JPH1077325A - Production of polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject polyurethane high in a value of a dissipation factor in a temperature range in the vicinity of a normal temperature, excellent in damping characteristics, by using a specific polyol as a polymer polyol component. SOLUTION: This polyurethane uses a polyester polyol consisting essentially of a cyclooctane dimethanol unit which may be substituted with a methyl group as a polymer polyol component when (A) the polymer polyol component is reacted with (B) a polyisocyanate component. The polyester polyol is obtained, for example, by esterifying or transesterifying a cyclooctane dimethanol which may be substituted with a methyl group with a dicarboxylic acid or its ester in a fixed ratio and subjecting the reaction product to a condensation polymerization in the presence of a condensation polymerization catalyst at a high temperature in vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polyurethane which exhibits excellent vibration damping characteristics in a wide temperature range around room temperature and has no tendency to crystallize.

[0002]

2. Description of the Related Art In recent years, with the development of the automobile industry, the electric industry, and the like, there has been an increasing demand for environmental improvement with respect to vibration and noise. Above all, importance has been placed on measures to absorb vibration and reduce noise. As a part of such vibration absorption measures and noise reduction measures, various types of vibration suppression performance (vibration absorption performance,
Materials such as rubbers and elastomers having noise prevention performance have been developed. Generally, the evaluation of the vibration damping performance of a material such as rubber or elastomer is widely performed using a value of a loss coefficient (tan δ) obtained by measuring a viscoelastic modulus of the material. Since a material having a large loss coefficient and a large loss coefficient over a wide temperature range can exhibit excellent vibration damping performance in a wide range of use environments, it is expected as a vibration damping material having a wide applicable range.

[0003]

As a material excellent in vibration damping performance using a polyurethane elastomer, it is composed of polyurethane using 1,4-cyclohexanedimethanol as an elongating agent component (see Japanese Patent Application Laid-Open No. Hei 7-2922061). Damping materials and the like are known. Some of these conventional polyurethane elastomers exhibit large loss factor values at room temperature.

An object of the present invention is to provide a material capable of exhibiting excellent vibration damping performance in a wide range of use environments, and has a large loss coefficient near room temperature and a wide temperature range. An object of the present invention is to newly provide a polyurethane having a large loss coefficient and excellent vibration damping performance.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies with the aim of solving the above-mentioned problems, and as a result, have completed the present invention. That is, the present invention, when producing a polyurethane by reacting a polymer polyol component and a polyisocyanate component, a polyester polyol mainly composed of cyclooctane dimethanol units that may be substituted with a methyl group as a polymer polyol component. This is a method for producing a polyurethane, which is used. ADVANTAGE OF THE INVENTION According to this invention, the polyurethane which is excellent in vibration damping performance which maintains the value of a large loss coefficient over a wide temperature range near normal temperature can be manufactured. The polyurethanes obtained according to the invention are very useful in a wide variety of applications. In addition, the polyester polyol used in the present invention is a liquid having a low viscosity, and has a feature of excellent workability.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, "mainly cyclooctane dimethanol units optionally substituted by a methyl group" means that at least 60 mol% of the polyol units constituting the polyester polyol are methyl groups. Means a cyclooctanedimethanol unit which may be substituted. The content of cyclooctane dimethanol unit which may be substituted by a methyl group in the polyol unit constituting the polyester polyol is 60.
If the amount is less than mol%, the value of the loss coefficient of the obtained polyurethane becomes small. The content of the cyclooctane dimethanol unit which may be substituted with a methyl group in the polyol unit constituting the polyester polyol is preferably at least 70 mol%, more preferably at least 80 mol%.

In the present invention, as the content of the cyclooctane dimethanol unit which may be substituted with a methyl group in the polyol unit constituting the polyester polyol increases, the value of the loss coefficient of the obtained polyurethane increases, and the loss factor increases. The temperature at which the value of the coefficient becomes maximum tends to shift to a higher temperature side.

The above-mentioned cyclooctane dimethanol unit which may be substituted by a methyl group includes, for example, 1,5-cyclooctane dimethanol, 1,4-cyclooctane dimethanol, 1,3-cyclooctane dimethanol,
It is derived from cyclooctane dimethanol which may be substituted with a methyl group such as 1,5-dimethyl-2,6-cyclooctane dimethanol and 1,6-dimethyl-2,5-cyclooctane dimethanol. Cyclooctane dimethanol optionally substituted with a methyl group may be used alone or in combination of two or more.

The cyclooctane dimethanol which may be substituted with a methyl group is, for example, 1,5-cyclooctadiene, 1,5-cyclooctadiene which is mass-produced and can be obtained at low cost.
Cyclooctadiene which may be substituted with a methyl group such as dimethyl-1,5-cyclooctadiene is hydroformylated to produce cyclooctanedicarbaldehydes, and the obtained cyclooctanedicarbaldehydes are hydrogenated. It can be produced industrially by reduction by a known method such as

The polyester polyol used in the present invention may contain another polyol unit other than the above-mentioned cyclooctane dimethanol unit which may be substituted by a methyl group. Examples of such other polyol units include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-
Propanediol, 1,3-butylene glycol, 1,
4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5
-Pentanediol, 1,6-hexanediol, 2-
Methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 1,9-nonanediol, 2-methyl-1,9-nonanediol, 2,8-dimethyl-1,9- Nonanediol, 1,10-decanediol, neopentyl glycol, 2,2-diethyl-
1,3-propanediol, 2-butyl-2-ethyl-
Aliphatic diol units such as 1,3-propanediol; cyclohexanedimethanol, 3 (or 4), 8 (or 9) -dihydroxymethyltricyclo [5.2.1.
[0 ^2,6 ] decane and the like; and aromatic ring-containing diol units such as 1,4-bis (β-hydroxyethoxy) benzene. Among them, 2-methyl-1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 2,7-
Dimethyl-1,8-octanediol, 1,9-nonanediol, 2-methyl-1,9-nonanediol, 2,
Aliphatic diol units having a branch such as 8-dimethyl-1,9-nonanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol; Alicyclic diol units such as 4-cyclohexanedimethanol, 3 (or 4), 8 (or 9) -dihydroxymethyltricyclo [5.2.1.0 ^2,6 ] decane are used to control the vibration of the resulting polyurethane. It is particularly preferable because the performance is not reduced. These other polyol units may be used alone or as a mixture of two or more.

If the vibration damping performance is not reduced, trimethylolpropane, trimethylolethane,
Glycerin, 1,2,6-hexanetriol, 1,
A unit composed of a trifunctional or higher functional low molecular polyol such as 2,4-butanetriol may be contained.

The polycarboxylic acid unit constituting the polyester polyol used in the present invention is not particularly limited. Examples thereof include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and brassic acid. Saturated aliphatic dicarboxylic acid units such as cyclohexanedicarboxylic acid; and aromatic dicarboxylic acid units such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid.

Among these, saturated aliphatic dicarboxylic acid units such as adipic acid, azelaic acid and sebacic acid are
It is particularly preferable because a polyurethane having a maximum value of the loss coefficient can be obtained in a relatively high temperature region near normal temperature. These polycarboxylic acids may be used alone or in combination of two or more. Also, 3
A polycarboxylic acid unit having a functionality higher than that of the functional group may be contained.

Further, the polyester polyol used in the present invention may have a partial structure such as a polyether polyol unit or a polycarbonate polyol unit in the molecule, as long as the gist of the present invention is not impaired.

[0015] The polyester polyol used in the present invention preferably has a number average molecular weight in the range of 500 to 10,000, more preferably in the range of 1500 to 6000.

The method for producing the polyester polyol used in the present invention is not particularly limited, and a known polyester condensation polymerization method can be applied. For example, a diol mixture containing cyclooctane dimethanol optionally substituted with a methyl group or cyclooctane dimethanol optionally substituted with a methyl group and a dicarboxylic acid or an ester thereof are charged at a desired ratio, and esterification is performed. Alternatively, a polyester polyol can be produced by conducting a transesterification reaction and subjecting the resulting reaction product to a further polycondensation reaction under high temperature and vacuum in the presence of a polycondensation catalyst.

In the present invention, as a high molecular polyol component to be reacted with a polyisocyanate component, in addition to a polyester polyol mainly composed of cyclooctane dimethanol units which may be substituted by a methyl group, a polyether polyol, a polycarbonate polyol, a polyester Other polymer polyols such as polycarbonate polyols, polyester polyether polyols, polybutadiene-based and / or polyisoprene-based both-end diols or hydrogenated products thereof can also be used. These other high molecular polyols are usually used in a range of 40% by weight or less based on the total high molecular polyol components. If the vibration damping performance is not reduced, 3
A small amount of a high-functional or higher-molecular polyol may be used in combination.

The polyisocyanate component used in the present invention is not particularly limited, and any of the polyisocyanate components conventionally used for producing polyurethane may be used. For example, 4,4'-diphenylmethane diisocyanate , Tolylene diisocyanate, phenylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dichloro-4,4'-diphenylmethane diisocyanate, xylylene diisocyanate,
Aromatic diisocyanates such as tolylene diisocyanate; and aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate. These polyisocyanates may be used alone or in combination of two or more. Further, a polyisocyanate having three or more functionalities can be used as long as the vibration damping performance is not reduced.

Further, in the present invention, a chain extender can be used if necessary. As a chain extender,
Low molecular compounds having two or more active hydrogen atoms conventionally used for producing polyurethane can be used. Examples of such low molecular weight compounds include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol,
1,3-butylene glycol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-
Octanediol, 2,7-dimethyl-1,8-octanediol, 1,9-nonanediol, 2-methyl-
1,9-nonanediol, 2,8-dimethyl-1,9-
Aliphatic diols such as nonanediol, 1,10-decanediol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol; cyclohexanedi Methanol, cyclooctanedimethanol, dimethylcyclooctanedimethanol, 3 (or 4), 8 (or 9) -dihydroxymethyltricyclo [5.2.1.0
^2,6 ] alicyclic diols such as decane; 1,4-bis (β
-Hydroxy-containing diols such as (hydroxyethoxy) benzene. These low molecular compounds may be used alone or in combination of two or more.

In the present invention, when a polyurethane is produced by reacting a high molecular polyol component with a polyisocyanate component and, if desired, a chain extender component, the mixing ratio of each component depends on the hardness to be imparted to the target polyurethane. The amount of isocyanate groups per mole of active hydrogen atoms is 0.9 to 1 based on the total amount of active hydrogen atoms contained in the polymer polyol component and the chain extender component. It is preferable to use the polyisocyanate component in such a ratio as to be 0.3 mol, and the isocyanate group is preferably 0.95 to 1.1 per mol of the active hydrogen atom.
It is more preferable to use the polyisocyanate component in a molar ratio.

The polyurethane obtained according to the present invention has a logarithmic viscosity of 0 when measured at 30 ° C. as an N, N-dimethylformamide (hereinafter abbreviated as DMF) solution having a polyurethane concentration of 0.5 g / dl. .4 to 2 dl /
It is desirably within the range of g.

In the present invention, a catalyst, a reaction accelerator, a foaming agent, an internal mold release agent, a filler, a reinforcing agent, a face dye, a coloring agent, a flame retardant, an ultraviolet ray, which are generally used in the production of polyurethane. Various additives such as absorbents, antioxidants, hydrolysis resistance improvers, fungicides, and stabilizers; glass fibers,
Various components such as polyester fibers; inorganic materials such as talc and silica; and optional components such as various coupling agents can be used as needed.

In the present invention, as a method for producing a polyurethane by reacting a polymer polyol component, a polyisocyanate component and a chain extender component, any of known urethanization reaction techniques such as melt polymerization and solution polymerization can be used. , Prepolymer method and one-shot method.

A specific example of a method for producing a polyurethane according to the present invention is as follows.
The mixture was heated to 0 to 100 ° C., and the obtained mixture was added with a molar ratio of active hydrogen atoms to isocyanate groups of 1:
A method of adding a polyisocyanate component in an amount of 1-1: 1.5 and stirring the mixture for a short time, and then heating the mixture to, for example, 50 to 160 ° C to produce a polyurethane. A method for producing a polyurethane by kneading a mixture of isocyanate components at a high temperature of, for example, 180 to 260 ° C. For example, a method of producing a polyurethane by continuous melt polymerization at a high temperature of 180 to 260 ° C., a method of performing a polyurethane forming reaction with a polymer polyol component, a chain extender component and a polyisocyanate component in an organic solvent, and the like. is there.

Among these, when producing polyurethane by the above-mentioned method, by controlling the concentrations of the high molecular weight polyol component, the chain extender component and the polyisocyanate component, a high molecular weight polyurethane can be easily produced. . At this time, the concentrations of the polymer polyol component, the chain extender component and the polyisocyanate component are 10 to 40.
It is preferably in the range of% by weight. As the organic solvent, DMF, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, toluene, methyl ethyl ketone, ethyl acetate, isopropanol, ethyl cellosolve and the like can be used. These organic solvents may be used alone or in combination of two or more.

The polyurethane obtained according to the present invention exhibits excellent vibration damping performance in a wide temperature range around room temperature, so that the mechanical parts, automobile parts,
Housing-related parts, electrical equipment materials, packaging materials, sheets, films, rolls, solid tires, belts, tubes, packing materials, shoe soles, sports shoes, sports equipment, elastic fibers, artificial leather, fiber treatment agents, adhesives, coatings Agent,
It can be used for a wide variety of applications such as various binders and paints. Further, since the polyurethane obtained by the present invention does not have a tendency to crystallize, the workability when used for these applications is good.

[0027]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the evaluation of the logarithmic viscosity and the vibration damping performance of the polyurethane was performed by the following methods.測定 Measurement of logarithmic viscosity of polyurethane A DMF solution of polyurethane having a concentration of 0.5 g / dl was prepared, the solution viscosity was measured at 30 ° C, and the logarithmic viscosity was determined based on the solution viscosity. ◎ Evaluation of vibration damping performance of polyurethane A test piece made from a polyurethane film having a thickness of 1 mm was subjected to a dynamic viscoelasticity measurement device (RHEOVIBRO).
N: Orientec Co., Ltd.) and frequency 11H
z, the storage elastic modulus (E ′) and the loss elastic modulus (E ″) were measured at a heating rate of 3 ° C./min, and the loss coefficient (tan δ = E ″) was measured.
/ E '), and a graph showing the change in the value of the loss coefficient with respect to the temperature was created. The maximum value of the loss coefficient (tan δ
(Peak value) and the temperature at which the loss coefficient reaches the maximum value (ta)
nδ) and the temperature at which the value of the loss coefficient is 0.5 or more. The loss coefficient is used as a measure of vibration damping, and the larger the value, the better the vibration damping performance (vibration absorption, noise prevention, etc.). Polyurethane having a loss coefficient peak temperature near normal temperature exhibits excellent vibration damping performance at temperatures near normal temperature. Furthermore, polyurethane having a wider temperature range in which the loss coefficient is 0.5 or more can exhibit excellent vibration damping performance over a wider temperature range.

The compounds used in Examples and Comparative Examples are represented by the following abbreviations. CODM: cyclooctanedimethanol DMCODM: dimethylcyclooctanedimethanol CHDM: 1,4-cyclohexanedimethanol (cis / trans mixture: cis / trans = 30/7)
0) MPD: 3-methyl-1,5-pentanediol BD: 1,4-butanediol AD: adipic acid MDI: 4,4'-diphenylmethane diisocyanate

Reference Example 1 (Synthesis of CODM) 0.42 g of rhodium dicarbonylacetylacetonate and 17 g of triphenylphosphine were placed in toluene in a 5-liter internal stainless steel autoclave equipped with a thermometer, an electromagnetic stirrer, and a gas inlet. A catalyst solution obtained by dissolving in 1.5 liters and 1.5 liters of 1,5-cyclooctadiene were charged in a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) atmosphere. Next, a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) was introduced into the autoclave, the internal pressure was adjusted to 90 absolute pressure, and the internal temperature was raised to 60 ° C. with stirring. Hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) so that the internal pressure is maintained at 90 absolute pressure
Is continuously supplied, and the reaction is carried out for 3 hours while maintaining the internal temperature at 60 to 70 ° C.
The reaction was completed by stirring for an hour. When the obtained reaction mixture was analyzed by gas chromatography, it was found that it contained 97% of a dialdehyde compound. The catalyst and toluene were removed from the reaction mixture obtained above using a wiper thin film still to obtain a hydroformylation reaction solution.

The hydroformylation reaction liquid 1.2 obtained above was placed in a 5-liter stainless steel autoclave equipped with a thermometer, an electromagnetic stirrer and a gas inlet.
Liter, 1.2 liter of isopropyl alcohol and 24 g of Raney nickel were charged. Next, hydrogen gas was introduced into the autoclave, and the internal temperature was increased to 100 ° C. with stirring while continuously supplying hydrogen gas so that the internal pressure was maintained at 10 absolute pressure. The reaction was completed by stirring for 5 hours while maintaining the internal temperature at 100 ° C. When the obtained reaction mixture was analyzed by gas chromatography, no unreacted dialdehyde compound was detected. The reaction mixture was filtered to remove Raney nickel, and isopropyl alcohol and high-boiling products were removed from the obtained filtrate using a wiper-type thin-film evaporator to obtain a colorless transparent viscous liquid. This colorless and transparent viscous liquid is heated at an internal temperature of about 20
Distillation was performed at 0 ° C. under a reduced pressure of 1 to 5 torr.
~ 160 ° C distillate is obtained and colorless and transparent liquid 1.05k
g was obtained. ¹ H-NMR analysis, elemental analysis and mass analysis confirmed that the liquid was cyclooctane dimethanol. The cyclooctane dimethanol (CODM) thus obtained was used in the following Reference Examples, Examples and Comparative Examples.

Reference Example 2 (Synthesis of DMCODM) Rhodium dicarbonylacetylacetonate (3.1 g) and triphenylphosphine (28.3 g) were placed in a 5-liter stainless autoclave equipped with a thermometer, an electromagnetic stirrer, and a gas inlet. Was dissolved in 2.8 liters of toluene and 1,5-dimethyl-1,
5-cyclooctadiene and 1,6-dimethyl-1,5-
Mixture of cyclooctadienes [1,5-dimethyl-1,1
5-cyclooctadiene / 1,6-dimethyl-1,5-
Cyclooctadiene = 8/2 (molar ratio)] was charged in an atmosphere of a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1). Next, a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) was introduced into the autoclave, the internal pressure was adjusted to 90 absolute pressure, and the internal temperature was raised to 60 ° C. with stirring. A hydrogen / carbon monoxide mixed gas (molar ratio = 1) is maintained such that the internal temperature is maintained at 60 ° C. and the internal pressure is maintained at 90 absolute pressure.
The reaction was carried out for 34 hours while continuously supplying (/ 1). When the obtained reaction mixture was analyzed by gas chromatography, it was found that 55% of the dialdehyde compound was contained. The catalyst and toluene were removed from the reaction mixture obtained above using a wiper thin film still to obtain a hydroformylation reaction solution.

In a 5-liter stainless steel autoclave equipped with a thermometer, an electromagnetic stirrer and a gas inlet, 750 g of the hydroformylation reaction solution obtained above was placed.
1.5 liters of isopropyl alcohol and 80 g of Raney nickel were charged. Next, hydrogen gas was introduced into the autoclave, and while the hydrogen gas was continuously supplied so that the internal pressure was maintained at 10 absolute pressure, the internal temperature was reduced to 10 while stirring.
The temperature was raised to 0 ° C. The reaction was completed by stirring for 5 hours while maintaining the internal temperature at 100 ° C. When the obtained reaction mixture was analyzed by gas chromatography, no unreacted dialdehyde compound was detected. The reaction mixture was filtered to remove Raney nickel, and isopropyl alcohol and high-boiling products were removed from the obtained filtrate using a wiper-type thin-film evaporator to obtain a colorless transparent viscous liquid. The colorless and transparent viscous liquid was purified by distillation at a reduced pressure of 0.5 torr to obtain a fraction at 130 to 137 ° C. to obtain 690 g of a colorless and transparent liquid. The liquid was confirmed to be dimethylcyclooctanedimethanol by ¹ H-NMR analysis, elemental analysis, and mass spectrometry. The dimethylcyclooctane dimethanol thus obtained (DMCO
DM) was used in the following Reference Examples, Examples and Comparative Examples.

Reference Example 3 (Production of Polyester Polyol) 360 g of CODM and 220 g of adipic acid obtained in Reference Example 1 were charged into a reaction vessel, and the mixture was charged at normal pressure under a nitrogen atmosphere.
The mixture was heated to 80 ° C., and an esterification reaction was performed while distilling out generated water from the system. When the amount of distilled water was reduced, 6 mg of tetraisopropyl titanate was added, and the reaction was continued while reducing the pressure to 200 to 100 torr with a vacuum pump. When the acid value reached 1.0 KOHmg / g, the degree of vacuum was gradually increased by a vacuum pump to complete the reaction. As a result, a hydroxyl value of 56.1 KOH mg / g and an acid value of 0.2
Polyester polyol having KOH mg / g and a number average molecular weight of 2,000 (hereinafter referred to as polyester polyol A
).

Reference Examples 4 to 7 (Production of Polyester Polyol) Reference Example 3 was the same as Reference Example 3 except that the diol and dicarboxylic acid shown in Table 1 were used in the same molar ratio as in Reference Example 3.
The esterification and the condensation polymerization reaction were carried out in the same manner as in Example 1 to obtain a polyester polyol (hereinafter, the polyester polyols obtained in Reference Examples 4 to 7 are abbreviated as polyester polyols B to E, respectively). Among the polyester polyols A to E, the polyester polyols A to D were liquid at room temperature (25 ° C.), and the polyester polyol E was solid at room temperature (melting point 99 ° C.).

[0035]

[Table 1]

EXAMPLE 1 0.05 mol (1 mol) of polyester polyol A was placed in a reaction vessel.
00g), MDI 0.15 mol (37.5 g), BD
0.1 mol (9 g) and 530 g of DMF were charged, and 8
The reaction was carried out at 0 ° C. for 6 hours to obtain a DMF solution of polyurethane (nonvolatile content: 25%). Table 2 shows the logarithmic viscosity of the obtained polyurethane. DMF of the polyurethane obtained above
The solution was cast on a glass plate and dried at 60 to 70 ° C. to obtain a polyurethane dry film. After the obtained polyurethane dry film is cut into small pieces,
By dehumidifying and drying for 4 hours, and then hot-pressing at 220 ° C., a film having a thickness of 1 mm was prepared, and the vibration-damping performance was evaluated according to the method described above. Table 2 shows the results.

Examples 2 to 4 and Comparative Examples 1 and 2 The procedure of Example 1 was repeated except that the polymer polyol component, polyisocyanate component and chain extender component shown in Table 2 were used in the same molar ratio as in Example 1. A polyurethane solution was obtained in the same manner as in Example 1. Here, the polyurethane solution obtained from the polyester polyol E (Comparative Example 2) became a wax having no fluidity at room temperature. This indicates that the polyurethane obtained in Comparative Example 2 has a tendency to crystallize. Next, a polyurethane film having a thickness of 1 mm was prepared in the same manner as in Example 1, and the vibration damping performance was evaluated. Table 2 also shows the evaluation results of the logarithmic viscosity and the vibration damping performance of the polyurethane.

[0038]

[Table 2]

From Table 2, it can be seen that the polyurethane of the present invention has a large maximum loss coefficient, excellent vibration damping performance, and the temperature at which the maximum loss coefficient is near normal temperature, particularly in a relatively high temperature range. From this, it can be seen that excellent vibration damping performance is exhibited when used in a temperature range from room temperature to slightly higher temperature. Moreover, the temperature range where the loss coefficient is 0.5 or more is wide, and excellent vibration damping performance can be exhibited over a wide temperature range.

[0040]

According to the present invention, the value of the loss coefficient is large near normal temperature, especially in a relatively high temperature range, and the value of the large loss coefficient is maintained over a wide temperature range. A polyurethane having no tendency to crystallize can be produced. The polyurethanes obtained according to the invention are very useful in a wide variety of applications.

Claims (1)

[Claims] When producing a polyurethane by reacting a high molecular polyol component and a polyisocyanate component,
A method for producing a polyurethane, comprising using a polyester polyol mainly composed of a cyclooctane dimethanol unit which may be substituted with a methyl group as a polymer polyol component.