JP7230366B2 - artificial leather or synthetic leather - Google Patents

Description

The present invention is an artificial leather that is excellent in rubbing and texturing properties, and can realize a texture and luxury feeling similar to natural leather, as well as excellent abrasion resistance, color transfer resistance (stain resistance), and chemical resistance. Relating to leather or synthetic leather.

BACKGROUND ART Artificial leather or synthetic leather has texture and durability comparable to or superior to natural leather, and is therefore widely used as fashion materials and interior materials. Artificial leather or synthetic leather is formed of a multilayer structure consisting of a base material made of non-woven fabric, woven or knitted fabric, a resin layer laminated or filled there, a porous resin film layer, an adhesive layer, a skin layer, etc. Polyurethane is generally used as the resin used for each layer.

Artificial leather or synthetic leather tends to have a texture more similar to natural leather, and is devised to impart aging and luxury unique to natural leather by applying natural leather-like crumpling processing.
Artificial leather or synthetic leather is required not only to have natural leather-like texture, but also to have durability such as abrasion resistance, chemical resistance, and color transfer resistance (antifouling property).

In order to satisfy these various required properties, it has been proposed that the polyurethane layer of the skin layer has a two-layer laminate structure (for example, Patent Documents 1 and 2). There is no product that exhibits fully satisfactory properties in terms of both property (antifouling property) and chemical resistance.

JP 2014-80713 A JP 2014-129622 A

The present invention is excellent in kneading and texturing, and can realize a texture and luxury feeling similar to natural leather, and is also excellent in wear resistance, color transfer resistance (stain resistance), and chemical resistance. An object of the present invention is to provide artificial leather or synthetic leather.

As a result of intensive studies in order to solve the above problems, the present inventors have found that the polyurethane layer constituting the skin layer of artificial leather or synthetic leather has a two-layer laminated structure of polyurethanes with 100% different moduli, and polyurethane on the surface side. The present inventors have found that the above problems can be solved by introducing a cyclic structure into the polyurethane constituting the layer.

The present invention has been achieved based on such findings, and the gist thereof is as follows.

[1] An artificial leather or synthetic leather having a first polyurethane layer serving as a surface side and a second polyurethane layer serving as a lower layer of the first polyurethane layer, wherein the first polyurethane layer comprises the following Polyurethane A having a 100% modulus measured by a tensile test of 20 MPa or more and 100 MPa or less is included, and the second polyurethane layer has a 100% modulus of 0.1 MPa or more and 40 MPa or less measured by the following tensile test. a polyurethane B, wherein the ratio of the 100% modulus of the polyurethane A to the 100% modulus of the polyurethane B is 1 or more and 1000 or less, and the polyurethane A contains a structural unit derived from a polycarbonate diol a containing a cyclic structure; Artificial leather or synthetic leather with.
<Tensile test>
According to JIS K6301 (2010), a strip-shaped polyurethane test piece having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm was measured using a tensile tester at a temperature of 23 at a chuck distance of 50 mm and a tensile speed of 500 mm/min. A tensile test is performed at °C and a relative humidity of 55%, and the stress is measured when the test piece is stretched 100%.

[2] The artificial leather or synthetic leather according to [1], wherein the polyurethane A exhibits a yield point strength of 20 MPa or more in a region with an elongation of 10% or less in the tensile test.

[3] The artificial leather or synthetic leather according to [1] or [2], wherein the polyurethane A exhibits a breaking elongation of 50% or more in the tensile test.

[4] The artificial leather according to any one of [1] to [3], wherein the polycarbonate diol a contains a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2) Or synthetic leather.

(R ¹ in the above formula (1) represents an acyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, and m is a number of 3 to 50. R ² in the above formula (2) has a carbon number represents a cycloaliphatic hydrocarbon group or heterocyclic group of 3 to 10, and n is a number of 1 to 30.)

[5] The molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) in the polycarbonate diol a (structural unit represented by the formula (1)/the structural unit represented by the formula The artificial leather or synthetic leather according to [4], wherein the structural unit represented by (2)) is 85/15 to 15/85.

[6] The structural unit represented by the formula (2) is a structural unit derived from at least one diol selected from isosorbide, isomannide, and isoidide [4] or [5] The artificial leather or Synthetic leather.

[7] The artificial leather or synthetic leather according to any one of [1] to [6], wherein the ratio of structural units derived from the polycarbonate diol a contained in the polyurethane A is 30 to 70% by weight.

[8] The artificial leather or synthetic leather according to any one of [1] to [7], wherein the polyurethane B has a structural unit derived from a polyol b having a molecular weight of 500 or more and 2500 or less.

[9] The artificial leather or synthetic leather according to [8], wherein the polyol b contains an acyclic aliphatic compound having two or more hydroxyl groups.

[10] The artificial leather or synthetic leather according to [8] or [9], wherein the polyol b contains a polycarbonate diol.

[11] The artificial leather or synthetic leather according to any one of [1] to [10], wherein the polyurethane A and/or the polyurethane B is a polyurethane obtained by reacting a polyamine compound as a chain extender.

[12] The artificial leather or synthetic leather according to any one of [1] to [11], wherein the ratio of the film thickness of the first polyurethane layer to the film thickness of the second polyurethane layer is 0.01 to 100. leather.

The artificial leather or synthetic leather of the present invention is excellent in kneading and texturing properties, and can realize a texture and luxury feeling similar to natural leather. Because of its excellent chemical resistance, it is possible to provide an artificial leather or synthetic leather product having a natural leather-like texture and excellent durability.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.
Here, in the present specification, "% by mass" and "% by weight", "ppm by mass" and "ppm by weight", and "parts by mass" and "parts by weight" are synonymous. Moreover, when simply described as "ppm", it indicates "weight ppm".

The artificial leather or synthetic leather of the present invention is an artificial leather or synthetic leather having a first polyurethane layer serving as a surface side and a second polyurethane layer serving as a lower layer of the first polyurethane layer, The first polyurethane layer contains polyurethane A having a 100% modulus of 20 MPa or more and 100 MPa or less as measured by the following tensile test, and the second polyurethane layer has a 100% modulus of 0.000001 as measured by the following tensile test. Polycarbonate diol (a) comprising a polyurethane B of 1 MPa or more and 40 MPa or less, wherein the ratio of the 100% modulus of the polyurethane A to the 100% modulus of the polyurethane B is 1 or more and 1000 or less, and the polyurethane A contains a cyclic structure It is characterized by having a structural unit derived from.
<Tensile test>
According to JIS K6301 (2010), a strip-shaped polyurethane test piece having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm was measured using a tensile tester at a temperature of 23 at a chuck distance of 50 mm and a tensile speed of 500 mm/min. A tensile test is performed at °C and a relative humidity of 55%, and the stress is measured when the test piece is stretched 100%.

In the present invention, by forming a laminated structure of two polyurethane layers having 100% different moduli, an artificial leather or synthetic leather having excellent kneading and texturing processability can be obtained. Further, by using the polycarbonate diol a containing a cyclic structure for the polyurethane A constituting the first polyurethane layer on the surface side, it is possible to make the polyurethane layer excellent in rubbing texturing processability and color transfer resistance.

[Polyols]
First, polyols suitable as raw materials for producing polyurethanes A and B used in the present invention will be described.

<Polyols for producing polyurethane A>
Polyurethane A is characterized by having a structural unit derived from polycarbonate diol a containing a cyclic structure. Therefore, as polyols for producing polyurethane A, at least polycarbonate diol a containing a cyclic structure is used. be done.

As the polycarbonate diol a, in particular, a structural unit represented by the following formula (1) (hereinafter sometimes referred to as “structural unit (1)”) and a structural unit represented by the following formula (2) (hereinafter “ (sometimes referred to as "structural unit (2)").

(R ¹ in the above formula (1) represents an acyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, and m is a number of 3 to 50. R ² in the above formula (2) has a carbon number represents a cycloaliphatic hydrocarbon group or heterocyclic group of 3 to 10, and n is a number of 1 to 30.)

With such a polycarbonate diol a, the structural unit (1) has the effect of imparting excellent breaking elongation, and the structural unit (2) imparts excellent rubbing texturing workability and color transfer resistance. Thus, it is possible to produce a polyurethane A suitable as a polyurethane for the outer layer of artificial leather or synthetic leather.

In the above formula (1), R ¹ is an acyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, preferably a linear or branched alkylene group having 3 to 15 carbon atoms, and is industrially available. , an n-butylene group and an n-hexylene group are particularly preferred from the viewpoint that the resulting polycarbonate diol and polyurethane have excellent physical properties.
Structural unit (1) can be introduced into polycarbonate diol a by using an acyclic aliphatic dihydroxy compound having 3 to 20 carbon atoms as a starting diol for polycarbonate diol a.

In the above formula (1), if m is less than 3, flexibility tends to be poor, and if it exceeds 50, color transfer resistance tends to be poor. Therefore, m is preferably 3-50, especially 3-40, especially 5-30.

On the other hand, in the above formula (2), R ² is a cycloaliphatic hydrocarbon group or heterocyclic group having 3 to 10 carbon atoms, preferably a cycloalkylene group having 5 to 10 carbon atoms, an isosorbide group, or an isomannide group. , an isoidide group, and the like.

In particular, the structural unit (2) is preferably a structural unit derived from at least one diol selected from isosorbide, isomannide, and isoidide represented by the following formula (3) from the viewpoint of rubbing texturing.

In the above formula (2), when n is less than 3, color transfer resistance tends to be poor, and when n exceeds 50, wear resistance tends to be poor. Therefore, n is preferably 1-30, especially 2-25, especially 3-20.

The polycarbonate diol a may contain only one type of the structural unit (1), or may contain two or more types. Further, only one kind of structural unit (2) may be contained, or two or more kinds thereof may be contained.

The molar ratio of the structural unit (1) to the structural unit (2) contained in the polycarbonate diol a (structural unit (1)/structural unit (2)) is preferably 85/15 to 15/85. , particularly preferably 80/20 to 20/80, particularly preferably 75/25 to 25/75. If the structural unit (1) is more than the above range and the structural unit (2) is less than the above range, the kneading texturing processability and the color transfer resistance tend to be inferior. If there is a large amount, the wear resistance tends to be inferior.

Polycarbonate diol a is a linear or branched aliphatic dihydroxy compound having 3 to 20 carbon atoms, preferably 3 to 15 carbon atoms, for introducing the structural unit (1), specifically 1,3-propanediol. , 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol , 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol , 1,12-octadecanediol, preferably 1,4-butanediol, 1,6-hexanediol or the like, and a ring having 3 to 10 carbon atoms for introducing the structural unit (2). Formula aliphatic dihydroxy compounds such as cyclohexanedimethanol and/or heterocyclic dihydroxy compounds having 3 to 10 carbon atoms such as isosorbide, isomannide, isoidide, preferably cyclohexanedimethanol, isosorbide, etc. is used as a raw material dihydroxy compound so that the above-mentioned suitable structural unit (1) / structural unit (2) weight ratio is obtained, and these dihydroxy compounds and polycarbonate compounds are polymerized in the presence of a catalyst in a conventional manner. It can be manufactured by

A carbonate compound that can be used in the production of polycarbonate diol a is not limited as long as it does not impair the effects of the present invention, and includes dialkyl carbonate, diaryl carbonate, and alkylene carbonate. These may be of one type or plural types. Among these, diaryl carbonate is preferable from the viewpoint of reactivity.

Specific examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, ethylene carbonate and the like, with diphenyl carbonate being preferred.

When producing polycarbonate diol a, a transesterification catalyst can be used as necessary to promote polymerization.
As the transesterification catalyst, any compound generally considered to have transesterification ability can be used without limitation.

Examples of transesterification catalysts include compounds of long period periodic table (hereinafter simply referred to as "periodic table") Group 1 metals (excluding hydrogen) such as lithium, sodium, potassium, rubidium, and cesium; Compounds of Group 2 metals of the periodic table such as magnesium, calcium, strontium and barium; compounds of Group 4 metals of the periodic table such as titanium and zirconium; compounds of Group 5 metals of the periodic table such as hafnium; Group 9 metal compounds; periodic table group 12 metal compounds such as zinc; periodic table group 13 metal compounds such as aluminum; periodic table group 14 metal compounds such as germanium, tin, lead; antimony, bismuth, etc. compounds of Group 15 metals of the periodic table; and compounds of lanthanide metals such as lanthanum, cerium, europium, and ytterbium. Among these, from the viewpoint of increasing the transesterification reaction rate, periodic table group 1 metal compounds (excluding hydrogen), periodic table group 2 metal compounds, periodic table group 4 metal compounds, periodic table 5 Group metal compounds, periodic table group 9 metal compounds, periodic table group 12 metal compounds, periodic table group 13 metal compounds, periodic table group 14 metal compounds are preferred, and periodic table group 1 metals ( excluding hydrogen) and compounds of metals of Group 2 of the periodic table are more preferred, and compounds of metals of Group 2 of the periodic table are even more preferred. Among the compounds of Group 1 metals (excluding hydrogen) of the periodic table, lithium, potassium and sodium compounds are preferred, lithium and sodium compounds are more preferred, and sodium compounds are even more preferred. Among the compounds of Group 2 metals of the periodic table, compounds of magnesium, calcium and barium are preferred, compounds of calcium and magnesium are more preferred, and compounds of magnesium are even more preferred. These metal compounds are mainly used as hydroxides, salts and the like. Examples of salts when used as salts include halide salts such as chlorides, bromides and iodides; carboxylates such as acetates, formates and benzoates; inorganic acid salts such as carbonates and nitrates. sulfonates such as methanesulfonic acid, toluenesulfonic acid and trifluoromethanesulfonic acid; phosphorus-containing salts such as phosphates, hydrogen phosphates and dihydrogen phosphates; acetylacetonate salts; Catalyst metals can also be used as alkoxides such as methoxides and ethoxides.

Among these, at least one metal acetate, nitrate, sulfate, carbonate, phosphate, hydroxide, halide, or alkoxide of at least one metal selected from Group 2 metals of the periodic table is preferably used, More preferably, acetates, carbonates, and hydroxides of Group 2 metals of the periodic table are used, more preferably acetates, carbonates, and hydroxides of magnesium and calcium, and particularly preferably magnesium and calcium. Acetates are used, most preferably magnesium acetate.

In the production of polycarbonate diol a, the amount of the carbonate compound used is not particularly limited, but usually the lower limit is preferably 0.35, more preferably 0.50, and still more preferably 0 in terms of molar ratio to the total 1 mol of the dihydroxy compounds. .60, and the upper limit is preferably 1.00, more preferably 0.98, even more preferably 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the ratio of the resulting polycarbonate diol a that does not have a hydroxyl terminal group may increase, or the molecular weight may not fall within the predetermined range. may not.

When the transesterification catalyst described above is used in the production of polycarbonate diol a, the amount of catalyst used is usually 1 μmole to 200 μmole times per 1 mol of the total dihydroxy compound used, and the lower limit is preferably 5 μm. It is mol-fold, more preferably 10 μmol-fold, still more preferably 15 μmol-fold. The upper limit is preferably 100 μmol times, more preferably 70 μmol times, still more preferably 50 μmol times. If the amount of the catalyst used is too small, sufficient polymerization activity will not be obtained and the progress of the polymerization reaction will be slowed down, making it difficult to obtain polycarbonate diol a with a desired molecular weight. During the polymerization reaction, it remains unreacted in the system for a long time, which may lead to deterioration of color tone. In addition, the amount of monomers distilled off together with the monohydroxy compound produced as a by-product increases, resulting in a deterioration in the raw material unit consumption and the need for extra energy to recover it. In the case of copolymerization using a compound, the composition ratio of the monomers used as raw materials and the composition ratio of the constituent monomer units in the resulting polycarbonate diol a may change. On the other hand, if the amount of the catalyst used is too large, an excessively large amount of the catalyst will remain after the transesterification reaction, and the polycarbonate diol a may become cloudy or easily colored by heating. Moreover, when producing polyurethane A using the obtained polycarbonate diol a, the reaction may be inhibited or the reaction may be excessively accelerated.

The lower limit of the hydroxyl value of the polycarbonate diol a is usually 20 mg-KOH/g, preferably 25 mg-KOH/g, more preferably 30 mg-KOH/g, still more preferably 35 mg-KOH/g. The upper limit is usually 450 mg-KOH/g, preferably 230 mg-KOH/g, more preferably 150 mg-KOH/g, still more preferably 120 mg-KOH/g, particularly preferably 75 mg-KOH/g, particularly preferably 60 mg. -KOH/g, most preferably 45 mg-KOH/g. If the hydroxyl value is less than the above lower limit, the viscosity becomes too high and handling may become difficult during polyurethane formation.
Specifically, the hydroxyl value of the polycarbonate diol a is measured by the method described in the Examples section below.

The lower limit of the number average molecular weight (Mn) obtained from the hydroxyl value of the polycarbonate diol a is preferably 250, more preferably 300, still more preferably 400. On the other hand, the upper limit is preferably 5,000, more preferably 4,000, still more preferably 3,000. If the Mn of the polycarbonate diol a is less than the above lower limit, the resulting polyurethane may not have sufficient flexibility. On the other hand, when the above upper limit is exceeded, the viscosity increases, which may impair the handling during polyurethane formation.
Specifically, the number average molecular weight (Mn) determined from the hydroxyl value of polycarbonate diol a is measured by the method described in the Examples section below.

Polyurethane A is one or more of the above polycarbonate diols a and any other polyols used as needed, such as polycarbonate diols other than polycarbonate diol a, polyether polyols, polyester polyols, polycaprolactone polyols, Using one or more of alkanediols and the like as raw material polyols, it is produced according to the method for producing polyurethane described below.
Polyurethane A is a polyurethane using one or more of the above polycarbonate diols a as a raw material and any other polyols, such as polycarbonate diols other than polycarbonate diol a, polyether polyols, polyester polyols, polycaprolactone polyols, One or two or more of alkanediols and the like may be mixed with polyurethane obtained using raw material polyols.

In order to more effectively obtain the above effects by using polycarbonate diol a as a raw material polyol for polyurethane A, polycarbonate diol a should have a ratio of structural units derived from polycarbonate diol a contained in polyurethane A to be 30. It is preferably used in an amount of up to 70% by weight, particularly 35 to 65% by weight. If this proportion is less than 30% by weight, the abrasion resistance tends to be poor, and if it exceeds 70% by weight, the color transfer resistance tends to be poor.

<Polyols for producing polyurethane B>
Polyurethane B is not particularly limited as long as it satisfies the above-mentioned 100% modulus. Polyol b having a molecular weight of 500 to 2500, particularly 1000 to 2500, particularly 1500 to 2500, is used from the viewpoint of abrasion resistance. Therefore, it is preferable to use a polyol b having a molecular weight of 500 to 2,500, particularly 1,000 to 2,500, and particularly 1,500 to 2,500 as the raw material polyol for polyurethane B. Here, the molecular weight of polyol b corresponds to the number average molecular weight determined from the hydroxyl value.

From the viewpoint of abrasion resistance, polyol b preferably contains an acyclic aliphatic compound having two or more hydroxyl groups.
As such a polyol b, linear or branched aliphatic dihydroxy compounds having 3 to 20 carbon atoms, preferably 3 to 15 carbon atoms, exemplified as the dihydroxy compounds for introducing the structural unit (1) of the polycarbonate diol a described above. and a polycarbonate diol produced in the same manner as the polycarbonate diol a described above using one or more of the above.

Polyol b may also be a polyalkylene ether glycol. A polyalkylene ether glycol is usually a polyhydroxy compound having one or more ether bonds in the main skeleton in the molecule.

Examples of repeating units in the main skeleton of polyalkylene ether glycol include 1,2-ethylene glycol units, 1,2-propylene glycol units, 1,3-propanediol (trimethylene glycol) units, 2-methyl-1 ,3-propanediol unit, 2,2-dimethyl-1,3-propanediol unit, 1,4-butanediol (tetramethylene glycol) unit, 2-methyl-1,4-butanediol unit, 3-methyl- 1,4-butanediol unit, 3-methyl-1,5-pentanediol unit, neopentyl glycol unit, 1,6-hexanediol unit, 1,7-heptanediol unit, 1,8-octanediol unit, 1 ,9-nonanediol units, 1,10-decanediol units and 1,4-cyclohexanedimethanol units, and other saturated hydrocarbon groups having 1 to 20 carbon atoms, and a single repeating unit forms a polyalkylene ether glycol. or two or more repeating units may form a copolymerized polyalkylene ether glycol. Raw materials that give these repeating units are not particularly limited, but cyclic ethers are preferred. In addition, these raw materials that provide repeating units may be derived from petroleum or biomass.

As the polyalkylene ether glycol, among the polyalkylene ether glycols having the repeating unit in the main skeleton, polytetramethylene ether glycol, polytrimethylene ether glycol, 1 to 20 mol% by reaction of 3-methyltetrahydrofuran and tetrahydrofuran Copolymerized polyether polyols obtained and copolymerized polyether glycols obtained by reacting neopentyl glycol with tetrahydrofuran are preferred, and polytetramethylene ether glycol is more preferred.

As the polyol b, a cyclic polyol may be used as long as the physical properties of the polyurethane B are satisfied. In this case, usable cyclic polyols include the aforementioned polycarbonate diol a. When the polyol b contains a cyclic polyol such as polycarbonate diol a, the effect of improving crumpling and texturing processability may be exhibited.

However, from the viewpoint of abrasion resistance, the content of cyclic polyol in polyol b is preferably 70% by weight or less with respect to the total weight of polyol b.

Polyurethane B is one or more of the above polyols b and any other polyols used as needed, such as polyols having a molecular weight outside the range of 500 to 2500, polyester polyols, polycaprolactone polyols, and alkanes. Using one or more of diols and the like as raw material polyols, it is produced according to the production method of polyurethane described below.

In order to more effectively obtain the above effects by using polyol b as a raw material polyol for polyurethane B, polyol b should have a ratio of structural units derived from polyol b contained in polyurethane B to be obtained from 30 to 30%. It is preferably used in an amount of 70% by weight, particularly 35 to 65% by weight. If this proportion is less than 30% by weight, the abrasion resistance tends to be poor, and if it exceeds 70% by weight, the color transfer resistance tends to be poor.

[Polyurethane A, B]
Polyurethanes A and B used in the present invention comprise at least (i) a compound containing two or more isocyanate groups in one molecule (hereinafter sometimes referred to as "polyisocyanate"), (ii) a chain extender, (iii) Polycarbonate diols and polyols suitable for the production of polyurethanes A and B (these may be hereinafter simply referred to as "polyols").
As for the method for producing the polyurethanes A and B used in the present invention, the known polyurethane reaction conditions for producing ordinary polyurethanes are used.

For example, polyurethanes A and B can be produced by reacting (iii) polyols with (i) polyisocyanate and (ii) chain extender at a temperature ranging from room temperature to 200°C.
In addition, (iii) polyols and excess (i) polyisocyanate are first reacted to produce a prepolymer having terminal isocyanate groups, and (ii) a chain extender is used to increase the degree of polymerization. of polyurethanes A and B can be produced.

<Polyisocyanate>
The (i) polyisocyanate used to produce the polyurethanes A and B includes various known aliphatic, alicyclic or aromatic polyisocyanate compounds.

For example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and dimer diisocyanate obtained by converting the carboxyl group of dimer acid to an isocyanate group. Aliphatic diisocyanates; 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and 1,3-bis Alicyclic diisocyanates such as (isocyanatomethyl)cyclohexane; 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl Aromatic diisocyanates such as -4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate and m-tetramethylxylylene diisocyanate. These may be used individually by 1 type, and may use 2 or more types together.

Among these, 4,4'-diphenylmethane diisocyanate (hereinafter sometimes referred to as "MDI") and hexamethylene are preferred because the resulting polyurethane has a good balance of physical properties and is industrially available in large quantities at low cost. Diisocyanates, 4,4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferred.

<Chain extender>
The (ii) chain extender used in producing polyurethanes A and B is a low-molecular-weight compound having at least two active hydrogens that react with isocyanate groups when producing a prepolymer having an isocyanate group, which will be described later. , usually polyols and polyamines.

Specific examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol, and other linear diols; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl -1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-heptanediol, 1,4-dimethylolhexane, 2-ethyl-1,3-hexanediol, 2 ,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, dimer diol, and other branched diols diols having an ether group such as diethylene glycol and propylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 1,4-dihydroxyethylcyclohexane; xylylene glycol; Diols having aromatic groups such as 1,4-dihydroxyethylbenzene and 4,4′-methylenebis(hydroxyethylbenzene); Polyols such as glycerin, trimethylolpropane and pentaerythritol; N-methylethanolamine and N-ethylethanol hydroxyamines such as amine; ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediamine, di-2-hydroxy ethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, 4,4′-diphenylmethanediamine, methylenebis(o-chloroaniline), xylylenediamine, diphenyldiamine, tri polyamines such as diamine, hydrazine, piperazine, N,N'-diaminopiperazine; and water.

These chain extenders may be used alone or in combination of two or more.

Among these, ethylenediamine, 1,3-diaminopropane, isophoronediamine, 4,4'-diaminodicyclohexylmethane, etc. are preferable in that the resulting polyurethane has a good balance of physical properties and is industrially available in large quantities at low cost. Polyamine compounds are preferred.

In addition, the chain extender in the case of producing a prepolymer having a hydroxyl group, which will be described later, is a low-molecular-weight compound having at least two isocyanate groups. compound.

<Chain terminating agent>
When producing polyurethanes A and B, a chain terminator having one active hydrogen group can be used as needed for the purpose of controlling the molecular weight of the resulting polyurethane.

These chain terminators include aliphatic monools having one hydroxyl group such as methanol, ethanol, propanol, butanol and hexanol, diethylamine, dibutylamine, n-butylamine, monoethanolamine and diethanolamine having one amino group. , and morpholine.
These may be used individually by 1 type, and may use 2 or more types together.

<Catalyst>
In the polyurethane-forming reaction when producing polyurethanes A and B, amine catalysts such as triethylamine, N-ethylmorpholine and triethylenediamine, acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid and sulfonic acid, and trimethyltinlau Known urethane polymerization catalysts typified by tin-based compounds such as dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanate, and organic metal salts such as titanium-based compounds can also be used. A urethane polymerization catalyst may be used individually by 1 type, and may use 2 or more types together.

<Solvent>
A solvent may be used in the polyurethane-forming reaction when producing the polyurethanes A and B of the present invention.
Preferred solvents include amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide and N-methylpyrrolidone; sulfoxide solvents such as dimethylsulfoxide; ketone solvents such as methylethylketone, cyclohexanone and methylisobutylketone; ether solvents; ester solvents such as methyl acetate, ethyl acetate and butyl acetate; and aromatic hydrocarbon solvents such as toluene and xylene. These solvents may be used alone or as a mixed solvent of two or more.

Among these, preferred organic solvents are methyl ethyl ketone, ethyl acetate, toluene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide.
Aqueous dispersion polyurethanes can also be produced from polyurethane compositions containing (iii) polyols, (i) polyisocyanates, and (ii) chain extenders.

<Manufacturing method>
As a method for producing polyurethanes A and B using the above-described reaction reagents, production methods that are generally used experimentally or industrially can be used.

Examples thereof include a method of mixing (iii) polyols, (i) polyisocyanate and (ii) a chain extender together and reacting them (hereinafter sometimes referred to as a “one-step method”), and (iii) ) A method of reacting polyols and (i) polyisocyanate to prepare a prepolymer having isocyanate groups at both ends, and then reacting the prepolymer with (ii) a chain extender (hereinafter referred to as a “two-step method” There are cases), etc.

The two-step method includes a step of reacting polyols with one or more equivalents of polyisocyanate in advance to prepare isocyanate intermediates at both ends corresponding to the soft segments of polyurethane. In this way, if the prepolymer is once prepared and then reacted with a chain extender, it may be easier to adjust the molecular weight of the soft segment portion, and it is useful when it is necessary to ensure phase separation between the soft segment and the hard segment. is useful.

(single stage method)
The one-step method, which is also called a one-shot method, is a method in which (iii) polyols, (i) polyisocyanate and (ii) a chain extender are charged all at once to carry out the reaction.

The amount of polyisocyanate used in the one-step method is not particularly limited, but when the total number of hydroxyl groups of the polyols used and the total number of hydroxyl groups and amino groups of the chain extender is 1 equivalent, the lower limit is preferably 0. 0.7 equivalents, more preferably 0.8 equivalents, more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents, more preferably 2.0 equivalents, and still more preferably is 1.5 equivalents, particularly preferably 1.1 equivalents.

If the amount of polyisocyanate used is too large, unreacted isocyanate groups will cause side reactions, and the viscosity of the resulting polyurethane will tend to be too high, making handling difficult and flexibility likely to be impaired. If it is too much, the molecular weight of the polyurethane will not be sufficiently large, and there will be a tendency that sufficient polyurethane strength will not be obtained.

In addition, the amount of the chain extender used is not particularly limited. preferably 0.8 equivalents, more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, the upper limit is preferably 3.0 equivalents, more preferably 2.0 equivalents, still more preferably 1.5 equivalents; Especially preferred is 1.1 equivalents. If the amount of chain extender used is too large, the resulting polyurethane tends to be difficult to dissolve in the solvent and processing becomes difficult. The retention performance may not be obtained, or the heat resistance may deteriorate.

(two-step method)
The two-step method, also called a prepolymer method, mainly includes the following methods.
[1] Polyols and an excess of polyisocyanate are reacted in advance at a reaction equivalent ratio of polyisocyanate/(polyols) of more than 1 to 10.0 to obtain a preform having an isocyanate group at the molecular chain end. A method of producing a polyurethane by producing a polymer and then adding a chain extender thereto
[2] Polyisocyanate and excess polyols are reacted in advance at a reaction equivalent ratio of polyisocyanate/(polyols) of 0.1 or more to less than 1.0 to produce a prepolymer whose molecular chain ends are hydroxyl groups. and then reacting it with a polyisocyanate having an isocyanate group at the end as a chain extender to produce a polyurethane.

The two-step method can be carried out without solvent or in the presence of solvent.

Polyurethane production by the two-step method can be carried out by any one of the methods (1) to (3) described below.
(1) Without using a solvent, a polyisocyanate and a polyol are directly reacted to synthesize a prepolymer, and the prepolymer is directly used for the chain extension reaction.
(2) A prepolymer is synthesized by the method of (1), then dissolved in a solvent and used for subsequent chain extension reaction.
(3) Using a solvent from the beginning, reacting polyisocyanate and polyols, and then carrying out chain extension reaction.

In the case of method (1), the chain extension reaction is carried out by dissolving the chain extender in a solvent, or dissolving the prepolymer and the chain extender in the solvent at the same time, to obtain the polyurethane in a form coexisting with the solvent. This is very important.
The amount of polyisocyanate used in the two-step method [1] is not particularly limited, but the lower limit is preferably 1.0 as the number of isocyanate groups when the total number of hydroxyl groups of the polyols used is 1 equivalent. An amount exceeding the equivalent, more preferably 1.2 equivalents, more preferably 1.5 equivalents, and the upper limit is preferably 10.0 equivalents, more preferably 5.0 equivalents, still more preferably 3.0 equivalents. be.

If the amount of isocyanate used is too large, the excessive isocyanate groups tend to cause side reactions, making it difficult to achieve the desired physical properties of the polyurethane. may become less viable.

The amount of the chain extender to be used is not particularly limited, but the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, still more preferably 0.5 equivalent, with respect to one equivalent of isocyanate groups contained in the prepolymer. It is 8 equivalents, and the upper limit is preferably 5.0 equivalents, more preferably 3.0 equivalents, and still more preferably 2.0 equivalents.

For the purpose of adjusting the molecular weight, monofunctional organic amines and alcohols may coexist during the chain extension reaction.

In addition, the amount of polyisocyanate used when preparing a prepolymer having a hydroxyl group at the end in the two-step method [2] is not particularly limited, but when the total number of hydroxyl groups of the polyols used is 1 equivalent, As the number of isocyanate groups, the lower limit is preferably 0.1 equivalents, more preferably 0.5 equivalents, more preferably 0.7 equivalents, and the upper limit is preferably 0.99 equivalents, more preferably 0.98 equivalents. , more preferably 0.97 equivalents.

If the amount of isocyanate used is too small, the subsequent chain elongation reaction takes a long time to obtain the desired molecular weight, and production efficiency tends to decrease. It may decrease, or handling may be bad and productivity may be inferior.

The amount of the chain extender used is not particularly limited, but when the total number of hydroxyl groups of the polyols used in the prepolymer is 1 equivalent, the total equivalent added with the equivalent of the isocyanate group used in the prepolymer has a lower limit of It is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, and the upper limit is preferably less than 1.0 equivalents, more preferably 0.99 equivalents, still more preferably 0.98 equivalents. is in the range of

For the purpose of adjusting the molecular weight, monofunctional organic amines and alcohols may coexist during the chain extension reaction.

The chain extension reaction is usually carried out at 0° C. to 250° C., but this temperature varies depending on the amount of solvent, reactivity of raw materials used, reaction equipment, etc., and is not particularly limited. If the temperature is too low, the reaction progresses too slowly, and the solubility of the raw materials and polymer may be low, which may lengthen the production time. . The chain extension reaction may be performed under reduced pressure while defoaming.

Moreover, a catalyst, a stabilizer, etc. can also be added to a chain extension reaction as needed.
Examples of catalysts include amine-based catalysts such as triethylamine, tributylamine, N-ethylmorpholine and triethylenediamine, acid-based catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid and sulfonic acid, trimethyltin laurate, dibutyltin dilaurate and dioctyltin. Known urethane polymerization catalysts typified by tin-based compounds such as dilaurate and dioctyltin dineodecanate, and organic metal salts such as titanium-based compounds can be used. A urethane polymerization catalyst may be used individually by 1 type, and may use 2 or more types together.
Examples of stabilizers include 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N,N'-di-2-naphthyl-1,4-phenylenediamine, tris(dinonylphenyl)phosphate, Compounds such as phyto may be mentioned, and one kind may be used alone, or two or more kinds may be used in combination. If the chain extender is highly reactive such as a short-chain aliphatic amine, the reaction may be carried out without adding a catalyst.

<Additive>
Various additives such as heat stabilizers, light stabilizers, colorants, fillers, stabilizers, UV absorbers, antioxidants, anti-adhesives, flame retardants, anti-aging agents, and inorganic fillers are added to polyurethanes A and B. Agents can be added and mixed within a range that does not impair the properties of polyurethanes A and B.

Compounds that can be used as heat stabilizers include phosphoric acid, aliphatic, aromatic or alkyl-substituted aromatic esters of phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, poly Phosphorus compounds such as phosphonates, dialkylpentaerythritol diphosphites, and dialkylbisphenol A diphosphites; compounds containing sulfur such as tin-based compounds; tin-based compounds such as tin malate and dibutyltin monoxide;

Specific examples of hindered phenol compounds include "Irganox1010" (trade name: manufactured by BASF Japan Ltd.), "Irganox1520" (trade name: manufactured by BASF Japan Ltd.), "Irganox245" (trade name: manufactured by BASF Japan Ltd.). ) and the like.
Phosphorus compounds include "PEP-36", "PEP-24G", "HP-10" (all trade names: manufactured by ADEKA Corporation), "Irgafos 168" (manufactured by BASF Japan Ltd.), etc. is mentioned.

Specific examples of sulfur-containing compounds include thioether compounds such as dilaurylthiopropionate (DLTP) and distearylthiopropionate (DSTP).

Examples of light stabilizers include benzotriazole-based and benzophenone-based compounds. LS-765" (manufactured by Sankyo Co., Ltd.) and the like can be used.

Examples of ultraviolet absorbers include "TINUVIN328" and "TINUVIN234" (manufactured by BASF Japan Ltd.).

Colorants include dyes such as direct dyes, acid dyes, basic dyes and metal complex dyes; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide and mica; Organic pigments such as anthraquinone-based, thioindigo-based, dioxazone-based, and phthalocyanine-based pigments can be used.

Examples of inorganic fillers include short glass fibers, carbon fibers, alumina, talc, graphite, melamine, and clay.

Examples of flame retardants include phosphorus-containing organic compounds, halogen-containing organic compounds such as bromine or chlorine, additive and reactive flame retardants such as ammonium polyphosphate, aluminum hydroxide, and antimony oxide.

These additives may be used alone, or two or more of them may be used in any combination and ratio.

As for the amount of these additives added, the lower limit is preferably 0.01% by weight, more preferably 0.05% by weight, still more preferably 0.1% by weight, and the upper limit is preferably is 10% by weight, more preferably 5% by weight, and even more preferably 1% by weight. If the amount of the additive added is too small, the effect of addition cannot be sufficiently obtained, and if it is too large, it may precipitate in the polyurethane or cause turbidity.

<Molecular weight>
The molecular weights of polyurethanes A and B are not particularly limited, but are preferably 50,000 to 500,000, more preferably 100,000 to 300,000, as polystyrene-equivalent weight average molecular weights (Mw) measured by GPC. preferable. If Mw is less than the above lower limit, sufficient strength and hardness may not be obtained.

<Polyurethane solution>
Polyurethanes A and B used in the present invention are usually used as a solution dissolved in an aprotic solvent (hereinafter also referred to as "polyurethane solution") for producing artificial leather or synthetic leather.

Aprotic solvents suitable for use in this polyurethane solution include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone and dimethylsulfoxide. and more preferably N,N-dimethylformamide and N,N-dimethylacetamide.

The content of polyurethanes A and B in the polyurethane solution is generally preferably 1 to 99% by weight, more preferably 5 to 90% by weight, still more preferably 10 to 70% by weight, based on the total weight of the polyurethane solution. %, particularly preferably 15 to 50% by weight. By setting the content of polyurethanes A and B in the polyurethane solution to 1% by weight or more, it is not necessary to remove a large amount of solvent, and productivity can be improved. Moreover, by making it 99% by weight or less, the viscosity of the solution can be suppressed, and the operability or workability can be improved.

<Tensile properties of polyurethanes A and B>
The polyurethane A used in the present invention has a 100% modulus of 20 MPa or more and 100 MPa or less measured by the following tensile test, and the polyurethane B used in the present invention has a 100% modulus of 0.1 MPa or more measured by the following tensile test. , 40 MPa or less, and the ratio of the 100% modulus of polyurethane A to the 100% modulus of polyurethane B is 1 or more and 1000 or less.
<Tensile test>
According to JIS K6301 (2010), a strip-shaped polyurethane test piece having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm was measured using a tensile tester at a temperature of 23 at a chuck distance of 50 mm and a tensile speed of 500 mm/min. A tensile test is performed at °C and a relative humidity of 55%, and the stress is measured when the test piece is stretched 100%.

If the 100% modulus of polyurethane A is less than 20 MPa, the obtained artificial leather or synthetic leather tends to have poor crumpling processability, color transfer resistance (stain resistance), and chemical resistance. sexuality is lost. The 100% modulus of polyurethane A is preferably 20-90 MPa, particularly preferably 20-80 MPa.

On the other hand, if the 100% modulus of polyurethane B is less than 0.1 MPa, the wear resistance of the resulting artificial leather or synthetic leather tends to be poor, and even if it exceeds 40 MPa, the wear resistance tends to be poor. The 100% modulus of polyurethane B is preferably 0.5 to 40 MPa, particularly preferably 1 to 40 MPa.

Further, even if the 100% modulus of each of polyurethanes A and B satisfies the above range, the ratio of the 100% modulus of polyurethane A to the 100% modulus of polyurethane B (100% modulus of polyurethane A/100% modulus of polyurethane B). is not within the range of 1 to 1,000, the wear resistance tends to be poor. This ratio is preferably 1-900, more preferably 1-750, particularly preferably 1-500.

In addition, the polyurethane A preferably exhibits a yield point strength of 20 MPa or more in a region with an elongation of 10% or less in the tensile test, and the yield point strength is particularly preferably 20 to 100 MPa, particularly preferably 25 to 80 MPa. If the yield point is not within the range of 10% of elongation, color transfer resistance and crumpling texturing tend to be inferior. Even if there is a yield point in this region, if the yield point strength is less than 20 MPa, the kneading texturing processability tends to be poor, and if it exceeds 100 MPa, the abrasion resistance tends to be poor.

Furthermore, the polyurethane A preferably exhibits a breaking elongation of 50% or more in the tensile test.
Polyurethanes having a breaking elongation of less than 50% tend to have poor abrasion resistance. From this point of view, the elongation at break of polyurethane A is preferably 50% or more, particularly preferably 80% or more. The breaking elongation of Polyurethane A is not particularly limited, but it is usually 500% or less from the viewpoint of color transfer resistance.

Polyurethane A having the above tensile properties can be easily produced by using polycarbonate diol a suitable as the raw material polyols for polyurethane A and controlling the ratio of polyisocyanate and chain extender to be reacted.
For polyurethane B having a modulus of 100%, polycarbonate diol, polytetramethylene ether glycol, and the like, which are polyols b suitable as raw material polyols for polyurethane B, are used. It can be easily manufactured by controlling the ratio.

<Chemical resistance of polyurethane A>
Polyurethane A is usually the outermost layer of artificial leather or synthetic leather, so it is preferable that it has excellent chemical resistance. It is preferable that the weight change rate during the evaluation test with ethanol is less than 40%.

[Manufacturing method of artificial leather or synthetic leather]
As for the method for producing the artificial leather or synthetic leather of the present invention using polyurethane A and polyurethane B, a known method can be used. Manufactured in the manner shown. Synthetic leather generally refers to a woven fabric or knitted fabric as a base material, and is sometimes distinguished as a different structure from artificial leather that uses a non-woven fabric as a base material. However, in recent years, the distinction between nonwoven fabrics and knitted fabrics has become less strict, such as attaching woven fabrics and knitted fabrics in order to impart strength to nonwoven fabrics.

The artificial leather or synthetic leather of the present invention can be produced, for example, by forming a microporous layer containing a polyurethane resin on a base fabric as a base material, and sequentially laminating polyurethane B and polyurethane A via an adhesive layer. , a base material filled with a resin such as polyurethane, containing a polyurethane resin, or further laminating a microporous layer thereon.
In particular, the artificial leather or synthetic leather of the present invention preferably uses a release material, and a first polyurethane layer (hereinafter sometimes referred to as "first layer") and a second polyurethane layer are formed on the release material. (Hereinafter, it may be referred to as a “second layer”.) A skin layer is formed, a base material is laminated thereon via an adhesive layer, and then the release material is peeled off.

<Base material>
As the base material, a base fabric can be used. Specifically, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, natural fibers such as cotton and hemp, and recycled rayon, staple fiber, acetate, and the like. Knitted fabrics, woven fabrics, non-woven fabrics, etc. made of single or blended fibers such as fibers, or multicomponent fibers modified into ultrafine fibers by dissolving at least one component or splitting bicomponent fibers can be used.
This base fabric may be raised. Raised fabric may be raised on one side or raised on both sides. Moreover, the base fabric may be not only a single layer but also a multi-layer structure composed of a plurality of fibers. Also, a knitted fabric having a raised surface may be used as the base fabric.

The substrate may have a microporous layer. A wet microporous layer is produced by a general fabric impregnation method. For example, the base fabric is immersed in a dimethylformamide solution containing a polyurethane resin, or the solution is applied to the base fabric, coagulated in water, the solvent is removed, dehydrated, and dried under hot air at about 120°C. A wet microporous layer having excellent surface smoothness can be formed.
The thickness of the wet microporous layer is preferably 50-400 μm, more preferably 100-300 μm. Within this thickness range, the optimum softness and voluminousness of synthetic leather are achieved.

<Adhesive layer>
A known polyurethane-based adhesive can be used for the adhesive layer, and a cross-linking agent and, if necessary, a cross-linking accelerator may be added to this adhesive.

<Skin layer>
In the present invention, the polyurethane A is used to form the first polyurethane layer on the surface side, and the polyurethane B is used to form the second polyurethane layer to be the lower layer.
In this case, polyurethanes A and B may be used as they are, or polyurethanes A and B are mixed with other resins, antioxidants, ultraviolet absorbers, etc. to prepare respective polyurethane solutions, which are added with colorants and organic compounds. It may be formed using a mixed liquid obtained by mixing a solvent or the like. In addition, hydrolysis inhibitors, pigments, dyes, flame retardants, fillers, cross-linking agents, and the like can be added to the polyurethane solution as necessary.

Examples of other resins include polyurethanes other than polyurethanes A and B, poly(meth)acrylic resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl propionate copolymers, polyvinyl butyral resins, and fibers. base resins, polyester resins, epoxy resins, phenoxy resins, polyamide resins, and the like. However, it is preferable that 10% by weight or more, particularly 15 to 100% by weight, of the resin constituting the first layer is polyurethane A, and 10% by weight or more, particularly 15 to 15% by weight, of the resin constituting the second layer 100% by weight Polyurethane B is preferred.

Examples of cross-linking agents include organic polyisocyanates, crude MDI, TDI adducts of trimethylolpropane, and polyisocyanate compounds such as triphenylmethane triisocyanate.

The first polyurethane layer can be formed by coating a liquid mixture containing polyurethane A on a release material, heating and drying the mixture to a desired thickness. The second polyurethane layer can be formed by coating the thus formed first polyurethane layer with a blended solution containing polyurethane B, followed by heating and drying to obtain a desired thickness. . After that, an adhesive is further applied to form an adhesive layer, and a base cloth such as a raised cloth is laminated on it, dried, aged at room temperature for several days, and then the release material is peeled off. An artificial leather or synthetic leather is obtained.

The thickness of the first layer constituting the surface layer of the artificial leather or synthetic leather of the present invention, that is, the first polyurethane layer containing polyurethane A, which is the surface side of the artificial leather or synthetic leather, has a thickness of 1 from the viewpoint of abrasion resistance. ~100 μm, preferably 3 to 50 μm, especially preferably 5 to 40 μm. In addition, the film thickness of the second polyurethane layer containing polyurethane B, which is the second layer, that is, the lower layer of the first polyurethane layer, is 3 to 200 μm, particularly 5 to 100 μm from the viewpoint of rubbing and texturing. Preferably, the total thickness of the first layer and the second layer is 5-200 μm, particularly preferably 10-100 μm.

In addition, in order to more reliably obtain crumpling processability by forming a laminated structure of the first layer of polyurethane A having the tensile properties described above and the second layer of polyurethane B, the thickness of the first layer and the thickness of the second layer were increased. The ratio of the film thicknesses of the layers (thickness of the first layer/thickness of the second layer) is preferably 0.01 to 100, more preferably 0.05 to 50, and most preferably 0.05 to 50. It is preferably 1-10.

The artificial leather or synthetic leather of the present invention comprises a first polyurethane layer, an antifouling layer such as a fluorine-based resin, a polyurethane containing a cross-linking agent, an organic filler, a lubricant, a flame retardant, etc., acrylic, You may have surface treatment layers, such as an elastomer. In addition, there is no particular limitation between the first polyurethane layer and the second polyurethane layer as long as it does not impair the object of the present invention, but it is preferably a polycarbonate-based urethane resin, a polyester-based urethane resin, or a polyether-based urethane resin. You may have adhesives layers, such as.

In the present invention, the artificial leather or synthetic leather thus produced may be kneaded with a liquid jet dyeing machine or the like to create natural leather-like wrinkles.

<Application>
The artificial leather or synthetic leather of the present invention can be used for automotive interior materials, furniture, clothing, shoes, bags, and the like.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

In the following examples and comparative examples, the analysis and evaluation methods of the physical properties of each component are as follows.

[Analysis and Evaluation of Polycarbonate Diol]
<Measurement of APHA value>
According to JIS K0071-1 (1998), the APHA value was measured by comparing the melted polycarbonate diol with a standard solution in a colorimetric tube. As a reagent, a chromaticity standard solution of 1000 degrees (1 mgPt/mL) (Kishida Chemical Co., Ltd.) was used.

<Quantification of residual diphenyl carbonate>
Carbonic acid diester (diphenyl carbonate) residual amount was measured by quantitative analysis by GPC under the following conditions.
(Analysis conditions)
Column: Tskgel G2000H XL 7.8 mm I.D. D × 30 cmL 4 Eluent: THF (tetrahydrofuran)
Flow rate: 1.0 mL/min
Column temperature: 40°C
RI detector: RID-10A (Shimadzu Corporation)

<Detection of Phenoxy Group Terminal Amount, Ether Bond Amount, Raw Material Diol Amount, and Phenol Amount>
Polycarbonate diol was dissolved in CDCl ₃ , 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, and from the signal position of each component, the phenoxy group terminal, ether bond, raw material diol, and phenol were identified, Each content was calculated from the integrated value. The detection limit at that time is 500 ppm as the weight of the ether group, 100 ppm as the weight of the starting material diol or phenol, and 0.1% as weight of isosorbide with respect to the weight of the entire sample. The ratio of phenoxy group ends is determined from the ratio of the integrated value for 1 proton at the phenoxy group end and the integrated value for 1 proton at the entire end, and the detection limit for the phenoxy group end is 0.05 for the entire end. %.

<Measurement of polystyrene equivalent weight average molecular weight (Mw) and number average molecular weight (Mn)>
Polystyrene-equivalent weight-average molecular weight (Mw) and polystyrene-equivalent number-average molecular weight (Mn) of the polycarbonate diol were determined by GPC measurement under the following conditions.
Apparatus: HLC-8020 manufactured by Tosoh Corporation
Column: TSKgel GMHXL-L (7.8 mm ID × 30 cmL
x 4)
Eluent: THF (tetrahydrofuran)
Flow rate: 1.0 mL/min
Column temperature: 40°C
RI detector: RI (equipment HLC-8020 built-in)
Then, the molecular weight distribution (Mw/Mn) was calculated.

<Weight ratio of structural unit (1) to structural unit (2): structural unit (1)/structural unit (2)>
Polycarbonate diol was dissolved in CDCl ₃ , 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, and the weight ratio of structural unit (1) to structural unit (2) was determined from the signal position of each component. (Structural unit (1)/Structural unit (2)) was determined. Also, the weight ratio of the structural unit (1) terminal to the structural unit (2) terminal was determined in the same manner.

<Number average molecular weight>
According to JIS K1557-1, the hydroxyl value of polycarbonate diol was measured by a method using an acetylation reagent, and the number average molecular weight was calculated by the following formula based on the ratio of hydroxyl value and terminal hydroxyl group.
Number average molecular weight = {(56.11 × 1000) / OH value} × 2

[Analysis and Evaluation of Polyurethane]
<Measurement of isocyanate group concentration>
After diluting 20 mL of a mixed solution of di-n-butylamine/toluene (weight ratio: 2/25) with 90 mL of acetone, titration was performed with a 0.5N hydrochloric acid aqueous solution to measure the amount of hydrochloric acid aqueous solution required for neutralization, and the blank value. and After that, 1 to 2 g of the reaction solution was taken out, 20 mL of a mixed solution of di-n-butylamine/toluene was added, and the mixture was stirred at room temperature for 30 minutes. The amount of aqueous hydrochloric acid solution required for neutralization was measured by titration with , and the amount of residual amine was quantified. The concentration of isocyanate groups was determined from the volume of the aqueous hydrochloric acid solution required for neutralization by the following formula.
Isocyanate group concentration (% by weight) = A x 42.02/D
A: isocyanate group (mol) contained in the sample used for this measurement
A = (BC) x 0.5/1000 x f
B: Amount (mL) of 0.5 N hydrochloric acid aqueous solution required for blank measurement
C: Amount (mL) of 0.5 N hydrochloric acid aqueous solution required for this measurement
D: sample used for this measurement (g)
f: titer of hydrochloric acid aqueous solution

<Measurement of molecular weight>
The molecular weight of the polyurethane was determined by preparing an N,N-dimethylacetamide solution so that the concentration of the polyurethane was 0.14% by weight, and using a GPC device [manufactured by Tosoh Corporation, product name "HLC-8220" (column: TskgelGMH-XL). 2), and a solution obtained by dissolving 2.6 g of lithium bromide in 1 L of dimethylacetamide was used as the eluent], and the weight average molecular weight (Mw) in terms of standard polystyrene was measured.

<Production of film>
A polyurethane solution was applied onto a fluororesin sheet (fluororesin tape Nitoflon 900, thickness 0.1 mm, manufactured by Nitto Denko Corporation) using a 9.5 mil applicator, followed by heating at 60°C for 1 hour, followed by heating at 100°C for 0.5 hour. dried. Further, after drying for 0.5 hours under vacuum conditions at 100° C. and 15 hours at 80° C., it was allowed to stand at constant temperature and humidity at 23° C. and 55% RH for 12 hours or more to obtain a film with a thickness of about 50 μm. .

<Evaluation of oleic acid resistance>
A test piece of 3 cm x 3 cm was cut out from the film obtained in the production of the above film. After measuring the weight of the test piece with a precision balance, it was placed in a 250 ml glass bottle containing 50 ml of oleic acid as a test solvent, and allowed to stand in a constant temperature bath at 80° C. under a nitrogen atmosphere for 16 hours. After the test, the test piece was taken out and lightly wiped on the front and back with a paper wiper, and the weight was measured with a precision balance to calculate the weight change rate (increase rate) from before the test. The closer the weight change rate is to 0%, the better the oleic acid resistance.

<Evaluation of ethanol resistance>
A test piece of 3 cm x 3 cm was cut out from the film obtained in the production of the above film. After measuring the weight of the test piece with a precision balance, it was placed in a glass petri dish with an inner diameter of 10 cmφ containing 50 ml of ethanol as a test solvent and immersed at room temperature of about 23° C. for 1 hour. After the test, the test piece was taken out and lightly wiped with a paper wiper, and the weight was measured with a precision balance to calculate the weight change rate (increase rate) from before the test. The closer the weight change rate is to 0%, the better the ethanol resistance.

<Evaluation of chemical resistance>
In the above evaluation of oleic acid resistance and ethanol resistance, chemical resistance was evaluated according to the following criteria.
○: less than 100% oleic acid resistance and less than 40% ethanol resistance △: 100% or more oleic acid resistance and less than 40% ethanol resistance, or less than 100% oleic acid resistance and 40% or more ethanol resistance ×: oleic acid resistance 100% or more and ethanol resistance of 40% or more

<Tensile test>
From the film obtained in the production of the above film, according to JIS K6301 (2010), a strip-shaped test piece with a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm is cut out, and a tensile tester (manufactured by Orientec, product (named "Tensilon UTM-III-100"), the distance between chucks is 50 mm, the tensile speed is 500 mm / min, the temperature is 23 ° C., and the relative humidity is 55%. stress at: 100% modulus was measured.
Also, the elongation at break was measured.
In addition, the presence or absence of a yield point in a region with an elongation of 10% or less was confirmed, and the yield point strength was measured.

[Evaluation of synthetic leather]
<Production of synthetic leather>
Using the polyurethane solution, a synthetic leather was produced by the following operation.
After adding 33 parts by weight of methyl ethyl ketone to 167 parts by weight of the polyurethane solution for the first layer to obtain a uniform solution, a 5-mil applicator was used on release paper (DNTP.APT.DE-3 manufactured by Dai Nippon Printing Co., Ltd.). was applied to This was dried in a dryer at 100°C for 2 minutes. Next, 40.1 parts by weight of methyl ethyl ketone and 20.3 parts by weight of a black pigment (carbon black manufactured by DIC Corporation) were added to 200 parts by weight of the polyurethane solution for the second layer to form a uniform solution, and then a 5 mil applicator was applied. It was applied over the dried first layer using This was dried in a dryer at 100°C for 2 minutes. Further, the following adhesive layer solution was applied onto the dried second layer and dried in a drier at 100° C. for 1 minute. After that, the polyurethane layer side of the wet base shown below was placed on the adhesive layer so as not to entrap air, and after pressing with a stretching bar, it was pressed with a tilt-type heat press at 100° C. for 15 seconds. After that, it was allowed to cool at room temperature and the release paper was peeled off to obtain a synthetic leather.
Regarding the obtained synthetic leather, the film thickness of the first layer measured by microscopic observation of the cross section of the synthetic leather was 10 μm, the film thickness of the second layer was 10 μm, and the first layer / second layer film thickness ratio was was 1.
(Urethane resin solution for adhesive layer)
Crisbon OA-360 (polyurethane solution manufactured by DIC Corporation) / DMF / ethyl acetate = 200/30/30 (weight ratio)
(wet base)
Polyurethane resin composed of polycarbonate diol, polytetramethylene glycol and MDI is wet coagulated on a woven fabric.

<Kneading texture workability>
For the obtained synthetic leather, a 12 cm square synthetic leather sample is folded in half with the back side of the leather facing up, sewn with a sewing machine, then turned over, so that the front side of the leather becomes the front side and the sewn part is rolled inside. A piece was made. A stirrer was set in a test bath adjusted to 80° C. with a water volume of 1500 mL, and two cylindrical test pieces were placed therein. From this state, the mixture was stirred at 100 rpm for 10 minutes while taking care not to entangle the cylindrical test piece with the stirrer. After that, take out the test piece, squeeze out the water by hand, untie the sewn part, and dry it in a constant temperature bath at 70°C. was evaluated as "x".

<Abrasion resistance>
According to JIS L1096-1972, two test pieces each of 3 cm×12 cm were cut longitudinally and laterally from the obtained synthetic leather. The obtained test piece is fixed between two grips that are opened to 20 mm in advance of a Scott-type testing machine (Scott-type anti-friction abrasion tester, manufactured by Toyo Seiki Seisakusho Co., Ltd.) in a state where the surfaces of the synthetic leather are mated, 1000 times of reciprocating rubbing was performed with a load of 9.81 N and a distance of between 40 mm. After the test, the surface appearance of the test piece was observed and evaluated according to the following evaluation criteria.
(criterion)
◎: No cracks ○: Slight cracks but usable level △: Cracks but usable level ×: Many cracks

<Color transfer resistance (antifouling property)>
A piece of denim (EMPA277, manufactured by Testfabrics) cut to a diameter of 140 mm was set on a Martindale tester conforming to ISO12947-1 with double-sided tape. A load of 12 kPa is applied to a rubbing element in which a synthetic leather cut to a diameter of 38 mm is attached so that the skin layer is in contact with a piece of denim, and a Lissajous figure motion with a stroke of 60 mm is applied for 5000 rotations to cause dirt to adhere to the skin layer. rice field. When the color of the denim did not transfer, it was evaluated as "○", and when the color of the denim did transfer, it was evaluated as "X".

[Production of Polycarbonate Diol]
<Production of Polycarbonate Diol A>
(First step reaction)
14.52 kg of 1,6-hexanediol, 17.95 kg of isosorbide, 37.9 kg of diphenyl carbonate, and 14.52 kg of 1,6-hexanediol were placed in a 180 L polymerization reactor equipped with a heat medium jacket, stirrer, reflux, condenser, distillate tank, cold trap, and vacuum pump. 53 kg, 5.3 mL of an aqueous magnesium acetate tetrahydrate solution (concentration: 200 g/L, 1.1 g of magnesium acetate tetrahydrate) was added (1,6-hexanediol and isosorbide were charged at a molar ratio of 50 mol% each). ) and replaced with nitrogen gas. Warm water of about 45°C was passed through the condenser as a refrigerant. First, oil was circulated through the jacket of the polymerization reactor to heat and dissolve the contents. After that, when the internal temperature reached 160° C., the pressure was lowered to 17.3 kPa over 5 minutes to start distilling off the by-product phenol. Thereafter, the pressure was lowered to 8.4 kPa over 120 minutes while keeping the internal temperature at 160° C. and distilling off the by-product phenol. At that time, the temperature of the heat medium oil in the polymerization reactor was 165 to 175°C. Distillation at this stage was 79% of theoretical phenol production.

(Second stage reaction)
Under a nitrogen atmosphere, the reaction mixture obtained in the first step was transferred to a 180 L polymerization reactor equipped with a heat medium jacket, a stirrer, a reflux device, a condenser, a distillate tank, a cold trap and a vacuum pump. Heat medium oil of 170° C. was circulated through the jacket of the polymerization reactor, and warm water of about 45° C. was passed through the condenser as a refrigerant. After transferring the reaction solution in the first stage, the pressure was lowered to 8.0 kPa over 5 minutes. At that stage, the temperature of the reaction liquid had reached 160° C., and the by-produced phenol began to distill out. Thereafter, the pressure was lowered to 0.4 kPa over 60 minutes, and the reaction was carried out while phenol and unreacted dihydroxy compounds were removed by distillation. After that, the reaction was continued at 171° C. and 0.40 kPa for 80 minutes, followed by filtration with a filter to obtain a polycarbonate diol-containing composition.

The resulting polycarbonate diol-containing composition was subjected to thin film distillation (temperature: 180°C, pressure: 0.067 kPa) at a flow rate of 20 g/min.
The polycarbonate diol contained in the polycarbonate diol product obtained by thin film distillation had a polystyrene-equivalent number average molecular weight (Mn) of 971 and a molecular weight distribution (Mw/Mn) of 1.98. Furthermore, the structural unit (1)/structural unit (2) molar ratio determined by NMR was 50/50, and the number average molecular weight determined from the hydroxyl value was 818.
The obtained polycarbonate diol product was a transparent solid at room temperature. In addition, the APHA value was 50, the content of isosorbide, which is a raw material diol, was 1.3% by weight, and no polymer with a phenoxy group terminal, a polymer containing an ether bond other than the isosorbide skeleton, or phenol was detected. The amount of residual diphenyl carbonate was below the limit of determination (0.01% by weight or less).

<Production of Polycarbonate Diol B>
Polycarbonate diol B was produced in the same manner as in the production of polycarbonate diol A above, except that the molar ratio of 1,6-hexanediol and isosorbide charged was isosorbide:1,6-hexanediol = 40:60 (mol%). manufactured.
The obtained polycarbonate diol had a number average molecular weight of 830 determined from the hydroxyl value, and a structural unit (1)/structural unit (2) molar ratio of 60/40.

<Production of Polycarbonate Diol C>
Polycarbonate diol C was produced in the same manner as polycarbonate diol B above, except that 1,4-butanediol was used instead of 1,6-hexanediol.
The obtained polycarbonate diol had a number average molecular weight of 797 determined from the hydroxyl value, and a structural unit (1)/structural unit (2) molar ratio of 60/40.

<Production of Polycarbonate Diol D>
Polycarbonate diol D was prepared in the same manner as in the production of polycarbonate diol C above, except that the molar ratio of 1,4-butanediol and isosorbide charged was isosorbide:1,4-butanediol=30:70 (molar ratio). manufactured.
The obtained polycarbonate diol had a number average molecular weight of 783 determined from the hydroxyl value, and a structural unit (1)/structural unit (2) molar ratio of 70/30.

<Production of Polycarbonate Diol E>
1,4-butanediol 1234.3 g, diphenyl carbonate 2765.7 g, magnesium acetate tetrahydrate aqueous solution 7.4 mL (concentration: 8.4 g/L, magnesium acetate tetrahydrate: 62 mg) was added, and the atmosphere was replaced with nitrogen gas. While stirring, the internal temperature was raised to 160° C. to heat and dissolve the contents. After that, the pressure was lowered to 24 kPa over 2 minutes, and the reaction was allowed to proceed for 90 minutes while removing phenol out of the system. The pressure was then lowered to 0.4 kPa over 120 minutes. Further, the temperature was raised to 170° C. in 30 minutes to remove phenol and unreacted dihydroxy compound out of the system, and reaction was continued for 90 minutes to obtain a polycarbonate diol-containing composition.
The obtained polycarbonate diol-containing composition was fed to a thin film distillation apparatus at a flow rate of 20 g/min, and subjected to thin film distillation (temperature: 210°C, pressure: 53 Pa) to obtain a polycarbonate diol. As the thin-film distillation apparatus, a molecular distillation apparatus MS-300 special type manufactured by Shibata Scientific Co., Ltd. with an internal condenser and a jacket having a diameter of 50 mm, a height of 200 mm and an area of 0.0314 m ² was used.
The obtained polycarbonate diol had a number average molecular weight of 2,089 determined from the hydroxyl value.

<Production of Polycarbonate Diol F>
Instead of 1,4-butanediol (100 mol%), 1,4-butanediol and neopentyl glycol were used in a ratio of 1,4-butanediol:neopentyl glycol = 70:30 (mol%). Polycarbonate Diol F was produced in the same manner as in the production of Polycarbonate Diol E above, except for the above.
The obtained polycarbonate diol had a number average molecular weight of 2,021 determined from the hydroxyl value.

<Production of Polycarbonate Diol G>
Instead of 1,4-butanediol (100 mol%), 1,4-butanediol and 1,10-decanediol were added to 1,4-butanediol:1,10-decanediol = 90:10 (mol%). Polycarbonate Diol G was produced in the same manner as in the production of Polycarbonate Diol E above, except that it was used at the ratio of ).
The obtained polycarbonate diol had a number average molecular weight of 3,066 determined from the hydroxyl value.

<Commercially available polycarbonate diol>
The following UM-90 and T6001 were prepared as commercially available polycarbonate diols.
UM-90: manufactured by Ube Industries, Ltd., polycarbonate diol using 50 mol % each of 1,6-hexanediol and cyclohexanedimethanol as starting diols, number average molecular weight: 903
T6001: manufactured by Asahi Kasei Chemical Co., Ltd., polycarbonate diol using 100 mol% of 1,6-hexanediol as raw material diol, number average molecular weight: 1004

[Manufacture of Polyurethane]
<Production of Polyurethane Using Polycarbonate Diol A>
Using Polycarbonate Diol A, a polyurethane was produced by the following procedure.

(Prepolymer (PP) formation reaction)
140.00 g of the above polycarbonate diol A preheated to 80° C. was placed in a separable flask equipped with a thermocouple and a cooling tube, and the flask was immersed in an oil bath at 60° C., followed by addition of 4,4′-dicyclohexyl. 90.72 g of methane diisocyanate (hereinafter H12MDI, manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.692 g of triisooctylphosphite (hereinafter TiOP, manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction inhibitor were added, and the flask was filled with a nitrogen atmosphere. The temperature was raised to 80° C. in about 1 hour while stirring at 60 rpm. After raising the temperature to 80° C., 11.5 mg of Neostan U-830 (hereinafter U-830, manufactured by Nitto Kasei Co., Ltd.) was added as a urethanization catalyst (50.0 ppm by weight based on the total weight of polycarbonate diol and isocyanate). After the heat generation subsided, the temperature of the oil bath was raised to 100° C., and the mixture was further stirred for about 2 hours. The concentration of isocyanate groups was analyzed to confirm that the theoretical amount of isocyanate groups had been consumed.

(chain extension reaction)
525.2 g of dehydrated N,N-dimethylformamide (hereinafter DMF, manufactured by Wako Pure Chemical Industries, Ltd.) was added to 225.1 g of the resulting prepolymer (PP), and the flask was immersed in an oil bath at 55° C. at about 200 rpm. The prepolymer was dissolved with stirring at . After analyzing the concentration of isocyanate groups in the prepolymer solution, the flask was immersed in an oil bath set at 35° C. and stirred at 150 rpm while adding the necessary amount of isophoronediamine (hereinafter IPDA, Tokyo Chemical Industry Co., Ltd.) calculated from the residual isocyanate. (manufactured) was added in divided portions. After stirring for about 1 hour, 2.80 g of morpholine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added as a chain terminating agent, and further stirred for 1 hour to obtain a polyurethane solution with a weight average molecular weight of 104,000 (polyurethane concentration: 32% by weight). got

<Production of other polyurethanes>
Polyurethane solutions were produced in the same manner as in the production of polyurethane using polycarbonate diol A above, except that those shown in Table 1 were used as raw material polycarbonate diols.
The weight average molecular weight of the obtained polyurethane was as shown in Table 1.

[Examples 1 to 8, Comparative Examples 1 to 3]
In the production of the synthetic leather described above, as the polyurethane solution for the first layer and the polyurethane solution for the second layer, synthetic leather was produced using the polyurethane solutions produced using the polycarbonate diols shown in Tables 2 to 4, respectively, and evaluated. did
Evaluation films were prepared as described above using the polyurethane solution for the first layer and the polyurethane solution for the second layer, and the 100% modulus of each was measured.
In addition, for the polyurethane solution for the first layer, the presence or absence of the yield point strength in the region with an elongation of 100% or less and its value were measured. Also, the breaking strength was measured.
Furthermore, the polyurethane solution for the first layer was evaluated for chemical resistance.
These results are shown in Tables 5 and 6.

From the above results, according to the present invention, the polyurethane layer constituting the skin layer has a two-layer laminate structure of polyurethanes having 100% different moduli, and a cyclic structure is introduced into the polyurethane constituting the polyurethane layer on the surface side. This artificial leather has excellent rubbing and texturing properties, and can achieve a texture and luxury similar to that of natural leather. Or it turns out that synthetic leather can be provided.

Claims (17)

An artificial leather or synthetic leather having a first polyurethane layer serving as a surface side and a second polyurethane layer serving as a lower layer of the first polyurethane layer,
The first polyurethane layer contains polyurethane A having a 100% modulus of 20 MPa or more and 100 MPa or less measured by the following tensile test,
The second polyurethane layer contains polyurethane B having a 100% modulus of 0.1 MPa or more and 40 MPa or less measured by the following tensile test,
The ratio of the 100% modulus of the polyurethane A to the 100% modulus of the polyurethane B is 1 or more and 1000 or less,
The polyurethane A has a structural unit derived from polycarbonate diol a containing a cyclic structure,
An artificial leather or synthetic leather in which 10% by weight or more of the first polyurethane layer is polyurethane A, and 10% by weight or more of the second polyurethane layer is polyurethane B.
<Tensile test>
According to JIS K6301 (2010), a strip-shaped polyurethane test piece having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm was measured using a tensile tester at a temperature of 23 at a chuck distance of 50 mm and a tensile speed of 500 mm/min. A tensile test is performed at °C and a relative humidity of 55%, and the stress is measured when the test piece is stretched 100%. 2. The artificial leather or synthetic leather according to claim 1, wherein said polyurethane A exhibits a yield point strength of 20 MPa or more in a region with an elongation of 10% or less in said tensile test. The artificial leather or synthetic leather according to claim 1 or 2, wherein the polyurethane A exhibits a breaking elongation of 50% or more in the tensile test. The artificial leather or synthetic leather according to any one of claims 1 to 3, wherein the polycarbonate diol a contains a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). .

(R ¹ in the above formula (1) represents an acyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms, and m is a number of 3 to 50. R ² in the above formula (2) has a number of carbon atoms represents a cycloaliphatic hydrocarbon group or heterocyclic group of 3 to 10, and n is a number of 1 to 30.) The molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) in the polycarbonate diol a (structural unit represented by the formula (1)/the structural unit represented by the formula (2) The artificial leather or synthetic leather according to claim 4, wherein the structural unit represented by is 85/15 to 15/85. The artificial leather or synthetic leather according to claim 4 or 5, wherein the structural unit represented by formula (2) is a structural unit derived from at least one diol selected from isosorbide, isomannide, and isoidide. The artificial leather or synthetic leather according to any one of claims 1 to 6, wherein the ratio of structural units derived from said polycarbonate diol a contained in said polyurethane A is 30 to 70% by weight. The artificial leather or synthetic leather according to any one of claims 1 to 7, wherein the polyurethane B has a structural unit derived from polyol b having a molecular weight of 500 or more and 2500 or less. The artificial leather or synthetic leather according to claim 8, wherein the polyol b contains an acyclic aliphatic compound having two or more hydroxyl groups. The artificial leather or synthetic leather according to claim 8 or 9, wherein the polyol b contains a polycarbonate diol. The artificial leather or synthetic leather according to any one of claims 1 to 10, wherein said polyurethane A and/or said polyurethane B is a polyurethane obtained by reacting a polyamine compound as a chain extender. The artificial leather or synthetic leather according to any one of claims 1 to 11, wherein the ratio of the film thickness of the first polyurethane layer to the film thickness of the second polyurethane layer is 0.01-100. The artificial leather or synthetic leather according to any one of claims 1 to 12, wherein the first polyurethane layer has a thickness of 1 to 100 µm. The artificial leather or synthetic leather according to any one of claims 1 to 13, wherein the second polyurethane layer has a thickness of 3 to 200 µm. The artificial leather or synthetic leather according to any one of claims 1 to 14, wherein the total thickness of the first polyurethane layer and the second polyurethane layer is 5 to 200 µm. A second polyurethane layer containing the polyurethane B and a first polyurethane layer containing the polyurethane A are sequentially laminated on a substrate having a microporous layer containing a polyurethane resin,
The artificial leather or synthetic leather according to any one of claims 1 to 15, wherein the base material is at least one selected from knitted fabric, woven fabric, and non-woven fabric. The artificial leather or synthetic leather according to claim 16, wherein the thickness of the microporous layer in the substrate is 50-400 µm.