JPH09324026A - Preparation of polyurethane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a polyurethane which has an excellent damping property, exhibits a large dissipation factor around room temp., and can maintain the large dissipation factor over a wide temp. range. SOLUTION: This process comprises reacting a polymeric polyol component with a polyisocyanate component and a chain extender component, and the chain extender component is composed mainly of at least one compd. selected from the group consisting of 2-methyl-1,8-octanediol, 2,7-dimethlyl-1,8-octanediol, 2-methyl-1,9-nonanediol, and 2,8-dimethyl-1,9-nonanediol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyurethane which exhibits excellent vibration damping performance in a wide temperature range around room temperature.

[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, 1,4-
Polyurethane using cyclohexanedimethanol as a chain extender component (see JP-A-7-292061)
A damping material made of is 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 inventors of the present invention have made extensive studies for the purpose of solving the above problems, and as a result, completed the present invention. That is, in the present invention, when a polyurethane is produced by reacting a polymer polyol component, a polyisocyanate component and a chain extender component,
Selected from the group consisting of methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol and 2,8-dimethyl-1,9-nonanediol. A method for producing a polyurethane, which comprises using a chain extender component containing at least one compound as a main component.

According to the present invention, it is possible to produce a polyurethane having a large loss coefficient at around room temperature and having a large loss coefficient over a wide temperature range and having excellent vibration damping performance. The polyurethanes obtained according to the invention are very useful in a wide variety of applications.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, "2-methyl-
1,8-octanediol, 2,7-dimethyl-1,8
-Octanediol, 2-methyl-1,9-nonanediol and 2,8-dimethyl-1,9-nonanediol is the main component of at least one compound selected from the group ". 40 mol% or more of which is 2
-Methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-
It means that it is at least one compound selected from the group consisting of nonanediol and 2,8-dimethyl-1,9-nonanediol (hereinafter, abbreviated as branched aliphatic diol). When the content of the branched aliphatic diol in the chain extender component is less than 40 mol%, the vibration damping performance of the obtained polyurethane is impaired. The content of the branched aliphatic diol in the chain extender component is preferably 60 mol% or more, more preferably 70 mol% or more.

In the present invention, the larger the content of the branched aliphatic diol in the chain extender component, the larger the value of the loss coefficient of the obtained polyurethane, and the temperature at which the value of the loss coefficient becomes maximum is higher. Tends to move to.

In the present invention, 2-methyl-1,8-octanediol, 2,7-dimethyl-1,8-octanediol, 2-methyl-1,9-nonanediol and 2,
8-Dimethyl-1,9-nonanediol may be used alone or in combination of two or more kinds.

Incidentally, 2-methyl-1,8-octanediol is, for example, 2-methyl-1,8-octanediol derived from 2,7-octadiene-1-ol, which is mass-produced and easily available.
It is industrially produced by hydrogenating 8-octanedial, and 2,7-dimethyl-1,8-octanediol is obtained by reacting the above 2-methyl-1,8-octanedial with formalin. The product thus obtained can be industrially produced by hydrogenating.
In addition, 2-methyl-1,9-nonanediol and 2,
8-dimethyl-1,9-nonanediol is 1,2-derived from 2,7-octadiene-1-ol
It can be industrially produced by hydrogenating the product obtained by reacting 9-nonanedial with formalin. At this time, depending on the amount of formalin used, 2-methyl-1,9-nonanediol and 2,8-dimethyl-1,
Although 9-nonanediol may be co-produced, both can be used separately if desired.

The chain extender component used in the present invention may contain a compound having two or more active hydrogen atoms in addition to the above branched aliphatic diol. The compound having two or more active hydrogen atoms is a known low molecular weight compound which has been conventionally used as a chain extender component in the production of polyurethane and has two or more active hydrogen atoms which react with an isocyanate group. A low molecular weight compound can be preferably used, for example, ethylene glycol, 1,2-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, neopentyl glycol, 3-methyl- Aliphatic diols such as 1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol; cyclohexanedimethanol, cyclooctanedimethanol, Alicyclic diols such as tricyclodecane dimethanol; 1,4-bis (β-
Examples thereof include aromatic ring-containing diols such as hydroxyethoxy) benzene. Among these, 2-methyl-1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-
Diethyl-1,3-propanediol, 2-butyl-2
-A branched aliphatic diol such as ethyl-1,3-propanediol; 1,4-cyclohexanedimethanol, 1,4 (or 5) -cyclooctanedimethanol, 3 (or 4), 8 (or 9) An alicyclic diol such as dihydroxymethyltricyclo (5,2,1,0 ^2,6 ) decane is particularly preferable because it does not reduce the vibration damping performance of the resulting polyurethane. These low molecular weight compounds may be used alone or in combination of two or more.

The polymer polyol component used in the present invention is not particularly limited, and examples thereof include polyester polyol, polyether polyol, polycarbonate polyol, polyester polycarbonate polyol,
Any of the polymeric polyols that have been commonly used in the production of polyurethanes, such as polyester polyether polyols, butadiene-based and / or isoprene-based both-end diols or hydrogenated products thereof, can be used.

The polymer polyol component preferably has a number average molecular weight in the range of 500 to 10,000.
More preferably, it is in the range of 500 to 6000.
The polymer polyol component may be used alone or in combination of two or more. In addition, a small amount of trifunctional or higher polymer polyol may be used in combination as long as the vibration damping performance is not deteriorated.

In the present invention, by using a polyester polyol having a specific aliphatic diol having a branch as a constituent component as a polymer polyol component, the value of the loss coefficient is large at around room temperature and the temperature range is wide. It is possible to more effectively achieve the object of the present invention, which is to provide a polyurethane having excellent vibration damping performance, which has a large loss coefficient value throughout.

Examples of such polyester polyols include the following formulas (1) to (3) -O- (CH ₂ ) _m -CH (CH ₃ )-(CH ₂ ) _n -O- (1) , m and n each represents an integer of 1-7 (provided that the sum of m and n is 2 to _{10)], -O-CH 2 -CH (CH} 3) - (CH 2) 4 -CH (CH ₃ ) -CH ₂ -O- (2), -O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _5- CH (CH ₃ ) -CH ₂ -O- (3), A polyester polyol containing at least one structural unit selected from the group consisting of structural units (hereinafter, abbreviated as an aliphatic diol unit) is preferably used.

The content of the aliphatic diol unit in the polyester polyol is not particularly limited, but generally 20 mol% or more of all the diol units constituting the polyester polyol makes the effect of the present invention more remarkable. Can be expressed. The content of the aliphatic diol unit in the polyester polyol is preferably 50 mol% or more, and more preferably 70 mol% or more of all the diol units constituting the polyester polyol.

The structural unit represented by the above general formula (1) is
For example, 2-methyl-1,3-propanediol, 2-
Methyl-1,4-butanediol, 3-methyl-1,5
-Derived from diols such as pentanediol, 2-methyl-1,8-octanediol, 2-methyl-1,9-nonanediol. The structural unit represented by the general formula (2) is derived from 2,7-dimethyl-1,8-octanediol, and the structural unit represented by the general formula (3) is 2,8-dimethyl-1. , 9-nonanediol. The structural units represented by formulas (1) to (3) may be used alone or in combination of two or more kinds.

Further, the polyester polyol may contain a diol unit other than the structural units represented by the above formulas (1) to (3). Examples of such other diol units include ethylene glycol, 1,2-propanediol, 1,4-butanediol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, and 2-butyl-2-. Mention may be made of structural units derived from diols such as ethyl-1,3-propanediol.

On the other hand, as the dicarboxylic acid component constituting the above polyester polyol, those commonly used in the production of polyesters such as aliphatic dicarboxylic acids and aromatic dicarboxylic acids can be used. Examples of such aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, methylsuccinic acid, and methylglutaric acid, and examples of aromatic dicarboxylic acids include phthalic acid. Acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid and the like can be mentioned. These dicarboxylic acids may be used alone or in combination of two or more. Incidentally, when a mixture of an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid is used as the dicarboxylic acid component, when the content of the aliphatic dicarboxylic acid in the dicarboxylic acid component is large, the value of the loss coefficient of the obtained polyurethane is the maximum. When the content of aromatic dicarboxylic acid in the dicarboxylic acid component is high, the temperature at which the resulting polyurethane has a maximum loss coefficient tends to shift to the high temperature side.

The polyisocyanate component used in the present invention is not particularly limited, and any polyisocyanate component conventionally used in the production of polyurethane may be used. For example, 4,4'- Diphenylmethane diisocyanate, tolylene diisocyanate,
Aromatic diisocyanates such as phenylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dichloro-4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, toluylene diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, 4,4 ' And aliphatic or alicyclic diisocyanates such as dicyclohexylmethane diisocyanate and hydrogenated xylylene diisocyanate. These polyisocyanates may be used alone or in combination of two or more. Also,
Trifunctional or higher polyisocyanates can be used as long as the vibration damping performance is not deteriorated.

When a polyurethane is produced by reacting a high molecular weight polyol component, a polyisocyanate component and a chain extender component, the mixing ratio of each component is appropriately selected in consideration of the hardness to be imparted to the target polyurethane. Depending on the total amount of active hydrogen atoms contained in the polymer polyol component and the chain extender component, the number of moles of isocyanate groups per 1 mole of the active hydrogen atoms is 0.9 to
It is preferable to use the polyisocyanate component in a ratio such that the amount is 1.3 mol, and the polyisocyanate is used in a ratio such that the number of moles of the isocyanate group per mol of the active hydrogen atom is 0.95 to 1.1 mol. It is more preferred to use components.

The polyurethane obtained according to the present invention is
The N, N-dimethylformamide (hereinafter, abbreviated as DMF) solution having a polyurethane concentration of 0.5 g / dl has a logarithmic viscosity of 0.4 to 2 d when measured at 30 ° C.
It is preferably within the range of 1 / g.

Further, 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 usually used in the production of polyurethane. Absorbents, antioxidants, hydrolysis resistance improvers, fungicides, various additives such as stabilizers, glass fibers,
If desired, various components such as polyester fibers, inorganic materials such as talc and silica, and various coupling agents can be used.

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 known urethanization reaction technique such as melt polymerization or solution polymerization can be used. The prepolymer method or the one-shot method may be used.

A specific example of the method for producing the polyurethane of the present invention is as follows. The polymer polyol component and the chain extender component are mixed to prepare
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 the concentration of the polymer polyol component, the chain extender component and the polyisocyanate component is controlled when the polyurethane is produced by the above method, 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 solvents may be used alone or in combination of two or more kinds.

The polyurethane obtained according to the present invention is
Since it exhibits excellent vibration damping performance in a wide temperature range around room temperature, it requires mechanical damping, automobile parts, housing-related parts, electrical equipment materials, packaging materials, sheets, etc.
Films, rolls, solid tires, belts, tubes, packing materials, shoe soles, sports shoes, sports equipment,
It can be used in a wide variety of applications such as elastic fibers, artificial leather, fiber treatment agents, adhesives, coating agents, various binders and paints.

[0028]

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.

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 this solution viscosity.

Evaluation of vibration damping performance of polyurethane For a test piece prepared from a polyurethane film having a thickness of 1 mm, a dynamic viscoelasticity measuring device [RHEOVIBRO
N: manufactured by Orientech Co., Ltd.], 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 value of the loss coefficient becomes maximum (t
and the temperature at which the loss coefficient value 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. DMOD: 2,7-dimethyl-1,8-octanediol DMND: 2,8-dimethyl-1,9-nonanediol MOD: 2-methyl-1,8-octanediol ND: 1,9-nonanediol BD: 1,4-butanediol NPG: neopentyl glycol MDI: 4,4'-diphenylmethane diisocyanate PMPA: 3-methyl-1,5-pentanediol and a polyester acid having a number average molecular weight of 2000 obtained from adipic acid [trade name: Kuraray Polyol P-2
010, manufactured by Kuraray Co., Ltd.] PBA: 1,4-butanediol and adipic acid polyester polyol having a number average molecular weight of 2000 [trade name: Kuraray Polyol A-2010, Co., Ltd.]
Kuraray] PKA-A: Polyester polyol having a number average molecular weight of 2000 obtained from a dicarboxylic acid mixture of 3-methyl-1,5-pentanediol and adipic acid / isophthalic acid = 1/1 (molar ratio) [trade name: Kuraray Polyol P-
2012, manufactured by Kuraray Co., Ltd.] PMIPA: polyester polyol having a number average molecular weight of 2000 obtained from a dicarboxylic acid mixture of 3-methyl-1,5-pentanediol and adipic acid / isophthalic acid = 3/1 (molar ratio) [ Product name: PMIPA-200
0, manufactured by Kuraray Co., Ltd.] PKA-A2: Polyester having a number average molecular weight of 2000, obtained from a dicarboxylic acid mixture of 3-methyl-1,5-pentanediol and adipic acid / terephthalic acid = 1/1 (molar ratio) Polyol [Product name: Kuraray Polyol P-
2011, manufactured by Kuraray Co., Ltd.] PKA-A3: Polyester having a number average molecular weight of 2000 obtained from a dicarboxylic acid mixture of 3-methyl-1,5-pentanediol and adipic acid / phthalic acid = 1/1 (molar ratio) Polyol [Product name: MPD / AA: PA (1:
1), manufactured by Kuraray Co., Ltd.] PBA8T: 1,4-butanediol and adipic acid /
Polyester polyol having a number average molecular weight of 2000 obtained from a dicarboxylic acid mixture of terephthalic acid = 4/1 (molar ratio)

Example 1 In a reaction vessel, 0.05 mol of PMPA (100 g), MD
I 0.2 mol (50 g), DMOD 0.15 mol (2
6.1 g) and DMF (530 g) were charged, and the mixture was mixed at 80 ° C for 6
After reacting for a time, a DMF solution of polyurethane (nonvolatile content 2
5%). The logarithmic viscosity of the obtained polyurethane is shown in Table 1.
Shown in

The polyurethane DMF solution obtained above was cast on a glass plate and dried at 60 to 70 ° C. to obtain a polyurethane dry film. The obtained polyurethane dry film was finely cut, dehumidified and dried at 80 ° C. for 24 hours, and then hot-pressed at 220 ° C. to form a film having a thickness of 1 mm, and the vibration damping performance was evaluated according to the above method. went. Table 1 shows the results.

Examples 2 to 11 and Comparative Examples 1 and 2 By the same procedure as in Example 1 except that the polymer polyol component, polyisocyanate component and chain extender component shown in Tables 1 and 2 were used, respectively. A dry film of polyurethane was obtained. A film with a thickness of 1 mm was prepared from the obtained polyurethane dry film in the same manner as in Example 1, and the vibration damping performance was evaluated. The evaluation results of the logarithmic viscosity and the vibration damping performance of polyurethane are also shown in Tables 1 and 2.

[0035]

[Table 1]

[0036]

[Table 2]

From Tables 1 and 2, 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 maximum is near room temperature. It can be seen that when used at around room temperature, it exhibits excellent vibration damping performance. Moreover, the loss factor is 0.5
The above temperature range is wide, and excellent vibration damping performance can be exhibited over a wide temperature range. The polyurethanes obtained in Examples 6 to 11 have the maximum loss coefficient values in a relatively high temperature range. These polyurethanes are suitable for use in the high temperature range.

On the other hand, in the polyurethane obtained by using the chain extender component containing no branched aliphatic diol, the temperature at which the value of the loss coefficient is maximum is low, and the maximum value of the loss coefficient is also small, so that the loss coefficient is small. Since the temperature range in which is 0.5 or more is also narrow, it is not possible to exhibit excellent vibration damping performance over a wide temperature range around normal temperature.

[0039]

According to the present invention, it is possible to produce a polyurethane having a large loss coefficient near room temperature and a large loss coefficient over a wide temperature range and excellent vibration damping performance. The polyurethanes obtained according to the invention are very useful in a wide variety of applications.

Claims (2)

[Claims] 1. When a polyurethane is produced by reacting a polymer polyol component, a polyisocyanate component and a chain extender component, 2-methyl-1,8-octanediol and 2,7-dimethyl-1,8-octane are used. Diol,
A chain extender component mainly comprising at least one compound selected from the group consisting of 2-methyl-1,9-nonanediol and 2,8-dimethyl-1,9-nonanediol. Method for producing polyurethane. 2. A polymer polyol component represented by the following formulas (1) to (3) —O— (CH ₂ ) _m —CH (CH ₃ ) — (CH ₂ ) _n —O— (1) [wherein , m and n each represents an integer of 1-7 (provided that the sum of m and n is 2 to _{10)], -O-CH 2 -CH (CH} 3) - (CH 2) 4 -CH (CH ₃ ) -CH ₂ -O- (2), -O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _5- CH (CH ₃ ) -CH ₂ -O- (3), The method for producing a polyurethane according to claim 1, wherein a polyester polyol containing at least one structural unit selected from the group consisting of structural units is used.