Polycarbonate diol, urethane resin and coating agent

Abstract

To provide a polycarbonate diol capable of combining moldability and viscosity stability at a temperature of 25°C.SOLUTION: A polycarbonate diol contains a repeating unit (A) of a carbonate structure and comprises terminal hydroxyl groups, wherein 90 to 100 mol% of the repeating unit (A) is constituted by a repeating unit (B) of a carbonate structure containing a 2-methyloctane-1,8-diyl group and / or a repeating unit (C) of a carbonate structure containing a 1,9-nonanediyl group, wherein the polycarbonate diol includes a polycarbonate diol (D) represented by the following formula (D), and wherein the number average molecular weight of the polycarbonate diol, the number of repeating units, and the viscosity characteristics take specific values. (In formula (D), R1 represents -(CH2)9- or -CH2CH(CH3)CH2CH2CH2CH2CH2CH2-.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a polycarbonate diol, a urethane resin, and a coating agent. [Background technology]

[0002] Polycarbonate polyols are useful as raw materials for producing urethane resins (also called polyurethane resins) by reacting them with polyisocyanate compounds, and are also useful as raw materials for adhesives, paints, and the like. As a polycarbonate diol, which is a type of polycarbonate polyol, a polycarbonate diol using 1,6-hexanediol alone as the diol component is generally used. However, such a polycarbonate diol is crystalline and therefore solid at room temperature, which makes it difficult to handle.

[0003] In order to solve these problems, it has been proposed to produce a polycarbonate diol using two or more types of diols. For example, Japanese Patent Laid-Open Publication No. 63-182337 (Patent Document 1) discloses a polycarbonate diol synthesized using 1,9-nonanediol and 2-methyl-1,8-octanediol as diol components. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 63-182337 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when polycarbonate diols are used in production equipment involving flow, there is a problem that it is difficult to achieve both moldability and viscosity stability. Even with the polycarbonate diols described in Patent Document 1, there is still room for improvement in achieving both moldability and viscosity stability. Therefore, an object of one aspect of the present disclosure is to provide a polycarbonate diol that has both moldability and viscosity stability at 25° C. Another object of the present disclosure is to provide a urethane resin and a coating agent obtained from the polycarbonate diol. [Means for solving the problem]

[0006] The present disclosure provides the following aspects.

[0007] [1] A polycarbonate diol containing a repeating unit (A) represented by the following formula (A) and having a terminal hydroxyl group: 90 to 100 mol % of the repeating units (A) are repeating units (B) represented by the following formula (B) and / or repeating units (C) represented by the following formula (C), The polycarbonate diol contains a polycarbonate diol (D) represented by the following formula (D): The number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is 300 to 2800 g / mol, In the LC spectrum measured for the polycarbonate diol, when the number of repeating units of the polycarbonate diol (D) corresponding to the peak of the molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is X0, there are 2 to 7 consecutive peaks, including the peak having the number of repeating units of X0, whose peak area ratios are 0.90 to 1.10 relative to the area of ​​the peak having the number of repeating units of X0, Shear rate 1 s -1 , viscosity η1 at temperature 25℃, shear rate 1000s -1 , viscosity η at 25°C 1000 The ratio of [η1000 / η1] is 0.40 to 0.80.

[0008] [ka]

[0009] (In formula (A), R represents a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

[0010] [ka]

[0011] [ka]

[0012] [ka]

[0013] (In formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, The * at both ends in the formula represents R 1 The bond sites with the two oxygen atoms bonded to both ends of q is an integer of 1 or more, and there are multiple R 1 may be the same or different.)

[0014] [2] The polycarbonate diol according to [1], wherein the amount of the repeating unit (B) is 20 to 100 mol % based on the total amount of the repeating unit (A).

[0015] [3] The polycarbonate diol according to [1] or [2], wherein the amount of the repeating unit (B) is 20 to 100 mol % based on the total amount of the repeating unit (B) and the repeating unit (C).

[0016] [4] The polycarbonate diol according to any one of [1] to [3], wherein all of the repeating units (A) are the repeating units (B) and / or the repeating units (C).

[0017] [5] The polycarbonate diol according to any one of [1] to [4], wherein 90 to 100 mol % of the polycarbonate diol is the polycarbonate diol (D).

[0018] [6] A urethane resin comprising a reaction product of the polycarbonate diol according to any one of [1] to [5] and an isocyanate.

[0019] [7] A coating agent comprising the urethane resin according to [6]. [Effects of the Invention]

[0020] According to one aspect of the present disclosure, it is possible to provide a polycarbonate diol that has both moldability and viscosity stability at 25° C. Furthermore, according to another aspect of the present disclosure, it is possible to provide a urethane resin and a coating agent obtained from the polycarbonate diol. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing the LC spectrum of the polycarbonate diol obtained in Example 1. [Figure 2] 1 is a graph showing the relationship between shear rate and viscosity of a polymer. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present disclosure will be described in detail. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. The minimum or maximum value of a numerical range indicated using "to" can be arbitrarily combined with the maximum or minimum value of another numerical range indicated using "to". Furthermore, individually stated upper and lower limit values ​​can also be arbitrarily combined.

[0023] <Polycarbonate diol> A polycarbonate diol according to one embodiment of the present disclosure is a polycarbonate diol containing a repeating unit (A) represented by the following formula (A) and having a terminal hydroxyl group: 90 to 100 mol % of the repeating units (A) are repeating units (B) represented by the following formula (B) and / or repeating units (C) represented by the following formula (C), The polycarbonate diol contains a polycarbonate diol (D) represented by the following formula (D): The number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is 300 to 2800, In the LC spectrum measured for the polycarbonate diol, when the number of repeating units of the polycarbonate diol (D) corresponding to the peak of the molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is X0, there are 2 to 7 consecutive peaks, including the peak having the number of repeating units of X0, whose peak area ratios are 0.90 to 1.10 relative to the area of ​​the peak having the number of repeating units of X0, Shear rate 1 s -1 , viscosity η1 at temperature 25℃, shear rate 1000s -1 , viscosity η at 25°C 1000 The ratio of [η 1000 / η1] is 0.40 to 0.80.

[0024] [ka]

[0025] (In formula (A), R represents a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] (In formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, The * at both ends in the formula represents R 1 The bond sites with the two oxygen atoms bonded to both ends of q is an integer of 1 or more, and there are multiple R 1 may be the same or different.)

[0030] In the present disclosure, "the peak of molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol" means, among the peaks of molecular weights calculated based on the number of repeating units of the polycarbonate diol (D), the peak of molecular weight having the smallest absolute value of difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol. When there are two peaks of molecular weights having the smallest absolute value of difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, the peak of the smallest molecular weight is used.

[0031] The polycarbonate diol according to one embodiment of the present disclosure is a polycarbonate diol containing the repeating unit (A) and having a terminal hydroxyl group. In the formula (A), R is a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms. The divalent aliphatic hydrocarbon group may be linear or branched. Furthermore, multiple R groups present in the polycarbonate diol may be the same or different.

[0032] The divalent linear aliphatic hydrocarbon group for R has 2 to 15 carbon atoms, preferably 3 to 12 carbon atoms, more preferably 4 to 10 carbon atoms, and particularly preferably 6 to 9 carbon atoms.

[0033] Specific examples of the divalent linear aliphatic hydrocarbon group having 2 to 15 carbon atoms in R are not particularly limited, and include, for example, an ethylene group, a propylene group (trimethylene group), a butylene group (tetramethylene group), a pentylene group (pentamethylene group), a hexylene group (hexamethylene group), a heptylene group (heptamethylene group), an octylene group (octamethylene group), a nonylene group (nonamethylene group), etc. Among these, from the viewpoint of versatility, a propylene group, a butylene group, a pentylene group, a hexylene group, or a nonylene group is preferred.

[0034] The divalent branched aliphatic hydrocarbon group for R has 3 to 15 carbon atoms, preferably 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and particularly preferably 6 to 9 carbon atoms.

[0035] Specific examples of the divalent branched aliphatic hydrocarbon group for R include, but are not limited to, an isopropylene group, an isobutylene group, a tert-butylene group, an isopentylene group, a 2,2-dimethylpropylene group, an isohexylene group, a 3-methylpentylene group, an isoheptylene group, an isooctylene group, a 2-methyloctylene group, etc. Among these, from the viewpoint of versatility, an isopentylene group, an isohexylene group, a 3-methylpentylene group, or a 2-methyloctylene group is preferred.

[0036] The divalent alicyclic hydrocarbon group for R has 3 to 15 carbon atoms, preferably 4 to 12 carbon atoms, and more preferably 6 to 9 carbon atoms.

[0037] Specific examples of the divalent alicyclic hydrocarbon group for R include, but are not limited to, a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, etc. Among these, from the viewpoint of versatility, a cyclopentylene group or a cyclohexylene group is preferred.

[0038] Among these divalent aliphatic or alicyclic hydrocarbons having 2 to 15 carbon atoms, R is preferably a divalent linear aliphatic hydrocarbon group having 3 to 9 carbon atoms or a divalent branched aliphatic hydrocarbon group having 3 to 9 carbon atoms, more preferably a divalent linear aliphatic hydrocarbon group having 6 to 9 carbon atoms or a divalent branched aliphatic hydrocarbon group having 6 to 9 carbon atoms, and even more preferably a nonylene group or a 2-methyloctylene group.

[0039] It is preferable that 90 to 100 mol % of the repeating unit (A) is the repeating unit (B) and / or the repeating unit (C) (preferably, the repeating unit (B) and the repeating unit (C)), and 95 to 100 mol % of the repeating unit (A) is the repeating unit (B) and / or the repeating unit (C) (more preferably, the repeating unit (B) and the repeating unit (C)), and more preferably, all of the repeating unit (A) is the repeating unit (B) and / or the repeating unit (C) (even more preferably, the repeating unit (B) and the repeating unit (C)). When the proportion of the repeating unit (B) and / or the repeating unit (C) is within the above range, a polycarbonate diol that has good handleability and that has both moldability and viscosity stability at 25°C tends to be easily obtained.

[0040] The amount of the repeating unit (B) is preferably 20 to 100 mol%, more preferably 30 to 99 mol%, further preferably 40 to 98 mol%, particularly preferably 50 to 95 mol%, and most preferably 65 to 90 mol%, based on the total amount of the repeating unit (A). When the ratio is within the above range, the obtained polycarbonate diol tends to be liquid at 25°C and has excellent handleability.

[0041] Furthermore, the amount of the repeating unit (B) is preferably 20 to 100 mol%, more preferably 30 to 99 mol%, even more preferably 40 to 98 mol%, particularly preferably 50 to 95 mol%, and most preferably 65 to 90 mol%, based on the total amount of the repeating unit (B) and the repeating unit (C). When the ratio is within the above range, the obtained polycarbonate diol tends to be liquid at 25°C and has excellent handleability.

[0042] The polycarbonate diol of one embodiment of the present disclosure includes the polycarbonate diol (D) represented by the above formula (D).

[0043] In the formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, and * at both ends in the formula represents R 1 represents a bonding site with two oxygen atoms bonded to both ends of R, and q represents an integer of 1 or more, preferably 1 to 23, more preferably 2 to 16, and even more preferably 3 to 11. 1 may be the same or different from each other.

[0044] Among such polycarbonate diols (D), R 1The polycarbonate diol (D) containing a 1,9-nonylene group (1,9-nonanediyl group) and a 2-methyl-1,8-octylene group (2-methyloctane-1,8-diyl group) as alkanediyl groups, i.e., containing two or more types of alkanediyl groups, tends to be liquid at 25°C and tends to have both moldability and viscosity stability at 25°C.

[0045] In addition, the polycarbonate diol (D) containing two or more kinds of alkanediyl groups is liquid at 25°C, and from the viewpoint of easily achieving both moldability and viscosity stability at 25°C, the polycarbonate diol (D) is preferably added with R 1 The ratio of the number of moles of 2-methyl-1,8-octylene groups to the total number of moles of alkanediyl groups contained as (the total number of moles of 1,9-nonylene groups and 2-methyl-1,8-octylene groups) is preferably 0.20 to 1.00, more preferably 0.30 to 0.99, even more preferably 0.40 to 0.98, still more preferably 0.50 to 0.95, particularly preferably 0.60 to 0.93, and most preferably 0.65 to 0.90.

[0046] The polycarbonate diol according to one embodiment of the present disclosure is liquid at 25°C, and from the viewpoint of easily achieving both moldability and viscosity stability at 25°C, it is preferred that 90 to 100 mol% of the polycarbonate diol (D) is the polycarbonate diol (D), more preferably 95 to 100 mol% of the polycarbonate diol (D), and particularly preferably that all of the polycarbonate diol (D) is the polycarbonate diol (D).

[0047] The hydroxyl value of the polycarbonate diol according to one embodiment of the present disclosure is preferably 30 to 350 mgKOH / g, more preferably 40 to 215 mgKOH / g, even more preferably 43 to 150 mgKOH / g, even more preferably 45 to 120 mgKOH / g, particularly preferably 50 to 105 mgKOH / g, and most preferably 55 to 100 mgKOH / g. The hydroxyl value of the polycarbonate diol may be 60 mgKOH / g or more, 65 mgKOH / g or more, 70 mgKOH / g or more, 75 mgKOH / g or more, 80 mgKOH / g or more, or 85 mgKOH / g or more, or 90 mgKOH / g or less, 85 mgKOH / g or less, 80 mgKOH / g or less, 75 mgKOH / g or less, 70 mgKOH / g or less, 65 mgKOH / g or less, or 60 mgKOH / g or less. The hydroxyl value of the polycarbonate diol means the number of milligrams (mg) of potassium hydroxide equivalent to the hydroxyl group in 1 g of the polycarbonate diol, and can be measured in accordance with JIS K1557-1.

[0048] Furthermore, the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol of one embodiment of the present disclosure is preferably 300 to 2800 g / mol, more preferably 500 to 2600 g / mol, even more preferably 800 to 2500 g / mol, particularly preferably 900 to 2300 g / mol, and most preferably 1000 to 2000 g / mol. The number average molecular weight calculated from the hydroxyl value of the polycarbonate diol may be 1200 g / mol or more, 1300 g / mol or more, 1450 g / mol or more, 1600 g / mol or more, 1700 g / mol or more, 1800 g / mol or more, or 1900 g / mol or more, or may be 1900 g / mol or less, 1800 g / mol or less, 1700 g / mol or less, 1600 g / mol or less, 1450 g / mol or less, or 1300 g / mol or less.

[0049] In the polycarbonate diol of one embodiment of the present disclosure, when the number of repeating units of the polycarbonate diol (D) corresponding to the peak of the molecular weight closest to the number average molecular weight (absolute molecular weight) calculated from the hydroxyl value of the polycarbonate diol is X0 in a measured LC spectrum, the polycarbonate diol has 2 to 7 consecutive peaks, preferably 3 to 6 consecutive peaks, and particularly preferably 4 to 5 consecutive peaks, in which the peak area ratio [S(X) / S(X0), S(X) is the area value of the peak where the number of repeating units of the polycarbonate diol (D) is X] is 0.90 to 1.10, including the peak where the number of repeating units is X0. When the number of consecutive peaks having the peak area ratio [S(X) / S(X0)] of 0.90 to 1.10, including the peak where the number of repeating units is X0, is equal to or greater than the lower limit, a polycarbonate diol with excellent moldability at 25° C. tends to be easily obtained. When the number of consecutive peaks having the peak area ratio [S(X) / S(X0)] of 0.90 to 1.10, including the peak where the number of repeating units is X0, is equal to or less than the upper limit, a polycarbonate diol with excellent viscosity stability at 25° C. tends to be easily obtained. Furthermore, when there is a peak where the number of repeating units is X=X0-α (α is a positive integer: 1, 2, 3, 4, . . .), the peak area ratio [S(X) / S(X0)] of 1.10 or more tends to be easily obtained.

[0050] The peak area ratio [S(X) / S(X0)] in the LC spectrum of a polycarbonate diol can be determined by the following method. That is, in the LC spectrum of a polycarbonate diol, the peak of the molecular weight having the smallest absolute difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is determined as the peak of the molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, and the number X0 of repeating units of the polycarbonate diol (D) corresponding to this peak is determined. Note that if there are two peaks of molecular weights having the smallest absolute difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, the peak with the smallest molecular weight is used. Next, the area value S(X) of each peak in the LC spectrum (X represents the number of repeating units of the polycarbonate diol (D), and X = , X0-2, X0-1, X0, X0+1, X0+2, ...) is calculated. and calculate the area ratio [S(X) / S(X0)] of each peak to the area value S(X0) of the peak where the number of repeating units is X0. Note that X and X0 are the numbers of repeating units of the polycarbonate diol (D) at the peak with a molecular weight of 300 to 3400 g / mol based on the detection limit of LC measurement, i.e., integers in the range of 1 to 17.

[0051] The correspondence between each peak obtained by LC measurement and the number X of repeating units of the polycarbonate diol (D) can be confirmed, for example, by performing MS measurement of each peak alone (apparatus: Bruker Daltonics microTOF, ion source: APCI, measurement mode: positive mode) and analyzing the main peak of the obtained spectrum.

[0052] The number of consecutive peaks having the area ratio [S(X) / S(X0)] calculated in this way in the range of 0.90 to 1.10, including the peak where the number of repeating units is X0, is determined.

[0053] Generally, the higher the molecular weight of a polymer, the more likely it is to exhibit good physical properties. However, due to the high viscosity, moldability during injection molding tends to be reduced. On the other hand, it is known that the viscosity of a polymer decreases with increasing shear rate. Therefore, even if a polymer has a high viscosity at a low shear rate (near a static state), if the polymer has a low viscosity in the flow state during molding, i.e., at a high shear rate, it tends to exhibit good physical properties and is likely to produce a polymer with excellent moldability.

[0054] In applications requiring flexibility, such as synthetic leather or artificial leather, polyols with high molecular weights are preferably used as raw materials for urethane resins in order to reduce the amount of urethane groups in the urethane resin.

[0055] In the present disclosure, the shear rate of 1 s is used as an index of a polymer that exhibits such good physical properties and has excellent moldability. -1 , viscosity η1 at temperature 25℃, shear rate 1000s -1 , viscosity η at 25°C 1000 The ratio of [η 1000 / η1] is used. 1000 As shown in Figure 2, the viscosity of a polymer decreases as the shear rate increases. However, if the viscosity becomes too low at high shear rates, that is, if the viscosity ratio [η 1000 If the viscosity ratio [η / η1] is too small, the molding processability will be good, but the viscosity will drop sharply near high shear rates, making it difficult to predict the amount of polymer discharged during molding and reducing discharge stability. On the other hand, if the viscosity drop at high shear rates is too small, that is, if the viscosity ratio [η 1000 When the viscosity ratio [η / η1] is around 1, the viscosity stability is good, but the viscosity is not reduced sufficiently, which may result in poor molding processability. Therefore, in order to achieve good physical properties of the polymer and to achieve both good molding processability and good viscosity stability (discharge stability), it is necessary to set the viscosity ratio [η 1000 / η1] is considered to be preferably within a particular range.

[0056] In the polycarbonate diol of one embodiment of the present disclosure, the shear rate is 1 s -1 , viscosity η1 at temperature 25℃, shear rate 1000s -1 , viscosity η at 25°C 1000 The ratio of [η 1000 The viscosity ratio [η / η1] is preferably 0.40 to 0.80, more preferably 0.42 to 0.75, and even more preferably 0.45 to 0.70. 1000 / η1] is equal to or greater than the lower limit, the shear rate is 1000 s -1 Since a sudden decrease in viscosity around the viscosity ratio [η 1000 / η1] is equal to or less than the upper limit, the shear rate is 1000 s -1 Since the viscosity is sufficiently reduced around this temperature, molding processability tends to be excellent.

[0057] In addition, the shear rate of the polycarbonate diol of one embodiment of the present disclosure is 1 s -1 The viscosity η1 at a temperature of 25°C is 20,000 to 80,000 mPa·s -1 Preferably, the viscosity is 25,000 to 70,000 mPa·s -1 More preferably, it is 30,000 to 60,000 mPa·s -1 It is more preferable that the viscosity η1 is 35000 mPa·s -1 More than 37500mPa·s -1 More than 40000mPa·s -1 More than 42500mPa s -1 More than 45000mPa·s -1 More than 47500mPa·s -1 More than 50000mPa·s -1 More than 52500mPa·s -1 or more, or 55,000 mPa·s -1 or more, 57,500 mPa·s -1 Below, 55000mPa·s -1 Below, 52500mPa·s -1Below, 50000mPa·s -1 Below, 47500mPa·s -1 Below, 45000mPa·s -1 Below, 42500mPa·s -1 Below, 40000mPa·s -1 or less, or 37500 mPa·s -1 When the viscosity η1 is equal to or higher than the lower limit, a polycarbonate diol exhibiting good physical properties tends to be easily obtained, while when the viscosity η1 is equal to or lower than the upper limit, a polycarbonate diol having excellent moldability tends to be easily obtained.

[0058] Furthermore, the shear rate of the polycarbonate diol of one embodiment of the present disclosure is 1000 s -1 , viscosity η at 25°C 1000 As for viscosity, it is 8000 to 60000 mPa·s -1 Preferably, the viscosity is 10,000 to 40,000 mPa·s -1 More preferably, it is 20,000 to 30,000 mPa·s -1 It is more preferable that the viscosity η 1000 is 22000mPa·s -1 More than 23000mPa·s -1 More than 24000mPa·s -1 More than 25000mPa·s -1 or more, or 26000mPa·s -1 It may be 27000 mPa·s or more. -1 Below, 26000mPa·s -1 Below 25000mPa s -1 Below, 24000mPa·s -1 or less, or 23000mPa·s -1 The viscosity η may be less than or equal to 1000 When the viscosity η is equal to or greater than the lower limit, a polycarbonate diol having excellent viscosity stability tends to be easily obtained. 1000 When the amount of the hydroxyl group is equal to or less than the upper limit, a polycarbonate diol having excellent moldability tends to be easily obtained.

[0059] <Method for producing polycarbonate diol> The polycarbonate diol of one embodiment of the present disclosure can be obtained, for example, by reacting a carbonate compound with a diol compound in the presence of a transesterification catalyst. Specifically, the polycarbonate diol can be obtained by heating a mixture containing the carbonate compound, the diol compound, and the transesterification catalyst to perform a reflux reaction (transesterification reaction) while removing alcohol derived from the carbonate compound from the reaction system. Therefore, the polycarbonate diol of one embodiment of the present disclosure may contain a transesterification catalyst.

[0060] (carbonate compounds) The carbonate compound used in the production of the polycarbonate diol of one embodiment of the present disclosure is not particularly limited, but examples thereof include alkylene carbonate, dialkyl carbonate, diaryl carbonate, and the like.

[0061] The alkylene carbonate is not particularly limited, but examples thereof include ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate.

[0062] The dialkyl carbonate is not particularly limited, but examples thereof include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, and dibutyl carbonate.

[0063] The diaryl carbonate is not particularly limited, but examples thereof include diphenyl carbonate.

[0064] Among these carbonate compounds, alkylene carbonates and dialkyl carbonates are preferred as carbonate compounds used in the production of polycarbonate diols, and ethylene carbonate, dimethyl carbonate and diethyl carbonate are more preferred.

[0065] (Diol compounds) The diol compound used in the production of the polycarbonate diol of one embodiment of the present disclosure includes at least 1,9-nonanediol and / or 2-methyl-1,8-octanediol.

[0066] Furthermore, the diol compound used in producing the polycarbonate diol of one embodiment of the present disclosure may contain a diol compound other than 1,9-nonanediol and / or 2-methyl-1,8-octanediol. The other diol compound is not particularly limited, but examples thereof include linear diols other than 1,9-nonanediol, branched diols other than 2-methyl-1,8-octanediol, cyclic diols, and diols having an aromatic ring.

[0067] The linear diol other than 1,9-nonanediol is not particularly limited, but examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0068] The branched diol other than 2-methyl-1,8-octanediol is not particularly limited, but examples thereof include 3-methyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 2,4-dimethyl-1,5-pentanediol, and 2,4-diethyl-1,5-pentanediol.

[0069] The cyclic diol is not particularly limited, but examples thereof include 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and 2-bis(4-hydroxycyclohexyl)-propane.

[0070] In the diol compounds used in producing the polycarbonate diol of one embodiment of the present disclosure, the ratio of the number of moles of 1,9-nonanediol and / or 2-methyl-1,8-octanediol (preferably 1,9-nonanediol and 2-methyl-1,8-octanediol) to the total number of moles of the diol compounds is 0.90 to 1.00, preferably 0.95 to 1.00, and more preferably all of the diol compounds are 1,9-nonanediol and / or 2-methyl-1,8-octanediol (more preferably 1,9-nonanediol and 2-methyl-1,8-octanediol). When the ratio of 1,9-nonanediol and / or 2-methyl-1,8-octanediol is within the above range, a polycarbonate diol that is liquid at 25°C and has excellent moldability and viscosity stability at 25°C tends to be easily obtained.

[0071] Furthermore, the ratio of the number of moles of 2-methyl-1,8-octanediol to the total number of moles of diol compounds is preferably 0.20 to 1.00, more preferably 0.30 to 0.99, even more preferably 0.40 to 0.98, even more preferably 0.50 to 0.95, particularly preferably 0.60 to 0.93, and most preferably 0.65 to 0.90. When the ratio is within the above range, the obtained polycarbonate diol is liquid at 25°C and has excellent handleability.

[0072] Furthermore, the ratio of the number of moles of 2-methyl-1,8-octanediol to the total number of moles of 1,9-nonanediol and 2-methyl-1,8-octanediol is preferably 0.20 to 1.00, more preferably 0.30 to 0.99, even more preferably 0.40 to 0.98, even more preferably 0.50 to 0.95, particularly preferably 0.60 to 0.93, and most preferably 0.65 to 0.90. When the ratio is within the above range, the obtained polycarbonate diol is liquid at 25°C and has excellent handleability.

[0073] In the polycarbonate diol of one embodiment of the present disclosure, a polyol compound having three or more hydroxy groups per molecule, such as trimethylolethane, trimethylolpropane, glycerin, or pentaerythritol, can also be used as a raw material for the polycarbonate diol, provided that its performance is not impaired. If too much of this polyol compound having three or more hydroxy groups per molecule is used as a raw material for the polycarbonate diol, crosslinking occurs during the polymerization reaction of the polycarbonate, causing gelation. Therefore, even when a polyol compound having three or more hydroxy groups per molecule is used as a raw material for the polycarbonate diol, the amount of this polyol compound is preferably 0.1 to 20 mol%, more preferably 0.5 to 15 mol%, even more preferably 1 to 10 mol%, and particularly preferably 2 to 5 mol%, based on the total number of moles of the diol compounds used as raw materials for the polycarbonate diol.

[0074] The mixing ratio of the carbonate compound to the diol compound (content of the carbonate compound in the mixed solution / content of the diol compound in the mixed solution) is preferably 1 / 3 to 3 / 1, more preferably 1 / 2 to 2 / 1, further preferably 1 / 1.3 to 1.3 / 1, and particularly preferably 1 / 1.2 to 1.2 / 1, by molar ratio. By setting the mixing ratio of the carbonate compound to the diol compound within the above range, polycarbonate diol can be efficiently obtained.

[0075] The transesterification catalyst used in the production of the polycarbonate diol of one embodiment of the present disclosure is preferably lithium acetylacetonate. By using lithium acetylacetonate as the transesterification catalyst, the polycarbonate diol having a desired molecular weight distribution can be obtained.

[0076] The content of the transesterification catalyst in the mixed solution may be 0.0001 to 0.10 parts by mass, preferably 0.001 to 0.07 parts by mass, more preferably 0.002 to 0.04 parts by mass, and even more preferably 0.003 to 0.03 parts by mass, relative to 100 parts by mass of the total amount of the carbonate compound and the diol compound in the mixed solution, from the viewpoint of easily controlling the reaction temperature and suppressing an increase in the color number of the reaction product. When the content of the transesterification catalyst is above the lower limit, the reaction temperature is easily controlled appropriately. However, when the obtained polycarbonate diol is used as a raw material for producing polyurethane, a lower content of the transesterification catalyst is preferable from the viewpoint of easily controlling the reactivity of the urethanization reaction. Furthermore, when the content of the transesterification catalyst is below the upper limit, an increase in the color number of the reaction product and the reactivity of the urethanization reaction can be suppressed.

[0077] The heating temperature (reaction temperature) of the mixed solution is, for example, 0 to 250°C, and may be 100 to 220°C. When the reaction temperature is equal to or higher than the lower limit, the transesterification reaction easily proceeds, and the desired polycarbonate diol is easily obtained. When the reaction temperature is equal to or lower than the upper limit, the color number of the obtained polycarbonate diol is reduced. The transesterification reaction may be carried out by keeping the temperature constant, or may be carried out by increasing the temperature stepwise or continuously depending on the degree of reaction progress. From the viewpoint of making it easier to obtain the desired polycarbonate diol, it is preferable to carry out heating at a temperature T1 that satisfies the relationship of the following formula (α), and then heating at a temperature T2 that satisfies the relationship of the following formula (β). It is preferable that the temperatures T1 and T2 satisfy the relationship of the following formula (γ). In addition, the average temperature T1 of the first heating temperature is m and the average temperature T2 of the second heating temperature m It is preferable that the relationship of the following formula (δ) is satisfied: Here, the degree of reaction progress can be estimated from the amount of distillate distilled. 110℃≦T1<140℃ (α) 120℃≦T2<140℃ (β) T1 <T2 ···(γ) T1 m <T2 m(δ)

[0078] The mixed solution can be heated under normal pressure, but in the latter half of the reaction, it can also be heated under reduced pressure (for example, under a pressure of 101 to 0.01 kPa). This can increase the distillation rate of the produced distillate and accelerate the progress of the reaction. In this specification, normal pressure means a pressure of 101.325 kPa ± 20.000 kPa. From the viewpoint of easily obtaining the desired polycarbonate diol, the heating of the mixed solution preferably includes heating under a pressure of 101.325 kPa ± 20.000 kPa (first heating) and then heating under a reduced pressure of 0.05 kPa or less (second heating). It is more preferable that the temperature of the first heating is temperature T1 that satisfies the relationship of the above formula (α), and the temperature of the second heating is temperature T2 that satisfies the relationship of the above formula (β), and it is even more preferable that the temperature of the first heating (temperature T1) and the temperature of the second heating (temperature T2) satisfy the relationship of the above formula (γ). Furthermore, from the viewpoint of facilitating the production of a desired polycarbonate diol, it is preferable to remove the alcohol derived from the carbonate compound from the reaction system by distilling it at a temperature close to the boiling point of the alcohol or lower (for example, 79°C or lower for ethanol derived from diethyl carbonate).

[0079] (urethane resin) The urethane resin according to one embodiment of the present disclosure includes a reaction product of the polycarbonate diol and an isocyanate. That is, the urethane resin is a polycondensation product of the polycarbonate diol and an isocyanate or a crosslinked product thereof. Here, the crosslinked product means a product in which polycondensates are crosslinked with each other using a chain extender or the like.

[0080] (Polyisocyanate) Examples of polyisocyanates include aromatic polyisocyanates, araliphatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. Modified polyisocyanates, which are modified versions of these, can also be used. Examples of modified polyisocyanates include isocyanurate-modified polyisocyanates (isocyanate trimers), allophanate-modified polyisocyanates, uretdione-modified polyisocyanates, urethane-modified polyisocyanates, biuret-modified polyisocyanates, uretonimine-modified polyisocyanates, and acylurea-modified polyisocyanates. These can be used alone, or two or more can be used in combination.

[0081] Examples of aromatic isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate mixture, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, a 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture, m-xylylene diisocyanate, p-xylylene diisocyanate, and 4,4'-diphenyl ether. Examples of suitable diisocyanates include 4,4'-diphenylmethane diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate. Among these, from the viewpoint of versatility, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and a 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture are preferred.

[0082] Examples of aromatic aliphatic isocyanates include 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, and mixtures thereof; 1,3-bis(1-isocyanato-1-methylethyl)benzene, 1,4-bis(1-isocyanato-1-methylethyl)benzene, and mixtures thereof; ω,ω'-diisocyanato-1,4-diethylbenzene, and the like.

[0083] Examples of aliphatic isocyanates include hexamethylene diisocyanate, pentamethylene diisocyanate, tetramethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, lysine diisocyanate, trioxyethylene diisocyanate, ethylene diisocyanate, trimethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, 2,2'-dimethylpentane diisocyanate, 2,2,4-trimethylhexane diisocyanate, decamethylene diisocyanate, butene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4, Examples of the isocyanate include 4-trimethylhexamethylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanato-4-(isocyanatomethyl)octane, 2,5,7-trimethyl-1,8-diisocyanato-5-(isocyanatomethyl)octane, bis(isocyanatoethyl)carbonate, bis(isocyanatoethyl)ether, 1,4-butylene glycol dipropyl ether-α,α'-diisocyanate, lysine diisocyanatomethyl ester, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and 2-isocyanatopropyl-2,6-diisocyanatohexanoate. Among these, hexamethylene diisocyanate, pentamethylene diisocyanate, and tetramethylene diisocyanate are preferred from the viewpoint of versatility.

[0084] Examples of alicyclic isocyanates include isophorone diisocyanate, cyclohexyl diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, methylcyclohexyl diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2'-dimethyldicyclohexylmethane diisocyanate, bis(4-isocyanato-n-butylidene)pentaerythritol, and hydrogenated dimer acid diisocyanate. ester, 2-isocyanatomethyl-3-(3-isocyanatopropyl)-5-(isocyanatomethyl)bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)3-(3-isocyanatopropyl)-6-(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)-2-(3-isocyanatopropyl)-5-(isocyanatomethyl)bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)-2-(3-isocyanatopropyl)-5-(isocyanatomethyl)bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)-3-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)bicyclo[2.2.1]heptane, 2-(isocyanatomethyl)-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)bicyclo[2.2.1]heptane Examples include cyclo[2.2.1]heptane, 2-(isocyanatomethyl)-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)bicyclo[2.2.1]heptane, 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethylxylene diisocyanate, etc. Among these, isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate are preferred from the viewpoint of versatility.

[0085] (Chain extender) The chain extender can be appropriately selected depending on the purpose, use, etc. Examples of the chain extender include water, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, xylylene glycol, bis(p-hydroxy)diphenyl, bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-hydroxyethoxy)phenyl]sulfonyl, and the like. Examples of suitable chain extenders include low molecular weight polyols such as cyclohexane and 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane; high molecular weight polyols such as polyester polyols, polyesteramide polyols, polyether polyols, polyetherester polyols, polycarbonate polyols, and polyolefin polyols; and polyamines such as ethylenediamine, isophoronediamine, 2-methyl-1,5-pentanediamine, aminoethylethanolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. The amount of chain extender (the proportion of the chain extender-derived structure contained in the urethane resin) may be 0.1 to 50 parts by mass per 100 parts by mass of the total amount of polycarbonate diol and isocyanate. When the chain extender is a polyol, the content of the polyol is calculated assuming that the polyol is included in both the chain extender and the polyol component.

[0086] (coating agent) The coating agent according to one embodiment of the present disclosure includes the urethane resin. Specific embodiments of the urethane resin may be as described above. [Example]

[0087] Examples of the present invention will be described below, but the present invention is not limited to these examples. The obtained polycarbonate diols were analyzed and evaluated by the following methods.

[0088] [Evaluation of properties] The obtained polycarbonate diol was heated at 80°C for 1 hour and then left to stand at 25°C for 3 days. After standing, the state of the sample was visually checked, and if it had even a slight fluidity at room temperature (25°C), it was rated as "liquid," and if it had no fluidity, it was rated as "solid."

[0089] [Measurement of number average molecular weight by GPC] The obtained polycarbonate diol was subjected to GPC analysis under the following conditions to measure the number average molecular weight of the polycarbonate diol. -conditions- (1) Measuring instrument: HLC-8420 (Tosoh Corporation) (2) Column: TSKgel (Tosoh Corporation) G3000H-XL G3000H-XL G2000H-XL G2000H-XL (3) Mobile phase: THF (tetrahydrofuran) (4) Detector: RI (refractive index) detector (accessory for HLC-8420) (5) Temperature: 40℃ (6)Flow rate: 1.000ml / min (7) Calibration curve: A calibration curve was obtained using the following products (all bifunctional polyoxypropylene polyols manufactured by Sanyo Chemical Industries, Ltd.). Sannix PP-200 (number average molecular weight: 200, average number of functional groups: 2) Sannix PP-400 (number average molecular weight: 400, average number of functional groups: 2) Sannix PP-1000 (number average molecular weight = 1000, average number of functional groups: 2) Sannix PP-2000 (number average molecular weight: 2000, average number of functional groups: 2) Sannix PP-3000 (number average molecular weight: 3200, average number of functional groups: 2) Sannix PP-4000 (number average molecular weight: 4160, average number of functional groups: 2) (8) Approximation of the calibration curve: cubic equation (9) Sample solution concentration: 0.5% by mass THF solution

[0090] [Hydroxyl value measurement] The hydroxyl value of the obtained polycarbonate diol was measured by a method using an acetylating reagent in accordance with JIS K1557-1.

[0091] [Calculation of number average molecular weight from hydroxyl value] The number average molecular weight of the obtained polycarbonate diol was calculated from the hydroxyl value using the following formula: The number average molecular weight calculated from the hydroxyl value corresponds to the absolute molecular weight (true molecular weight) of the polymer. Number average molecular weight calculated from hydroxyl value [g / mol] = 2 x 56.11 [KOHg / mol] x 1000 / hydroxyl value [KOHmg / g]

[0092] [LC measurement] The obtained polycarbonate diol was subjected to liquid chromatography (LC) measurement under the following conditions to obtain an LC spectrum of the polycarbonate diol. -conditions- (1) Measuring instrument: Agilent 1290 Infinity II series (Agilent Technologies) (2) Column: TSKgel (Tosoh Corporation) ·TSKgel ODS-100V(4.6mmI.D.×15cm) (3) Mobile phase: Solution A: Water / methanol = 5 / 5 (vol / vol%) Solution B: tetrahydrofuran (THF) Water: Purified water THF: Fujifilm Wako Pure Chemical for HPLC Methanol: Fujifilm Wako Pure Chemical Industries, Ltd., HPLC grade (4) Pretreatment The obtained polycarbonate diol was weighed, and a predetermined mobile phase (liquid B) was added and the mixture was left to stand overnight at room temperature to dissolve. The obtained sample solution was gently shaken and filtered through a 0.45 μm PTFE cartridge filter. (5) Solvent gradient conditions The solvent gradient conditions were as shown in Table 1.

[0093] [Table 1]

[0094] (6) Detector: Evaporative Light Scattering Detector (ELSD) G4260B (Agilemt Technologies) (7) Temperature: 40℃ (8)Flow rate: 0.40ml / min (9) Injection volume: 10μL (10) Sample solution concentration (THF): 2.0 mg / L The molecular structure of each peak in the obtained LC spectrum was identified by MS measurement of each peak individually (instrument: Bruker Daltonics microTOF, ion source: APCI, measurement mode: positive mode).

[0095] [Calculation of peak area ratio] In the obtained LC spectrum, the peak of the molecular weight closest to the number average molecular weight (absolute molecular weight) calculated from the hydroxyl value was determined, and the number of repeating units X0 of the polycarbonate diol (D) corresponding to this peak was calculated. The "peak of the molecular weight closest to the number average molecular weight calculated from the hydroxyl value" was defined as the peak of the molecular weight with the smallest absolute difference from the number average molecular weight calculated from the hydroxyl value. When there are two molecular weight peaks with the smallest absolute difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, the peak with the smallest molecular weight is used. Next, the area value S(X) of each peak in the LC spectrum (X represents the number of repeating units of the polycarbonate diol (D), and X = , X0-2, X0-1, X0, X0+1, X0+2, ...) was calculated. The area ratio [S(X) / S(X0)] of each peak to the area value S(X0) of the peak whose repeating unit is X0 was calculated. Furthermore, the number of consecutive peaks whose area ratio [S(X) / S(X0)] was in the range of 0.90 to 1.10, including the peak whose repeating unit is X0, was calculated.

[0096] [Viscosity measurement] The viscosity of the obtained polycarbonate diol was measured under the following conditions in accordance with JIS Z 8803:2011, Section 10 "Viscosity measurement method using a cone-plate rotational viscometer." Specifically, a cone-plate viscometer (HAAKE MARS Modular Advanced Rheometer System: manufactured by Thermo Scientific) was used, and 0.20 cm of polycarbonate diol was placed between the flat plate and the cone. 3 The cone was rotated at a constant shear rate, and after 5 minutes had passed, the torque acting on the flat disk or cone was measured when a steady state was reached, and the viscosity of the polycarbonate diol was calculated. -conditions- (1) Rotor: Thermo Scientific rotor (type (product number): C25 1° / Ti, diameter: 25.00 mm, angle between the flat disc and the cone (cone angle: α): 1°) (2) Shear rate: 1 s -1 , or 1000s -1 (3) Measurement temperature: 25℃

[0097] Example 1 76.9 g of 1,9-nonanediol, 435.9 g of 2-methyl-1,8-octanediol, 367.8 g of diethyl carbonate, and 0.048 g of lithium acetylacetonate were mixed in a 1 L two-neck glass reactor (Reactor A) equipped with a stirrer, thermometer, heater, and condenser. The resulting mixture was heated at 110-138°C (initial temperature: 110°C, final temperature: 138°C) under atmospheric pressure and reacted for 8 hours while removing low-boiling components (such as alcohol derived from carbonate esters). The distillate temperature was kept between 77°C and 79°C. The pressure in the flask was then gradually reduced to 0.04 kPa at 138°C, and the reaction was continued for another 8 hours to obtain polycarbonate diol (PCD-1), which is liquid at room temperature.

[0098] (Comparative Example 1) A polycarbonate diol (PCD-2) that is liquid at room temperature was obtained in the same manner as in Example 1, except that a mixed liquid obtained by mixing 76.9 g of 1,9-nonanediol, 436.0 g of 2-methyl-1,8-octanediol, 389.8 g of diethyl carbonate, and 0.047 g of lithium acetylacetonate was used in reactor A.

[0099] (Comparative Example 2) Into reactor A, 88.9 g of 1,9-nonanediol, 504.0 g of 2-methyl-1,8-octanediol, 393.5 g of diethyl carbonate, and 0.033 g of tetrabutyl titanate were mixed. The resulting mixture was heated at 120 to 190°C (initial temperature: 120°C, final temperature: 190°C) under atmospheric pressure and reacted for 8 hours while removing low-boiling components (such as alcohol derived from carbonate esters). The distillate temperature was 77°C or higher but less than 79°C. The pressure in the flask was then gradually reduced to 0.5 kPa at a reaction temperature of 190°C, and the reaction was continued for another 8 hours to obtain polycarbonate diol (PCD-3), which is liquid at room temperature.

[0100] (Comparative Example 3) A polycarbonate diol (PCD-4) that is liquid at room temperature was obtained in the same manner as in Example 1, except that a mixed liquid obtained by mixing 88.9 g of 1,9-nonanediol, 504.0 g of 2-methyl-1,8-octanediol, 310.6 g of diethyl carbonate, and 0.048 g of lithium acetylacetonate was used in reactor A.

[0101] (Production Example 1) A polycarbonate diol (PCD-5) that is liquid at room temperature was obtained in the same manner as in Comparative Example 2, except that a mixed liquid obtained by mixing 247.7 g of 1,9-nonanediol, 1403.4 g of 2-methyl-1,8-octanediol, 1262.9 g of diethyl carbonate, and 0.095 g of tetrabutyl titanate was used in reactor A.

[0102] (Production Example 2) A polycarbonate diol (PCD-6) that is liquid at room temperature was obtained in the same manner as in Example 1, except that a mixed liquid obtained by mixing 81.7 g of 1,9-nonanediol, 463.2 g of 2-methyl-1,8-octanediol, 361.2 g of diethyl carbonate, and 0.049 g of lithium acetylacetonate was used in reactor A.

[0103] (Production Example 3) A polycarbonate diol (PCD-7) that is liquid at room temperature was obtained in the same manner as in Example 1, except that a mixed liquid obtained by mixing 96.2 g of 1,9-nonanediol, 544.9 g of 2-methyl-1,8-octanediol, 168.9 g of diethyl carbonate, and 0.042 g of lithium acetylacetonate was used in reactor A.

[0104] (Examples 2 to 7, Comparative Examples 4 to 11) PCD-1 obtained in Example 1, PCD-2 and PCD-4 obtained in Comparative Examples 1 and 3, and PCD-5 to PCD-7 obtained in Production Examples 1 to 3 were mixed at 40°C according to the blending amounts shown in Table 1, to obtain polycarbonate diols (PCD-8 to PCD-21).

[0105] The properties at room temperature (25°C) measured for the polycarbonate diols obtained in Examples 1 to 7 and Comparative Examples 1 to 11 according to the above methods are shown in Tables 2 and 3. These include the properties at room temperature (25°C), the number average molecular weight measured by GPC, the hydroxyl value, the number average molecular weight calculated from the hydroxyl value, the number of repeating units X0 of the polycarbonate diol (D) corresponding to the peak with the molecular weight closest to the number average molecular weight calculated from the hydroxyl value, the area ratio [S(X) / S(X0)] of each peak relative to the area value S(X0) of the peak with the number of repeating units X0, and the number of consecutive peaks with the area ratio [S(X) / S(X0)] within a predetermined range, including the peak with the number of repeating units X0. For reference, the LC spectrum of the polycarbonate diol (PCD-1) obtained in Example 1 is shown in Figure 1.

[0106] [Table 2]

[0107] [Table 3]

[0108] According to the above method, the polycarbonate diols obtained in Examples 1 to 7 and Comparative Examples 1 to 11 were measured at a shear rate of 1 s -1 or 1000s -1 Viscosity at 25°C (η1 and η 1000 ] and shear rate 1 s -1 Viscosity (25°C) η1 vs. shear rate 1000s -1 Viscosity at 25°C η 1000 The ratio of [η 1000 / η1) are shown in Tables 4-5.

[0109] [Table 4]

[0110] [Table 5]

[0111] As described above, according to the present disclosure, it is possible to obtain a polycarbonate diol that has both moldability and viscosity stability at 25° C. Furthermore, the polycarbonate diol according to one embodiment of the present disclosure has excellent abrasion resistance and can form a surface treatment layer or coating film that has good resistance to moist heat and sweat.

[0112] Therefore, the polycarbonate diol of one embodiment of the present disclosure is useful as a surface treatment agent capable of stably forming a surface treatment layer having the above-mentioned properties on synthetic leather or artificial leather, or as a constituent material of a coating agent capable of stably forming a coating film having the above-mentioned properties on a film.

Claims

1. A polycarbonate diol containing a repeating unit (A) represented by the following formula (A) and having a terminal hydroxyl group: 90 to 100 mol % of the repeating units (A) are repeating units (B) represented by the following formula (B) and repeating units (C) represented by the following formula (C), The polycarbonate diol contains a polycarbonate diol (D) represented by the following formula (D): the amount of the repeating unit (B) is 20 to 99 mol % based on the total amount of the repeating unit (B) and the repeating unit (C); The number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is 300 to 2800 g / mol, The viscosity η 1 at a shear rate of 1 s −1 and a temperature of 25° C. is 20,000 to 80,000 mPa·s −1 , the viscosity η 1000 at a shear rate of 1000 s −1 and a temperature of 25° C. is 8000 to 60000 mPa·s −1 , Shear rate 1 s －１ , viscosity η at 25°C １ Shear rate 1000 s －１ , viscosity η at 25°C １０００ The ratio of [η １０００ / η １ ] is 0.40 to 0.80, 90 to 100 mol % of the polycarbonate diol is the polycarbonate diol (D), A polycarbonate diol, wherein the ratio of the number of moles of 2-methyl-1,8-octylene groups to the total number of moles of alkanediyl groups (total number of moles of 1,9-nonylene groups and 2-methyl-1,8-octylene groups) contained as R 1 in the polycarbonate diol (D) is 0.20 to 1.

00. 【Chemical 1】 (In formula (A), R represents a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 (In formula (D), R １ is *-(CH ２ ) ９ -* or *-CH ２ CH (CH ３ ) CH ２ CH ２ CH ２ CH ２ CH ２ CH ２ - represents *, The * at both ends in the formula represents R １ The bond sites with the two oxygen atoms bonded to both ends of q represents an integer of 1 or more, and a plurality of R １ may be the same or different.) 2. The polycarbonate diol according to claim 1, which has a viscosity η 1 at a shear rate of 1 s −1 and a temperature of 25° C. of 25,000 to 70,000 mPa·s −1 .

3. The polycarbonate diol according to claim 1, which has a viscosity η 1 at a shear rate of 1 s −1 and a temperature of 25° C. of 30,000 to 60,000 mPa·s −1 .

4. The polycarbonate diol according to claim 1, which has a viscosity η 1000 at a shear rate of 1000 s −1 and a temperature of 25° C. of 10,000 to 40,000 mPa·s −1 .

5. The polycarbonate diol according to claim 1, which has a viscosity η 1000 at a shear rate of 1000 s −1 and a temperature of 25° C. of 20,000 to 30,000 mPa·s −1 .

6. A urethane resin comprising a reaction product of the polycarbonate diol according to any one of claims 1 to 5 and an isocyanate.

7. A coating agent comprising the urethane resin described in claim 6.

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