JP2022145545A - Polycarbonate diol and polyurethane using the same - Google Patents

Abstract

To provide a polycarbonate diol which is a raw material for a polyurethane having excellent balance of physical properties such as solution stability, low-temperature flexibility, and chemical resistance, especially, ethanol resistance.SOLUTION: There is provided a polycarbonate diol comprising a structural unit derived from a compound represented by the following formula (A) and a structural unit derived from a compound represented by the following formula (B). The polycarbonate diol has a hydroxyl value of 37.4 mg-KOH/g or more and 140 mg-KOH/g or less, a weight average molecular weight/number average molecular weight (Mw/Mn) of 1.5 or more and 3.5 or less, and a molar ratio (A)/(B) of the structural unit represented by the following formula (A) to the structural unit represented by the following formula (B) of 89/11 to 51/49. HO-R1-OH...(A), HO-R2-OH...(B). (R1 is a substituted or unsubstituted divalent alkylene group having 4 carbon atoms; and R2 is a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms.)SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polycarbonate diol useful as a raw material for polycarbonate-based polyurethane and a polyurethane using the same.

Conventionally, the raw materials for the soft segment of polyurethane produced on an industrial scale are the ether type typified by polytetramethylene ether glycol, the polyester polyol type typified by adipate ester, and the polylactone typified by polycaprolactone. type or polycarbonate type represented by polycarbonate diol (Non-Patent Document 1).

Of these, ether-type polyurethanes are said to be excellent in hydrolysis resistance, flexibility and stretchability, but inferior in heat resistance and weather resistance. On the other hand, polyurethanes using polyester polyols have improved heat resistance and weather resistance, but cannot be used in some applications due to the low hydrolysis resistance of the ester groups.

On the other hand, polyurethane using polylactone type is considered to be a grade with excellent hydrolysis resistance compared to polyurethane using polyester polyol type, but likewise, hydrolysis can be completely suppressed due to the presence of ester groups. can't. It has also been proposed to use a mixture of these polyester polyol type, ether type and polylactone type mixtures as raw materials for polyurethane, but the drawbacks of each have not been completely compensated for.

On the other hand, polyurethane using polycarbonate type represented by polycarbonate diol is considered to be the best durable grade in terms of heat resistance and hydrolysis resistance. Widely used as an adhesive.
However, the polycarbonate diols currently widely available on the market are mainly those synthesized from 1,6-hexanediol, and due to their high crystallinity, when they are made into polyurethanes, the cohesiveness of the soft segments is reduced. However, there are problems such as the stability of the polyurethane solution, poor flexibility at low temperatures, elongation, and bending, which limits its use.
Accordingly, polycarbonate diols having various structures have been proposed to solve the above problems.

For example, there is a method of copolymerizing polycarbonate diol using 1,6-hexanediol and another dihydroxy compound as starting materials. Specifically, polycarbonate is obtained by copolymerizing 1,6-hexanediol and 1,4-butanediol as starting materials. Diol (Patent Document 1), polycarbonate diol (Patent Document 2) obtained by copolymerizing 1,6-hexanediol and 1,5-pentanediol as raw materials, and copolymerizing 1,3-propanediol and other dihydroxy compounds as raw materials A polycarbonate diol (Patent Document 3) has been proposed.

In addition, a method using a dihydroxy compound having a substituent on the main chain has been proposed as a powerful method for inhibiting the crystallinity of the site derived from the dihydroxy compound. Polycarbonate diol (Patent Document 4) obtained by copolymerizing glycol as a raw material, and polycarbonate diol (Patent Document 5) obtained by copolymerizing 3-methyl-1,5-pentanediol and another alkylene diol as raw materials.

In addition, polyurethanes using polycarbonate diols made from long-chain diols such as 2-methyl-1,8-octanediol and 1,9-nonanediol have been proposed. (Patent Document 6)
Further, a polycarbonate diol having an average carbon number of more than 6 has been proposed as a polycarbonate diol having excellent chemical resistance, low-temperature properties, and heat resistance. (Patent Document 7)
In addition, flexibility and chemical resistance are improved by mixing polycarbonate diols made from diols with 3 to 6 carbon atoms and polycarbonate diols made from diols with 7 to 12 carbon atoms. Polyurethanes using polycarbonate diols having been prepared have been proposed. (Patent Documents 8 to 10)

JP-A-5-51428 JP-A-2-289616 WO2002/070584 WO2006/088152 JP-A-60-195117 Japanese Patent Publication No. 3-54967 JP-A-2000-95852 Japanese Patent No. 4177318 Japanese Patent No. 4506754 Japanese Patent No. 6347397

"Fundamentals and Applications of Polyurethane" pp.96-106 Supervised by Katsuji Matsunaga, CMC Publishing Co., Ltd., November 2006

However, these conventionally known techniques, such as the polycarbonate diols described in Patent Documents 1 to 3, have insufficient low-temperature flexibility when made into polyurethanes. In addition, the polycarbonate diols described in Patent Documents 4 and 5, etc. are inferior in chemical resistance when made into polyurethane. In addition, the polycarbonate diols disclosed in Patent Documents 7 to 10 are inferior in chemical resistance and solution stability when formed into polyurethanes.

In addition, in terms of chemical resistance, due to recent social conditions, there is a strong demand for durability against ethanol formulations used for sterilization and disinfection.

An object of the present invention is to provide a polycarbonate diol which can be used as a raw material for polyurethane and has an excellent balance of physical properties such as solution stability, low-temperature flexibility, chemical resistance, and especially ethanol resistance, which could not be achieved by the above-mentioned prior art.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the above problems can be solved by a polyurethane produced using a copolymerized polycarbonate diol having a specific structure as a raw material.

The present invention has been achieved based on such findings, and the gist thereof is as follows.

[1] A polycarbonate diol containing a structural unit derived from a compound represented by the following formula (A) and a structural unit derived from a compound represented by the following formula (B), wherein the hydroxyl value is 38.0 mg-KOH /g or more and 145 mg-KOH/g or less, and the molar ratio of the structural unit represented by the following formula (A) to the structural unit represented by the following formula (B) is (A) / (B) = 89 /11 to 51/49.
HO—R ¹ —OH (A)
HO—R ² —OH (B)
(In formula (A) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms, and in formula (B) above, R ² represents a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms. represents a valent alkylene group.)

[2] The total proportion of the structural units derived from the compound represented by the formula (A) and the structural units derived from the compound represented by the formula (B) is 50 mol in all the structural units of the polycarbonate diol. % or more, the polycarbonate diol according to [1].

[3] The polycarbonate diol according to [1] or [2], wherein the hydroxyl value is 44.8 mg-KOH/g or more and 125 mg-KOH/g or less.

[4] The polycarbonate diols of [1] to [3], wherein the compound represented by formula (A) is 1,4-butanediol.

[5] The compound represented by formula (B) is at least one compound selected from the group consisting of 1,10-decanediol, 1,11-undecanediol and 1,12-dodecanediol [ 1] The polycarbonate diol according to any one of [4].

[6] The polycarbonate diol according to any one of [1] to [5], wherein at least one of the compound represented by formula (A) and the compound represented by formula (B) is derived from a plant.

[7] A polyurethane using the polycarbonate diol according to any one of [1] to [6].

[8] Artificial leather or synthetic leather produced using the polyurethane according to [7].

[9] A paint or coating agent produced using the polyurethane of [7].

[10] An elastic fiber produced using the polyurethane described in [7].

[11] A water-based polyurethane paint produced using the polyurethane described in [7].

[12] A pressure-sensitive adhesive or adhesive produced using the polyurethane described in [7].

[13] A method for storing a polyurethane solution obtained using a polycarbonate diol at −5° C. or lower, wherein the polycarbonate diol contains a structural unit derived from a compound represented by the following formula (A) and the following formula (B): Including a structural unit derived from a compound represented by the ratio of a structural unit represented by the following formula (A) to a structural unit represented by the following formula (B) is (A)/(B) = 89/ 11 to 51/49, a hydroxyl value of 38.0 mg-KOH/g or more and 140 mg-KOH/g or less, and a weight average molecular weight/number average molecular weight (Mw/Mn) of 1.5 or more and 3.5 or less. A method for storing a polyurethane solution at -5°C or below.
HO—R ¹ —OH (A)
HO—R ² —OH (B)
(In formula (A) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms, and in formula (B) above, R ² represents a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms. represents a valent alkylene group.)

According to the present invention, by introducing a specific structure into the raw material, it is possible to provide a polycarbonate diol that can be used as a raw material for polyurethane having an excellent balance of physical properties such as solution stability, low-temperature flexibility, chemical resistance, and especially ethanol resistance. and is industrially extremely useful.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

[1. Polycarbonate diol]
The polycarbonate diol of the present invention is a polycarbonate diol containing a structural unit derived from a compound represented by the following formula (A) and a structural unit derived from a compound represented by the following formula (B), and has a hydroxyl value of 38. .0 mg-KOH / g or more and 145 mg-KOH / g or less, and the molar ratio of the structural unit represented by the following formula (A) and the structural unit represented by the following formula (B) is (A) / ( B) Polycarbonate diols characterized in that = 89/11 to 51/49.
HO—R ¹ —OH (A)
HO—R ² —OH (B)

(In formula (A) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms, and in formula (B) above, R ² represents a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms. represents a valent alkylene group.)

<1-1. Structural Features>
The structural unit derived from the compound represented by the formula (A) according to the present invention is represented by, for example, the following formula (C). Further, the structural unit derived from the compound represented by the formula (B) is represented by, for example, the following formula (D).

(In formula (C) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms or a polymethylene group.)

(In formula (D) above, R ² represents a substituted or unsubstituted divalent alkylene group or polymethylene group having 8 to 20 carbon atoms.)

In formula (C), R ¹ may be of one type or of multiple types. Further, in the above formula (D), R ² may be of one type or plural types.
In the above formula (C), R ¹ is preferably unsubstituted because chemical resistance and low temperature flexibility are improved.

In the above formula (D), R ² is a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms or a polymethylene group. , low-temperature flexibility, and the like, and the number of carbon atoms in the substituent is preferably 2 or less, more preferably 1 or less, and still more preferably unsubstituted.

The polycarbonate diol of the present invention contains a structural unit derived from the compound represented by the formula (A) and a structural unit derived from the compound represented by the formula (B). Solution stability, chemical resistance and low temperature flexibility can be obtained. Furthermore, the ratio of the structural unit derived from the compound represented by the formula (A) to the structural unit derived from the compound represented by the formula (B) (hereinafter sometimes referred to as "(A) / (B)" ) is preferably (A)/(B) = 89/11 to 51/49, more preferably 85/15 to 55/45, even more preferably 80/20 to 60/40, and 75 /25 to 65/35 are most preferred.

When the content ratio of the structural units derived from the compound represented by the formula (A) is high and the content ratio of the structural units derived from the compound represented by the formula (B) is too low, the resulting polyurethane is In some cases, sufficient solution stability may not be obtained, and in some cases low temperature flexibility may not be sufficient. If the content of the structural units derived from the compound represented by the formula (A) is low and the content of the structural units derived from the compound represented by the formula (B) is too high, the polyurethane will not be formed. Sufficient chemical resistance may not be obtained.

The total ratio of the structural units derived from the compound represented by the formula (A) and the structural units derived from the compound represented by the formula (B) to the total structural units of the polycarbonate diol is In view of the balance between chemical properties and low-temperature flexibility, the content is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, particularly preferably 90 mol% or more, and 95 mol% or more. is most preferred, and may be 100 mol %.

The polycarbonate diol of the present invention can be produced by polycondensing the compound represented by the formula (A), the compound represented by the formula (B), and a carbonate compound by transesterification reaction.

<1-2. Dihydroxy compound>
Examples of the compound represented by formula (A), which is a dihydroxy compound that is a raw material for the polycarbonate diol of the present invention, include 2-methyl-1,3-propanediol and 1,4-butanediol. Among them, 1,4-butanediol is preferable from the viewpoint of the balance between chemical resistance and low-temperature flexibility when made into polyurethane.

Examples of the compound represented by the formula (B), which is a dihydroxy compound used as a raw material for the polycarbonate diol of the present invention, include 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol. , 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol , 1,12-octadecanediol, 1,20-eicosanediol, and the like. Among them, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1 ,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol are preferred, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11 -undecanediol and 1,12-dodecanediol are more preferred, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol and 1,12-dodecanediol are more preferred, and 1,10-decane Particularly preferred are diols, 1,11-undecanediol, 1,12-dodecanediol, and most preferred is 1,10-decanediol. In addition, the compound represented by the formula (B) may be of one type or plural types.

It is preferable that the compound represented by the above formula (A) is derived from a plant from the viewpoint of reducing the burden on the environment. A plant-derived compound represented by formula (A) that can be applied includes 1,4-butanediol.

It is preferable that the compound represented by the formula (B) is derived from a plant, from the viewpoint of reducing the burden on the environment. Compounds represented by the formula (B) that can be derived from plants include 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13 -tridecanediol, 1,12-octadecanediol, 1,20-eicosanediol, and the like.

As a plant-derived dihydroxy compound, for example, in the case of 1,4-butanediol, succinic acid, succinic anhydride, succinic acid ester, maleic acid, maleic anhydride, maleic acid ester, tetrahydrofuran and γ obtained by a fermentation method - 1,4-butanediol may be produced by chemical synthesis from butyrolactone or the like, 1,4-butanediol may be produced directly by fermentation, or 1,3-butadiene obtained by fermentation 1,4-butanediol may be produced from Among these, the method of directly producing 1,4-butanediol by fermentation and the method of hydrogenating succinic acid with a reducing catalyst to obtain 1,4-butanediol are efficient and preferable.

Also, 1,10-decanediol can be synthesized by synthesizing sebacic acid from castor oil by melting with an alkali, followed by hydrogenation directly or after an esterification reaction.

<1-3. Carbonate compound>
The carbonate compound (sometimes referred to as "carbonic acid diester") that can be used in the production of the polycarbonate diol of the present invention is not limited as long as it does not impair the effects of the present invention, and examples thereof include dialkyl carbonate, diaryl carbonate and alkylene carbonate. be done. Among these, diaryl carbonate is preferable from the viewpoint of reactivity.

Specific examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, ethylene carbonate and the like, with diphenyl carbonate being preferred.

<1-4. Usage ratio of raw materials, etc.>
In the production of the polycarbonate diol of the present invention, the amount of the carbonate compound used is not particularly limited, but usually the lower limit is preferably 0.35, more preferably 0.50, and still more preferably 0.50 in terms of molar ratio to the total 1 mol of the dihydroxy compounds. is 0.60, and the upper limit is preferably 1.00, more preferably 0.98, still more preferably 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the ratio of non-hydroxy terminal groups in the resulting polycarbonate diol may increase, or the molecular weight may not fall within the predetermined range. Sometimes.

<1-5. transesterification catalyst>
When producing the polycarbonate diol of the present invention, a transesterification catalyst (hereinafter sometimes referred to as a catalyst) can be used as necessary to promote polymerization.
However, in that case, if too much catalyst remains in the polycarbonate diol obtained, the reaction may be inhibited or accelerated excessively in the production of polyurethane using the polycarbonate diol. be.
Therefore, the amount of the catalyst remaining in the polycarbonate diol is not particularly limited, but is preferably 100 ppm or less, more preferably 50 ppm or less, and still more preferably 10 ppm or less in terms of catalyst metal.

As the transesterification catalyst, any compound generally considered to have transesterification ability can be used without limitation.

Examples of transesterification catalysts include compounds of Group 1 metals of the periodic table such as lithium, sodium, potassium, rubidium and cesium; compounds of Group 2 metals of the periodic table such as magnesium, calcium, strontium and barium; titanium and zirconium. Compounds of Group 4 metals of the periodic table such as hafnium; compounds of Group 5 metals of the periodic table such as hafnium; compounds of Group 9 metals of the periodic table such as cobalt; compounds of Group 12 metals of the periodic table such as zinc; Group 13 metal compounds of the periodic table; compounds of group 14 metals of the periodic table such as germanium, tin and lead; compounds of group 15 metals of the periodic table such as antimony and bismuth; lanthanide metals such as lanthanum, cerium, europium and ytterbium and the like. Among these, from the viewpoint of increasing the transesterification reaction rate, periodic table group 1 metal compounds, periodic table group 2 metal compounds, periodic table group 4 metal compounds, periodic table group 5 metal compounds, A compound of a metal of Group 9 of the periodic table, a compound of a metal of Group 12 of the periodic table, a compound of a metal of Group 13 of the periodic table, a compound of a metal of Group 14 of the periodic table, a compound of a metal of Group 1 of the periodic table, a compound of a metal of Group 1 of the periodic table, Compounds of Group 2 metals are more preferred, and compounds of Group 2 metals of the periodic table are even more preferred. Among the compounds of Group 1 metals of the periodic table, lithium, potassium and sodium compounds are preferred, lithium and sodium compounds are more preferred, and sodium compounds are even more preferred. Among the compounds of Group 2 metals of the periodic table, compounds of magnesium, calcium and barium are preferred, compounds of calcium and magnesium are more preferred, and compounds of magnesium are even more preferred. These metal compounds are mainly used as hydroxides, salts and the like. Examples of salts when used as salts include halide salts such as chlorides, bromides and iodides; carboxylates such as acetates, formates and benzoates; sulfonates such as romethanesulfonic acid; phosphorus-containing salts such as phosphates, hydrogen phosphates and dihydrogen phosphates; acetylacetonate salts; Catalyst metals can also be used as alkoxides such as methoxides and ethoxides.

Among these, at least one metal acetate, nitrate, sulfate, carbonate, phosphate, hydroxide, halide, or alkoxide of at least one metal selected from Group 2 metals of the periodic table is preferably used, More preferably, acetates, carbonates, and hydroxides of Group 2 metals of the periodic table are used, more preferably acetates, carbonates, and hydroxides of magnesium and calcium, and particularly preferably magnesium and calcium. Acetates are used, most preferably magnesium acetate.

The upper limit of the amount of the transesterification catalyst used is preferably 500 ppm by mass, more preferably 100 ppm by mass, and even more preferably 50 ppm by mass, as the mass ratio of the metal to the mass of the raw material dihydroxy compound. , 10 ppm by weight. On the other hand, the lower limit is preferably 0.01 ppm by mass, more preferably 0.1 ppm by mass, and even more preferably 1 ppm by mass, as the amount at which sufficient polymerization activity can be obtained.

<1-6. Reaction conditions>
The reaction temperature for the transesterification reaction can be arbitrarily adopted as long as it is a temperature at which a practical reaction rate can be obtained. The lower limit of the normal reaction temperature is preferably 70°C, more preferably 100°C, and even more preferably 130°C. The upper limit of the reaction temperature is generally preferably 250°C, more preferably 230°C, and even more preferably 200°C. If the reaction temperature is at least the above lower limit, the transesterification reaction can proceed at a practical rate. By setting the reaction temperature to the above upper limit or lower, it is possible to prevent quality problems such as coloring of the resulting polycarbonate diol and generation of an ether structure.

Furthermore, the reaction temperature is preferably 180° C. or lower, more preferably 170° C. or lower, and even more preferably 160° C. or lower throughout the whole process of the transesterification reaction for producing the polycarbonate diol. By keeping the reaction temperature at 180° C. or lower throughout the entire process, it is possible to prevent coloration from occurring depending on the conditions.

Although the reaction can be carried out under normal pressure, the transesterification reaction is an equilibrium reaction, and the reaction can be biased toward the production system by distilling off the low-boiling components to be produced out of the system. Therefore, in the latter half of the reaction process, it is usually preferable to employ reduced pressure conditions and carry out the reaction while distilling off the low-boiling components. Alternatively, it is also possible to carry out the reaction while gradually lowering the pressure from the middle of the reaction to distill off the low-boiling components produced. In particular, it is preferable to carry out the reaction by increasing the degree of pressure reduction in the final stage of the reaction, because by-products such as monoalcohols, phenols and cyclic carbonates can be distilled off.
In this case, the upper limit of the reaction pressure at the end of the reaction is preferably 10 kPa, more preferably 5 kPa, and even more preferably 1 kPa.

In this case, the upper limit of the reaction pressure at the end of the reaction is preferably 10 kPa, more preferably 5 kPa, and even more preferably 1 kPa.

In order to effectively distill off the light-boiling components, the reaction can be carried out while passing an inert gas such as nitrogen, argon and helium through the reaction system.

When a low-boiling carbonate compound or dihydroxy compound is used in the transesterification reaction, the reaction should be carried out near the boiling point of the carbonate compound or dihydroxy compound at the beginning of the reaction. A method of allowing the reaction to proceed can also be employed. By doing so, it is possible to prevent the unreacted carbonate compound from being distilled off in the initial stage of the reaction.

Furthermore, in order to prevent the distillation of these raw materials, it is possible to attach a reflux pipe to the reactor and carry out the reaction while refluxing the carbonate compound and the dihydroxy compound. The ratio can be matched precisely.

The polymerization reaction can be carried out in a batch system or a continuous system, but is preferably carried out in a continuous system from the viewpoint of product stability and the like. The apparatus to be used may be of any type of tank type, tubular type or column type, and known polymerization tanks equipped with various stirring blades and the like can be used. The atmosphere during heating of the device is not particularly limited, but from the viewpoint of product quality, it is preferable to carry out the heating in an inert gas such as nitrogen gas under normal pressure or reduced pressure.

The polymerization reaction is terminated when the target molecular weight is reached while measuring the molecular weight of the resulting polycarbonate diol. The reaction time required for polymerization varies greatly depending on the dihydroxy compound, the carbonate compound, and the presence or absence and type of catalyst used. It is more preferably 1 hour or less, and further preferably 10 hours or less.

<1-7. Catalyst deactivator>
As described above, when a catalyst is used in the polymerization reaction, the catalyst usually remains in the polycarbonate diol obtained, and the remaining catalyst causes an increase in molecular weight, a change in composition, deterioration of color tone, etc. due to heating of the polycarbonate diol. Or, it may become impossible to control the polyurethane formation reaction. In order to suppress the effect of this remaining catalyst, it is preferable to add a phosphorus-based compound or the like in a molar amount approximately equal to that of the transesterification catalyst used to deactivate the transesterification catalyst. Furthermore, after the addition, the transesterification catalyst can be efficiently deactivated by heat treatment or the like as described later. As the phosphorus-based compound, phosphoric acid and phosphorous acid are preferred, and phosphoric acid is more preferred, since they are highly effective even in small amounts.

Phosphorus compounds used to inactivate transesterification catalysts include, for example, inorganic phosphoric acids such as phosphoric acid and phosphorous acid, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, Examples thereof include organic phosphates such as triphenyl phosphate. These may be used individually by 1 type, and may use 2 or more types together.

The amount of the phosphorus-based compound used is not particularly limited, but as described above, it is sufficient if it is approximately equimolar with the used ester exchange catalyst. The upper limit is preferably 5 mol, more preferably 2 mol, and the lower limit is preferably 0.6 mol, more preferably 0.8 mol, and still more preferably 1.0 mol. If the phosphorus-based compound is used in an amount less than this, heating the polycarbonate diol may cause an increase in the molecular weight of the polycarbonate diol, a change in the composition, deterioration of the color tone, etc., or the inactivation of the transesterification catalyst may not be sufficient, resulting in When such a polycarbonate diol is used as a raw material for polyurethane production, for example, the reactivity of the polycarbonate diol to isocyanate groups may not be reduced sufficiently. If a phosphorus-based compound exceeding this range is used, the resulting polycarbonate diol is colored, or when the polycarbonate diol is used as a raw material to produce polyurethane, the polyurethane is likely to hydrolyze, and the phosphorus-based compound bleeds out. There is a possibility that

Deactivation of the transesterification catalyst by adding a phosphorus-based compound can be performed at room temperature, but is more efficient with heat treatment. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 180° C., more preferably 150° C., still more preferably 120° C., and even more preferably 100° C., and the lower limit is preferably 50° C. or more. It is preferably 60°C, more preferably 70°C. If the temperature is lower than this, deactivation of the transesterification catalyst takes a long time and is not efficient, and the degree of deactivation may be insufficient. On the other hand, at temperatures exceeding 180°C, the resulting polycarbonate diol may be colored.
Although the reaction time with the phosphorus compound is not particularly limited, it is usually 0.1 to 5 hours.

<1-8. Purification>
The reaction product contains impurities having no hydroxyl group at the end of the polymer as described above, phenols, raw material dihydroxy compounds, carbonate compounds, by-produced low-boiling cyclic carbonates and added catalysts. It can be purified for the purpose of its removal.

For the purification at that time, a method of distilling off light boiling compounds by distillation can be adopted. Specific methods of distillation include reduced-pressure distillation, steam distillation, thin-film distillation, and the like, and any method can be employed without particular limitation. Among them, thin-film distillation is most effective.

The conditions for thin film distillation are not particularly limited, but the upper limit of the temperature during thin film distillation is preferably 250°C, more preferably 200°C. Also, the lower limit is preferably 120°C, more preferably 150°C. By setting the lower limit of the temperature during thin-film distillation to the above lower limit or more, the effect of removing low-boiling components becomes sufficient. Further, by making the upper limit equal to or less than the above upper limit, it is possible to prevent the polycarbonate diol obtained after thin-film distillation from being colored.

The upper limit of the pressure during thin film distillation is preferably 500 Pa, more preferably 150 Pa, even more preferably 70 Pa, and particularly preferably 60 Pa. By setting the pressure during thin-film distillation to the above upper limit or less, a sufficient effect of removing light-boiling components can be obtained.

In addition, the upper limit of the temperature for keeping the polycarbonate diol immediately before thin film distillation is preferably 250°C, more preferably 150°C. Also, the lower limit is preferably 80°C, more preferably 120°C.
By setting the temperature at which the polycarbonate diol is kept warm just before the thin film distillation to be equal to or higher than the above lower limit, it is possible to prevent the fluidity of the polycarbonate diol from decreasing just before the thin film distillation. On the other hand, by making the amount equal to or less than the above upper limit, it is possible to prevent the polycarbonate diol obtained after thin-film distillation from being colored.

Also, in order to remove water-soluble impurities, washing may be performed with water, alkaline water, acidic water, a chelating agent-dissolved solution, or the like. In that case, the compound to be dissolved in water can be arbitrarily selected.

<1-9. Molecular chain end>
The molecular chain ends of the polycarbonate diol of the present invention are mainly hydroxyl groups. However, in the case of a polycarbonate diol obtained by the reaction of a dihydroxy compound and a carbonate compound, there is a possibility that a portion of the molecular chain ends that are not hydroxyl groups may be present as impurities. Specific examples thereof include those having an alkyloxy group or an aryloxy group at the molecular chain end, and most of them are structures derived from carbonate compounds.

For example, when diphenyl carbonate is used as the carbonate compound, the aryloxy group is the phenoxy group (PhO-), when dimethyl carbonate is used, the alkyloxy group is the methoxy group (MeO-), and when diethyl carbonate is used, the ethoxy group. (EtO-), when ethylene carbonate is used, a hydroxyethoxy group (HOCH ₂ CH ₂ O-) may remain as a molecular chain terminal (where Ph represents a phenyl group and Me represents a methyl group). , Et represents an ethyl group).

The molecular chain terminals of the polycarbonate diol of the present invention are the number of terminals derived from the compound represented by the formula (A) and the number of terminals derived from the compound represented by the formula (B) with respect to the total number of terminals. The total number ratio is preferably 80 mol % or more, more preferably 90 mol % or more, still more preferably 95 mol % or more, particularly preferably 97 mol % or more, and most preferably 99 mol % or more. By setting the content within the above range, it becomes easy to obtain a desired molecular weight when it is made into a polyurethane, and it becomes possible to obtain a raw material for a polyurethane having an excellent balance of solution stability, chemical resistance, and low-temperature flexibility.

In addition, the ratio of the number of terminal groups whose molecular chain terminals of the polycarbonate diol are derived from a carbonate compound is preferably 10 mol% or less, more preferably 5 mol% or less, and still more preferably 3 mol% of the total number of terminals. Below, it is particularly preferably 1 mol % or less.

<1-10. Hydroxyl value>
The hydroxyl value of the polycarbonate diol of the present invention has a lower limit of usually 37.4 mg-KOH/g, preferably 38.7 mg-KOH/g, more preferably 40 mg-KOH/g, still more preferably 42 mg-KOH/g, particularly Preferably 44.8 mg-KOH/g, particularly preferably 45 mg-KOH/g. Also, the upper limit is usually 140 mg-KOH/g, preferably 135 mg-KOH/g, more preferably 130 mg-KOH/g, still more preferably 125 mg-KOH/g. If the hydroxyl value is less than the above lower limit, the viscosity becomes too high and handling may become difficult during polyurethane formation. be.

<1-11. Molecular Weight/Molecular Weight Distribution>
The lower limit of the number average molecular weight (Mn) obtained from the hydroxyl value of the polycarbonate diol of the present invention is preferably 800, more preferably 900, still more preferably 1,000. On the other hand, the upper limit is preferably 2,800, more preferably 2,700, and still more preferably 2,500. If the Mn of the polycarbonate diol is less than the above lower limit, sufficient low-temperature flexibility may not be obtained when the urethane is made. On the other hand, when the above upper limit is exceeded, the viscosity increases, which may impair the handling during polyurethane formation.

The lower limit of weight average molecular weight/number average molecular weight (Mw/Mn), which is the molecular weight distribution of the polycarbonate diol of the present invention, is usually 1.5, preferably 1.8. The upper limit is usually 3.5, preferably 3.0. If the molecular weight distribution exceeds the above range, the physical properties of the polyurethane produced using this polycarbonate diol tend to be hard at low temperatures, elongation is reduced, and the like. If an attempt is made to produce a polycarbonate diol having a molecular weight distribution less than the above range, a sophisticated purification operation such as removal of oligomers may be required.

The weight average molecular weight and number average molecular weight of the polycarbonate diol in the molecular weight distribution of the polycarbonate diol are the weight average molecular weight and number average molecular weight in terms of polystyrene, respectively, and are usually measured by gel permeation chromatography (sometimes abbreviated as GPC). can ask.

<1-12. Residual Monomers, etc.>
When an aromatic diester such as diphenyl carbonate is used as a starting material, phenols are produced as a by-product during the production of polycarbonate diol. Since phenols are monofunctional compounds, they may become an inhibitory factor in the production of polyurethane, and the urethane bonds formed by phenols have weak bonding strength, so they can be damaged by heat in subsequent processes. It may dissociate, regenerate isocyanate and phenols, and cause problems. Moreover, since phenols are also stimulating substances, it is preferable that the residual amount of phenols in the polycarbonate diol is as small as possible. Specifically, the mass ratio to the polycarbonate diol is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 300 ppm or less, and most preferably 100 ppm or less. In order to reduce the amount of phenols in the polycarbonate diol, it is possible to set the pressure of the polymerization reaction of the polycarbonate diol to a high vacuum of 1 kPa or less as an absolute pressure, or to perform thin film distillation or the like after the polymerization of the polycarbonate diol, as described later. It is valid.

Carbonic acid diesters used as raw materials during production may remain in the polycarbonate diol. The amount of the diester carbonate remaining in the polycarbonate diol is not limited, but is preferably as small as possible. be. If the diester carbonate content of the polycarbonate diol is too high, the reaction during polyurethane formation may be inhibited. On the other hand, the lower limit is not particularly limited, but is preferably 0.1% by mass, more preferably 0.01% by mass, and still more preferably 0% by mass.

A dihydroxy compound used during production may remain in the polycarbonate diol. The amount of the dihydroxy compound remaining in the polycarbonate diol is not limited, but is preferably as small as possible, and is preferably 1% by mass or less, more preferably 0.1% by mass or less, and still more preferably 0.1% by mass or less as a mass ratio to the polycarbonate diol. is 0.05% by mass or less. If the residual amount of the dihydroxy compound in the polycarbonate diol is large, the molecular length of the soft segment portion of the polyurethane becomes insufficient, and desired physical properties may not be obtained.

Polycarbonate diols sometimes contain cyclic carbonates (cyclic oligomers) that are by-produced during production. For example, when 1,4-butanediol is used as the compound represented by the formula (A), 1,3-dioxepan-2-one or a cyclic carbonate obtained by combining two or more molecules thereof, etc. may be produced and contained in polycarbonate diols. These compounds may cause side reactions in the polyurethane formation reaction and cause turbidity. It is preferable to remove as much as possible by performing thin film distillation or the like afterwards. The content of these cyclic carbonates contained in the polycarbonate diol is not limited, but is preferably 3% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less as a mass ratio to the polycarbonate diol. .

[2. Polyurethane]
Polyurethanes can be made using the polycarbonate diols of the present invention described above. The method for producing the polyurethane of the present invention using the polycarbonate diol of the present invention employs known polyurethane-forming reaction conditions for producing ordinary polyurethanes.

<2-1. Polyisocyanate>
Polyisocyanates used to produce polyurethanes using the polycarbonate diols of the present invention include various known aliphatic, alicyclic or aromatic polyisocyanate compounds.

For example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and dimer diisocyanate obtained by converting the carboxyl group of dimer acid to an isocyanate group. Aliphatic diisocyanates; 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and 1,3-bis Alicyclic diisocyanates such as (isocyanatomethyl)cyclohexane; 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl Aromatic diisocyanates such as -4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate and m-tetramethylxylylene diisocyanate. These may be used individually by 1 type, and may use 2 or more types together.

Among these, 4,4′-diphenylmethane diisocyanate (hereinafter sometimes referred to as MDI), hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferred.

<2-2. Chain extender>
The chain extender used in producing the polyurethane of the present invention is a low-molecular-weight compound having at least two active hydrogens that react with the isocyanate group when producing a prepolymer having an isocyanate group, which will be described later. Generally, polyols and polyamines can be mentioned.

Specific examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol and 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol, and other linear diols; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl -1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-heptanediol, 1,4-dimethylolhexane, 2-ethyl-1,3-hexanediol, 2 ,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, dimer diol, and other branched diols diols having an ether group such as diethylene glycol and propylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 1,4-dihydroxyethylcyclohexane; xylylene glycol; Diols having aromatic groups such as 1,4-dihydroxyethylbenzene and 4,4′-methylenebis(hydroxyethylbenzene); Polyols such as glycerin, trimethylolpropane and pentaerythritol; N-methylethanolamine and N-ethylethanol hydroxyamines such as amine; ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediamine, di-2-hydroxy ethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, 4,4′-diphenylmethanediamine, methylenebis(o-chloroaniline), xylylenediamine, diphenyldiamine, tri polyamines such as diamine, hydrazine, piperazine, N,N'-diaminopiperazine; and water. These chain extenders may be used alone or in combination of two or more.

1,4-butanediol (hereinafter sometimes referred to as 1,4BD), 1,5 -pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxyethylcyclohexane, ethylenediamine, 1,3-diaminopropane, isophoronediamine, 4,4'-diaminodicyclohexylmethane are preferred.

In addition, the chain extender in the case of producing a prepolymer having a hydroxyl group, which will be described later, is a low molecular weight compound having at least two isocyanate groups, specifically <2-1. polyisocyanate>.

<2-3. Chain terminator>
When producing the polyurethane of the present invention, a chain terminating agent having one active hydrogen group can be used as necessary for the purpose of controlling the molecular weight of the resulting polyurethane.

These chain terminators include aliphatic monools having one hydroxyl group such as methanol, ethanol, propanol, butanol and hexanol, diethylamine, dibutylamine, n-butylamine, monoethanolamine and diethanolamine having one amino group. , and morpholine. These may be used individually by 1 type, and may use 2 or more types together.

<2-4. Catalyst>
Amine-based catalysts such as triethylamine, N-ethylmorpholine, and triethylenediamine or tins such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanate in the polyurethane-forming reaction when producing the polyurethane of the present invention. Known urethane polymerization catalysts typified by organic metal salts such as titanium-based compounds can also be used. A urethane polymerization catalyst may be used individually by 1 type, and may use 2 or more types together.

Among the above urethanization reaction catalysts, organic tin compounds are preferred. Examples of organic tin compounds include tin-containing acylate compounds and tin-containing mercaptocarboxylates. Specifically, tin octylate, monomethyltin mercaptoacetate, monobutyltin triacetate, monobutyltin monooctylate, monobutyltin monoacetate, monobutyltin maleate, monobutyltin maleate benzyl ester salt, monooctyltin maleate , monooctyltin thiodipropionate, monooctyltin tris (isooctylthioglycolate), monophenyltin triacetate, dimethyltin maleate, dimethyltinbis (ethylene glycol monothioglycolate), dimethyltinbis (mercaptoacetic acid) salt, dimethyltin bis(3-mercaptopropionic acid) salt, dimethyltin bis(isooctylmercaptoacetate), dibutyltin diacetate, dibutyltin dioctoate, dibutyltin distearate, dibutyltin dilaurate, dibutyltin maleate, Dibutyltin maleate polymer, dibutyltin maleate salt, dibutyltin bis (mercaptoacetic acid), dibutyltin bis (mercaptoacetic acid alkyl ester) salt, dibutyltin bis (3-mercaptopropionic acid alkoxybutyl ester) salt, dibutyltin bis octylthioglycol ester salt , dibutyltin (3-mercaptopropionate) salt, dioctyltin maleate, dioctyltin maleate salt, dioctyltin maleate polymer, dioctyltin dilaurate, dioctyltin bis (isooctyl mercaptoacetate), dioctyltin bis (iso octylthioglycolic acid ester), dioctyltin bis(3-mercaptopropionic acid) salt, and the like.

In particular, when using an aliphatic polyisocyanate and/or an alicyclic polyisocyanate as a raw material as the polyisocyanate, the reactivity is lower than that of the aromatic polyisocyanate, so it is recommended to use a tin-based urethanization reaction catalyst. It is more preferable to use these urethanization reaction catalysts when using 4,4'-dicyclohexylmethane diisocyanate, which has particularly low reactivity.

<2-5. Polyol other than the polycarbonate diol of the present invention>
In the polyurethane-forming reaction when producing the polyurethane of the present invention, the polycarbonate diol of the present invention may be used in combination with other polyols, if necessary. Here, the polyol other than the polycarbonate diol of the present invention is not particularly limited as long as it is used in ordinary polyurethane production. Polycarbonate polyols may be mentioned. For example, when used in combination with a polyether-based polyol, a polyurethane having further improved solution stability and low-temperature flexibility, which are characteristics of the polycarbonate diol of the present invention, can be obtained. Here, with respect to the combined mass of the polycarbonate diol of the present invention and other polyols. The mass ratio of the polycarbonate diol of the present invention is preferably 70% or more, more preferably 90% or more. If the mass ratio of the polycarbonate diol of the present invention is small, the balance of solution stability, chemical resistance and low-temperature flexibility, which are features of the present invention, may be lost.

<2-6. Solvent>
A solvent may be used in the polyurethane-forming reaction when producing the polyurethane of the present invention.
Preferred solvents include amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide and N-methylpyrrolidone; sulfoxide solvents such as dimethylsulfoxide; ketone solvents such as methylethylketone, cyclohexanone and methylisobutylketone; ether solvents; ester solvents such as methyl acetate, ethyl acetate and butyl acetate; and aromatic hydrocarbon solvents such as toluene and xylene. These solvents may be used alone or as a mixed solvent of two or more.

Among these, preferred organic solvents are methyl ethyl ketone, ethyl acetate, toluene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide.
Aqueous dispersion polyurethane can also be produced from a polyurethane composition containing the polycarbonate diol of the present invention, polyisocyanate, and the chain extender.

<2-7. Polyurethane manufacturing method>
As a method for producing the polyurethane of the present invention using the above-mentioned reaction reagents, production methods generally used experimentally or industrially can be used.
Examples thereof include a method of collectively mixing and reacting the polycarbonate diol of the present invention, other polyols, polyisocyanate and a chain extender (hereinafter sometimes referred to as a “one-step method”); A method of reacting a polycarbonate diol, other polyol and polyisocyanate to prepare a prepolymer having isocyanate groups at both ends and then reacting the prepolymer with a chain extender (hereinafter sometimes referred to as a “two-step method”). Yes), etc.

In the two-stage method, the polycarbonate diol of the present invention and other polyols are preliminarily reacted with one or more equivalents of polyisocyanate to prepare isocyanate intermediates at both ends corresponding to the soft segment of the polyurethane. It is. In this way, if the prepolymer is once prepared and then reacted with a chain extender, it may be easier to adjust the molecular weight of the soft segment portion, and it is useful when it is necessary to ensure phase separation between the soft segment and the hard segment. is useful.

<2-8. Single stage method>
The one-step method, which is also called a one-shot method, is a method in which the polycarbonate diol of the present invention, other polyols, polyisocyanate, and chain extender are charged all at once to carry out the reaction.
The amount of polyisocyanate used in the one-step method is not particularly limited, but the sum of the total number of hydroxyl groups of the polycarbonate diol of the present invention and other polyols, the number of hydroxyl groups and the number of amino groups of the chain extender is set to 1 equivalent. When the is 2.0 equivalents, more preferably 1.5 equivalents, and particularly preferably 1.1 equivalents.

If the amount of polyisocyanate used is too large, unreacted isocyanate groups will cause side reactions, and the viscosity of the resulting polyurethane will tend to be too high, making handling difficult and flexibility likely to be impaired. If it is too much, the molecular weight of the polyurethane will not be sufficiently large, and there will be a tendency that sufficient polyurethane strength will not be obtained.

The amount of the chain extender to be used is not particularly limited. is 0.7 equivalents, more preferably 0.8 equivalents, more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents, more preferably 2.0 equivalents, and further Preferably 1.5 equivalents, particularly preferably 1.1 equivalents. If the amount of chain extender used is too large, the resulting polyurethane tends to be difficult to dissolve in the solvent and processing becomes difficult. Sometimes.

<2-9. Two-step method>
The two-step method, also called a prepolymer method, mainly includes the following methods.
(a) The polycarbonate diol of the present invention and other polyols and excess polyisocyanate are added in advance in an amount having a reaction equivalent ratio of polyisocyanate/(polycarbonate diol of the present invention and other polyols) exceeding 1 to 10. A method of producing a polyurethane by reacting at 0 or less to produce a prepolymer having an isocyanate group at the molecular chain end and then adding a chain extender thereto (b) Preliminary polyisocyanate, excess polycarbonate diol and A polyol other than the above is reacted at a reaction equivalent ratio of polyisocyanate/(polycarbonate diol of the present invention and other polyol) of 0.1 or more to less than 1.0 to produce a prepolymer having a hydroxyl group at the molecular chain end. and then reacting it with a polyisocyanate having an isocyanate group at the end as a chain extender to produce a polyurethane.

The two-step method can be carried out without solvent or in the presence of solvent.
Polyurethane production by the two-step method can be carried out by any one of the methods (1) to (3) described below.
(1) Without using a solvent, first, polyisocyanate, polycarbonate diol, and other polyols are directly reacted to synthesize a prepolymer, which is directly used for the chain extension reaction.
(2) A prepolymer is synthesized by the method of (1), then dissolved in a solvent and used for subsequent chain extension reaction.
(3) A solvent is used from the beginning to react polyisocyanate, polycarbonate diol, and other polyols, followed by chain extension reaction.

In the case of method (1), the chain extension reaction is carried out by dissolving the chain extender in a solvent, or dissolving the prepolymer and the chain extender in the solvent at the same time, to obtain the polyurethane in a form coexisting with the solvent. This is very important.
The amount of polyisocyanate used in the two-step method (a) is not particularly limited, but the lower limit is preferable as the number of isocyanate groups when the total number of hydroxyl groups of polycarbonate diol and other polyols is 1 equivalent. is an amount exceeding 1.0 equivalents, more preferably 1.2 equivalents, more preferably 1.5 equivalents, and the upper limit is preferably 10.0 equivalents, more preferably 5.0 equivalents, more preferably 3.0 equivalents Equivalent range.

If the amount of polyisocyanate used is too large, the excessive isocyanate groups tend to cause side reactions, making it difficult to achieve the desired physical properties of the polyurethane. May be less stable.
The amount of the chain extender used is not particularly limited, but the lower limit is preferably 0.1 equivalents, more preferably 0.5 equivalents, and still more preferably 0 equivalents per equivalent of the number of isocyanate groups contained in the prepolymer. 8 equivalents, and the upper limit is preferably 5.0 equivalents, more preferably 3.0 equivalents, and still more preferably 2.0 equivalents.

For the purpose of adjusting the molecular weight, monofunctional organic amines and alcohols may coexist during the chain extension reaction.

In the two-step method (b), the amount of polyisocyanate to be used when producing a prepolymer having a terminal hydroxyl group is not particularly limited. As the number of isocyanate groups in terms of equivalents, the lower limit is preferably 0.1 equivalents, more preferably 0.5 equivalents, still more preferably 0.7 equivalents, and the upper limit is preferably 0.99 equivalents, more preferably 0.98 equivalents, more preferably 0.97 equivalents.

If the amount of polyisocyanate used is too small, the subsequent chain elongation reaction will take a long time to obtain the desired molecular weight, which tends to reduce production efficiency. may decrease, or poor handling may result in poor productivity.
The amount of the chain extender used is not particularly limited, but when the total number of hydroxyl groups of the polycarbonate diol used in the prepolymer and the other polyols is 1 equivalent, the total amount obtained by adding the equivalent of the isocyanate group used in the prepolymer As equivalents, the lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, and still more preferably 0.9 equivalents, and the upper limit is preferably less than 1.0 equivalents, more preferably 0.99 equivalents, and still more preferably. is in the range of 0.98 equivalents.

For the purpose of adjusting the molecular weight, monofunctional organic amines and alcohols may coexist during the chain extension reaction.

The chain extension reaction is usually carried out at 0° C. to 250° C., but this temperature varies depending on the amount of solvent, reactivity of raw materials used, reaction equipment, etc., and is not particularly limited. If the temperature is too low, the reaction progresses too slowly, and the solubility of the raw materials and polymer may be low, which may lengthen the production time. . The chain extension reaction may be performed under reduced pressure while defoaming.

Moreover, a catalyst, a stabilizer, etc. can also be added to a chain extension reaction as needed.

Examples of the catalyst include compounds such as triethylamine, tributylamine, dibutyltin dilaurate, stannous octoate, acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid. The above may be used in combination.
Examples of stabilizers include 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N,N'-di-2-naphthyl-1,4-phenylenediamine, tris(dinonylphenyl)phosphate, Compounds such as phyto may be mentioned, and one kind may be used alone, or two or more kinds may be used in combination.
If the chain extender is highly reactive such as a short-chain aliphatic amine, the reaction may be carried out without adding a catalyst.

<2-10. Aqueous polyurethane emulsion>
It is also possible to produce aqueous polyurethane emulsions using the polycarbonate diols of the present invention. In that case, a compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is mixed in the reaction of the polyol containing the polycarbonate diol with the excess polyisocyanate to produce the prepolymer. A prepolymer is formed, and a water-based polyurethane emulsion is obtained through a process of neutralization and chlorination of hydrophilic functional groups, an emulsification process by adding water, and a chain extension reaction process.

The hydrophilic functional group of the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups used herein is, for example, a carboxyl group or a sulfonic acid group, which can be neutralized with an alkaline group. It is a base. In addition, the isocyanate-reactive group is a group that generally reacts with isocyanate to form a urethane bond or a urea bond, such as a hydroxyl group, a primary amino group, or a secondary amino group. It doesn't matter if you are.

Specific examples of compounds having at least one hydrophilic functional group and at least two isocyanate-reactive groups include 2,2′-dimethylolpropionic acid, 2,2-methylolbutyric acid, 2,2′ - dimethylol valeric acid and the like. Also included are diaminocarboxylic acids such as lysine, cystine, 3,5-diaminocarboxylic acid and the like. These may be used individually by 1 type, and may use 2 or more types together. When these are actually used, they are neutralized with amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine and triethanolamine, and alkaline compounds such as sodium hydroxide, potassium hydroxide and ammonia. be able to.

When producing a water-based polyurethane emulsion, the amount of the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups should be adjusted to increase the dispersibility in water. It is preferably 1% by mass, more preferably 5% by mass, still more preferably 10% by mass, based on the total weight of the polycarbonate diol and other polyols. On the other hand, if too much is added, the properties of the polycarbonate diol of the present invention may not be maintained. is.

When producing an aqueous polyurethane emulsion, the reaction may be carried out in the presence of a solvent such as methyl ethyl ketone, acetone, or N-methyl-2-pyrrolidone in the prepolymer step, or may be carried out without a solvent. Moreover, when using a solvent, it is preferable to distill off the solvent by distillation after manufacturing an aqueous emulsion.

Higher fatty acid, resin acid, acidic fatty alcohol, sulfate, higher alkyl sulfonate, higher alkyl sulfonate, alkylaryl sulfonate, sulfonated castor oil, sulfosuccinate, etc. Cationic surfactants such as anionic surfactants, primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts, pyridinium salts, or ethylene oxide and long-chain fatty alcohols or phenols The emulsification stability may be maintained by using a nonionic surfactant or the like in combination, which is represented by a known reaction product with .

In addition, when making a water-based polyurethane emulsion, water is mechanically mixed under high shear in the presence of an emulsifier with an organic solvent solution of the prepolymer, if necessary, without the neutralization and chlorination step, to produce the emulsion. You can also

The water-based polyurethane emulsion thus produced can be used for various purposes. In particular, there is a recent demand for chemical raw materials with less environmental impact, and it is possible to replace conventional products for the purpose of not using organic solvents.

Specific uses of water-based polyurethane emulsions include, for example, coating agents, water-based paints, adhesives, synthetic leathers, and artificial leathers. In particular, the water-based polyurethane emulsion produced using the polycarbonate diol of the present invention has a structural unit derived from the compound represented by the formula (B) in the polycarbonate diol, so that it is flexible and a coating agent. As such, it can be used more effectively than conventional water-based polyurethane emulsions using polycarbonate diols.

<2-11. Additive>
Polyurethanes of the present invention produced using the polycarbonate diols of the present invention contain heat stabilizers, light stabilizers, colorants, fillers, stabilizers, UV absorbers, antioxidants, antiblocking agents, flame retardants, anti-aging agents. Various additives such as inhibitors and inorganic fillers can be added and mixed within limits that do not impair the properties of the polyurethane of the present invention.

Compounds that can be used as heat stabilizers include phosphoric acid, aliphatic, aromatic or alkyl-substituted aromatic esters of phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkyl Phosphorus compounds such as pentaerythritol diphosphite and dialkylbisphenol A diphosphite; phenol derivatives, especially hindered phenol compounds; Compounds containing sulfur; tin-based compounds such as tin malate, dibutyltin monoxide, and the like can be used.

Specific examples of the hindered phenol compound include Irganox1010 (trade name: manufactured by BASF Japan Ltd.), Irganox1520 (trade name: manufactured by BASF Japan Ltd.), Irganox245 (trade name: manufactured by BASF Japan Ltd.), and the like.

Phosphorus compounds include PEP-36, PEP-24G, HP-10 (all trade names: manufactured by ADEKA Corporation) and Irgafos 168 (trade name: manufactured by BASF Japan Ltd.).

Specific examples of sulfur-containing compounds include thioether compounds such as dilaurylthiopropionate (DLTP) and distearylthiopropionate (DSTP).

Examples of light stabilizers include benzotriazole-based compounds and benzophenone-based compounds. ”, “SANOL LS-765” (manufactured by Sankyo Co., Ltd.) and the like can be used.

Examples of ultraviolet absorbers include "TINUVIN328" and "TINUVIN234" (manufactured by Ciba Specialty Chemicals Co., Ltd.).

Colorants include dyes such as direct dyes, acid dyes, basic dyes and metal complex dyes; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide and mica; Organic pigments such as anthraquinone-based, thioindigo-based, dioxazone-based, and phthalocyanine-based pigments can be used.

Examples of inorganic fillers include short glass fibers, carbon fibers, alumina, talc, graphite, melamine, and clay.

Examples of flame retardants include additive and reactive flame retardants such as phosphorous and halogen containing organic compounds, bromine or chlorine containing organic compounds, ammonium polyphosphate, aluminum hydroxide, antimony oxide and the like.

These additives may be used alone, or two or more of them may be used in any combination and ratio.

Regarding the amount of these additives added, the lower limit is preferably 0.01% by mass, more preferably 0.05% by mass, still more preferably 0.1% by mass, and the upper limit is preferably 10% by mass, as a mass ratio to polyurethane. % by mass, more preferably 5% by mass, still more preferably 1% by mass. If the amount of the additive added is too small, the effect of addition cannot be sufficiently obtained, and if it is too large, it may precipitate in the polyurethane or cause turbidity.

<2-12. Molecular weight>
The molecular weight of the polyurethane of the present invention is appropriately adjusted according to its use, and is not particularly limited. and more preferably 100,000 to 300,000. If Mw is less than the above lower limit, sufficient strength and hardness may not be obtained.

<2-13. Low temperature flexibility>
The polyurethane of the present invention has a ratio of 100% modulus at -10°C to 100% modulus at 23°C (100% modulus (-10°C) /100% modulus (23°C)) is preferably small, and the smaller this ratio, the better the low-temperature flexibility. Preferably, this ratio is less than 4.0, more preferably less than 3.0.

<2-14. Oleic Acid Resistance>
The polyurethane of the present invention is evaluated, for example, by the method described in the section of Examples below, and the rate of change in the mass of the polyurethane test piece after immersion in oleic acid with respect to the weight of the polyurethane test piece before immersion in oleic acid. (%) is preferably less than 16%, more preferably less than 8%. If this mass change rate exceeds the above upper limit, sufficient oleic acid resistance may not be obtained.

<2-15. Ethanol resistance>
The polyurethane of the present invention can be evaluated, for example, by the method described in the section of Examples below, the rate of change (% ) is preferably less than 16%, more preferably less than 8%. If this mass change rate exceeds the above upper limit, sufficient ethanol resistance may not be obtained.

<2-16. Solution stability>
A solution obtained by dissolving the polyurethane of the present invention in an aprotic solvent (hereinafter also referred to as "polyurethane solution") was stored at -10°C for 1 month by the method described in the Examples section below. It is preferred that the solution does not change. If the solution stability is low, crystals may precipitate during storage or the solution viscosity may increase.

The polyurethane of the present invention using the polycarbonate diol of the present invention has excellent solution stability at low temperatures when made into a polyurethane solution, and the polyurethane solution does not change even when stored at -5°C or lower, or even -10°C or lower. can be stably stored.

Aprotic solvents suitable for use in the polyurethane solution of the present invention include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone and dimethyl sulfoxide. and more preferably N,N-dimethylformamide and N,N-dimethylacetamide.

The polyurethane content in the polyurethane solution is generally preferably 1 to 99% by mass, more preferably 5 to 90% by mass, still more preferably 10 to 70% by mass, and particularly It is preferably 15 to 50% by mass. By setting the content of polyurethane in the polyurethane solution to 1% by mass or more, it is not necessary to remove a large amount of solvent, and productivity can be improved. Moreover, by making it 99 mass % or less, the viscosity of a solution can be suppressed and operability or workability can be improved.

<2-18. Polyurethane film/polyurethane plate>
When the polyurethane of the present invention is used to produce a film, the lower limit of the film thickness is preferably 10 μm, more preferably 20 μm, still more preferably 30 μm, and the upper limit is preferably 1000 μm, more preferably 500 μm, and even more preferably. is 100 μm.

If the thickness of the film is too thick, there is a tendency that sufficient moisture permeability cannot be obtained.

<2-19. Application>
Since the polyurethane of the present invention has an excellent balance of physical properties such as solution stability, low-temperature flexibility, chemical resistance, especially ethanol resistance, it can be used for foams, elastomers, elastic fibers, paints, fibers, adhesives, adhesives, flooring materials, It can be widely used for sealants, medical materials, artificial leathers, synthetic leathers, coating agents, water-based polyurethane paints, active energy ray-curable resin compositions, and the like.

In particular, when the polyurethane of the present invention is used in applications such as artificial leather, synthetic leather, water-based polyurethane, adhesives, elastic fibers, medical materials, flooring materials, paints, coating agents, etc., it exhibits excellent solution stability, chemical resistance, low temperature resistance, and the like. Because it has a good balance of flexibility, it is highly durable in areas where it comes into contact with human skin, or where cosmetic chemicals or alcohol for disinfection are used, and it has sufficient flexibility at low temperatures, and is physically resistant. It is possible to impart good properties such as being strong against strong impacts and the like. It is also suitable for use as an intermediate coating for automotive exteriors, which requires flexibility at even lower temperatures.

The polyurethane of the present invention can be used as a resin for the outer surface of artificial leather. Specific uses include surface materials and wall materials for chairs, sofas, furniture, and various interiors; interior materials and seat skin materials for automobiles, railway vehicles, aircraft, and ships; clothing such as jackets, coats, shoes, and belts. It can be used for materials, small items such as bags and handbags, and decorative items such as ribbons and emblems.

A well-known method can be used for the manufacturing method of artificial leather. Specifically, after impregnating or applying a urethane emulsion using the polyurethane of the present invention to the interior of the fiber material that will be the base fabric of the artificial leather, the polyurethane is applied to the interior of the fiber material by coagulating and drying. It can be manufactured by polishing the surface of the fiber material according to the requirements.

A known method can be used for impregnating or coating the fiber material with the polyurethane emulsion, and the method is not particularly limited. For example, there is a method of squeezing with a mangle roll after impregnation to adjust the pick-up amount, a method of directly applying with a floating knife coater, knife over roll coater, reverse roll coater, roll doctor coater, gravure roll coater, kiss roll coater, etc. .

As the fibrous material, conventionally used nonwoven fabrics, woven fabrics, knitted fabrics, and the like can be used.

Also, as the fiber material, it is possible to use a multi-layered three-dimensional entangled body having a two-layer structure or more of a surface fiber layer and a woven or knitted scrim. When a multi-layered three-dimensional entangled body is used, it is preferable to use a multi-layered three-dimensional entangled body having a three-layer structure or more in which a scrim is sandwiched between the front fiber layer and the back fiber layer.

When using a multi-layer structure three-dimensional entangled body, it is preferable that only the surface fiber layer, or the surface fiber layer and the back surface fiber layer are paper sheets. Furthermore, it is preferable that the multilayer structure three-dimensional entangled body is hydroentangled and integrated.

The fibers that make up the fiber material include those directly spun by the melt spinning method, sea-island type fibers using copolymer polyethylene terephthalate as the sea component and regular polyethylene terephthalate as the island component, and the sea component is dissolved or decomposed. Ultrafine fibers obtained by removal, and the like, which are taken out from ultrafine fiber-generating fibers, can be used.

The thread constituting the fibrous material may be monofilament or multifilament. The monofilament fineness of the yarn is preferably 5.5 dtex or less in order to easily obtain a flexible artificial leather.

The amount of polyurethane emulsion adhered to the fiber material is preferably 5 to 100 parts by mass in solid content per 100 parts by mass of the base fabric in the case of impregnation, and in the case of coating, the thickness of the coating after drying is 0.1 to 10 mm. It is preferable that the amount is such that

The polyurethanes of the invention can be used in cast polyurethane elastomers. Specific applications include rolling rolls, paper manufacturing rolls, office equipment, rolls such as pretension rolls, solid tires for forklifts, automobile vehicle nutrams, trolleys, trucks, casters, etc. Industrial products include conveyor belt idlers and guides. Rolls, pulleys, steel pipe linings, ore rubber screens, gears, connection rings, liners, pump impellers, cyclone cones, cyclone liners, etc. It can also be used for OA equipment belts, paper feed rolls, copying cleaning blades, snow plows, toothed belts, surf rollers and the like.

The polyurethanes of the invention also find application as thermoplastic elastomers. For example, it can be used for tubes and hoses, spiral tubes, fire hoses, etc. in pneumatic equipment used in the food and medical fields, coating equipment, analytical equipment, physical and chemical equipment, metering pumps, water treatment equipment, industrial robots, and the like. In addition, it is used as a belt such as a round belt, a V belt, a flat belt, etc. in various transmission mechanisms, spinning machines, packing machines, printing machines, and the like. It can also be used for heel tops and soles of footwear, couplings, packings, pole joints, bushes, gears, machine parts such as rolls, sporting goods, leisure goods, watch belts and the like. Automobile parts include oil stoppers, gearboxes, spacers, chassis parts, interior parts, and tire chain substitutes. Also, it can be used for films such as keyboard films and films for automobiles, curled cords, cable sheaths, bellows, conveyor belts, flexible containers, binders, synthetic leathers, dipping products, adhesives and the like.

The polyurethane of the present invention can also be applied as a solvent-based two-component paint, and can be applied to wood products such as musical instruments, Buddhist altars, furniture, decorative plywood, and sporting goods. It can also be used for automobile repair as tar epoxy urethane.
The polyurethane of the present invention can be used as a component of moisture-curable one-pack paints, blocked isocyanate-based solvent paints, alkyd resin paints, urethane-modified synthetic resin paints, ultraviolet-curable paints, water-based urethane paints, and the like. Paints for plastic bumpers, strippable paints, coating agents for magnetic tapes, overprint varnishes for floor tiles, flooring materials, paper, wood grain printing films, etc., varnishes for wood, coil coats for high processing, optical fiber protective coatings, solder resists, metals It can be applied to printing top coats, vapor deposition base coats, white coats for food cans, and the like.

The polyurethane of the present invention can also be applied as a pressure-sensitive adhesive or adhesive to food packaging, shoes, footwear, magnetic tape binders, decorative paper, wood, structural members, and the like. can also be used.
The polyurethane of the present invention can be used as a binder for magnetic recording media, inks, castings, baked bricks, graft materials, microcapsules, granular fertilizers, granular pesticides, polymer cement mortar, resin mortar, rubber chip binders, recycled foams, glass fiber sizing, and the like. Available.

The polyurethane of the present invention can be used as a component of a fiber processing agent for shrink-proofing, wrinkle-proofing, water-repellent finishing, and the like.
When the polyurethane of the present invention is used as an elastic fiber, the fiberization method is not particularly limited as long as it can be spun. For example, a melt spinning method can be employed in which the material is pelletized, melted, and spun directly through a spinneret. When the elastic fiber is obtained from the polyurethane of the present invention by melt spinning, the spinning temperature is preferably 250°C or lower, more preferably 200°C or higher and 235°C or lower.

The polyurethane elastic fiber of the present invention can be used as it is as a bare yarn, or can be coated with other fibers and used as a covered yarn. Examples of other fibers include conventionally known fibers such as polyamide fibers, wool, cotton and polyester fibers, among which polyester fibers are preferably used in the present invention. Further, the polyurethane elastic fiber of the present invention may contain a dyeing type disperse dye.

The polyurethane of the present invention can be used as a sealant and caulking for concrete walls, induced joints, around sashes, wall-type PC joints, ALC joints, board joints, composite glass sealants, heat-insulating sash sealants, automotive sealants, and the like. .
The polyurethane of the present invention can be used as a medical material, including blood compatible materials such as tubes, catheters, artificial hearts, artificial blood vessels, and artificial valves, and disposable materials such as catheters, tubes, bags, and surgical gloves. , artificial kidney potting materials, etc.
By modifying the terminal of the polyurethane of the present invention, it can be used as a raw material for UV curable coatings, electron beam curable coatings, photosensitive resin compositions for flexographic printing plates, photocurable optical fiber coating compositions, and the like. can.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

[Evaluation method]
Various evaluation methods in the following examples and comparative examples are as follows.

[Method for evaluating polycarbonate diol]
<Hydroxyl value/number average molecular weight>
According to JIS K1557-1, the hydroxyl value of the polycarbonate diol was measured by a method using an acetylation reagent. Also, from the hydroxyl value, the number average molecular weight was determined by the following formula (1).
Number average molecular weight = 2 × 56.1 / (hydroxyl value × 10 ^-3 ) (1)

<Measurement of polystyrene equivalent weight average molecular weight (Mw) and number average molecular weight (Mn)>
Polystyrene-equivalent weight-average molecular weight (Mw) and polystyrene-equivalent number-average molecular weight (Mn) of the polycarbonate diol were determined by GPC measurement under the following conditions.
Apparatus: HLC-8020 manufactured by Tosoh Corporation
Column: TSKgel GMHXL-L (7.8 mm ID × 30 cmL
x 4)
Eluent: THF (tetrahydrofuran)
Flow rate: 1.0 mL/min
Column temperature: 40°C
RI detector: RI (equipment HLC-8020 built-in)
Then, the molecular weight distribution (Mw/Mn) was calculated.

<Molar Ratio of Structural Units Derived from the Compound Represented by Formula (A) to Structural Units Derived from the Compound Represented by Formula (B)>
Polycarbonate diol is dissolved in CDCl ₃ , 400 MHz ¹ H-NMR ("AL-400" manufactured by JEOL Ltd.) is measured, and from the signal position of each component, the structure derived from the compound represented by formula (A) The molar ratio (A)/(B) of the unit and the structural unit derived from the compound represented by formula (B) was determined.

<Phenol content>
Polycarbonate diol was dissolved in CDCl ₃ and 400 MHz ¹ H-NMR ("AVANCE 400" manufactured by BRUKER) was measured, and calculation was performed from the integrated value of the signal of each component. The detection limit in that case is 100 ppm as the mass of phenol.

<Content of catalyst metal in polycarbonate diol>
About 0.1 g of polycarbonate diol was measured and dissolved in 4 mL of acetonitrile, and then 20 mL of pure water was added to precipitate the polycarbonate diol, which was removed by filtration. The filtered solution was diluted with pure water to a predetermined concentration, and the concentration of metal ions was analyzed by ion chromatography. The metal ion concentration of acetonitrile used as a solvent was measured as a blank value, and the value obtained by subtracting the metal ion concentration of the solvent was taken as the amount of metal in the polycarbonate diol. Measurement conditions are as shown in Table 1 below. The magnesium concentration was determined using the analytical results and a pre-made calibration curve.

[Evaluation method of polyurethane]
<Molecular weight>
Polyurethane was dissolved in dimethylacetamide to prepare a dimethylacetamide solution having a concentration of 0.14% by mass. Using a GPC apparatus [manufactured by Tosoh Corporation, product name "HLC-8220" (column: TskgelGMH-XL, 2 columns)], the dimethylacetamide solution is injected, and the weight average molecular weight (Mw) of the polyurethane is calculated in terms of standard polystyrene. was measured.

<Tensile test>
The polyurethane solution was applied onto a fluororesin sheet (fluorocarbon tape Nitoflon 900, thickness 0.1 mm, manufactured by Nitto Denko Corporation) using a 9.5 mil applicator, and then heated at 60°C for 1 hour, followed by 0.5 at 100°C. dried for an hour. After further drying at 100°C under vacuum for 0.5 hour and at 80°C for 15 hours, it was allowed to stand at constant temperature and humidity at 23°C and 55% RH for 12 hours or longer. A test piece is cut out, and this test piece is used in accordance with JIS K6301 (2010) using a tensile tester (manufactured by Orientec, product name “Tensilon UTM-III-100”) with a chuck distance of 50 mm and a tensile speed. At 500 mm / min, a tensile test was performed at a temperature of 23 ° C. or -10 ° C. and a relative humidity of 55%, and the stress at the time when the test piece was stretched 100%: 100% modulus was measured, -10 ° C. /23°C ratio was calculated. The lower the 100% modulus ratio, the better the low temperature flexibility. Using the calculated ratio, low-temperature flexibility was evaluated according to the following evaluation criteria.
◎: -10 ° C./23 ° C. ratio of 100% modulus is less than 3.0 ○: -10 ° C./23 ° C. ratio of 100% modulus is 3.0 or more and less than 4.0% ×: -10 ° C. of 100% modulus /23°C ratio is 4.0 or more

<Evaluation of oleic acid resistance>
A test piece of 3 cm x 3 cm was cut out from the polyurethane film prepared for the above tensile test. After measuring the mass of the test piece with a precision balance, it was placed in a 250 mL glass bottle containing 50 mL of oleic acid as a test solvent, and allowed to stand in a constant temperature bath at 80° C. under a nitrogen atmosphere for 16 hours. After the test, the test piece was taken out and lightly wiped on the front and back with a paper wiper, and the mass was measured with a precision balance to calculate the mass change rate (increase rate) from before the test. The oleic acid resistance was evaluated from the mass change rate according to the following criteria.
◎: Mass change rate is less than 8% ○: Mass change rate is 8% or more and less than 16% ×: Mass change rate is 16% or more

<Evaluation of ethanol resistance>
A test piece of 3 cm x 3 cm was cut out from the polyurethane film prepared for the above tensile test. After measuring the weight of the test piece with a precision balance, it was placed in a glass petri dish with an inner diameter of 10 cmφ containing 50 mL of ethanol as a test solvent and immersed at room temperature of about 23° C. for 1 hour. After the test, the test piece was taken out and lightly wiped on the front and back with a paper wiper, and the mass was measured with a precision balance to calculate the mass change rate (increase rate) from before the test. Ethanol resistance was evaluated from the mass change rate according to the following criteria.
◎: Mass change rate is less than 8% ○: Mass change rate is 8% or more and less than 16% ×: Mass change rate is 16% or more

<Low temperature solution stability>
50 mL of a polyurethane solution (polyurethane concentration: 30% by mass) in which polyurethane is dissolved in dimethylformamide is placed in a sample bottle and allowed to stand in a freezer at −10° C. for 30 days. It was evaluated according to the evaluation criteria.
◎: No crystallization, fluidity ○: No crystallization, fluidity slightly decreased △: Not crystallized, but no fluidity ×: Crystallized

[Production and Evaluation of Polycarbonate Diol]
<Example I-1>
1,4-butanediol: 837.2 g, 1,10-decanediol: 629.6 g, diphenyl carbonate: 2533.4 g in a 5 L glass separable flask equipped with a stirrer, distillate trap, and pressure regulator. , magnesium acetate tetrahydrate aqueous solution: 6.6 mL (concentration: 8.4 g/L, magnesium acetate tetrahydrate: 56 mg) was added, and nitrogen gas was substituted. While stirring, the internal temperature was raised to 160° C. to heat and dissolve the contents. After that, the pressure was lowered to 24 kPa over 2 minutes, and the reaction was allowed to proceed for 90 minutes while removing phenol out of the system. Next, the pressure was lowered to 9.3 kPa over 90 minutes, and further lowered to 0.4 kPa over 30 minutes to continue the reaction, and then the temperature was raised to 170° C. to remove phenol and unreacted dihydroxy compounds out of the system. while reacting for 60 minutes to obtain a polycarbonate diol-containing composition. Thereafter, 2.6 mL of 0.85% by mass phosphoric acid aqueous solution (22 mg as phosphoric acid) was added to deactivate magnesium acetate to obtain a polycarbonate diol-containing composition.

The resulting polycarbonate diol-containing composition was fed to a thin film distillation apparatus at a flow rate of about 20 g/min, and subjected to thin film distillation (temperature: 170°C, pressure: 53 to 67 Pa). As the thin film distillation apparatus, a jacketed molecular distillation apparatus "MS-300 Special Model" manufactured by Shibata Scientific Co., Ltd. with an internal condenser having a diameter of 50 mm, a height of 200 mm and an area of 0.0314 m ² was used.

The content of phenols in the polycarbonate diol obtained by thin film distillation was 100 mass ppm or less. Moreover, the content of magnesium was 100 mass ppm or less.
The polycarbonate diol prepared in this Example I-1 is referred to as "PCD-1".
Table 2 shows the evaluation results of the properties and physical properties of this PCD1.

[Example I-2]
A polycarbonate diol was obtained in the same manner as in Example I-1 except that the composition of the raw materials used was changed to the amount shown in Table 2. The polycarbonate diol prepared in Example I-2 is referred to as "PCD-2." Table 2 shows the evaluation results of the properties and physical properties of this PCD-2.

[Comparative Example I-1]
A polycarbonate diol was obtained in the same manner as in Example I-1 except that the composition of the raw materials used was changed to the amount shown in Table 2. The polycarbonate diol produced in Comparative Example I-1 is referred to as "PCD-3." Table 2 shows the evaluation results of the properties and physical properties of this PCD-3.

[Comparative Example I-2]
A polycarbonate diol was obtained in the same manner as in Example I-1 except that the composition of the raw materials used was changed to the amount shown in Table 2. The polycarbonate diol produced in Comparative Example I-2 is referred to as "PCD-4." Table 2 shows the evaluation results of the properties and physical properties of this PCD-4.

[Example II-1]
<Production of Polyurethane>
Using the PCD-1 obtained in Example I-1 as a starting material, a polyurethane was produced by the following procedure.
A separable flask equipped with a thermocouple, a condenser tube and a stirrer was placed on an oil bath at 60°C, and 69.8 g of PCD1 preheated to 80°C was added to 1,4-butanediol (hereinafter “1, 4BD”) was added, and 241.49 g of dehydrated N,N-dimethylformamide (hereinafter sometimes abbreviated as “DMF”; manufactured by Wako Pure Chemical Industries, Ltd.) was added. 24.00 g of 4′-diphenylmethane diisocyanate (hereinafter sometimes referred to as “MDI”) was added, and the inside of the separable flask was heated to 70° C. in about 1 hour while stirring at 60 rpm in a nitrogen atmosphere. After reaching 70° C., 0.026 g of Neostan U-830 (hereinafter sometimes referred to as “U-830”, manufactured by Nitto Kasei Co., Ltd.) is added as a urethanization reaction catalyst, and the temperature is maintained at 70° C. for about 2 hours. Stirred. Thereafter, 3.24 g of MDI was added in portions (the total amount of MDI added was 27.24 g) to adjust the molecular weight, and a polyurethane having a molecular weight of 165,000 was obtained. Table 3 shows the properties and physical properties of this polyurethane.

[Example II-2]
A polyurethane was obtained in the same manner as in Example II-1, except that PCD-2 was used in place of PCD-1 and the raw materials were changed to the amounts shown in Table 3. Table 3 shows the properties and physical properties of the obtained polyurethane.

[Comparative Example II-1]
A polyurethane was obtained in the same manner as in Example II-1, except that PCD-3 was used in place of PCD-1 and the raw materials were changed to the amounts shown in Table 3. Table 3 shows the properties and physical properties of the obtained polyurethane.

[Comparative Example II-2]
A polyurethane was obtained in the same manner as in Example II-1, except that PCD-4 was used in place of PCD-1 and the raw materials were changed to the amounts shown in Table 3. Table 3 shows the properties and physical properties of the obtained polyurethane.

Table 3 shows the following.
It is clear that the polyurethanes of Examples II-1 and 2 using the specific copolymerized polycarbonate diol of the present invention are excellent in low-temperature flexibility and solution stability. It also has excellent chemical resistance, especially ethanol resistance. On the other hand, the polyurethanes described in Comparative Examples II-1 and II-2 are inferior in solution stability and deteriorate in low-temperature flexibility. Also, the ethanol resistance is not as good as the polyurethane using the polycarbonate diol described in the examples.

Claims (13)

A polycarbonate diol containing a structural unit derived from a compound represented by the following formula (A) and a structural unit derived from a compound represented by the following formula (B), wherein the hydroxyl value is 37.4 mg-KOH/g or more. 140 mg-KOH / g or less, the weight average molecular weight / number average molecular weight (Mw / Mn) is 1.5 or more and 3.5 or less, the structural unit represented by the following formula (A) and the following formula (B) (A)/(B)=89/11 to 51/49.
HO—R ¹ —OH (A)
HO—R ² —OH (B)
(In formula (A) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms, and in formula (B) above, R ² represents a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms. represents a valent alkylene group.) The total ratio of the structural units derived from the compound represented by the formula (A) and the structural units derived from the compound represented by the formula (B) is 50 mol% or more in all the structural units of the polycarbonate diol. The polycarbonate diol according to claim 1, characterized in that 3. The polycarbonate diol according to claim 1, wherein the hydroxyl value is 44.8 mg-KOH/g or more and 125 mg-KOH/g or less. The polycarbonate diol according to any one of claims 1 to 3, wherein the compound represented by formula (A) is 1,4-butanediol. wherein the compound represented by the formula (B) is at least one compound selected from the group consisting of 1,10-decanediol, 1,11-undecanediol and 1,12-dodecanediol; 5. The polycarbonate diol according to any one of 4. 6. The polycarbonate diol according to any one of claims 1 to 5, wherein at least one of the compound represented by formula (A) and the compound represented by formula (B) is derived from a plant. A polyurethane using the polycarbonate diol according to any one of claims 1 to 6. Artificial leather or synthetic leather produced using the polyurethane according to claim 7. A paint or coating agent produced using the polyurethane according to claim 7. An elastic fiber produced using the polyurethane of claim 7. A water-based polyurethane paint produced using the polyurethane according to claim 7. A pressure-sensitive adhesive or adhesive produced using the polyurethane according to claim 7. A method for storing a polyurethane solution obtained using a polycarbonate diol at −5° C. or lower, wherein the polycarbonate diol is a structural unit derived from a compound represented by the following formula (A) and a structural unit represented by the following formula (B): The ratio of the structural unit represented by the following formula (A) to the structural unit represented by the following formula (B) is (A)/(B) = 89/11 to 51 /49, a hydroxyl value of 38.0 mg-KOH/g or more and 140 mg-KOH/g or less, and a weight average molecular weight/number average molecular weight (Mw/Mn) of 1.5 or more and 3.5 or less. How to store the solution at -5°C or below.
HO—R ¹ —OH (A)
HO—R ² —OH (B)
(In formula (A) above, R ¹ represents a substituted or unsubstituted divalent alkylene group having 4 carbon atoms, and in formula (B) above, R ² represents a substituted or unsubstituted divalent alkylene group having 8 to 20 carbon atoms. represents a valent alkylene group.)