JP3281126B2 - Coating composition and synthetic leather and artificial leather obtained using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is suitable for materials such as shoes, bags, bags, belts, gloves, clothing, furniture, and automobile seats, which are excellent in oleic acid resistance, hydrolysis resistance and alcohol resistance. And a coating agent suitable for producing synthetic leather and artificial leather, and a synthetic leather and an artificial leather having the above-mentioned properties processed using the coating agent.

[0002]

2. Description of the Related Art Conventionally, a nonwoven fabric mainly composed of ultrafine fibers is impregnated with a coating agent composition mainly composed of polyurethane, and artificial leather is obtained by raising the ultrafine fibers or the like. It is widely known to apply agent compositions to obtain synthetic leather. The synthetic leather and artificial leather thus obtained have been highly evaluated for their texture, appearance and the like, and have been used in various applications as described above. However, most of the polyurethanes used in these products are polyester or polyether-based polyurethanes, so that various problems have occurred.

For example, in furniture such as reception chairs and office chairs, and those used for a long period of time such as automobile seats, the surface of the polyester-based polyurethane resin becomes tacky and sticky due to hydrolysis of the polyester-based polyurethane resin. In some cases, the polyurethane resin layer deteriorates due to hydrolysis and peels off from the substrate, and the like, and cannot be used for a long time. In the case of polyether-based polyurethane, although hydrolysis resistance is excellent, oleic acid resistance and alcohol resistance are insufficient, so if the use period is prolonged, it is a component of sebum together with human sweat. The polyurethane resin layer is deteriorated by absorbing oleic acid or alcohol contained in a lotion or the like used for hair styling, so that the polyurethane resin layer cannot withstand use in terms of strength.

In order to solve these problems, the use of polycarbonate polyurethane has been studied (JP-A-56-63079, JP-A-59-100778).
JP, JP-A-59-100779). surely,
This polycarbonate polyurethane has hydrolysis resistance,
Alcohol resistance, oleic acid resistance, etc. are improved as compared to polyester-based polyurethane and polyether-based polyurethane, but these properties are not exhibited in non-yellowing type polyurethanes, and in the case of yellowing type polyurethanes. Is considerably improved, but still insufficient and problematic.

[0005]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the prior art and, when practical, provides a polyurethane coating agent having excellent oleic acid resistance, alcohol resistance and hydrolysis resistance. An object of the present invention is to obtain a synthetic leather and an artificial leather having the above characteristics by using a coating agent.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, they have obtained a polytetramethylene carbonate diol in place of the conventional polyhexamethylene carbonate diol. The present inventors have found that polyurethane has excellent hydrolysis resistance, alcohol resistance, and oleic acid resistance, and have accomplished the present invention.

That is, polytetramethylene carbonate diol cannot be easily made into a high molecular weight like polyhexamethylene carbonate diol which is generally commercially available (Japanese Patent Application Laid-Open No. 63-12896), and has been industrially put to practical use. Absent. Therefore, there is little description about polyurethane using polytetramethylene carbonate diol, and it is slightly described in Polymer, 1992, Vol. 3
3, No. 7, 1384-1390, which relates to a cross-linked type polyurethane, and there is no description about a thermoplastic thermoplastic polyurethane, and it is a fact that little is known about these properties. . However, the present applicant has found an industrially advantageous method for synthesizing high molecular weight polytetramethylene carbonate diol (Japanese Patent Application No. 4-258748), and as a result of studying polyurethane using the same, polytetramethylene carbonate was found. Polyurethane obtained using diol,
The inventors have found that they have excellent hydrolysis resistance, alcohol resistance, and oleic acid resistance, and have accomplished the present invention.

[0008] That is, the present invention is based on the structural unit represented by the general formula (1) obtained by reacting polytetramethylene carbonate diol with one or more organic diisocyanates in an isocyanate-inactive organic solvent. (A), and a chain extender (B) having two active hydrogens capable of reacting with the isocyanate of the prepolymer
Having a molar ratio of (A) / (B) exceeding 1 and having a molecular weight of 3 terminated by a reaction terminator (C) having one active hydrogen capable of reacting with unreacted isocyanate at the terminal. A synthetic leather obtained by applying the above-mentioned thermoplastic polyurethane-containing coating composition, which is a coating composition containing a thermoplastic polyurethane having a gel percentage of 5% or less by 200,000; An artificial leather obtained by immersing a coating composition containing a thermoplastic polyurethane in a fabric.

[0009]

Embedded image

Hereinafter, the present invention will be described. The polytetramethylene carbonate diol used in the present invention is used when 1,4-butanediol is reacted with phosgene, dialkyl carbonate, diallyl carbonate, or an alkylene carbonate in the presence or absence of a catalyst. A molecular weight of 5 obtained by adding an acidic compound
00 to 10,000.

The organic diisocyanate used in the present invention includes, for example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate and its mixture (T
DI), 4,4'-diphenylmethane diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3-dimethyl-4,4-biphenylene diisocyanate (TODI), crude TDI, polymethylene polyphenylene diisocyanate, crude Aromatic diisocyanates such as MDI, xylylene diisocyanate (XDI), aromatic alicyclic diisocyanates such as phenylene diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HDI), isophorone Examples include aliphatic diisocyanates such as diisocyanate (IPDI) and cyclohexane diisocyanate (hydrogenated XDI).

The chain extenders used in the present invention include short-chain diols such as ethylene glycol and 1,4-butanediol, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, diaminodiamine. Diphenylmethane, diaminocyclohexylmethane, piperazine, 2-
Examples include various diamines such as methylpiperazine and isophoronediamine, and water.

Examples of the terminal terminator used in the present invention include monoalcohols such as methanol and ethanol, and alkylamines such as ethylamine, isopropylamine, diethylamine and 2-ethylhexylamine. The organic solvent used in the present invention is preferably a solvent inert to isocyanate, for example, one or two of dimethylformamide, diethylformamide, dimethylsulfoxide, dimethylacetamide, tetrahydrofuran, methylisobutylketone, dioxane, cyclohexanone, toluene and the like. Mixtures of more than one species.

As a method for producing the polyurethane of the present invention, a urethane-forming reaction technique known in the polyurethane industry is used. For example, a long-chain diol and an organic diisocyanate in an organic solvent inert to isocyanate,
This is a prepolymer method in which an NCO-terminated urethane prepolymer is synthesized by reacting at room temperature to 200 ° C, a chain extender is added thereto, and the mixture is further reacted at room temperature to 200 ° C to increase the molecular weight to obtain a desired polyurethane. In this reaction, it is needless to say that, if necessary, a known polymerization catalyst can be used in the urethane-forming reaction represented by an appropriate amount of a tertiary amine, an organic metal salt such as tin, titanium or the like.

The polyurethane of the present invention preferably has a molecular weight of 30,000 to 200,000, more preferably 40,000 to 100,000. If the molecular weight is less than 30,000, the mechanical properties, particularly the strength, of the coating composition will be insufficient, and if it exceeds 200,000, the viscosity of the solution will be high and practical coatability will not be obtained. Furthermore, the gel% of the polyurethane of the present invention is preferably 5% or less. More preferably, it is substantially 0. If the gel percentage exceeds 5%, the solubility is poor, and a coating composition having a stable viscosity cannot be obtained.

As shown in FIG. 1, the synthetic leather of the present invention comprises a thermoplastic polyurethane-containing coating composition (hereinafter referred to as a polyurethane coating composition) obtained by the present invention and a synthetic leather substrate (hereinafter referred to as a base). Material)
It is a skin layer. The synthetic leather of the present invention is manufactured by a usual method. For example, the solvent is removed after directly applying the polyurethane coating composition of the present invention to a substrate or applying the composition via an intermediate layer or an adhesive layer. Furthermore, the polyurethane coating composition of the present invention is bonded to a substrate via an adhesive, or a film of the polyurethane coating agent of the present invention applied on a release material is bonded to a substrate via an adhesive layer. After the combination, the release material may be peeled off to form a synthetic leather. Among the above methods, a method of laminating a film of the polyurethane coating composition of the present invention applied on a release material to a substrate via an adhesive layer and then peeling the release material to obtain a synthetic leather. Is particularly preferred.

The base material used in the production of the synthetic leather of the present invention includes, for example, natural fibers such as cellulose fibers and regenerated cellulose fibers, and synthetic fibers such as polyester, nylon, vinylon and acrylic, or a mixture of two or more thereof. Knitted and woven fabric of fiber. Further, these substrates may be raised or may be impregnated with a urethane resin or the like.

As the adhesive used in the present invention, for example, the polyurethane coating composition of the present invention itself may be used, or another polyurethane resin or the like may be used. As the bonding method, the polyurethane coating composition solution of the present invention is used alone or a mixture of a curing agent such as polyisocyanate is used as an adhesive to form a substrate or a film of the polyurethane coating composition of the present invention. After applying and bonding these adhesives, the solvent is volatilized. Further, the above-mentioned adhesive may be applied to a substrate or a film of the polyurethane coating composition of the present invention, and after the solvent is volatilized, the substrate and the film of the composition may be pressed.

The release material used in the present invention includes, for example, silicone release paper, polypropylene release paper, and polyester film. On the other hand, the artificial leather of the present invention does not cover the surface of the base material with the polyurethane coating composition as in the above-described synthetic leather,
The inside of the artificial leather substrate is impregnated with the polyurethane coating composition, and the solid material is retained in the substrate.

[0020] The artificial leather of the present invention is, for example, a cloth, in particular, a brushed non-woven fabric having raised fibers made of ultrafine fibers partially containing PVA fibers which can be dissolved and removed by post-treatment, as a base material for the artificial leather, and this base material is coated with CMC. After that, the polyurethane coating composition of the present invention is immersed, dried and CM
C, obtained by extracting PVA fibers. As for the ultrafine fibers constituting the raised portion of the raised fabric serving as the base material of the artificial leather of the present invention, the material and the fiber length can be arbitrarily selected, but the fineness is suede-like or nubuck-like sheet surface quality. In order to obtain the fineness and lighting effect of
It is preferably 0.5 denier or less. Preferred examples of the material include polyester, polyamide, polyacrylonitrile, cellulose, cupra, and the like. The fiber length may be appropriately selected depending on the purpose, such as a short fiber cut into a length of 1 to 50 mm, a fiber having a length of 100 mm or more or a substantially long fiber. As a method for producing such an ultrafine fiber, a known sea-island fiber method, a mixed fiber method, a direct spinning method, a melt blow method, a spun bond method, or the like can be used.

As the reinforcing sheet for reinforcing the raised fabric serving as the base material of the artificial leather of the present invention, a knitted fabric such as a flat knit or a tricot, a woven fabric having a plain weave or the like is preferably used. Straight yarns, false twisted yarns, and the like are preferable as constituent yarns of these knitted fabrics. In order to obtain a raised fabric composed of the above ultrafine fibers and a knitted fabric, a nonwoven fabric is formed by, for example, a random weber, a cross layer, or a papermaking method, and the knitted fabrics are inserted into the middle and laminated, and needle punching or high pressure It can be obtained by entanglement and integration of ultrafine fibers such as columnar water flow and the like and ultrafine fibers and knitted fabrics.

[0022]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Parts and% used below are parts by weight and% by weight unless otherwise specified. The evaluation results used in the examples are the results measured by the following evaluation methods.

(Mechanical physical properties of film): Sample (width 10)
mm, length 60 mm, thickness 100 μm) under the following conditions, and mechanical properties (strength) are measured according to JIS K-7311. Measuring machine: Tensilon tensile tester Orientec RTA-100 Co., Ltd. Grasp length: 30 mm Tension speed: 300 mm / min Measurement atmosphere: 25 ° C. × 65% RH (hydrolysis resistance of film): 100 ° C.
For 7 days in hot water, and the molecular weight retention was determined by the following formula.

Molecular weight retention (%) = (M2 / M1) × 100 M1: Molecular weight of film before immersion (measured by GPC) M2: Molecular weight of film after immersion (measured by GPC) (Alcohol resistance of film) : The above sample was immersed in ethanol at room temperature or 50 ° C. for one week, and the retention of mechanical properties (strength) was determined by the following formula.

Strength retention (%) = (S2 / S1) × 100 M1: Strength of film before immersion (Kg / cm ² ) M2: Strength of film after immersion (Kg / cm ² ) (Olein resistance of film) Properties): After the above-mentioned sample was immersed in oleic acid at room temperature for one week, the swelling ratio and the retention of mechanical properties (strength) were determined by the following formulas.

Swelling ratio (%) = {(W2-W1) / W1} × 100 W1: Mass of polymer in air before immersion (g) W2: Mass of polymer in air after immersion (g) Strength retention Rate (%) = (S2 / S1) × 100 M1: Strength of film before immersion (Kg / cm ² ) M2: Strength of film after immersion (Kg / cm ² ) (hydrolysis resistance of synthetic leather): The sample piece of the synthetic leather was left for 4 weeks at a condition of a relative humidity of 95% and a temperature of 70 ° C., and then the resin layer of the sample piece was subjected to a 1 kg load using a Taber abrasion tester.
The degree of surface wear at 500 times of friction was observed.

(Oleic acid resistance of synthetic leather): A sample piece of synthetic leather was immersed in oleic acid at room temperature for one week, and the resin layer of the sample piece was subjected to a 1 kg load using a Taber abrasion tester.
The degree of surface wear at 500 times of friction was observed. (Alcohol resistance of synthetic leather): After immersing a sample piece of synthetic leather in ethanol at room temperature for one week, the resin layer of the sample piece was subjected to a Taber abrasion tester with a load of 1 kg and a number of times of friction of 50.
The degree of surface wear at 0 times was observed.

(Hydrolysis-resistant acidity of artificial leather): A sample of artificial leather was subjected to 10% under conditions of 95% relative humidity and 70 ° C.
The surface stickiness resulting from standing for a week was examined. (Oleic acid resistance of artificial leather):
After being immersed in oleic acid at room temperature for one week, surface tackiness was examined.

(Alcohol resistance of artificial leather): A sample piece of artificial leather was immersed in ethanol at room temperature for one week, and the stickiness of the surface was examined. (Measurement of molecular weight of polyurethane): A 1% by weight solution of the obtained polyurethane in dimethylformamide (DMF) is prepared, and the number average molecular weight in terms of standard polystyrene is determined using GPC under the following conditions.

Column Showa Denko Shodex KD-804 & DD805 (two in series) Column oven Shimadzu CTO-6A Temperature 40 ° C Flow rate 1 ml / min Detector Differential refractometer (Shimadzu RID-6A) Data processor CP-Tosoh Corporation 8000 (measurement of gel% of polyurethane): 10 g of the obtained polyurethane was weighed into a 200 ml Erlenmeyer flask, 90 g of DMF was added, and the mixture was shaken for 60 minutes with a shaker adjusted to 50 ° C., and then a 400-mesh wire mesh was used. And the undissolved components are filtered off. After drying the undissolved portion separated by filtration, the weight was measured, and the gel% was determined by the following formula.

Gel% = (X / 10) × 100 X: Weight of undissolved component (g) [Example of synthesis of polytetramethylene carbonate diol]
In a 3 liter reactor equipped with a stirrer, thermometer, and distillation tube,
1584 g (18 mol) of ethylene carbonate, 1,4
-1440 g (16 mol) of butanediol, 3 m of lead acetate
g at a temperature of 130 ° C. and a pressure of 35 mmHg to 17
The reaction was performed at mmHg for 10 hours. At this time, ethylene carbonate and ethylene glycol having an azeotropic composition were distilled out from the top of the distillation tube, and formation of 1 mol% of THF (tetrahydrofuran) with respect to the charged butanediol was observed in a trap for a vacuum pump. Was done.

Next, the pressure was returned to normal pressure, and 0.1 g of di (2-ethylhexyl) phosphate was added.
C. and reacted at a pressure of 35 mmHg to 17 mmHg for 8 hours. Also at this time, ethylene carbonate and ethylene glycol having an azeotropic composition are distilled out from the top of the distillation tube.
Mole% of THF had formed. At this time, there were 2170 g of polytetramethylene carbonate diol in the reactor, and its molecular weight was measured by GPC.
00 (hydroxyl value = 280 mg · KOH / g).

Next, the distillation tube was removed to allow direct evacuation, and then the pressure was set to 6 mmHg, and the unreacted monomer was distilled off for 1 hour. Next, the pressure was set to 4 mmHg, the reaction temperature was set to 190 ° C., and while distilling butanediol, 7
The reaction was carried out for 20 hours, and the molecular weight was 2050 (hydroxyl value = 54.6).
mg · KOH / g) of polytetramethylene carbonate diol was obtained. At this time, 1 mol% of THF was produced with respect to the charged butanediol. The total amount of by-product THF from the beginning of the reaction was 4 mol%.

[Synthesis example of polyhexamethylene carbonate diol] 1179.7 parts of 1,6-hexanediol (109.7 parts) was placed in a reactor equipped with a stirrer, a thermometer, and a distillation tube.
Mol), and 1.84 metallic sodium at 70-80 ° C.
Parts (0.08 mol) were added with stirring. After the sodium had completely reacted, 472 parts (8.0 mol) of diethyl carbonate were introduced. As the reaction temperature was raised to 95-100 ° C, ethanol began to distill. The temperature was gradually raised to 160 ° C. in about 6 hours. During this time, about 10
% Ethanol containing diethyl carbonate was distilled off. Thereafter, the reactor pressure was further reduced to 10 mmHg or less, and the reaction was carried out at 200 ° C. for 4 hours under strong stirring. The resulting polymer was cooled, dissolved in dichloromethane, neutralized with dilute acid, washed several times with water, dehydrated with anhydrous sodium sulfate, distilled off the solvent, and further distilled off at 2-3 mmH.
g, dried at 140 ° C. for several hours. The molecular weight of the obtained polyhexamethylene carbonate diol was 2,000.

[0035]

Example 1 Polytetramethylene carbonate diol (molecular weight: 2050) 1025 obtained in the above synthesis example
Parts, 3470 parts of dimethylformamide in a reflux condenser,
After putting into a reactor having a thermometer and a stirrer, thoroughly mixing and stirring, 375 parts of 4,4′-diphenylmethane diisocyanate (MDI) was added, and the mixture was reacted at 30 ° C. for 3 hours to prepare an NCO-terminated prepolymer. Obtained. 80 parts by adding 83.3 parts of 1,4-butanediol (1,4-BD)
After raising the temperature to 2 ° C. and performing a chain extension reaction for about 2 hours, 4.8 parts of dibutylamine was added as a reaction terminator, and the reaction was further continued for 100
The reaction was continued at 2 ° C. for 2 hours. The resulting polyurethane solution (1) had a solid content of 30%, a gel% of polyurethane of 0, and a number average molecular weight of 80000 (measured by GPC, manufactured by Tosoh Corporation).

The obtained polyurethane solution (1) was applied on a glass plate, dried at 80 ° C. for 15 hours, and dried under reduced pressure at 50 ° C. for 4 hours to obtain a film having a thickness of 100 μm. . Using the obtained film, hydrolysis resistance, oleic acid resistance, and alcohol resistance were measured, and the results are shown in Table 1.

[0037]

Example 2 The diisocyanate was changed to tolylene diisocyanate (TDI), and dibutyltin dilaurate 50p
A polyurethane solution having a solid content of 30%, a polyurethane gel percentage of 0, and a number average molecular weight of 80,000 (2) in the same manner as in Example 1 except that the reaction temperature of the prepolymer was changed to 50 ° C. by adding pm. I got This polyurethane solution (2) was applied on a glass plate, and a film having a thickness of 100 μm was obtained in the same manner as in Example 1. Using the obtained film, hydrolysis resistance, oleic acid resistance and alcohol resistance were measured, and the results are shown in Table 1.

[0038]

Example 3 2050 parts of the above-mentioned polytetramethylene carbonate diol (molecular weight: 2050) and 6396 parts of dimethylformamide were put into a reactor having a reflux condenser, a thermometer and a stirrer.
524 parts of 4'-methylenebis (cyclohexyl diisocyanate) (hydrogenated MDI) and 20 ppm of dibutyltin dilaurate were added, and the mixture was reacted at 80 ° C. for 3 hours.
A terminal prepolymer was obtained. Isophorone diamine (I
After adding 158.3 parts of PDA and performing a chain extension reaction for about 2 hours, dibutylamine 8.85 was used as a reaction terminator.
The reaction was continued for an additional hour after adding 1 part. The obtained polyurethane solution (3) has a solid content of 30%, a gel% of polyurethane of 0, and a number average molecular weight of 80,000 (G by Tosoh Corporation).
(Measured by PC).

The obtained polyurethane solution (3) was applied on a glass plate, dried at 80 ° C. for 15 hours, and dried under reduced pressure at 50 ° C. for 4 hours to obtain a film having a thickness of 100 μm. . Using the obtained film, hydrolysis resistance, oleic acid resistance and alcohol resistance were measured, and the results are shown in Table 1.

[0040]

Example 4 A solid content of 30% was obtained in the same manner as in Example 3 except that hydrogenated MDI was changed to isophorone diisocyanate.
%, Polyurethane gel% is 0, number average molecular weight 8000
Thus, a polyurethane solution (4) was obtained. From this polyurethane solution (4), a film thickness of 100 μm was obtained in the same manner as in Example 1.
Was obtained, and various physical properties were measured. Table 1 shows the results.

[0041]

Comparative Example 1 The procedure of Example 1 was repeated, except that the polytetramethylene carbonate diol was changed to the polyhexamethylene carbonate diol obtained in the above synthesis example.
A polyurethane solution (5) was obtained. The obtained polyurethane solution (5) was applied on a glass plate, dried at 80 ° C. for 15 hours, and then dried under reduced pressure at 50 ° C. for 4 hours.
A film of 00 μm was obtained. Using the obtained film, hydrolysis resistance, oleic acid resistance and alcohol resistance were measured, and the results are shown in Table 1.

[0042]

Comparative Examples 2 to 4 Polyurethane solutions (6) to (8) were prepared in the same manner as in Examples 2 to 4, except that the polytetramethylene carbonate diol was changed to the polyhexamethylene carbonate diol obtained in the above synthesis example. ) Got. The obtained polyurethane solutions (6) to (8) were coated on a glass plate, dried at 80 ° C for 15 hours, and then dried under reduced pressure at 50 ° C.
For 4 hours to obtain a film having a thickness of 100 μm.
Using the obtained film, hydrolysis resistance, oleic acid resistance and alcohol resistance were measured, and the results are shown in Table 1.

[0043]

Comparative Examples 5 and 6 Polycaprolactone diol (Placel 220N manufactured by Daicel Chemical Co., Ltd.) and polytetramethylene glycol (PTMG-2000 manufactured by Mitsubishi Kasei Co., Ltd.) were used instead of polytetramethylene carbonate diol. In the same manner as in Example 1, polyurethane solutions (9) to (10) were obtained.

The obtained polyurethane solutions (9) to (10) were applied on a glass plate, dried at 80 ° C. for 15 hours, and dried under reduced pressure at 50 ° C. for 4 hours to obtain a film having a thickness of 100 μm.
Was obtained. Using the obtained film, hydrolysis resistance, oleic acid resistance and alcohol resistance were measured, and the results are shown in Table 1.

[0045]

Comparative Examples 7 and 8 Except that polycaprolactone diol (Placcel 220N manufactured by Daicel Chemical Co., Ltd.) and polytetramethylene glycol (PTMG-2000 manufactured by Mitsubishi Kasei Co., Ltd.) were used instead of polytetramethylene carbonate diol. In the same manner as in Example 3, polyurethane solutions (11) and (12) were obtained.

The obtained polyurethane solutions (11) and (12) were applied on a glass plate, dried at 80 ° C. for 15 hours, and dried under reduced pressure at 50 ° C. for 4 hours to obtain a film having a thickness of 100 μm.
m was obtained. Using the obtained film, hydrolysis resistance, oleic acid resistance, and alcohol resistance were measured,
The results are shown in Table 1.

[0047]

Example 5 The polyurethane solution (1) synthesized in Example 1 was applied to the surface of silicon paper so as to have a dry thickness of 45 μm, and was heated and dried to form a polyurethane film layer. IPDI / P on this polyurethane film layer
TMG-2000 / N- (2-hydroxyethyl) propylenediamine / monoethanolamine / hydrazine hydrate = 2/1 / 0.5 / 0.4 / 0.2 A PTMG two-component polyurethane adhesive added as a crosslinking agent was applied at a basis weight of 130 g / m ² and a thickness of about 118 μm to form a polyurethane adhesive layer. The brushed surface of a cotton brushed cloth as a base material for synthetic leather is stuck to this adhesive layer,
After heating for minutes for the adhesive to react and solidify, the silicone paper release paper was peeled off to obtain synthetic leather A. The physical properties of the obtained synthetic leather were evaluated, and the results are shown in Table 2.

[0048]

Example 6 The polyurethane solution (3) synthesized in Example 3 was applied to the surface of silicon paper so as to have a dry thickness of 45 μm, and this was heated and dried to form a polyurethane film layer. On this polyurethane film layer, the PTMG-based two-pack type polyurethane adhesive used in Example 5 was applied with a basis weight of 130 g / m ² and a thickness of about 118 μm to form a polyurethane adhesive layer. The brushed surface of a cotton brushed cloth as a material was stuck and heated at 120 ° C. for 4 minutes to react and solidify the adhesive, and then the silicone paper release paper was peeled off to obtain synthetic leather B. The physical properties of the obtained synthetic leather were evaluated, and the results are shown in Table 2.

[0049]

Comparative Example 9 The polyurethane solution (5) synthesized in Comparative Example 1 was applied to the surface of a silicon paper so as to have a dry thickness of 45 μm, and dried by heating to form a polyurethane film layer. On this polyurethane film layer, the PTMG-based two-component polyurethane adhesive used in Example 5 was applied with a basis weight of 1
30 g / m ² , applied at a thickness of about 118 μm to form a polyurethane adhesive layer. A brushed surface of a cotton brushed cloth as a base material for synthetic leather is bonded to the adhesive layer surface, and heated at 120 ° C. for 4 minutes to react the adhesive. After solidification, the silicone paper release paper was peeled off to obtain synthetic leather C. The physical properties of the obtained synthetic leather were evaluated, and the results are shown in Table 2.

[0050]

Comparative Examples 10 to 14 In the same manner as in Comparative Example 9, the polyurethane solutions (7), (9), (10), (11), (1)
Synthetic leathers D, E, F, G and H were obtained using 2), and their physical properties were evaluated. Table 2 shows the results.

[0051]

Example 7 A 0.1 denier single yarn polyethylene terephthalate (hereinafter abbreviated as PET) fiber obtained by a direct spinning method was cut into 3 mm. On the other hand, short fibers of 1 denier and a cut length of 3 mm of polyvinyl alcohol (hereinafter abbreviated as PVA) are prepared, mixed at a PET fiber / PVA fiber ratio of 70/30% by weight, and the basis weight is 80 g / sheet by a papermaking method.
m ² sheets were obtained.

75 denier / 36 between these two sheets
A woven fabric having a basis weight of 50 g / m ² of a plain weave structure made of a false twisted yarn of PET fiber of the filament was inserted in a sandwich form to form a laminated sheet. Alternately from the front and back of the laminated sheet, treated with a jet of water at a pressure of 15 kg / cm ² from a number of nozzles having orifices of 0.2 mm,
The ultrafine fibers and the woven fabric were sufficiently three-dimensionally entangled.

Next, after drying this entangled sheet,
The front and back surfaces were brushed with a belt sander equipped with mesh emery paper. Carboxymethyl cellulose (CMC) having a thickness of 0.1 was applied to the raised surface on the back of this sheet.
mm was coated with a doctor knife and dried. The solid content of the polyurethane solution (3) obtained in Example 3 was adjusted to 15% by weight with dimethylformamide, and a foam stabilizer (Toray Industries, Inc.) was used.
Dow Corning Silicon Co., Ltd., SF8427) was added at 10% by weight based on the solid content of the polyurethane solution to obtain a polyurethane composition solution.

The impregnated sheet coated with CMC was impregnated with a solution of this polyurethane composition,
After coagulation in water, it was dried. Thereafter, the PVA fiber and CMC were extracted and dried in boiling water for about 20 minutes. The sheet-like material thus obtained was dispersed with a loco-type dyeing machine using a disperse dye [Sumitomo Chemical Industry Co., Ltd., trade name: Sumikar
on Red-SBL] 10% owf, followed by reduction washing with hydrosulfite soda 5% owf. Further, the sheet was impregnated with a 1% aqueous dispersion of an acrylic ester-based antistatic agent and a silicon-based water repellent, squeezed with a mangle, and then 3% with a pin tenter dryer set at a temperature of 140 ° C. Dry with a residence time of 5 minutes at an overfeed rate.

The obtained sheet material A has a suede-like dense surface nap, has an excellent lighting effect,
Excellent touch without stickiness. Table 3 shows the results.
Shown in

[0056]

Example 8 In the same manner as in Example 7, a sheet B was obtained using the polyurethane solution (4) obtained in Example 4. Table 3 shows the results of the touch.

[0057]

Comparative Example 15 In the same manner as in Example 7, a sheet C was obtained using the polyurethane solution 7 obtained in Comparative Example 3. Table 3 shows the results of the touch.

[0058]

Comparative Examples 16 to 20 In the same manner as in Example 7, the polyurethane solutions (8), (9), (10), (11), (1)
Sheet materials D, E, F, G and H were obtained using 2). Table 3 shows the results of the touch.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

The polytetramethylene carbonate diol of the present invention, one or more organic diisocyanates, and a chain extender having two or more active hydrogens capable of reacting with isocyanate are mixed in an isocyanate-inactive organic solvent. The polyurethane coating composition obtained by the above reaction gives a film excellent in hydrolysis resistance, oleic acid resistance, and alcohol resistance as compared with other polyurethane coating agents. Synthetic leather and artificial leather have excellent touch without stickiness.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an embodiment of a synthetic leather (Examples 5 to 6) of the present invention. 1 Base material for synthetic leather 2 Polyurethane adhesive layer 3 Polyurethane coating layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C09D 175/04

Claims (3)

(57) [Claims] 1. A prepolymer comprising a structural unit represented by the general formula (1) obtained by reacting polytetramethylene carbonate diol with one or more organic diisocyanates in an isocyanate-inactive organic solvent. A) and a chain extender (B) having two active hydrogens capable of reacting with the isocyanate of the prepolymer, wherein the molar ratio of (A) / (B) exceeds 1 and It contains a thermoplastic polyurethane having a molecular weight of 300,000 to 200,000 and a gel% of 5% or less, terminated by a reaction terminator (C) having one active hydrogen capable of reacting with an unreacted isocyanate at the terminal of (A). Coating composition. Embedded image 2. A synthetic leather obtained by applying the coating composition containing the thermoplastic polyurethane according to claim 1. 3. An artificial leather obtained by immersing a coating composition containing the thermoplastic polyurethane according to claim 1 in a fabric.