Curable composition and polyurethane

Abstract

To provide a curable composition that enables production of a polyurethane that satisfies, in a well-balanced manner, all capabilities of mechanical properties, wear resistance and chemical resistance.SOLUTION: A curable composition comprises: a polycarbonate diol (A) that contains a structural unit (1) represented by the general formula (I) in the figure and a structural unit (2) represented by the general formula (II) in the figure; a difunctional isocyanate (B); and an at least trifunctional isocyanate (C).

Description

[Technical Field]

[0001] The present invention relates to a curable composition and a polyurethane. Furthermore, the present invention relates to a coating film, a blanket for a printing roller, a printing roller and a printing press. [Background technology]

[0002] Polyurethane rubber, polyurethane resin, and polyurethane elastomer (hereinafter collectively referred to as "polyurethane") are characterized by their excellent rubber elasticity, high mechanical strength, low abrasion, and excellent chemical resistance, and in recent years their use in printing roller blankets has been considered. For example, Patent Document 1 proposes a polyurethane elastomer using an ether-based polyol as a raw material polyol as a thermosetting polyurethane elastomer used in various rollers used in copying machines and the like. Furthermore, Patent Document 2 proposes a thermosetting polyurethane elastomer using polycarbonate diol as the raw material polyol. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-290324 [Patent Document 2] Patent Publication No. 2021-55029 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the thermosetting polyurethane elastomer disclosed in Patent Document 1 has insufficient chemical resistance. Furthermore, the thermosetting polyurethane elastomer disclosed in Patent Document 2 has high hardness and insufficient abrasion resistance.

[0005] The present invention aims to solve these problems. That is, an object of the present invention is to provide a curable composition that can be used to produce a polyurethane that satisfies all of the performance requirements, including mechanical properties, abrasion resistance, and chemical resistance, in a well-balanced manner. Another object of the present invention is to provide a polyurethane that satisfies all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner. [Means for solving the problem]

[0006] As a result of extensive investigations to solve the above problems, the present inventors have found that the above problems can be solved by using a polycarbonate diol having a specific structure as a raw material for a curable composition or polyurethane. That is, the present invention provides the following. [1] A curable composition comprising a polycarbonate diol (A) containing a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), a bifunctional isocyanate (B), and a tri- or higher functional isocyanate (C).

[0007] [ka]

[0008] (In the above general formula (I), R 1 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms.

[0009] [ka]

[0010] (In the above general formula (II), R 2 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms. [2] The curable composition according to [1], wherein the structural unit (1) includes a structural unit (1a) represented by the following general formula (Ia):

[0011] [ka]

[0012] (In the above general formula (I), m represents an integer of 3 to 5.) [3] The curable composition according to [1] to [2], wherein the structural unit (2) includes a structural unit (2a) represented by the following general formula (IIa):

[0013] [ka]

[0014] (In the above general formula (II), n represents an integer of 6 to 20.) [4] The curable composition according to any one of [1] to [3], wherein in the polycarbonate diol (A), the ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) is 0.10 or more and 20.00 or less. [5] The curable composition according to any one of [1] to [4], wherein in the polycarbonate diol (A), the content of the structural unit (1) is 10 mol% or more and 90 mol% or less, and the content of the structural unit (2) is 10 mol% or more and 90 mol% or less, relative to 100% of the total molar amount of the diol-derived structural units constituting the polycarbonate diol. [6] The curable composition according to any one of [1] to [5], wherein in the polycarbonate diol (A), the structural unit (1) contains a structural unit derived from at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. [7] The curable composition according to any one of [1] to [6], wherein in the polycarbonate diol (A), the structural unit (2) contains a structural unit derived from at least one selected from the group consisting of 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol. [8] The curable composition according to any one of [1] to [7], wherein the polycarbonate diol (A) has a number average molecular weight (Mn) calculated from the hydroxyl value of 250 or more and 5,000 or less. [9] The curable composition according to any one of [1] to [8], wherein the mass ratio ((C) / (B)) of the content of the tri- or higher functional isocyanate (C) to the content of the bifunctional isocyanate (B) is within the range of 0.05 or more and 1.10 or less.

[10] The curable composition according to any one of [1] to [9], wherein the content of the polycarbonate diol (A) is from 70% by mass to 94% by mass, the content of the bifunctional isocyanate (B) is from 5% by mass to 20% by mass, and the content of the tri- or higher functional isocyanate (C) is from 1% by mass to 10% by mass, relative to 100% by mass of the total mass of the curable composition.

[11] The curable composition according to any one of [1] to

[10] , wherein the mass ratio (((B)+(C)) / (A)) of the total content of the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) to the content of the polycarbonate diol (A) is 0.06 or more and 0.42 or less.

[12] A polyurethane obtained by curing the curable composition according to any one of [1] to

[11] .

[13] A coating film comprising the polyurethane according to

[12] .

[14] A printing roller blanket comprising the polyurethane according to

[12] .

[15] A printing roller comprising the printing roller blanket according to

[14] .

[16] A printing press including the printing roller according to

[15] .

[17] A polyurethane comprising a structural unit (A) derived from a polycarbonate diol (A) containing a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), a structural unit (B) derived from a bifunctional isocyanate (B), and a structural unit (C) derived from a trifunctional or higher functional isocyanate (C):

[0015] [ka]

[0016] (In the above general formula (I), R 1 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms.

[0017] [ka]

[0018] (In the above general formula (II), R 2 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms.

[18] The polyurethane according to

[17] , wherein the structural unit (1) includes a structural unit (1a) represented by the following general formula (Ia):

[0019] [ka]

[0020] (In the above general formula (I), m represents an integer of 3 to 5.)

[19] The polyurethane according to

[17] to

[18] , wherein the structural unit (2) includes a structural unit (2a) represented by the following general formula (IIa):

[0021] [ka]

[0022] (In the above general formula (II), n represents an integer of 6 to 20.)

[20] The polyurethane according to any one of

[17] to

[19] , which has a calculated network crosslinking molecular weight of 3,000 to 20,000.

[21] The polyurethane according to any one of

[17] to

[20] , wherein in the structural unit (A), the ratio of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) ((1) / (2)) is 0.10 or more and 20.00 or less.

[22] The polyurethane according to any one of

[17] to

[21] , wherein, in the structural unit (A), the content of the structural unit (1) is from 10 mol % to 90 mol % and the content of the structural unit (2) is from 10 mol % to 90 mol % relative to 100% of the total molar amount of the structural unit (A).

[23] The polyurethane according to any one of

[17] to

[22] , wherein in the structural unit (A), the structural unit (1) includes a structural unit derived from at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol.

[24] The polyurethane according to any one of

[17] to

[23] , wherein in the structural unit (A), the structural unit (2) comprises a structural unit derived from at least one selected from the group consisting of 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[25] The polyurethane according to any one of

[17] to

[24] , wherein the mass ratio ((C) / (B)) of the content of the structural unit (C) to the content of the structural unit (B) is within the range of 0.05 or more and 1.10 or less.

[26] The polyurethane according to any one of

[17] to

[25] , wherein the content of the structural unit (A) is 70 to 94 mass%, the content of the structural unit (B) is 5 to 20 mass%, and the content of the structural unit (C) is 1 to 10 mass%, relative to 100% of the total mass of the polyurethane.

[27] The polyurethane according to any one of

[17] to

[26] , wherein the mass ratio (((B)+(C)) / (A)) of the total content of the structural unit (B) and the structural unit (C) to the content of the structural unit (A) is 0.06 or more and 0.42 or less.

[28] A coating film comprising the polyurethane according to any one of

[17] to

[27] .

[29] A printing roller blanket comprising the polyurethane according to any one of

[17] to

[27] .

[30]

[29] A printing roller comprising the printing roller blanket described in

[30]

[29] .

[31]

[30] A printing press including the printing roller described in

[31]

[30] . [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a curable composition that can be used to produce a polyurethane that satisfies all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner. Furthermore, the present invention can provide a polyurethane that satisfies all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner. Furthermore, according to the present invention, there can be provided a coating film, a blanket for a printing roller, a printing roller, and a printing machine, each of which contains the polyurethane of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be described in detail below, but the present invention is not limited to the following description and can be practiced in any modified form without departing from the gist of the present invention. Unless otherwise specified, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits, and "A to B" means A or more and B or less.

[0025] In this specification, "A or B" means "A," "B," and "A and B," unless otherwise specified. For example, "including A or B" means "including A," "including B," and "including A and B," unless otherwise specified. In this specification, "% by mass" indicates the content ratio of a given component contained in a total amount of 100% by mass.

[0026] In this specification, "mass %" and "wt %", "mass ppm" and "wt ppm", and "parts by mass" and "parts by weight" have the same meaning. Furthermore, when simply written as "ppm", it means "ppm by mass".

[0027] In this specification, the term "structural unit" refers to a unit derived from a raw material compound used in the production of a polycarbonate diol, formed by polymerization of the raw material compound, and refers to a partial structure sandwiched between any linking groups in the obtained polymer. It also includes a partial structure at the terminal portion of a polymer, one of which is a linking group and the other of which is a polymerization reactive group. The structural unit may be a unit formed directly by a polymerization reaction, or may be a unit obtained by converting a part of the unit into another structure by treating the obtained polymer. In this specification, the term "repeating unit" has the same meaning as "structural unit."

[0028] "Optional" or "optionally" means that the subsequently described circumstance may or may not occur, and thus the description includes both the occurrence and non-occurrence of the circumstance. Additionally, the term "about" as used herein can mean a range above or below 20% of the stated value. For example, about 75°C encompasses the range of 60°C to 90°C.

[0029] In this specification, the term "obtained polyurethane" refers to a polyurethane produced using the polycarbonate diol of the present invention and an isocyanate compound as raw materials. In this specification, "the polycarbonate diol of the present invention" and "the polyurethane of the present invention" are collectively referred to as "the present invention."

[0030] All steps described herein can be performed in any suitable order unless otherwise stated herein or clearly contradicted by context.

[0031] <Curable composition> The curable composition of the present invention is a composition containing a polycarbonate diol (A) described below, a difunctional isocyanate (B) described below, and a tri- or higher functional isocyanate (C) described below. The curable composition of the present invention contains the polycarbonate diol (A), and thus the polyurethane obtained using this curable composition has good chemical resistance and abrasion resistance. The curable composition of the present invention contains the bifunctional isocyanate (B), and thus the polyurethane obtained using this curable composition has good hardness and tensile strength. The curable composition of the present invention contains the tri- or higher functional isocyanate (C), and thus the polyurethane obtained using this curable composition has good chemical resistance and abrasion resistance.

[0032] (Polycarbonate diol (A)) The polycarbonate diol (A) in the present invention is a component constituting the curable composition of the present invention, and is a polycarbonate diol containing the structural unit (1) described below and the structural unit (2) described below.

[0033] When the polycarbonate diol (A) in the present invention contains the structural unit (1), the polyurethane obtained using the curable composition of the present invention has good chemical resistance. Furthermore, when the polycarbonate diol (A) in the present invention contains the structural unit (2), the hardness of the polyurethane obtained using the curable composition of the present invention becomes good. Furthermore, the polycarbonate diol (A) in the present invention may contain the structural unit (3) described below, as needed, within the range that does not impair the effects of the present invention.

[0034] (Molecular weight of polycarbonate diol) The number average molecular weight (Mn) of the polycarbonate diol (A) in the present invention is preferably 250 to 5,000, more preferably 300 to 4,000, and even more preferably 400 to 3,000. When the number average molecular weight of the polycarbonate diol (A) is not less than the above lower limit, the strength and chemical resistance of the resulting polyurethane resin are good, and when it is not more than the above upper limit, the flexibility of the resulting polyurethane resin is good. The number average molecular weight (Mn) is a molecular weight calculated from the hydroxyl value, and is determined by the method described in the Examples section below.

[0035] (Structural unit (1)) The structural unit (1) described above is a structural unit contained in the polycarbonate diol (A) and represented by the following general formula (I).

[0036] [ka]

[0037] (In the above general formula (I), R 1 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms.

[0038] In the formula (I), R 1 Examples of the linear aliphatic hydrocarbon group having 3 to 5 carbon atoms include a substituted or unsubstituted divalent alkylene group or polymethylene group having 3 to 5 carbon atoms. When a substituent is present, it is preferable that the number of carbon atoms in the substituent is small, as this leads to better chemical resistance and low-temperature flexibility, and the number of carbon atoms in the substituent is preferably 2 or less, more preferably 1 or less, and even more preferably unsubstituted. Note that the number of carbon atoms in the substituent does not include the number of carbon atoms of 3 to 5.

[0039] In the formula (I), R 1 The linear aliphatic hydrocarbon group having 3 to 5 carbon atoms can be introduced into the polycarbonate diol by using a substituted or unsubstituted linear aliphatic dihydroxy compound having 3 to 5 carbon atoms. Specific examples of such linear aliphatic dihydroxy compounds include compounds represented by the following formula (I-1).

[0040] In the formula (I), R 1 may be one type or multiple types.

[0041] In the polycarbonate diol of the present invention, the structural unit (1) represented by the formula (I) can be a structural unit derived from a compound represented by the following formula (I-1).

[0042] [ka]

[0043] (In the general formula (I-1), R 1 is a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms. In the above general formula (I-1), R 1 represents R in the above general formula (I). 1 are treated as synonymous with

[0044] The compound represented by the formula (I-1) is not particularly limited, and known dihydroxy compounds used as raw materials for polycarbonate diols can be appropriately selected and used. Examples of the compound represented by the formula (I-1) include linear diols such as 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol; Diols having side chains such as 1,3-butanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, and 2,2-dimethyl-1,3-propanediol; Those skilled in the art can select an appropriate one depending on the use of the polycarbonate diol, production conditions, etc.

[0045] (Content of structural unit (1) in polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the content of the structural unit (1) in the polycarbonate diol (A) is not particularly limited, but from the viewpoint of excellent hardness, abrasion resistance, and chemical resistance of the obtained polyurethane, it is preferable that the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A) is 100%. Preferably, 10 mol % or more, More preferably, 20 mol% or more, More preferably, it is 30 mol% or more. A content of 47 mol % or more is particularly preferred. On the other hand, the upper limit of the content of the structural unit (1) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the resulting polyurethane, it is preferably 100% by weight of the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A). Preferably, it is 90 mol% or less, More preferably, 80 mol% or less, More preferably, it is 70 mol% or less, It is particularly preferably 75 mol % or less. The upper and lower limits can be arbitrarily combined. For example, the content ratio of the structural unit (1) in the polycarbonate diol (A) is not particularly limited, but it is possible to use the following ratio relative to the total molar amount of the diol-derived structural units constituting the polycarbonate diol (A), which is 100%: Preferably, it is 10 mol % or more and 90 mol % or less, More preferably, the content is 20 mol% or more and 80 mol% or less. More preferably, it is 30 mol% or more and 70 mol% or less, A range of 47 mol % to 75 mol % is particularly preferred.

[0046] In the polycarbonate diol (A) of the present invention, the structural unit (1) preferably contains a structural unit (1a) represented by the following general formula (Ia), from the viewpoint of improving the hardness, abrasion resistance, and chemical resistance of the obtained polyurethane.

[0047] [ka]

[0048] (In the above general formula (I), m represents an integer of 3 to 5.)

[0049] In the general formula (Ia), m is an integer of 3 to 5, preferably 3 to 4, and more preferably 4, from the viewpoint of improving the hardness, abrasion resistance, and chemical resistance of the resulting polyurethane.

[0050] In the polycarbonate diol of the present invention, the structural unit represented by the general formula (Ia) can be a structural unit derived from a compound represented by the following general formula (Ia-1).

[0051] [ka]

[0052] (In the above general formula (Ia-1), m is an integer of 3 to 5.) In the above general formula (Ia-1), m is treated as having the same meaning as m in the above general formula (Ia).

[0053] The compound represented by the formula (Ia-1) is not particularly limited, and known dihydroxy compounds used as raw materials for polycarbonate diols can be appropriately selected and used. Examples of the compound represented by the formula (Ia-1) include 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol, and those skilled in the art can appropriately select the compound depending on the use of the polycarbonate diol, production conditions, etc. These compounds may be used alone or in combination of two or more. Among these, 1,4-butanediol is preferred from the viewpoint of providing the resulting polyurethane with better hardness, abrasion resistance, and chemical resistance.

[0054] (Structural unit (2)) The structural unit (2) described above is a structural unit represented by the following general formula (II) contained in the polycarbonate diol (A).

[0055] [ka]

[0056] (In the above general formula (II), R 2 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms.

[0057] In the formula (II), R 2 Examples of the linear aliphatic hydrocarbon group having 6 to 20 carbon atoms include a substituted or unsubstituted divalent alkylene group or polymethylene group having 6 to 20 carbon atoms. When a substituent is present, the fewer carbon atoms in the substituent, the better the chemical resistance and low-temperature flexibility will be, and the number of carbon atoms in the substituent is preferably 2 or less, more preferably 1 or less, and even more preferably unsubstituted. Note that the number of carbon atoms in the substituent is not included in the number of carbon atoms of 6 to 20.

[0058] In the formula (II), R 2 The linear aliphatic hydrocarbon group having 6 to 20 carbon atoms can be introduced into the polycarbonate diol by using a substituted or unsubstituted linear aliphatic dihydroxy compound having 6 to 20 carbon atoms. Specific examples of such linear aliphatic dihydroxy compounds include compounds represented by the following formula (II-1).

[0059] In the formula (II), R 2 may be one type or multiple types.

[0060] In the polycarbonate diol (A) of the present invention, the structural unit (2) represented by the formula (II) can be a structural unit derived from a compound represented by the following formula (II-1).

[0061] [ka]

[0062] (In the above general formula (II-1), R 2 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms. In the above general formula (II-1), R 2 represents R in the above general formula (II). 2 are treated as synonymous with

[0063] The compound represented by the formula (II-1) is not particularly limited, and known dihydroxy compounds used as raw materials for polycarbonate diols can be appropriately selected and used. Examples of the compound represented by the formula (II-1) include linear diols such as 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, 1,16-hexadecanediol, 1,18-octadecanediol, and 1,20-eicosanediol; Diols having a side chain such as 3-methyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, and 2-butyl-2-ethyl-1,3-propanediol; and the like, can be appropriately selected by a person skilled in the art depending on the use of the polycarbonate diol, production conditions, etc.

[0064] (Content of structural unit (2) in polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the content of the structural unit (2) in the polycarbonate diol (A) is not particularly limited, but from the viewpoint of improving the breaking strength of the resulting polyurethane, it is preferable that the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A) is 100%. Preferably, 10 mol % or more, More preferably, 15 mol% or more, More preferably, it is 20 mol% or more. A content of 25 mol % or more is particularly preferred. On the other hand, the upper limit of the content of the structural unit (2) is not particularly limited, but from the viewpoint of maintaining good hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, it is preferably 100% by weight of the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A). Preferably, it is 90 mol% or less, More preferably, 80 mol% or less, More preferably, it is 65 mol% or less, A content of 53 mol % or less is particularly preferred. The upper and lower limits can be combined arbitrarily. For example, the content ratio of the structural unit (2) in the polycarbonate diol (A) is not particularly limited, but it is possible to use the following ratio relative to the total molar amount of the diol-derived structural units constituting the polycarbonate diol (A), which is 100%: Preferably, it is 10 mol % or more and 90 mol % or less, More preferably, the content is 15 mol% or more and 80 mol% or less. More preferably, it is 20 mol% or more and 65 mol% or less, A range of 25 mol % to 53 mol % is particularly preferred.

[0065] (Total content of structural unit (1) and structural unit (2) in polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the total content of the structural unit (1) and the structural unit (2) in the polycarbonate diol (A) is not particularly limited, but from the viewpoint of obtaining a better balance between hardness, abrasion resistance, chemical resistance, and mechanical strength of the resulting polyurethane, it is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, and particularly preferably 90 mol% relative to the total molar amount (100%) of the structural units derived from diols constituting the polycarbonate diol (A). On the other hand, the upper limit of the total content of the structural unit (1) and the structural unit (2) is not particularly limited, and may be 100 mol% relative to the total molar amount (100%) of the diol-derived structural units constituting the polycarbonate diol (A), or may be 99 mol% or less, preferably 98 mol% or less.

[0066] In the polycarbonate diol (A) of the present invention, the structural unit (2) preferably contains a structural unit (2a) represented by the following general formula (IIa), from the viewpoint of improving the breaking strength of the resulting polyurethane.

[0067] [ka]

[0068] (In the above general formula (IIa), n represents an integer of 6 to 20.)

[0069] In the general formula (IIa), n is an integer of 6 to 20, preferably 6 to 12, and more preferably 6 to 10, from the viewpoint of improving the breaking strength of the resulting polyurethane.

[0070] In the polycarbonate diol of the present invention, the structural unit represented by the general formula (IIa) can be a structural unit derived from a compound represented by the following general formula (IIa-1).

[0071] [ka]

[0072] (In the above general formula (IIa-1), n ​​is an integer of 6 to 20.) In the above general formula (IIa-1), n ​​is treated as having the same meaning as n in the above general formula (IIa).

[0073] The compound represented by the formula (IIa-1) is not particularly limited, and can be appropriately selected from known dihydroxy compounds used as raw materials for polycarbonate diols. Examples of the compound represented by the formula (IIa-1) include 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, 1,16-hexadecanediol, 1,18-octadecanediol, and 1,20-eicosanediol, and can be appropriately selected by those skilled in the art depending on the use of the polycarbonate diol, production conditions, etc. For example, from the viewpoint of achieving superior breaking strength of the resulting polyurethane, at least one compound selected from the group consisting of 1,6-hexanediol, 1,7-pentanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol is preferred, and 1,6-hexanediol or 1,10-decanediol is more preferred. These compounds may be used alone or in combination of two or more.

[0074] (Structural unit (3)) Furthermore, the polycarbonate diol (A) in the present invention may contain, as necessary, a structural unit (3) derived from a polyhydric alcohol (excluding the structural units (1) and (2)) within a range that does not impair the effects of the present invention. Specific examples of the polyhydric alcohol include cyclic diols such as 1,4-cyclohexanedimethanol and 2,2-bis(4-hydroxycyclohexyl)-propane; oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; Stereoisomeric diols having a cyclic ether structure, such as isosorbide, isomannide, and isoidet; Polyols with three or more hydroxyl groups per molecule, such as glycerol, trimethylolmethane, trimethylolethane, trimethylolpropane, trimethylolbutane, 1,2,4-butanetriol, 1,2,3-hexanetriol, 1,2,4-hexanetriol, hexanetriol, pentaerythritol, diglycerol, triglycerol, bis(trimethylolpropane), and polyglycerol: Examples include: These compounds may be used alone or in combination of two or more.

[0075] (Content of structural unit (3) in polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the content of the structural unit (3) in the polycarbonate diol (A) is not particularly limited, but from the viewpoint of obtaining the effects brought about by the structural unit (3), it is preferable that the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A) is 100%. Preferably, it is 1.0 mol% or more, More preferably, 3.0 mol% or more, More preferably, it is 5.0 mol% or more. A content of 7.0 mol % or more is particularly preferred. On the other hand, the upper limit of the content of the structural unit (3) is not particularly limited, but from the viewpoint of sufficiently obtaining the effects of the present invention brought about by the structural unit (1) and the structural unit (2), it is preferable that the total molar amount of the structural units derived from the diol constituting the polycarbonate diol (A) is 100%. Preferably, it is 50 mol% or less, More preferably, 40 mol% or less, More preferably, it is 30 mol% or less, A content of 20 mol % or less is particularly preferred. The upper and lower limits can be arbitrarily combined. For example, the content ratio of the structural unit (3) in the polycarbonate diol (A) is not particularly limited, but it is possible to use the following ratio relative to the total molar amount of the diol-derived structural units constituting the polycarbonate diol (A), which is 100%: Preferably, the content is 1.0 mol% or more and 50 mol% or less, More preferably, the content is 3.0 mol% or more and 40 mol% or less. More preferably, it is 5.0 mol% or more and 30 mol% or less, A range of 7.0 mol % to 20 mol % is particularly preferred.

[0076] (carbonate compounds) The carbonate compound that can be used for producing the polycarbonate diol (A) is not limited as long as it does not impair the effects of the present invention, and examples thereof include dialkyl carbonates, diaryl carbonates, and alkylene carbonates. Among these, diaryl carbonates are preferred from the viewpoint of reactivity. These may be used alone or in combination of two or more. Specific examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, and ethylene carbonate, with diphenyl carbonate being preferred.

[0077] (Method for producing polycarbonate diol (A)) The method for producing the polycarbonate diol (A) in the present invention is not particularly limited, and for example, a known method for producing a polycarbonate diol described in WO2014 / 104134 or the like can be suitably optimized by a person skilled in the art according to known techniques and used.

[0078] (Difunctional isocyanate (B)) The bifunctional isocyanate (B) in the present invention is a component constituting the curable composition of the present invention, and is an isocyanate compound having two isocyanate groups in the molecule. The bifunctional isocyanate (B) in the present invention is not particularly limited, and examples thereof include aromatic diisocyanates such as xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate, and m-tetramethylxylylene diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and dimer diisocyanate in which the carboxyl groups of dimer acids are converted into isocyanate groups; Alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane: etc. These may be used alone or in combination of two or more. Among these, 4,4'-diphenylmethane diisocyanate is preferred among aromatic diisocyanates, and hexamethylene diisocyanate and 1,5-pentamethylene diisocyanate are preferred among aliphatic diisocyanates, from the viewpoint of achieving an excellent balance between hardness, breaking strength, and abrasion resistance in the resulting polyurethane.

[0079] As a bifunctional isocyanate, specifically, Duranate manufactured by Asahi Kasei Corporation TM Examples include HDI, Stabio (registered trademark) PDI, and Millionate MT manufactured by Tosoh Corporation.

[0080] (Trifunctional or higher isocyanates (C)) The tri- or higher functional isocyanate (C) in the present invention is a component constituting the curable composition of the present invention, and is an isocyanate-based compound having three or more isocyanate groups in the molecule. The tri- or higher functional isocyanate (C) in the present invention reacts with the hydroxyl groups of the polycarbonate diol to form urethane bonds, increasing the crosslink density of the resulting polyurethane and improving the breaking strength, abrasion resistance, and chemical resistance.

[0081] The tri- or higher functional isocyanate (C) in the present invention is not particularly limited, and examples thereof include biuret compounds synthesized using a bifunctional isocyanate as a starting material, trimethylolpropane adduct compounds, polyisocyanurates, allophanates, etc. Among these, polyisocyanurates are preferred from the viewpoint of providing polyurethanes with superior breaking strength, abrasion resistance, and chemical resistance.

[0082] Examples of the polyisocyanurate include compounds having one isocyanuric acid skeleton in the molecule, represented by the following general formula (III), which are obtained by trimerizing pentamethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, trimethylhexamethylene diisocyanate, etc. The presence of one isocyanuric acid skeleton in the monomer molecule has the effect of further improving the breaking strength, abrasion resistance, and chemical resistance of the resulting polyurethane.

[0083] [ka]

[0084] (In formula (III), R represents a divalent hydrocarbon group having 1 to 12 carbon atoms, which may contain a substituent.)

[0085] Specific examples of tri- or higher functional isocyanates include biuret-type hexamethylene diisocyanate (trade name: Duranate (registered trademark) 24A-100), adduct-type hexamethylene diisocyanate (trade name: Duranate P-301-75E), isocyanurate-type hexamethylene diisocyanate (trade name: Duranate TPA-100), and blocked isocyanate (trade name: Duranate MF-K60X), all manufactured by Asahi Kasei Corporation; and trimethylolpropane of 1,3-bis(isocyanatomethyl)cyclohexane (trade name: Duranate MF-K60X), all manufactured by Mitsui Chemicals, Inc. Examples of materials that can be used include a panadduct (trade name: Takenate (registered trademark) D-120N), an isocyanurate of 1,3-bis(isocyanatomethyl)cyclohexane (trade name: Takenate D-127N), a trimethylolpropane adduct of isophorone diisocyanate (trade name: Takenate D-140N), an allophanate of hexamethylene diisocyanate (trade name: Desmodur (registered trademark) XP2679) manufactured by Sumika Covestro Urethane Co., Ltd., and an isocyanurate of isophorone diisocyanate (trade name: VESTANAT T-1890 / 100) manufactured by EVONIK.

[0086] <Catalyst> The curable composition of the present invention may contain a known urethane polymerization catalyst, if necessary. Examples of the urethane polymerization catalyst include known urethane polymerization catalysts such as amine compounds, such as triethylamine, N-ethylmorpholine, and triethylenediamine; acid catalysts, such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid; and organotin compounds, such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanoate; and organometallic salts, such as organozinc compounds, organobismuth compounds, organotitanium compounds, and organozirconium compounds. These may be used alone or in combination of two or more.

[0087] <Additives> The curable composition of the present invention may contain additives as needed, provided that the effects of the present invention are not impaired. Examples of the additives include known additives such as diluents, pigments, dyes, fillers, ultraviolet absorbers, thickeners, shrinkage reducing agents, antioxidants, plasticizers, aggregates, flame retardants, stabilizers, fiber reinforcements, antioxidants, leveling agents, and anti-sagging agents.

[0088] <Chain extender> The curable composition of the present invention may contain a chain extender as needed, as long as the effects of the present invention are not impaired. The chain extender is a low molecular weight compound having two or more active hydrogen groups at its terminal that react with an isocyanate group, such as a short-chain polyol or polyamine. Specifically, the compounds disclosed in WO2020 / 218506 and JP2022-054109A can be used.

[0089] <Chain terminator> The curable composition of the present invention may contain a chain terminator, if necessary, for the purpose of controlling the molecular weight of the resulting polyurethane, within a range that does not impair the effects of the present invention. The chain terminator is a low-molecular-weight compound having one active hydrogen group, and examples thereof include aliphatic monools having one hydroxyl group, such as methanol, ethanol, propanol, butanol, and hexanol, and aliphatic monoamines having one amino group, such as diethylamine, dibutylamine, n-butylamine, monoethanolamine, diethanolamine, and morpholine. These may be used alone or in combination of two or more.

[0090] (mass ratio of trifunctional or higher isocyanate (C) to bifunctional isocyanate (B)) In the curable composition of the present invention, the lower limit of the mass ratio ((C) / (B)) of the content ratio of the tri- or higher functional isocyanate (C) to the content ratio of the difunctional isocyanate (B) is not particularly limited. However, from the viewpoint of improving the breaking strength, abrasion resistance, and chemical resistance of the obtained polyurethane, 0.05 or more is preferable, 0.10 or more is more preferable, 0.12 or more is more preferable, A value of 0.15 or greater is particularly preferred. On the other hand, the upper limit of the ratio is not particularly limited, but from the viewpoint of preventing the hardness of the resulting polyurethane from becoming excessively high, 1.10 or less is more preferable, 0.80 or less is more preferable, 0.70 or less is more preferable, A value of 0.60 or less is particularly preferred. The above upper and lower limits can be combined in any manner. For example, in the curable composition of the present invention, the ratio of the content of the tri- or higher functional isocyanate (C) to the content of the bifunctional isocyanate (B) is not particularly limited, but may be Preferably, it is 0.05 or more and 1.10 or less, More preferably, it is 0.10 or more and 0.80 or less. More preferably, it is 0.12 or more and 0.70 or less, A range of 0.15 or more and 0.60 or less is particularly preferred.

[0091] (Content of Polycarbonate Diol (A) in Curable Composition) In the curable composition of the present invention, the lower limit of the content of the polycarbonate diol (A) is not particularly limited, but from the viewpoint of excellent mechanical properties, abrasion resistance, and chemical resistance of the obtained polyurethane, it is preferable that the content of the polycarbonate diol (A) is 100% by total mass of the curable composition. Preferably 70% by mass or more, More preferably, 80% by mass or more, More preferably, it is 85% by mass or more. On the other hand, the upper limit of the content of the polycarbonate diol (A) is not particularly limited, but from the viewpoint of fully obtaining the effects of the present invention brought about by the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C), it is preferably set to: Preferably 94% by mass or less, 93% by mass or less is more preferable, It is more preferably 92 mass % or less. The upper and lower limits can be combined in any way. For example, in the curable composition of the present invention, the content of the polycarbonate diol (A) is not particularly limited, but may be, for example, 100% by mass of the total curable composition. Preferably, it is 70% by mass or more and 94% by mass or less, More preferably, 80% by mass or more and 93% by mass or less, It is more preferably 85% by mass or more and 92% by mass or less.

[0092] (Content of bifunctional isocyanate (B) in curable composition) In the curable composition of the present invention, the lower limit of the content of the bifunctional isocyanate (B) is not particularly limited, but from the viewpoint of excellent mechanical properties and abrasion resistance of the resulting polyurethane, it is preferred that the content of the bifunctional isocyanate (B) be 100% by mass of the total curable composition. Preferably, 1% by mass or more, More preferably, 3% by mass or more, More preferably, it is 5% by mass or more. On the other hand, the upper limit of the content of the bifunctional isocyanate (B) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the resulting polyurethane, it is preferably 100% by mass of the total mass of the curable composition. Preferably 20% by mass or less, 15% by mass or less is more preferable, It is more preferably 10% by mass or less. The upper and lower limits can be arbitrarily combined. For example, in the curable composition of the present invention, the content of the bifunctional isocyanate (B) is not particularly limited, but may be, for example, 100% by mass of the total curable composition. Preferably, it is 1% by mass or more and 20% by mass or less, More preferably, the content is 3% by mass or more and 15% by mass or less. It is more preferably 5% by mass or more and 10% by mass or less.

[0093] (Content of Tri- or More Functional Isocyanate (C) in Curable Composition) In the curable composition of the present invention, the lower limit of the content of the tri- or higher functional isocyanate (C) is not particularly limited, but from the viewpoint of excellent breaking strength, abrasion resistance, and chemical resistance of the resulting polyurethane, it is preferred that the content of the tri- or higher functional isocyanate (C) be: Preferably, 1.0 mass% or more, More preferably, 1.5% by mass or more, It is more preferably 2.0 mass % or more. On the other hand, the upper limit of the content of the tri- or higher functional isocyanate (C) is not particularly limited, but from the viewpoint of suppressing an increase in hardness of the resulting polyurethane and maintaining good abrasion resistance, it is preferably 100% by mass of the total mass of the curable composition. Preferably, 10.0 mass% or less, 7.0% by mass or less is more preferable, It is more preferably 5.0 mass % or less. The upper and lower limits can be arbitrarily combined. For example, in the curable composition of the present invention, the content of the tri- or higher functional isocyanate (C) is not particularly limited, but may be, for example, Preferably, the content is 1.0% by mass or more and 10.0% by mass or less, More preferably, the content is 1.5% by mass or more and 7.0% by mass or less. The content is more preferably 2.0% by mass or more and 5.0% by mass or less.

[0094] (The ratio of the total content of difunctional isocyanate (B) and trifunctional or higher isocyanate (C) to the content of polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the mass ratio (((B)+(C)) / (A)) of the total content of the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) relative to the content of the polycarbonate diol (A) is not particularly limited. However, from the viewpoint of achieving an excellent balance between hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, 0.06 or more is preferable, 0.07 or more is more preferable, A value of 0.08 or more is even more preferable. On the other hand, the upper limit of the mass ratio (((B)+(C)) / (A)) is not particularly limited, but from the viewpoint of suppressing an increase in hardness of the obtained polyurethane and maintaining good abrasion resistance, Preferably 0.42 or less, 0.30 or less is more preferable, It is more preferably 0.15 or less. The above upper and lower limits can be combined in any combination. For example, in the curable composition of the present invention, the mass ratio (((B) + (C)) / (A)) of the total content of the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) to the content of the polycarbonate diol (A) is not particularly limited, but may be Preferably, it is 0.06 or more and 0.42 or less, More preferably, it is 0.07 or more and 0.30 or less. A range of 0.08 to 0.15 is more preferable.

[0095] (Ratio of the content of structural unit (1) to structural unit (2) in polycarbonate diol (A)) In the curable composition of the present invention, the lower limit of the ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) in the polycarbonate diol (A) is not particularly limited. However, from the viewpoint of excellent hardness, abrasion resistance, and chemical resistance of the obtained polyurethane, 0.10 or more is preferable, 0.50 or more is more preferable, 0.90 or more is more preferable, A value of 1.50 or greater is particularly preferred. On the other hand, the upper limit of the ratio ((1) / (2)) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the resulting polyurethane, 20.00 or less is preferable, 10.00 or less is more preferable, 5.00 or less is more preferable, A value of 3.00 or less is particularly preferred. The above upper and lower limits can be combined in any combination. For example, in the curable composition of the present invention, the ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) in the polycarbonate diol (A) is not particularly limited, but Preferably, it is 0.10 or more and 20.00 or less, More preferably, it is 0.50 or more and 10.00 or less. More preferably, it is 0.90 or more and 5.00 or less. A range of 1.50 or more and 3.00 or less is particularly preferred.

[0096] (Method of producing curable composition) The method for producing the curable composition of the present invention is not particularly limited, and a person skilled in the art can use a known method for producing a curable composition, such as that described in JP-A-2014-185320, by optimizing it as appropriate according to known techniques. Specifically, the curable composition of the present invention can be produced by mixing the polycarbonate diol (A), the bifunctional isocyanate (B), the tri- or higher functional isocyanate (C), and, if necessary, a known urethane polymerization catalyst and other components by a known method.

[0097] <Polyurethane> (Polyurethane of the first embodiment) A first embodiment of the polyurethane of the present invention is a polyurethane obtained as a cured product by curing the curable composition of the present invention. As described above, the curable composition of the present invention can produce a polyurethane that satisfies all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner. As a result, the polyurethane of the present invention obtained from the curable composition has an excellent balance of all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance.

[0098] The method for producing the polyurethane of the present invention according to the first embodiment of the present invention is not particularly limited. For example, a person skilled in the art can use the curable composition of the present invention by appropriately optimizing the known heat curing method described in JP 2014-185320 A in accordance with known techniques.

[0099] (Polyurethane of the second embodiment) A second embodiment of the polyurethane of the present invention is a polyurethane containing a structural unit (A) derived from a polycarbonate diol (A) containing a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), a structural unit (B) derived from a bifunctional isocyanate (B), and a structural unit (C) derived from a trifunctional or higher functional isocyanate (C). [ka] (In the above general formula (I), R 1 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms. [ka] (In the above general formula (II), R 2 represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms.

[0100] The structural units (B) and (C) will be described in detail below.

[0101] In the second embodiment of the polyurethane of the present invention, the polycarbonate diol (A) and the structural unit (1) and the structural unit (2) forming the polycarbonate diol (A) are treated as having the same meaning as the polycarbonate diol (A) and the structural unit (1) and the structural unit (2) forming the polycarbonate diol (A) described in the description of the curable composition of the present invention, respectively. In the second embodiment of the polyurethane of the present invention, the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) are treated as having the same meanings as the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) described in the description of the curable composition of the present invention, respectively.

[0102] The method for producing the polyurethane of the second embodiment of the present invention is not particularly limited, and for example, a known method for producing polyurethane as described in JP 2024-24789 A can be suitably optimized by a person skilled in the art in accordance with known techniques.

[0103] The polyurethane of the first embodiment and the polyurethane of the second embodiment of the present invention are collectively referred to as "the polyurethane of the present invention."

[0104] (Structural unit (A)) The above-mentioned structural unit (A) is a structural unit derived from the polycarbonate diol (A) contained in the polyurethane of the present invention. The polyurethane of the present invention has the structural unit (A) and therefore exhibits excellent mechanical properties such as hardness and breaking strength, as well as excellent abrasion resistance and chemical resistance. Specifically, since the polyurethane of the present invention contains the structural unit (1) in the structural unit (A), the polyurethane has good hardness, abrasion resistance, and chemical resistance, and further contains the structural unit (2), the polyurethane has good breaking strength.

[0105] (Structural unit (B)) The above-mentioned structural unit (B) is a structural unit derived from the difunctional isocyanate (B) contained in the polyurethane of the present invention. The polyurethane of the present invention has excellent hardness and breaking strength because the distance between crosslinking points in the polyurethane increases due to the presence of the structural unit (B). Furthermore, the combined use of the structural unit (A) and the structural unit (B) in a polyurethane can improve the hardness and breaking strength of the polyurethane. Although the reason for this is unclear, it is presumed that the structural unit (B) increases the distance between crosslinking points in the polyurethane, suppressing crystallization of units derived from the structural unit (A) and aggregation due to carbonate bonds, thereby more significantly demonstrating the effect of the structural unit (1) in the structural unit (A) of maintaining low hardness and the effect of the structural unit (2) of improving breaking strength.

[0106] (Structural unit (C)) The above-mentioned structural unit (C) is a structural unit derived from a tri- or higher functional isocyanate (C) contained in the polyurethane of the present invention. By virtue of having the structural unit (C), the polyurethane of the present invention can achieve a good balance between abrasion resistance and chemical resistance, which have conventionally been in a trade-off relationship with hardness. Furthermore, by using the structural unit (A) and the structural unit (C) in combination in a polyurethane, an excessive increase in the hardness of the polyurethane can be suppressed, and the abrasion resistance and chemical resistance can be further improved. Although the reason for this is unclear, the structural unit (2) in the structural unit (A) may increase the crystallinity of the polyurethane, which may increase the hardness of the polyurethane and reduce the abrasion resistance. However, it is presumed that the introduction of a crosslinked structure into the polyurethane by the structural unit (C) suppresses the increase in the crystallinity of the polyurethane and the resulting decrease in abrasion resistance, thereby achieving both abrasion resistance and chemical resistance, which previously had a trade-off relationship.

[0107] (Molar ratio of structural unit (1) to structural unit (2) in structural unit (A)) In the polyurethane of the present invention, the lower limit of the molar ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) in the structural unit (A) is not particularly limited. However, from the viewpoint of achieving excellent hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, 0.10 or more is preferable, 0.50 or more is more preferable, 0.90 or more is more preferable, A value of 1.50 or greater is particularly preferred. On the other hand, the upper limit of the molar ratio ((1) / (2)) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the resulting polyurethane, 20.00 or less is preferable, 10.00 or less is more preferable, 5.00 or less is more preferable, A value of 3.00 or less is particularly preferred. The upper and lower limits can be combined in any desired manner. For example, in the polyurethane of the present invention, the molar ratio ((1) / (2)) in the structural unit (A) is not particularly limited, but may be: Preferably, it is 0.10 or more and 20.00 or less, More preferably, it is 0.50 or more and 10.00 or less. More preferably, it is 0.90 or more and 5.00 or less. A range of 1.50 or more and 3.00 or less is particularly preferred.

[0108] (Ratio of structural unit (1) in structural unit (A)) In the polyurethane of the present invention, the lower limit of the content of the structural unit (1) in the structural unit (A) is not particularly limited, but from the viewpoint of improving the hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, it is preferred that the total molar amount of the structural unit (A) be 100%. Preferably, 10 mol % or more, More preferably, 20 mol% or more, More preferably, it is 30 mol% or more. A content of 47 mol % or more is particularly preferred. On the other hand, the upper limit of the content of the structural unit (1) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the resulting polyurethane, it is preferred that the total molar content of the structural unit (A) be 100%. Preferably, it is 90 mol% or less, More preferably, 80 mol% or less, More preferably, it is 70 mol% or less, It is particularly preferably 75 mol % or less. The upper and lower limits can be arbitrarily combined. For example, in the polyurethane of the present invention, the content of the structural unit (1) in the structural unit (A) is not particularly limited, but may be, for example, 100% by mole of the total structural unit (A). Preferably, it is 10 mol % or more and 90 mol % or less, More preferably, the content is 20 mol% or more and 80 mol% or less. More preferably, it is 30 mol% or more and 70 mol% or less, A range of 47 mol % to 75 mol % is particularly preferred.

[0109] (Ratio of structural unit (2) in structural unit (A)) In the polyurethane of the present invention, the lower limit of the content of the structural unit (2) in the structural unit (A) is not particularly limited, but from the viewpoint of improving the breaking strength of the resulting polyurethane, it is set to be Preferably, 10 mol % or more, More preferably, 15 mol% or more, More preferably, it is 20 mol% or more. A content of 25 mol % or more is particularly preferred. On the other hand, the upper limit of the content of the structural unit (1) is not particularly limited, but from the viewpoint of maintaining good hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, it is preferred that the total molar content of the structural unit (A) be 100%. Preferably, it is 90 mol% or less, More preferably, 80 mol% or less, More preferably, it is 65 mol% or less, A content of 53 mol % or less is particularly preferred. The upper and lower limits can be arbitrarily combined. For example, in the polyurethane of the present invention, the content of the structural unit (1) in the structural unit (A) is not particularly limited, but may be, for example, 100% by mole of the total structural unit (A). Preferably, it is 10 mol % or more and 90 mol % or less, More preferably, the content is 15 mol% or more and 80 mol% or less. More preferably, it is 20 mol% or more and 65 mol% or less, A range of 25 mol % to 53 mol % is particularly preferred.

[0110] (Ratio of the content of structural unit (C) to structural unit (B)) In the polyurethane of the present invention, the lower limit of the mass ratio ((C) / (B)) of the content of the structural unit (C) to the content of the structural unit (B) is not particularly limited. However, from the viewpoint of achieving an excellent balance between hardness, abrasion resistance, and chemical resistance of the resulting polyurethane, 0.05 or more is preferable, 0.10 or more is more preferable, 0.12 or more is more preferable, A value of 0.15 or greater is particularly preferred. On the other hand, the upper limit of the mass ratio ((C) / (B)) is not particularly limited, but from the viewpoint of suppressing an increase in hardness of the obtained polyurethane and maintaining good abrasion resistance, it is preferable that the upper limit be: Preferably 1.10 or less, 0.80 or less is more preferable, 0.70 or less is more preferable, A value of 0.60 or less is particularly preferred. The above upper and lower limits can be combined in any manner. For example, in the polyurethane of the present invention, the mass ratio ((C) / (B)) of the content of the structural unit (C) to the content of the structural unit (B) is not particularly limited, but may be Preferably, it is 0.05 or more and 1.10 or less, More preferably, it is 0.10 or more and 0.80 or less. More preferably, it is 0.12 or more and 0.70 or less, A range of 0.15 or more and 0.60 or less is particularly preferred.

[0111] (Ratio of structural unit (A) in polyurethane) In the polyurethane of the present invention, the lower limit of the content of the structural unit (A) is not particularly limited, but from the viewpoint of excellent mechanical properties, abrasion resistance, and chemical resistance of the resulting polyurethane, it is preferred that the lower limit of the content of the structural unit (A) is: Preferably 70% by mass or more, More preferably, 80% by mass or more, The most preferable amount is 85% by mass or more. On the other hand, the upper limit of the content of the structural unit (A) is not particularly limited, but from the viewpoint of fully obtaining the effects of the present invention brought about by the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C), it is preferred that the upper limit of the content of the structural unit (A) is 100% by mass of the total polyurethane. Preferably 94% by mass or less, 93% by mass or less is more preferable, It is most preferably 92% by mass or less. The upper and lower limits can be arbitrarily combined. For example, in the polyurethane of the present invention, the content of the structural unit (A) is not particularly limited, but may be, for example, 100% by mass of the total polyurethane. Preferably, it is 70% by mass or more and 94% by mass or less, More preferably, 80% by mass or more and 93% by mass or less, The most preferable range is 85% by mass or more and 92% by mass or less.

[0112] (Ratio of structural unit (B) in polyurethane) In the polyurethane of the present invention, the lower limit of the content of the structural unit (B) is not particularly limited, but from the viewpoint of excellent mechanical properties and abrasion resistance of the resulting polyurethane, it is preferred that the lower limit of the content of the structural unit (B) is 100% by mass of the total polyurethane. Preferably, 1% by mass or more, More preferably, 3% by mass or more, It is most preferably 5% by mass or more. On the other hand, the upper limit of the content of the structural unit (B) is not particularly limited, but from the viewpoint of maintaining good breaking strength of the polyurethane obtained, it is preferably: Preferably 20% by mass or less, 15% by mass or less is more preferable, It is most preferably 10% by mass or less. The upper and lower limits can be arbitrarily combined. For example, in the polyurethane of the present invention, the content of the structural unit (B) is not particularly limited, but may be, for example, 100% by mass of the total polyurethane. Preferably, it is 1% by mass or more and 20% by mass or less, More preferably, the content is 3% by mass or more and 15% by mass or less. The most preferable range is 5% by mass or more and 10% by mass or less.

[0113] (Ratio of structural unit (C) in polyurethane) In the polyurethane of the present invention, the lower limit of the content of the structural unit (C) is not particularly limited, but from the viewpoint of the resulting polyurethane having excellent breaking strength, abrasion resistance, and chemical resistance, it is preferred that the lower limit be: Preferably, 1.0 mass% or more, More preferably, 1.5% by mass or more, It is most preferably 2.0 mass % or more. On the other hand, the upper limit of the content of the structural unit (C) is not particularly limited, but from the viewpoint of suppressing an increase in hardness of the obtained polyurethane and maintaining good abrasion resistance, it is preferably set to: Preferably 10% by mass or less, 7% by mass or less is more preferable, It is most preferably 5% by mass or less. The upper and lower limits can be arbitrarily combined. For example, in the polyurethane of the present invention, the content of the structural unit (C) is not particularly limited, but may be, for example, 100% by mass of the total polyurethane. Preferably, the content is 1.0 mass% or more and 10 mass% or less, More preferably, the content is 1.5% by mass or more and 7% by mass or less. The most preferable range is 2.0% by mass or more and 5% by mass or less.

[0114] (The ratio of the total content of structural units (B) and (C) to the content of structural unit (A)) In the polyurethane of the present invention, the lower limit of the mass ratio (((B)+(C)) / (A)) of the total content of the structural unit (B) and the structural unit (C) to the content of the structural unit (A) is not particularly limited. However, from the viewpoint of achieving an excellent balance between the hardness, chemical resistance, and mechanical strength of the resulting polyurethane, 0.06 or more is preferable, 0.07 or more is more preferable, A value of 0.08 or more is even more preferable. On the other hand, the upper limit of the mass ratio (((B)+(C)) / (A)) is not particularly limited, but from the viewpoint of suppressing an increase in hardness of the obtained polyurethane and maintaining good abrasion resistance, Preferably 0.42 or less, 0.30 or less is more preferable, It is more preferably 0.15 or less. The above upper and lower limits can be combined in any combination. For example, in the polyurethane of the present invention, the mass ratio (((B) + (C)) / (A)) of the total content of the structural unit (B) and the structural unit (C) to the content of the structural unit (A) is Preferably, it is 0.06 or more and 0.42 or less, More preferably, it is 0.07 or more and 0.30 or less. A range of 0.08 to 0.15 is more preferable.

[0115] (Calculated network crosslink molecular weight of polyurethane) The polyurethane of the present invention preferably has a calculated network crosslinking molecular weight of 500 to 10,000. Furthermore, the curable composition of the present invention preferably contains the polycarbonate diol (A), the bifunctional isocyanate (B), and the tri- or higher functional isocyanate (C) so that the calculated network crosslinking molecular weight of the resulting polyurethane is within the range of 500 to 10,000.

[0116] In this specification, the calculated network inter-crosslinking molecular weight of a polyurethane represents the average molecular weight between thermally crosslinkable reactive groups (hereinafter sometimes referred to as "crosslinking points") that form the network structure in the entire polyurethane. This calculated network inter-crosslinking molecular weight correlates with the network area when the network structure is formed, and the larger the calculated network inter-crosslinking molecular weight, the lower the crosslink density. In a thermosetting reaction, a linear polymer is formed when a compound having only one thermally crosslinkable reactive group (hereinafter sometimes referred to as a "monofunctional compound") reacts, while a network structure is formed when a compound having two or more thermally crosslinkable reactive groups (hereinafter sometimes referred to as a "polyfunctional compound") reacts.

[0117] Therefore, here, the thermally crosslinkable reactive groups of the polyfunctional compound are crosslinking points, and the calculation of the calculated network molecular weight between crosslinking points is centered on the polyfunctional compound having crosslinking points, and the monofunctional compound is treated as having the effect of extending the molecular weight between crosslinking points of the polyfunctional compound, and the calculated network molecular weight between crosslinking points is calculated. In addition, the calculation of the calculated network molecular weight between crosslinking points is performed under the assumption that all thermally crosslinkable reactive groups have the same reactivity and all thermally crosslinkable reactive groups react by heating.

[0118] In a single-component polyfunctional compound composition in which only one type of polyfunctional compound reacts, the calculated molecular weight between crosslinking points is twice the average molecular weight per thermally crosslinkable reactive group of the polyfunctional compound. For example, for a bifunctional compound with a molecular weight of 1,000, it is (1000 / 2) x 2 = 1000, and for a trifunctional compound with a molecular weight of 300, it is (300 / 3) x 2 = 200. In a polyfunctional compound mixed composition in which multiple polyfunctional compounds are reacted, the calculated network inter-crosslink molecular weight of the composition is the average of the calculated network inter-crosslink molecular weights of each of the single compounds relative to the total number of thermally crosslinkable reactive groups contained in the polyurethane. For example, in a polyurethane obtained from a curable composition consisting of a mixture of 4 moles of a bifunctional compound with a molecular weight of 1,000 and 4 moles of a trifunctional compound with a molecular weight of 300, the total number of thermally crosslinkable reactive groups in the polyurethane is 2 × 4 + 3 × 4 = 20, and the calculated network inter-crosslink molecular weight of the polyurethane is {(1000 / 2) × 8 + (300 / 3) × 12} × 2 / 20 = 520.

[0119] When a curable composition contains a monofunctional compound, assuming that the monofunctional compound reacts with the thermally crosslinkable reactive groups (i.e., crosslinking points) of the polyfunctional compound in equimolar amounts and is located at the center of the molecular chain formed by the monofunctional compound linking to the crosslinking points, the amount of molecular chain elongation due to the monofunctional compound at one crosslinking point is half the value obtained by dividing the total molecular weight of the monofunctional compound by the total number of thermally crosslinkable reactive groups of the polyfunctional compounds in the polyurethane. Here, since the calculated network molecular weight between crosslinking points is considered to be twice the average molecular weight per crosslinking point, the amount of elongation due to the monofunctional compound relative to the calculated network molecular weight between crosslinking points calculated for the polyfunctional compound is the value obtained by dividing the total molecular weight of the monofunctional compounds by the total number of thermally crosslinkable reactive groups of the polyfunctional compounds in the composition.

[0120] For example, in a polyurethane consisting of a mixture of 40 moles of a monofunctional compound with a molecular weight of 100 and 4 moles of a bifunctional compound with a molecular weight of 1,000, the number of thermally crosslinkable reactive groups in the polyfunctional compound is 2 × 4 = 8, so the elongation due to the monofunctional compound in the calculated network inter-crosslink molecular weight is 100 × 40 / 8 = 500. In other words, the calculated network inter-crosslink molecular weight of the composition is 1,000 + 500 = 1,500. From the above, the molecular weight W A Monofunctional compound M A moles and molecular weight W B f B Functional compound M B moles and molecular weight W C f C Functional compound M C In the case of a mixture of 100% by weight and 100% by weight of terpolymer, the calculated network crosslinking molecular weight of the composition can be expressed by the following formula:

[0121]

number

[0122] The lower limit of the calculated network inter-crosslinking molecular weight of the polyurethane of the present invention calculated in this manner is not particularly limited. However, from the viewpoint of improving the chemical resistance of the resulting polyurethane, Preferably, it is 3000 or more, More preferably, it is 5000 or more, More preferably, it is 10,000 or more, It is particularly preferable that it is 13,000 or more. On the other hand, the upper limit of the calculated network inter-crosslinking molecular weight is not particularly limited, but from the viewpoint of maintaining good abrasion resistance of the resulting polyurethane, Preferably, it is 20,000 or less, More preferably, it is 19,000 or less, It is more preferable that the value is 18,000 or less, It is particularly more preferable that it is 17,000 or less. This is presumably because chemical resistance and hardness depend on the distance between crosslinking points in the network structure; when this distance is long, the structure becomes flexible and easily stretched, resulting in good hardness, and when this distance is short, the network structure becomes strong, resulting in excellent chemical resistance.

[0123] The above upper and lower limits can be combined arbitrarily. For example, the calculated network crosslinking molecular weight of the polyurethane of the present invention is Preferably, it is 3,000 or more and 20,000 or less, More preferably, it is 5,000 or more and 19,000 or less, It is more preferable that the molecular weight is 10,000 or more and 18,000 or less. It is particularly preferable that the molecular weight is 13,000 or more and 17,000 or less.

[0124] <Polyurethane applications> The polyurethane of the present invention satisfies all of the performance requirements of mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner, and therefore can be suitably used in applications such as polyurethane-based paints and coating films obtained from such paints, as well as blankets for printing rollers, foams, elastomers, elastic fibers, paints such as polyurethane paints, fibers, pressure-sensitive adhesives, adhesives, flooring materials, sealants, medical materials, artificial leather, synthetic leather, coating agents, thermosetting compositions, and active energy ray-curable compositions. In particular, the polyurethane of the present invention is more suitably applicable to applications such as blankets for printing rollers. As a result, in a printing roller including the blanket for printing rollers or in a printing machine including the printing roller, the frequency of replacement of the printing roller is reduced, thereby making it possible to reduce manufacturing costs related to equipment upkeep and maintenance, and further enabling a stable supply of high-quality printed matter over an extended period of time. [Example]

[0125] The present invention will be explained in more detail below by way of 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.

[0126] The abbreviations for the raw materials used in the examples and comparative examples are as follows: 14BD: 1,4-butanediol (Mitsubishi Chemical Corporation) 15PD: 1,5-pentanediol (Tokyo Chemical Industry Co., Ltd.) 16HD: 1,6-hexanediol (BASF) 110DD: 1,10-decanediol (Toyokuni Oil Mills) NPG: Neopentyl glycol (Mitsubishi Gas Chemical Company, Inc.) DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation) DMC: Dimethyl carbonate (Tokyo Chemical Industry Co., Ltd.) PPG2000: Polypropylene glycol (Fujifilm Wako Pure Chemical Industries, Ltd.) MDI: 4,4'-diphenylmethane diisocyanate (trade name: Monomeric MDI Millionate MT, manufactured by Tosoh Corporation) p-MDI: Polymethylene polyphenyl polyisocyanate (product name: Polymeric MDI Millionate MR-200, manufactured by Tosoh Corporation) HDI: Hexamethylene diisocyanate (trade name: Duranate) TM HDI, manufactured by Asahi Kasei Corporation) Modified HDI: A compound obtained by trimerizing hexamethylene diisocyanate, which has one isocyanuric acid skeleton in the molecule (trade name: Duranate) TM TPA-100, manufactured by Mitsui Chemicals, Inc. PDI: 1,5-pentamethylene diisocyanate (product name: plant-derived PDI polyisocyanate, Stabio (registered trademark) PDI, manufactured by Asahi Kasei Corporation) Modified PDI: A compound obtained by trimerization of 1,5-pentamethylene diisocyanate, having one isocyanuric acid skeleton in the molecule (product name: Plant-derived PDI-based polyisocyanate, Stabio® D-376N, manufactured by Mitsui Chemicals, Inc.) U-830: Dioctyltin monodecanoate (trade name: Neostan U-830, manufactured by Nitto Kasei Kogyo Co., Ltd.) Silicone sheet: Silicone resin sheet (product name: SMM-A60-2-290KAKU, manufactured by Tanac Co., Ltd.)

[0127] In the following examples and comparative examples, various physical properties were measured by the following methods.

[0128] [Evaluation of Polycarbonate Diol] (Hydroxyl value (OH value)) The hydroxyl value of the polycarbonate diol was measured by a method using an acetylation reagent in accordance with JIS K1557-1.

[0129] (Number average molecular weight (Mn)) The number average molecular weight (Mn) of the polycarbonate diol was calculated using the above hydroxyl value according to the following formula. Number average molecular weight (Mn) = 2 × 56.1 / (hydroxyl value × 10 -3 )

[0130] <Content of structural units derived from raw material diol> Polycarbonate diol was dissolved in CDCl3 and measured at 400 MHz. 1H-NMR (model number: AL-400, manufactured by JEOL Ltd.) was measured, and the content ratio (unit: mol%) of structural units derived from the raw material diol contained in the polycarbonate diol was determined from the signal position of each component.

[0131] (Melting point (Tm), enthalpy of fusion (ΔH)) The melting point (Tm) and melting enthalpy (ΔH) of the polycarbonate diol obtained in the synthesis examples were evaluated using a differential scanning calorimeter (DSC) by the following method. Approximately 5 mg of polycarbonate diol was weighed into an aluminum pan as an evaluation sample. Alumina was used as a standard sample. The sample was placed in a DSC and heated from room temperature to 180°C at a heating rate of ±10°C / min under a nitrogen atmosphere. Next, the temperature was lowered from 180°C to -100°C at a heating rate of ±10°C / min and held for 1 minute. After that, the sample was again heated to 180°C at a heating rate of ±10°C / min, and the peak temperature (melting point (Tm)) of the endothermic peak accompanying melting of the polycarbonate diol and the melting enthalpy ΔH (unit: mJ / mg) were measured in the range of 0 to 100°C and listed in Table 1. When no endothermic peak was observed, it was marked as "ND" (Non Detected) in Table 1.

[0132] [Polyurethane evaluation] (specific gravity) Measurement was performed according to JIS K2249-1:2011.

[0133] (glass transition temperature (Tg)) The glass transition temperatures of the polyurethanes obtained in the examples and comparative examples were evaluated by the following method. A test piece measuring 2 mm wide, 40 mm long, and 1 mm thick was obtained from a 2 mm thick polyurethane resin sheet. The dynamic viscoelasticity of this test piece was measured using a dynamic viscoelasticity measuring device (RSA-III, manufactured by TA Instruments) under the following conditions: tensile mode (Dynamic Temp Sweep), frequency 10 Hz, temperature range -100 to 250°C, heating rate 3°C / min, and strain 0.1%. The maximum peak temperature of tan δ in the obtained "temperature-tan δ curve" was taken as the glass transition temperature (Tg) (unit: °C).

[0134] (Mechanical properties: hardness) As an index of the mechanical properties of the polyurethanes obtained in the examples and comparative examples, durometer hardness was evaluated by the following method. A 2mm thick polyurethane resin sheet was cut into 3cm squares and three of the sheets were stacked together to form a test specimen. Using an Asker Rubber Hardness Tester ISO-A Type (manufactured by Kobunshi Keiki Co., Ltd.), the durometer hardness (A hardness) was measured 15 seconds after indenter contact, in accordance with ISO 7619-1, and rated according to the following criteria. Measurements were performed on three samples, n = 3, and the median value of the three data points was selected. (Judgment criteria) ○: A hardness less than 60 △: A hardness is 60 or more and less than 80 ×: A hardness of 80 or more

[0135] (Mechanical properties: Breaking strength) As an index of the mechanical properties of the polyurethanes obtained in the examples and comparative examples, the breaking strength was evaluated by the following method in accordance with JIS K6251:2023. A 2 mm thick polyurethane resin sheet was punched out using a lever-type sample cutter (device name: DL-200, manufactured by Dumbbell Co., Ltd.) and a Super Dumbbell (model number: SDMP-1000, manufactured by Dumbbell Co., Ltd.) to obtain dumbbell-shaped No. 7 test pieces. A tensile test was carried out on this test piece using a tensile testing machine (AGS-10kNX, manufactured by Shimadzu Corporation) and an extensometer (DSES-1000, manufactured by Shimadzu Corporation) in accordance with JIS K6251 under conditions of a gauge length of 10 mm, a tension speed of 200 mm / min, and a temperature of 23°C (relative humidity of 60%). The stress at the time when the test piece broke (tensile breaking strength) was measured and evaluated according to the following criteria. The measurement was performed on three samples (n = 3), and the median value of the three measured values ​​was selected. If the test piece was broken due to its brittleness when clamped and held in the chuck of the tensile tester, and the tensile test could not be performed, the result was recorded as "measurement not possible." (Judgment criteria) 〇: Breaking strength is 20.0 MPa or more △: Breaking strength is 10.0 MPa or more and less than 20.0 MPa ×: Breaking strength is less than 10.0 MPa

[0136] (wear resistance) The abrasion resistance of the polyurethanes obtained in the examples and comparative examples was evaluated by the following method. The polyurethane resin sheet was punched out using a lever-type sample cutter (device name: SDL-200, manufactured by Dumbbell Co., Ltd.) and a Super Dumbbell (model number: SDRSK-1347-91, manufactured by Dumbbell Co., Ltd.) to obtain circular test pieces with a diameter of 107 mm. This test piece was subjected to a preliminary abrasion treatment using a Taber abrasion tester (device name: TS-2, manufactured by Toyo Seiki Seisaku-sho, Ltd.) and an abrasion wheel (model number: H-18, manufactured by Toyo Seiki Seisaku-sho, Ltd.) under conditions of a load of 9.8 N and rotation speeds of 72 rpm and 100 rotations, and then to a main abrasion treatment under conditions of a rotation speed of 72 rpm and 1000 rotations. The wear volume (unit: mm) was calculated from the difference in mass of the test piece before and after the wear resistance test. 3 ) was calculated and the abrasion resistance was evaluated according to the following criteria. (Judgment criteria) ○: Wear volume is 5.0mm 3 less than △: Wear volume is 5.0 mm 3 Over 30.0mm 3 less than ×: Wear volume is 30.0 mm 3 End

[0137] (chemical resistance) As an index of the chemical resistance of the polyurethanes obtained in the Examples and Comparative Examples, the mass change rate when the polyurethanes were immersed in oleic acid was measured using the method described below. A square piece of polyurethane resin film (1 cm long, 1 cm wide, 2 mm thick) was cut out from the polyurethane resin sheet and used as a sample piece. The mass of this test piece was measured using a precision balance, and then the test piece was immersed in a 250 mL glass bottle containing 50 mL of oleic acid as a test solvent and left to stand in a thermostatic chamber under a nitrogen atmosphere at a temperature of 80°C for 16 hours. Next, the test piece was removed from the glass bottle, lightly wiped on both sides with a paper wiper, and then the mass was measured using a precision balance. The mass change rate (increase rate) of the test piece before and after the test was calculated and evaluated according to the following criteria. The measurement was performed on three samples (n = 3), and the average value was calculated. (Judgment criteria) ◎: Mass change rate is less than 20.0% ○: Mass change rate is 20.0% or more and less than 33.0% △: Mass change rate is 33.0% or more and less than 100.0% ×: Mass change rate is 100.0% or more

[0138] [Synthesis and Evaluation of Polycarbonate Diol] [Synthesis Example 1] A 5L glass separable flask equipped with a stirrer, distillate trap, and pressure regulator was charged with 837.2 g of 14BD and 629.6 g of 110DD as raw diols, 2533.4 g of DPC as a carbonate source, and 6.6 mL of magnesium acetate tetrahydrate aqueous solution (concentration: 8.4 g / L, magnesium acetate tetrahydrate: 56 mg) as a transesterification catalyst, followed by nitrogen gas replacement. With stirring, the internal temperature was raised to 160°C, and the contents were heated and dissolved. The pressure was then reduced to 24 kPa over 2 minutes, and the reaction was allowed to proceed for 90 minutes while removing phenol from the system. The pressure was then reduced to 9.3 kPa over 90 minutes, and further reduced to 0.4 kPa over 30 minutes, and the reaction was continued. The temperature was then raised to 170°C, and the reaction was allowed to proceed for 60 minutes while removing phenol and unreacted diol from the system, to obtain a polycarbonate diol-containing composition. Thereafter, 2.6 mL of a 0.85 wt % aqueous phosphoric acid solution was added to deactivate the catalyst, thereby obtaining a polycarbonate diol-containing composition. The obtained polycarbonate diol-containing composition was sent to a thin-film distillation apparatus at a flow rate of about 20 g / min, and thin-film distillation (temperature: 170°C, pressure: 53 to 67 Pa) was carried out to obtain polycarbonate diol (PCD). The thin-film distillation apparatus had a diameter of 50 mm, a height of 200 mm, and an area of ​​0.0314 m. 2 The molecular distillation apparatus used was a special model MS-300 manufactured by Shibata Scientific Co., Ltd., equipped with an internal condenser and a jacket. The polycarbonate diol (PCD) produced in Example 1 is referred to as "PCD1." The evaluation results of PCD1 are shown in Table 1.

[0139] [Synthesis Examples 2 to 5] Polycarbonate diols (PCDs) were obtained by carrying out the reaction in the same manner as in Synthesis Example 1, except that the types and amounts of the raw material diol and carbonate source in Synthesis Example 1 were changed as shown in Table 1. The polycarbonate diols obtained in Synthesis Examples 2 to 5 are called "PCD2" to "PCD5" as shown in Table 1, and their evaluation results are shown in Table 1.

[0140] [Reference example 6] Using the same evaluation method as above, PPG2000 was evaluated as polypropylene glycol, and the results are shown in Table 1.

[0141] [Table 1]

[0142] [Production and Evaluation of Curable Compositions and Polyurethanes]

[0143] [Example 1] <Production of Curable Composition and Polyurethane Elastomer> Using PCD1 obtained in Synthesis Example 1 as a raw material, a curable composition and polyurethane were produced by the following procedures. A 500 mL metal reactor equipped with a stirrer was charged with 210.0 g of PCD1, a polycarbonate diol preheated to 100°C, and 0.0160 g of U-830 as a urethane polymerization catalyst. The reactor was heated to 80°C over approximately 5 minutes under a nitrogen atmosphere while stirring at 300 rpm. When the reaction solution reached 80°C, 14.0 g of pentamethylene diisocyanate (hereinafter referred to as "PDI") as a difunctional isocyanate and 5.5 g of modified PDI as a trifunctional isocyanate were added. The mixture was allowed to react for 210 seconds at 80°C while stirring at 300 rpm. The reaction solution was then poured into a mold preheated to 120°C and heated at 120°C for 24 hours. A 2 mm thick polyurethane resin sheet, the thermoset product of the reaction solution, was then removed from the mold. The evaluation results of the physical properties of this polyurethane resin sheet are shown in Table 3.

[0144] [Examples 2 to 6, Comparative Example 1] A polyurethane resin sheet was obtained under the same conditions as in Example 1, except that the type and amount of polycarbonate diol (A), the type and amount of bifunctional isocyanate (B), the type and amount of trifunctional isocyanate (C), the amount of catalyst, and the polyurethane synthesis conditions were changed as shown in Table 2. Table 3 shows the evaluation results of the physical properties of the obtained polyurethane.

[0145] Comparative Example 2 A cured polyurethane resin sheet was obtained under the same conditions as in Example 1, except that PPG2000 was used as the polypropylene glycol instead of PCD1 in Example 1 and the polyurethane synthesis conditions were changed as shown in Table 2. The evaluation results of the physical properties of this polyurethane resin sheet are shown in Table 3.

[0146] Comparative Example 3 A commercially available silicone sheet (product name: SMM-A60-2-290KAKU, manufactured by Tanac Co., Ltd.) having a hardness similar to that of the polyurethane resin sheet obtained in the example was evaluated in the same manner as in Example 1, and the results are shown in Table 3.

[0147] The following can be seen from Tables 1 to 3. The polyurethanes produced in Examples 1 to 6 satisfied all of the performance requirements for mechanical properties, abrasion resistance, and chemical resistance in a well-balanced manner. The polyurethane produced in Comparative Example 1 had high hardness and poor abrasion resistance because the polycarbonate diol (A) did not have the structural unit (1). This is presumably because the structural unit (A) in the polyurethane has high crystallinity, which increases the hardness and results in a decrease in abrasion resistance. The polyurethane produced in Comparative Example 2 was inferior in breaking strength, abrasion resistance, and chemical resistance because polypropylene glycol was used instead of polycarbonate diol (A). This is presumably because the structural units derived from polypropylene glycol in the polyurethane have lower intermolecular cohesive force than the structural units (A), resulting in lower breaking strength and abrasion resistance, and also because they have high solubility in oleic acid, resulting in lower chemical resistance. The Ricon sheet evaluated in Comparative Example 3 was poor in breaking strength and abrasion resistance.

[0148] [Table 2]

[0149] Table 3

Claims

1. A curable composition comprising a polycarbonate diol (A) containing a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), a bifunctional isocyanate (B), and a tri- or higher functional isocyanate (C). 【Chemistry 1】 (In the above general formula (I), R １ represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms. 【Chemistry 2】 (In the above general formula (II), R ２ represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms.

2. The structural unit (1) includes a structural unit (1a) represented by the following general formula (Ia): The curable composition of claim 1. 【Transformation 3】 (In the above general formula (I), m represents an integer of 3 to 5.)

3. The curable composition according to claim 1, wherein the structural unit (2) includes a structural unit (2a) represented by the following general formula (IIa): 【Chemistry 4】 (In the above general formula (II), n represents an integer of 6 to 20.)

4. 2. The curable composition according to claim 1, wherein in the polycarbonate diol (A), a ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) is 0.10 or more and 20.00 or less.

5. 2. The curable composition according to claim 1, wherein in the polycarbonate diol (A), a content ratio of the structural unit (1) is 10 mol% or more and 90 mol% or less, and a content ratio of the structural unit (2) is 10 mol% or more and 90 mol% or less, relative to 100% of the total molar amount of structural units derived from diols constituting the polycarbonate diol.

6. The curable composition according to claim 1, wherein in the polycarbonate diol (A), the structural unit (1) includes a structural unit derived from at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol.

7. The curable composition according to claim 1, wherein in the polycarbonate diol (A), the structural unit (2) comprises a structural unit derived from at least one selected from the group consisting of 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

8. The curable composition according to claim 1, wherein the polycarbonate diol (A) has a number average molecular weight (Mn) calculated from a hydroxyl value of 250 or more and 5,000 or less.

9. 2. The curable composition according to claim 1, wherein a mass ratio ((C) / (B)) of a content ratio of the tri- or higher functional isocyanate (C) to a content ratio of the bifunctional isocyanate (B) is within a range of 0.05 or more and 1.10 or less.

10. 2. The curable composition according to claim 1, wherein, relative to 100% by total mass of the curable composition, a content ratio of the polycarbonate diol (A) is 70% by mass or more and 94% by mass or less, a content ratio of the bifunctional isocyanate (B) is 5% by mass or more and 20% by mass or less, and a content ratio of the tri- or higher functional isocyanate (C) is 1% by mass or more and 10% by mass or less.

11. 2. The curable composition according to claim 1, wherein a mass ratio (((B)+(C)) / (A)) of a total content of the bifunctional isocyanate (B) and the tri- or higher functional isocyanate (C) to a content of the polycarbonate diol (A) is 0.06 or more and 0.42 or less.

12. A polyurethane obtained by curing the curable composition according to any one of claims 1 to 11.

13. A coating comprising the polyurethane of claim 12.

14. A printing roller blanket comprising the polyurethane of claim 12.

15. A printing roller comprising the printing roller blanket of claim 14.

16. A printing press comprising the printing roller of claim 15.

17. A polyurethane comprising a structural unit (A) derived from a polycarbonate diol (A) containing a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), a structural unit (B) derived from a bifunctional isocyanate (B), and a structural unit (C) derived from a tri- or higher functional isocyanate (C): 【Transformation 5】 (In the above general formula (I), R １ represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 3 to 5 carbon atoms. 【Transformation 6】 (In the above general formula (II), R ２ represents a substituted or unsubstituted linear aliphatic hydrocarbon group having 6 to 20 carbon atoms.

18. The polyurethane according to claim 17, wherein the structural unit (1) includes a structural unit (1a) represented by the following general formula (Ia): 【Transformation 7】 (In the above general formula (I), m represents an integer of 3 to 5.)

19. The polyurethane according to claim 17, wherein the structural unit (2) includes a structural unit (2a) represented by the following general formula (IIa): 【Transformation 8】 (In the above general formula (II), n represents an integer of 6 to 20.)

20. The polyurethane according to claim 17, having a calculated crosslinking molecular weight of 3,000 to 20,000.

21. 18. The polyurethane according to claim 17, wherein in the structural unit (A), the ratio ((1) / (2)) of the number of moles of the structural unit (1) to the number of moles of the structural unit (2) is 0.10 or more and 20.00 or less.

22. 18. The polyurethane according to claim 17, wherein the structural unit (A) contains the structural unit (1) in an amount of 10 mol % or more and 90 mol % or less, and the structural unit (2) in an amount of 10 mol % or more and 90 mol % or less, relative to 100% of the total molar amount of the structural unit (A).

23. The polyurethane according to claim 17, wherein in the structural unit (A), the structural unit (1) includes a structural unit derived from at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol.

24. The polyurethane according to claim 17, wherein in the structural unit (A), the structural unit (2) includes a structural unit derived from at least one selected from the group consisting of 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

25. 18. The polyurethane according to claim 17, wherein the mass ratio ((C) / (B)) of the content of the structural unit (C) to the content of the structural unit (B) is within the range of 0.05 or more and 1.10 or less.

26. 18. The polyurethane according to claim 17, wherein, relative to 100% total mass of the polyurethane, the content of the structural unit (A) is 70% by mass or more and 94% by mass or less, the content of the structural unit (B) is 5% by mass or more and 20% by mass or less, and the content of the structural unit (C) is 1% by mass or more and 10% by mass or less.

27. 18. The polyurethane according to claim 17, wherein the mass ratio (((B)+(C)) / (A)) of the total content of the structural unit (B) and the structural unit (C) to the content of the structural unit (A) is 0.06 or more and 0.42 or less.

28. A coating film comprising the polyurethane of any one of claims 17 to 27.

29. A printing roller blanket comprising the polyurethane of any one of claims 17 to 27.

30. 30. A print roller comprising the print roller blanket of claim 29.

31. A printing press comprising the printing roller of claim 30.

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