JP7190806B2 - Synthetic leather - Google Patents

Description

The present invention relates to synthetic leather.

Since urethane resins have excellent mechanical strength, they are widely used in various fields such as films, adhesives, automotive interior materials, abrasives, home appliance parts, packaging materials, and printing rolls. Among them, in recent years, many studies have been made on synthetic leather applications because of the flexibility of polyurethane resins, which provides an excellent texture (see, for example, Patent Document 1).

JP 2007-100289 A

Polyurethane resins used in the production of synthetic leathers (including artificial leathers) have recently been required to have high durability, especially for automobile interior materials. In particular, vehicle interior materials are required to have chemical resistance in addition to conventional durability (heat resistance, weather resistance, hydrolysis resistance, etc.). However, conventionally known synthetic leathers sometimes do not have satisfactory chemical resistance.

The problem to be solved by the present invention is to provide a urethane resin composition capable of forming a synthetic leather having excellent chemical resistance.

As a result of intensive research aimed at solving the above problems, the present inventors found that the above problems can be solved by using a specific amount of a polycarbonate polyol using a specific hydroxy compound as a raw material as the polyol component of the urethane resin. I completed the present invention.

That is, the present invention relates to a synthetic leather having a base fabric (i), an adhesive layer (ii) and/or an intermediate layer (iii), and a skin layer (iv) in this order, and the intermediate layer ( iii) and/or the skin layer (iv) is formed from a composition containing a polyurethane resin that is a reaction product of a polyol (A), a polyisocyanate (B), and a chain extender (C). , The polyol (A) is characterized by containing a polycarbonate polyol (a1) having a unit derived from a hydroxy compound (d1) represented by the general formula (1).

［一般式（１）中、ｎは、１以上７以下の整数を表す。］

[In general formula (1), n represents an integer of 1 or more and 7 or less. ]

Since the synthetic leather of the present invention has excellent chemical resistance, it can be suitably used for applications such as automobile parts, home appliance parts, packaging materials, and leather-like sheets.

The synthetic leather of the present invention has a base fabric (i), an adhesive layer (ii), an intermediate layer (iii) and / or a skin layer (iv) in this order, and the intermediate layer (iii) And/or the skin layer (iv) is formed from a composition containing a polyurethane resin which is a reaction product of a polyol (A), a polyisocyanate (B) and a chain extender (C).

The polyol (A) is a compound having two or more hydroxyl groups and includes a polycarbonate polyol (a1) having units derived from the hydroxyl compound (D). The content of the polycarbonate polyol (a1) is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass in 100% by mass of the polyol (A). 99% by mass or less, more preferably 99% by mass or less.

The hydroxy compound (D) is a compound having two or more hydroxy groups. As the hydroxy compound (D), one or more can be used, and examples thereof include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene. diols such as glycol, polyethylene glycol and polypropylene glycol; and polyols such as trimethylolmethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol and dipentaerythritol.

In particular, the hydroxy compound (D) includes a hydroxy compound (d1) represented by general formula (1). The polycarbonate polyol (a1) contains units (—O—(—(CH ₂ ) ₂ O—) _n —) derived from the compound (d1) represented by the general formula (1), thereby improving chemical resistance. becomes good.

［一般式（１）中、ｎは、１以上７以下の整数を表す。］

[In general formula (1), n represents an integer of 1 or more and 7 or less. ]

As the hydroxy compound (d1), one or more can be used. Examples include ethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol (preferably molecular weight 160 to 360, more preferably molecular weight 190 to 330). etc. Among them, diethylene glycol and triethylene glycol are preferable from the viewpoint of further excellent chemical resistance.

The content of the hydroxy compound (d1) is preferably 40% by mass or more, more preferably 60% by mass or more, preferably 100% by mass or less, more preferably 99% by mass, based on 100% by mass of the hydroxy compound (D). % or less. When the content of the hydroxy compound (d1) is within the above range, the chemical resistance is good.

Among them, the hydroxy compound (d1) preferably contains diethylene glycol. In this case, the diethylene glycol content is preferably 30% by mass or more, more preferably 40% by mass or more, based on 100% by mass of the compound (d1). , preferably 100% by mass or less, more preferably 99% by mass or less. When the diethylene glycol content is within the above range, the chemical resistance is even better.

When the hydroxy compound (D) contains a hydroxy compound other than the hydroxy compound (d1), the other hydroxy compound is preferably butanediol or trimethylolpropane from the viewpoint of maintaining chemical resistance.

As the polycarbonate polyol (a1), those obtained by transesterifying a hydroxy compound (D) containing a hydroxy compound (d1) and a carbonate compound (E) can be used. Titanium compounds such as titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate may coexist as polycarbonate formation or transesterification catalysts during the reaction. A metal catalyst, an acid catalyst, or the like may be used as the polycarbonate-forming or esterification catalyst.
The amount of the polycarbonate formation or transesterification catalyst is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, relative to a total of 100 parts by mass of the hydroxy compound (D) and the carbonate compound (E). , preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.3 parts by mass or less.
As the polycarbonate polyol (a1), one obtained by a known production method such as one obtained by reacting the hydroxy compound (D) with phosgene can be used.

As the carbonate compound (E), one type or two or more types can be used, and examples thereof include aliphatic carbonates and aromatic ring-containing carbonates. The aliphatic carbonates include saturated aliphatic carbonates such as dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, di-n-butyl carbonate, diisobutyl carbonate, ethyl-n-butyl carbonate, ethyl isobutyl carbonate; ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,3-pentylene carbonate, 1, and unsaturated aliphatic carbonates such as 4-pentylene carbonate, 1,5-pentylene carbonate, 2,3-pentylene carbonate and 2,4-pentylene carbonate. Examples of aromatic ring-containing carbonates include diphenyl carbonate and dibenzyl carbonate. Among them, saturated aliphatic carbonates such as dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate;

The number average molecular weight of the polycarbonate polyol (a1) is preferably 500 or more, more preferably 1,000 or more, and preferably 8,000 or less, more preferably 6,000 or less.
In addition, in this specification, a number average molecular weight and a weight average molecular weight shall represent the value measured by the gel permeation chromatography (GPC) method.

The hydroxyl value of the polycarbonate polyol is preferably 10 mgKOH/g or more, more preferably 20 mgKOH/g or more, and preferably 210 mgKOH/g or less, more preferably 120 mgKOH/g or less. The hydroxyl value is defined as mg of potassium hydroxide corresponding to hydroxyl groups in 1 g of polycarbonate polyol, and represents a value measured according to JISK1557-1:2007.

The polycarbonate polyol (a1) can be produced by reacting the hydroxy compound (D) and the carbonate compound (E) in the presence of an optional polycarbonate formation or transesterification catalyst.

The polyol (A) may contain other polyol (a2) in addition to the polycarbonate polyol (a1). Examples of the other polyol (a2) include polyester polyols, polyether polyols, and polycarbonate polyols other than the polycarbonate polyol (a1).

As the polyester polyol, one or more kinds can be used. For example, a polyester polyol obtained by reacting a low-molecular-weight polyol with a polycarboxylic acid; a ring-opening ester compound such as ε-caprolactone; polyester polyols obtained by polymerization reaction; and polyester polyols obtained by copolymerizing these.

As the low-molecular-weight polyol, one or two or more can be used. Examples include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1, Aliphatic polyols having a molecular weight of 50 to 300, such as 3-butanediol; polyols having an alicyclic structure, such as cyclohexanedimethanol; and polyols having an aromatic structure, such as bisphenol A and bisphenol F.

As the polycarboxylic acid, one or more can be used. For example, aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid; terephthalic acid, isophthalic acid, phthalic acid, aromatic polycarboxylic acids such as naphthalene dicarboxylic acid; and anhydrides or esters thereof.

As the polyether polyol, one or two or more can be used. For example, a compound obtained by addition polymerization of an alkylene oxide using one or two or more compounds having two or more active hydrogen atoms as an initiator. etc. Examples of the compound having two or more active hydrogen atoms include propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, di glycerin, trimethylolethane, trimethylolpropane, water, hexanetriol and the like. Examples of the alkylene oxide include propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran and the like.

Examples of polycarbonate polyols other than the polycarbonate polyol (a1) include polycarbonate polyol compounds having units derived from the other hydroxy compound and not having units derived from the hydroxy compound (d1).

As the polyisocyanate (B), it is preferable to use an aliphatic or alicyclic polyisocyanate. As the aliphatic or alicyclic polyisocyanate, one or two or more can be used. - cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate and the like can be used. Among these, it is preferable to use isophorone diisocyanate and/or dicyclohexylmethane diisocyanate from the viewpoint of obtaining even better chemical resistance.

For the polyisocyanate (B), for the purpose of improving the texture of the synthetic leather, an aromatic polyisocyanate is used in combination with an aliphatic or alicyclic polyisocyanate within a range that does not impair the effects of the present invention. good too.

Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl- 2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate , 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl -3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1 ,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2′-diisocyanate, biphenyl-2, 4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4 - Diisocyanates and the like can be used. These aromatic polyisocyanates may be used alone or in combination of two or more.

The content of the aliphatic or alicyclic polyisocyanate is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more in the polyisocyanate (B).

As the chain extender (C), one or two or more can be used, and examples thereof include a chain extender (c1) having an amino group, a chain extender (c2) having a hydroxyl group, and the like. Among them, it is preferable to contain a chain extender (c1) having an amino group from the viewpoint of even better chemical resistance.

As the chain extender (c1) having an amino group, one or more can be used, and examples thereof include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methyl piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine , aminoethylethanolamine, hydrazine, diethylenetriamine, triethylenetetramine and the like. Among them, isophoronediamine and/or 4,4'-dicyclohexylmethanediamine are preferred, and 4,4'-dicyclohexylmethanediamine is more preferred, from the viewpoint of even better chemical resistance.
The content of the chain extender (c1) having an amino group is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more in 100% by mass of the chain extender (C). is.

As the chain extender (c2) having a hydroxyl group, one or more can be used, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3 Aliphatic polyol compounds such as -butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methylene glycol, glycerin, sorbitol; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4 ,4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, aromatic polyol compounds such as hydroquinone; and water.

Also, known reaction modifiers or polymerization degree modifiers can be used, and examples thereof include monofunctional monools such as butanol and monofunctional monoamines such as diethylamine and dibutylamine.

The molar ratio (NCO/OH+NH) between the sum of the hydroxyl groups and/or amino groups possessed by the polyol (A) and the chain extender (C) and the isocyanate groups possessed by the polyisocyanate (B) is preferably 0. It is 95 or more and 1.05 or less. After the urethane resin (A) is produced, an alcohol solvent such as methanol or 1,3-butanediol may be added for the purpose of deactivating the remaining isocyanate groups.

The weight-average molecular weight of the polyurethane resin is preferably 5,000 or more, more preferably 10,000 or more, and preferably 500,000 or less, more preferably, from the viewpoint of even better chemical resistance and film-forming properties. 300,000 or less.

The content of urethane bonds in the polyurethane resin is preferably 500 μmol/g or more, more preferably 700 μmol/g or more, and preferably 1200 μmol/g or less, more preferably 1000 μmol/g or less. The urethane bond content represents the urethane bond content relative to the total mass of the polyol (A), the polyisocyanate (B) and the chain extender (C).

The content of the polyurethane resin is preferably 20% by mass or more, more preferably 30% by mass or more in 100% by mass of the composition containing the polyurethane resin (hereinafter sometimes referred to as "polyurethane resin composition"). Yes, preferably 60% by mass or less, more preferably 50% by mass or less.

The polyurethane resin can be produced, for example, by mixing the polyol (A) and an optional organic solvent, and then mixing the polyisocyanate (B) and the chain extender (C). A catalyst may coexist during the reaction. As the organic solvent, the same organic solvent as the organic solvent that may be contained in the polyurethane resin composition, which will be described later, can be used. As the catalyst, one or more can be used, and examples thereof include compounds such as triethylamine, tributylamine, dibutyltin dilaurate, stannous octoate, acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid. . The reaction temperature is preferably 50° C. or more and 100° C. or less, and the reaction time is preferably 3 hours or more and 10 hours or less. After the reaction, an alcohol solvent such as methanol or 1,3-butanediol may be added for the purpose of deactivating the remaining isocyanate groups.

The polyurethane resin composition preferably further contains an organic solvent. As the organic solvent, one or more can be used, for example, amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone; ketone solvents such as n-propyl ketone, acetone and methyl isobutyl ketone; ester solvents such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, isopropyl acetate, isobutyl acetate, isobutyl acetate and sec-butyl acetate; Examples include alcohol solvents such as ethanol, isopropyl alcohol, and butanol. Among them, amide solvents and alcohol solvents are preferred. When an amide solvent and an alcohol solvent are contained, the content ratio of the amide solvent to the alcohol solvent (amide solvent/alcohol solvent) is preferably 5 or more, more preferably 10 or more, and still more preferably 15 or more on a mass basis. , preferably 50 or less, more preferably 30 or less, still more preferably 20 or less.

The polyurethane resin composition may or may not contain a cross-linking agent such as a polyisocyanate cross-linking agent or an epoxy cross-linking agent.

The composition containing the polyurethane resin may further contain one or more additives such as plasticizers, fillers, pigments, dyes, stabilizers and flame retardants, if necessary.

The intermediate layer (iii) of the synthetic leather of the present invention can be formed, for example, by thermoforming the polyurethane resin composition. Heat molding is preferably carried out in two stages, and after primary curing at 60° C. or higher and 120° C. or lower, secondary curing is preferably performed at 90° C. or higher and 130° C. or lower. The primary curing time is preferably 1 minute or more and 20 minutes or less, and the secondary curing time is preferably 1 minute or more and 20 minutes or less. After heat curing, it is preferable that the urethanization reaction of the polyurethane resin contained in the polyurethane resin composition is simple.

In the synthetic leather of the present invention, the fibers constituting the base fabric (i) include, for example, polyester fiber, polyethylene fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, rayon fiber, polylactic acid fiber, cotton, hemp. , silk, wool, glass fiber, carbon fiber, and blended fibers thereof, etc., and the form of the base fabric (i) may be any of non-woven fabric, woven fabric and knitted fabric.

The adhesive layer (ii) can be formed using a resin composition containing, for example, a solvent-based urethane resin, a water-based urethane resin, a non-solvent-based urethane resin, a silicone resin, a polypropylene resin, a polyester resin, or the like.

The skin layer (iv) can be formed using a resin composition containing, for example, a solvent-based urethane resin, a water-based urethane resin, a non-solvent-based urethane resin, a silicone resin, a polypropylene resin, a polyester resin, or the like.

The synthetic leather of the present invention is produced by, for example, forming a skin layer (iv) on a release-treated substrate, and then coating the polyurethane resin composition on the skin layer (iv), An intermediate layer (iii) is obtained by drying, an adhesive layer (ii) is then formed on the intermediate layer (iii), and the adhesive layer (ii) and the base fabric (i) are laminated together. be able to.

Examples of the coating method of the resin composition when forming the layers (ii) to (iv) include a method using a gravure coater, knife coater, pipe coater, comma coater, roll coater, knife coater, applicator, and the like. is mentioned.

After coating the resin composition, the resin composition can be dried by holding for 1 to 60 minutes, for example, using a dryer adjusted to 80 to 120°C.

The film thickness of the layers (ii) to (iv) after drying is appropriately determined depending on the application, but is preferably in the range of 0.001 to 10 mm, for example.

A surface treatment layer (v) may be provided on the skin layer (iv), if necessary.

The synthetic leather of the present invention has good chemical resistance, and is publicly used for films, adhesives, automotive interior materials, abrasives, home appliance parts, packaging materials, and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

In the examples, the number average molecular weight and weight average molecular weight were measured by gel permeation chromatography (GPC method) under the following conditions.
Measuring device: high-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.
"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 Book "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was created using the following standard polystyrene.

(standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

(Synthesis Example 1: Synthesis of Polycarbonate Polyol (1))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 100 parts by mass of diethylene glycol and 193 parts by mass of diphenyl carbonate. C. for 5 hours and then under reduced pressure for 10 hours to obtain Polycarbonate Polyol (1). The hydroxyl group value of this polycarbonate polyol (1) was 32 mgKOH/g.

(Synthesis Example 2: Synthesis of Polycarbonate Polyol (2))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 50 parts by mass of diethylene glycol, 50 parts by mass of triethylene glycol and 152 parts by mass of diphenyl carbonate, and 0.0 part of tetraisopropyl titanate was added as a catalyst. 01% by weight was added, reacted at 200° C. for 5 hours, and then reacted under reduced pressure conditions for 10 hours to obtain Polycarbonate Polyol (2). The hydroxyl group value of this polycarbonate polyol (2) was 55 mgKOH/g.

(Synthesis Example 3: Synthesis of Polycarbonate Polyol (3))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 70 parts by weight of diethylene glycol, 30 parts by weight of polyethylene glycol ("PEG#200" manufactured by NOF Corporation) and 153 parts by weight of diphenyl carbonate. was charged, 0.01% by weight of tetraisopropyl titanate was added as a catalyst, reacted at 200° C. for 5 hours, and then reacted under reduced pressure conditions for 10 hours to obtain polycarbonate polyol (3). The hydroxyl group value of this polycarbonate polyol (3) was 57 mgKOH/g.

(Synthesis Example 4: Synthesis of Polycarbonate Polyol (4))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 80 parts by weight of diethylene glycol, 20 parts by weight of polyethylene glycol ("PEG#400" manufactured by NOF Corporation) and 152 parts by weight of diphenyl carbonate. was charged, 0.01% by weight of tetraisopropyl titanate was added as a catalyst, reacted at 200° C. for 5 hours, and then reacted under reduced pressure conditions for 10 hours to obtain polycarbonate polyol (4). The hydroxyl group value of this polycarbonate polyol (4) was 56 mgKOH/g.

(Synthesis Example 5: Synthesis of Polycarbonate Polyol (5))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 40 parts by mass of diethylene glycol, 60 parts by mass of 1,4-butanediol and 130 parts by mass of diethyl carbonate, and tetraisopropyl titanate as a catalyst. was added in an amount of 0.01% by weight, reacted at 120° C. for 10 hours, reacted at 190° C. for 2 hours, and then reacted under reduced pressure for 10 hours to obtain Polycarbonate Polyol (5). The hydroxyl group value of this polycarbonate polyol (5) was 37 mgKOH/g.

(Synthesis Example 6: Synthesis of Polycarbonate Polyol (6))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 20 parts by mass of polyethylene glycol ("PEG#400" manufactured by NOF Corporation) and 80 parts by mass of 1,4-butanediol. 117 parts by mass of diethyl carbonate was charged, 0.01% by weight of tetraisopropyl titanate was added as a catalyst, reacted at 120° C. for 10 hours, then reacted at 190° C. for 2 hours, and then reacted under reduced pressure for 10 hours to obtain polycarbonate. A polyol (6) was obtained. The hydroxyl group value of this polycarbonate polyol (6) was 33 mgKOH/g.

[Synthesis Example 7] Synthesis of polyurethane resin (X-1) for intermediate layer 75 parts by mass of polycarbonate polyol (1) and 25 parts by mass of polycarbonate polyol (T4691) were added to a reactor equipped with a stirrer, a reflux tube, and a thermometer. , and dehydration was performed at 120 to 130° C. under a reduced pressure of 0.095 MPa. After that, the mixture is cooled to 50° C., and 124 parts by mass of N,N-dimethylformamide (hereinafter abbreviated as “DMF”), 26 parts by mass of isophorone diisocyanate (hereinafter abbreviated as “IPDI”), and octylic acid. 0.05 part by mass of stannous was added and reacted at 75° C. to obtain an organic solvent solution of a urethane prepolymer having an isocyanate group. Next, add 186 parts by mass of DMF, cool to 35° C., add 7 parts by mass of 4,4′-methylenebis(cyclohexylamine) (hereinafter abbreviated as “H12MDA”), and mix and stir. , chain extended the polyurethane resin. Next, 0.4 part by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-1) composition.

[Synthesis Example 8] Synthesis of polyurethane resin (X-2) for intermediate layer 75 parts by mass of polycarbonate polyol (2) and 25 parts by mass of polycarbonate polyol (T4692) were added to a reactor equipped with a stirrer, a reflux tube, and a thermometer. , and dehydration was performed at 120 to 130° C. under a reduced pressure of 0.095 MPa. Then, it is cooled to 50°C, 126 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 189 parts by mass of DMF was added thereto, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-2) composition.

[Synthesis Example 9] Synthesis of Polyurethane Resin (X-3) for Intermediate Layer 90 parts by mass of polycarbonate polyol (3) and 10 parts by mass of polycarbonate polyol (T4692) were added to a reactor equipped with a stirrer, a reflux tube, and a thermometer. , and dehydration was performed at 120 to 130° C. under a reduced pressure of 0.095 MPa. After that, it is cooled to 50°C, 127 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 190 parts by mass of DMF was added to this, the mixture was cooled to 35° C., 8 parts by mass of H12MDA was added, and the mixture was stirred to extend the chain of the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-3) composition.

[Synthesis Example 10] Synthesis of Polyurethane Resin (X-4) for Intermediate Layer 90 parts by mass of polycarbonate polyol (4) and 10 parts by mass of polycarbonate polyol (T4692) were added to a reactor equipped with a stirrer, a reflux tube, and a thermometer. , and dehydration was performed at 120 to 130° C. under a reduced pressure of 0.095 MPa. Then, it is cooled to 50°C, 126 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 189 parts by mass of DMF was added thereto, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-4) composition.

[Synthesis Example 11] Synthesis of polyurethane resin (X-5) for intermediate layer 75 parts by mass of polycarbonate polyol (5) and 25 parts by mass of polycarbonate polyol (T4691) were added to a reactor equipped with a stirrer, a reflux tube, and a thermometer. , and dehydration was performed at 120 to 130° C. under a reduced pressure of 0.095 MPa. Then, it is cooled to 50°C, 126 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 189 parts by mass of DMF was added thereto, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-5) composition.

[Synthesis Example 12] Synthesis of Polyurethane Resin (X-6) for Intermediate Layer 50 parts by mass of polycarbonate polyol (1), 20 parts by mass of polycarbonate polyol (T4691) and polycarbonate were placed in a reactor equipped with a stirrer, a reflux tube, and a thermometer. 30 parts by mass of polyol (T4692) was added, the pressure was reduced to 0.095 MPa, and dehydration was carried out at 120 to 130°C. Then, it is cooled to 50°C, 126 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 189 parts by mass of DMF was added thereto, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-6) composition.

[Synthesis Example 13] Synthesis of Polyurethane Resin (X-7) for Intermediate Layer 30 parts by mass of polycarbonate polyol (1), 14 parts by mass of polycarbonate polyol (T4691) and polycarbonate were placed in a reactor equipped with a stirrer, a reflux tube and a thermometer. 56 parts by mass of polyol (T4692) was added, the pressure was reduced to 0.095 MPa, and dehydration was carried out at 120 to 130°C. After that, it is cooled to 50°C, 127 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 190 parts by mass of DMF was added to this, the mixture was cooled to 35° C., 8 parts by mass of H12MDA was added, and the mixture was stirred to extend the chain of the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X-7) composition.

[Comparative Synthesis Example 1] Synthesis of Polyurethane Resin (X'-1) for Intermediate Layer 75 parts by mass of polycarbonate polyol (6) and 25 parts by mass of polycarbonate polyol (T4691) were placed in a reactor equipped with a stirrer, a reflux tube, and a thermometer. was added, the pressure was reduced to 0.095 MPa, and dehydration was carried out at 120 to 130°C. After that, it is cooled to 50°C, and 125 parts by mass of DMF, 26 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 186 parts by mass of DMF was added to this, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X'-1) composition.

[Comparative Synthesis Example 2] Synthesis of polyurethane resin (X'-2) for intermediate layer 100 parts by mass of polycarbonate polyol (T4692) was added to a reactor equipped with a stirrer, a reflux tube, and a thermometer, and the pressure was reduced to 0.095 MPa. Dehydration was carried out at 120-130°C. Then, it is cooled to 50°C, 126 parts by mass of DMF, 28 parts by mass of IPDI, and 0.05 part by mass of stannous octoate are added and reacted at 75°C to form a urethane prepolymer having an isocyanate group. An organic solvent solution was obtained. Next, 189 parts by mass of DMF was added thereto, the mixture was cooled to 35° C., 7 parts by mass of H12MDA was added, and the mixture was stirred to chain extend the polyurethane resin. Next, 0.4 parts by mass of N,N-dibutylamine was added and mixed to obtain a polyurethane resin (X'-2) composition.

[Preparation Example 1] Preparation of compound liquid for skin layer 100 parts by mass of solvent-based urethane resin ("Crisbon NY-331" manufactured by DIC Corporation) and 20 parts by mass of black pigment ("DILAC L-1770S" manufactured by DIC Corporation) were mechanically added. The mixture was stirred at 2,000 rpm for 2 minutes with a mixer, and then defoamed using a vacuum deaerator to obtain a blended liquid for the skin layer.

[Preparation Example 2] Preparation of Adhesive Layer Formulation Solution A polycarbonate diol (number average molecular weight: 2,000, "PC- 1”) was added, and dehydration was performed at 120 to 130° C. under reduced pressure to 0.095 MPa. Thereafter, the mixture is cooled to 50° C., and 340 parts by mass of N,N-dimethylformamide (hereinafter abbreviated as “DMF”), 73 parts by mass of isophorone diisocyanate (hereinafter abbreviated as “IPDI”), and octylic acid. 0.2 parts by mass of stannous was added and reacted at 75° C. to obtain an organic solvent solution of a urethane prepolymer having an isocyanate group. Next, 636 parts by mass of DMF was added thereto, cooled to 40° C., 10 parts by mass of isophoronediamine (hereinafter abbreviated as “IPDA”) was added, and the mixture was stirred to extend the chain of the polyurethane resin. . Then, 6.0 parts by mass of monoethanolamine was added and mixed to obtain a polyurethane resin (X-1-1) composition. To this polyurethane resin (X-1-1) composition, 10% by mass of an adduct of hexamethylene diisocyanate (hereinafter abbreviated as "HDI adduct") immediately before coating to form an adhesive layer. were blended to obtain a polyurethane resin composition.

[Example 1]
After applying the formulation for the skin layer obtained in Preparation Example 1 on a textured release paper (“ARX-120” manufactured by Asahi Roll Co., Ltd.) with a knife coater (coating thickness: 150 μm), a hot air dryer is applied. The skin layer was obtained by applying at 70° C. for 2 minutes and then drying at 120° C. for 2 minutes. Furthermore, on this skin layer, the polyurethane resin compositions obtained in Synthesis Examples and Comparative Synthesis Examples were applied using a knife coater (coating thickness: 150 μm), and then dried for 2 minutes at 70° C. using a hot air dryer. minutes, then 120° C. for 2 minutes. Next, after applying the adhesive layer formulation liquid obtained in Preparation Example 2 with a knife coater (coating thickness: 150 μm), use a hot air dryer to dry at 70° C. for 2 minutes, then at 120° C. for 2 minutes. An adhesive layer was thus obtained. Finally, a nonwoven fabric base material (basis weight: 300 g/m ² ) is superimposed on the adhesive layer and thermocompression bonded with a hot roll press (roll temperature: 130°C, press linear pressure: 8 MPa/m ² , feed rate: 1 m/min), Got synthetic leather.
Next, the polyurethane resin compositions obtained in Synthesis Examples and Comparative Synthesis Examples were applied onto flat release paper (“EK-100D” manufactured by Lintec Corporation) using a knife coater (coating thickness: 150 μm). using a hot air dryer at 70° C. for 2 minutes and then at 120° C. for 2 minutes to obtain a dry film.

[Examples 2-7, Comparative Examples 1-2]
A synthetic leather and a dry film were obtained in the same manner as in Example 1, except that the polyurethane resin composition used for the intermediate layer (iii) was changed as shown in the table.

[Measurement method 1 for resistance to oleic acid]
Absorbent cotton moistened with oleic acid was placed on the synthetic leathers obtained in Examples and Comparative Examples, and allowed to stand at 23° C. for 24 hours, after which the surface shape was visually confirmed.

[Measurement method 2 for resistance to oleic acid]
The dry films obtained in Examples and Comparative Examples were cut into strips with a width of 5 mm and a length of 50 mm, and a tensile tester "Autograph AG-I" (manufactured by Shimadzu Corporation) was used to test at a temperature of 23 ° C. The 100% modulus (MPa) of the test piece was measured under the condition of a crosshead speed of 10 mm/sec in an atmosphere, and the measured value before the test oleic acid immersion was obtained. The chuck-to-chuck distance at this time was set to 40 mm.
Also, a test piece prepared in the same manner was immersed in oleic acid at room temperature at 23° C. for 24 hours, then taken out, and oleic acid adhering to the surface was lightly wiped off with a paper cloth. Thereafter, the 100% modulus value of the test piece was measured and used as the measured value after immersion in oleic acid. The value obtained by dividing this value by the measured value before immersion in oleic acid was defined as the retention rate of the 100% modulus value, and the resistance to oleic acid was evaluated as follows.
[criterion]
◎: No change in surface shape of synthetic leather and 100% modulus retention rate of 60% or more ○: No change in synthetic leather surface shape and 100% modulus retention rate of 50 to 60%
△: No change in surface shape of synthetic leather and 100% modulus retention rate of 40 to 50%
×: Change in surface shape of synthetic leather, or 100% modulus retention rate less than 40%

Tables 2 and 3 show the above evaluation results.

The synthetic leathers of Examples 1 to 7, which are the synthetic leathers of the present invention, had good chemical resistance.

On the other hand, the synthetic leathers of Comparative Examples 1 and 2 were formed using a polyol that does not contain a polycarbonate polyol (a1) having a unit derived from a hydroxy compound (d1) represented by the general formula (1). and was inferior in chemical resistance.

Claims (3)

A synthetic leather having a base fabric (i), an adhesive layer (ii), an intermediate layer (iii), and a skin layer (iv),
The intermediate layer (iii ) is formed from a composition containing a polyurethane resin that is a reaction product of a polyol (A), a polyisocyanate (B), and a chain extender (C),
The polyol (A) contains a polycarbonate polyol (a1) having units derived from the hydroxy compound (d1) represented by the general formula (1), and the hydroxy compound (d1) is diethylene glycol alone, or , consisting of diethylene glycol and triethylene glycol ,
The content of the polycarbonate polyol (a1) is 40% by mass or more in the polyol (A),
The polyol (A) further contains a polyol (a2) made of a polycarbonate polyol other than the polycarbonate polyol (a1),
The synthetic leather , wherein the skin layer (iv) is formed from a composition containing a solvent-based urethane resin .

[In general formula (1), n represents an integer of 1 or more and 7 or less. ] The synthetic leather according to claim 1 , wherein the polycarbonate polyol (a1) has a number average molecular weight of 500 or more and 8,000 or less. The synthetic leather according to claim 1 or 2 , wherein the content of the compound (d1) is 40% by mass or more in the hydroxy compound (D) that is the raw material of the polycarbonate polyol (a1).