JP3334295B2 - Method for producing polyurethane resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyurethane resin excellent in high-frequency fusion property useful for synthetic leather and a synthetic leather using the polyurethane resin obtained therefrom.

[0002]

2. Description of the Related Art Conventionally, polyurethane resins have been used in many applications by utilizing their excellent mechanical properties and durability, and are also useful as resins for synthetic leather.

[0003] However, the conventional polyurethane synthetic leather has a disadvantage that it has to be stitched at the time of joining because of its low high-frequency fusion property. If polyurethane synthetic leather can be joined by high frequency, such as PVC leather, polyurethane synthetic leather products, such as bags,
Since the processing of shoes, clothing, and the like is extremely efficient, improvement in high-frequency fusion property is strongly demanded in the synthetic leather industry.

[0004] Therefore, a polyurethane resin which does not use a conventional chain extender, a polyurethane resin mixed with a chain extender, or a polyurethane obtained by mixing a polyvinyl chloride copolymer with a polyurethane resin is used. It has been proposed to use a resin.

[0005] However, the former has a drawback that sticking occurs at high temperatures, and the latter has a drawback that it becomes hard or inferior in bending.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a polyurethane resin excellent in high-frequency fusing properties and free from sticking, hardening and inferior bending at high temperatures, and a synthetic leather. Is what you do.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned drawbacks, and as a result, completed the present invention.

That is, the present invention relates to a polyoxyalkylene glycol having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit, preferably a polyoxytetramethylene diol and a 3 carbon atom having an alkyl group having 2 or more carbon atoms in a side chain. A method for producing a polyurethane resin, comprising reacting an alkylene diol of from 10 to 10, preferably 2-ethyl-2-butyl-1,3-propanediol, with a diol having a molecular weight of less than 500 and an organic diisocyanate, And a synthetic leather using the polyurethane resin as one of the constituent components of the leather.

As the long-chain dihydroxy compound used in the present invention, a polyoxyalkylene diol compound having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit is used. Examples of the polyoxyalkylene diol compound having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit include, for example, polyoxytetramethylene glycol, polyoxypentamethylene glycol, polyoxyhexamethylene glycol, and the like. Of these, polyoxytetramethylene glycol is preferred because of its availability and low cost.

These may be used alone or as a mixture of two or more,
Alternatively, a mixture of a polyoxyalkylene diol compound and a polyester diol compound is used. The mixing ratio between the polyoxyalkylene diol compound and the polyester diol compound is not limited. Polyoxyalkylene diol alone has low compatibility with commercially available colorants and requires a special colorant to color synthetic leather. Therefore, it is desirable to use a polyoxyalkylene diol in combination with a polyester diol in terms of cost. However, the polyester-based diol alone is inferior in high-frequency fusion property.

When a polyoxyalkylene diol compound having an oxyalkylene chain having less than 4 carbon atoms as a repeating unit is used, when a urethane resin is used as a film, various properties such as tackiness, tackiness, durability, light resistance and water resistance are obtained. There are drawbacks.

As the polyester diol compound used in the present invention, for example, ethylene glycol, 1,2
-Propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1 , 5-
One or more low-molecular compounds such as pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, and cyclohexane-1,4-dimethanol. Examples include condensates of molecular diols with one or more dicarboxylic acids such as succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and the like. Further, ring-opening polymers such as γ-butyrolactone and ε-caprolactone using the low-molecular-weight diol as an initiator are exemplified. Furthermore, polyalkylene carbonate diols obtained by condensation of one or more of the above-mentioned low molecular weight diols with diallyl carbonate, dialkyl carbonate, alkylene carbonate or the like can be mentioned.

The average molecular weight of these long-chain dihydroxy compounds is usually from 500 to 5,000, preferably from 1,000 to 3,000.
000. As the chain extender of the present invention, an alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in a side chain and a low molecular diol having a molecular weight of less than 500 are used.

The alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in the side chain includes, for example, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-propyl-1, 3-propanediol, 2-
Ethyl-2-butyl-1,3-propanediol, 2,
2-dipropyl-1,3-diol, 2,2-diethyl-1,4-butanediol, 2,3-diethyl-1,4
-Butanediol, 2-ethyl-3-butyl-1,4-butanediol, 2,3-diethyl-1,5-pentanediol, 3-ethyl-3-propyl-1,5-pentanediol, 2, 2-dibutyl-1,5-pentanediol, 2,3-diethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol,
3,3-diethyl-1,5-pentanediol, 2,2
-Propyl-1,5-pentanediol, 2-ethyl-
2-propyl-1,5-pentanediol, 2,5-diethyl-1,6-hexanediol, 3-ethyl-3-
Propyl-1,6-hexanediol and the like.
Among these, 2-ethyl-2-butyl-1,3-propanediol is particularly preferred in terms of availability and price.

Examples of the low molecular weight diol compound include ethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentane Diol, 1,8
-Octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol,
And diols such as cyclohexane-1,4-dimethanol.

An alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in a side chain and a molecular weight of 500
Two or three or more diols of low molecular weight diols are mixed. When these diols are used alone, the crystallinity of the glycol urethane segment is increased, and the high-frequency fusion property is reduced. Further, when an alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in the side chain is not used, those having good high-frequency fusion property cause adhesion at high temperatures.

The alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in the side chain alone has a molecular weight of 5
When a low molecular diol having a molecular weight of less than 00 is not used, the film strength when a urethane resin is used as a film is weak, and the practicability is poor.

The amount of the alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in the side chain is not limited. And it is desirable in terms of price. If it is less than 5 equivalent%, the surface activity is low. On the other hand, when the content is more than 50 equivalent%, the strength becomes low, and it is not practically used in terms of price.

The organic diisocyanate of the present invention includes
Aromatic diisocyanates, aliphatic or alicyclic diisocyanates are used. Examples of the aromatic diisocyanate include phenylene diisocyanate, tolylene diisocyanate, and diphenylmethane diisocyanate. As the aliphatic or alicyclic diisocyanate, for example, hexamethylene diisocyanate, lysine diisocyanate,
Cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate,
Xylylene diisocyanate, tetramethylxylylene isocyanate and the like can be mentioned. Among these, diphenylmethane diisocyanate is particularly preferable because a polyurethane resin having good physical properties can be obtained without lowering high-frequency fusion property.

The polyurethane resin of the present invention is produced by a known method. For example, it may be manufactured in a lump or in a solution. The reaction order of the dihydroxy compound, the organic diisocyanate and the chain extender does not matter. For example, an organic diisocyanate may be added and reacted after mixing a dihydroxy compound and a chain extender, or a chain extender may be added and reacted after reacting a dihydroxy compound and an organic diisocyanate.

In the case of preparing a solution, a solvent may be added at any stage of the reaction. For example, whether the whole amount of the solvent is added at the beginning of the reaction, or if a part of the solvent is added at the beginning of the reaction and then the remainder of the solvent is added during the reaction and / or at the end of the reaction, After the reaction, a solvent may be added during the reaction and / or at the end of the reaction.

The reaction may be carried out without a solvent, that is, in a lump, and then dissolved in a solvent. The bulk reaction is usually 30 to 200
At C, the solution reaction is carried out at 30-130C. Solvents that can be used for the reaction and / or dissolution include, for example, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, tetrahydrofuran,
Organic solvents such as dioxane, cyclohexanone and dimethylformamide are exemplified. In the reaction, a catalyst can be used.

As the catalyst, for example, triethylamine,
Examples include nitrogen-containing compounds such as triethylenediamine and morpholine, metal salts such as potassium acetate, zinc stearate and tin octylate, and organic metal compounds such as dibutyltin dilaurate. One or more of these catalysts can be added once or in two or more portions at any time of the reaction.

In the reaction, a stabilizer can be used. Examples of the stabilizer include a stabilizer against ultraviolet rays such as substituted benzotriazoles and a stabilizer against thermal oxidation such as phenol derivatives. One or more of these stabilizers can be added at any time during the reaction or at the end of the reaction in one or more portions.

In the reaction, for example, monoalcohol, 3
Polyfunctional or higher functional polyols, organic monoamines, trifunctional or higher functional polyamines, organic monoisocyanates and / or trifunctional or higher functional organic polyisocyanates can be used. One or more of these can be added at any time of the reaction or at the end of the reaction, once or in two or more portions.

The polyurethane resin of the present invention may contain other resins, antioxidants, ultraviolet absorbers, hydrolysis inhibitors, pigments, dyes, antistatic agents, flame retardants, fillers and the like.

As other resins, for example, polyurethane resins other than the present invention, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl propionate copolymer, polyvinyl butyral resin, cellulose resin, polyester resin , Epoxy resin, phenoxy resin, polyamide resin and the like.

[0028] Synthetic leather can be produced using the polyurethane resin obtained above as one component of synthetic leather. In the synthetic leather of the present invention, the polyurethane resin of the present invention is particularly preferably used as a skin layer of the leather.

The synthetic leather of the present invention is produced by a known method. For example, even if the solvent is removed by applying the polyurethane resin solution of the present invention to a substrate directly or through an intermediate layer or through an adhesive layer, the polyurethane resin film of the present invention is applied to the substrate through an adhesive. Even after bonding, the release material may be peeled off after the polyurethane resin film of the present invention formed on the release material is bonded via an adhesive layer. In particular, it is preferable that the polyurethane resin film of the present invention formed on the release material is bonded via an adhesive layer, and then the release material is peeled off.

The polyurethane resin solution of the present invention can also be used as a porous membrane obtained by coating or impregnating a substrate with a solvent and immersing it in a solvent that is insoluble in the polyurethane resin of the present invention and compatible with the solvent.

The substrate used in the present invention includes, for example, natural fibers such as cellulose fiber and regenerated cellulose fiber;
Knitted or woven fabrics of single or two or more types of mixed fibers of synthetic fibers such as polyester, nylon, vinylon, and acryl.

Further, even if these substrates are raised,
Urethane resin or the like may be impregnated. Examples of the adhesive layer used in the present invention include a polyurethane resin of the present invention and a polyurethane resin other than the polyurethane resin of the present invention.

As a bonding method, a resin solution is used alone or mixed with a curing agent such as polyisocyanate to form a substrate and / or
Alternatively, the solvent may be volatilized after being applied to and bonded to the polyurethane resin of the present invention, or the resin solution may be applied to the base material and / or the polyurethane resin of the present invention, and then the solvent may be volatilized and then pressure-bonded.

The release material used in the present invention includes, for example, silicone release paper, polypropylene release paper, and polyester film. The thickness of the skin layer of the synthetic leather of the present invention is not particularly limited, but is usually 20 to 50 microns. Further, the synthetic leather of the present invention may be surface-treated with a urethane resin, a polyamino acid resin, a blend thereof, or the like.

The synthetic leather of the present invention is excellent in high-frequency fusion property. The high-frequency welding is usually performed between the surface layers of the synthetic leather. The surface of the skin layer of synthetic leather is overlapped and fused with a welder. During high-frequency fusion, the higher the imprint pressure, the easier the fusion is, but the invention is not particularly limited to the imprint pressure.

In high-frequency fusion, the higher the temperature, the easier the fusion, but the temperature is not particularly limited. At the time of high-frequency fusion, the longer the time, the easier the fusion is, but usually about several seconds.

The polyurethane resin of the present invention is useful as a resin for synthetic leather capable of high frequency, and can be used for various uses such as shoes, bags, and clothing.

[0038]

Next, the present invention will be described by way of examples. However, this is only one mode, and the present invention is not limited only to the examples. All parts in the text are based on weight.

Example 1 450 parts of polybutylene adipate diol having an average molecular weight of 2,000, 450 parts of polyoxytetramethylene glycol having an average molecular weight of 2,000, 25 parts of 1,4-butylene glycol and 2,2-diethyl-1,3-propanediol 30 parts were mixed, 1406 parts of dimethylformamide was added to make the mixture uniform, 250 parts of diphenylmethane diisocyanate was added and reacted at 80 ° C., and 1406 parts of methyl ethyl ketone was added to give a solid content of 30% and a viscosity of 600 parts.
A Poise polyurethane resin solution (a) was obtained. The film obtained from this resin solution had a tensile strength at break of 640 kg / cm ² , an elongation at break of 700% and a stress at 100% elongation of 20 kg / cm ² .

Using the above polyurethane resin solution (a), synthetic leathers were respectively produced. First, the following skin layer composition is applied to release paper so as to have a thickness of 100 μm, and
Dry for 3 minutes at ° C. Next, the following adhesive layer composition was applied thereon so as to have a thickness of 120 μm, and immediately, a brushed cloth was attached and dried at 120 ° C. for 3 minutes.
After aging for days, the release paper was peeled off to obtain a synthetic leather. The surfaces of the polyurethane layers of this synthetic leather were overlapped with each other, and high-frequency welding was performed using Welder R-203DAIH manufactured by Pearl Industries Co., Ltd. As a result, this synthetic leather has no surface blocking and shows good coloring properties, high-frequency fusing property shows good adhesion at a printing time of 4 seconds, and its adhesive strength is 1.7 per centimeter. Kilograms.

Epidermal layer formulation liquid Polyurethane resin solution (a) 100 parts Dirac Brown L color 15 parts [Coloring agent manufactured by Dainippon Ink and Chemicals, Inc.] Dimethylformamide 30 parts Adhesive layer formulation liquid Chrisbon 4010 100 parts [Large Nippon Ink and Chemicals, Inc. polyurethane resin, solid content 50%] Crisbon NX 10 parts [Dai Nippon Ink and Chemicals, Inc. organic polyisocyanate crosslinking agent, active ingredient 75%] Chrisbon Axel HM 3 parts [Dainippon Ink Amine-based catalyst manufactured by Chemical Industry Co., Ltd.] Toluene 15 parts Example 2 450 parts of polyethylene hexamethylene adipate diol having an average molecular weight of 2,000, 450 parts of polyoxyhexamethylene glycol having an average molecular weight of 700, 30 parts of 1,6-hexamethylene glycol, and 2,2-diethyl-
30 parts of 1,3-propanediol were mixed, 1517 parts of dimethylformamide was added to make the mixture uniform, 340 parts of diphenylmethane diisocyanate was added, and the mixture was reacted at 80 ° C. After that, 1517 parts of methyl ethyl ketone was added to give a solid content of 30% and a viscosity of 200. A poisoned polyurethane resin solution (b) was obtained. The film obtained from this resin solution had a tensile strength at break of 550 kg / cm ² , an elongation at break of 600% and a stress at 100% elongation of 46 kg / cm ² .

Instead of the polyurethane resin solution (a),
Using this polyurethane resin solution (b), synthetic leather was prepared in the same manner as in Example 1, and high-frequency fusion was performed. As a result, this synthetic leather has no surface blocking, has good coloring properties, and has a high frequency fusing property with good adhesion at a loading time of 4 seconds, and an adhesive force of 1 cm. The weight was 1.5 kilograms.

Example 3 450 parts of polyhexamethylene adipate diol having an average molecular weight of 2,000, 450 parts of polyoxytetramethylene glycol having an average molecular weight of 3,000, 15 parts of 1,6-hexamethylene glycol, and 1,4-butylene glycol 10
Parts and 2-ethyl-2-butyl-1,3-propanediol (60 parts) were mixed, and dimethylformamide 1447 was added.
After adding 255 parts of diphenylmethane diisocyanate and reacting at 80 ° C., 1447 parts of methyl ethyl ketone was added to give a solid content of 30% and a viscosity of 50 parts.
A 0 poise polyurethane resin solution (c) was obtained. The film obtained from this resin solution has a breaking tensile strength of 590 kg / cm ² ,
Elongation at break 625%, stress at 100% elongation 19 kg / cm ²
Met. Using this polyurethane resin solution (c) instead of the polyurethane resin solution (a), synthetic leather was prepared in the same manner as in Example 1, and high-frequency fusion was performed.

As a result, this synthetic leather has no surface blocking, has good coloring properties, has high-frequency fusing properties, has good adhesive properties in a printing time of 3 seconds, and has an adhesive force of 1.6 kilograms per centimeter.

Example 4 450 parts of polyoxytetramethylene glycol having an average molecular weight of 2,000, 35 parts of 1,4-butylene glycol and 60 parts of 2-ethyl-2-butyl-1,3-propanediol were mixed, and dimethylformamide 1523 was added. And then homogenized with diphenylmethane diisocyanate 3
After adding 10 parts and reacting at 80 ° C., 1523 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (d) having a solid content of 30% and a viscosity of 500 poise. The film obtained from this resin solution has a tensile strength of 620 kg / cm ² and an elongation at break of 5
The stress at the time of 00% and 100% elongation was 44 kg / cm ² .
Using this polyurethane resin solution (d) instead of the polyurethane resin solution (a), synthetic leather was prepared in the same manner as in Example 1, and high-frequency fusion was performed.

As a result, this synthetic leather had surface blocking, and the coloring was partially shaded. However, the high-frequency fusing property shows good adhesion at a printing time of 3.5 seconds,
Its adhesion was 2.1 kilograms per centimeter.

Example 5 450 parts of polyethylene hexamethylene adipate diol having an average molecular weight of 2,000, 450 parts of polyoxytetramethylene glycol having an average molecular weight of 3,000, 30 parts of 1,6-hexamethylene glycol, 20 parts of 1,4-butylene glycol, 30 parts of pentyl glycol and 2
-Ethyl-2-butyl-1,3-propanediol (6 parts) was mixed, 1500 parts of dimethylformamide was added to make the mixture uniform, then 300 parts of diphenylmethane diisocyanate was added, and the mixture was reacted at 80 ° C.
By adding 500 parts, a polyurethane resin solution (e) having a solid content of 30% and a viscosity of 500 poise was obtained. The film obtained from this resin solution had a tensile strength at break of 480 kg / cm ² and an elongation at break of 52.
The stress at the time of 5% and 100% elongation was 35 kg / cm ² . Using this polyurethane resin solution (e) instead of the polyurethane resin solution (a), synthetic leather was prepared in the same manner as in Example 1, and high-frequency fusion was performed.

As a result, although this synthetic leather had surface blocking, it exhibited good coloring properties, and high-frequency fusing properties showed good adhesiveness with a printing time of 5 seconds, and its adhesive strength was 1 cm. The weight was 1.5 kilograms.

Example 6 450 parts of polybutylene adipate diol having an average molecular weight of 2,000, 150 parts of polyoxytetramethylene glycol having an average molecular weight of 1,000, 150 parts of polyoxytetramethylene diol having an average molecular weight of 2,000, and 60 parts of 1,4-butylene glycol 2-ethyl-2-butyl-
After mixing 70 parts of 1,3-propanediol and adding 1365 parts of dimethylformamide to make it homogeneous, 300 parts of paraxylene diisocyanate was added and reacted at 80 ° C., and 1365 parts of methyl ethyl ketone was added to obtain a solid content of 3 parts.
Polyurethane resin solution with 0% viscosity and 500 poise (f)
I got The film obtained from this resin solution has a breaking tensile strength of 5
It was 00 kg / cm ² , elongation at break 450%, and stress at 100% elongation of 68 kg / cm ² .

Instead of the polyurethane resin solution (a),
Using this polyurethane resin solution (f), synthetic leather was produced in the same manner as in Example 1, and high-frequency fusion was performed. As a result, this synthetic leather has no surface blocking and shows a good coloring property, and a high-frequency fusing property shows a good adhesive property with a coloring and imprinting time of 3 seconds, and an adhesive strength of 1. 1 per centimeter. 8 kilograms.

Comparative Example 1 900 parts of polybutylene adipate diol having an average molecular weight of 2,000, 25 parts of 1,4-butylene glycol, 50 parts of 3-methyl-1.5-pentane glycol, 2-ethyl-2-butyl-1,3 -50 parts of propane glycol, 2
-Ethyl-2-butyl-1,3-propanediol 70
Were mixed, and 1709 parts of dimethylformamide was added to make the mixture homogeneous, and then diphenylmethane diisocyanate 410 was added.
After reacting at 80 ° C., 1709 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (g) having a solid content of 30% and a viscosity of 350 poise. The film obtained from this resin solution has a tensile strength of 340 kg / cm ² and a breaking elongation of 400.
%, And the stress at the time of 100% elongation was 58 kg / cm ² .

Instead of the polyurethane resin solution (a),
Using this polyurethane resin solution (g), synthetic leather was produced in the same manner as in Example 1, and high-frequency fusion was performed. As a result, although this synthetic leather had no surface blocking and exhibited good coloring properties, the high frequency fusing property was not fused even after a printing time of 10 seconds.

Comparative Example 2 Polyethylene glycol 900 having an average molecular weight of 2000
, 50 parts of 1,4-butylene glycol and 30 parts of 2,2-diethyl-1,3-propane glycol, and mixed with 1505 parts of dimethylformamide, and then homogenized with 310 parts of diphenylmethane diisocyanate.
After the reaction at 150 ° C., 1505 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (h) having a solid content of 30% and a viscosity of 500 poise.

The film obtained from this resin solution has a tensile strength of 3
It was 40 kg / cm ² , elongation at break 400%, and stress at the time of 100% elongation 25 kg / cm ² . Polyurethane resin solution (a)
Instead of this, synthetic leather was prepared in the same manner as in Example 1 using this polyurethane resin solution (h).

As a result, this synthetic leather had surface blocking, coloring property was dark and light, and had no commercial value. Comparative Example 3 450 parts of polybutylene adipate diol having an average molecular weight of 2,000, 450 parts of polyoxytetramethylene glycol having an average molecular weight of 2,000, and 100 parts of 1,4-butylene glycol were mixed, and 1622 parts of dimethylformamide was added thereto. After adding 390 parts of diisocyanate and reacting at 80 ° C., 1622 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution (i) having a solid content of 30% and a viscosity of 500 poise. The film obtained from this resin solution had a breaking tensile strength of 500 kg / cm ² , a breaking elongation of 630%, and a stress at the time of 100% elongation of 46 kg / cm ² . Using this polyurethane resin solution (i) instead of the polyurethane resin solution (a), synthetic leather was prepared in the same manner as in Example 1, and high-frequency fusion was performed.

As a result, although this synthetic leather had no surface blocking and exhibited good coloring properties, the high-frequency fusion property did not fuse even after a printing time of 10 seconds.

[0057]

Industrial Applicability The polyurethane resin of the present invention has good high-frequency fusing properties. Synthetic leather using this polyurethane resin as one of the leather constituents has good coloring properties and anti-blocking properties. Wearing is possible. Therefore, it is useful as a synthetic leather for shoes, bags, clothing, etc., which requires the above properties.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-224817 (JP, A) JP-A-58-79008 (JP, A) JP-A-46-40430 (JP, A) 18598 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/00-18/87 D06M 15/564 D06N 3/14

Claims (6)

(57) [Claims] 1. A polyoxyalkylene glycol having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit, and a 3-1 carbon atom having an alkyl group having 2 or more carbon atoms in a side chain.
A method for producing a polyurethane resin, which comprises reacting an alkylene diol of 0 with a diol having a molecular weight of less than 500 and an organic diisocyanate. 2. The process for producing a polyurethane resin according to claim 1, wherein the polyalkylene glycol having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit is polyoxytetramethylenediol. 3. The process for producing a polyurethane resin according to claim 1, wherein a polyalkylene glycol having an oxyalkylene chain having 4 or more carbon atoms as a repeating unit and a polyester diol are used in combination. 4. An alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in a side chain is 2-ethyl-
2. A compound according to claim 1, which is 2-butyl-1,3-propanediol.
A method for producing the polyurethane resin as described above. 5. The method according to claim 1, wherein the alkylene diol having 3 to 10 carbon atoms having an alkyl group having 2 or more carbon atoms in the side chain accounts for 5 to 50 equivalent% of the total diol. Method. 6. Synthetic leather comprising the polyurethane resin according to claim 1 as one of the constituents of the leather.