)acrylate, mention may in particular be made of n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate. Among these (meth)acrylates, ethyl acrylate, n-butyl acrylate and methyl methacrylate are preferred.

Alternatively, it is based on ethylene and (meth)acrylic acid, which represents in general up to 10 mol%. The acid functions may be completely or partly neutralized with a cation (in particular a metal cation).

The ethylene/vinyl monomer/alkyl (meth) acrylate terpolymer is based on 2 Q O

ethylene and the two comonomers described above (vinyl monomer and termonomer which is the carbonyl group), the latter being present in the same general proportions. One example is the E/VA/CO terpolymer. These polymers are in particular sold by DuPont under the trademark Elvaloy®. These copolymers may optionally be functionalized. As an example of a function, mention may be made of anhydrides, epoxides, isocyanates, isoxazones, etc. The unsaturated carboxylic acid anhydride may be chosen, for example, from maleic anhydride, itaconic anhydride, citraconic anhydride, allylsuecinic anhydride, etc. By way of example of unsaturated epoxides, mention may be made of: aliphatic glycidyl esters and ethers such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate, glycidyl itaconate or glycidyl (meth)acrylate, and alicyclic glycidyl esters and ethers.

These functionalities may be introduced by grafting or co- or tert- polymerization, according to known methods. Examples of such functionalized or nonfunctionalized polymers are the following products: Elvaloy® from DuPont, and Lotryl®, Loader®, Evatane® and Orevac® from Arkema.

The ethylene/vinyl monomer/carbonyl terpolymer is based on ethylene and on alkyl (meth)acrylate, vinyl monomer and a termonomer which is the carbonyl group. One example is the E/nBA/CO terpolymer. These polymers are in particular sold by DuPont under the trademark Elvaloy®.

The MBS -type polymer is a polymer with a conventional "core- shell" structure, used as an impact modifier. It is obtained conventionally by polymerization of the acrylic monomer on a suspension or latex of a butadiene/styrene copolymer. One example is the product Metablends from Arkema.

In general, all the impact modifiers that have good cold properties can also be used in the invention.

The SBM block terpolymer contains a first block of acrylic type, a second block of diene type and a third block of styrene type, these blocks being obtained in particular by anionic synthesis (on a first monomer which is a styrene monomer, then with a diene block, and then, to finish, with an acrylic block). The first block is advantageously chosen from homopolymers and copolymers of alkyl (meth)acrylate and, for example, of methyl methacrylate (PMMA) and/or of methyl acrylate or ethyl acrylate and, optionally, vinyl acetate.

The second block is advantageously a poly(dienes), in particular poly (butadiene) (PB), poly(isoprene), and random copolymers thereof, which are partially or completely hydrogenated.

The third block is advantageously chosen from homopolymers or copolymers of styrene (PS) or of α-methylstyrene.

Preferably, the SBM triblock is a PMMA/PB/PS, with proportions, for example, of 30-50/30-50/20-40, and/or a molar mass Mn for the PS of 20 000 to 50 000.

The chlorinated or chlorosulphonated polyethylene is conventional. Examples of chlorinated or chlorosulphonated polyethylene are Tyrine from DuPont and Hypalone from DuPont-Dow, respectively. The polyvinylidene difluoride PVDF is itself also conventional.

Copolymers are also possible, with other (per)fluorinated monomers.

The melt processable elastomer, also called melt processable rubber is for example the product Alcryn from APA.

Blends and/or combinations are also possible, between polymers of the same nature or of different natures.

The thermoplastic compositions according to the invention may also comprise from 0 to 15%, preferably from 0.1% to 10% by weight, relative to the total weight of the composition, of at least one colouring agent.

The term "colouring agent" is intended to mean any pigments and dyes which give the composition according to the invention a colour effect.

A pigment is a dyestuff and/or a material providing a "metallic" or "iridescent" appearance, which is in the form of a powder (coloured, white or black), and insoluble, unlike "dyes" per se, in the solvents and substrates. Said colouring agent may be chosen from dyes, conventional pigments, pigments with effects, such as diffractive pigments, interference pigments, such as pearlescent agents, reflective pigments and mixtures thereof. The term "pigment with an effect" is intended to mean any material with a specific optical effect. This effect is different from a simple conventional hue effect, i.e. a unified and stabilized effect as produced by standard dyestuffs, for instance monochromatic pigments. For the purposes of the invention, the term "stabilized" means lacking an effect of variability of the colour as a function of the angle of observation or alternatively in response to a temperature change. For example, this material may be chosen from particles with a metallic tint, goniochromatic colouring agents, diffractive pigments, thermochromic agents, optical brighteners, and also fibres, especially interference fibres. Of course, these various materials may be combined so as to simultaneously afford two effects, or even a novel effect.

The term "colouring agent" is also intended to mean mineral fillers such as Tiθ2, carbon black, or organic or mineral pigments of any type. Organic or mineral compounds with good light-fastness and heat-fastness are preferably chosen.

By way of examples of colouring agents that can be envisaged, mention may be made of the white TiO 2 pigment known under the trade name "RHD 2", manufactured by HUNTSMAN, the black pigment "Monarch 800" from the manufacturer CABOT, the black pigment "Black PK 3097" from the manufacturer FERRO, the yellow pigment "Yellow Light 6R" from the manufacturer HEUBACH, the yellow pigment "Yellow Light 8G" from the manufacturer HEUBACH, and the brown pigment "Brown 645T" from the manufacturer BAYER.

The thermoplastic compositions according to the invention also comprise from 0.05% to 5%, preferably from 0.1% to 2% by weight, relative to the total weight of the composition, of at least one agent for improving castability of the composition, in particular when it is in the molten state, which in particular enables the composition to correctly fill an imprint of a mould, for example.

By way of examples of agents for improving castability (also called fluidizing agents) of the composition, mention may be made of: silica, such as "Aerosil® R972" sold by Evonik, "CAB-O-SIL®" from the manufacturer CABOT, aluminas, such as "Alumina C" from the manufacturer EVONIK, or fine polyamide powders, such as those of the Orgasol® or Rilsan® trademark, manufactured by Arkema.

The thermoplastic compositions according to the invention also comprise from 0.05% to 6%, preferably from 0.1% to 4% by weight, relative to the total weight of the composition, of at least one anti-ageing agent, such as an antioxidant and/or an anti-UV agent and/or a stabilizer. By way of examples of antioxidants that are particularly suitable for the formulations based on PEBA in the form of powdered cryo milled granules (for example, PEBAX® 40R53SA01 from Arkema), mention may in particular be made of phenolic agents and phosphorus-containing agents. Mention may in particular be made of "Irganox® 1010" which is in powder form, from the manufacturer CIBA. Mention may also be made of "ADK pep 36" in powder form (its preferred content in the compositions of the invention: 0.15% by mass) from the manufacturer: ADEKA PALMAROLE.

By way of example of anti-UV agents, mention may be made of agents with blocked amine and/or phenolic functions, for example Tinuvin® 144 in powder form (at a preferred content of 0.10% (by mass) in the compositions of the invention), from the manufacturer CIBA. Mention may also be made of Tinuvin 312 in powder form (at a preferred content of 0.30% (by mass) in the compositions of the invention), from the manufacturer CIBA.

If the compositions were to contain plasticizers, fillers, carbon nanotubes, impact modifiers and/or any other additive well known in the polymer field, this would not depart from the context of the invention. The composition according to the invention may be converted into the form of a powder, of granules, etc, for a subsequent use or conversion.

Preferably, the compositions according to the invention are in the form of a powder, the particles of which have a volume median diameter of less than 400 H m, preferably less than 200 β m, or better still substantially equal to 150 \ι m. If the composition of the invention is in the present description, in accordance with a preferred (but nonlimiting) embodiment of the invention, applied to the manufacture of skins, it goes without saying that the composition of the invention is also particularly suitable for coatings (anticorrosion, paints, etc). The compositions according to the invention, when they are in powder form, may also be used as additives for paper or alternatively in electrophoresis or in powder agglomeration technologies using metal agglomeration or irradiation sintering, for instance laser sintering or infrared sintering (IR sintering), for manufacturing articles. Said powders may also be used as spacers in composite materials, in particular between the layers of multilayer materials. Uses thereof in the packaging industry, toy industry, textile industry, automobile and electronics industries, cosmetics, pharmacy and/or perfumery can also be envisaged.

By way of examples, the granules comprising the composition of the invention are used for the manufacture, in particular by extrusion, of filaments, tubes, films and/or moulded articles. A subject of the present invention is also a process for the manufacture of skins, said process using a PEBA or a composition according to the invention. In particular, the process of the invention makes it possible to manufacture fogging- resistant skins, said process comprising the following steps: a) producing a powder of particles with a volume median diameter of less than 600 Dm, preferably less than 400 Dm, preferably less than

200 Dm, more preferably equal to 150 Dm, by cryo milling or by microgranulation of said PEBA and/or of said composition; b) mixing said powder with at least one agent for improving castability and/or at least one anti-ageing agent, for instance an antioxidant and/or an anti-UV agent; and, optionally, with one or more colouring agent(s), fluidizing agent(s), anti-abrasion agent(s), demoulding agents, and/or any other additive common in the polymer field; c) heating (generally for 5 minutes) a mould at a temperature TO above the melting point Mp of the powder; for example at a temperature within the range of from 280 to 400⁰C, preferably at a temperature from 280 to 300°C, preferably at a temperature of 340⁰C; d) applying an excess of the powder to a surface of said mould, said mould then being at a temperature Tl below TO while at the same time also being above Mp, for example when the surface of the mould reaches a temperature within the range of from 200 to 260°C, preferably a temperature of 23O⁰C; e) leaving a sufficient contact time between the powder and said surface, i.e. for 10 to 30 seconds, preferably for 10 to 20 seconds; f) removing the excess powder, and leaving a further contact time between the powder and said surface, generally for 20 to 100 seconds, preferably 20 to 40 seconds, the time necessary for the powder to form a film; g) cooling the mould, preferably in water, for example for 10 seconds to two minutes, preferably 40 seconds; h) demoulding the skin. Among the methods for producing powder (step a)) according to the invention, the following can be envisaged: cryogenic milling: which makes it possible to obtain particles with a diameter of less than 400 μ m, or better still with a median diameter of less than 200 \i m; - micro granulation: which makes it possible to obtain spherical particles with a diameter of between 400 and 1000 ii m. For the process for the manufacture of skins according to the invention, granules or powders with a small diameter, i.e. with a diameter within the range of from 400 to 600 β m, are preferred. Another possible embodiment of the process of the present invention may also comprise a preliminary step of compounding PEBA with dyes, and/or any other additive, before said step (a)) of producing powder, by microgranulation and/or cyrogenic milling (cryo milling), followed by step b) of mixing the powder with a castability agent and/or an anti-ageing agent, by rapid mixing for example, and the other successive steps (c) to h)) already described above.

A subject of the present invention is also the use of the thermoplastic composition in accordance with the invention, for the manufacture of skins, of synthetic and/or vegetable-tanned leather, of coverings, of passenger compartment elements, of dashboards, of furnishings, of decoration products, of furniture, of seats, of armchairs, of bags and/or of shoes. According to the application, the skins of the composition in accordance with the invention have a thickness ranging from 0.1 to 3 mm, preferably from 0.3 to 1.5 mm, preferably from 0.3 to 1.2 mm.

Mode for the Invention The examples below illustrate the present invention without limiting the scope thereof. In the examples, unless otherwise indicated, all the percentages and parts are expressed by weight.

One type of PEBA manufactured by Arkema (Pebax®Rnew range), of PAIl-PTMG type, is tested, in which the PAlI-PTMG block size ratio is approximately 1 (Ex 1). The carbon renewable content of this PEBA PAlI-PTMG is 45% by mass, relative to the total mass of carbon of the PEBA. Granules of PAlI-PTMG are cryo milled so as to obtain a fine powder with a median diameter of 150 μ m, The particles with a median diameter of greater than 400 U m are removed by sieving. 0.4% of Aerosil R972 from the company Evonik is added to these powders so as to improve the castability thereof. A small content of TiO2 and carbon black are added to give coloration.

Skins are obtained from these powders by the slush moulding process. The powder is applied to the mould when the surface of the mould reaches 23O⁰C. Mold rotation is 5 rpm. After 1 minute during which the powder forms a film, the mould is cooled with water. After cooling for one minute, the skin is demoulded. The thickness obtained is approximately 0.7 mm. The tensile properties are measured (according to standard ISO 527) on dumbbell- shaped pieces cut out of the skin with a hole punch. The tensile properties of these dumbbells Ex 1 (example according to the invention) are compared with that (dumbbell) of a skin made of plasticized PVC (TP009B from Zeon Kasei), called Comp 1 (comparative of a composition not in accordance with the present invention) in Table 1. Tensile properties of samples were also checked after heat ageing and light ageing. Compared to the plasticized PVC of comparative 1, the PAIl-PTMG of example 1 shows advantage in density, tensile elongation and ductility at - 35°C, higher retention after heat ageing and comparable properties after light ageing. [Table 1]

Table 2 below compares the properties of the Pebax products based on PAIl-PTMG and PA12-PTMG (Comp 2), in which the PA 11 block or the PA 12 block has a molar mass of 1000 g/mol, and the polyether block has a molar mass of 1000 g/mol. The fogging test is carried out by placing the Pebax or the reference PVC in a bottle stoppered with a glass slide. The lower part of the bottle is immersed in a bath of oil at 100°C for 20 hours. The haze due to the deposit of volatile organic compounds on the glass plate is measured. The test is carried out on at least 4 samples.

The PAlI-PTMG PEBAs have a better fogging performance than their PA12-PTMG equivalents and are also better than the plasticized PVC generally used for this application. [Table 2]

Claims

[1] Use of a copolymer comprising a polyether block and a polyamide block, for the manufacture of skins having a stable appearance over time and improved resistance to fogging, said copolymer being of at least partially renewable origin.

[2] Use of a thermoplastic polymer composition containing at least 35% by weight of a copolymer according to Claim 1, for the manufacture of skins having a stable appearance over time and improved resistance to fogging.

[3] Use according to either one of Claims 1 and 2, for the manufacture of dashboard skins.

[4] Use according to any one of the preceding claims, in which said copolymer comprises at least one PA block of at least partially renewable origin and/or at least one PE block of at least partially renewable origin.

[5] Use according to any one of the preceding claims, in which said at least one PA block comprises at least one of the following polyamides : PA 6, PA 12, PA 11, PA 10.10, PA 10.12, PA 10.14, PA 10.18, PA 6.10, PA 6.18, PA 6.12, PA 6.14; and/or at least one of the following copolyamides: PA 11/10.10, PA 6/11, PA 6.6/6, PA 11/12, PA 10.10/10.12, PA 10.10/10.14, PA 11/10.36, PA 11/6.36 and/or PA 10.10/10.36.

[6] Use according to any one of the preceding claims, in which said at least one PE block comprises at least one polyether of at least partially renewable origin, chosen from: PEG, PPG, PO3G and PTMG, and blends thereof in the form of random and/or block copolymers.

[7] Use according to any one of the preceding claims, in which said copolymer comprises at least PAlI-PTMG, PAlO.lO-PTMG, PA10.12-PTMG,

PA10.14-PTMG, PA6.10-PTMG, PA6.12-PTMG, and/or PA6.18-PTMG, preferably PAlI-PTMG.

[8] Use according to claim 7, in which the PAlI block has a molar mass of between 500 and 1500 g/mol, preferably substantially equal to 1000 g/mol, and the PTMG block has a molar mass of between 500 and 1500 g/mol, preferably substantially equal to 1000 g/mol.

[9] Thermoplastic polymer composition for the manufacture of skins having a stable appearance over time and improved resistance to fogging, containing at least 35% by weight of a copolymer comprising a polyether block and a polyamide block of at least partially renewable origin.

[10] Thermoplastic polymer composition comprising: from 35 to 99% by weight of at least one copolymer comprising a polyether block and a polyamide block, of at least partially renewable origin, from 0 to 39%, preferably from 0.1% to 30%, by weight of at least a second polymer which is compatible with said at least one copolymer, from 0 to 15%, preferably from 0.1% to 10%, by weight of at least one colouring agent, from 0.05% to 5%, preferably from 0.1% to 2%, by weight of at least one agent for improving castability, from 0.05% to 6%, preferably from 0.1% to 4%, by weight of at least one anti-ageing agent, relative to the total weight of the composition.

[11] Composition according to Claim 10, in which said at least one anti-ageing agent comprises an anti-UV agent and/or an antioxidant.

[12] Composition according to any one of Claims 9 to 11, comprising at least one additional agent chosen from: colouring agents, fluidizing agents, anti- abrasion agents and/or demoulding agents.

[13] Composition according to any one of Claims 9 to 12, said composition being in the form of a powder, the particles of which have a volume median diameter of less than 600 ji m, preferably less than 400 ι± ni, preferably less than 200 /i m.

[14] Composition according to any one of Claims 10 to 13, in which the second polymer is chosen from the following polymers: thermoplastic polyurethane; thermoplastic polyetherester; PEBA of fossil origin; grafted or ungrafted thermoplastic polyolefin; functionalized or nonfunctionalized ethylene/vinyl monomer polymer; functionalized or nonfunctionalized ethylene/alkyl (meth)acrylate or (meth) acrylic acid polymer; functionalized or nonfunctionalized ethylene/vinyl monomer/alkyl (meth)acrylate terpolymer; ethylene/vinyl monomer/carbonyl terpolymer; ethylene/alkyl (meth)acrylate/carbonyl terpolymer; MBS -type core- shell polymer; SBM block terpolymer; chlorinated or chlorosulphonated polyethylene; PVDF; melt processable elastomer; TPEs, homopolymers and copolymers such as polyolefins; polyamides; polyesters; polyethers; polyimides; polycarbonates; phenolic resins; crosslinked or noncrosslinked polyurethanes, in particular in the form of a foam; poly(ethylene/vinyl acetate) s ; natural or synthetic elastomers such as polybutadienes, polyisoprenes, (styrene-butadiene-styrene)s (SBSs), (styrene-butadiene- acrylonitrile)s (SBNs), polyacrylonitriles; silicones; organic polymer fibres such as fibres of polypropylene, polyethylene, polyesters, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polyamide; glass fibres, carbon fibres; and combinations thereof.

[15] Composition according to any one of Claims 10 to 14, in which the second polymer comprises polyamide 11.

[16] Composition according to any one of Claims 9 to 15, characterized in that it comprises ¹⁴C.

[17] Composition according to any one of Claims 9 to 16, comprising at least 20% by mass of carbon of renewable origin, preferably 50% by mass of carbon of renewable origin.

[18] Composition according to any one of Claims 9 to 17, comprising a ¹⁴C/¹²C isotope ratio of at least 0.2x10 ¹², preferably of at least O.βxlO-¹², and not exceeding 1.2xlO"¹².

[19] Process for the manufacture of a fogging-resistant skin, said process comprising the following successives steps: producing a powder of particles with a volume median diameter of less than 600 M m, preferably less than 400 |i m, preferably less than 200 β m, more preferably equal to 150 β m, by cryomilling and/or by microgranulation of PEBA of partially renewable origin in accordance with that defined in any one of Claims 1 to 8; mixing said powder with at least one agent for improving castability and/or at least one anti- ageing agent; heating a mould at a temperature TO above the melting point Mp of the powder; - applying an excess of the powder to a surface of said mould, said mould being at a temperature Tl below TO while at the same time also being above Mp; leaving a sufficient contact time between the powder and said surface; - removing the excess powder, and leaving the powder still in contact with said surface for the amount of time necessary for the powder to form a film; cooling the mould; and then demoulding the skin.

[20] Use of a PEBA in accordance with any one of Claims 1 to 8 and/or of a thermoplastic composition in accordance with any one of Claims 9 to 18, for the manufacture of skins, of synthetic and/or vegetable-tanned leather, of coverings, of passenger compartment elements, of dashboards, of furnishings, of decoration products, of furniture, of seats, of armchairs, of computer material, of bags and/or of shoes.

[21] Skin of composition in accordance with any one of Claims 9 to 18. [22] Skin according to Claim 21, which has a thickness within the range of from 0.1 to 3 mm, preferably from 0.3 to 1.5 mm, more preferably from 0.3 to 1.2 mm. [23] Part of a passenger compartment of a vehicle comprising a skin according to Claim 21 or 22. [24] Part of a passenger compartment according to Claim 23, which is chosen from dashboards, door panels and/or airbags. [25] Vehicle comprising a part according to Claim 23 or 24.