JPH09272731A - Polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester having excellent hydrolysis resistance and no tendency toward crystallization and being useful for coating materials, adhesives, etc., by selecting a polyester consisting mainly of specified repeating units and having a specified number-average molecular weight. SOLUTION: This polyester mainly consists of repeating units represented by the formula: -CO-R-CO-O-CH2 -CH(CH3 )-(CH2 )4 -CH-(CH3 )-CH2 -O- and/or formula: -CO-R-CO-O-CH2 -CH(CH3 )(CH2 )5 -CH(CH3 )-CH2 -O- [wherein R is a 2-20C alkylene, a cycloalkylene, an arylene or -C6 H4 -X-C6 -H4 - (X is O, S, SO2 , a 2-8C alkylidene or a 1 or 2C alkylene)] and has a number-average molecular weight of 300-30,000. The polyester is useful for polyurethanes, polyamide elastomers, etc., and gives articles having excellent flexibility and hydrolysis resistance.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to novel polyesters, and more particularly to polyesters suitable for applications such as paints, adhesives, polyurethanes and polyamide elastomers and polyester elastomers.

[0002]

2. Description of the Related Art In the field of paints, adhesives, polyurethanes and the like, polyesters having a hydroxyl group at the molecular terminal have been used. Such polyesters include ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6
Polyesters obtained from polyhydric alcohols such as hexanediol, trimethylolpropane and glycerin and polybasic acids or their anhydrides or their ester derivatives are known. Among these polyesters, aromatic dicarboxylic acids such as phthalic anhydride, isophthalic acid and terephthalic acid are used as polybasic acids in combination with aliphatic dicarboxylic acids such as adipic acid to prepare polyhydric alcohols and dihydric or higher polyhydric alcohols and esters. The hydroxyl-terminated polyester obtained by the chemical reaction is widely used in the fields of paints and adhesives.

Further, a polyester having a hydroxyl group terminal obtained by an esterification reaction of an aliphatic dicarboxylic acid such as adipic acid and a divalent or trivalent or more polyhydric alcohol is 2
Polyurethane can be obtained by reacting with an isocyanate compound having a functionality or higher, and is used for a wide range of applications such as elastomers, paints, adhesives, coating agents and foams.

Further, a polyester having a carboxyl group at its molecular end can be made into a polyester polyamide having excellent heat resistance by reacting with a bifunctional or higher functional isocyanate compound, and is used for applications such as elastomers.

[0005]

A conventional polyester having a hydroxyl group or a carboxyl group at a molecular terminal generally has poor hydrolysis resistance. Therefore, the products obtained from these conventional polyesters have a problem that the surface thereof tends to be tacky or cracked in a relatively short period of time.

In order to improve the hydrolysis resistance of polyester, it is generally effective to reduce the ester group concentration of the polyester. In order to reduce the ester group concentration in the polyester, it is preferable to form a polyester from a glycol having a large number of carbon atoms and a dicarboxylic acid having a large number of carbon atoms, but the resulting polyester has a high tendency to crystallize, and generally has a high viscosity liquid or There is a problem that it becomes solid and inferior in workability. Further, coatings, adhesives, polyurethanes, polyamide elastomers, polyester elastomers, etc. obtained from polyesters formed from glycols having a large number of carbon atoms and dicarboxylic acids having a large number of carbon atoms are observed to have improved hydrolysis resistance, but are crystallized. When it is left in a low temperature atmosphere such as −20 ° C., the low temperature characteristics represented by bending resistance, flexibility, low temperature adhesiveness, etc. are remarkably deteriorated.

The inventors of the present invention have conducted various studies to provide polyesters having excellent hydrolysis resistance and no tendency to crystallize using industrially available raw materials. 8-octanediol and / or 1,9-
A polyester containing nonanediol has been found and a patent application has already been filed (see JP-A-63-182330).

However, even in the case of this polyester, a slight crystallization tendency may be observed in the temperature range usually used, and there is room for improvement in flexibility when the polyurethane or polyamide elastomer is used. .

Therefore, the present invention is excellent in hydrolysis resistance,
Moreover, it is a polyester that does not have a tendency to crystallize, and when used in applications such as paints, adhesives, polyurethane and polyamide elastomers and polyester elastomers, it has excellent flexibility, hydrolysis resistance and low temperature properties. It is an object to provide a novel polyester that gives a product having the following.

[0010]

According to the present invention, the above-mentioned problems are solved by the following formula (1) and / or the following formula (2) -CO-R-CO-O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _4- CH (CH ₃ ) -CH ₂ -O- (1) -CO-R-CO-O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _5- CH (CH _{3) -CH 2 -O- (2)} [ wherein, R is an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group, an arylene group or a -C ₆ H ₄ -X-C,
₆ H ₄ — (X represents O, S, SO ₂ , an alkylidene group having 2 to 8 carbon atoms or an alkylene group having 1 to 2 carbon atoms)
Which represents at least one group selected from the group consisting of
The solution is to provide a polyester characterized in that it is between 0 and 30000.

In the present invention, "mainly consisting of repeating units represented by the formula (1) and / or formula (2)" means that at least 20 mol% or more of the repeating units constituting the polyester are represented by the formula (1). And / or formula (2)
It means that it is composed of a repeating unit represented by.

When the content of the repeating unit represented by the formula (1) and / or the formula (2) in the repeating unit constituting the polyester is less than 20 mol%, the obtained polyester has flexibility (flexibility). Etc. and physical properties such as hydrolysis resistance are deteriorated. The content of the repeating unit represented by the formula (1) and / or the formula (2) in the repeating unit constituting the polyester is more preferably 50 mol% or more.

In the above formula (1) and / or formula (2), the alkylene group having 2 to 20 carbon atoms represented by R is, for example, a methylene group, an ethylene group, a propylene group, a hexamethylene group, Examples thereof include a heptamethylene group and an octamethylene group, examples of the cycloalkylene group include a 1,4-cyclohexylene group, and examples of the arylene group include a phenylene group and a naphthylene group.

Examples of the alkylidene group having 2 to 8 carbon atoms represented by X include an ethylidene group and an isopropylidene group, and examples of the alkylene group having 1 to 2 carbon atoms include a methylene group and an ethylene group. .

The repeating unit represented by the formula (1) is composed of a diol unit represented by the following formula (3) and a dicarboxylic acid unit represented by the formula (4). _{-O-CH 2 -CH (CH 3} ) - (CH 2) 4 -CH (CH 3) -CH 2 -O- (3) -CO-R-CO- (4) ( wherein, R defined The repeating unit represented by the formula (2) is composed of a diol unit represented by the following formula (5) and a dicarboxylic acid unit represented by the above formula (4). _{-O-CH 2 -CH (CH 3} ) - (CH 2) 5 -CH (CH 3) -CH 2 -O- (5)

The diol unit represented by the formula (3) is derived from 2,7-dimethyl-1,8-octanediol, and the diol unit represented by the formula (5) is 2,8-dimethyl-. Derived from 1,9-nonanediol. 2,
7-Dimethyl-1,8-ontandiol is, for example,
Industrially produced by hydrogenating the product obtained by reacting 2-methyl-1,8-octanedial derived from 2,7-octadien-1-ol, which is mass-produced and readily available, with formaldehyde can do. Further, 2,8-dithymer-1,9-nonanediol is obtained, for example, by reacting 1,9-nonanedial derived from 2,7-octadiene-1-ol, which is mass-produced and easily available, with formaldehyde. It can be industrially produced by hydrogenating the product.

The polyester provided by the present invention is
Other polyol units besides the 2,7-dimethyl-1,8-octanediol unit and the 2,8-dimethyl-1,9-nonanediol unit can be contained. A low molecular weight polyol unit is preferably used as the other polyol unit, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, and 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, 1,9-
Nonanediol, 1,10-decanediol, 2,2-
Examples thereof include low-molecular diol units such as diethyl-1,3-propanediol, 1,4-cyclohexanediol, cyclohexanedimethanol. These low molecular weight polyol units may be used alone or in combination of two or more. In addition, trimethylolpropane, trimethylolethane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol and the like 3
You may contain the unit which consists of a low molecular weight polyol more than functionality.

The content of these low molecular weight polyol units is
It is desirable that the amount is less than 20 mol% with respect to the total amount of the polyol unit constituting the polyester.

The dicarboxylic acid unit represented by the formula (4) includes an aliphatic dicarboxylic acid unit such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid; an alicyclic ring such as cyclohexanedicarboxylic acid. Group dicarboxylic acid units; aromatic dicarboxylic acid units such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid can be mentioned, and among them, aliphatic dicarboxylic acid units are preferable. These polycarboxylic acid units are derived from the corresponding polycarboxylic acid or its ester derivative.

These polycarboxylic acid units are appropriately selected and used according to the intended use of the obtained polyester. For example, in order to obtain a polyester that gives a polyurethane excellent in flexibility (hydrolysis), hydrolysis resistance, and low temperature characteristics, adipic acid among aliphatic dicarboxylic acid units,
The use of azelaic acid and sebacic acid is preferred. These polycarboxylic acid units may be used alone or in combination of two or more. Moreover, you may make the polycarboxylic acid unit more than trifunctional contain.

The polyester provided by the present invention should have a number average molecular weight of 300 to 30,000. When the number average molecular weight is less than 300, low temperature characteristics and flexibility are poor, while the number average molecular weight is 300.
If it is larger than 00, mechanical properties such as strength and flexibility are deteriorated. The number average molecular weight of polyester is 700 to 200
More preferably, it is within the range of 00.

When the polyester of the present invention is used for producing polyurethane, for example, it is necessary that the polyester has a hydroxyl group at its molecular end. Further, when it is used for applications such as production of a polyamide elastomer, it is necessary to have a carboxyl group at the molecular end. The terminal structure of the polyester can be appropriately adjusted by changing the charged molar ratio of the starting polyol component and the polycarboxylic acid component.

The optimum number of hydroxyl groups or carboxyl groups present in the polyester varies depending on the application, but the number of hydroxyl groups or carboxyl groups is generally 2 or more per molecule, and especially within the range of 2 to 3. If
Polyester can be used for most purposes and has versatility.

The method for producing the polyester of the present invention is not particularly limited, and a known polyester polycondensation method can be applied. For example, 2,7-dimethyl-1,8-octanediol, or 2,8-dimethyl-1,9-nonanediol, or 2,7-dimethyl-1,8-octanediol and 2,8-dimethyl-1. , 9-nonanediol mixture, or low molecular weight diol mixture containing 2,7-dimethyl-1,8-octanediol and / or 2,8-dimethyl-1,9-nonanediol and carboxylic acid component or ester thereof Charge the derivative with a predetermined ratio,
A polyester having a desired molecular weight can be produced by carrying out an esterification or transesterification reaction, and further subjecting the resulting reaction product to a polycondensation reaction in the presence of a polycondensation catalyst at high temperature under vacuum. A wide range of polycondensation catalysts can be used for the polyester production. Examples of such polycondensation catalysts include titanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, and tetrabutoxytitanium, and di-n.
Examples include a combination of a tin compound such as -butyltin oxide, di-n-butyltin dilaurate and dibutyltin diacetate, an acetate salt such as magnesium, calcium and zinc and antimony oxide or the above titanium compound. These polycondensation catalysts are preferably used in the range of 5 to 500 ppm based on the total polyester produced.

The polyester obtained by the present invention is excellent in hydrolysis resistance and has no tendency to crystallize, and when used in paints, adhesives, polyurethanes and polyamide elastomers and polyester elastomers, it has excellent flexibility. A product having properties (flexibility), hydrolysis resistance, low temperature characteristics, etc. is provided. Further, the polyester obtained by the present invention is a novel high performance material which can be applied to various other uses.

[0026]

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 number average molecular weight of the polyester was calculated based on the hydroxyl value and acid value of the polyester.

Example 1 480 g of 2,7-dimethyl-1,8-octanediol
Then, 292 g of adipic acid was charged into the reactor, which was heated to 200 ° C. in a nitrogen atmosphere under normal pressure, and the esterification reaction was carried out while distilling the produced water out of the system. When the amount of water produced diminished, 20 mg of tetraisopropyl titanate was added, and a vacuum pump was used for 150 to 100 mm.
The reaction was continued while reducing the pressure to Hg. Acid value is 1.0KOH
When the amount reached mg / g, the degree of vacuum was gradually increased by a vacuum pump to complete the reaction. As a result, the hydroxyl value was 56.1 KOHmg / g and the acid value was 0.20 KOHmg / g.
A polyester having hydroxyl groups at both ends and having a number average molecular weight of 2000 (hereinafter, abbreviated as polyester A) was obtained.

Examples 2 to 5 and Comparative Examples 1 to 3 Esterification reaction and polycondensation reaction were carried out in the same manner as in Example 1 except that the diol component and dicarboxylic acid component shown in Table 1 were used, and both terminals were subjected. To have a hydroxyl group (hereinafter, the polyesters obtained in Examples 2 to 5 are respectively referred to as polyesters B to E, and the polyesters obtained in Comparative Examples 1 to 3 are referred to as polyesters F to H, respectively). Table 1 shows the physical properties of the polyesters B to H.
Among polyesters A to H, polyesters A to E are 20
It was liquid at 0 ° C, and polyesters F to H were waxy or solid at 20 ° C.

[0029]

[Table 1]

In Table 1, the diol component and dicarboxylic acid are shown 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 AD: Adipic acid AZ: Azelaic acid

Example 6 337 g of adipic acid, 296 g of 2,7-dimethyl-1,8-octanediol and 2,8-dimethyl-1,9
-57 g of nonanediol was charged into a reactor and heated to 200 to 210 ° C in a nitrogen atmosphere under normal pressure, and an esterification reaction was carried out while distilling the produced water out of the system. When the amount of water produced diminished, 25 mg of tetraisopropyl titanate was added, the reaction was driven in while gradually reducing the pressure with a vacuum pump, and the reaction was completed when the terminal hydroxyl groups were almost eliminated. As a result, the hydroxyl value is 0.15K
A polyester having OH mg / g, an acid value of 56.5 KOH mg / g, and a number average molecular weight of 1986 and having carboxyl groups at both ends (hereinafter referred to as polyester I) was obtained.

Examples 7 to 8 and Comparative Example 4 An esterification reaction and a polycondensation reaction were carried out in the same manner as in Example 6 except that the diol component and dicarboxylic acid shown in Table 2 were used, and a carboxyl group was formed at both ends. (Hereinafter, the polyesters obtained in Examples 7 and 8 are referred to as polyesters J and K, respectively, and the polyester obtained in Comparative Example 4 is referred to as polyester L). Table 2 shows the physical properties of polyesters J to L. Among the polyesters I to L, the polyesters I to K were liquid at 20 ° C, and the polyester L was solid at 20 ° C.

[0033]

[Table 2]

The abbreviations in Table 2 mean the same compounds as those in Table 1.

Reference Examples 1 to 8 Polyurethanes A to H obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were used to produce polyurethane by the following method. That is, 0.05 mol (100 g) of each of the polyesters A to H and 0.1 mol (9 g of 1,4-butanediol).
g) and 0.15 mol of 4,4′-diphenylmethane diisocyanate (37.5 g) were reacted in dimethylformamide (DMF) under a nitrogen atmosphere at 80 ° C. for 5 to 8 hours to give a polyurethane DMF solution (nonvolatile content 30%). ) Got. The DMF solution of polyurethane thus obtained was cast on a glass plate and dried to obtain a dry film having a thickness of 100 μm. Using this film, the mechanical performance [stress against strain of 400% (400%
Modulus: M ₄₀₀ ) Breaking strength and breaking elongation], and hydrolysis resistance was evaluated. The results are shown in Table 3 below.

Evaluation of Mechanical Performance The mechanical performance was evaluated according to the method specified in JIS K7311. That is, a polyurethane film having a thickness of 100 μm was formed, and a dumbbell-shaped test piece was produced from this film. Using the obtained test piece, M ₄₀₀ , breaking strength and breaking elongation were measured at a tensile speed of 50 cm / min using an Instron universal testing machine (manufactured by Instron).

Evaluation of Hydrolysis Resistance A polyurethane film having a thickness of 100 μm was formed, and this film was allowed to stand in hot water at 100 ° C. for 7 days, and the breaking strength of the film before and after that was measured at a pulling speed of 50 cm / min. The breaking strength retention rate (%) was determined according to the following formula, and used as an index of hydrolysis resistance.

[0038]

[Equation 1]

◎ Low temperature property A polyurethane film piece of about 10 mg was formed, and this film was analyzed by a differential scanning calorimetry (DSC) device to obtain -1.
The temperature was raised from 50 ° C. at a rate of 10 ° C./min, the glass transition temperature (° C.) was determined, and it was used as an index of low temperature characteristics.

[0040]

[Table 3]

From the results shown in Table 3, when polyesters A to E containing repeating units represented by the formula (1) and / or the formula (2) were used (Reference Examples 1 to 5) and the formula (1),
Alternatively, when the polyesters F to H containing no repeating unit represented by the formula (2) are used (Reference Examples 6 to 8), it is apparent that the obtained polyurethane has different physical properties as follows. .

That is, the polyurethanes obtained in Reference Examples 1 to 5 have smaller values of stress (M ₄₀₀ ) with respect to strain of 400% than the polyurethanes obtained in Reference Examples 6 to 8,
The value of elongation at break is also larger than that of the polyurethanes obtained in Reference Examples 6 to 8, and the flexibility is excellent. further,
Mechanical strength, hydrolysis resistance, low temperature properties, etc. are 2-methyl-
It is equivalent to polyester containing 1,8-octanediol and 1,9-nonanediol, and is comparable to polyester.

Reference Examples 9 to 12 Polyamide elastomers were produced by the following method using the polyesters (IL) having carboxyl groups at both terminals obtained in Examples 6 to 8 and Comparative Example 4. That is, each of the polyesters I to L is 0.1 mol (200
g), 0.25 mol of azelaic acid (47 g) and 4,
0.35 mol (87.5 g) of 4'-diphenylmethane diisocyanate was added to 1-methyl-2-phospholen-1-oxide as a catalyst under a nitrogen atmosphere in sulfolane and reacted at 180 ° C for 7 to 10 hours. A sulfolane solution of polyamide elastomer (nonvolatile content 30%) was obtained. The sulfolane solution of the polyamide elastomer thus obtained was cast on a glass plate and dried to a thickness of 0.
2 mm and 100 μm dry films were obtained. Using this film, low temperature flexibility and hydrolysis resistance were evaluated by the following methods. The results are shown in Table 4 below.

◎ Low temperature flexibility (low temperature flexibility) A 0.2 mm thick polyamide elastomer film piece was formed, and this film was measured for dynamic viscoelasticity (Vibron).
Using the apparatus, the glass transition temperature (° C.) was determined under the condition of 110 Hz. Furthermore, the sulfolane solution of the polyamide elastomer was applied onto the artificial leather substrate and dried, and the bending resistance at −20 ° C. of the molded article obtained was evaluated according to the following criteria. That is, the longest is 3 cm and the shortest is 1 cm
Flex resistance "○" when there is no change after 100,000 times of bending under the bending test condition of 8600 times / hour of bending width with a stroke width, "△" when slightly scratched, substrate When it is scratched to the extent that it can be seen, the flex resistance is rated as "x". The results are shown in Table 4. A polyamide elastomer having a low glass transition temperature and good bending resistance at low temperatures has no crystallization tendency and is excellent in low temperature flexibility (low temperature flexibility).

Evaluation of Hydrolysis Resistance A film of a polyamide elastomer having a thickness of 100 μm was formed, and this film was allowed to stand in hot water at 100 ° C. for 7 days, and before and after that, the film was dissolved in a DMF solvent to give 30
The retention rate (%) of the logarithmic viscosity measured at ° C was obtained according to the following formula and used as an index of hydrolysis resistance. The results are shown in Table 4 below.

[0046]

[Equation 2]

[0047]

[Table 4]

From the results shown in Table 4, when polyesters I to K containing the repeating unit represented by the formula (1) and / or the formula (2) were used (Reference Examples 9 to 11) and the formula (1). Alternatively, when the polyester L not containing the repeating unit represented by the formula (2) is used (Reference Example 12), it is apparent that the obtained polyamide elastomer has different physical properties as follows.

That is, the polyamide elastomers obtained in Reference Examples 9 to 11 have a glass transition temperature lower than that of the polyamide elastomer obtained in Reference Example 12, are excellent in bending resistance, and are excellent in low-temperature flexibility. Furthermore, the hydrolysis resistance is comparable to that of polyesters containing 2-methyl-1,8-octanediol and 1,9-nonanediol, and is comparable to that of polyesters.

[0050]

According to the present invention, hydrolysis resistance is excellent,
Moreover, it is a polyester that does not have a tendency to crystallize, and when used in applications such as paints, adhesives, polyurethane and polyamide elastomers and polyester elastomers, it has excellent flexibility, hydrolysis resistance and low temperature properties. A new polyester is provided which gives a product having

Claims (1)

[Claims] 1. The following formula (1) and / or the following formula (2) -CO-R-CO-O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _4- CH (CH ₃ )- CH ₂ -O- (1) -CO-R-CO-O-CH ₂ -CH (CH ₃ )-(CH ₂ ) _5- CH (CH ₃ ) -CH ₂ -O- (2) [wherein R is an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group, an arylene group or a -C ₆ H ₄ -X-C,
₆ H ₄ — (X represents O, S, SO ₂ , an alkylidene group having 2 to 8 carbon atoms or an alkylene group having 1 to 2 carbon atoms)
Which represents at least one group selected from the group consisting of
A polyester characterized in that it is 0 to 30,000.