JP2020128461A - Polyurethane elastomer and method for producing the same - Google Patents

Abstract

To provide a polyurethane elastomer having excellent transparency, flexibility and durability.SOLUTION: An elastomer has an isocyanate group-derived structural unit, a unit of the following formula (A), and units of the following (B), (C) and/or units of the following (D), (E).SELECTED DRAWING: None

Description

The present invention relates to a polyurethane elastomer having excellent transparency, flexibility, mechanical strength and durability, and a method for producing this polyurethane elastomer.

Polyurethane elastomers include a thermoplastic polyurethane elastomer (TPU) that softens when heated and then hardens when cooled, and a thermosetting polyurethane elastomer (TSU) that hardens by heating, but both have excellent elasticity and mechanical strength. , Low temperature characteristics, abrasion resistance, weather resistance, oil resistance, excellent workability, and easy to process into various shapes. Therefore, industrial parts such as rolls and casters, automobiles such as solid tires and belts. In addition to parts, paper feed rolls, copier rolls, and other OA equipment parts, they are widely used in sports and leisure goods.

In Patent Document 1, diphenylmethane diisocyanate is used as a polyisocyanate compound, polycarbonate diol is used as a polyol, and three components having a specific molecular weight range of a diol, a polyether polyol, and a propylene oxide adduct of glycerin are used together as a curing agent. Has proposed a two-component thermosetting polyurethane elastomer having improved mechanical strength (tensile strength, elongation), low compression strain, low impact resilience, water resistance and the like.

Patent Document 2 discloses a main component obtained by reacting a polycarbonate polyol, a polyether polyol and a polyisocyanate compound as a polyurethane elastomer having improved flexibility, strength and water resistance, and a curing agent such as 1,4-butanediol. A polyurethane elastomer using is proposed.

Patent Document 3 proposes a thermoplastic polyurethane elastomer obtained by reacting a polyisocyanate and a polyether carbonate diol as a thermoplastic polyurethane elastomer having oil lubrication resistance, tensile strength, and optical characteristics.

JP, 2013-163778, A JP, 2005-081278, A JP-A-4-214713

With respect to the polyurethane elastomer, further improvement in flexibility and durability is desired in its application, but in the conventional polyurethane elastomers proposed in Patent Documents 1 and 2, the flexibility, mechanical strength and durability are improved. It was difficult to achieve compatibility between the properties, and the transparency was poor.
That is, in conventional polyurethane elastomers, a combination of a polyether polyol and a polycarbonate diol has been proposed in order to impart flexibility, but due to the effect of mass transfer due to the low compatibility of the polyol during the urethanization reaction, However, in the solvent-free system, it was not sufficient to obtain the design properties such as physical properties and transparency of the obtained polyurethane elastomer molded product. For example, in the polyurethane elastomer synthesized by the method proposed in Patent Document 1, since the compatibility of the polyols is poor, the polycarbonate diol is previously reacted with an isocyanate compound to form a prepolymer, and then polytetramethylene glycol or the like is used. It was necessary to mix with a curing agent, and the resulting polyurethane elastomer had an insufficient balance of physical properties such as durability, flexibility and mechanical strength.

Patent Document 3 does not disclose a polyurethane elastomer in which a polyether polycarbonate diol used in the present invention and a polycarbonate diol or a polyalkylene ether glycol are used in combination.

An object of the present invention is to provide a polyurethane elastomer having excellent transparency, flexibility, mechanical strength and durability.

The present inventors have conducted extensive studies to solve the above problems, and as a result, by using a specific polyether polycarbonate diol and a polycarbonate diol as a polyol raw material, or a polyalkylene ether glycol in combination, a polyurethane elastomer is produced. We have found that we can solve the problems.

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

[1] A structural unit derived from a compound having a plurality of isocyanate groups, a structural unit derived from at least one compound selected from the group consisting of polyols and polyamines, a polyether carbonate diol represented by the following formula (A): And a polycarbonate diol having at least a repeating unit represented by the following formula (B) and a repeating unit represented by the following formula (C) and/or a repeating unit represented by the following formula (D) And a polyurethane elastomer containing a structural unit derived from a polyalkylene ether glycol having a repeating unit represented by the following formula (E).

(In the formula (A), R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. In A), a plurality of R ¹ may be the same or different.

（上記式（Ｂ）において、Ｒ^２は炭素数２〜２０の二価の炭化水素基を表し、ｐは３〜５０の整数であり、上記式（Ｃ）においてＲ^３はＲ^２とは異なるものであり、炭素数３〜２０の二価の炭化水素基を表し、又は、脂環式構造若しくは複素環式構造を含む炭素数３〜２０の二価の炭化水素基を表し、ｑは０〜５０の整数である。
上記式（Ｄ）において、Ｒ^４は炭素数２〜２０のアルキレン基、ｒは３〜５０の整数であり、上記式（Ｅ）においてＲ^５はＲ^４とは異なるものであり、炭素数３〜２０の二価の炭化水素基、又は、脂環式構造若しくは複素環式構造を含む炭素数３〜２０の二価の炭化水素基を表し、ｓは０〜５０の整数である。）

(In the above formula (B), R ² represents a divalent hydrocarbon group having 2 to 20 carbon atoms, p is an integer of 3 to 50, and in the above formula (C), R ³ is different from R ^2. And represents a divalent hydrocarbon group having 3 to 20 carbon atoms, or a divalent hydrocarbon group having 3 to 20 carbon atoms and containing an alicyclic structure or a heterocyclic structure, and q is 0. Is an integer of -50.
In the above formula (D), R ⁴ is an alkylene group having 2 to 20 carbon atoms, r is an integer of 3 to 50, and in the above formula (E), R ⁵ is different from R ⁴ and has 3 carbon atoms. To a divalent hydrocarbon group having 20 to 20 carbon atoms or a divalent hydrocarbon group having 3 to 20 carbon atoms and having an alicyclic structure or a heterocyclic structure, and s is an integer of 0 to 50. )

[2] The ratio of the structural unit derived from the polyether polycarbonate diol to the total of the structural unit derived from the polycarbonate diol and the structural unit derived from the polyalkylene ether glycol is 10% by weight to 90% by weight [1]. The polyurethane elastomer according to 1.

[3] The polyurethane elastomer according to [1] or [2], wherein R ¹ in the formula (A) is an n-butylene group and/or a 2-methylbutylene group.

[4] The molar ratio of the repeating unit represented by the formula (C) to the repeating unit represented by the formula (B) is 0.03 to 10, and the molar ratio is 1 to 3. Polyurethane elastomer.

[5] The polyurethane elastomer according to any one of [1] to [4], wherein R ² in the formula (B) is a divalent hydrocarbon group having 3 to 6 carbon atoms.

[6] The polyurethane elastomer according to any one of [1] to [5], wherein R ³ in the formula (C) is a divalent hydrocarbon group having 4 to 12 carbon atoms.

[7] The structural unit derived from the formula (C) includes neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol and 2-methyl-1,4-butane. The polyurethane elastomer according to any one of [1] to [5], which is a structural unit derived from at least one selected from the group consisting of diols.

[8] The structural unit derived from the formula (C) is a structural unit derived from at least one selected from the group consisting of isosorbide, isomannide, isoidide, and 1,4-cyclohexanedimethanol [1] to The polyurethane elastomer according to any one of [5].

[9] The polyurethane elastomer according to any one of [1] to [8], wherein the structural unit derived from the polyalkylene ether glycol has a number average molecular weight of 200 to 5,000 on the basis of a hydroxyl value.

[10] The polyalkylene ether glycol is polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, copolymerization polytetramethylene ether glycol of 3-methyltetrahydrofuran and tetrahydrofuran, copolymerization polyether polyol of neopentyl glycol and tetrahydrofuran, ethylene The polyurethane elastomer according to any one of [1] to [9], which is at least one selected from the group consisting of a copolymerized polyether polyol of oxide and tetrahydrofuran and a copolymerized polyether glycol of propylene oxide and tetrahydrofuran.

[11] The polyurethane elastomer according to any one of [1] to [10], wherein the compound having a plurality of isocyanate groups is an aromatic diisocyanate compound.

[12] The polyurethane elastomer according to [11], wherein the aromatic diisocyanate compound is at least one selected from the group consisting of 1,4-diphenylmethane diisocyanate, toluene diisocyanate, and xylylene diisocyanate.

[13] At least one compound selected from the group consisting of the polyol and polyamine is at least one compound selected from the group consisting of ethylene glycol, 1,4-butanediol and 1,6-hexanediol. The polyurethane elastomer according to any one of [1] to [12].

[14] The polyurethane elastomer according to any one of [1] to [13], wherein the polyurethane elastomer is a thermoplastic elastomer.

[15] A method for producing the polyurethane elastomer according to any one of [1] to [14], which comprises at least one compound selected from the group consisting of a compound having a plurality of isocyanate groups, the polyol, and a polyamine. A method for producing a polyurethane elastomer, wherein the addition polymerization reaction of the compound, the polycarbonate diol and/or the polyalkylene ether glycol is carried out without a solvent.

According to the present invention, a polyurethane elastomer having excellent transparency, flexibility and durability is provided.
In the present invention, “durability” means chemical resistance, weather resistance, and resistance performance against various other chemical and physical influences.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and various modifications can be carried out within the scope of the gist thereof.

[Polyurethane elastomer]
The polyurethane elastomer of the present invention is a compound having a plurality of isocyanate groups (hereinafter sometimes referred to as “polyisocyanate compound”), at least one compound selected from the group consisting of polyols and polyamines (hereinafter, “chain”). Sometimes referred to as an "extender"), a polyether polycarbonate diol having a structure represented by the following formula (A) (hereinafter sometimes referred to as "polyether polycarbonate diol (A)"), and at least the following: A repeating unit represented by the formula (B) (hereinafter sometimes referred to as “repeating unit (B)”) and a repeating unit represented by the following formula (C) (hereinafter, “repeating unit (C)”) And/or a repeating unit represented by the following formula (D) (hereinafter, sometimes referred to as “repeating unit (D)”) and the following formula (E). A repeating unit (hereinafter sometimes referred to as "repeating unit (E)") derived from a polyalkylene ether glycol, and a polyisocyanate compound and a chain extender. , A polyether polycarbonate diol (A), a polycarbonate diol having a repeating unit (B) and a repeating unit (C) and/or a polyalkylene ether glycol having a repeating unit (D) and a repeating unit (E) are used as raw materials. Manufactured.

(In the formula (A), R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. In A), a plurality of R ¹ may be the same or different.

(In the above formula (B), R ² represents a divalent hydrocarbon group having 2 to 20 carbon atoms, p is an integer of 3 to 50, and in the above formula (C), R ³ is different from R ^2. And represents a divalent hydrocarbon group having 3 to 20 carbon atoms, or a divalent hydrocarbon group having 3 to 20 carbon atoms and containing an alicyclic structure or a heterocyclic structure, and q is 0. Is an integer of -50.
In the above formula (D), R ⁴ is an alkylene group having 2 to 20 carbon atoms, r is an integer of 3 to 50, and in the above formula (E), R ⁵ is different from R ⁴ and has 3 carbon atoms. To a divalent hydrocarbon group having 20 to 20 carbon atoms or a divalent hydrocarbon group having 3 to 20 carbon atoms and having an alicyclic structure or a heterocyclic structure, and s is an integer of 0 to 50. )

<Polyisocyanate compound>
The polyisocyanate compound used as a raw material for producing the polyurethane elastomer of the present invention may be any polyisocyanate compound having two or more isocyanate groups, and various known aliphatic, alicyclic or aromatic polyisocyanate compounds can be mentioned.

For example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and dimerisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group. Aliphatic diisocyanate compound; 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- Alicyclic diisocyanate compounds such as bis(isocyanatomethyl)cyclohexane; xylylene diisocyanate, 4,4'-diphenyl diisocyanate, toluene diisocyanate (2,4-toluene diisocyanate, 2,6-toluene 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, Aromatic diisocyanate compounds such as 3′-dimethyl-4,4′-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate and m-tetramethylxylylene diisocyanate can be used. These may be used alone or in combination of two or more.

Of these, aromatic polyisocyanate compounds are preferred because of their high reactivity with polyols and the high curability of the resulting polyurethane elastomers, and in particular, because they are industrially inexpensive and available in large quantities, 4,4′-diphenylmethane is preferred. Diisocyanate (hereinafter sometimes referred to as “MDI”), toluene diisocyanate (TDI), and xylylene diisocyanate are preferable.

<Chain extender>
The chain extender used as a raw material for producing the polyurethane elastomer of the present invention is a low molecular weight compound having at least two active hydrogens that react with an isocyanate group, and is selected from polyols and polyamines.

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-propanediol, dimer diols having a branched chain Diols having an ether group such as diethylene glycol and propylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 1,4-dihydroxyethylcyclohexane, xylylene glycol, Diols having an aromatic group such as 1,4-dihydroxyethylbenzene and 4,4′-methylenebis(hydroxyethylbenzene); polyols such as glycerin, trimethylolpropane and pentaerythritol; N-methylethanolamine, N-ethylethanol Hydroxyamines such as amines; ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediamine, di-2-hydroxy. Ethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, 4,4'-diphenylmethanediamine, methylenebis(o-chloroaniline), xylylenediamine, diphenyldiamine, tri Polyamines such as diamine, hydrazine, piperazine and N,N′-diaminopiperazine;

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

Among these, ethylene glycol, 1, in terms of excellent flexibility and elastic recovery due to excellent phase separation of the soft segment and hard segment of the polyurethane elastomer obtained, and industrially inexpensively available in large quantities, 4-butanediol and 1,6-hexanediol are preferred.

<Polyether polycarbonate diol (A)>
The polyether polycarbonate diol (A) used as a raw material for producing the polyurethane elastomer of the present invention is represented by the following formula (A).
In the following formula (A), when m=1, it is referred to as “polyether carbonate diol” instead of “polyether polycarbonate diol”, but in the present invention, it is represented by formula (A). Such polyether carbonate diol is also referred to as "polyether polycarbonate diol (A)".

(In the formula (A), R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. In A), a plurality of R ¹ may be the same or different.

In the above formula (A), R ¹ is preferably a linear or branched alkylene group having 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and particularly preferably a butylene group having 4 carbon atoms or 5 carbon atoms. 2-Methylbutylene group, particularly preferably n-butylene group. That is, it is preferable that R ¹ —O— in the formula (A) is derived from polytetramethylene ether glycol from the viewpoints of industrial availability and excellent physical properties of the resulting polyurethane elastomer.

In the above formula (A), when n is less than 2, the flexibility of the obtained polyurethane elastomer tends to be poor, and when it exceeds 30, the viscosity and crystallinity of the obtained polyether polycarbonate diol are high and the handleability is deteriorated. However, the transparency of the polyurethane elastomer obtained due to poor compatibility with other polyols tends to decrease. Therefore, n is 2 to 30, preferably 3 to 25, and more preferably 3 to 20.

Further, in the above formula (A), when m is less than 1, the durability of the polyurethane elastomer tends to be poor, and when it exceeds 20, the viscosity is increased and the handling during polyurethane conversion may be impaired. Therefore, m is 1 to 20, preferably 2 to 10, and more preferably 2 to 6.

The polyether polycarbonate diol (A) can be produced by polymerizing a polyoxyalkylene glycol and a carbonate compound in the presence of a catalyst according to a conventional method.

The polyoxyalkylene glycol used for producing the polyether polycarbonate diol (A) includes polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, copolymerization of 3-methyltetrahydrofuran and tetrahydrofuran, polytetramethylene ether glycol, neopentyl glycol and tetrahydrofuran. From the viewpoint of the mechanical strength of the obtained polyurethane elastomer, polytetramethylene ether glycol (PTMG) is preferable, for example, a copolymerized polyether polyol of, a copolymerized polyether polyol of ethylene oxide and tetrahydrofuran, and a copolymerized polyether glycol of propylene oxide and tetrahydrofuran. ) Is more preferable.
The polyoxyalkylene glycols may be used alone or in combination of two or more.

The number average molecular weight (Mn) determined from the hydroxyl value of the polyoxyalkylene glycol used for producing the polyether polycarbonate diol (A) is preferably 150 to 2000, more preferably 200 to 1500, and further preferably 250 to 1200. .. When the molecular weight is less than 300, the flexibility of the obtained polyurethane elastomer tends to be poor, and when it exceeds 2000, the viscosity and crystallinity of the obtained polyether polycarbonate diol (A) are high, and the handling property is deteriorated, and other polyurethane The resulting polyurethane elastomer tends to have low transparency due to poor compatibility with the resin. The number average molecular weight (Mn) obtained from the hydroxyl value is specifically measured by the method described in the section of Examples below.

The carbonate compound that can be used for producing the polyether polycarbonate diol (A) is not limited as long as the effects of the present invention are not impaired, and examples thereof include dialkyl carbonate, diaryl carbonate, and alkylene carbonate. These may be one kind or plural kinds. Of these, dialkyl carbonate and alkylene carbonate are preferable from the viewpoint of reactivity.

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

When producing the polyether polycarbonate diol (A), an ester exchange catalyst can be used if necessary in order to accelerate the polymerization.
As the transesterification catalyst, any compound generally known to have transesterification ability can be used without limitation.

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

Of these, preferably, acetate, nitrate, sulfate, carbonate, phosphate, hydroxide, halide, acetylacetonate salt of at least one metal selected from Group 2 metals of the periodic table, Alkoxides are used, more preferably acetates, carbonates, hydroxides and acetylacetonates of Group 2 metals of the periodic table are used, and further preferably acetates, carbonates, hydroxides of magnesium and calcium, Acetylacetonate salts are used, particularly preferably magnesium and calcium acetate salts and acetylacetonate salts, and most preferably magnesium acetylacetonate salts.

In the production of the polyether polycarbonate diol (A), the amount of the carbonate compound to be used is not particularly limited, but the lower limit is usually 0.35, more preferably 0. 50, more preferably 0.60, and the upper limit is preferably 1.00, more preferably 0.98, and further preferably 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the proportion of the obtained polyether polycarbonate diol (A) in which the terminal group is not a hydroxyl group may increase, or the molecular weight may not fall within the predetermined range. The polymerization may not proceed until.

When the above-mentioned transesterification catalyst is used in the production of the polyether polycarbonate diol (A), the amount used is preferably an amount that does not affect the performance even if it remains in the obtained polycarbonate diol.

As for the amount of the transesterification catalyst used, the upper limit of the weight ratio of the metal to the weight of the raw material polyoxyalkylene glycol is preferably 500 ppm by weight, more preferably 100 ppm by weight, and more preferably 50 ppm by weight. More preferably, it is particularly preferably 10 ppm by weight. On the other hand, the lower limit is preferably 0.01 ppm by weight, more preferably 0.1 ppm by weight, and further preferably 1 ppm by weight, as an amount capable of obtaining sufficient polymerization activity.

The reaction temperature in the transesterification reaction can be arbitrarily selected as long as it is a temperature at which a practical reaction rate can be obtained. Usually, the lower limit of the reaction temperature is preferably 70°C, more preferably 100°C, and further preferably 130°C. The upper limit of the reaction temperature is usually preferably 250°C, more preferably 230°C, and further preferably 200°C. By setting the reaction temperature to the above upper limit or less, it is possible to prevent quality problems such as coloring of the obtained polyether polycarbonate diol (A) and formation of an ether structure.

Furthermore, the reaction temperature is preferably 180° C. or lower, more preferably 170° C. or lower, and further preferably 160° C. or lower throughout the entire transesterification process for producing the polyether polycarbonate diol (A). preferable. By setting the reaction temperature to 180° C. or lower throughout all the steps, it becomes possible to prevent the coloring from becoming easy depending on the conditions.

The transesterification reaction can be carried out at normal pressure, but the transesterification reaction is an equilibrium reaction, and the light-boiling component produced can be distilled out of the system to bias the reaction to the production system. Therefore, in the latter half of the reaction, it is usually preferable to employ a reduced pressure condition to distill away the light-boiling component and to react. Alternatively, it is possible to gradually lower the pressure from the middle of the reaction to distill away the light-boiling component that is produced and to carry out the reaction. Particularly, it is preferable to carry out the reaction by increasing the degree of reduced pressure at the end of the reaction, because by-products such as monoalcohol, phenols and cyclic carbonate can be distilled off.
The upper limit of the reaction pressure at the end of the reaction is preferably 10 kPa, more preferably 5 kPa, and even more preferably 1 kPa.
In order to effectively distill the light-boiling component, the reaction can be carried out while flowing an inert gas such as nitrogen, argon and helium into the reaction system.

When a low boiling carbonate compound is used in the transesterification reaction, the reaction is carried out near the boiling point of the carbonate compound in the initial stage of the reaction, and as the reaction proceeds, the temperature is gradually raised to further advance the reaction. A method can also be adopted. By doing so, it is possible to prevent the unreacted carbonate compound from being distilled off at the initial stage of the reaction.

Furthermore, in order to prevent the distillation of these raw materials, it is possible to attach a reflux tube to the reactor and carry out the reaction while refluxing the carbonate compound.In this case, the raw materials charged are not lost and the amount ratio of the reagents is accurate. Can be adjusted to

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

The polymerization reaction is terminated when the molecular weight of the produced polyether polycarbonate diol (A) is measured and the target molecular weight is reached. The reaction time required for the polymerization varies greatly depending on the presence and type of the polyoxyalkylene glycol, carbonate compound, and catalyst used, and therefore cannot be unconditionally specified, but it is usually preferably 50 hours or less, It is more preferably 30 hours or less, further preferably 20 hours or less.

When a catalyst is used during the polymerization reaction, the catalyst usually remains in the obtained polyether polycarbonate diol (A), and the remaining catalyst may make it impossible to control the polyurethane-forming reaction. In order to suppress the influence of the remaining catalyst, it is preferable to deactivate the transesterification catalyst by adding a catalyst deactivator such as a phosphorus compound in approximately equimolar amount to the used transesterification catalyst. Furthermore, after the catalyst deactivator is added, the transesterification catalyst can be efficiently deactivated by a heat treatment or the like as described later.

Examples of the phosphorus-based compound used for deactivating the transesterification catalyst include, for example, inorganic phosphoric acid such as phosphoric acid and phosphorous acid, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, and phosphite. Examples thereof include organic phosphoric acid esters such as triphenyl phosphate. These may be used alone or in combination of two or more.

The amount of the phosphorus-based compound used is not particularly limited as long as it is almost equimolar to the transesterification catalyst used, and specifically, the upper limit is preferably 1 mol per transesterification catalyst used. It is 5 mol, more preferably 2 mol, and the lower limit is preferably 0.8 mol, more preferably 1.0 mol. When a phosphorus compound in an amount smaller than this is used, the inactivation of the transesterification catalyst in the reaction product is not sufficient, and the obtained polyether polycarbonate diol (A) is used as a raw material for producing a polyurethane elastomer. At times, the reactivity of the polyether polycarbonate diol (A) with respect to isocyanate groups may not be sufficiently reduced. Further, when a phosphorus compound exceeding this range is used, the obtained polyether polycarbonate diol (A) may be colored.

Deactivation of the transesterification catalyst by adding a phosphorus compound can be performed at room temperature, but heat treatment is more efficient. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 180°C, more preferably 150°C, further preferably 120°C, particularly preferably 100°C, and the lower limit is preferably 50°C, more preferably Is 60° C., more preferably 70° C. If 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 a temperature higher than 180°C, the obtained polyether polycarbonate diol (A) may be colored. The reaction time with the phosphorus compound is not particularly limited, but is usually 1 hour to 5 hours.

The amount of catalyst remaining in the polyether polycarbonate diol (A) is preferably 100 ppm by weight or less, particularly 10 ppm by weight or less in terms of metal, from the viewpoint of controlling the polyurethane reaction. On the other hand, it is preferable that the required amount of the catalyst is 0.01 weight ppm or more, particularly 0.1 weight ppm or more, and particularly 5 weight ppm or more in terms of metal.

In the polyether polycarbonate diol (A), the carbonate compound used as a raw material during production may remain. Although the residual amount of the carbonate compound in the polyether polycarbonate diol (A) is not limited, it is preferably small, and the upper limit of the weight ratio to the polycarbonate diol (A) is preferably 5% by weight, more preferably 3% by weight. , And more preferably 1% by weight. If the content of the carbonate compound in the polyether polycarbonate diol (A) is too large, the reaction at the time of forming a polyurethane may be hindered. 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 further preferably 0% by weight.

The polyoxyalkylene glycol used during production may remain in the polyether polycarbonate diol (A). The residual amount of the polyoxyalkylene glycol in the polyether polycarbonate diol (A) is not limited, but is preferably as small as possible, and the weight ratio to the polyether polycarbonate diol (A) is preferably 1% by weight or less, more preferably Is 0.1% by weight or less, more preferably 0.05% by weight or less. If the amount of remaining polyoxyalkylene glycol in the polyether polycarbonate diol (A) is large, the molecular length of the soft segment portion in the case of the polyurethane elastomer may be insufficient and desired physical properties may not be obtained.

The lower limit of the hydroxyl value of the polyether polycarbonate diol (A) is usually 22.4 mg-KOH/g, preferably 28.1 mg-KOH/g, more preferably 37.4 mg-KOH/g, and the upper limit is usually 187.0 mg. -KOH/g, preferably 140.3 mg-KOH/g, more preferably 112.2 mg-KOH/g. If the hydroxyl value is less than the above lower limit, the viscosity may be too high, which may make it difficult to handle when converting into a polyurethane. If the hydroxyl value exceeds the above upper limit, the flexibility of the obtained polyurethane elastomer may be insufficient.
The hydroxyl value of the polyether polycarbonate diol (A) is specifically measured by the method described in the section of Examples below.

The lower limit of the number average molecular weight (Mn) obtained from the hydroxyl value of the polyether polycarbonate diol used in the present invention is preferably 600, more preferably 800, and even more preferably 1000. On the other hand, the upper limit is preferably 5,000, more preferably 4,000, further preferably 3,000. If the Mn of the polyether polycarbonate diol is less than the lower limit, sufficient flexibility may not be obtained when the polyurethane elastomer is used. On the other hand, if the upper limit is exceeded, the viscosity will increase and the handling during polyurethane conversion may be impaired.

<Polycarbonate diol>
The polycarbonate diol used as a raw material for producing the polyurethane elastomer of the present invention (hereinafter sometimes referred to as the “polycarbonate diol of the present invention”) includes a repeating unit (B) represented by the following formula (B) and a following formula (C). ) Has a repeating unit (C). In the formula (C), when q is 0, the repeating unit (C) does not exist in the polycarbonate diol of the present invention.

(In the above formula (B), R ² represents a divalent hydrocarbon group having 2 to 20 carbon atoms, p is an integer of 3 to 50, and in the above formula (C), R ³ is different from R ^2. And represents a divalent hydrocarbon group having 3 to 20 carbon atoms, or a divalent hydrocarbon group having 3 to 20 carbon atoms and containing an alicyclic structure or a heterocyclic structure, and q is 0. It is an integer of -50.)

In the repeating unit (B), R ² is preferably a linear or branched alkylene group having 3 to 12 carbon atoms, more preferably 3 to 6 carbon atoms, and particularly preferably 4 or 6 carbon atoms. ) Is preferably derived from 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol, from the viewpoints of industrial availability and excellent physical properties of the resulting polyurethane elastomer, Particularly, an n-butylene group and an n-hexylene group are preferable.

In the repeating unit (B), when p is less than 3, the compatibility with other polyols tends to be low, and the flexibility and durability of the resulting polyurethane elastomer tend to be poor, and when it exceeds 50, the abrasion resistance tends to be poor. is there. Therefore, p is 3 to 50, preferably 3 to 40, and more preferably 5 to 30.

R ³ of the repeating unit (C) is a divalent hydrocarbon group having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms, and may be a linear alkylene group. By using a chain aliphatic dihydroxy compound, it can be introduced into a polycarbonate diol. Specific examples of the linear aliphatic dihydroxy compound include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, preferably 1,4-butane One or more of diol, 1,5-pentadiol, 1,6-hexanediol and 1,10-decanediol may be mentioned.

R ³ of the repeating unit (C) may also be an alkylene group having a branched chain and having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms. Examples of such branched alkylene group include neopentyl glycol and 3-methyl. Examples thereof include those derived from one kind or two or more kinds of -1,5-pentanediol, 2-methyl-1,3-propanediol and 2-methyl-1,4-butanediol.

Further, R ³ of the repeating unit (C) may be an aliphatic hydrocarbon group having an alicyclic structure or a heterocyclic structure, and specifically, one of isosorbide, isomannide, isoidide and 1,4-cyclohexanedimethanol. Or the thing derived from 2 or more types is mentioned.

In the repeating unit (C), when q is 0 and the polycarbonate diol of the present invention does not contain the repeating unit (C), the compatibility with other polyols is lowered, and the flexibility and durability of the resulting polyurethane elastomer are reduced. If it exceeds 50, the abrasion resistance tends to be poor. Therefore, m is preferably 1 to 50, more preferably 2 to 50, further preferably 2 to 40, and particularly preferably 2 to 30.

The polycarbonate diol of the present invention may contain only one type of repeating unit (B) or may contain two or more types thereof. Moreover, also about repeating unit (C), only 1 type may be contained and 2 or more types may be contained. Further, the repeating unit (B) and the repeating unit (C) may have the same structure.

In addition, the polycarbonate diol of the present invention contains a repeating unit other than the repeating unit (B) and the repeating unit (C) in an amount not exceeding 5.0 mol% in all repeating units, as long as the effect of the present invention is not impaired. It may be.

The molar ratio of the repeating unit (C) to the repeating unit (B) contained in the polycarbonate diol of the present invention (repeating unit (C)/repeating unit (B), sometimes referred to as “molar ratio (C)/(B)”). Is preferably 0.03 to 10, particularly preferably 0.05 to 4, and particularly preferably 0.10 to 1.00. If the repeating unit (B) is more than the above range and the repeating unit (C) is less than the above range, the compatibility with other polyols tends to decrease, and on the contrary, the repeating unit (B) is small and the repeating unit (C) is less than the above range. If the amount is large, the flexibility of the obtained polyurethane elastomer, especially at low temperature, and the chemical resistance tend to be lowered.
The molar ratio (C)/(B) of the polycarbonate diol is measured by the method described in the section of Examples below.

The polycarbonate diol of the present invention is, for example, a linear aliphatic dihydroxy compound having 2 to 20 carbon atoms, preferably 3 to 6 carbon atoms for introducing the repeating unit (B), specifically 1,3-propane. Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanedi All, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, preferably 1,4-butanediol, 1,5-pentadiol, 1,6-hexanediol or the like, or Two or more kinds and a branched aliphatic dihydroxy compound having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms for introducing the repeating unit (C), preferably neopentyl glycol, 3-methyl-1,5-pentane Alicyclic structure or heterocyclic structure such as diol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, or isosorbide, isomannide, isoidide, 1,4-cyclohexanedimethanol 1 or 2 or more such as an aliphatic dihydroxy compound containing is used as a raw material dihydroxy compound so as to have the above-mentioned suitable molar ratio (C)/(B), and these dihydroxy compound and the polycarbonate compound are It can be produced by carrying out a polymerization reaction according to a conventional method in the presence of a catalyst.

The carbonate compound that can be used for producing the polycarbonate diol of the present invention is not limited as long as the effects of the present invention are not impaired, and examples thereof include dialkyl carbonate, diaryl carbonate, and alkylene carbonate. These may be one kind or plural kinds. Of these, diaryl carbonate is preferable from the viewpoint of reactivity.

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

The polycarbonate diol of the present invention has a dihydroxy compound for introducing the repeating unit (B) and a repeating unit (C) instead of the polyoxyalkylene glycol in the method for producing the polyether polycarbonate diol (A). It can be manufactured in the same manner except that a dihydroxy compound is used.

The amount of catalyst remaining in the polycarbonate diol of the present invention is preferably 100 ppm by weight or less, particularly 10 ppm by weight or less in terms of metal, from the viewpoint of controlling the polyurethane-forming reaction. On the other hand, it is preferable that the required amount of the catalyst is 0.01 weight ppm or more, particularly 0.1 weight ppm or more, and particularly 5 weight ppm or more in terms of metal.

In the production of the polycarbonate diol of the present invention, the reaction product was added with impurities having no hydroxyl group at the polymer terminal in the product, phenols, raw material dihydroxy compound, carbonate compound, by-produced light boiling cyclic carbonate and added. It can be purified for the purpose of removing the catalyst and the like.

For the purification at that time, a method of distilling a light boiling compound by distillation can be adopted. The distillation method is not particularly limited in its form such as vacuum distillation, steam distillation and thin film distillation, and any method can be adopted, but thin film distillation is particularly effective.

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

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

The upper limit of the temperature for keeping the temperature of the polycarbonate diol immediately before thin film distillation is preferably 250°C, more preferably 150°C. The lower limit is preferably 80°C, more preferably 120°C.
By setting the temperature for keeping the temperature of the polycarbonate diol immediately before the thin film distillation to the above lower limit or more, it is possible to prevent the fluidity of the polycarbonate diol immediately before the thin film distillation from decreasing. On the other hand, when the content is not more than the above upper limit, the polycarbonate diol obtained after thin film distillation can be prevented from being colored.

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

When a 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 elastomers, and the urethane bond formed by phenols has a weak bonding force, so it will not be heated in subsequent steps. May dissociate, and isocyanates and phenols may be regenerated and cause problems. Further, since phenols are also stimulants, it is preferable that the residual amount of phenols in the polycarbonate diol is smaller. Specifically, the residual amount of phenols in 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, as a weight ratio to the polycarbonate diol. In order to reduce the phenols in the polycarbonate diol, as described above, 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 thin film distillation or the like is performed after the polymerization reaction of the polycarbonate diol. Is effective.

The carbonate compound used as a raw material during production may remain in the polycarbonate diol. Although the residual amount of the carbonate compound in the polycarbonate diol is not limited, it is preferably as small as possible, and the upper limit of the weight ratio to the polycarbonate diol is preferably 5% by weight, more preferably 3% by weight, further preferably 1% by weight. is there. If the content of the carbonate compound in the polycarbonate diol is too large, the reaction at the time of forming a polyurethane may be hindered. 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 further preferably 0% by weight.

The dihydroxy compound used during production may remain in the polycarbonate diol. Although the residual amount of the dihydroxy compound in the polycarbonate diol is not limited, it is preferably small, and the weight ratio to the polycarbonate diol is preferably 1% by weight or less, more preferably 0.1% by weight or less, and further 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 in the case of using the polyurethane elastomer may be insufficient and desired physical properties may not be obtained.

The polycarbonate diol may contain a cyclic carbonate (cyclic oligomer) produced as a by-product during the production. For example, when 2,2-dialkyl-1,3-propanediol is used as the starting dihydroxy compound of the repeating unit (B) or (C), 5,5-dialkyl-1,3-dioxan-2-one or further these In some cases, a compound in which 2 or more molecules are converted into a cyclic carbonate is contained in the polycarbonate diol. More specifically, when 2,2-dimethyl-1,3-propanediol is used, 5,5-dimethyl-1,3-dioxan-2-one or two or more of these molecules are cyclic carbonates. And the like may be produced and contained in the polycarbonate diol. These compounds may cause side reactions in the polyurethane 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 cyclic carbonate such as 5,5-dialkyl-1,3-dioxan-3-one contained in the polycarbonate diol is not limited, but the weight ratio to the polycarbonate diol is preferably 3% by weight or less, more preferably It is 1% by weight or less, more preferably 0.5% by weight or less.

Regarding the hydroxyl value of the polycarbonate diol of the present invention, the lower limit is usually 22.4 mg-KOH/g, preferably 28.1 mg-KOH/g, more preferably 37.4 mg-KOH/g, and the upper limit is usually 448.8 mg-. KOH/g, preferably 374.0 mg-KOH/g, more preferably 280.5 mg-KOH/g. If the hydroxyl value is less than the above lower limit, the viscosity may be too high, which may make it difficult to handle when converting into a polyurethane. If the hydroxyl value exceeds the above upper limit, the flexibility of the obtained polyurethane elastomer may be insufficient.
The hydroxyl value of the polycarbonate diol is specifically measured by the method described in the section of Examples below.

The lower limit of the number average molecular weight (Mn) determined from the hydroxyl value of the polycarbonate diol of the present invention is preferably 250, more preferably 300, and still more preferably 400. On the other hand, the upper limit is preferably 5,000, more preferably 4,000, further preferably 3,000. If the Mn of the polycarbonate diol is less than the above lower limit, sufficient flexibility may not be obtained in the case of using a polyurethane elastomer. On the other hand, if the upper limit is exceeded, the viscosity will increase and the handling during polyurethane conversion may be impaired.
The number average molecular weight (Mn) determined from the hydroxyl value of the polycarbonate diol is specifically measured by the method described in the section of Examples below.

As the polycarbonate diol as a raw material for producing the polyurethane elastomer of the present invention, only one kind may be used, or two or more kinds having different repeating units, molar ratios thereof, physical properties and the like may be used.

<Polyalkylene ether glycol>
The polyalkylene ether glycol used as a raw material for producing the polyurethane elastomer of the present invention (hereinafter sometimes referred to as “the polyalkylene ether glycol of the present invention”) is a repeating unit (D) represented by the following formula (D): It has a repeating unit (E) represented by the following formula (E). In the formula (E), when s is 0, the repeating unit (E) does not exist in the polyalkylene ether glycol of the present invention.

(In the above formula (D), R ⁴ is an alkylene group having 2 to 20 carbon atoms, r is an integer of 3 to 50, and in the above formula (E), R ⁵ is different from R ^4, and A divalent hydrocarbon group of 3 to 20 or a divalent hydrocarbon group of 3 to 20 carbon atoms containing an alicyclic structure or a heterocyclic structure is represented, and s is an integer of 0 to 50.)

The polyalkylene ether glycol is usually a polyhydroxy compound having one or more ether bonds in the main skeleton in the molecule, as in the repeating units (D) and (E).

From the viewpoint of industrial availability, R ⁴ in the repeating unit (D) is particularly preferably an alkylene group having 2 to 4 carbon atoms, and r is preferably 3 to 100, particularly 3 to 50.
From the viewpoint of compatibility with other polyols, R ⁵ in the repeating unit (E) is preferably a 2-butylene group or a neopentylene group, and s is preferably 0 to 30, particularly preferably 0 to 20.

The molar ratio of the repeating unit (E) to the repeating unit (D) contained in the polyalkylene ether glycol of the present invention (repeating unit (E)/repeating unit (D), referred to as “molar ratio (E)/(D)”. In some cases) is preferably 0 to 50, particularly preferably 0 to 40, and particularly preferably 0 to 30. When the repeating unit (E) is more than the above range, the viscosity becomes too high, and handling during polyurethane conversion may become difficult.
The molar ratio (E)/(D) of the polyalkylene ether glycol is measured by the same method as the measuring method of the molar ratio (B)/(A) of the polycarbonate diol described in the section of Examples below. ..

Examples of the repeating unit in the main skeleton of the polyalkylene ether glycol of the present invention include 1,2-ethylene glycol unit, 1,2-propylene glycol unit, 1,3-propanediol (trimethylene glycol) unit, 2- Methyl-1,3-propanediol unit, 2,2-dimethyl-1,3-propanediol unit, 1,4-butanediol (tetramethylene glycol) unit, 2-methyl-1,4-butanediol unit, 3 -Methyl-1,4-butanediol unit, 3-methyl-1,5-pentanediol unit, neopentyl glycol unit, 1,6-hexanediol unit, 1,7-heptanediol unit, 1,8-octanediol Units, 1,9-nonanediol units, 1,10-decanediol units, 1,4-cyclohexanedimethanol units, and other saturated hydrocarbon groups having 1 to 20 carbon atoms, and polyalkylene ethers having a single repeating unit. A glycol may be formed, or a copolymerized polyalkylene ether glycol may be formed with two or more kinds of repeating units.

The polyalkylene ether glycol used in the present invention includes polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and copolymerized polytetrahydrofuran of 3-methyltetrahydrofuran and tetrahydrofuran among polyalkylene ether glycols having the repeating unit in the main skeleton. Methylene ether glycol, neopentyl glycol-tetrahydrofuran copolymer polyether polyol, ethylene oxide-tetrahydrofuran copolymer polyether polyol, propylene oxide-tetrahydrofuran copolymer polyether glycol and the like are preferable from the viewpoint of mechanical strength of the resulting polyurethane elastomer. Polytetramethylene ether glycol (PTMG) is more preferable.

The molecular weight of the polyalkylene ether glycol of the present invention is based on a hydroxyl value, the lower limit is usually 200 or more, preferably 300 or more, more preferably 400 or more, further preferably 500 or more, and the upper limit is usually 5000 or less, preferably 4000. Or less, more preferably 3500 or less, still more preferably 2500 or less.

By controlling the molecular weight of the polyalkylene ether glycol to the above upper limit or less, the viscosity is suppressed and the handling property during polyurethane formation is not impaired, while the molecular weight of the polyalkylene ether glycol is set to the above lower limit or more, polyurethane It is preferable because it gives sufficient flexibility when used as an elastomer.
The molecular weight based on the hydroxyl value of the polyalkylene ether glycol is usually specifically measured by the method described in the section of Examples below.

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

<Proportion of use of polyether polycarbonate diol (A) and polycarbonate diol of the present invention and/or polyalkylene ether glycol of the present invention>
The ratio of the polyether polycarbonate diol (A) used in the production of the polyurethane elastomer of the present invention to the polycarbonate diol (A) of the present invention and/or the polyalkylene ether glycol of the present invention is the same as that of the polyether polycarbonate diol (A) and the present invention. The ratio of the polyether polycarbonate diol (A) (hereinafter, sometimes referred to as “PEPCD ratio”) to the total of the polycarbonate diol and the polyalkylene ether glycol of the present invention is 10 wt% to 90 wt %. It is preferable that the ratio is high. Either one of the polycarbonate diol of the present invention and the polyalkylene ether glycol of the present invention may be used, or both may be used.

When the PEPCD ratio is at least the above lower limit, the compatibility between the polyether polycarbonate diol (A) and the polycarbonate diol of the present invention and/or the polyalkylene ether glycol of the present invention is improved, resulting in high transparency and chemical resistance. When the above upper limit is not exceeded, the flexibility and mechanical strength are excellent, and the effects such as elastic recovery can be sufficiently obtained. The PEPCD ratio is particularly preferably 20% by weight to 80% by weight, particularly preferably 30% by weight to 70% by weight.

[Method for producing polyurethane elastomer]
The polyurethane elastomer of the present invention comprises the polyether polycarbonate diol (A), the polycarbonate diol of the present invention and/or the polyalkylene ether glycol of the present invention (hereinafter, the polycarbonate diol of the present invention and the polyalkylene ether glycol of the present invention It may be referred to as "the diol of the present invention"), a polyisocyanate compound and the above-mentioned chain extender.
Here, when a solvent is used in the production of the polyurethane elastomer of the present invention, a step of removing the solvent at the time of molding is required, which is not industrially advantageous. Since the solvent has a large load on the environment, it is preferable to carry out the reaction without a solvent (in the absence of the solvent).
In the present invention, by using the polyether polycarbonate diol (A) having a high compatibility with both the polycarbonate diol of the present invention and the polyalkylene glycol of the present invention such as polytetramethylene glycol, solvent-free conditions having a large effect of mass transfer However, it is possible to obtain a polyurethane elastomer that is uniform and has an excellent balance of physical properties.

For example, the polyurethane elastomer of the present invention can be produced by reacting the polyether polycarbonate diol (A) and the diol of the present invention with a polyisocyanate compound and a chain extender in the range of room temperature to 200°C.
Further, the polyether polycarbonate diol (A) and the diol of the present invention and an excess polyisocyanate compound are first reacted to produce a prepolymer having an isocyanate group at a terminal, and a chain extender is used to increase the degree of polymerization. The polyurethane elastomer of the present invention can be manufactured.

<Chain terminator>
When producing the polyurethane elastomer of the present invention, a chain terminator having one active hydrogen group can be used, if necessary, for the purpose of controlling the molecular weight of the obtained polyurethane.
These chain terminators include aliphatic monools having one hydroxyl group such as methanol, ethanol, propanol, butanol, and hexanol, diethylamine having one amino group, dibutylamine, n-butylamine, monoethanolamine, diethanolamine. And aliphatic monoamines such as morpholine.
These may be used alone or in combination of two or more.

<Catalyst>
In the polyurethane-forming reaction for producing the polyurethane elastomer of the present invention, amine-based catalysts such as triethylamine, N-ethylmorpholine and triethylenediamine, or acid-based catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid and sulfonic acid, trimethyltin laur It is also possible to use known urethane polymerization catalysts represented by tin compounds such as phthalate, dibutyltin dilaurate, dioctyltin dilaurate and dioctyltin dineodecanate, and organic metal salts such as titanium compounds. The urethane polymerization catalyst may be used alone or in combination of two or more.

<Polyether polycarbonate diol (A) and polyol other than the diol of the present invention>
In the polyurethane-forming reaction for producing the polyurethane elastomer of the present invention, the polyether polycarbonate diol (A) and the diol of the present invention may be used in combination with other polyols if necessary. Here, the polyether polycarbonate diol (A) and the polyol other than the diol of the present invention are not particularly limited as long as they are used in ordinary polyurethane production, and examples thereof include polyester polyol, polycaprolactone polyol, and the polycarbonate of the present invention. Polycarbonate polyols other than diols may be mentioned. Here, the weight ratio of the polyether polycarbonate diol (A) and the diol of the present invention to the combined weight of the diol of the present invention and the other polyol is preferably 70% or more, and 90%. The above is more preferable. When the weight ratio of the polyether polycarbonate diol (A) and the diol of the present invention is small, the flexibility and durability of the polyurethane elastomer, which is a feature of the present invention, may be lost.

In the present invention, the above-mentioned polycarbonate diol used in the present invention may be modified and used in the production of the polyurethane elastomer. Examples of the method for modifying the polycarbonate diol include 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, or a cyclic lactone such as ε-caprolactone of the polycarbonate diol, adipic acid or succinic acid. There is a method of introducing an ester group by reacting with a dicarboxylic acid compound such as sebacic acid and terephthalic acid, and an ester compound thereof. The ether modification is preferable for reasons such as handleability because the viscosity of the polycarbonate diol decreases due to modification with ethylene oxide, propylene oxide or the like. In particular, when the polycarbonate diol of the present invention is modified with ethylene oxide or propylene oxide, the crystallinity of the polycarbonate diol is reduced and the flexibility at low temperature is improved, and in the case of ethylene oxide modification, it is produced using an ethylene oxide modified polycarbonate diol. The water absorbency and moisture permeability of the obtained polyurethane elastomer may be improved. However, when the amount of ethylene oxide or propylene oxide added increases, the physical properties of the polyurethane elastomer produced using the modified polycarbonate diol, such as mechanical strength, heat resistance, and chemical resistance, decrease. 5 wt% to 50 wt% is suitable, preferably 5 wt% to 40 wt%, and more preferably 5 wt% to 30 wt%. In addition, the method of introducing an ester group is preferable for reasons such as handleability because the viscosity of the polycarbonate diol decreases due to modification with ε-caprolactone. The amount of ε-caprolactone added to the polycarbonate diol is preferably 5% by weight to 50% by weight, preferably 5% by weight to 40% by weight, and more preferably 5% by weight to 30% by weight. When the amount of ε-caprolactone added exceeds 50% by weight, the hydrolysis resistance and chemical resistance of the polyurethane elastomer produced by using the modified polycarbonate diol are deteriorated.

<Method for producing polyurethane elastomer>
As a method for producing the polyurethane elastomer of the present invention using the above-mentioned reaction agent, a production method that is generally used experimentally or industrially can be used.
Examples thereof include a method in which the polyether polycarbonate diol (A) and the diol of the present invention, other optional polyols, a polyisocyanate compound, and a chain extender are mixed and reacted at once (hereinafter, referred to as "one step". Method)), or first, a polyether polycarbonate diol (A) and the diol of the present invention, and other polyols and polyisocyanate compounds which are used as necessary are reacted to give a prepolymer having isocyanate groups at both ends. After preparing the above, there is a method of reacting the prepolymer with a chain extender (hereinafter sometimes referred to as "two-step method").

In the two-step method, the polyether polycarbonate diol (A), the diol of the present invention, and a polyol other than the above are reacted in advance with one or more equivalents of a polyisocyanate compound, whereby isocyanates at both ends of a portion corresponding to the soft segment of polyurethane are It goes through the step of preparing an intermediate. In this way, once the prepolymer is prepared and then reacted with a chain extender, it may be easier to adjust the molecular weight of the soft segment, and when it is necessary to reliably perform phase separation of the soft segment and the hard segment. Is useful.

<One-step method>
The one-step method is also called a one-shot method, and is a method in which the reaction is carried out by charging the polyether polycarbonate diol (A) and the diol of the present invention, the other polyols, the polyisocyanate compound and the chain extender all at once.
The amount of the polyisocyanate compound used in the one-step method is not particularly limited, but the total number of hydroxyl groups of the polyether polycarbonate diol (A) and the diol of the present invention and the other polyols, the number of hydroxyl groups and the number of amino groups of the chain extender are used. When the total of and 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 Is 3.0 equivalents, more preferably 2.0 equivalents, even more preferably 1.5 equivalents, and particularly preferably 1.1 equivalents.

If the amount of polyisocyanate compound used is too large, unreacted isocyanate groups cause side reactions, and the viscosity of the resulting polyurethane elastomer tends to be too high, making handling difficult and tending to impair flexibility. If the amount is too small, the molecular weight of the polyurethane elastomer does not become sufficiently large, and sufficient strength tends to be unobtainable.

The amount of the chain extender used is not particularly limited, but one equivalent of the total number of hydroxyl groups of the polyether polycarbonate diol (A), the diol of the present invention and the other polyols is subtracted from the number of isocyanate groups of the polyisocyanate compound. , The lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, further preferably 0.9 equivalents, particularly preferably 0.95 equivalents, the upper limit is preferably 3.0 equivalents, It is preferably 2.0 equivalents, more preferably 1.5 equivalents, particularly preferably 1.1 equivalents. If the amount of chain extender used is too large, the resulting polyurethane elastomer tends to be difficult to dissolve in the solvent and difficult to process, and if it is too small, the resulting polyurethane elastomer is too soft and has sufficient strength, hardness, and elastic recovery performance. In some cases, elastic retention performance may not be obtained, or in some cases, heat resistance may deteriorate.

<Two-step method>
The two-step method is also called a prepolymer method and mainly includes the following methods.
(A) The polyether polycarbonate diol (A), the diol of the present invention, the other polyol, and an excess of the polyisocyanate compound are previously added to the polyisocyanate compound/(polyether polycarbonate diol (A) and the diol of the present invention and the same. The reaction equivalent ratio of polyols other than 1) to 10.0 or less is reacted to produce a prepolymer having an isocyanate group at the molecular chain end, and a chain extender is added to this to give a polyurethane elastomer. Method of manufacturing.
(B) The polyisocyanate compound and the excess polyether polycarbonate diol (A) and the diol of the present invention and other polyols are previously added to the polyisocyanate compound/(polyether polycarbonate diol (A) and the diol of the present invention and To produce a prepolymer having a hydroxyl group at the molecular chain end, and then a polyisocyanate compound having an isocyanate group at the end as a chain extender. A method for producing a polyurethane elastomer by reacting with.

The two-step method can be carried out with or without a solvent.
The polyurethane elastomer production by the two-step method can be carried out by any of the methods (1) to (3) described below.
(1) Without using a solvent, first, the polyisocyanate compound is directly reacted with the polyether polycarbonate diol (A) and the diol of the present invention and the other polyol to synthesize a prepolymer, which is directly used for the chain extension reaction. ..
(2) A prepolymer is synthesized by the method of (1), then dissolved in a solvent and used in the subsequent chain extension reaction.
(3) Using a solvent from the beginning, the polyisocyanate compound is reacted with the polyether polycarbonate diol (A) and the diol of the present invention with other polyols, and then a chain extension reaction is carried out.

In the case of the method (1), in the chain extension reaction, the polyurethane elastomer is coexistent with the solvent by, for example, dissolving the chain extender in a solvent or simultaneously dissolving the prepolymer and the chain extender in the solvent. It is important to get in shape.
The amount of the polyisocyanate compound used in the two-step method (a) is not particularly limited, but the total number of hydroxyl groups of the polyether polycarbonate diol (A) and the diol of the present invention and other polyols is 1 equivalent. In this case, as the number of isocyanate groups, the lower limit is preferably more than 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 The range is 5.0 equivalents, more preferably 3.0 equivalents.

If the amount of this polyisocyanate compound used is too large, excess isocyanate groups tend to cause side reactions to reach the desired physical properties of the polyurethane elastomer, and if it is too small, the molecular weight of the resulting polyurethane elastomer does not rise sufficiently. The strength and thermal stability may decrease.
The amount of the chain extender to be used is not particularly limited, but the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, and still more preferably 0 equivalent to 1 equivalent of the isocyanate group contained in the prepolymer. It is 0.8 equivalent, and the upper limit is preferably 5.0 equivalent, more preferably 3.0 equivalent, and further preferably 2.0 equivalent.

When carrying out the above chain extension reaction, monofunctional organic amines and alcohols may be allowed to coexist for the purpose of adjusting the molecular weight.
The amount of the polyisocyanate compound used in preparing the prepolymer having a hydroxyl group at the terminal in the method of the two-step method (b) is not particularly limited, but is not limited to the polyether polycarbonate diol (A) and the diol of the present invention. As for the number of isocyanate groups when the number of total hydroxyl groups of other polyols is 1 equivalent, the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, further preferably 0.7 equivalent, and the upper limit. Is preferably 0.99 equivalents, more preferably 0.98 equivalents, still more preferably 0.97 equivalents.

If the amount of this polyisocyanate compound used is too small, the process until the desired molecular weight is obtained in the subsequent chain extension reaction tends to be long and the production efficiency tends to be low, and if it is too large, the viscosity of the polyurethane elastomer obtained becomes too high. The flexibility may be reduced, or the handling may be poor and the productivity may be poor.
The amount of the chain extender used is not particularly limited, but when the total number of hydroxyl groups of the polyether polycarbonate diol (A) used in the prepolymer and the diol of the present invention and other polyols is 1 equivalent, As the total equivalent including the equivalents of the isocyanate groups used, the lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, the upper limit is preferably less than 1.0 equivalents, The range is more preferably 0.99 equivalents, and even more preferably 0.98 equivalents.

When carrying out the above chain extension reaction, monofunctional organic amines and alcohols may be allowed to 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 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 slow, or the solubility of the raw materials or the polymer may be low, which may increase the production time.If it is too high, side reactions or decomposition of the resulting polyurethane may occur. .. The chain extension reaction may be performed while defoaming under reduced pressure.

Further, a catalyst, a stabilizer and the like can be added to the chain extension reaction, if necessary.
Examples of the catalyst include compounds such as triethylamine, tributylamine, dibutyltin dilaurate, stannous octoate, acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid. One kind may be used alone, or two or more kinds may be used. You may use together. Examples of the stabilizer include 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N,N'-di-2-naphthyl-1,4-phenylenediamine, tris(dinonylphenyl)phosphite, and the like. Compounds may be used, and one kind may be used alone, or two or more kinds may be used in combination. When the chain extender is a highly reactive one such as a short chain aliphatic amine, it may be carried out without adding a catalyst.
Also, a reaction inhibitor such as tris(2-ethylhexyl) phosphite can be used.

<Additive>
The polyurethane elastomer of the present invention includes various kinds of heat stabilizers, light stabilizers, colorants, fillers, stabilizers, ultraviolet absorbers, antioxidants, anti-adhesive agents, flame retardants, anti-aging agents, inorganic fillers and the like. Additives can be added and mixed within a range that does not impair the properties of the polyurethane elastomer of the present invention.

Examples of the compound that can be used as the heat stabilizer include phosphoric acid, aliphatic, aromatic or alkyl group-substituted aromatic esters of phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates and dialkyls. Phosphorus compounds such as pentaerythritol diphosphite and dialkylbisphenol A diphosphite; phenol derivatives, particularly hindered phenol compounds; thioethers, dithioate salts, mercaptobenzimidazoles, thiocarbanilides, thiodipropionate esters, etc. Compounds containing sulfur; 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.
As the phosphorus compound, "PEP-36", "PEP-24G", "HP-10" (all are trade names: manufactured by ADEKA CORPORATION), "Irgafos 168" (trade name: manufactured by BASF Japan Ltd.), etc. Is mentioned.

Specific examples of the compound containing sulfur include thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP).
Examples of the light stabilizer include benzotriazole-based and benzophenone-based compounds, and specifically, "TINUVIN622LD", "TINUVIN765" (above, manufactured by Ciba Specialty Chemicals Co., Ltd.), "SANOL LS-2626". , "SANOL LS-765" (above, Sankyo Co., Ltd. make) etc. can be used.

Examples of the ultraviolet absorber include "TINUVIN328", "TINUVIN234" (above, manufactured by Ciba Specialty Chemicals Co., Ltd.) and the like.

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

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

Examples of the flame retardant include phosphorus- and halogen-containing organic compounds, bromine- or chlorine-containing organic compounds, 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 to the polyurethane elastomer is preferably 0.01% by weight, more preferably 0.05% by weight, further preferably 0.1% by weight, and the upper limit is preferably It is 10% by weight, more preferably 5% by weight, still more preferably 1% by weight. If the addition amount of the additive is too small, the effect of the addition cannot be sufficiently obtained, and if it is too large, the polyurethane elastomer may be precipitated or turbidity may occur.

<Molecular weight>
The molecular weight of the polyurethane elastomer of the present invention is appropriately adjusted depending on its application and is not particularly limited, but it is preferably 50,000 to 500,000 as a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC, More preferably, it is 100,000 to 300,000. If Mw is less than the above lower limit, sufficient strength and hardness may not be obtained, and if it is more than the above upper limit, handling properties such as workability tend to be impaired.

<Use>
INDUSTRIAL APPLICABILITY The polyurethane elastomer of the present invention is excellent in transparency, flexibility and durability, has good heat resistance and abrasion resistance, and is excellent in processability, and therefore can be used for various applications.

For example, the polyurethane elastomer of the present invention can be used as a cast polyurethane elastomer. Specific applications include rolling rolls, papermaking rolls, office equipment, rolls such as pretension rolls, forklifts, solid tires such as automobiles new trams, trolleys, and carriers, casters, and industrial products such as conveyor belt idlers and guides. Rolls, pulleys, steel pipe linings, ore rubber screens, gears, connection rings, liners, pump impellers, cyclone cones, cyclone liners, etc. It can also be used for belts of OA equipment, paper feed rolls, cleaning blades for copying, snow plows, toothed belts, surfrollers, and the like.

The polyurethane elastomers of the present invention also find application in applications as thermoplastic elastomers. That is, a molded article having excellent elasticity can be obtained by molding the thermoplastic polyurethane elastomer of the present invention. The molding method of the thermoplastic polyurethane elastomer of the present invention is not particularly limited, and various molding methods generally used for thermoplastic polymers can be used. For example, any molding method such as injection molding, extrusion molding, press molding, blow molding, calendar molding, cast molding, and roll processing can be adopted, and resin plate, film, sheet, tube, hose, belt, roll can be adopted. Molded products of various shapes such as synthetic leather, shoe soles, automobile parts, escalator handrails, road marking members, and fibers can be manufactured.

Specific examples of applications of the thermoplastic polyurethane elastomer of the present invention include food, pneumatic equipment used in the medical field, coating equipment, analytical equipment, physicochemical equipment, metering pumps, water treatment equipment, industrial robots, etc. It can be used for tubes, hoses, spiral tubes, fire hoses, etc. Further, it is used as a belt such as a round belt, a V-belt, and a flat belt in various transmission mechanisms, spinning machines, packing machines, printing machines, and the like. Further, it can be used for heel tops and soles of footwear, device parts such as couplings, packings, pole joints, bushes, gears, rolls, sports goods, leisure goods, and belts for watches. Further, examples of automobile parts include oil stoppers, gear boxes, spacers, chassis parts, interior parts, tire chain substitutes and the like. Further, it can be used for films such as keyboard films and automobile films, curl cords, cable sheaths, bellows, conveyor belts, flexible containers, binders, synthetic leather, depinning products and adhesives.

The polyurethane elastomer of the present invention may be a foamed polyurethane elastomer or polyurethane foam. As a method of foaming or foaming the polyurethane elastomer, for example, any of chemical foaming using water or mechanical foaming such as mechanical floss may be used, and other spray foaming or slab, injection, hard foam obtained by molding, or the like. Similarly, slabs and flexible foams obtained by molding can be used.
Specific applications of the foamed polyurethane elastomer or polyurethane foam include heat insulating materials and vibration insulating materials for electronic devices and buildings, automobile seats, automobile ceiling cushions, bedding such as mattresses, insoles, midsoles and shoe soles.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

〔Evaluation method〕
The polycarbonate diols and polyurethane elastomers obtained in the following Examples and Comparative Examples and the evaluation methods for the polyalkylene ether glycols used and the like are as follows.

[Evaluation method of polyether polycarbonate diol, polycarbonate diol, polyoxyalkylene glycol]
<Hydroxyl value/number average molecular weight>
According to JIS K1557-1, the hydroxyl value of polycarbonate diol, polyether polycarbonate diol, and polyoxyalkylene glycol was measured by a method using an acetylating reagent.
Further, the number average molecular weight (Mn) was determined from the hydroxyl value by the following formula (I).
Number average molecular weight=2×56.1/(hydroxyl value×10 ⁻³ )... (I)

<Molar ratio of repeating unit (B) and repeating unit (C)>
Polycarbonate diol was dissolved in CDCl ₃ and 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured. From the signal position of each component, the molar ratio of repeating unit (B) and repeating unit (C) ( C)/(B) was determined.

[Evaluation method of polyurethane elastomer]
<Molecular weight>
The polyurethane elastomer was dissolved in dimethylacetamide to obtain a dimethylacetamide solution having a concentration of 0.14% by weight. The dimethylacetamide solution was injected using a GPC device [manufactured by Tosoh Corporation, product name “HLC-8220” (column: TskgelGMH-XL, 2 tubes)], and the weight average molecular weight (Mw) of the polyurethane elastomer was calculated in terms of standard polystyrene. ) Was measured.

<Tensile test>
In accordance with JIS K6301 (2010), a sheet-shaped polyurethane elastomer having a thickness of 1 mm obtained in Examples and Comparative Examples was cut into a strip-shaped test piece having a width of 10 mm and a length of 100 mm, and a tensile tester (Orientech Co., Ltd.) was used. Manufactured by Tensilon UTM-III-100)), a chucking distance of 50 mm, a pulling speed of 500 mm/min, a temperature of 23° C., and a relative humidity of 55%. Stress at extension: 100% modulus was measured. Those having a 100% modulus of 5 MPa or more have a high elastic modulus. The elongation and strength when the test piece broke were also measured. The higher the elongation and the higher the strength, the better the flexibility and mechanical strength.

<Durability evaluation: oleic acid resistance>
A 3 cm×3 cm test piece was cut out from the sheet-shaped polyurethane elastomer having a thickness of 2 mm obtained in Examples and Comparative Examples, and the cut piece was put into a glass bottle having a capacity of 50 ml containing 10 ml of oleic acid as a test solvent, and then at 80° C. The state after standing for 18 hours was visually observed and evaluated as follows.
◯: The shape of the sheet is maintained.
Δ: The sheet is partially swollen.
X: The sheet is damaged by swelling.

<Evaluation of transparency>
A 3 cm×3 cm test piece was cut out from the sheet-shaped polyurethane elastomer having a thickness of 2 mm obtained in Examples and Comparative Examples, and visually observed to determine transparency as follows.
◯: Entire sheet is transparent Δ: Sheet is partially clouded.
X: The sheet is cloudy as a whole.

[Production and evaluation of polyether polycarbonate diol]
[Synthesis example 1]
A 2 L glass separable flask equipped with a stirrer, a distillate trap, a pressure adjusting device, a distillation column containing 30 mmφ ordered packing, and a fractionator was used as a polytetramethylene ether glycol PTMG#250 (number average molecular weight 247) manufactured by Mitsubishi Chemical Corporation. : 423 g (1.7 mol), ethylene carbonate (EC): 176 g (2.0 mol) and magnesium (II) acetylacetonate: 62 mg (0.28 mmol) were added, and the atmosphere was replaced with nitrogen gas. The internal temperature was raised to 150° C. with stirring to heat and dissolve the contents. Then, after reacting at normal pressure for 1 hour, the pressure was lowered to 6 kPa, and the reaction was performed for 12 hours while removing ethylene glycol and ethylene carbonate with the azeotropic composition outside the system. Then, the reaction was performed at 150° C. to 170° C. while lowering the pressure to 1 kPa over 12 hours. It was confirmed by ¹ H-NMR that the number average molecular weight was about 1,000, and a polyether polycarbonate diol-containing composition was obtained.
Then, 8.5 mL of phosphoric acid aqueous solution: 0.4 mL (0.4 mmol) was added to the polyether polycarbonate diol-containing composition to deactivate the catalyst. Then, the distillation column was removed, and the residual monomer was removed at 0.5 kPa and 170° C. to obtain a polyether polycarbonate diol-containing composition.

The obtained polyether polycarbonate diol-containing composition was sent to a thin film distillation apparatus at a flow rate of 20 g/min, and thin film distillation (temperature: 210° C., pressure: 53 Pa) was performed to obtain a polyether polycarbonate diol. As the thin film distillation apparatus, a molecular distillation apparatus MS-300 special model manufactured by Shibata Scientific Co., Ltd. with an internal condenser having a diameter of 50 mm, a height of 200 mm and an area of 0.0314 m ² and having a jacket was used.
The polyether polycarbonate diol produced in Synthesis Example 1 is referred to as "PEPCD1".
Table 1 shows the evaluation results of the properties and physical properties of PEPCD1.

[Polycarbonate diol]
As the polycarbonate diol, a 1,6-hexanediol homotype polycarbonate diol “T6001” (hereinafter referred to as “T6001”) manufactured by Asahi Kasei Corporation, which is a commercially available polycarbonate diol having a hydroxyl number-based number average molecular weight (Mn) of 1,000. Described) was used.

[Polyalkylene ether glycol]
As the polyalkylene ether glycol, a commercially available polyalkylene ether glycol having a hydroxyl number-based number average molecular weight (Mn) of 1000 is Mitsubishi Chemical Corporation's polytetramethylene ether glycol "PTMG#1000" (hereinafter, "#1000"). ]) was used.

[Production and evaluation of polyurethane elastomer]
[Example 1]
<Manufacture of polyurethane elastomer>
In a reactor equipped with a 300 mL SUS type stirrer preheated to 90° C., PEPCD 1:36.5 g heated to 90° C., #1000:36.5 g, 4,4′-diphenylmethane diisocyanate (hereinafter referred to as “MDI , And 40.4 g, and tris(2-ethylhexyl) phosphite: 0.9 g as an inhibitor for the urethanization reaction. Then, the reactor was capped and reacted under reduced pressure (10 torr or less) for about 90 minutes while stirring and mixing at 2000 rpm. After the reaction, when heat generation stopped, 1,4BD:6.98 g was gradually added to the reactor, stirred for 2 minutes, and then the lid of the reactor was removed. Fluorine resin sheet (fluorine tape NITOFLON 900, thickness 0.1 mm, Nitto Denko Corporation) is attached on the glass plate, and a silicon mold (dimensions: 10 cm x 10 cm, thickness 2 mm) is set on it. did. The reaction solution was poured into this silicon mold, and the upper part of the silicon mold was covered with a glass plate having a fluororesin sheet attached to the lower side. Then, a weight of 4.5 kg was placed on the glass plate on the upper part of the mold and inserted into the dryer. It was dried by heating (110° C.×1 hour) in a nitrogen atmosphere in the dryer.

<Melting>
The resulting polyurethane elastomer (size 10 cm×10 cm, thickness 2 mm) was left overnight and then removed from the silicone mold.
A fluororesin sheet and a mold for melt molding were placed in this order on a plate of a heating press machine (manufactured by Toyo Seiki Seisakusho, product name "Minitest Press") which had been heated to 180°C in advance. As a mold for melt molding, one of two types of 4 cm×4 cm×thickness 2 mm and 10 cm×5 cm×thickness 1 mm was used depending on the use such as the evaluation of physical properties. The mold was filled with polyurethane elastomer, and further covered with a fluororesin sheet. The polyurethane elastomer was melted using a plate of a heat press (pressure: 1 MPa x temperature: 180°C x time: 5 minutes). After melting, the pressure setting of the heating press machine was gradually increased, and heating was performed at a maximum of 10 MPa for 5 minutes to mold. After that, lower the pressure of the heating press machine to remove the polyurethane elastomer molded product, install it on a cooling press machine (manufactured by Toyo Seiki Co., Ltd., product name "Mini Test Press") that has been cooled by flowing cooling water in advance, and quench it. (Pressure 10 MPa×time 2 minutes) to obtain a sheet-shaped polyurethane elastomer molded article. Table 2 shows the evaluation results of the physical properties of the polyurethane elastomer molded product.

[Example 2, Comparative Examples 1 to 4]
A sheet-shaped polyurethane elastomer molded article was obtained in the same manner as in Example 1 except that the raw materials used were changed to the amounts shown in Table 2 and evaluated in the same manner. Table 2 shows the evaluation results of the physical properties of the polyurethane elastomer molded product.

The following can be seen from Table 2.
In Examples 1 and 2 in which the polyether polycarbonate diol (A) was used in combination with PTMG and/or PCD, transparency, flexibility, mechanical strength, and durability were all excellent.
On the other hand, Comparative Example 1 using only the polyether polycarbonate diol (A) and not using PTMG and/or PCD together, and Comparative Examples 2 and 3 using only PTMG or PCD were excellent in flexibility and mechanical strength. Inferior, Comparative Examples 1 and 2 also have insufficient durability.
Even when PTMG and PCD are used together, Comparative Example 4 in which the polyether polycarbonate diol (A) is not used has poor compatibility when mixed with a polyol, and thus is inferior in flexibility, mechanical strength and transparency.

Claims (15)

Structural units derived from a compound having a plurality of isocyanate groups, structural units derived from at least one compound selected from the group consisting of polyols and polyamines, derived from polyether carbonate diol represented by the following formula (A): A structural unit, a polycarbonate diol having at least a repeating unit represented by the following formula (B) and a repeating unit represented by the following formula (C), and/or a repeating unit represented by the following formula (D) and the following formula A polyurethane elastomer containing a structural unit derived from a polyalkylene ether glycol having a repeating unit represented by (E).

(In the formula (A), R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. In A), a plurality of R ¹ may be the same or different.

(In the above formula (B), R ² represents a divalent hydrocarbon group having 2 to 20 carbon atoms, p is an integer of 3 to 50, and in the above formula (C), R ³ is different from R ^2. And represents a divalent hydrocarbon group having 3 to 20 carbon atoms, or a divalent hydrocarbon group having 3 to 20 carbon atoms and containing an alicyclic structure or a heterocyclic structure, and q is 0. Is an integer of -50.
In the above formula (D), R ⁴ is an alkylene group having 2 to 20 carbon atoms, r is an integer of 3 to 50, and in the above formula (E), R ⁵ is different from R ⁴ and has 3 carbon atoms. To a divalent hydrocarbon group having 20 to 20 carbon atoms or a divalent hydrocarbon group having 3 to 20 carbon atoms and having an alicyclic structure or a heterocyclic structure, and s is an integer of 0 to 50. ) The ratio of the structural unit derived from the polyether polycarbonate diol to the total of the structural unit derived from the polycarbonate diol and the structural unit derived from the polyalkylene ether glycol is 10% by weight to 90% by weight. Polyurethane elastomer. The polyurethane elastomer according to claim 1, wherein R ¹ in the formula (A) is an n-butylene group and/or a 2-methylbutylene group. The polyurethane elastomer according to any one of claims 1 to 3, wherein a molar ratio of the repeating unit represented by the formula (C) to the repeating unit represented by the formula (B) is 0.03 to 10. The polyurethane elastomer according to any one of claims 1 to 4, wherein R ² in the formula (B) is a divalent hydrocarbon group having 3 to 6 carbon atoms. The polyurethane elastomer according to any one of claims 1 to 5, wherein R ³ in the formula (C) is a divalent hydrocarbon group having 4 to 12 carbon atoms. The structural unit derived from the formula (C) consists of neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol and 2-methyl-1,4-butanediol. The polyurethane elastomer according to any one of claims 1 to 5, which is a structural unit derived from at least one selected from the group. The structural unit derived from the formula (C) is a structural unit derived from at least one selected from the group consisting of isosorbide, isomannide, isoidide, and 1,4-cyclohexanedimethanol. 2. The polyurethane elastomer according to item 1. The polyurethane elastomer according to any one of claims 1 to 8, wherein the number average molecular weight of the structural unit derived from the polyalkylene ether glycol is 200 to 5,000 based on a hydroxyl value. The polyalkylene ether glycol is polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, copolymerized polytetramethylene ether glycol of 3-methyltetrahydrofuran and tetrahydrofuran, copolymerized polyether polyol of neopentyl glycol and tetrahydrofuran, ethylene oxide and tetrahydrofuran. 10. The polyurethane elastomer according to any one of claims 1 to 9, which is at least one selected from the group consisting of the copolymerized polyether polyol of 1) and a copolymerized polyether glycol of propylene oxide and tetrahydrofuran. The polyurethane elastomer according to claim 1, wherein the compound having a plurality of isocyanate groups is an aromatic diisocyanate compound. The polyurethane elastomer according to claim 11, wherein the aromatic diisocyanate compound is at least one selected from the group consisting of 1,4-diphenylmethane diisocyanate, toluene diisocyanate, and xylylene diisocyanate. The at least one compound selected from the group consisting of the polyol and the polyamine is at least one compound selected from the group consisting of ethylene glycol, 1,4-butanediol and 1,6-hexanediol. 13. The polyurethane elastomer according to any one of 1 to 12. The polyurethane elastomer according to any one of claims 1 to 13, wherein the polyurethane elastomer is a thermoplastic elastomer. A method for producing the polyurethane elastomer according to any one of claims 1 to 14, wherein at least one compound selected from the group consisting of the compound having a plurality of isocyanate groups, the polyol and the polyamine, A method for producing a polyurethane elastomer, which comprises carrying out an addition polymerization reaction of a polycarbonate diol and/or the polyalkylene ether glycol without using a solvent.