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 polyolefin (a) block, and a polyalkylene glycol (b) block. The polyolefin (a) contains propylene and ethylene as constituent monomers and has a weight ratio of propylene to ethylene (propylene / ethylene) of 90 / 10-99.5 / 0.5. The polyalkylene glycol (b) contains a C3-4 alkylene glycol as a constituent monomer.

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 their 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 have conducted extensive research to solve the above problems and have arrived at the present invention, which relates to a block polymer (X) for shoe soles, which has, as structural units, a block of the following polyolefin (a) and a block of the following polyalkylene glycol (b); Polyolefin (a): Contains propylene and ethylene as constituent monomers, and the weight ratio of propylene to ethylene (propylene / ethylene) is 90 / 10 to 99.5 / 0.5; Polyalkylene glycol (b): containing an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer; shoe sole resin composition (Y) containing the shoe sole block polymer (X) and a thermoplastic resin (E) other than the shoe sole block polymer (X); shoe sole (Z) which is a foamed molded product of the shoe sole block polymer (X) or the shoe sole resin composition (Y). [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] <Polyolefin (a)> Examples of the polyolefin (a) in the present invention include polyolefins (a1-1) having carboxyl groups or carboxylic anhydride groups at both polymer terminals, polyolefins (a1-2) having hydroxyl groups at both polymer terminals, polyolefins (a1-3) having amino groups at both polymer terminals, polyolefins (a1-4) having isocyanate groups at both polymer terminals, polyolefins (a1-5) having both carboxyl groups and hydroxyl groups at both polymer terminals, polyolefins (a2-1) having a carboxyl group or carboxylic anhydride group at one polymer terminal, polyolefins (a2-2) having a hydroxyl group at one polymer terminal, polyolefins (a2-3) having an amino group at one polymer terminal, polyolefins (a2-4) having an isocyanate group at one polymer terminal, and polyolefins (a2-5) having both a carboxyl group and a hydroxyl group at one polymer terminal. The polyolefins (a1-1) to (a2-5) can be obtained by known production methods.

[0008] Among these, polyolefins (a1-1) and (a2-1) having a carboxyl group or a carboxylic anhydride group at the terminal are preferred from the viewpoints of ease of modification and heat resistance during molding. In this specification, "terminal" refers to the terminal portion where the repeating structure of the monomer units constituting the polymer is interrupted. Furthermore, "both terminals" refers to both terminals in the main chain of the polymer, and "one terminal" refers to either terminal in the main chain of the polymer.

[0009] The polyolefin (a) can be obtained, for example, by introducing a carboxyl group, a carboxylic acid anhydride group, a hydroxyl group, an amino group, or an isocyanate group into both ends of a polyolefin (a1-0) mainly composed of a polyolefin whose both ends can be modified. Here, "main component" means that the weight of the polyolefin whose both ends can be modified is 50% by weight or more (preferably more than 50% by weight) of the total weight of the polyolefin. However, even if the weight of the polyolefin capable of being modified at both ends is less than 50% by weight of the total weight of the polyolefin, if the sum of the weight of the polyolefin capable of being modified at both ends and the weight of the polyolefin capable of being modified at one end, which will be described later, is 50% by weight or more of the total weight of the polyolefin, and the weight of the polyolefin capable of being modified at both ends is equal to or greater than the weight of the polyolefin capable of being modified at one end, then this polyolefin is considered to be polyolefin (a1-0).

[0010] The polyolefin (a1-0) includes those obtained by polymerization methods and those obtained by degradation methods. Examples of polyolefins obtained by polymerization include polyolefins obtained by (co)polymerization of one or a mixture of two or more olefins having 2 to 30 carbon atoms (preferably 2 to 12, more preferably 2 to 10) ["(co)polymerization" means polymerization or copolymerization, the same applies hereinafter], and containing 30 mol % or more of structural units derived from propylene in the polyolefin. Examples of polyolefins obtained by degradation include polyolefins obtained by mechanically, thermally, or chemically degrading polyolefins having a high molecular weight [preferably a number average molecular weight (hereinafter abbreviated as Mn) of 10,000 to 150,000].

[0011] Among these, polyolefins obtained by degradation methods are preferred, and polyolefins obtained by thermal degradation are more preferred, from the viewpoints of ease of modification when introducing a carboxyl group, a carboxylic anhydride group, a hydroxyl group, an amino group, or an isocyanate group, and ease of availability. Thermal degradation easily produces low-molecular-weight polyolefins having one to two terminal double bonds per molecule, and since these low-molecular-weight polyolefins have terminal carbon-carbon double bonds, they can easily be modified by introducing a carboxyl group, a carboxylic anhydride group, a hydroxyl group, an amino group, an isocyanate group, or the like.

[0012] 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 of 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]

[0013] Polyolefins obtained by thermal degradation are not particularly limited, but examples include those obtained by heating high molecular weight polyolefins in an inert gas (for example, those obtained by heating at 300 to 450°C for 0.5 to 10 hours according to the method described in JP-A-3-62804), and those thermally degraded by heating in air.

[0014] The high molecular weight polyolefin used in the thermal degradation method is a (co)polymer of one or a mixture of two or more olefins having 2 to 30 carbon atoms (preferably 2 to 12, more preferably 2 to 10) [Mn is preferably 12,000 to 100,000, more preferably 15,000 to 70,000; melt flow rate (hereinafter abbreviated as MFR, in g / 10 min) is preferably 0.5 to 150, more preferably 1 to 100], and preferably includes those having 30 mol% or more of structural units derived from propylene in the polyolefin. Here, MFR is a value that represents the melt viscosity of a resin, with a higher value indicating a lower melt viscosity. MFR is measured using an extrusion plastometer specified in JIS K6760, and the measurement method complies with the method specified in JIS K7210-1 (2014). For example, in the case of polypropylene, it is measured under conditions of 230°C and a load of 2.16 kgf.

[0015] Examples of the olefin having 2 to 30 carbon atoms include α-olefins having 2 to 30 carbon atoms and dienes having 4 to 30 carbon atoms. Examples of the α-olefin having 2 to 30 carbon atoms include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene, 1-dodecene, 1-icosene, and 1-tetracosene. Examples of dienes having 4 to 30 carbon atoms include butadiene, isoprene, cyclopentadiene, and 1,11-dodecadiene. Among the olefins having 2 to 30 carbon atoms, from the viewpoint of molecular weight control, preferred are ethylene, propylene, α-olefins having 4 to 12 carbon atoms, butadiene, isoprene, and mixtures thereof, more preferred are ethylene, propylene, α-olefins having 4 to 10 carbon atoms, butadiene, and mixtures thereof, and particularly preferred are ethylene, propylene, and mixtures thereof.

[0016] From the viewpoints of compression set and resilience, the Mn of the polyolefin (a1-0) is preferably from 800 to 10,000, more preferably from 1,000 to 8,000, and particularly preferably from 1,200 to 6,000.

[0017] Among the polyolefins (a1-0), those having carbon-carbon double bonds at both ends are preferred, and the average number of terminal double bonds per molecule of such polyolefins (a1-0) is preferably 1.1 to 2.5, more preferably 1.3 to 2.2, and particularly preferably 1.5 to 2.0, from the viewpoints of compression set and resilience.

[0018] When a method for obtaining a low molecular weight polyolefin is used, a polyolefin (a1-0) having an Mn in the range of 800 to 10,000 and an average number of terminal double bonds per molecule of 1.1 to 2.0 can be easily obtained. The conditions for thermal degradation are appropriately selected so as to obtain the desired Mn and average number of terminal double bonds.

[0019] The polyolefin (a2-0) mainly composed of a polyolefin whose one end can be modified can be obtained by the above-mentioned polymerization method or degradation method. From the viewpoints of compression set and resilience, the Mn of the polyolefin (a2-0) is preferably 800 to 10,000, more preferably 1,000 to 10,000, and particularly preferably 1,200 to 6,000. Here, "main component" means that the weight of the polyolefin capable of being modified at one end accounts for 50% by weight or more (preferably more than 50% by weight) of the total weight of the polyolefin. However, even if the weight of the polyolefin capable of being modified at one end is less than 50% by weight of the total weight of the polyolefin, if the sum of the weight of the polyolefin capable of being modified at one end and the weight of the polyolefin capable of being modified at both ends is 50% by weight or more of the total weight of the polyolefin, and the weight of the polyolefin capable of being modified at one end is equal to or greater than the weight of the polyolefin capable of being modified at both ends, then this polyolefin is considered to be polyolefin (a2-0).

[0020] Among the polyolefins (a2-0), those having a carbon-carbon double bond at one terminal are preferred, and the average number of terminal double bonds per molecule of such polyolefins (a2-0) is preferably 0.5 to 1.4, more preferably 0.6 to 1.3, particularly preferably 0.7 to 1.2, and most preferably 0.8 to 1.1, from the viewpoints of compression set and resilience.

[0021] When a method for obtaining a low molecular weight polyolefin by thermal degradation is used, a polyolefin (a2-0) having an Mn in the range of 800 to 10,000 and an average number of terminal double bonds per molecule of 0.5 to 1.4 can be easily obtained. Since this low-molecular-weight polyolefin has terminal carbon-carbon double bonds, it can be easily modified by introducing carboxyl groups, carboxylic anhydride groups, hydroxyl groups, amino groups, isocyanate groups, etc. The conditions for thermal degradation are appropriately selected so as to obtain the desired Mn and average number of terminal double bonds.

[0022] The polyolefin (a1-0) and the polyolefin (a2-0) are generally obtained as a mixture thereof, and the mixture may be used as is or after purification and separation. Of these, the mixture is preferred from the viewpoint of production costs, etc.

[0023] Polyolefins (a1-1) to (a1-5) having a carboxyl group, a carboxylic acid anhydride group, a hydroxyl group, an amino group, or an isocyanate group at both polymer terminals will be described below. Polyolefins (a2-1) to (a2-5) having such a group at one polymer terminal can be obtained in the same manner as the polyolefins (a1-1) to (a1-5) above, except that polyolefin (a1-0) is replaced with polyolefin (a2-0).

[0024] Examples of polyolefin (a1-1) that can be used include polyolefin (a1-1-1) having a structure in which the terminals of polyolefin (a1-0) are modified with an α,β-unsaturated carboxylic acid (anhydride), polyolefin (a1-1-2) having a structure in which the polyolefin (a1-1-1) is secondarily modified with a lactam or an aminocarboxylic acid, polyolefin (a1-1-3) having a structure in which polyolefin (a1-0) is modified by oxidation or hydroformylation, polyolefin (a1-1-4) having a structure in which the polyolefin (a1-1-3) is secondarily modified with a lactam or an aminocarboxylic acid, and mixtures of two or more of these. The term "α,β-unsaturated carboxylic acid (anhydride)" means an α,β-unsaturated carboxylic acid or an anhydride thereof.

[0025] The polyolefin (a1-1-1) can be obtained by modifying the polyolefin (a1-0) with an α,β-unsaturated carboxylic acid (anhydride). The α,β-unsaturated carboxylic acid (anhydride) used for modification includes monocarboxylic acids, dicarboxylic acids, and anhydrides thereof, and specific examples thereof include (meth)acrylic acid, maleic acid (or its anhydride), fumaric acid, itaconic acid (or its anhydride), and citraconic acid (or its anhydride). Among these, from the viewpoint of ease of modification, dicarboxylic acids and anhydrides of mono- or dicarboxylic acids are preferred, maleic acid (or its anhydride) and fumaric acid are more preferred, and maleic acid (or its anhydride) is particularly preferred. The term "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0026] The amount of α,β-unsaturated carboxylic acid (anhydride) used for modification is preferably 0.5 to 20% by weight, more preferably 1 to 15% by weight, and particularly preferably 2 to 10% by weight, based on the weight of polyolefin (a1-0), from the viewpoints of compression set and resilience. The modification with an α,β-unsaturated carboxylic acid (anhydride) can be carried out, for example, by subjecting the α,β-unsaturated carboxylic acid (anhydride) to an addition reaction (ene reaction) with the terminal double bond of the polyolefin (a1-0) by either a solution method or a melt method, and the reaction temperature is preferably 170 to 230°C.

[0027] Furthermore, in the polyolefin (a1-1-2) having a structure in which the polyolefin (a1-1-1) is secondarily modified with a lactam or an aminocarboxylic acid, examples of the lactam used for the second modification include lactams having 6 to 12 carbon atoms, such as caprolactam and laurolactam, and examples of the aminocarboxylic acid include aminocarboxylic acids having 6 to 12 carbon atoms, such as ω-aminocaproic acid, ω-aminocaprylic acid, ω-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Of these, caprolactam and 12-aminododecanoic acid are preferred.

[0028] The acid value (unit: mgKOH / g) of the polyolefin (a1-1) is preferably 4 to 100 mgKOH / g, more preferably 4 to 50 mgKOH / g, and particularly preferably 10 to 50 mgKOH / g, from the viewpoints of reactivity with the polyalkylene glycol (b) and ease of structural control of the block polymer (X) for shoe soles [hereinafter sometimes abbreviated as block polymer (X)]. 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.

[0029] As the polyolefin (a1-2), a polyolefin having a hydroxyl group obtained by modifying the polyolefin (a1-1) with an amine having a hydroxyl group, or a mixture of two or more of these can be used. Examples of amines having a hydroxyl group that can be used for modification include amines having a hydroxyl group and having 2 to 10 carbon atoms, such as 2-aminoethanol, 3-aminopropanol, 1-amino-2-propanol, 4-aminobutanol, 5-aminopentanol, 6-aminohexanol, and 3-aminomethyl-3,5,5-trimethylcyclohexanol. Among these, from the viewpoint of ease of modification, preferred are amines having a hydroxyl group having 2 to 6 carbon atoms (2-aminoethanol, 3-aminopropanol, 4-aminobutanol, 5-aminopentanol, 6-aminohexanol, etc.), more preferred are 2-aminoethanol and 4-aminobutanol, and particularly preferred is 2-aminoethanol.

[0030] The amount of the amine having a hydroxyl group used for modification is preferably 0.5 to 20% by weight, more preferably 1 to 15% by weight, and particularly preferably 2 to 10% by weight, based on the weight of the polyolefin (a1-1), from the viewpoints of compression set and resilience.

[0031] The hydroxyl value of the polyolefin (a1-2) is preferably 10 to 120 mgKOH / g, more preferably 15 to 110 mgKOH / g, and particularly preferably 20 to 100 mgKOH / g, from the viewpoints of reactivity with the polyalkylene glycol (b) and ease of control of the structure of the block polymer (X).

[0032] As the polyolefin (a1-3), polyolefins having amino groups obtained by modifying the polyolefin (a1-1) with diamine, and mixtures of two or more of these can be used.

[0033] Examples of diamines include aliphatic diamines having 2 to 12 carbon atoms [linear diamines (ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-, 1,3-, or 2,3-diaminobutane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecane, etc.) and diamines having branched alkyl chains (1,5-diamino-3-methylpentane, 1,3-diamino-2,2-diethylpropanediamine, etc.)] and alicyclic diamines having 6 to 20 carbon atoms [1,4-diaminocyclohexane, 1,4-bis(aminomethyl)cyclohexane, 2,2-bis(4-aminocyclohexyl)propane, etc.]. Of these, from the viewpoint of ease of modification, diamines having 2 to 8 carbon atoms are preferred, ethylenediamine, 1,6-diaminohexane, 1,7-diaminoheptane, and 1,8-diaminooctane are more preferred, ethylenediamine and 1,6-diaminohexane are particularly preferred, and ethylenediamine is most preferred.

[0034] The amount of diamine used to modify polyolefin (a1-1) is preferably 0.5 to 20 wt %, more preferably 1 to 15 wt %, and particularly preferably 2 to 10 wt %, based on the weight of polyolefin (a1-1), from the viewpoints of compression set and resilience. The modification of polyolefin (a1-1) with diamine is preferably carried out by using preferably 0.5 to 1,000 wt %, more preferably 1 to 500 wt %, and particularly preferably 2 to 300 wt %, based on the weight of polyolefin (a1-1), and then removing unreacted diamine under reduced pressure at 120 to 230° C., from the viewpoint of preventing crosslinking between polymer molecules.

[0035] The amine value of the polyolefin (a1-3) is preferably from 10 to 120 mgKOH / g, more preferably from 15 to 110 mgKOH / g, and particularly preferably from 20 to 100 mgKOH / g, from the viewpoints of compression set and resilience.

[0036] Examples of the polyolefin (a1-4) include polyolefins having isocyanate groups obtained by modifying the polyolefin (a1-2) with polyisocyanate (a compound having two or more isocyanate (NCO) groups), and mixtures of two or more of these. Examples of polyisocyanates include aromatic polyisocyanates having 6 to 20 carbon atoms (excluding carbon atoms in isocyanate groups; the same applies below), aliphatic polyisocyanates having 2 to 18 carbon atoms, alicyclic polyisocyanates having 4 to 15 carbon atoms, aromatic aliphatic polyisocyanates having 8 to 15 carbon atoms, modified products of these polyisocyanates, and mixtures of two or more of these.

[0037] Examples of aromatic polyisocyanates include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'- or 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, and 1,5-naphthylene diisocyanate.

[0038] Examples of aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0039] Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- or 2,6-norbornane diisocyanate.

[0040] Examples of the aromatic aliphatic polyisocyanate include m- or p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI).

[0041] Examples of modified polyisocyanates include urethane modified, urea modified, carbodiimide modified, and uretdione modified polyisocyanates. Among the polyisocyanates, TDI, MDI and HDI are preferred, and HDI is more preferred.

[0042] The reaction between the polyisocyanate and the polyolefin (a1-2) can be carried out in the same manner as in a general urethane reaction. The equivalent ratio (NCO:OH) of the isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyolefin (a1-2) is preferably 1.8:1 to 3:1, and more preferably 2:1. To accelerate the urethanization reaction, a catalyst commonly used in urethanization reactions may be used, if necessary. Examples of the catalyst include metal catalysts (such as tin catalysts (dibutyltin dilaurate and stannous octoate), lead catalysts (such as lead 2-ethylhexanoate and lead octenate), and other metal catalysts (such as metal naphthenates (cobalt naphthenate) and phenylmercury propionate)); amine catalysts (such as triethylenediamine, diazabicycloalkenes (such as 1,8-diazabicyclo[5.4.0]undecene-7), dialkylaminoalkylamines (such as dimethylaminoethylamine and dimethylaminooctylamine), carbonates or organic acid (such as formates) salts of heterocyclic aminoalkylamines (such as 2-(1-aziridinyl)ethylamine and 4-(1-piperidinyl)-2-hexylamine), N-methyl or ethylmorpholine, triethylamine, and diethyl- or dimethylethanolamine); and combinations of two or more of these catalysts. The amount of the catalyst used is preferably 3% by weight or less, and more preferably 0.001 to 2% by weight, based on the total weight of the polyisocyanate and the polyolefin (a1-2).

[0043] As the polyolefin (a1-5), a polyolefin (a1-5-1) having a structure in which both ends of the polyolefin (a1-0) are modified with an α,β-unsaturated carboxylic acid anhydride and then further modified with a diolamine can be used. An example of the diolamine used for the secondary modification is diethanolamine.

[0044] From the viewpoint of compression set and resilience, the Mn of the polyolefin (a) is preferably from 1,000 to 10,000, more preferably from 1,500 to 8,500, and particularly preferably from 2,000 to 7,000.

[0045] The polyolefin (a) contains propylene and ethylene as constituent monomers, and the weight ratio of propylene to ethylene (propylene / ethylene) is 90 / 10 to 99.5 / 0.5, preferably 96 / 4 to 98 / 2. If the weight ratio (propylene / ethylene) is less than 90 / 10 or more than 99.5 / 0.5, the resilience will be poor. The weight ratio (propylene / ethylene) tends to directly reflect the weight ratio of the constituent monomers of the high molecular weight polyolefin and the constituent monomers used in the polymerization method described above, and therefore, the desired weight ratio can be obtained by appropriately adjusting the weight ratio of the constituent monomers. Moreover, from the viewpoint of resilience, the polyolefin (a) is preferably a propylene / ethylene copolymer.

[0046] Of the above polyolefins (a), from the industrial viewpoint of compression set and resilience, polyolefin (a1-1) is preferred, and polyolefin (a1-1-2) is more preferred.

[0047] <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). Among these, from the viewpoint of productivity of the block polymer (X), those having a hydroxyl 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). Its modified product can also be obtained by a known production method. The polyalkylene glycol (b) can be obtained by the above-mentioned method, or a commercially available product can be used.

[0048] The number average molecular weight (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, from the viewpoints of compression set and resilience.

[0049] <Block polymer (X) for shoe soles> The block polymer (X) for shoe soles of the present invention has the above-mentioned polyolefin (a) and polyalkylene glycol (b) as constituent units. The polyolefin (a) and polyalkylene glycol (b) constituting the block polymer (X) may each be one type or two or more types.

[0050] From the viewpoints of compression set and resilience, the Mn of the polyolefin (a) block is preferably 1,000 to 10,000, more preferably 1,500 to 8,500, and particularly preferably 2,000 to 7,000.

[0051] 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.

[0052] The structure in which a block of polyolefin (a) and a block of polyalkylene glycol (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.

[0053] The block polymer (X) can be produced, for example, by reacting the above polyolefin (a1-1) with a polyalkylene glycol (b).

[0054] When the block polymer (X) has a structure in which a block of polyolefin (a) 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 the polyolefin (a) and the 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.

[0055] From the viewpoint of compression set and resilience, it is preferable that the block polymer (X) contains a crosslinking agent (K) as a constituent unit. In this case, the block polymer (X) has a structure in which a polyolefin (a) and / or a polyalkylene glycol (b) are crosslinked with the crosslinking agent (K). It is preferable that the block polymer (X) has a structure in which a crosslinking agent (K) has at least three functional groups capable of reacting with the terminal functional groups of the polyolefin (a) and / or the polyalkylene glycol (b).

[0056] The weight ratio [(a) / (b)] of the block of polyolefin (a) to the block of polyalkylene glycol (b) constituting the block polymer (X) is preferably 20 / 80 to 80 / 20, more preferably 25 / 75 to 75 / 25, and particularly preferably 30 / 70 to 70 / 30, from the viewpoints of compression set and resilience.

[0057] The Mn of the block polymer (X) is preferably 5,000 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).

[0058] <Crosslinking agent (K)> The crosslinking agent (K) in the present invention is a compound capable of crosslinking the polyolefin (a) and / or 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 polyolefin (a) and / or 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 carboxyl groups. Of these functional groups, carboxyl groups are preferred from the viewpoint of reactivity.

[0059] Examples of the crosslinking agent (K) 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. Among the above crosslinking agents (K), from the viewpoints of reactivity and compression set, trivalent or higher polycarboxylic acids (K1) are preferred, and trimellitic anhydride is more preferred.

[0060] 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 polyolefin (a) with the polyalkylene glycol (b). From the viewpoints of compression set and resilience, the amount of the crosslinking agent (K) is such that the molar ratio of the crosslinking agent (K) to the total of the polyolefin (a) and the polyalkylene glycol (b) {(K) / [(a)+(b)]} is preferably 3 / 97 to 35 / 65, more preferably 5 / 95 to 15 / 85.

[0061] <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), polyolefin resin (E1) is preferred from the viewpoints of compression set and resilience. The number average molecular weight (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 75 / 25 to 90 / 10.

[0062] 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), provided that the effects of the present invention are not impaired. Each additive may be used alone or in combination of two or more.

[0063] 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.

[0064] <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.

[0065] 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.

[0066] In addition, a foaming agent (C) may be used during foam molding. Examples of the foaming 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.

[0067] 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).

[0068] The present specification discloses the following:

[0069] [1] A block polymer (X) for shoe soles, which has, as constituent units, a block of the following polyolefin (a) and a block of the following polyalkylene glycol (b). Polyolefin (a): Contains propylene and ethylene as constituent monomers, and the weight ratio of propylene to ethylene (propylene / ethylene) is 90 / 10 to 99.5 / 0.5; Polyalkylene glycol (b): Contains an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer.

[0070] [2] The block polymer (X) for shoe soles according to [1], wherein the number average molecular weight of the block of the polyolefin (a) is 1,000 to 10,000.

[0071] [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.

[0072] [4] The block polymer (X) for shoe soles according to any one of [1] to [3], wherein the weight ratio [(a) / (b)] of the block of the polyolefin (a) to the block of the polyalkylene glycol (b) is 20 / 80 to 80 / 20.

[0073] [5] The block polymer (X) for shoe soles according to any one of [1] to [4], which has a structure crosslinked with a crosslinking agent (K) having at least three functional groups capable of reacting with terminal functional groups of the polyolefin (a) and / or polyalkylene glycol (b).

[0074] [6] The block polymer (X) for shoe soles according to any one of [1] to [5], which has a number average molecular weight of 5,000 to 150,000.

[0075] [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.

[0076] [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].

[0077] [9] Density: 0.20 to 0.90 g / cm 3 The shoe sole (Z) according to [8], [Example]

[0078] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, parts below mean parts by weight.

[0079] <Production Example 1> [Production of polyolefin (a-1)] A reaction vessel was charged with 1,000 parts of a polyolefin having structural units of 98% by weight of propylene and 2% by weight of ethylene [trade name "SunAllomer PZA20A", manufactured by SunAllomer Co., Ltd., Mn 100,000, the same applies hereinafter], and while nitrogen was passed through the liquid phase, the mixture was heated to melt using a mantle heater and thermally degraded at 380°C for 70 minutes with stirring, to obtain a polyolefin (a1-0-1) [Mn: 2,500] having carbon-carbon double bonds at both ends. Next, 100 parts of polyolefin (a1-0-1) was melted at 160° C. in a reaction vessel, and 14.1 parts of maleic anhydride was added. The mixture was reacted at 200° C. for 10 hours under nitrogen, and excess maleic anhydride was removed under reduced pressure. Next, 15.5 parts of 12-aminododecanoic acid was added and the mixture was reacted at 200° C. for 1 hour to obtain polyolefin (a-1). The polyolefin (a-1) had an acid value of 33.0 and an Mn of 3,000.

[0080] <Production Example 2> [Production of polyolefin (a-2)] A polyolefin (a-2) was obtained by carrying out a reaction in the same manner as in Production Example 1, except that the amount of 12-aminododecanoic acid used was changed to 12.4 parts. The acid value of the polyolefin (a-2) was 33.4 and Mn was 3,000.

[0081] <Production Example 3> [Production of polyolefin (a-3)] A polyolefin (a-3) was obtained by carrying out a reaction in the same manner as in Production Example 1, except that the amount of 12-aminododecanoic acid used was changed to 9.3 parts. The acid value of the polyolefin (a-3) was 34.2 and Mn was 2,900.

[0082] <Production Example 4> [Production of polyolefin (a-4)] A reaction vessel was charged with 1,000 parts of a polyolefin having structural units of 98% by weight of propylene and 2% by weight of ethylene [the above-mentioned "Sunallomer PZA20A"], and while nitrogen was passed through the liquid phase, the mixture was heated to melt using a mantle heater. With stirring, the mixture was subjected to thermal degradation at 380°C for 90 minutes, yielding a polyolefin (a1-0-2) [Mn: 1,500] having carbon-carbon double bonds at both ends. Next, 100 parts of polyolefin (a1-0-2) was melted in a reaction vessel at 160°C, and 23.5 parts of maleic anhydride was added. The reaction was carried out under nitrogen at 200°C for 10 hours, and the excess maleic anhydride was removed under reduced pressure. 20.7 parts of 12-aminododecanoic acid was then added, and the reaction was carried out at 200°C for 1 hour to obtain polyolefin (a-4). The acid value of polyolefin (a-4) was 51.5 and Mn was 2,000.

[0083] <Production Example 5> [Production of polyolefin (a-5)] A reaction vessel was charged with 1,000 parts of a polyolefin having structural units of 98% by weight of propylene and 2% by weight of ethylene [the above-mentioned "Sunallomer PZA20A"], and while nitrogen was passed through the liquid phase, the mixture was heated to melt using a mantle heater. With stirring, the mixture was subjected to thermal degradation at 370°C for 40 minutes, yielding a polyolefin (a1-0-3) [Mn: 6,100] having carbon-carbon double bonds at both ends. Next, 100 parts of polyolefin (a1-0-3) was melted in a reaction vessel at 160°C, and 5.3 parts of maleic anhydride was added. The reaction was carried out under nitrogen at 200°C for 10 hours, and the excess maleic anhydride was removed under reduced pressure. Next, 5.8 parts of 12-aminododecanoic acid was added, and the reaction was carried out at 200°C for 1 hour to obtain polyolefin (a-5). The acid value of polyolefin (a-5) was 14.1 and Mn was 6,600.

[0084] <Production Example 6> [Production of polyolefin (a-6)] A reaction vessel was charged with 1,000 parts of a polyolefin having structural units of 96% by weight of propylene and 4% by weight of ethylene [trade name "Wintec WFX6", manufactured by Japan Polypropylene Corporation, Mn 150,000, the same applies hereinafter], and while nitrogen was passed through the liquid phase, the mixture was heated to melt using a mantle heater and thermally degraded at 370°C for 100 minutes with stirring, to obtain a polyolefin (a1-0-4) [Mn: 2,800] having carbon-carbon double bonds at both ends. Next, 100 parts of polyolefin (a1-0-4) was melted in a reaction vessel at 160°C, and 12.2 parts of maleic anhydride was added. The reaction was carried out under nitrogen at 200°C for 10 hours, and the excess maleic anhydride was removed under reduced pressure. Next, 13.4 parts of 12-aminododecanoic acid was added, and the reaction was carried out at 200°C for 1 hour to obtain polyolefin (a-6). The acid value of polyolefin (a-6) was 29.5, and Mn was 3,300.

[0085] <Production Example 7> [Production of polyolefin (a-7)] A reaction vessel was charged with 1,000 parts of a polyolefin having structural units of 96% by weight of propylene and 4% by weight of ethylene [the above-mentioned "Wintec WFX6"], and while nitrogen was passed through the liquid phase, the mixture was heated to melt using a mantle heater. Thermal degradation was carried out at 370°C for 40 minutes while stirring, yielding a polyolefin (a1-0-5) [Mn: 6,700] having carbon-carbon double bonds at both ends. Next, 100 parts of polyolefin (a1-0-5) was melted in a reaction vessel at 160°C, and 4.9 parts of maleic anhydride was added. The reaction was carried out under nitrogen at 200°C for 10 hours, and the excess maleic anhydride was removed under reduced pressure. Next, 5.4 parts of 12-aminododecanoic acid was added, and the reaction was carried out at 200°C for 1 hour to obtain polyolefin (a-7). The acid value of polyolefin (a-7) was 13.1, and Mn was 7,200.

[0086] Example 1 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 159 parts of polyolefin (a-1), 140 parts of polytetramethylene glycol (b-1) (PTMG, Mn: 3,000), 0.3 parts of an antioxidant [trade name "Irganox 1010", manufactured by BASF Japan Ltd.], and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-1) for shoe soles (Mn: 37,000).

[0087] <Example 2> 157 parts of polyolefin (a-2), 142 parts of polytetramethylene glycol (b-1), 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-2) for shoe soles (Mn: 46,000).

[0088] Example 3 155 parts of polyolefin (a-3), 144 parts of polytetramethylene glycol (b-1), 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-3) for shoe soles (Mn: 65,000).

[0089] Example 4 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 153 parts of polyolefin (a-1), 142 parts of polytetramethylene glycol (b-1), 4.3 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-4) for shoe soles (Mn: 51,000).

[0090] <Example 5> Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 157 parts of polyolefin (a-4), 142 parts of polytetramethylene glycol (b-2) (PTMG, Mn: 2,000), 0.3 parts of an antioxidant [the above-mentioned "Irganox 1010"], and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-5) for shoe soles (Mn: 41,000).

[0091] Example 6 127 parts of polyolefin (a-4), 173 parts of polytetramethylene glycol (b-1), 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-6) for shoe soles (Mn: 47,000).

[0092] Example 7 206 parts of polyolefin (a-2), 93 parts of polytetramethylene glycol (b-3) (PTMG, Mn: 1,500), 0.3 parts of antioxidant [the above-mentioned "Irganox 1010"], and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-7) for shoe soles (Mn: 47,000).

[0093] Example 8 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 146 parts of polyolefin (a-1), 152 parts of polytetramethylene glycol (b-1), 0.9 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-8) for shoe soles (Mn: 41,000).

[0094] Example 9 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 133 parts of polyolefin (a-1), 164 parts of polytetramethylene glycol (b-1), 1.9 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-9) for shoe soles (Mn: 46,000).

[0095] Example 10 207 parts of polyolefin (a-5), 91 parts of polytetramethylene glycol (b-1), 0.6 parts of trimellitic anhydride, 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-10) for shoe soles (Mn: 40,000).

[0096] Example 11 231 parts of polyolefin (a-5), 68 parts of polytetramethylene glycol (b-2), 0.6 parts of trimellitic anhydride, 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-11) for shoe soles (Mn: 36,000).

[0097] Example 12 167 parts of polyolefin (a-6), 132 parts of polytetramethylene glycol (b-1), 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-12) for shoe soles (Mn: 37,000).

[0098] Example 13 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 155 parts of polyolefin (a-6), 143 parts of polytetramethylene glycol (b-1), 0.9 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-13) for shoe soles (Mn: 39,000).

[0099] Example 14 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 143 parts of polyolefin (a-6), 155 parts of polytetramethylene glycol (b-1), 1.8 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-14) for shoe soles (Mn: 47,000).

[0100] Example 15 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 129 parts of polyolefin (a-6), 167 parts of polytetramethylene glycol (b-1), 2.8 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-15) for shoe soles (Mn: 53,000).

[0101] Example 16 212 parts of polyolefin (a-7), 87 parts of polytetramethylene glycol (b-1), 0.5 parts of trimellitic anhydride, 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and polymerization was carried out for 6 hours at 220°C under a reduced pressure of 0.13 kPa or less with stirring, to obtain a block polymer (X-16) for shoe soles (Mn: 34,000).

[0102] Example 17 Into a stainless steel pressure-resistant reactor equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, 146 parts of polyolefin (a-1), 152 parts of polypropylene glycol (b-4) (PPG, Mn: 3,000), 0.9 parts of trimellitic anhydride, 0.3 parts of an antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged, and polymerization was carried out with stirring at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours to obtain a block polymer (X-17) (Mn: 40,000) for shoe soles.

[0103] Example 18 221 parts of polyolefin (a-1), 77 parts of polypropylene glycol (b-5) (PPG, Mn: 1,000), 1.4 parts of trimellitic anhydride, 0.3 parts of antioxidant (the above-mentioned "Irganox 1010"), and 0.6 parts of dibutyltin oxide were charged into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating / cooling device, a nitrogen inlet tube, and a pressure reducing device, and the mixture was polymerized at 220°C under a reduced pressure of 0.13 kPa or less for 6 hours with stirring to obtain a block polymer (X-18) for shoe soles (Mn: 37,000).

[0104] Example 19 90 parts of the block polymer (X-1) obtained in Example 1 and 10 parts of a polyolefin resin (E-1) [propylene homopolymer, trade name "PM801A", manufactured by SunAllomer Co., Ltd.] were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and pelletized to obtain a resin composition for shoe soles (Y-19).

[0105] Example 20 70 parts of the block polymer (X-1) obtained in Example 1 and 30 parts of the polyolefin resin (E-1) were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and pelletized to obtain a resin composition for shoe soles (Y-20).

[0106] <Example 21> 90 parts of the block polymer (X-1) obtained in Example 1 and 10 parts of a polyolefin resin (E-2) [a polyolefin having structural units of 96% by weight of propylene and 4% by weight of ethylene, the above-mentioned "Wintec WFX6"] were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-21).

[0107] <Example 22> 70 parts of the block polymer (X-1) obtained in Example 1 and 30 parts of the polyolefin resin (E-2) were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-22).

[0108] Example 23 70 parts of the block polymer (X-8) obtained in Example 8 and 30 parts of the polyolefin resin (E-1) were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and pelletized to obtain a resin composition for shoe soles (Y-23).

[0109] Example 24 70 parts of the block polymer (X-13) obtained in Example 13 and 30 parts of the polyolefin resin (E-2) were kneaded in a twin-screw extruder at 190°C for a residence time of 30 seconds, and then pelletized to obtain a resin composition for shoe soles (Y-24).

[0110] <Comparative Example 1> A commercially available EVA resin (manufactured by Mitsui Chemicals, Inc., trade name "Evaflex 270") was used as a block polymer for comparison.

[0111] Example 31 100 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 160°C and 15 MPa to obtain a shoe sole (Z-1). The obtained shoe sole (Z-1) was evaluated.

[0112] <Examples 32 to 54, Comparative Example 2> Shoe soles (Z-2) to (Z-24) and (Comparative Z-1) were obtained in the same manner as in Example 31, except that the raw material compositions (parts) were in accordance with Table 1 or Table 2. In Comparative Example 2, the EVA resin of Comparative Example 1 was used. The results are shown in Tables 1 and 2.

[0113] <Evaluation> (1) Density Density (g / cm 3 ) was determined at 23°C in accordance with ASTM D1505.

[0114] (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 criteria. Compressive strain (%) = (L0-L5) x 100 / L0

[0115] [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

[0116] (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. The loss coefficient (tan δ) at 23° C. was determined and 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

[0117] [Evaluation criteria] ◎: Less than 0.08 〇: 0.08 or more and less than 0.1 △: 0.1 or more and less than 0.15 ×: 0.15 or more

[0118] (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 determined from the measurement data of dynamic viscoelasticity, and -20°C [tanδ] / 25°C [tanδ] was evaluated according to the following criteria.

[0119] [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

[0120] (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 dependency of sole resilience = L -20 ×100 / L 20

[0121] [Evaluation criteria] ◎: 90 or above 〇: 80 or more, less than 90 △: 70 or more, less than 80 ×: Less than 70

[0122] [Table 1]

[0123] [Table 2]

[0124] In Tables 1 and 2, 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"]

[0125] The results in Tables 1 and 2 show that the shoe sole (Z) using the block polymer for shoe soles (X) of the present invention has a smaller compression strain, is more durable, and has better resilience (a smaller loss coefficient and less change in resilience due to temperature) than the comparative sole. [Industrial Applicability]

[0126] 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 resin composition (Y) for shoe soles containing a block polymer (X) for shoe soles having, as structural units, a block of the following polyolefin (a) and a block of the following polyalkylene glycol (b). Polyolefin (a): Contains propylene and ethylene as constituent monomers, and the weight ratio of propylene to ethylene (propylene / ethylene) is 90 / 10 to 99.5 / 0.5; Polyalkylene glycol (b): Contains an alkylene glycol having 3 to 4 carbon atoms as a constituent monomer.

2. 2. The shoe sole resin composition (Y) according to claim 1, wherein the number average molecular weight of the block of the polyolefin (a) is 1,000 to 10,000.

3. 2. The shoe sole resin composition (Y) according to claim 1, wherein the number average molecular weight of the block of the polyalkylene glycol (b) is 500 to 4,000.

4. 2. The resin composition (Y) for shoe soles according to claim 1, wherein the weight ratio [(a) / (b)] of the block of polyolefin (a) to the block of polyalkylene glycol (b) is 20 / 80 to 80 / 20.

5. The block polymer (X) for shoe soles has a structure crosslinked with a crosslinking agent (K), the crosslinking agent (K) has at least three functional groups capable of reacting with terminal functional groups of the polyolefin (a) and / or the polyalkylene glycol (b); the terminal functional group is a hydroxyl group and / or a carboxyl group, the functional group capable of reacting with the terminal functional group is selected from the group consisting of a carboxyl group, an amino group, an epoxy group, and a hydroxyl group; The shoe sole resin composition (Y) according to claim 1.

6. A resin composition (Y) for shoe soles according to claim 1, wherein the block polymer (X) for shoe soles has a number average molecular weight of 5,000 to 150,000.

7. A resin composition (Y) for shoe soles according to claim 1, further comprising a thermoplastic resin (E) other than the block polymer (X) for shoe soles.

8. A shoe sole (Z) which is a foam-molded product of the resin composition (Y) for shoe soles according to any one of claims 1 to 7.

9. Density is 0.20 to 0.90 g / cm ３ The shoe sole (Z) according to claim 8,

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