JP3354679B2 - Polyurethane and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyurethane and a method for producing the same. More specifically, the present invention relates to a polyurethane having a structural unit derived from a crystalline aromatic polyester diol and a structural unit derived from a specific polycarbonate diol, and a method for producing the same. It has excellent abrasion resistance and rubber elasticity inherent to plastic polyurethane, and also has oxidation resistance such as light resistance and heat resistance, hydrolysis resistance,
It is also excellent in various performances such as cold resistance and mechanical performance, and can be effectively used for various applications including various molded articles and fibers.

[0002]

2. Description of the Related Art Thermoplastic elastomers can be melt-molded and melt-spun like thermoplastic resins and are excellent in moldability and spinnability, and because of their excellent mechanical properties and rubber elasticity, etc. Widely used in various applications such as automotive parts, electric / electronic parts, general mechanical parts, and miscellaneous goods. Among such thermoplastic elastomers, polyester-based elastomers and thermoplastic polyurethanes have excellent performance. Occupies an important position.

[0003] As polyester-based elastomers, block copolymers having a structural unit composed of polybutylene terephthalate as a main hard segment and a structural unit composed of polytetramethylene ether glycol or polycaprolactone as a soft segment are used for cold resistance and weather resistance. It is practically used because of its excellent moldability. However, the block copolymerized polyester elastomer having a structural unit composed of polytetramethylene ether glycol as a soft segment is inferior in oxidation resistance such as light resistance and heat resistance, and a structural unit composed of polycaprolactone is referred to as a soft segment. The resulting block copolymerized polyester elastomers are inferior in hydrolysis resistance, and both are not yet sufficiently satisfactory.
In addition, these polyester elastomers are inferior to polyurethane in abrasion resistance and rubber elasticity.

On the other hand, thermoplastic polyurethanes can be arbitrarily obtained from very hard ones to flexible ones by changing the type and reaction rate of isocyanate compounds, polymer diols, chain extenders and the like. Excellent wear resistance and rubber elasticity. However, heat resistance is insufficient due to urethane bonds, and its mechanical properties are expressed by intermolecular cohesion, so its melting properties have a large temperature dependence and its moldability is poor. Have.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polyurethane which has excellent abrasion resistance and rubber elasticity inherently, and furthermore has resistance to oxidation and deterioration such as light resistance and heat resistance.
An object of the present invention is to provide a polyurethane excellent in mechanical performance represented by hydrolysis resistance, cold resistance, tensile strength and the like, and also excellent in moldability and spinnability, and a method for producing the same.

[0006]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors, in producing polyurethane, a polycarbonate diol having an alkylene group having a methyl branch in a molecule is used as a soft segment component, and furthermore, in the molecule. Using a crystalline polyester diol having an aromatic group as a hard segment component and reacting them with an organic diisocyanate to form a polyurethane, it is possible to obtain a polyurethane having the above-mentioned excellent properties. Thus, the present invention has been completed.

[0007] That is, the present invention provides substantially the following formula (I):

[0008]

Embedded image (Wherein, R ¹ is a divalent organic group having 4 to 10 carbon atoms, m is 3
A structural unit (I) represented by the following formula (II);

[0009]

Embedded image [ Wherein, R ² represents a divalent saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms (provided that 1,5-
Petanediol, 1, which may be substituted with a methyl group
Substituted with 8-octanediol and a methyl group
Divalent saturated fat derived from 1,9-nonanediol
Aliphatic hydrocarbon radicals) or saturated alicyclic hydrocarbon radicals,
R ³ is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, n represents an integer of 6 to 70), and a structural unit (II) represented by the following formula (III):

[0010]

Embedded image (Wherein R ⁴ represents a divalent hydrocarbon group having 6 to 15 carbon atoms), wherein the structural unit (I) and the structural unit (II) are represented by the above formula Structural unit (III)
A polyurethane having a structure in which at least 20 mol% of R ^{1 in} the polyurethane is an alkylene group having 4 to 10 carbon atoms and having one methyl branch. It is.

The present invention relates to the following formula (IIIa):

[0012]

Embedded image (Wherein, R ⁴ represents a divalent hydrocarbon group having 6 to 15 carbon atoms) and an organic diisocyanate represented by the following formula (I
a);

[0013]

Embedded image (Wherein, R ¹ is a divalent organic group having 4 to 10 carbon atoms, m is 3
A polycarbonate diol (Ia) represented by the following formula (IIa):

[0014]

Embedded image [ Wherein, R ² represents a divalent saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms (provided that 1,5-
Petanediol, 1, which may be substituted with a methyl group
Substituted with 8-octanediol and a methyl group
Divalent saturated fat derived from 1,9-nonanediol
Aliphatic hydrocarbon radicals) or saturated alicyclic hydrocarbon radicals,
R ³ is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and n is an integer of 6 to 70 ]. The polyester diol (IIa) represented by the following formula is reacted simultaneously or sequentially by a one-shot method or a prepolymer method. A method for producing a polyurethane by subjecting a polycarbonate diol (Ia) to a polycarbonate diol in which at least 20 mol% of R ¹ is an alkylene group having 4 to 10 carbon atoms and having one methyl branch. This is a method for producing a polyurethane.

The structural unit (I) in the polyurethane of the present invention is derived from the polycarbonate diol (Ia). In the present invention, R ¹ contained in the polycarbonate diol (Ia), and thus the structural unit (I) derived therefrom.
, It is necessary that at least 20 mol% of them be alkylene groups having 4 to 10 carbon atoms having one methyl branch, and at least 30 mol% having 4 to 4 carbon atoms having one methyl branch. It is preferably 10 alkylene groups. If the content of the alkylene group having 4 to 10 carbon atoms having one methyl branch is too low, the polyurethane has poor cold resistance. This polycarbonate diol (Ia) has the following formula:

[0016]

Embedded image A diol represented by HO—R ¹ —OH (wherein R ¹ is the same group as described above) or an ester-forming derivative thereof, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, It can be produced by a method known per se using diphenyl carbonate, phosgene or other polycarbonate-forming carbonate compounds.Specifically, the above-mentioned diol and carbonate compound are subjected to an esterification reaction or a transesterification reaction to produce an intermediate product. And a polycondensation reaction under heating and reduced pressure in the presence of a catalyst if necessary.

HO-R ¹ described above for introducing an alkylene group R ¹ having 4 to 10 carbon atoms having one methyl branch into the polycarbonate diol (Ia), and thus the structural unit (I) derived therefrom; As -OH,
Specifically, 2-methyl-1,3-propanediol, 2-methyl-1,3-propanediol,
Methyl-1,4-butanediol, 2-methyl-1,5
-Pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,6-hexanediol, 3-
Methyl-1,6-hexanediol, 2-methyl-1,
7-heptanediol, 3-methyl-1,7-heptanediol, 4-methyl-1,7-heptanediol, 2
-Methyl-1,8-octanediol, 3-methyl-
1,8-octanediol, 4-methyl-1,8-octanediol, 2-methyl-1,9-nonanediol,
3-methyl-1,9-nonanediol, 4-methyl-
1,9-nonanediol, 2-methyl-1,10-decanediol, 3-methyl-1,10-decanediol,
Examples thereof include 4-methyl-1,10-decanediol and 5-methyl-1,10-decanediol. These diols may be used alone or in combination of two or more.

Also, polycarbonate diol (Ia),
As long as it is not more than 80 mol% based on the total amount of R ¹ contained in the structural unit (I) derived therefrom, the group R ¹ has 4 to 10 carbon atoms other than an alkylene group having one methyl branch. It may be a divalent organic group. Such a divalent organic group is converted to a polycarbonate diol (I
Examples of diols that can be introduced into a) include those having 4 to 4 carbon atoms.
10 straight-chain saturated aliphatic diols and alicyclic diols, aromatic diols having 6 to 10 carbon atoms, and the like, among which straight-chain saturated aliphatic diols having 4 to 10 carbon atoms are preferable, and Specifically, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10- Decanediol and the like are preferably used.

When the number of carbon atoms in the group R ¹ in the polycarbonate diol (Ia) is 3 or less, the cold resistance of the obtained polyurethane decreases, and when one of them has 11 or more carbon atoms, the mechanical properties of the obtained polyurethane are reduced. Decrease.

The polycarbonate diol (Ia) forming the structural unit (I) has a number average molecular weight of 800 to 10,000.
It is preferably 0, and when the number average molecular weight is less than 800, cold resistance, low-temperature properties and flexibility tend to be poor,
On the other hand, if it exceeds 10,000, the mechanical properties and elastic properties tend to be poor. The structural unit (I) derived from the polycarbonate diol (Ia) forms a soft segment in the polyurethane.

The structural unit (II) in the polyurethane of the present invention is derived from a polyester diol (IIa), and the polyester diol (IIa) has the following formula:

[0022]

Embedded image A diol represented by HO—R ² —OH (where R ² is the same group as described above) or an ester-forming derivative thereof, and the following formula;

[0023]

Embedded image embedded image embedded image embedded image embedded image embedded image embedded image embedded image embedded image embedded image embedded image embedded image It is obtained by reacting with a dicarboxylic acid represented by HOOC—R ³ —COOH (where R ³ is the same group as described above) or an ester-forming derivative thereof. In the present invention, the polyester diol (IIa) and the structural unit derived therefrom (I
In I), the group R ² may be any of a divalent saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms or a saturated alicyclic hydrocarbon group, and such a group R ² may be a polyester diol (IIa)
Diol as described above for introduction into HO—R ² —O
Examples of H include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,7-heptanediol, 1,10
Examples thereof include -decanediol and 1,4-cyclohexanedimethanol. These diols may be used alone or in combination of two or more. Among them, 1,4-butanediol is preferably used.

Further, the group R in the polyester diol (IIa) and thus the structural unit (II) derived therefrom
³ may be any divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and may be any of the above formulas for introducing such a group R ³ into the polyester diol (IIa);
Examples of the dicarboxylic acid represented by R ³ —COOH include:
Examples thereof include terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. One or more of these dicarboxylic acids may be used. Among them, terephthalic acid or its ester-forming derivative is preferably used.

The number average molecular weight of the polyester diol (IIa) for forming the structural unit (II) in the polyurethane is preferably from 1500 to 15000, and if the number average molecular weight of the polyester diol (IIa) is less than 1500. Heat resistance tends to be poor, while if it exceeds 15,000, mechanical properties and elastic properties tend to be poor.

The production method of the polyester diol (IIa) is not particularly limited, and diol: HO—R ² —OH or its ester-forming derivative and dicarboxylic acid; HOOC—R ³
-COOH or an ester-forming derivative thereof can be produced by a method known per se. Specifically, the diol component and the dicarboxylic acid component are subjected to an esterification reaction or a transesterification reaction to form an intermediate product. It can be produced by subjecting it to a polycondensation reaction under heating and reduced pressure in the presence of a catalyst or the like, if necessary. This polyester diol (IIa) is a crystalline polyester, and the structural unit (II) derived therefrom constitutes a hard segment in the polyurethane.

The polyurethane of the present invention is obtained by reacting the above-mentioned polycarbonate diol (Ia) and polyester diol (IIa) with the organic diisocyanate represented by the above formula (IIIa) simultaneously or sequentially by a one-shot method or a prepolymer method. Wherein the structural unit (I) and the structural unit (II) are derived from an organic diisocyanate.
To form a polyurethane bonded via In that case, the structural unit (I) and the structural unit (II)
It may be linked randomly via I), linked alternately, or linked in other ways.
Generally, when the one-shot method of producing a polyurethane by simultaneously reacting the polycarbonate diol (Ia), the polyester diol (IIa) and the organic diisocyanate is employed, the structural unit (I) and the structural unit (II) in the resulting polyurethane are used. There is a great tendency for the arrangement of the polyesters to be random, and one of the polycarbonate diol (Ia) and the polyester diol (IIa) is reacted with an organic diisocyanate to form an isocyanate group-terminated prepolymer, and then the other diol is reacted to form a polyurethane. In the case where the prepolymer method for producing a polymer is adopted, the structural unit (I) and the structural unit (II) are
A relatively regularly linked polyurethane is obtained via I).

The polycarbonate diol (Ia) and the polyester diol (IIa) used in the production of the polyurethane of the present invention have substantially a molecular structure as shown by the corresponding formulas (Ia) and (IIa), respectively. Both ends of the main chain are hydroxyl groups, but a small amount may have a carboxyl group at the end. The content ratio of the terminal carboxyl group is preferably 2 mol% or less of the total terminal groups in the polycarbonate diol (Ia), and 20 g equivalent / 10 ⁶ g or less in the polyester diol (IIa).

In this case, in the organic diisocyanate represented by the above formula (IIIa) which forms the structural unit (III), the group R ⁴ may be any divalent hydrocarbon group having 6 to 15 carbon atoms. For example, it may be any of a divalent saturated aliphatic hydrocarbon group having 6 to 15 carbon atoms, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Specific examples of such organic diisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated xylylene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate. ; Tolylene diisocyanate, 4,
4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate,
1,5-naphthylene diisocyanate, 3,3′-dichloro-4,4′-diphenylmethane diisocyanate,
Examples thereof include aromatic diisocyanates such as toluylene diisocyanate, and these organic diisocyanates may be used alone or in combination of two or more.

The proportion of the organic diisocyanate used is, based on the total amount of active hydrogen atoms contained in the polycarbonate diol (Ia) and polyester diol (IIa), that the isocyanate group equivalent is about 0.9 per equivalent of active hydrogen atom. Preferably, the ratio is about 1.5, more preferably about 0.95 to 1.3.

In the present invention, the ratio of {total weight of polycarbonate diol (Ia) and organic diisocyanate}: {weight of polyester diol (IIa)} is in the range of 1: 6 to 5: 1. , Polycarbonate diol (Ia), polyester diol (II
a) and reacting the organic diisocyanate to obtain a polyurethane having excellent oxidation resistance such as light resistance, heat resistance, hydrolysis resistance, and cold resistance, and also having excellent chemical resistance, flexibility and rubber elasticity. This is preferable. If the above ratio is less than 1/6, the flexibility and rubber elasticity of the polyurethane are likely to be poor, while if it exceeds 5/1, the crystallinity is reduced and the heat resistance and the chemical resistance are likely to be poor.

Depending on the type of organic diisocyanate used, the content and molecular weight of the polycarbonate diol (Ia) and polyester diol (IIa), the molecular weight and viscosity of the polyurethane obtained by reacting them are different. It is preferable that the polyurethane has an intrinsic viscosity of 1.0 dl / g or more because various physical properties are improved.

In producing the polyurethane of the present invention, in addition to the above-mentioned polycarbonate diol (Ia), polyester diol (IIa) and organic diisocyanate, if necessary, other components may be used in a small amount. Examples of such other components include chain extenders such as low molecular weight diols, diamines and dihydrazides, and trifunctional or higher functional crosslinkable components such as glycerin and pentaerythritol. Further, in the present invention, optional components such as a catalyst, a reaction accelerator, an internal mold release agent, a filler, a reinforcing agent, a dye and a pigment, a stabilizer, etc., which are usually used when producing polyurethane are used as required. can do.

As an example of the method for producing the polyurethane of the present invention, polycarbonate diol (Ia), polyester diol (II
a) and the organic diisocyanate are supplied simultaneously or almost simultaneously and continuously at 160 to 280 ° C., preferably at 18 ° C.
A method of producing a polyurethane by continuous melt polymerization at a temperature of 0 to 260 ° C., and pelletizing if necessary, a method of extruding an organic diisocyanate with one of polycarbonate diol (Ia) and polyester diol (IIa) in an extruder.
After producing an isocyanate group-terminated urethane prepolymer by reacting at 0 to 260 ° C., a method of producing a polyurethane by adding the other diol and reacting at 180 to 260 ° C. can be mentioned, of course. The method is not limited.

In particular, in the case of the above method, the desired polyurethane can be continuously produced by an extremely simple operation only by supplying all or all of the reaction components to the extruder simultaneously or almost simultaneously. Further, in the case of the above method, a polyurethane having structural properties (I) and a structural unit (II) which is relatively regularly bonded to the polyurethane via the structural unit (III) is used. Obtainable.

The polyurethane of the present invention is thermoplastic and can be heated and melt-molded. Extrusion molding which is generally employed for thermoplastic resins and thermoplastic elastomers can be used.
Molding methods such as injection molding, blow molding, press molding, and cast molding, and melt spinning methods can be applied, whereby sheets, films, rolls, gears, solid tires, belts, hoses, tubes, packing materials, vibration-proof materials, Soles, sports shoes, machine parts, auto parts, sports equipment, elastic fibers,
In some cases, various products such as an adhesive and a sealing agent can be manufactured smoothly. Hereinafter, the present invention will be described specifically with reference to Examples and the like, but the present invention is not limited thereto.

[0037]

In the following Examples, Comparative Examples and Reference Examples, the number average molecular weight of the polycarbonate diol (Ia), the number average molecular weight of the polyester diol (IIa) and the amount of terminal carboxyl groups were determined by the following methods.
The measurement of the intrinsic viscosity of the polyurethane, and the evaluation of the mechanical properties (stress at 100% elongation, breaking strength and breaking elongation), hydrolysis resistance, cold resistance and light resistance of the polyurethane were performed according to the following methods.

Number average of polycarbonate diol (Ia)
Molecular weight : It was calculated from the hydroxyl value of the polycarbonate diol (Ia).

Number average of polyester diol (IIa)
Molecular weight and terminal carboxyl group content : Reference [Die Makromolekul
are Chemie 26 , 226-335 (1956)], the terminal hydroxyl value and the terminal carboxyl group amount were measured, and the number average molecular weight was determined from the hydroxyl value.

Intrinsic viscosity of polyurethane: Polyurethane was dissolved in phenol / tetrachloroethane (1/1 weight ratio) and measured at 30 ° C.

Evaluation of mechanical performance : Polyurethane 240
A dumbbell-shaped test piece was prepared from a 100 μm thick film obtained by hot pressing at
At 0 cm / min, the stress at 100% elongation (M100), the breaking strength and the breaking elongation were measured according to the method specified in JIS K7311, and the mechanical performance was evaluated based on these.

Evaluation of hydrolysis resistance : A polyurethane film having a thickness of 100 μm was dried at 70 ° C. and 95% relative humidity.
After standing for 8 days, the breaking strength of the film before and after that was measured, and the strength retention ratio after standing against the strength before standing (%)
Was evaluated.

Evaluation of cold resistance : The dynamic viscoelasticity of a test piece made of a polyurethane film having a thickness of 100 μm was measured at a frequency of 11 Hz, and the temperature (Tα) at which the dynamic loss modulus E ″ peaked was determined. Thereby, cold resistance was evaluated.

Evaluation of light resistance : A polyurethane film having a thickness of 100 μm was irradiated with ultraviolet rays at 83 ° C. for 20 hours using a carbon arc type fade meter FAL-5 manufactured by Suga Test Instruments Co., Ltd., and the breaking strength of the film before and after the irradiation was measured. Measured, intensity retention ratio after irradiation with respect to intensity before irradiation (%)
Was evaluated.

In Tables 2 to 4 below, the diols and organic diisocyanates used are indicated by the abbreviations in Table 1 below.

[0046]

[Table 1] Abbreviation: Compound MPD: 3-methyl-1,5-pentanediol MOD: 2-methyl-1,8-octanediol HD: 1,6-hexanediol ND: 1,9-nonanediol MDI: 4,4′- Diphenylmethane diisocyanate HDI: Hexamethylene diisocyanate

Reference Example 1 [Production of Polycarbonate Diol (Ia)] In a nitrogen stream, 528 g of ethylene carbonate, 320 g of 2-methyl-1,8-octanediol and 1,9
-640 g of nonanediol was charged into a reactor under normal pressure.
At 190 ° C., ethylene glycol was distilled off from the reaction system.
The temperature was gradually raised to 210 to 220 ° C., and after almost all ethylene glycol was distilled off, the pressure was reduced to 1 to 3 mmH.
In g, the remaining ethylene glycol was completely distilled off. As a result, a polycarbonate diol (Ia) (polycarbonate diol A) having a hydroxyl value of 37.4, an acid value of 0.08 and a number average molecular weight of 3000 was obtained.

Reference Examples 2 to 6 The reaction was carried out in the same manner as in Reference Example 1 except that the diols shown in Table 2 below were used to obtain corresponding polycarbonate diols (polycarbonate diols B to F). .

[0049]

[Table 2]

Reference Example 7 [Production of Polyester Diol (IIa)] 388 g of dimethyl terephthalate, 270 g of 1,4-butanediol and 20 mg of tetraisopropyl titanate were charged into a reactor, and a transesterification reaction was started at 160 ° C. with stirring. did. It took about 60 minutes to gradually raise the temperature to 200 ° C. to distill off methanol produced by the transesterification reaction and tetrahydrofuran and water produced by the side reaction. Then, while gradually reducing the pressure in the system to 200 to 20 mmHg, excess 1,4-butane was distilled off until the total amount of methanol, tetrahydrofuran and water distilled off and 1,4-butanediol distilled off reached 204 g. The diol was removed. As a result, a polyesterdiol (IIa) [polybutylene terephthalate; PBT (L)] having a number average molecular weight of 3,000 and a terminal carboxyl group content of 3.8 eq / 10 ⁶ g and having hydroxyl groups at both ends was obtained.

Reference Example 8 In the same manner as in Reference Example 7, the amount of excess 1,4-butanediol distilled was adjusted to obtain a polyester diol having hydroxyl groups at both ends as shown in Table 3 below. IIa) [Polybutylene terephthalate; PB
T (M)].

[0052]

[Table 3] Reference example PBT type Terminal carboxyl group amount Number average molecular weight (eq / 10 ⁶ g) 7 L 3.8 3000 8 M 4.5 5000

Example 1 0.01 mol (30 g) of polycarbonate diol A and 0.01 mol (30 g)
g) The finely ground PBT (L) was taken in a three-necked flask and kept at 80 ° C. To this, 0.022 mol (5.5 g) of 4,4′-diphenylmethane diisocyanate was added, and the mixture was stirred for 1 minute. And transferred to a Labo Plastomill kept for 10 minutes. Thereafter, the mixture was aged at 100 ° C. for 8 hours to obtain a polyurethane. This was hot-pressed at 240 ° C. to produce a film having a thickness of 100 μm, and the mechanical performance, hydrolysis resistance, cold resistance and light resistance were evaluated using this film by the method described above. The results are shown in Table 4 below.

Examples 2 to 8 and Comparative Examples 1 and 2 The polycarbonate diols A to F and polycaprolactone diol (polyester diol G) obtained in Reference Examples 1 to 6 as polycarbonate diol (Ia): number average molecular weight 3000; an ester group concentration of 0.167) and one of the above-prepared PBT (L) or PBT (M) as the polyester diol (IIa) is reacted with an organic diisocyanate. In the same manner as in Example 1, a polyurethane was produced. A film was prepared from the obtained polyurethane, and various physical properties were evaluated in the same manner as in Example 1. Table 4 shows the results.

<< Comparative Example 3 >> Dimethyl terephthalate 1
35 g, 70 g of polytetramethylene ether glycol having a number average molecular weight of 1,000 and 95 g of 1,4-butanediol were charged into a reactor, and the temperature was increased from 150 ° C to 210 ° C.
The temperature was gradually raised over time, and 95% of the theoretical methanol amount was distilled out of the system. Add Irganox 101 to the reaction mixture
0 (manufactured by Ciba Geigy), and then 245
° C, and then the pressure in the system was raised to 0.2 over 50 minutes.
Polymerization was performed for 2 hours under the reduced pressure of mmHg to obtain a polyetherester elastomer (PEES). A film having a thickness of 100 μm was produced from this elastomer, and various physical properties were evaluated in the same manner as in Example 1. Table 4 shows the results.

[0056]

[Table 4]

From the results in Table 4 above, it can be seen that the films obtained from the polyurethanes of the present invention of Examples 1 to 8 are excellent in all of mechanical performance, hydrolysis resistance, cold resistance and light resistance. Understand. On the other hand, it can be seen that the polyurethane of Comparative Example 1 obtained using the polycarbonate diol F having no methyl branch in the group corresponding to the group R ¹ has poor cold resistance. The polyurethane of Comparative Example 2 obtained by using polycaprolactone diol (polyester diol G) instead of the polycarbonate diol was inferior in cold resistance and hydrolysis resistance, and the polyetherester elastomer of Comparative Example 3 Indicates that the light resistance is inferior.

[0058]

The polyurethane of the present invention has excellent abrasion resistance and rubber elasticity inherent to thermoplastic polyurethane, and furthermore has resistance to oxidation and deterioration such as light resistance and heat resistance, hydrolysis resistance and cold resistance. Excellent in various mechanical performances represented by rupture strength and elongation at break, as well as excellent in thermoplasticity, heat-meltability and moldability, making it extremely suitable for a wide range of applications. Can be used effectively.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 18/00-18/87

Claims (2)

(57) [Claims] 1. A compound of the formula (I): (Wherein, R ¹ is a divalent organic group having 4 to 10 carbon atoms, m is 3
A structural unit (I) represented by the following formula (II): [ Wherein, R ² represents a divalent saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms (provided that 1,5-
Petanediol, 1, which may be substituted with a methyl group
Substituted with 8-octanediol and a methyl group
Divalent saturated fat derived from 1,9-nonanediol
Aliphatic hydrocarbon radicals) or saturated alicyclic hydrocarbon radicals,
R ³ represents a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, n represents an integer of 6 to 70 ] , and a structural unit (II) represented by the following formula (III): (Wherein R ⁴ represents a divalent hydrocarbon group having 6 to 15 carbon atoms), wherein the structural unit (I) and the structural unit (II) are represented by the above formula Structural unit (III)
A polyurethane having a structure in which at least 20 mol% of R ^{1 in} the polyurethane is an alkylene group having 4 to 10 carbon atoms and having one methyl branch. . 2. The following formula (IIIa): (Wherein, R ⁴ represents a divalent hydrocarbon group having 6 to 15 carbon atoms) and an organic diisocyanate represented by the following formula (I
a); (Wherein, R ¹ is a divalent organic group having 4 to 10 carbon atoms, m is 3
A polycarbonate diol (Ia) represented by the following formula (IIa): [ Wherein, R ² represents a divalent saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms (provided that 1,5-
Petanediol, 1, which may be substituted with a methyl group
Substituted with 8-octanediol and a methyl group
Divalent saturated fat derived from 1,9-nonanediol
Aliphatic hydrocarbon radicals) or saturated alicyclic hydrocarbon radicals,
R ³ is a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, and n is an integer of 6 to 70 ]. The polyester diol (IIa) represented by the following formula is reacted simultaneously or sequentially by a one-shot method or a prepolymer method. A method for producing a polyurethane by subjecting the polycarbonate diol (Ia) to a polycarbonate diol in which at least 20 mol% of R ¹ is an alkylene group having 4 to 10 carbon atoms and having one methyl branch. Method for producing polyurethane.