KR20190045334A - Synthetic Leather - Google Patents

Abstract

The present invention relates to a moisture curable polyurethane hot melt resin composition containing a polyol (A) containing an alicyclic polyester polyol (a1) and a hot melt urethane prepolymer (i) which is a reaction product of a polyisocyanate (B) Layer of synthetic leather. It is preferable that the polyol (A) further comprises polyoxypropylene glycol (a2). The moisture-curable polyurethane hot melt resin composition preferably contains a hindered amine compound (ii) and a triazole compound (iii). The synthetic leather of the present invention is excellent in weather resistance and adhesive strength, and can be suitably used as a split ladder.

Description

Synthetic Leather

The present invention relates to a synthetic leather having a cured layer of a moisture-curing polyurethane hot melt resin composition.

The moisture-curing polyurethane hot-melt resin composition is widely used in the production of synthetic leather because of its excellent mechanical strength, flexibility and adhesiveness. Among them, demand for split leather having a floor leather, an adhesive layer and a skin layer has increased in recent years due to the price hike of natural leather, because appearance and feel are close to natural leather.

As a resin composition for forming the adhesive layer of the split ladder, for example, a composition comprising a hot melt urethane prepolymer using an aliphatic polyester polyol or the like as a raw material is disclosed (for example, refer to Patent Document 1).

However, such a composition is required to further improve the adhesive strength. Further, in the split leather application, in recent years, various colored skin layers have been often used from the standpoint of designability. For example, in the case of using a panty skin layer, the adhesive layer is free from fading Excellent weather resistance is also required. However, a material that can achieve both excellent weather resistance and adhesive strength has not been found yet.

Japanese Patent Application Laid-Open No. 2009-297985

A problem to be solved by the present invention is to provide a synthetic leather having a cured layer of a moisture-curing polyurethane hot melt resin composition excellent in weather resistance and adhesive strength.

The present invention relates to a moisture curable polyurethane hot melt resin composition containing a polyol (A) containing an alicyclic polyester polyol (a1) and a hot melt urethane prepolymer (i) which is a reaction product of a polyisocyanate (B) Layer of synthetic leather.

The synthetic leather of the present invention has a layer having strong adhesive strength (particularly, initial adhesive strength) and excellent weather resistance.

The synthetic leather of the present invention is a moisture-curing polyurethane hot melt resin composition containing a polyol (A) containing an alicyclic polyester polyol (a1) and a hot melt urethane prepolymer (i) which is a reaction product of a polyisocyanate (B) As shown in Fig.

The alicyclic polyester polyol (a1) is an essential component in obtaining excellent weather resistance and adhesion strength. In order to obtain an excellent initial bonding strength, it is common to use an aromatic polyester polyol having an aromatic compound such as phthalic acid as a raw material. However, when an aromatic polyester polyol is used, there is a problem that it is discolored by time-lapse irradiation of sunlight in particular. On the other hand, in the present invention, by using the alicyclic polyesterpolyol (al), a cured product layer having excellent initial strength and weather resistance due to cohesive force (in particular, discoloration resistance even at the time of solar irradiation) can be obtained. Further, in the embodiment of the present invention, the results of the weather resistance test by a QUV-accelerated weathering tester (manufactured by Q-LAB Corporation) equipped with a UVA-340 lamp that faithfully simulates the short wavelength region of sunlight at 295 to 365 nm are shown.

Examples of the alicyclic polyester polyol (a1) include a reaction product of an alicyclic compound having two or more hydroxyl groups and an aliphatic polybasic acid, and a reaction product of an aliphatic compound having two or more hydroxyl groups and an alicyclic polybasic acid. These reactants can also be obtained by known esterification reactions.

Examples of the alicyclic compound having two or more hydroxyl groups include cyclopentanediol, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A; And alkylene oxide adducts thereof. These compounds may be used alone or in combination of two or more. Of these, cyclohexanedimethanol is preferably used in view of better weathering resistance and adhesive strength.

Examples of the aliphatic polybasic acid include aliphatic polybasic acids such as succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, eicosific acid, citraconic acid, itaconic acid, Itaconic anhydride and the like can be used. These compounds may be used alone or in combination of two or more.

Examples of the aliphatic compound having two or more hydroxyl groups include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7- , 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethyleneglycol, triethyleneglycol, tetraethyleneglycol, neopentylglycol, Butanediol, 2,2-diethyl-1,3-propanediol, 2,2-diethylpropanediol, 3-methyl-1,5-pentanediol, , 2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These compounds may be used alone or in combination of two or more. Of these, from the viewpoint of obtaining even more excellent weather resistance and adhesive strength, it is preferred to use 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, neopentyl glycol, Neopentyl glycol and / or 3-methyl-1,5-pentanediol are more preferable because they have a higher cohesive strength by having a branched structure and furthermore have superior weather resistance and adhesive strength. desirable.

As the alicyclic polybasic acid, for example, cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanediadipate and the like can be used. These compounds may be used alone or in combination of two or more. Among them, it is preferable to use cyclohexanedicarboxylic acid and / or cyclohexanediadipate because further superior weather resistance and adhesive strength can be obtained.

The number average molecular weight of the alicyclic polyester polyol (a1) is preferably in the range of 400 to 10,000, more preferably in the range of 500 to 5,000, more preferably in the range of 600 to 5,000, 3,000 is more preferable. The number average molecular weight of the alicyclic polyester polyol (a1) is a value measured by a gel permeation chromatography (GPC) method.

The content of the alicyclic polyester polyol (a1) is preferably 10% by mass or more, more preferably 20% by mass to 80% by mass in the polyol (A), from the viewpoint of obtaining more excellent weather resistance and adhesive strength , More preferably from 30 to 70 mass%, and still more preferably from 30 to 50 mass%.

Examples of other polyols which can be used as the polyol (A) in addition to the alicyclic polyester polyol (a1) include polyester polyols other than the alicyclic polyester polyol (a1), polyether polyols, polycarbonates Polyol, polybutadiene polyol, dimer diol, acryl polyol, and the like. These polyols may be used singly or in combination of two or more. Among them, when the alicyclic polyester polyol (a1) is used in combination with the alicyclic polyester polyol (a1), the high viscosity derived from (a1) can be alleviated and the coating property can be improved by lowering the viscosity, It is preferable to use a polyether polyol, and polyoxypropylene glycol (a2) is more preferable.

When the polyoxypropylene glycol (a2) is used, the content of the polyoxypropylene glycol (a2) is preferably in the range of 5 to 90% by mass in the polyol (A) from the viewpoint that the low viscosity can be further improved while maintaining weatherability and adhesive strength , More preferably in the range of 10 to 80 mass%, and still more preferably in the range of 30 to 70 mass%.

In the case of using polyoxypropylene glycol (a2), it is preferable to use aliphatic polyester polyol and / or polytetramethylene glycol in combination in order to further improve the balance of weather resistance, adhesive strength and low viscosity. Do.

The number average molecular weight of the other polyol is preferably in the range of 500 to 10,000, more preferably in the range of 700 to 5,000 from the viewpoint of mechanical strength. When polyoxypropylene glycol (a2) is used as the other polyol, the number average molecular weight thereof is preferably in the range of 1,100 to 5,000, more preferably 1,500 to 3,000 Is more preferable. The number average molecular weight of the other polyol represents a value obtained by measurement in the same manner as the number average molecular weight of the alicyclic polyester polyol (a1).

Examples of the polyisocyanate (B) include polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate and naphthalene diisocyanate Aromatic polyisocyanates; Aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate, and the like can be used. These polyisocyanates may be used singly or in combination of two or more. Of these, aromatic polyisocyanates are preferably used, and diphenylmethane diisocyanate is more preferable because excellent reactivity and peel strength can be obtained.

The amount of the polyisocyanate (B) to be used is preferably in the range of 5 to 40 mass%, and more preferably in the range of 10 to 30 mass%, based on the total mass of the raw materials constituting the hot melt urethane prepolymer (i).

The hot melt urethane prepolymer (i) is obtained by reacting the polyol (A) with the polyisocyanate (B), and reacts with moisture present in the substrate to which the airborne or moisture-curing polyurethane hot melt resin composition is applied to crosslink Having an isocyanate group capable of forming a structure.

The hot melt urethane prepolymer (i) can be produced, for example, by introducing the polyol (A) into a reaction vessel containing the polyisocyanate (B) and reacting the isocyanate group of the polyisocyanate (B) In the presence of an excess of the hydroxyl group of the compound (A).

As to the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group of the polyisocyanate (B) to the hydroxyl group of the polyol (A) when the hot melt urethane prepolymer (i) is produced, , It is preferably in the range of 1.1 to 5, and more preferably in the range of 1.5 to 3. [

The isocyanate group content (hereinafter abbreviated as " NCO% ") of the hot melt urethane prepolymer (i) obtained by the above method is preferably in the range of 1.7 to 5 from the viewpoint of obtaining further excellent peel strength, And a range of 1.8 to 3 is more preferable. The NCO% of the hot-melt urethane prepolymer (i) is a value measured by a potentiometric titration method in accordance with JIS K 1603-1: 2007.

The moisture-curing polyurethane hot-melt resin composition used in the present invention contains the hot-melt urethane prepolymer as an essential component, but may contain other additives if necessary.

As the other additives, for example, weathering stabilizers, curing catalysts, tackifiers, plasticizers, fillers, dyes, pigments, fluorescent whitening agents, silane coupling agents, waxes, thermoplastic resins and the like can be used. These additives may be used singly or in combination of two or more. Among them, it is preferable to use a weathering stabilizer because further excellent weathering resistance can be obtained.

As the weather stabilizer, for example, a hindered amine compound (ii), a triazole compound (iii), a hindered phenol compound, a phosphorus compound and the like can be used. These weatherability stabilizers may be used alone or in combination of two or more. Of these, hindered amine compounds (ii) are preferably used, and hindered amine compounds (ii) and triazole compounds (iii) are more preferably used because more excellent weather resistance is obtained.

The hindered amine compound (ii) replenishes radicals generated by photodegradation, and examples thereof include sebacic acid bis (2,2,6,6-tetramethyl-4-piperidyl), sebacic acid bis (1,2,2,6,6-pentamethylpiperidin-4-yl), tetrakis (2,2,6,6-tetramethyl-4-piperidyl) Tetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, (mixed 2,2,6,6 -Tetramethyl-4-piperidyl / tridecyl) 1,2,3,4-butanetetracarboxylate, (mixed 1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl ) 1,2,3,4-butanetetracarboxylate, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] , 4-dione, and the like can be used. These compounds may be used alone or in combination of two or more.

The content of the hindered amine compound (ii) is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the hot melt urethane prepolymer (i) More preferably in the range of 0.1 to 3 parts by mass.

The triazole compound (iii) is capable of preventing discoloration and includes, for example, N, N-bis (2-ethylhexyl) - [(1,2,4-triazol-1-yl) methyl] amine; Benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl Phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl- (2'-hydroxy-3'-isobutyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5'-propylphenyl) -5-chlorobenzotriazole, 2- Triazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- [2'-hydroxy-5 '- (1,1,3,3-tetramethyl) phenyl] benzotriazole Benzotriazole compounds such as benzotriazole compounds. These triazole compounds may be used singly or in combination of two or more. Among them, it is preferable to use a benzotriazole compound from the viewpoint that even more excellent weather resistance can be obtained.

The content of the triazole compound (iii) is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 10 parts by mass, per 100 parts by mass of the hot melt urethane prepolymer (i) To 5 parts by mass is more preferable, and a range of 0.1 to 3 parts by mass is more preferable.

Next, the synthetic leather of the present invention will be described.

The synthetic leather of the present invention has a layer having excellent weather resistance formed by the moisture-curing polyurethane hot melt resin composition. Thereby, the layer is free from discoloration due to the deterioration of time due to sunlight or the like, and therefore, the use range of the split ladder, which is in particular in demand, can be widened as compared with the conventional range.

The split ladder includes a topsheet, an adhesive layer, and a skin layer, and the moisture-curing polyurethane hot-melt resin composition can be suitably used as an adhesive layer of a split ladder. Hereinafter, a method for producing a split ladder when the moisture-curing polyurethane hot melt resin composition is used for the adhesive layer will be described.

The above-mentioned topsheet may be any of those known in the art, and may be composed of natural leather such as cattle, horses, sheep, goats, deer, and kangaroo, and a layer in which the epidermis and the nipple layer are removed. It is preferable to use those obtained through a known tanning process, a tanning process, and a dyeing and finishing process. The thickness of the topsheet is appropriately determined depending on the intended use, but is, for example, in the range of 0.1 to 2 mm.

Examples of the method for forming the adhesive layer on the upper surface include a method of coating the moisture-curing polyurethane hot melt resin composition melted at 50 to 130 占 폚, for example, on the upper surface of the upper layer; A method of coating the moisture-curable polyurethane hot melt resin composition melted at 50 to 130 占 폚, for example, on a release paper, and then bonding the cured material layer to the topsheet; A method of coating the moisture-curable polyurethane hot melt resin composition melted at 50 to 130 占 폚, for example, on a skin layer formed on a release paper, and then bonding the cured layer to the upper skin .

In any of the above methods, a method using a roll coater, a knife coater, a spray coater, a gravure coater, a comma coater, a T-die coater, an applicator, or the like may be used as a method of coating the moisture-curing polyurethane hot- .

After coating the moisture-curing polyurethane hot melt resin composition, it can be cured by a known method.

The thickness of the cured layer (adhesive layer) of the moisture-curing urethane hot-melt resin composition is, for example, in the range of 5 to 200 占 퐉.

As the resin for forming the skin layer, known resins can be used, and for example, a solvent-based urethane resin, a water-based urethane resin, a solvent-based urethane resin, a solvent-based acrylic resin, and an aqueous acrylic resin can be used. These resins may be used singly or in combination of two or more kinds.

Examples of the heating method for removing the solvent in the resin for forming the skin layer include a method of performing the treatment at a temperature of 50 to 120 DEG C for 2 to 20 minutes.

The thickness of the skin layer is, for example, in the range of 5 to 100 mu m.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples.

[Example 1]

A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with an alicyclic polyester polyol (neopentyl glycol, 3-methyl-1,5-pentanediol and cyclohexanedicarboxylic acid , 40 parts by mass of polyoxyethylene (number average molecular weight: 1,000, hereinafter abbreviated as "alicyclic PEs1") and 60 parts by mass of polyoxypropylene glycol (number average molecular weight: 2,000, hereinafter abbreviated as "PPG2000" And dehydrated under reduced pressure at 100 캜 until the water content in the flask became 0.05% by mass or less.

Then, 26.5 parts by mass of 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as " MDI ") melted at 70 DEG C was added to the inside of the flask at 90 DEG C, and the isocyanate group content Gt; 110 C < / RTI > for about 3 hours to give NCO%; 2.4 mass% of hot melt urethane prepolymer was obtained.

Subsequently, a solvent-based urethane resin ("Chrisborn TF-50P-C" manufactured by DIC Co.) was coated on the release paper so that the film thickness after drying was 30 탆 and dried at 120 캜 for 10 minutes to obtain a skin layer. Subsequently, the hot-melt urethane prepolymer melted at 110 DEG C for 1 hour was coated on the skin layer to a thickness of 30 mu m using a comma coater. Then, the epidermis and the teat layer were removed from the bovine natural leather, And then left for 3 days under conditions of a temperature of 23 캜 and a relative humidity of 65% to obtain a split ladder.

[Examples 2 to 4 and Comparative Examples 1 to 2]

A split ladder was obtained in the same manner as in Example 1 except that the hot melt urethane prepolymer was obtained in the kind and the blending amount of the polyol (A) and the polyisocyanate (B) shown in Table 1.

[Example 5]

40 parts by mass of alicyclic PEs1 and 60 parts by mass of PPG2000 were put into a four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, mixed and heated under reduced pressure at 100 deg. %. ≪ / RTI >

Subsequently, the inside of the flask was cooled to 90 DEG C, 26.5 parts by mass of MDI melted at 70 DEG C was added, and the mixture was allowed to react at 110 DEG C for about 3 hours until the isocyanate group content became constant under a nitrogen atmosphere. 2.4 mass% of hot melt urethane prepolymer was obtained. To this, abbreviated as sebacic acid bis (1,2,2,6,6-pentamethylpiperidin-4-yl) ("Sanol LS-765" manufactured by Sankyo Co., Ltd., hereinafter referred to as "LS-765" ) Was mixed in an amount of 0.5% by mass to obtain a moisture-curable polyurethane hot melt resin composition.

Subsequently, a solvent-based urethane resin ("Chrisborn TF-50P-C" manufactured by DIC Co.) was coated on the release paper so that the film thickness after drying was 30 탆 and dried at 120 캜 for 10 minutes to obtain a skin layer. Subsequently, the moisture-curing polyurethane hot melt resin composition melted at 110 DEG C for 1 hour was coated on the skin layer to a thickness of 30 mu m using a comma coater, and then the epidermis and the teat layer were removed from the bovine natural leather, And then left for 3 days under conditions of a temperature of 23 캜 and a relative humidity of 65% to obtain a split leather.

[Example 6]

In the moisture-curing polyurethane hot-melt resin composition, 0.5 mass% of a benzotriazole compound (Tinuvin (registered trademark) 234, hereinafter abbreviated as "T234", hereinafter referred to as BASF) was further blended with the hot melt urethane prepolymer , A moisture-curing polyurethane hot-melt resin composition was obtained in the same manner as in Example 1, and a split leather was produced.

[Examples 7 to 9]

Except that a moisture-curing polyurethane hot melt resin composition was obtained in the kind and amount of the polyol (A), the polyisocyanate (B), the hindered amine compound (ii) and the triazole compound (iii) as shown in Table 2, Split leather was obtained in the same manner as in Example 6.

[Method for measuring number average molecular weight]

The number average molecular weights of the polyols and the like used in Examples and Comparative Examples indicate values measured by gel permeation chromatography (GPC) under the following conditions.

Measuring apparatus: High-speed GPC apparatus ("HLC-8220GPC" manufactured by Tosoh Corporation)

Column: The following columns of the product of Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8mm ID × 30cm) × 1

"TSKgel G4000" (7.8mm ID × 30cm) × 1

"TSKgel G3000" (7.8mm ID × 30cm) × 1

"TSKgel G2000" (7.8mm ID × 30cm) × 1

Detector: RI (differential refractometer)

Column temperature: 40 DEG C

Eluent: tetrahydrofuran (THF)

Flow rate: 1.0 mL / min

Injection amount: 100 mu L (tetrahydrofuran solution with 0.4 mass% of sample concentration)

Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)

Quot; TSKgel standard polystyrene A-500 " made by Tosoh Corporation

Quot; TSKgel standard polystyrene A-1000 " made by Tosoh Corporation

Quot; TSKgel standard polystyrene A-2500 " made by Tosoh Corporation

Quot; TSKgel Standard Polystyrene A-5000 " made by Tosoh Corporation

Quot; TSKgel standard polystyrene F-1 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-2 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-4 " made by Tosoh Corporation

Quot; TSKgel standard polystyrene F-10 " manufactured by TOSOH CORPORATION

Quot; TSKgel standard polystyrene F-20 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-40 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-80 " manufactured by Tosoh Corporation

Quot; TSKgel standard polystyrene F-128 " made by Tosoh Corporation

Quot; TSKgel standard polystyrene F-288 " manufactured by TOSOH CORPORATION

Quot; TSKgel standard polystyrene F-550 " made by Tosoh Corporation

[Evaluation method of weather resistance]

The urethane prepolymer obtained in Examples and Comparative Examples was melted at 110 캜 for 1 hour and then coated on a release paper placed on a hot plate preheated to 110 캜 at a thickness of 100 탆. This coated article was stored at 25 캜 and 50% humidity for 24 hours to obtain a film. Using this film, a UV irradiation test was carried out using a QUV accelerated weathering tester "QUV / basic" equipped with a UVA-340 bulb (UV irradiation amount: 0.78 W / m ² , temperature: 45 ° C.) , The evaluation of the weather resistance was evaluated as follows.

"4"; ΔE is 10 or less.

"3"; ΔE is more than 10 and not more than 13.

"2"; ΔE is more than 13 and not more than 15.

"One"; ΔE exceeds 15.

[Evaluation method of adhesive strength]

The urethane prepolymer obtained in Examples and Comparative Examples was melted at 120 占 폚 for 1 hour and then coated on a PET film placed on a hot plate preheated to 110 占 폚 in a thickness of 100 占 퐉. Immediately after coating, the PET film was removed from the hot plate and another PET film was immediately bonded to the hand roller. After the bonding, the test piece was cut to a width of 1 inch and the peel strength between the PETs after 1 minute of bonding was measured using a digital force gauge ("DS2-220N" manufactured by Imadate Kabushiki Kaisha) Respectively.

"T"; 5N / inch or more

"F"; Less than 5 N / inch

[Measuring method of low viscosity]

The urethane prepolymer obtained in Examples and Comparative Examples was melted at 120 ° C for 1 hour and then 1 ml was sampled and the melt viscosity was measured with a cone plate viscometer (40P cone, rotor rotation number: 50 rpm) and evaluated as follows.

"T"; Less than 4,000 mPa · s

"F"; 4,000 mPa · s or more

Abbreviations in Table 1 are as follows.

&Quot; alicyclic PEs2 ": a product obtained by reacting 1,4-cyclohexanedimethanol and adipic acid, number average molecular weight; 1,000

&Quot; aromatic PEs "; Diethylene glycol, neopentyl glycol and terephthalic anhydride, number average molecular weight; 1,000

"Aliphatic PEs"; 1,4-butanediol and adipic acid, number average molecular weight; 1,000)

It has been found that the synthetic leather of the present invention has a cured layer of a moisture-curing polyurethane hot melt resin composition excellent in weatherability, adhesive strength and low viscosity.

On the other hand, in Comparative Example 1, an aromatic polyester polyol was used in place of the alicyclic polyester polyol (a1), and the adhesion strength was excellent, but the weather resistance and the low viscosity were poor.

In Comparative Example 2, an aliphatic polyester polyol was used in place of the alicyclic polyester polyol (a1), and the bonding strength was poor.

Claims (8)

Having a layer formed of a moisture-curing polyurethane hot melt resin composition containing a polyol (A) containing an alicyclic polyester polyol (a1) and a hot melt urethane prepolymer (i) which is a reaction product of a polyisocyanate (B) Features a synthetic leather. The synthetic leather according to claim 1, wherein the polyol (A) further comprises polyoxypropylene glycol (a2). The synthetic leather according to claim 1 or 2, further comprising a hindered amine compound (ii). The synthetic leather according to claim 3, wherein the content of the hindered amine compound (ii) is in the range of 0.01 to 10 parts by mass based on 100 parts by mass of the hot melt urethane prepolymer (i). The synthetic leather according to claim 3 or 4, further comprising a triazole compound (iii). The synthetic leather according to claim 5, wherein the content of the triazole compound (iii) is in the range of 0.01 to 10 parts by mass based on 100 parts by mass of the hot melt urethane prepolymer (i). The synthetic leather according to claim 5 or 6, wherein the triazole compound (iii) is a benzotriazole compound. 8. Synthetic leather according to any one of claims 1 to 7, which is split leather.