Polymer composition for waterproof breathable membrane

Abstract

The invention relates to a composition consisting of: 75 to 98% by weight, relative to the weight of the composition, of at least one copolymer A, containing polyamide blocks and polyether blocks; 2 to 15% by weight, relative to the weight of the composition, of at least one copolymer B, containing units derived from ethylene, alkyl (meth)acrylate and a comonomer containing at least one acid, anhydride or epoxide function; and 0 to 10% by weight, relative to the weight of the composition, of at least one additive. The polyether blocks of copolymer A contain polyethylene glycol blocks. The invention further relates to a process for producing a membrane and to the membrane.

Description

Technical Field

[0001] The present invention relates to a polymer composition and a waterproof breathable film obtained by using the composition. Background Art

[0002] Membranes that are impermeable to liquid water and permeable to water vapor are used in various fields such as textiles, construction, agriculture, packaging, etc. For example, these films can be used as packaging to cover articles or as coatings adhered to the surface of articles.

[0003] In general, breathable films must meet certain requirements, such as uniform appearance, wind resistance, high permeability to water vapor, a certain elasticity, and the ability to adhere to different substrates. In addition, these films must be easy to process during production (especially by extrusion) without causing deformations in the film. Poor processability is reflected by defects on the film, such as holes or irregular edges.

[0004] It is known practice to form such films using compositions comprising polyamide blocks and polyether blocks. However, despite the high permeability to water vapor, the films formed are rarely stretchable, which causes problems when they are manufactured by extrusion, especially by extrusion coating.

[0005] Furthermore, the use of terpolymer compositions, in particular terpolymers derived from olefinic, acrylic and butylene monomers, makes it possible to obtain films that can be easily processed by extrusion. However, these films have very low air permeability.

[0006] US 2004 / 0 029 467 relates to a breathable film comprising at least one polymer (a) selected from ethylene / alkyl (meth)acrylate copolymers (a1), optionally neutralized ethylene / (meth)acrylic acid copolymers (a2), ethylene / vinyl monomer copolymers (a3), mixtures (a1) / (a2), mixtures (a1) / (a3), mixtures (a2) / (a3) and mixtures (a1) / (a2) / (a3), and / or the breathable film comprises at least one functionalized polyethylene (b); and at least one copolymer (c) comprising copolyamide blocks or polyester blocks and polyether blocks.

[0007] US 5 614 588 relates to a polymer blend comprising: a polyether block amide consisting of 30% to 60% by weight of polyamide-12, polyamide-11 and / or polyamide-12,12 blocks and 70% to 40% by weight of polyethylene glycol blocks; a polyether block amide consisting of 65% to 85% by weight of polyamide-12, polyamide-11 and / or polyamide-12,12 blocks and 35% to 15% by weight of polyethylene glycol blocks; and a poly(ethylene-co-vinyl acetate-g-maleic anhydride) polymer consisting of 75% to 95% by weight of ethylene, 5% to 25% by weight of vinyl acetate and 0.1% to 2% by weight of maleic anhydride. The compositions of the document are used for producing membranes permeable to water vapor.

[0008] US Pat. No. 5,506,024 relates to membranes permeable to water vapor which are produced from thermoplastic elastomers based on polyetheresteramides (and preferably on polyether block amides).

[0009] US Pat. No. 5,800,928 relates to membranes which are permeable to water vapor and which comprise at least one thermoplastic elastomer comprising polyether blocks and at least one copolymer comprising ethylene and at least one alkyl (meth)acrylate.

[0010] There is a need to provide compositions which allow the manufacture of films having good permeability to water vapour and good processability during the manufacture of the films. Summary of the invention

[0011] The present invention firstly relates to a composition consisting of:

[0012] - 75% to 98% by weight, relative to the weight of the composition, of at least one copolymer A containing polyamide blocks and polyether blocks;

[0013] - 2% to 15% by weight, relative to the weight of the composition, of at least one copolymer B comprising units derived from ethylene, an alkyl (meth)acrylate and a comonomer comprising at least one acid, anhydride or epoxide function; and

[0014] - 0 to 10% by weight of at least one additive, relative to the weight of the composition,

[0015] The polyether block of copolymer A comprises a polyethylene glycol block.

[0016] According to certain embodiments, the polyamide blocks of copolymer A are blocks of polyamide 11, or polyamide 12, or polyamide 6, or polyamide 10.10, or polyamide 10.12, or polyamide 6.10, and combinations thereof.

[0017] According to certain embodiments, the alkyl (meth)acrylate includes an alkyl group containing 1 to 24 carbon atoms, and preferably 1 to 5 carbon atoms.

[0018] According to certain embodiments, the alkyl (meth)acrylate is selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, and combinations thereof.

[0019] According to certain embodiments, the molar content of units derived from alkyl (meth)acrylate in copolymer B is from 5% to 35%.

[0020] According to certain embodiments, the molar content of the comonomer comprising at least one acid, anhydride or epoxide functional group in copolymer B is between 0.1% and 15%.

[0021] According to certain embodiments, the comonomer comprising at least one acid, anhydride or epoxide functional group is chosen from unsaturated carboxylic acid anhydrides, and preferably is maleic anhydride.

[0022] According to certain embodiments, the comonomer comprising at least one acid, anhydride or epoxide functional group has an unsaturated epoxide functional group and is preferably glycidyl methacrylate.

[0023] According to certain embodiments, copolymer B does not contain units derived from vinyl acetate.

[0024] According to certain embodiments, the additive is selected from inert dyes such as titanium dioxide, fillers, surfactants, crosslinkers, nucleating agents, reactive compounds, mineral or organic flame retardants, ultraviolet (UV) or infrared (IR) light absorbers, UV or IR fluorescent agents, and combinations thereof.

[0025] The present invention also relates to a process for producing a film using the composition described above.

[0026] The film according to the invention can be prepared by any process making it possible to obtain an intimate or homogeneous mixture, such as melt blending, extrusion, pressing or roll milling, containing the copolymer A and copolymer B according to the invention, and optionally one or more additives.

[0027] According to one embodiment, a step of dry-blending copolymer A and copolymer B in pellet form ("dry-blend") is applied.

[0028] The customary mixing and kneading apparatus of the thermoplastics industry are advantageously used, such as extruders, twin-screw extruders, in particular self-cleaning gear co-rotating twin-screw extruders, and kneaders, for example Buss co-kneaders or internal mixers.

[0029] According to a preferred embodiment, the process for manufacturing the film is an extrusion process. According to certain embodiments, the extrusion is carried out at a temperature ranging from 100 to 300°C, and preferably from 150 to 250°C.

[0030] The process generally comprises a step of drawing the composition. The drawing step can be carried out by extrusion blow molding.

[0031] According to one embodiment, the drawing step is performed by extrusion coating.

[0032] According to one embodiment, the drawing step is performed by flat extrusion.

[0033] The invention also relates to a membrane obtained by the process described above.

[0034] The present invention makes it possible to overcome the drawbacks of the prior art. More particularly, it provides a composition allowing the manufacture of films having both good permeability to water vapour and good processability during the manufacture of the film.

[0035] This is achieved by a composition consisting of at least one copolymer A containing polyamide blocks and polyether blocks, and at least one copolymer B comprising units derived from at least three comonomers: a first ethylene comonomer, a second (meth)acrylate comonomer, and a third comonomer comprising at least one reactive functional group in the form of an acid, anhydride or epoxide group; and optionally one or more additives. More particularly, this composition consisting of 75% to 98% by weight of copolymer A, 2% to 15% by weight of copolymer B and 0 to 10% by weight of at least one additive makes it possible to obtain films having good permeability to water vapor and very good processability, especially by extrusion, and in particular by hot extrusion. DETAILED DESCRIPTION

[0036] The invention is now described in more detail in a non-limiting manner in the following description.

[0037] Composition

[0038] The composition according to the invention consists of:

[0039] - at least one copolymer A comprising polyamide blocks and polyether blocks;

[0040] at least one copolymer B comprising units derived from at least three comonomers: a first ethylene comonomer, a second alkyl (meth)acrylate comonomer and a third comonomer comprising at least one reactive functional group in the form of an acid, anhydride or epoxide group; and

[0041] - optionally at least one additive.

[0042] As regards the copolymers A containing polyamide blocks and polyether blocks (abbreviated to "PEBA"), these are obtained by polycondensation of polyamide blocks with reactive ends and polyether blocks with reactive ends, such as, inter alia:

[0043] 1) polyamide blocks with diamine chain ends and polyoxyalkylene blocks with dicarboxylic acid chain ends;

[0044] 2) polyamide blocks with dicarboxylic acid chain ends and polyoxyalkylene blocks with diamine chain ends, which are obtained, for example, by cyanoethylation and hydrogenation of α,ω-dihydroxylated aliphatic polyoxyalkylene blocks (known as polyether diols);

[0045] 3) Polyamide blocks with dicarboxylic acid chain ends with polyether diols, the products obtained in this particular case being polyetheresteramides.

[0046] Polyamide blocks with dicarboxylic acid chain ends originate, for example, from the condensation of polyamide precursors in the presence of chain-limiting dicarboxylic acids. Polyamide blocks with diamine chain ends originate, for example, from the condensation of polyamide precursors in the presence of chain-limiting diamines.

[0047] The polymers with polyamide blocks and polyether blocks may also contain randomly distributed units.

[0048] Three types of polyamide blocks can advantageously be used.

[0049] According to a first type, the polyamide blocks are derived from the condensation of dicarboxylic acids, in particular those containing 4 to 20 carbon atoms, preferably those containing 6 to 18 carbon atoms, and aliphatic or aromatic diamines, in particular those containing 2 to 20 carbon atoms, preferably those containing 6 to 14 carbon atoms.

[0050] As examples of dicarboxylic acids, mention may be made of 1,4-cyclohexanedicarboxylic acid, butane dicarboxylic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, terephthalic acid and isophthalic acid, and also dimer fatty acids.

[0051] As examples of diamines, mention may be made of tetramethylenediamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM) and isomers of 2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), and p-aminodicyclohexylmethane (PACM), and isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN) and piperazine (Pip).

[0052] Advantageously, PA 4.12, PA 4.14, PA 4.18, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA 9.12, PA 10.10, PA 10.12, PA 10.14 and PA 10.18 blocks are used. In the notation PA XY, by convention X represents the number of carbon atoms derived from the diamine residue and Y represents the number of carbon atoms derived from the diacid residue.

[0053] According to a second type, the polyamide blocks are obtained from the condensation of one or more α,ω-aminocarboxylic acids containing 6 to 12 carbon atoms and / or one or more lactams in the presence of dicarboxylic acids or diamines containing 4 to 12 carbon atoms. As examples of lactams, mention may be made of caprolactam, enantholactam and laurolactam. As examples of α,ω-aminocarboxylic acids, mention may be made of aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid.

[0054] Advantageously, the second type of polyamide blocks is made from polyamide 11, polyamide 12 or polyamide 6. In the notation PAX, X represents the number of carbon atoms derived from the amino acid residue.

[0055] According to a third type, the polyamide blocks are obtained from the condensation of at least one α,ω-aminocarboxylic acid (or lactam), at least one diamine and at least one dicarboxylic acid.

[0056] In this case, the polyamide PA blocks are prepared by the polycondensation of:

[0057] - linear aliphatic or aromatic diamine(s) containing X carbon atoms;

[0058] - dicarboxylic acid(s) containing Y carbon atoms; and

[0059] - comonomer(s) {Z} selected from an equimolar mixture of lactams and α,ω-aminocarboxylic acids containing Z carbon atoms and at least one diamine containing X1 carbon atoms and at least one dicarboxylic acid containing Y1 carbon atoms, (X1,Y1) being different from (X,Y),

[0060] - said comonomer(s) {Z} are introduced in a weight proportion ranging up to 50%, preferably up to 20%, even more advantageously up to 10%, relative to the total amount of polyamide precursor monomers;

[0061] The polycondensation is carried out in the presence of a chain limiter chosen from: dicarboxylic acids; advantageously, a dicarboxylic acid containing Y carbon atoms is used as chain limiter, which is introduced in a stoichiometric excess relative to the diamine(s).

[0062] According to one variant of this third type, the polyamide blocks are obtained from the condensation of at least two α,ω-aminocarboxylic acids or at least two lactams containing 6 to 12 carbon atoms, or the condensation of a lactam and an aminocarboxylic acid not having the same number of carbon atoms, in the presence of an optional chain limiter. As examples of aliphatic α,ω-aminocarboxylic acids, mention may be made of: aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid. As examples of lactams, mention may be made of caprolactam, enantholactam and laurolactam. As examples of aliphatic diamines, mention may be made of hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine. As examples of cycloaliphatic diacids, mention may be made of 1,4-cyclohexanedicarboxylic acid. As examples of aliphatic diacids, mention may be made of butane diacid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, dimerized fatty acids (these dimerized fatty acids preferably have a dimer content of at least 98%; they are preferably hydrogenated; they are sold under the brand name Pripol by the company Unichema or under the brand name Empol by the company Henkel) and α,ω-diacid polyoxyalkylenes. As examples of aromatic diacids, mention may be made of terephthalic acid (T) and isophthalic acid (I). As examples of alicyclic diamines, mention may be made of bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM) and isomers of 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), and para-aminodicyclohexylmethane (PACM). Other diamines commonly used may be isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN) and piperazine.

[0063] As examples of polyamide blocks of the third type, the following may be mentioned:

[0064] PA 6.6 / 6, wherein 6.6 represents hexamethylenediamine units condensed with adipic acid and 6 represents condensed units resulting in caprolactam;

[0065] PA 6.6 / 6.10 / 11 / 12, wherein 6.6 represents hexamethylenediamine condensed with adipic acid; 6.10 represents hexamethylenediamine condensed with sebacic acid; 11 represents units resulting from the condensation of aminoundecanoic acid; and 12 represents units resulting from the condensation of laurolactam.

[0066] The notations PA X / Y, PA X / Y / Z etc. relate to copolyamides, wherein X, Y, Z etc. represent homopolyamide units as described above.

[0067] Advantageously, the at least one polyamide block of the copolymer(s) used in the composition of the invention comprises at least one of the following polyamide monomers: 6, 11, 12, 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; and are preferably selected from the following polyamide monomers: 6, 11, 12, 6.10, 10.10, 10.12, and mixtures or copolymers thereof.

[0068] Preferably, the polyamide block comprises at least 30% by weight, preferably at least 50% by weight, preferably at least 75% by weight, preferably 100% by weight, of PA 6, PA 11 or PA 12, relative to the total weight of the polyamide block.

[0069] The polyether blocks may constitute from 50% to 80% by weight of the copolymer with polyamide and polyether blocks.

[0070] The polyether blocks may in particular be blocks derived from PEG (polyethylene glycol), i.e. blocks formed from ethylene oxide units, and / or blocks derived from PPG (propylene glycol), i.e. blocks formed from propylene oxide units, and / or blocks derived from PO3G (polytrimethylene glycol), i.e. blocks formed from polytrimethylene glycol ether units. The polyether blocks may also comprise blocks derived from PTMG, i.e. blocks formed from tetramethylene glycol units, also known as polytetramethylene glycol. The PEBA copolymers may comprise several types of polyethers in their chain, the copolyethers being either block or statistical.

[0071] In the context of the present invention, the PEBA copolymer comprises PEG blocks, optionally in combination with PPG blocks, PO3G blocks, and / or PTMG blocks.

[0072] Thus, according to certain embodiments, the PEBA copolymer comprises PEG blocks. These blocks may be present in the PEBA copolymer in a content of 40% to 80% by weight, preferably 40% to 75% by weight, and even more preferably 40% to 60% by weight, relative to the weight of the copolymer. For example, the content may be 40% to 45% by weight; or 45% to 50% by weight; or 50% to 55% by weight; or 55% to 60% by weight; or 60% to 65% by weight; or 65% to 70% by weight; or 70% to 75% by weight; or 75% to 80% by weight, relative to the weight of the copolymer.

[0073] Preferably, the polyether block comprises at least 30% by weight, preferably at least 50% by weight, preferably at least 75% by weight, preferably 100% by weight, of PEG blocks, relative to the total weight of the polyether block.

[0074] According to one embodiment, the PEBA copolymer of the composition may also comprise at least one polyether different from PEG, chosen from PTMG, PPG, PO3G, and mixtures thereof.

[0075] It is also possible to use blocks obtained by oxyethylation of bisphenols, for example bisphenol A. The latter products are described in patent EP613919.

[0076] The polyether blocks may also consist of ethoxylated primary amines. As examples of ethoxylated primary amines, mention may be made of products of the formula:

[0077] [Chemical formula 1]

[0078]

[0079] wherein m and n are between 1 and 20 and x is between 8 and 18. These products are available from Arkema under the brand name Commercially available from Clariant under the brand name Commercially available.

[0080] The flexible polyether blocks may comprise polyoxyalkylene blocks with NH2 chain ends, such blocks being obtainable by cyanoacetylation of α,ω-dihydroxylated aliphatic polyoxyalkylene blocks (known as polyether diols). More particularly, Jeffamine products (e.g. D400, D2000, ED 2003, XTJ 542, which are commercial products of Huntsman Company and are also described in patents JP2004346274, JP2004352794 and EP1482011).

[0081] The polyetherdiol blocks are used in unmodified form and co-polycondensed with polyamide blocks bearing carboxylic acid end groups, or they are aminated to be converted into polyetherdiamines and condensed with polyamide blocks bearing carboxylic acid end groups. The general process for preparing PEBA copolymers containing ester bonds between PA blocks and PE blocks in two steps is known and is described, for example, in French patent FR 2846332. The general process for preparing the PEBA copolymers of the invention containing amide bonds between PA blocks and PE blocks is known and is described, for example, in European patent EP 1 482 011. The polyether blocks can also be mixed with polyamide precursors and chain-limiting diacids to prepare polymers containing polyamide blocks and polyether blocks with randomly distributed units (one-step process).

[0082] It goes without saying that the name PEBA in this description of the invention relates not only to the Products by For sale Products and sold by EMS products, but also involves the type PEBA product or any other PEBA from other suppliers.

[0083] Advantageously, the PEBA copolymer may contain polyamide blocks, such as PA 6, such as PA 11, such as PA 12, PA 6.10, PA 6.12, such as PA 6.6 / 6, such as PA 10.10 and / or such as PA 6.14, preferably PA 11 and / or PA 12 blocks; and polyether blocks, such as PEG.

[0084] Particularly preferred PEBA copolymers in the context of the present invention are copolymers comprising blocks from:

[0085] -PA11 and blocks derived from PEG;

[0086] -PA12 and blocks derived from PEG;

[0087] -PA6.10 and blocks derived from PEG;

[0088] -PA10.10 and blocks derived from PEG;

[0089] -PA10.12 and blocks derived from PEG;

[0090] -PA6.12 and blocks derived from PEG;

[0091] -PA6 and blocks derived from PEG.

[0092] If the block copolymers described above generally contain at least one polyamide block and at least one polyether block, the invention also covers all copolymers comprising two, three, four (or even more) different blocks, said blocks being selected from those described in this description, provided that these blocks comprise at least polyamide and polyether blocks.

[0093] Advantageously, the copolymer alloy according to the invention comprises a block segmented copolymer comprising three different types of blocks (referred to as "triblocks" in this specification of the invention) resulting from the condensation of several of the above described blocks. The triblocks are preferably selected from copolyetheresteramides, copolyetheramideurethanes, wherein:

[0094] - The mass percentage of polyamide blocks is greater than 10%;

[0095] -The mass percentage of PEG block is greater than 50%;

[0096] Relative to the total mass of the triblock.

[0097] The number-average molar mass of the polyamide blocks in the PEBA copolymer is preferably from 400 to 20 000 g / mol, more preferentially from 500 to 10 000 g / mol and even more preferentially from 200 to 2000 g / mol. In certain embodiments, the number average molar mass of the polyamide block in the PEBA copolymer is from 400 to 1000 g / mol, or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 5000 g / mol, or from 5000 to 6000 g / mol, or from 6000 to 7000 g / mol, or from 7000 to 8000 g / mol, or from 8000 to 9000 g / mol, or from 9000 to 10 000 g / mol, or from 10 000 to 11 000 g / mol, or from 11 000 to 12 000 g / mol, or from 12 000 to 13 000 g / mol, or 13 000 to 14 000 g / mol, or 14 000 to 15 000 g / mol, or 15 000 to 16 000 g / mol, or 16 000 to 17 000 g / mol, or 17 000 to 18 000 g / mol, or 18 000 to 19 000 g / mol, or 19 000 to 20 000 g / mol.

[0098] The number average molar mass of the polyether block is preferably 100 to 6000 g / mol, more preferably 200 to 3000 g / mol. In certain embodiments, the number average molar mass of the polyether block is 100 to 200 g / mol, or 200 to 500 g / mol, or 500 to 800 g / mol, or 800 to 1000 g / mol, or 1000 to 1500 g / mol, or 1500 to 2000 g / mol, or 2000 to 2500 g / mol, or 2500 to 3000 g / mol, or 3000 to 3500 g / mol, or 3500 to 4000 g / mol, or 4000 to 4500 g / mol, or 4500 to 5000 g / mol, or 5000 to 5500 g / mol, or 5500 to 6000 g / mol.

[0099] The number-average molar mass is set by the content of chain limiters. It can be calculated according to the following equation:

[0100] M n =n 单体 ×MW 重复单元 / n 链限制剂 +MW 链限制剂

[0101] In this formula, n 单体 represents the number of moles of monomer, n 链限制剂 represents the number of moles of excess limiting agent (e.g. diacid), MW 重复单元 represents the molar mass of the repeating unit, and MW 链限制剂 represents the molar mass of the limiting agent (eg diacid) in excess.

[0102] The number average molar masses of the polyamide blocks and the polyether blocks can be measured by gel permeation chromatography (GPC) before copolymerization of the blocks.

[0103] The mass ratio of the polyamide blocks relative to the polyether blocks of the PEBA copolymer may especially be between 0.1 and 20. This mass ratio can be calculated by dividing the number average molar mass of the polyamide blocks by the number average molar mass of the polyether blocks.

[0104] Thus, the mass ratio of the polyamide blocks relative to the polyether blocks of the PEBA copolymer may be from 0.1 to 0.2; or from 0.2 to 0.3; or from 0.3 to 0.4; or from 0.4 to 0.5; or from 0.5 to 1; or from 1 to 2; or from 2 to 3; or from 3 to 4; or from 4 to 5; or from 5 to 7; or from 7 to 10; or from 10 to 13; or from 13 to 16; or from 16 to 19; or from 19 to 20.

[0105] A range of 2 to 19 and more particularly 4 to 10 is particularly preferred.

[0106] The PEBA copolymer is present in the composition in an amount ranging from 75% to 98% by weight and preferably from 75% to 95% by weight, relative to the weight of the composition. For example, the PEBA copolymer may be present in the composition in an amount ranging from 75% to 78% by weight; or from 78% to 80% by weight; or from 80% to 82% by weight; or from 82% to 84% by weight; or from 84% to 86% by weight; or from 86% to 88% by weight; or from 88% to 90% by weight; or from 90% to 92% by weight; or from 92% to 94% by weight; or from 94% to 96% by weight; or from 96% to 98% by weight, relative to the weight of the composition.

[0107] As for the copolymer B comprising units derived from at least three comonomers, it is present in an amount of 2 to 15% by weight, and preferably 5 to 15% by weight, relative to the weight of the composition. For example, this copolymer B may be present in the composition in an amount of 2 to 3% by weight; or 3 to 4% by weight; or 4 to 5% by weight; or 5 to 6% by weight; or 6 to 7% by weight; or 7 to 8% by weight; or 8 to 9% by weight; or 9 to 10% by weight; or 10 to 11% by weight; or 11 to 12% by weight; or 12 to 13% by weight; or 13 to 14% by weight; or 14 to 15% by weight, relative to the weight of the composition.

[0108] The first comonomer for making this copolymer B is ethylene. The units derived from ethylene may have a molar content in copolymer B of 50% to 94.9%, and preferably 58% to 79%. This molar content may especially be 50% to 55%; or 55% to 60%; or 60% to 65%; or 65% to 70%; or 70% to 75%; or 75% to 80%; or 80% to 85%; or 85% to 90%; or 90% to 94.9%.

[0109] The second comonomer for making this copolymer B is an alkyl (meth)acrylate. The term "alkyl (meth)acrylate" refers to alkyl acrylates and alkyl methacrylates. Preferably, the alkyl group of the alkyl (meth)acrylate contains 1 to 24 carbon atoms and preferably 1 to 5 carbon atoms. For example, it may contain 1 to 2; or 2 to 4; or 4 to 6; or 6 to 8; or 8 to 10; or 10 to 12; or 12 to 14; or 14 to 16; or 16 to 18; or 18 to 20; or 20 to 22; or 22 to 24 carbon atoms.

[0110] According to certain preferred embodiments, the second comonomer is selected from methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and combinations thereof. Preferably, the second comonomer is selected from methyl (meth)acrylate, ethyl (meth)acrylate and butyl (meth)acrylate.

[0111] According to certain embodiments, only one second alkyl (meth)acrylate comonomer is used to make copolymer B.

[0112] According to other embodiments, copolymer B can be made from more than one second alkyl (meth)acrylate comonomer (e.g., two or three second comonomers). For example, copolymer B can be made from ethyl (meth)acrylate and / or methyl (meth)acrylate and / or butyl (meth)acrylate.

[0113] The units derived from the second comonomer(s) may have a molar content in copolymer B of 5% to 35%, and preferably 20% to 30%. This molar content may especially be 5% to 10%; or 10% to 15%; or 15% to 20%; or 20% to 25%; or 25% to 30%; or 30% to 35%.

[0114] The third comonomer includes at least one reactive functional group in the form of an acid, anhydride or epoxide group.

[0115] According to certain embodiments, the third comonomer is selected from unsaturated carboxylic acids or carboxylic anhydride derivatives thereof, and preferably selected from unsaturated dicarboxylic acids or dicarboxylic anhydride derivatives thereof.

[0116] Examples of unsaturated dicarboxylic anhydrides are, inter alia, maleic anhydride, itaconic anhydride, citraconic anhydride, and tetrahydrophthalic anhydride. Maleic anhydride is preferably used.

[0117] Unsaturated mono- or dicarboxylic acid monomers such as (meth)acrylic acid may also be used.

[0118] Alternatively, the third comonomer may contain an unsaturated epoxide-type functional group.

[0119] Notable examples include:

[0120] - aliphatic glycidyl esters and ethers, such as allyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and glycidyl itaconate, glycidyl methacrylate (GMA) and glycidyl acrylate; and

[0121] - Cycloaliphatic glycidyl esters and ethers, such as glycidyl 2-cyclohex-1-ene ether, 4,5-cyclohexenecarboxylic acid diglycidyl ester, 4-cyclohexenecarboxylic acid glycidyl ester, 5-norbornene-2-methyl-2-carboxylic acid glycidyl ester and endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid diglycidyl ester.

[0122] The units derived from the third comonomer may be present in the copolymer B in a molar content of 0.1% to 15%, and preferably 1% to 12%. This molar content may especially be 0.1% to 1%; or 1% to 3%; or 3% to 5%; or 5% to 7%; or 7% to 9%; or 9% to 11%; or 11% to 13%; or 13% to 15%.

[0123] According to certain embodiments, only one third alkyl (meth)acrylate comonomer is used to make copolymer B.

[0124] According to other embodiments, copolymer B may comprise units derived from more than one third comonomer, for example two or three third comonomers. For example, the composition according to the invention may comprise units from maleic anhydride and glycidyl methacrylate.

[0125] In this case, the content of the units derived from the third comonomer is provided relative to the total amount of the various third comonomers.

[0126] Preferably, copolymer B does not comprise any units derived from comonomers other than the first, second and third comonomers described above.

[0127] Preferably, copolymer B is a terpolymer, ie it comprises units derived from only three comonomers.

[0128] Examples of preferred copolymers B are: terpolymers derived from ethylene, methyl acrylate and maleic anhydride; terpolymers derived from ethylene, ethyl acrylate and maleic anhydride; terpolymers derived from ethylene, butyl acrylate and maleic anhydride; terpolymers derived from ethylene, methyl acrylate and glycidyl methacrylate; terpolymers derived from ethylene, ethyl acrylate and glycidyl methacrylate; terpolymers derived from ethylene, butyl acrylate and glycidyl methacrylate.

[0129] Copolymer B is preferably produced by copolymerization of various comonomers, especially high pressure free radical type copolymerization. For example, the second and third comonomers can be copolymerized directly with ethylene, especially by high pressure free radical polymerization.

[0130] According to certain preferred embodiments, the composition according to the invention, and more particularly the copolymer B, does not contain units derived from vinyl acetate. The reason for this is that said monomer may have toxic properties. Furthermore, it is not suitable for hot extrusion, which makes it difficult or even impossible to form a film from a composition comprising units derived from this monomer.

[0131] Regarding additives, they are optionally present in the following weight content: 0 to 10% and preferably 0 to 5%. For example, one or more additives can be present in the following weight content: 0 to 0.5%; or 0.5% to 1%; or 1% to 2%; or 2% to 3%; or 3% to 4%; or 4% to 5%; or 5% to 6%; or 6% to 7%; or 7% to 8%; or 8% to 9%; or 9% to 10%.

[0132] These additives may include, for example, inert dyes such as titanium dioxide, fillers, surfactants, crosslinking agents, nucleating agents, reactive compounds, mineral or organic flame retardants, ultraviolet (UV) or infrared (IR) light absorbers, and UV or IR fluorescent agents. Typical fillers include talc, calcium carbonate, clay, silica, mica, wollastonite, feldspar, aluminum silicate, alumina, hydrated alumina, glass microspheres, ceramic microspheres, thermoplastic microspheres, barite, and wood flour.

[0133] These additives make it possible to modify one or more physical properties of the composition.

[0134] membrane

[0135] The invention also relates to films obtained using the composition described above.

[0136] This film can preferably be produced by extrusion. Preferably, the extrusion is carried out thermally at a temperature in the range of 100 to 300°C, preferably 150 to 300°C, for example 180 to 280°C.

[0137] According to certain embodiments, the film is manufactured by extrusion coating the composition according to the invention on a substrate. In this case, the extrusion temperature may be, for example, 250 to 300° C. The substrate may be selected from aluminum, paper, board, cellophane, films based on polyethylene, polypropylene, polyamide, polyester, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC) or polyacrylonitrile (PAN) resins, which are optionally oriented, optionally metallized, optionally treated by physical or chemical means, and films coated with a thin inorganic barrier layer, such as polyester (PET SiOx or AlOx) and woven or nonwoven fabrics. When the film is not a woven or nonwoven fabric, it is preferably perforated, especially microperforated.

[0138] According to other embodiments, the film can be produced by flat film extrusion ("extrusion casting") of the composition according to the invention. In this case, the extrusion temperature can be, for example, from 180 to 230°C.

[0139] The membrane according to the present invention is a waterproof breathable membrane. The term "waterproof breathable" means permeable to water vapor and impermeable to liquid water.

[0140] The film according to the present invention may have a thickness of 2 to 100 μm, preferably 2 to 50 μm, or more preferably 10 to 50 μm.

[0141] According to one embodiment, the waterproof breathable membrane has a thickness of less than or equal to 50 mm, preferably less than or equal to 40 mm, 30 mm, or 25 mm, preferably between 5 and 25 mm.

[0142] The thicknesses described above provide good properties in terms of permeability to water vapor.

[0143] Preferably, the film according to the invention has a relative humidity of at least 700 g / m2 at 23° C. and 50% relative humidity for a film thickness of 30 μm. 2 / 24 hours permeability to water vapor (MVTR, stands for "moisture vapor transmission rate"). More preferably, for a film thickness of 30 μm at 23° C. and at a relative humidity of 50%, the film has a permeability to water vapor of at least 800 g / m 2 In particular, for a film thickness of 30 μm at 23°C and at a relative humidity of 50%, the MVTR film layer permeability may range from 700 to 800 g / m 2 / 24h, or 800 to 900g / m 2 / 24h, or 900 to 1000g / m 2 / 24h, or 1000 to 1200g / m 2 / 24h, or 1200 to 1500g / m 2 / 24h, or 1500 to 2000g / m 2 / 24h, or 2000 to 2500g / m 2 / 24h, or 2500 to 3000g / m 2 / 24h, or 3000 to 3500g / m 2 / 24h, or 3500 to 4000g / m 2 / 24h, or 4000 to 4500g / m 2 / 24h, or 4500 to 5000g / m 2 / 24h. The permeability of a film to water vapor (MVTR) can be measured according to standard ASTM E96 B at 23°C, for a relative humidity of 50%, for a film thickness of 30 μm.

[0144] The invention also relates to the use of the membranes described in the invention in the medical, hygiene, luggage, manufacturing, clothing, home or household appliances, furnishings, blankets, motor vehicles, industry, especially industrial filtration, agriculture and / or construction sectors.

[0145] The present invention also relates to a laminated product (hereinafter referred to as a laminate) comprising at least one material and at least one waterproof breathable membrane according to the present invention, wherein the material can be selected, for example, from textiles, building materials, packaging or coatings.

[0146] According to a particular embodiment, the material is a textile material, the film being adhered to at least one surface of the textile material, wherein the peel force is in the range of 0.5 to 50 N, preferably 0.5 to 10 N.

[0147] Advantageously, the film according to the invention is applied to the textile material in particular by any known process, preferably without using any adhesive between the film and the textile.

[0148] Examples that may be mentioned include extrusion coating of a film of the composition onto a textile, or heat pressing (thermal lamination or lamination bonding) the film onto a textile or between two textiles at a temperature sufficient for the film to impregnate and entangle the textile fibers.

[0149] According to an alternative embodiment or an embodiment in combination with the preceding embodiment(s), mention may be made of joining using an adhesive sealant, preferably an aqueous adhesive sealant, ie the adhesive sealant composition comprises less than 5% by weight of solvents.

[0150] Preferably, the film has a thickness of between 5 and 50 mm, and preferably between about 5 and 10 mm. Advantageously, in an extrusion-coating application, 10 to 50 g / m2 of the thermoplastic film is applied to the textile.

[0151] In this description of the invention, the following definitions apply:

[0152] - the term "textile material" or "textile" means any material made of fibers or filaments, and also any material forming a porous membrane layer characterized by a length / thickness ratio of at least 300, including paper and cardboard;

[0153] - the term "fiber" means any synthetic or natural material characterized by a length / diameter ratio of at least 300;

[0154] - The term "filament" means any fiber of unlimited length.

[0155] In textiles, in particular, fiber lay-ups (dressings, filters, felts), rovings (dressings), yarns (for stitching, knitting or weaving), woven fabrics (linear, circular, fully formed), fabrics (conventional, jacquard, multiple, double-sided, multiaxial, 2.5D, 3D) and many others.

[0156] According to a preferred embodiment of the present invention, the at least one textile material is in the form of a porous membrane layer, a woven textile or a nonwoven textile.

[0157] Advantageously, the at least one textile material comprises synthetic fibers, in particular synthetic fibers obtained from bio-based raw materials, natural fibers, artificial fibers produced from natural raw materials, mineral fibers and / or metal fibers.

[0158] Advantageously, the textile comprises synthetic fibers obtained from bio-based raw materials, such as polyamide fibers, in particular polyamide 11. Advantageously, the textile also comprises natural fibers, such as cotton, wool and / or silk, artificial fibers made from natural raw materials, and mineral fibers, such as carbon, glass, silica and / or magnesium fibers.

[0159] The textiles are in particular selected from fabrics or textile surfaces, such as woven, knitted, nonwoven or blanket surfaces. These articles can be, for example, blankets, carpets, upholstery, surface coverings, sofas, curtains, bedding, mattresses and pillows, clothing and medical textile materials.

[0160] The textile according to the invention advantageously constitutes a felt, a filter membrane, a membrane, a gauze, a cloth, a dressing, a layer, a fabric, a woven fabric, an article of clothing, a garment, a bedding article, an article of furnishings, a curtain, a passenger compartment covering, a functional technical textile, a geotextile and / or an agrotextile.

[0161] Example

[0162] The following examples illustrate but do not limit the invention.

[0163] Films were prepared from different compositions (A to G) in the following two ways to evaluate the permeability to water vapor and the stability limit (processability) of the films.

[0164] To assess the permeability to water vapor:

[0165] Films were prepared from various compositions (A to G) by a flat film extrusion process ("extrusion casting") using an extruder with the following parameters:

[0166] -Screw diameter: 30mm;

[0167] -L / D ratio: 25

[0168] - Shape: screw-barrier;

[0169] - Die: T-shaped, 250 μm width and 300 μm air gap.

[0170] The extrusion temperature is between 180°C and 230°C and is adapted to the grade of the copolymer.

[0171] The permeability to water vapor, MVTR, is measured at 23° C. and 50% relative humidity according to standard ASTM E96B.

[0172] The obtained film had a thickness of 50 μm.

[0173] To evaluate processability:

[0174] Films were prepared by extrusion coating various compositions (A to G) on aluminum (37 μm) / polymer support using a Collin extrusion coating line with the following parameters:

[0175] - Air gap: 70mm;

[0176] -Screw speed: 80rpm

[0177] - Die gap: 300 μm.

[0178] The extrusion temperature was 280°C.

[0179] The films had an initial thickness of 50 μm (which decreased with increasing line speed).

[0180] Therefore, in order to evaluate the stability limit of the film, the line speed was gradually increased from 5 m / min until instability was observed. The instability may be the rupture of the film, the formation of one or more holes on the film, or the instability of the film width. These observations were performed three times to confirm the results, and the average value was taken.

[0181] The membrane stability limit corresponds to the speed at or above which instabilities occur.

[0182] In both cases:

[0183] The terpolymers (polymers comprising units derived from at least three comonomers) used were the following:

[0184] [Table 1]

[0185] Terpolymer First monomer Second monomer (molar content) The third monomer (molar content) Terpo1 Ethylene Ethyl acrylate (29%) Maleic anhydride (1.3%) Terpo2 Ethylene Butyl acrylate (25%) Glycidyl methacrylate (8%) Terpo3 Ethylene Butyl acrylate (25%) Glycidyl methacrylate (5%)

[0186] The copolymers used for comparative purposes were the following:

[0187] [Table 2]

[0188] Copolymer First monomer Second monomer (molar content) Copo1 Ethylene Ethyl acrylate (25%) Copo2 Ethylene Butyl acrylate (30%)

[0189] The characteristics of compositions A to G are provided in the following table:

[0190] [Table 3]

[0191]

[0192] [Table 4]

[0193]

[0194] Compositions A to C are according to the invention and D to I correspond to comparative examples (composition D comprises copolymer B according to the invention, but in a higher content than claimed, and composition G comprises only PEBA copolymer).

[0195] The results for the permeability to water vapor and also the stability limit of the films (A to I) obtained with the compositions (A to I) are shown below:

[0196] [Table 5]

[0197] membrane Stability limit (m / min) Permeability to water vapor A(Invention) 35 845 B(Invention) 40 855 C (Invention) 37 850 D(contrast) 50 645 E(Comparison) 25 850 F(Comparison) 25 840 G(Contrast) 15 950 H 20 300 I 40 300

[0198] It was observed that the membranes according to the invention (A to C) have both a high permeability to water vapor and a good processability (stability limit of the membrane).

Claims

1. A composition consisting of: - 75% to 98% by weight, relative to the weight of the composition, of at least one copolymer A containing polyamide blocks and polyether blocks; - 2% to 15% by weight, relative to the weight of the composition, of at least one copolymer B comprising units derived from ethylene, an alkyl (meth)acrylate and a comonomer comprising at least one acid, anhydride or epoxide function; and - 0% to 10% by weight of at least one additive, relative to the weight of the composition, wherein the polyether block of copolymer A comprises a polyethylene glycol block, wherein the alkyl (meth)acrylate comprises an alkyl group containing 1 to 24 carbon atoms, and The molar content of the comonomer comprising at least one acid, anhydride or epoxide functional group in copolymer B is 0.1% to 15%.

2. The composition as claimed in claim 1, wherein the polyamide blocks of copolymer A are blocks of polyamide 11, or polyamide 12, or polyamide 6, or polyamide 10.10, or polyamide 10.12, or polyamide 6.10, and combinations thereof.

3. The composition of any one of claims 1 and 2, wherein the alkyl (meth)acrylate comprises an alkyl group containing 1 to 5 carbon atoms.

4. The composition as claimed in claim 1 or 2, wherein the alkyl (meth)acrylate is selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate and combinations thereof.

5. The composition as claimed in claim 1 or 2, wherein the molar content of units derived from alkyl (meth)acrylate in copolymer B is from 5% to 35%.

6. A composition as claimed in claim 1 or 2, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is selected from unsaturated carboxylic acid anhydrides.

7. A composition as claimed in claim 6, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is maleic anhydride.

8. A composition as claimed in claim 1 or 2, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group has an unsaturated epoxide functional group.

9. A composition as claimed in claim 8, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is glycidyl methacrylate.

10. A composition as claimed in claim 1 or 2, wherein copolymer B contains no units derived from vinyl acetate.

11. The composition of claim 1 or 2, wherein the additive is selected from an inert dye, a filler, a surfactant, a crosslinking agent, a nucleating agent, a reactive compound, or an organic flame retardant, an ultraviolet (UV) or infrared (IR) light absorber, a UV or IR fluorescent agent, and combinations thereof.

12. A composition as claimed in claim 11 wherein the inert dye is titanium dioxide.

13. A composition as claimed in claim 1 or 2, wherein the additive is selected from minerals.

14. Process for producing a film comprising extruding a composition as claimed in one of claims 1 to 13.

15. A process as claimed in claim 14, wherein the extrusion is carried out at a temperature of from 100 to 300°C.

16. The process of any one of claims 14 and 15, wherein the extrusion is extrusion coating or extrusion casting.

17. Film obtainable by a process as claimed in one of claims 14 to 16.

18. Use of a film as claimed in claim 17 in the medical, hygiene, luggage, manufacturing, clothing, home or household equipment, furnishings, blankets, motor vehicles, industry, agriculture and / or construction fields.

19. The use as claimed in claim 18, wherein the industrial field is the industrial filtration field.

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