Block polymer for shoe sole, resin composition for shoe sole, and shoe sole

Abstract

An objective of the present invention is to provide a shoe sole having a small compression set. The present invention pertains to a shoe sole block polymer (X) having, as structural units, a polyamide (am) block, and a polyalkylene glycol (b) block containing a C3-4 alkylene glycol as a constituent monomer, the shoe sole block polymer (X) having a cross-linked structure in which a crosslinking agent (K) and the polyalkylene glycol (b) block are bonded to each other.

Description

[Technical Field]

[0001] The present invention relates to a block polymer for shoe soles, a resin composition for shoe soles, and a shoe sole. [Background technology]

[0002] Ethylene vinyl acetate (EVA) resin is commonly used as a resin for shoe soles. For example, a sports shoe sole made of multiple components using EVA resin has been proposed (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-093412 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while soles made of EVA resin are inexpensive, they have poor durability due to large compression strain and also have poor resilience, so there was a need to solve these problems. An object of the present invention is to provide a shoe sole with a small compressive strain. [Means for solving the problem]

[0005] The present inventors conducted extensive research to solve the above-mentioned problems and arrived at the present invention. Specifically, the present invention relates to a block polymer (X) for shoe soles, the block polymer (X) having as its constituent units a block of polyamide (am) and a block of polyalkylene glycol (b) containing an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer, the block polymer (X) having a crosslinked structure formed by bonding a crosslinking agent (K) to the block of polyalkylene glycol (b); a resin composition (Y) for shoe soles containing the block polymer (X) for shoe soles and a thermoplastic resin (E) other than the block polymer (X); and a shoe sole (Z) which is an expansion-molded product of the block polymer (X) for shoe soles or the resin composition (Y) for shoe soles. [Effects of the Invention]

[0006] The shoe sole (Z) using the block polymer for shoe soles (X) or the resin composition for shoe soles (Y) of the present invention exhibits the effects of small compression set, excellent durability, and excellent resilience. DETAILED DESCRIPTION OF THE INVENTION

[0007] <Polyamide (am)> Examples of the polyamide (am) in the present invention include polyamide (am1) having a dicarboxylic acid or its amide-forming derivative and a diamine as essential constituent monomers, polyamide (am2) obtained by ring-opening polymerization of a lactam with a dicarboxylic acid or a monocarboxylic acid, polyamide (am3) obtained by ring-opening polymerization of a lactam with water, a diamine or a monoamine, polyamide (am4) obtained by polycondensation of an aminocarboxylic acid, and polyamide (am5) obtained by synthesizing two or more of (am1) to (am4) in one shot. The polyamide (am) block in the present invention contains one or more types of the above polyamide (am).

[0008] Examples of dicarboxylic acids used in the polyamides (am1) and (am2) include dicarboxylic acids having 2 to 20 carbon atoms (aliphatic dicarboxylic acids having 2 to 20 carbon atoms (succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, maleic acid, fumaric acid, itaconic acid, etc.), aromatic dicarboxylic acids having 8 to 20 carbon atoms (terephthalic acid, phthalic acid, 2,6- or 2,7-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, tolylenedicarboxylic acid, xylylenedicarboxylic acid, 5-sulfoisophthalic acid, etc.), and alicyclic dicarboxylic acids having 5 to 20 carbon atoms (cyclopropanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, bicyclohexyl-4,4'-dicarboxylic acid, camphoric acid, etc.)).

[0009] Examples of the amide-forming derivatives of dicarboxylic acids include alkyl (alkyl having 1 to 4 carbon atoms) esters (methyl esters, ethyl esters, etc.) of the above dicarboxylic acids and acid anhydrides of the above dicarboxylic acids. The dicarboxylic acids and amide-forming derivatives thereof may each be used alone or in combination of two or more.

[0010] Of the dicarboxylic acids and amide-forming derivatives thereof used in the polyamide (am1), from the viewpoints of compression set and resilience, preferred are aliphatic dicarboxylic acids having 2 to 20 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and amide-forming derivatives thereof, more preferred are aliphatic dicarboxylic acids having 2 to 20 carbon atoms and amide-forming derivatives thereof, particularly preferred are aliphatic dicarboxylic acids having 6 to 12 carbon atoms and amide-forming derivatives thereof, particularly preferred are adipic acid, undecanedioic acid, dodecanedioic acid, and amide-forming derivatives thereof, and most preferred are adipic acid and amide-forming derivatives thereof.

[0011] Of the dicarboxylic acids and their amide-forming derivatives used in the polyamide (am2), from the viewpoints of compression set and resilience, preferred are aliphatic dicarboxylic acids having 2 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms, more preferred are aromatic dicarboxylic acids having 8 to 20 carbon atoms (terephthalic acid, phthalic acid, 2,6- or 2,7-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, tolylenedicarboxylic acid, xylylenedicarboxylic acid, 5-sulfoisophthalic acid, etc.), and particularly preferred are terephthalic acid and 2,6- or 2,7-naphthalenedicarboxylic acid.

[0012] Diamines used in the polyamides (am1) and (am3) include diamines having 2 to 12 carbon atoms [aliphatic diamines having 2 to 12 carbon atoms (ethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, decamethylenediamine, etc.)]. Of these, preferred are aliphatic diamines having 6 or 10 carbon atoms, more preferred are 1,6-diaminohexane and 1,10-diaminodecane, and particularly preferred is 1,6-diaminohexane. The diamines may be used alone or in combination of two or more.

[0013] Examples of the monocarboxylic acid used in the polyamide (am2) include monocarboxylic acids having 1 to 20 carbon atoms (capric acid, lauric acid, myristic acid, benzoic acid, t-butylbenzoic acid, 2-naphthalenecarboxylic acid, etc.).

[0014] Examples of the monoamine used in the polyamide (am3) include monoamines having 1 to 20 carbon atoms (such as methylamine, ethylamine, propylamine, hexylamine, octylamine, decylamine, and dodecylamine).

[0015] As the lactam used in the polyamides (am2) and (am3), from the viewpoints of ease of synthesis and dimensional stability, ε-caprolactam, 11-undecane lactam, and 12-laurolactam are preferred, and ε-caprolactam and 12-laurolactam are more preferred.

[0016] The aminocarboxylic acid used in the polyamide (am4) includes aminocarboxylic acids having 2 to 12 carbon atoms (preferably 4 to 12, and more preferably 6 to 12), and specific examples thereof include amino acids (glycine, alanine, valine, leucine, isoleucine, phenylalanine, etc.), ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocaprylic acid, ω-aminopelargonic acid, ω-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Of the above aminocarboxylic acids, from the viewpoints of compression set and resilience, preferred are glycine, leucine, 8-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, more preferred are 8-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, particularly preferred are 11-aminoundecanoic acid and 12-aminododecanoic acid, and most preferred is 12-aminododecanoic acid.

[0017] The content of carboxyl groups in the polyamide (am) block is expressed by an acid value (unit: mgKOH / g), and the content of amino groups in the polyamide (am) is expressed by an amine value (unit: mgKOH / g). The acid value in the present invention is measured by titration using a KOH / methanol solution containing phenolphthalein as an indicator, and when the acid group is a carboxylic anhydride group, the acid value is measured as the half-esterified acid value after half-esterification with methanol.

[0018] From the viewpoint of ease of synthesis of the block polymer, the polyamide (am) preferably has a carboxyl group. From the viewpoint of compression set and resilience, the acid value of the polyamide (am) having a carboxyl group is preferably 20 to 220 mgKOH / g, more preferably 25 to 150 mgKOH / g, and particularly preferably 30 to 120 mgKOH / g.

[0019] Furthermore, from the viewpoint of compression set and resilience, the polyamide (am) is preferably a polyamide containing at least one essential constituent monomer selected from the group consisting of 1,6-diaminohexane, 1,10-diaminodecane, ε-caprolactam, 11-undecane lactam, 12-laurolactam, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

[0020] The number average molecular weight (hereinafter abbreviated as Mn) of the polyamide (am) is preferably 500 to 5,000, more preferably 750 to 4,000, and particularly preferably 1,000 to 4,000, from the viewpoints of compression set and resilience.

[0021] The number average molecular weight (Mn) of the polymer in the present invention can be measured using gel permeation chromatography (GPC) under the following conditions. Equipment: "HLC-8120" [Tosoh Corporation] Columns: "TSKgelGMHXL" [manufactured by Tosoh Corporation] (2 tubes), and "TSKgelMultiporeHXL-M" [manufactured by Tosoh Corporation] (1 tube) Sample solution: 0.3% by weight orthodichlorobenzene solution ·Solution injection volume: 100μl ·Flow rate: 1ml / min ·Measurement temperature: 135℃ Detector: Refractive index detector Reference material: Standard polystyrene (TSKstandardPOLYSTYRENE) 12 points (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [Tosoh Corporation]

[0022] The polyamide (am) can be produced by a general polyamide production method. The polyamidation reaction is carried out, for example, under reduced pressure at a temperature of 150 to 300°C, and the reaction time is preferably 0.5 to 20 hours. If necessary, a catalyst generally used in polyamidation reactions may be used.

[0023] <Polyalkylene glycol (b)> The polyalkylene glycol (b) in the present invention contains, as a constituent monomer, an alkylene glycol having a carbon number of 3 to 4. The alkylene glycol preferably has 4 carbon atoms. Examples of the polyalkylene glycol (b) include polytetramethylene glycol, polypropylene glycol, and terminal-modified products thereof (amino group-modified products, glycidyl etherified products). The block of polyalkylene glycol (b) in the present invention contains one or more types of the above polyalkylene glycol (b). Among these, from the viewpoint of productivity of the block polymer, those having a hydroxyl group or an amino group at at least one end of the polymer main chain are preferred. The polyalkylene glycol (b) can be obtained by a known production method (polymerizing tetrahydrofuran and propylene oxide in the presence of a catalyst). Modified products thereof can also be obtained by known production methods. The polyalkylene glycol (b) can be obtained by the above-mentioned method, or a commercially available product can be used.

[0024] From the viewpoint of compression set and resilience, the Mn of the polyalkylene glycol (b) is preferably 500 to 4,000, more preferably 750 to 3,000, and particularly preferably 1,000 to 3,000.

[0025] <Block polymer (X) for shoe soles> The block polymer (X) for shoe soles of the present invention (hereinafter sometimes abbreviated as block polymer (X)) has, as constituent units, a block of the polyamide (am) and a block of the polyalkylene glycol (b).

[0026] From the viewpoint of compression set and resilience, the Mn of the polyamide (am) block is preferably 500 to 5,000, more preferably 750 to 4,000, and particularly preferably 1,000 to 4,000.

[0027] From the viewpoint of compression set and resilience, the Mn of the block of polyalkylene glycol (b) is preferably 500 to 4,000, more preferably 750 to 3,000, and particularly preferably 1,000 to 3,000.

[0028] The structure in which the block of polyamide (am) and the block of polyolefin (b) constituting the block polymer (X) are bonded includes (a)-(b) type, (a)-(b)-(a) type, (b)-(a)-(b) type and [(a)-(b)] type. n The types (n represents the average number of repetitions) are included.

[0029] The block polymer (X) can be produced, for example, by reacting the above polyamide (am) with the polyalkylene glycol (b).

[0030] When the block polymer (X) has a structure in which a block of polyamide (am) and a block of polyalkylene glycol (b) are bonded via an amide bond, an imide bond, or an ester bond, the block polymer (X) can be produced, for example, by a method in which polyamide (am) and polyalkylene glycol (b) are charged into a reaction vessel and reacted under stirring at a reaction temperature of 100 to 250°C and a pressure of 0.1 MPa or less for 1 to 50 hours while removing water produced in the amidation reaction, imidization reaction, or esterification reaction from the reaction system.

[0031] The block polymer (X) has a crosslinking agent (K) (described later) as a constituent unit. The block polymer (X) has a crosslinked structure in which the crosslinking agent (K) and a block of polyalkylene glycol (b) are bonded together. In the block polymer (X), the crosslinking agent (K) and the block of polyalkylene glycol (b) are preferably bonded together via three or more bonds, and more preferably bonded together via three or more ester bonds and / or amide bonds.

[0032] The weight ratio [(am) / (b)] of the polyamide (am) block to the polytetramethylene glycol (b) block constituting the block polymer (X) is preferably 15 / 85 to 90 / 10, more preferably 20 / 80 to 80 / 20, and particularly preferably 30 / 70 to 80 / 20, from the viewpoints of compression set, resilience, and hardness.

[0033] The Mn of the block polymer (X) is preferably 10,000 to 150,000, more preferably 10,000 to 100,000, and particularly preferably 20,000 to 80,000. The block polymer (X) for shoe soles of the present invention can be suitably used as a raw material resin for various shoe soles (outsoles and midsoles).

[0034] <Crosslinking agent (K)> The crosslinking agent (K) in the present invention is a compound capable of crosslinking the polyalkylene glycol (b), and is preferably a compound having at least three functional groups capable of reacting with the terminal functional groups of the polyalkylene glycol (b). The crosslinking agent (K) is preferably a compound having at least three functional groups (e.g., carboxyl, amino, epoxy, and hydroxyl groups) that can react with hydroxyl and / or amino groups. Of these functional groups, carboxyl groups are preferred in terms of reactivity with polyalkylene glycol (b).

[0035] The crosslinking agent (K) is not particularly limited as long as it reacts with the polyalkylene glycol (b), and examples thereof include trivalent or higher polycarboxylic acids (K1), trivalent or higher polyepoxides (K2), trivalent or higher polyamines (K3), and trivalent or higher polyols (K4). Examples of the trivalent or higher polycarboxylic acid (K1) include trimesic acid, trimellitic acid, pyromellitic acid, hexanetricarboxylic acid, decanetricarboxylic acid, and acid anhydrides thereof and alkyl (alkyl having 1 to 2 carbon atoms) esters thereof. An example of the trivalent or higher polyepoxide (K2) is triglycidyl ether of trimethylolpropane. An example of the trivalent or higher polyamine (K3) is triethylenetetramine. An example of the trihydric or higher polyol (K4) is triethanolamine.

[0036] Among the crosslinking agents (K), from the viewpoints of reactivity and compression set, trivalent or higher polycarboxylic acids (K1) are preferred, trivalent or higher aromatic polycarboxylic acids are more preferred, and trimellitic acid, its acid anhydride, or alkyl (alkyl having 1 to 2 carbon atoms) esters are particularly preferred.

[0037] When a crosslinked structure is introduced into the block polymer (X), the crosslinking agent (K) may be added at any timing before, during, or after the reaction of the polyamide (am) with the polyalkylene glycol (b). Regarding the amount of the crosslinking agent (K), the molar ratio of the crosslinking agent (K) to the polyamide (am) [(K) / (am)] is preferably 3 / 97 to 35 / 65, more preferably 5 / 95 to 20 / 80, from the viewpoints of compression set and resilience.

[0038] <Resin composition for shoe soles (Y)> The shoe sole resin composition (Y) of the present invention (hereinafter sometimes abbreviated as resin composition (Y)) contains the shoe sole block polymer (X) of the present invention and a thermoplastic resin (E) other than the block polymer (X). Examples of the thermoplastic resin (E) include polyolefin resin (E1), polystyrene resin (E2), acrylic resin (E3), polyamide resin (E4), polyester resin (E5), polyacetal resin (E6), polycarbonate resin (E7), and polyurethane resin (E8). Among the above thermoplastic resins (E), polyamide resin (E4) is preferred from the viewpoints of compression set and resilience.

[0039] The Mn of the thermoplastic resin (E) is preferably 7,000 to 500,000, and more preferably 10,000 to 200,000. The weight ratio [(X) / (E)] of the block polymer (X) for shoe soles to the thermoplastic resin (E) other than the block polymer (X) is preferably 60 / 40 to 95 / 5, more preferably 70 / 30 to 90 / 10.

[0040] The block polymer (X) for shoe soles and the resin composition (Y) for shoe soles may contain additives (D), such as colorants (D1) [e.g., azo pigments], release agents (D2) [e.g., liquid paraffin], antioxidants (D3) [e.g., triphenyl phosphite], flame retardants (D4) [e.g., antimony trioxide], ultraviolet absorbers (D5) [e.g., phenyl salicylate], antibacterial agents (D6) [e.g., benzimidazole], compatibilizers (D7) [e.g., modified vinyl copolymers], fillers (D8) [e.g., calcium carbide], and transesterification inhibitors (D9) [e.g., monooctadecyl phosphate], within the scope of the present invention. Each additive may be used alone or in combination of two or more.

[0041] The total content of additives (D) based on the weight of the block polymer for shoe soles (X) and the resin composition for shoe soles (Y) is generally 45% by weight or less, and from the viewpoints of the effect of each additive and the mechanical strength of the molded product, it is preferably 0.001 to 40% by weight, more preferably 0.01 to 35% by weight; from the same viewpoints, the content of each additive (D) is preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight for the colorant (D1); preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for the mold release agent (D2); and preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for the antioxidant (D3). or 0.05 to 1% by weight; the flame retardant (D4) is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight; the ultraviolet absorber (D5) is preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight; the antibacterial agent (D6) is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight; the compatibilizer (D7) is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight; the filler (D8) is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight; and the transesterification inhibitor (D9) is preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight.

[0042] <Shoe sole (Z)> The shoe sole (Z) of the present invention is a foam-molded product of the block polymer for shoe soles (X) or the resin composition for shoe soles (Y). The density of the shoe sole (Z) is preferably 0.20 to 0.90 g / cm 3 and more preferably 0.30 to 0.80 g / cm 3 is. In the present invention, the density is a value measured at 23°C in accordance with ASTM D1505.

[0043] The shoe sole (Z) of the present invention can be produced by mixing the block polymer (X) for shoe soles or the resin composition (Y) for shoe soles, for example, using an open roll, followed by foam molding. After foam molding, further processing may be carried out, if necessary. The molding temperature during foam molding is, for example, 150°C to 220°C.

[0044] In addition, a foaming agent (C) may be used during the foam molding. Examples of the blowing agent (C) include azodicarbonamide (ADCA), azobisisobutyronitrile (AIBN), and dinitrosopentamethylenetetramine (DPT). The weight ratio of the block polymer (X) to the foaming agent (C) [(X) / (C)] and the weight ratio of the resin composition (Y) to the foaming agent (C) [(Y) / (C)] vary depending on the desired density, but are both preferably 90 / 10 to 99 / 1, more preferably 93 / 7 to 99 / 2.

[0045] The block polymer (X) for shoe soles of the present invention can be suitably used as a raw material resin for various shoe soles (outsoles, midsoles). Furthermore, a shoe sole (Z) using the block polymer (X) for shoe soles is useful as a midsole or outsole because it has a small compression set, excellent durability, and excellent resilience (a small loss coefficient and small temperature-dependent change in resilience).

[0046] The present specification discloses the following:

[0047] [1] A block polymer (X) for shoe soles, which has as its constituent units a block of polyamide (am) and a block of polyalkylene glycol (b) containing an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer, and which has a crosslinked structure in which a crosslinking agent (K) and the block of polyalkylene glycol (b) are bonded.

[0048] [2] The block polymer (X) for shoe soles according to [1], wherein the number average molecular weight of the polyamide (am) block is 500 to 5,000.

[0049] [3] The block polymer (X) for shoe soles according to [1] or [2], wherein the number average molecular weight of the block of the polyalkylene glycol (b) is 500 to 4,000.

[0050] [4] The block polymer (X) for shoe soles according to any one of [1] to [3], wherein the weight ratio [(am) / (b)] of the block of the polyamide (am) to the block of the polyalkylene glycol (b) is 15 / 85 to 90 / 10.

[0051] [5] The block polymer (X) for shoe soles according to any one of [1] to [4], wherein the crosslinking agent (K) and the block of polyalkylene glycol (b) are bonded via three or more ester bonds and / or amide bonds.

[0052] [6] The block polymer (X) for shoe soles according to any one of [1] to [5], which has a number average molecular weight of 10,000 to 150,000.

[0053] [7] A resin composition (Y) for shoe soles, comprising the block polymer (X) for shoe soles according to any one of [1] to [6] and a thermoplastic resin (E) other than the block polymer (X) for shoe soles.

[0054] [8] A shoe sole (Z) which is a foam-molded product of the block polymer for shoe soles (X) according to any one of [1] to [6] or the resin composition for shoe soles (Y) according to [7].

[0055] [9] Density: 0.20 to 0.90 g / cm 3 The shoe sole (Z) according to [8]. [Example]

[0056] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, % means % by weight and parts means parts by weight.

[0057] <Production Example 1> [Production of polyamide (am-1)] A pressure-resistant reactor was charged with 82.5 parts of 12-laurolactam, 16.3 parts of terephthalic acid, 0.3 parts of an antioxidant (trade name "Irganox 1010" manufactured by BASF Japan Ltd.), and 10 parts of water. After replacing the atmosphere with nitrogen, the mixture was heated to 220°C with stirring under a sealed condition, and stirred at 220°C under a pressure of 0.2 to 0.3 MPa for 4 hours to obtain a polyamide (am-1) having carboxyl groups at both ends. The acid value of the polyamide (am-1) was 109 and the Mn was 1,000.

[0058] <Production Example 2> [Production of polyamide (am-2)] Into a pressure-resistant reactor similar to that used in Production Example 1, 89.9 parts of 12-laurolactam, 8.9 parts of terephthalic acid, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 10 parts of water were placed, and after replacing with nitrogen, the mixture was heated to 220°C with stirring in a sealed state, and stirred at 220°C under a pressure of 0.2 to 0.3 MPa for 4 hours to obtain a polyamide (am-2) having carboxyl groups at both ends. The acid value of the polyamide (am-2) was 54.5 and Mn was 2,000.

[0059] <Production Example 3> [Production of polyamide (am-3)] Into a pressure-resistant reactor similar to that in Production Example 1, 95.9 parts of 12-laurolactam, 4.1 parts of terephthalic acid, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 10 parts of water were placed, and after replacing with nitrogen, the mixture was heated to 220°C with stirring in a sealed state, and stirred at 220°C under a pressure of 0.2 to 0.3 MPa for 4 hours to obtain a polyamide (am-3) having carboxyl groups at both ends. The acid value of the polyamide (am-3) was 27.4 and Mn was 4,100.

[0060] Example 1 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 92 parts of polyamide (am-1), 205 parts of polytetramethylene glycol (b-1) (PTMG, Mn: 2,000), 1.9 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours, yielding a block polymer (X-1) for shoe soles (Mn: 43,000).

[0061] <Example 2> 71 parts of polyamide (am-1), 229 parts of polytetramethylene glycol (b-1), 5.7 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were placed in a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer (X-2) for shoe soles (Mn: 60,000).

[0062] Example 3 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 190 parts of polyamide (am-2), 107 parts of polytetramethylene glycol (b-2) (PTMG, Mn: 1,000), 2.0 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer (X-3) for shoe soles (Mn: 52,000).

[0063] Example 4 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 177 parts of polyamide (am-2), 118 parts of polytetramethylene glycol (b-2), 4.1 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours, yielding a block polymer (X-4) for shoe soles (Mn: 58,000).

[0064] <Example 5> Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 163 parts of polyamide (am-2), 118 parts of polytetramethylene glycol (b-2), 6.3 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours, yielding a block polymer (X-5) for shoe soles (Mn: 65,000).

[0065] Example 6 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 191 parts of polyamide (am-3), 130 parts of polytetramethylene glycol (b-1), 1.0 part of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer (X-6) for shoe soles (Mn: 57,000).

[0066] Example 7 233 parts of polyamide (am-3), 66 parts of polytetramethylene glycol (b-2), 1.2 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were placed in a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature for 6 hours under reduced pressure (0.13 kPa or less), yielding a block polymer (X-7) for shoe soles (Mn: 54,000).

[0067] Example 8 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 92 parts of polyamide (am-1), 205 parts of polypropylene glycol (b-3) (PPG, Mn: 2,000), 1.9 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours, yielding a block polymer (X-8) for shoe soles (Mn: 42,000).

[0068] Example 9 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 190 parts of polyamide (am-2), 108 parts of polypropylene glycol (b-4) (PPG, Mn: 1,000), 2.0 parts of trimellitic anhydride, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer (X-9) (Mn: 50,000) for shoe soles.

[0069] Example 10 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 139 parts of polyamide (am-2), 159 parts of polytetramethylene glycol (b-1) (Mn: 2,000), 1.6 parts of trimesic acid, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature for 6 hours under reduced pressure (0.13 kPa or less), to obtain a block polymer (X-10) (Mn: 53,000) for shoe soles.

[0070] Example 11 Into a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, 139 parts of polyamide (am-2), 159 parts of polypropylene glycol diamine (b-5), 1.6 parts of trimesic acid, and 0.6 parts of zirconium acetate were charged, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours, yielding a block polymer (X-11) (Mn: 62,000) for shoe soles.

[0071] Example 12 70 parts of the block polymer (X-3) for shoe soles obtained in Example 3 and 30 parts of a polyamide resin (E-1) [6 nylon resin, trade name "UBE Nylon 1013B", manufactured by UBE Corporation, Mn 13,000] were kneaded in a twin-screw extruder at 240°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-12).

[0072] Example 13 90 parts of the block polymer (X-3) for shoe soles obtained in Example 3 and 10 parts of polyamide resin (E-2) [12 nylon resin, trade name "UBE Nylon 3014U", manufactured by UBE Corporation, Mn 14,000] were kneaded in a twin-screw extruder at 200°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition (Y-13) for shoe soles.

[0073] Example 14 70 parts of the block polymer (X-3) for shoe soles obtained in Example 3 and 30 parts of polyamide resin (E-2) [the above-mentioned "UBE Nylon 3014U"] were kneaded in a twin-screw extruder at 200°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition (Y-14) for shoe soles.

[0074] Example 15 90 parts of the block polymer (X-5) for shoe soles obtained in Example 5 and 10 parts of polyamide resin (E-2) [the above-mentioned "UBE Nylon 3014U"] were kneaded in a twin-screw extruder at 200°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-15).

[0075] Example 16 70 parts of the block polymer (X-5) for shoe soles obtained in Example 5 and 30 parts of polyamide resin (E-2) [the above-mentioned "UBE Nylon 3014U"] were kneaded in a twin-screw extruder at 200°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-16).

[0076] <Comparative Example 1> 202 parts of polyamide (am-2), 98 parts of polytetramethylene glycol (b-2), and 0.6 parts of zirconium acetate were added to a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer for shoe soles (component X-1) (Mn: 40,000).

[0077] <Comparative Example 2> 206 parts of polyamide (am-2), 93 parts of polytetramethylene glycol (b-2), 1.0 part of glycerin, and 0.6 parts of zirconium acetate were added to a reaction vessel equipped with a stirrer, a thermometer, and a heating / cooling device, and the mixture was heated to 240°C with stirring. Polymerization was carried out at the same temperature under reduced pressure (0.13 kPa or less) for 6 hours to obtain a block polymer for shoe soles (component X-2) (Mn: 45,000).

[0078] <Comparative Example 3> As a block polymer for comparison, a commercially available EVA resin, manufactured by Mitsui Chemicals, Inc., under the trade name "Evaflex 270," was used.

[0079] Example 17 100 parts of the block polymer (X-1) for shoe soles and 4 parts of the foaming agent (C-1) were mixed in an open roll, and then foam-molded at 200°C and 15 MPa to obtain a shoe sole (Z-1). The obtained shoe sole (Z-1) was evaluated.

[0080] <Examples 18 to 32 and Comparative Examples 4 to 6> Each shoe sole (Z) was obtained in the same manner as in Example 17, except that the raw material composition (parts) was in accordance with Table 1. The results are shown in Table 1.

[0081] <Evaluation> (1) Density Density (g / cm 3 ) was determined at 23°C in accordance with ASTM D1505.

[0082] (2) Compression strain The resulting sole (5cm length x 5cm width x 5cm height) was subjected to 10kgf / cm2 pressure at 50°C. 2 The test was carried out five times in total, with one test being a test in which a load was applied for 20 hours at 1000 kJ / s and then released for 4 hours. The height before the test was L0 and the height after the test was L5, and the compressive strain was calculated using the following formula and evaluated according to the following <evaluation criteria>. Compressive strain (%) = (L0-L5) x 100 / L0 <Evaluation criteria> ◎: Compression strain less than 10% 〇: Compression strain is 10% or more to less than 15% △: Compression strain is 15% or more to less than 20% ×: Compression distortion is 20% or more

[0083] (3) Resilience A sample was taken from the obtained sole, and the dynamic viscoelasticity was measured under the following (measurement conditions) in accordance with JIS K7244-4 to determine the loss coefficient [tan δ] at 23°C, which was then evaluated according to the following <evaluation criteria>. (Measurement conditions) Measuring equipment: Dynamic viscoelasticity measuring device Rheogel-E4000, manufactured by UBM Corporation Sample shape: Strip shape, length 40±3mm, width 5±0.3mm, thickness 3±0.3mm Measurement mode: Tensile mode with sinusoidal strain Distance between chucks: 30±0.2mm ·Temperature: -50~200℃ Frequency: 10Hz Load: Automatic static load Dynamic strain: 3μm

[0084] <Evaluation criteria> ◎: Less than 0.06 〇: 0.06 or more and less than 0.1 △: 0.1 or more and less than 0.15 ×: 0.15 or more

[0085] (4) Change in resilience with temperature (-20℃ [tanδ] / 25℃ [tanδ]) As in (3) above, the loss coefficient at -20°C (-20°C [tanδ]) and the loss coefficient at 25°C (25°C [tanδ]) were calculated from the measurement data of dynamic viscoelasticity, and -20°C [tanδ] / 25°C [tanδ] was evaluated according to the following <evaluation criteria>.

[0086] <Evaluation criteria> ◎: 0.75 or more to less than 1.25 〇: 0.6 or more and less than 0.75, or 1.25 or more and less than 1.4 △: 0.4 or more and less than 0.6, or 1.4 or more and less than 1.6 ×: Less than 0.4 or 1.6 or more

[0087] (5) Temperature dependence of sole resilience The sole was cut into a size of 25 cm length x 10 cm width x 3 cm thickness to obtain a test piece. The test piece was placed in a room at 20°C and 50% RH (relative humidity) and the temperature was regulated for 24 hours. An aluminum ball with a diameter of 2 cm is dropped from the top of the test piece from a height of 50 cm, and the distance from the test piece to the bottom of the aluminum ball at the time of maximum rebound is measured. The rebound distance is L. 20 It was decided. In addition, the test piece was placed in a room at -20°C and 50% RH, and the same test was carried out after 24 hours of temperature control. The rebound distance was recorded as L -20 It was decided. The L measured above 20 And, L -20 From this, the temperature dependency of the sole resilience was calculated using the following formula and evaluated according to the following evaluation criteria. (Temperature dependence of sole resilience) = L -20 ×100 / L 20

[0088] <Evaluation criteria> ◎: 90 or above 〇: 80 or more, less than 90 △: 70 or more, less than 80 ×: Less than 70

[0089] [Table 1]

[0090] In Table 1, the ingredients are as follows: EVA resin: Mitsui Chemicals, Inc., product name "Evaflex 270" Crosslinking agent: dicumyl peroxide (DCP) [NOF Corporation, trade name "Percumyl D"] Foaming agent (C-1): Azodicarbonamide [manufactured by Eiwa Chemical Industry Co., Ltd., product name "Vinihole DW#6"]

[0091] The results in Table 1 show that the shoe sole (Z) using the block polymer for shoe soles (X) of the present invention has a smaller compression strain, better durability, and better resilience (smaller loss coefficient and less change in resilience due to temperature) than the comparative sole. [Industrial Applicability]

[0092] The block polymer (X) for shoe soles of the present invention can be suitably used as a raw material resin for various shoe soles (outsoles, midsoles). Furthermore, the shoe sole (Z) using the block polymer (X) for shoe soles has small compression strain, excellent durability, and excellent resilience, and is therefore useful as a midsole or outsole.

Claims

1. A shoe sole (Z) which is a foam molded body of a block polymer (X) for shoe soles, The block polymer (X) for shoe soles is The polymer has a block of polyamide (am) and a block of polyalkylene glycol (b) containing an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer as constituent units, A shoe sole (Z) having a crosslinked structure in which a crosslinking agent (K) and a block of polyalkylene glycol (b) are bonded together.

2. A shoe sole (Z) according to claim 1, wherein the number average molecular weight of the polyamide (am) block is 500 to 5,000.

3. A shoe sole (Z) according to claim 1, wherein the number average molecular weight of the block of polyalkylene glycol (b) is 500 to 4,000.

4. A shoe sole (Z) according to claim 1, wherein the weight ratio [(am) / (b)] of the polyamide (am) block to the polyalkylene glycol (b) block is 15 / 85 to 90 / 10.

5. A shoe sole (Z) according to claim 1, wherein the crosslinking agent (K) and the block of polyalkylene glycol (b) are bonded via three or more ester bonds and / or amide bonds.

6. A shoe sole (Z) according to claim 1, wherein the number average molecular weight of the block polymer (X) for shoe soles is 10,000 to 150,000.

7. A shoe sole (Z) which is a foamed molded body of a shoe sole resin composition (Y) containing a shoe sole block polymer (X) and a thermoplastic resin (E) other than the shoe sole block polymer (X), The block polymer (X) for shoe soles is The polymer has a block of polyamide (am) and a block of polyalkylene glycol (b) containing an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer as constituent units, A shoe sole (Z) having a crosslinked structure in which a crosslinking agent (K) and a block of polyalkylene glycol (b) are bonded together.

8. A shoe sole (Z) according to claim 7, wherein the number average molecular weight of the polyamide (am) block is 500 to 5,000.

9. A shoe sole (Z) according to claim 7, wherein the number average molecular weight of the block of polyalkylene glycol (b) is 500 to 4,000.

10. A shoe sole (Z) according to claim 7, wherein the weight ratio [(am) / (b)] of the polyamide (am) block to the polyalkylene glycol (b) block is 15 / 85 to 90 / 10.

11. A shoe sole (Z) according to claim 7, wherein the crosslinking agent (K) and the block of polyalkylene glycol (b) are bonded via three or more ester bonds and / or amide bonds.

12. A shoe sole (Z) according to claim 7, wherein the number average molecular weight of the block polymer (X) for shoe soles is 10,000 to 150,000.

13. Density: 0.20 to 0.90 g / cm ３ The shoe sole (Z) according to any one of claims 1 to 12.

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