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 polycarbonate diol, urethane resin, and coating agent.

Background Art

[0002] Polycarbonate polyol is useful as a raw material for producing urethane resin (also called polyurethane resin) by reacting with polyisocyanate compound, and is useful as a raw material for adhesives, paints, etc. As polycarbonate diol, which is one kind of polycarbonate polyol, generally, polycarbonate diol using 1,6 - hexanediol alone as the diol component is used. However, such polycarbonate diol has a problem that it is crystalline and thus solid at room temperature, making it difficult to handle.

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when polycarbonate diol is used in a manufacturing facility involving flow, there has been a problem that it is difficult to achieve both moldability and viscosity stability. And even with the polycarbonate diol described in Patent Document 1 above, there is still room for improvement in achieving both moldability and viscosity stability. Therefore, an aspect of the present disclosure aims to provide a polycarbonate diol that achieves both moldability and viscosity stability at 25°C. Another aspect of the present disclosure aims to provide a urethane resin and a coating agent obtained from the polycarbonate diol.

Means for Solving the Problems

[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 terminal hydroxyl groups, 90 to 100 mol% of the repeating unit (A) is a repeating unit (B) represented by the following formula (B) and / or a repeating unit (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 with 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 with the number of repeating units being X0, and the peak area ratio is 0.90 to 1.10 with respect to the area value of the peak with the number of repeating units being X0, Shear rate 1 s -1 , the ratio of the viscosity η at a shear rate of 1000 s -1 and a temperature of 25°C to the viscosity η1 at a shear rate of 1 s 1000 at a temperature of 25°C [η1000 A polycarbonate diol in which [η1] is 0.40 to 0.80.

[0008] [Chemical formula]

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

[0010] [Chemical formula]

[0011] [Chemical formula]

[0012] [Chemical formula]

[0013] (In formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, the * at both ends in the above formula indicates the bonding sites with two oxygen atoms respectively bonded to both ends of R 1 , q represents an integer of 1 or more, and a plurality of Rs 1 may be the same as or different from each other.)

[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 of the repeating unit (B) and the repeating unit (C).

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

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

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

[0019] [7] A coating agent containing the urethane resin according to [6].

Advantages of the Invention

[0020] According to one aspect of the present disclosure, a polycarbonate diol that achieves both moldability and viscosity stability at 25°C can be provided. Further, according to another aspect of the present disclosure, a urethane resin and a coating agent obtained from the polycarbonate diol can be provided.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present disclosure will be described in detail. In this specification, a numerical range indicated by "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. The minimum value or the maximum value of a numerical range indicated by "~" can be arbitrarily combined with the maximum value or the minimum value of another numerical range indicated by "~". Also, the individually described upper limit value and lower limit value can be arbitrarily combined.

[0023] <Polycarbonate diol> The polycarbonate diol according to one aspect of the present disclosure contains a repeating unit (A) represented by the following formula (A) and is a polycarbonate diol containing terminal hydroxyl groups, 90 to 100 mol% of the repeating unit (A) is a repeating unit (B) represented by the following formula (B) and / or a repeating unit (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 with the molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is X0, for the peak area value of the peak with the number of repeating units being X0, there are 2 to 7 consecutive peaks including the peak with the number of repeating units being X0, and the peak area ratio is 0.90 to 1.10. Shear rate 1 s -1 , the ratio [η -1 / η1] of the viscosity η at a shear rate of 1000 s 1000 and a temperature of 25°C to the viscosity η1 at a shear rate of 1 s 1000 and a temperature of 25°C is 0.40 to 0.80, and it is a polycarbonate diol.

[0024] [Chemical formula]

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

[0026]

Chemical formula

[0027]

Chemical formula

[0028]

Chemical formula

[0029] (In formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, and the * at both ends in the above formula indicates the bonding sites with two oxygen atoms respectively bonded to both ends of R 1 . q represents an integer of 1 or more, and multiple Rs 1 may be the same as or different from each other.)

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

[0031] ​The polycarbonate diol of one aspect of the present disclosure contains the repeating unit (A) and is a polycarbonate diol containing terminal hydroxyl groups. 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. Further, a plurality of Rs present in the polycarbonate diol may be the same as or different from each other.

[0032] As the divalent linear aliphatic hydrocarbon group in R, the number of carbon atoms is 2 to 15, preferably 3 to 12, more preferably 4 to 10, and particularly preferably 6 to 9.

[0033] Specific examples of the divalent linear aliphatic hydrocarbon group having 2 to 15 carbon atoms in R are not particularly limited, and examples include 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 them, from the viewpoint of versatility, a propylene group, a butylene group, a pentylene group, a hexylene group or a nonylene group is preferable.

[0034] As the divalent branched aliphatic hydrocarbon group in R, the number of carbon atoms is 3 to 15, preferably 4 to 12, more preferably 5 to 10, and particularly preferably 6 to 9.

[0035] Specific examples of the divalent branched aliphatic hydrocarbon group in R are not particularly limited, and examples include 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 them, from the viewpoint of versatility, an isopentylene group, an isohexylene group, a 3-methylpentylene group or a 2-methyloctylene group is preferable.

[0036] The divalent alicyclic hydrocarbon group in 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 in R are not particularly limited, and examples include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, etc. Among them, from the viewpoint of versatility, a cyclopentylene group or a cyclohexylene group is preferable.

[0038] Among these divalent aliphatic or alicyclic hydrocarbons having 2 to 15 carbon atoms, as R, 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 is preferable, 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 is more preferable, and a nonylene group or a 2-methyloctylene group is even more preferable.

[0039] In the repeating unit (A), 90 to 100 mol% thereof 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% thereof is the repeating unit (B) and / or the repeating unit (C) (more preferably, the repeating unit (B) and the repeating unit (C)) is preferable, and all of them being the repeating unit (B) and / or the repeating unit (C) (even more preferably, the repeating unit (B) and the repeating unit (C)) is more preferable. When the ratio of the repeating unit (B) and / or the repeating unit (C) is within the above range, the handleability is good, and a polycarbonate diol that achieves both moldability and viscosity stability at 25°C is likely to be obtained.

[0040] The amount of the repeating unit (B) is preferably 20 to 100 mol%, more preferably 30 to 99 mol%, still 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 (A). When the ratio is within the above range, the resulting polycarbonate diol tends to be in a liquid state at 25°C and is easy to handle.

[0041] Also, the amount of the repeating unit (B) is preferably 20 to 100 mol%, more preferably 30 to 99 mol%, still 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 resulting polycarbonate diol tends to be in a liquid state at 25°C and is easy to handle.

[0042] The polycarbonate diol according to one aspect of the present disclosure contains a polycarbonate diol (D) represented by the formula (D).

[0043] In the formula (D), R 1 represents *-(CH2)9-* or *-CH2CH(CH3)CH2CH2CH2CH2CH2CH2-*, and the * at both ends in the formula indicates the bonding sites with two oxygen atoms respectively bonded to both ends of R 1 . q represents an integer of 1 or more, preferably 1 to 23, more preferably 2 to 16, and still more preferably 3 to 11. Also, a plurality of R 1 may be the same as 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), that is, containing two or more alkanediyl groups, tends to be liquid at 25°C and is likely to achieve both moldability and viscosity stability at 25°C.

[0045] Further, in the polycarbonate diol (D) containing two or more alkanediyl groups, from the viewpoint of being liquid at 25°C and achieving both moldability and viscosity stability at 25°C, R is added to the polycarbonate diol (D). 1 The ratio of the number of moles of the 2-methyl-1,8-octylene group to the total number of moles of the alkanediyl groups (the total number of moles of the 1,9-nonylene group and the 2-methyl-1,8-octylene group) contained as R is preferably 0.20 to 1.00, more preferably 0.30 to 0.99, still 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.

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

[0047] Also, 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, still 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, and may also be 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. Note that the hydroxyl value of the polycarbonate diol means the number of milligrams (mg) of potassium hydroxide equivalent to the hydroxy groups 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 according to one embodiment of the present disclosure is preferably 300 to 2800 g / mol, more preferably 500 to 2600 g / mol, still 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, and may also 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 aspect of the present disclosure, when the number of repeating units of the polycarbonate diol (D) corresponding to the peak having the molecular weight closest to the number average molecular weight (absolute molecular weight) calculated from the hydroxyl value of the polycarbonate diol in the measured LC spectrum is X0, with respect to the area value S(X0) of the peak having the number of repeating units of X0, the peak area value ratio [S(X) / S(X0), where S(X) is the area value of the peak having the number of repeating units of X of the polycarbonate diol (D)] is 0.90 to 1.10, and 2 to 7 such peaks are continuous, preferably 3 to 6 are continuous, and particularly preferably 4 to 5 are continuous, including the peak having the number of repeating units of X0. When the number of continuous peaks with the peak area value ratio [S(X) / S(X0)] of 0.90 to 1.10 is equal to or greater than the lower limit including the peak having the number of repeating units of X0, a polycarbonate diol excellent in moldability at 25°C is likely to be obtained. Also, when the number of continuous peaks with the peak area value ratio [S(X) / S(X0)] of 0.90 to 1.10 is equal to or less than the upper limit including the peak having the number of repeating units of X0, a polycarbonate diol excellent in viscosity stability at 25°C is likely to be obtained. Furthermore, when there is a peak with the peak area value ratio [S(X) / S(X0)] of 1.10 or more at the peak where the number of repeating units is X = X0 - α (α is a positive integer: 1, 2, 3, 4, ···), a polycarbonate diol further excellent in moldability at 25°C is likely to be obtained.

[0050] The area value ratio [S(X) / S(X0)] of the peaks in the LC spectrum of the polycarbonate diol can be determined by the following method. That is, in the LC spectrum of the polycarbonate diol, as the peak with the molecular weight closest to the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, the peak with the smallest absolute value of the difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol is determined, and the number X0 of repeating units of the polycarbonate diol (D) corresponding to this peak is obtained. When there are two peaks with the smallest absolute value of the difference from the number average molecular weight calculated from the hydroxyl value of the polycarbonate diol, the peak with the smaller molecular weight is adopted. Next, in the LC spectrum, the area value S(X) of each peak [X represents the number of repeating units of the polycarbonate diol (D), and X = ···, X0 - 2, X0 - 1, X0, X0 + 1, X0 + 2, ···.] is obtained, and the area value ratio [S(X) / S(X0)] of each peak to the area value S(X0) of the peak with the number of repeating units being X0 is calculated. Note that X and X0 are integers within the range of 1 to 17, which are the numbers of repeating units of the polycarbonate diol (D) for peaks with molecular weights of 300 to 3400 g / mol from the detection limit of the LC measurement.

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

[0052] The number of consecutive peaks including the peak with the number of repeating units being X0, for which the area value ratio [S(X) / S(X0)] calculated in this way is within the range of 0.90 to 1.10, 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 its high viscosity, the moldability tends to decrease during injection molding. On the other hand, it is known that the viscosity of a polymer decreases as the shear rate increases. Therefore, even for a polymer with high viscosity in a state where the shear rate is slow (close to static state), if it is a polymer with low viscosity in the flow state during molding, that is, in a state where the shear rate is fast, it tends to easily exhibit good physical properties and is likely to obtain a polymer with excellent moldability.

[0054] The polyol used as a raw material for urethane resins is preferably a polyol with a high molecular weight in applications that require flexibility such as synthetic leather or artificial leather in order to reduce the amount of urethane groups in the urethane resin.

[0055] In the present disclosure, as an index of a polymer that exhibits such good physical properties and has excellent moldability, the ratio [η -1 / η1] of the viscosity η -1 at a shear rate of 1000 s 1000 and a temperature of 25 °C to the viscosity η1 at a shear rate of 1 s 1000 and a temperature of 25 °C is adopted. The technical significance of this viscosity ratio [η 1000 / η1] will be explained. As shown in Figure 2, the viscosity of a polymer decreases as the shear rate increases. However, if the viscosity becomes too low under a high shear rate, that is, if the viscosity ratio [η 1000 / η1] becomes too small, although the moldability is good, the viscosity decreases rapidly near the high shear rate, so the discharge amount of the polymer during molding becomes difficult to estimate and the discharge stability may decrease. On the other hand, if the decrease in viscosity under a high shear rate is too small, that is, if the viscosity ratio [η 1000 / η1] is near 1, although the viscosity stability is good, the viscosity does not decrease sufficiently, so the moldability may be inferior. Therefore, in order to exhibit good physical properties of the polymer and to achieve both good moldability and good viscosity stability (discharge stability), it is considered preferable that the viscosity ratio [η 1000 / η1] is within a specific range.

[0056] In the polycarbonate diol of one embodiment of the present disclosure, the shear rate is 1 s -1 , viscosity η1 at 25°C, shear rate 1000s -1 , viscosity η at 25℃ 1000 The ratio of 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 When the shear rate is 1000 s / η1] or more, -1 Since a sudden drop in viscosity around the viscosity ratio [η 1000 When the shear rate is 1000 s / η1, the shear rate is 1000 s -1 Since the viscosity is sufficiently reduced in this range, the 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 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, the viscosity 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 55000mPa·s -1 or more, 57500 mPa·s -1 Below, 55000mPa·s -1 Below, 52500mPa·s -1Hereinafter, 50,000 mPa·s -1 Hereinafter, 47,500 mPa·s -1 Hereinafter, 45,000 mPa·s -1 Hereinafter, 42,500 mPa·s -1 Hereinafter, 40,000 mPa·s -1 Hereinafter, or 37,500 mPa·s -1 Hereinafter may be acceptable. When the viscosity η1 is equal to or higher than the lower limit, a polycarbonate diol that exhibits good physical properties tends to be easily obtained. On the other hand, when the viscosity η1 is equal to or lower than the upper limit, a polycarbonate diol with excellent moldability tends to be easily obtained.

[0058] Furthermore, for the polycarbonate diol according to one aspect of the present disclosure, the viscosity η at a shear rate of 1000 s -1 and a temperature of 25°C 1000 is preferably 8000 to 60000 mPa·s -1 more preferably 10000 to 40000 mPa·s -1 even more preferably 20000 to 30000 mPa·s -1 The viscosity η 1000 is 22000 mPa·s -1 or more, 23000 mPa·s -1 or more, 24000 mPa·s -1 or more, 25000 mPa·s -1 or more, or 26000 mPa·s -1 or more may be acceptable, and 27000 mPa·s -1 or less, 26000 mPa·s -1 or less, 25000 mPa·s -1 or less, 24000 mPa·s -1 or less, or 23000 mPa·s -1 or less may be acceptable. When the viscosity η 1000 is equal to or higher than the lower limit, a polycarbonate diol with excellent viscosity stability tends to be easily obtained. On the other hand, when the viscosity η 1000 is equal to or lower than the upper limit, a polycarbonate diol with excellent moldability tends to be easily obtained.

[0059] <Method for producing polycarbonate diol> The polycarbonate diol of one aspect of the present disclosure can be obtained, for example, by reacting a carbonate compound and a diol compound in the presence of a transesterification catalyst. Specifically, a mixed solution containing a carbonate compound, a diol compound, and a transesterification catalyst is heated, and while removing the alcohol derived from the carbonate compound from the reaction system, a reflux reaction (transesterification reaction) is carried out to obtain a polycarbonate diol. Therefore, the polycarbonate diol of one aspect of the present disclosure may contain a transesterification catalyst.

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

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

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

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

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

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

[0066] In addition, the diol compound used in the production of the polycarbonate diol according to one embodiment of the present disclosure may contain other diol compounds other than 1,9-nonanediol and / or 2-methyl-1,8-octanediol. The other diol compounds are not particularly limited, and examples thereof include linear diols other than 1,9-nonanediol, branched-chain diols other than 2-methyl-1,8-octanediol, cyclic diols, and diols having an aromatic ring.

[0067] The linear diols other than 1,9-nonanediol are not particularly limited, and 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, 1,12-dodecanediol, and the like.

[0068] The branched-chain diols other than 2-methyl-1,8-octanediol are not particularly limited, and 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, 2,4-diethyl-1,5-pentanediol, and the like.

[0069] The cyclic diols are not particularly limited, and examples thereof include 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-bis(4-hydroxycyclohexyl)-propane, and the like.

[0070] In the diol compound used for the production of the polycarbonate diol according to one aspect 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 compound is 0.90 to 1.00, preferably 0.95 to 1.00, and more preferably all of the diol compound is 1,9-nonanediol and / or 2-methyl-1,8-octanediol (even more preferably 1,9-nonanediol and 2-methyl-1,8-octanediol). When the proportion of 1,9-nonanediol and / or 2-methyl-1,8-octanediol is within the above range, the polycarbonate diol is likely to have a liquid state at 25°C and excellent moldability and viscosity stability at 25°C.

[0071] Also, the ratio of the number of moles of 2-methyl-1,8-octanediol to the total number of moles of the diol compound 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. When the proportion is within the above range, the resulting polycarbonate diol has a liquid state at 25°C and 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, still more preferably 0.50 to 0.95, particularly preferably 0.60 to 0.93, and most preferably 0.65 to 0.90. When the proportion is within the above range, the resulting polycarbonate diol has a liquid state at 25°C and excellent handleability.

[0073] In the polycarbonate diol of one embodiment of the present disclosure, within a range that does not impair its performance, a polyol compound having 3 or more hydroxy groups in one molecule, such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, etc., can also be used as a raw material for the polycarbonate diol. If too much of the polyol compound having 3 or more hydroxy groups in one molecule is used as a raw material for the polycarbonate diol, crosslinking occurs during the polymerization reaction of the polycarbonate and gelation occurs. Therefore, even when a polyol compound having 3 or more hydroxy groups in one molecule is used as a raw material for the polycarbonate diol, this polyol compound is preferably 0.1 to 20 mol%, more preferably 0.5 to 15 mol%, still more preferably 1 to 10 mol%, and particularly preferably 2 to 5 mol% based on the total number of moles of the diol compound used as a raw material for the polycarbonate diol.

[0074] The mixing ratio of the carbonate compound and 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, still more preferably 1 / 1.3 to 1.3 / 1, and particularly preferably 1 / 1.2 to 1.2 / 1 in terms of molar ratio. By setting the mixing ratio of the carbonate compound and the diol compound within the above range, the polycarbonate diol can be efficiently obtained.

[0075] As the transesterification catalyst used in the production of the polycarbonate diol of one embodiment of the present disclosure, lithium acetylacetonate is preferred. 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 still more preferably 0.003 to 0.03 parts by mass, based on 100 parts by mass of the total amount of the carbonate compound and the diol compound in the mixed solution, from the viewpoint of facilitating appropriate control of the reaction temperature and suppressing an increase in the color number of the reaction product. When the content of the transesterification catalyst is at least the above lower limit, it becomes easier to appropriately control the reaction temperature. However, from the viewpoint of facilitating control of the reactivity of the urethanization reaction when the obtained polycarbonate diol is used as a raw material for producing polyurethane, the lower the content of the transesterification catalyst, the more preferable. Further, when the content of the transesterification catalyst is at most the above 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 at least the above lower limit, the transesterification reaction easily proceeds, and a desired polycarbonate diol is easily obtained. When the reaction temperature is at most the above upper limit, the color number of the obtained polycarbonate diol can be suppressed. Further, the transesterification reaction may be carried out while maintaining the temperature constant, or may be carried out while increasing the temperature stepwise or continuously according to the progress of the reaction. From the viewpoint of easily obtaining a desired polycarbonate diol, it is preferable to carry out heating at a temperature T1 satisfying the following formula (α) and then carry out heating at a temperature T2 satisfying the following formula (β). Note that the temperature T1 and the temperature T2 preferably satisfy the following formula (γ). Also, the average temperature T1 of the temperature of the first heating m and the average temperature T2 of the temperature of the second heating m preferably satisfy the following formula (δ). Here, the progress of the reaction can be estimated from the distillation amount of the distillate. 110 °C ≤ T1 < 140 °C ···(α) 120 °C ≤ T2 < 140 °C ···(β) T1 < T2 ···(γ) T1 m < T2 m···(δ)

[0078] The heating of the mixture can be carried out under normal pressure, but in the latter half of the reaction, it can also be carried out under reduced pressure (for example, under a pressure of 101 to 0.01 kPa). Thereby, the distillation rate of the produced distillate can be increased, and the progress of the reaction can be accelerated. In the present specification, normal pressure means a pressure of 101.325 kPa ± 20.000 kPa. From the viewpoint of facilitating the obtaining of the desired polycarbonate diol, the heating of the mixture 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 the temperature T1 satisfying the relationship of the above formula (α), the temperature of the second heating is the temperature T2 satisfying 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). Further, from the viewpoint of facilitating the obtaining of the desired polycarbonate diol, it is preferable to distill off the alcohol derived from the carbonate compound at a temperature equal to or lower than the boiling point of the alcohol (for example, ethanol derived from diethyl carbonate at 79°C or lower) and remove it from the reaction system.

[0079] (Urethane resin) The urethane resin according to one aspect of the present disclosure includes a reaction product of the above polycarbonate diol and an isocyanate. That is, the urethane resin is a polycondensate or a cross-linked product thereof of the above polycarbonate diol and an isocyanate. Here, the cross-linked product means a product in which polycondensates are cross-linked by a chain extender or the like.

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

[0081] Examples of the aromatic isocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate mixture, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture, m-xylylene diisocyanate, p-xylylene diisocyanate, 4,4'-diphenyl ether 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, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, and the like. Among these, from the viewpoint of versatility, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture are preferable.

[0082] Examples of the aromatic aliphatic isocyanate 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 the aliphatic isocyanate 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, 2,4,4-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 isocyanatomethyl ester, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, 2-isocyanatopropyl-2,6-diisocyanatohexanoate, and the like. Among these, from the viewpoint of versatility, hexamethylene diisocyanate, pentamethylene diisocyanate, and tetramethylene diisocyanate are preferred.

[0084] Examples of alicyclic isocyanates include isophorone diisocyanate, cyclohexyl diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate, methylcyclohexyl diisocyanate, dicyclohexyldimethylmethane diisocyanate, 2,2'-dimethyl dicyclohexylmethane diisocyanate, bis(4-isocyanato-n-butylidene) pentaerythritol, hydrogenated dimer acid diisocyanate, 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)-6-(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, 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, and the like. Among these, from the viewpoint of versatility, isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate are preferred.

[0085] (Chain extender) The chain extender can be appropriately selected according to the purpose, use, etc. Examples of the chain extender include water; low molecular weight polyols such as 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]sulfone, 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane; high molecular weight polyols such as polyester polyol, polyester amide polyol, polyether polyol, polyether ester polyol, polycarbonate polyol, polyolefin polyol; polyamines such as ethylenediamine, isophoronediamine, 2-methyl-1,5-pentanediamine, aminoethylethanolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, etc. The blending amount of the chain extender (the proportion of the structure derived from the chain extender contained in the urethane resin) may be 0.1 to 50 parts by mass with respect to 100 parts by mass of the total amount of the polycarbonate diol and the isocyanate. When the chain extender is a polyol, the content of the polyol is calculated as being included in both the chain extender and the polyol component.

[0086] (Coating agent) The coating agent according to one aspect of the present disclosure contains the above urethane resin. The specific embodiment of the urethane resin may be as described above.

Examples

[0087] Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples. The analysis and evaluation of the obtained polycarbonate diol were performed by the following methods.

[0088] [Evaluation of Properties] The obtained polycarbonate diol was heated at 80 °C for 1 hour and then left standing at 25 °C for 3 days. The state of the sample after standing was visually confirmed, and at room temperature (25 °C), if it had even the slightest fluidity, it was designated as "liquid", and if it had no fluidity, it was designated as "solid".

[0089] [Measurement of Number-Average Molecular Weight by GPC] Under the following conditions, GPC analysis of the obtained polycarbonate diol was performed to measure the number-average molecular weight of the polycarbonate diol. -Conditions- (1) Measuring instrument: HLC-8420 (manufactured by Tosoh Corporation) (2) Column: TSKgel (manufactured by Tosoh Corporation) · G3000H-XL · G3000H-XL · G2000H-XL · G2000H-XL (3) Mobile phase: THF (tetrahydrofuran) (4) Detector: RI (refractive index) detector (accessory of HLC-8420) (5) Temperature: 40 °C (6) Flow rate: 1.000 ml / min (7) Calibration curve: A calibration curve was obtained using the following products (all bifunctional polyoxypropylene polyols manufactured by Sanyo Chemical Industries, Ltd.). · "Sunnex PP-200" (number-average molecular weight = 200, average number of functional groups: 2) · "Sunnex PP-400" (number-average molecular weight = 400, average number of functional groups: 2) · "Sunnex PP-1000" (number-average molecular weight = 1000, average number of functional groups: 2) · "Sunnex PP-2000" (number-average molecular weight = 2000, average number of functional groups: 2) · "Sunnex PP-3000" (number-average molecular weight = 3200, average number of functional groups: 2) · "Sunnex PP-4000" (number-average molecular weight = 4160, average number of functional groups: 2) (8) Approximation formula of calibration curve: Cubic equation (9) Concentration of sample solution: 0.5 mass% THF solution

[0090] [Measurement of hydroxyl value] In accordance with JIS K1557-1, the hydroxyl value of the obtained polycarbonate diol was measured by a method using an acetylation reagent.

[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 by the following formula. Note that 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 × 56.11 [KOH g / mol] × 1000 / hydroxyl value [KOH mg / g]

[0092] [LC measurement] Under the following conditions, liquid chromatography (LC) measurement of the obtained polycarbonate diol was performed to obtain the LC spectrum of the polycarbonate diol. -Conditions- (1) Measuring instrument: Agilent 1290 Infinity II series (manufactured by Agilent Technologies) (2) Column: TSKgel (manufactured by Tosoh Corporation) ·TSKgel ODS-100V (4.6 mm I.D. × 15 cm) (3) Mobile phase: Solution A: water / methanol = 5 / 5 (vol / vol%) Solution B: tetrahydrofuran (THF) Water: purified water THF: for HPLC manufactured by FUJIFILM Wako Pure Chemical Corporation Methanol: for HPLC manufactured by FUJIFILM Wako Pure Chemical Corporation (4) Pretreatment The obtained polycarbonate diol was weighed, a predetermined mobile phase (Solution B) was added, and it was allowed 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 set as shown in Table 1.

[0093] [Table 1]

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

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

[0096] [Viscosity measurement] In accordance with Paragraph 10, "Cone - Plate - Type Rotational Viscometer - Viscosity Measurement Method" of JIS Z 8803:2011, the viscosity of the obtained polycarbonate diol was measured under the following conditions. Specifically, a cone - plate viscometer (HAAKE MARS Modular Advanced Rheometer System, manufactured by Thermo Scientific) was used. 0.20 cm of polycarbonate diol was placed between the flat plate and the cone, and the cone was rotated at a constant shear rate. After 5 minutes, when a steady state was reached, the torque received by the flat plate or the cone was measured, and the viscosity of the polycarbonate diol was calculated. 3 - Conditions - - Conditions - (1) Rotor: Rotor manufactured by Thermo scientific (Type (Part number): C25 1° / Ti, Diameter: 25.00 mm, Angle between the flat plate and the cone (Cone angle: α): 1°) (2) Shear rate: 1 s -1 or 1000 s -1 (3) Measurement temperature: 25 °C

[0097] (Example 1) In a 1 - L two - necked glass reactor (Reactor A) equipped with a stirrer, a thermometer, a heating device, and a cooler, 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. The obtained mixture was heated at 110 - 138 °C (initially 110 °C, finally 138 °C) under normal pressure for 8 hours while removing low - boiling components (such as alcohols derived from carbonates), and the distillate temperature was set to be 77 °C or higher and lower than 79 °C. Further, the pressure in the flask was gradually reduced to 0.04 kPa at a reaction temperature of 138 °C, and the reaction was carried out for another 8 hours to obtain a polycarbonate diol (PCD - 1) that was 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 solution 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 in Reactor A was used.

[0099] (Comparative Example 2) In 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 mixed solution was heated at 120 to 190 °C (120 °C at the beginning and 190 °C at the end) under normal pressure for 8 hours while removing low-boiling components (such as alcohol derived from carbonic ester). The distillate temperature was set to be 77 °C or higher and less than 79 °C. Further, the pressure in the flask was gradually reduced to 0.5 kPa at a reaction temperature of 190 °C, and the reaction was carried out for another 8 hours to obtain a polycarbonate diol (PCD-3) that 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 solution 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 in Reactor A was used.

[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 solution 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 in Reactor A was used.

[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 solution 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 in reactor A was used.

[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 solution 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 in reactor A was used.

[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 compounding amounts shown in Table 1, respectively, to obtain polycarbonate diols (PCD-8 to PCD-21).

[0105] The properties at room temperature (25°C), number average molecular weight measured by GPC, hydroxyl value, number average molecular weight calculated from the hydroxyl value, number X0 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, area value ratio [S(X) / S(X0)] of each peak to the area value S(X0) of the peak with the number of repeating units X0, and the number of peaks within a predetermined range of the area value ratio [S(X) / S(X0)] that are continuous including the peak with the number of repeating units X0 were measured for the polycarbonate diols obtained in Examples 1 to 7 and Comparative Examples 1 to 11 according to the above method, and are shown in Tables 2 to 3. Also, 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] Measured for the polycarbonate diols obtained in Examples 1 to 7 and Comparative Examples 1 to 11 according to the above method, at a shear rate of 1 s -1 or 1000 s -1 the viscosity at (25 °C) [η1 and η 1000 , and the ratio of the viscosity at a shear rate of 1000 s -1 to the viscosity at a shear rate of 1 s (25 °C) η1 [η -1 at (25 °C) are shown in Tables 4 to 5. 1000 / η1] is shown in Tables 4 to 5. 1000 / η1] are shown in Tables 4 to 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 achieves both moldability at 25 °C and viscosity stability. Further, the polycarbonate diol of one aspect of the present disclosure is excellent in wear resistance and can form a surface treatment layer or a coating film having good wet heat resistance and sweat resistance.

[0112] Therefore, the polycarbonate diol of one aspect of the present disclosure is useful as a surface treatment agent capable of stably forming a surface treatment layer having the above characteristics 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 characteristics 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: The repeating unit (A) is a repeating unit (B) represented by the following formula (B) and a repeating unit (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 1s －１ , viscosity η at 25°C １ Shear rate 1000 s －１ , viscosity η at 25°C １０００ The ratio of １０００ / １ ] is 0.40 to 0.80, 90 to 100 mol % of the polycarbonate diol is the polycarbonate diol (D), A polycarbonate diol, in which 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 R 1 in the polycarbonate diol (D) (the total number of moles of 1,9-nonylene groups and 2-methyl-1,8-octylene groups) is 0.20 to 1.

00. 【Chemistry 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 *, In the above formula, * at both ends represents R １ The bond sites with the two oxygen atoms bonded to each end of the molecule are shown. 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, having 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, having 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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