JP2016008234A - Polyurethane for synthetic leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyurethane for a synthetic leather that has well-balanced physical properties of flexibility, chemical resistance, low temperature characteristics, heat resistance and touch feeling.SOLUTION: The polyurethane for a synthetic leather is obtained by reacting (a) a compound containing two or more isocyanate groups in one molecule, (b) a chain extender and (c) a polycarbonate diol. For the (c) polycarbonate diol, the hydroxyl value is 20 mg-KOH/g or more and 45 mg-KOH/g or less, the glass-transition temperature measured by a differential scanning calorimeter is -30°C or less, and the average carbon number of a dihydroxy compound obtained by hydrolyzing the polycarbonate diol is 3 or more and 5.5 or less.

Description

  The present invention relates to a polyurethane for human synthetic leather, in which the balance of physical properties of flexibility, chemical resistance, low temperature characteristics, heat resistance, and touch is improved by using a specific polycarbonate diol as a raw material polycarbonate diol.

  In recent years, synthetic leather has been used in a wide variety of fashion materials and interior materials because it has a texture and durability that is not inferior to that of natural leather. Artificial leather or synthetic leather is formed of a multilayer structure such as a base material made of non-woven fabric, woven fabric or knitted fabric, a resin layer laminated or filled therein, a porous resin film layer, an adhesive layer, or a skin layer. Polyurethane is generally used as the resin used for each of these layers.

  Conventionally, the raw material of the main soft segment part of polyurethane produced on an industrial scale is ether type typified by polytetramethylene glycol, polyester polyol type typified by adipate ester, polylactone type typified by polycaprolactone Or it is divided into the polycarbonate type represented by polycarbonate diol (nonpatent literature 1).

  Among these, polyurethane using ether type is said to be inferior in heat resistance and weather resistance, although it is excellent in hydrolysis resistance, flexibility and stretchability. On the other hand, polyurethane using a polyester polyol type is improved in heat resistance and weather resistance, but has low ester group hydrolysis resistance and cannot be used depending on the application.

  On the other hand, polyurethanes using polylactone type are considered to be superior in hydrolysis resistance compared to polyurethanes using polyester polyol type, but the hydrolysis is completely suppressed due to the presence of ester groups. I can't. In addition, it has been proposed to mix these polyester polyol type, ether type and polylactone type and use them as raw materials for polyurethane, but it has not been possible to completely compensate for the respective drawbacks.

  On the other hand, polyurethane using a polycarbonate type typified by polycarbonate diol is the best durability grade in heat resistance and hydrolysis resistance, and is widely used as a resin for high-quality synthetic leather. .

  However, the polycarbonate diol that is currently widely marketed is a polycarbonate diol synthesized mainly from 1,6-hexanediol, but since this has high crystallinity, the cohesiveness of the soft segment when polyurethane is used. In particular, there is a problem that flexibility, elongation, bending, or elastic recovery at low temperatures is poor, and the application is limited. Furthermore, it has been pointed out that the synthetic leather produced from this polyurethane as a raw material has a hard texture and has a “feel” that is worse than that of natural leather.

In order to solve the above problems, polycarbonate diols using 1,3-propanediol or 1,4-butanediol as raw materials have been proposed.
For example, polycarbonate diol copolymerized using 1,4-butanediol and 1,6-hexanediol as raw materials (Patent Document 1), polycarbonate diol copolymerized using 1,4-butanediol and 1,5-pentanediol as raw materials (Patent Document 2), polycarbonate diol (Patent Document 3) obtained by copolymerization using 1,3-propanediol and another dihydroxy compound as raw materials has been proposed.

  In addition, a polycarbonate diol using only 1,4-butanediol as a raw material for a dihydroxy compound, a synthetic leather using a polyurethane prepared using the polycarbonate diol, and the like have been proposed. (Patent Documents 4 to 6)

  Furthermore, as a high molecular weight polycarbonate diol, polycarbonate diol copolymerized using 1,5-pentanediol and 1,6-hexanediol as raw materials (Patent Document 7), 1,4-butanediol and 1,6-hexanediol A polycarbonate diol (Patent Document 8) obtained by copolymerization using as a raw material has been proposed.

  On the other hand, as a method for producing a polycarbonate diol, a method for synthesizing a high-molecular weight polycarbonate diol has been proposed. After reacting a dihydroxy compound with an alkyl carbonate to obtain a polycarbonate diol having a molecular weight of 500 to 2000, an aryl carbonate is further added. A method for producing a polycarbonate diol having a molecular weight exceeding 2000 (Patent Document 9), and a method for producing a high-quality polycarbonate diol having a hydroxyl group at the molecular end and little coloring by reacting dimethyl carbonate with an aliphatic dihydroxy compound (Patent Document 10). Is described.

JP-A-5-51428 Japanese Patent Laid-Open No. 4-7327 International Publication No. 2002/070584 Pamphlet JP-A-6-206965 JP 7-41539 A JP 7-41540 A JP-A-2-289616 JP 2009-051888 A JP 2001-261811 A JP 2001-270938 A

"Basics and Applications of Polyurethane" pages 96-106, supervised by Katsuharu Matsunaga, CMC Publishing Co., Ltd., published in November 2006

However, these previously known techniques cannot satisfy the required characteristics of polyurethane for synthetic leather as follows.
The polycarbonate diols described in Patent Documents 1 to 3 have insufficient low temperature characteristics and chemical resistance when used as polyurethane.
Although the polycarbonate diols described in Patent Documents 4 to 6 have excellent chemical resistance when used as polyurethane, the low-temperature characteristics are inferior to polyurethanes using polycarbonate diol synthesized from 1,6-hexanediol. It was. In particular, Patent Document 4 describes a method for producing a polytetramethylene carbonate diol having a molecular weight of 500 to 10,000, but the polycarbonate produced substantially has a low molecular weight, so that the low temperature characteristics are insufficient. It was.
Further, the polycarbonate diol disclosed in Patent Document 7 does not have sufficient solvent resistance of polyurethane, and the polycarbonate diol disclosed in Patent Document 8 does not have sufficient low temperature characteristics of polyurethane. Regarding the polycarbonate diol of Patent Document 8, there is no description that it is preferable to use polyurethane using the polycarbonate diol as artificial leather or synthetic leather.
Further, Patent Document 9 or 10 describes a method for producing a high molecular weight polycarbonate diol, which relates to a polycarbonate diol using 1,6-hexanediol as a raw material, for example, 1,3-propanediol. As for polycarbonate diol using at least one of 1,4-butanediol and 1,5-pentanediol as a raw material, a polycarbonate diol having a substantially high molecular weight could not be synthesized.

  An object of the present invention is to provide a polyurethane for synthetic leather excellent in balance of physical properties such as flexibility, chemical resistance, low temperature characteristics, heat resistance, and tactile sensation, which could not be achieved by the prior art.

As a result of intensive studies to solve the above problems, the inventors of the present invention have a hydroxyl value of 20 mg-KOH / g or more and 45 mg-KOH / g or less as a polycarbonate diol as a polyurethane raw material. By using a polycarbonate diol having a measured glass transition temperature of −30 ° C. or less and an average number of carbon atoms of a dihydroxy compound obtained by hydrolysis of the polycarbonate diol of 3 to 5.5, flexibility, resistance The present inventors have found that a polyurethane having a good balance of chemical properties, low temperature characteristics, heat resistance, and tactile properties can be obtained, and the present invention has been achieved.
That is, the gist of the present invention is as follows.

[1] A polyurethane for synthetic leather obtained by reacting at least (a) a compound containing two or more isocyanate groups in one molecule, (b) a chain extender and (c) a polycarbonate diol, ) The polycarbonate diol has a hydroxyl value of 20 mg-KOH / g or more and 45 mg-KOH / g or less, a glass transition temperature measured by a differential operation calorimeter is -30 ° C. or less, and the polycarbonate diol is hydrolyzed. A polyurethane for synthetic leather, wherein the obtained dihydroxy compound is a polycarbonate diol having an average carbon number of 3 or more and 5.5 or less.

[2] The polyurethane for synthetic leather according to [1], wherein the ratio of ether bonds to carbonate bonds in the (c) polycarbonate diol is 0.01% or more and 5% or less.

[3] The polyurethane for synthetic leather according to [1] or [2], wherein the dihydroxy compound is only a linear aliphatic dihydroxy compound having no substituent.

[4] The ratio (Mw / Mn) of polystyrene-equivalent weight average molecular weight (Mw) to polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography of (c) polycarbonate diol is 1.5. It is the range of -3.0, The polyurethane for synthetic leathers in any one of [1]-[3] characterized by the above-mentioned.

[5] The dihydroxy compound includes at least one selected from the group consisting of 1,3-propanediol and 1,4-butanediol, according to any one of [1] to [4], Polyurethane for synthetic leather.

[6] The polyurethane for synthetic leather according to any one of [1] to [5], wherein the dihydroxy compound includes a plant-derived compound.

[7] The Hazen color number measured according to JIS K0071-1 (1998) of the (c) polycarbonate diol is 60 or less, according to any one of [1] to [6] Polyurethane for synthetic leather.

[8] A synthetic leather produced using the polyurethane for synthetic leather according to any one of [1] to [7].

  Synthetic leather produced using the polyurethane for synthetic leather of the present invention has an excellent balance of flexibility, chemical resistance, low temperature characteristics, heat resistance, and tactile physical properties, and is extremely useful industrially.

Hereinafter, although the form of this invention is demonstrated in detail, this invention is not limited to the following embodiment, Various deformation | transformation can be implemented within the range of the summary.
Here, in the present specification, “mass%” and “weight%”, “mass ppm” and “weight ppm”, and “mass part” and “weight part” are synonymous, respectively. In addition, when “ppm” is simply described, it indicates “weight ppm”.

[1. Polycarbonate diol]
First, specific (c) polycarbonate diol (hereinafter may be referred to as “polycarbonate diol of the present invention”) which is a raw material of the polyurethane for synthetic leather of the present invention will be described.

  The polycarbonate diol of the present invention has a hydroxyl value of 20 mg-KOH / g or more and 45 mg-KOH / g or less, a glass transition temperature measured by a differential operation calorimeter of -30 ° C. or less, and hydrolysis of the polycarbonate diol. The dihydroxy compound thus obtained has an average carbon number of 3 or more and 5.5 or less.

  That is, the present invention has all the conditions that the hydroxyl value is in a specific range, the glass transition temperature is below a specific value, and the average carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol is in the specific range. This is based on the finding that the polycarbonate diol to be filled is a polycarbonate diol which is a raw material for polyurethane having excellent physical properties such as flexibility, chemical resistance, low temperature characteristics, heat resistance and tactile properties.

<1-1. Hydroxyl value>
The hydroxyl value of the polycarbonate diol of the present invention is 20 mg-KOH / g or more and 45 mg-KOH / g or less. The lower limit of the hydroxyl value of the polycarbonate diol of the present invention is preferably 25 mg-KOH / g, more preferably 30 mg-KOH / g, still more preferably 35 mg-KOH / g. The upper limit is preferably 42 mg-KOH / g, more preferably 40 mg-KOH / g, and still more preferably 38 mg-KOH / g. If the hydroxyl value is less than the above lower limit, the viscosity of the polycarbonate diol becomes too high, and handling when making the polyurethane using the polycarbonate diol may be difficult. If the upper limit is exceeded, the polycarbonate diol is flexible when the polyurethane is made using the polycarbonate diol. Properties, low temperature characteristics, elastic recovery properties, etc. may be insufficient. Within the above range, the polyurethane has excellent flexibility, low temperature characteristics, elastic recovery, and tactile sensation, and good physical properties with respect to chemical resistance and heat resistance.
Specifically, the hydroxyl value of the polycarbonate diol is measured by the method described in the Examples section below.

<1-2. Structural features>
The polycarbonate diol of the present invention has an average carbon number (hereinafter sometimes simply referred to as “average carbon number”) of a dihydroxy compound obtained by hydrolyzing the polycarbonate diol of 3 or more and 5.5 or less. When polyurethane is used, good chemical resistance and heat resistance can be obtained. The upper limit of this average carbon number is 5.5, preferably 5.4, more preferably 5.3, still more preferably 5.0, particularly preferably 4.7, and most preferably 4.5. The lower limit of the average carbon number is 3, preferably 3.2, more preferably 3.4, and particularly preferably 3.5. When the average carbon number is less than the above lower limit, flexibility and low temperature characteristics may be insufficient, and when it exceeds the upper limit, chemical resistance and heat resistance may be insufficient.

  The average carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol in the present invention is determined from the result of gas chromatography analysis of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol by heating in the presence of an alkali. be able to. Specifically, it is calculated from the carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol and the molar ratio of the dihydroxy compound to the total dihydroxy compound. The specific method is as described in the Examples section.

  The dihydroxy compound obtained by hydrolyzing the polycarbonate diol may be one kind or plural kinds. In the case of a plurality of types, the polycarbonate diol of the present invention may be a copolymer or a mixture of different types of polycarbonate diols. Polymers are preferred. In the case of a copolymer, a block copolymer or a random copolymer may be used, but a polycarbonate diol of a random copolymer is preferable because the low temperature characteristics and flexibility of the resulting polyurethane are improved.

  The dihydroxy compound obtained by hydrolyzing the polycarbonate diol is preferably an aliphatic dihydroxy compound, particularly an aliphatic dihydroxy compound having 3 to 20 carbon atoms, and the aliphatic dihydroxy compound may be 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5 -Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12- Dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-he Xadecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and the like. Among these, a straight-chain aliphatic dihydroxy compound having no substituent is preferable because the physical properties of the polyurethane such as chemical resistance and heat resistance are improved. Further, at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol as the dihydroxy compound having a small carbon number that provides good chemical resistance and heat resistance properties. It is preferable to contain a seed, and it is more preferable to include any one of 1,3-propanediol and 1,4-butanediol. Furthermore, since the obtained polyurethane has good flexibility and low-temperature properties, the polycarbonate diol of the present invention preferably has low crystallinity. Therefore, the dihydroxy compound obtained by hydrolyzing the polycarbonate diol has an odd number of carbon atoms. Or a dihydroxy compound of two or more.

  The dihydroxy compound obtained by hydrolyzing the polycarbonate diol of the present invention is preferably a plant-derived compound. The compounds applicable as plant origin include 1,3-propanediol, 1,4-butanediol, 1,5-propanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decane. Examples include diol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,20-eicosanediol, and the like.

In the polycarbonate diol of the present invention, the flexibility and chemical resistance of the polyurethane obtained by making the hydroxyl value and the average carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol within the above preferred ranges, The mechanism for achieving a good balance between low-temperature characteristics and heat resistance is not clear, but is estimated as follows.
Conventionally, the hydroxyl value generally used as polycarbonate diol is 55 mg-KOH / g to 120 mg-KOH / g, while the polycarbonate diol of the present invention has a hydroxyl value of 20 mg-KOH / g to 45 mg-KOH / g, When converted into molecular weight, the molecular weight of the polycarbonate diol generally used is larger, so that the chain length of the soft segment portion in the obtained polyurethane becomes longer, and flexibility, low temperature characteristics, processability, etc. are improved. However, when the molecular weight is increased by using the conventionally used polycarbonate diol structural unit, the above properties are improved, but the chemical resistance of the resulting polyurethane is reduced due to the decrease in cohesive force due to the increase in the soft segment chain length. The alkali resistance, water resistance, and heat resistance tended to be inferior. On the other hand, the polycarbonate of the present invention adjusts the distance between carbonate bonds having a relatively strong cohesion by adjusting the average carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol within a certain range. It has become possible to achieve both flexibility, low temperature characteristics, processability, etc. while suppressing the decrease in chemical resistance, alkali resistance, water resistance, and heat resistance accompanying the increase in the molecular weight. In other words, it is estimated that by using the polycarbonate diol of the present invention, a polyurethane having an excellent balance of physical properties such as flexibility, low temperature characteristics, processability, chemical resistance, alkali resistance, water resistance, and heat resistance can be obtained. Is done.

  The polycarbonate diol of the present invention is based on a structure in which a dihydroxy compound is polymerized by a carbonate group. However, depending on the production method, those having an ether structure due to the dehydration reaction of the dihydroxy compound are mixed, and as a result, the polycarbonate diol contains an ether bond. In the polycarbonate diol of the present invention, the ratio of the ether bond to the carbonate bond in the polycarbonate diol (hereinafter sometimes referred to as “ether / carbonate bond ratio”) is preferably 0.01% or more and 5% or less. When the ether / carbonate bond ratio is 0.01% or more, productivity can be improved, for example, by increasing the polymerization rate of the polycarbonate diol. In terms of productivity, the ether / carbonate bond ratio is more preferably 0.03% or more, and even more preferably 0.05% or more. Moreover, when the ether / carbonate bond ratio is 5% or less, it becomes possible to improve the chemical resistance and heat resistance of the polyurethane for artificial leather or synthetic leather using the polycarbonate diol. From the viewpoint of chemical resistance and heat resistance, the ether / carbonate bond ratio is preferably 4% or less, more preferably 3% or less, still more preferably 2% or less, particularly preferably 1% or less, and 0.8% or less. Most preferred.

  The ratio of the ether bond to the carbonate bond in the polycarbonate diol of the present invention is determined by gas chromatography (hereinafter sometimes referred to as GC) of a dihydroxy compound obtained by hydrolysis of the polycarbonate diol by heating in the presence of an alkali. It can be obtained from the analysis result.

Specifically, the structure of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol is analyzed by GC-MS analysis, and the weight% calculated by GC analysis of the dihydroxy compound containing an ether group and all dihydroxy compounds, Calculated from the molecular weight of the dihydroxy compound.
The specific method is as described in the Examples section.

<1-3. Glass transition temperature>
The glass transition temperature (Tg) measured by the differential scanning calorimeter (hereinafter sometimes referred to as “DSC”) of the polycarbonate diol of the present invention is −30 ° C. or lower, preferably −35 ° C. or lower. If the Tg is too high, the Tg for polyurethane is also increased, and the low temperature characteristics may be deteriorated. However, if the lower limit of Tg is too low, the elastic modulus tends to be too low or the tackiness tends to be strong when polyurethane is used, so it is usually −100 ° C. or higher.

<1-4. Molecular chain end>
The molecular chain terminal of the polycarbonate diol of the present invention is mainly a hydroxyl group. 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 some molecular chain terminals are not hydroxyl groups as impurities. As specific examples thereof, the molecular chain terminal is an alkyloxy group or an aryloxy group, and many have a structure derived from a carbonate compound.

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

  The molecular chain terminals other than hydroxyl groups in the polycarbonate diol of the present invention are preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably 3 mol% or less, particularly preferably 1 mol%, based on the total number of terminals. It is as follows.

<1-5. Molecular Weight / Molecular Weight Distribution>
Ratio of polystyrene-equivalent weight average molecular weight (Mw) to polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (hereinafter sometimes abbreviated as “GPC”) of the polycarbonate diol of the present invention ( Mw / Mn) is preferably 1.5 to 3.0. The lower limit of Mw / Mn is more preferably 1.7, and still more preferably 1.8. The upper limit of Mw / Mn is more preferably 2.5, and still more preferably 2.3. When the Mw / Mn ratio exceeds the above range, the properties of the polyurethane produced using this polycarbonate diol tend to become hard at low temperatures and decrease in elongation, and a polycarbonate diol having an Mw / Mn less than the above range. In order to produce the product, an advanced purification operation such as removal of the oligomer may be required.
Specifically, the weight average molecular weight and the number average molecular weight in the molecular weight distribution of the polycarbonate diol are measured by the methods described in the Examples section described later.

Further, the number average molecular weight (Mn) of the polycarbonate diol can be determined from the hydroxyl value, and the lower limit of the number average molecular weight (Mn) is preferably 2,500, more preferably 2,700, still more preferably 2,800. Particularly preferred is 2,900. On the other hand, the upper limit is preferably 5,500, more preferably 4,500, and still more preferably 3,500. When Mn of the polycarbonate diol is less than the lower limit, flexibility, low temperature characteristics, and elastic recoverability may not be sufficiently obtained when polyurethane is used. On the other hand, if the upper limit is exceeded, the viscosity increases, and handling during polyurethane formation may be impaired. In particular, within the above preferred range, the polyurethane is particularly excellent in flexibility, low-temperature characteristics and elastic recovery, and also has good physical properties with respect to chemical resistance and heat resistance.
Specifically, the number average molecular weight (Mn) determined from the hydroxyl value of the polycarbonate diol is measured by the method described in the Examples section described later.

<1-6. APHA value>
The color of the polycarbonate diol of the present invention is preferably 60 or less, more preferably a value (hereinafter referred to as “APHA value”) in terms of Hazen color number (based on JIS K0071-1: 1998). Is 50 or less, more preferably 30 or less, and particularly preferably 20 or less. When the APHA value exceeds 60, the color tone of polyurethane obtained using polycarbonate diol as a raw material is deteriorated, and the commercial value is lowered or the thermal stability is deteriorated. In order to reduce the APHA value to 60 or less, the catalyst for polycarbonate diol production, selection of additive type and amount, thermal history, concentration of monohydroxy compound during polymerization and after completion of polymerization, and concentration of unreacted monomer are integrated. Need to be controlled. Further, light shielding during and after the polymerization is effective. It is also important to set the molecular weight of the polycarbonate diol and to select the dihydroxy compound species that is a monomer. Polycarbonate diols made from aliphatic dihydroxy compounds having alcoholic hydroxyl groups as raw materials show various excellent performances such as flexibility, water resistance, and light resistance when processed into polyurethane, but aromatic dihydroxy compounds are used as raw materials. The above control is important because the thermal history and the coloration due to the catalyst tend to be more noticeable than in the case of the above.
Specifically, APHA is measured by the method described in the Examples section below.

<1-7. Melt viscosity>
The polycarbonate diol of the present invention has a melt viscosity of 100 mPa.s measured by the method described in the Examples section below. s or more, particularly 300 mPa.s. s or more, especially 500 mPa.s. s or more and 1,000,000 mPa.s. s or less, particularly 15000 mPa.s. s or less, especially 10,000 mPa.s. It is preferable that it is s or less. When the melt viscosity of the polycarbonate diol is not less than the above lower limit, the degree of polymerization of the polycarbonate diol is sufficient, and the urethane produced using this tends to have excellent flexibility and elastic recovery properties. It is preferable because the handleability is improved and the production efficiency is not lowered.

[2. Production method of polycarbonate diol]
The polycarbonate diol of the present invention can be produced by polycondensing a dihydroxy compound obtained by hydrolyzing the above polycarbonate diol and a carbonate compound by a transesterification reaction.

<2-1. Dihydroxy Compound>
In the production of the polycarbonate diol of the present invention, the dihydroxy compound used as a raw material is 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2- Methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1, 9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1, Examples thereof include 18-octadecanediol and 1,20-eicosanediol.

  In the polycarbonate diol of the present invention, since the average number of carbon atoms of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol is 3 or more and 5.5 or less, the dihydroxy compound as a raw material is 1,3-propanediol, 1,4 -It is preferable to include at least one selected from the group consisting of butanediol and 1,5-propanediol. From the chemical resistance when polyurethane is used, 1,3-propanediol and / or 1,4-butane More preferably, it contains a diol. Furthermore, since the resulting polyurethane has good flexibility and low-temperature properties, the polycarbonate diol preferably has low crystallinity, so that it is a dihydroxy compound having an odd number of carbon atoms or two or more dihydroxy compounds. It is preferable.

  The dihydroxy compound used as a raw material in the method for producing polycarbonate diol of the present invention is preferably derived from a plant from the viewpoint of reducing environmental burden. The compounds applicable as plant origin include 1,3-propanediol, 1,4-butanediol, 1,5-propanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decane. Examples include diol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,20-eicosanediol, and the like.

<2-2. Carbonate compound>
As the carbonate compound that can be used in the production of the polycarbonate diol of the present invention, diaryl carbonate is preferable from the viewpoint of reactivity. In particular, in the synthesis of a polycarbonate diol having a number average molecular weight (Mn) of 2,500 or more determined from the above hydroxyl value, it is preferable to use diaryl carbonate.

  Specific examples of the carbonate compound that can be used in the production of the polycarbonate diol of the present invention include diphenyl carbonate.

<2-3. Ratio of raw materials used>
In the production of the polycarbonate diol of the present invention, the amount of the carbonate compound used is not particularly limited, but is usually a molar ratio based on a total of 1 mol of the dihydroxy compound, and the lower limit is preferably 0.90, more preferably 0.92, and even more preferably. Is 0.94, and the upper limit is preferably 1.00, more preferably 0.98, and still more preferably 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the proportion of the polycarbonate diol end group that is not a hydroxyl group may increase or the molecular weight may not fall within the predetermined range. If the amount is less than the lower limit, the polymerization does not proceed to the predetermined molecular weight. There is a case.

<2-4. Transesterification Catalyst>
When the polycarbonate diol of the present invention is produced, a transesterification catalyst (hereinafter sometimes referred to as “catalyst”) can be used to promote the transesterification reaction.

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

  Examples of transesterification catalysts include compounds of Group 1 metals (excluding hydrogen) of a long-period periodic table (hereinafter simply referred to as “periodic table”) such as lithium, sodium, potassium, rubidium, and cesium; Periodic table Group 2 metal compounds such as magnesium, calcium, strontium, barium; Periodic table Group 4 metal compounds such as titanium and zirconium; Periodic table Group 5 metal compounds such as hafnium; Cobalt etc. Group 9 metal compounds; zinc and other periodic table group 12 metal compounds; aluminum and other periodic table group 13 metal compounds; germanium, tin, lead and other periodic group 14 metal compounds; antimony, bismuth, etc. And compounds of Group 15 metals of the periodic table; compounds of lanthanide metals such as lanthanum, cerium, europium, ytterbium, and the like. Among these, from the viewpoint of increasing the transesterification reaction rate, compounds of Group 1 metals (excluding hydrogen), compounds of Group 2 metals of the periodic table, compounds of Group 4 metals of the periodic table, periodic table 5 Group metal compounds, periodic table group 9 metal compounds, periodic table group 12 metal compounds, periodic table group 13 metal compounds, and periodic table group 14 metal compounds are preferred. (Excluding hydrogen) and periodic table group 2 metal compounds are more preferred, and periodic table group 2 metal compounds are more preferred. Among the compounds of Group 1 metals (excluding hydrogen) in 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, magnesium, calcium and barium compounds are preferred, calcium and magnesium compounds are more preferred, and magnesium compounds are more preferred. These metal compounds are mainly used as hydroxides and salts. Examples of salts when used as salts include halide salts such as chloride, bromide and iodide; carboxylates such as acetate, formate and benzoate; inorganic acid salts such as carbonate and nitrate Sulfonic acid salts such as methanesulfonic acid, toluenesulfonic acid, and trifluoromethanesulfonic acid; phosphorus-containing salts such as phosphate, hydrogen phosphate, and dihydrogen phosphate; acetylacetonate salts; The catalyst metal can also be used as an alkoxide such as methoxide or ethoxide.

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

  When the above-described transesterification catalyst is used for the production of the polycarbonate diol of the present invention, the amount of the catalyst used is usually 1 μmol times or more and 200 μmol times or less per 1 mol of all dihydroxy compounds used, and the lower limit is preferable. Is 5 μmol times, more preferably 10 μmol times, and even more preferably 15 μmol times. The upper limit is preferably 100 μmol times, more preferably 70 μmol times, and even more preferably 50 μmol times. If the amount of the catalyst used is too small, sufficient polymerization activity cannot be obtained and the progress of the polymerization reaction is slowed down, so that it is difficult to obtain a polycarbonate diol having a desired molecular weight, not only the production efficiency is lowered, but also the raw material monomer is polymerized. During the reaction, the time remaining in the system in an unreacted state becomes long, so that the color tone may be deteriorated. In addition, the amount of monomer distilling with the by-produced monohydroxy compound increases, and as a result, the raw material basic unit may be deteriorated and extra energy may be required for its recovery. In the case of copolymerization using a compound, the composition ratio of the monomer used as the raw material and the composition ratio of the constituent monomer units in the product polycarbonate diol may change. On the other hand, if the amount of catalyst used is too large, an excessive amount of catalyst may remain after the transesterification reaction, and the polycarbonate diol may become cloudy or may be easily colored by heating. Moreover, when manufacturing polyurethane using the obtained polycarbonate diol, reaction may be inhibited or reaction may be accelerated | stimulated too much.

<2-5. Catalyst Deactivator>
When a catalyst is used in the transesterification reaction, the catalyst remains in the usually obtained polycarbonate diol, and due to the remaining catalyst, heating of the polycarbonate diol causes an increase in molecular weight, composition change, deterioration of color tone, etc. It may become impossible to control the chemical reaction. In order to suppress the influence of the remaining catalyst, it is preferable to add a substantially equimolar amount of, for example, a phosphorus compound or the like to the transesterification catalyst used to inactivate the transesterification catalyst. Further, after the addition, the transesterification catalyst can be efficiently inactivated by heat treatment or the like as described later.

  Examples of phosphorus compounds used for inactivating the transesterification catalyst include inorganic phosphoric acid such as phosphoric acid and phosphorous acid, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, Organic phosphoric acid esters such as triphenyl phosphate are exemplified, but phosphoric acid and phosphorous acid are preferred, and phosphoric acid is more preferred because of its large effect.

  These may be used alone or in combination of two or more.

  The amount of the phosphorus compound used is not particularly limited, but as described above, it may be approximately equimolar with the transesterification catalyst used, and specifically, with respect to 1 mol of the transesterification catalyst used. The upper limit is preferably 5 mol, more preferably 2 mol, and the lower limit is preferably 0.8 mol, more preferably 1.0 mol. When a smaller amount of a phosphorus compound is used, heating the polycarbonate diol may result in an increase in the molecular weight of the polycarbonate diol, composition change, deterioration of color tone, etc., or inactivation of the transesterification catalyst is not sufficient. When the polycarbonate diol is used as a raw material for polyurethane production, for example, the reactivity of the polycarbonate diol with respect to the isocyanate group may not be sufficiently lowered. In addition, when a phosphorous compound exceeding this range is used, the obtained polycarbonate diol is colored, or when the polycarbonate diol is used as a raw material, the polyurethane is easily hydrolyzed, and the phosphorous compound bleeds out. There is a possibility.

The inactivation of the transesterification catalyst by adding a phosphorus compound can be performed at room temperature, but it is more efficient when heat-treated. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 150 ° C., more preferably 120 ° C., still more preferably 100 ° C., and the lower limit is preferably 50 ° C., more preferably 60 ° C., even more preferably. Is 70 ° C. When the temperature is lower than this, it takes time to inactivate the transesterification catalyst, which is not efficient, and the degree of inactivation may be insufficient. On the other hand, at temperatures exceeding 150 ° C., the obtained polycarbonate diol may be colored.
The time for reacting with the phosphorus compound is not particularly limited, but is usually 1 to 5 hours.

<2-6. Production of polycarbonate diol>
The polycarbonate diol of the present invention can be produced by polymerizing the above-mentioned dihydroxy compound and the above-mentioned carbonate compound by an ester exchange reaction, preferably using the above-mentioned catalyst.
There are no particular restrictions on the method for charging the reaction raw material, and a method in which all of the dihydroxy compound, carbonate compound and catalyst are charged simultaneously and used for the reaction, or if the carbonate compound is solid, the carbonate compound is first charged and heated and melted. The method can be freely selected, for example, a method of adding a dihydroxy compound and a catalyst, or a method of charging a dihydroxy compound first and melting it, and then adding the carbonate compound and catalyst thereto.

  The reaction temperature in the transesterification reaction can be arbitrarily adopted as long as a practical reaction rate can be obtained. The temperature is not particularly limited, but the lower limit is usually 70 ° C, preferably 100 ° C, more preferably 130 ° C. Moreover, the upper limit of reaction temperature is 250 degreeC normally, Preferably it is 200 degreeC, More preferably, it is 190 degreeC, More preferably, it is 180 degreeC, Most preferably, it is 170 degreeC. If the reaction temperature is below the lower limit, the transesterification reaction may not proceed at a practical rate. If the reaction temperature exceeds the above upper limit, the obtained polycarbonate diol may be colored, an ether structure may be generated, or turbidity may be deteriorated.

  Although the reaction can be carried out at normal pressure, the transesterification reaction is an equilibrium reaction, and the reaction can be biased toward the production system by distilling by-produced monohydroxy compounds and dihydroxy compounds out of the system. Therefore, it is usually preferable to carry out the reaction while distilling off by-product monohydroxy compounds and dihydroxy compounds by adopting reduced pressure conditions in the latter half of the reaction process. Or it is also possible to make it react, distilling off the monohydroxy compound and dihydroxy compound byproduced by reducing pressure gradually in the middle of reaction. If the pressure is too low at the beginning of the reaction, the low boiling point unreacted monomer is promoted to volatilize, and a polycarbonate diol having a predetermined molecular weight cannot be obtained, or in the case of copolymerization, a polycarbonate diol having a predetermined copolymer composition ratio is obtained. It may not be possible.

On the other hand, if the reaction is carried out at a higher pressure reduction at the end of the reaction, by-product monohydroxy compounds such as phenols, dihydroxy compounds, residual monomers such as carbonate compounds, and cyclic carbonates that may cause turbidity Since (cyclic oligomer) etc. can be distilled off, it is preferable.
The reaction pressure at the end of the reaction is not particularly limited, but the upper limit is usually 10 kPa as an absolute pressure, preferably 5 kPa, more preferably 1 kPa. In order to effectively distill off these light boiling components, the reaction can be carried out while passing a small amount of an inert gas such as nitrogen, argon or helium into the reaction system.

  When using a carbonate compound or dihydroxy compound having a low boiling point during the transesterification reaction, the reaction is initially performed near the boiling point of the carbonate compound or dihydroxy compound, and the temperature is gradually increased as the reaction proceeds. A method of allowing the reaction to proceed can also be employed. In this case, the unreacted carbonate compound or dihydroxy compound can be prevented from being distilled off at the initial stage of the reaction, which is preferable. Furthermore, a reflux pipe is attached to the reactor in order to prevent the raw materials from distilling off at the initial stage of the reaction, and the monohydroxy compounds and dihydroxy compounds by-produced from the carbonate compounds are distilled off while refluxing the carbonate compounds and dihydroxy compounds of the raw materials. It is also possible to carry out a transesterification reaction. In this case, the charged raw material monomers are not lost, and the amount ratio of the reagents can be adjusted accurately, which is preferable.

  The polycondensation reaction can be carried out either batchwise or continuously, but the continuous method is superior in terms of the stability of the quality such as the molecular weight of the product. The apparatus to be used may be any of a tank type, a tube type and a tower type, and a known polymerization tank equipped with various stirring blades can be used. The atmosphere during the temperature rise of the apparatus is not particularly limited, but from the viewpoint of product quality, it is preferably carried out in an inert gas such as nitrogen gas under normal pressure or reduced pressure.

  The time required for the transesterification reaction to obtain the polycarbonate diol of the present invention cannot be generally defined because it varies greatly depending on the dihydroxy compound, carbonate compound, presence / absence of the catalyst used, and the type of catalyst used. The reaction time required to reach the predetermined molecular weight is 50 hours or less, preferably 20 hours or less, more preferably 10 hours or less.

<2-7. Purification>
After the polymerization reaction, the terminal structure in the polycarbonate diol is an impurity having an alkyloxy group, an impurity having an aryloxy group, an unreacted dihydroxy compound or carbonate compound, a by-product monohydroxy compound or dihydroxy compound and a light boiling cyclic carbonate, Furthermore, purification can be performed for the purpose of removing the added catalyst and the like. In the purification at that time, a method of distilling off a light boiling compound by distillation can be employed. The specific method of distillation is not particularly limited, such as vacuum distillation, steam distillation, thin film distillation, etc., but thin film distillation is particularly effective. Further, in order to remove water-soluble impurities, it may be washed with water, alkaline water, acidic water, a chelating agent solution or the like. In that case, the compound dissolved in water can be selected arbitrarily.

  Although there is no restriction | limiting in particular as thin film distillation conditions, As for the temperature at the time of thin film distillation, it is preferable that an upper limit is 250 degreeC, and it is preferable that it is 210 degreeC. Moreover, it is preferable that a minimum is 120 degreeC, and it is more preferable that it is 150 degreeC. By setting the lower limit of the temperature during thin film distillation to the above value, the effect of removing light boiling components is sufficient. Moreover, it can prevent that the polycarbonate diol obtained after thin film distillation is colored by making an upper limit into said value.

  The upper limit of the pressure during thin film distillation is preferably 500 Pa, more preferably 150 Pa, and even more preferably 70 Pa. By setting the pressure during thin film distillation to the upper limit value or less, a light boiling component removal effect can be sufficiently obtained.

Moreover, the upper limit of the temperature of the polycarbonate diol just before thin film distillation is preferably 250 ° C, and more preferably 150 ° C. Moreover, it is preferable that a minimum is 80 degreeC, and it is more preferable that it is 120 degreeC.
By setting the temperature for keeping the polycarbonate diol just before the thin film distillation to the above lower limit or more, it is possible to prevent the flowability of the polycarbonate diol just before the thin film distillation from being lowered. On the other hand, by setting it to the upper limit or less, it is possible to prevent the polycarbonate diol obtained after thin film distillation from being colored.

<2-8. Residual monomers, etc.>
When diaryl carbonate such as diphenyl carbonate is used as a raw material, phenols are by-produced during the production of polycarbonate diol. Since phenols are monofunctional compounds, they may be an inhibitory factor in the production of polyurethane, and the urethane bonds formed by phenols are weak in their bonding strength, so they are heated by subsequent processes. It may dissociate, causing isocyanates and phenols to be regenerated and causing problems. Moreover, since phenols are also stimulating substances, it is preferable that the residual amount of phenols in the polycarbonate diol is smaller. Specifically, the weight ratio with respect to the polycarbonate diol is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 300 ppm or less, and particularly preferably 100 ppm or less. In order to reduce the phenols in the polycarbonate diol, as described above, the pressure of the polymerization reaction of the polycarbonate diol may be set to a high vacuum of 1 kPa or less as an absolute pressure, or thin film distillation may be performed after the polymerization of the polycarbonate diol. It is valid.

  In the polycarbonate diol, the carbonate compound used as a raw material during production may remain. The remaining amount of the carbonate compound in the polycarbonate diol is not limited, but a smaller amount is preferable, and the upper limit of the weight ratio with respect to the polycarbonate diol is preferably 5% by weight, more preferably 3% by weight, still more preferably 1% by weight. is there. If the carbonic diester content of the polycarbonate diol is too large, 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 weight, more preferably 0.01% by weight, and still more preferably 0% by weight.

  In polycarbonate diol, the dihydroxy compound used at the time of manufacture may remain. The residual amount of the dihydroxy compound in the polycarbonate diol is not limited, but a smaller amount is preferable, and the weight ratio with respect to the polycarbonate diol is preferably 1% by weight or less, more preferably 0.1% by weight or less, and still more preferably. Is 0.05% by weight or less. If the residual amount of the dihydroxy compound in the polycarbonate diol is large, the molecular length of the soft segment portion when polyurethane is used may be insufficient, and desired physical properties may not be obtained.

  In polycarbonate diol, the cyclic carbonate (cyclic oligomer) byproduced in the case of manufacture may be contained. For example, when 1,3-propanediol is used, 1,3-dioxan-2-one or a compound obtained by forming two or more of these molecules into a cyclic carbonate may be produced and contained in the polycarbonate diol. is there. These compounds may cause side reactions in the polyurethane formation reaction and cause turbidity. Therefore, the pressure of the polymerization reaction of the polycarbonate diol is set to a high vacuum of 1 kPa or less as an absolute pressure, or the synthesis of the polycarbonate diol is performed. It is preferable to remove as much as possible by performing thin film distillation or the like later. The content of these cyclic carbonates contained in the polycarbonate diol is not limited, but is preferably 3% by weight or less, more preferably 1% by weight or less, still more preferably 0.5% by weight or less, particularly as a weight ratio to the polycarbonate diol. Preferably it is 0.1 weight% or less.

When an ester exchange catalyst is used in the production of the polycarbonate diol of the present invention, if an excessive amount of catalyst remains in the obtained polycarbonate diol, a reaction is caused in producing a polyurethane using the polycarbonate diol. May interfere or excessively promote the reaction.
For this reason, the amount of catalyst remaining in the polycarbonate diol is not particularly limited, but is preferably 100 ppm or less, more preferably 50 ppm or less, and even more preferably 10 ppm or less as the content in terms of catalyst metal.

[3. Polyurethane]
The polyurethane for artificial leather or synthetic leather of the present invention (hereinafter sometimes referred to as “polyurethane of the present invention”) is at least (a) a compound containing at least two isocyanate groups in one molecule (hereinafter “polyisocyanate”). ), (B) a chain extender, and (c) the polycarbonate diol of the present invention described above.
In the method for producing the polyurethane of the present invention using the polycarbonate diol of the present invention, generally known polyurethane reaction conditions for producing a polyurethane are used.

For example, the polyurethane of the present invention can be produced by reacting (c) the polycarbonate diol of the present invention with (a) a polyisocyanate and (b) a chain extender in the range from room temperature to 200 ° C.
Also, (c) the polycarbonate diol of the present invention and excess (a) polyisocyanate are first reacted to produce a prepolymer having an isocyanate group at the terminal, and (b) the degree of polymerization is increased using a chain extender. Thus, the polyurethane of the present invention can be produced.

<3-1. Polyisocyanate>
Examples of the (a) polyisocyanate used for producing a polyurethane using the polycarbonate diol of the present invention include various known polyisocyanate compounds such as aliphatic, alicyclic or aromatic.

  For example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and dimerized isocyanate 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 (Isocyanatomethyl) cycloaliphatic diisocyanates such as cyclohexane; xylylene diisocyanate, 4,4′-diphenyldi Socyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4 ' -Dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate and m-tetramethyl And aromatic diisocyanates such as xylylene diisocyanate. These may be used alone or in combination of two or more.

  Among these, 4,4′-diphenylmethane diisocyanate (hereinafter sometimes referred to as “MDI”), hexamethylene is preferable in that the balance of physical properties of the obtained polyurethane is preferable, and a large amount is industrially available at low cost. Diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferred.

<3-2. Chain extender>
The (b) 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 an isocyanate group when producing a prepolymer having an isocyanate group, which will be described later. Usually, a polyol, a polyamine, etc. can be mentioned.

  Specific examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, and 1,9-nonanediol. Linear diols such as 1,10-decanediol and 1,12-dodecanediol; 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-propanedi Diols having a branched chain such as diol and dimer diol; diols having an ether group such as diethylene glycol and propylene glycol; 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxyethylcyclohexane, etc. Diols having an alicyclic structure, diols having an aromatic group such as xylylene glycol, 1,4-dihydroxyethylbenzene, 4,4′-methylenebis (hydroxyethylbenzene); glycerin, trimethylolpropane, pentaerythritol, etc. Polyols; hydroxyamines such as N-methylethanolamine and N-ethylethanolamine; ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethyleneto Amine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropyl Polyamines such as ethylenediamine, 4,4′-diphenylmethanediamine, methylenebis (o-chloroaniline), xylylenediamine, diphenyldiamine, tolylenediamine, hydrazine, piperazine, N, N′-diaminopiperazine; and water be able to.

  These chain extenders may be used alone or in combination of two or more.

  Among these, 1,4-butanediol (hereinafter sometimes referred to as “1,4BD”), 1 is a point that the balance of physical properties of the obtained polyurethane is preferable, and that a large amount can be obtained industrially at low cost. , 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 (hereinafter sometimes referred to as “IPDA”) and 4,4′-diaminodicyclohexylmethane are preferred.

  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 <3-1. And polyisocyanates>.

<3-3. Hardness adjuster>
When producing polyurethane, a hardness adjusting agent may be used. As the hardness adjusting agent, a dihydroxy compound that is a raw material of polycarbonate diol may be used. The reason why the hardness adjusting agent is used will be described below. For example, when a polyurethane is produced using a polycarbonate diol having a large molecular weight, if the molar composition of the polyisocyanate and the chain extender is the same as that of the polycarbonate diol having a low molecular weight, the weight ratio of the polycarbonate diol in the entire polyurethane molecule increases. As a result, the elastic modulus and hardness are reduced. Therefore, by adding a dihydroxy compound or the like, which is a raw material of polycarbonate diol, as a hardness adjuster, it becomes possible to adjust the weight ratio of polycarbonate diol in the entire polyurethane equally, which is the case when polycarbonate diols having different molecular weights are used. However, it can prevent that the elasticity modulus and hardness of the obtained polyurethane fall. This method is generally widely used.

  As the hardness adjusting agent, it is preferable to use a dihydroxy compound which is a raw material of polycarbonate diol. 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol 1,18-octadecanediol, 1,20-eicosanediol, etc. And the like.

<3-4. Chain terminator>
In producing the polyurethane of the present invention, a chain terminator 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 such as methanol, ethanol, propanol, butanol and hexanol having one hydroxyl group, diethylamine, dibutylamine, n-butylamine, monoethanolamine and diethanolamine having one amino group. And aliphatic monoamines such as morpholine.
These may be used alone or in combination of two or more.

<3-5. Catalyst>
In the polyurethane formation reaction in producing the polyurethane of the present invention, an amine catalyst such as triethylamine, N-ethylmorpholine, triethylenediamine, or an acid catalyst such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, sulfonic acid, trimethyltin laurate Further, known urethane polymerization catalysts represented by tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, dioctyltin dineodecanate, and organic metal salts such as titanium compounds can also be used. A urethane polymerization catalyst may be used individually by 1 type, and may use 2 or more types together.

<3-6. Polyols Other than Polycarbonate Diol of the Present Invention>
In the polyurethane formation reaction in producing the polyurethane of the present invention, the polycarbonate diol of the present invention may be used in combination with other polyols as necessary. Here, the polyol other than the polycarbonate diol of the present invention is not particularly limited as long as it is used in normal polyurethane production. For example, the polyol other than the polyether polyol, polyester polyol, polycaprolactone polyol, and polycarbonate diol of the present invention. A polycarbonate polyol is mentioned. For example, when used in combination with a polyether-based polyol, a polyurethane having further improved low temperature characteristics, which is a feature of the polycarbonate diol of the present invention, can be obtained. Here, the weight ratio of the polycarbonate diol of the present invention to the combined weight of the polycarbonate diol of the present invention and the other polyol is preferably 70% or more, more preferably 90% or more. When the weight ratio of the polycarbonate diol of the present invention is small, there is a possibility that the balance of physical properties such as flexibility, chemical resistance, low temperature characteristics, heat resistance, and touch, which are features of the present invention, may be lost.

  In the present invention, the above-mentioned polycarbonate diol of the present invention can be modified for use in the production of polyurethane. As a modification method of the polycarbonate diol, a method of introducing an ether group by adding an epoxy compound such as ethylene oxide, propylene oxide or butylene oxide to the polycarbonate diol, a cyclic lactone such as ε-caprolactone, adipic acid, or succinic acid is used as the polycarbonate diol. There is a method of introducing an ester group by reacting with dicarboxylic acid compounds such as sebacic acid and terephthalic acid and ester compounds thereof. In the ether modification, the viscosity of the polycarbonate diol is lowered by modification with ethylene oxide, propylene oxide or the like, which is preferable for reasons such as handling. In particular, the polycarbonate diol of the present invention is modified with ethylene oxide or propylene oxide, so that the crystallinity of the polycarbonate diol is lowered and the flexibility at low temperature is improved. Since the water absorption and moisture permeability of the polyurethane produced in this way increases, the performance as artificial leather / synthetic leather may be improved. However, as the addition amount of ethylene oxide and propylene oxide increases, the physical properties such as mechanical strength, heat resistance, chemical resistance, and touch of polyurethane produced using modified polycarbonate diol are reduced. Is preferably 5 to 50% by weight, preferably 5 to 40% by weight, and more preferably 5 to 30% by weight. In addition, the method of introducing an ester group is preferable for reasons such as handling because the viscosity of the polycarbonate diol is reduced by modification with ε-caprolactone. The amount of ε-caprolactone added to the polycarbonate diol is preferably 5 to 50% by weight, preferably 5 to 40% by weight, and more preferably 5 to 30% by weight. When the added amount of ε-caprolactone exceeds 50% by weight, the hydrolysis resistance, chemical resistance, etc. of the polyurethane produced using the modified polycarbonate diol are lowered.

<3-7. Solvent>
You may use a solvent for the polyurethane formation reaction at the time of manufacturing the polyurethane of this invention.
Preferred solvents include amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; ketone solvents such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; tetrahydrofuran, dioxane, and the like. Examples include 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, dimethyl sulfoxide and the like.
Moreover, the polyurethane of an aqueous dispersion can also be manufactured from the polyurethane composition with which the polycarbonate diol of this invention, polyisocyanate, and the said chain extender were mix | blended.

<3-8. Polyurethane production method>
As a method for producing the polyurethane of the present invention using the above-mentioned reaction reagent, a production method generally used experimentally or industrially can be used.

  Examples thereof include (c) the polycarbonate diol of the present invention, other polyols used as necessary, (a) a polyisocyanate, and (b) a method in which a chain extender is mixed and reacted (hereinafter, “ First, (c) the polycarbonate diol of the present invention, other polyols used if necessary, and (a) a polyisocyanate are reacted to form a prepolymer having isocyanate groups at both ends. After the preparation, there is a method of reacting the prepolymer with (b) a chain extender (hereinafter sometimes referred to as “two-stage method”).

  In the two-stage method, the polycarbonate diol of the present invention and other polyols used as necessary are reacted with one or more equivalents of a polyisocyanate in advance, so that both ends of the isocyanate intermediate corresponding to the soft segment of the polyurethane are obtained. It goes through the process of preparing. In this way, once the prepolymer is prepared and reacted with the chain extender, it may be easy to adjust the molecular weight of the soft segment part, and when it is necessary to ensure phase separation of the soft segment and the hard segment. Is useful.

<3-9. One-step method>
The one-stage method is also called a one-shot method, and (c) the polycarbonate diol of the present invention is used as necessary (hereinafter, this description is omitted), other polyols, (a) polyisocyanates and (b ) The reaction is carried out by charging the chain extender all at once.

  The amount of polyisocyanate used in the one-stage method is not particularly limited, but the total number of hydroxyl groups of the polycarbonate diol of the present invention and other polyols and the total number of hydroxyl groups and amino groups of the chain extender is 1 equivalent. The lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents, more preferably 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 resulting polyurethane will have too high a viscosity, making it difficult to handle and tending to reduce flexibility. If it is too high, the molecular weight of the polyurethane will not be sufficiently large, and sufficient polyurethane strength will not be obtained.

  The amount of chain extender used is not particularly limited, but when the number obtained by subtracting the number of isocyanate groups of the polyisocyanate from the total number of hydroxyl groups of the polycarbonate diol of the present invention and other polyols is 1 equivalent, the lower limit is preferably Is 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents, more preferably 2.0 equivalents, Preferably it is 1.5 equivalent, Most preferably, it is 1.1 equivalent. If the amount of chain extender used is too large, the resulting polyurethane tends to be difficult to dissolve in the solvent and difficult to process. If too small, the resulting polyurethane is too soft and has sufficient strength, hardness, elastic recovery performance and elasticity. Holding performance may not be obtained or heat resistance may deteriorate.

<3-10. Two-stage method>
The two-stage method is also called a prepolymer method, and mainly includes the following methods.
(I) The polycarbonate diol of the present invention and other polyols and an excess of polyisocyanate are preliminarily added in an amount in which the reaction equivalent ratio of polyisocyanate / (polycarbonate diol of the present invention and other polyols) exceeds 1 to 10. A method of producing a polyurethane by reacting at 0 or less to produce a prepolymer having a molecular chain terminal at an isocyanate group, and then adding a chain extender thereto (ii) a polyisocyanate in advance and an excess of the polycarbonate of the present invention A diol and other polyol are reacted at a reaction equivalent ratio of polyisocyanate / (polycarbonate diol of the present invention and other polyol) of 0.1 or more and less than 1.0, and the molecular chain terminal is a hydroxyl group. A polymer is produced, which is then end-isolated as a chain extender. Method for producing a polyurethane by reacting a polyisocyanate Aneto groups.

  The two-stage method can be carried out without a solvent or in the presence of a solvent.

The polyurethane production by the two-stage method can be carried out by any of the methods (1) to (3) described below.
(1) Without using a solvent, first, a polyisocyanate, a polycarbonate diol of the present invention and a polyol other than that are directly reacted to synthesize a prepolymer, and used as it is in a chain extension reaction.
(2) A prepolymer is synthesized by the method of (1), then dissolved in a solvent, and used for the subsequent chain extension reaction.
(3) Using a solvent from the beginning, the polyisocyanate, the polycarbonate diol of the present invention and the other polyol are reacted, and then a chain extension reaction is performed.

In the case of the method (1), in the chain extension reaction, the polyurethane is obtained in the form of coexisting with the solvent by dissolving the chain extender in the solvent or simultaneously dissolving the prepolymer and the chain extender in the solvent. This is very important.
The amount of polyisocyanate used in the method of the two-stage method (i) is not particularly limited, but as the number of isocyanate groups when the total number of hydroxyl groups of the polycarbonate diol of the present invention and other polyols is 1 equivalent, The lower limit is preferably an amount exceeding 1.0 equivalent, more preferably 1.2 equivalents, still more preferably 1.5 equivalents, and the upper limit is preferably 10.0 equivalents, more preferably 5.0 equivalents, still more preferably The range is 3.0 equivalents.

  If the amount of isocyanate used is too large, there will be a tendency for excess isocyanate groups to cause side reactions and it will be difficult to reach the desired properties of polyurethane, and if it is too small, the molecular weight of the resulting polyurethane will not increase sufficiently and the strength and heat stability will be increased. May be low.

  The amount of chain extender used is not particularly limited, but the lower limit is preferably 0.1 equivalents, more preferably 0.5 equivalents, still more preferably 0.8 equivalents relative to the number of equivalents of isocyanate groups contained in the prepolymer. The upper limit is preferably 5.0 equivalents, more preferably 3.0 equivalents, and even more preferably 2.0 equivalents.

  When performing the chain extension reaction, monofunctional organic amines or alcohols may coexist for the purpose of adjusting the molecular weight.

  Further, the amount of polyisocyanate used in preparing the prepolymer having a terminal hydroxyl group in the method of the two-step method (ii) is not particularly limited, but the total hydroxyl groups of the polycarbonate diol of the present invention and other polyols are not limited. As the number of isocyanate groups when the number is 1 equivalent, the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, still more preferably 0.7 equivalent, and the upper limit is preferably 0.99 equivalent, More preferably, it is 0.98 equivalent, More preferably, it is 0.97 equivalent.

  If the amount of isocyanate used is too small, the process until obtaining the desired molecular weight in the subsequent chain extension reaction tends to be long and production efficiency tends to decrease.If the amount is too large, the viscosity becomes too high and the flexibility of the polyurethane obtained is too high. In some cases, the productivity may be lowered or the productivity may be poor.

  The amount of the chain extender is not particularly limited, but when the total number of hydroxyl groups of the polycarbonate diol of the present invention and other polyols used in the prepolymer is 1 equivalent, the equivalent of the isocyanate group used in the prepolymer is As the total equivalent added, the lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, and the upper limit is preferably less than 1.0 equivalents, more preferably 0.99 equivalents. More preferably, it is in the range of 0.98 equivalent.

  When performing the chain extension reaction, monofunctional organic amines or alcohols may coexist for the purpose of adjusting the molecular weight.

  The chain extension reaction is usually carried out at 0 ° C. to 250 ° C., but this temperature varies depending on the amount of the solvent, the reactivity of the raw materials used, the reaction equipment, etc., and is not particularly limited. If the temperature is too low, the progress of the reaction may be too slow, or the production time may be prolonged due to the low solubility of the raw materials and polymer, and if it is too high, side reactions and decomposition of the resulting polyurethane may occur. . The chain extension reaction may be performed while degassing under reduced pressure.

Moreover, a catalyst, a stabilizer, etc. can also be added to chain extension reaction as needed.
Examples of the catalyst include amine catalysts such as triethylamine, tributylamine, N-ethylmorpholine, and triethylenediamine, or acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid, trimethyltin laurate, dibutyltin dilaurate, and dioctyltin. Known urethane polymerization catalysts typified by tin compounds such as dilaurate and dioctyltin dineodecanate and organic metal salts such as titanium compounds can be used. A urethane polymerization catalyst may be used individually by 1 type, and may use 2 or more types together.
Examples of stabilizers include 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N, N'-di-2-naphthyl-1,4-phenylenediamine, and tris (dinonylphenyl) phos. A compound such as phyto may be mentioned, and one kind may be used alone, or two or more kinds may be used in combination. In the case where the chain extender is highly reactive such as a short chain aliphatic amine, the reaction may be carried out without adding a catalyst.

<3-11. Water-based polyurethane emulsion>
It is also possible to produce an aqueous polyurethane emulsion using the polycarbonate diol of the present invention.
In that case, when the prepolymer is produced by reacting the polyol containing the polycarbonate diol of the present invention with an excess of polyisocyanate, a compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is prepared. A prepolymer is formed by mixing, and a water-based polyurethane emulsion is obtained through a neutralization chlorination step of hydrophilic functional groups, an emulsification step by addition of water, and a chain extension reaction step.

  The hydrophilic functional group of the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups used here is, for example, a carboxyl group or a sulfonic acid group, and can be neutralized with an alkaline group. It is a basic group. 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, and these are mixed in the same molecule. It does not matter.

  Specific examples of the compound 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 etc. are mentioned. Further, diaminocarboxylic acids such as lysine, cystine, 3,5-diaminocarboxylic acid and the like can also be mentioned. These may be used alone or in combination of two or more. When these are actually used, they are used after neutralizing with an amine such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine or triethanolamine, or an alkaline compound such as sodium hydroxide, potassium hydroxide or ammonia. be able to.

  When an aqueous polyurethane emulsion is produced, the amount of the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is used in order to increase the dispersion performance in water. Preferably it is 1 weight% with respect to the total weight of polycarbonate diol and the other polyol, More preferably, it is 5 weight%, More preferably, it is 10 weight%. On the other hand, if too much is added, the properties of the polycarbonate diol of the present invention may not be maintained, so the upper limit is preferably 50% by weight, more preferably 40% by weight, and even more preferably 30% by weight. It is.

  In the case of 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 process, or may be carried out without a solvent. Moreover, when using a solvent, after manufacturing an aqueous | water-based emulsion, it is preferable to distill a solvent off by distillation.

  The upper limit of the number average molecular weight determined from the hydroxyl value of the polycarbonate diol used when the aqueous polyurethane emulsion is produced without using a solvent with the polycarbonate diol of the present invention as a raw material is preferably 5000, more preferably 4500, and still more preferably 4000. . The lower limit is preferably 300, more preferably 500, and still more preferably 800. If the number average molecular weight determined from the hydroxyl value exceeds 5000 or is smaller than 300, emulsification may be difficult.

  In the synthesis or storage of water-based polyurethane emulsions, anionic interfaces represented by higher fatty acids, resin acids, acidic fatty alcohols, sulfate esters, higher alkyl sulfonates, alkyl aryl sulfonates, sulfonated castor oil, sulfosuccinate esters, etc. Activators, primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts, cationic surfactants such as pyridinium salts, or known ethylene oxide and long-chain aliphatic alcohols or phenols Emulsion stability may be maintained by using a nonionic surfactant or the like typified by a reaction product.

  In addition, when preparing a water-based polyurethane emulsion, water is mechanically mixed under high shear in the presence of an emulsifier in the presence of an emulsifier in a prepolymer organic solvent solution, if necessary, to produce an emulsion. You can also

  The water-based polyurethane emulsion thus produced can be used for various applications. In particular, recently, there has been a demand for chemical raw materials with a small environmental load, and it is possible to replace conventional products for the purpose of using no organic solvent.

<3-12. Additives>
The polyurethane of the present invention produced using the polycarbonate diol of the present invention includes a heat stabilizer, a light stabilizer, a colorant, a filler, a stabilizer, an ultraviolet absorber, an antioxidant, an anti-tacking agent, a flame retardant, and aging. Various additives such as an inhibitor and an inorganic filler can be added and mixed as long as the properties of the polyurethane of the present invention are not impaired.

  Compounds that can be used as heat stabilizers include phosphoric acid, phosphorous acid aliphatic, aromatic or alkyl group-substituted aromatic esters and hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, poly Phosphorus compounds such as phosphonates, dialkylpentaerythritol diphosphites, dialkylbisphenol A diphosphites; phenol derivatives, especially hindered phenol compounds; thioethers, dithioacid salts, mercaptobenzimidazoles, thiocarbanilides, thiodipropionic acid esters Compounds containing sulfur such as tin; tin compounds such as tin malate and dibutyltin monoxide can be used.

Specific examples of the hindered phenol compound include “Irganox 1010” (trade name: manufactured by BASF Japan Ltd.), “Irganox 1520” (trade name: manufactured by BASF Japan Ltd.), “Irganox 245” (trade name: manufactured by BASF Japan Ltd.). ) And the like.
Examples of phosphorus compounds include “PEP-36”, “PEP-24G”, “HP-10” (all trade names: manufactured by ADEKA Corporation), “Irgafos 168” (trade name: manufactured by BASF Japan Corporation), and the like. Is mentioned.

  Specific examples of the sulfur-containing compound include thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP).

  Examples of the light stabilizer include benzotriazole-based compounds, benzophenone-based compounds, and the like. Specifically, “TINUVIN 622LD”, “TINUVIN 765” (manufactured by Ciba Specialty Chemicals Co., Ltd.), “SANOL LS-2626”. "SANOL LS-765" (manufactured by Sankyo Co., Ltd.) or the like can be used.

  Examples of the ultraviolet absorber include “TINUVIN 328” and “TINUVIN 234” (manufactured by Ciba Specialty Chemicals Co., Ltd.).

  Examples of the colorant include direct dyes, acid dyes, basic dyes, metal complex dyes and the like; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide and mica; and coupling azo series, condensed azo series, And organic pigments such as anthraquinone, thioindigo, dioxazone, and phthalocyanine.

  Examples of the inorganic filler include short glass fiber, carbon fiber, alumina, talc, graphite, melamine, and clay.

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

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

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

<3-13. Molecular weight>
The molecular weight of the polyurethane of the present invention is appropriately adjusted according to its use and is not particularly limited, but is preferably 50,000 to 500,000 as a weight average molecular weight (Mw) in terms of polystyrene measured by GPC. More preferably, it is 10,000 to 300,000. If Mw is smaller than the lower limit, sufficient strength and hardness may not be obtained. If Mw is larger than the upper limit, handling properties such as workability tend to be impaired.

<3-14. Oleic acid resistance>
The polyurethane of the present invention has a rate of change in the weight of the polyurethane test piece after being immersed in oleic acid with respect to the weight of the polyurethane test piece before being immersed in oleic acid, for example, in the evaluation by the method described in the Examples section below. (Increase rate) (%) is preferably 50% or less, more preferably 35% or less, further preferably 30% or less, and particularly preferably 25% or less.
If the weight change rate exceeds the upper limit, sufficient oleic acid resistance may not be obtained.

<3-15. Ethanol resistance>
The polyurethane of the present invention is, for example, evaluated by the method described in the Examples section below, and the change rate (increase in the weight of the polyurethane test piece after being immersed in ethanol relative to the weight of the polyurethane test piece before being immersed in ethanol) (%) Is preferably 25% or less, more preferably 20% or less, further preferably 17% or less, particularly preferably 16% or less, and most preferably 15% or less.
If the weight change rate exceeds the upper limit, sufficient ethanol resistance may not be obtained.

<3-16. Ethyl acetate resistance>
The polyurethane of the present invention has a rate of change in the weight of the polyurethane test piece after being immersed in ethyl acetate relative to the weight of the polyurethane test piece before being immersed in ethyl acetate, for example, in the evaluation by the method described in the Examples section below. (Increase rate) (%) is preferably 150% or less, more preferably 130% or less, further preferably 110% or less, and particularly preferably 100% or less.
If the weight change rate exceeds the upper limit, sufficient ethyl acetate resistance may not be obtained.

<3-17. Tensile breaking elongation>
The polyurethane of the present invention was measured on a strip-shaped sample having a width of 10 mm, a length of 100 mm, and a thickness of about 50 to 100 μm at a temperature of 23 ° C. and a relative humidity of 50% at a chuck distance of 50 mm and a tensile speed of 500 mm / min. The lower limit of the tensile elongation at break is preferably 50%, more preferably 100%, still more preferably 150%, and the upper limit is preferably 900%, more preferably 850%, still more preferably 800%. If the tensile elongation at break is less than the above lower limit, handling properties such as workability tend to be impaired, and if the upper limit is exceeded, sufficient chemical resistance may not be obtained.

<3-18. 100% modulus>
The polyurethane of the present invention was measured on a strip-shaped sample having a width of 10 mm, a length of 100 mm, and a thickness of about 50 to 100 μm at a temperature of 23 ° C. and a relative humidity of 55% at a distance between chucks of 50 mm and a tensile speed of 500 mm / min. The lower limit of the 100% modulus is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, more preferably 1 MPa or more, and the upper limit is preferably 20 MPa or less, more preferably 15 MPa or less, even more preferably 10 MPa or less, particularly Preferably it is 5 MPa or less. If the 100% modulus is less than the above lower limit, chemical resistance may not be sufficient, and if it exceeds the upper limit, flexibility tends to be insufficient or handling properties such as workability tend to be impaired.

  Furthermore, the 100% modulus at −10 ° C. of the polyurethane of the present invention is preferably 0.5 MPa or more, more preferably 1.0 MPa or more, further preferably 1.5 MPa or more, and particularly preferably 2.0 MPa or more. Further, it is preferably 20 MPa or less, more preferably 15 MPa or less, further preferably 13 MPa or less, particularly preferably 10 MPa or less, and most preferably 8 MPa or less. If the 100% modulus at −10 ° C. is less than the above lower limit, chemical resistance may be insufficient. When the 100% modulus at −10 ° C. exceeds the above upper limit, flexibility at low temperatures may be insufficient, and handling properties such as workability may be impaired.

<3-19. Low temperature characteristics>
The polyurethane of the present invention has good low-temperature characteristics. The low-temperature characteristics of the present invention can be evaluated by tensile elongation at break, Young's modulus, and 100% modulus in a tensile test at a low temperature such as −10 ° C. Moreover, it can evaluate by the stress ratio in a cycle test at low temperature, such as -10 degreeC, and a permanent set. Specifically, it refers to flexibility at low temperature, elastic recovery, impact resistance, flex resistance, and durability.

<3-20. Heat resistance>
The polyurethane of the present invention is a sample before heating calculated by the following formula when a urethane film having a width of 100 mm, a length of 100 mm, and a thickness of about 50 to 100 μm is heated in a gear oven at a temperature of 120 ° C. for 400 hours. The lower limit of the rate of change (increase rate) of the weight average molecular weight (Mw (after heating)) of the sample after heating relative to the weight average molecular weight (Mw (before heating)) is preferably −40% or more, more preferably −30 % Or more, more preferably −20% or more, particularly preferably −15% or more, and the upper limit is preferably 120% or less, more preferably 110% or less, still more preferably 100% or less. When the heat resistance of polyurethane is low, the molecular weight is reduced by thermal decomposition or oxidative decomposition by heating, and the molecular weight is increased by crosslinking reaction. The degree of increase / decrease in molecular weight is preferably small.
Mw change rate (%) = Mw (after heating) ÷ Mw (before heating) × 100-100
Here, the weight average molecular weight (Mw) is a polystyrene equivalent value measured by GPC.

<3-21. Glass transition temperature>
A glass transition temperature of a specific polyurethane having a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC of 140,000 to 210,000 produced by a two-stage method using the polycarbonate diol of the present invention, H12MDI and IPDA ( The lower limit of Tg) is preferably −80 ° C., more preferably −70 ° C., further preferably −60 ° C., and the upper limit is preferably −10 ° C., more preferably −20 ° C., further preferably −30 ° C. . If Tg is less than the above lower limit, chemical resistance may not be sufficient, and if it exceeds the upper limit, low temperature characteristics may not be sufficient.

<3-22. Polyurethane solution>
A solution in which the polyurethane of the present invention is dissolved in an aprotic solvent (hereinafter, also referred to as “polyurethane solution”) is less prone to gelation, has a good storage stability such as a small change in viscosity with time, and has thixotropy. Since the property is small, it is convenient for processing into a film or the like.

  Examples of the aprotic solvent suitably used 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. More preferred are N, N-dimethylformamide and N, N-dimethylacetamide.

  The content of polyurethane in the polyurethane solution is usually preferably 1 to 99% by weight, more preferably 5 to 90% by weight, still more preferably 10 to 70% by weight, particularly based on the total weight of the polyurethane solution. Preferably it is 15 to 50% by weight. By setting the content of polyurethane in the polyurethane solution to 1% by weight or more, it is not necessary to remove a large amount of solvent, and productivity can be improved. Moreover, by setting it as 99 weight% or less, the viscosity of a solution can be suppressed and operativity or workability can be improved.

  The viscosity of the polyurethane solution of the present invention is preferably 10 Pa · s or more, more preferably 30 Pa · s or more, more preferably 50 Pa, as the solution viscosity measured by the method described in the Examples section below. -It is especially preferable that it is s or more. On the other hand, it is preferably 400 Pa · s or less, more preferably 300 Pa · s or less, and particularly preferably 200 Pa · s or less. When the viscosity of the polyurethane solution is not less than the above lower limit, the processability of the polyurethane solution becomes easy during production, and sufficient mechanical properties tend to be exhibited, and when it is not more than the above upper limit, the handleability of the polyurethane solution is improved. It is preferable because productivity is improved.

  The polyurethane solution is not particularly specified, but is preferably stored in an atmosphere of an inert gas such as nitrogen or argon when stored over a long period of time.

[4. Synthetic leather]
As a method for producing synthetic leather using the polyurethane for synthetic leather of the present invention, a known method can be used, for example, as shown in “Artificial leather / synthetic leather Japan Textile Products Consumer Science Association (2010)”. Manufactured by the method. In general, synthetic leather refers to a woven fabric or a knitted fabric as a base material, and may be distinguished from a synthetic leather using a non-woven fabric as a base material. However, in recent years, the distinction has become less strict, such as attaching a woven fabric or a knitted fabric to impart strength to the nonwoven fabric. The synthetic leather in the present invention includes a composition distinguished from artificial leather, and the effects of the present invention are manifested in all cases.
The synthetic leather using the polyurethane for synthetic leather of the present invention specifically includes, for example, a microporous layer containing a polyurethane resin formed on a base fabric serving as a base material, and is used for an outer skin layer through an adhesive layer. It is manufactured by laminating a polyurethane resin, or by containing a polyurethane resin on a base material filled with a resin such as polyurethane, and further laminating a microporous layer thereon. The polyurethane of the present invention may be applied or impregnated on the above-mentioned substrate, may be contained in an adhesive layer, may be used as a skin layer, and may be used in other layers.

<4-1. Base material>
As a base material, a base fabric can be used. Specifically, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, natural fibers such as cotton and hemp, rayon, suf, acetate, etc. A knitted fabric, a woven fabric, a non-woven fabric, etc., consisting of multicomponent fibers such as fibers alone or mixed blended fibers thereof, or modified into ultrafine fibers by dissolving at least one component or dividing a bicomponent fiber Can be used.
This base fabric may be brushed. The raising may be single-sided raising or double-sided raising. Further, the base fabric may be not only a single layer but also a multilayer structure composed of a plurality of fibers. Moreover, you may use the knitted fabric which has raising on the surface as a base fabric.

<4-2. Microporous layer>
The base material may have a microporous layer. The wet microporous layer is produced by a general base cloth impregnation method. For example, the base fabric is immersed in the dimethylformamide solution containing the polyurethane of the present invention, or the solution is applied to the base fabric, solidified in water, desolvated, dehydrated, and dried under hot air at about 120 ° C. Thus, a wet microporous layer having excellent surface smoothness can be formed.
The thickness of the wet microporous layer is preferably 50 to 400 μm, and more preferably 100 to 300 μm. Within this thickness range, optimal flexibility and volume are achieved as a synthetic leather.

<4-3. Polyurethane adhesive layer>
The polyurethane of the present invention can also be used for an adhesive layer. A cross-linking agent and, if necessary, a cross-linking accelerator may be added to the adhesive used for the adhesive layer.

<4-4. Skin layer>
The polyurethane of the present invention can also be used for the skin layer.
In this case, the polyurethane of the present invention may be used as it is for the skin layer, or a polyurethane solution is prepared by mixing the polyurethane of the present invention with other resins, antioxidants, ultraviolet absorbers, and the like. You may form using the skin layer compounded liquid obtained by mixing an organic solvent etc. In addition, a hydrolysis inhibitor, a pigment, a dye, a flame retardant, a filler, a crosslinking agent, and the like can be added to the polyurethane solution as necessary.

  Examples of other resins include polyurethanes other than the polyurethane of the present invention, poly (meth) acrylic resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl propionate copolymers, polyvinyl butyral resins, fibers Examples thereof include a base resin, a polyester resin, an epoxy resin and a phenoxy resin, and a polyamide resin.

  Examples of the cross-linking agent include organic polyisocyanates, crude MDI, TDI adduct of trimethylolpropane, and polyisocyanate compounds such as triphenylmethane triisocyanate.

  The skin layer can be formed to have a desired thickness by applying the skin layer-containing liquid containing the polyurethane of the present invention onto a release material, followed by heating and drying. After that, an adhesive is further applied to form an adhesive layer, a base fabric such as a raised cloth is pasted and dried, and after aging at room temperature for several days, a release material is peeled off to obtain a synthetic leather. It is done.

<4-5. Characteristics>
In the synthetic leather using the polyurethane of the present invention, the dynamic friction coefficient (MIU) and the standard deviation (MMD) of the dynamic friction coefficient of the KES test by the method as shown in the examples were detected, and the MIU value and the MIU to MMD value were detected. From the value of MIU / MMD excluding the value, the wet feeling and slimy feeling were quantified and evaluated. A large MIU value and a large MIU / MMD value means that the coefficient of dynamic friction is large and there is a feeling of wetness, and that it has a smooth feel with little roughness, and that the feeling of wetness and sliminess is good. Show. The MIU value is preferably 1.7 or more, more preferably 1.9 or more, still more preferably 2.0 or more, and particularly preferably 2.1 or more. Further, the MIU / MMD value is preferably 67 or more, more preferably 69 or more, still more preferably 70 or more, particularly preferably 73 or more, and most preferably 75 or more.

  In the synthetic leather using the polyurethane of the present invention, the tactile sensation test by the method shown in Examples is preferably 2 points or more, more preferably 3 points or more, and further preferably 4 points or more.

  The mechanism by which the tactile sensation such as a wet feeling and a slimy feeling of the synthetic leather obtained by using the polyurethane of the present invention is not clear, but is estimated as follows. The polyurethane of the present invention has high flexibility, and it is easy to follow the shape of the unevenness etc. of the object to be contacted, and sinking of the contacted part occurs, so dynamic friction when sliding the object to be contacted on the urethane surface The coefficient, that is, the resistance increases. Further, the polycarbonate diol used in the polyurethane of the present invention has a relatively large molecular weight, and the phase separation between the hard segment and the soft segment in the polyurethane is likely to proceed. The outermost surface of the polyurethane molded product is unevenly distributed with soft segment sites having relatively strong hydrophobicity. However, the polyurethane having undergone phase separation is markedly unevenly distributed, and the outermost surface is highly hydrophobic. Therefore, since the intermolecular force is small and the affinity is low with respect to a contact object having a relatively high polarity such as a human finger, it becomes a smooth feeling that is not easily roughened or caught. Therefore, when a human finger or the like is touched, the resistance is large but smooth, and it is estimated that the tactile sensation feels good wet feeling and slimy feeling.

  In the synthetic leather using the polyurethane of the present invention, the oleic acid resistance test by the method shown in Examples is preferably 3 points or more, more preferably 4 points or more, and most preferably 5 points.

  In the synthetic leather using the polyurethane of the present invention, the weather resistance by the method shown in the examples is preferably 2 points or more, more preferably 3 points or more, and further preferably 4 points or more.

<4-6. Application>
Synthetic leather obtained using the polyurethane for synthetic leather of the present invention can be used for automobile interior materials, furniture, clothing, shoes, bags, and the like.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited to these Examples, unless the summary is exceeded.

  In the following examples and comparative examples, analysis and evaluation methods for physical properties of each component are as follows.

[Analysis and evaluation of polycarbonate diol]
<Quantification of terminal amount of phenoxy group>
Polycarbonate diol was dissolved in CDCl ₃ , 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, phenoxy group was identified from the signal position of each component, and each content was calculated from the integral value. did. The ratio of the phenoxy group is determined from the ratio of the integral value for one proton of the phenoxy group to the integral value for one proton of the entire terminal, and the detection limit of the phenoxy group is 0.05% with respect to the entire terminal.

<Measurement of hydroxyl value and number average molecular weight in terms of hydroxyl value (Mn (OHV))>
Based on JIS K1557-1, the hydroxyl value of polycarbonate diol was measured by a method using an acetylating reagent, and Mn (OHV) was calculated from the value by the following formula.
Mn (OHV) = 56.1 × 2 × 1000 ÷ hydroxyl value

<Measurement of APHA value>
According to JIS K0071-1 (1998), the APHA value was measured by comparing a melted polycarbonate diol with a standard solution in a colorimetric tube. As a reagent, a chromaticity standard solution of 1000 degrees (1 mg Pt / mL) (Kishida Chemical) was used.

<Measurement of melt viscosity>
After the polycarbonate diol was heated to 80 ° C. and melted, the melt viscosity was measured at 80 ° C. using an E-type viscometer (BROOKFIELD DV-II + Pro, Cone: CPE-52).

<Measurement of glass transition temperature (Tg), melting peak temperature, heat of fusion>
About 10 mg of polycarbonate diol is enclosed in an aluminum pan, and using EXSTAR DSC6200 (manufactured by Seiko Instruments Inc.), in a nitrogen atmosphere at a rate of 20 ° C./minute, from 30 ° C. to 150 ° C., at a rate of 40 ° C./minute The temperature increases and decreases from 150 ° C. to −120 ° C. at a rate of 20 ° C./minute, from −120 ° C. to 120 ° C., the inflection point at the second temperature increase is the glass transition temperature (Tg), and the melting peak to melting peak temperature And the heat of fusion was determined.

<Analysis of molar ratio and average carbon number of dihydroxy compound after hydrolysis>
About 0.5 g of polycarbonate diol was precisely weighed and placed in a 100 mL Erlenmeyer flask, and 5 mL of tetrahydrofuran was added and dissolved. Next, 45 mL of methanol and 5 mL of a 25 wt% aqueous sodium hydroxide solution were added. A condenser was set in a 100 mL Erlenmeyer flask and heated in a water bath at 75 to 80 ° C. for 30 minutes for hydrolysis. After allowing to cool at room temperature, 5 mL of 6N hydrochloric acid was added to neutralize sodium hydroxide, and the pH was adjusted to 2-4. The whole amount was transferred to a 100 mL volumetric flask, the inside of the Erlenmeyer flask was washed twice with an appropriate amount of methanol, and the washing solution was also transferred to the 100 mL volumetric flask. After adding an appropriate amount of methanol to 100 mL, the liquid was mixed in a volumetric flask. The supernatant was collected, filtered through a filter, and then analyzed by GC. For the concentration of each dihydroxy compound, a calibration curve was prepared in advance from each dihydroxy compound known as a standard substance, and weight percent was calculated from the area ratio obtained by GC. The molar ratio of each dihydroxy compound was calculated from the weight% obtained by GC and the molecular weight of each dihydroxy compound. Moreover, the average carbon number was calculated from the carbon number and molar ratio of each dihydroxy compound.

(Analysis conditions)
Apparatus: Agilent 6850 (manufactured by Agilent Technologies)
Column: Agilent J & W GC column DB-WAX
Inner diameter 0.25mm, length 60m, film thickness 0.25μm
Detector: Hydrogen flame ionization detector (FID)
Temperature rising program: 150 ° C. (2 minutes), 150 ° C. → 245 ° C. (5 ° C./min, 19 minutes),
245 ° C (2 minutes)

<Measurement of ether / carbonate bond ratio>
The polycarbonate diol was hydrolyzed in the same manner as the molar ratio of the dihydroxy compound after hydrolysis, and analyzed by GC. For unidentified products, the compounds were identified by GC-MS. For the concentration of the dihydroxy compound containing an ether group after hydrolysis, a calibration curve was prepared in advance with diethylene glycol, and the weight percent was calculated from the area ratio obtained by GC. The molar ratio of each dihydroxy compound was calculated from the weight% obtained by GC and the molecular weight of the dihydroxy compound. From the molar ratio of each dihydroxy compound, the molar ratio of the dihydroxy compound containing an ether group, and the molecular weight of the polycarbonate diol calculated from the hydroxyl value, the ether group content ratio relative to the carbonate group was calculated.

(Analysis conditions)
Apparatus: Agilent 7890B (manufactured by Agilent Technologies)
Column: Agilent J & W GC column DB-WAXETR
Inner diameter 0.25mm, length 30m, film thickness 0.25μm
Detector: Hydrogen flame ionization detector (FID)
Temperature rising program: 100 ° C. → 250 ° C. (5 ° C./min)

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

[Analysis and evaluation of polyurethane]
<Measurement of isocyanate group concentration>
After diluting 20 mL of di-n-butylamine / toluene (weight ratio: 2/25) mixed solution with 90 mL of acetone, titrating with 0.5 N hydrochloric acid aqueous solution, measuring the amount of hydrochloric acid aqueous solution required for neutralization, and blank value It was. Thereafter, 1 to 2 g of the reaction solution was extracted, 20 mL of a mixed solution of di-n-butylamine / toluene was added, and the mixture was stirred at room temperature for 30 minutes, and then diluted with 90 mL of acetone in the same manner as in the blank measurement. The amount of hydrochloric acid aqueous solution required for neutralization was measured by titration with, and the amount of remaining amine was quantified. The concentration of the isocyanate group was determined from the volume of the aqueous hydrochloric acid solution required for neutralization by the following formula.
Isocyanate group concentration (% by weight) = A × 42.02 / D
A: Isocyanate group (mol) contained in the sample used in this measurement
A = (B−C) × 0.5 / 1000 × f
B: Amount of 0.5N hydrochloric acid aqueous solution required for blank measurement (mL)
C: Amount of 0.5N hydrochloric acid aqueous solution required for this measurement (mL)
D: Sample used for this measurement (g)
f: Potency of aqueous hydrochloric acid solution

<Measurement of solution viscosity>
A solution of polyurethane dissolved in dimethylformamide (concentration: 30% by weight) was set on a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) with a 3 ° × R14 rotor, and the solution viscosity of the polyurethane solution was measured at 25 ° C. .

<Measurement of molecular weight>
The molecular weight of the polyurethane is such that an N, N-dimethylacetamide solution is prepared so that the concentration of polyurethane is 0.14% by weight, and a GPC apparatus [product name “HLC-8220” manufactured by Tosoh Corporation (column: Tskel GMH-XL 2) and a solution in which 2.6 g of lithium bromide was dissolved in 1 L of dimethylacetamide was used as the eluent], and the number average molecular weight (Mn) and the weight average molecular weight (Mw) in terms of standard polystyrene were measured.

<Evaluation of oleic acid resistance>
The polyurethane solution was applied on a fluororesin sheet (fluorine tape Nitoflon 900, thickness 0.1 mm, manufactured by Nitto Denko Corporation) with a 9.5 mil applicator, and then at 60 ° C. for 1 hour and subsequently at 100 ° C. for 0.5 hour. Dried. The film was further dried at 100 ° C. under vacuum conditions for 0.5 hours and at 80 ° C. for 15 hours, and then allowed to stand for 12 hours or more under constant temperature and humidity at 23 ° C. and 55% RH, and 3 cm × 3 cm from the resulting film. The test piece was cut out. After measuring the weight of the test piece with a precision balance, it was put into a 250 ml glass bottle containing 50 ml of oleic acid as a test solvent and allowed to stand for 16 hours in a constant temperature bath at 80 ° C. in a nitrogen atmosphere. After the test, the test piece was taken out, and the front and back surfaces were lightly wiped with a paper wiper, and then the weight was measured with a precision balance, and the weight change rate (increase rate) from before the test was calculated. A weight change rate closer to 0% indicates better oleic acid resistance.

<Evaluation of ethanol resistance>
A urethane film was prepared in the same manner as described above in <Evaluation of oleic acid resistance>, and a urethane film test piece was cut out to 3 cm × 3 cm. After measuring the weight of the test piece with a precision balance, it was put into a glass petri dish having 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 with a paper wiper, and then the weight was measured with a precision balance, and the weight change rate (increase rate) from before the test was calculated. A weight change rate closer to 0% indicates better ethanol resistance.

<Evaluation of ethyl acetate resistance>
A urethane film was prepared in the same manner as described above in <Evaluation of oleic acid resistance>, and a urethane film test piece was cut out to 3 cm × 3 cm. After measuring the weight of the test piece with a precision balance, it was put into a glass petri dish having an inner diameter of 10 cmφ containing 50 ml of ethyl acetate as a test solvent and immersed at room temperature of about 23 ° C. for 20 minutes. After the test, the test piece was taken out and lightly wiped with a paper wiper, and then the weight was measured with a precision balance, and the weight change rate (increase rate) from before the test was calculated. A weight change rate closer to 0% indicates better ethyl acetate resistance.

<Measurement of glass transition temperature (Tg)>
After making a urethane film by the same method as in the above <Evaluation of oleic acid resistance>, about 5 mg of the film piece was enclosed in an aluminum pan, and an EXSTAR DSC6200 (manufactured by Seiko Instruments Inc.) was used in a nitrogen atmosphere. The temperature is raised and lowered at a rate of 10 ° C. per minute from −100 ° C. to 250 ° C., 250 ° C. to −100 ° C., and −100 ° C. to 250 ° C. The glass transition temperature ( Tg).

<Room temperature tensile test>
After creating a urethane film by the same method as described above in <Evaluation of oleic acid resistance>, a polyurethane test piece having a strip shape having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm according to JIS K6301 (2010) was pulled. Using a testing machine (Orientec Co., Ltd., product name “Tensilon UTM-III-100”) at a temperature of 23 ° C. (relative humidity 55%) at a distance between chucks of 50 mm and a tensile speed of 500 mm / min. Then, the stress at the time when the test piece was extended by 100% was measured.

<Low temperature tensile test>
After creating a urethane film by the same method as described above in <Evaluation of oleic acid resistance>, a polyurethane test piece having a strip shape having a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm according to JIS K6301 (2010) was pulled. Using a testing machine [manufactured by Shimadzu Corporation, product name “Autograph AG-X 5kN”], a thermostatic bath set to −10 ° C. [manufactured by Shimadzu Corporation, product name “THERMOSTATIC CHAMBER TCR2W- 200T "], a film was placed with a chuck distance of 50 mm. Then, after leaving still at -10 degreeC for 3 minute (s), the tension test was implemented at the tension speed of 500 mm / min, and the stress at the time of test piece extending | stretching 100% was measured.

<Evaluation of heat resistance>
After making a urethane film in the same manner as in the above <Evaluation of oleic acid resistance>, this film is formed into a strip shape having a width of 100 mm, a length of 100 mm, and a thickness of about 50 μm, and a temperature of 120 ° C. in a gear oven for 400 hours. Heating was performed. The weight average molecular weight (Mw) of the sample after heating was measured by the method described in <Measurement of molecular weight>, and the rate of change (increase rate) relative to the weight average molecular weight (Mw) before heating was calculated according to the following formula.
Mw change rate (%) = Mw (after heating) ÷ Mw (before heating) × 100-100

[Evaluation of synthetic leather]
<KES test>
A synthetic leather sample was cut into 8 cm × 20 cm, and attached to a KES surface testing machine (KES-FB4 manufactured by Kato Tech Co., Ltd.) in which a silicone rubber sensor (5 mm square) was installed in an environment of a temperature of 20 ° C. and a humidity of 50%. . The sensor was mounted on the sample, and the dynamic friction coefficient (MID) and the standard deviation (MMD) of the dynamic friction coefficient were detected by moving the sample at a speed of 1 mm / second with a load of 50 gf. Also, the value of MID / MMD was calculated by dividing the value of MID by the value of MMD. When MID is large and the value of MID / MMD is large, it indicates that the wet feeling and the slimy feeling are good.

<Tactile test>
The feeling when sliding on the synthetic leather with a finger was evaluated as follows.
4 points: heavy feel like wet 3 points: feel slightly wet 2 points: slightly dry feel 1 point: feel dry and slippery

<Oleic acid resistance test>
A test piece obtained by cutting a synthetic leather sample into 2 cm × 2 cm was put into a 250 ml glass bottle containing 50 ml of oleic acid, and allowed to stand at 80 ° C. for 72 hours in a covered state. Take out the test piece from the glass bottle, lightly absorb the oleic acid adhering to the test piece surface with a paper towel (manufactured by Oji Napier, Napier Super Absorbing Kitchen Towel), observe the surface of the test piece at that time, A point where the surface of the coating film was lifted was defined as one point.
About the thing which the coating-film surface did not change visually, it rubbed with the said paper towel with a fixed force, and evaluated by the following score by the frequency | count that float or peeling occurred on the coating-film surface.
(Number of frictions where peeling was recognized on the coating surface)
5 points: 50 times or more (no peeling)
4 points: 40 times or more and less than 50 times 3 points: 30 times or more and less than 40 times 2 points: less than 30 times 1 point: 0 times

<Weather resistance>
According to JIS L1096-1972, two pieces of 3 cm × 12 cm test pieces were cut in the longitudinal direction and the transverse direction of the synthetic leather. The obtained test piece is fixed between two grips opened in advance to 20 mm of a Scott type tester (Scott type abrasion resistant tester, manufactured by Toyo Seiki Seisakusho Co., Ltd.) with the synthetic leather surfaces being joined together, Reciprocating friction was performed 1000 times with a load of 9.81 N and a distance of 40 mm. The appearance change on the surface of the test piece obtained as a result was evaluated as follows.
5 points: No change 4 points: Slight skin lifting is confirmed on the leather surface 3 points: Clear skin lifting is confirmed from the leather surface 2 points: Skin lifting and cracks occur from the leather surface 1 point: The skin is torn from the leather surface, causing peeling

[Raw materials]
The raw materials used for the production of the polycarbonate diol in the following examples are as follows.
1,4-butanediol (hereinafter sometimes abbreviated as “1,4BD”): manufactured by Mitsubishi Chemical Corporation 1,10-decanediol (hereinafter sometimes abbreviated as “1,10DD”): Toyokuni Oil Co., Ltd. Company-made diphenyl carbonate (hereinafter sometimes abbreviated as “DPC”): Mitsubishi Chemical Corporation ethylene carbonate (sometimes abbreviated as “EC”): Mitsubishi Chemical Corporation magnesium acetate tetrahydrate: Japanese Made by Kojun Pharmaceutical Co., Ltd.

[Example 1]
<Production and evaluation of polycarbonate diol>
In a 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure regulator, 1,4-butanediol (1,4BD): 131.2 g, diphenyl carbonate (DPC): 2988. 8 g, magnesium acetate tetrahydrate aqueous solution (concentration: 8.4 g / L, magnesium acetate tetrahydrate: 55 mg) (hereinafter referred to as “catalyst aqueous solution”): 7.4 mL was added, and the nitrogen gas was replaced. Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Next, the pressure is lowered to 9.3 kPa over 90 minutes and further lowered to 0.7 kPa over 30 minutes, and then the reaction is continued, and then the temperature is raised to 170 ° C. to remove phenol and unreacted dihydroxy compounds out of the system. For 60 minutes to obtain a polycarbonate diol-containing composition.

The obtained polycarbonate diol-containing composition was fed to a thin film distillation apparatus at a flow rate of 20 g / min, and thin film distillation (temperature: 180 to 190 ° C., pressure: 40 to 67 Pa) was performed. As a thin-film distillation apparatus, an internal condenser having a diameter of 50 mm, a height of 200 mm, and an area of 0.0314 m ² , a jacketed Shibata Kagaku Co., Ltd. molecular distillation apparatus MS-300 special type was used. The same applies to the following examples and comparative examples.
Table 1 shows the evaluation results of properties and physical properties of the polycarbonate diol obtained by thin film distillation.

<Manufacture and evaluation of polyurethane>
Using the polycarbonate diol obtained by the above method, a specific polyurethane was produced by the following operation.

(Prepolymer (PP) reaction)
114.06 g of the above polycarbonate diol (hereinafter sometimes abbreviated as “PCD”) previously heated to 80 ° C. is placed in a separable flask equipped with a thermocouple and a cooling tube, and the flask is placed in an oil bath at 60 ° C. Then, 20.21 g of 4,4′-dicyclohexylmethane diisocyanate (hereinafter abbreviated as “H12MDI”; manufactured by Tokyo Chemical Industry Co., Ltd.) and triisooctyl phosphite (hereinafter “TiOP” as a reaction inhibitor). And 0.402 g (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the temperature in the flask was raised to 80 ° C. in about 1 hour while stirring at 60 rpm in a nitrogen atmosphere. After raising the temperature to 80 ° C., 13.7 mg of Neostan U-830 (hereinafter referred to as “U-830”, manufactured by Nitto Kasei Co., Ltd.) as a urethanization catalyst (102 ppm by weight based on the total weight of polycarbonate dio and isocyanate) After the exotherm subsided, the oil bath was heated to 100 ° C. and further stirred for about 2 hours. The concentration of the isocyanate group was analyzed, and it was confirmed that the theoretical amount of the isocyanate group was consumed.

(Chain extension reaction)
117.22 g of the obtained prepolymer (hereinafter sometimes abbreviated as “PP”) was diluted with 12.17 g of dehydrated toluene (manufactured by Wako Pure Chemical Industries, Ltd.). Subsequently, 261.84 g of dehydrated N, N-dimethylformamide (hereinafter sometimes abbreviated as “DMF”; manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the flask was immersed in an oil bath at 55 ° C. and stirred at about 200 rpm. While dissolving the prepolymer. After analyzing the concentration of isocyanate groups in the prepolymer solution, the required amount of isophoronediamine (hereinafter referred to as “IPDA”) calculated from the residual isocyanate is immersed in an oil bath set at 35 ° C. and stirred at 150 rpm. (Tokyo Chemical Industry Co., Ltd.) 5.04 g was added in portions. After stirring for about 1 hour, 0.343 g of morpholine (manufactured by Tokyo Chemical Industry Co., Ltd.) is added as a chain terminator, and the mixture is further stirred for 1 hour to obtain a polyurethane solution having a viscosity of 204 Pa · s and a weight average molecular weight of 184,000. It was. Table 3 shows the evaluation results of the properties and physical properties of this polyurethane.

<Manufacture and evaluation of synthetic leather>
Using the polyurethane solution obtained by the above method, synthetic leather was produced by the following operation.

  After adding 20 parts by weight of methyl ethyl ketone to 100 parts by weight of the polyurethane solution obtained by the above-mentioned method to obtain a uniform solution, a release paper (DNTP.APT.DE- manufactured by Dai Nippon Printing Co., Ltd.) was used using a 6 mil applicator. 3) Coated on top. After drying this with a dryer at 100 ° C. for 2 minutes, the adhesive urethane resin solution <100 parts by weight of the urethane resin for adhesive below, a black pigment (DIC ) Carbon black) 20 parts by weight, methyl ethyl ketone (MEK) 30 parts by weight, DMF 10 parts by weight of a mixed solution> was applied and dried with a dryer at 100 ° C. for 1 minute. The wet base urethane layer side shown below is placed on the adhesive so that air does not enter, and after pressure-bonding with a stretch bar, it is dried with a dryer at 100 ° C. for 2 minutes, and further with a dryer at 80 ° C. for 15 hours. Dried. Thereafter, it was allowed to cool at room temperature, and the release paper was peeled off to obtain a synthetic leather. Table 4 shows the evaluation results of the obtained synthetic leather.

In addition, the raw material used for synthetic leather preparation is as follows.
(Urethane resin for adhesives)
Urethane solution having a solid content of 30% by weight Solvent composition: MEK / DMF = 40/60 weight ratio Urethane composition:
PC-2000 / 1,4BDG / MDI = 0.9 / 1.1 / 2.0 mol ratio PC-2000: Polycarbonate diol molecular weight 2000
14BG: 1,4-butanediol MDI: 4,4′-diphenylmethane diisocyanate (wet base)
Made by wet coagulation of polyurethane resin composed of polycarbonate diol, polytetramethylene glycol and MDI on woven or knitted fabric

[Example 2, Comparative Examples 1-3]
<Production and evaluation of polycarbonate diol>
In the production of the polycarbonate diol (PCD) of Example 1, the same conditions and methods were used except that the types and amounts charged of the PCD polymerization raw materials were changed to the types and amounts charged of the raw materials shown in Tables 1 and 2. Reaction was performed and the polycarbonate containing composition was obtained.
Thin film distillation was performed on the obtained polycarbonate diol-containing composition in the same manner as in Example 1. Tables 1 and 2 show the evaluation results of properties and physical properties of polycarbonate diol obtained by thin film distillation.

<Manufacture and evaluation of polyurethane>
In the production of the polyurethane of Example 1, all except that the polycarbonate diol (PCD) used was changed to the PCD produced in each Example, and the amount of each raw material was changed to the amount described in Table 3, respectively. Reaction was carried out under the same conditions and methods to obtain polyurethane. Table 3 shows the properties and physical properties of this polyurethane.

<Manufacture and evaluation of synthetic leather>
In the production of the synthetic leather of Example 1, synthetic leather was produced under the same conditions and methods except that the polyurethane used was changed from the polyurethane produced in each Example. The evaluation results of this synthetic leather are shown in Table 4.

[Production Examples 1-2]
<Production and evaluation of polycarbonate diol>
In the production of polycarbonate diol (PCD) in Example 1, the reaction was carried out under the same conditions and methods except that the type and amount of the PCD polymerization raw material were changed to the type and amount of the raw material shown in Table 1. And a polycarbonate-containing composition was obtained.
Thin film distillation was performed on the obtained polycarbonate diol-containing composition in the same manner as in Example 1. Table 1 shows the evaluation results of properties and physical properties of the polycarbonate diol obtained by thin film distillation.

[Example 3]
<Production and evaluation of polycarbonate diol>
A 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure regulator is charged with 360 g of the polycarbonate diol obtained in Production Example 1 and 640 g of the polycarbonate diol obtained in Production Example 2, and nitrogen gas. Replaced. After raising the internal temperature to 120 ° C., the mixture was stirred for 30 minutes in a nitrogen stream, and polycarbonate diol was mixed.
Table 1 shows the evaluation results of the properties and physical properties of the obtained polycarbonate diol.

<Manufacture and evaluation of polyurethane>
In the production of the polyurethane of Example 1, all the same conditions except that the polycarbonate diol (PCD) to be used was changed to the PCD produced above and the amount of each raw material was changed to the amount shown in Table 3, respectively. And reacted to obtain a polyurethane. Table 3 shows the properties and physical properties of this polyurethane.

[Comparative Examples 4 to 6]
<Evaluation of polycarbonate diol>
The following polycarbonate diols were used. Table 2 shows the evaluation results of properties and physical properties of each polycarbonate diol.
Comparative Example 4: Polycarbonate diol produced from 1,6-hexanediol (hereinafter sometimes abbreviated as “1,6HD”) (“Duranol (registered trademark)” manufactured by Asahi Kasei Chemicals Corporation Grade: T-6002 )
Comparative Example 5: Polycarbonate diol produced from 1,5-pentanediol (hereinafter sometimes abbreviated as “1,5PD”) and 1,6HD (“Duranol (registered trademark)” grade manufactured by Asahi Kasei Chemicals Corporation : T-5552)
Comparative Example 6: Polycarbonate diol produced using 1,4BD and 1,6HD as raw materials ("Duranol (registered trademark)" grade: T-4672 manufactured by Asahi Kasei Chemicals Corporation)

<Manufacture and evaluation of polyurethane>
Polyurethane was produced using the above polycarbonate diol as PCD as a polyurethane production raw material.
In the production of the polyurethane of Example 1, the reaction was carried out under the same conditions and methods except that the polycarbonate diol used as the raw material and the raw material charge amount were changed to the raw material types and respective charge amounts shown in Table 3. To obtain a polyurethane. Table 3 shows the evaluation results of the properties and physical properties of this polyurethane.

<Manufacture and evaluation of synthetic leather>
In the production of the synthetic leather of Example 1, synthetic leather was produced under the same conditions and methods except that the polyurethane used was changed to the polyurethane produced in each comparative example. The evaluation results of this synthetic leather are shown in Table 4.

[Production Example 3]
<Production and evaluation of polycarbonate diol>
In a 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure regulator, 1,4BD: 1378.5 g, 1,10DD: 585.2 g, EC: 1584.0 g, tetrabutyl orthotitanate (Hereafter, it may be abbreviated as “TBT”): 159 mg was added, and nitrogen gas substitution was performed. Under stirring, the internal temperature was raised to 130 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 4.7 kPa over 2 minutes, and then reacted while lowering the pressure to 3.3 kPa over 900 minutes. Next, after adding 379.7 g of EC, the temperature was changed to 180 ° C. and the pressure was changed to 16.7 kPa, and the mixture was reacted for 480 minutes. Furthermore, after changing the temperature to 190 ° C. and the pressure to 24.0 kPa, the pressure was lowered to 0.7 kPa over 240 minutes, and further reacted at 0.7 kPa for 150 minutes to obtain a polycarbonate diol.

[Production Example 4]
<Production and evaluation of polycarbonate diol>
Into a 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure control device, 1,4BD: 1821.8 g, EC: 1584.0 g, tetrabutyl orthotitanate (TBT): 345 mg as a raw material, Nitrogen gas replacement was performed. Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 12.0 kPa over 2 minutes and the reaction was carried out for 760 minutes. Next, after adding EC: 396.0 g, after changing the temperature to 180 ° C. and the pressure to 12.0 kPa, the pressure was decreased to 3.3 kPa over 380 minutes, and further reacted at 0.7 kPa for 270 minutes, A polycarbonate diol was obtained.

[Comparative Example 7]
<Production and evaluation of polycarbonate diol>
A 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure adjusting device was charged with 127 g of the polycarbonate diol obtained in Production Example 3 and 451 g of the polycarbonate diol obtained in Production Example 4, and nitrogen gas. Replaced. After raising the internal temperature to 120 ° C., the mixture was stirred for 30 minutes in a nitrogen stream, and polycarbonate diol was mixed.
Table 2 shows the evaluation results of properties and physical properties of the obtained polycarbonate diol.

<Manufacture and evaluation of polyurethane>
Polyurethane was produced using the above polycarbonate diol as PCD as a polyurethane production raw material.
In the production of the polyurethane of Example 1, all the reactions were carried out under the same conditions and methods except that the raw material charge amounts were changed to the raw material types and the respective charge amounts shown in Table 3, and polyurethane was obtained. Table 3 shows the evaluation results of the properties and physical properties of this polyurethane.

From the above results, the following can be understood.
In “−10 ° C./100% modulus” in Table 3, the value of the example is smaller than that of the comparative example, indicating that the flexibility at low temperature is good. Further, in the examples, the values of “80 ° C. resistance to oleic acid weight change” and “room temperature resistance to ethanol weight change” were smaller than those in the comparative example, indicating that the chemical resistance was good. Furthermore, since the value of “change rate of polystyrene-equivalent weight average molecular weight after the heat test” is small, it can be seen that the heat resistance is good, and the examples show that the physical properties are good. Therefore, it can be seen that the polycarbonate diol of the present invention is a polycarbonate diol as a raw material for polyurethane, which is excellent in the balance of flexibility, chemical resistance, low temperature characteristics, and heat resistant physical properties as compared with the conventional polycarbonate diol.

  Moreover, it is understood from the comparison between Example 3 and Comparative Example 7 that when the content of the ether bond in the polycarbonate diol is large, the resulting polyurethane has poor chemical resistance and heat resistance.

  From the “KES test” in Table 4, it can be seen that in the example, the MIU value is larger and the MIU / MMD is larger than in the comparative example, so that the wet feeling and the slimy feeling are good. Furthermore, “tactile sensation” is better in the examples than in the comparative examples, and “olein resistance” shows that the examples tend to be better than in the comparative examples. Therefore, together with the results in Table 3, when the polycarbonate diol of the present invention is used as a polyurethane raw material for synthetic / artificial leather, flexibility, chemical resistance, low temperature characteristics, heat resistance, and tactile sensation are compared with conventional polycarbonate diol. It can be seen that it is possible to obtain a synthetic / artificial leather having an excellent balance of physical properties.

Claims (8)

A polyurethane for synthetic leather obtained by reacting at least (a) a compound containing two or more isocyanate groups in one molecule, (b) a chain extender and (c) a polycarbonate diol,
The (c) polycarbonate diol has a hydroxyl value of 20 mg-KOH / g or more and 45 mg-KOH / g or less, a glass transition temperature measured by a differential operation calorimeter is -30 ° C. or less, and the polycarbonate diol is hydrolyzed. A polyurethane for synthetic leather, which is a polycarbonate diol having an average carbon number of 3 or more and 5.5 or less in a dihydroxy compound obtained by decomposition.   2. The polyurethane for synthetic leather according to claim 1, wherein the ratio of the ether bond to the carbonate bond in the (c) polycarbonate diol is 0.01% or more and 5% or less.   The polyurethane for synthetic leather according to claim 1 or 2, wherein the dihydroxy compound is only a linear aliphatic dihydroxy compound having no substituent.   (C) Ratio (Mw / Mn) of polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography of polycarbonate diol to polystyrene-equivalent number average molecular weight (Mn) is 1.5-3. The polyurethane for synthetic leather according to any one of claims 1 to 3, wherein the range is 0.   The synthetic leather according to any one of claims 1 to 4, wherein the dihydroxy compound contains at least one selected from the group consisting of 1,3-propanediol and 1,4-butanediol. Polyurethane.   The polyurethane for synthetic leather according to any one of claims 1 to 5, wherein the dihydroxy compound contains a plant-derived compound.   The Hazen color number measured according to JIS K0071-1 (1998) of the (c) polycarbonate diol is 60 or less, for synthetic leather according to any one of claims 1 to 6, Polyurethane.   The synthetic leather manufactured using the polyurethane for synthetic leather of any one of Claims 1-7.