Polyester Polycarbonate Polyol

Abstract

This polyester polycarbonate polyol has a repeating unit represented by a specific formula (1) and a repeating unit represented by a specific formula (2), has a hydroxyl value of 35-85 mgKOH / g, has a hydroxyl group at a terminal, and is liquid at an ordinary temperature.

Description

[Technical Field]

[0001] The present invention relates to novel polyester polycarbonate polyols. [Background technology]

[0002] Conventionally, synthetic leathers with good flexibility have been produced by applying a polyurethane resin solution polymerized using polyether polyols such as polypropylene glycol and polytetramethylene glycol to a fibrous substrate or a film-forming plate and coagulating it in water. While these synthetic leathers offer excellent flexibility, they are susceptible to degradation by components such as sweat and have durability problems. Another type of synthetic leather is produced by coagulating a polyurethane resin solution polymerized using a polyester polyol obtained by reacting a hydroxy compound with a dibasic acid. However, this synthetic leather has problems with hydrolysis resistance.

[0003] As a synthetic leather that solves these problems, for example, Patent Document 1 discloses synthetic leather obtained from a polyurethane resin polymerized using a polycarbonate diol. Specifically, Patent Document 1 discloses a porous sheet-like material in which a urethane composition composed of 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 or bonded to a fibrous substrate and / or on the fibrous substrate.

[0004] Patent Document 2 discloses a porous sheet material obtained by a wet film-forming method in which a solution of a polyurethane resin comprising a polymeric diol, an organic isocyanate, and optionally a chain extender is applied to a substrate. The porous sheet material is characterized in that the polymeric diol is a mixed diol of a polycarbonate diol and a polyester diol, the polycarbonate diol is composed of 1,4-butanediol and one or more other alkanediols having 4 to 6 carbon atoms, the diol contains 50 to 90 mol% of 1,4-butanediol based on the total number of moles of the diols, and is a copolymeric polycarbonate diol with a number average molecular weight of 500 to 5,000, and the polyurethane resin has a coagulation value of 7 to 14.

[0005] Patent Document 3 discloses a surface coating layer for synthetic leather, which is formed using a polyurethane resin comprising a polyester polycarbonate polyol obtained by a transesterification reaction between an aliphatic oligocarbonate diol obtained by a transesterification reaction between an aliphatic diol and a dialkyl carbonate, and a polyester polyol obtained by ring-opening addition polymerization of a cyclic ester compound using a compound having an active hydrogen group as an initiator, polyisocyanate, and a chain extender.

[0006] Patent Document 4 discloses a porous sheet material obtained by wet coagulation, which is composed of a polycarbonate diol (a1) made of an alkanediol having 4 to 6 carbon atoms and a polycarbonate diol (a2) made of an alkanediol having 7 to 12 carbon atoms, both of which are copolymer polycarbonate diols, and which is obtained by reacting a polymer diol, an organic isocyanate, and a chain extender, in which the percentage by weight of (a1) to the total weight of (a1) and (a2) is 10% to 80%.

[0007] Patent Document 5 discloses a synthetic leather comprising a surface layer formed from a composition for forming a surface layer material for a textile laminate, which is composed of a base agent and a curing agent, wherein the base agent is a polycarbonate diol obtained from 1,6-hexanediol and a low molecular weight carbonate, and the curing agent is a hexamethylene diisocyanate-modified polyisocyanate (B1) having a number average molecular weight of 350 to 500 and an average functionality (f) of 2≦f<3, and an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate (B2) having f≧3, wherein the weight ratio of (B1):(B2) is 50:50 to 95:5, and neither the base agent nor the curing agent contains any organic solvent.

[0008] Patent Document 6 proposes synthetic leather that uses a specific polycarbonate diol (a copolymer polycarbonate diol derived from 1,5-pentanediol and 1,6-hexanediol) to provide synthetic leather that has an excellent balance of physical properties such as sweat resistance and flexibility and that does not crack or wrinkle during storage.

[0009] Patent Document 7 discloses a polyurethane adhesive that uses a polyester carbonate diol having an ester bond and a carbonate bond in the molecule in order to improve the low-temperature flexibility of polycarbonate diol, and describes that the diol used is mainly a mixed diol of 3-methyl-1,5-pentanediol and a linear alkylene glycol having 6 to 10 carbon atoms.

[0010] Patent Document 8 proposes a polyurethane for synthetic leather that has an excellent balance of physical properties including flexibility, chemical resistance, low-temperature characteristics, heat resistance, and tactile feel. The proposed polyurethane is obtained by reacting at least (a) a compound containing two or more isocyanate groups per molecule, (b) a chain extender, and (c) a polycarbonate diol, wherein the (c) 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 the dihydroxy compound obtained by hydrolyzing the polycarbonate diol has an average carbon number of 3 or more and 5.5 or less.

[0011] In recent years, environmentally friendly polyurethanes have been proposed. For example, Patent Document 9 proposes a two-component, solvent-free polyurethane for synthetic leather, which is a urethane prepolymer composition that is used by reacting a crosslinking agent with active hydrogen in the components to increase the molecular weight, and which contains at least 20 to 80 mass% of a hydroxyl-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g, and further contains, as a medium for the polymer, 20 to 80 mass% of an oligomer having a hydroxyl value of 20 to 400 mgKOH / g and no urethane bond that can crosslink with the crosslinking agent, and which is substantially 100% nonvolatile and liquid at least at a temperature of 30°C, and which contains 90 to 150 equivalent% of a polyisocyanate crosslinking agent having an NCO content of 5 to 35 mass% relative to the average hydroxyl value of the urethane prepolymer composition. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Patent No. 3142102 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-119314 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-346094 [Patent Document 4] Patent No. 4177318 [Patent Document 5] Japanese Patent Application Laid-Open No. 2009-185260 [Patent Document 6] Japanese Patent Application Laid-Open No. 2013-108196 [Patent Document 7] Japanese Patent Application Publication No. 4-342785 [Patent Document 8] Japanese Patent Application Laid-Open No. 2016-8234 [Patent Document 9] Japanese Patent Application Laid-Open No. 2014-105250 Summary of the Invention [Problem to be solved by the invention]

[0013] However, although the synthetic leathers disclosed in Patent Documents 1 to 5 have hydrolysis resistance, they do not have sufficient sweat resistance for applications requiring high durability, such as automobile seats.

[0014] Furthermore, although the polycarbonate diol described in Patent Document 6 can provide synthetic leather with excellent sweat resistance, etc., it is necessary to use a large amount of organic solvent when producing synthetic leather as a polyurethane resin solution, and there is room for further improvement in terms of environmental impact.

[0015] Furthermore, although the invention described in Patent Document 7 mentions leather applications, there is no mention of its suitability for applications requiring high durability, such as automobile seats, and there is no mention of reducing the amount of solvent used in producing synthetic leather.

[0016] Furthermore, the polyurethane for synthetic leather disclosed in Patent Document 8 also requires the use of a large amount of organic solvent when producing synthetic leather as a polyurethane resin solution, which is undesirable in terms of environmental impact.

[0017] Furthermore, the polyurethane prepolymer composition for synthetic leather disclosed in Patent Document 9 uses an ether-based polyol such as poly-THF or THF-neopentyl glycol copolymer polyol, each having a hydroxyl value of 20 to 400 mgKOH / g, as an oligomer without a urethane bond in order to achieve a solvent-free state, which results in reduced heat resistance and limits its applications.

[0018] In view of the above circumstances, an object of the present invention is to provide an environmentally friendly polyester polycarbonate polyol that can be used to produce polyurethanes that have an excellent balance of physical properties, including flexibility (tactile feel), chemical resistance, low-temperature characteristics, heat resistance, hydrolysis resistance, abrasion resistance, adhesion, and appearance, and that requires a small amount of solvent when producing synthetic leather using the polyurethane. [Means for solving the problem]

[0019] As a result of extensive research, the present inventors have discovered that by using a specific polyester polycarbonate polyol that is liquid at room temperature, it is possible to produce a polyurethane that has an excellent balance of physical properties, including flexibility (tactile feel), chemical resistance, hydrolysis resistance, low-temperature characteristics, heat resistance, abrasion resistance, adhesion, and appearance, and that it is possible to reduce the amount of solvent used in producing synthetic leather using the polyurethane, thereby completing the present invention.

[0020] That is, the present invention includes the following aspects. [1] A polyester polycarbonate polyol having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), having a hydroxyl value of 35 to 85 mgKOH / g, having hydroxyl groups at the terminals, and being liquid at room temperature. [ka] (In formula (1), R1 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) [ka] (In formula (2), R2 represents an alkylene group having 2 to 15 carbon atoms, and R3 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) [2] The polyester polycarbonate polyol according to [1], wherein the molar ratio of the repeating unit represented by the formula (1) to the repeating unit represented by the formula (2) (formula (1) / formula (2)) is 30 / 70 to 90 / 10. [3] The polyester polycarbonate polyol according to [1] or [2], wherein R1 in the formula (1) and / or R3 in the formula (2) contain at least one selected from the group consisting of branched alkylene groups having 4 to 15 carbon atoms and at least two selected from the group consisting of linear alkylene groups having 2 to 10 carbon atoms. [4] The polyester polycarbonate polyol according to any one of [1] to [3], which has a viscosity of 1,000 to 10,000 mPa·s as measured at 50°C with a rotational viscometer. [5] The polyester polycarbonate polyol according to any one of [1] to [4], wherein the repeating unit represented by formula (1) contains 50 mol % or more of at least two repeating units selected from the group consisting of a repeating unit represented by formula (3) below, a repeating unit represented by formula (4) below, a repeating unit represented by formula (5) below, a repeating unit represented by formula (6) below, and a repeating unit represented by formula (7) below: [ka] [ka] [ka] [ka] [ka] [6] The raw material used for the polyol according to any one of [1] to [5] above is a polyester polycarbonate polyol that is bio-derived. [7] A curable composition produced by reacting the polyester polycarbonate polyol according to any one of [1] to [6] with an organic diisocyanate and a chain extender. [8] [1] to [6]. Synthetic leather produced using the polyester polycarbonate polyol according to any one of [1] to [6]. [9] A water-based polyurethane produced using the polyester polycarbonate polyol according to any one of [1] to [6]. [Effects of the Invention]

[0021] Use of the polyester polycarbonate polyol of the present invention makes it possible to produce polyurethanes that have an excellent balance of physical properties, including flexibility (touch), chemical resistance, low-temperature characteristics, heat resistance, hydrolysis resistance, abrasion resistance, adhesion, and appearance, and also makes it possible to reduce the amount of solvent used when producing synthetic leather using polyurethanes. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view of an example of synthetic leather using the polyester polycarbonate polyol of the present invention. [Figure 2] FIG. 1 is a diagram showing an example of a process for producing synthetic leather using the polyester polycarbonate polyol of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention (hereinafter abbreviated as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0024] <Polyester polycarbonate polyol> The polyester polycarbonate polyol of the present embodiment has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), has a hydroxyl value of 35 to 85 mgKOH / g, has hydroxyl groups at its terminals, and is liquid at room temperature. [ka] (In formula (1), R1 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) [ka] (In formula (2), R2 represents an alkylene group having 2 to 15 carbon atoms, and R3 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) The polyester polycarbonate polyol of this embodiment is usually cured using a curing agent such as polyisocyanate, and can be used as polyurethane for various molded articles, adhesives, coating agents, etc.

[0025] In this embodiment, room temperature refers to a temperature range of 5° C. to 35° C. In addition, in this embodiment, liquid refers to a state in which the material exhibits even a slight degree of fluidity.

[0026] The polyester polycarbonate polyol of this embodiment has a hydroxyl value of 35 to 85 mgKOH / g, preferably 40 to 75 mgKOH / g, and more preferably 50 to 65 mgKOH / g. The polyester polycarbonate polyol of this embodiment has a hydroxyl value of 35 mgKOH / g or more, which tends to result in polyurethanes with excellent strength and chemical resistance. Also, the polyester polycarbonate polyol of this embodiment has a hydroxyl value of 85 mgKOH / g or less, which tends to result in synthetic leathers with improved flexibility (touch) and low-temperature properties.

[0027] Furthermore, the viscosity of the polyester polycarbonate polyol of this embodiment, measured with a rotational viscometer at 50°C (hereinafter also referred to as "melt viscosity at 50°C"), is preferably 1000 to 10,000 mPa·s, more preferably 1200 to 9,500 mPa·s, and even more preferably 1300 to 9,000 mPa·s. When the polyester polycarbonate polyol of this embodiment has a melt viscosity at 50°C of 1000 mPa·s or more, the flexibility and low-temperature properties of the resulting polyurethane tend to be enhanced. When the polyester polycarbonate polyol of this embodiment has a melt viscosity at 50°C of 10,000 mPa·s or less, not only does it tend to produce a polyurethane with excellent strength and chemical resistance, but it also allows for a reduction in the amount of solvent used in producing the polyurethane. The method for obtaining a polyester polycarbonate polyol having a melt viscosity at 50°C within the above range is not particularly limited, and examples thereof include a method of adjusting the average molecular weight of the polyester polycarbonate polyol. Specifically, for example, the smaller the average molecular weight of the polyester polycarbonate polyol, the smaller the melt viscosity at 50°C tends to be, and the larger the average molecular weight of the polyester polycarbonate polyol, the larger the melt viscosity at 50°C tends to be. The average molecular weight of the polyester polycarbonate polyol can be controlled, for example, by the molecular weight of each raw material and the reaction time.

[0028] The polyester polycarbonate polyol of this embodiment preferably has an average number of hydroxyl groups per molecule of 1.7 to 3.5, more preferably 1.8 to 3.0, and even more preferably 2.0 to 2.5. Since the polyester polycarbonate polyol of this embodiment has an average number of hydroxyl groups per molecule of 1.7 or more, the strength, chemical resistance, heat resistance, and hydrolysis resistance of the resulting polyurethane tend to be enhanced. Furthermore, since the polyester polycarbonate polyol of this embodiment has an average number of hydroxyl groups per molecule of 3.5 or less, not only is an appropriate curing time obtained during polyurethane production, but the resulting polyurethane also tends to have good flexibility.

[0029] The polyester polycarbonate polyol of this embodiment preferably has a carbonate group content per molecule of 15 to 40% by mass, more preferably 21 to 38% by mass, and even more preferably 25 to 35% by mass. When the polyester polycarbonate polyol of this embodiment has a carbonate group content of 15% by mass or more, the resulting polyurethane tends to have excellent strength, chemical resistance, abrasion resistance, and hydrolysis resistance. Furthermore, when the polyester polycarbonate polyol of this embodiment has a carbonate group content of 40% by mass or less, the resulting polyurethane tends to have excellent low-temperature properties and flexibility, and the viscosity of the resulting polyurethane tends to be kept low, resulting in excellent appearance of the polyurethane product.

[0030] In this embodiment, the carbonate group content is the amount of carbonate groups contained in one molecule of the polyester polycarbonate polyol, and is specifically calculated by the following formula (i). Carbonate group content (mass%) = (molecular weight of carbonate group) × (number of carbonate groups per molecule) / (number average molecular weight of polyester polycarbonate polyol) × 100 (i) (Here, the molecular weight of the carbonate group (-OC=OO-) is 60.01.)

[0031] The polyester polycarbonate polyol of this embodiment has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), and has a hydroxyl group at the molecular terminal. [ka] (In formula (1), R1 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms).) [ka] (In formula (2), R2 represents an alkylene group having 2 to 15 carbon atoms, and R3 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms).)

[0032] It is preferable that R1 in the formula (1) and / or R3 in the formula (2) contain at least one selected from the group consisting of branched alkylene groups having 4 to 15 carbon atoms and at least two selected from the group consisting of linear alkylene groups having 2 to 10 carbon atoms. When such alkylene groups are contained, the resulting synthetic leather tends to have particularly excellent washing resistance and hydrolysis resistance. Furthermore, when the carbon number of the linear alkylene group having 2 to 10 carbon atoms contained in R1 and / or R3 is smaller, the chemical resistance of the resulting polyurethane tends to be better. From this perspective, the linear alkylene group having 2 to 10 carbon atoms contained in R1 and / or R3 is preferably a linear alkylene group having 2 to 8 carbon atoms, more preferably a linear alkylene group having 2 to 6 carbon atoms, and particularly preferably a linear alkylene group having 2 to 5 carbon atoms.

[0033] In the polyester polycarbonate polyol of this embodiment, the molar ratio (formula (1) / formula (2)) of the content of the repeating unit represented by formula (1) (hereinafter also referred to as "polycarbonate structural unit") to the content of the repeating unit represented by formula (2) (hereinafter also referred to as "polyester structural unit") is preferably 5 / 95 to 95 / 5, more preferably 30 / 70 to 90 / 10, and even more preferably 50 / 50 to 80 / 20. When the molar ratio of the content of the polycarbonate structural unit to the content of the polyester structural unit in the polyester polycarbonate polyol of this embodiment is within the above range, polyurethanes excellent in flexibility, chemical resistance, adhesion, and hydrolysis resistance tend to be obtained.

[0034] The method for producing the polyester polycarbonate polyol of the present embodiment is not particularly limited, but for example, the polyester polycarbonate polyol can be synthesized by using a bifunctional diol compound, and optionally a trifunctional or higher polyhydric alcohol, a dibasic acid, and a carbonate ester as raw materials, for example, by a transesterification reaction as described in "Polymer Reviews, Vol. 9, pp. 9-20" or the like.

[0035] Examples of bifunctional diol compounds used in the transesterification reaction include diol compounds having a divalent linear aliphatic or alicyclic hydrocarbon skeleton having 2 to 15 carbon atoms, and diol compounds having a branched alkylene group having 4 to 15 carbon atoms (hereinafter also referred to as a "branched alkylene group"). Two or more bifunctional diol compounds are used in combination, and at least one of the two or more bifunctional diol compounds is a diol compound having a branched alkylene group having 4 to 15 carbon atoms, and at least one of the two or more bifunctional diol compounds is a diol compound having a linear alkylene group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms). Specific examples of the diol compound having a divalent linear aliphatic or alicyclic hydrocarbon skeleton having 2 to 15 carbon atoms include, but are not particularly limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. Specific examples of the diol compound having a branched alkylene group having 4 to 15 carbon atoms include, but are not limited to, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2-ethyl-1,6-hexanediol, 2,4-dimethyl-1,5-pentanediol, and 2,4-diethyl-1,5-pentanediol. Among these, from the viewpoint of obtaining a polyurethane excellent in flexibility (touch), chemical resistance, low-temperature properties, and heat resistance, diol compounds having a linear alkylene group with 3 to 12 carbon atoms and diol compounds having a branched alkylene group with 4 to 9 carbon atoms are preferred, and diol compounds having a linear alkylene group with 4 to 6 carbon atoms and diol compounds having a branched alkylene group with 4 to 6 carbon atoms are more preferred. Furthermore, the plant-derived raw material, i.e., the bio-derived raw material, is not particularly limited, but examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol.

[0036] Among the bifunctional diol compounds, diol compounds having a branched alkylene group have 2 or more carbon atoms, which allows the viscosity of the polyurethane to be kept low, allowing the amount of organic solvent used to be reduced when producing synthetic leather using the polyurethane, and also tends to improve the flexibility and low-temperature properties of the resulting cured product. When the diol compound having a branched alkylene group has 15 or less carbon atoms, the resulting polyurethane tends to have excellent chemical resistance. Among the diol compounds having a branched alkylene group, diol compounds having a branched alkylene group with 4 to 6 carbon atoms are particularly preferred, as they tend to provide polyurethanes with excellent hydrolysis resistance.

[0037] When the bifunctional diol compound has two or more carbon atoms, the viscosity of the polyurethane can be kept low, allowing for a reduction in the amount of organic solvent used when producing synthetic leather using the polyurethane, and the flexibility and low-temperature properties of the resulting cured product tend to be improved. When the bifunctional diol compound has 15 or less carbon atoms, the resulting polyurethane tends to have excellent chemical resistance. In particular, by using a diol compound having a linear alkylene group with 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms) among the bifunctional diol compounds, the resulting polyurethane tends to have excellent chemical resistance and adhesion.

[0038] By using two or more bifunctional diol compounds in combination, at least one of which is a diol compound having a branched alkylene group with 4 to 15 carbon atoms, the structural unit regularity of the resulting polyester polycarbonate polyol is reduced, resulting in reduced crystallinity. This not only tends to produce a polyester polycarbonate polyol that is liquid at room temperature, but also tends to increase the flexibility of the polyurethane. Furthermore, when an organic solvent is used in the production of polyurethane, the amount of organic solvent used tends to be reduced. In particular, by using at least one diol compound selected from the group consisting of a branched alkylene group with 4 to 15 carbon atoms in combination with at least two diol compounds selected from the group consisting of a linear alkylene group with 2 to 10 carbon atoms, the resulting polyester polycarbonate polyol tends to exhibit particularly excellent washing resistance and hydrolysis resistance when used to make synthetic leather. Furthermore, when the carbon number of the diol compound used as a raw material for the polyester polycarbonate polyol is reduced, the resulting polyester polycarbonate polyol tends to exhibit better chemical resistance when used to make polyurethane. From this viewpoint, the diol compound used as the raw material is preferably a diol compound having a linear alkylene group having 2 to 8 carbon atoms, more preferably a diol compound having a linear alkylene group having 2 to 6 carbon atoms, and particularly preferably a diol compound having a linear alkylene group having 2 to 5 carbon atoms.

[0039] In this embodiment, in addition to the bifunctional diol, a trifunctional or higher polyhydric alcohol compound can be used as the raw material for the polyester polycarbonate polyol, if necessary.

[0040] In this embodiment, the repeating unit represented by the above formula (1) preferably contains 50 mol % or more, more preferably 70 mol % or more, and even more preferably 80 mol % or more of at least two repeating units selected from the group consisting of repeating units represented by the following formula (3), repeating units represented by the following formula (4), repeating units represented by the following formula (5), repeating units represented by the following formula (6), and repeating units represented by the following formula (7).

[0041] [ka] [ka] [ka] [ka] [ka]

[0042] In the repeating unit represented by formula (1), when the content of at least two types of repeating units selected from the group consisting of the repeating unit represented by formula (3), the repeating unit represented by formula (4), the repeating unit represented by formula (5), the repeating unit represented by formula (6), and the repeating unit represented by formula (7) is 50 mol% or more, the polyurethane obtained will have excellent flexibility (feel), chemical resistance, low-temperature properties, and heat resistance, and in addition, when a solvent is used in the production of the polyurethane, the amount of solvent used will tend to be reduced. In the repeating unit represented by formula (1), the upper limit of the content of at least two repeating units selected from the group consisting of the repeating unit represented by formula (3), the repeating unit represented by formula (4), the repeating unit represented by formula (5), the repeating unit represented by formula (6), and the repeating unit represented by formula (7) is not particularly limited, but is, for example, 90 mol% or less.

[0043] In this embodiment, when two repeating units are selected from the repeating units represented by formula (3), formula (4), formula (5), formula (6), and formula (7), the copolymerization ratio of the two repeating units is preferably 90:10 to 10:90, more preferably 70:30 to 30:70, and even more preferably 60:40 to 40:60, in molar ratio. Having a copolymerization ratio within this range tends to reduce the crystallinity of the polyester polycarbonate polyol, resulting in a polyurethane with high flexibility, good low-temperature properties, and good feel. Furthermore, having a copolymerization ratio within this range tends to allow for a reduction in the amount of solvent used when producing the polyurethane.

[0044] In this embodiment, when three types of repeating units are selected from the repeating units represented by the above formulas (3), (4), (5), (6), and (7), the proportion of each structural unit is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, when the total of the three types of repeating units represented by the above formulas (3), (4), (5), (6), and (7) is taken as 100 mol%. When the proportion of each repeating unit in the total of the three types of repeating units represented by the above formulas (3), (4), (5), (6), and (7) is within the above range, the crystallinity of the polycarbonate polyol tends to be reduced, and a polyurethane with high flexibility, good low-temperature properties, and good feel tends to be obtained. Furthermore, by having the proportions of the three types of repeating units represented by the formula (3), the formula (4), the formula (5), the formula (6), and the formula (7) fall within the above ranges, when a solvent is used in producing the polyurethane, the amount of solvent used tends to be reduced.

[0045] The tri- or higher functional polyhydric alcohol compound is not particularly limited, but examples thereof include trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, etc. By using a tri- or higher functional polyhydric alcohol, the average number of hydroxyl groups per molecule can be easily adjusted to the range of 1.7 to 3.5.

[0046] Dibasic acids that can be used in the synthesis of the polyester polycarbonate polyol of this embodiment include, but are not limited to, aliphatic and / or aromatic dicarboxylic acids. Aliphatic dicarboxylic acids include, but are not limited to, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Aromatic dicarboxylic acids include, but are not limited to, phthalic acid, isophthalic acid, and terephthalic acid. In order to obtain a cured product with excellent flexibility, aliphatic dicarboxylic acids are particularly preferred, and among these, succinic acid, glutaric acid, and adipic acid are particularly preferred. These dicarboxylic acids can also be used as alcohol esters, for example, as methyl esters of dimethyl succinate, dimethyl glutarate, and dimethyl adipate. These dicarboxylic acids may be used alone or in combination. Plant-derived raw materials, i.e., bio-derived raw materials, are not particularly limited, but may include, for example, succinic acid and sebacic acid.

[0047] The carbonate ester that can be used in synthesizing the polyester polycarbonate polyol of this embodiment is not particularly limited, and examples thereof include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate. From the viewpoints of ease of availability and ease of setting polymerization reaction conditions, it is preferable to use dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or ethylene carbonate as the carbonate ester.

[0048] A catalyst may or may not be added when producing the polyester polycarbonate polyol of this embodiment. When a catalyst is added, it can be freely selected from catalysts used in ordinary transesterification reactions. The catalyst is not particularly limited, but examples include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, zirconium, hafnium, cobalt, germanium, tin, lead, antimony, arsenic, and cerium, as well as metal salts, metal alkoxides, and organic compounds containing these metals. Among the above catalysts, metal alkoxides are preferred, and alkoxides of titanium, zirconium, and hafnium, which are Group 4 of the periodic table, are particularly preferred because they are less susceptible to the effects of the water produced and can maintain high activity. The amount of catalyst used is usually 0.00001 to 0.1 mass% of the mass of the raw materials (bifunctional diol compound and optionally trifunctional or higher polyhydric alcohol), preferably 0.001 to 0.05 mass%, and more preferably 0.01 to 0.03 mass%. When the amount of catalyst is 0.0001 mass% or more, the reaction rate can be shortened and productivity is improved. When the amount of catalyst is 0.1 mass% or less, the color tone of the obtained polyester carbonate polyol is excellent.

[0049] In the method for producing the polyester polycarbonate polyol in this embodiment, as described above, the polyester polycarbonate polyol can be synthesized by a transesterification reaction using a bifunctional diol compound, and optionally a trifunctional or higher polyhydric alcohol, a dibasic acid, and a carbonate ester as raw materials. More specifically, the transesterification reaction is carried out according to the following procedure. First, two or more bifunctional diol compounds are used in combination in a predetermined ratio, at least one of which is a diol compound having a branched alkylene group having 4 to 15 carbon atoms, and at least one of which is a diol compound having a linear alkylene group having 2 to 10 carbon atoms. If necessary, one or two or more trifunctional or higher polyhydric alcohols in a predetermined ratio, a dibasic acid in a predetermined ratio, and one or two or more carbonate esters in a predetermined ratio are mixed together, and a transesterification reaction is carried out at normal pressure or reduced pressure, in the absence or presence of a transesterification catalyst, preferably at a temperature of 100 to 200°C, more preferably at 140 to 180°C. Subsequently, the alcohol derived from the carbonate ester and the water derived from the dibasic acid (when a dibasic acid ester is used, the monoalcohol derived from the dibasic acid ester) produced during the reaction are distilled off to obtain, for example, a polyester polycarbonate polyol having a molecular weight of about 300 to 500 g / mol. Next, under reduced pressure, preferably at 130 to 230°C, more preferably at 150 to 200°C, the unreacted carbonate ester and bifunctional diol, and any optionally contained trifunctional or higher polyhydric alcohol and water produced by the condensation reaction of the dibasic acid (when a dibasic acid ester is used, the monoalcohol derived from the dibasic acid ester) are distilled off, and a polyester polycarbonate polyol having a desired hydroxyl value can be obtained by a condensation reaction. Specifically, for example, shortening the reaction time of the condensation reaction tends to increase the hydroxyl value of the resulting polyester polycarbonate polyol, while lengthening the reaction time of the condensation reaction tends to decrease the hydroxyl value of the polyester polycarbonate polyol. The average number of hydroxyl groups in the polyester polycarbonate polyol can be adjusted by controlling the initial charging ratio of each component, the amount of each raw material distilled during production, and the amount of reaction product.

[0050] Alternatively, the polyester polycarbonate polyol of the present embodiment can be produced by first preparing a polycarbonate polyol and a polyester polyol, then mixing the polycarbonate polyol and the polyester polyol, and carrying out a transesterification reaction at a temperature of 100 to 250°C under stirring in the presence or absence of a transesterification catalyst.

[0051] The method for producing polycarbonate polyol and polyester polyol is not particularly limited, and known methods can be used. For example, the above-described carbonate compound and diol compound can be reacted in the presence of a transesterification catalyst to obtain a polycarbonate polyol. Also, the above-described dibasic acid compound and diol compound can be reacted in the presence of a transesterification catalyst to obtain a polyester polyol.

[0052] The carbonate ester that can be used in the synthesis of the polycarbonate polyol used in this embodiment is not particularly limited, and examples thereof include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate. From the viewpoints of ease of availability and ease of setting polymerization reaction conditions, it is preferable to use dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or ethylene carbonate as the carbonate ester.

[0053] The bifunctional diol compound that can be used in the synthesis of the polycarbonate polyol and polyester polyol used in this embodiment is not particularly limited, but examples thereof include diols having a divalent linear aliphatic or alicyclic hydrocarbon skeleton having 2 to 15 carbon atoms, and diols having a branched alkylene group having 4 to 15 carbon atoms. Specific examples of the diol compound having a divalent linear aliphatic or alicyclic hydrocarbon skeleton having 2 to 15 carbon atoms include, but are not particularly limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. Specific examples of the diol compound having a branched alkylene group having 4 to 15 carbon atoms include, but are not limited to, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2-ethyl-1,6-hexanediol, 2,4-dimethyl-1,5-pentanediol, and 2,4-diethyl-1,5-pentanediol. Other examples include cyclic diols and diols having an aromatic ring. The cyclic diol is not particularly limited, but examples thereof include 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-bis(4-hydroxycyclohexyl)-propane, and 1,8-cyclooctanedimethanol. The diol having an aromatic ring is not particularly limited, but examples thereof include p-xylene diol, p-tetrachloroxylene diol, 1,4-bis(hydroxyethoxy)benzene, and 2,2-bis[(4-hydroxyethoxy)phenyl]propane.

[0054] Dibasic acids that can be used in the synthesis of the polyester polyol used in this embodiment include, but are not limited to, aliphatic and / or aromatic dicarboxylic acids. Aliphatic dicarboxylic acids include, but are not limited to, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Aromatic dicarboxylic acids include, but are not limited to, phthalic acid, isophthalic acid, and terephthalic acid. To obtain a cured product with excellent flexibility, aliphatic dicarboxylic acids are particularly preferred, with succinic acid, glutaric acid, and adipic acid being particularly preferred. These dicarboxylic acids can also be used as alcohol esters, such as methyl esters of dimethyl succinate, dimethyl glutarate, and dimethyl adipate. These dicarboxylic acids may be used alone or in combination.

[0055] Commercially available polycarbonate polyols used in the present embodiment are not particularly limited, and examples thereof include those manufactured by Asahi Kasei Corporation under the trade names "Duranol T6001", "Duranol T6002", "Duranol S6002", "Duranol T5651", "Duranol T5652", "Duranol T5650E", "Duranol T5650J", "Duranol T4671", "Duranol T4672", "Duranol T4691", "Duranol T4692", "Duranol G3452", and "Duranol G3450J". Manufactured by Ube Industries, Ltd.; product names: "ETERNACOLL UH-50", "ETERNACOLL UH-100", "ETERNACOLL UH-200", "ETERNACOLL UH-300", "ETERNACOLL PH-50", "ETERNACOLL PH-100", "ETERNACOLL PH-200", "ETERNACOLL PH-300", "ETERNACOLL UHC50-100", "ETERNACOLL UHC50-200", "ETERNACOLL UC-100", "ETERNACOLL UM-90(1 / 3)", "ETERNACOLL UM-90(1 / 1)", "ETERNACOLL UM-90(3 / 1)", "ETERNACOLL UP-50", "ETERNACOLL UP-100", "ETERNACOLL UP-200", Manufactured by Kuraray Co., Ltd.; product names: "Kuraray Polyol C-1065N," "Kuraray Polyol C-2065N," "Kuraray Polyol C-1090," "Kuraray Polyol C-2090," "Kuraray Polyol C-3090," "Kuraray Polyol C-1050," "Kuraray Polyol C-2050," "Kuraray Polyol C-3050," "Kuraray Polyol C-1015N," and "Kuraray Polyol C-2015N." Manufactured by Daicel Corporation; product names: "Plaxel 220EC", "Plaxel CD205", "Plaxel CD210", "Plaxel CD220", "Plaxel CD205PL", "Plaxel CD205HL", "Plaxel CD210PL", "Plaxel CD210HL", "Plaxel CD220PL", "Plaxel CD220HL", "Plaxel CD220EC", "Plaxel CD221T", Manufactured by Tosoh Corporation; product names: Nipporan 981, Nipporan 980R, Nipporan 982R, Nipporan 976, Nipporan 965, Nipporan 963, Nipporan 964, Nipporan 968 Perstorp's Oxymer N112 Manufactured by Mitsubishi Chemical Corporation; product names: "BENEBiOL NL1010DB", "BENEBiOL NL2010DB", "BENEBiOL NL3010DB", "BENEBiOL NL1005B", "BENEBiOL NL2005B", "BENEBiOL NL1030B", "BENEBiOL HS0830B", "BENEBiOL HS0840B", "BENEBiOL HS0840H", "BENEBiOL HS0850H" These may be used alone or in any combination of two or more.

[0056] Commercially available polyester polyols for use in the present embodiment are not particularly limited, but examples thereof include the "Kyowapol" series (trade name) manufactured by Kyowa Hakko Chemical Co., Ltd., the "Kuraray Polyol" series (trade name) manufactured by Kuraray Co., Ltd., the "Placcel" series (trade name) manufactured by Daicel Corporation, the "Polylite" series (trade name) manufactured by DIC Corporation, the "Nippolan" series (trade name) manufactured by Tosoh Corporation, castor oil-modified polyols, polyesters obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone, and copolymerized polyesters thereof.

[0057] Two or more types of bifunctional diol compounds are used in combination as the bifunctional diol compounds contained in the polycarbonate polyol and polyester polyol used in the production of the polyester polycarbonate polyol of this embodiment, and at least one of the two or more types of bifunctional diol compounds is a diol compound having a branched alkylene group having 4 to 15 carbon atoms, and at least one of the two or more types of bifunctional diol compounds is a diol compound having a linear alkylene group having 2 to 10 carbon atoms (preferably 2 to 5 carbon atoms). Among these, from the viewpoint of obtaining polyurethanes excellent in flexibility (touch), chemical resistance, low-temperature properties, and heat resistance, diol compounds having a linear alkylene group with 3 to 12 carbon atoms and diol compounds having a branched alkylene group with 4 to 9 carbon atoms are preferred, and diol compounds having a linear alkylene group with 4 to 6 carbon atoms and diol compounds having a branched alkylene group with 4 to 6 carbon atoms are more preferred.

[0058] The polycarbonate polyol and polyester polyol used in the production of the polyester polycarbonate polyol of this embodiment may contain a catalyst poison such as a phosphoric acid ester compound added thereto in order to deactivate the transesterification catalyst used in the production thereof.

[0059] When the raw material polycarbonate polyol or polyester polyol contains a catalyst poison or the like of the transesterification catalyst used in its production, the transesterification reaction between the polycarbonate polyol and the polyester polyol usually tends to proceed less easily. Therefore, when producing the polyester polycarbonate polyol of this embodiment, a required amount of the above-mentioned transesterification catalyst can be newly added.

[0060] On the other hand, in the present embodiment, when the raw material polycarbonate polyol or polyester polyol does not contain a catalyst poison for the transesterification catalyst, the transesterification reaction usually tends to proceed easily. However, when it is desired to lower the reaction temperature or shorten the reaction time in the production process of the polyester polycarbonate polyol of the present embodiment, a necessary amount of a new transesterification reaction catalyst can be added. In this case, the catalyst can be freely selected from the catalysts used in the above-mentioned ordinary transesterification reactions.

[0061] In the method for producing polyurethane using the polyester polycarbonate polyol of the present embodiment (hereinafter also referred to as "component (a)"), a curing agent such as polyisocyanate (hereinafter also referred to as "component (b)") and, if necessary, a chain extender (hereinafter also referred to as "component (c)") are usually used. A method for producing a polyurethane using the polyester polycarbonate polyol of the present embodiment may involve simultaneously blending the constituent components (a), (b), and (c) to form a mixture to produce a curable composition, or may involve first reacting component (a) with component (b) to prepare an isocyanate-terminated prepolymer composition, and then blending this isocyanate-terminated prepolymer composition with component (c) to produce a mixture to produce a curable composition.

[0062] The curable composition of the present embodiment is prepared by using the above-described polyester polycarbonate polyol and reacting it with an organic diisocyanate and a chain extender.

[0063] When producing polyurethane using the polyester polycarbonate polyol of this embodiment, the polyisocyanate used is usually a polyisocyanate having an average of 2 to 10 functional groups per molecule (component (b)). The polyisocyanate of component (b) is not particularly limited, but examples thereof include 2,4-tolyresin diisocyanate, 2,6-tolyresin diisocyanate and mixtures thereof, diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI), polymethylene polyphenylene polyisocyanate (PMDI), etc. aromatic aliphatic diisocyanates such as xylylene diisocyanate (XDI) and phenylene diisocyanate; and aliphatic diisocyanates such as 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and cyclohexane diisocyanate (hydrogenated XDI).

[0064] The polyisocyanate of component (b) may be a polyisocyanate having an average of 2.1 or more isocyanate groups per molecule. The polyisocyanate having an average of 2.1 or more isocyanate groups per molecule is not particularly limited, but examples thereof include aromatic polyisocyanates such as crude MDI and crude TDI; derivatives of aliphatic isocyanates such as HDI and IPDI, specifically diisocyanate derivatives such as biuret, allophanate, uretdione, and isocyanurate; and polyhydric alcohol adducts. The polyisocyanate having 2.1 or more isocyanate groups per molecule is not particularly limited, but examples thereof include trade names Sumidur 44S and 44V70 (both manufactured by Sumika Bayer Urethane), a copolymer of TDI and HDI called Dismodur HL (manufactured by Sumika Bayer Urethane), and various Duranates manufactured by Asahi Kasei Corporation, namely trade names Duranate 24A-100, Duranate 22A-75PX, Duranate 18H-70B, Duranate 21S-75E, Duranate THA-100, Duranate TPA-100, Duranate MFA-75X, Duranate TSA-100, Duranate 16S-75E, Duranate 18 ... 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.

[0065] It is preferable to use an aromatic polyisocyanate such as MDI as the polyisocyanate of component (b). The use of an aromatic polyisocyanate tends to result in a cured product with excellent mechanical properties. When an aromatic polyisocyanate such as MDI is used as component (b) in the curable composition, the curable composition can be suitably used as an adhesive between the base fabric and the surface layer of synthetic leather. Furthermore, when an aliphatic polyisocyanate such as hydrogenated MDI is used as component (b) in the curable composition, the curable composition can provide synthetic leather with excellent weather resistance, and therefore the curable composition is suitably used as a curable composition for synthetic leather for the surface layer, etc.

[0066] It is also possible to use a so-called blocked isocyanate obtained by blocking the polyisocyanate of component (b) with a known blocking agent such as a lower alcohol such as butanol or 2-ethylhexanol, methyl ethyl ketone oxime, lactams, phenols, imidazoles, or an active methylene compound.

[0067] When producing polyurethane using the polyester polycarbonate polyol of this embodiment, a chain extender (component (c)) can be used as needed. Chain extenders are used to improve the abrasion resistance and strength of the resulting polyurethane, but they can also reduce the flexibility of the resulting polyurethane, so they are used appropriately and 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; and the like. Examples of chain extenders include, but are not limited to, diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, and 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA); and water.

[0068] 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, and even more preferably 5% by mass or more and 10% by mass or less, based on the total amount of components (a) and (b). Furthermore, by using a polyhydric alcohol as a chain extender, the crosslink density of the resulting polyurethane can be increased, and the strength, abrasion resistance, and chemical resistance can be improved.

[0069] The amounts of the polyester polycarbonate polyol (a), the polyisocyanate (b), and the chain extender (c) used are adjusted so that the ratio (isocyanate equivalent of component (b) / total hydroxyl equivalents of both components (a) and (c)) is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. When the ratio (isocyanate equivalent of component (b) / total hydroxyl equivalents of both components (a) and (c)) is 0.7 or more and 1.3 or less, the molecular weight of the resulting polyurethane can be appropriately controlled, and the resulting polyurethane tends to have excellent mechanical properties such as strength, elongation, and abrasion resistance.

[0070] When polyurethane is produced using the polyester polycarbonate polyol of this embodiment, an inert organic solvent may be added as necessary to adjust workability during urethane production. The content of the inert organic solvent is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the polyurethane. Addition of an inert organic solvent is effective for reducing the viscosity of the curable composition, improving its workability, and further improving the appearance of the resulting cured product.

[0071] The inert organic solvent is not particularly limited as long as it is an organic solvent that 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; fluorine-based inert liquids such as fluorinated oils such as trichlorofluoroethane, tetrachlorodifluoroethane, and perfluoroether; perfluorocyclohexane, perfluorobutyltetrahydrofuran, perfluorodecalin, perfluoro-n-butylamine, perfluoropolyether, and dimethylpolysiloxane. These may be used alone or in combination. Examples of inert organic solvents include methyl ethyl ketone (also referred to as MEK), acetone, ethyl acetate, butyl acetate, toluene, and xylene, either alone or in combination.

[0072] The curable composition of the present embodiment may contain a polyol other than the polyester polycarbonate polyol, if necessary. The polyol other than the polyester polycarbonate polyol is not particularly limited, and examples thereof include polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, polyacrylic polyols, and oil-modified polyols. The amount of polyol other than polyester polycarbonate polyol added is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the combined mass of polyester polycarbonate polyol and polyol other than polyester polycarbonate polyol.

[0073] <Other additives> When polyurethane is produced using the polyester polycarbonate polyol of the present embodiment, curing accelerators (catalysts), fillers, flame retardants, dyes, organic or inorganic pigments, mold release agents, flowability modifiers, plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, antifoaming agents, leveling agents, colorants, foaming agents, and the like may be added depending on the intended use.

[0074] The curing accelerator is not particularly limited, but examples thereof include amines and metal catalysts. The amine effect accelerator is not particularly limited, but examples thereof include monoamines such as triethylamine and N,N-dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, other triamines, cyclic amines, alcohol amines such as dimethylethanolamine, and ether amines. The metal catalyst is not particularly limited, but examples thereof include potassium acetate, potassium 2-ethylhexanoate, calcium acetate, lead octoate, dibutyltin dilaurate, tin octoate, bismuth neodecanoate, bismuth oxycarbonate, bismuth 2-ethylhexanoate, zinc octoate, zinc neodecanoate, phosphine, and phospholine.

[0075] The filler or pigment is not particularly limited, but examples thereof include woven fabric, glass fiber, carbon fiber, polyamide fiber, mica, kaolin, bentonite, metal powder, azo pigment, carbon black, clay, silica, talc, gypsum, alumina white, barium carbonate, and calcium carbonate.

[0076] The release agent, flow control agent, and leveling agent are not particularly limited, but examples thereof include silicone, aerosil, wax, stearates, and polysiloxanes such as BYK-331 (manufactured by BYK Chemicals).

[0077] When polyurethane is produced using the polyester polycarbonate polyol of this embodiment, it is preferable to use an antioxidant, a light stabilizer, and a heat stabilizer as additives. The antioxidant is not particularly limited, but examples thereof include aliphatic, aromatic, or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds such as phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diphosphites, and dialkylbisphenol A diphosphites; phenol derivatives, particularly hindered phenol compounds; sulfur-containing compounds such as thioethers, dithioacid salts, mercaptobenzimidazoles, thiocarbanilides, and thiodipropionic acid esters; and tin compounds such as tin maleates and dibutyltin monoxide. These may be used alone or in combination of two or more.

[0078] <Manufacturing method for synthetic leather> Synthetic leather can be produced by applying the method for producing polyurethane using the polyester polycarbonate polyol of this embodiment. The method for producing synthetic leather using the polyester polycarbonate polyol of this embodiment is not particularly limited, and examples include a wet method in which a polyurethane produced using the polyester polycarbonate polyol of this embodiment is applied to or impregnated into a substrate (base fabric) and wet-coagulated, and a dry method in which a polyurethane produced using the polyester polycarbonate polyol of this embodiment is applied to release paper or a substrate (base fabric) and dried. Furthermore, as a method for producing synthetic leather, a transfer coating method (a type of dry method) can also be used, in which a polyurethane produced using the polyester polycarbonate polyol of the present embodiment is applied to release paper to form a skin material, and then another polyurethane produced using the polyester polycarbonate polyol of the present embodiment is used as an adhesive layer on top of the skin material, and the release paper is removed after bonding to a substrate (base fabric).

[0079] The method for producing synthetic leather will be explained below using the dry method as an example. Various substrates (base fabrics) can be used, and examples thereof include, but are not limited to, fibrous substrates. Examples of fibrous substrates include, but are not limited to, fiber aggregates in the form of nonwoven fabrics, woven fabrics, mesh fabrics, etc., or fiber aggregates in which the fibers are bonded together with an elastic polymer. Examples of fibers used in these fiber aggregates include, but are not limited to, natural fibers such as cotton, linen, and wool; recycled or semi-synthetic fibers such as rayon and acetate; and synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, and polyolefin. These fibers may be either single-spun or mixed-spun fibers. Other substrates include, but are not limited to, paper, release paper, polyester or polyolefin plastic films, metal plates such as aluminum, and glass plates.

[0080] The curable composition for synthetic leather of this embodiment can be applied by a commonly used method, which is not particularly limited, but includes, for example, a floating knife coater, a knife-over-roll coater, a reverse roll coater, a roll doctor coater, a gravure roll coater, a kiss roll coater, etc.

[0081] The resulting synthetic leather can be used as is. Alternatively, to impart various additional properties, this synthetic leather can be obtained by coating the synthetic leather with a polymer solution or emulsion such as polyurethane resin, vinyl chloride, or cellulose-based resin. Alternatively, the synthetic leather can be obtained in the form of a laminate obtained by laminating a coating film obtained by drying the polymer solution or emulsion coated on a separate release paper, and then peeling off the release paper.

[0082] The present embodiment will be described below with reference to the drawings. The drawings and manufacturing conditions described below are one example of the present embodiment, and the present embodiment is not limited thereto.

[0083] Figure 1 is a schematic cross-sectional view of a synthetic leather laminate produced by the dry method shown in Figure 2. The structure of this laminate has a surface layer 2 on a substrate (nonwoven fabric) 4 with an adhesive layer 3 interposed therebetween. The outermost layer has release paper 1, which was used during production, attached, but is peeled off before use.

[0084] 2 is a schematic diagram showing one method for producing a dry-type synthetic leather laminate sheet using polyurethane, which is produced using the polyester polycarbonate polyol of this embodiment. In this production method, first, the raw materials of the curable composition of this embodiment, which have been adjusted to a predetermined temperature in advance, are mixed in a mixing head 5, and the resulting curable composition is then poured onto release paper 1 (which usually has a leather-like pattern on it). When the one-shot method is applied, component (a), component (b), and optionally component (c), as well as optionally an inert organic solvent and additives, are fed separately, or component (b) and other raw materials (a mixture of component (a), component (c), as needed an inert organic solvent, and additives) are continuously fed into a mixing head 5, mixed, and allowed to flow down onto the release paper 1. When the prepolymer method is applied, the prepolymer composition and a mixture of a non-prepolymerized polycarbonate polyol (component (a)) and / or a chain extender (component (c)), and optionally an inert organic solvent and additives, are continuously fed into a mixing head 5, mixed, and allowed to flow down onto release paper 1.

[0085] Before mixing, the components are adjusted to a temperature of typically 20 to 80°C, preferably 30 to 70°C, and more preferably 40 to 60°C. The temperature of the mixing head 5 is also adjusted to a temperature of typically 20 to 80°C, preferably 30 to 70°C, and more preferably 40 to 60°C. By keeping the temperatures of the components and the mixing head 5 before mixing at 20°C or higher, the viscosity of the raw materials used, particularly the polycarbonate polyol, tends to be suppressed, and the flow rate tends to be stable. By keeping the temperatures of the components and the mixing head 5 before mixing at 80°C or lower, the curing rate of the curable composition of this embodiment is appropriately controlled, a rapid increase in the viscosity of the curable composition is suppressed, and a synthetic leather with a uniform thickness tends to be obtained.

[0086] The mixture is then passed through a coating roll 8 to form a sheet of a uniform thickness, and then passed through a dryer 11 to harden and dry the inert organic solvent, forming the synthetic leather skin layer 2. The temperature of the dryer is usually set to 60 to 150°C, preferably 70 to 130°C, and more preferably 80 to 110°C. The drying time is usually 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0087] Next, the raw materials of the curable composition of this embodiment, which have been adjusted to a predetermined temperature in advance, are mixed in a mixing head 6, and the curable composition of this embodiment obtained is allowed to flow down to form an adhesive layer 3. When the one-shot method is applied to the production of the adhesive layer, components (a), (b), and (c), as well as an inert organic solvent and additives as required, are fed separately, or component (b) is continuously fed into a mixing head 6 as a mixture of the other raw material components (a), (c), as required, an inert organic solvent, and additives, and the mixture is then mixed and allowed to flow down onto the skin layer. When the prepolymer method is applied to the production of the adhesive layer, the prepolymer composition and the non-prepolymerized polyester polycarbonate polyol (component (a)), if necessary, an inert organic solvent and additives are fed separately, or alternatively, a mixture of the prepolymer composition and other raw materials (non-prepolymerized polyester polycarbonate polyol (component (a) and / or a chain extender (component (c)), if necessary, an inert organic solvent and additives)) are continuously fed into a mixing head 6, mixed, and allowed to flow down onto the surface layer.

[0088] Before mixing, the components are adjusted to a temperature of typically 20 to 60°C, preferably 30 to 50°C, and more preferably 35 to 45°C. The temperature of the mixing head 6 is also adjusted to a temperature of typically 20 to 60°C, preferably 30 to 50°C, and more preferably 35 to 45°C. By keeping the temperatures of the components before mixing and the temperature of the mixing head 6 at 20°C or higher, the viscosity of the raw materials used, particularly the polyester polycarbonate polyol, tends to be reduced, and the flow rate tends to be stable. By keeping the temperatures of the components before mixing and the temperature of the mixing head 6 at 60°C or lower, the curing rate of the curable composition of this embodiment is appropriately controlled, a rapid increase in the viscosity of the curable composition is suppressed, and a synthetic leather with a uniform thickness tends to be obtained.

[0089] The resulting mixture is then passed through a coating roll 8 to form a sheet of a uniform thickness, which is then passed through a dryer 11 to harden and dry the inert organic solvent, forming a synthetic leather adhesive layer 3. The substrate 4 and adhesive layer 3 are then superimposed and pressed together with a pressure roll 9, yielding a sheet structure 7, which is then taken up on a take-up roll 10 to obtain the desired synthetic leather laminate. The temperature of the dryer 11 is typically set to 50 to 110°C, preferably 60 to 100°C, and more preferably 70 to 90°C. The drying time is typically 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0090] While FIG. 2 shows an example of the production of synthetic leather comprising three layers: a skin layer, an adhesive layer, and a substrate, a synthetic leather laminate comprising two layers (skin layer / substrate) without the adhesive layer can also be produced using the same equipment. The adhesion between the skin layer and the substrate is controlled by adjusting the curing state of the curable composition. Specifically, this can be achieved by pressing the curable composition of this embodiment onto the substrate in a state where it is not completely cured. Therefore, the curing temperature of the dryer 11 is set to 50 to 110°C, preferably 60 to 100°C, and more preferably 70 to 90°C. The drying time is usually set to 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0091] <Application> Synthetic leather obtained using a polyurethane produced using the polyester polycarbonate polyol of this embodiment can be used for automobile interior materials such as automobile seats, furniture such as sofas, clothing, shoes, bags, and other miscellaneous products. It can also be used as a laminating adhesive for various films, a surface protective agent, etc. The water-based polyurethane produced using the polyester polycarbonate polyol of this embodiment can be used as various materials such as paints and coating agents in addition to the synthetic leather described above. [Example]

[0092] 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 depart from the gist of the invention. In the following examples and comparative examples, the methods for analyzing and evaluating the physical properties of each component are as follows.

[0093] [Analysis and Evaluation of Polyester Polycarbonate Polyols] <Hydroxyl value of polyester polycarbonate polyol> Measurement was performed in accordance with JIS K1557-1. The average molecular weight (g / mol) of the polyester polycarbonate polyol was also calculated from the hydroxyl value of the polyester polycarbonate polyol obtained. The average number of hydroxyl groups in one molecule of the polyester polycarbonate polyol was13 It can be calculated from C-NMR.

[0094] <Polyester polycarbonate polyol composition (copolymerization ratio)> A 1g sample of polyester polycarbonate polyol was placed in a 100mL recovery flask, and 30g of methanol and 8g of 28% sodium methoxide in methanol were added. The reaction mixture was then allowed to react at 100°C for 1 hour. After cooling to room temperature, 2-3 drops of phenolphthalein were added as an indicator and neutralized with hydrochloric acid. After cooling in a refrigerator for 1 hour, the mixture was filtered and analyzed by gas chromatography (GC). GC analysis was performed using a GC-14B gas chromatograph (Shimadzu Corporation, Japan) equipped with a DB-WAX column (J&W, USA). The GC analysis was performed using diethylene glycol diethyl ester as the internal standard and a flame ionization detector (FID) to quantitatively analyze each component. The column temperature profile was as follows: 60°C for 5 minutes, followed by a 10°C / min increase to 250°C. The composition (copolymerization ratio) of the polyester polycarbonate polyol was determined from the alcohol components and the methyl ester components derived from the dibasic acid detected from the above analysis results. For the composition of polyester polycarbonate polyols containing dibasic acids, the number of moles of diols constituting the carbonate skeleton can be determined by subtracting the same number of moles of diol from the number of moles of methyl ester derived from the dibasic acid (when multiple diols are used, the calculation is performed assuming that the composition of the diol in the carbonate skeleton and the composition of the diol in the ester skeleton are the same, based on the ratio of diols determined by gas chromatography).

[0095] <Melt viscosity measurement> The polyester polycarbonate polyol or polyol was preheated to 50°C, and then the melt viscosity was measured at 50°C using a rotational viscometer (E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-22HT, cone: No. 6)).

[0096] <Carbonate group content of polyester polycarbonate polyol> The carbonate group content is the amount of carbonate groups contained in one molecule of the polyester polycarbonate polyol, and is specifically calculated by the following formula (i). Carbonate group content (%) = (molecular weight of carbonate group) × (number of carbonate groups per molecule) / (number average molecular weight of polyester polycarbonate polyol) × 100 (i) (Here, the molecular weight of the carbonate group (-OC=OO-) is 60.01.) The number of carbonate groups in one molecule was calculated from the number of repeating units (x) of the carbonate structure using the following formula (9) based on the structure of the following formula (8). [ka] (Here, R' represents a linear methylene chain and / or a branched methylene chain, and the average number of methylene groups contained in R' is (m). x represents the number of repeating units of the carbonate structural skeleton in one molecule, y represents the number of repeating units of the ester structural skeleton, and the underlined parts represent terminal groups. R2 represents the hydrocarbon derived from the dibasic acid used.)

[0097] The structure of each segment constituting the polycarbonate was determined from the composition of the polyester polycarbonate polyol obtained from the composition (copolymerization ratio) of the polyester polycarbonate polyol. From this, the number of methylenes in each constituting segment was determined, and the average number of methylenes (m) was calculated from the ratio. When a branch was included in the methylene chain, the number of branched methylene carbon atoms was taken into account in the calculation. Number of carbonate group repeating units (x) = [(number average molecular weight (Mn) - (molecular weight of ester skeleton) - (molecular weight of terminal group)) / (molecular weight of carbonate skeleton repeating unit) (9) The molecular weight of the ester skeleton was determined from the composition of the carbonate skeleton and the composition of the ester skeleton determined by gas chromatography. Specifically, the molecular weight of the ester skeleton was determined by multiplying the molecular weight obtained by subtracting the average molecular weight of the average terminal diol group from the average molecular weight of the polyester polycarbonate polyol by the mass ratio obtained by converting the molar composition of the ester skeleton determined separately by gas chromatography into a mass composition.

[0098] <Properties of polyester polycarbonate polyol> The polyester polycarbonate polyol was rated as liquid if it exhibited even slight fluidity at 23°C, and as solid if it did not exhibit any fluidity.

[0099] [Analysis and evaluation of polyurethane films] <Preparation of polyurethane film> Using an applicator, a polyurethane DMF solution was applied to a polypropylene resin sheet (100 mm wide, 1200 mm long, 1 mm thick), and the sheet was dried on a hot plate at a surface temperature of 60°C for 1 hour, followed by 24 hours in an oven at 80°C. The sheet was then left to stand at a constant temperature and humidity of 23°C and 55% RH for at least 24 hours, yielding a polyurethane film approximately 50 μm thick. The resulting polyurethane film was then subjected to evaluation of various physical properties.

[0100] <Flexibility of polyurethane film> The flexibility of the polyurethane film was evaluated by five examiners who evaluated the feel of the film when touched with their hands. The evaluation criteria were as follows: ○ indicates flexibility, and the evaluation results of the five inspectors were consistent. △ indicates that the product was slightly hard, and the evaluation results of the five inspectors were consistent. The symbol × indicates that the sample was hard, and the evaluation results of the five inspectors were consistent.

[0101] <Appearance of polyurethane film> The surface appearance of the polyurethane film prepared above was visually evaluated according to the following criteria. A circle indicates that the surface was smooth. △ indicates that a few streaks were observed on the surface in the direction of applicator movement. × indicates that many streaks were observed on the surface in the direction of applicator movement.

[0102] <Molecular weight measurement> A portion of the polyurethane film was cut out and dissolved in N,N-dimethylacetamide to give a polyurethane concentration of 0.1% by mass. The number-average molecular weight (Mn) and weight-average molecular weight (Mw) were measured using a GPC system (Tosoh Corporation, product name "HLC-8320"; four Tskgel SuperHM-H columns; eluent: 2.6 g of lithium bromide dissolved in 1 L of N,N-dimethylacetamide) in terms of standard polystyrene.

[0103] <Evaluation of resistance to oleic acid> A 3cm x 3cm test piece was cut from the polyurethane film, its weight measured using a precision balance, and then placed in a 250mL glass bottle containing 50mL of oleic acid as the test solvent. The bottle was then placed in a constant temperature bath at 80°C under a nitrogen atmosphere for 24 hours. After the test, the test piece was removed and lightly wiped on both sides with a paper wiper. The weight was then measured using a precision balance, and the weight change (increase) from before the test was calculated. A weight change rate closer to 0% indicated better oleic acid resistance, and the results were evaluated according to the following criteria. ○ indicates that the weight change rate is 11% or less. △ indicates that the weight change rate is more than 11% and 13% or less. × indicates that the weight change rate exceeds 13%.

[0104] <Measurement of glass transition temperature (Tg)> A test piece measuring 10 mm wide, 40 mm long, and approximately 50 μm thick was cut from the polyurethane film. Using a viscoelasticity measuring device (Hitachi High-Tech Science Corporation, [TA7000 series, DMA7100]), the test piece was set with a chuck distance of 20 mm, and the viscoelasticity was measured while the temperature was raised from -100°C to 100°C at a rate of 5°C / min. The glass transition temperature (Tg) was calculated from the peak value of tan δ.

[0105] <Room temperature tensile test> In accordance with JIS K6301 (2010), a tensile test was performed on rectangular polyurethane test pieces measuring 10 mm in width, 100 mm in length, and approximately 50 μm in thickness using a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon, Model RTE-1210") at a chuck distance of 20 mm, a tensile speed of 100 mm / min, and a temperature of 23°C (relative humidity of 55%). The stress at the time when the test piece was elongated to 100% (100% modulus), as well as the strength at break and elongation at break were measured.

[0106] <Low temperature tensile test> In accordance with JIS K6301 (2010), rectangular polyurethane test pieces measuring 10 mm wide, 100 mm long, and approximately 50 μm thick were placed on a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon, Model RTE-1210") equipped with a thermostatic chamber (manufactured by Orientec Co., Ltd., "Model TLF-R3T-EW") with a chuck distance of 20 mm. After allowing to stand at -20°C for 5 minutes, a tensile test was conducted at a tensile speed of 100 mm / min, and the stress at 5% elongation (5% modulus), strength at break, and elongation at break were measured.

[0107] <Evaluation of heat resistance> The polyurethane film was cut into a strip of 10 mm width, 100 mm length, and approximately 50 μm thickness, and heated in a Geer oven at 120°C for 7 days. The breaking strength of the heated sample was measured in the same manner as in the above <Room temperature tensile test>, and the breaking strength retention (%) before and after heating was calculated using the following formula. Breaking strength retention rate (%) = Breaking strength after heating / Breaking strength before heating × 100 The evaluation was also carried out according to the following criteria. ○ indicates that the breaking strength retention rate is 70% or more. △ indicates that the breaking strength retention rate is 60% or more but less than 70%. × indicates that the breaking strength retention rate is less than 60%.

[0108] <Evaluation of hydrolysis resistance> The polyurethane film was cut into a strip of 10 mm wide, 100 mm long, and approximately 50 μm thick, and heated in a thermo-hygrostat at a temperature of 85°C and a relative humidity of 85% for 14 days. The breaking strength of the heated sample was measured in the same manner as in the above <Room temperature tensile test>, and the breaking strength retention (%) before and after heating was calculated using the following formula. Breaking strength retention rate (%) = Breaking strength after heating / Breaking strength before heating × 100 The evaluation was also carried out according to the following criteria. ○ indicates that the breaking strength retention rate is 70% or more. △ indicates that the breaking strength retention rate is 55% or more but less than 70%. × indicates that the breaking strength retention rate is less than 55%.

[0109] [Analysis and evaluation of synthetic leather] <Flexibility of synthetic leather> The softness of the synthetic leather was evaluated by five panelists who evaluated the feel of the synthetic leather when touched with their hands. The evaluation criteria were as follows: ○ indicates flexibility, and the evaluation results of the five inspectors were consistent. △ indicates that the product was slightly hard, and the evaluation results of the five inspectors were consistent. The symbol × indicates that the sample was hard, and the evaluation results of the five inspectors were consistent.

[0110] <Synthetic leather appearance> The surface appearance of the synthetic leather prepared above was visually evaluated according to the following criteria. ○ indicates that the surface is smooth and has a uniform grain pattern. △: The surface is smooth, but streaks other than the grain pattern are observed on the surface. × indicates that streaks other than the grain pattern are observed on the surface, and the surface is not smooth but has irregularities.

[0111] <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 rubbed back and forth 10,000 times over a distance of 140 mm on the surface of the synthetic leather at a speed of 60 strokes per minute. The synthetic leather was observed after abrasion and rated according to the following criteria. A circle indicates that the resin layer was free of cracks and tears. △ indicates that cracks occurred in the resin layer. × indicates that the resin layer was torn.

[0112] <Low temperature storage stability of synthetic leather> The synthetic leather was wrapped around a 10 cm diameter paper tube and stored in a thermostatic chamber at -20°C for one month. The synthetic leather was removed from the paper tube and left in a thermostatic chamber at 23°C and 50% humidity for one day, after which the surface was visually observed and evaluated according to the following criteria. A circle indicates that there are no cracks or wrinkles at all. △ indicates that small cracks or wrinkles of 1 mm or less are observed. × indicates that cracks or wrinkles exceeding 1 mm are observed.

[0113] <Low temperature flexibility (cold resistance flexibility) of synthetic leather> The synthetic leather was cut into test pieces measuring 5 cm wide and 10 cm long, and a low-temperature flex test was carried out using a DeMacha flex tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) at a temperature of -10°C, a stroke of 15 mm, and a speed of 100 flexes / min for 10,000 times. The test pieces were removed, and the surfaces were visually observed and evaluated according to the following criteria. A circle indicates that there are no cracks or wrinkles at all. △ indicates that small cracks or wrinkles of 1 mm or less are observed. × indicates that cracks or wrinkles exceeding 1 mm were observed, or that peeling between the base fabric and the adhesive layer was observed.

[0114] <Washing resistance of synthetic leather> The surface of the synthetic leather was filled in with an oil-based marker (Teranishi Chemical Industry Co., Ltd., Magic Ink No. 500) in 1cm x 1cm areas, dried for 4 hours, and then wiped completely with a cotton ball soaked in ethanol until all the dirt was gone. Washing resistance was evaluated according to the following criteria. A circle indicates that no cracks or wrinkles are found on the surface. △ indicates that the surface is smooth, but streaks other than the grain pattern are observed on the surface. "X" indicates that cracks, wrinkles, or streaks are observed on the surface, and the surface is not smooth but has irregularities.

[0115] <Method for evaluating adhesiveness> An incision was made in advance at the interface between the polyester base fabric and the polyurethane resin layer of the synthetic leather, and the peeled urethane resin layer and base fabric were each fixed in place with a zipper. The peel strength between the polyurethane layer and base fabric was measured at a temperature of 23°C and a speed of 200 mm / min using a tensile tester (manufactured by Orientec Co., Ltd., product name "Tensilon, Model RTE-1210") in accordance with JIS K6854-2, and evaluated according to the following criteria. ○ indicates that the strength is 10N / 25mm or more. × indicates that the strength is less than 10N / 25mm.

[0116] <Hydrolysis resistance of synthetic leather> The synthetic leather was heated in advance in a thermo-hygrostat at a temperature of 85°C and a relative humidity of 85% for 14 days, and the peel strength was measured in the same manner as in the above <Method for evaluating adhesion>. The peel strength retention rate (%) before and after heating was calculated using the following formula. Peel strength retention rate (%) = Peel strength after heating / Peel strength before heating × 100 The evaluation was also carried out according to the following criteria. ○ indicates that the peel strength retention rate is 70% or more. △ indicates that the peel strength retention rate is 55% or more but less than 70%. × indicates that the peel strength retention rate is less than 55%.

[0117] [Example 1] [Synthesis Example 1 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a stirrer was charged with 420 g of polycarbonate polyol (trade name "Duranol T5652", manufactured by Asahi Kasei Corporation, number average molecular weight: approximately 2000, diol composition ratio: 1,5-pentanediol (hereinafter also referred to as "1,5-PDO") / 1,6-hexanediol (hereinafter also referred to as "1,6-HDO") = 50 mol% / 50 mol%) and 180 g of polyester polyol (trade name "Kuraray Polyol P-2010", manufactured by Kuraray Co., Ltd., number average molecular weight: approximately 2000, condensation product of 3-methyl-1,5-pentanediol (hereinafter also referred to as "3MPD") and adipic acid), and the mixture was heated with stirring to a reactor temperature of approximately 175°C for 10 hours to react, thereby obtaining polyester polycarbonate polyol (hereinafter also referred to as "PEC1"). The obtained PEC1 was 1 Analysis by H-NMR confirmed that the polymer had a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), and that, as a result of a transesterification reaction, branched 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). [ka] (In formula (1), R1 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) [ka] (In formula (2), R2 represents an alkylene group having 2 to 15 carbon atoms, and R3 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) The results of analysis of the obtained PEC1 are shown in Table 1.

[0118] [Example 2] [Synthesis Example 2 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, the reaction was carried out in the same manner as in Example 1, except that 300 g of the polycarbonate polyol (trade name "Duranol T5652") and 300 g of the polyester polyol (trade name "Kuraray Polyol P-2010") were used, to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC2"). 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC2 are shown in Table 1.

[0119] [Example 3] [Synthesis Example 3 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, and except that the polycarbonate polyol used was trade name "Duranol G4672" (manufactured by Asahi Kasei Corporation, number average molecular weight: approximately 2000, diol composition ratio: 1,4-butanediol (hereinafter also referred to as "1,4-BDO") / 1,6-hexanediol = 70 mol% / 30 mol%), a reaction was carried out in the same manner as in Example 1 to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC3"). The obtained PEC3 was 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC3 are shown in Table 1.

[0120] [Example 4] [Synthesis Example 4 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, the reaction was carried out in the same manner as in Example 1, except that the polycarbonate polyol was trade name "Kuraray Polyol C-2090" (manufactured by Kuraray Co., Ltd., number average molecular weight: approximately 2000, diol composition ratio: 3-methyl-1,5-pentanediol / 1,6-hexanediol = 90 mol% / 10 mol%), and the polyester polyol was trade name "Polylite OD-X-668" (manufactured by DIC Corporation, number average molecular weight: approximately 2000, condensation product of 1,4-butanediol and adipic acid), to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC4"). The obtained PEC4 was 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC4 are shown in Table 1.

[0121] [Example 5] [Synthesis Example 5 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column filled with structured packing and a stirrer was charged with 293 g (3.33 mol) of ethylene carbonate, 275 g (3.05 mol) of 1,4-butanediol, and 57.2 g (0.33 mol) of 1,10-decanediol (hereinafter also referred to as "1,10-DDO"). 0.06 g of titanium tetra-n-butoxide was added as a catalyst, and the reaction temperature was raised to 150-170°C. The pressure was reduced from 10 kPa to 3 kPa, and the resulting mixture of ethylene glycol and ethylene carbonate was distilled off for 12 hours. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa. The reaction was continued at 170°C for 5 hours, and the monomers were distilled off to obtain polycarbonate polyol (hereinafter also referred to as "PC1"). The hydroxyl value was 57.1 mg KOH / g, and the copolymerization ratio was 1,4-butanediol / 1,10-decanediol = 90 mol% / 10 mol%. Next, using the same apparatus as in Example 1, the reaction was carried out in the same manner as in Example 1, except that 200 g of the PC1 obtained by the above procedure was used as the polycarbonate polyol and 200 g of a product name "Kuraray Polyol P-2010" was used as the polyester polyol, to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC5"). 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC5 are shown in Table 1.

[0122] [Example 6] [Synthesis Example 6 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, a reaction was carried out in the same manner as in Example 1, except that 420 g of "Duranol T6002" (manufactured by Asahi Kasei Corporation, number average molecular weight: approximately 2000, diol composition: 1,6-hexanediol = 100 mol%) was used as the polycarbonate polyol, and 120 g of "Kuraray Polyol P-2010" and 60 g of "Polylite OD-X-668" were used as the polyester polyol, to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC6"). The obtained PEC6 was 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC6 are shown in Table 1.

[0123] [Example 7] [Synthesis Example 7 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 221 g (2.51 mol) of ethylene carbonate, 137 g (1.32 mol) of 1,5-pentanediol, 156 g (1.32 mol) of 1,6-hexanediol, 78.0 g (0.66 mol) of 3-methyl-1,5-pentanediol, and 90.6 g (0.62 mol) of adipic acid. 0.06 g of titanium tetra-n-butoxide was added as a catalyst. The reaction temperature was raised to 150-170 °C, and the pressure was reduced from 10 kPa to 3 kPa. The resulting water, ethylene glycol, and ethylene carbonate mixture were distilled off for 12 hours. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa. The reaction was continued at 170 °C for 5 hours to distill off the monomer. The analysis results of the obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC7") are shown in Table 1. 1 As a result of H-NMR analysis, it was confirmed that the compound has a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD is incorporated into R1 in formula (1) and R3 in formula (2).

[0124] [Example 8] [Synthesis Example 8 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 221 g (2.51 mol) of ethylene carbonate, 137 g (1.32 mol) of 1,5-pentanediol, 156 g (1.32 mol) of 1,6-hexanediol, 78.0 g (0.66 mol) of 3-methyl-1,5-pentanediol, and 90.6 g (0.62 mol) of adipic acid. 0.06 g of titanium tetra-n-butoxide was added as a catalyst. The reaction temperature was raised to 150-170 °C, and the pressure was reduced from 10 kPa to 3 kPa. The resulting water, ethylene glycol, and ethylene carbonate mixture were distilled off for 12 hours. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa. The reaction was continued at 170 °C for 3 hours to distill off the resulting monomer. The analysis results of the obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC8") are shown in Table 1. 1 As a result of H-NMR analysis, it was confirmed that the compound has a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD is incorporated into R1 in formula (1) and R3 in formula (2).

[0125] [Example 9] [Synthesis Example 9 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column filled with structured packing and a stirrer was charged with 194 g (2.20 mol) of ethylene carbonate, 202 g (1.71 mol) of 1,6-hexanediol, 114 g (0.96 mol) of 3-methyl-1,5-pentanediol, 62.7 g (0.70 mol) of 2-methyl-1,3-propanediol (hereinafter also referred to as "2MPD"), and 131 g (0.89 mol) of adipic acid. 0.10 g of titanium tetra-n-butoxide was added as a catalyst, and the reaction temperature was raised to 150-170°C. The pressure was reduced from 10 kPa to 3 kPa, and the reaction was carried out for 15 hours while distilling off the resulting water and a mixture of ethylene glycol and ethylene carbonate. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa while the reaction was carried out at 170°C for 5 hours to distill off the monomer. The analysis results of the obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC9") are shown in Table 1. Furthermore, the obtained PEC9 was 1 As a result of H-NMR analysis, it was confirmed that the compound has a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 2MPD and 3MPD are incorporated into R1 in formula (1) and R3 in formula (2).

[0126] [Example 10] [Synthesis Example 10 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, a reaction was carried out in the same manner as in Example 1, except that 420 g of the polycarbonate polyol (trade name "Duranol T5652") and 180 g of polyester polyol (trade name "Kuraray Polyol P-2050", manufactured by Kuraray Co., Ltd., number average molecular weight: approximately 2000, condensation product of 3MPD and sebacic acid) were used, and a polyester polycarbonate polyol (hereinafter also referred to as "PEC10") was obtained. 1 Analysis by H-NMR confirmed that the product had a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD was incorporated into R1 in formula (1) and R3 in formula (2). The analysis results of the obtained PEC10 are shown in Table 1.

[0127] [Example 11] [Synthesis Example 11 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 205 g (2.33 mol) of ethylene carbonate, 187 g (2.46 mol) of 1,3-propanediol (hereinafter also referred to as "1,3-PDO"), 27.0 g (0.30 mol) of 1,4-butanediol, 63.1 g (0.53 mol) of 3-methyl-1,5-pentanediol, and 113 g (0.78 mol) of adipic acid. 0.05 g of titanium tetra-n-butoxide was added as a catalyst. The reaction temperature was raised to 150-170 °C, and the pressure was reduced from 10 kPa to 3 kPa. The reaction was continued for 18 hours while distilling off the resulting water, ethylene glycol, and ethylene carbonate mixture. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa while the reaction was continued at 170 °C for 5 hours to distill off the monomer. The analysis results of the obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC11") are shown in Table 1. 1 As a result of H-NMR analysis, it was confirmed that the compound has a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and that 3MPD is incorporated into R1 in formula (1) and R3 in formula (2).

[0128] [Comparative Example 1] [Synthesis Example 12 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, a reaction was carried out in the same manner as in Example 1, except that 420 g of Duranol T5652 (trade name) was used as the polycarbonate polyol and 180 g of Polylite OD-X-2640 (manufactured by DIC Corporation, number average molecular weight: approximately 2000, condensate of 1,6-hexanediol and adipic acid) was used as the polyester polyol, to obtain polyester polycarbonate polyol (hereinafter also referred to as "PEC12"). The analysis results of the obtained PEC12 are shown in Table 1. Note that no branched alkylene group-derived diol was confirmed in this compound.

[0129] Comparative Example 2 [Synthesis Example 13 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, a reaction was carried out in the same manner as in Example 1, except that the polycarbonate polyol was trade name "Duranol T6002" and the polyester polyol was trade name "Polylite OD-X-668," to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC13"). The results of analysis of the obtained PEC13 are shown in Table 1. The compound was solid at room temperature, and no branched alkylene group-derived diol was confirmed.

[0130] Comparative Example 3 [Synthesis Example 14 of Polyester Polycarbonate Polyol] Using the same apparatus as in Example 1, a reaction was carried out in the same manner as in Example 1, except that the polycarbonate polyol was trade name "Duranol T6002" and the polyester polyol was trade name "Polylite OD-X-2640," to obtain a polyester polycarbonate polyol (hereinafter also referred to as "PEC14"). The analysis results of the obtained PEC14 are shown in Table 1. The compound was solid at room temperature, and no branched alkylene group-derived diol was confirmed.

[0131] Comparative Example 4 [Synthesis Example 15 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 221 g (2.51 mol) of ethylene carbonate, 137 g (1.32 mol) of 1,5-pentanediol, 156 g (1.32 mol) of 1,6-hexanediol, 78.0 g (0.66 mol) of 3-methyl-1,5-pentanediol, and 90.6 g (0.62 mol) of adipic acid. 0.06 g of titanium tetra-n-butoxide was added as a catalyst. The reaction temperature was raised to 150-170 °C, and the pressure was reduced from 10 kPa to 3 kPa. The resulting water, ethylene glycol, and ethylene carbonate mixture were distilled off for 12 hours. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa. The reaction was continued at 170 °C for 2.5 hours to distill off the monomer. The obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC15") was analyzed, and the results are shown in Table 1.

[0132] Comparative Example 5 [Synthesis Example 16 of Polyester Polycarbonate Polyol] A 1 L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 221 g (2.51 mol) of ethylene carbonate, 137 g (1.32 mol) of 1,5-pentanediol, 156 g (1.32 mol) of 1,6-hexanediol, 78.0 g (0.66 mol) of 3-methyl-1,5-pentanediol, and 90.6 g (0.62 mol) of adipic acid. 0.06 g of titanium tetra-n-butoxide was added as a catalyst. The reaction temperature was raised to 150-170 °C, and the pressure was reduced from 10 kPa to 3 kPa. The resulting water, ethylene glycol, and ethylene carbonate mixture were distilled off for 12 hours. The reaction was then switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa. The reaction was continued for 6.5 hours at 170 °C to distill off the resulting monomer. The obtained polyester polycarbonate polyol (hereinafter also referred to as "PEC16") was analyzed, and the results are shown in Table 1.

[0133] Comparative Example 6 [Synthesis Example 17 of Polyester Polycarbonate Polyol] A 1-L glass flask equipped with a rectification column packed with structured packing and a stirrer was charged with 300 g of Duranol T5652 (trade name) as the polycarbonate polyol and 300 g of Polylite OD-X-2640 (trade name) as the polyester polyol, and the reaction was carried out in the same manner as in Example 1 to obtain polyester polycarbonate polyol (hereinafter also referred to as "PEC17"). The analysis results of the obtained PEC17 are shown in Table 1. Note that no branched alkylene group-derived diol was confirmed in this compound.

[0134] [Table 1]

[0135] [Example 12] A 500 mL separable flask equipped with a stirrer and sealed with nitrogen gas was charged with 15.3 g (0.06 mol) of diphenylmethane-4,4'-diisocyanate (MDI, average number of isocyanate groups per molecule: 2.0) and 80.0 g of N,N-dimethylformamide (DMF), and heated to 40 °C to obtain a solution. 60 g of N,N-dimethylformamide (DMF) and 40.0 g (0.02 mol) of polyester polycarbonate polyol PEC1, which had been added with 2.8 mg of dibutyltin dilaurate as a catalyst, were added dropwise to the flask over 30 minutes while stirring the solution. The reaction was carried out at 40 °C with stirring for 2 hours to obtain a prepolymer with a terminal isocyanate group. Next, 3.6 g (0.04 mol) of 1,4-butanediol (BDO) was added as a chain extender, and the mixture was heated to 60°C and reacted for 1 hour. Then, 0.5 g of ethanol was added as a reaction terminator to obtain a DMF solution of polyurethane (solid content: approximately 30% by mass). A polyurethane film was produced using the obtained DMF solution of polyurethane (curable composition) according to the procedure described above in <Preparation of Polyurethane Film>. The evaluation results are shown in Table 2.

[0136] [Examples 13 to 22] Polyurethane films were obtained in the same manner as in Example 12, except that PEC2 to PEC11 were used as the polyester polycarbonate polyols, the masses of the polyester polycarbonate polyols used were as shown in Table 2, and the amount of DMF was adjusted to a solid content of approximately 30 mass%. Various physical properties were evaluated. The evaluation results are shown in Table 2.

[0137] [Comparative Examples 7 to 12] Polyurethane films were obtained in the same manner as in Example 12, except that PEC12 to PEC17 were used as the polyester polycarbonate polyols, the masses of the polyester polycarbonate polyols used were as shown in Table 2, and the amount of DMF was adjusted to a solid content of approximately 30 mass%, and the films were subjected to evaluation of various physical properties. The evaluation results are shown in Table 2.

[0138] [Table 2]

[0139] [Example 23] A 500 mL separable flask equipped with a stirrer and sealed with nitrogen gas was charged with 15.7 g (0.06 mol) of 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI, average number of isocyanate groups per molecule: 2.0) and 80 g of N,N-dimethylformamide (DMF), and heated to 50 °C to obtain a solution. 60 g of N,N-dimethylformamide (DMF) and 40 g (0.02 mol) of polyester polycarbonate polyol PEC1, which had been added with 2.8 mg of dibutyltin dilaurate as a catalyst, were added dropwise to the flask over 30 minutes while stirring the solution. The mixture was allowed to react for 2 hours at 70 °C with stirring to obtain a prepolymer with a terminal isocyanate. Next, 6.8 g (0.04 mol) of isophoronediamine (IPDA) was added as a chain extender, and the reaction was carried out at 70°C for 2 hours. Then, 0.5 g of ethanol was added as a reaction terminator to obtain a DMF solution of polyurethane (solid content: approximately 30% by mass). A polyurethane film was produced using the obtained DMF solution of polyurethane (curable composition) according to the procedure described above in "Preparation of Polyurethane Film." The evaluation results are shown in Table 3.

[0140] [Examples 24 to 32] Polyurethane films were obtained in the same manner as in Example 23, except that PEC2 to 11 were used as the polyester polycarbonate polyol, the mass of the polyester polycarbonate polyol used was the mass shown in Table 3, and the amount of DMF was adjusted to a solid content of approximately 30 mass%, and the films were subjected to evaluation of various physical properties. The evaluation results are shown in Table 3.

[0141] [Comparative Examples 13 to 18] Polyurethane films were obtained in the same manner as in Example 23, except that PEC12 to 17 were used as the polyester polycarbonate polyol, the mass of the polyester polycarbonate polyol used was the mass shown in Table 3, and the amount of DMF was adjusted to a solid content of approximately 30 mass%, and the films were subjected to evaluation of various physical properties. The evaluation results are shown in Table 3.

[0142] [Table 3]

[0143] [Example 33] (Manufacturing of synthetic leather) Using an apparatus similar to that shown in FIG. 2 and release paper with a grained pattern (R-8, manufactured by Lintec Corporation), a composition having the same composition ratio as in Example 23 (two components, a prepolymer obtained by reacting isocyanate with polyester polycarbonate polyol and a chain extender, were mixed continuously in a mixing head at a temperature of 70°C immediately beforehand) was continuously poured onto the release paper and adjusted to a thickness of 50 μm with a coating roll. The mixture was passed through a dryer at 120°C to form a urethane layer that would become the surface layer. In this way, in this embodiment, the amount of solvent used to produce polyurethane synthetic leather can be reduced, allowing for solvent-free production. Next, a composition having the same composition ratio as in Example 12 (a prepolymer obtained by reacting isocyanate with polyester polycarbonate polyol and a chain extender were mixed continuously in a mixing head at 40°C just beforehand) was continuously poured onto release paper and adjusted to a thickness of 250 μm with a coating roll. The mixture was then passed through a dryer at 120°C to form a urethane layer that would become the adhesive layer. The adhesive layer was then laminated to a 500 μm thick base fabric (a nonwoven fabric made of polyester fiber) using a pressure roller, and the laminate was wound up using a take-up roller to obtain a synthetic leather made of a polyurethane laminate. The synthetic leather thus obtained was evaluated, and the results are shown in Table 4.

[0144] [Examples 34 to 42] Synthetic leather consisting of a polyurethane laminate was obtained in the same manner as in Example 33, except that the type of polyurethane for the surface layer and the type of polyurethane for the adhesive layer were changed as shown in Table 4. The obtained synthetic leather was evaluated, and the results are shown in Table 4.

[0145] [Comparative Examples 19 to 24] Synthetic leather consisting of a polyurethane laminate was obtained in the same manner as in Example 33, except that the type of polyurethane for the surface layer and the type of polyurethane for the adhesive layer were changed as shown in Table 4. The obtained synthetic leather was evaluated, and the results are shown in Table 4.

[0146] [Table 4]

[0147] This application is based on a Japanese patent application (Patent Application No. 2021-180342) filed on November 4, 2021, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0148] Polyurethanes using the polyester polycarbonate polyols of the present invention have an excellent balance of flexibility, chemical resistance, low-temperature properties, heat resistance, hydrolysis resistance, adhesiveness, abrasion resistance, touch, and appearance, and are therefore particularly suitable for use as constituent materials for synthetic leathers and artificial leathers, which can also be used for automobile seats and other applications requiring durability. The polyester polycarbonate polyol of the present invention is also used as a laminating adhesive for various films, a surface protective agent, etc. In particular, a curable composition using the polyester polycarbonate polyol of the present invention is used as an adhesive or coating agent for synthetic leather and other products that require flexibility. [Explanation of symbols]

[0149] 1 Release paper 2 Epidermal 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. Crimping Roll 10 Winding roll 11 Dryer

Claims

1. The polymer has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), has a hydroxyl value of 35 to 85 mgKOH / g, has a hydroxyl group at a terminal, and is liquid at room temperature: A polyester polycarbonate polyol, in which the molar ratio of the content of the repeating unit represented by the formula (1) to the content of the repeating unit represented by the formula (2) (formula (1) / formula (2)) is 30 / 70 to 90 / 10. 【Chemical 1】 (In formula (1), R1 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.) 【Chemistry 2】 (In formula (2), R2 represents an alkylene group having 2 to 15 carbon atoms, and R3 is composed of at least two groups selected from the group consisting of linear alkylene groups having 2 to 15 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 15 carbon atoms, and branched alkylene groups having 4 to 15 carbon atoms, and includes at least one branched alkylene group having 4 to 15 carbon atoms and at least one linear alkylene group having 2 to 10 carbon atoms.)

2. 2. The polyester polycarbonate polyol according to claim 1, wherein R1 in formula (1) and / or R3 in formula (2) comprise at least one selected from the group consisting of branched alkylene groups having 4 to 15 carbon atoms and at least two selected from the group consisting of linear alkylene groups having 2 to 10 carbon atoms.

3. 3. The polyester polycarbonate polyol according to claim 1, which has a viscosity of 1,000 to 10,000 mPa·s as measured at 50°C with a rotational viscometer.

4. 3. The polyester polycarbonate polyol according to claim 1 or 2, wherein the repeating unit represented by formula (1) contains 50 mol % or more of at least two repeating units selected from the group consisting of a repeating unit represented by formula (3), a repeating unit represented by formula (4), a repeating unit represented by formula (5), a repeating unit represented by formula (6), and a repeating unit represented by formula (7): 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】

5. The polyester polycarbonate polyol according to claim 1 or 2, wherein the raw material used for the polyol is bio-derived.

6. A curable composition prepared by reacting the polyester polycarbonate polyol according to claim 1 or 2 with an organic diisocyanate and a chain extender.

7. A synthetic leather produced using the polyester polycarbonate polyol according to claim 1 or 2.

8. A water-based polyurethane produced using the polyester polycarbonate polyol according to claim 1 or 2.

Images