WO2022191102A1 - Curable composition and synthetic leather - Google Patents

Abstract

The present invention provides a curable composition comprising component (a), which is a polyester polycarbonate polyol having a hydroxyl value of 40-75 mgKOH/g and having a specific structure, component (b), which is a polyol having a hydroxyl value of 100-280 mgKOH/g, and component (c), which is a polyisocyanate having two to six functional groups per molecule on average.

Description

Curable composition and synthetic leather

The present invention relates to a curable composition and synthetic leather.

Conventionally, as a synthetic leather with good flexibility, a polyurethane resin solution polymerized using a polyether polyol such as polypropylene glycol or polytetramethylene glycol is applied to a fibrous base material or membrane plate and solidified in water. There is something to be gained. Although these synthetic leathers are excellent in flexibility, they are susceptible to decomposition by components such as perspiration and have a problem in durability. There is also a synthetic leather obtained by coagulating a polyurethane resin solution polymerized using a polyester polyol obtained by reacting a hydroxy compound with a dibasic acid. This synthetic leather has a problem with hydrolysis resistance.

As a synthetic leather for solving these problems, for example, Patent Document 1 discloses a synthetic leather obtained from a polyurene resin polymerized using a polycarbonate diol. Specifically, in Patent Document 1, a urethane composition comprising a polyurethane composed of a polycarbonate diol, an organic isocyanate and a low-molecular-weight diol and a polyurethane composed of a polyester-based diol, an organic diisocyanate and a low-molecular-weight diol is contained in a fiber base material. and/or a porous sheet containing or attached to a fibrous substrate is disclosed.

Patent Document 2 discloses a porous sheet material obtained by applying a solution of a polyurethane resin composed of a polymeric diol, an organic isocyanate and, if necessary, a chain extender to a substrate and applying a wet film forming method. In the porous sheet material, the polymer diol is a mixed diol of polycarbonate diol and polyester diol, and the polycarbonate diol is 1,4-butanediol and one or more other alkanediols having 4 to 6 carbon atoms, and the diol is a copolymerized polycarbonate diol containing 50 to 90 mol % of 1,4-butanediol based on the total number of moles of the diol and having a number average molecular weight of 500 to 5000, and the coagulation value of the polyurethane resin is 7 to 14.

Patent Document 3 discloses an aliphatic oligocarbonate diol obtained by transesterification of an aliphatic diol and a dialkyl carbonate, and a polyester obtained by ring-opening addition polymerization of a cyclic ester compound using a compound having an active hydrogen group as an initiator. A synthetic leather surface coating layer using a polyurethane resin comprising a polyester polycarbonate diol obtained by transesterification reaction with a polyol, a polyisocyanate, and a chain extender is disclosed.

Patent Document 4 discloses a polycarbonate diol (a1) composed of an alkanediol having 4 to 6 carbon atoms and a polycarbonate diol (a2) composed of an alkanediol having 7 to 12 carbon atoms. is a copolymerized polycarbonate diol, and the percentage weight percentage of (a1) relative to the total weight of (a1) and (a2) is 10% or more and 80% or less, a polymer diol, an organic isocyanate, and a chain extender. A porous sheet material obtained by wet coagulation is disclosed.

Patent Document 5 discloses a fiber laminate surface layer material-forming composition composed of a main agent and a curing agent, wherein the main agent is a polycarbonate diol obtained from 1,6-hexanediol and a low-molecular-weight carbonate, and several curing agents are used. Composed of a hexamethylene diisocyanate-modified polyisocyanate (B1) having an average molecular weight of 350 to 500 and an average functional group number (f) of 2≦f<3 and an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate having f≧3 (B2). A surface layer material for a fiber laminate, wherein (B1):(B2) = 50:50 to 95:5 (weight ratio), and both the main agent and the curing agent do not contain an organic solvent. Synthetic leather is disclosed comprising a facing layer formed from a formative composition and a textile fabric.

Therefore, in Patent Document 6, a specific polycarbonate diol (1,5-pentanediol and 1,6-hexanediol) have been proposed.

Patent Document 7 proposes a polyurethane for synthetic leather that has an excellent balance of physical properties such as flexibility, chemical resistance, low temperature properties, heat resistance, and tactile feel. Here, a synthetic leather polyurethane obtained by reacting at least (a) a compound containing two or more isocyanate groups in one molecule, (b) a chain extender and (c) a polycarbonate diol, wherein the (c ) The polycarbonate diol has a hydroxyl value of 20 mg-KOH/g or more and 45 mg-KOH/g or less, a glass transition temperature measured by a differential scanning calorimeter of −30° C. or less, and is hydrolyzed A polyurethane for synthetic leather has been proposed, which is a polycarbonate diol having an average carbon number of 3 or more and 5.5 or less in the obtained dihydroxy compound.

In recent years, proposals have been made for environmentally friendly polyurethanes. For example, Patent Document 8 discloses a urethane prepolymer composition that is used by reacting active hydrogen in its components with a cross-linking agent to increase the molecular weight, and comprising at least , containing 20 to 80% by mass of a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH/g, and further, as a medium of the polymer, a urethane bond having a hydroxyl value of 20 to 400 mgKOH/g, which can be crosslinked with the above-mentioned crosslinking agent. a urethane prepolymer composition characterized by containing 20 to 80% by mass of a non-retaining oligomer, having substantially 100% non-volatile content, and being liquid at a temperature of at least 30° C., and the urethane A two-liquid solvent-free synthetic leather characterized by containing 90 to 150% by equivalent of a polyisocyanate cross-linking agent having an NCO content of 5 to 35% by mass with respect to the average hydroxyl value of the prepolymer composition. Polyurethanes have been proposed for

Patent No. 3142102 JP 2003-119314 A JP 2004-346094 A Patent No. 4177318 JP 2009-185260 A JP 2013-108196 A JP 2016-8234 A JP 2014-105250 A

However, although the synthetic leathers disclosed in Patent Documents 1 to 5 have hydrolysis resistance, they do not have sufficient sweat resistance for applications such as automobile seats that require high durability.

In addition, with the polycarbonate diol described in Patent Document 6, it is necessary to use a large amount of organic solvent during polyurethane polymerization, and further improvement is desired from the viewpoint of environmental load.

Furthermore, the polyurethane for synthetic leather disclosed in Patent Document 7 requires the use of a large amount of organic solvent during polyurethane polymerization, which is undesirable in terms of environmental load.

In addition, in order to make the polyurethane prepolymer composition for synthetic leather disclosed in Patent Document 8 solvent-free, poly-THF or THF- Since an ether-based polyol such as neopentyl glycol copolymerized polyol is used, the problem is that the heat resistance is lowered and the application is limited.

In view of the above problems, the present invention provides an environmentally friendly curable composition that has excellent balance of physical properties such as flexibility (tactile sensation), chemical resistance, low-temperature properties, and heat resistance, and uses a small amount of solvent. It is intended for The curable composition is provided for adhesives and coating agents that require flexibility such as synthetic leather.

As a result of intensive studies, the present inventors have found that a curable composition containing a polyester polycarbonate polyol having a predetermined structure, a polyol having a predetermined hydroxyl value, and a predetermined polyisocyanate has flexibility (feel) and chemical resistance. The inventors have found that it is possible to provide an eco-friendly synthetic leather which has an excellent balance of physical properties such as toughness, low-temperature properties, and heat resistance, and which can be produced using a reduced amount of solvent, thus completing the present invention.

 
（式（１）中、Ｒ_１は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（２）中、Ｒ_２は、炭素数２～１５の二価の炭化水素、Ｒ_３は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（３）中、Ｒ_４は、炭素数２～１５の二価の炭化水素である。）
　成分（ｂ）：水酸基価１００～２８０ｍｇＫＯＨ／ｇのポリオール、
　成分（ｃ）：１分子当たりの平均官能基数２～６のポリイソシアネート、を含む、硬化性組成物。
［２］
　成分（ｄ）:成分（ａ）の水酸基価４０～７５ｍｇＫＯＨ／ｇのポリエステルポリカーボネートポリオールと、成分（ｃ）の１分子当たりの平均官能基数２～６のポリイソシアネートとを、当量比［イソシアネート当量］／［水酸基当量］を１．５～３．０として予め反応させた、イソシアネート末端プレポリマー組成物、及び
　成分（ｂ）の水酸基価１００～２８０ｍｇＫＯＨ／ｇのポリオール、
を含む、[１]に記載の硬化性組成物。
［３］
　成分（ｅ）：成分（ｂ）の水酸基価１００～２８０ｍｇＫＯＨ／ｇのポリオールと、成分（ｃ）の１分子当たりの平均官能基数２～６のポリイソシアネートとを、当量比［イソシアネート当量］／［水酸基当量］を１．５～３．０として予め反応させた、イソシアネート末端プレポリマー組成物、及び
　成分（ａ）の水酸基価４０～７５ｍｇＫＯＨ／ｇのポリエステルポリカーボネートポリオール、
を含む、［１］に記載の硬化性組成物。
［４］
　成分（ａ）のポリエステルポリカーボネートポリオールと、成分（ｂ）のポリオールの質量割合が、９５／５～４０／６０である、［１］～［３］のいずれかに記載の硬化性組成物。
［５］
　式（１）で示される構造単位と、式（２）及び／又は式（３）で示される構造単位のモル比が９０／１０～１０／９０である、［１］～［４］のいずれかに記載の硬化性組成物。
［６］
　式（１）で表される繰り返し単位の内５０モル％以上が、式（４）、式（５）、及び式（６）から選ばれる少なくとも２種の繰り返し単位を含む、［１］～［５］のいずれかに記載の硬化性組成物。

 

 

 
［７］
　前記成分（ｂ）のポリオールが、式（７）で表される繰り返し単位と、末端水酸基とを有するポリカーボネートポリオールである、［１］～［６］のいずれかに記載の硬化性組成物。

 
（式（７）中、Ｒ_５は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）
［８］
　式（７）で表される繰り返し単位の内５０モル％以上が、式（８）、式（９）、及び式（１０）から選ばれる少なくとも２種の繰り返し単位を含む、［７］に記載の硬化性組成物。

 

 

 
［９］
　前記硬化性組成物全量に対し４０質量％以下の不活性有機溶剤を含む、［１］～［８］のいずれかに記載の硬化性組成物。
［１０］
　前記硬化性組成物全量に対し５０質量％以下のポリエステルポリオールを含む、［１］～［９］のいずれかに記載の硬化性組成物。
［１１］
　［１］～［１０］のいずれかに記載の硬化性組成物を用いてなる、合成皮革。 That is, the present invention includes the following aspects.
[1]
Component (a): a hydroxyl value having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) and/or the following formula (3), and having a hydroxyl group at the molecular end 40-75 mg KOH/g polyester polycarbonate polyol

(In formula (1), R ₁ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (2), R ₂ is a divalent hydrocarbon having 2 to 15 carbon atoms, and R ₃ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (3), R ₄ is a divalent hydrocarbon having 2 to 15 carbon atoms.)
Component (b): a polyol with a hydroxyl value of 100 to 280 mgKOH/g,
Component (c): a curable composition comprising a polyisocyanate having an average functionality of 2 to 6 per molecule.
[2]
Component (d): Polyester polycarbonate polyol of component (a) having a hydroxyl value of 40 to 75 mgKOH/g and polyisocyanate of component (c) having an average functional group number of 2 to 6 per molecule, equivalent ratio [isocyanate equivalent] / An isocyanate-terminated prepolymer composition pre-reacted with a [hydroxyl equivalent] of 1.5 to 3.0, and a polyol of component (b) having a hydroxyl value of 100 to 280 mgKOH/g,
The curable composition according to [1], comprising:
[3]
Component (e): A polyol having a hydroxyl value of 100 to 280 mgKOH/g of component (b) and a polyisocyanate having an average functional group of 2 to 6 per molecule of component (c) are mixed at an equivalent ratio [isocyanate equivalent]/[ an isocyanate-terminated prepolymer composition pre-reacted with a hydroxyl equivalent] of 1.5 to 3.0, and a polyester polycarbonate polyol of component (a) having a hydroxyl value of 40 to 75 mgKOH/g,
The curable composition according to [1], comprising:
[4]
The curable composition according to any one of [1] to [3], wherein the weight ratio of the component (a) polyester polycarbonate polyol and the component (b) polyol is 95/5 to 40/60.
[5]
Any of [1] to [4], wherein the molar ratio of the structural unit represented by formula (1) to the structural unit represented by formula (2) and/or formula (3) is 90/10 to 10/90 The curable composition according to 1.
[6]
50 mol% or more of the repeating units represented by formula (1) contain at least two repeating units selected from formula (4), formula (5), and formula (6), [1] to [ 5], the curable composition according to any one of the items.

[7]
The curable composition according to any one of [1] to [6], wherein the polyol of component (b) is a polycarbonate polyol having a repeating unit represented by formula (7) and a terminal hydroxyl group.

(In formula (7), R ₅ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)
[8]
50 mol% or more of the repeating units represented by formula (7) contain at least two repeating units selected from formula (8), formula (9), and formula (10), according to [7] curable composition.

[9]
The curable composition according to any one of [1] to [8], which contains an inert organic solvent in an amount of 40% by mass or less relative to the total amount of the curable composition.
[10]
The curable composition according to any one of [1] to [9], comprising a polyester polyol in an amount of 50% by mass or less relative to the total amount of the curable composition.
[11]
Synthetic leather using the curable composition according to any one of [1] to [10].

According to the curable composition of the present invention, it is possible to provide an environment-friendly cured product that is excellent in the balance of physical properties such as flexibility (touch), chemical resistance, low-temperature properties, and heat resistance, and that uses a small amount of solvent. can.

It is a cross-sectional view of an example of synthetic leather using the curable composition of the present embodiment. It is a figure which shows an example of the manufacturing-process drawing of the synthetic leather using the curable composition of this embodiment.

Hereinafter, the form for carrying out the present invention (hereinafter abbreviated as "this embodiment") will be described in detail. It should be noted that 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.

 
（式（１）中、Ｒ_１は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（２）中、Ｒ_２は、炭素数２～１５の二価の炭化水素、Ｒ_３は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（３）中、Ｒ_４は、炭素数２～１５の二価の炭化水素である。）
　成分（ｂ）：水酸基価１００～２８０ｍｇＫＯＨ／ｇのポリオール、及び
　成分（ｃ）：１分子当たりの平均官能基数２～６のポリイソシアネート、を含む、硬化性組成物である。本実施形態の硬化性組成物は、硬化することにより、すなわち、成分（ａ）及び成分（ｂ）と、成分（ｃ）とが反応することにより、ポリウレタンを形成する。この反応により得られるポリウレタンを合成皮革などの柔軟性の必要な接着剤やコーティング剤などとして使用することができる。 The composition of this embodiment is
Component (a): a hydroxyl value having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) and/or the following formula (3), and having a hydroxyl group at the molecular end 40-75 mg KOH/g polyester polycarbonate polyol

(In formula (1), R ₁ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (2), R ₂ is a divalent hydrocarbon having 2 to 15 carbon atoms, and R ₃ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (3), R ₄ is a divalent hydrocarbon having 2 to 15 carbon atoms.)
A curable composition comprising component (b): a polyol having a hydroxyl value of 100 to 280 mgKOH/g, and component (c): a polyisocyanate having an average functional group number of 2 to 6 per molecule. The curable composition of this embodiment forms a polyurethane by curing, that is, by reacting components (a) and (b) with component (c). Polyurethanes obtained by this reaction can be used as adhesives or coating agents that require flexibility such as synthetic leather.

Components (a), (b), and (c) are used in the curable composition of this embodiment.
The curable composition of the present embodiment may be a mixture of component (a), component (b) and component (c) as a curable composition, which can be obtained by a one-shot method described later. . Alternatively, the curable composition of the present embodiment prepares an isocyanate-terminated prepolymer composition obtained by reacting component (a) or component (b) with component (c) in advance, and the isocyanate-terminated prepolymer composition and component (b) or component (a) may be used as a curable composition. Therefore, the composition of the present embodiment also includes curable compositions of the following two aspects. The following two aspects can be obtained by a prepolymer method, which will be described later.

That is, in one aspect, the composition of the present embodiment is
Component (d):
Component (a) polyester polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH/g and component (c) polyisocyanate having an average functional group number of 2 to 6 per molecule were mixed at an equivalent ratio [isocyanate equivalent]/[hydroxy group equivalent]. A curable composition comprising: an isocyanate-terminated prepolymer composition pre-reacted at a 1.5 to 3.0;

In one aspect, the composition of the present embodiment is
Component (e):
A polyol having a hydroxyl value of 100 to 280 mgKOH/g of component (b) and a polyisocyanate having an average functional group of 2 to 6 per molecule of component (c) are combined so that the equivalent ratio [isocyanate equivalent]/[hydroxyl equivalent] is 1. A curable composition comprising: an isocyanate-terminated prepolymer composition, pre-reacted at .5 to 3.0;

The isocyanate-terminated prepolymer compositions of component (d) and component (e) may contain unreacted component (c) and/or unreacted component (a) or component (b).

The synthetic leather obtained from the curable composition of this embodiment has an excellent balance of physical properties such as flexibility (tactile feel), chemical resistance, low temperature properties, and heat resistance. In addition, the synthetic leather obtained from the curable composition of the present embodiment is an eco-friendly synthetic leather that can be produced using less solvent.

At least two types of polyols (a) and (b) having different hydroxyl values are used in the curable composition of the present embodiment. By using two kinds of polyols having different hydroxyl values, the solubility in solvents is increased, so that the amount of solvent to be used can be reduced as compared with the use of one kind of polyol alone. Although not bound by theory, polyester polycarbonate polyol with a low hydroxyl value (large molecular weight) (contributes to main physical properties such as flexibility) and polyol with a high hydroxyl value (low molecular weight) (reactive dilution Contributes to reducing the amount of solvent used as an agent), and has a good balance of flexibility (tactile sensation), chemical resistance, low-temperature properties, and heat resistance.

<Component (a)>
The polyester polycarbonate polyol used in the curable composition of the present embodiment is a polyester polycarbonate polyol (component (a)) having a hydroxyl value of 40 to 75 mgKOH/g. The hydroxyl value of component (a) is preferably 45-70 mgKOH/g, more preferably 50-65 mgKOH/g.
When the hydroxyl value of component (a) is 40 mgKOH/g or more, the resulting curable composition can be kept low in viscosity and the amount of organic solvent used can be reduced. Further, when the hydroxyl value of component (a) is 75 mgKOH/g or less, the resulting synthetic leather tends to have enhanced flexibility (feel) and low-temperature properties.

The melt viscosity at 50° C. of component (a) polyester polycarbonate polyol is preferably 1000 to 6000 mPa·s, more preferably 1500 to 5000 mPa·s, still more preferably 1800 to 4500 mPa·s, particularly preferably 2000 to 4500 mPa·s. It is 4500 mPa·s. When the melt viscosity of component (a) at 50° C. is 1000 mPa·s or more, the flexibility and low-temperature properties of the obtained cured product tend to be enhanced. Further, when the melt viscosity of the component (a) at 50° C. is 6000 mPa·s or less, the viscosity of the resulting curable composition can be kept low, and the amount of organic solvent used can be reduced.

The average number of hydroxyl groups in one molecule of component (a) polyester polycarbonate polyol is preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and more preferably 2.0 to 2.0. 5 is more preferred. When the average number of hydroxyl groups is 1.7 or more, the strength, chemical resistance, heat resistance, and hydrolysis resistance of the resulting cured product tend to increase. Further, when the average number of hydroxyl groups is 3.0 or less, not only can a suitable curing time be obtained, but also flexibility of the cured product can be obtained.

 
（式（１）中、Ｒ_１は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（２）中、Ｒ_２は、炭素数２～１５の二価の炭化水素、Ｒ_３は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。）

 
（式（３）中、Ｒ_４は、炭素数２～１５の二価の炭化水素である。） In the present embodiment, the component (a) polyester polycarbonate polyol has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) and/or the following formula (3), and the molecule The terminal is a hydroxyl group. Component (a) polyester polycarbonate polyol is not particularly limited, but for example, a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol), a dibasic acid and/or a cyclic ester compound, and a carbonate ester is used as a raw material, for example, it can be synthesized by the transesterification reaction described in "Polymer Reviews, Vol. 9, pp. 9-20".

(In formula (1), R ₁ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (2), R ₂ is a divalent hydrocarbon having 2 to 15 carbon atoms, and R ₃ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (3), R ₄ is a divalent hydrocarbon having 2 to 15 carbon atoms.)

Here, from the viewpoint of flexibility, R ₂ in formula (2) is preferably a divalent hydrocarbon having 2 to 15 carbon atoms and not containing an alicyclic structure.

The bifunctional diol compound used in the transesterification reaction is not particularly limited, but includes, for example, diols having a divalent aliphatic or alicyclic hydrocarbon skeleton with 2 to 15 carbon atoms. Specific examples of the bifunctional diol compound include ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,8-octanediol, 1, 11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 2-isopropyl-1,4-butanediol, 2-ethyl-1 ,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like.
These bifunctional diol compounds may be used alone or in combination of two or more.
Among these, from the viewpoint of obtaining a curable composition excellent in flexibility (feel), chemical resistance, low-temperature properties, and heat resistance, alkylenediols having 3 to 9 carbon atoms are preferred, and alkylenediols having 4 to 6 carbon atoms are preferred. more preferred. Moreover, it is preferable to use two or more kinds of alkylene diols together.

When the number of carbon atoms in the bifunctional diol compound is 2 or more, the viscosity of the curable composition can be kept low and the amount of organic solvent used can be reduced. tend to rise. When the number of carbon atoms in the bifunctional diol compound is 15 or less, the obtained cured product tends to have excellent chemical resistance.

By using two or more bifunctional diol compounds together, the regularity of the structural units of the obtained polyester polycarbonate polyol is lowered, and the crystallinity is lowered, so that a polyester polycarbonate polyol that is liquid at normal temperature (25 ° C.) can be obtained. Moreover, the flexibility of the curable composition tends to increase. In addition, there is a tendency that the amount of organic solvent to be used can be suppressed.
In addition, in the present embodiment, as a raw material for component (a) polyester polycarbonate polyol, a polyhydric alcohol compound having a functionality of 3 or more can be used, if necessary, in addition to the bifunctional diol.
Examples of polyhydric alcohol compounds include, but are not limited to, trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, and the like. By using a polyhydric alcohol, the average number of hydroxyl groups per molecule in component (a) can be easily adjusted within the range of 1.7 to 3.5.

In the present embodiment, 50 mol% or more of the repeating units represented by formula (1) contain at least two repeating units selected from formulas (4), (5), and (6). is preferred. The content of repeating units of formulas (4), (5) and (6) is preferably 70 mol % or more, more preferably 80 mol % or more.

 

 

 

 

 

 

In one aspect, among the repeating units represented by formula (1), at least two kinds of repeating units selected from formulas (4), (5), and (6) are 50 mol% or more, preferably 65 mol % or more, more preferably 80 mol % or more. When the repeating unit is 50 mol% or more, the resulting synthetic leather has excellent flexibility (feel), chemical resistance, low temperature properties, and heat resistance, and the amount of inert organic solvent used can be reduced. tends to be possible.

In the present embodiment, when two types of repeating units are selected from formulas (4), (5), and (6), the ratio of the two types of repeating units is 90:10 to 10:90 in terms of molar ratio. , preferably 70:30 to 30:70, more preferably 60:40 to 40:60. When the copolymerization ratio is within the above range, the crystallinity of the polyester polycarbonate polyol tends to decrease, and a cured product having high flexibility, good low-temperature properties, and good feel can be obtained. Furthermore, if the copolymerization ratio is within this range, there is a tendency that the amount of the inert organic solvent to be used can be reduced.

In the present embodiment, when three types of repeating units of formulas (4), (5), and (6) are selected, the structural units of formulas (4), (5), and (6) The ratio is preferably 5 mol% or more, more preferably 10 mol% or more, when the total of the three types of repeating units of formula (4), formula (5), and formula (6) is 100 mol%. , more preferably 20 mol % or more. Each of the three types of repeating units of formula (4), formula (5), and formula (6) in the total of the three types of repeating units of formula (4), formula (5), and formula (6) When the ratio is within the above range, the crystallinity of the polycarbonate diol tends to decrease, and a synthetic leather having high flexibility, good low-temperature properties, and good feel can be obtained. Furthermore, when the ratio of each of the three types of repeating units of formulas (4), (5), and (6) is within the above range, there is a tendency that the amount of inert organic solvent used can be reduced. It is in.

Dibasic acids that can be used to synthesize the component (a) polyester polycarbonate polyol include aliphatic and/or aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, and the like. Aliphatic dicarboxylic acids are particularly preferred for obtaining a cured product with excellent flexibility, and among these, succinic acid, glutaric acid and adipic acid are preferred. These dicarboxylic acids can also be used as esters of alcohols, such as methyl esters such as dimethyl succinate, dimethyl glutarate, and dimethyl adipate. These dicarboxylic acids may be used alone, or may be used in combination.

Cyclic esters that can be used to synthesize component (a) polyester polycarbonate polyols include α-acetolactone, β-propiolactone, γ-butyrolactone, σ-valerolactone, ε-caprolactone, cyclopentadecanolide, and cyclohexadecadecano. Norid, and the like. γ-butyrolactone, σ-valerolactone, and ε-caprolactone are particularly preferred, since the curable composition has an excellent balance between flexibility and chemical resistance.

The molar ratio of the polycarbonate structural unit represented by formula (1) and the polyester structural unit represented by formula (2) and/or formula (3) in component (a) polyester polycarbonate polyol is preferably 90/10 to 10 /90, more preferably 70/30 to 30/70, still more preferably 60/40 to 40/60.
Flexibility, chemical resistance, adhesion, A cured product having excellent hydrolysis resistance can be obtained. Furthermore, if the molar ratio of the polycarbonate structural unit represented by formula (1) and the polyester structural unit represented by formula (2) and/or formula (3) is within the above range, the amount of solvent used is reduced. be able to.

Examples of carbonate esters that can be used to synthesize component (a) polyester polycarbonate polyols include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; ethylene carbonate, trimethylene carbonate; Alkylene carbonates such as 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate and 1,2-pentylene carbonate; Dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or ethylene carbonate is preferably used as the carbonate from the viewpoint of availability and ease of setting conditions for the polymerization reaction.

A catalyst may or may not be added during the production of the component (a) polyester polycarbonate polyol. When a catalyst is added, it can be freely selected from catalysts used in ordinary transesterification reactions. Examples of catalysts include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, and cerium, and their Catalysts selected from metal salts, metal alkoxides thereof, and organic compounds containing the metals can be used. Among the above catalysts, organic compounds containing titanium, tin or lead are preferred. In addition, the amount of the catalyst used is usually 0.00001 to 0.1% of the mass of the bifunctional diol compound, which is the raw material, and the trifunctional or higher polyhydric alcohol which may be included as necessary.

In the present embodiment, as described above, the method for producing component (a) comprises a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol), a dibasic acid and/or a cyclic ester compound, and carbonic acid. It can be synthesized by transesterification using an ester as a raw material.
More specifically, the transesterification reaction is carried out according to the following procedure.
First, a predetermined ratio of one or more bifunctional diol compounds, a predetermined ratio of dibasic acid and/or a cyclic ester compound, a predetermined ratio of one or more carbonic acid esters, and necessary 1 or 2 or more trifunctional or higher polyhydric alcohols in a predetermined ratio according to the above, under normal pressure or reduced pressure, in the absence or presence of a transesterification catalyst, at 100 to 200 ° C., preferably The transesterification reaction is carried out at a temperature of 140-180°C.

Subsequently, by distilling off the alcohol derived from the carbonate ester and the water derived from the dibasic acid (when using the dibasic ester, the monoalcohol derived from the dibasic ester) produced during the reaction, the molecular weight of 300 ~ A polyester polycarbonate polyol of the order of 500 g/mol is obtained.

Next, under reduced pressure, at 130 to 230° C., preferably 150 to 200° C., a condensation reaction of the unreacted carbonate ester and difunctional diol, and the optionally contained trifunctional or higher polyhydric alcohol and dibasic acid. The resulting water (when using a dibasic ester, the monoalcohol derived from the dibasic ester) is distilled off, and a condensation reaction is performed to obtain the component (a) polyester polycarbonate polyol with a desired hydroxyl value.
The average number of hydroxyl groups of the component (a) polyester polycarbonate polyol can be adjusted by controlling the initial charge ratio of each component, the amount of each raw material distilled during production, and the amount of the reaction product.
When producing a polyester polycarbonate polyol using a cyclic ester, it is possible to synthesize it by the transesterification reaction described above, but after synthesizing the polycarbonate polyol first, the terminal hydroxyl groups of the polycarbonate polyol are modified with an alkali metal or the like. It can also be synthesized by carrying out ring-opening polymerization using this as the polymerization initiation point.

In the present embodiment, as a method for producing the component (a) polyester polycarbonate polyol, after producing a polycarbonate polyol and a polyester polyol in advance, the polycarbonate polyol and the polyester polyol are mixed, and under stirring, the transesterification catalyst is added. It can also be produced by transesterification at a temperature of 100 to 200° C. in the presence or absence.

<Component (b)>
Examples of component (b) polyols used in the curable composition of the present embodiment include polyether-based polyols, polyester-based polyols, polycarbonate-based polyols, polyolefin-based polyols, polybutadiene-based polyols, polyacrylic-based polyols, and oil-modified polyols. be done. Among these, polycarbonate-based polyols are more preferable because the resulting cured product is excellent in heat resistance, chemical resistance, and hydrolysis resistance.

The component (b) polyol used in the curable composition of the present embodiment is a polyol having a hydroxyl value of 100 to 280 mgKOH/g. The hydroxyl value of the component (b) polyol is preferably 130-250 mgKOH/g, more preferably 160-240 mgKOH/g.
When the hydroxyl value of the component (b) polyol is 100 mgKOH/g or more, the viscosity of the resulting curable composition can be kept low, and the amount of organic solvent used can be reduced. Further, when the hydroxyl value of the component (b) polyol is 280 mgKOH/g or less, the obtained synthetic leather is excellent in flexibility (feel) and low temperature properties.

The melt viscosity of component (b) at 50° C. is preferably 150 to 2000 mPa·s, more preferably 200 to 1500 mPa·s, still more preferably 300 to 1300 mPa·s, and particularly preferably 300 to 1000 mPa·s. . When the component (b) polyol has a melt viscosity of 150 mPa·s or more at 50° C., the resulting synthetic leather tends to have excellent flexibility (feel) and low-temperature properties. Further, when the melt viscosity of the component (b) at 50° C. is 2000 mPa·s or less, the viscosity of the resulting curable composition can be kept low, and the amount of organic solvent used can be reduced.

The average number of hydroxyl groups in one molecule of the component (b) polyol is preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and 2.0 to 2.5. It is even more preferable to have

 
（式（７）中、Ｒ_５は、炭素数２～１５の二価の脂肪族又は脂環族炭化水素である。） As the component (b) polyol, a polycarbonate polyol having a repeating unit represented by formula (7) and a terminal hydroxyl group is preferred.

(In formula (7), R ₅ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

When the polyol of the component (b) is a polycarbonate polyol, it is not particularly limited. , "Polymer Reviews, Vol. 9, pp. 9-20" and the like.

The bifunctional diol compound used in the transesterification reaction is not particularly limited, but includes, for example, diols having a divalent aliphatic or alicyclic hydrocarbon skeleton with 2 to 15 carbon atoms. Specific examples of the bifunctional diol compound include ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, and 1,5-pentane. Diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,8-octanediol, 1, 11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 2-isopropyl-1,4-butanediol, 2-ethyl-1 ,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like.
These bifunctional diol compounds may be used alone or in combination of two or more.
Among these, from the viewpoint of obtaining a curable composition excellent in flexibility (feel), chemical resistance, low-temperature properties, and heat resistance, alkylenediols having 3 to 9 carbon atoms are preferred, and alkylenediols having 4 to 6 carbon atoms are preferred. more preferred. Moreover, it is preferable to use two or more kinds of alkylene diols together.

When the number of carbon atoms in the bifunctional diol compound is 2 or more, the viscosity of the curable composition can be kept low and the amount of organic solvent used can be reduced. tend to rise. When the number of carbon atoms in the bifunctional diol compound is 15 or less, the obtained cured product tends to have excellent chemical resistance.

By using two or more kinds of bifunctional diol compounds in combination, the regularity of the structural units of the resulting polycarbonate polyol is lowered, and the crystallinity is lowered, so that a liquid polycarbonate polyol tends to be obtained at room temperature (25°C). Not only that, the flexibility of the curable composition is enhanced. In addition, there is a tendency that the amount of organic solvent to be used can be suppressed.
In addition, in the present embodiment, a trifunctional or higher polyhydric alcohol compound can be used as a raw material for the polycarbonate polyol, in addition to the bifunctional diol, if necessary.
Examples of polyhydric alcohol compounds include, but are not limited to, trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, and the like. By using a polyhydric alcohol, the average number of hydroxyl groups per molecule in component (b) can be easily adjusted within the range of 1.7 to 3.5.

 

 

  When the component (b) polyol in the present embodiment is a polycarbonate polyol of formula (7), 50 mol% or more of the repeating units represented by formula (7) are represented by formula (8), formula (9), and It preferably contains at least two repeating units selected from formula (10).

In the present embodiment, the preferred mass ratio of component (a) polyester polycarbonate polyol and component (b) polyol is the component ( The proportion of a) is preferably 40 to 95% by weight, more preferably 60 to 85% by weight, even more preferably 75 to 80% by weight. When the proportion of component (a) is 40% by mass or more, the resulting cured product tends to be more excellent in flexibility (feel) and low-temperature properties. When the proportion of component (a) is 95% by mass or less, the resulting curable composition tends to have a low viscosity and the amount of organic solvent used can be reduced.

Although component (a) and component (b) are used in the curable composition of the present embodiment, polyols other than component (a) and component (b) may be used in combination, if necessary. Here, the polyol other than the components (a) and (b) is not particularly limited as long as it is used in normal polyurethane production. Polyester-based polyols, polycarbonate-based polyols, polyolefin-based polyols, polybutadiene-based polyols, polyacrylic-based polyols, oil-modified polyols, and the like can be mentioned.
The mass ratio of components (a) and (b) to the combined mass of components (a) and (b) and other polyols is preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass. % by mass or more is more preferable. When the mass ratio of component (a) and component (b) is 50% by mass or more, the cured product tends to have an excellent balance of flexibility (feel), chemical resistance, low-temperature properties, and heat resistance. .

<Component (c)>
In the curable composition of the present embodiment, a polyisocyanate having an average functionality of 2 to 6 per molecule (component (c)) is used.
Examples of component (c) in the present embodiment include 2,4-triresin diisocyanate, 2,6-triresin diisocyanate and mixtures thereof, diphenylmethane-4,4′-diisocyanate (MDI), naphthalene-1,5- Aromatic diisocyanates such as diisocyanate (NDI), 3,3'-dimethyl-4,4'biphenylene diisocyanate (TODI) and polymethylene polyphenylene polyisocyanate (PMDI); aromatic aliphatics such as xylylene diisocyanate (XDI) and phenylene diisocyanate Diisocyanate; 4,4′-methylenebiscyclohexyl diisocyanate (hydrogenated (also referred to as hydrogenated) MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI) and other aliphatic diisocyanates; can be mentioned.

A polyisocyanate having an average of 2.1 or more isocyanate groups per molecule can also be used as the component (c) used in the present embodiment. Polyisocyanates having an average of 2.1 or more isocyanate groups per molecule include aromatic polyisocyanates such as crude MDI and crude TDI; derivatives of aliphatic isocyanates such as HDI and IPDI, specifically biuret; Diisocyanate derivatives such as allophanates, uretdiones, isocyanurates; and polyhydric alcohol adduct types can be used.
The polyisocyanate having 2.1 or more isocyanate groups in one molecule is not particularly limited. HL (manufactured by Sumika Bayer Urethane), various duranates manufactured by Asahi Kasei Corporation, namely Duranate 24A-100, Duranate 22A-75PX, Duranate 18H-70B, Duranate 21S-75E, Duranate THA-100, Duranate TPA-100, Duranate- TKA100, DURANATE MFA-75X, DURANATE TSA-100, DURANATE TSS-100, DURANATE TSE-100, DURANATE D-101, DURANATE D-201, DURANATE P-301-75E, DURANATE E-402-90T, DURANATE E-402 -90T, DURANATE E-405-80T, DURANATE ME20-100, DURANATE 17B-60PX, DURANATE TPA-B80X, DURANATE MF-B60X, DURANATE E-402-B80T, DURANATE ME20-B80S, DURANATE WB40-100, DURANATE WB40- 80D, Duranate WT20-100, Duranate WT30-100, etc.

Furthermore, component (c) is blocked with known blocking agents such as lower alcohols such as butanol and 2-ethylhexanol, methyl ethyl ketone oxime, lactams, phenols, imidazoles, and active methylene compounds, ie, so-called blocked Isocyanates can also be used.

The amount of component (c) used is preferably 0.7 to 1.0 when expressed as [isocyanate equivalent of component (c)]/[sum of hydroxyl equivalents of both component (a) and component (b)]. 3, more preferably 0.8 to 1.2, more preferably 0.9 to 1.1. [isocyanate equivalent of component (c)]/[sum of hydroxyl equivalents of both component (a) and component (b)] is 0.7 or more and 1.3 or less, so that the molecular weight of the obtained polyurethane is appropriately controlled. It tends to be excellent in mechanical properties such as strength, elongation, and wear resistance.

It is preferred to use an aromatic polyisocyanate such as MDI as component (c). By using an aromatic polyisocyanate, there is a tendency to obtain a cured product having excellent mechanical properties. When an aromatic polyisocyanate such as MDI is used as the component (c) in the curable composition, the curable composition can be suitably used as an adhesive between the base fabric and skin layer of synthetic leather.
In addition, when an aliphatic polyisocyanate such as hydrogenated MDI is used in the curable composition as the component (c), the curable composition provides a synthetic leather with excellent weather resistance. It is suitably used as a curable composition and the like.

<Chain extender>
A chain extender can be used in the curable composition of the present embodiment, if necessary. A chain extender is used to increase the abrasion resistance and strength of the resulting polyurethane, but it may reduce the flexibility of the resulting polyurethane, so it is used as needed. Examples of chain extenders include, but are not limited to, short-chain diols such as ethylene glycol and 1,4-butanediol; polyhydric alcohols such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, and glycerin; etc. The chain extender is not particularly limited, but examples include ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, and isophorone. Diamines such as diamine, and water.

The amount of the chain extender added is preferably 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, still more preferably 5% by mass or more and 10% by mass, based on the total of component (a) and component (b). % or less. It is desirable to adjust the amount of isocyanate according to the added amount of the chain extender. For example, the isocyanate equivalent of component (c) to be used is preferably 0.5 to the sum of the hydroxyl equivalents of both components (a) and (b) plus the functional group equivalents of the chain extender. It is adjusted to 7 to 1.3 equivalents, more preferably 0.8 to 1.2 equivalents, still more preferably 0.9 to 1.1 equivalents.

A chain extender can be used to adjust physical properties such as strength, abrasion resistance, and flexibility of polyurethane after curing. In addition, by using a polyhydric alcohol as a chain extender, the crosslink density of the polyurethane obtained can be increased, and the strength, abrasion resistance, and chemical resistance can be improved. It can be suitably used as a skin material for.

<Inert organic solvent>
The curable composition of the present embodiment may optionally contain an inert organic solvent in order to adjust workability during urethane production. The content of the inert organic solvent is preferably 40% by mass or less, more preferably 3% by mass or more and 35% by mass or less, still more preferably 3% by mass or more and 30% by mass or less, particularly preferably 40% by mass or less, based on the total amount of the curable composition. is 5% by mass or more and 20% by mass or less. Addition of an inert organic solvent is effective in reducing the viscosity of the curable composition, improving its workability, and further improving the appearance of the resulting cured product. On the other hand, the content of the inert organic solvent is preferably suppressed to a small amount from the viewpoint of reducing the environmental load.

The inert organic solvent is not particularly limited as long as it is substantially inert to polyisocyanate, and preferably does not have active hydrogen. Examples of inert organic solvents include, but are not limited to, hydrocarbons such as pentane, hexane, heptane, octane, decane, petroleum ether, petroleum benzine, ligroin, petroleum spirit, cyclohexane, and methylcyclohexane; Fluorinated inert liquids such as fluorinated oils such as chlorodifluoroethane and perfluoroether; perfluorocyclohexane, perfluorobutyltetrahydrofuran, perfluorodecalin, perfluoro-n-butylamine, perfluoropolyether, dimethylpolysiloxane be done. These may be used singly or as a mixture. Examples of inert organic solvents further include methyl ethyl ketone (also referred to as MEK), acetone, ethyl acetate, butyl acetate, toluene, xylene and the like alone or in mixtures.

<Polyester polyol>
In order to improve workability and adhesiveness during production, the curable composition of the present embodiment contains a polyester polyol as necessary relative to the total amount of the curable composition, usually 50% by mass or less, preferably 5% by mass. 40 mass % or less, more preferably 10 mass % or more and 30 mass % or less may be contained. When the polyester polyol content is 50% by mass or less, the wet heat resistance (hydrolyzability) tends to increase.

Examples of polyester polyols include, but are not limited to, ethylene glycol adipate, propanediol adipate, butanediol adipate, 3-methyl-1,5-pentanediol adipate, and polycaprolactone polyol. The hydroxyl value of the polyester polyol is preferably 25-200 mgKOH/g, more preferably 30-130 mgKOH/g, and still more preferably 40-70 mgKOH/g.

<Other additives>
The curable composition of the present embodiment contains curing accelerators (catalysts), fillers, flame retardants, dyes, organic or inorganic pigments, release agents, fluidity modifiers, plasticizers, antioxidants, and agents, ultraviolet absorbers, light stabilizers, antifoaming agents, leveling agents, coloring agents, foaming agents and the like can be added.

Curing accelerators include, but are not limited to, amines and metal catalysts.
The effect accelerator of amines is not particularly limited, but for example, monoamines such as triethylamine and N,N-dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, other triamines, cyclic amines, and alcohol amines such as dimethylethanolamine. , ether amines, and the like.
Examples of metal catalysts include, but are not limited to, potassium acetate, potassium 2-ethylhexanoate, calcium acetate, lead octylate, dibutyltin dilaurate, tin octoate, bismuth neodecanoate, bismuth oxycarbonate, bismuth 2 - ethylhexanoate, zinc octoate, zinc neodecanoate, phosphine, phospholine, and the like.

Examples of fillers and pigments include, but are not limited to, woven fabric, glass fiber, carbon fiber, polyamide fiber, mica, kaolin, bentonite, metal powder, azo pigment, carbon black, clay, silica, talc, gypsum, and alumina. white, barium carbonate, and the like.

Release agents, fluidity modifiers, and leveling agents are not particularly limited, but examples include silicone, aerosil, wax, stearate, and polysiloxane such as BYK-331 (manufactured by BYK Chemicals).

Antioxidants, light stabilizers and heat stabilizers are preferably used as additives used in this embodiment.
Antioxidants are not particularly limited, but examples include phosphoric acid, phosphorous acid, aliphatic, aromatic or alkyl-substituted aromatic esters, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, and polyphosphonates. Phosphorus compounds such as dialkylpentaerythritol diphosphite and dialkylbisphenol A diphosphite; Compounds containing; tin-based compounds such as tin malate and dibutyltin monoxide can be used. These may be used alone or in combination of two or more.

<Method for producing cured product>
A cured product using the curable composition of the present embodiment can be produced by a generally industrial production method.

The curable composition of the present embodiment is produced by, for example, a method of mixing and reacting components (a), (b), and (c) together (hereinafter referred to as “one-shot method”). be able to.
The curable composition of the present embodiment can be prepared, for example, by first reacting component (a) and component (c) in advance to prepare a prepolymer composition (component (d)) having an isocyanate group at the end, and then component ( A method of blending b) (hereinafter referred to as "prepolymer method"), and first, pre-reacting component (b) and component (c) to form a prepolymer composition having an isocyanate group at the end (component (e) ) is prepared and then the component (a) is blended (this method is also classified as a “prepolymer method”).

(One-shot method)
When the curable composition is obtained by the one-shot method, the amount of component (c) to be used is usually preferably 0.00 in terms of isocyanate equivalent with respect to the sum of the hydroxyl group equivalents of both component (a) and component (b). 7 to 1.3 equivalents, more preferably 0.8 to 1.2 equivalents, still more preferably 0.9 to 1.1 equivalents. When the amount of component (c) used is 0.7 equivalents or more and 1.3 equivalents or less, the molecular weight of the resulting polyurethane can be appropriately controlled, and mechanical properties such as strength, elongation and abrasion resistance tend to be excellent. be. When obtaining a curable composition by the one-shot method, an inert organic solvent can be used for the purpose of improving workability during production. In general, when polyols (corresponding to components (a) and (b)) and polyisocyanates (corresponding to component (c)) are mixed, the viscosity of the curable mixture increases over time. By adding an inert organic solvent to the curable composition, the viscosity of the composition can be lowered, and there is a tendency that the coating time can be extended.

When using other additives, the other additives may be added at the same time when component (a), component (b), and component (c) are mixed together, and component (a) and / or component (a) and / or component (a) may be added in advance. You may mix with (b).

(Prepolymer method)
As the prepolymer method, component (a) and component (c) are reacted in advance to prepare a terminal isocyanate group prepolymer composition (simply referred to as a prepolymer composition), and then component (b) is added. method.
Further, as the prepolymer method, there is also a method in which component (b) and component (c) are preliminarily reacted to prepare an isocyanate-terminated prepolymer composition, and then component (a) is added.

The ratio of component (a) or component (b) to component (c) during prepolymer synthesis is the isocyanate group contained in component (c) and the hydroxyl group contained in component (a) or component (b). The equivalent ratio [isocyanate equivalent]/[hydroxyl equivalent] is adjusted to 1.5 to 3.0, preferably 1.8 to 2.7, more preferably 1.9 to 2.3. By setting the [isocyanate equivalent]/[hydroxy equivalent] at the time of prepolymer synthesis to 1.5 or more, the molecular weight of the obtained prepolymer is appropriately controlled, the viscosity of the prepolymer is suppressed, and the use of organic solvents is reduced. can do. When the [isocyanate equivalent]/[hydroxy group equivalent] is 3.0 or less at the time of prepolymer synthesis, unreacted component (c) is suppressed, and there is a tendency to suppress hardening of the resulting polyurethane.

The ratio of the isocyanate group-terminated prepolymer composition obtained by pre-reacting the component (a) and the component (c) to the component (b), or the isocyanate obtained by pre-reacting the component (b) and the component (c) The ratio of the group-terminated prepolymer composition to component (a) is preferably 0.7 to 0.7 as [isocyanate equivalent of prepolymer composition]/[hydroxyl equivalent of component (a) or component (b)]. 1.3, more preferably 0.8 to 1.2, still more preferably 0.9 to 1.1. [isocyanate equivalent of the prepolymer composition]/[hydroxyl value equivalent of component (a) or component (b)] is 0.7 equivalent or more and 1.3 equivalent or less, so that the molecular weight of the obtained polyurethane is appropriately controlled. It tends to be excellent in mechanical properties such as strength, elongation, and wear resistance.

When obtaining a curable composition by the prepolymer method, an inert organic solvent can be used for the purpose of improving workability during production. The amount of the inert organic solvent used is preferably 40% by mass or less. Mixing the isocyanate-terminated prepolymer composition with the polycarbonate polyol increases the viscosity of the curable composition over time. By adding an inert organic solvent to the curable composition, the viscosity of the composition can be lowered, and there is a tendency that the coating time can be extended.

When using an inert organic solvent, the viscosity increases during prepolymer synthesis. It is preferred to carry out the reaction. In addition, the use of an inert organic solvent during prepolymer synthesis tends to allow the reaction to proceed uniformly.

When other additives are used, the polycarbonate polyol tends to increase in viscosity by prepolymerization. Therefore, when mixing other additives, the non-prepolymerized polycarbonate polyol (component (a) to be added later) or component (b)).

Comparing the one-shot method and the prepolymer method, the prepolymer method makes it easier to adjust the molecular weight of the soft segment portion, and as a result, phase separation between the soft segment and the hard segment occurs more easily, and the flexibility of the resulting polyurethane increases. tend to be excellent in terms of heat resistance and low-temperature properties. Therefore, in one aspect, the prepolymer method is preferred.

In the prepolymer method, when comparing the method of prepolymerizing the component (a) with the method of prepolymerizing the component (b), the method of prepolymerizing the component (b) is the prepolymer obtained. viscosity can be lowered, and the amount of inert organic solvent to be used tends to be reduced. Therefore, in one aspect, the method of prepolymerizing component (b) is preferred.

<Manufacturing method of synthetic leather>
A synthetic leather can be produced from the curable composition of the present embodiment. Methods for producing synthetic leather from the curable composition of the present embodiment include, for example, a wet method in which the curable composition of the present embodiment is applied or impregnated onto a base material (base fabric) and wet coagulated; A dry method in which the curable composition of is applied to a release paper or a base material (base fabric) and dried.
Furthermore, as a method for producing synthetic leather, the curable composition of the present embodiment is applied to release paper to form a skin material, and then the curable composition of the present embodiment is used as an adhesive layer thereon. , a transfer coating method (a kind of dry method) can also be used in which the release paper is removed after bonding the base material (base fabric).
A dry method (transfer coating method) is preferably used for the curable composition of the present embodiment, since the amount of inert organic solvent used can be suppressed.

The method for producing synthetic leather will be described below using the dry method as an example.
As the base material (base fabric), various materials can be used, and examples thereof include fibrous base materials. Examples of the fibrous base material include a fiber assembly in which fibers are formed into a nonwoven fabric, a woven fabric, a net cloth, or the like, or a fiber assembly in which each fiber is bonded with an elastic polymer. Examples of fibers used in this fiber aggregate include natural fibers such as cotton, hemp and wool; regenerated or semi-synthetic fibers such as rayon and acetate; and synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol and polyolefin. be done. These fibers may be singly spun fibers or mixed spun fibers. Other substrates include paper, release paper, polyester and polyolefin plastic films, metal plates such as aluminum, and glass plates.

The curable composition of this embodiment can be applied by a commonly used method. Examples of the coating method include floating knife coater, knife over roll coater, reverse roll coater, roll doctor coater, gravure roll coater, kiss roll coater and the like.

The obtained synthetic leather can be used as it is. Alternatively, this synthetic leather can be obtained in a form in which a solution or emulsion of a polymer such as polyurethane resin, vinyl chloride or cellulose resin is applied to the synthetic leather for the purpose of further imparting various properties. In addition, the synthetic leather can also be obtained in the form of a laminate obtained by peeling off the release paper after laminating the synthetic leather with the coating film obtained by drying the polymer solution or emulsion separately coated on the release paper. can.

The present embodiment will be described below with reference to the drawings. The drawings and manufacturing conditions described below are one form of the present embodiment, and the present embodiment is not limited thereto.

FIG. 1 is a schematic cross-sectional view of the synthetic leather laminate produced by the dry method shown in FIG. This laminate structure has a skin layer 2 on a substrate (nonwoven fabric) 4 with an adhesive layer 3 interposed therebetween. The release paper 1 used at the time of manufacture is adhered to the outermost layer, but is peeled off when used.

FIG. 2 is a schematic diagram showing one method for producing a dry synthetic leather laminate sheet using the curable composition of the present invention of the present embodiment. In this production method, first, each raw material of the curable composition of the present embodiment, which has been adjusted to a predetermined temperature in advance, is mixed with the mixing head 5, and the resulting curable composition is spread on the release paper 1 (usually leather-like). patterned).
When applying the one-shot method, components (a), (b), and (c), and optionally inert organic solvents, chain extenders, and additives are added separately or together with component (c). Two of the other raw materials (component (a), component (b), a mixture of an inert organic solvent, a chain extender, and an additive if necessary) are continuously fed to the mixing head 5. , mixed, and flowed down onto the release paper 1 .
When applying the prepolymer method, a prepolymer composition, a non-prepolymerized polycarbonate polyol or polyol (component (a) or component (b)), if necessary an inert organic solvent, a chain extender, an additive separately, or the prepolymer composition and other raw materials (non-prepolymerized polycarbonate polyol or polyol (component (a) or component (b)), if necessary an inert organic solvent, a chain extender, addition agent mixture) are continuously fed to the mixing head 5, mixed and run down onto the release paper 1.

Each component before mixing is usually adjusted to a temperature of 20-80°C, preferably 30-70°C, more preferably 40-60°C. The temperature of the mixing head 5 is also adjusted to a temperature of usually 20.degree. C. to 80.degree. C., preferably 30 to 70.degree. C., more preferably 40 to 60.degree. By setting the temperature of each component before mixing and the temperature of the mixing head 5 to 20° C. or higher, the viscosity of the raw materials used, particularly the polycarbonate polyol or polyol, is suppressed, and the flow rate tends to be stabilized. In addition, by setting the temperature of each component before mixing and the temperature of the mixing head 5 to 80° C. or less, the curing speed of the curable composition of the present embodiment is appropriately controlled, and the viscosity of the curable composition rises sharply. It tends to suppress and obtain a uniform thickness of synthetic leather.

After that, it is passed through a coating roll 8 to form a sheet of a certain thickness, and then passed through a dryer 11 for curing and drying of the inert organic solvent to form the skin layer 2 of synthetic leather. The temperature of the dryer is usually set at 60-150°C, preferably 70-130°C, more preferably 80-120°C. The drying time is typically 2 to 15 minutes, preferably 3 to 10 minutes, more preferably 4 to 7 minutes.

Next, the curable composition of the present embodiment obtained by mixing raw materials of the curable composition of the present embodiment adjusted to a predetermined temperature in advance with the mixing head 6 is flowed down to form the adhesive layer 3 .
When applying the one-shot method to manufacture the adhesive layer, components (a), (b), and (c), and optionally inert organic solvents, chain extenders, and additives are added separately, or A mixture of component (c) and other raw materials (component (a), component (b), an inert organic solvent, a chain extender, and an additive if necessary) is mixed with the mixing head 6 continuously fed to, mixed and run down onto the epidermal layer.
When applying the prepolymer method to the production of the adhesive layer, a prepolymer composition, a non-prepolymerized polyol (component (a) or component (b)), an inert organic solvent as necessary, a chain extender, Additives separately, or prepolymer composition and other raw materials (non-prepolymerized polyol (component (a) or component (b)), inert organic solvent as necessary, chain extender, additives ) are continuously fed to the mixing head 6, mixed and flowed down onto the skin layer.

Each component before mixing is usually adjusted to a temperature of 20-60°C, preferably 30-50°C, more preferably 35-45°C. The temperature of the mixing head 6 is also adjusted to a temperature of usually 20-60°C, preferably 30-50°C, more preferably 35-45°C. By setting the temperature of each component before mixing and the temperature of the mixing head 6 to 20° C. or higher, the viscosity of the raw materials used, particularly the polyester polycarbonate polyol, is suppressed, and the flow rate tends to be stabilized. Further, by setting the temperature of each component before mixing and the temperature of the mixing head 6 to 60° C. or less, the curing speed of the curable composition of the present embodiment is appropriately controlled, and the viscosity of the curable composition rises rapidly. It tends to suppress and obtain a uniform thickness of synthetic leather.

After that, it is passed through a coating roll 8 to form a sheet of a certain thickness, and then passed through a dryer 11 to cure and dry the inert organic solvent to form an adhesive layer 3 of synthetic leather. Next, the base material 4 and the adhesive layer 3 are superimposed and pressed together by a pressing roll 9 to obtain a sheet structure 7, which is wound by a winding roll 10 to obtain a desired synthetic leather laminate. The temperature of the dryer 11 is usually set at 60-150°C, preferably 70-130°C, more preferably 80-120°C. The drying time is usually 2 to 15 minutes, preferably 3 to 10 minutes, more preferably 4 to 7 minutes.

FIG. 2 shows an example of manufacturing a synthetic leather containing three layers of skin layer / adhesive layer / base material, but a synthetic leather laminate containing two layers of skin layer / base material, omitting the adhesive layer, is also similar. Can be manufactured on-site. Adhesion between the skin layer and the substrate is controlled by adjusting the curing state of the curable composition. Specifically, it can be obtained by press-bonding the curable composition of the present embodiment with a substrate in a state in which it is not completely cured. Therefore, the curing temperature of the dryer 11 is set to 60 to 150.degree. C., preferably 70 to 130.degree. C., more preferably 80 to 120.degree. The drying time is usually set to 2 to 15 minutes, preferably 3 to 10 minutes, more preferably 4 to 7 minutes.

<Application>
Synthetic leather obtained using the curable composition of the present embodiment can be used for automobile interior materials such as automobile seats, furniture such as sofas, clothing, shoes, bags, miscellaneous goods, and the like. It is also used as a lamination welding adhesive for various films and as a surface protective agent.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as it does not exceed the gist thereof. 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 Polyester Polycarbonate Polyol and Polyol]
<Polyester polycarbonate polyol and hydroxyl value of polyol>
Measured according to JIS K1557-1.

<Composition of polyester polycarbonate polyol and polyol (copolymerization ratio)>
1 g of a polycarbonate polyol or a sample of polyol was placed in a 100 mL eggplant flask, 30 g of methanol and 8 g of a 28% sodium methoxide methanol solution were added, and reacted at 100° C. for 1 hour. After cooling the reaction solution to room temperature, 2 to 3 drops of phenolphthalein were added to the indicator and neutralized with hydrochloric acid. After cooling in a refrigerator for 1 hour, it was filtered and analyzed by gas chromatography (GC). GC analysis uses gas chromatography GC-14B (manufactured by Shimadzu Corporation, Japan) equipped with DB-WAX (manufactured by J&W, USA) as a column, diethylene glycol diethyl ester as an internal standard, flame ionization type detection group (FID ) was used as a detector to quantitatively analyze each component. The temperature rise profile of the column was as follows: after holding at 60°C for 5 minutes, the temperature was raised to 250°C at 10°C/min.
From the molar ratio of each alcohol component detected from the above analysis results and the methyl ester component derived from dibasic acid and / or the methyl ester component derived from cyclic ester, polyester polycarbonate polyol or polyol composition (copolymerization ratio) is obtained. rice field.
For the composition of polyester polycarbonate polyol containing dibasic acid, the number of moles of diols constituting the carbonate skeleton is obtained by using the value obtained by subtracting the same number of moles of diol as the number of moles of methyl ester derived from dibasic acid. (When multiple diols are used, the ratio of diols determined by gas chromatography is subtracted as the same).

<Polycarbonate polyol and average functional group number of polyol>
The average number of functional groups of the polycarbonate polyol synthesized using only the diol monomer as the raw material was 2. When a polyfunctional monomer was included as a raw material, the average number of functional groups was determined as follows. The number average molecular weight (Mn) of the polycarbonate polyols was determined by gel permeation chromatography (GPC) analysis (see below for GPC apparatus and analysis conditions) with a standard polystyrene standard of known molecular weight. Based on the separately analyzed hydroxyl value and the number average molecular weight (Mn) determined by GPC, the average number of functional groups (n) per molecule was determined by the following formula (11). Polyol was also obtained by the same method.

Average functional group number (n) = [Mn] x ([OH value] x 10-3/56.1) (11)

GPC device: HLC-8320 manufactured by Tosoh Corporation
Column: TSKgel G4000H 1, G3000H 1, G2000H 2 Eluent: THF (tetrahydrofuran)
Flow rate: 1.0 mL/min
Column temperature: 40°C
RI detector: RI (equipment HLC-8320 built-in)

<Measurement of melt viscosity>
After preheating the polyester polycarbonate polyol or polyol to 50° C., the melt viscosity was measured at 50° C. using an E-type viscometer (TVE-22HT, cone: No. 6, manufactured by Toki Sangyo Co., Ltd.).

[Analysis and Evaluation of Prepolymer Composition]
<Measurement of melt viscosity>
After preheating the prepolymer composition to 50° C., the melt viscosity is measured at 50° C. using an E-type viscometer (TVE-22HT, cone: No. 6, manufactured by Toki Sangyo Co., Ltd.) under a nitrogen atmosphere. did.

<Measurement of isocyanate group concentration>
After diluting 10 mL of a mixed solution of di-n-butylamine/toluene (weight ratio: 25.85/865) with 10 mL of dimethylformamide (DMF), titration was performed with a 0.1 N hydrochloric acid propanol solution. was measured and used as a blank value. After that, 2 g of the prepolymer liquid was taken out, 10 mL of a mixed solution of di-n-butylamine/toluene was added, and after stirring at room temperature for 30 minutes, it was diluted with 10 mL of DMF in the same manner as the blank measurement, and a 0.1 N hydrochloride propanol solution was prepared. The amount of propanol hydrochloride solution required for neutralization was determined by titration with , and the amount of residual amine was quantified. From the volume of the hydrochloride propanol solution required for neutralization, the concentration of the isocyanate group was obtained by the following formula (12).

Isocyanate group concentration (mass%)
= (V1-V2) x f x 42 x 100/(W x 1000) (12)

V1: Amount (mL) of 0.1 N hydrochloride propanol solution required for blank measurement
V2: Amount (mL) of 0.1 N hydrochloride propanol solution required for this measurement
W: sample used for this measurement (g)
f: factor of propanol hydrochloride solution

<Isocyanate equivalent>
The isocyanate equivalent was determined by the following formula (13) based on the number of functional groups according to the type of polyisocyanate or prepolymer.
Isocyanate equivalent (mol) = charged weight (g)/molecular weight of isocyanate (g/mol) x number of functional groups (13)

<Hydroxyl equivalent>
Similarly, the hydroxyl group equivalent was determined by the following formula (14) based on the number of functional groups according to the type of polyester polycarbonate polyol or polyol.
Hydroxyl equivalent (mol) = charged weight (g) / molecular weight of polyester polycarbonate polyol or polyol (g/mol) x number of functional groups (14)

[Analysis and Evaluation of Polyurethane Film]
<Preparation of polyurethane film>
Each component of the curable composition, preheated to 40° C., was placed in a 200 mL separable four-necked flask with stirring blades (45-degree inclined four-paddle type) in an amount of 80 g as a cured composition under a nitrogen atmosphere. In addition, after stirring at 40 ° C. for 5 minutes, an applicator was used to apply a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) to a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm, It was dried on a hot plate with a surface temperature of 60° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties.

<Flexibility of Polyurethane Film>
The flexibility of the polyurethane film was evaluated by five inspectors, who evaluated the feeling when the film was touched by hand. Evaluation criteria were as follows.
○ indicates that it was flexible, and the evaluation results of the five inspectors agreed.
△ indicates that it was slightly hard, and the evaluation results of the five inspectors agreed.
X indicates that it was hard, and the evaluation results of the five inspectors agreed.

<Appearance of polyurethane film>
The surface appearance of the polyurethane film prepared above was visually evaluated according to the following criteria.
○ indicates that the surface was smooth.
Δ indicates that a few streaks were observed on the surface in the direction of applicator movement.
X indicates that many streaks were observed on the surface in the applicator moving direction.

<Measurement of molecular weight>
A part of the polyurethane film was cut off, an N,N-dimethylacetamide solution was prepared so that the concentration of polyurethane was 0.1% by mass, and a GPC apparatus [manufactured by Tosoh Corporation, product name "HLC-8320" (column : Tskgel SuperHM-H, 4 bottles), and a solution of 2.6 g of lithium bromide dissolved in 1 L of dimethylacetamide is used as the eluent], and the number average molecular weight (Mn) and weight average molecular weight ( Mw) was measured.

<Evaluation of oleic acid resistance>
A 3 cm x 3 cm test piece was cut from the polyurethane 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>
After producing a urethane film in the same manner as in <Evaluation of resistance to oleic acid> described above, a test piece of 3 cm x 3 cm was cut out of the urethane 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.

<Measurement of glass transition temperature (Tg)>
A test piece having a width of 10 mm, a length of 40 mm and a thickness of 0.4 mm was cut from the polyurethane film. Using a viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Co., Ltd., [TA7000 series, DMA7100]), the test piece was set at a distance between chucks of 20 mm, and the viscosity was measured while increasing the temperature from -100 ° C. to 100 ° C. at a rate of 5 ° C./min. Elasticity measurements were taken. A tan δ peak was read to determine the glass transition temperature (Tg).

<Room temperature 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 0.5 mm was subjected to a tensile tester (manufactured by Orientec Co., Ltd., product name: Tensilon, model RTE-1210). ”), a tensile test was performed at a temperature of 23 ° C. (55% relative humidity) at a distance between chucks of 20 mm and a tensile speed of 100 mm / min. Strength and elongation at break were measured.

<Low temperature 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 0.5 mm was placed in a constant temperature bath ("Model TLF-R3T-EW" manufactured by Orientec Co., Ltd.). ) with a tensile tester (manufactured by Orientec Co., Ltd., product name “Tensilon, model RTE-1210”). The film was installed at a distance between chucks of 20 mm. Subsequently, after standing at -20 ° C. for 5 minutes, the tensile speed was 100 mm. /min, and the stress was measured when the test piece was stretched 100%.

<Evaluation of heat resistance>
The polyurethane film was cut into strips having a width of 10 mm, a length of 100 mm and a thickness of about 50 μm, and heated in a gear oven at a temperature of 120° C. for 1000 hours. The rupture strength of the heated sample was measured in the same manner as in the <room temperature tensile test> above, and the retention rate (%) was determined.

<Evaluation of hydrolysis resistance>
The polyurethane film was cut into strips having a width of 10 mm, a length of 100 mm and a thickness of about 50 μm, and was heated in a constant temperature and humidity chamber at a temperature of 70° C. and a relative humidity of 95% for 400 hours. The rupture strength of the heated sample was measured in the same manner as in the <room temperature tensile test> above, and the retention rate (%) was determined.

[Analysis and Evaluation of Synthetic Leather]
<Flexibility of synthetic leather>
The flexibility of the synthetic leather was evaluated by five inspectors, who evaluated the feel of the synthetic leather when it was touched by hand. Evaluation criteria were as follows.
○ indicates that it was flexible, and the evaluation results of the five inspectors agreed.
△ indicates that it was slightly hard, and the evaluation results of the five inspectors agreed.
X indicates that it was hard, and the evaluation results of the five inspectors agreed.

<Abrasion resistance of synthetic leather>
A load of 9.8 N was applied to a friction element covered with cotton cloth to abrade the surface of the synthetic leather. The friction element was reciprocated 10,000 times at a speed of 60 reciprocations/minute over a distance of 140 mm on the surface of the synthetic leather. The synthetic leather after abrasion was observed and judged according to the following criteria.
○ indicates that there was no crack or break in the resin layer.
Δ indicates that cracks occurred in the resin layer.
x indicates that the resin layer was torn.

<Low temperature storage stability of synthetic leather>
The synthetic leather was wrapped around a paper tube with a diameter of 10 cm and stored in a constant temperature bath at -20°C for one month. After removing the synthetic leather from the paper tube and leaving it for one day in a constant temperature room with a temperature of 23° C. and a humidity of 50%, the surface was visually observed.
The case where there were no cracks or wrinkles was evaluated as ◯, the case where fine cracks or wrinkles of 1 mm or less were observed was evaluated as Δ, and the case where cracks or wrinkles exceeding 1 mm were observed was evaluated as ×.

<Method for evaluating adhesiveness>
A notch was made in advance at the interface between the polyester base fabric of the synthetic leather and the polyurethane resin layer, and the peeled urethane resin layer and the base fabric were each fixed with a chuck. -2, the peel strength between the polyurethane layer and the base fabric was measured using a tensile tester (manufactured by Orientec Co., Ltd., using Tensilon Model RTE-1210) to evaluate adhesion.

[Polymerization Example 1 of Polyester Polycarbonate Polyol]
221 g (2.51 mol) of ethylene carbonate, 148 g (1.64 mol) of 1,4-butanediol, 1,6- 195 g (1.65 mol) of hexanediol and 202 g (1.38 mol) of adipic acid were charged. 0.10 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 150 to 170° C. and the pressure from 10 kPa to 3 kPa while distilling off the produced water and a mixture of ethylene glycol and ethylene carbonate. .
After that, the system was switched to simple distillation, and while the pressure was gradually reduced to 0.1 kPa, reaction was carried out at 170° C. for 5 hours to distill the monomer. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC1).

[Polymerization Example 2 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 221 g (2.51 mol) of ethylene carbonate, 148 g (1.64 mol) of 1,4-butanediol, and 172 g (1.64 mol) of 1,5-pentanediol. 65 mol), 202 g (1.38 mol) of adipic acid, and 0.10 g of titanium tetrabutoxide as a catalyst. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC2).

[Polymerization Example 3 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 198 g (2.25 mol) of ethylene carbonate, 413 g (3.49 mol) of 1,6-hexanediol, 188 g (1.28 mol) of adipic acid, and titanium as a catalyst. Polymerization was carried out in the same manner as in Polymerization Example 1, except that 0.10 g of tetrabutoxide was used. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC3).

[Polymerization Example 4 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 250 g (2.84 mol) of ethylene carbonate, 377 g (4.18 mol) of 1,4-butanediol, 215 g (1.47 mol) of adipic acid, and titanium as a catalyst. Polymerization was carried out in the same manner as in Polymerization Example 1, except that 0.10 g of tetrabutoxide was used. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC4).

[Polymerization Example 5 of Polyester Polycarbonate Polyol]
Polymerization was carried out in the same manner as in Polymerization Example 1, except that the polymerization time after switching to simple distillation was 4 hours. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC5).

[Polymerization Example 6 of Polyester Polycarbonate Polyol]
Polymerization was carried out in the same manner as in Polymerization Example 1, except that the polymerization time after switching to simple distillation was 7 hours. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC6).

[Polymerization Example 7 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 221 g (2.51 mol) of ethylene carbonate, 207 g (2.30 mol) of 1,4-butanediol, and 117 g (0.30 mol) of 1,6-hexanediol. 99 mol), 202 g (1.38 mol) of adipic acid, and 0.10 g of titanium tetrabutoxide as a catalyst. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC7).

[Polymerization Example 8 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 221 g (2.51 mol) of ethylene carbonate, 89 g (0.99 mol) of 1,4-butanediol, and 272 g (2.51 mol) of 1,6-hexanediol. 30 mol), 202 g (1.38 mol) of adipic acid, and 0.10 g of titanium tetrabutoxide as a catalyst. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC8).

[Polymerization Example 9 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amounts charged were 221 g (2.51 mol) of ethylene carbonate, 207 g (2.30 mol) of 1,4-butanediol, and 271 g (2.30 mol) of 1,6-hexanediol. 30 mol), 121 g (0.83 mol) of adipic acid, and 0.10 g of titanium tetrabutoxide as a catalyst. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC9).

[Polymerization Example 10 of Polyester Polycarbonate Polyol]
Using the same apparatus as in Polymerization Example 1, the amount of charged ethylene carbonate was 221 g (2.51 mol), 1,4-butanediol was 79.3 g (0.88 mol), and 1,6-hexanediol was 104 g (0.88 mol). Polymerization was carried out in the same manner as in Polymerization Example 1 except that 0 g (0.88 mol) of adipic acid, 282 g (1.93 mol) of adipic acid, and 0.10 g of titanium tetrabutoxide as a catalyst were used. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC10).

[Polymerization Example 11 of Polyester Polycarbonate Polyol]
226 g (2.51 mol) of dimethyl carbonate, 148 g (1.64 mol) of 1,4-butanediol, 1,6- 195 g (1.65 mol) of hexanediol and 240 g (1.38 mol) of dimethyl adipate were charged. 0.10 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 130 to 190° C. and the pressure from normal pressure to 3 kPa while distilling off the resulting mixture of methanol and dimethyl carbonate.
After that, the system was switched to simple distillation, and while the pressure was gradually reduced to 0.1 kPa, reaction was carried out at 180° C. for 5 hours to distill the monomer. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC11).

[Polymerization Example 12 of Polyester Polycarbonate Polyol]
Polymerization was carried out in the same manner as in Polymerization Example 1 of Polyester Polycarbonate Polyol, except that 229 g (1.38 mol) of phthalic acid was used instead of adipic acid. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC12).

[Polymerization Example 13 of Polyester Polycarbonate Polyol]
221 g (2.51 mol) of ethylene carbonate, 148 g (1.64 mol) of 1,4-butanediol, 1,6- 195 g (1.65 mol) of hexanediol and 158 g (1.38 mol) of ε-caprolactone were charged. 0.10 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 150 to 170° C. and the pressure from 10 kPa to 3 kPa while distilling off the produced water and a mixture of ethylene glycol and ethylene carbonate. .
After that, the system was switched to simple distillation, and while the pressure was gradually reduced to 0.1 kPa, reaction was carried out at 170° C. for 5 hours to distill the monomer. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC13).

[Polymerization Example 14 of Polyester Polycarbonate Polyol]
Polymerization was carried out in the same manner as in Polymerization Example 1, except that the polymerization time after switching to simple distillation was 10 hours. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC14).

[Polymerization Example 15 of Polyester Polycarbonate Polyol]
Polymerization was carried out in the same manner as in Polymerization Example 1, except that the polymerization time after switching to simple distillation was 2.5 hours. Table 1 shows the analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC15).

[Polycarbonate polyol polymerization example 1 (also referred to as polymerization example 16)]
423 g (4.8 mol) of ethylene carbonate, 216 g (2.4 mol) of 1,4-butanediol, 1,6- 284 g (2.4 mol) of hexanediol was charged. 0.09 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 140 to 160° C. and the pressure from 10 kPa to 2 kPa while distilling off the resulting mixture of ethylene glycol and ethylene carbonate.
After that, the system was switched to simple distillation, and while the pressure was gradually reduced to 0.5 kPa, reaction was carried out at 180° C. for 1 hour to distill the monomer. Table 1 shows the analysis results of the obtained polycarbonate diol (also referred to as PC1).

[Polycarbonate polyol polymerization example 2 (also referred to as polymerization example 17)]
Using the same apparatus as in Polycarbonate Polyol Polymerization Example 1, 423 g (4.8 mol) of ethylene carbonate, 250 g (2.4 mol) of 1,5-pentanediol, and 284 g (2.4 mol) of 1,6-hexanediol were prepared. Polymerization was carried out in the same manner as in Polycarbonate Polyol Polymerization Example 1, except that 0.09 g of titanium tetrabutoxide was used as a catalyst. Table 1 shows the analysis results of the obtained polycarbonate polyol (also referred to as PC2).

[Polycarbonate polyol polymerization example 3 (also referred to as polymerization example 18)]
Polymerization was carried out in the same manner as in Polycarbonate Polyol Polymerization Example 1, except that the polymerization time after switching to simple distillation was 1.5 hours. Table 1 shows the analysis results of the obtained polycarbonate polyol (also referred to as PC3).

[Polycarbonate polyol polymerization example 4 (also referred to as polymerization example 19)]
Polymerization was carried out in the same manner as in Polycarbonate Polyol Polymerization Example 1, except that the polymerization time after switching to simple distillation was set to 2.0 hours. Table 1 shows the analysis results of the obtained polycarbonate polyol (also referred to as PC4).

[Polycarbonate polyol polymerization example 5 (also referred to as polymerization example 20)]
Polymerization was carried out in the same manner as in Polycarbonate Polyol Polymerization Example 1, except that the polymerization time after switching to simple distillation was 3.0 hours. Table 1 shows the analysis results of the obtained polycarbonate polyol (also referred to as PC5).

[Polycarbonate polyol polymerization example 6 (also referred to as polymerization example 21)]
Into a 2 L glass flask equipped with a rectifying column packed with structured packing and a stirrer, 423 g (4.8 mol) of ethylene carbonate, 250 g (2.4 mol) of 1,5-pentanediol, 1,6- 284 g (2.4 mol) of hexanediol was charged. 0.09 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 140 to 160° C. and the pressure from 10 kPa to 2 kPa while distilling off the resulting mixture of ethylene glycol and ethylene carbonate.
Thereafter, the system was switched to simple distillation, and the reaction was carried out at 180° C. for 5 hours while the pressure was gradually reduced to 0.5 kPa to distill the monomer. Table 1 shows the analysis results of the obtained polycarbonate diol (also referred to as PC6).

[Polymerization Example 22 of Polyester Polycarbonate Polyol]
221 g (2.51 mol) of ethylene carbonate, 236.5 g (1.64 mol) of 1,4-cyclohexanedimethanol, 1 195 g (1.65 mol) of ,6-hexanediol and 202 g (1.38 mol) of adipic acid were charged. 0.10 g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours while reducing the reaction temperature from 150 to 170° C. and the pressure from 10 kPa to 3 kPa while distilling off the produced water and a mixture of ethylene glycol and ethylene carbonate. .
After that, the system was switched to simple distillation, and while the pressure was gradually reduced to 0.1 kPa, the reaction was carried out at 170° C. for 5 hours to distill the monomers to obtain a polyester polycarbonate polyol (PEC16). The resulting polyester polycarbonate polyol had a hydroxyl value of 56.6 mgKOH/g, an average molecular weight of 1982, and a melt viscosity of 6800 mPa·s at 50°C.

 

 

[Synthesis example 1 of prepolymer composition]
A 500 mL separable flask sealed with nitrogen gas was charged with 30 g (0.12 mol) of MDI and heated to 50°C. 100 g of methyl ethyl ketone (MEK) heated to 50° C. and 121 g (0.06 mol) of polyester polycarbonate polyol PEC1 containing 0.007 g of dibutyltin dilaurate as a catalyst were added dropwise over 30 minutes with stirring. Reaction was carried out at 50° C. for 2 hours while stirring to obtain a prepolymer composition having isocyanate at both ends. Table 2 shows the results of analyzing the obtained prepolymer composition (also referred to as PCP1).

[Prepolymer Composition Synthesis Examples 2 to 28]
A prepolymer composition was synthesized in the same manner as in Prepolymer Composition Synthesis Example 1, except that the amount of polycarbonate polyol, the amount of MDI, and the amount of MEK used were set to the amounts shown in Table 2. Table 2 shows the results of analyzing the obtained prepolymer compositions (also referred to as PCP2 to PCP28, respectively).

 

 

[Prepolymer composition synthesis example 29]
A 500 mL separable flask sealed with nitrogen gas was charged with 31.5 g (0.12 mol) of hydrogenated MDI and heated to 50°C. 120 g (0.06 mol) of polyester polycarbonate polyol PEC1 containing 120 g of methyl ethyl ketone (MEK) and 0.028 g of dibutyltin dilaurate as a catalyst heated to 50° C. was added dropwise over 30 minutes with stirring. Reaction was carried out at 50° C. for 2 hours while stirring to obtain a prepolymer composition having isocyanate at both ends. Table 3 shows the results of analyzing the obtained prepolymer composition (also referred to as PCP29).

[Prepolymer Composition Synthesis Examples 30 to 33]
A prepolymer composition was synthesized in the same manner as in Prepolymer Composition Synthesis Example 29, except that the amount of polyester polycarbonate polyol, the amount of hydrogenated MDI, and the amount of MEK used were set to the amounts shown in Table 3. Table 3 shows the results of analyzing the obtained prepolymer compositions (also referred to as PCP30 to PCP33, respectively).

 

 

[Example 1]
Preheated to 40° C., 40 g of polyester polycarbonate polyol PEC1, 10 g of polyol PC1, 10 g of MDI pre-dissolved at 80° C., 10 g of methyl ethyl ketone (MEK), 0.003 g of dibutyltin dilaurate as a catalyst, and a nitrogen seal. It was charged in a 200 mL separable flask equipped with a stirring blade. After stirring at 40 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. It was dried on a hot plate at 100° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 4 shows the evaluation results.

[Examples 2 to 22]
Polyester polycarbonate polyol, polyol, commercially available polyester polyol (Polylite OD-X2420 manufactured by DIC Corporation; liquid at normal temperature, hydroxyl value 56 mgKOH/g) types and amounts are shown in Table 4. A polyurethane film was obtained in the same manner as in Example 1. Table 4 shows the evaluation results of the obtained polyurethane film.

[Example 69]
Preheated to 40° C., 40 g of polyester polycarbonate polyol PEC16, 10 g of polyol PC1, 10 g of MDI pre-dissolved at 80° C., 10 g of methyl ethyl ketone (MEK), 0.003 g of dibutyltin dilaurate as a catalyst, sealed with nitrogen. It was charged in a 200 mL separable flask equipped with a stirring blade. After stirring at 40 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. It was dried on a hot plate at 100° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 4 shows the evaluation results.

[Comparative Examples 1 to 4]
A polyurethane film was obtained in the same manner as in Example 1, except that the type and amount of polycarbonate polyol and polyol were set to those shown in Table 4. Table 4 shows the evaluation results of the obtained polyurethane film.

 

 

[Example 23]
40 g of polyester polycarbonate polyol PEC1, 10 g of polyol PC1, 10.5 g of hydrogenated MDI, 10 g of methyl ethyl ketone (MEK), and 0.009 g of dibutyltin dilaurate as a catalyst, preheated to 40° C., were mixed with a nitrogen-sealed stirring blade. It was charged in a 200 mL separable flask with. After stirring at 40 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. C. hot plate for 2 hours, followed by drying in an oven at 110.degree. C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 5 shows the evaluation results.

[Examples 24 to 30]
A polyurethane film was obtained in the same manner as in Example 23, except that the polyester polycarbonate polyol and the type and amount of polyol were set to those shown in Table 5. Table 5 shows the evaluation results of the obtained polyurethane film.

[Comparative Examples 5 to 8]
A polyurethane film was obtained in the same manner as in Example 23, except that the polyester polycarbonate polyol and the type and amount of polyol were set to those shown in Table 5. Table 5 shows the evaluation results of the obtained polyurethane film.

[Example 31]
Preheated to 40 ° C., 40 g of polyester polycarbonate polyol PEC1, 10 g of polyol PC1, Duranate TKA-100 (manufactured by Asahi Kasei Corporation: hexamethylene diisocyanate-based isocyanurate curing agent, NCO content = 21.8 wt%, 1 Isocyanate group in the molecule: 3) 7.7 g, 10 g of methyl ethyl ketone (MEK), and 0.003 g of dibutyltin dilaurate as a catalyst were placed in a nitrogen-sealed 200 mL separable flask equipped with a stirring blade. After stirring at 40 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. C. hot plate for 2 hours, followed by drying in an oven at 110.degree. C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 5 shows the evaluation results.

 

 

[Example 32]
80 g of the prepolymer composition PCP1 and 13 g of the polyol PC1, which had been heated to 50° C. in advance, were placed in a nitrogen-sealed 200 mL separable flask equipped with a stirring blade. After stirring at 50 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. It was dried on a hot plate at 100° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 6 shows the evaluation results.

[Examples 33 to 50]
A polyurethane film was obtained in the same manner as in Example 32, except that the types and amounts of the prepolymer composition and polyol were as shown in Table 6. Table 6 shows the evaluation results of the obtained polyurethane film.

[Comparative Examples 9 to 12]
A polyurethane film was obtained in the same manner as in Example 32, except that the types and amounts of the prepolymer composition and polyol were as shown in Table 6. Table 6 shows the evaluation results of the obtained polyurethane film.

 

 

[Example 51]
80 g of polyester polycarbonate polyol PEC1 and 61.5 g of prepolymer composition PCP16, which had been heated to 50° C. in advance, were placed in a nitrogen-sealed 200 mL separable flask equipped with a stirring blade. After stirring at 50 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. It was dried on a hot plate at 100° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 7 shows the evaluation results.

[Examples 52-54]
A polyurethane film was obtained in the same manner as in Example 51, except that the type and amount of the polyester polycarbonate polyol and the type and amount of the prepolymer composition were set as shown in Table 7. Table 7 shows the evaluation results of the obtained polyurethane film.

[Comparative Example 13]
A polyurethane film was obtained in the same manner as in Example 51, except that the type and amount of the polyester polycarbonate polyol and the type and amount of the prepolymer composition were set as shown in Table 7. Table 7 shows the evaluation results of the obtained polyurethane film.

 

 

[Example 55]
80 g of prepolymer composition PCP26 and 10 g of polyol PC1, which had been heated to 50° C. in advance, were placed in a nitrogen-sealed 200 mL separable flask equipped with a stirring blade. After stirring at 50 ° C. for 5 minutes, using an applicator, it was applied on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) at a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm. It was dried on a hot plate at 100° C. for 2 hours and then in an oven at 100° C. for 12 hours. Further, it was allowed to stand at constant temperature and humidity of 23° C. and 55% RH for 12 hours or more to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. Table 8 shows the evaluation results.

[Examples 56-60]
A polyurethane film was obtained in the same manner as in Example 55, except that the types and amounts of the prepolymer composition and polyol were as shown in Table 8. Table 8 shows the evaluation results of the obtained polyurethane film.

[Comparative Example 14]
A polyurethane film was obtained in the same manner as in Example 55, except that the types and amounts of the prepolymer composition and polyol were as shown in Table 8. Table 8 shows the evaluation results of the obtained polyurethane film.

 

 

[Example 61]
Using the same device as the device shown in FIG. At temperature, the mixture was continuously mixed with a mixing head, poured continuously onto release paper, and adjusted to a thickness of 50 μm with a coating roll. A urethane layer serving as a skin layer was formed by passing through a drier at 120°C.
Next, the composition having the same composition ratio as in Example 1 was continuously mixed with a mixing head at a temperature of 40° C., continuously flowed down onto release paper, and adjusted to a thickness of 250 μm with a coating roll. . A urethane layer serving as an adhesive layer was formed by passing through a drier at 120°C.
Then, it was laminated with a 500 μm-thick base fabric (non-woven fabric made of polyester fibers) using a pressing roll and wound up using a take-up roll to obtain a synthetic leather made of a polyurethane laminate. The obtained synthetic leather was evaluated and the results are shown in Table 9.

[Examples 62-68]
Synthesis of a polyurethane laminate in the same manner as in Example 61, except that the type of the curable composition for the skin layer and the type of the curable composition for the adhesive layer were the compositions shown in Table 9. got leather. The obtained synthetic leather was evaluated, and the results are shown in Table 9.

[Comparative Examples 15 to 19]
Synthesis of a polyurethane laminate in the same manner as in Example 61, except that the type of the curable composition for the skin layer and the type of the curable composition for the adhesive layer were the compositions shown in Table 9. got leather. The obtained synthetic leather was evaluated and the results are shown in Table 9.

 

 

INDUSTRIAL APPLICABILITY The curable composition of the present invention is excellent in the balance of physical properties such as flexibility, chemical resistance, low-temperature properties, heat resistance and tactile feel, and can be used for environment-friendly synthetic leathers that use less solvent.
The curable composition of the present embodiment is also used as a lamination welding adhesive for various films, a surface protective agent, and the like.

The disclosure of Japanese Patent Application No. 2021-036424 filed on March 8, 2021 is incorporated herein by reference in its entirety.
In addition, all publications, patent applications and technical standards mentioned in the specification shall be referred to to the same extent as if each individual publication, patent application or technical standard were specifically and individually noted to be incorporated by reference. , incorporated herein by reference.

REFERENCE SIGNS LIST 1 release paper 2 skin layer 3 adhesive layer 4 base material (nonwoven fabric)
5 Mixing head (skin layer)
6 Mixing head (adhesive layer)
7 Seat structure (dry synthetic leather product)
8 coating roll 9 pressing roll 10 take-up roll 11 dryer

Claims (11)

Component (a): a hydroxyl value having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) and/or the following formula (3), and having a hydroxyl group at the molecular end 40-75 mg KOH/g polyester polycarbonate polyol

(In formula (1), R ₁ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (2), R ₂ is a divalent hydrocarbon having 2 to 15 carbon atoms, and R ₃ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

(In formula (3), R ₄ is a divalent hydrocarbon having 2 to 15 carbon atoms.)
Component (b): a polyol with a hydroxyl value of 100 to 280 mgKOH/g,
Component (c): a curable composition comprising a polyisocyanate having an average functionality of 2 to 6 per molecule. Component (d): Polyester polycarbonate polyol of component (a) having a hydroxyl value of 40 to 75 mgKOH/g and polyisocyanate of component (c) having an average functional group number of 2 to 6 per molecule, equivalent ratio [isocyanate equivalent] / An isocyanate-terminated prepolymer composition pre-reacted with a [hydroxyl equivalent] of 1.5 to 3.0, and a polyol of component (b) having a hydroxyl value of 100 to 280 mgKOH/g,
2. The curable composition of claim 1, comprising: Component (e): A polyol having a hydroxyl value of 100 to 280 mgKOH/g of component (b) and a polyisocyanate having an average functional group of 2 to 6 per molecule of component (c) are mixed at an equivalent ratio [isocyanate equivalent]/[ an isocyanate-terminated prepolymer composition pre-reacted with a hydroxyl equivalent] of 1.5 to 3.0, and a polyester polycarbonate polyol of component (a) having a hydroxyl value of 40 to 75 mgKOH/g,
2. The curable composition of claim 1, comprising: The curable composition according to any one of claims 1 to 3, wherein the weight ratio of the component (a) polyester polycarbonate polyol and the component (b) polyol is 95/5 to 40/60. Any one of claims 1 to 4, wherein the molar ratio of the structural unit represented by formula (1) and the structural unit represented by formula (2) and/or formula (3) is 90/10 to 10/90. The curable composition according to the item. 50 mol% or more of the repeating units represented by formula (1) contain at least two repeating units selected from formulas (4), (5), and (6);
The curable composition according to any one of claims 1-5.

The curable composition according to any one of claims 1 to 6, wherein the polyol of component (b) is a polycarbonate polyol having a repeating unit represented by formula (7) and a terminal hydroxyl group.

(In formula (7), R ₅ is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) 50 mol% or more of the repeating units represented by formula (7) contain at least two repeating units selected from formulas (8), (9), and (10),
A curable composition according to claim 7 .

The curable composition according to any one of claims 1 to 8, which contains an inert organic solvent in an amount of 40% by mass or less relative to the total amount of the curable composition. The curable composition according to any one of claims 1 to 9, which contains polyester polyol in an amount of 50% by mass or less relative to the total amount of the curable composition. Synthetic leather using the curable composition according to any one of claims 1 to 10.

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