Polycarbonate diol, method for producing polycarbonate diol, and polyurethane

Abstract

This polycarbonate diol contains a terminal structure (2-1) represented by general formula (II-1). The present invention can provide a polycarbonate diol used for obtaining a polyurethane which exhibits excellent mechanical properties and chemical resistance and in which variations in the mechanical properties are suppressed.

Description

Polycarbonate diol, method for producing polycarbonate diol, and polyurethane

[0001] This invention relates to polycarbonate diols and methods for producing the same. Furthermore, this invention relates to polyurethanes obtained using the polycarbonate diols.

[0002] As a polyurethane produced on an industrial scale, a polycarbonate-type polyurethane has been proposed that uses polycarbonate diol as the raw material for the soft segment (Non-Patent Literature 1). Polycarbonate-type polyurethanes are widely used in applications such as artificial leather for automobiles, building materials such as furniture, paints and coatings such as water-based paints for clothing, adhesives, and durable films due to their excellent heat resistance and hydrolysis resistance. In particular, polycarbonate-type polyurethanes with excellent adhesion to the substrate and chemical resistance are required for applications such as paints, coatings, and adhesives.

[0003] For the above applications, polyurethane is required to have excellent mechanical properties such as breaking strength, elongation at breaking, and modulus strength, and to have suppressed variations in these mechanical properties from the viewpoint of uniformity of quality. In recent years, polyurethane has also been required to have resistance to alcohol contained in hair styling products and to oleic acid, which is the main component of sebum secreted from the human body.

[0004] To solve these problems, polycarbonate diols containing diol-derived structural units such as 1,5-pentanediol have been proposed as raw materials for polycarbonate-type polyurethanes.

[0005] For example, Patent Document 1 discloses a polycarbonate diol made from 1,6-hexanediol and 1,5-pentanediol, and a polyurethane obtained from said polycarbonate diol. Patent Document 2 discloses a polycarbonate diol made from 1,4-butanediol and 1,5-pentanediol, and a polyurethane obtained from said polycarbonate diol.

[0006] JP-A-2-289616 JP-A-4-7327

[0007] "Fundamentals and Applications of Polyurethane," pages 96-106, supervised by Katsuji Matsunaga, CMC Publishing Co., Ltd., published November 2006.

[0008] As described above, Patent Documents 1 and 2 disclose polyurethanes obtained from polycarbonate diols using diols such as 1,5-pentanediol as raw materials. However, for applications in paints, coatings, and adhesives, the mechanical properties such as tensile strength, elongation at break, and strength at low elongation rates (modulus strength) are insufficient, and furthermore, there is a large variation in these mechanical properties, and chemical resistance is also insufficient.

[0009] This invention has been made in view of the above problems. Specifically, the object of this invention is to provide a polycarbonate diol and a method for producing the same, which can be obtained as a polyurethane having excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed.

[0010] The inventors of this invention have conducted extensive research to solve the above problems and have found that the above problems can be solved by incorporating a specific terminal structure (2-1) described later into the polycarbonate diol.

[0011] The present invention was achieved based on the above findings and is summarized as follows: [1] A polycarbonate diol comprising a terminal structure (2-1) represented by the following general formula (II-1). [2] The polycarbonate diol according to [1] above, wherein the terminal structure (2-1) includes a terminal structure (2-2) represented by the following general formula (II-2). (In the above general formula (II-2), m is an integer from 2 to 12.) [3] The polycarbonate diol according to [1] or [2] above, wherein the number average molecular weight (Mn) of the polycarbonate diol is 250 or more and 5000 or less. [4] The polycarbonate diol according to any one of [1] to [3] above, wherein the content of the terminal structure (2-1) in the polycarbonate diol is 0.01 mol% or more and 10.0 mol% or less with respect to 100% of the total mol amount of the hydroxyl group terminals and the terminal structure (2-1) of the polycarbonate diol. [5] The polycarbonate diol according to [4] above, wherein the content of the hydroxyl group terminals in the polycarbonate diol is 90 mol% or more with respect to 100% of the total mol amount of all terminal groups of the polycarbonate diol. [6] The polycarbonate diol according to any one of [1] to [5] above, wherein the content of the terminal structure (2-1) in the polycarbonate diol is 0.01 mol% or more and 1.00 mol% or less with respect to 100% of the total amount of all structural units of the polycarbonate diol. [7] The polycarbonate diol according to any one of [1] to [6] above, which contains a structural unit (1-1) represented by the following general formula (I-1). (In the above general formula (I-1), R represents a divalent hydrocarbon group having 3 to 12 carbon atoms, which may have substituents or heteroatoms.) [8] The polycarbonate diol according to [7] above, wherein the structural unit (1-1) includes a structural unit (1-2) represented by the following general formula (I-2). (In the above general formula (I-2), n is an integer from 3 to 12.) [9] The polycarbonate diol according to [7] or [8] above, wherein the structural unit (1-1) includes a structural unit (1-3) represented by the following general formula (I-3).

[10] A polycarbonate diol according to any one of [7] to [9] above, wherein the structural unit (1-1) includes a structural unit derived from a diol compound derived from a bio-raw material.

[11] A polyurethane obtained using the polycarbonate diol according to any one of [1] to

[10] above.

[12] The polyurethane according to

[11] above, used in any of the group consisting of active energy ray curable polymer compositions, artificial leather, synthetic leather, paints, coatings, elastic fibers, adhesives, and glues.

[13] An epoxy resin obtained using the polycarbonate diol according to any one of [1] to

[10] above.

[14] A polyester obtained using the polycarbonate diol according to any one of [1] to

[10] above.

[15] A method for producing a polycarbonate diol, comprising polycondensing a diol-containing composition and a carbonate compound by transesterification in the presence of a catalyst to obtain a polycarbonate diol, wherein the diol-containing composition contains a diol compound (4) represented by the following general formula (IV) and a tetrahydropyran compound (3-1) represented by the following general formula (III-1). (In the general formula (IV) above, n is an integer between 3 and 6.) (In the above general formula (III-1), R １ (wherein is a C2-C12 alkyl group or hydrogen atom which may have substituents or heteroatoms.)

[16] The method for producing a polycarbonate diol according to

[15] above, wherein the tetrahydropyran compound (3-1) contains a tetrahydropyran compound (3-2) represented by the following general formula (III-2). (In the above general formula (III-2), R ２ (wherein is a C2-C12 alkyl group or hydrogen atom containing a hydroxyl group terminus which may have a side chain.)

[17] A method for producing a polycarbonate diol according to

[15] or

[16] , wherein the tetrahydropyran compound (3-1) contains a tetrahydropyran compound (3-3) represented by the following general formula (III-3). (In the above general formula (III-3), m is an integer from 2 to 12.)

[18] A method for producing a polycarbonate diol according to any one of

[15] to

[17] , wherein the diol-containing composition contains 0.01% by mass or more of the tetrahydropyran compound (3-1) based on the total mass of the diol-containing composition.

[19] A method for producing a polycarbonate diol according to any one of

[15] to

[18] , wherein the diol-containing composition contains 2.00% by mass or less of the tetrahydropyran compound (3-1) based on the total mass of the diol-containing composition.

[0012] According to the present invention, it is possible to provide a polycarbonate diol and a method for producing the same, which can be obtained from a polyurethane that has excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed.

[0013] (a) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the breaking strength of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the breaking strength of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the breaking elongation of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the elongation at break of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the 300% modulus of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the 300% modulus of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1, and the rate of mass change (increase) obtained in the oleic acid resistance test of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1, and the rate of mass change (increase) obtained in the ethanol resistance test of the polyurethane obtained using the polycarbonate diol.This graph shows the relationship between the content ratio (1) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1, II-3, II-4 and Comparative Example II-1, and the molecular weight (Mw) retention rate obtained in the hydrolysis resistance test of the polyurethane obtained using the polycarbonate diol.

[0014] (a) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the breaking strength of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the breaking strength of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the breaking elongation of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the elongation at break of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the 300% modulus of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1 and the coefficient of variation of the 300% modulus of the polyurethane obtained using the polycarbonate diol. (a) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1, and the rate of mass change (increase) obtained in the oleic acid resistance test of the polyurethane obtained using the polycarbonate diol. (b) A graph showing the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1 to II-4 and Comparative Example II-1, and the rate of mass change (increase) obtained in the ethanol resistance test of the polyurethane obtained using the polycarbonate diol.This graph shows the relationship between the content ratio (2) of the terminal structure (2-1) of the polycarbonate diol obtained in Examples II-1, II-3, II-4 and Comparative Example II-1, and the molecular weight (Mw) retention rate obtained in the hydrolysis resistance test of the polyurethane obtained using the polycarbonate diol.

[0015] The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below, and can be implemented in various ways within the scope of its gist.

[0016] In this specification, "structural unit" refers to a unit derived from a raw material compound used in the production of a polycarbonate diol, formed by the polymerization of the raw material compound, and representing a substructure sandwiched between arbitrary linking groups in the resulting polymer. A structural unit also includes a substructure in which one end of the polymer is a linking group and the other is a polymerization-reactive group. A structural unit may be a unit directly formed by a polymerization reaction, or a part of the unit may be converted to a different structure by processing the resulting polymer. In this specification, "repeating unit" is synonymous with "structural unit".

[0017] In this specification, numerical ranges expressed using "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits, respectively, unless otherwise specified. For example, "A~B" means A or greater and B or less.

[0018] In this specification, "including A or B" means "including A," "including B," and "including A and B," unless otherwise specified.

[0019] In this specification, "mass%" indicates the percentage of a given component contained in 100% of the total amount. In this specification, "mass%" and "weight%", "mass ppm" and "weight ppm", and "parts by mass" and "parts by weight" are all synonymous. Furthermore, when simply written as "ppm", it refers to "weight ppm".

[0020] In this specification, the "obtained polyurethane" refers to a polyurethane produced using the polycarbonate diol of the present invention and a polyurethane produced using a polycarbonate diol obtained by the method for producing the polycarbonate diol of the present invention.

[0021] [Polycarbonate Diol] The polycarbonate diol of the present invention is a polycarbonate diol containing a terminal structure (2-1) represented by the following general formula (II-1) (hereinafter, may be referred to as "the polycarbonate diol of the present invention").

[0022] By including the terminal structure (2-1), the polycarbonate diol of the present invention can provide excellent mechanical properties and chemical resistance to the polyurethane obtained from the polycarbonate diol, and can suppress variations in the mechanical properties. Furthermore, the hydrolysis resistance of the obtained polyurethane can be maintained well or made more excellent.

[0023] The polycarbonate diol of the present invention refers to a mixture of a polycarbonate compound containing the terminal structure (2-1) at at least one terminal and a polycarbonate compound not containing the terminal structure (2-1) at the terminal. Examples of the polycarbonate compound not containing the terminal structure (2-1) at the terminal described above include a polycarbonate compound having hydroxyl groups at both terminals, a polycarbonate compound having a hydroxyl group at one terminal and a terminal structure other than the terminal structure (2-1) and other than a hydroxyl group at the other terminal. As a more specific embodiment, there may be mentioned a mixture of a polycarbonate diol in which one terminal of the polycarbonate diol is substituted with the terminal structure (2-1), a polycarbonate diol in which both terminals are substituted with the terminal structure (2-1), and a polycarbonate diol in which neither of the two terminals is substituted.

[0024] <Content ratio of terminal structure (2-1) in polycarbonate diol> The content ratio of the terminal structure (2-1) contained in the polycarbonate diol of the present invention can be determined by one of the following methods: (Method 1) A method expressing it as a ratio to the terminals of the polycarbonate diol (Method 2) A method expressing it as a ratio to the total structural units of the polycarbonate diol

[0025] (Method 1) The lower limit of the content ratio of the terminal structure (2-1) in the polycarbonate diol of the present invention is not particularly limited as long as the effects of the present invention are achieved. From the viewpoint of having excellent mechanical properties and chemical resistance of the obtained polyurethane and suppressing variations in the mechanical properties, it is preferable that the content is 0.01 mol% or more, more preferably 0.02 mol% or more, even more preferably 0.10 mol% or more, particularly preferably 0.30 mol% or more, and most preferably 0.60 mol% or more, based on 100% of the total mol amount of the hydroxyl group terminals and terminal structure (2-1) of the polycarbonate diol. On the other hand, the upper limit of the content of the terminal structure (2-1) is not particularly limited as long as the effects of the present invention are achieved. From the viewpoint of maintaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferable that the content be 10.0 mol% or less, more preferably 3.50 mol% or less, even more preferably 3.00 mol% or less, particularly preferably 2.50 mol% or less, and most preferably 2.00 mol% or less, relative to 100% of the total mol amount of the hydroxyl group terminals of the polycarbonate diol and the terminal structure (2-1). The above upper and lower limits can be combined arbitrarily. For example, in the polycarbonate diol of the present invention, the content of the terminal structure (2-1) is preferably 0.01 mol% to 10.0 mol%, more preferably 0.02 mol% to 3.50 mol%, even more preferably 0.10 mol% to 3.00 mol%, particularly preferably 0.30 mol% to 2.50 mol%, and most preferably 0.60 mol% to 2.00 mol%.

[0026] When determining the content ratio of the terminal structure (2-1) using the method 1 described above, the lower limit of the content ratio of the hydroxyl group terminals contained in the polycarbonate diol is not particularly limited as long as the effects of the present invention are achieved, and can be 90.00 mol% or more, more preferably 92.00 mol% or more, even more preferably 94.00 mol% or more, and particularly preferably 96.00 mol% or more, based on 100% of the total mol amount of all terminal groups in the polycarbonate diol. On the other hand, the upper limit of the content ratio of the hydroxyl group terminals contained in the polycarbonate diol is not particularly limited as long as the effects of the present invention are achieved, and can be less than 100 mol%, more preferably 99.98 mol% or less, even more preferably 99.90 mol% or less, and particularly preferably 99.70 mol% or less, based on 100% of the total mol amount of all terminal groups in the polycarbonate diol. The above upper and lower limits can be combined arbitrarily. For example, the content of the hydroxyl group terminals in the polycarbonate diol is preferably 90.00 mol% or more and less than 100 mol%, more preferably 92.00 mol% or more and 99.98 mol%, even more preferably 94.00 mol% or more and 99.90 mol%, and particularly preferably 96.00 mol% or more and 99.70 mol%, based on 100% of the total mol amount of all terminal groups in the polycarbonate diol.

[0027] (Method 2) When determining the content ratio of the terminal structure (2-1) using Method 2 described above, the lower limit of the content ratio of the terminal structure (2-1) contained in the polycarbonate diol is not particularly limited. From the viewpoint of having excellent mechanical properties and chemical resistance of the obtained polyurethane and suppressing variations in the mechanical properties, it is preferable that it be 0.01 mol% or more, more preferably 0.02 mol% or more, even more preferably 0.10 mol% or more, and particularly preferably 0.30 mol% or more, based on 100% of the total mol amount of all structural units in the polycarbonate diol. On the other hand, the upper limit of the content of the terminal structure (2-1) is not particularly limited, and from the viewpoint of maintaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 1.00 mol% or less, more preferably 0.70 mol% or less, even more preferably 0.65 mol% or less, and particularly preferably 0.60 mol% or less, based on 100% of the total amount of structural units in the polycarbonate diol. The above upper and lower limits can be combined arbitrarily. For example, in the polycarbonate diol of the present invention, the content of the terminal structure (2-1) is preferably 0.01 mol% to 1.00 mol%, more preferably 0.02 mol% to 0.70 mol%, even more preferably 0.10 mol% to 0.65 mol%, and particularly preferably 0.30 mol% to 0.60 mol%, based on 100% of the total mol amount of all structural units of the polycarbonate diol.

[0028] Furthermore, the polycarbonate diol of the present invention may contain structural units (1-1) represented by the following general formula (I-1). (In the above general formula (I-1), R represents a divalent hydrocarbon group having 3 to 12 carbon atoms, which may have substituents or heteroatoms.)

[0029] It is expected that the polycarbonate diol of the present invention, by containing the structural unit (1-1), will have improved mechanical properties and chemical resistance of the resulting polyurethane. Details of the structural unit (1-1) will be described later.

[0030] Furthermore, the polycarbonate diol of the present invention may contain structural units derived from diol compounds other than the diol compound (4) described later, to the extent that it does not impair the effects of the present invention. The "diol compounds other than diol compound (4)" are not particularly limited, and examples include the compounds shown in (i) to (v) below. (i) Linear hydrocarbon diols such as ethylene glycol, 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; (ii) Anhydrous sugar alcohols such as isosorbide, isomannide, and isoidet; (iii) Oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol. (iv) Branched hydrocarbon diols such as 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 2-methyl-1,4-butanediol, and 2-methyl-1,8-octanediol. (v) Fluorene derivatives having two or more hydroxyl groups in the molecule, such as 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl)fluorene, and 9,9-bis(4-(2-hydroxyethoxy)-3-isobutylphenyl)fluorene.

[0031] These compounds can be appropriately selected by those skilled in the art depending on the intended use and manufacturing conditions of the polycarbonate diol. Furthermore, these compounds may be used individually or in combination of two or more.

[0032] (Structural Unit (I-1)) The structural unit (I-1) described above is a structural unit represented by the following general formula (I-1) that is included in the structure of the polycarbonate diol of the present invention.

[0033] (In the above general formula (I-1), R represents a divalent hydrocarbon group having 3 to 12 carbon atoms, which may have substituents or heteroatoms.)

[0034] The lower limit of the content of structural unit (1-1) in the polycarbonate diol of the present invention is not particularly limited. From the viewpoint of obtaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 75% by mass or more, and particularly preferably 80% by mass or more, based on 100% of the total mass of the polycarbonate diol. On the other hand, the upper limit of the content of structural unit (1-1) is not particularly limited. It may be 100% by mass of the polycarbonate diol other than the terminal structure (2-1) of the present invention, or it may be less than 100% by mass. Alternatively, from the viewpoint of maintaining good chemical resistance of the obtained polyurethane, it is more preferably 99% by mass or less, even more preferably 98% by mass or less, and particularly preferably 95% by mass or less, based on 100% of the total mass of the polycarbonate diol. The above upper and lower limits can be arbitrarily combined. For example, the content of the structural unit (1-1) in the polycarbonate diol of the present invention is preferably 40% by mass or more and less than 100% by mass, more preferably 60% by mass or more and 99% by mass or less, even more preferably 75% by mass or more and 98% by mass or less, and particularly preferably 80% by mass or more and 95% by mass or less, based on 100% of the total mass of the polycarbonate diol.

[0035] In the polycarbonate diol of the present invention, the structural unit (1-1) preferably includes the structural unit (1-2) represented by the following general formula (I-2), from the viewpoint of improving the mechanical properties and chemical resistance of the obtained polyurethane.

[0036] (In the general formula (I-2) above, n is an integer between 3 and 12.)

[0037] In the general formula (I-2) above, n is an integer from 3 to 12, preferably from 3 to 10, more preferably from 3 to 6, and even more preferably from 4 to 6, from the viewpoint of obtaining better mechanical properties and chemical resistance of the polyurethane.

[0038] The content ratio of structural unit (1-2) contained in structural unit (1-1) is not particularly limited as long as the effects of the present invention are achieved. From the viewpoint of good handling properties of the polycarbonate diol and good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 10 mol% or more, more preferably 30 mol% or more, even more preferably 50 mol% or more, and particularly preferably 70 mol% or more, based on 100% of the total mol amount of structural unit (1-1). This content ratio can also be 90 mol% or more. On the other hand, the upper limit of the content ratio of structural unit (1-2) in structural unit (1-1) is not particularly limited as long as the effects of the present invention are achieved. It may be 100 mol% or less than 100 mol% relative to 100% of the total mol amount of structural unit (1-1), more preferably 99 mol% or less, even more preferably 98 mol% or less, and particularly preferably 95 mol% or less. The above upper and lower limits can be combined arbitrarily. For example, the content ratio of structural unit (1-2) in structural unit (1-1) is preferably 10 mol% or more and less than 100 mol%, more preferably 30 mol% or more and 99 mol%, even more preferably 50 mol% or more and 98 mol%, and particularly preferably 70 mol% or more and 95 mol%, relative to 100% of the total mol amount of structural unit (1-1).

[0039] In the polycarbonate diol of the present invention, the structural unit (1-1) preferably includes a structural unit (1-3) represented by the following formula (I-3), from the viewpoint of improving the mechanical properties and chemical resistance of the obtained polyurethane.

[0040]

[0041] In the polycarbonate diol of the present invention, the structural unit (1-1) may include a structural unit derived from a diol compound derived from a bio-based raw material, from the viewpoint of achieving the Sustainable Development Goals (SDGs). Details of the bio-based diol compound described above will be described later.

[0042] The content ratio of structural unit (1-3) contained in structural unit (1-1) is not particularly limited, but from the viewpoint of good handling properties of the polycarbonate diol and good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 50 mol% or more, based on 100% of the total mol content of structural unit (1-1). This content ratio can also be 90 mol% or more. On the other hand, the upper limit of the content ratio of structural unit (1-3) in structural unit (1-1) is not particularly limited, and may be 100 mol% or less, based on 100% of the total mol content of structural unit (1-1), even more preferably 95 mol% or less, even more preferably 90 mol% or less, and particularly preferably 80 mol% or less. The above upper and lower limits can be combined arbitrarily. For example, the content ratio of structural unit (1-3) in structural unit (1-1) is preferably 10 mol% or more and less than 100 mol%, more preferably 20 mol% or more and 95 mol%, even more preferably 30 mol% or more and 90 mol%, and particularly preferably 50 mol% or more and 80 mol%, based on 100% of the total mol amount of structural unit (1-1).

[0043] (Terminal structure (2-1)) The terminal structure (2-1) described above is a terminal structure represented by the following general formula (II-1) that is included in the structure of the polycarbonate diol of the present invention.

[0044]

[0045] The method for producing a polycarbonate diol containing the terminal structure (2-1) according to the present invention is not particularly limited. For example, one method involves mixing a tetrahydropyran compound (3-1) (e.g., 2-hydroxytetrahydropyran, tetrahydropyranylethylene glycol, 5-(2-oxytetrahydropyran)-1-pentanol), described later, with the diol-containing composition, which is the raw material, before starting the polymerization of the polycarbonate diol, and then starting the polymerization. Another method involves adding the tetrahydropyran compound (3-1) at an appropriate timing after starting the polymerization of the polycarbonate diol, and then heating and stirring. By adjusting the amount of the tetrahydropyran compound (3-1), the proportion of the terminal structure (2-1) in the polycarbonate diol can be controlled. As for the heating and stirring conditions, for example, stirring can be performed at 120 to 200°C for 1 to 24 hours. Alternatively, as a specific embodiment of the method for producing a polycarbonate diol containing the terminal structure (2-1) according to the present invention, the method for producing a polycarbonate diol according to the present invention, described later, can be cited.

[0046] In the polycarbonate diol of the present invention, the terminal structure (2-1) preferably includes a terminal structure (2-2) represented by the following general formula (II-2), from the viewpoint of having excellent mechanical properties and chemical resistance of the obtained polyurethane and suppressing variations in the mechanical properties.

[0047] (In the general formula (II-2) above, m is an integer between 2 and 12.)

[0048] In the general formula (II-2) above, the lower limit of m is 2 or more, preferably 3 or more, and more preferably 4 or more, from the viewpoint of obtaining better mechanical properties and chemical resistance of the polyurethane and suppressing variations in the mechanical properties. On the other hand, the upper limit of m is 12 or less, preferably 10 or less, and more preferably 6 or less. It is even more preferable that m is 5. The above upper and lower limits can be combined arbitrarily. For example, m is an integer from 2 to 12, preferably 2 to 10, more preferably 3 to 10, even more preferably 3 to 6, even more preferably 4 to 6, and particularly preferably 5.

[0049] (Molecular weight of polycarbonate diol) The lower limit of the number average molecular weight (Mn) of the polycarbonate diol of the present invention is not particularly limited, but from the viewpoint of having good mechanical properties of the obtained polyurethane, it is preferably 250 or more, more preferably 300 or more, and even more preferably 400 or more. On the other hand, the upper limit of the number average molecular weight (Mn) is not particularly limited, but from the viewpoint of moderately suppressing the viscosity of the polycarbonate diol of the present invention and maintaining good handling properties, and from the viewpoint of maintaining good chemical resistance of the obtained polyurethane, it is preferably 5000 or less, more preferably 4000 or less, and even more preferably 3000 or less. The above upper and lower limits can be arbitrarily combined. For example, the number average molecular weight (Mn) of the polycarbonate diol in the present invention is preferably 250 or more and 5000 or less, more preferably 300 or more and 4000 or less, and even more preferably 400 or more and 3000 or less.

[0050] The number-average molecular weight (Mn) of the polycarbonate diol of the present invention is calculated, for example, using the hydroxyl value, by the following formula: Number-average molecular weight (Mn) = 2 × 56.1 / (Hydroxyl value × 10 －３ In this case, the hydroxyl value can be measured by a known method using an acetylation reagent in accordance with JIS K1557-1.

[0051] [Polycarbonate Diol Composition] The polycarbonate diol composition of the present invention contains the polycarbonate diol of the present invention.

[0052] The lower limit of the content of the polycarbonate diol of the present invention in the polycarbonate diol composition is not particularly limited, and can be 85.0% by mass or more, more preferably 90.0% by mass or more, even more preferably 95.0% by mass or more, and particularly preferably 98.0% by mass or more, based on 100% of the total mass of the polycarbonate diol composition. On the other hand, the upper limit of the content of the polycarbonate diol of the present invention in the polycarbonate diol composition is not particularly limited, and can be 100% by mass or less, based on 100% of the total mass of the polycarbonate diol composition, and can be 99.9% by mass or less, even more preferably 99.8% by mass or less, and particularly preferably 99.5% by mass or less. The above upper and lower limits can be combined arbitrarily. For example, the content of the polycarbonate diol of the present invention in the polycarbonate diol composition is preferably 85.0% by mass or more and less than 100% by mass, more preferably 90.0% by mass or more and 99.9% by mass or less, even more preferably 95.0% by mass or more and 99.8% by mass or less, and particularly preferably 98.0% by mass or more and 99.5% by mass or less, based on 100% of the total mass of the polycarbonate diol composition.

[0053] Furthermore, the polycarbonate diol composition may contain a tetrahydropyran compound (3-1) represented by the following general formula (III-1).

[0054] (In the above general formula (III-1), R １ (This is a C2-C12 alkyl group or hydrogen atom, which may have substituents or heteroatoms.)

[0055] (Tetrahydropyran compound (3-1)) The tetrahydropyran compound (3-1) in the present invention (hereinafter sometimes referred to as "THP") is not particularly limited and includes known compounds containing terminal structures (2-1) such as tetrahydropyranyl groups, and compounds obtained by replacing some of the hydroxyl groups contained in the diol compound (4) with terminal structures (2-1) such as tetrahydropyranyl groups.

[0056] The tetrahydropyran compound (3-1) may contain the tetrahydropyran compound (3-2) represented by the following general formula (III-2).

[0057] (In the above general formula (III-2), R ２ (This is an alkyl group having 2 to 12 carbon atoms or a hydrogen atom containing a hydroxyl group terminus, which may have a side chain.)

[0058] In the above general formula (III-1), R １ an alkyl group which may have substituents or heteroatoms and in the general formula (III-2), R ２ The number of carbon atoms in the alkyl group containing a hydroxyl group terminus, which may have a side chain, is an integer from 2 to 12, preferably an integer from 2 to 10, more preferably an integer from 3 to 10, more preferably an integer from 3 to 6, even more preferably an integer from 4 to 6, and particularly preferably 5, from the viewpoint of obtaining better mechanical properties and chemical resistance of the resulting polyurethane.

[0059] The tetrahydropyran compound (3-1) may contain the tetrahydropyran compound (3-3) represented by the following general formula (III-3).

[0060] (In the above general formula (III-3), m is the same as m in formula (II-2) above, and is an integer between 2 and 12.)

[0061] In the general formula (III-3) above, the lower limit of m is, for example, 2 or more, preferably 3 or more, and more preferably 4 or more. On the other hand, the upper limit of m is 12 or less, preferably 10 or less, and more preferably 6 or less. It is even more preferable that m is 5. The above upper and lower limits can be combined arbitrarily. For example, m is an integer from 2 to 12, preferably 2 to 10, more preferably 3 to 10, even more preferably 3 to 6, even more preferably 4 to 6, and particularly preferably 5.

[0062] The type of tetrahydropyran compound (3-1) is not particularly limited, and examples include compounds having 5 to 11 carbon atoms and having 1 to 2, preferably 1, terminal structures (2-1) such as tetrahydropyranyl groups in the molecule. Specifically, examples include 2-hydroxytetrahydropyran, tetrahydropyranylethylene glycol, 3-(2-oxytetrahydropyran)-1-propanol, 4-(2-oxytetrahydropyran)-1-butanol, 5-(2-oxytetrahydropyran)-1-pentanol, and 6-(2-oxytetrahydropyran)-1-hexanol.

[0063] <Content ratio of compound (3-1) in the polycarbonate diol composition> In the polycarbonate diol composition described above, the content ratio of compound (3-1) is not particularly limited as long as it does not impair the effects of the present invention, and is usually 0.005% by mass or more and 1.50% by mass or less based on 100% of the total mass of the polycarbonate diol composition, and can be 0.01% by mass or more and 1.00% by mass or less, 0.02% by mass or more and 0.80% by mass or less, or 0.03% by mass or more and 0.50% by mass or less.

[0064] [Method for Producing Polycarbonate Diols] The method for producing polycarbonate diols according to the present invention is not particularly limited, and known methods for producing polycarbonate diols described in, for example, Schnell, Polymer Reviews Vol. 9, pp. 9-20 (1994) and International Publication No. 2015 / 199070 can be used.

[0065] Alternatively, as a specific embodiment of the method for producing a polycarbonate diol of the present invention, a method for producing a polycarbonate diol of the present invention is provided, which includes polycondensing a diol-containing composition and a carbonate-based compound by transesterification in the presence of a catalyst to obtain a polycarbonate diol. In the method for producing a polycarbonate diol of the present invention, the diol-containing composition contains a diol compound (4) represented by the following general formula (IV) and a tetrahydropyran compound (3-1) represented by the following general formula (III-1).

[0066] (In the general formula (IV) above, n is an integer between 3 and 6.)

[0067] (In the above general formula (III-1), R １ (This is a C2-C12 alkyl group or hydrogen atom, which may have substituents or heteroatoms.)

[0068] (Diol compound (4)) The diol compound (4) is not particularly limited, and known diol compounds used as raw materials for polycarbonate diols can be appropriately selected and used. Specifically, examples include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. The diol compound (4) may be used alone or in combination of two or more.

[0069] Furthermore, in the polycarbonate diol of the present invention, the diol compound (4) that forms the structural unit may contain a compound (4-1) represented by the following general formula (IV-1), i.e., 1,5-pentanediol, from the viewpoint of improving the mechanical properties and chemical resistance of the resulting polyurethane.

[0070]

[0071] In such cases, the content of compound (4-1) in the diol compound (4) is not particularly limited. From the viewpoint of improving the handling properties of the obtained polycarbonate diol and the mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, and particularly preferably 70% by mass or more, based on 100% of the total mass of the diol (1). This content can also be 90% by mass or more. On the other hand, the upper limit of the content of compound (4-1) in the diol compound (4) is not particularly limited. It may be 100% by mass, or less than 100% by mass, more preferably 99% by mass or less, even more preferably 98% by mass or less, and particularly preferably 97% by mass or less, based on 100% of the total mass of the diol compound (4). The above upper and lower limits can be combined arbitrarily. For example, the content of compound (4-1) in the diol compound (4) is preferably 10% by mass or more and less than 100% by mass, more preferably 30% by mass or more and 99% by mass or less, even more preferably 50% by mass or more and 98% by mass or less, and particularly preferably 70% by mass or more and 97% by mass or less, based on 100% of the total mass of the diol compound (4).

[0072] (Diol-containing composition) In the method for producing polycarbonate diol of the present invention, a single diol compound (4) derived from fossil fuels can be used as the diol-containing composition. Alternatively, in the method for producing polycarbonate diol of the present invention, a diol-containing composition containing a diol compound (4) derived from bio-based raw materials can be used as the diol-containing composition, from the viewpoint of achieving the Sustainable Development Goals (SDGs). Specifically, a single diol compound (4) derived from bio-based raw materials, or a mixture containing a diol compound (4) derived from bio-based raw materials and a diol compound (4) derived from fossil fuels can be used. The diol compound (4) derived from bio-based raw materials is a diol compound derived from non-edible biomass and / or non-fossil fuels.

[0073] In this invention, non-edible biomass refers to resources derived from non-edible grasses and trees. Specifically, this includes, but is not limited to, cellulose, hemicellulose, and lignin obtained from woody biomass such as coniferous and broad-leaved trees, as well as bioethanol, biodiesel, and plant-derived waste oil obtained from herbaceous biomass such as corn and sugarcane stalks, soybeans, and rapeseed. In this invention, non-fossil fuels refer to, for example, hydrogen, or organic matter of animal and plant origin that does not originate from fossil fuels or non-edible biomass. Specifically, this includes, but is not limited to, methane and sugar ethanol obtained from firewood, charcoal, dried livestock manure, etc.

[0074] In the present invention, the fossil fuel-derived diol compound (4) refers to at least one selected from petroleum-derived diols, coal-derived diols, and natural gas-derived diols.

[0075] The above-mentioned diol compound (4) derived from bio-raw materials may contain the tetrahydropyran compound (3-1) depending on its origin. Therefore, by controlling the content ratio of the tetrahydropyran compound (3-1) to produce the diol-containing composition of the present invention, the effects of the present invention described above can be obtained.

[0076] For example, the diol-containing composition may use a single 1,5-pentanediol derived from fossil fuels as the diol compound (4). Alternatively, the diol-containing composition may use a 1,5-pentanediol containing 1,5-pentanediol derived from bio-based raw materials, specifically a single 1,5-pentanediol derived from bio-based raw materials, or a mixture containing 1,5-pentanediol derived from bio-based raw materials and 1,5-pentanediol derived from fossil fuels, thereby contributing to the achievement of the Sustainable Development Goals (SDGs). 1,5-pentanediol derived from bio-based raw materials refers to 1,5-pentanediol derived from non-edible biomass and / or non-fossil fuels.

[0077] In the present invention, the 1,5-pentanediol derived from fossil fuels refers to at least one selected from 1,5-pentanediol derived from petroleum, 1,5-pentanediol derived from coal, and 1,5-pentanediol derived from natural gas.

[0078] Since the above-mentioned 1,5-pentanediol derived from the bio-based raw material may contain the tetrahydropyran compound (3-1) depending on its origin, by controlling the content ratio of the tetrahydropyran compound (3-1) in the 1,5-pentanediol to produce the diol-containing composition, the effects of the present invention described above can be obtained.

[0079] (Tetrahydropyran compound (3-1)) The tetrahydropyran compound (3-1) in the present invention is a compound represented by the following general formula (III-1) and is one component constituting the diol-containing composition.

[0080] (In the above general formula (III-1), R １ is an alkyl group having 2 to 12 carbon atoms or a hydrogen atom which may have a substituent or a heteroatom.)

[0081] The tetrahydropyran compound (3-1) in the method for producing the polycarbonate diol of the present invention is treated synonymously with the tetrahydropyran compound (3-1) described in the description of the polycarbonate diol of the present invention and the polycarbonate diol composition in the present invention.

[0082] The tetrahydropyran compound (3-1) may be contained in the diol-containing composition when the diol compound (4) contains the above-mentioned compound (4-1) derived from the bio-based raw material, that is, 1,5-pentanediol derived from the bio-based raw material, and 2-hydroxytetrahydropyran, which is a precursor of the 1,5-pentanediol, remains unreacted, or when 2-hydroxytetrahydropyran reacts with the diol compound (4) during the production of the diol-containing composition, and a part or all of the hydroxy groups contained in the diol compound are replaced with a terminal structure (2-1) such as a tetrahydropyranyl group.

[0083] In the method for producing the polycarbonate diol of the present invention, the tetrahydropyran compound (3-1) preferably contains the tetrahydropyran compound (3-2) represented by the following general formula (III-2), from the viewpoint of having excellent mechanical properties and chemical resistance of the polyurethane obtained from the polycarbonate diol of the present invention and suppressing variations in the mechanical properties.

[0084] (In the above general formula (III-2), R ２ (This is an alkyl group having 2 to 12 carbon atoms or a hydrogen atom containing a hydroxyl group terminus, which may have a side chain.)

[0085] In the method for producing polycarbonate diols of the present invention, the tetrahydropyran compound (3-2) is treated as synonymous with the tetrahydropyran compound (3-2) mentioned in the description of the polycarbonate diol and the polycarbonate diol composition of the present invention.

[0086] In the method for producing polycarbonate diol of the present invention, the tetrahydropyran compound (3-1) preferably contains a tetrahydropyran compound (3-3) represented by the following general formula (III-3), from the viewpoint of having excellent mechanical properties and chemical resistance of the obtained polyurethane and suppressing variations in the mechanical properties.

[0087] (In the above general formula (III-3), m is the same as m in formula (II-2) above, and is an integer between 2 and 12.)

[0088] In the method for producing the polycarbonate diol of the present invention, the tetrahydropyran compound (3-3) is treated as synonymous with the tetrahydropyran compound (3-3) mentioned in the description of the polycarbonate diol and the polycarbonate diol composition of the present invention.

[0089] In the method for producing a polycarbonate diol of the present invention, one specific embodiment of the diol-containing composition is a diol-containing composition in which the diol compound (4) contains 1,5-pentanediol and the tetrahydropyran compound (3-1) contains 5-(2-oxytetrahydropyran)-1-pentanol, from the viewpoint of excellent mechanical strength and chemical resistance of the obtained polyurethane.

[0090] <Content of Tetrahydropyran Compound (3-1)> The lower limit of the content of tetrahydropyran compound (3-1) in the diol-containing composition is not particularly limited. From the viewpoint of excellent mechanical properties and chemical resistance of the obtained polyurethane, suppression of variations in the mechanical properties, and further from the viewpoint of economic efficiency in reducing the amount of tetrahydropyran compound (3-1), it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, and particularly preferably 0.10% by mass or more, relative to the total mass of the diol-containing composition. On the other hand, the upper limit of the content of tetrahydropyran compound (3-1) is not particularly limited. From the viewpoint of maintaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 2.00% by mass or less, more preferably 1.80% by mass or less, even more preferably 1.50% by mass or less, and particularly preferably 1.00% by mass or less, relative to the total mass of the diol-containing composition. The above upper and lower limits can be combined arbitrarily. For example, the content of the tetrahydropyran compound (3-1) contained in the diol-containing composition of the present invention is preferably 0.01% by mass or more and 2.00% by mass or less, more preferably 0.02% by mass or more and 1.80% by mass or less, even more preferably 0.05% by mass or more and 1.50% by mass or less, and particularly preferably 0.10% by mass or more and 1.00% by mass or less, based on the total mass of the diol-containing composition.

[0091] <Carbonate Compounds> The carbonate compounds (sometimes referred to as "carbonate diesters") that can be used in the method for producing polycarbonate diols of the present invention are not particularly limited, as long as they do not impair the effects of the present invention. Examples of usable carbonate compounds include known carbonate compounds used in the synthesis of polycarbonate diols, such as dialkyl carbonates, diaryl carbonates, or alkylene carbonates. The carbonate compound to be used can be appropriately selected by those skilled in the art depending on the intended use of the polycarbonate diol and the manufacturing conditions. For example, from the viewpoint of reactivity between the diol-containing composition and the carbonate compound, diaryl carbonates are preferred as the carbonate compound, and from the viewpoint of economy, dialkyl carbonates or alkylene carbonates are preferred as the carbonate compound. Specific examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, and ethylene carbonate.

[0092] The amount of carbonate compound used is not particularly limited, and for example, the conditions described in International Publication No. 2015 / 199070 can be used by those skilled in the art, optimizing them as appropriate according to the known art.

[0093] <Catalyst> In the method for producing polycarbonate diols of the present invention, when polycondensing a diol-containing composition with a carbonate compound by a transesterification reaction to obtain a polycarbonate diol, a known transesterification catalyst used in the synthesis of polycarbonate diols (hereinafter sometimes referred to as "catalyst") can be used as a catalyst to promote the transesterification reaction. In this case, if an excessive amount of catalyst remains in the composition containing the obtained polycarbonate diol, it may inhibit or excessively promote the reaction when producing polyurethane using the polycarbonate diol. The type of catalyst and the amount of catalyst remaining in the composition containing the polycarbonate diol are not particularly limited. As a catalyst, for example, the conditions described in International Publication No. 2015 / 199070 can be used by a person skilled in the art, optimized as appropriate according to the known art.

[0094] <Catalyst Deactivator> As mentioned above, when a catalyst is used in the polymerization reaction, the resulting composition containing polycarbonate diol usually contains residual catalyst. This residual catalyst can cause an increase in molecular weight or a change in composition when the composition containing polycarbonate diol is heated, or it may become impossible to control the polyurethaneization reaction. To suppress the effects of this residual catalyst, a catalyst deactivator, such as a phosphorus-based compound, can be added as needed in an amount approximately equivalent to the transesterification catalyst used, thereby deactivating the transesterification catalyst. Furthermore, the transesterification catalyst can be efficiently deactivated by heat treatment after addition. The type and amount of catalyst deactivator used and the conditions for heat treatment are not particularly limited. As for the catalyst deactivator, for example, the conditions described in International Publication No. 2015 / 199070 can be used by those skilled in the art, optimized as appropriate according to the known art.

[0095] [Polyurethane] The polyurethane of the present invention is a polyurethane made from the polycarbonate diol and isocyanate compound of the present invention as raw materials. The method for producing the polyurethane of the present invention is not particularly limited. As a method for producing the polyurethane of the present invention, for example, a person skilled in the art can use known polyurethane reaction conditions described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575, etc., which can be appropriately optimized according to the known art.

[0096] For example, the polyurethane of the present invention can be produced by reacting the polycarbonate diol of the present invention with a polyol other than the polycarbonate diol of the present invention, which is used as needed, a polyisocyanate described later, and a chain extender described later, which is used as needed, in a temperature range from room temperature to 200°C.

[0097] When using a chain extender, it may be added from the beginning of the reaction or added midway through the reaction. For example, the polyurethane of the present invention can be produced by first reacting the polycarbonate diol of the present invention with an excess of polyisocyanate to produce a prepolymer having isocyanate groups at the ends, and then adding a chain extender and reacting it with the prepolymer to increase the degree of polymerization of the polymer.

[0098] <Polyisocyanate> As the polyisocyanate used in the production of polyurethane according to the present invention, any known polyisocyanate used in the production of polyurethane can be used. The polyisocyanate is not particularly limited. For example, various aliphatic, alicyclic, or aromatic polyisocyanate compounds described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575 can be used.

[0099] Specifically, examples include known aliphatic diisocyanates such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate; known alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,3-bis(isocyanate-methyl)cyclohexane; and known aromatic diisocyanates such as xylylene diisocyanate, 4,4'-diphenyl diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 4,4'-diphenyldimethylmethane diisocyanate. These may be used individually or in combination of two or more.

[0100] Among these, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and isophorone diisocyanate are preferred because they offer a favorable balance of the physical properties of the resulting polyurethane and are readily available in large quantities at low cost for industrial use.

[0101] <Chain Extender> As the chain extender used in the production of polyurethane of the present invention, known chain extenders used in the production of polyurethane can be used. The chain extender is not particularly limited. Examples of chain extenders include low molecular weight polyols, amines, water, etc., as described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0102] Specifically, linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; branched diols such as 2-methyl-1,3-propanediol and 2,2-dimethyl-1,3-propanediol; diols with ether groups such as diethylene glycol and propylene glycol; alicyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and 1,4-dihydroxyethylcyclohexane; xylylene glycol and 1,4-dihydroxy Examples include diols having aromatic groups such as oxyethylbenzene and 4,4'-methylenebis(hydroxyethylbenzene); polyols such as glycerin, trimethylolpropane, and pentaerythritol; hydroxyamines such as N-methylethanolamine and N-ethylethanolamine; polyamines such as ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediamine, 4,4'-diphenylmethanediamine, xylylenediamine, diphenyldiamine, hydrazine, and piperazine; and water. These chain extenders may be used alone or in combination of two or more.

[0103] Among these, ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxyethylcyclohexane, ethylenediamine, 1,3-diaminopropane, isophoronediamine, and 4,4'-diaminodicyclohexylmethane are preferred because they offer a favorable balance of the physical properties of the resulting polyurethane and are readily available in large quantities at low cost for industrial use.

[0104] <Chain Arrestors> When producing the polyurethane of the present invention, known chain arrestors used in the production of polyurethanes may be used as needed to control the molecular weight of the polyurethane. The chain arrestors are not particularly limited. Examples of chain arrestors include compounds having one active hydrogen group, as described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0105] Specifically, examples include monohydric alcohols such as methanol, ethanol, propanol, butanol, and hexanol, and secondary amines such as diethylamine, dibutylamine, di-n-propylamine, n-butylamine, monoethanolamine, and diethanolamine. These may be used individually or in combination of two or more.

[0106] <Catalyst> When producing the polyurethane of the present invention, known catalysts used in the production of polyurethane can be used. The catalyst is not particularly limited. As catalysts, for example, known polymerization catalysts such as tertiary amines and organometallic salts such as tin and titanium, as described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575, can be used.

[0107] <Solvent> When manufacturing the polyurethane of the present invention, a solvent may be used as needed. The solvent is not particularly limited and includes, for example, solvents described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0108] Specifically, examples include dimethylformamide, diethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, methyl isobutyl ketone, dioxane, cyclohexanone, benzene, toluene, and ethyl cellsolve. These may be used individually or in combination of two or more.

[0109] <Usage Amount and Method> In the polyurethane manufacturing method of the present invention, the amount and method of use of the polyisocyanate, the chain extender, the chain arrester, the catalyst, and the solvent are not particularly limited, and those skilled in the art can use the conditions described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575 by optimizing them as appropriate in accordance with the known art.

[0110] <Weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of polyurethane> The lower limit of the weight-average molecular weight (Mw) of the polyurethane of the present invention is not particularly limited. From the viewpoint of obtaining good mechanical properties and chemical resistance of the obtained polyurethane, the lower limit of the weight-average molecular weight (Mw) is preferably 50,000 or more, more preferably 100,000 or more, and even more preferably 150,000 or more. On the other hand, the upper limit of the weight-average molecular weight (Mw) is not particularly limited. From the viewpoint of maintaining good chemical resistance of the obtained polyurethane, the upper limit of the weight-average molecular weight (Mw) is preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less. The above upper and lower limits can be arbitrarily combined. For example, the weight-average molecular weight (Mw) of the polyurethane of the present invention is preferably 50,000 to 500,000, more preferably 100,000 to 300,000, and even more preferably 150,000 to 200,000.

[0111] The lower limit of the molecular weight distribution (Mw / Mn) of the polyurethane of the present invention is not particularly limited. From the viewpoint of obtaining good mechanical properties and chemical resistance of the obtained polyurethane, the lower limit of the molecular weight distribution (Mw / Mn) is preferably 1.50 or higher, more preferably 2.00 or higher, and even more preferably 2.50 or higher. On the other hand, the upper limit of the molecular weight distribution (Mw / Mn) is not particularly limited. From the viewpoint of maintaining good mechanical properties and chemical resistance of the obtained polyurethane, the upper limit of the molecular weight distribution (Mw / Mn) is preferably 4.00 or lower, more preferably 3.00 or lower, and even more preferably 2.90 or lower. The above upper and lower limits can be arbitrarily combined. For example, the molecular weight distribution (Mw / Mn) of the polyurethane of the present invention is preferably 1.50 or more and 4.00 or less, more preferably 2.00 or more and 3.00 or less, and even more preferably 2.50 or more and 2.90 or less.

[0112] The weight-average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were measured using gel permeation chromatography (GPC measurement), and the measurement conditions were as described in the examples below.

[0113] <Applications of Polyurethane> The polyurethane of the present invention has excellent mechanical properties and chemical resistance, as well as good heat resistance and weather resistance. For this reason, the polyurethane of the present invention can be widely used in foams, elastomers, elastic fibers, paints, fibers, adhesives, flooring materials, sealants, medical materials, artificial leather, synthetic leather, coatings, active energy ray curable polymer compositions, and the like.

[0114] In particular, when the polyurethane of the present invention is used in applications such as active energy ray curable polymer compositions, artificial leather, synthetic leather, paints and coatings such as water-based polyurethane paints, elastic fibers, adhesives, and glues, the following effects can be obtained. Specifically, because the polyurethane of the present invention has a good balance of chemical resistance, flexibility, heat resistance, and weather resistance, it can be given excellent properties such as high durability in parts that come into contact with human skin or where cosmetic agents and disinfectant alcohols are used, as well as sufficient flexibility and resistance to physical impacts. Furthermore, the polyurethane of the present invention can be suitably used in automotive applications where heat resistance is required and in outdoor applications where weather resistance is required.

[0115] [Epoxy Resin] The epoxy resin of the present invention is an epoxy resin obtained using the polycarbonate diol of the present invention, and is an epoxy resin in which mechanical properties and chemical resistance are improved by using the polycarbonate diol of the present invention as a modifier or copolymer component. Other raw materials besides polycarbonate diol include bisphenols (e.g., bisphenol A, bisphenol F, etc.), aliphatic diols (e.g., ethylene glycol, propylene glycol, butanediol, etc.), alicyclic diols (e.g., cyclohexanediol), aromatic diols (e.g., hydroquinone, resorcinol), etc. The type of epoxy resin of the present invention is not particularly limited, but examples include glycidyl ether types consisting of bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, phenol novolac type, etc.; glycidyl ester types consisting of glycidyl hexahydrophthalate ester, glycidyl methacrylate copolymer, etc.; glycidylamine types consisting of tetraglycidyldiaminodiphenylmethane, etc.; and cyclic oxirane types consisting of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, etc., which are used in applications such as paints, adhesives, and electronic materials. As for curing methods to obtain epoxy resins, known curing methods such as room temperature curing with aliphatic polyamines, etc., thermosetting using amines (aliphatic amines, aromatic amines, imidazoles, etc.) and acid anhydrides, powder coating, and cationic electrodeposition by emulsification can be used.

[0116] [Polyester] The polyester of the present invention is a polyester obtained using the polycarbonate diol of the present invention. Other raw materials besides polycarbonate diol include dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, adipic acid, sebacic acid, succinic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, etc.), dicarboxylic acid derivatives (these acid chlorides, acid anhydrides, dimethyl esters, etc.), and diols (e.g., ethylene glycol, 1,4-butanediol, 1,3-propanediol, cyclohexanedimethanol, diethylene glycol, etc.). The polyester of the present invention is obtained by condensing the polycarbonate diol with the other raw materials mentioned above using known polyester synthesis methods, and is used in applications such as adhesives and electronic materials.

[0117] [Effects] By containing the terminal structure (2-1) of the present invention, the resulting polyurethane exhibits excellent mechanical properties and chemical resistance, and also exhibits the remarkable effect of suppressing variations in the mechanical properties. The reason for this is not clear, but it is presumed to be as follows.

[0118] In other words, when polyurethane is produced using the polycarbonate diol of the present invention as a raw material, the terminal structure (2-1) contained in the polycarbonate diol is incorporated into the reaction system during polyurethane synthesis and is ultimately introduced in the form of terminal structures (2-1) at the ends of the polyurethane. Such terminal structures (2-1) have a highly polar structure, which improves the interaction between the molecular chains of the polyurethane. This is presumed to improve the mechanical properties (e.g., breaking strength, elongation at break, modulus) and chemical resistance of the resulting polyurethane, and furthermore, suppress variations in the mechanical properties, resulting in excellent effects.

[0119] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the essence of the invention.

[0120] [Raw Materials Used] The abbreviations for the raw materials used in the examples and comparative examples are as follows: 15PD: 1,5-pentanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) 16HD: 1,6-hexanediol (manufactured by BASF Japan Ltd.) DPC: diphenyl carbonate (manufactured by Mitsubishi Chemical Corporation) Mg catalyst: magnesium acetate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Tetrahydropyranyl ethylene glycol (manufactured by Sigma-Aldrich) 5-(2-oxytetrahydropyran)-1-pentanol: synthesized according to the synthesis method described in the Supporting Information of Org. Lett., Vol. 8, No. 6, 2006, pp. 1013-1016. MDI: Diphenylmethane diisocyanate (manufactured by Tosoh Corporation) 14BD: 1,4-butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) U-830: Dioctyl tin monodecanate (product name: Neostan U-830, manufactured by Nitto Chemical Co., Ltd.) DMF: N,N-dimethylformamide dehydrated (manufactured by Fujifilm Wako Pure Chemical Industries Ltd.)

[0121] [Evaluation Method] The evaluation method for each physical property value is as follows:

[0122] <Content ratio of terminal structure (2-1) in PCD composition (1)> For the compositions containing polycarbonate diol obtained in the examples and comparative examples (hereinafter referred to as "PCD composition"), the content ratio of terminal structure (2-1) in the PCD composition relative to 100% of the total mol amount of hydroxyl terminals of polycarbonate diol and the terminal structure (2-1) was measured according to the following procedure.

[0123] PCD composition CDCl ３ Dissolve it in a solution to a concentration of 3% by mass, and use a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ-400) under the conditions of a measurement temperature of 30°C and 64 cumulative measurements. １ 1H-NMR measurements were performed. １From the 1H-NMR spectrum, the peaks observed at the signal positions shown below were identified, and the integral values ​​A and B of each peak were obtained. In this evaluation, the tetrahydropyranyl group corresponds to terminal structure (2-1) in the present invention.

[0124] The integral of the peak of the 1H proton of the methylene group of the tetrahydropyranyl group located at δ4.65–4.50 ppm = A The integral of the peak of the 2H proton of the methylene group adjacent to the hydroxyl group end located at δ3.70–3.50 ppm = B

[0125] Next, the percentage (1) (unit: mol%) of the terminal structure (2-1) relative to 100% of the total mol amount of hydroxyl terminals and terminal structures (2-1) in the polycarbonate diol contained in the PCD composition was calculated using the following formula.

[0126]

[0127] <Content ratio of terminal structures (2-1) in PCD compositions (2)> For the PCD compositions obtained in the examples and comparative examples, the content ratio of terminal structures (2-1) in the PCD compositions relative to 100% of the total mol amount of all structural units in the polycarbonate diol was measured according to the following procedure.

[0128] PCD composition CDCl ３ Dissolve it in a solution to a concentration of 3% by mass, and use a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ-400) under the conditions of a measurement temperature of 30°C and 64 cumulative measurements. １ 1H-NMR measurements were performed. １ From the 1H-NMR spectrum, the peaks observed at the signal positions shown below were identified, and the integral values ​​A and C of each peak were obtained. In this evaluation, the tetrahydropyranyl group corresponds to terminal structure (2-1) in the present invention.

[0129] The integral of the peak of the 1H proton of the methylene group of the tetrahydropyranyl group present at δ4.65–4.50 ppm = A The integral of the peaks of the 6H protons of the β-methylene and γ-methylene groups of the structure derived from 1,5-pentanediol in the polycarbonate diol present at δ1.90–1.30 ppm = C

[0130] Next, the percentage (2) (unit: mol%) of the terminal structure (2-1) relative to 100% of the total mol amount of all structural units in the polycarbonate diol contained in the PCD composition was calculated using the following formula.

[0131]

[0132] Similarly, the content ratio (2) of terminal structures (2-1) in the PCD compositions produced using 15PD and 16HD as raw materials, as used in Example 6 and Comparative Example 2, is also as follows: １ From the 1H-NMR spectrum, the integral values ​​of the 1H proton peaks of the β-methylene group and γ-methylene group of the structural units derived from 15PD and 16HD in the PCD, and the content ratio (2) (unit: mol%) of the terminal structure (2-1) relative to 100% of the total mol amount of all structural units in the PCD contained in the PCD composition were calculated using the above formula and an equivalent formula.

[0133] <Number average molecular weight M of PCD> PCD composition is CDCl ３ Dissolve it in a solution to a concentration of 3% by mass, and use a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ-400) under the conditions of a measurement temperature of 30°C and 64 cumulative measurements. １ 1H-NMR measurements were performed. １ From the 1H-NMR spectrum, the peaks observed at the signal positions shown below were identified, and the integral values ​​A to C of each peak were obtained. In this evaluation, the tetrahydropyranyl group corresponds to terminal structure (2-1) in the present invention.

[0134] The methylene group in the tetrahydropyranyl group present at δ4.65–4.50 ppm １Integrated value of the H proton peak = A Integrated value of the 2H proton peak of the methylene group adjacent to the hydroxyl group end, located at δ 3.70–3.50 ppm = B Integrated value of the 6H proton peaks of the β-methylene and γ-methylene groups of the structural unit derived from 1,5-pentanediol in the polycarbonate diol, located at δ 1.90–1.30 ppm = C

[0135] The integral value of the peak of the 1H proton originating from the polycarbonate diol terminal structural unit derived from 15PD is "15PD ｍ ", the integral value of the peak of the 1H proton derived from the tetrahydropyranyl group is "THP ｍ " was also defined as "15PD". ｏ Based on the number of protons in the structural unit derived from 15PD, the integral value of the peak of the 1H proton derived from each of the above-mentioned structural units was calculated using the following formula. 15PD ｍ = B ÷ 2 15PD ｏ = (C-15PD) ｍ ×4) ÷6 THP ｍ = A

[0136] Next, the number-average molecular weight M (PCD) of the polycarbonate diol was calculated using the following formula.

[0137]

[0138] In the above formula, M(15PD) ｏ ) represents the molecular weight (=102) of the structural unit derived from 15PD in the polycarbonate diol other than the polycarbonate diol terminus. M(THP) represents the molecular weight (=145) of the structural unit derived from tetrahydropyranylethylene glycol in Examples 1-4 and 6, and the molecular weight (=187) of the structural unit derived from 5-(2-oxytetrahydropyran)-1-pentanol in Examples 5 and 7. M(15PD ｍ ) represents the molecular weight of the structural unit derived from 15PD in the polycarbonate diol terminus (=103), and M (carbonyl group) represents the molecular weight of the carbonyl group (=28).

[0139] Similarly, the number-average molecular weight M (PCD) of the polycarbonate diols produced using 15PD and 16HD as raw materials in Example 6 and Comparative Example 2 is also as follows: １ From the 1H-NMR spectrum, the integral value of the 1H proton peak of the methylene group in the tetrahydropyranyl group, the integral value of the 1H proton peak of the methylene group adjacent to the hydroxyl group in the polycarbonate diol and compound (3-1), the integral value of the 1H proton peaks of the β-methylene group and γ-methylene group of the structural unit in the polycarbonate diol, and the number-average molecular weight M (PCD) of the polycarbonate diol were calculated using a formula similar to the above formula.

[0140] At that time, M (16HD ｏ ) Molecular weight of the structural unit derived from 16HD in the polycarbonate diol other than the polycarbonate diol terminal (=116), M(16HD ｍ ) was used as the molecular weight (=117) of the structural unit derived from 16HD in the polycarbonate diol terminus.

[0141] <Content of Compound (3-1) in PCD Composition> For the PCD compositions obtained in the examples and comparative examples, the content of compound (3-1) in the PCD composition was measured according to the following procedure. 1.0 g of the PCD composition and 5.0 g of a mixed solution of 2-propanol and heptane containing 0.1% by mass of indole (the mixing ratio of 2-propanol and heptane is 1:9 by volume) were weighed and mixed to prepare a mixed solution in which PCD was suspended. The mixed solution was then stirred at 50°C for 10 minutes, and then left to stand in an ice bath for 30 minutes. Next, 1 g of the supernatant of the mixed solution was taken and filtered using a filter with a pore size of 0.45 μm to obtain a filtrate from which the polycarbonate diol suspended in the supernatant was removed. Next, 2-propanol and heptane were removed from the obtained filtrate under reduced pressure, and the filtrate from which 2-propanol and heptane had been removed was converted to CDCl ３ Dissolve it in a solution to a concentration of 3% by mass, and use a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ-400) under the conditions of a measurement temperature of 30°C and 32 cumulative measurements. １ H-NMR measurements were performed.

[0142] obtained １ From the 1H-NMR spectrum, the peaks observed at the following signal positions were identified, and the integral values ​​D and E for each peak were obtained. Integral value D of the peak of the 1H proton of the methylene group of the tetrahydropyranyl group in compound (3-1) located at δ4.56 ppm Integral value E of the peak of the 1H proton of indole located at δ7.51 ppm

[0143] Next, the percentage of compound (3-1) in the PCD composition was calculated using the following formula.

[0144]

[0145] In the above formula, M(THP) represents the molecular weight of compound (3-1). In Examples 1-4 and 6, it is the molecular weight of tetrahydropyranylethylene glycol (=146), while in Examples 5 and 7, it is the molecular weight derived from 5-(2-oxytetrahydropyran)-1-pentanol (=188).

[0146] <Content ratio of terminal structure (2-1) in PCD (1)> For the PCD compositions obtained in the examples and comparative examples, the content ratio (1) of terminal structure (2-1) in PCD relative to 100% of the total mol amount of hydroxyl group terminals and the terminal structure (2-1) in PCD was calculated using the following formula.

[0147]

[0148] In the above formula, m(3-1) represents the percentage (mass%) of compound (3-1) in the PCD composition. M(PCD) represents the number-average molecular weight of PCD. M(THP) represents the molecular weight of compound (3-1), which in Examples 1-4 and 6 represents the molecular weight of tetrahydropyranylethylene glycol (=146), and in Examples 5 and 7 represents the molecular weight derived from 5-(2-oxytetrahydropyran)-1-pentanol (=188).

[0149] <Content ratio of terminal structures (2-1) in PCD (2)> Using the content ratio of terminal structures (2-1) in PCD (1), the content ratio of terminal structures (2-1) in the PCD composition (1), and the content ratio of terminal structures (2-1) in the PCD composition (2) obtained by the method described above, the content ratio of terminal structures (2-1) in PCD (2) relative to 100% of the total mol amount of all structural units in PCD was calculated using the following formula.

[0150]

[0151] <Content ratio of hydroxyl group terminals in PCD> For the PCD compositions obtained in the examples and comparative examples, the content ratio of hydroxyl group terminals in PCD relative to 100% of the total mol amount of all terminal groups in PCD was analyzed according to the following procedure.

[0152] PCD composition CDCl ３ Dissolve it in a solution to a concentration of 3% by mass, and use a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ-400) under the conditions of a measurement temperature of 30°C and 64 cumulative measurements. １ 1H-NMR measurements were performed. １ In the 1H-NMR spectrum, we checked for the presence or absence of a 2H proton peak at δ7.4–7.3 ppm corresponding to the phenoxy group derived from DPC, and a 1H proton peak at δ6.0–5.8 ppm corresponding to the vinyl group generated by the dehydration reaction of the hydroxyl group at the molecular end of the PCD, as these are PCD terminal structures formed as byproducts during the synthesis of PCD. As a result, the peaks corresponding to the phenoxy group and the vinyl group were not observed. Therefore, it was confirmed that there are two types of molecular ends of the PCD obtained in the examples and comparative examples: hydroxyl group ends and terminal structure (2-1). Accordingly, the total amount of all terminal groups in the PCD was set to 100 mol%, and the content of terminal structure (2-1) obtained in the PCD by the method described above (1) (unit: mol%) was subtracted from this to obtain the content of hydroxyl group ends in the PCD (unit: mol%).

[0153] <Weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyurethane> For the polyurethanes obtained in the examples and comparative examples, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were determined using gel permeation chromatography (GPC measurement) according to the following procedure.

[0154] Polyurethane samples were dissolved in dimethylacetamide (containing 0.3% by mass of anhydrous lithium bromide) to a polyurethane concentration of 0.07% by mass, and this was used as the sample for GPC measurement. GPC measurements were performed using a GPC instrument (Tosoh Corporation, model name: HLC-8420, column: two Tosoh Corporation TSKgel SuperAWM-H columns) under the following measurement conditions: sample injection volume of approximately 40 μL, column temperature of 40°C, measurement solvent (mobile phase) of dimethylacetamide (containing 0.3% by mass of anhydrous lithium bromide), and flow rate of 0.6 mL / min. The molecular weight of polyurethane was measured using a commercially available monodisperse polystyrene solution as a standard sample, and the number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn) were measured in terms of standard polystyrene.

[0155] <Mechanical Properties of Polyurethane> As an indicator of the mechanical properties of polyurethane, tensile tests were performed on polyurethane using the following method, and various mechanical properties were evaluated.

[0156] The polyurethane solutions obtained in the examples and comparative examples were applied to a 0.1 mm thick fluororesin sheet (product name: Fluorine Tape "Nitoflon 900", manufactured by Nitto Denko Corporation) using an applicator with a clearance of 500 μm. The solutions were dried at 80°C for 1 hour, followed by 100°C for 0.5 hours, and then in a vacuum at 100°C for 1.0 hour to remove the solvent (DMF). After that, the film was left to stand for 12 hours or more under constant temperature and humidity conditions of 23 ± 1°C and 50 ± 10% RH to obtain a laminated film in which a polyurethane layer was formed on the surface of the fluororesin sheet. The thickness of the polyurethane layer after drying was 90 ± 20 μm. After peeling the polyurethane layer from the obtained laminated film, strips of polyurethane film (length 150 mm, width 10 mm, thickness 90 ± 20 μm) were cut out and used as samples for tensile testing.

[0157] (Tensile Test) The above tensile test specimens were subjected to tensile testing in accordance with JIS K6301 (2010) using a benchtop precision universal testing machine (manufactured by Shimadzu Corporation, product name: Autograph AGS-X) at a chuck distance of 50 mm, a tensile speed of 500 mm / min, and a temperature of 23 ± 1 °C (relative humidity of 50 ± 10%). Measurements were taken using three tensile test specimens to determine the 300% modulus, as well as the mean and standard deviation of the stress (breaking strength) and elongation (breaking elongation) at the time of fracture. The following formulas were used to calculate the coefficient of variation of the 300% modulus, breaking strength, and breaking elongation: Coefficient of variation (%) = (standard deviation / mean) × 100

[0158] The coefficient of variation is an index used to evaluate the relative variability of the aforementioned data. A smaller value for the coefficient of variation indicates less variation in the numerical values ​​of the tensile test characteristics, and therefore, a more homogeneous polyurethane can be obtained.

[0159] <Chemical Resistance of Polyurethane> As an indicator of the chemical resistance of polyurethane, the rate of mass change when polyurethane was immersed in a test solution was measured using the following method.

[0160] The polyurethane solutions obtained in the examples and comparative examples were applied to a 0.1 mm thick fluororesin sheet (product name: Fluorine Tape "Nitoflon 900", manufactured by Nitto Denko Corporation) using an applicator with a clearance of 500 μm. The solution was dried at 80°C for 1 hour, followed by 100°C for 0.5 hours, and then at 100°C under vacuum for 1.0 hour to remove the solvent (DMF), thereby obtaining a laminated film in which a polyurethane layer was formed on the surface of the fluororesin sheet. The thickness of the polyurethane layer after drying was 90 ± 20 μm. After peeling the polyurethane layer from the obtained laminated film, a square-shaped polyurethane film (3 cm long, 3 cm wide, 90 ± 20 μm thick) was cut out and used as a sample for chemical resistance testing.

[0161] (Oleic Acid Resistance Test) After measuring the mass of the test specimen for the chemical resistance test using a precision balance, the specimen was placed in a 250 mL glass bottle containing 50 mL of oleic acid as the test solvent, and then immersed in an inert oven set to 80°C for 16 hours. After that, the test specimen was removed, and the solvent was wiped off by lightly wiping both sides of the specimen with a paper wiper, and then the mass of the test specimen was measured using a precision balance. The mass change rate (increase rate) (unit: mass%) was calculated from the mass change of the test specimen before and after the immersion treatment. The closer the mass change rate is to 0%, the better the oleic acid resistance.

[0162] (Ethanol Resistance Test) After measuring the mass of the test specimen for the chemical resistance test using a precision balance, the specimen was placed in a glass petri dish with an inner diameter of 10 cm containing 50 mL of ethanol as the test solvent and immersed at room temperature of approximately 23°C for 1 hour. After that, the specimen was removed, and the solvent was wiped off by lightly wiping both sides of the specimen with a paper wiper, and then the mass of the specimen was measured using a precision balance. The mass change rate (increase rate) (unit: mass%) was calculated from the change in mass of the specimen before and after the immersion treatment. The closer the mass change rate is to 0%, the better the ethanol resistance.

[0163] <Hydrolysis Resistance of Polyurethane> As an indicator of the hydrolysis resistance of polyurethane, the rate of retention of tensile strength when polyurethane was stored in a constant temperature and humidity environment was measured using the following method.

[0164] The polyurethane solutions obtained in the examples and comparative examples were applied to a 0.1 mm thick fluororesin sheet (product name: Fluorine Tape "Nitoflon 900", manufactured by Nitto Denko Corporation) using an applicator with a clearance of 500 μm. The solutions were dried at 80°C for 1 hour, followed by 100°C for 0.5 hours, and then under vacuum at 100°C for 1.0 hour to remove the solvent (DMF). After that, the film was left to stand for 12 hours or more under constant temperature and humidity conditions of 23 ± 1°C and 50 ± 10% RH to obtain a laminated film in which a polyurethane layer was formed on the surface of the fluororesin sheet. The thickness of the polyurethane layer after drying was 90 ± 20 μm. After peeling the polyurethane layer from the obtained laminated film, strips of polyurethane film (length 150 mm, width 10 mm, thickness 90 ± 20 μm) were cut out and used as sample pieces for the hydrolysis resistance test.

[0165] The hydrolysis-resistant specimens described above were stored for four weeks in a constant temperature and humidity chamber under conditions of 70°C and 95% RH. After the test, the specimens were removed from the constant temperature and humidity chamber and left to stand for at least 48 hours in an environment of 23±1°C and 50±10% RH.

[0166] The test specimens after the hydrolysis resistance test described above were dissolved in dimethylacetamide (containing 0.3% by mass of anhydrous lithium bromide) to a polyurethane concentration of 0.07% by mass, and this was used as the sample for GPC measurement. GPC measurements were performed using a GPC instrument (Tosoh Corporation, model name: HLC-8420, column: Tosoh Corporation TSKgel SuperAWM-H x 2) under the following measurement conditions: sample injection volume of approximately 40 μL, column temperature of 40°C, measurement solvent (mobile phase) of dimethylacetamide (containing 0.3% by mass of anhydrous lithium bromide), and flow rate of 0.6 mL / min. The molecular weight of polyurethane was measured using a commercially available monodisperse polystyrene solution as a standard sample, and the weight-average molecular weight (Mw) in terms of standard polystyrene was measured. The following formula was used to calculate the retention rate of the weight-average molecular weight (Mw): Retention rate of weight-average molecular weight (Mw) (%) = (Weight-average molecular weight (Mw) after hydrolysis resistance test / Weight-average molecular weight (Mw) before hydrolysis resistance test) × 100

[0167] The closer the retention rate of the weight average molecular weight (Mw) before and after the hydrolysis resistance test is to 100%, the better the hydrolysis resistance of the polyurethane is indicated.

[0168] [Production and Evaluation of Polycarbonate Diol] [Example 1] Into a 1 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure regulator, 15PD as a diol compound, tetrahydropyranyl ethylene glycol as a tetrahydropyran compound (3-1), DPC as a carbonate compound, and a Mg catalyst as a transesterification reaction catalyst were charged according to the compounding amounts shown in Table 1. Next, after replacing the inside of the flask with a nitrogen atmosphere, while stirring the contents in the flask, the temperature of the contents was heated and raised until it reached 160 °C to dissolve the contents by heating. The pressure inside the flask at this time was 101 kPa. Thereafter, the pressure inside the flask was gradually reduced from 101 kPa to 24 kPa over 2 minutes, and then the reaction was carried out for 90 minutes while removing the generated phenol outside the reaction system. Next, the pressure inside the flask was gradually reduced to 9.3 kPa over 90 minutes, and then further gradually reduced to 0.7 kPa over 60 minutes to continue the reaction. Thereafter, the temperature of the contents in the flask was heated and raised until it reached 170 °C, and the reaction was further carried out for 90 minutes while removing phenol and unreacted diol compounds outside the reaction system. Thereafter, the contents were allowed to cool until the temperature thereof was near room temperature (about 25 °C) to obtain 247 g of polycarbonate diol. Regarding the obtained polycarbonate diol, the above-described evaluation was carried out, and the evaluation results are shown in Table 1.

[0169] [Comparative Example 1] In Example 1, the reaction was carried out under the same conditions as in Example 1 except that the tetrahydropyran compound (3-1) was not used, and 247 g of polycarbonate diol was obtained. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0170] [Examples 2 to 3] In Example 1, the reaction was carried out under the same conditions as in Example 1 except that the compounding amount of the tetrahydropyran compound (3-1) was changed as shown in Table 1, and 247 g of polycarbonate diol was obtained. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0171] [Example 4] The reaction was carried out under the same conditions as in Example 1, except that the amounts of 15PD, DPC, Mg catalyst, and tetrahydropyran compound (3-1) were changed as shown in Table 1, to obtain 224 g of polycarbonate diol. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0172] [Example 5] The reaction was carried out under the same conditions as in Example 1, except that 5-(2-oxytetrahydropyran)-1-pentanol was used instead of tetrahydropyranylethylene glycol as the tetrahydropyran compound (3-1), and the amounts of 15PD, 5-(2-oxytetrahydropyran)-1-pentanol, DCP, and Mg catalyst were changed as shown in Table 1, to obtain 159 g of polycarbonate diol. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0173] [Example 6] The reaction was carried out under the same conditions as in Example 1, except that 15PD and 16HD were used as the diol compounds, and the amounts of 15PD, 16HD, DPC, Mg catalyst, and tetrahydropyran compound (3-1) were changed as shown in Table 1, to obtain 259 g of polycarbonate diol. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0174] [Comparative Example 2] The reaction was carried out under the same conditions as in Example 1, except that the tetrahydropyran compound (3-1) was not used in Example 6, and 255 g of polycarbonate diol was obtained. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0175] [Example 7] The reaction was carried out under the same conditions as in Example 1, except that 5-(2-oxytetrahydropyran)-1-pentanol was used as the tetrahydropyran compound (3-1) and the amount of tetrahydropyran compound (3-1) was changed as shown in Table 1, to obtain 250 g of polycarbonate diol. The evaluation results of the obtained polycarbonate diol are shown in Table 1.

[0176] [Purification Treatment of Polycarbonate Diols] In order to deactivate the catalyst and remove residual monomers such as phenol from the polycarbonate diols obtained in Examples 1-4, Examples 6-7, and Comparative Examples 1-2, first, 0.25 g of a 0.85% by mass aqueous phosphoric acid solution was added to 150 g of polycarbonate diol as a catalyst deactivator, and the mixture was heated at 80-120°C for 10-120 minutes to deactivate the residual catalyst (magnesium acetate). Next, to remove monomers such as phenol, the obtained polycarbonate diol was fed into a thin-film distillation apparatus at a flow rate of 20 g / min and thin-film distillation was performed (temperature: 180-190°C, pressure: 40-67 Pa). The thin-film distillation apparatus had a diameter of 50 mm, a height of 200 mm, and an area of ​​0.0314 m². ２ A special type MS-300 molecular distillation apparatus manufactured by Shibata Scientific Co., Ltd., with an internal capacitor and jacket, was used. The contents were then allowed to cool to near room temperature (approximately 25°C) to obtain the purified polycarbonate diol. The polycarbonate diols obtained by thin-film distillation of the polycarbonate diols of Examples 1-4, Examples 6-7, and Comparative Examples 1-2 were referred to as PCD1A-8A as shown in Table 1, and the content ratio of terminal structures (2-1) and hydroxyl group terminals in the PCD of each polycarbonate diol is shown in Table 1.

[0177]

[0178] [Production and Evaluation of Polyurethane] Polyurethane was produced using the polycarbonate diols (PCD1A to 8A) obtained in the examples and comparative examples after thin-film distillation, by the method described below.

[0179] [Comparative Example II-1] Using PCD1A obtained by thin-film distillation, polyurethane was synthesized and evaluated according to the following procedure. (Synthesis of Polyurethane) In a separable flask equipped with a thermocouple and a condenser, 64.8 g of PCD1A preheated to 80°C, 6.1 g of 1,4-butanediol (14BD) as a chain extender, 0.02 g of U-830 as a catalyst, and 240 g of DMF as a reaction solvent were added. The flask was then immersed in an oil bath set to 55°C and stirred at a stirring speed of 60 rpm until homogeneous. The amount of water in the reaction solution in the flask was measured and the amount of MDI consumed by the water was calculated. The amount sampled and extracted was also recorded and the amount of each raw material added was corrected. To the above reaction solution, MDI weighed so that the NCO / OH molar ratio was equivalent to 0.900 (including water correction) was added in solid form using a funnel and stirred at a stirring speed of 60 rpm until homogeneous.

[0180] In this specification, the term "NCO / OH molar ratio" refers to the ratio (molar ratio) of the total amount of substance (moles) of MDI to the value obtained by subtracting the total amount of water content (moles) from the total amount of substance (moles) of polycarbonate diol and 14BD when MDI is added.

[0181] Immediately after adding MDI, an exothermic peak accompanied by a rise in the reaction solution temperature of +10 to +15°C was observed. Five minutes after this exothermic peak subsided, the oil bath temperature was set to 70°C and the temperature was increased. One hour after adding MDI, the molecular weight of the polyurethane in the reaction solution was measured to confirm whether the target molecular weight (Mw = 170,000 to 220,000) had been reached. If the target had not been reached, additional MDI equivalent to an NCO / OH molar ratio of 0.005 to 0.015 was added, and the reaction was allowed to proceed for at least 30 minutes before measuring the molecular weight of the polyurethane in the reaction solution. The addition of MDI and molecular weight measurement were repeated until the target Mw was reached. Finally, 30.3 g of MDI was added to obtain a polyurethane solution containing polyurethane with Mw = 193,794. The evaluation results of the obtained polyurethane are shown in Table 2.

[0182] [Examples II-1 to II-6, Comparative Example II-2] In Comparative Example II-1, the polymerization of polyurethane was carried out under the same conditions and methods as in Comparative Example II-1, except that PCD2A to PCD8A were used instead of PCD1A as shown in Table 2, and the amount of each raw material was changed to the amount shown in Table 2, to obtain a polyurethane solution. The evaluation results of the obtained polyurethane are shown in Table 2.

[0183]

[0184] The evaluation results for the mechanical properties test in Table 2, specifically for breaking strength, elongation at breaking, and 300% modulus, are shown in Figures 1(a), 2(a), 3(a), 6(a), 7(a), and 8(a), respectively. Furthermore, the evaluation results for the coefficient of variation of the mechanical properties test in Table 2, specifically for breaking strength, elongation at breaking, and 300% modulus, are shown in Figures 1(b), 2(b), 3(b), 6(b), 7(b), and 8(b), respectively. In addition, the evaluation results for the chemical resistance test in Table 2, specifically for oleic acid resistance, are shown in Figures 4(a) and 9(a), and for ethanol resistance, are shown in Figures 4(b) and 9(b). The evaluation results for the hydrolysis resistance test in Table 2, specifically for molecular weight (Mw) retention, are shown in Figures 5 and 10.

[0185] From Table 2 and Figures 1 to 10, the following can be seen: The polyurethanes obtained in Examples II-1 to II-6 were superior in mechanical properties (breaking strength, elongation at break, modulus) and chemical resistance compared to the polyurethane obtained in the corresponding Comparative Example II, and furthermore, the coefficient of variation (variation) of breaking strength and modulus was smaller.

[0186] On the other hand, the polyurethanes obtained in Comparative Examples II-1 and II-2 were inferior to the polyurethane obtained in the corresponding Example II in terms of mechanical properties (breaking strength, elongation at break, modulus) and chemical resistance, and the coefficient of variation (variation) of breaking strength and modulus was large, because the polycarbonate diol used as a raw material did not contain terminal structural units derived from the THP in the polycarbonate diol structure.

[0187] Furthermore, regarding the evaluation results of the hydrolysis resistance test shown in Table 2, the polyurethanes obtained in Example II-1 and Example II-3 exhibited superior hydrolysis resistance compared to the polyurethane obtained in Comparative Example II-1.

[0188] In other words, the polycarbonate diol of the present invention makes it possible to obtain polyurethane with excellent mechanical properties (breaking strength, elongation at break, modulus) and chemical resistance, and with suppressed variation in said mechanical properties. Furthermore, it is found that the hydrolysis resistance of the obtained polyurethane can be maintained well or made even better.

[0189] By using the polycarbonate diol of the present invention, it is possible to obtain polyurethane with excellent mechanical properties and chemical resistance, and suppressed variation in the mechanical properties, which is suitable for use in paints, coatings, and adhesives. Furthermore, it is possible to provide a method for stably producing polycarbonate diol for obtaining such polyurethane suitable for use in paints, coatings, and adhesives. As described above, the present invention discloses an industrially important technology and is a technology with high industrial applicability.

Claims

1. A polycarbonate diol containing the terminal structure (2-1) represented by the following general formula (II-1).

2. The polycarbonate diol according to claim 1, wherein the terminal structure (2-1) includes a terminal structure (2-2) represented by the following general formula (II-2). (In the general formula (II-2) above, m is an integer between 2 and 12.) 3. The polycarbonate diol according to claim 1, wherein the number-average molecular weight (Mn) of the polycarbonate diol is 250 or more and 5000 or less.

4. The polycarbonate diol according to claim 1, wherein the content of the terminal structure (2-1) in the polycarbonate diol is 0.01 mol% or more and 10.0 mol% or less, based on 100% of the total mol amount of the hydroxyl group terminals and the terminal structure (2-1) of the polycarbonate diol.

5. The polycarbonate diol according to claim 4, wherein the content of hydroxyl group terminals in the polycarbonate diol is 90.00 mol% or more with respect to 100% of the total mol amount of all terminal groups in the polycarbonate diol.

6. The polycarbonate diol according to claim 1, wherein the content of the terminal structure (2-1) in the polycarbonate diol is 0.01 mol% or more and 1.00 mol% or less, based on 100% of the total amount of structural units of the polycarbonate diol.

7. The polycarbonate diol according to claim 1, comprising a structural unit (1-1) represented by the following general formula (I-1). (In the above general formula (I-1), R represents a divalent hydrocarbon group having 3 to 12 carbon atoms, which may have substituents or heteroatoms.) 8. The polycarbonate diol according to claim 7, wherein the structural unit (1-1) includes a structural unit (1-2) represented by the following general formula (I-2). (In the general formula (I-2) above, n is an integer between 3 and 12.) 9. The polycarbonate diol according to claim 7, wherein the structural unit (1-1) includes a structural unit (1-3) represented by the following general formula (I-3).

10. The polycarbonate diol according to claim 7, wherein the structural unit (1-1) includes a structural unit derived from a diol compound derived from a bio-raw material.

11. A polyurethane obtained using the polycarbonate diol described in any one of claims 1 to 10.

12. The polyurethane according to claim 11, which is used in any of the group selected from the group consisting of active energy ray curable polymer compositions, artificial leather, synthetic leather, paints, coatings, elastic fibers, adhesives, and glues.

13. An epoxy resin obtained using the polycarbonate diol described in any one of claims 1 to 10.

14. A polyester obtained using the polycarbonate diol described in any one of claims 1 to 10.

15. A method for producing a polycarbonate diol, comprising polycondensing a diol-containing composition and a carbonate compound by transesterification in the presence of a catalyst, wherein the diol-containing composition contains a diol compound (4) represented by the following general formula (IV) and a tetrahydropyran compound (3-1) represented by the following general formula (III-1). (In the general formula (IV) above, n is an integer between 3 and 6.) (In the above general formula (III-1), R １ (This is a C2-C12 alkyl group or hydrogen atom, which may have substituents or heteroatoms.) 16. The method for producing a polycarbonate diol according to claim 15, wherein the tetrahydropyran compound (3-1) contains a tetrahydropyran compound (3-2) represented by the following general formula (III-2). (In the above general formula (III-2), R ２ (This is an alkyl group having 2 to 12 carbon atoms or a hydrogen atom containing a hydroxyl group terminus, which may have a side chain.) 17. The method for producing a polycarbonate diol according to claim 15, wherein the tetrahydropyran compound (3-1) contains a tetrahydropyran compound (3-3) represented by the following general formula (III-3). (In the general formula (III-3) above, m is an integer between 2 and 12.) 18. The method for producing a polycarbonate diol according to claim 15, wherein the diol-containing composition contains 0.01% by mass or more of the tetrahydropyran compound (3-1) based on the total mass of the diol-containing composition.

19. The method for producing a polycarbonate diol according to claim 15, wherein the diol-containing composition contains 2.00% by mass or less of the tetrahydropyran compound (3-1) based on the total mass of the diol-containing composition.

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