Thermoplastic polyurethanes and polyamide foams

Abstract

The present invention relates to a polymer foam comprising at least one thermoplastic polyurethane and at least one amine-chain-terminated polyamide, wherein the polyamide is a reaction product of one or more monomers selected from amino acids or aminocarboxylic acids, lactams, and monomers obtained from the reaction between aliphatic diamines and dicarboxylic acids. The present invention also relates to a method for preparing such a foam and an article comprising such a foam.

Description

[Technical Field]

[0001] The present invention relates to a polymer foam comprising a thermoplastic polyurethane and an amine chain-terminated polyamide, and to a method for preparing the same. [Background technology]

[0002] Various polymer foams are used particularly in the field of sports equipment, such as shoe soles or sole components, gloves, rackets or golf balls, and especially in personal protective equipment for sports practice (jackets, helmet linings, shells, etc.).

[0003] Such applications require a set of specific physical properties that ensure resilience, low compression set, and the ability to withstand repeated impacts without deformation and return to their original shape.

[0004] WO2022 / 162048 relates to an expandable particle comprising a first thermoplastic elastomer having a Shore D hardness of 20 to 90 and a second thermoplastic elastomer. The first thermoplastic elastomer is in particular a thermoplastic polyurethane, thermoplastic polyetheramide, thermoplastic copolyester, polyether ester, or polyester ester, and the second thermoplastic elastomer is in particular a thermoplastic polyurethane, thermoplastic polyetheramide, polyether ester, or polyester ester, or a thermoplastic styrene-butadiene copolymer.

[0005] There is a need to provide a polymer foam that has a fine and homogeneous cell structure, low density, good rebound elasticity, and satisfactory flexibility and tear resistance. [Overview of the project]

[0006] The present invention first relates to a polymer foam, wherein, relative to the total weight of the foam, - 10% to 99% by weight, preferably 15% to 89% by weight of at least one thermoplastic polyurethane, - At least one polyamide containing amine chain ends, detected by potentiometric assay in meta-cresol using a 0.02 N perchloric acid solution in a concentration of 1% to 40% by weight, preferably 1% to 30% by weight, and The present invention relates to a polymer foam comprising, wherein the polyamide is a reaction product of one or more monomers selected from amino acids or aminocarboxylic acids, lactams, and monomers obtained from the reaction between aliphatic diamines and dicarboxylic acids.

[0007] In a given embodiment, the foam comprises 60% to 99% by weight of at least one thermoplastic polyurethane and 1% to 40% by weight of at least one amine-chain-terminated polyamide, based on the total weight of the foam.

[0008] In a given embodiment, at least a portion of the total amount of polyamide is covalently bonded to a thermoplastic polyurethane molecule via urea functional groups.

[0009] In a given embodiment, the urea functional group concentration is measured by 13C NMR in DMSO-D6 and is 0.001 meq / g to 0.1 meq / g, more preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g.

[0010] In a given embodiment, the polyamide has an NH2 amine functional group concentration of 0.01 meq / g to 2.0 meq / g, preferably 0.02 meq / g to 1.5 meq / g, more preferably 0.02 to 1 meq / g, and even more preferably 0.02 to 0.4 meq / g, as measured by potentiometric assay in meta-cresol using a 0.02 N perchloric acid solution.

[0011] In a given embodiment, at least one thermoplastic polyurethane is a copolymer comprising a rigid block and a flexible block. - The soft block is selected from a polyether block, a polyester block, a polycarbonate block, and combinations thereof; preferably, the soft block is selected from a polyether block, a polyester block, and combinations thereof, more preferably a polytetrahydrofuran block, a polypropylene glycol block, and / or a polyethylene glycol block; and / or - The hard block contains units derived from 4,4'-diphenylmethane diisocyanate and / or 1,6-hexamethylene diisocyanate, preferably units derived from at least one chain extender selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol.

[0012] In a given embodiment, the amine-terminated polyamide is selected from the group consisting of polyamide 11, polyamide 12, polyamide 10, polyamide 6, polyamide 6.10, polyamide 6.6, polyamide 10.10, polyamide 10.12, polyamide 6.13, polyamide 10.9, polyamide 12.9, and combinations thereof.

[0013] In a given embodiment, the foam also contains at least one polyamide block-polyether block copolymer.

[0014] In a given embodiment, the foam, based on the total weight of the foam, - 10 wt% to 99 wt%, preferably 15 wt% to 89 wt% of at least one thermoplastic polyurethane, - 1 wt% to 40 wt%, preferably 1 wt% to 30 wt% of at least one amine-terminated polyamide, and - 0 to 89 wt%, preferably 10 wt% to 70 wt% of at least one polyamide block-polyether block copolymer and contains.

[0015] In a given embodiment, the polyamide block-polyether block copolymer contains at least 30% by weight, preferably at least 40% by weight, of the polyamide block relative to the total weight of the copolymer, as measured by proton NMR in a TFA / CDCl3(1 / 4v / v) mixture.

[0016] In a given embodiment, the polyamide block of the polyamide block-polyether block copolymer is selected from polyamide 6, polyamide 6.10, polyamide 6.12, polyamide 11, polyamide 10, polyamide 12, polyamide 6.13, polyamide 10.9 and / or polyamide 12.9; and / or the polyether block of the polyamide block-polyether block copolymer is polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran block.

[0017] In a given embodiment, the amine-chain-terminated polyamide has a number-average molar mass of 1,000 to 60,000 g / mol, preferably 2,000 to 40,000 g / mol, and more preferably 3,000 to 20,000 g / mol.

[0018] In a given embodiment, the foam is measured at 23°C in accordance with ISO 1183-1 standard and has a density of 800 kg / m³. 3 Preferably 400 kg / m 3 Below, 300 kg / m² is given higher priority. 3 Below, with even higher priority, is 230 kg / m 3 It has the following density:

[0019] The present invention also involves the following steps: - A step of providing a polymer composition comprising at least one thermoplastic polyurethane, at least one amine chain-terminated polyamide, and, if appropriate, at least one polyamide block-polyether block copolymer; - A step of mixing the polymer composition with a foaming agent; and - A process of foaming a mixture of a polymer composition and a foaming agent. The present invention relates to a method for producing the foam described above, including the above.

[0020] In a given embodiment, a foaming agent is mixed with a molten polymer composition, and the foaming of the mixture is preferentially carried out within the mold.

[0021] In a given embodiment, the blowing agent is a physical blowing agent, which is mixed with a polymer composition in the form of a solid preform, and the foaming of the mixture is preferably carried out in an autoclave.

[0022] The present invention also relates to articles which are formed from or include at least one element made of the aforementioned foam, preferably selected from sports shoe soles, balloons or balls, gloves, personal protective equipment, rail pads, automotive parts, construction parts, and electrical and electronic equipment components.

[0023] The present invention makes it possible to satisfy the needs described above. More specifically, it provides a regular, homogeneous, low-density polymer foam that has improved flexibility and good mechanical properties, in particular good tear resistance and good abrasion resistance, while simultaneously maintaining high rebound elasticity and relatively low compression set.

[0024] This is achieved by using a mixture of thermoplastic polyurethane (TPU) and the amine (NH2) chain-terminated polyamide (PA) described above for the formation of the foam.

[0025] According to a certain advantageous embodiment, a covalent bond is formed between at least a portion of the amine-terminal polyamide and at least a portion of the thermoplastic polyurethane, more specifically, between the amine functional group of the polyamide and the urethane functional group of the thermoplastic polyurethane, or between the isocyanate functional group present in the precursor of the thermoplastic polyurethane. This reaction between at least a portion of the amine-terminal polyamide and at least a portion of the thermoplastic polyurethane improves the compatibility between these polymers. This improves the foamability of the alloy, and thus improves the structure (finer and more homogeneous cell structure, lower density) and properties (in particular, higher rebound elasticity, lower compression set, and higher flexibility) of the foam obtained from these alloys. [Modes for carrying out the invention]

[0026] The present invention will be described in more detail and in a non-limiting manner in the following description. Unless otherwise specified, all percentages are mass percentages. In this specification, the quantities given for a given species may be applied to that species according to all of its definitions (as referred to herein), including more limited definitions.

[0027] The present invention first relates to a foam comprising at least one amine-chain-terminated polyamide and at least one thermoplastic polyurethane.

[0028] The presence of amine chain ends in polyamides can be detected by potentiometric assay according to the following method: the material sample is dissolved in meta-cresol at 80°C, and then the NH2 functional groups of this sample are measured by potentiometric assay using a 0.02 N perchloric acid solution.

[0029] [Amine chain terminal-containing polyamide (PA)] Amine-terminal polyamides may be homopolyamides and / or copolyamides. The term "polyamide" is - Amino acid or aminocarboxylic acid type monomer, preferably containing 6 to 14 carbon atoms, preferably α,ω-aminocarboxylic acid type monomer; - Preferably a lactam-type monomer containing 3 to 18 carbon atoms in the main ring, which may be substituted; - Diamine-diacid type monomers obtained from the reaction between an aliphatic diamine preferably containing 2 to 48 carbon atoms, more preferably 2 to 20 carbon atoms, and a dicarboxylic acid preferably containing 4 to 48 carbon atoms, more preferably 4 to 20 carbon atoms; and - In the case of a mixture of amino acid type monomers and lactam type monomers, a mixture of those monomers with different numbers of carbon atoms. This refers to polymerization products of one or more monomers selected from the following.

[0030] In this specification, the term "monomer" should be understood to mean "repeating unit." In fact, the case where the repeating unit of a polyamide consists of a combination of diacid and diamine is a special case. The monomer is considered to be a combination of diamine and diacid, i.e., a diamine-diacid pair (equomolar amount). This is explained by the fact that, individually, diacid or diamine are merely structural units and are insufficient on their own to polymerize.

[0031] For the purposes of the present invention, the amine-terminal polyamide consists solely of polyamide. In particular, it does not include any other type of block, such as polyether blocks, polyester blocks, polysiloxane blocks, polyolefin blocks, or polycarbonate blocks. More specifically, the amine-terminal polyamide is not a polyamide block-polyether block copolymer. However, the foam according to the present invention may include polyamides containing blocks other than polyamide blocks, whether or not they have amine-terminals, and also includes amine-terminal polyamides consisting solely of polyamide.

[0032] If a polyamide is a homopolyamide, it is a polymerization product of a single monomer. If a polyamide is a copolyamide, it is a polymerization product of at least two different monomers.

[0033] Advantageously, three types of polyamide can be used.

[0034] According to the first type, polyamides are obtained by condensation of dicarboxylic acids, particularly those having 4 to 48 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 6 to 18 carbon atoms, with aliphatic or aromatic diamines, particularly those having 2 to 48 carbon atoms, preferably 2 to 20 carbon atoms, more preferably 5 to 14 carbon atoms.

[0035] Examples of dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid, butanediic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, terephthalic acid, and isophthalic acid, as well as dimerized fatty acids.

[0036] Examples of diamines include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, isomers of bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), para-aminodicyclohexylmethane (PACM), isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine (Pip).

[0037] Advantageously, polyamides PA4.12, PA4.14, PA4.18, PA5.10, PA5.12, PA5.14, PA5.16, PA5.18, PA6.10, PA6.12, PA6.14, PA6.18, PA9.12, PA10.10, PA10.12, PA10.14, and PA10.18 are used. In the PA XY notation, as before, 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.

[0038] According to the second type, polyamides are obtained from the condensation of one or more α,ω-aminocarboxylic acids and / or one or more lactams having 3 to 18 carbon atoms, preferably 6 to 14 carbon atoms, in the presence of a dicarboxylic acid or diamine having 2 to 48 carbon atoms, preferably 4 to 20 carbon atoms. Examples of lactams include caprolactam, enantractam, and lauryllactam. Examples of α,ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0039] Advantageously, the second type of polyamide is PA10 (polydecaneamide), PA11 (polyundecaneamide), PA12 (polydodecaneamide), or PA6 (polycaprolactam). In the notation PA X, X represents the number of carbon atoms derived from an amino acid residue or lactam residue.

[0040] According to the third type, polyamides are obtained by the condensation of at least one α,ω-aminocarboxylic acid (or lactam), at least one diamine, and at least one dicarboxylic acid.

[0041] In this case, polyamide PA is - A linear aliphatic or aromatic diamine containing X carbon atoms; - Dicarboxylic acid containing Y carbon atoms; and - Comonomer {Z} selected from lactams containing Z carbon atoms and α,ω-aminocarboxylic acids and equimolar mixtures of at least one diamine containing X1 carbon atoms and at least one dicarboxylic acid containing Y1 carbon atoms (where (X1,Y1) is different from (X,Y)). It is a polycondensation of, - The comonomer {Z} is introduced in a weight proportion of up to 50%, preferably up to 20%, and more preferably up to 10%, relative to the total amount of the polyamide precursor monomer; - In the presence of a chain limiting agent selected from dicarboxylic acids It is prepared by polycondensation.

[0042] Advantageously, a dicarboxylic acid containing Y carbon atoms is used as a chain limiting agent, which is introduced in excess of the diamine's stoichiometry.

[0043] According to one variation of this third type, polyamides 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 one lactam having a different number of carbon atoms and one aminocarboxylic acid, optionally in the presence of a chain limiting agent. Examples of aliphatic α,ω-aminocarboxylic acids include aminocaproic acid, 7-aminoheptanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of lactams include caprolactam, enantractam, and lauryllactam. Examples of aliphatic diamines include pentamethylenediamine, hexamethylenediamine, dodecamethylenediamine, and trimethylhexamethylenediamine. An example of an alicyclic diacid is 1,4-cyclohexanedicarboxylic acid. Examples of aliphatic diacids include butanediic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, α,ω-diacid polyoxyalkylenes, and dimerized fatty acids. These dimerized fatty acids correspond to the dimerization reaction products of fatty acids (generally containing 18 carbon atoms, often mixtures of oleic acid and / or linoleic acid); they preferably have a dimer content of at least 98%; they are preferably hydrogenated; they are preferably mixtures containing 0-15% by weight of a C18 monoacid, 60-99% by weight of a C36 diacid, and 0.2-35% by weight of a C54 or higher triacid or polyacid; these are products sold, for example, under the brand name Pripol by Croda, Empol by BASF, or Radiacid by Oleon. Examples of aromatic diacids include terephthalic acid (T) and isophthalic acid (I). Examples of alicyclic diamines include isomers of bis(4-aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2,2-bis(3-methyl-4-aminocyclohexyl)propane (BMACP), as well as para-aminodicyclohexylmethane (PACM).Other commonly used diamines may include isophoronediamine (IPDA), 2,6-bis(aminomethyl)norbornane (BAMN), and piperazine.

[0044] Examples of a third type of polyamide include the following: - PA6.6 / 6 (where 6.6 represents the hexamethylenediamine unit condensed with adipic acid, and 6 represents the unit produced by the condensation of caprolactam); - PA6.6 / 6.10 / 11 / 12 (wherein 6.6 represents a hexamethylenediamine unit condensed with adipic acid, 6.10 represents a hexamethylenediamine unit condensed with sebaciic acid, 11 represents a unit produced by the condensation of aminoundecanoic acid, and 12 represents a unit produced by the condensation of lauryl lactam).

[0045] The notations PA X / Y, PA X / Y / Z, etc., relate to copolyamides, where X, Y, Z, etc., represent the homopolyamide units mentioned above.

[0046] Advantageously, the polyamides used in this invention are polyamides PA6, PA10, PA11, PA12, PA5.4, PA5.9, PA5.10, PA5.12, PA5.13, PA5.14, PA5.16, PA5.18, PA5.36, PA6.4, PA6.6, PA6.9, PA6.10, PA6.12, PA6.13, PA6.14, PA6.16, P A6.18, PA6.36, PA10.4, PA10.9, PA10.10, PA10.12, PA10.13, PA10.14, PA10.16, PA10.18, PA10. 36, PA10.T, PA12.4, PA12.9, PA12.10, PA12.12, PA12.13, PA12.14, PA12.16, PA12.18, PA12.36, P A12.T, or mixtures or copolymers thereof; preferably, polyamide blocks PA6, PA10, PA11, PA12, PA6.10, PA6.12, PA6.13, PA10.9, PA10.10, PA10.12, PA12.9, or mixtures or copolymers thereof, more preferably polyamide blocks PA6, PA10, PA11, PA12, PA6.10, PA6.12, PA6.13, PA10.9, PA12.9, or mixtures or copolymers thereof, even more preferably polyamide blocks PA6, PA11, PA12, PA6.12, PA6.13, PA10.9, PA12.9, or mixtures or copolymers thereof.

[0047] Preferably, the amide bonds of the polyamide do not contain tertiary amides (i.e., amides in which the amine is a tertiary amine). More preferably, all of the amide bonds of the polyamide are secondary amides (i.e., the amines in the amide bonds are secondary amines).

[0048] The polyamide containing an amine chain end advantageously has a number average molar mass of 1,000 to 60,000 g / mol, preferably 2,000 to 40,000 g / mol, and very advantageously 3,000 to 20,000 g / mol. In certain embodiments, the polyamide containing an amine chain end can have a number average molar mass of 1,000 to 2,000 g / mol; or 2,000 to 3,000 g / mol; or 3,000 to 5,000 g / mol; or 5,000 to 10,000 g / mol; or 10,000 to 15,000 g / mol; or 15,000 to 20,000 g / mol; or 20,000 to 25,000 g / mol; or 25,000 to 30,000 g / mol; or 30,000 to 35,000 g / mol; or 35,000 to 40,000 g / mol; or 40,000 to 45,000 g / mol; or 45,000 to 50,000 g / mol; or 50,000 to 55,000 g / mol; or 55,000 to 60,000 g / mol.

[0049] The number average molar mass is set by the content of the chain limiter. This can be calculated according to the equation: M n =n モノマー ×MW 反復単位 / n 連鎖制限剤 +MW 連鎖制限剤 can be calculated according to. In this formula, n モノマー represents the number of moles of the monomer, n 連鎖制限剤 represents the excess number of moles of the diacid limiter, MW 反復単位 represents the molar mass of the repeating unit, MW 連鎖制限剤 represents the excess molar mass of the diacid.

[0050] The number average molar mass of the polyamide can be measured by gel permeation chromatography (GPC).

[0051] Preferably, at least 50% by weight of the amine-terminal polyamide (relative to the total weight of the amine-terminal polyamide) has a molar mass of 20,000 g / mol or less; more preferably, 50% to 80% by weight of the amine-terminal polyamide has a molar mass of 20,000 g / mol or less. These amounts of polyamide can be quantified by GPC. These ranges result in a low foam density.

[0052] The amine-terminal polyamide may be monofunctional (i.e., containing a single amine-terminal per PA molecule) or difunctional (i.e., containing two amine-terminals per PA molecule); preferably monofunctional.

[0053] The polyamide preferably has an amine (NH2) functional group concentration of 0.01 meq / g to 2.0 meq / g, preferably 0.04 meq / g to 1.5 meq / g, more preferably 0.1 to 1.5 meq / g, and more preferably 0.35 to 1.5 meq / g. In particular, the amine-chain-terminated polyamide has an amine (NH2) functional group concentration of 0.01 to 0.04 meq / g, or 0.04 to 0.06 meq / g, or 0.06 to 0.08 meq / g, or 0.08 to 0.1 meq / g, or 0.1 to 0.2 meq / g, or 0.2 to 0.3 meq / g, or 0.3 to 0.4 meq / g, or 0.4 to 0.5 meq / g, or 0.5 to 0.6 meq / g, or 0.6 to 0.7 meq / g, or 0.7 to 0.8 meq / g, or 0 The NH2 functional group concentration may be 0.8-0.9 meq / g, or 0.9-1.0 meq / g, or 1.0-1.1 meq / g, or 1.1-1.2 meq / g, or 1.2-1.3 meq / g, or 1.3-1.4 meq / g, or 1.4-1.5 meq / g, or 1.5-1.6 meq / g, or 1.6-1.7 meq / g, or 1.7-1.8 meq / g, or 1.8-1.9 meq / g, or 1.9-2.0 meq / g. The NH2 functional group concentration can be measured by potentiometric assay according to the following method: Dissolve the foam sample in meta-cresol at 80°C, and then analyze the NH2 functional group of this sample by potentiometric assay using a 0.02 N perchloric acid solution.

[0054] The amine-terminal polyamide may have a COOH functional group concentration of 0.002 meq / g to 0.2 meq / g, preferably 0.005 meq / g to 0.1 meq / g, and more preferably 0.01 meq / g to 0.08 meq / g. In particular, polyamides may have COOH functional group concentrations of 0.002-0.005 meq / g, or 0.005-0.01 meq / g, or 0.01-0.02 meq / g, or 0.02-0.03 meq / g, or 0.03-0.04 meq / g, or 0.04-0.05 meq / g, or 0.05-0.06 meq / g, or 0.06-0.07 meq / g, or 0.07-0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.15 meq / g, or 0.15-0.2 meq / g. The COOH functional group concentration can be quantified by potentiometric assay according to the following method: the material sample is dissolved in benzyl alcohol, and the COOH functional groups of this sample are then analyzed by potentiometric assay using a 0.02 N tetrabutylammonium hydroxide solution.

[0055] The above concentrations (of amines and COOH functional groups) correspond to the total concentration of amine-terminal polyamides (i.e., if the foam contains several amine-terminal polyamides, all of these polyamides are taken into consideration).

[0056] Amine-terminal polyamides can be prepared by condensation of polyamide precursors (i.e., the monomers mentioned above). Advantageously, the concentration of amine-terminal groups in the polyamide can be increased by adding chain-limiting diamines. The concentration of amine-terminal groups in the polyamide can be determined by the molar ratio of NH2 amine functional groups to COOH functional groups of all monomers introduced into the reactor during polyamide synthesis.

[0057] The molar ratio of NH2 amine functional groups to COOH functional groups is favorably 0.7–1.3, and preferably 0.85–1.25.

[0058] The amine-terminal polyamide is advantageously semi-crystalline. Preferably, its enthalpy of fusion is greater than 5 J / g. The enthalpy of fusion can be measured by differential scanning calorimetry (DSC) analysis in accordance with ISO 11357-3 standard (plastics - differential scanning calorimetry (DSC) Part 3).

[0059] [Thermoplastic Polyurethane (TPU)] Thermoplastic polyurethane is a copolymer containing rigid and flexible blocks.

[0060] In general, in this specification, the term "hard block" refers to a block having a melting point above 50°C. The presence of a melting point can be quantified by differential scanning calorimetry in accordance with ISO 11357-3 (Plastics - Differential Scanning Calorimetry (DSC) Part 3). The term "soft block" refers to a block having a glass transition temperature (Tg) of 0°C or lower. The glass transition temperature can be quantified by differential scanning calorimetry in accordance with ISO 11357-2 (Plastics - Differential Scanning Calorimetry (DSC) Part 2).

[0061] Thermoplastic polyurethanes are obtained by the reaction of at least one polyisocyanate, at least one isocyanate-reactive compound, more preferably a polyol, containing two isocyanate-reactive functional groups, and a chain extender, optionally in the presence of a catalyst. Rigid blocks of TPU consist of units derived from polyisocyanates and chain extenders, while soft blocks mainly consist of units derived from isocyanate-reactive compounds, preferably polyols, having a molar mass between 0.5 kg / mol and 100 kg / mol.

[0062] Polyisocyanates can be aliphatic, alicyclic, aromatic aliphatic, and / or aromatic. Preferably, the polyisocyanate is aliphatic or aromatic. More advantageously, the polyisocyanate is aliphatic. Preferably, the polyisocyanate is a diisocyanate.

[0063] Advantageously, polyisocyanates include tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene-diisocyanates, 2-methylpentamethylene-1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, 1,5-pentamethylene-diisocyanate, 1,4-butylene-diisocyanate, and 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclo Xane(isophorone-diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-paraphenylene-diisocyanate (PPDI), 2,4-tetramethylenexylene-diisocyanate (TMXDI), 4,4'-, 2,4'- and / or 2,2'-dicyclohexylmethane-diisocyanate (H12 Selected from the group consisting of MDI), 1,4-cyclohexane-diisocyanate, 1-methyl-2,4- and / or 1-methyl-2,6-cyclohexane-diisocyanate, 2,2'-, 2,4'- and / or 4,4'-diphenylmethane-diisocyanate (MDI), 1,5-naphthylene-diisocyanate (NDI), 2,4- and / or 2,6-toluene-diisocyanate (TDI), diphenylmethane-diisocyanate, 3,3'-dimethyldiphenyl-diisocyanate, 1,2-diphenylethane-diisocyanate, phenylene-diisocyanate, methylenebis(4-cyclohexyl isocyanate) (HMDI), and mixtures thereof.

[0064] More preferably, the polyisocyanate is selected from the group consisting of diphenylmethane-diisocyanate (MDI), toluene-diisocyanate (TDI), pentamethylene-diisocyanate (PDI), hexamethylene-diisocyanate (HDI), methylenebis(4-cyclohexyl isocyanate) (HMDI), and mixtures thereof.

[0065] More preferably, the polyisocyanate is 4,4'-MDI (4,4'-diphenylmethane diisocyanate), 1,6-HDI (1,6-hexamethylene diisocyanate), or a mixture thereof. Even more favorably, the polyisocyanate is 1,6-HDI.

[0066] The isocyanate-reactive compound preferably has an average functional value between 1.8 and 3, more preferably between 1.8 and 2.6, and more preferably between 1.8 and 2.2. The average functional value of the isocyanate-reactive compound corresponds to the number of isocyanate-reactive functional groups of a molecule theoretically calculated per molecule from a given amount of the compound. Preferably, the isocyanate-reactive compound has a number of Zerewitinoff active hydrogens within the above range, according to a statistical mean.

[0067] Preferably, the isocyanate-reactive compound (preferably a polyol) has a number-average molar mass of 500 to 100,000 g / mol. The isocyanate-reactive compound may have a number-average molar mass in the range of 500 to 8,000 g / mol, preferably 700 to 6,000 g / mol, and more specifically 800 to 4,000 g / mol. In a given embodiment, the isocyanate-reactive compound is present in concentrations of 500-600 g / mol, or 600-700 g / mol, or 700-800 g / mol, or 800-1000 g / mol, or 1000-1500 g / mol, or 1500-2000 g / mol, or 2000-2500 g / mol, or 2500-3000 g / mol, or 3000-3500 g / mol, or 3500-4000 g / mol, or 4000-5000 g / mol, or 5000-6000 g / mol, or 6000-70 The number-average molar mass is in the range of 00 g / mol, or 7000-8000 g / mol, or 8000-10000 g / mol, or 10000-15000 g / mol, or 15000-20000 g / mol, or 20000-30000 g / mol, or 30000-40000 g / mol, or 40000-50000 g / mol, or 50000-60000 g / mol, or 60000-70000 g / mol, or 70000-80000 g / mol, or 80000-100000 g / mol. The number-average molar mass can preferably be quantified by GPC in accordance with the ISO 16014-1:2012 standard.

[0068] Advantageously, the isocyanate-reactive compound has at least one reactive group selected from a hydroxyl group, an amine group, a thiol group, and a carboxylic acid group. Preferably, the isocyanate-reactive compound has at least one hydroxyl-reactive group, more preferably several hydroxyl groups. And, in a particularly advantageous form, the isocyanate-reactive compound contains or consists of a polyol.

[0069] Preferably, the polyol is selected from the group consisting of polyester polyols, polyether polyols, polycarbonate diols, polysiloxane diols, polyalkylenediols, and mixtures thereof. More preferably, the polyol is a polyether polyol, a polyester polyol, and / or a polycarbonate diol, resulting in the flexible blocks of thermoplastic polyurethane being a polyether block, a polyester block, and / or a polycarbonate block, respectively. Also preferably, the flexible blocks of thermoplastic polyurethane are a polyether block and / or a polyester block (the polyol is a polyether polyol and / or a polyester polyol).

[0070] Examples of polyester polyols include polycaprolactone polyols and / or copolyesters based on one or more carboxylic acids selected from adipic acid, succinic acid, pentanediol, and / or sebacic acid, and one or more alcohols selected from 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and / or polytetrahydrofuran. More specifically, the copolyester may be based on adipic acid and a mixture of 1,2-ethanediol and 1,4-butanediol, or the copolyester may be based on adipic acid, succinic acid, pentanediol, sebacic acid, or a mixture thereof, and polytetrahydrofuran (tetramethylene glycol), or the copolyester may be a mixture of these copolyesters.

[0071] As the polyether polyol, polyetherdiol (i.e., aliphatic α,ω-dihydroxylated polyoxyalkylene block) is preferably used. Preferably, the polyether polyol is a polyetherdiol based on ethylene oxide, propylene oxide and / or butylene oxide, a block copolymer based on ethylene oxide and propylene oxide, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetrahydrofuran, polybutanediol, or a mixture thereof. The polyether polyol is preferably polytetrahydrofuran (the flexible block of thermoplastic polyurethane is therefore a polytetrahydrofuran block) and / or polypropylene glycol (the flexible block of thermoplastic polyurethane is therefore a polypropylene glycol block) and / or polyethylene glycol (the flexible block of thermoplastic polyurethane is therefore a polyethylene glycol block), preferably polytetrahydrofuran having a number average molar mass of 500 to 15000 g / mol, preferably 1000 to 3000 g / mol. Polyether polyols can be polyether diols which are reaction products of ethylene oxide and propylene oxide; the molar ratio of ethylene oxide to propylene oxide is preferably 0.01 to 100, more preferably 0.1 to 9, more preferably 0.25 to 4, more preferably 0.4 to 2.5, more preferably 0.6 to 1.5, and more preferably 1.

[0072] The polysiloxane diols that can be used in the present invention preferably have a number-average molar mass of 500 to 15000 g / mol, and more preferably 1000 to 3000 g / mol. The number-average molar mass can preferably be quantified by GPC in accordance with ISO 16014-1:2012. Advantageously, the polysiloxane diol is of formula (I): [ka] (In the above formula, R is preferably a C2-C4 alkylene, R' is preferably a C1-C4 alkyl, and each of n, m, and p independently represents an integer preferably between 0 and 50, with m being more preferably between 1 and 50, and more preferably between 2 and 50) the polysiloxane is of the following formula (II): [ka] (In the above formula, Me is a methyl group.) Or the following equation (III): [ka] It holds.

[0073] The polyalkylenediol that can be used in the present invention is preferably butadiene-based.

[0074] The polycarbonate diols that can be used in the present invention are preferably aliphatic polycarbonate diols. The polycarbonate diols are preferably alkanediol-based. Preferably, they are strictly bifunctional. Preferred polycarbonate diols are butanediols, pentanediols and / or hexanediols, particularly 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentane-(1,5)-diol, or mixtures thereof, more preferably based on 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or mixtures thereof. In particular, the polycarbonate diols may be based on butanediol and hexanediol, or based on pentanediol and hexanediol, or based on hexanediol, or may be mixtures of two or more of these polycarbonate diols. Polycarbonate diols have a number-average molar mass in the range of 500 to 4000 g / mol, preferably 650 to 3500 g / mol, and more preferably 800 to 3000 g / mol. The number-average molar mass can be quantified by GPC, preferably in accordance with the ISO 16014-1:2012 standard.

[0075] One or more types of polyols can be used as isocyanate-reactive compounds.

[0076] In a particularly preferred form, the flexible block of the TPU is a block of polytetrahydrofuran, polypropylene glycol, and / or polyethylene glycol.

[0077] In addition to isocyanates and isocyanate-reactive compounds, chain extenders are used in the preparation of thermoplastic polyurethanes.

[0078] The chain extender may be aliphatic, aromaticaliphatic, aromatic, and / or alicyclic. Advantageously, it has a number-average molar mass of 50 to 499 g / mol. The number-average molar mass can be quantified by GPC, preferably in accordance with the ISO 16014-1:2012 standard. The chain extender preferably has two isocyanate reactive groups (also known as "functional groups"). A single chain extender or a mixture of at least two chain extenders may be used.

[0079] The chain extender is preferably bifunctional. Examples of chain extenders are diamines and alkanediols containing 2 to 10 carbon atoms. In particular, the chain extender may be selected from the group consisting of 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-dimethanolcyclohexane, neopentyl glycol, hydroquinone bis(beta-hydroxyethyl) ether (HQEE), di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or deca-alkylene glycols, their respective oligomers, polypropylene glycol, and mixtures thereof. More preferably, the chain extender is selected from the group consisting of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and mixtures thereof, more preferably selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol. Even more preferably, the chain extender is a mixture of 1,4-butanediol and 1,6-hexanediol, and more preferably, the molar ratio is 6:1 to 10:1.

[0080] Advantageously, a catalyst is used to synthesize thermoplastic polyurethanes. The catalyst plays a role in facilitating the chain-extending reaction between the NCO group of the polyisocyanate and the isocyanate-reactive compound (preferably the hydroxyl group of the isocyanate-reactive compound).

[0081] The catalyst is preferably a tertiary amine, more preferably selected from triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol and / or diazabicyclo(2,2,2)octane. Alternatively or additionally, the catalyst is an organometallic compound, such as a titanate ester, an iron compound, preferably iron(III) acetylacetonate, a tin compound, preferably a carboxylic acid, more preferably tin diacetate, tin dioctanoate, tin dilaurate, or a dialkyltin salt, preferably dibutyltin diacetate and / or dibutyltin dilaurate, a bismuth carboxylate, preferably bismuth decanoate, or a mixture thereof.

[0082] More preferably, the catalyst is selected from the group consisting of tin dioctanoate, bismuth decanoate, titanate esters, and mixtures thereof. More preferably, the catalyst is tin dioctanoate.

[0083] When preparing thermoplastic polyurethanes, the hardness and melt flow index of the TPU can be adjusted by changing the molar ratio of the isocyanate-reactive compound to the chain extender. Specifically, as the proportion of the chain extender increases, the hardness and melt viscosity of the TPU increase, while the melt flow index of the TPU decreases. In the production of soft TPUs, preferably with a Shore A hardness of less than 95, more preferably 75 to 95, the isocyanate-reactive compound and chain extender can be used in a molar ratio of 1:1 to 1:5, preferably 1:1.5 to 1:4.5, and preferably the mixture of the isocyanate-reactive compound and chain extender has a hydroxyl equivalent weight greater than 200, more specifically 230 to 650, and even more preferably 230 to 500. When producing a harder TPU, preferably with a Shore A hardness greater than 98 and a Shore D hardness of 55-75, the isocyanate reactive compound and the chain extender may be used in a molar ratio of 1:5.5-1:15, preferably 1:6-1:12, and the mixture of the isocyanate reactive compound and the chain extender has a hydroxyl equivalent weight of 110-200, more preferably 120-180.

[0084] Advantageously, to prepare TPU, a polyisocyanate, an isocyanate-reactive compound, and a chain extender are reacted, preferably in the presence of a catalyst, in amounts such that the ratio of the NCO group equivalents of the polyisocyanate to the total hydroxyl groups of the isocyanate-reactive compound and chain extender is 0.95:1 to 1.10:1, preferably 0.98:1 to 1.08:1, and more preferably 1:1 to 1.05:1. The catalyst is preferably present in an amount of 0.0001 to 0.1 parts by weight per 100 parts by weight of the TPU synthesis reagent.

[0085] The TPU preferably has a weight-average molar mass of 10,000 g / mol or more, preferably 40,000 g / mol or more, and more preferably 60,000 g / mol or more. Preferably, the weight-average molar mass of the TPU is 80,000 g / mol or less. In a given embodiment, the weight-average molar mass of the TPU is 10,000 to 25,000 g / mol, or 25,000 to 40,000 g / mol, or 40,000 to 50,000 g / mol, or 50,000 to 60,000 g / mol, or 60,000 to 70,000 g / mol, or 70,000 to 80,000 g / mol. The weight-average molar mass can be quantified by gel permeation chromatography (GPC).

[0086] The hard block content in the TPU is preferably 90% by weight or less, more preferably 80% by weight or less (relative to the total weight of the TPU). More advantageously, the hard block content in the TPU is 30% to 60% by weight (the soft block content is 40% to 70% by weight). More specifically, the hard block content in the TPU can be 10% to 20% by weight (the amount of soft blocks is 80% to 90% by weight), or 20% to 30% by weight (the amount of soft blocks is 70% to 80% by weight), or 30% to 40% by weight (the amount of soft blocks is 60% to 70% by weight), or 40% to 50% by weight (the amount of soft blocks is 50% to 60% by weight), or 50% to 60% by weight (the amount of soft blocks is 40% to 50% by weight), or 60% to 70% by weight (the amount of soft blocks is 30% to 40% by weight), or 70% to 80% by weight (the amount of soft blocks is 20% to 30% by weight), or 80% to 90% by weight (the amount of soft blocks is 10% to 20% by weight). These quantities result in a foam with low density, high flexibility, and good rebound elasticity. The hard block content is expressed as a percentage and is defined as follows: [(Mass fraction of polyisocyanate + Mass fraction of chain extender) / (Mass fraction of polyisocyanate + Mass fraction of chain extender + Mass fraction of isocyanate-reactive compound)] × 100 This can be measured by proton NMR in DMSO-D6 according to the protocol described in the paper “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0087] Advantageously, TPU is semi-crystalline. Its melting point Tf is preferably between 100°C and 230°C, more preferably between 120°C and 200°C. The melting point can be measured in accordance with ISO 11357-3 standard (plastics - differential scanning calorimetry (DSC) Part III).

[0088] Advantageously, the TPU can be recycled TPU and / or partially or completely bio-based TPU.

[0089] Advantageously, TPUs have a melt flow index (MFI) of 10–100 g / 10 min, preferably 25–80 g / 10 min, and more preferably 35–65 g / 10 min. In particular, the melt flow index of TPUs can be 10–25 g / 10 min, or 25–35 g / 10 min, or 35–45 g / 10 min, or 45–55 g / 10 min, or 55–65 g / 10 min, or 65–80 g / 10 min, or 80–100 g / 10 min. The melt flow index is measured at 200°C under a 10 kg load in accordance with ASTM D1238 standard.

[0090] Preferably, the TPU has a Shore D hardness of 75 or less, more preferably 65 or less. In particular, the TPU used in the present invention may have a hardness of 65 Shore A to 70 Shore D, preferably 75 Shore A to 60 Shore D. Hardness measurement may be performed in accordance with the ISO 7619-1 standard.

[0091] Advantageously, the TPU according to the present invention has an OH functional group concentration of 0.002 meq / g to 0.6 meq / g, preferably 0.01 meq / g to 0.4 meq / g, and more preferably 0.03 meq / g to 0.2 meq / g. In a given embodiment, the TPU has an OH functional group concentration of 0.002 to 0.005 meq / g, or 0.005 to 0.01 meq / g, or 0.01 to 0.02 meq / g, or 0.02 to 0.04 meq / g, or 0.04 to 0.06 meq / g, or 0.06 to 0.08 meq / g, or 0.08 to 0.1 meq / g, or 0.1 to 0.2 meq / g, or 0.2 to 0.3 meq / g, or 0.3 to 0.4 meq / g, or 0.4 to 0.5 meq / g, or 0.5 to 0.6 meq / g. The OH functional group concentration can be quantified by proton NMR in DMSO-D6 according to the protocol described in the following document: “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0092] A significant advantage is that the TPU is not cross-linked.

[0093] [Polyamide block-polyether block copolymer (PEBA)] The foam according to the present invention may also contain a polyamide block-polyether block copolymer.

[0094] The presence of polyamide block-polyether block copolymer in the foam provides the foam with greater flexibility and good elasticity.

[0095] PEBA is formed by the polycondensation of a polyamide block (rigid or hard block) having reactive ends and a polyether block (flexible or soft block) having reactive ends, for example, in particular, 1) A polyamide block having a diamine chain terminus and a polyoxyalkylene block having a dicarboxylic acid chain terminus; 2) For example, a polyamide block having a dicarboxylic acid chain terminus and a polyoxyalkylene block having a diamine chain terminus, obtained by cyanoethylation and hydrogenation of an α,ω-dihydroxylated aliphatic polyoxyalkylene block known as a polyetherdiol; 3) A polyamide block having a dicarboxylic acid chain terminus and a polyetherdiol (in this particular case, the resulting product is a polyether ester amide) It is obtained by polycondensation.

[0096] Polyamide blocks having dicarboxylic acid chain ends can be obtained, for example, by condensation of a polyamide precursor in the presence of a chain-restricted dicarboxylic acid. Polyamide blocks having diamine chain ends can be obtained, for example, by condensation of a polyamide precursor in the presence of a chain-restricted diamine.

[0097] The polyamide blocks of PEBA (i.e., the properties of the polyamide) may be similar to those of the polyamides described in the previous section, in relation to amine-chain-terminated polyamides (regardless of whether the PEBA polyamide blocks originate from diamine-chain-terminated polyamide blocks or dicarboxylic acid-chain-terminated polyamide blocks). In particular, the three polyamide blocks corresponding to the three polyamides mentioned above can be used advantageously.

[0098] More specifically, the polyamide blocks of copolymers used in this invention are polyamides PA6, PA10, PA11, PA12, PA5.4, PA5.9, PA5.10, PA5.12, PA5.13, PA5.14, PA5.16, PA5.18, PA5.36, PA6.4, PA6.6, PA6.9, PA6.10, PA6.12, PA6.13, PA6.14, PA6.16, PA6.18, PA6.3 6. May contain blocks of PA10.4, PA10.9, PA10.10, PA10.12, PA10.13, PA10.14, PA10.16, PA10.18, PA10.36, PA10.T, PA12.4, PA12.9, PA12.10, PA12.12, PA12.13, PA12.14, PA12.16, PA12.18, PA12.36, PA12.T, or mixtures or copolymers thereof.

[0099] Preferably, the polyamide block of the copolymer comprises blocks of polyamide PA6, PA10, PA11, PA12, PA6.10, PA6.12, PA10.10, PA10.12, or mixtures or copolymers thereof, more preferably, blocks of polyamide PA6, PA11, PA12, PA6.12, or mixtures or copolymers thereof.

[0100] Polyether blocks are formed from alkylene oxide units. Polyether blocks may be, in particular, PEG (polyethylene glycol) blocks, i.e., blocks formed from ethylene oxide units, and / or PPG (polypropylene glycol) blocks, i.e., blocks formed from propylene oxide units, and / or PO3G (polytrimethylene glycol) blocks, i.e., blocks formed from polytrimethylene glycol ether units, and / or PTMG blocks, i.e., blocks formed from tetramethylene glycol units, also known as polytetrahydrofuran. Preferably, PEBA polyether blocks are polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran blocks. PEBA copolymers may contain several types of polyethers in their chains, and the copolyethers may be in block form or statistical form.

[0101] Blocks obtained by oxyethylation of bisphenols, such as bisphenol A, can also be used. The latter products are described in particular in EP613919.

[0102] Polyether blocks can also consist of ethoxylated primary amines. Examples of ethoxylated primary amines include the products of the following formulas: [ka] (In the above formula, m and n are integers between 1 and 20, and x is an integer between 8 and 18). These products are marketed, for example, under the brand name Noramox® by CECA and under the brand name Genamin® by Clariant.

[0103] Polyether soft blocks may include polyoxyalkylene blocks having NH2 chain termini, such blocks can be obtained by cyanoacetylation of α,ω-dihydroxylated aliphatic polyoxyalkylene blocks called polyetherdiols. More specifically, commercially available Jeffamine or Elastamine can be used (e.g., Huntsman's commercially available Jeffamine® D400, D2000, ED2003, XTJ542, also described in JP2004 / 346274, JP2004 / 352794 and EP1482011).

[0104] The polyetherdiol block is used in its unmodified form and copolymerized with a carboxyl-terminated hard block, or amination is performed to convert it to a polyetherdiamine and then condensed with a carboxyl-terminated hard block.

[0105] A general method for preparing PEBA copolymers containing an ester bond between a PA block and a PE block in two steps is known, for example, described in FR2846332. A general method for preparing PEBA copolymers having an amide bond between a PA block and a PE block is known, for example, described in EP1482011. A polyether block can also be mixed with a polyamide precursor and a chain-limiting diacitor to prepare polymers containing polyamide and polyether blocks with randomly distributed units (one-step process).

[0106] Needless to say, the name PEBA in this specification of the present invention refers not only to the Pebax® products sold by Arkema, the Vestamid® products sold by Evonik, and the Grilamid® products sold by EMS, but also to the Pelestat® PEBA-type products sold by Sanyo, or any other PEBA from other suppliers.

[0107] The PEBAs that can be used in the present invention include not only copolymers comprising a single polyamide block and a single polyether block, but also copolymers comprising three, four (or more) different blocks selected from those described herein, as long as these blocks comprise at least one polyamide block and one polyether block. In addition, the PEBAs that can be used in the present invention also include copolymers comprising, in addition to polyamide and polyether blocks, one or more blocks of different properties, selected from the group consisting of polyester blocks, polysiloxane blocks, e.g., polydimethylsiloxane (or PDMS) blocks, polyolefin blocks, polycarbonate blocks, and mixtures thereof, and preferably selected from the group consisting of polyester blocks, polysiloxane blocks, and mixtures thereof.

[0108] For example, the copolymer may be a segmented block copolymer (or "triblock" copolymer) containing three different types of blocks, which is obtained by the condensation of several of the blocks described above. The triblock may be, for example, a copolymer containing a polyamide block, a polyester block and a polyether block, or a copolymer containing a polyamide block and two different polyether blocks, such as a PEG block and a PTMG block.

[0109] Particularly preferred PEBA copolymers in the context of the present invention are copolymers comprising, in particular, the following blocks: PA10 and PEG; PA10 and PTMG; PA11 and PEG; PA11 and PTMG; PA12 and PEG; PA12 and PTMG; PA6.10 and PEG; PA6.10 and PTMG; PA6 and PEG; PA6 and PTMG; PA6.12 and PEG; PA6.12 and PTMG.

[0110] The number-average molar mass of polyamide blocks in the PEBA copolymer is preferably 400 to 20000 g / mol, more preferably 500 to 10000 g / mol. In a given embodiment, the number-average molar mass of polyamide blocks in the PEBA copolymer is 400 to 500 g / mol, or 500 to 600 g / mol, or 600 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 5000 g / mol, or 5000 to 6000 g / mol, or 6000 to 7000 g / mol, or 70 The ranges are 0-8000 g / mol, or 8000-9000 g / mol, or 9000-10000 g / mol, or 10000-11000 g / mol, or 11000-12000 g / mol, or 12000-13000 g / mol, or 13000-14000 g / mol, or 14000-15000 g / mol, or 15000-16000 g / mol, or 16000-17000 g / mol, or 17000-18000 g / mol, or 18000-19000 g / mol, or 19000-20000 g / mol.

[0111] The number-average molar mass of the polyether block is preferably 100 to 6000 g / mol, more preferably 200 to 3000 g / mol. In a given embodiment, 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.

[0112] The number-average molar mass is given by the equation: M n =nモノマー ×MW 反復単位 / n 連鎖制限剤 +MW 連鎖制限剤 It can be calculated according to [the formula]. In this equation, n モノマー n represents the number of moles of monomer, 連鎖制限剤 represents the excess number of moles of the dioxide limiting agent, MW 反復単位 represents the molar mass of the repeating unit, MW 連鎖制限剤 This represents the excess molar mass of the diacitor.

[0113] The number-average molar mass of polyamide and polyether blocks can be measured by gel permeation chromatography (GPC) before copolymerization of the blocks.

[0114] Advantageously, the amount of polyamide blocks in PEBA is at least 10% by weight, preferably at least 20% by weight (relative to the total weight of PEBA). More advantageously, the amount of polyamide blocks in PEBA is at least 30% by weight, more preferably at least 40% by weight, and even more preferably at least 50% by weight. The amount of polyamide blocks in PEBA can be 10% to 95% by weight (the amount of polyether blocks is preferably 5% to 90%), preferably 30% to 90% by weight (the amount of polyether blocks is preferably 10% to 70%), and more preferably 40% to 85% by weight (the amount of polyether blocks is preferably 15% to 60%). More specifically, the amount of polyamide block in PEBA can be 10% to 30% by weight (preferably 70% to 90% by weight of polyether block), or 30% to 40% by weight (preferably 60% to 70% by weight of polyether block), or 40% to 50% by weight (preferably 50% to 60% by weight of polyether block), or 50% to 60% by weight (preferably 40% to 50% by weight of polyether block), or 60% to 70% by weight (preferably 30% to 40% by weight of polyether block), or 70% to 80% by weight (preferably 20% to 30% by weight of polyether block), or 80% to 95% by weight (preferably 5% to 20% by weight of polyether block).

[0115] Advantageously, the polyamide block-polyether block copolymer has a Shore D hardness of 30 or higher. Preferably, the copolymer used in the present invention has an instantaneous hardness of 65 Shore A to 80 Shore D, more preferably 75 Shore A to 65 Shore D, and more preferably 80 Shore A to 55 Shore D. Hardness measurement may be performed in accordance with ISO 7619-1.

[0116] PEBA may have an OH functional group concentration of 0.002 meq / g to 0.2 meq / g, preferably 0.005 meq / g to 0.1 meq / g, more preferably 0.01 meq / g to 0.08 meq / g, and / or a COOH functional group concentration of 0.002 meq / g to 0.2 meq / g, preferably 0.005 meq / g to 0.1 meq / g, more preferably 0.01 meq / g to 0.08 meq / g. In particular, PEBA has OH functional group concentrations of 0.002~0.005 meq / g, or 0.005~0.01 meq / g, or 0.01~0.02 meq / g, or 0.02~0.03 meq / g, or 0.03~0.04 meq / g, or 0.04~0.05 meq / g, or 0.05~0.06 meq / g, or 0.06~0.07 meq / g, or 0.07~0.08 meq / g, or 0.08~0.09 meq / g, or 0.09~0.1 meq / g, or 0.1~0.15 meq / g, or 0.15~0.2 meq / g, and It may have a COOH functional group concentration of 0.002-0.005 meq / g, or 0.005-0.01 meq / g, or 0.01-0.02 meq / g, or 0.02-0.03 meq / g, or 0.03-0.04 meq / g, or 0.04-0.05 meq / g, or 0.05-0.06 meq / g, or 0.06-0.07 meq / g, or 0.07-0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.15 meq / g, or 0.15-0.2 meq / g. The COOH functional group concentration can be quantified by potentiometric assay according to the following method: the material sample is dissolved in benzyl alcohol, and the COOH functional groups of this sample are then analyzed by potentiometric assay using a 0.02 N tetrabutylammonium hydroxide solution. The OH functional group concentration can be quantified by proton (1H) NMR in a TFA / CDCl3 (1 / 4 v / v) mixture, preferably using a Brueker AM500 spectrometer.The measurement protocol is described in detail in the paper “Synthesis and characterization of poly(copolyethers-block-polyamides)-II. Characterization and properties of the multiblock copolymers”, Marechal et al., Polymer, Volume 41, 2000, 3561-3580, and signal assignment is performed using Figure 5 of the said paper.

[0117] PEBA may have an NH2 functional group concentration of 0.01 meq / g to 1 meq / g, preferably 0.02 meq / g to 0.4 meq / g. PEBA may have concentrations of 0.01 to 0.015 meq / g, or 0.015 to 0.02 meq / g, or 0.02 to 0.025 meq / g, or 0.025 to 0.03 meq / g, or 0.03 to 0.035 meq / g, or 0.035 to 0.04 meq / g, or 0.04 to 0.045 meq / g, or 0.045 to 0.05 meq / g, or 0.05 to 0.06 meq / g, or 0.06 to 0.07 meq / g, or 0.07 The NH2 functional group concentration may be 0.08 meq / g, or 0.08-0.09 meq / g, or 0.09-0.1 meq / g, or 0.1-0.2 meq / g, or 0.2-0.3 meq / g, or 0.3-0.4 meq / g, or 0.4-0.5 meq / g, or 0.5-0.6 meq / g, or 0.6-0.7 meq / g, or 0.7-0.8 meq / g, or 0.8-0.9 meq / g, or 0.9-1 meq / g. The NH2 functional group concentration can be measured by potentiometric assay according to the following method: The foam sample is dissolved in meta-cresol at 80°C, and then the NH2 functional groups of this sample are analyzed by potentiometric assay using a 0.02 N perchloric acid solution.

[0118] [TPU and PA foam] The foam according to the present invention comprises at least one type of PA, at least one type of TPU, and optionally at least one type of PEBA.

[0119] Preferably, the amount of amine-chain-terminated polyamide in the foam is 40% by weight or less, more preferably 30% by weight or less.

[0120] More preferably, the foam according to the present invention comprises, with respect to the total weight of the amine-end-containing polyamide and thermoplastic polyurethane, 1% to 40% by weight of at least one amine-end-containing polyamide and 60% to 99% by weight of at least one thermoplastic polyurethane, preferably 1% to 30% by weight of at least one amine-end-containing polyamide and 70% to 99% by weight of at least one thermoplastic polyurethane, preferably 1% to 25% by weight of at least one amine-end-containing polyamide and 75% to 99% by weight of at least one thermoplastic polyurethane, more preferably 1.5% to 25% by weight of at least one amine-end-containing polyamide and 75% to 98.5% by weight of at least one thermoplastic polyurethane, and even more preferably 2% to 20% by weight of at least one amine-end-containing polyamide and 80% to 98% by weight of at least one thermoplastic polyurethane. When the polyamide and TPU are within the above ranges, the resulting foam is optimal in terms of low density and high flexibility.In a given embodiment, the foam is composed of, relative to the total weight of the amine-end-containing polyamide and thermoplastic polyurethane, 1% to 5% by weight of at least one amine-end-containing polyamide and 95% to 99% by weight of at least one thermoplastic polyurethane, or 5% to 10% by weight of at least one amine-end-containing polyamide and 90% to 95% by weight of at least one thermoplastic polyurethane, or 10% to 15% by weight of at least one amine-end-containing polyamide and 85% to 90% by weight of at least one thermoplastic polyurethane, or 15% to 20% by weight of at least one amine-end-containing polyamide and 80% to 85% by weight The material comprises at least one thermoplastic polyurethane, or 20% to 25% by weight of at least one amine-terminal polyamide and 75% to 80% by weight of at least one thermoplastic polyurethane, or 25% to 30% by weight of at least one amine-terminal polyamide and 70% to 75% by weight of at least one thermoplastic polyurethane, or 30% to 35% by weight of at least one amine-terminal polyamide and 65% to 70% by weight of at least one thermoplastic polyurethane, or 35% to 40% by weight of at least one amine-terminal polyamide and 60% to 65% by weight of at least one thermoplastic polyurethane.

[0121] The foam according to the present invention advantageously comprises 1% to 40% by weight of at least one amine-end containing polyamide and 10% to 99% by weight of at least one thermoplastic polyurethane, preferably 1% to 30% by weight of at least one amine-end containing polyamide and 15% to 89% by weight of at least one thermoplastic polyurethane, more preferably 1% to 25% by weight of at least one amine-end containing polyamide and 15% to 89% by weight of at least one thermoplastic polyurethane. The foam may contain 1% to 5%, or 5% to 10%, or 10% to 15%, or 15% to 20%, or 20% to 25%, or 25% to 30%, or 30% to 35%, or 35% to 40% by weight of at least one amine-end containing polyamide, relative to the total weight of the foam. The foam may contain, by weight, at least one type of thermoplastic polyurethane in amounts of 10% to 20%, or 20% to 30%, or 30% to 40%, or 40% to 50%, or 50% to 60%, or 60% to 70%, or 70% to 80%, or 80% to 90%, or 90% to 99%, relative to the total weight of the foam.

[0122] The foam may also contain at least one type of PEBA in an amount of 0 to 89% by weight, more preferably 10% to 70% by weight, relative to the total weight of the foam. In particular, the foam may contain 0 to 10% by weight, or 10% to 20%, or 20% to 30%, or 30% to 40%, or 40% to 50%, or 50% to 60%, or 60% to 70%, or 70% to 80%, or 80% to 89% by weight, relative to the total weight of the foam. The foam may not contain a polyamide block-polyether block copolymer. The above ranges for the amount of PEBA can each be combined with any of the ranges for the amount of amine-chain-terminated polyamide and / or any of the above ranges for the amount of thermoplastic polyurethane.

[0123] Preferably, the mass of the total soft block (i.e., the soft block of thermoplastic polyurethane and PEBA (if present)) is 20% to 90%, more preferably 40% to 80%, and even more preferably 50% to 75%, of the total weight of the TPU and PEBA (if present). The mass of the total soft block can be quantified by nuclear magnetic resonance (NMR).

[0124] The molar ratio of urethane functional groups to NH2 amine functional groups in an assembly comprising at least one amine-chain-terminated polyamide and at least one thermoplastic polyurethane in the foam according to the present invention may be 15 to 350, preferably 25 to 250, and more preferably 40 to 200. The concentrations of the amine functional groups and urethane functional groups can be quantified by 13C NMR in DMSO-D6, as described in the following paper, “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapbrand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373.

[0125] Preferably, the total amount of polyamide (PA containing amine chain ends and optional PEBA) in the foam is at least 15% by weight, preferably at least 20% by weight, more preferably at least 25% by weight, more preferably at least 30% by weight, and more preferably at least 35% by weight (relative to the total weight of the foam). The amount of polyamide in the foam can be quantified by proton NMR in a TFA / CDCl3 (1 / 4v / v) mixture, preferably using a Brueker AM500 spectrometer, according to the protocol described in the paper “Synthesis and characterization of poly(copolyethers-block-polyamides)-II. Characterization and properties of the multiblock copolymers”, Marechal et al., Polymer, Volume 41, 2000, 3561-3580 (signal assignment is performed using Figure 5 of the said paper).

[0126] Advantageously, the TPU and PA foams according to the present invention contain at least a portion of the total amount of polyamide covalently bonded to the thermoplastic polyurethane via urea functional groups.

[0127] Preferably, the foam according to the present invention has a urea functional group concentration of 0.001 meq / g to 0.1 meq / g, preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g. The urea functional group concentration in the foam may be 0.001 to 0.005 meq / g, or 0.005 to 0.01 meq / g, or 0.01 to 0.02 meq / g, or 0.02 to 0.03 meq / g, or 0.03 to 0.04 meq / g, or 0.04 to 0.05 meq / g, or 0.05 to 0.08 meq / g, or 0.08 to 0.1 meq / g. The urea functional group concentration can be measured by 13C NMR in DMSO-D6, as described in the paper “Reactivity of isocyanates with urethanes: Conditions for allophanate formation”, Lapprand et al., Polymer Degradation and Stability, Volume 90, No. 2, 2005, 363-373. The urea functional group content is quantified by integrating the signals corresponding to the carbonyl groups of the urethane and urea functional groups, and the signals are assigned using Figure 6 of the aforementioned paper.

[0128] Preferably, the portion of polyamide covalently bonded to the thermoplastic polyurethane via a urea functional group accounts for 10% by weight or less, more preferably 5% by weight or less, more preferably 3% by weight or less, and more preferably 2% by weight or less of the total amount of polyamide.

[0129] The foam according to the present invention, particularly in the case of closed-cell foams, may essentially consist of, or be composed of, at least one amine-terminal chain-containing polyamide, at least one thermoplastic polyurethane, optionally at least one polyamide block-polyether block copolymer, and optionally a blowing agent in the foam matrix and / or foam pores. The foam matrix may essentially consist of, or be composed of, at least one TPU, at least one amine-terminal chain-containing PA, and optionally at least one PEBA. Particularly when a chemical blowing agent is used to form the foam, the foam may also contain decomposition products of the blowing agent (particularly in its matrix).

[0130] Alternatively, the foam may contain one or more additives, such as ethylene-vinyl acetate copolymer, i.e., EVA (e.g., sold by SK Chemical Co., Ltd. under the name Evatane®), or ethylene-acrylate copolymer, or ethylene-alkyl (meth)acrylate copolymer, e.g., sold by SK Chemical Co., Ltd. under the name Lotryl®. These additives may allow for adjustment of the hardness, appearance, and comfort of the foam component. Other additives suitable for the present invention include pigments (such as TiO2 and other compatible coloring pigments), adhesion promoters (to improve the adhesion between the foam and other materials), fillers (e.g., calcium carbonate, barium sulfate and / or silicon dioxide), nucleating agents (especially in pure or concentrated form, e.g., CaCO3, ZnO, SiO2, or combinations of two or more thereof), rubber (to improve rubber elasticity, e.g., natural rubber, SBR, polybutadiene and / or ethylene propylene polymer), stabilizers (e.g., antioxidants, UV absorbers and / or flame retardants), processing aids (e.g., stearic acid), antioxidants, especially phenolic antioxidants such as Irganox from Ciba Geigy. Additives may be present in an amount of 0 to 30% by weight, preferably 0.1% to 20% by weight, and more preferably 0.2% to 10% by weight, relative to the total weight of the foam.

[0131] According to one embodiment, the foam does not contain any crosslinking agent. Advantageously, the foam is a non-crosslinked foam.

[0132] The foam according to the present invention preferably has a density of 800 kg / m³. 3 More preferably 600 kg / m 3 Below, 400 kg / m² is given higher priority. 3 Below, with even higher priority, is 300 kg / m 3 The following is particularly preferred: 230 kg / m 3 The foam has the following densities: for example, 25-600 kg / m³ 3 , more preferably 50-300 kg / m 3 It can have a density of 25-100 kg / m³. 3 , or 100-200 kg / m 3 , or 200-250 kg / m 3 , or 250-300 kg / m 3 , or 300-400 kg / m 3 , or 400-500 kg / m 3 , or 500-600 kg / m 3 , or 600-800 kg / m 3 It is possible. Density can be controlled by adjusting the parameters of the manufacturing process. Density can be measured at 23°C in accordance with the ISO 1183-1 standard.

[0133] Preferably, the foam according to the present invention has an Asker C hardness of 20 to 90, preferably 25 to 70. In particular, the Asker C hardness of the foam may be 20 to 25, or 25 to 30, or 30 to 40, or 40 to 50, or 50 to 60, or 60 to 70, or 70 to 80, or 80 to 90. The Asker C hardness can be quantified after 15 seconds at 23°C in accordance with ISO 7619-1 standard.

[0134] Preferably, the foam has a rebound elasticity of 50% or more, preferably 55% or more. The rebound elasticity is measured in accordance with the ISO 8307:2007 standard, but using an 18.8g ball.

[0135] Preferably, the foam has a compression set of 65% or less, preferably 50% or less, for example, 45% or less, or 40% or less, or 35% or less, in accordance with ISO 7214 standards. The compression set is measured by applying 25% compression at 23°C for 70 hours, followed by relaxation for 30 minutes.

[0136] Preferably, this foam also has excellent properties in terms of fatigue strength and damping capacity.

[0137] Preferably, the foam also has good resistance to tearing and crack propagation.

[0138] The foam according to the present invention can be used in the manufacture of sports equipment, such as functional sole components in the form of inserts into various parts of the sole (e.g., heel or arch), or upper components of shoes in the form of reinforcing materials or inserts to the upper structure of shoes, or protective materials.

[0139] The foam can also be used in the manufacture of balls, sports gloves (e.g., soccer gloves), golf ball components, rackets, and protective gear (jackets, helmet linings, shells, etc.).

[0140] The foam according to the present invention possesses advantageous impact resistance, vibration resistance, and noise resistance, combined with tactile properties suitable for equipment. Therefore, the foam can be used in the manufacture of rail pads for railway rails, or in the manufacture of various components in the automotive industry, transportation, electrical and electronic equipment, construction, or manufacturing industries.

[0141] According to an advantageous embodiment, the foam according to the present invention can be easily recycled by melting it (after optionally shredding it) in an extruder equipped with a vent.

[0142] [Preparation of foam] The foam according to the present invention can be prepared by mixing a polymer composition containing at least one TPU, at least one amine-terminal chain-containing PA, and optionally at least one PEBA with a foaming agent (and optionally one or more additives), followed by a foaming step.

[0143] The blowing agent may be a chemical or physical blowing agent, or it may consist of any kind of hollow body or any kind of expandable microsphere. Preferably, the blowing agent is a physical blowing agent, such as dinitrogen or carbon dioxide, or hydrocarbons, chlorofluorocarbons, hydrochlorocarbons, hydrofluorocarbons (saturated or unsaturated), or mixtures thereof. For example, butane or pentane may be used. Also preferably, the blowing agent may be a chemical blowing agent, such as azodicarbonamide, or a mixture based on citric acid and sodium bicarbonate (NaHCO3) (for example, Clariant's Hydrocerol® series products).

[0144] In a given embodiment, a physical blowing agent is used and mixed with a molten polymer composition. The physical blowing agent may be in liquid or supercritical form and is then converted to a gas phase during the foaming process. Foaming can be brought about, for example, by a pressure drop occurring at the outlet of an extruder.

[0145] Advantageously, a mixture of polymer composition and foaming agent is injected into a mold, and foaming is carried out within the mold. Foaming can be induced by opening the mold, under-injecting, applying gas back pressure, using a permeable mold, or a mold equipped with a Variotherm® system. This technology makes it possible to directly manufacture three-dimensional foams of complex shapes. Furthermore, these are relatively easy to implement compared to certain processes that melt foam particles, in particular: specifically, the complex operation of filling a mold with foam polymer granules and then melting the particles to ensure the mechanical strength of the part without destroying the structure of the foam.

[0146] In alternative embodiments, the polymer composition is used to produce a preform. This preform can be prepared by compression molding, extrusion molding, injection molding, lamination molding, or 3D printing processes. Preferably, the preform is produced by extrusion molding or injection molding. The preform is brought into contact with a physical blowing agent in a solid state, either in gaseous or supercritical form. The physical blowing agent is impregnated into the solid preform, preferably by applying positive pressure. Preferably, foaming is carried out in an autoclave, preferably at a temperature slightly below the melting point of the polymer composition. Preferably, during foaming, the pressure in the autoclave is maintained between 0.20 MPa and 50 MPa. Advantageously, the foaming of the preform is carried out in a mold.

[0147] Other foaming techniques that may be used include, in particular, batch foaming, extrusion foaming, such as uniscrew or twinscrew extrusion foaming, and microwave foaming.

[0148] In a particularly preferred form, a polymer composition comprising TPU, PA, and optionally PEBA is prepared before being mixed with a foaming agent. Preferably, the polymer composition is an alloy of TPU, PA, and optionally PEBA. The term "alloy" means a homogeneous mixture (macroscopically, i.e., visible to the naked eye).

[0149] According to a first advantageous modification, the polymer composition can be prepared by a method comprising the step of mixing a molten amine-chain-terminated polyamide with a thermoplastic polyurethane and an optional polyamide block-polyether block copolymer. Such a preparation method allows a reaction to occur between some of the amine functional groups of the polyamide and the urethane functional groups of the TPU under predetermined mixing time and temperature conditions, thereby improving the compatibility between the polyamide and the thermoplastic polyurethane.

[0150] The mixing of TPU, PA, and optionally PEBA may be carried out in any apparatus known to those skilled in the art for mixing, kneading, or extruding molten plastics, such as an internal mixer, open mill, extruder, e.g., a single-screw extruder or a twin-screw extruder rotating in opposite directions or co-rotating directions, cone kneader, e.g., a continuous cone kneader, or a stirring reactor. Preferably, the mixing is carried out in an extruder or cone kneader, more preferably in an extruder, and even more preferably in a twin-screw extruder.

[0151] Preferably, the mixing is carried out at a temperature of 160°C or higher, preferably 160-300°C, and more preferably 180-260°C. These temperature ranges allow for optimal reaction between the amine-terminal polyamide and the thermoplastic polyurethane, thereby enabling better compatibility between the two polymers.

[0152] Advantageously, the mixing is carried out for 30 seconds to 15 minutes, preferably 40 seconds to 10 minutes. Preferably, the mixing is carried out with stirring. These mixing conditions allow for an optimal reaction between the amine-chain-terminated polyamide and the thermoplastic polyurethane, thus enabling better compatibility between the two polymers.

[0153] The step of mixing TPU with PA (and optionally PEBA) may include mixing a molten amine-chain-terminated polyamide with a thermoplastic polyurethane and optionally a polyamide block-polyether block copolymer together with an additive.

[0154] According to another advantageous modification, the polymer composition may be prepared by introducing an amine-chain-terminated polyamide and optionally a polyamide block-polyether block copolymer during the synthesis of a thermoplastic polyurethane. In such a preparation method, the amine-chain-terminated polyamide and optionally a polyamide block-polyether block copolymer are used as isocyanate-reactive compounds (as described in the "Thermoplastic Polyurethane (TPU)" section above), optionally in addition to another isocyanate-reactive compound, preferably the polyol described above.

[0155] Therefore, the preparation method is - A step of introducing a thermoplastic polyurethane precursor (i.e., at least one polyisocyanate, at least one chain extender, and optionally at least one isocyanate-reactive compound) into the reactor; - A step of introducing amine-chain-terminated polyamide into the reactor; - A step of optionally introducing polyamide block-polyether block copolymer into the reactor; - A step of synthesizing thermoplastic polyurethane in a reactor in the presence of amine-chain-terminated polyamide (and optionally polyamide block-polyether block copolymer) to obtain a polymer composition. It may include.

[0156] Through such a preparation method, during the synthesis of thermoplastic polyurethane, some amine NH2 functional groups of the polyamide react with some isocyanate functional groups of the polyisocyanate, forming a covalent bond between the polyamide and the thermoplastic polyurethane, thereby improving the compatibility between the polyamide and the thermoplastic polyurethane.

[0157] The steps of adding the thermoplastic polyurethane precursor, the amine-chain-terminated polyamide, and the polyamide block-polyether block copolymer may be carried out simultaneously or in any order. In particular, catalysts such as those described above may be added to the reactor again.

[0158] The reactor may be a batch reactor, a stirred reactor, a static mixer, an internal mixer, an open mill, an extruder, such as a single-screw extruder or a twin-screw extruder that rotates in opposite directions or in conjunction with another, a continuous kneader, or a combination thereof. Preferably, the reactor is an extruder, more preferably a twin-screw extruder.

[0159] Preferably, the step of synthesizing the thermoplastic polyurethane (in the presence of an amine-terminal polyamide and optionally a polyamide block-polyether block copolymer) is carried out at a temperature of 160°C or higher, preferably 160-300°C, and more preferably 180-270°C. This temperature range allows for an optimal reaction between the amine-terminal polyamide and the thermoplastic polyurethane, resulting in good compatibility between the two polymers.

[0160] One or more additives can be added to the reactor (at any point during the process) and mixed in the reactor with thermoplastic polyurethane, amine-chain-terminated polyamide, and optionally polyamide block-polyether block copolymer.

[0161] In any of the modifications used, the preparation method may include the step of forming a mixture of TPU, PA, and optionally PEBA into granules or powder. When forming the mixture into a powder, it is preferable to first form it into granules and then grind the granules into a powder. Any type of mill can be used, such as a hammer mill, pin mill, attrition disc mill, or impact classifier.

[0162] In the methods for preparing the polymer compositions described above, all the characteristics described above in relation to polyamides, thermoplastic polyurethanes, and polyamide block-polyether block copolymers (in particular, their properties, quantities, concentrations of OH groups, COOH and / or amine functional groups, etc.) can also be applied to the polyamides, thermoplastic polyurethanes, and polyamide block-polyether block copolymers used in these methods. [Examples]

[0163] The following embodiments illustrate the present invention without limiting it.

[0164] The following polymers were used: - PEBA: A PEBA copolymer containing PA11 blocks with a number-average molar mass of 1000 g / mol and PTMG blocks with a number-average molar mass of 1000 g / mol, with a hardness of 40 Shore D. - PA1: Polyamide 11 containing an average of one amine chain terminus per molecule and having an NH2 functional group concentration of 0.476 meq / g. - PA2: A polyamide 6 / 6.6 / 12 (mass ratio 40 / 25 / 35) containing amine chain terminals and having an NH2 functional group concentration of 0.305 meq / g. - TPU: TPU containing a hard block and a soft polyether block (PTMG) based on 4,4'-MDI and 1,4-BDO (1,4-butanediol), hardness 85 Shore A.

[0165] Polymer composition 1 was prepared by mixing 5 wt% PA1 and 95 wt% TPU using an 18 mm ZSK twin-screw extruder (Coperion). The barrel temperature was set to 210°C, the screw speed to 280 rpm, and the flow rate to 8 kg / h. The composition was then dried under reduced pressure at 80°C to achieve a moisture content of less than 0.04%.

[0166] Polymer composition 2 was prepared by mixing 50% by weight of PA1 and 50% by weight of TPU using an 18mm ZSK twin-screw extruder (Coperion). The barrel temperature was set to 210°C, the screw speed to 280 rpm, and the flow rate to 8 kg / h. The composition was then dried under reduced pressure at 80°C to achieve a moisture content of less than 0.04%.

[0167] Polymer composition 3 was prepared by mixing 5 wt% PA2, 25 wt% PEBA, and 70 wt% TPU using an 18 mm ZSK twin-screw extruder (Coperion). The barrel temperature was set to 210°C, the screw speed to 280 rpm, and the flow rate to 8 kg / h. The composition was then dried under reduced pressure at 80°C to achieve a moisture content of less than 0.04%.

[0168] [Evaluation of foam] Next, a foam was prepared. - Foam 1 (Comparative Example): Manufactured from TPU alone. - Foam 2 (Example of the present invention): Produced from polymer composition 1. - Foam 3 (Comparative Example): Produced from polymer composition 2. - Foam 4 (Example of the present invention): Produced from polymer composition 3.

[0169] A 15mm thick foam was prepared using an Arburg Allrounder 520A 150T injection molding machine with a Trexel Series II physical foaming agent injection system. This machine utilizes Mucell® technology with partial mold release (core-back process). The operating parameters were as follows: - Barrel temperature: 250℃ - Mold geometry (mm): 200 x 100 x 1.6 mm - Injection speed: 120cm 3 / sec - Holding time before mold release: 1 second - Holding pressure: 25.0 MPa - Cooling time: 240 seconds - Mold temperature: 15℃ - Mold opening length: 15mm The foaming agent used was dinitrogen (N2), added at a concentration of 0.7% by weight.

[0170] The following foam properties were evaluated: - Density: In accordance with ISO 1183-1 standard, the test was conducted at 23°C using the underwater vertical thrust method; five repeated tests were performed. - ΔDensity: Characterizes the homogeneity of the foam and corresponds to the density difference of the foam between the point closest to the injection point and the point furthest from the injection point; the lower this value, the higher the homogeneity of the foam. - Rebound elasticity: In accordance with ISO 8307 standard, however, an 18.8g ball was used (when a steel ball weighing 18.8g and with a diameter of 16mm is dropped from a height of 500mm onto a foam sample, the rebound elasticity corresponds to the proportion of energy returned to the ball or the proportion of the initial height reached when the ball bounced back); the test was repeated 5 times. - Asker C hardness (15 seconds): Measured using a Hildebrand Asker C hardness tester in accordance with ISO 7619-1 standard.

[0171] The results are shown in the table below. [Table 1]

[0172] Composition 2 (Comparative Example) did not yield a homogeneous foam (Foam 3). Therefore, the parameters were not measured. The content of amine-chain-terminated polyamide in Composition 2 was too high.

[0173] The foam according to the present invention has a lower density and is more homogeneous than comparative foams prepared from TPU alone or from compositions having a polyamide content containing an excess amount of amine chain terminals. Furthermore, foam 2 has a lower density and higher rebound elasticity for equivalent hardness. Foam 4 has a lower density and lower hardness for equivalent rebound elasticity. In conclusion, the foam according to the present invention provides a better balance of properties.

Claims

1. A polymer foam, wherein, with respect to the total weight of the foam, - At least one thermoplastic polyurethane in an amount of 10% to 99% by weight, preferably 15% to 89% by weight, - At least one polyamide containing amine chain ends, detected by potentiometric assay in meth-cresol using a 0.02 N perchloric acid solution in a concentration of 1% to 40% by weight, preferably 1% to 30% by weight, and A polymer foam comprising, where the polyamide is a reaction product of one or more monomers selected from amino acids or aminocarboxylic acids, lactams, and monomers obtained from the reaction between aliphatic diamines and dicarboxylic acids.

2. The foam according to claim 1, wherein at least a portion of the total amount of polyamide is covalently bonded to thermoplastic polyurethane molecules via urea functional groups.

3. The urea functional group concentration is DMSO-D ６ The foam according to claim 2, wherein the concentration measured by 13C NMR in the middle is 0.001 meq / g to 0.1 meq / g, more preferably 0.003 meq / g to 0.08 meq / g, and more preferably 0.005 meq / g to 0.05 meq / g.

4. The polyamide was measured by potentiometric assay in metha-cresol using a 0.02 N perchloric acid solution, and showed a concentration of 0.01 meq / g to 2.0 meq / g, preferably 0.02 meq / g to 1.5 meq / g, more preferably 0.02 to 1 meq / g, and even more preferably 0.02 meq / g to 0.4 meq / g of NH. ２ A foam according to any one of claims 1 to 3, having an amine functional group concentration.

5. At least one type of thermoplastic polyurethane is a copolymer comprising a rigid block and a flexible block. - The flexible block is selected from polyether blocks, polyester blocks, polycarbonate blocks, and combinations thereof; preferably, the flexible block is selected from polyether blocks, polyester blocks, and combinations thereof, more preferably polytetrahydrofuran blocks, polypropylene glycol blocks, and / or polyethylene glycol blocks; and / or - The hard block contains units derived from 4,4'-diphenylmethane diisocyanate and / or 1,6-hexamethylene diisocyanate, preferably units derived from at least one chain extender selected from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol. The foam according to any one of claims 1 to 4.

6. The foam according to any one of claims 1 to 5, wherein the amine chain-terminus-containing polyamide is selected from the group consisting of polyamide 11, polyamide 12, polyamide 10, polyamide 6, polyamide 6.10, polyamide 6.6, polyamide 10.10, polyamide 10.12, polyamide 6.13, polyamide 10.9, polyamide 12.9, and combinations thereof.

7. The foam according to any one of claims 1 to 6, further comprising at least one polyamide block-polyether block copolymer.

8. The foam according to any one of claims 1 to 7, comprising 0 to 89% by weight, preferably 10% to 70% by weight, of at least one polyamide block-polyether block copolymer based on the total weight of the foam.

9. Polyamide block-polyether block copolymer, TFA / CDCl ３ The foam according to claim 7 or 8, comprising at least 30% by weight, preferably at least 40% by weight, of polyamide blocks relative to the total weight of the copolymer, as measured by proton NMR in a (1 / 4 v / v) mixture.

10. The foam according to any one of claims 7 to 9, wherein the polyamide block of the polyamide block-polyether block copolymer is selected from polyamide 6, polyamide 6.10, polyamide 6.12, polyamide 11, polyamide 10, polyamide 12, polyamide 6.13, polyamide 10.9 and / or polyamide 12.9; and / or the polyether block of the polyamide block-polyether block copolymer is polyethylene glycol and / or polypropylene glycol and / or polytetrahydrofuran block.

11. The foam according to any one of claims 1 to 10, wherein the amine chain-terminus-containing polyamide has a number average molar mass of 1,000 to 60,000 g / mol, preferably 2,000 to 40,000 g / mol, and more preferably 3,000 to 20,000 g / mol.

12. Measured at 23°C in accordance with ISO 1183-1 standard, the result was 800 kg / m³. ３ Preferably 400 kg / m ３ Below, 300 kg / m is given higher priority. ３ Below, with even higher priority, is 230 kg / m ３ A foam according to any one of claims 1 to 11, having the following density.

13. A method for producing a foam according to any one of claims 1 to 12, - A step of providing a polymer composition comprising at least one thermoplastic polyurethane, at least one amine chain-terminus-containing polyamide, and, if appropriate, at least one polyamide block-polyether block copolymer; - A step of mixing the polymer composition with a foaming agent; and - A process of foaming a mixture of polymer composition and foaming agent. Methods that include...

14. The method according to claim 13, wherein a foaming agent is mixed with a molten polymer composition, and the foaming of the mixture is preferentially carried out in a mold.

15. The method according to claim 13, wherein the blowing agent is a physical blowing agent, which is mixed with a polymer composition in the form of a solid preform, and the foaming of the mixture is preferably carried out in an autoclave.

16. Preferably, an article formed from or comprising at least one element made of the foam described in any one of claims 1 to 12, selected from sports shoe soles, balloons or balls, gloves, personal protective equipment, rail pads, automotive parts, construction parts, and electrical and electronic equipment components.

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