JPH11255860A - Polyurethane foam for soles - Google Patents

Abstract

(57) [Summary] [Problem] To provide a polyurethane foam for shoe soles which is excellent in hydrolysis resistance, has an average density of 0.15 to 0.5 g / cm ³ , does not have skin peeling or molding shrinkage, and has excellent appearance. thing. SOLUTION: (A) Polyether polyol A having two or more hydroxyl groups, (B) Polymer polyol B containing polymer fine particles based on polyether polyol having two or more hydroxyl groups, and (C) chain extender A polyisocyanate compound and a polyisocyanate compound in the presence of a blowing agent and a catalyst, and the amount of polymer fine particles is 10 parts by weight based on 100 parts by weight of the total amount of polyether polyol A and polymer polyol B. Polyurethane foam for shoe soles having an average density of 0.15 to 0.5 g / cm ³ in an amount of up to 30 parts by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane foam for soles which can be suitably used for soles of sports shoes and the like, especially for low density soles and the like.

[0002]

2. Description of the Related Art Polyether-based polyurethanes are superior to polyester-based polyurethanes in antibacterial properties, low-temperature flexibility and especially hydrolysis resistance, but are inferior in mechanical properties such as abrasion resistance and room-temperature flexibility. In addition, there is a disadvantage that the skin is easily peeled or molded during foaming.

[0003] In order to improve the mechanical properties of polyether polyurethane, it has been proposed to replace all or part of the polyoxypropylene polyol as a polyol component with polyoxytetramethylene glycol. General polyurethane foam has a high density (0.5 to
1.3g / cm ³ ) The sole can be actually used,
Even if a polyurethane foam using polyoxytetramethylene glycol is used for a low density (0.15 to 0.5 g / cm ³ ) sole or the like, practical use is difficult.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyether-based polyurethane having excellent hydrolysis resistance, having an average density of 0.15 to 0.5 g / cm ³ .
An object of the present invention is to provide a polyurethane foam for shoe soles which is excellent in appearance without skin peeling, molding shrinkage and the like.

[0005]

The present invention relates to a polymer comprising (A) a polyether polyol A having two or more hydroxyl groups and (B) a polyether polyol having two or more hydroxyl groups as a base and containing polymer fine particles. It is obtained by reacting a polyol component comprising a polyol B and a (C) chain extender with a polyisocyanate compound in the presence of a blowing agent and a catalyst. 10 to 30 parts by weight with respect to 100 parts by weight in total, and the average density is 0.1
The present invention relates to a polyurethane foam for shoe soles having a weight of 5 to 0.5 g / cm ³ .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyurethane foam for shoe soles of the present invention is obtained by reacting a polyol component with a polyisocyanate compound in the presence of a blowing agent and a catalyst.

The polyol component is based on (A) a polyether polyol A having two or more hydroxyl groups (hereinafter referred to as polyether polyol A), and (B) a polyether polyol having two or more hydroxyl groups as a base. It comprises polymer polyol B (hereinafter referred to as polymer polyol B) and (C) a chain extender.

As the polyether polyol A, a polyether polyol having two or more hydroxyl groups is used.

As the polyether polyol A, polyoxypropylene polyol having ethylene oxide added to terminal hydroxyl groups and having a molecular weight of 15 per hydroxyl group is used.
Polyoxypropylene polyol having a molecular weight of not less than 00, and a molecular weight of 1000 obtained by ring-opening polymerization of tetrahydrofuran
The above polyoxytetramethylene glycol and a mixture thereof are exemplified.

Polyoxypropylene polyols in which ethylene oxide is added to the terminal hydroxyl groups of the polyoxypropylene polyol and the molecular weight per hydroxyl group is 1500 or more have a long repeating oxypropylene chain, so that the soft segment in the polyurethane foam It works effectively and plays a role of improving elongation characteristics and bending characteristics, so that it can be suitably used. The molecular weight per hydroxyl group of the polyoxypropylene-based polyol is desirably 1500 or more, preferably 1800 or more, from the viewpoint of making the role of the soft segment of the oxypropylene chain effective, but the upper limit of the molecular weight is set at the time of handling. From the viewpoint of viscosity, it is desirably 20,000 or less, preferably 10,000 or less. The preferred range of the molecular weight is from 1500 to 2000
0, more preferably 1800 to 10000.

The polyoxypropylene-based polyol is
The above compound having active hydrogen is used as a starting material, a ring-opening addition reaction of an alkylene oxide is performed on the compound, and ethylene oxide is block-added to the molecular terminal.

The starting materials include polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines and the like. As the starting materials, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol,
Examples thereof include diglycerin, dextrose, sucrose, bisphenol A, ethylenediamine, and their modified products, and these can be used alone or in combination of two or more.

Examples of the alkylene oxide to be subjected to the ring-opening addition reaction to the starting material include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, and copolymers thereof. Among these, propylene oxide is used alone or propylene oxide is the main component (50% by weight or more)
Random copolymers or block copolymers with other alkylene oxides are preferred.

After the reaction of the starting material with the alkylene oxide, a blockwise addition reaction of ethylene oxide is carried out so that the terminal hydroxyl groups are primary in order to increase the urethane-forming reactivity in producing a polyurethane foam. preferable. The primary conversion rate of terminal hydroxyl groups by ethylene oxide (the number of primary hydroxyl groups at the terminal / the total number of hydroxyl groups at the terminal) increases the urethane-forming reactivity in producing a polyurethane foam, shortens the demolding time, and increases the resin-forming rate. From the viewpoint of improving the balance between the foaming rate and the foaming rate so that the polyurethane foam does not shrink, 50% or more is preferable,
80% or more is more preferable.

The content of oxyethylene groups in the polyoxypropylene-based polyol is preferably 35% by weight or less from the viewpoint of water resistance, and from the viewpoint of the degree of primary hydroxyl group termination,
It is preferably at least 5% by weight. The polyoxypropylene-based polyol may have several types of polyoxyalkylene polyols as long as the molecular weight per hydroxyl group as a whole of the polyether polyol A, the content of oxyethylene groups, and the degree of primary hydroxyl group termination are within the ranges. May be mixed and prepared.

Polyoxytetramethylene glycol having a molecular weight of 1000 or more obtained by ring-opening polymerization of tetrahydrofuran has a property of improving mechanical properties from its molecular structure, and can be suitably used. The molecular weight of polyoxytetramethylene glycol is 1 in view of its effectiveness as a soft segment of the oxytetramethylene chain.
The molecular weight is desirably at least 000, preferably at least 1,400, but the upper limit of the molecular weight is desirably at most 3,000, preferably at most 2,300, from the viewpoint of maintaining the liquidity at the handling temperature.

When polyoxytetramethylene glycol is used, the mechanical properties are synergistically improved by the combined use with the polymer polyol B, and 0.15 to 0.5 g / cm ³
It is possible to obtain a polyurethane foam having mechanical properties that can be sufficiently used for applications such as low density soles.

The polymer polyol B is based on a polyether polyol having two or more hydroxyl groups. By using the polymer polyol B, in comparison with the case where the polyether polyol A is used alone, it has a high hardness, promotes communication of cells, and has a breaking strength, a breaking elongation, a tear strength, a split tear, A polyurethane foam having excellent physical properties such as low compression set can be obtained.

Examples of the polymer polyol B include those obtained by dispersing polymer fine particles obtained by polymerizing a monomer having a polymerizable unsaturated group in a polyether polyol having two or more hydroxyl groups.

The polymer polyol B in which polymer fine particles are dispersed in a polyether polyol having two or more hydroxyl groups is, for example, a polymer fine particle obtained by polymerizing a monomer having a polymerizable unsaturated group, and a polymer polyol B having two or more hydroxyl groups. A method of mixing and dispersing a polyether polyol having a polymerizable unsaturated group-containing monomer by polymerizing a polymerizable unsaturated group-containing monomer in a polyether polyol having two or more hydroxyl groups. A method of dispersing polymer fine particles obtained from a monomer in a polyether polyol having two or more hydroxyl groups [hereinafter, referred to as
Method B]. The method B can be preferably used because the polymer polyol B in which the polymer fine particles are uniformly dispersed in the polyether polyol having two or more hydroxyl groups can be easily obtained.

The particle size of the polymer fine particles is not particularly limited, but is preferably 30 μm from the viewpoint of avoiding poor dispersion due to sedimentation or the like.
m or less, preferably 10 μm or less, and 0.1 μm or more, preferably 0.5 μm or more from the viewpoint of avoiding inconvenience of handling due to viscosity increase.

Examples of the polymerizable unsaturated group-containing monomer include styrene; acrylonitrile; alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; glycidyl methacrylate; methyl acrylate, ethyl acrylate, and butyl. And glycidyl acrylate having 1 to 4 carbon atoms in an alkyl group such as acrylate. These monomers may be used alone or in combination of two or more. Among these, one or more monomers selected from the group consisting of styrene, acrylonitrile and methyl methacrylate are preferred.

When producing a white polyurethane foam, particularly when the acrylonitrile-styrene copolymer type polymer polyol B is used, the whiteness of the polyurethane foam is affected by the styrene content. When the styrene content in the polymer fine particles in the polymer polyol B is 40% by weight or more, the styrene content is at a level usable in a white polyurethane foam. In particular, when the styrene content is 50% by weight or more,
Polymer polyol B is desirable because it exhibits a more white color. The upper limit of the styrene content in the polymer fine particles in the polymer polyol B is not particularly limited, and the styrene content may be 100% by weight, that is, styrene alone.

When the method B is employed, the polymerizable unsaturated group-containing monomer may be polymerized in a polyether polyol having two or more hydroxyl groups by a known method, for example, by dispersing the polymerizable unsaturated group-containing monomer. There is a method in which polymerization is carried out in a polyether polyol having two or more hydroxyl groups in the presence of a stabilizer and a radical polymerization initiator.

The content of the fine polymer particles in the polymer polyol B is preferably 15% by weight or more, and more preferably 20% or more, in order to impart high hardness to the obtained polyurethane foam.
At least 30% by weight, more preferably at least 30% by weight. From the viewpoint of improving the uniform dispersion stability of the polymer fine particles and the workability in terms of viscosity and improving the moldability of the polyurethane foam, at most 50% by weight. , Preferably 4
5% by weight or less is desirable.

The polyether polyol having two or more hydroxyl groups used in the polymer polyol B may be a polyoxypropylene-based polyol used as the polyether polyol A.

As the polyether polyol having two or more hydroxyl groups, a polyoxypropylene polyol having a relatively high molecular weight is preferable from the viewpoint of dispersion stability of the polymer fine particles. In particular, a polyoxypropylene-based triol in which a trifunctional hydroxyl group-containing compound such as glycerin or trimethylolpropane is used alone or as a main component (50% by weight or more) as a starting material is preferable. When two or more polyether polyols having two or more hydroxyl groups are used, the average number of hydroxyl functional groups per molecule of the polyether polyol is preferably 2.5 to 4.0. The molecular weight is desirably 1800 or more, preferably 3000 or more, from the viewpoint of dispersion stability of the polymer fine particles, and 20,000 or less, from the viewpoint of easy handling.
Preferably, it is 10,000 or less. Furthermore, regarding the content of the oxyethylene group and the primary hydroxylation rate of the terminal hydroxyl group,
For the same reason, it is desirable to use the same as the polyoxypropylene-based polyol used as the polyether polyol A.

The polyoxypropylene-based polyol used for the polymer polyol B has an average number of functional groups, an average molecular weight, an oxyethylene group content and a primary hydroxyl group terminal hydroxyl group in the whole polyol as a base of the polymer polyol B. May be prepared by mixing several kinds of polyoxyalkylene polyols.

The ratio between the polyether polyol A and the polymer polyol B varies depending on the content and the composition ratio of the polymer fine particles in the polymer polyol B. Usually, when the ratio of polyether polyol A / polymer polyol B (weight ratio) is large, the hardness of the obtained polyurethane foam tends to be relatively low. For this reason, in order to obtain a polyurethane foam having a desired hardness, it is necessary to increase the amount of the extender, but on the other hand, the elongation at break decreases. Therefore, polyether polyol A
/ Polymer polyol B [weight ratio] is desirably 80/20 or less, preferably 70/30 or less. On the other hand, when the polyether polyol A / polymer polyol B [weight ratio] is small, the polyether polyol A / polymer polyol B is used from the viewpoint of lowering the viscosity of the polyol component and improving the moldability of the polyurethane foam.
[Weight ratio] is 20/80 or more, preferably 30/70.
The above is desirable.

Further, the amount of the polymer fine particles is a total amount of polyether polyol A and polymer polyol B of 10%.
With respect to 0 parts by weight, the amount is 10 parts by weight or more from the viewpoint of avoiding shrinkage of the polyurethane foam, and 30 parts by weight from the viewpoint of improving the uniform dispersion stability of the polymer fine particles and improving the moldability of the polyurethane foam. Department,
Preferably, it is 25 parts by weight or less.

Examples of the chain extender include low molecular weight compounds having two or more active hydrogen-containing groups capable of reacting with an isocyanate group such as a hydroxyl group, a primary amino group and a secondary amino group.

As the chain extender, ethylene glycol,
Diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-
Hexanediol, neopentyl glycol, glycerin, trimethylolpropane, triethanolamine,
Examples thereof include polyhydric alcohols such as an alkylene oxide adduct of bisphenol A, and polyamines such as diethyltoluenediamine, chlorodiaminobenzene, ethylenediamine, and 1,6-hexanediamine. These may be used alone or as a mixture of two or more. be able to.

Examples of the polyisocyanate compound include aromatic, alicyclic, and aliphatic polyisocyanates having two or more isocyanate groups, mixtures thereof, and modified polyisocyanates obtained by modifying them. . Examples of such polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, methylene diphenyl diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, and polymethylene polyphenylene diisocyanate, hydrogenated methylene diphenyl diisocyanate, hydrogenated tolylene diisocyanate, and isophorone diisocyanate. Aliphatic polyisocyanates such as alicyclic polyisocyanate, hexamethylene diisocyanate, and lysine diisocyanate, mixtures thereof, and modified products thereof, and the like. Examples of the modified product include a prepolymer-based modified product, a nurate modified product, a urea modified product, a carbodiimide modified product, an allophanate modified product, and a buret modified product, which are reaction products with a polyol. Among these, aromatic polyisocyanates excluding polymers such as polymethylene polyphenylene diisocyanate and modified products thereof are preferred. In particular, those containing a soft segment composed of polyoxyalkylene glycol and prepolymerized with methylene diphenyl diisocyanate and / or a modified product thereof have a structure containing a soft segment composed of polyoxyalkylene glycol, and have a low density. It is highly desirable because it is effective in improving the mechanical properties of polyurethane foam.

The polyoxyalkylene glycol can be produced by the same method as that for preparing the above-mentioned polyoxypropylene-based polyol. Among the polyoxyalkylene glycols, a polyoxypropylene glycol having a molecular weight per hydroxyl group of 1000 or more can be suitably used, and the repetition of the oxyalkylene chain is long.
The role as the soft segment in the urethane foam works effectively, and the elongation characteristics and the bending characteristics are improved. Since the polyoxyalkylene glycol reacts with the polyisocyanate compound in advance, it is not always necessary to primaryize the hydroxyl group, and ethylene oxide may or may not be added to the terminal. The prepolymer may contain a reaction product of methylene diphenyl diisocyanate or a modified product thereof and a chain extender.

Examples of the foaming agent include water, hydrocarbons, chlorofluorocarbons, hydrogenated fluorocarbons and the like. These foaming agents can be used alone or as a mixture of two or more. From the viewpoint of environmental protection, it is preferable to use water alone.

From the viewpoint of improving the reaction rate, a catalyst is used. As a catalyst, a tertiary amine is mainly used.

As the catalyst, 1,4-diazabicyclo-
(2,2,2) -octane (hereinafter referred to as TEDA),
Kao Riser No., manufactured by Kao Corporation. N, N, N ', N'-tetramethylhexamethylenediamine represented by Kao Corporation, trade name: N, N, N ', N'-tetramethylpropylenediamine represented by Kao Corporation No. 2 N, N, N ', represented by 3 etc.
N ', N "-pentamethyldiethylenetriamine, manufactured by Kao Corporation, trade name: trimethylaminoethylpiperazine represented by Kaorizer No. 8, etc .; Kao Corporation
Product name: Kaorizer No. N, N-dimethylcyclohexylamine represented by 10 mag., Kao Corporation
Product name: Kaorizer No. N, N-dimethylbenzylamine represented by Kao Riser No. 20 or the like, manufactured by Kao Corporation. N-methylmorpholine represented by Kao Riser No. 21 or the like, manufactured by Kao Corporation. 22, N-ethylmorpholine, triethylamine, tributylamine, bis (dimethylaminoalkyl) piperazine, N, N, N ′, N′-tetramethylethylenediamine, N, N-diethylbenzylamine, bis (N, N-diethylaminoethyl) adipate, N, N, N ', N'-tetramethyl-1,3-butanediamine, N, N-dimethyl-β-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole and the like These catalysts may be used alone or as a mixture of two or more. As a catalyst other than the tertiary amine, an organic metal compound such as dibutyltin dilaurate, stannous oleate, cobalt naphthenate, or lead naphthenate may be used.

As other additives, silicone-based foam stabilizers,
Pigments, antioxidants, yellowing inhibitors and the like may be used as appropriate.

When the polyol component is reacted with the polyisocyanate compound, the ratio of the two is such that the isocyanate index is 85 to 115, preferably 85 to 105,
It is more desirable to adjust so as to be 95 to 105.

As a method for producing the polyurethane foam of the present invention, a polyol component obtained by previously mixing a catalyst, a foaming agent and other additives and a polyisocyanate compound are mixed and stirred by a molding machine and injected into a molding die. And
A foaming method and the like can be mentioned. More specifically, the polyol component is usually adjusted to about 40 ° C. using a tank or the like, and then the polyisocyanate compound is mixed with a foaming machine such as an automatic mixing injection foaming machine and an automatic mixing injection foaming machine. Reaction, foaming method and the like can be mentioned.

The polyurethane foam of the present invention has a content of 0.1
It has an average density of 5 to 0.5 g / cm ³ , has no peeling of the skin, no molding shrinkage, etc., and has excellent appearance.

[0042]

Examples 1 to 8 and Comparative Examples 1 to 3 The compounds shown in Table 1 were used as the polyol components polyether polyol A and polymer polyol B.
Was adjusted so as to have the ratio shown in FIG.

Ethylene glycol was used as a chain extender, and the blending amount of the ethylene glycol was adjusted as shown in Table 1 so that the obtained polyurethane foam had a desired hardness.

A total of 100 parts by weight of the polyether polyol A and the polymer polyol B was used as a catalyst for TE.
0.5 part by weight of DA and a predetermined amount of a chain extender and water were added and stirred to prepare a polyol component of a foaming machine.

The amount of the fine polymer particles is a part by weight based on 100 parts by weight of the total amount of the polyether polyol A and the polymer polyol B.

As the polyisocyanate compound, a methylene diphenyl diisocyanate-modified prepolymer was used. This methylene diphenyl diisocyanate-modified prepolymer is a methylene diphenyl diisocyanate 6
To 0 parts by weight, a mixture of 35 parts by weight of the following polyol III and 5 parts by weight of dipropylene glycol was added dropwise to 5 parts by weight.
It prepared by heating and stirring at 0-60 degreeC for 2 hours.

The mixing ratio of the polyol component and the polyisocyanate compound is determined from the free-form state in the foaming reaction, and the isocyanate index is 90 to 100.
It was about.

A polyol component having the compounding ratio shown in Table 1 is placed in one tank of a pouring type low-pressure foaming machine, the liquid temperature is adjusted to 35 to 45 ° C., and the polyisocyanate compound is placed in the other tank. And the liquid temperature is 35
４５45 ° C.

Using a foaming machine, the polyol component and the polyisocyanate compound were mixed and stirred, injected into a mold and foamed to obtain a 100 mm × 300 mm × 10 mm polyurethane foam.

The foam properties of the obtained urethane foam were examined according to the following methods. Table 1 shows the results.

The abbreviations of the polyol components used in each of the examples and comparative examples mean the following.

[Polyether polyol A] Polyether polyol I: polyoxytetramethylene glycol having a molecular weight of 2000 [manufactured by Hodogaya Chemical Industry Co., Ltd., trade name: PTG-2000SNW] Polyether polyol II: propylene oxide and ethylene oxide to glycerin Are sequentially added. Polyoxyethylene triol having a molecular weight of 6000 and having a molecular weight of 6000 (oxyethylene group content: 20% by weight, terminal hydroxyl group primary conversion rate: 88%) Polyether polyol III: dipropylene glycol and propylene oxide Polyoxyethylene glycol with a molecular weight of 4000 to which ethylene oxide is sequentially added (oxyethylene group content: 20% by weight, terminal hydroxyl group primary rate: 91%)

[Polymer Polyol B] Polymer Polyol I: a molecular weight of 3 in which propylene oxide and ethylene oxide are sequentially added to glycerin.
000 polyoxyethylene-terminated polyoxypropylene triol (oxyethylene group content 20% by weight,
Acrylonitrile 3 in terminal hydroxyl group primary conversion rate 71%)
0% by weight / 70% by weight of styrene are polymerized. Polymer polyol having a content of fine particles of 40% by weight (that is, 60% by weight of a polyol component) [white] Polymer polyol II: propylene oxide and ethylene oxide are sequentially added to glycerin. Molecular weight 3
000 polyoxyethylene-terminated polyoxypropylene triol (oxyethylene group content 20% by weight,
Acrylonitrile 5 in the primary hydroxyl group at a terminal hydroxyl ratio of 71%)
0% by weight / 50% by weight of styrene polymerized 20% by weight of fine particles (that is, 80% by weight of the polyol component) [polyol] Polymer polyol III: propylene oxide and ethylene oxide are sequentially added to glycerin Acrylonitrile 75% by weight / styrene 25% by weight was polymerized in the polyoxyethylene-terminated polyoxypropylene triol having a molecular weight of 3000 (oxyethylene group content 20% by weight, terminal hydroxyl group primary conversion rate 71% by weight). Polymer polyol [yellow white] having a content of fine particles of 40% by weight (ie, 60% by weight of polyol component)

[Foam Characteristics] (Average density) The weight of a polyurethane foam of 100 mm × 300 mm × 10 mm was measured and divided by the volume of 300 cm ³ .

(Hardness) The hardness was measured with an Asker C hardness meter.

(Skin peeling) The obtained polyurethane foam was visually observed and evaluated based on the following criteria.

"Skin peeling" means that the surface layer (skin) of the polyurethane foam is peeled off or a gap is formed between the skin and the polyurethane foam main body.

[Judgment Criteria] A: Skin peeling was not observed. X: Skin peeling is observed.

(Foam shrinkage) The obtained polyurethane foam was visually observed and evaluated based on the following criteria.

The “shrinkage of the foam” refers to an inner diameter of 6.6 cm,
The polyurethane foam raw material is poured into a polypropylene mold having a depth of 10.5 cm, foamed to produce a polyurethane foam, and left at room temperature for one day. Means that a gap is generated between the two.

[Judgment Criteria] A: No shrinkage of the foam was observed. ×: Shrinkage of the foam is observed.

(Break strength) Measured according to the method described in JIS K-6301, replacing the resin with a polyurethane foam.

(Elongation at break) The elongation at break was measured according to the method described in JIS K-6301, except that the resin was changed to polyurethane foam.

(Tear Strength) The tear strength was measured according to the method described in JIS K-6301, except that the resin was changed to polyurethane foam.

(Split tear) ASTM D-35
According to the method described in No. 74, the resin was measured in place of the polyurethane foam. That is, as shown in FIG.
A test piece 1 of 25.4 mm x 150 mm x 10 mm was cut out from a polyurethane foam of mx 300 mm x 10 mm, and a cut 2 having a length from one end to 50 mm was horizontally inserted into the center of the thickness (10 mm).

Autograph DCS manufactured by Shimadzu Corporation
The split tear was measured at a speed of 50 mm / min using -50M (trade name), and the value was converted to a unit of KN / m.

(Foam color) The obtained polyurethane foam is visually observed.

[0068]

[Table 1]

From the results shown in Table 1, the polyurethane foams obtained in Examples 1 to 7 are all white, have no skin peeling or foam shrinkage, and have excellent breaking strength, breaking elongation and split. It can be seen from the fact that the shoe sole has all the physical properties required for the shoe sole.

On the other hand, the polyurethane foams obtained in Comparative Examples 1 and 2 are different from Examples 1 to 7 in the composition and the amount of the polyol component. In addition, it can be seen that this is not preferable.

In the polyurethane foam obtained in Example 8, the amount of acrylonitrile contained in the polymer fine particles was excessive, so that the foam was slightly yellowish, and only the white midsole was slightly colored. Although there was a problem, the dark color had no practical problem.

[0072]

According to the present invention, 0.15 to 0.5 g / c
In the density range of m ³ , it is possible to provide a polyurethane foam for shoe soles having excellent appearance without peeling of the skin or molding shrinkage.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view relating to a method for producing a test piece of polyurethane foam used for split tear measurement.

[Explanation of symbols]

 1 Test piece 2 Notch

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08J 9/00 CFF C08J 9/00 CFFZ // B29C 67/20 B29C 67/20 C (C08G 18/48 101: 00) C08L 75 : 04

Claims (5)

[Claims] 1. A polymer polyol B containing (A) a polyether polyol A having two or more hydroxyl groups, (B) a polyether polyol having two or more hydroxyl groups, and polymer fine particles, and (C) a chain extension. And a polyisocyanate compound obtained by reacting a polyisocyanate compound with a polyisocyanate compound in the presence of a blowing agent and a catalyst. A polyurethane foam for shoe soles, which is 10 to 30 parts by weight and has an average density of 0.15 to 0.5 g / cm ³ . 2. The polymer polyol B according to claim 1, wherein the polymer fine particles obtained by polymerizing a polymerizable unsaturated group-containing monomer are dispersed in a polyether polyol having two or more hydroxyl groups. Polyurethane foam for soles. 3. Polymer fine particles obtained from the polymerizable unsaturated group-containing monomer by polymerizing a polymerizable unsaturated group-containing monomer in a polyether polyol having two or more hydroxyl groups, The polyurethane foam for shoe soles according to claim 1 or 2, wherein the polyurethane foam is dispersed in a polyether polyol having two or more hydroxyl groups. 4. The polyurethane foam for shoe soles according to claim 3, wherein the polymerizable unsaturated group-containing monomer is at least one monomer selected from the group consisting of styrene, acrylonitrile and methyl methacrylate. 5. The polyisocyanate compound contains a soft segment comprising a polyoxyalkylene glycol and is prepolymerized with methylene diphenyl diisocyanate and / or a modified product thereof.
Polyurethane foam for shoe sole as described.