Polycarbonate diol, method for producing polycarbonate diol, polyurethane, and composition containing a dihydroxy compound.

Abstract

This polycarbonate diol contains a structural unit (1) represented by general formula (I) and a structural unit (2) represented by general formula (II). The percentage content of the structural unit (2) in the polycarbonate diol is 4.3 mol% or less relative to the total structural units of the polycarbonate diol which is 100 mol%.　The present invention can provide: a method for producing a polycarbonate diol, in which a diol such as 1,4-butanediol is used as a raw material and a polycarbonate diol with a molecular weight close to the theoretical molecular weight in high yield can be obtained; and a polycarbonate diol that makes it possible to obtain a polyurethane having excellent mechanical properties and chemical resistance and configured to suppress variation in the mechanical properties.　In general formula (I), n is an integer of 4-6. Also, in general formula (II), m is an integer of 2-4.

Description

[Technical Field]

[0001] This invention relates to polycarbonate diols and methods for producing polycarbonate diols. Furthermore, the present invention relates to polyurethane obtained using the polycarbonate diol.

[0002] Furthermore, the present invention relates to a composition containing a dihydroxy compound. Furthermore, the present invention relates to a polycarbonate diol made from the dihydroxy compound-containing composition, and a polyurethane made from the polycarbonate diol. [Background technology]

[0003] 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 Document 1). Polycarbonate-type polyurethane is considered the most durable grade in terms of heat resistance and hydrolysis resistance, and is widely used in durable films, automotive artificial leather, water-based paints and other coatings, and adhesives. For the above applications, polyurethane is required that exhibits excellent mechanical properties and suppresses variations in mechanical properties from the standpoint of uniform quality. Furthermore, in recent years, polyurethanes have been required to have properties such as resistance to alcohol contained in hair styling products and resistance to oleic acid, the main component of sebum secreted from the human body.

[0004] To solve these problems, polycarbonate diols containing structural units derived from diols such as 1,4-butanediol have been proposed. Specifically, Patent Document 1 proposes a polycarbonate diol copolymerized using 1,4-butanediol and 1,5-pentanediol as raw materials, and a method for producing the same. In addition, Patent Document 2 proposes a polycarbonate diol copolymerized from 1,4-butanediol and 1,6-hexanediol as raw materials and a method for producing the same.

[0005] In addition, in order to obtain a polyurethane excellent in physical property balance such as flexibility, chemical resistance, and hydrolysis resistance, Patent Documents 3 and 4 propose a polyester carbonate diol containing a structural unit derived from 1,4-butanediol and a dicarboxylic acid and a method for producing the same. Furthermore, Patent Document 5 proposes a method for producing a polycarbonate diol excellent in industrial productivity, in which, when producing a polycarbonate diol containing a structural unit derived from 1,4-butanediol, the content of an acid component such as a dicarboxylic acid contained in the raw material diol is controlled to a predetermined value or less to reduce the by-production of tetrahydrofuran.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the methods for producing polycarbonate diols described in Patent Documents 1 to 5, the yield of the polycarbonate diol was insufficient. In addition, the polycarbonate diols obtained by the production methods described in Patent Documents 1 to 5 have a molecular weight higher than the theoretical molecular weight, so that the mechanical properties of the obtained polyurethane are deteriorated, which has been a problem. Furthermore, in the polyurethane obtained by using a polycarbonate diol having a diol such as 1,4-butanediol as a raw material, Patent Documents 1 to 5 do not disclose or suggest anything about the dicarboxylic acid or dicarboxylic acid derivative contained in the diol improving the mechanical properties and chemical resistance of the polyurethane and further reducing the variation in the mechanical strength. Therefore, conventionally, in terms of the quality in industrially producing and using polyurethane using a polycarbonate diol obtained using a diol such as 1,4-butanediol as a raw material, satisfactory results have not been obtained.

[0009] The present invention has been made in view of the above problems. That is, the present invention relates to a polycarbonate diol obtained using a diol such as 1,4-butanediol as a raw material, and the polyurethane obtained using the polycarbonate diol is excellent in mechanical properties and chemical resistance, and the variation in the mechanical properties is suppressed. The present invention aims to provide a polycarbonate diol capable of obtaining such a polyurethane having excellent performance. Furthermore, the present invention can obtain a polycarbonate diol having a molecular weight close to the theoretical molecular weight in a high yield, and the polyurethane obtained using the polycarbonate diol is excellent in mechanical properties and chemical resistance, and the variation in the mechanical properties is suppressed. The present invention aims to provide a method for producing a polycarbonate diol capable of obtaining such a polyurethane having excellent performance.

[0010] Furthermore, the present invention aims to provide a dihydroxy compound-containing composition that includes a dihydroxy compound such as 1,4-butanediol, and that can produce a polycarbonate diol having a molecular weight close to the theoretical molecular weight in high yield. [Means for solving the problem]

[0011] The inventors of the present invention have conducted extensive research to solve the above problems and have found that the above problems can be solved by producing polycarbonate diols using diols such as 1,4-butanediol and specific dicarboxylic acids or dicarboxylic acid derivatives as raw materials.

[0012] In other words, the gist of this invention is as follows:

[0013] [1] A polycarbonate diol comprising structural unit (1) represented by the following general formula (I) and structural unit (2) represented by the following general formula (II), wherein the content of structural unit (2) in the polycarbonate diol is 4.3 mol% or less with respect to 100 mol% of the total structural units of the polycarbonate diol.

[0014] [ka]

[0015] (In the general formula (I) above, n is an integer between 4 and 6.)

[0016] [ka]

[0017] (In the general formula (II) above, m is an integer between 2 and 4.)

[0018] [2] The polycarbonate diol according to [1] above, wherein the content of the structural unit (2) in the polycarbonate diol is 3.0 mol% or less with respect to 100 mol% of the total structural units of the polycarbonate diol. [3] The polycarbonate diol according to [1] or [2] above, wherein the structural unit (1) represented by the general formula (I) includes a structural unit derived from a biomass-derived dihydroxy compound. [4] A polycarbonate diol according to any of [1] to [3] above, wherein the structural unit (1) represented by the general formula (I) is derived from a biomass-derived dihydroxy compound alone, or from a mixture containing a biomass-derived dihydroxy compound and a fossil fuel-derived dihydroxy compound. [5] The polycarbonate diol according to [3] or [4], wherein the biomass-derived dihydroxy compound is a compound derived from non-edible biomass and / or non-fossil fuels. [6] The polycarbonate diol according to any one of [1] to [5], wherein the number average molecular weight (Mn) of the polycarbonate diol is 250 or more and 5000 or less. [7] A method for producing a polycarbonate diol, comprising transesterifying a dihydroxy compound-containing composition containing a compound (1-1) represented by the following general formula (I-1) and a compound (2-1) represented by the following general formula (II-1) with a carbonate compound in the presence of a catalyst to obtain a polycarbonate diol, wherein the content of compound (2-1) in the dihydroxy compound-containing composition is 5.3% by mass or less with respect to 100% of the total mass of the dihydroxy compound-containing composition.

[0019] [ka]

[0020] (In the general formula (I-1) above, n is an integer between 4 and 6.)

[0021] [ka]

[0022] (In the above general formula (II-1), m is an integer between 2 and 4. 1 R represents a hydrogen atom, a heteroatom, or a C2-C20 alkyl group which may have a heteroatom or substituent. The two R in formula (II-1) 1 They may be the same or different from each other.

[0023] [8] In the above compound (2-1), R 1 The method for producing a polycarbonate diol according to [7] above, wherein at least one of the members is a C2-C20 alkyl group which may have a heteroatom or substituent. [9] The method for producing a polycarbonate diol according to [7] or [8], wherein the catalyst is a catalyst containing titanium atoms, and the amount of the catalyst is 50 ppm by mass or less in terms of titanium atoms relative to the total mass of the dihydroxy compound-containing composition.

[0024]

[10] A polyurethane made from a polycarbonate diol described in any of [1] to [6] above and an isocyanate compound.

[11] The polyurethane described in

[10] above, which is 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.

[0025]

[12] A dihydroxy compound-containing composition comprising a compound (1-1) represented by the following general formula (I-1) and a compound (2-1) represented by the following general formula (II-1), wherein the content of compound (2-1) in the dihydroxy compound-containing composition is 5.3% by mass or less with respect to 100% of the total mass of the dihydroxy compound-containing composition.

[0026] [ka]

[0027] (In the general formula (I-1) above, n is an integer between 4 and 6.)

[0028] [ka]

[0029] (In the above general formula (II-1), m is an integer between 2 and 4. 1 R represents a hydrogen atom, a heteroatom, or a C2-C20 alkyl group which may have a heteroatom or substituent. The two R in formula (II-1) 1 They may be the same or different from each other.

[0030]

[13] The dihydroxy compound-containing composition according to

[12] above, wherein the content of compound (1-1) in the dihydroxy compound-containing composition is 40.0% by mass or more with respect to 100% of the total mass of the dihydroxy compound-containing composition.

[14] In the above compound (2-1), R 1 The dihydroxy compound-containing composition according to

[12] or

[13] above, wherein at least one of the is a C2-C20 alkyl group which may have a heteroatom or substituent.

[15] A dihydroxy compound-containing composition according to any one of

[12] to

[14] above, wherein the compound (1-1) contains 1,4-butanediol.

[16] In the above compound (2-1), R 1 The dihydroxy compound-containing composition according to

[14] or

[15] above, wherein at least one of the is a C4 alkyl group which may have a heteroatom or substituent.

[17] A dihydroxy compound-containing composition according to any one of

[12] to

[16] above, wherein the compound (I-1) contains a biomass-derived diol.

[18] A dihydroxy compound-containing composition according to any one of

[12] to

[17] above, used in the process of producing a polycarbonate diol.

[0031]

[19] A polycarbonate diol made from a dihydroxy compound-containing composition described in any of

[12] to

[18] above and a carbonate compound.

[20] A polyurethane made from the polycarbonate diol and isocyanate compound described in

[19] above. [Effects of the Invention]

[0032] According to the present invention, a polycarbonate diol obtained from a diol such as 1,4-butanediol as a raw material is provided, which allows for the creation of a polyurethane obtained using the polycarbonate diol that has excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed. Furthermore, the present invention provides a method for producing polycarbonate diols that can obtain polycarbonate diols having a molecular weight close to the theoretical molecular weight in high yield, and that produce polyurethanes with excellent mechanical properties and chemical resistance, and with suppressed variations in the mechanical properties.

[0033] Furthermore, according to the present invention, it is possible to provide a dihydroxy compound-containing composition that can produce polycarbonate diols having a molecular weight close to that of the theoretical molecular weight. Furthermore, according to the present invention, it is possible to provide a polycarbonate diol that uses the dihydroxy compound-containing composition as a raw material, which is capable of producing a polyurethane with excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed. [Brief explanation of the drawing]

[0034] [Figure 1] This graph shows the relationship between the content ratio of compound (2-1) in the dihydroxy compound-containing compositions obtained in the examples and comparative examples, and the molecular weight (M(PCD)) of the polycarbonate diol. [Figure 2]This graph shows the relationship between the content ratio of compound (2-1) in the dihydroxy compound-containing compositions obtained in the examples and comparative examples, and the yield of polycarbonate diol. [Figure 3] This graph shows the relationship between the content ratio of structural unit (2) in the polycarbonate diol obtained in the examples and comparative examples, and the molecular weight (M(PCD)) of the polycarbonate diol. [Figure 4] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the tensile strength of the polyurethane obtained using the polycarbonate diol. [Figure 5] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diols obtained in the examples and comparative examples, and the 100% modulus of the polyurethane obtained using the polycarbonate diols. [Figure 6] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diols obtained in the examples and comparative examples, and the 300% modulus of the polyurethane obtained using the polycarbonate diols. [Figure 7] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the coefficient of variation of the tensile strength of the polyurethane obtained using the polycarbonate diol. [Figure 8] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the coefficient of variation of the 100% modulus of the polyurethane obtained using the polycarbonate diol. [Figure 9] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the coefficient of variation of the 300% modulus of the polyurethane obtained using the polycarbonate diol. [Figure 10]This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the mass change rate (increase rate) obtained in the oleic acid resistance test of the polyurethane obtained using the polycarbonate diol. [Figure 11] This graph shows the relationship between the content ratio of structural units (2) of the polycarbonate diol obtained in the examples and comparative examples, and the rate of mass change (increase rate) obtained in the ethanol resistance test of the polyurethane obtained using the polycarbonate diol. [Figure 12] This graph shows the relationship between the content ratio of structural units (2) of polycarbonate diols obtained in the examples and comparative examples, and the tensile strength retention rate obtained in the hydrolysis resistance test of polyurethane obtained using the polycarbonate diol. [Modes for carrying out the invention]

[0035] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the embodiments described below and can be implemented in various ways within the scope of its gist. Unless otherwise specified, numerical ranges represented using "~" in this specification mean a range that includes the numbers before and after "~" as the lower and upper limits, respectively, and "A~B" means A or greater and B or less.

[0036] In this specification, "A or B" means "A," "B," and "A and B" unless otherwise specified. For example, "including A or B" means "including A," "including B," and "including A and B" unless otherwise specified. In this specification, "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 synonymous. Furthermore, when simply written as “ppm”, it refers to “weight ppm”.

[0037] 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. This also includes substructures in which one end of the polymer is a linking group and the other is a polymerization-reactive group. The 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."

[0038] In this specification, “optional” or “optionally” means that the circumstances described below may or may not occur, and therefore the description includes both the cases in which the circumstances occur and the cases in which they do not occur.

[0039] As used herein, the term "approximately" can mean within 20% above or below the indicated value. For example, approximately 75°C encompasses the range of 60°C to 90°C.

[0040] In this specification, "obtained polyurethane" refers to polyurethane obtained using the polycarbonate diol and isocyanate compound of the present invention as raw materials.

[0041] In this specification, "the polycarbonate diol of the present invention," "the method for producing the polycarbonate diol of the present invention," "the dihydroxy compound-containing composition of the present invention," and "the polyurethane of the present invention" are collectively referred to as "the present invention."

[0042] All steps described herein may be carried out in any preferred order, unless otherwise specified herein or unless the context clearly contradicts it.

[0043] <Polycarbonate diol> The polycarbonate diol of the present invention is a polycarbonate diol (hereinafter sometimes referred to as "the polycarbonate diol of the present invention") that includes a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II). Details of the aforementioned structural unit (1) and structural unit (2) will be described later.

[0044] [ka]

[0045] (In the general formula (I) above, n is an integer between 4 and 6.)

[0046] [ka]

[0047] (In the general formula (II) above, m is an integer between 2 and 4.)

[0048] Furthermore, the polycarbonate diol of the present invention has a content ratio of the structural unit (2) in the polycarbonate diol of 4.3 mol% or less relative to 100 mol% of the total structural units of the polycarbonate diol.

[0049] The polycarbonate diol of the present invention, by containing the aforementioned structural unit (1), provides excellent mechanical strength and chemical resistance to the polyurethane obtained using this polycarbonate diol.

[0050] The polycarbonate diol of the present invention, by containing the structural unit (2), exhibits excellent mechanical properties and chemical resistance in polyurethane obtained using this polycarbonate diol, and suppresses variations in the mechanical properties.

[0051] Furthermore, the polycarbonate diol of the present invention may optionally contain structural units (3) derived from hydroxyl group-containing compounds (3-1), excluding the compounds (1-1) and (2-1) described later, to the extent that they do not impair the effects of the present invention.

[0052] (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 obtaining 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 combined in any way. For example, the number-average molecular weight (Mn) of the polycarbonate diol in the present invention is preferably 250 to 5000, more preferably 300 to 4000, and even more preferably 400 to 3000.

[0053] The aforementioned number-average molecular weight (Mn) is the molecular weight calculated 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 acetylating reagent in accordance with JIS K1557-1.

[0054] (Metal atom content of polycarbonate diol composition) In the method for producing polycarbonate diols of the present invention, the catalyst used in the production of the polycarbonate diol may remain and be present. Thus, a polycarbonate diol containing metal derived from the catalyst may be described as a polycarbonate diol composition. As described later, a catalyst containing titanium atoms is preferred as this catalyst. Therefore, the polycarbonate diol composition of the present invention contains metal atoms such as titanium atoms derived from the catalyst.

[0055] In the method for producing polycarbonate diol of the present invention, the content of metal atoms such as titanium atoms in the polycarbonate diol composition is preferably 50 ppm by mass or less, more preferably 40 ppm by mass or less, even more preferably 30 ppm by mass or less, and particularly preferably 20 ppm by mass or less, relative to the total mass of the polycarbonate diol composition of the present invention. If the content of metal atoms in the polycarbonate diol composition of the present invention exceeds the above upper limit, problems such as discoloration of the polycarbonate diol composition and inhibition of the reaction when producing polyurethane using this polycarbonate diol composition occur, which is undesirable. On the other hand, in order to reduce the content of metal atoms in the polycarbonate diol composition of the present invention, it is necessary to reduce the amount of catalyst used in the production stage of the polycarbonate diol composition of the present invention. However, reducing the amount of catalyst reduces the polymerization reaction efficiency and necessitates high-level purification of the obtained polycarbonate diol composition, which is undesirable in terms of production efficiency. From this viewpoint, the content of metal atoms in the polycarbonate diol composition of the present invention is preferably 1 ppm by mass or more, more preferably 2 ppm by mass or more, even more preferably 3 ppm by mass or more, and particularly preferably 4 ppm by mass or more. The above upper and lower limits can be combined arbitrarily. For example, the content of metal atoms such as titanium atoms in the polycarbonate diol composition of the present invention is preferably 1 ppm to 50 ppm by mass, more preferably 2 ppm to 40 ppm by mass, even more preferably 3 ppm to 30 ppm by mass, and particularly preferably 4 ppm to 20 ppm by mass, based on the total mass of the polycarbonate diol composition.

[0056] In the method for producing polycarbonate diols of the present invention, by using compound (2-1) together with compound (1-1) described later, polycarbonate diols can be efficiently produced with a relatively small amount of catalyst, and the amount of residual metal atoms in the polycarbonate diol can be reduced.

[0057] Although the polycarbonate diol of the present invention contains metal atoms as described above, and is therefore sometimes referred to as a "polycarbonate diol composition" rather than a "polycarbonate diol," the metal atom content is typically in the extremely small amount in the mass ppm range, and is a trace component found as an impurity in general industrial products. Therefore, to those skilled in the art, it is referred to as a "polycarbonate diol." Therefore, in the embodiments described later, polycarbonate diols containing metal atoms are simply referred to as "polycarbonate diols," and the metal atom content in the polycarbonate diols is measured and evaluated.

[0058] (Structural unit (1)) The structural unit (1) described above is a structural unit contained in the structure of the polycarbonate diol of the present invention, represented by the following general formula (I).

[0059] [ka]

[0060] (In the general formula (I) above, n is an integer between 4 and 6.)

[0061] In the above general formula (I), n is an integer between 4 and 6, preferably 4 or 6, and more preferably 4, from the viewpoint of obtaining better mechanical properties and chemical resistance of the polyurethane. Furthermore, the structural unit (1) may be used alone or in combination of two or more types.

[0062] The lower limit of the content of the structural unit (1) in the polycarbonate diol of the present invention is not particularly limited, but from the viewpoint of obtaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 20 mol% or more, more preferably 40 mol% or more, even more preferably 50 mol% or more, and particularly preferably 60 mol% or more, based on 100 mol% of the structural unit of the polycarbonate diol. On the other hand, the upper limit of the content of the structural unit (1) is not particularly limited, and from the viewpoint of maintaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferable that it be less than 100 mol%, more preferably 99.999 mol% or less, even more preferably 99.998 mol% or less, and particularly preferably 99.997 mol% or less, relative to 100 mol% of the polycarbonate diol structural unit. The above upper and lower limits can be combined arbitrarily. For example, the content of the structural unit (1) in the polycarbonate diol of the present invention is preferably 20 mol% or more and less than 100 mol% per 100 mol% of the structural units of the polycarbonate diol. A concentration of 40 mol% to 99.999 mol% is more preferable, 50 mol% to 99.998 mol% is even more preferable, and 60 mol% to 99.997 mol% is particularly preferable.

[0063] In the polycarbonate diol of the present invention, the structural unit (1) preferably includes a structural unit (1b) represented by the following formula (Ib) from the viewpoint of improving the mechanical properties and chemical resistance of the obtained polyurethane.

[0064] [ka]

[0065] In the polycarbonate diol of the present invention, the structural unit (1b) represented by formula (Ib) can be a structural unit derived from the compound represented by the following formula (Ib-1), i.e., 1,4-butanediol.

[0066] [ka]

[0067] The lower limit of the content of the structural unit (1b) in the polycarbonate diol of the present invention is not particularly limited, but from the viewpoint of obtaining good mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 20 mol% or more, more preferably 40 mol% or more, even more preferably 50 mol% or more, and particularly preferably 60 mol% or more, based on 100 mol% of the structural unit of the polycarbonate diol. On the other hand, the upper limit of the content of the structural unit (1b) is not particularly limited, and from the viewpoint of maintaining good mechanical properties and chemical resistance of the resulting polyurethane, it is preferable that it be less than 100 mol%, more preferably 99.999 mol% or less, even more preferably 99.998 mol% or less, and particularly preferably 99.997 mol% or less, relative to 100 mol% of the polycarbonate diol structural unit. The above upper and lower limits can be combined arbitrarily. For example, the content of the structural unit (1b) in the polycarbonate diol of the present invention is preferably 20 mol% or more and less than 100 mol%, more preferably 40 mol% or more and 99.999 mol%, even more preferably 50 mol% or more and 99.998 mol%, and particularly preferably 60 mol% or more and 99.997 mol%, based on 100 mol% of the structural units of the polycarbonate diol.

[0068] In the polycarbonate diol of the present invention, the specific method for controlling the content ratio of the structural unit (1) in the polycarbonate diol to within the above-mentioned numerical range is not particularly limited, and those skilled in the art can control it by appropriately optimizing the manufacturing conditions for the method of producing the polycarbonate diol of the present invention, which will be described later, based on well-known technology.

[0069] In the polycarbonate diol of the present invention, in order to introduce the structural unit (1) represented by the general formula (I), a structural unit derived from a dihydroxy compound (1-1) represented by the following general formula (I-1) (hereinafter also simply referred to as "compound (1-1)") can be used.

[0070] [ka]

[0071] (In the general formula (I-1) above, n is an integer between 4 and 6.)

[0072] In the general formula (I-1) above, n is the same as n in the general formula (I) above, and from the viewpoint of obtaining better mechanical properties and chemical resistance of the obtained polyurethane, n is an integer from 4 to 6, preferably 4 or 6, and more preferably 4.

[0073] The compound represented by formula (I-1) is not particularly limited, and known dihydroxy compounds used as raw materials for polycarbonate diols can be appropriately selected and used. Examples of compound (1-1) represented by formula (I-1) include 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. From the viewpoint of excellent durability such as chemical resistance, 1,4-butanediol and 1,6-hexanediol are preferred, and 1,4-butanediol (n=4 in the general formula (I-1)) is particularly preferred. Compound (1-1) can be appropriately selected by a person 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.

[0074] The polycarbonate diol of the present invention can contribute to achieving the Sustainable Development Goals (SDGs) by using a biomass-derived compound (1-1) as the compound (1-1). Specifically, a biomass-derived diol alone, or a mixture containing a biomass-derived diol and a fossil fuel-derived diol can be used. Biomass-derived compounds (1-1) are compounds (1-1) derived from non-edible biomass and / or non-fossil fuels.

[0075] 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 derived from plants and animals that does not originate from fossil fuels or non-edible biomass. Specifically, examples include, but are not limited to, methane and sugar ethanol obtained from firewood, charcoal, dried livestock manure, etc.

[0076] In the present invention, the compound derived from fossil fuels (1-1) refers to at least one selected from the compounds derived from petroleum (1-1), the compounds derived from coal (1-1), and the compounds derived from natural gas (1-1).

[0077] The biomass-derived compound (1-1) described above may contain compound (2-1) which is the source of the structural unit (2) described above, depending on its origin. Therefore, the effects of the present invention described above can be obtained by controlling the content ratio of compound (2-1) in compound (1-1) to produce polycarbonate diol, or by controlling the content ratio of structural unit (2) in the polycarbonate diol obtained using compound (1-1) as a raw material.

[0078] For example, in the present invention, the polycarbonate diol can use a single 1,4-butanediol derived from fossil fuels as the compound (1-1) from which the structural unit (1) originates. In the present invention, the polycarbonate diol can be used as compound (1-1) to achieve the Sustainable Development Goals (SDGs) by using a 1,4-butanediol containing biomass-derived 1,4-butanediol, specifically a single biomass-derived 1,4-butanediol, or a mixture containing biomass-derived 1,4-butanediol and fossil fuel-derived 1,4-butanediol. Biomass-derived 1,4-butanediol is 1,4-butanediol derived from non-edible biomass and / or non-fossil fuels.

[0079] Furthermore, in the present invention, 1,4-butanediol derived from fossil fuels refers to at least one selected from 1,4-butanediol derived from petroleum, 1,4-butanediol derived from coal, and 1,4-butanediol derived from natural gas.

[0080] As described above, the biomass-derived 1,4-butanediol may contain the aforementioned compound (2-1) depending on its origin. Therefore, the effects of the present invention described above can be obtained by controlling the content ratio of the aforementioned compound (2-1) in the 1,4-butanediol to produce polycarbonate diols, or by controlling the content ratio of structural unit (2) in the polycarbonate diol obtained using the 1,4-butanediol as a raw material.

[0081] (Structural unit (2)) The structural unit (2) described above is a structural unit contained in the structure of the polycarbonate diol of the present invention, represented by the following general formula (II).

[0082] [ka]

[0083] (In the general formula (II) above, m is an integer between 2 and 4.)

[0084] In the general formula (II) above, m is an integer between 2 and 4, and from the viewpoint of obtaining better mechanical properties of the resulting polyurethane, m is preferably 2 or 4, and more preferably 2. The aforementioned structural unit (2) may be used alone or in combination of two or more types.

[0085] The upper limit of the content of structural units (2) in the polycarbonate diol is, from the viewpoint of maintaining good mechanical properties and durability such as chemical resistance and hydrolysis resistance of the obtained polyurethane, usually 4.3 mol% or less, preferably 3.0 mol% or less, more preferably 0.9 mol% or less, even more preferably 0.8 mol% or less, particularly preferably 0.7 mol% or less, and most preferably 0.5 mol% or less, based on 100 mol% of the structural units of the polycarbonate diol. On the other hand, the lower limit of the content of the structural unit (2) is not particularly limited, and from the viewpoint of having excellent mechanical properties and chemical resistance of the resulting polyurethane and suppressing variations in the mechanical properties, it can be 0.0001 mol% or more, preferably 0.0005 mol% or more, more preferably 0.001 mol% or more, even more preferably 0.002 mol% or more, particularly preferably 0.003 mol% or more, and most preferably 0.005 mol% or more, based on 100 mol% of the structural unit of the polycarbonate diol. The above upper and lower limits can be arbitrarily combined. For example, the content ratio of the structural unit (2) of the polycarbonate diol of the present invention can be 0.0001 mol% or more and 4.3 mol% or less, preferably 0.0005 mol% or more and 3.0 mol% or less, more preferably 0.001 mol% or more and 0.9 mol% or less, still more preferably 0.002 mol% or more and 0.8 mol% or less, particularly preferably 0.003 mol% or more and 0.7 mol% or less, and most preferably 0.005 mol% or more and 0.5 mol% or less, based on 100 mol% of the structural unit of the polycarbonate diol.

[0086] In the polycarbonate diol of the present invention, the specific method for controlling the content ratio of the structural unit (2) in the polycarbonate diol within the above-described numerical range is not particularly limited. For example, when using sugars or the like as biomass resources as raw materials and fermenting them with microbial cells to obtain the compound (1-1), a compound (2-1) such as a dicarboxylic acid or a dicarboxylic acid derivative is by-produced, so it can be controlled by adjusting the type of microbial cells, fermentation time, distillation purification conditions, etc. For other methods, those skilled in the art can control by appropriately optimizing the production conditions of the production method of the polycarbonate diol of the present invention described below based on well-known techniques.

[0087] In the polycarbonate diol of the present invention, as the structural unit represented by the general formula (II), a structural unit derived from the compound (2-1) represented by the following general formula (II-1) can be used.

[0088] [Chemical formula]

[0089] [[ID=二十]](In the above general formula (II-1), m is an integer of 2 to 4. R [[ID=二十一]]<(0000009)>[[ID=二十二]]represents any one of a hydrogen atom, a hetero atom, or an alkyl group having 2 to 20 carbon atoms which may have a hetero atom or a substituent. Two Rs in the formula (II-1) [[ID=二十三]]<(0000010)>They may be the same or different from each other.

[0090] In the general formula (II-1) above, m is the same as m in the general formula (II) above, and is an integer between 2 and 4. From the viewpoint of obtaining better mechanical properties of the resulting polyurethane, m is preferably 2 or 4, and more preferably 2.

[0091] In the above general formula (II-1), R 1 This is a hydrogen atom, a heteroatom, or an alkyl group having 2 to 20 carbon atoms, which may have a heteroatom or substituent. R 1 If at least one of the elements is a heteroatom, compound (2-1) becomes a carboxylate salt. In such cases, the heteroatom is not particularly limited, but lithium, sodium, and potassium are preferred from the viewpoint of good solubility of compound (2-1) in solution when producing the polycarbonate diol in the present invention. R 1 If at least one of the members is a C2-C20 alkyl group which may have a heteroatom or substituent, compound (2-1) becomes a carboxylic acid ester. The C2-C20 alkyl group is not particularly limited, and from the viewpoint of ensuring good solubility of compound (2-1) in solution when producing the polycarbonate diol in the present invention, the number of carbon atoms of the alkyl group is preferably 3-10, more preferably 3-6, even more preferably 4-6, and a C4-C6 alkyl group containing an oxygen atom is particularly preferred.

[0092] In the above general formula (II-1), R 1 From the viewpoint of obtaining polycarbonate diols having a molecular weight close to the theoretical molecular weight in high yield, at least one of them is preferably a C2-C20 alkyl group which may have a heteroatom or substituent, and more preferably a C4 alkyl group which may have a heteroatom or substituent. 1Examples of the C2-C20 alkyl group include ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hydroxybutyl group, pentyl group, hexyl group, hydroxyhexyl group, octyl group, decyl group, hydroxydecyl group, dodecyl group, octadecyl group, eicosyl group, and the like.

[0093] The compound (2-1) is not particularly limited and includes, for example, known dicarboxylic acids, known dicarboxylic acid salts, and known dicarboxylic acid esters. Among these, carboxylic acids or carboxylic acid esters are preferred from the viewpoint of suppressing discoloration of polycarbonate diols and solubility. Carboxylic acid esters are more preferred from the viewpoint of polymerization stability when producing polycarbonate diols.

[0094] Examples of the compound (2-1) include the precursor compound of the compound (1-1). For example, as compound (2-1), at least one selected from the group consisting of dicarboxylic acids, dicarboxylic acid salts, and dicarboxylic acid esters having 4 to 6 carbon atoms is mentioned. More specifically, as the compound (2-1), a precursor of the compound (1-1) represented by the general formula (I-1), If n=4, then succinic acid, succinate salt, succinate ester; If n=5, then glutaric acid, glutarate, glutaric acid ester; If n=6, then adipic acid, adipic acid salt, adipic acid ester: These are some examples. These compounds may be used individually or in combination of two or more.

[0095] (Structural unit (3)) As described above, the polycarbonate diol of the present invention may optionally contain structural units (3) derived from hydroxyl group-containing compounds (3-1) other than compounds (1-1) and (2-1), to the extent that it does not impair the effects of the present invention. Specifically, the dihydroxy compound (3-1) includes linear diols such as 1,3-propanediol, 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; 1,3-butanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, and 2,2-dimethyl-1,3-propanediol. Examples include diols with side chains such as 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol; cyclic diols such as 1,4-cyclohexanedimethanol and 2-bis(4-hydroxycyclohexyl)-propane; oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; diols with cyclic ether structures such as isosorbide, isomannide, and isoidette, which are stereoisomers; and polyols having three or more hydroxyl groups in one molecule, such as trimethylolethane, trimethylolpropane, hexanetriol, and pentaerythritol. These compounds may be used individually or in combination of two or more.

[0096] The upper limit of the content of structural units (3) in the polycarbonate diol is preferably 70 mol% or less, more preferably 50 mol% or less, even more preferably 40 mol% or less, and particularly preferably 30 mol% or more, based on 100 mol% of the structural units of the polycarbonate diol, from the viewpoint of maintaining good mechanical properties and chemical resistance of the polyurethane obtained using the polycarbonate diol as a raw material. On the other hand, the lower limit of the content of the structural unit (3) is not particularly limited, but from the viewpoint of maintaining good mechanical properties of the polyurethane obtained using the polycarbonate diol as a raw material, it is preferably 1 mol% or more, more preferably 2 mol% or more, even more preferably 3 mol% or more, and particularly preferably 4 mol% or more, based on 100 mol% of the structural units of the polycarbonate diol. The above upper and lower limits can be combined arbitrarily. For example, the content of the structural unit (3) of the polycarbonate diol of the present invention is preferably 1 mol% to 70 mol%, more preferably 2 mol% to 50 mol%, even more preferably 3 mol% to 40 mol%, and particularly preferably 4 mol% to 30 mol%, based on 100 mol% of the structural unit of the polycarbonate diol.

[0097] In the polycarbonate diol of the present invention, the specific method for controlling the content ratio of the structural unit (3) in the polycarbonate diol to within the above-mentioned numerical range is not particularly limited, and those skilled in the art can control it by appropriately optimizing the manufacturing conditions for the method of producing the polycarbonate diol of the present invention, which will be described later, based on well-known technology.

[0098] When the polycarbonate diol of the present invention contains the structural unit (3), the content of compound (1-1) in the dihydroxy compound-containing composition described later, which is used as a raw material for producing the polycarbonate diol of the present invention, is not particularly limited. From the viewpoint of good handling properties of the polycarbonate diol and good mechanical properties and durability of the obtained polyurethane, it is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, based on 100% of the total mass of the dihydroxy compound-containing composition. On the other hand, the upper limit of the content ratio of compound (1-1) in the dihydroxy compound-containing composition is not particularly limited, but is preferably less than 100% by mass, more preferably 98% by mass or less, even more preferably 95% by mass or less, and particularly preferably 90% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition. The above upper and lower limits can be combined in any way. For example, the content of compound (1-1) in the dihydroxy compound-containing composition of the present invention is preferably 5% by mass or more and less than 100% by mass, more preferably 10% by mass or more and 98% by mass or less, even more preferably 40% by mass or more and 95% by mass or less, and particularly preferably 50% by mass or more and 90% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition.

[0099] <Dihydroxy compound-containing composition> The dihydroxy compound-containing composition of the present invention is a composition containing compound (1-1) represented by the following general formula (I-1) and compound (2-1) represented by the following general formula (II-1).

[0100] [ka]

[0101] (In the general formula (I-1) above, n is an integer between 4 and 6.)

[0102] [ka]

[0103] (In the above general formula (II-1), m is an integer between 2 and 4. 1 R represents a hydrogen atom, a heteroatom, or a C2-C20 alkyl group which may have a heteroatom or substituent. The two R in formula (II-1) 1 They may be the same or different from each other.

[0104] In the dihydroxy compound-containing composition of the present invention, compound (1-1) and compound (2-1) are treated as synonymous with compound (1-1) and compound (2-1) listed in the description of the polycarbonate diol of the present invention, respectively.

[0105] In the present invention, the upper limit of the content of compound (2-1) in the dihydroxy compound-containing composition is 5.3% by mass or less, preferably 4.0% by mass or less, more preferably 3.2% by mass or less, even more preferably 2.5% by mass or less, still more preferably 1.5% by mass or less, particularly preferably 1.0% by mass or less, and most preferably 0.5% by mass or less, from the viewpoint of facilitating molecular weight control during polycarbonate diol polymerization and ensuring good mechanical properties and chemical resistance of the polyurethane obtained from the polycarbonate diol. On the other hand, the lower limit of the content of compound (2-1) is not particularly limited. From the viewpoint of obtaining a polycarbonate diol with a molecular weight close to the theoretical molecular weight in high yield, it can usually be 0.0001% by mass or more, preferably 0.001% by mass or more, more preferably 0.002% by mass or more, even more preferably 0.003% by mass or more, still more preferably 0.005% by mass or more, particularly preferably 0.007% by mass or more, and most preferably 0.010% by mass or more. The above upper and lower limits can be combined in any way. For example, in the present invention, the content of compound (2-1) contained in the dihydroxy compound-containing composition can be 0.0001% by mass or more and 5.3% by mass or less, preferably 0.001% by mass or more and 4.0% by mass or less, more preferably 0.002% by mass or more and 3.2% by mass or less, even more preferably 0.003% by mass or more and 2.5% by mass or less, still more preferably 0.005% by mass or more and 1.5% by mass or less, particularly preferably 0.007% by mass or more and 1.0% by mass or less, and most preferably 0.010% by mass or more and 0.5% by mass or less.

[0106] The method for adjusting the content ratio of compound (2-1) in the dihydroxy compound-containing composition is not particularly limited. For example, when obtaining compound (1-1) by hydrogenation reaction of a carboxylic acid or carboxylic acid ester, it can be controlled by adjusting the conversion rate of the carboxylic acid or carboxylic acid ester in the hydrogenation reaction step.

[0107] For example, as a method to reduce the content of compound (2-1) in the manufacturing stage of the dihydroxy compound-containing composition, the higher the conversion rate is achieved by increasing the amount of catalyst used in the hydrogenation reaction, extending the residence time, or increasing the hydrogen pressure, the lower the content of compound (2-1) will be in the resulting dihydroxy compound-containing composition. On the other hand, in the manufacturing stage of the dihydroxy compound-containing composition, the lower the conversion rate is, such as by reducing the amount of catalyst used in the hydrogenation reaction, shortening the residence time, or lowering the hydrogen pressure, the higher the content of compound (2-1) becomes.

[0108] In addition, to reduce the content of compound (2-1) to less than 0.0001% by mass during the manufacturing stage of the dihydroxy compound-containing composition, methods such as increasing the amount of catalyst used in the hydrogenation reaction of carboxylic acids or carboxylic acid esters, which are the raw materials for the dihydroxy compound, or increasing the residence time or hydrogen pressure can be used, but these methods place a heavy burden on the manufacturing stage and are not easy to implement.

[0109] If the aforementioned compound (1-1) is 1,4-butanediol (compound (1-1), n=4) and is derived from biomass, then carboxylic acids such as succinic acid, carboxylate salts such as sodium succinate, and carboxylic acid esters such as bis(4-hydroxybutyl)succinic acid and mono(4-hydroxybutyl)succinic acid may be included in the 1,4-butanediol as compound (2-1).

[0110] In the present invention, the lower limit of the content of compound (1-1) in the dihydroxy compound-containing composition is preferably 40.0% by mass or more, more preferably 50.0% by mass or more, even more preferably 60.0% by mass or more, particularly preferably 80.0% by mass or more, and most preferably 90.0% by mass or more, based on 100% of the total mass of the dihydroxy compound-containing composition, from the viewpoint of facilitating molecular weight control during polycarbonate diol polymerization and ensuring good mechanical properties and chemical resistance of the polyurethane obtained from the polycarbonate diol. The proportion of compound (1-1) in the dihydroxy compound-containing composition may be the total amount of all compounds other than compound (2-1) contained in the dihydroxy compound-containing composition. On the other hand, the upper limit of the content of compound (1-1) is not particularly limited. From the viewpoint of obtaining polycarbonate diols having a molecular weight close to the theoretical molecular weight in high yield, it is usually preferable that the content is 99.999% by mass or less, more preferably 99.998% by mass or less, even more preferably 99.995% by mass or less, particularly preferably 99.993% by mass or less, and most preferably 99.990% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition. The above upper and lower limits can be combined arbitrarily. For example, in the present invention, the content ratio of compound (1-1) contained in the dihydroxy compound-containing composition is preferably 40.0% by mass or more and 99.999% by mass or less, and more preferably 50.0% by mass or more and 99.998% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition. A ratio of 60.0% by mass or more and 99.995% by mass or less is more preferable, 80.0% by mass or more and 99.993% by mass or less is particularly preferable, and 90.0% by mass or more and 99.990% by mass or less is most preferable.

[0111] <Method for producing polycarbonate diol> The method for producing the polycarbonate diol of 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. As a preferred embodiment of the method for producing the polycarbonate diol of the present invention, the method for producing the polycarbonate diol of the present invention will be described below.

[0112] The present invention provides a method for producing a polycarbonate diol, which involves polycondensing a dihydroxy compound-containing composition of the present invention, specifically a dihydroxy compound-containing composition containing compound (1-1) represented by the general formula (I-1) and compound (2-1) represented by the general formula (II-1), with a carbonate compound by transesterification in the presence of a catalyst to obtain a polycarbonate diol. Furthermore, in the method for producing polycarbonate diol of the present invention, the content of compound (2-1) in the dihydroxy compound-containing composition is 5.3% by mass or less with respect to 100% of the total mass of the dihydroxy compound-containing composition. Details of the carbonate-based compound and the catalyst will be described later.

[0113] In the method for producing polycarbonate diols of the present invention, by including compound (2-1) in the dihydroxy compound-containing composition, polycarbonate diols having a molecular weight close to the theoretical molecular weight can be obtained in high yield. Furthermore, the obtained polycarbonate diol can be used to obtain a polyurethane with excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed.

[0114] In this invention, the theoretical molecular weight of the polycarbonate diol is the molecular weight calculated from the charging ratio of the dihydroxy compound and the carbonate compound when the dihydroxy compound and the carbonate compound react 100% and all of the dihydroxy compound becomes the constituent unit of the polycarbonate diol. It is calculated using the molecular weight and molar amount of the dihydroxy compound, the molar amount of the carbonate compound, and the following formula.

[0115]

number

[0116] In the method for producing the polycarbonate diol of the present invention, compound (1-1) and compound (2-1) are treated as synonymous with compound (1-1) and compound (2-1) listed in the description of the polycarbonate diol of the present invention, respectively.

[0117] As one embodiment of the method for producing polycarbonate diols according to the present invention, a method using diphenyl carbonate as the carbonate compound is described below. The production of polycarbonate diols can be carried out in two stages. In the first reaction stage, compound (1-1), compound (2-1), and diphenyl carbonate are mixed in a molar ratio of compound (1-1):{carbonate compound + compound (2-1)} = 20:1 to 1:10, preferably 10:1 to 1:2. After adding a catalyst described later, the reaction is carried out at atmospheric pressure at 100 to 250°C, removing the phenol produced by the decomposition of diphenyl carbonate from the reaction system, and obtaining a reaction product containing a low molecular weight polycarbonate diol. In the second reaction stage, the reaction product from the first stage is heated under reduced pressure at 130 to 250°C, removing the phenol and unreacted compound (1-1) and compound (2-1) from the reaction system, and the low molecular weight polycarbonate diol undergoes self-condensation to obtain a polycarbonate diol of a predetermined molecular weight.

[0118] (Carbonate compounds) The carbonate compounds 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, and include, for example, dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; alkylene carbonates such as ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate; and one or more carbonate compounds from among these can be used as raw materials. Among these, from the viewpoint of reactivity with compound (1-1), ease of availability, and ease of setting the conditions for polymerization, it is preferable to use one or more carbonate compounds selected from the group consisting of dimethyl carbonate, diethyl carbonate, diphenyl carbonate, dibutyl carbonate, and ethylene carbonate. 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 a person skilled in the art, optimized as appropriate according to the known art.

[0119] (catalyst) In the method for producing polycarbonate diols of the present invention, when polycondensing compound (1-1) and compound (2-1) with a carbonate-based 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 that case, if an excessive amount of catalyst remains in the resulting polycarbonate diol, the polycarbonate diol may become discolored, or the reaction may be inhibited or excessively accelerated when using the polycarbonate diol to produce polyurethane. The type and amount of catalyst used, as well as the amount of catalyst remaining in the polycarbonate diol, are not particularly limited. As a catalyst, for example, catalysts described in International Publication No. 2015 / 199070 and Japanese Patent Application Publication No. 2022-92121 can be used by those skilled in the art, after being appropriately optimized according to the known art.

[0120] In the method for producing polycarbonate diol of the present invention, it is preferable to use a catalyst containing magnesium atoms or a catalyst containing titanium atoms as the catalyst. Catalysts containing magnesium atoms are not particularly limited and include, for example, magnesium hydroxide, magnesium bicarbonate, magnesium carbonate, magnesium acetate, magnesium stearate, and magnesium phenylphosphate. Catalysts containing titanium atoms are not particularly limited and include, for example, titanium alkoxides such as tetraethyl titanate, tetraisopropyl titanate, and tetra-n-butyl titanate; and titanium halides such as titanium tetrachloride. In particular, in the present invention, by using a catalyst containing titanium atoms, even when producing polycarbonate diols using compound (1-1) and compound (2-1), it is possible to improve the yield of polycarbonate diols, suppress excessive increases in the molecular weight of polycarbonate diols, and reduce the amount of catalyst residue in the polycarbonate diols obtained with a relatively small amount of catalyst used. The amount of catalyst containing titanium atoms used can be 50 ppm or less by mass, 35 ppm or less, or 25 ppm or less, relative to the total mass of the dihydroxy compound-containing composition in terms of titanium atoms. However, if the amount of catalyst is too small, a sufficient catalytic effect cannot be obtained, so it is preferable that the amount of catalyst containing titanium atoms used be 1 ppm or more by mass, particularly 2 ppm or more, and especially 3 ppm or more, relative to the total mass of the dihydroxy compound-containing composition in terms of titanium atoms.

[0121] (Catalyst deactivator) As mentioned above, when a catalyst is used in the polymerization reaction, the resulting polycarbonate diol usually retains some of the catalyst. This residual catalyst can cause an increase in molecular weight or a change in composition when the polycarbonate diol is heated, or it may become impossible to control the polyurethaneization reaction. To suppress the effects of this residual catalyst, the catalyst deactivator, such as a phosphorus-based compound, can be added in an amount approximately equivalent to the transesterification catalyst used, as needed, to deactivate the transesterification catalyst. Furthermore, the transesterification catalyst can be efficiently deactivated by heat treatment or other methods after addition. The type and amount of catalyst deactivator used, as well as the heat treatment conditions, are not particularly limited. As catalyst deactivators, for example, those described in International Publication No. 2015 / 199070 and Japanese Patent Publication No. 2022-92121 can be used by those skilled in the art, after being appropriately optimized according to the known art.

[0122] (purification) The reaction product obtained by the transesterification reaction contains impurities that do not have hydroxyl groups at the polymer ends, phenol, the starting dihydroxy compound, the starting carbonate compound, the by-product light-boiling cyclic carbonate, and the added catalyst, and can therefore be purified to remove these impurities. The aforementioned purification conditions are not particularly limited. For example, the conditions described in Japanese Patent Application Publication No. 2022-92121 can be used by a person skilled in the art, after being appropriately optimized in accordance with the known art.

[0123] (Molecular weight of polycarbonate diol) In the method for producing polycarbonate diols of the present invention, the number-average molecular weight (Mn) of the obtained polycarbonate diol is preferably 250 to 5000, more preferably 300 to 4000, and even more preferably 400 to 3000, for the same reasons as described for the polycarbonate diols of the present invention.

[0124] <Polyurethane> The polyurethane of the present invention is a polyurethane obtained using the polycarbonate diol and isocyanate compound of the present invention as raw materials. Furthermore, the polyurethane of the present invention may use compounds other than the polycarbonate diol and the isocyanate compound as raw materials, as long as they do not impair the effects of the present invention. The polycarbonate diol of the present invention exhibits improved crystallinity due to the inclusion of the aforementioned structural unit (2). As a result, the crystallinity of the polyurethane obtained using the polycarbonate diol of the present invention as a raw material is also improved. Furthermore, it is expected that the interaction between polyurethane chains will be strengthened, resulting in superior mechanical properties and chemical resistance of the polyurethane, and that variations in the mechanical properties will be suppressed.

[0125] The method for producing polyurethane according to the present invention is not particularly limited, and a person skilled in the art can use known polyurethane reaction conditions, such as those described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575, by appropriately optimizing them in accordance with the known art.

[0126] 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, an isocyanate compound described later, and a chain extender described later, which is used as needed, in a temperature range from room temperature to 200°C. 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.

[0127] (Isocyanate compounds) As the isocyanate compound used in the production of polyurethane according to the present invention, known isocyanate compounds used in the production of polyurethane can be used. The isocyanate compounds are not particularly limited, and for example, isocyanate compounds described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575 can be used.

[0128] (Chain extender) As the chain extender used in the production of polyurethane according to the present invention, known chain extenders used in the production of polyurethane can be used. The chain extender is not particularly limited and includes, for example, diols, amines, water, etc., as described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0129] (Chain inhibitors) When producing the polyurethane of the present invention, known chain arresters used in the production of polyurethanes may be used as needed to control the molecular weight of the polyurethane. The chain arresting agent is not particularly limited and includes, for example, compounds having one active hydrogen group, such as monohydric alcohols and secondary amines, as described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0130] (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, and 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.

[0131] (solvent) When producing the polyurethane of the present invention, a solvent may be used as needed. The solvent is not particularly limited, and examples include the solvents described in International Publication No. 2015 / 016261 and International Publication No. 2018 / 088575.

[0132] (Amount / How to use) In the polyurethane manufacturing method of the present invention, the amounts and methods of use of the polyisocyanate, chain extender, chain arrester, catalyst, and 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.

[0133] (Weight-average molecular weight (Mw) of polyurethane) The weight-average molecular weight (Mw) of the polyurethane of the present invention is not particularly limited, but from the viewpoint of achieving a good balance between the mechanical properties and chemical resistance of the obtained polyurethane, it is preferably 50,000 to 500,000, more preferably 100,000 to 300,000, and even more preferably 120,000 to 200,000.

[0134] <Applications of Polyurethane> Because the polyurethane of the present invention has good mechanical properties and chemical resistance, it can be widely used in foams, elastomers, elastic fibers, paints such as water-based polyurethane coatings, fibers, adhesives, flooring materials, sealants, medical materials, artificial leather, synthetic leather, coating agents, active energy ray curable polymer compositions, and the like.

[0135] [Effects and Effects] The polycarbonate diol of the present invention can improve catalytic activity because the dihydroxy compound-containing composition used to produce the polycarbonate diol contains a predetermined amount of the aforementioned compound (2-1), which is a dicarboxylic acid or dicarboxylic acid derivative. This allows for the provision of a polycarbonate diol with a controlled molecular weight in high yield. Although the reason why a predetermined amount of dicarboxylic acid or dicarboxylic acid derivative improves catalytic activity is not clear, it is presumed to be as follows. According to our studies, when polycarbonate diols are polymerized, the molecular weight of the polycarbonate diol increases when unreacted diol is distilled off. When polycarbonate diols are polymerized using a dihydroxy compound-containing composition containing a dicarboxylic acid or dicarboxylic acid derivative, it is presumed that the catalytic activity is improved by the coordination of the dicarboxylic acid or dicarboxylic acid derivative with the catalyst. If the catalytic activity is improved, the reaction between the dihydroxy compound and the carbonate compound is promoted, and the amount of unreacted dihydroxy compound is reduced, so it is presumed that the amount of distilled dihydroxy compound is reduced and the increase in the molecular weight of the polycarbonate diol is suppressed. Furthermore, if there is an excess of dicarboxylic acid or dicarboxylic acid derivative, the remaining dicarboxylic acid or dicarboxylic acid derivative reacts with the polycarbonate diol during the reaction, causing a chain extension reaction to proceed. As a result, it is presumed that the molecular weight of the polycarbonate diol increased.

[0136] Furthermore, the polycarbonate diol composition of the present invention, by containing the structural unit (2), can provide a polyurethane with excellent mechanical properties and chemical resistance, and in which variations in the mechanical properties are suppressed. The reason for this is not clear, but it is presumed to be as follows.

[0137] When polyurethane is produced using the polycarbonate diol of the present invention as a raw material, the structural unit (2) contained in the polycarbonate diol has ester bonds, and the interaction between polyurethane molecules via hydrogen bonding, either between ester bonds or between ester bonds and amide bonds, is improved. It is presumed that, due to the interaction via hydrogen bonding, the bond portion acts as a crosslinking point or a crystalline hard segment structure, thereby improving the mechanical properties of the polyurethane.

[0138] Furthermore, the polyurethane obtained using the polycarbonate diol containing the structural unit (2) is given an appropriate viscosity due to the improved interaction of hydrogen bonds between polyurethane molecules. As a result, the uniformity of the polyurethane composition can be efficiently improved by stirring. In addition, the appropriate improvement in viscosity improves the coating stability and molding stability of the polyurethane or polyurethane-containing composition, thereby improving the dimensional stability of the resulting film-like material, fibrous material, and other molded articles. It is presumed that this suppresses variations in the mechanical properties of the resulting polyurethane product. [Examples]

[0139] 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.

[0140] [Raw materials used] The abbreviations for the raw materials used in the examples and comparative examples are as follows: <Compound (1-1)> 16HD: 1,6-Hexanediol (manufactured by BASF Corporation) 14BD:1,4-Butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) <Carbonate compounds> DPC: Diphenyl carbonate (manufactured by Mitsubishi Chemical Corporation) DEC: Diethyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.) <Catalyst> TBT: Tetrabutyl orthotitanate (manufactured by Tokyo Chemical Industry Co., Ltd.) <Compound (2-1)> Dibutyl succinate (manufactured by Tokyo Chemical Industry Co., Ltd.) Succinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) Disodium succinate (manufactured by Tokyo Chemical Industry Co., Ltd.) <Raw materials for urethane synthesis> MDI: Diphenylmethane diisocyanate (manufactured by Tosoh Corporation) U-830: Dioctyl tin monodecanate (Product name: Neostan U-830, manufactured by Nitto Kasei Co., Ltd.) DMF: N,N-dimethylformamide dehydrated product (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0141] [Evaluation Method] The evaluation methods for each physical property are as follows:

[0142] <14BD / 16HD ratio in polycarbonate diol (percentage of structural unit (1b) content)> The polycarbonate diols obtained in the examples and comparative examples were dissolved in CDCl3 (deuterated chloroform), and measured using a nuclear magnetic resonance spectroscopy analyzer (400 MHz, manufactured by JEOL Ltd., model name: ECZ400S) at a measurement temperature of 30°C and with 64 cumulative measurements. 1 1H-NMR measurements were performed. obtained 1 Based on the 1H-NMR measurement results, the peaks observed at the following signal positions were identified, and the integral values ​​A to E of each peak were obtained. The integral value of the 4H proton of the methylene group in the structure derived from succinic acids in polycarbonate diols present at δ2.60~2.55 ppm = A The integral value of the 4H proton peak of the methylene group adjacent to the carbonate bond in polycarbonate diols present at δ4.35~3.85 ppm = B The integral value of the 2H proton peak of the methylene group adjacent to the hydroxyl group end in polycarbonate diols present at δ3.70~3.50 ppm = C The integral value of the 4H proton peak of the β-methylene group in the structure derived from 1,6-hexanediol and 1,4-butanediol in polycarbonate diols present at δ1.90~1.50 ppm = D The integral value of the 4H proton peak of the γ-methylene group in the structure derived from 1,6-hexanediol in polycarbonate diols present at δ1.45~1.25 ppm = E

[0143] Based on the number of protons in the structural units derived from 1,4-butanediol (hereinafter abbreviated as "14BD") and the structural units derived from 1,6-hexanediol (hereinafter abbreviated as "16HD"), the 14BD / 16HD ratio was calculated using the following formula. (16HD ratio) = E / D (14BD ratio) = 1 - E / D (14BD / 16HD ratio) = (14BD ratio) × 100 / (16HD ratio) × 100

[0144] <Molecular weight M (PCD) of polycarbonate diol> The results obtained from the measurement of the "14BD / 16HD ratio in polycarbonate diol" described above. 1 From the 1H-NMR measurement results, the integral value of the peak originating from the structural units in the polycarbonate diol derived from succinic acids (hereinafter referred to as "structural units derived from succinic acids") is "SA o This was stated. Furthermore, the aforementioned "structural unit derived from succinic acids" can be treated as synonymous with "structural unit (2)" in the present invention. Furthermore, the integral value of the peak originating from the polycarbonate diol terminal structural unit derived from 16HD is "16HD m ", the integral value of the peak derived from the polycarbonate diol terminal structural unit derived from 14BD is "14BD m " he said. Furthermore, the integral value of the peak originating from 16HD-derived structural units in polycarbonate diols other than the polycarbonate diol ends is "16HD o ", the integral value of the peak derived from the structural unit derived from 14BD is "14BD o " he said. Considering the number of protons in each case, the number of integrals per proton was calculated using the following formula. (SA o ) = A ÷ 4 (16HD m ) = E ÷ D × C ÷ 2 (16HD o )=(E÷D×B-16HD m (x2)÷4 (14 BD) m) = (1 - E ÷ D) × C ÷ 2 (14 BD) o ) = {(1-E÷D)×B-14BD} m ×2}÷4

[0145] Next, the molecular weight M(PCD) of the polycarbonate diol was calculated using the following formula.

[0146]

number

[0147] In the above formula, M(SA o ) is the molecular weight (=84) of the structural unit derived from succinic acid in polycarbonate diol, M(16HD o ) is the molecular weight (=144) of the carbonate structural unit derived from 16HD in the polycarbonate diol other than the polycarbonate diol terminal, M(14BD) o ) is the molecular weight (=116) of the carbonate structural unit derived from 14BD in the polycarbonate diol other than the polycarbonate diol terminal, M(16HD m ) is the molecular weight (=262) of the carbonate structural unit derived from 16HD at the polycarbonate diol terminus, M(14BD m ) refers to the molecular weight (=206) of the carbonate structural unit derived from 14BD at the polycarbonate diol terminus.

[0148] <Content ratio of structural units derived from succinic acids in polycarbonate diol (content ratio of structural unit (2))> The results obtained from the measurement of the "14BD / 16HD ratio in polycarbonate diol" described above. 1 The integral values ​​of the peaks originating from each structural unit, obtained from the 1H-NMR measurement results, and the content percentage (in mol%) of structural units derived from succinic acids in the polycarbonate diol were calculated using the following formula.

[0149]

number

[0150] <Hydroxyl value of polycarbonate diol> The hydroxyl value (unit: mgKOH / g) of the polycarbonate diols obtained in the examples and comparative examples was measured using an acetylation reagent in accordance with JIS K1557-1.

[0151] <Weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyurethane> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polyurethanes obtained in the examples and comparative examples were determined using gel permeation chromatography (GPC measurement) according to the following procedure.

[0152] The polyurethane sample was 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 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 determined by using a commercially available monodisperse polystyrene solution as a standard sample, and measuring the number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn) in terms of standard polystyrene.

[0153] <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.

[0154] 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°C and 55% 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 (150 mm in length, 10 mm in width, and 90 ± 20 μm in thickness) were cut out and used as sample pieces for tensile testing.

[0155] (Tensile test) The above-mentioned 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°C (relative humidity 60%). Measurements were taken using four tensile test specimens to determine the 100% modulus, 300% modulus, and the mean and standard deviation of the stress (breaking strength) at the time of fracture. The following formulas were used to calculate the 100% modulus, 300% modulus, and coefficient of variation of fracture strength. Coefficient of variation (%) = (Standard deviation / Mean) × 100

[0156] 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.

[0157] <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.

[0158] 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.

[0159] (Oleic acid resistance test) After measuring the weight of the test specimens for the chemical resistance test using a precision balance, they were placed in a glass petri dish with an inner diameter of 10 cm containing 50 mL of oleic acid as the test solvent and immersed at 80°C for 16 hours. After the test, the test specimens were removed, lightly wiped on both sides with a paper wiper, and then their mass was measured using a precision balance. The rate of mass change (increase rate) was calculated from the change in mass of the test specimens before and after the test. A mass change rate close to 0% indicates good resistance to oleic acid.

[0160] (Ethanol resistance test) After measuring the weight of the test specimens for the chemical resistance test using a precision balance, they were 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 the test, the test specimens were removed, lightly wiped on both sides with a paper wiper, and then their mass was measured using a precision balance. The rate of mass change (increase rate) was calculated from the change in mass of the test specimens before and after the test. A mass change rate close to 0% indicates good ethanol resistance.

[0161] <Hydrolysis resistance of polyurethane> As an indicator of polyurethane's hydrolysis resistance, the rate at which tensile strength is retained when polyurethane is stored in a constant temperature and humidity environment was measured using the following method.

[0162] 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°C and 55% 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 (150 mm in length, 10 mm in width, and 90 ± 20 μm in thickness) were cut out and used as sample pieces for the hydrolysis resistance test.

[0163] The hydrolysis-resistant specimens described above were stored for two 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 chamber and left to stand for at least 48 hours in an environment of 23°C and 55% RH.

[0164] Following the hydrolysis resistance test described above, the 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°C (relative humidity 60%). Measurements were taken using three tensile test specimens, and the average value of the stress (breaking strength) at the time of fracture was measured. The following formula was used to calculate the fracture strength retention rate.

[0165] Breaking strength retention rate (%) = (Average breaking strength after hydrolysis resistance test / Average breaking strength before hydrolysis resistance test) × 100

[0166] The closer the retention rate of tensile strength before and after the hydrolysis resistance test is to 100%, the better the hydrolysis resistance of the polyurethane.

[0167] <Evaluation of polycarbonate diols (1)> To investigate the effect of compound (2-1) in the dihydroxy compound-containing composition on the molecular weight and yield of the obtained polycarbonate diol, the following experiment was conducted.

[0168] [Comparative Example 1] In a 1 L glass separable flask equipped with a stirrer, distillate trap, and pressure regulator, 16HD and 14BD were added as dihydroxy compounds, DPC as a carbonate compound, and TBT as a transesterification catalyst in the proportions shown in Table 1. After replacing the atmosphere inside the flask with nitrogen, the contents were heated and stirred until the temperature reached 160°C, and the contents were heated and dissolved. At this time, the pressure inside the flask was 101 kPa. Subsequently, the pressure inside the flask was gradually reduced from 101 kPa to 24 kPa over 2 minutes, and the reaction was continued for 90 minutes while removing the generated phenol from 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, and the reaction continued. After that, the temperature of the contents was raised to 170°C, and the reaction was continued for another 90 minutes while removing the phenol and unreacted dihydroxy compounds from the reaction system. Subsequently, the contents were allowed to cool to room temperature to obtain 144 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was subjected to the evaluation described above, and the evaluation results are shown in Table 1.

[0169] [Example 1] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 7 mg of dibutyl succinate was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 148 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0170] [Example 2] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 13 mg of dibutyl succinate was added to the raw materials. After the reaction, the contents were allowed to cool to room temperature to obtain 149 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0171] [Example 3] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 66 mg of dibutyl succinate was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 149 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0172] [Example 4] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 1317 mg of dibutyl succinate was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 148 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0173] [Example 5] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 33 mg of succinic acid was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 149 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0174] [Example 6] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 71 mg of disodium succinate was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 147 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0175] [Example 7] In Comparative Example 1, the reaction was carried out under the same conditions as in Comparative Example 1, except that 3970 mg of dibutyl succinate was added as a raw material. After the reaction, the contents were allowed to cool to room temperature to obtain 151 g of polycarbonate diol. The obtained polycarbonate diol (PCD) was evaluated as described above, and the evaluation results are shown in Table 1.

[0176] [Comparative Example 2] In a 1 L glass separable flask equipped with a stirrer, distillate trap, packed column, and pressure regulator, 16HD and 14BD were added as dihydroxy compounds, DEC as a carbonate compound, and TBT as a transesterification catalyst in the proportions shown in Table 1. After replacing the atmosphere inside the flask with nitrogen, the contents were heated and stirred until the temperature reached 130°C, thereby dissolving the contents. At this time, the pressure inside the flask was 101 kPa. Subsequently, the pressure inside the flask was reduced from 101 kPa to 93 kPa, and the temperature of the flask contents was adjusted to 130-145°C so that the top temperature of the distillate piping was 75°C, while the reaction was carried out for 240 minutes, removing the generated ethanol from the reaction system. Next, the temperature of the flask contents was raised to 150°C, and the pressure inside the flask was gradually reduced from 93 kPa to 1.3 kPa over 210 minutes. Subsequently, the packed column of the distillation piping was removed, the temperature of the contents was raised to 165°C, and the pressure inside the flask was reduced to 0.7 kPa. Then, the temperature of the contents was gradually raised from 165°C to 175°C, while the ethanol and unreacted diethyl carbonate and dihydroxy compounds were removed from the reaction system, and the reaction was carried out at 0.7 kPa for 360 minutes. After that, the contents were allowed to cool to room temperature to obtain 134 g of polycarbonate diol. The obtained polycarbonate diol was evaluated as described above, and the evaluation results are shown in Table 1.

[0177] [Example 8] In Comparative Example 2, the reaction was carried out under the same conditions as in Comparative Example 2, except that 67 mg of dibutyl succinate was added as a raw material. After the reaction, the temperature of the content was allowed to cool to room temperature to obtain 140 g of polycarbonate diol. The obtained polycarbonate diol was evaluated as described above, and the evaluation results are shown in Table 1.

[0178] Further, from the results of Comparative Example 1 and Examples 1 to 7, the relationship between the content ratio of compound (2-1) in the dihydroxy compound-containing composition and the molecular weight M(PCD) of the polycarbonate diol is shown in Figure 1, the relationship between the content ratio of compound (2-1) in the dihydroxy compound-containing composition and the yield of the polycarbonate diol is shown in Figure 2, and the relationship between the content ratio of structural unit (2) in the polycarbonate diol and the molecular weight M(PCD) of the polycarbonate diol is shown in Figure 3, respectively, and graphed.

[0179] [Table 1]

[0180] From Table 1, the following can be understood. In Examples 1 to 7, polycarbonate diol having a molecular weight close to the theoretical molecular weight was obtained in a high yield. On the other hand, in Comparative Example 1, since the dihydroxy compound-containing composition did not contain compound (2-1), compared with the examples, the molecular weight of the obtained polycarbonate diol was higher than the theoretical molecular weight, and the yield of the polycarbonate diol was low. Also, from Example 8 and Comparative Example 2, for the polycarbonate diol synthesized with not only DPC but also DEC, since the dihydroxy compound-containing composition contained compound (2-1), in Example 8, compared with Comparative Example 2, the molecular weight of the obtained polycarbonate diol was close to the theoretical molecular weight, and the yield of the polycarbonate diol was high. Furthermore, as shown in Figure 1, a comparison between the examples and comparative examples confirms that the inclusion of compound (2-1) in the dihydroxy compound-containing composition brings the molecular weight (M(PCD)) of the polycarbonate diol closer to the theoretical molecular weight. In particular, when the content of compound (2-1) in the dihydroxy compound-containing composition is in the range of 0.005% by mass to 1.500% by mass, the molecular weight (M(PCD)) of the polycarbonate diol is close to the theoretical molecular weight. Figure 2 shows that, from a comparison of the examples and comparative examples, the inclusion of compound (2-1) in the dihydroxy compound-containing composition improved the yield of polycarbonate diol. Figure 3 confirms that the molecular weight (M(PCD)) of the obtained polycarbonate diol approaches the theoretical molecular weight when structural unit (2) is included. In particular, it can be seen that the molecular weight (M(PCD)) of the polycarbonate diol is close to the theoretical molecular weight when the content of structural unit (2) in the polycarbonate diol is in the range of 0.001 mol% to 0.900 mol%.

[0181] <Evaluation of polycarbonate diols (2)> To investigate the effect of compound (2-1) in the dihydroxy compound-containing composition on the molecular weight of the polycarbonate diol obtained after thin-film distillation, the following experiment was conducted. By examining the molecular weight of polycarbonate diols after thin-film distillation, it is possible to understand the effect of thin-film distillation on the molecular weight of PCD (polycarbonate diols) due to the removal of low molecular weight components such as monomers. Since polycarbonate diols with a high proportion of low molecular weight components appear to have a molecular weight close to the theoretical molecular weight, the molecular weight of PCD was confirmed under conditions where the low molecular weight components were removed.

[0182] [Comparative Example 3-1] In a 1 L glass separable flask equipped with a stirrer, distillate trap, and pressure regulator, 16HD and 14BD were added as dihydroxy compounds, DPC as a carbonate compound, and TBT as a transesterification catalyst in the amounts shown in Table 2. After replacing the atmosphere inside the flask with nitrogen, the contents were heated and stirred until the temperature reached 160°C, and the contents were heated and dissolved. At this time, the pressure inside the flask was 101 kPa. Subsequently, the pressure inside the flask was gradually reduced from 101 kPa to 24 kPa over 2 minutes, and the reaction was continued for 90 minutes while removing the generated phenol from 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, and the reaction continued. After that, the temperature of the contents was raised to 170°C, and the reaction was continued for another 90 minutes while removing the phenol and unreacted dihydroxy compounds from the reaction system. Subsequently, the contents were allowed to cool to 120°C, and the pressure was increased to atmospheric pressure to obtain polycarbonate diol. The obtained polycarbonate diol was mixed with 0.85% by mass aqueous phosphoric acid solution in the amount shown in Table 2 to deactivate the TBT catalyst, and stirred at 120°C for 1 hour. The mixture was then transferred to a thin-film distillation apparatus at a flow rate of 20 g / min for thin-film distillation (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 Shibata Scientific Co., Ltd. MS-300 special molecular distillation apparatus with an internal capacitor and jacket was used. The obtained polycarbonate diol was designated "PCD1". The evaluation results of PCD1 are shown in Table 2.

[0183] [Example 9-1] In Comparative Example 3-1, the reaction was carried out under the same conditions as in Comparative Example 3-1, except that 23 mg of dibutyl succinate was added as a raw material. The resulting polycarbonate diol was designated "PCD2". The evaluation results of PCD2 are shown in Table 2.

[0184] [Example 10-1] In Comparative Example 3-1, the reaction was carried out under the same conditions as in Comparative Example 3-1, except that 115 mg of dibutyl succinate was added as a raw material. The resulting polycarbonate diol was designated "PCD3". The evaluation results of PCD3 are shown in Table 2.

[0185] [Example 11-1] In Comparative Example 3-1, the reaction was carried out under the same conditions as in Comparative Example 3-1, except that 2298 mg of dibutyl succinate was added as a raw material. The resulting polycarbonate diol was designated "PCD4". The evaluation results of PCD4 are shown in Table 2.

[0186] [Example 12-1] In Comparative Example 3-1, the reaction was carried out under the same conditions as in Comparative Example 3-1, except that 6915 mg of dibutyl succinate was added as a raw material. The resulting polycarbonate diol was designated "PCD5". The evaluation results of PCD5 are shown in Table 2.

[0187] [Table 2]

[0188] Table 2 shows the following: In Examples 9-1 to 12-1, polycarbonate diols with molecular weights close to the theoretical molecular weight were obtained in high yield. On the other hand, in Comparative Example 3-1, since the dihydroxy compound-containing composition did not contain compound (2-1), the molecular weight of the resulting polycarbonate diol was larger than the theoretical molecular weight compared to the example. Even in polycarbonate diols after low molecular weight components have been removed by thin-film distillation, it was confirmed that the molecular weight of the obtained polycarbonate diol was close to the theoretical molecular weight when the dihydroxy compound-containing composition included compound (2-1).

[0189] <Evaluation of Polyurethane> To investigate the influence of structural units (2) in polycarbonate diols on the performance of the resulting polyurethane, the following experiment was conducted.

[0190] [Comparative Example 3-2] Using PCD1 obtained in Comparative Example 3-1, polyurethane was synthesized and evaluated according to the following procedure. In a separable flask equipped with a thermocouple and condenser, 77.8 g of PCD1 preheated to 80°C, 4.72 g of 14BD as a chain extender, 0.02 g of U-830 as a catalyst, and 239 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 water content of the reaction solution in the flask was measured, and the amount of MDI consumed by the water was calculated. The amount of samples taken was also recorded, and the amount of each raw material added was corrected. To the reaction solution, MDI, an isocyanate compound with a molar ratio of NCO / OH equivalent to 0.900 (including water content correction), was added in solid form using a funnel, and the mixture was stirred at a stirring speed of 60 rpm until homogeneous. In this specification, the "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. 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.

[0191] One hour after adding MDI, the molecular weight of the polyurethane in the reaction solution was measured to confirm whether the target molecular weight had been reached. If the target was not 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 another 30 minutes or more 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, a polyurethane solution containing polyurethane with Mw = 147163 was obtained. The evaluation results for the obtained polyurethane are shown in Table 3.

[0192] [Examples 9-2 to 12-2] In Comparative Example 3-2, instead of PCD1, PCD2, PCD3, PCD4, and PCD5 obtained in each of Examples 9-1 to 12-1 were used, and the polymerization of polyurethane was carried out under the same conditions and by the same method as in Comparative Example 3-2, except that the charged amounts of each raw material were changed to the charged amounts shown in Table 3, respectively, to obtain a polyurethane solution. The evaluation results of the obtained polyurethane are shown in Table 3.

[0193]

Table 3

[0194] Regarding the evaluation results of the mechanical property tests in Table 3, the results of the breaking strength, 100% modulus, and 300% modulus are shown in Figures 4 to 6, respectively. Furthermore, regarding the evaluation results of the coefficient of variation in the mechanical property tests in Table 3, the coefficients of variation of the breaking strength, 100% modulus, and 300% modulus are shown in Figures 7 to 9, respectively. Also, regarding the evaluation results of the chemical resistance tests in Table 3, the result of oleic acid resistance is shown in Figure 10, and the test result of ethanol resistance is shown in Figure 11.

[0195] It can be seen from Table 3 and Figures 4 to (11) as follows. The polyurethanes obtained in Examples 9-2 to 12-2 were superior in the values of the breaking strength, 100% modulus, and 300% modulus compared to the polyurethane obtained in Comparative Example 3-2. Furthermore, the mechanical properties were particularly excellent when the content ratio of the structural unit (2) in PCD was around 0.001 to 0.35 mol%. Also, the polyurethanes obtained in Examples 9-2 to 12-2 had a smaller coefficient of variation (variation) in any of the mechanical properties compared to the polyurethane obtained in Comparative Example 3-2. Furthermore, the coefficient of variation (variation) was particularly small when the content ratio of the structural unit (2) in PCD was around 0.001 to 0.35 mol%. Furthermore, the polyurethanes obtained in Examples 9-2 to 12-2 exhibited superior chemical resistance compared to the polyurethane obtained in Comparative Example 3-2. In addition, the chemical resistance was particularly excellent when the content of structural unit (2) in the PCD was around 0.001 to 0.02 mol%.

[0196] On the other hand, the polyurethane obtained in Comparative Example 3-2 had inferior mechanical properties and chemical resistance, and a large coefficient of variation (variation) in mechanical properties, because the polycarbonate diol used as a raw material did not contain the structural units derived from succinic acid in the polycarbonate diol structure.

[0197] From the above, it can be seen that the polycarbonate diol of the present invention makes it possible to obtain polyurethane with excellent mechanical properties and chemical resistance, and in which variations in said mechanical properties are suppressed.

[0198] Furthermore, regarding the evaluation results of the hydrolysis resistance test in Table 3, the results of the tensile strength retention rate are shown in Figure 12. From Table 3 and Figure 12, the polyurethanes obtained in Examples 9-2 to 11-2 showed superior hydrolysis resistance compared to the polyurethane obtained in Comparative Example 3-2. In other words, the polycarbonate diol of the present invention not only provides polyurethane with excellent mechanical properties and chemical resistance, and suppresses variations in said mechanical properties, but also, by setting the content ratio of structural units derived from succinic acid within a specific range, the hydrolysis resistance of the obtained polyurethane can be further improved.

Claims

1. A polycarbonate diol comprising a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II), A polycarbonate diol in which the content of the structural unit (2) in the polycarbonate diol is 0.0005 mol% or more and 4.3 mol% or less, relative to 100 mol% of the total structural units of the polycarbonate diol. 【Chemistry 1】 (In the general formula (I) above, n is an integer between 4 and 6.) 【Chemistry 2】 (In the general formula (II) above, m is an integer between 2 and 4.)

2. The polycarbonate diol according to claim 1, wherein the content of the structural unit (2) in the polycarbonate diol is 3.0 mol% or less with respect to 100 mol% of the total structural units of the polycarbonate diol.

3. The polycarbonate diol according to claim 1, wherein the structural unit (1) represented by the general formula (I) includes a structural unit derived from a biomass-derived dihydroxy compound.

4. The polycarbonate diol according to claim 1, wherein the structural unit (1) represented by the general formula (I) is derived from a biomass-derived dihydroxy compound alone, or from a mixture containing a biomass-derived dihydroxy compound and a fossil fuel-derived dihydroxy compound.

5. The polycarbonate diol according to claim 3, wherein the biomass-derived dihydroxy compound is a compound derived from non-edible biomass and / or non-fossil fuels.

6. 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.

7. A method for producing a polycarbonate diol, comprising transesterifying a dihydroxy compound-containing composition containing a compound (1-1) represented by the following general formula (I-1) and a compound (2-1) represented by the following general formula (II-1) with a carbonate compound in the presence of a catalyst to obtain a polycarbonate diol, A method for producing a polycarbonate diol, wherein the content of compound (2-1) in the dihydroxy compound-containing composition is 0.003% by mass or more and 5.3% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition. 【Transformation 3】 (In the general formula (I-1) above, n is an integer between 4 and 6.) 【Chemistry 4】 (In the above general formula (II-1), m is an integer between 2 and 4. １ R represents a hydrogen atom, a heteroatom, or a C2-C20 alkyl group which may have a heteroatom or substituent. The two R in formula (II-1) １ They may be the same or different from each other.

8. In the above compound (2-1), R １ The method for producing a polycarbonate diol according to claim 7, wherein at least one of the members is a C2 to C20 alkyl group which may have a heteroatom or substituent.

9. The method for producing a polycarbonate diol according to claim 7, wherein the catalyst is a catalyst containing titanium atoms, and the amount of the catalyst is 50 ppm by mass or less in terms of titanium atoms relative to the total mass of the dihydroxy compound-containing composition.

10. A polyurethane made from a polycarbonate diol according to any one of claims 1 to 6 and an isocyanate compound.

11. The polyurethane according to claim 10, 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.

12. A dihydroxy compound-containing composition comprising compound (1-1) represented by the following general formula (I-1) and compound (2-1) represented by the following general formula (II-1), A dihydroxy compound-containing composition in which the content of the compound (2-1) in the dihydroxy compound-containing composition is 0.003% by mass or more and 5.3% by mass or less, based on 100% of the total mass of the dihydroxy compound-containing composition. 【Transformation 5】 (In the general formula (I-1) above, n is an integer between 4 and 6.) 【Transformation 6】 (In the above general formula (II-1), m is an integer between 2 and 4. １ R represents a hydrogen atom, a heteroatom, or a C2-C20 alkyl group which may have a heteroatom or substituent. The two R in formula (II-1) １ They may be the same or different from each other.

13. The dihydroxy compound-containing composition according to claim 12, wherein the content of compound (1-1) in the dihydroxy compound-containing composition is 40.0% by mass or more based on 100% of the total mass of the dihydroxy compound-containing composition.

14. In the above compound (2-1), R １ The dihydroxy compound-containing composition according to claim 12, wherein at least one of the members is a C2-C20 alkyl group which may have a heteroatom or substituent.

15. The dihydroxy compound-containing composition according to claim 12, wherein the compound (1-1) comprises 1,4-butanediol.

16. In the above compound (2-1), R １ The dihydroxy compound-containing composition according to claim 14, wherein at least one of them is a C4 alkyl group which may have a heteroatom or substituent.

17. The dihydroxy compound-containing composition according to claim 12, wherein the compound (I-1) contains a biomass-derived diol.

18. A dihydroxy compound-containing composition according to claim 12, used in the process of producing a polycarbonate diol.

19. A polycarbonate diol made from a dihydroxy compound-containing composition according to any one of claims 12 to 18 and a carbonate compound as raw materials.

20. A polyurethane made from a polycarbonate diol and an isocyanate compound as raw materials, as described in claim 19.

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