TWI441861B - Foaming and foaming compositions - Google Patents

Description

Foam and foam composition

The present invention relates to a foam and a composition for a foam which are suitable for a material for a midsole, an insole or an outsole for shoes.

The foam material used for sports shoes and the like is required to have cushioning properties, impact cushioning properties, and light weight. Materials that satisfy this characteristic have been used for a long time: a foam containing ethylene-vinyl acetate copolymer (EVA) as a main component or a foam containing polyurethane (PU) as a main component or a base. In the rubber material, a crosslinked foam for shoes containing a bubble in a rubber composition containing a filler such as cerium oxide or carbon black is blended. The air bubbles may be contained by foaming of a foaming agent, blending of fine hollow spheres, etc., and further weight reduction is being studied in the crosslinked foam for shoes.

Previously, various foam materials as will be described later have been proposed.

For example, Patent Document 1 discloses a material containing syndiotactic 1,2-polybutadiene as a foamed rubber sole which is excellent in abrasion resistance, lightweight, and non-slip.

Patent Document 2 discloses a block copolymer-based crosslinked foam which is intended to be lightweight, has cushioning air permeability, and sound insulating properties.

Patent Document 3 discloses a foam comprising a material containing a styrene-butadiene block copolymer having a styrene content of 60% or less, which is small in hardness change even in a high-temperature and low-temperature environment, and has a cushioning property. A foam excellent in impact cushioning properties.

Patent Document 4 discloses a composition comprising a radiation-type thermoplastic elastomer, a linear thermoplastic elastomer, and 1,2-polybutadiene, which is excellent in moldability and excellent in flexibility and moldability.

Patent Document 5 discloses a hydrogenated block copolymer useful for producing a foam having excellent tear strength, compression set resistance, low rebound resilience, and abrasion resistance.

Prior technical literature

Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. SHO 63-200702

Patent Document 2: Japanese Patent Laid-Open Publication No. SHO 63-225638

Patent Document 3: Japanese Patent Laid-Open Publication No. 2001-340105

Patent Document 4: Japanese Patent Laid-Open Publication No. 2004-217846

Patent Document 5: International Publication No. 2007/094216

However, the various foam materials previously disclosed as described above still have room for improvement in hardness, dimensional stability, thermoformability, and mechanical strength, and do not have sufficient characteristics as a foam for shoes (sole). .

Accordingly, it is an object of the present invention to provide a foam which is particularly suitable for a shoe midsole, an insole and an outsole which is excellent in hardness, dimensional stability, thermoformability and mechanical strength.

The inventors of the present invention have intensively studied in order to solve the problems of the prior art regarding the foam as described above, and as a result, have found that a vinyl aromatic hydrocarbon and a conjugated diene having a specific viscoelastic behavior are contained in a specific ratio. a block copolymer, a specific rubber component, a filler, and a foam of a foaming agent, or a block copolymer containing a vinyl aromatic hydrocarbon and a conjugated diene, a specific rubber component, a filler, and a foaming agent The above object can be attained by a foam having a specific hardness in a specific range of specific gravity, thereby completing the present invention.

That is, the present invention is as follows.

[1] A foam having a specific gravity of 0.1 to 0.98 g/cc and cross-linking a composition for a foam; the composition for a foam comprising: (a) a block copolymer; It comprises at least two vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon, wherein the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass. The content of the conjugated diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass, and the storage elasticity at 30 ° C in the dynamic viscoelasticity measurement The modulus (E') is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the peak temperature of the function of the dynamic viscoelasticity measurement tan δ is at least one at 85 ° C or more and 125 ° C or less; (b) isoprene a rubber and/or a diene rubber; (c) a filler; (d) a foaming agent; and the above (a) block copolymer and the above (b) isoprene rubber and/or diene rubber The mass ratio is 1 to 30/70 to 99; and the above-mentioned (a) block copolymer and the above (b) isoprene-based rubber and/or diene-based rubber are contained in an amount of 100 parts by mass, and the above ( c) filler 1~100 The amount of parts, (d) above 0.1 to 30 parts by mass of a foaming agent.

[2] The foam according to the above [1], wherein the (a) block copolymer is at least one of a peak temperature of a function of dynamic viscoelasticity measurement tan δ of 90 ° C or more and 125 ° C or less.

[3] The foam according to [1] or [2] above, wherein the (a) block copolymer contains at least one vinyl aromatic hydrocarbon content of 70% by mass or more and less than 100% by mass of a vinyl group. A random copolymer block of an aromatic hydrocarbon and a conjugated diene.

[4] The foam according to any one of the above [1] to [3], wherein the (a) block copolymer contains at least one vinyl aromatic hydrocarbon content of 75% by mass or more and 98% by mass or less. A random copolymer block of a vinyl aromatic hydrocarbon and a conjugated diene.

[5] The foam according to any one of the above [1] to [4], wherein the (a) block copolymer and the (b) isoprene-based rubber and/or a diene system are The total amount of the rubber is 100 parts by mass, and the (c) filler is 2 to 90 parts by mass, and the (d) foaming agent is 0.5 to 20 parts by mass.

[6] The foam according to any one of the above [1] to [5], wherein the (a) block copolymer and the (b) isoprene-based rubber and/or a diene system are The total amount of the rubber is 100 parts by mass, and further contains (e) 1 to 100 parts by mass of the thermoplastic elastomer and/or the thermoplastic resin.

[7]

The foam according to any one of the above [1] to [6] wherein the specific gravity is 0.1 to 0.7 g/cc or the specific gravity is 0.8 to 0.98 g/cc.

[8]

A shoe sole formed by molding the foam of any one of the above [1] to [7].

[9]

A composition for a foam comprising: (a) a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one comprising a conjugated diene and a vinyl aromatic hydrocarbon a copolymer block having a vinyl aromatic hydrocarbon content of 65 to 95% by mass and a conjugated diene content of 5 to 35% by mass, and a block of a vinyl aromatic hydrocarbon polymer contained in the block copolymer The rate is 40 to 98% by mass, and the storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the peak temperature of the function of dynamic viscoelasticity is tan δ At least one of 85 ° C or more and 125 ° C or less; (b) isoprene-based rubber and/or diene rubber; (c) filler; (d) foaming agent; (a) block copolymer The mass ratio of the (b) isoprene-based rubber and/or the diene-based rubber is from 1 to 30/70 to 99; and the (a) block copolymer and the above (b) isoprene-based The total amount of the rubber and/or the diene rubber is 100 parts by mass, and the (c) filler is contained in an amount of from 1 to 100 parts by mass, and the (d) foaming agent is contained in an amount of from 0.1 to 30 parts by mass.

[10]

A foam comprising: (a') a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer comprising a conjugated diene and a vinyl aromatic hydrocarbon Block, and the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass, the content of the conjugated diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass; (b) isoprene-based rubber and/or diene-based rubber; (c) filler; (d) foaming agent; when the specific gravity is 0.1 to 0.7 g/cc, by type C The hardness measured is 45 to 98; when the specific gravity is 0.8 to 0.98 g/cc, the hardness measured by the model A is 60 to 98.

According to the present invention, a foam which is excellent in hardness, dimensional stability, thermoformability and mechanical strength and which is mainly suitable for a midsole, an insole or an outsole for shoes can be obtained.

Hereinafter, a mode for carrying out the invention (hereinafter referred to as "this embodiment") will be described. The present invention is not limited to the following description, and various modifications can be made without departing from the spirit and scope of the invention.

[foam] [Foam according to the first embodiment]

The foam of the first embodiment in the foam of the present embodiment contains the following components (a) to (d).

(a) a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon, and a vinyl aromatic hydrocarbon The content is 65 to 95% by mass, the content of the conjugated diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass, dynamic viscoelasticity. The storage elastic modulus (E') at 30 ° C in the measurement is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the peak temperature of the function of dynamic viscoelasticity measurement of tan δ is at least 1 at 85 ° C or more and 125 ° C or less. .

(b) Isoprene-based rubber and/or diene-based rubber.

(c) a filler.

(d) a blowing agent.

Further, in the foam of the present embodiment, the mass ratio of the (a) block copolymer to the (b) isoprene-based rubber and/or the diene-based rubber is 1 to 30/70 to 99. Furthermore, the (c) filler is contained in an amount of 1 to 100 parts by mass based on 100 parts by mass of the total of the (a) block copolymer and the (b) isoprene-based rubber and/or the diene-based rubber. And (d) the foaming agent is 0.1 to 30 parts by mass of the foam composition, and the specific gravity is 0.1 to 0.98 g/cc.

The components (a) to (d) will be described below.

(ingredient (a): block copolymer)

Component (a) contains a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene as described above.

The content of the vinyl aromatic hydrocarbon in the component (a) is from 65 to 95% by mass, preferably from 68 to 93% by mass, more preferably from 70 to 90% by mass.

The content of the conjugated diene in the component (a) is 5 to 35 mass%, preferably 7 to 32 mass%, more preferably 10 to 30 mass%.

When the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass and the content of the conjugated diene is in the range of 5 to 35% by mass, the hardness of the foam is excellent in the balance between the elongation and the thermoformability. Suitable for foams for shoes.

The content of the vinyl aromatic hydrocarbon in the component (a) and the content of the conjugated diene are determined by measuring the absorption luminosity of light of a specific wavelength by using an ultraviolet spectrophotometer.

The block ratio of the vinyl aromatic hydrocarbon polymer contained in the component (a) is 40 to 98% by mass, preferably 50 to 95% by mass, more preferably 60 to 90% by mass. When the block ratio of the vinyl aromatic hydrocarbon polymer is in the range of 40 to 98% by mass, it is excellent in dimensional stability and thermoformability, and is suitable as a foam for shoes.

The block ratio of the vinyl aromatic hydrocarbon polymer can be determined by the weight of the random copolymer chain containing the vinyl aromatic hydrocarbon and the conjugated diene in the component (a) and the content of the vinyl aromatic hydrocarbon (% by mass). ) to adjust.

The more the amount of the vinyl aromatic hydrocarbons in the random copolymer chain of the component (a) block copolymer, the lower the block ratio of the vinyl aromatic hydrocarbon polymer, and the smaller the block rate becomes. .

As for the block ratio of the vinyl aromatic hydrocarbon polymer, a method of oxidative decomposition of the component (a) block copolymer by using perylene tetroxide as a catalyst by peroxidizing third butanol is used (oxidative decomposition method: IMKOLTHOFF) , et al., J. Polym. Sci. 1, 429 (1946), a vinyl aromatic hydrocarbon polymer block chain component (a vinyl aromatic hydrocarbon polymer having an average degree of polymerization of about 30 or less) The components were separated, and the weight of the block chain of the vinyl aromatic hydrocarbon polymer was measured and found according to the following formula.

Block ratio (% by mass) = (weight of vinyl aromatic hydrocarbon polymer block polymer chain in block copolymer / total weight of vinyl aromatic hydrocarbon in block copolymer) × 100

In addition, the "total weight of the vinyl aromatic hydrocarbon in the block copolymer" is determined based on the input ratio at the time of polymerization or by analysis by NMR or the like.

Component (a) contains at least two vinyl aromatic hydrocarbon polymer blocks and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon.

The polymer structure of the component (a) is not particularly limited, and for example, a linear block copolymer or a radial block copolymer represented by the following formula or a mixture of any of the polymer structures may be used. Further, in the radial block copolymer represented by the following formula, at least one of the block A and/or the block B may be bonded to X.

(AB) _n+1 , A-(BA) _n , B-(AB) _n+1 , [(AB) _k ] _m+1 -X, [(AB) _k -A] _m+1 -X, [ (BA) _k ] _m+1 -X, [(BA) _k -B] _m+1 -X,

In the above various formulae, the block A is composed of a vinyl aromatic hydrocarbon polymer, and the block B is composed of a copolymer containing a conjugated diene and a vinyl aromatic hydrocarbon.

In the above formula, X represents, for example, a residue of a coupling agent such as antimony tetrachloride, tin tetrachloride, 1,3 bis(N,N-glycidylaminomethyl)cyclohexane or epoxidized soybean oil. Or a residue of a starter such as a polyfunctional organolithium compound.

n, k, and m are each an integer of 1 or more, and are usually an integer of 1 to 5. Further, the structure of the plurality of bonded polymer chains may be the same or different.

The component (a) contained in the foam: the vinyl aromatic hydrocarbon in the copolymer of the vinyl aromatic hydrocarbon and the conjugated diene in the block B of the block copolymer can be uniformly distributed or formed Wedge (decreasing) distribution.

Further, in the copolymer, a portion in which a plurality of vinyl aromatic hydrocarbons are uniformly distributed and/or a portion in which a wedge shape is distributed may be coexisted in the block.

Component (a): The block copolymer preferably contains at least one random copolymer block comprising a vinyl aromatic hydrocarbon and a conjugated diene, and the random aromatic copolymer block has a vinyl aromatic hydrocarbon content of 70% by mass is less than 100% by mass, preferably 75% by mass or more and 98% by mass or less.

Thereby, a foam having good hardness and dimensional stability can be obtained.

<Method for Producing Component (a) Block Copolymer>

The component (a) can be obtained by polymerizing a vinyl aromatic hydrocarbon and a conjugated diene by using an organolithium compound as a starter in a hydrocarbon solvent.

Examples of the vinyl aromatic hydrocarbon include styrene, o-methyl styrene, p-methyl styrene, p-tert-butyl styrene, 1,3-dimethyl styrene, and α-methyl styrene. Vinyl naphthalene, vinyl anthracene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, etc. In particular, styrene is exemplified as an ordinary one. These may be used alone or in combination of two or more.

As the conjugated diene, it is a diene having one pair of conjugated double bonds, for example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2, 3 - dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc., and particularly as a general one, 1,3-butadiene, isoprene Wait. These may be used alone or in combination of two or more.

As the hydrocarbon solvent, for example, an aliphatic hydrocarbon such as n-butane, isobutane, n-pentane, n-hexane, n-heptane or n-octane, cyclopentane, methylcyclopentane or cyclohexane can be used. An alicyclic hydrocarbon such as methylcyclohexane, cycloheptane or methylcycloheptane, or an aromatic hydrocarbon such as benzene, toluene, xylene or ethylbenzene. These may be used alone or in combination of two or more.

As the polymerization initiator which is used in the polymerization of the component (a), an aliphatic hydrocarbon alkali metal compound or an aromatic hydrocarbon alkali metal compound which is known to have an anionic polymerization activity for a conjugated diene and a vinyl aromatic compound can be usually used. , an organic amine-based alkali metal compound, and the like.

Examples of the alkali metal constituting these include lithium, sodium, potassium, and the like. Preferred examples of the organic alkali metal compound include aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, and 1 molecule per molecule. A lithium compound or a plurality of lithium dilithium compounds, a trilithium compound, and a tetralithium compound in one molecule.

Specific examples thereof include n-propyl lithium, n-butyl lithium, second butyl lithium, t-butyl lithium, hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium, and diiso a reaction product of propylene benzene and a second butyllithium, and further a reaction product of divinylbenzene with a second butyllithium and a small amount of 1,3-butadiene.

Further, an organic alkali metal compound disclosed in the specification of U.S. Patent No. 5,708,092, the specification of U.S. Patent No. 2,241,239, and the specification of U.S. Patent No. 5,527,753, etc., may be used. These may be used alone or in combination of two or more.

The polymerization temperature at the time of producing the component (a) is usually -10 ° C to 150 ° C, preferably 40 ° C to 120 ° C.

The time required for the polymerization varies depending on the conditions, and is usually within 10 hours, and particularly preferably 0.5 to 5 hours.

Further, the ambient gas of the polymerization system is preferably replaced with an inert gas such as nitrogen.

The polymerization pressure is not particularly limited as long as it is a range sufficient to maintain the monomer and the solvent in a liquid layer within the above polymerization temperature range.

Further, it is preferable to note that impurities which inactivate the catalyst and the living polymer, such as water, oxygen, carbon dioxide or the like, are not mixed into the polymerization system.

Component (a): The block copolymer contains at least two vinyl aromatic hydrocarbon polymer blocks and at least one block copolymer comprising a copolymer block of a conjugated diene and a vinyl aromatic hydrocarbon.

In order to obtain such a configuration, in the polymerization step of the component (a): block copolymer, the timing of the vinyl aromatic compound or the conjugated diene compound which is a monomer to be a raw material may be controlled.

Component (a): The content of the vinyl aromatic hydrocarbon in the block copolymer is 65 to 95% by mass, and the content of the conjugated diene is 5 to 35% by mass.

In order to obtain such a configuration, the amount of the vinyl aromatic compound or the conjugated diene compound to be used as the monomer of the raw material may be adjusted in the polymerization step of the component (a): block copolymer.

Further, the component (a): the block copolymer contains at least one vinyl aromatic hydrocarbon content of 70% by mass or more and less than 100% by mass, preferably 75% by mass or more and 98% by mass or less of the vinyl aromatic hydrocarbon-containing A random copolymer block with a conjugated diene.

In order to obtain such a configuration, in the step of producing the component (a): block copolymer, the amount of the monomer to be used as the raw material may be adjusted in the polymerization step of the random block.

<Component (a): Physical properties of block copolymer>

As described above, in the component (a): block copolymer, the storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and dynamic viscoelasticity The peak temperature of the measured function tan δ is at least one of 85 ° C or more and 125 ° C or less.

Preferably, the storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement is 5 × 10 ⁸ Pa or more and 2.33 × 10 ⁹ Pa or less, and the peak temperature of the function of the dynamic viscoelasticity measurement tan δ is 90 ° C or higher. There is at least one below 125 °C.

The temperature indicating the peak of tan δ is a temperature at which the value of tan δ is zero with respect to the first differential value of the amount of change in temperature.

In the dynamic viscoelasticity measurement of the component (a): block copolymer, the storage elastic modulus (E') at 30 ° C is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the function of dynamic viscoelasticity is tan δ. When the peak temperature is at least one of 85 ° C or more and 125 ° C or less, the foam of the present embodiment is excellent in the balance of hardness, elongation, and thermoformability, and is suitable for the sole.

The storage elastic modulus (E') and tan δ in the dynamic viscoelasticity measurement of the component (a) can be measured by the method described in the examples below.

For example, it can be measured by a viscoelasticity measuring and analyzing device DVE-V4 manufactured by Rheology Co., Ltd. or a Rheovibron DDV-3 type manufactured by TOYO Baldwin Co., Ltd., specifically, an oscillation frequency of 35 Hz and a temperature rising rate of 3 ° C/ Under the condition of min, the test piece having a thickness of 0.5 to 2 mm was used for measurement.

The storage elastic modulus (E') at 30 ° C in the above dynamic viscoelasticity measurement can be improved by, for example, the block A containing the vinyl aromatic hydrocarbon polymer constituting the above component (a), and In the ratio of the block B containing a copolymer of a conjugated diene and a vinyl aromatic hydrocarbon, the block A is increased. That is, by appropriately adjusting the ratio of the block A to the block B of the component (a), the storage elastic modulus (E') at 30 ° C can be controlled to 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa. The following range of values.

The peak temperature of the function of dynamic viscoelasticity of the component (a) can be controlled to a high degree by, for example, increasing the content of the vinyl aromatic hydrocarbon of the component (a) and increasing the molecular weight of the component (a). The ratio of the vinyl aromatic hydrocarbon in the random copolymer block including the vinyl aromatic hydrocarbon and the conjugated diene of the component (a) is 70% by mass or more and less than 100% by mass, preferably 75. In the range of mass% or more and 98% by mass or less, the ratio of the vinyl aromatic hydrocarbon is increased within the range; on the contrary, the vinyl aromatic hydrocarbon containing the constituent (a) is controlled to a lower degree by the following manner. The ratio of the vinyl aromatic hydrocarbon in the random copolymer block of the conjugated diene is in the range of 70% by mass or more and less than 100% by mass, preferably 75% by mass or more and 98% by mass or less. The ratio of vinyl aromatic hydrocarbons is reduced and the ratio of the random copolymer blocks to the vinyl aromatic hydrocarbon homopolymer blocks is increased.

That is, by performing the above various adjustments, the peak temperature of the function tan δ of the dynamic viscoelasticity measurement of the component (a) can be controlled to be 85 ° C or more and 125 ° C or less.

The molecular weight of the component (a) is not particularly limited, and the number average molecular weight in terms of polystyrene in the gel permeation chromatography (GPC method) is preferably 30,000 to 1,000,000, more preferably 40,000 to 500,000. It is 50,000~300,000.

By setting the molecular weight of the component (a) to the above range, a composition for a foam having excellent fluidity and workability can be obtained.

(Component (b): Isoprene-based rubber and/or diene-based rubber)

The isoprene rubber is a natural rubber and an isoprene rubber, a diene rubber, a styrene ‧ butadiene copolymer rubber, a polybutadiene rubber, an acrylonitrile ‧ butadiene copolymer rubber In the case of the component (b) which constitutes the foam of the present embodiment, it may be used singly or in combination of two or more kinds.

The component (b) may contain oils such as paraffin oil, naphthenic oil, and aromatic oil, or dioctyl phthalate, dibutyl phthalate, dioctyl sebacate, dioctyl adipate, and the like. Various plasticizers.

Examples of the above-mentioned paraffin oil include Diana Process Oil PW-90, PW-380, PS-32, PS-90, and PS-430 manufactured by Idemitsu Kosan Co., Ltd., and Fukkol Process P-100 manufactured by Toei Manufacturing Co., Ltd. P-200, P-300, P-400, P-500, Kyoseki Process P-200, P-300, P-500, Kyoseki EPT750, Kyoseki 1000, Kyoseki Process S90, Shell Chemicals Manufactured by Lubrex 26, Lubrex 100, Lubrex 460, Esso Process Oil 815 manufactured by Exxon Mobil, Esso Process Oil 845, Esso Process Oil B-1, Naprex 32 manufactured by Exxon Mobil, Mitsubishi 10 Light manufactured by Nippon Oil Corporation Process Oil, etc.

As the naphthenic oil, Diana Process Oil NS-24, NS-100, NM-26, NM-280, NP-24 manufactured by Idemitsu Kosan Co., Ltd., Naprex 38 manufactured by Exxon Mobil Co., Ltd., Fuji Xingyo Co., Ltd. Manufactured by Fukkol FLEX #1060N, #1150N, #1400N, #2040N, #2050N, Kyoseki Process R25, R50, R200, R1000 manufactured by Nippon Mining & Co., Ltd., Shellflex 371JY, Shellflex 371N, Shellflex 451 manufactured by Shell Chemicals. Shellflex N-40, Shellflex 22, Shellflex 22R, Shellflex 32R, Shellflex 100R, Shellflex 100S, Shellflex 100SA, Shellflex 220RS, Shellflex 220S, Shellflex 260, Shellflex 320R, Shellflex 680, Koumorex No. 2 Process Oil by Nippon Oil Corporation Esso Process Oil L-2, Esso Process Oil 765 manufactured by Exxon Mobit, Mitsubishi 20 Light Process Oil manufactured by Nippon Oil Corporation, etc.

Examples of the aromatic oil include Diana Process Oil AC-12, AC460, AH-16, and AH-58 manufactured by Idemitsu Kosan Co., Ltd., Mobile Sol K, Mobile Sol 22, and Mobile Sol 130 manufactured by Exxon Mobil Co., Ltd. Kyoseki Process X50, X100, X140 manufactured by Kashiwa Co., Ltd., Rezox No. 3 manufactured by Shell Chemicals Co., Ltd., Dutorex 729UK, Koumorex 200, 300, 500, 700 manufactured by Nippon Oil Corporation, Esso Process Oil 110 manufactured by Exxon Mobil Co., Ltd. Esso Process Oil 120, Mitsubishi 34 Heavy Process Oil, Mitsubishi 44 Heavy Process Oil, Mitsubishi 38 Heavy Process Oil, Mitsubishi 39 Heavy Process Oil, etc. manufactured by Nippon Oil Corporation.

The blending amount of the plasticizer is preferably from 1 to 200 parts by mass, more preferably from 10 to 100 parts by mass, even more preferably from 15 to 80 parts by mass, per 100 parts by mass of the component (b).

When the compounding amount of the plasticizer is from 1 to 200 parts by mass, the foam of the present embodiment is excellent in workability.

As the component (b), polybutadiene is preferred, and as the polybutadiene rubber, the inclusion of the 1,2-bond (vinyl) 5% to 20% and the inverse 1,4 bond 0~ 3%, the remaining components are cis 1,4 bond vinyl cis-polybutadiene rubber, or contain cis 1,4 bond 92% or more, including 1,2 bond 0% ~ 3%, the remaining components are inverse 1,4 High-poly butadiene rubber of the rubber of the key.

In the foam of the first embodiment of the present embodiment, the mass ratio of the component (a) to the component (b) (component (a) / component (b)) = (1 to 30) / (70 to 99) ), preferably (2~25)/(75~98), more preferably (5~20)/(80~95).

When the mass ratio of the component (a) to the component (b) is (1 to 30) / (70 to 99), the foam can obtain excellent hardness and dimensional stability.

(ingredient (c): filler)

Examples of the filler include cerium oxide, calcium carbonate, clay, talc, mica, barium sulfate, magnesium carbonate, glass fiber, glass beads, potassium titanate, carbon black, carbon-niobium dioxide, and a duplex filler. .

In the foam of the first embodiment, the amount of the filler is from 1 to 100 parts by mass, preferably from 2 to 90 parts by mass, per 100 parts by mass of the total of the component (a) and the component (b). More preferably, it is 3 to 75 parts by mass, and particularly preferably 5 to 50 parts by mass.

When the amount of the component (c): the filler is from 1 to 100 parts by mass, the foam of the present embodiment can obtain a preferable hardness and a preferable specific gravity.

(ingredient (d): foaming agent)

As the foaming agent, for example, an inorganic foaming agent or an organic foaming agent known per se can be used.

For example, sodium bicarbonate, ammonium bicarbonate, sodium carbonate, ammonium carbonate, azodimethylamine, dinitrosopentamethylenetetramine, dinitroso-p-xylamine, azodi Sulfoxime such as isobutyronitrile, azodicarboxylate or toluenesulfonate. More preferably, it is azomethamine, dinitrosopentamethylenetetramine, sulfonium, sodium bicarbonate. These foaming agents may be used in combination with a known foaming aid such as urea or a urea derivative.

Further, as the foaming agent, a heat-expandable microcapsule can be used.

The heat-expandable microcapsules include a foamed particle of a thermoplastic hollow sphere and a shell containing a thermoplastic resin enclosing the gas.

When the heat-expandable microcapsules are heated, the thermoplastic shell softens and the gas increases the pressure, and as a result, the sphere expands to function as a foaming agent.

Examples of the thermoplastic resin constituting the shell of the above microcapsules include a vinylidene chloride-acrylonitrile copolymer, a vinylidene chloride-methyl methacrylate copolymer, a vinylidene chloride-ethyl methacrylate, and a propylene. Nitrile-methyl methacrylate copolymer, acrylonitrile-ethyl methacrylate, and the like.

Further, examples of the compound which becomes a gas by heating include isopentane, isobutane, and isopropane.

The mass average particle diameter of the heat-expandable microcapsules is usually from 10 to 100 μm, preferably from about 20 to 80 μm.

Examples of the heat-expandable microcapsules include EXPANCEL DU manufactured by JAPAN FILLITE Co., Ltd., WU series, Microsphere F-30, F-50, F-80S, and F-85 manufactured by Matsumoto Oil Co., Ltd.

When the heat-expandable microcapsules are used as a foaming agent, by heating, the gas-forming components contained in the respective microcapsules are uniformly expanded by gasification, whereby a homogeneous foam can be obtained.

Further, by using a heat-generating foaming agent and an endothermic foaming agent as a foaming agent in combination, it is possible to suppress heat generation during foam molding, which is preferable.

Examples of the heat-generating foaming agent include azodimethylamine, dinitrosopentamethylenetetramine, and the like.

Further, examples of the endothermic foaming agent include sodium hydrogencarbonate. In this case, the generated gas is carbon dioxide.

In the foam of the first embodiment, the amount of the component (d): the foaming agent is preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the total of the component (a) and the component (b). It is 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass.

When the blending amount of the component (d): the foaming agent is 0.1 to 30 parts by mass, the foam of the present embodiment can obtain excellent hardness and a specific gravity.

(ingredient (e): thermoplastic elastomer and/or thermoplastic resin)

In addition to the above components (a) to (d), the foam of the present embodiment may further contain the component (e): a thermoplastic elastomer and/or a thermoplastic resin.

Examples of the thermoplastic elastomer include olefin-based thermoplastic elastomer (TPO), urethane-based thermoplastic elastomer (TPU), and ester-based thermoplastic elastomer (TPEE), for example, according to the chemical composition of the hard segment. ), a guanamine-based thermoplastic elastomer (TPAE) or the like.

Further, there are a vinyl chloride-based thermoplastic elastomer (TPVC), an ion cluster-type thermoplastic elastomer (ionic polymer), a fluorine-based thermoplastic elastomer containing a fluororesin as a restraining block, and the like (further, it may be used by In the thermoplastic elastomer in which the resin/rubber is mixed, the rubber which is a soft segment is cross-linked while being kneaded, and the rubber dispersed particle diameter is refined, and the dynamically crosslinked TPO which improves the performance is called TPV). The thermoplastic elastomer may be used alone or in combination of two or more.

Further, as the other thermoplastic elastomer, a synthetic rubber other than the above component (a) or component (b) may be used, and examples thereof include a fluororubber, a polyoxyethylene rubber, and a halogenated butyl rubber (for example, chlorobutyl rubber, bromination). One type of these may be used alone or two or more types may be used in combination.

The thermoplastic resin is a thermoplastic resin having a plasticizing temperature of 50 to 300 ° C, and can be used without particular limitation.

For example, styrene resin (for example, polystyrene, acrylonitrile ‧ styrene copolymer, acrylonitrile ‧ butadiene styrene copolymer, etc.), ABS (Acrylonitrile Butadiene Styrene, acrylonitrile-butadiene-benzene) Ethylene resin, AES (Acrylonitrile-Ethylene-Styrene) resin, AAS (Acrylnitrile-Acrylicester-Styrene, acrylonitrile-acrylate-styrene) resin, polyethylene, polypropylene, ethylene-propylene Resin, ethylene-ethyl acrylate resin, polyvinyl chloride, polyvinylidene chloride, polybutene, polycarbonate, polyacetal, polyphenylene ether, polymethyl methacrylate, saturated polyester resin (eg polylactic acid) a hydroxycarboxylic acid condensate, a condensate of a diol such as polybutylene succinate and a dicarboxylic acid, etc., a polyamide resin, a fluororesin, a polyfluorene, a polyether oxime, a polyarylate, Polyetheretherketone, liquid crystal polymer, and the like. These may be used alone or in combination of two or more.

Preferred among the thermoplastic resins are polystyrene, acrylonitrile ‧ styrene copolymer, ABS resin, AES resin, AAS resin, polyethylene, polypropylene, polyvinyl chloride, saturated polyester resin, and polyamide resin.

By blending these thermoplastic resins, it is preferable to prevent dents or deformation in the molded body of the foam of the present embodiment.

The component (e): the blending amount of the thermoplastic elastomer and/or the thermoplastic resin is preferably from 1 to 100 parts by mass, more preferably from 3 to 100 parts by mass, based on 100 parts by mass of the total of the component (a) and the component (b). 75 parts by mass, particularly preferably 5 to 50 parts by mass.

When the amount of the component (e): the thermoplastic elastomer and/or the thermoplastic resin is from 1 to 100 parts by mass, the foam of the present embodiment can obtain a preferable mechanical strength.

(composition for foam)

The composition for a foam obtained by obtaining the foam of the first embodiment of the present embodiment includes the above components (a) to (d), the component (a) block copolymer, and the above (b) The mass ratio (component (a) / component (b)) of the isoprene-based rubber and/or the diene rubber is (1 to 30) / (70 to 99), preferably (2 to 25) / ( 75 to 98), more preferably (5 to 20) / (80 to 95), based on the total of the above (a) block copolymer and the above (b) isoprene-based rubber and/or diene rubber The amount of the above (c) filler is from 1 to 100 parts by mass, preferably from 2 to 90 parts by mass, more preferably from 3 to 75 parts by mass, even more preferably from 5 to 50 parts by mass, per 100 parts by mass, and the above (d) is contained. The foaming agent is used in an amount of 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass.

Further, the component (e) may be contained, and it is preferably contained in an amount of from 1 to 100 parts by mass, more preferably from 3 to 75 parts by mass, based on 100 parts by mass of the total of the component (a) and the component (b). 5 to 50 parts by mass.

When preparing a composition for a foam, a previously known kneader, extruder, or the like can be used.

In addition, as a method of blending the (c) filler, (d) a foaming agent, and the like, the order of the blending, for example, the component (a) and the component (b) are 100 to 180 in advance by a Banbury mixer or the like. The mixture is melt-kneaded at ° C, and the resultant is blended with (c) a filler using a Banbury mixer or the like, and then a method of adding (d) a foaming agent, a crosslinking agent, or the like using a roll or the like, but is not limited thereto.

[foam] [Foam according to the second embodiment]

The foam of the second embodiment contains the following components (a') to (d). (a') a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon, and a vinyl aromatic The content of the hydrocarbon is 65 to 95% by mass, the content of the conjugated diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass.

(b) Isoprene-based rubber and/or diene-based rubber.

(c) a filler.

(d) a blowing agent.

When the specific gravity of the foam of the second embodiment is 0.1 to 0.7 g/cc, the hardness measured by the model C is 45 to 98, and when the specific gravity is 0.8 to 0.98 g/cc, the hardness measured by the model A is 60~98.

(ingredient (a'): block copolymer)

The component (a') contains a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene as described above.

The content of the vinyl aromatic hydrocarbon in the component (a') is from 65 to 95% by mass, preferably from 68 to 93% by mass, more preferably from 70 to 90% by mass.

The content of the conjugated diene in the component (a') is 5 to 35 mass%, preferably 7 to 32 mass%, more preferably 10 to 30 mass%.

When the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass and the content of the conjugated diene is in the range of 5 to 35% by mass, the hardness of the foam is excellent in the balance between the elongation and the thermoformability. Suitable for foams for shoes.

The content of the vinyl aromatic hydrocarbon in the component (a') and the content of the conjugated diene are determined by measuring the absorption luminosity of light with respect to a specific wavelength by using an ultraviolet spectrophotometer.

The block ratio of the vinyl aromatic hydrocarbon polymer contained in the component (a') is from 40 to 98% by mass, preferably from 50 to 95% by mass, more preferably from 60 to 90% by mass. When the block ratio of the vinyl aromatic hydrocarbon polymer is in the range of 40 to 98% by mass, it is excellent in dimensional stability and thermoformability, and is suitable as a foam for shoes.

The block ratio of the vinyl aromatic hydrocarbon polymer can be determined by the weight of the random copolymer chain containing the vinyl aromatic hydrocarbon and the conjugated diene in the component (a') and the content of the vinyl aromatic hydrocarbon (quality) %) to adjust.

The more the amount of the vinyl aromatic hydrocarbons in the random copolymer chain of the component (a') block copolymer, the lower the block rate of the vinyl aromatic hydrocarbon polymer, and the smaller the block rate is. high.

The block ratio of the vinyl aromatic hydrocarbon polymer can be determined by the same method as the above component (a).

The component (a') has at least two vinyl aromatic hydrocarbon polymer blocks and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon.

The polymer structure of the component (a') is not particularly limited, and for example, a linear block copolymer or a radial block copolymer represented by the following formula or a mixture of any of the polymer structures may be used. Further, in the radial block copolymer represented by the following formula, at least one of the block A and/or the block B may be bonded to X.

(AB) _n+1 , A-(BA) _n , B-(AB) _n+1 ,

[(AB) _k ] _m+1 -X, [(AB) _k -A] _m+1 -X,

[(BA) _k ] _m+1 -X, [(BA) _k -B] _m+1 -X,

In the above various formulae, the block A is composed of a vinyl aromatic hydrocarbon polymer, and the block B is composed of a copolymer containing a conjugated diene and a vinyl aromatic hydrocarbon.

In the above formula, X represents, for example, a residue of a coupling agent such as antimony tetrachloride, tin tetrachloride, 1,3 bis(N,N-glycidylaminomethyl)cyclohexane or epoxidized soybean oil. Or a residue of a starter such as a polyfunctional organolithium compound.

n, k, and m are each an integer of 1 or more, and are usually an integer of 1 to 5. Further, the structure of the plurality of bonded polymer chains may be the same or different.

The component (a') contained in the foam: the vinyl aromatic hydrocarbon in the copolymer of the vinyl aromatic hydrocarbon and the conjugated diene in the block B of the block copolymer may be uniformly distributed, or Wedge (decreasing) distribution.

Further, in the copolymer, a portion in which a plurality of vinyl aromatic hydrocarbons are uniformly distributed and/or a portion in which a wedge shape is distributed may be coexisted in the block.

Component (a'): The block copolymer preferably contains at least one random copolymer block comprising a vinyl aromatic hydrocarbon and a conjugated diene, and the content of the vinyl aromatic hydrocarbon in the random copolymer block 70% by mass is less than 100% by mass, preferably 75% by mass or more and 98% by mass or less.

Thereby, a foam having good hardness and dimensional stability can be obtained.

<Method for Producing Component (a') Block Copolymer>

The component (a') can be produced by the same method as the above component (a).

As the vinyl aromatic hydrocarbon, the conjugated diene, the hydrocarbon solvent, the polymerization initiator or the like which is a raw material, the same material as the component (a) can be used.

Further, the polymerization conditions such as the polymerization temperature and the ambient gas may be selected under the same conditions as the component (a).

<Component (a'): Physical properties of block copolymers>

Component (a'): The block copolymer preferably has a storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement of 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and is preferably dynamic viscosity. The peak temperature of the function tan δ of the elastic measurement is at least one of 85 ° C or more and 125 ° C or less.

More preferably, the storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement is 5 × 10 ⁸ Pa or more and 2.33 × 10 ⁹ Pa or less, and more preferably a function of dynamic viscoelasticity measurement. The peak temperature of tan δ is 90 There is at least one above °C above 125 °C.

Thereby, the foam is excellent in the balance of hardness, elongation, and thermoformability, and is suitable for a shoe sole.

The molecular weight of the component (a') is not particularly limited, and the number average molecular weight in terms of polystyrene in the gel permeation chromatography (GPC method) is preferably 30,000 to 1,000,000, more preferably 40,000 to 500,000. Good is 50,000~300,000.

By setting the molecular weight of the component (a') to the above range, a composition for a foam having excellent fluidity and workability can be obtained.

As the component (b), the component (c), and the component (d) constituting the foam of the second embodiment, the same material as the foam of the first embodiment described above can be used.

Further, the foam of the second embodiment may contain the component (e).

[Method for Producing Foam]

In the foaming system according to the first embodiment of the present embodiment, the component (a), the component (b), the component (c), and the component (d) are essential components, and the foaming system of the second embodiment has the above component (a). '), the component (b), the component (c), and the component (d) are essential components, and the component for foaming is prepared by adding the component (e) as needed, and the composition for the foam is applied. Obtained by bubble and cross-linking treatment.

(foaming ‧ cross-linking treatment)

In the step of foaming the above-mentioned composition for a foam, the foam can be obtained by foaming by adding it to a specific mold to raise the temperature, or molding into an arbitrary shape by using an extrusion molding machine. It is heated in a heating bath to foam.

At this time, after the foaming is performed once, the foaming may be performed twice to increase the expansion ratio.

The foaming condition is preferably such that the heating temperature is set to 120 to 300 ° C, more preferably 140 to 200 ° C, and it is preferred to set the heating time to 3 to 120 minutes, more preferably to 5 to 60 minutes. .

In the above foaming process, crosslinking can be carried out simultaneously.

The crosslinking form of the foam of the present embodiment is not particularly limited, and for example, sulfur crosslinking, peroxide crosslinking, or the like can be applied.

From the viewpoint of the cost and strength of the foam, sulfur crosslinking is preferred.

Further, the foam may be blended with an appropriate amount of a decylating agent, a decane coupling agent, an anti-aging agent, a vulcanization accelerator, a crosslinking assistant, a colorant, or the like as needed.

[Physical properties of foam]

The specific gravity of the foam of the present embodiment is 0.1 to 0.98 g/cc, preferably 0.1 to 0.95 g/cc, in the foams of the first embodiment and the second embodiment.

The specific gravity can be measured by the method described in the examples below. Specifically, it can be measured in accordance with JIS K 7112.

A foam having a specific gravity of 0.1 to 0.7 g/cc is suitable for use in applications requiring cushioning properties such as cushioning properties, impact cushioning properties, and light weight, such as a midsole material such as sports shoes.

A foam having a specific gravity of 0.8 to 0.98 g/cc is suitable for use in applications requiring characteristics of hardness, dimensional stability, and mechanical strength, such as an outsole material for shoes.

The specific gravity of the foam can be controlled by adjusting the composition of the compound (c): the filling dose, and the component (d): the foaming dose.

By increasing the component (c): the filling dose and the specific gravity becomes large, the specific gravity can be reduced by increasing the component (d): the foaming amount.

Further, in the foam of the present embodiment, the hardness measured by the model C is 45 to 98, preferably 48 to 90, more preferably 50 to 85, when the specific gravity is 0.1 to 0.7 g/cc.

When the specific gravity is 0.8 to 0.98 g/cc, the hardness measured by the model A is 60 to 98, preferably 63 to 90, more preferably 65 to 85.

Further, the hardness measured by the model C refers to the hardness measured by an ASKER C type hardness tester (model C) using a plate-shaped test piece having a thickness of 12 mm.

Further, the hardness measured by the model A means a hardness measured by using a plate-shaped test piece having a thickness of 12 mm in accordance with JIS K 6301 spring type hardness tester A shape (model A).

The hardness of the foam can be controlled by adjusting the composition and specific gravity of the components (a) to (d), the components (a') to (d).

For example, the hardness can be increased by increasing the content of the component (c): the filler, and the foaming ratio can be increased by increasing the content of the component (d): the amount of the foaming agent, and the hardness can be lowered. That is, by adjusting the above components, the strength of the foam having a specific specific gravity can be controlled to the above specific value.

[Use of foam]

The foam of the embodiment can be effectively used as a midsole, an insole or an outsole material for shoes, specifically for men's shoes, ladies' shoes, casual shoes, running shoes, jogging shoes, track shoes, various competitive shoes, hiking shoes, The soles of all kinds of footwear such as dress shoes, golf shoes, indoor shoes, slippers, beach shoes, etc. are midsole, insole or outsole material.

Further, the foam of the present embodiment can be used for various molded articles such as conveyor belts, automobile parts, building materials parts, industrial parts, toys, miscellaneous parts, sports, health parts, and care products, or various sheets, films, and the like, as needed. Industrial supplies, cushioning materials, packaging materials, etc.

Further, the foam of the present embodiment is excellent in dimensional accuracy, excellent in durability and cushioning properties, and can be applied to a thermoformed sponge, and can be used for the above various applications after being processed into the thermoformed sponge. The thermoformed sponge is prepared by cutting the foam into a desired shape, heating and pressurizing in a mold heated to 100 to 150 ° C, and forming a firm molten film on the outer surface of the foam to cool the mold. The foam was taken out and produced.

Example

Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited to the examples described below.

(Component (a): Production Example of Block Copolymer) <Block copolymer A-1>

Using an autoclave equipped with a stirrer, 0.019 parts by mass of n-butyllithium and 0.1 times of moles of n-butyllithium were added to a cyclohexane solution containing 18 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 25 minutes for polymerization.

Then, a cyclohexane solution containing 21 parts by mass of styrene and 32 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 65 minutes to carry out polymerization.

Then, a cyclohexane solution containing 29 parts by mass of styrene was continuously supplied at 70 ° C for 35 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-1.

<Block copolymer A-2>

Using an autoclave equipped with a stirrer, 0.087 parts by mass of n-butyllithium and 0.1 times of moles of n-butyllithium were added to a cyclohexane solution containing 24 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 30 minutes for polymerization.

Then, a cyclohexane solution containing 22 parts by mass of styrene and 27 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 60 minutes to carry out polymerization.

Then, a cyclohexane solution containing 27 parts by mass of styrene was continuously supplied at 70 ° C for 35 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-2.

<Block copolymer A-3>

Using an autoclave equipped with a stirrer, 0.082 parts by mass of n-butyllithium and 0.1 times of moles of n-butyllithium were added to a cyclohexane solution containing 31 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 40 minutes for polymerization.

Then, 20 parts by mass of styrene and 20 parts by mass of 1,3-butadiene in a cyclohexane solution were continuously supplied at 70 ° C for 50 minutes to carry out polymerization.

Then, a cyclohexane solution containing 6 parts by mass of styrene and 2 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 21 parts by mass of styrene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-3.

<Block copolymer A-4>

Using an autoclave equipped with a stirrer, 0.076 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 32 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 40 minutes for polymerization.

Then, a cyclohexane solution containing 21 parts by mass of styrene and 12 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 40 minutes to carry out polymerization.

Then, a cyclohexane solution containing 8 parts by mass of styrene and 3 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 24 parts by mass of styrene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-4.

<Block copolymer A-5>

Using an autoclave equipped with a stirrer, 0.052 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 26 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 35 minutes for polymerization.

Then, a cyclohexane solution containing 30 parts by mass of styrene and 6.5 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 45 minutes to carry out polymerization.

Then, a cyclohexane solution containing 10 parts by mass of styrene and 1.5 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 26 parts by mass of styrene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-5.

<Block copolymer A-6>

Using an autoclave equipped with a stirrer, 0.092 parts by mass of n-butyllithium and 0.1 times of moles of n-butyllithium were added to a cyclohexane solution containing 15 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 20 minutes for polymerization.

Then, a cyclohexane solution containing 16 parts by mass of styrene and 38 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 60 minutes to carry out polymerization.

Then, a cyclohexane solution containing 6 parts by mass of styrene and 2 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 23 parts by mass of styrene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-6.

<Block copolymer A-7>

Using an autoclave equipped with a stirrer, 0.054 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 39 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 45 minutes for polymerization.

Then, a cyclohexane solution containing 20 parts by mass of styrene and 2 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, a cyclohexane solution containing 39 parts by mass of styrene was continuously supplied at 70 ° C for 45 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-7.

<Block copolymer A-8>

Using an autoclave equipped with a stirrer, 0.090 parts by mass of n-butyllithium and 0.1 times of moles of n-butyllithium were added to a cyclohexane solution containing 20 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 25 minutes for polymerization.

Then, a cyclohexane solution containing 16 parts by mass of styrene and 32 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 55 minutes to carry out polymerization.

Then, a cyclohexane solution containing 8 parts by mass of styrene and 2 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 22 parts by mass of styrene was continuously supplied at 70 ° C for 30 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-8.

<Block copolymer A-9>

Using an autoclave equipped with a stirrer, 0.074 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 15 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 20 minutes for polymerization.

Then, a cyclohexane solution containing 10 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 20 minutes to carry out polymerization.

Then, a cyclohexane solution containing 57 parts by mass of styrene and 18 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 80 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-9.

<Block copolymer A-10>

Using an autoclave equipped with a stirrer, 0.051 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 47 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 55 minutes for polymerization.

Then, a cyclohexane solution containing 6 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 15 minutes to carry out polymerization.

Then, a cyclohexane solution containing 47 parts by mass of styrene was continuously supplied at 70 ° C for 55 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-10.

<Block copolymer A-11>

Using an autoclave equipped with a stirrer, 0.083 parts by mass of n-butyllithium and 0.3 times of moles of n-butyllithium were added to a cyclohexane solution containing 27 parts by mass of styrene under a nitrogen atmosphere. Methylethylenediamine was continuously supplied at 70 ° C for 30 minutes for polymerization.

Then, a cyclohexane solution containing 10 parts by mass of styrene and 26 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 45 minutes to carry out polymerization.

Then, a cyclohexane solution containing 12 parts by mass of styrene and 3 parts by mass of 1,3-butadiene was continuously supplied at 70 ° C for 20 minutes to carry out polymerization.

Then, a cyclohexane solution containing 22 parts by mass of styrene was continuously supplied at 70 ° C for 25 minutes to carry out polymerization.

Then, in the polymerization vessel, isomolar methanol was added to n-butyllithium, and 0.3 parts by mass of 2-[1-(2-hydroxy-) as a stabilizer was added to 100 parts by mass of the block copolymer. 3,5-Di-t-pentylphenyl)ethyl]-4,6-di-p-pentyl phenyl acrylate.

Then, solvent removal was carried out to obtain block copolymer A-11.

Component (a): structure of block copolymers A-1 to A-11, styrene content (% by mass), storage elastic modulus (E') at 30 ° C, and peak value of tan δ of dynamic viscoelasticity measurement The block ratio of styrene contained in the temperature and block copolymer is shown in Table 1 below.

(Component (a): Method for measuring physical properties of block copolymer) <(1) Styrene content (% by mass)>

Using an ultraviolet spectrophotometer (Hitachi UV200), it was calculated from the absorption intensity at 262 nm.

<(2) Storage elastic modulus (E') at 30 °C and the peak temperature of tan δ as a function of dynamic viscoelasticity >

Using a viscoelasticity measuring and analyzing device DVE-V4 manufactured by Rheology, a test piece having a thickness of 2 mm was used under the conditions of an oscillation frequency of 35 Hz and a temperature rising rate of 3 ° C/min, and the temperature was measured in the range of -50 ° C to 150 ° C. And ask for it.

<(3) Block rate of styrene contained in the block copolymer>

A method for oxidatively decomposing a block copolymer by using perylene tetroxide as a catalyst by peroxidizing tert-butanol (oxidative decomposition method: IM KOLTHOFF, et al., J. Polym. Sci. 1, 429 (1946) In the method, the block chain component of styrene (excluding the styrene block component having an average degree of polymerization of about 30 or less) is separated, and the weight of the styrene block chain is measured and determined according to the following formula.

Block ratio (% by mass) of styrene = (weight of styrene block polymeric chain in block copolymer / total weight of styrene in block copolymer) × 100

In Table 1, in the structure of the block copolymers A-1 to A-11, A represents a polystyrene block, B represents a random copolymer block of styrene and butadiene, and C represents a polybutadiene embedded. segment.

The added word (number) is used to distinguish each part, and the structure may be the same or different.

(Method for measuring characteristics of foam and evaluation method)

The measurement method and evaluation method of the characteristics of the foam produced in the examples and the comparative examples will be described.

<(4) Specific gravity>

The measurement was carried out in accordance with JIS K 7112.

<(5) Hardness (Model A)>

A plate-shaped test piece having a thickness of 12 mm was used, and it was measured in accordance with JIS K 6301 spring type hardness tester A shape (model A).

<(6) Hardness (Model C)>

A plate-shaped test piece having a thickness of 12 mm was used for measurement by an Asker C type hardness tester (Model C).

<(7) Tensile strength (Tb), elongation at break (Eb)>

A plate-shaped test piece having a thickness of 2 mm was measured in accordance with JIS K 6251.

The unit of Tb is set to (MPa), and the unit of Eb is set to (%).

<(8) dimensional stability (α)>

The shrinkage rate of the sheet formed twice by a mold of 150 (vertical) × 150 (horizontal) × 4 mm (thickness) was measured for 24 hours.

Further, the index was calculated by setting Comparative Example 1 to 100.

The smaller the index, the smaller the shrinkage ratio and the more excellent the dimensional stability.

Further, the shrinkage ratio after foaming in Comparative Example 1 was 1.8%.

<(9) dimensional stability (β)>

The shrinkage ratio after vulcanization foaming of the sheet of 150 (vertical) × 150 (horizontal) × 4 mm (thickness) was measured for 24 hours.

Further, the index was calculated by setting Comparative Example 10 to 100.

The smaller the index, the smaller the shrinkage ratio and the more excellent the dimensional stability.

Further, the shrinkage ratio after foaming in Comparative Example 10 was 1.2%.

<(10) Thermoformability>

The state of the molded article after the thermoforming was investigated twice.

○ indicates a state in which there is no problem in practical use, and × indicates a state in which the unevenness state is poor and the product is defective.

[Examples 1 to 6], [Comparative Examples 1 to 5]

Using the block copolymers A-1 to A-11 of the component (a) and BR and SBR as the component (b), the cerium oxide as the component (c) and the hair as the component (d) are used therein. The foaming agent and other additives were used, and the composition and the physical properties of the foam were shown in Table 2 below.

Using a 1.7 L test Banbury mixer, the maximum temperature was adjusted to 170-180 ° C, and the blending materials other than the foaming agent and other additives in the blending composition shown in Table 2 were mixed.

Then, the kneaded material was kneaded by adding a foaming agent and other additives to a 10-size roll, and the mixture was rolled into a sheet shape, and then subjected to hot press molding (crosslinking, foaming) at 140 ° C.

The pressing conditions are appropriately adjusted in such a manner that the internal hardness of the molded article is 35 to 50 (model C).

The molded article produced by the above conditions was subjected to secondary molding at a compression ratio of 30% (heat-pressed at 150 ° C for 7 minutes, and cooled for 15 minutes) to obtain a foam.

The details of the symbols and the like in Table 2 above are as follows.

BR; polybutadiene ("Nipol BR1220" manufactured by ZEON Co., Ltd.)

SBR; styrene-butadiene copolymer ("SBR1502" manufactured by KUMHO)

Ceria; "Nipsil VN3" manufactured by Tosoh Silica Co., Ltd.

Blowing agent 1; P, P'-oxybisbenzenesulfonate (OBSH)

Foaming agent 2; azomethicin (ADCA)

Other additives; polyethylene glycol (manufactured by Shanyang Chemical Industry Co., Ltd., trade name "PEG#4000") 1 part by mass of stearic acid (manufactured by Asahi Kasei Co., Ltd.) 1 part by mass of foaming aid (urea derived) 1 part by mass of DCP (produced by 98% dicumyl peroxide, manufactured by Nippon Oil & Fats Co., Ltd., trade name "PERCUMYL D" 0.4 parts by mass, manufactured by Sankyo Chemical Co., Ltd., trade name "Selton NF"

[Examples 7 to 10], [Comparative Examples 6 to 9]

As shown in Table 3, the foam was obtained by the same method as in Example 1 by changing the kind and amount of the component (a) and the amounts of the components (b), (c) and (d).

The details of the symbols and the like in Table 3 are the same as those in Table 2, and the measurement method of the physical properties is also the same as described above.

[Example 11]

With respect to the compounding composition of the above [Example 11], 5 parts by mass of EVA (ethylene-vinyl acetate copolymer, manufactured by Tosoh, EVAUE 633, vinyl acetate) was added with respect to 100 parts by mass of the component (a) and the component (b). Ester content = 20%, MI = 20).

The foam was obtained by the same method as in Example 1 under other conditions.

The obtained foam had a specific gravity of 0.39 g/cc, a hardness of 54, a Tb of 3.0 MPa, an Eb of 390%, a dimensional stability of 93, and a thermoformability of ○.

The foams of Examples 1 to 11 were all foams excellent in hardness, dimensional stability, thermoformability, and mechanical strength.

[Examples 12 to 17], [Comparative Examples 10 to 14]

Using block copolymers A-1 to 11 as component (a) and BR (cis 1,4 polybutadiene) as component (b): high-cis polybutadiene and S-SBR, used as component (c) The cerium oxide and the foaming agent as the component (d), and other additives were used, and the composition of the above-mentioned compound and the physical properties of the foam were shown in Table 4 below.

The maximum temperature was adjusted to 170 to 180 ° C using a 1.7 L test Banbury mixer, and the blending materials other than the foaming agent and other additives were mixed in the blending compositions shown in Table 4 below.

Then, the kneaded material was kneaded by adding a foaming agent and other additives to a 10-size roll, and the mixture was rolled into a sheet shape, and then placed in a mold to be vulcanized (sulfur cross-linked) and foamed to obtain a foam. The vulcanization was carried out at 160 ° C for 10 minutes.

The details of the symbols and the like in Table 4 above are as follows.

BR (cis 1,4 polybutadiene); "BR-18" manufactured by Japan Synthetic Rubber Co., Ltd.

S-SBR; styrene-butadiene copolymer ("Asaprene 303" manufactured by Asahi Kasei Chemicals Co., Ltd.)

Ceria; "Nipsil VN3" manufactured by Tosoh Silica Co., Ltd.

Blowing agent 1; P, P'-oxybisbenzenesulfonate (OBSH)

Foaming agent 2; azomethicin (ADCA)

Other additives; polyethylene glycol (manufactured by Shanyang Chemical Industry Co., Ltd., trade name "PEG #4000") 1 part by mass of zinc oxide 3 parts by mass of stearic acid (manufactured by Asahi Kasei Co., Ltd.) 1 part by mass of titanium oxide (anatase type) 4 parts by mass of a foaming auxiliary (urea derivative, manufactured by Sankyo Chemical Co., Ltd., trade name "Selton NF") 1 part by mass of DCP (98% dicumyl peroxide, Japanese fat) (Stock) company made, trade name "PERCUMYL D" 0.05 parts by mass sulfur 0.05 parts by mass

[Examples 18 to 21], [Comparative Examples 15 to 18]

As shown in the following Table 5, the foam was obtained by the same method as in Example 12 except that the kind and amount of the component (a) and the amounts of the components (b), (c) and (d) were changed.

The details of the symbols and the like in Table 5 are the same as those in Table 4, and the measurement method of the physical properties is also the same as described above.

[Example 22]

With respect to the compounding composition of the above [Example 18], 5 parts by mass of EVA (ethylene-vinyl acetate copolymer, manufactured by Tosoh, EVAUE 633, vinyl acetate) was added to 100 parts by mass of the component (a) and the component (b). Ester content = 20%, MI = 20).

The foam was obtained by the same method as [Example 18] under other conditions.

The obtained foam had a specific gravity of 0.90 g/cc, a hardness of 68, a Tb of 9.2 MPa, an Eb of 110%, and a dimensional stability of 95.

The foams of Examples 12 to 22 were all foams excellent in hardness, dimensional stability, and mechanical strength.

Industrial availability

The foam of the present invention is suitable for a midsole, an insole or an outsole material for shoes, and more specifically, as a sole material for all footwear such as men's shoes, women's shoes, and casual shoes, and has industrial applicability.

Claims (10)

A foam having a specific gravity of 0.1 to 0.98 g/cc and crosslinked by a composition for a foam; the composition for a foam comprising: (a) a block copolymer containing at least 2 vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer block comprising a conjugated diene and a vinyl aromatic hydrocarbon, wherein the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass, conjugated The content of the diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass, and the storage elastic modulus at 30 ° C in the dynamic viscoelasticity measurement ( E') is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the peak temperature of the function of dynamic viscoelasticity measurement tan δ is at least one of 85 ° C or more and 125 ° C or less; (b) isoprene-based rubber and / or diene rubber; (c) filler; (d) foaming agent; and the mass ratio of the above (a) block copolymer to the above (b) isoprene rubber and / or diene rubber ((a)/(b)) is (1~30)/(70-99); relative to the above (a) block copolymer and the above (b) isoprene-based rubber and/or diene rubber 100 parts by mass of the total amount, containing the above (c) filling 1 to 100 parts by mass of the agent, and 0.1 to 30 parts by mass of the above (d) foaming agent. The foam of claim 1, wherein the (a) block copolymer is at least one of a peak temperature of a function of dynamic viscoelasticity measurement tan δ of from 90 ° C to 125 ° C. The foam according to claim 1 or 2, wherein the (a) block copolymer contains at least one vinyl aromatic hydrocarbon having a content of 70% by mass or more and less than 100% by mass of a vinyl aromatic hydrocarbon and a conjugate A random copolymer block of a diene. The foam according to claim 1 or 2, wherein the (a) block copolymer contains at least one vinyl aromatic hydrocarbon content of 75% by mass or more and 98% by mass or less of a vinyl aromatic hydrocarbon and a conjugated second a random copolymer block of an alkene. The foam of claim 1 or 2, wherein: 100 parts by mass of the total amount of the (a) block copolymer and the (b) isoprene-based rubber and/or the diene-based rubber, (c) 2 to 90 parts by mass of the filler and 0.5 to 20 parts by mass of the above (d) foaming agent. The foam of claim 1 or 2, which further comprises: 100 parts by mass of the total of the (a) block copolymer and the (b) isoprene-based rubber and/or the diene-based rubber, further comprising: (e) 1 to 100 parts by mass of the thermoplastic elastomer and/or the thermoplastic resin. The foam of claim 1 or 2 has a specific gravity of 0.1 to 0.7 g/cc or a specific gravity of 0.8 to 0.98 g/cc. A shoe sole formed by molding the foam of any one of claims 1 to 7. A composition for a foam comprising: (a) a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one comprising a conjugated diene and a vinyl aromatic hydrocarbon a copolymer block having a vinyl aromatic hydrocarbon content of 65 to 95% by mass and a conjugated diene content of 5 to 35% by mass, and a block of a vinyl aromatic hydrocarbon polymer contained in the block copolymer The rate is 40 to 98% by mass, and the storage elastic modulus (E') at 30 ° C in the dynamic viscoelasticity measurement is 3 × 10 ⁸ Pa or more and 2.35 × 10 ⁹ Pa or less, and the peak temperature of the function of dynamic viscoelasticity is tan δ At least one of 85 ° C or more and 125 ° C or less; (b) isoprene-based rubber and/or diene rubber; (c) filler; (d) foaming agent; (a) block copolymer The mass ratio ((a)/(b)) to the above (b) isoprene-based rubber and/or diene-based rubber is (1 to 30) / (70 to 99); 100 parts by mass of the total amount of the segment (b) isoprene-based rubber and/or the diene-based rubber, and 1 to 100 parts by mass of the above (c) filler, and the above (d) foaming agent 0.1 ~30 parts by mass. A foam comprising: (a') a block copolymer comprising at least two vinyl aromatic hydrocarbon polymer blocks, and at least one copolymer comprising a conjugated diene and a vinyl aromatic hydrocarbon Block, and the content of the vinyl aromatic hydrocarbon is 65 to 95% by mass, the content of the conjugated diene is 5 to 35% by mass, and the block ratio of the vinyl aromatic hydrocarbon polymer contained in the block copolymer is 40 to 98% by mass; (b) isoprene-based rubber and/or diene-based rubber; (c) filler; (d) foaming agent; When the specific gravity is 0.1 to 0.7 g/cc, the hardness measured by the model C is 45 to 98; and when the specific gravity is 0.8 to 0.98 g/cc, the hardness measured by the model A is 60 to 98.