JPH11236436A - Polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel polyester excellent in hydrolysis resistance, having no tendency to crystallize and capable of presenting products having excellent hydrolysis resistance when used for coatings, etc. SOLUTION: This polyester contains >=20 mole % of a repeating unit expressed by the formula (R is a 2-20C alkylene, cycloalkylene or arylene) and has 300-30,000 number average molecular weight. The objective polyester is obtained by, e.g. loading 3-methyl-1,7-octane diol and a dicarboxylic acid or its ester derivative in a prescribed ratio, carrying out an esterification or a transesterification and bringing the reaction product to a polycondensation reaction in the presence of a polycondensation catalyst at a high temperature under vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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 anhydrides or ester derivatives thereof are known. Among these polyesters, an aromatic dicarboxylic acid such as phthalic anhydride, isophthalic acid and terephthalic acid is used in combination with an aliphatic dicarboxylic acid such as adipic acid as a polybasic acid, and a dihydric or trihydric or higher polyhydric alcohol and an ester are used. Hydroxyl-terminated polyesters obtained by the chemical reaction are widely used in the fields of paints and adhesives.

A hydroxyl-terminated polyester obtained by subjecting an aliphatic dicarboxylic acid such as adipic acid to an esterification reaction with a dihydric or trihydric or higher polyhydric alcohol is a 2-terminal polyester.
Polyurethane can be made by reacting with isocyanate compounds having functionalities 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 the molecular end can be reacted with a bifunctional or more isocyanate compound to obtain a polyester polyamide having excellent heat resistance.

[0005]

A conventional polyester having a hydroxyl group or a carboxyl group at a molecular terminal generally has poor hydrolysis resistance. For this reason, the products obtained from these conventional polyesters have a problem that the surface tends to become tacky or crack easily in a relatively short time.

In order to improve the hydrolysis resistance of the 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 the polyester from a glycol having a large number of carbon atoms and a dicarboxylic acid having a large number of carbon atoms.However, the obtained polyester has a high tendency to crystallize and generally has a high viscosity liquid or There is a problem that it becomes solid and is inferior in workability. In addition, paints, adhesives, polyurethanes, and polyamide elastomers and polyester elastomers obtained from polyesters formed from glycols having a large number of carbon atoms and dicarboxylic acids having a large number of carbon atoms have improved hydrolysis resistance, but are not crystallized. When left in a low-temperature atmosphere such as −20 ° C., for example, the low-temperature characteristics represented by bending resistance, flexibility (flexibility), low-temperature adhesion, and the like are significantly reduced.

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 as a diol component has been found, and a patent application has already been filed (JP-A-63-1823).
No. 30).

However, even in the case of this polyester, a slight tendency to crystallize may be observed at a temperature within a range usually used. Further, it is practically desirable to further improve the hydrolysis resistance of the polyester itself.

Thus, the present invention has excellent hydrolysis resistance,
A novel polyester which does not have a tendency to crystallize and provides a product having excellent hydrolysis resistance when used for applications such as paints, adhesives, polyurethanes, polyamide elastomers and polyester elastomers. That is the task.

[0010]

According to the present invention, the above object is achieved by the following formula (1): -O- (CH ₂ ) ₂ CH (CH ₃ )-(CH ₂ ) ₃ CH (CH ₃ ) -O-CO-R-CO- (1) (wherein, R represents at least one group selected from the group consisting of an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group, and an arylene group). Contains a repeating unit of 20 mol% or more, and has a number average molecular weight of 300 to 300.
The problem is solved by providing a polyester that is 00.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyester of the present invention must contain at least 20 mol% of a repeating unit represented by the formula (1).

In the repeating unit constituting the polyester, the content of the repeating unit represented by the formula (1) is 20.
When the amount is less than mol%, the crystallization tendency of the obtained polyester is increased, and physical properties such as hydrolysis resistance are reduced. The content of the repeating unit represented by the formula (1) in the repeating unit constituting the polyester is preferably at least 40 mol%, more preferably at least 60 mol%.

In the above formula (1), examples of the alkylene group having 2 to 20 carbon atoms represented by R include an ethylene group, a propylene group, a hexamethylene group, 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 1,2-phenylene group, a 1,3-phenylene group,
1,4-phenylene group and the like. These may have a branch appropriately.

The repeating unit represented by the formula (1) comprises a diol unit represented by the following formula (2) and a dicarboxylic acid unit represented by the following formula (3). —O— (CH ₂ ) ₂ CH (CH ₃ ) — (CH ₂ ) ₃ CH (CH ₃ ) —O— (2) —CO—R—CO— (3) (where R is as defined above) Is)

The diol unit represented by the formula (2)
Derived from 3-methyl-1,7-octanediol, which can be prepared by reducing methyl-7-oxo-1-octanol. Where 3-methyl-
7-oxo-1-octanol is a known substance, for example, ozonolysis of rhodinol [Journal of Organic Chemistr.
y), Vol. 26, p. 3027, 1961] or oxidative ozonolysis of mono (3,7-dimethyloctyl) succinate [Journal of Chemical Soc.
690, 1979]].

The reduction of 3-methyl-7-oxo-1-octanol can be carried out, for example, by a method such as catalytic hydrogenation using a hydrogenation catalyst or reaction with a metal hydride complex compound. In the above, as the hydrogenation catalyst, those conventionally used as a catalyst in a catalytic hydrogenation reaction can be used. For example, nickel catalysts such as Raney nickel and nickel / diatomaceous earth; palladium / carbon and palladium black; Palladium catalyst and the like can be mentioned. The hydrogenation catalyst may be used alone or in combination of two or more. The amount of the hydrogenation catalyst to be used is generally 0.001% by weight to 20% by weight, preferably 0.05% by weight to 5% by weight, based on 3-methyl-7-oxo-1-octanol.

In the catalytic hydrogenation of 3-methyl-7-oxo-1-octanol, a solvent can be used as long as it does not inhibit the reaction. Examples of usable solvents include saturated aliphatic hydrocarbons such as hexane and octane; alcohols such as methanol and ethanol; esters such as ethyl acetate and methyl butyrate; and aromatic hydrocarbons such as toluene and xylene. Can be One type of solvent may be used, or two or more types may be mixed and used. When a solvent is used, the amount of the solvent is usually 0.01 to 50 times the weight of 3-methyl-7-oxo-1-octanol, preferably 0.1 to 50 times.
It is 1 to 10 times the weight.

In the catalytic hydrogenation of 3-methyl-7-oxo-1-octanol, the pressure of hydrogen is usually from normal pressure to normal pressure.
The pressure is set in the range of 100 atm, preferably 2 to 20 atm. The reaction temperature of the catalytic hydrogenation is usually 20 to 2
00 ° C, preferably 40 to 150 ° C.

After completion of the reaction, 3-methyl-1,7-octanediol is separated from the reaction mixture by a conventional method such as, for example, removing the hydrogenation catalyst by means such as filtration and then distilling the reaction mixture. be able to. 3-methyl-1,7-octanediol thus obtained is
If desired, the purity can be further increased by a known method such as distillation under reduced pressure or column chromatography.

In the above, examples of the metal hydride complex compound that can be used for the reduction of 3-methyl-7-oxo-1-octanol include, for example, lithium aluminum hydride and sodium borohydride. . The amount of the metal hydride complex used is 3-methyl-7-
Per mole of oxo-1-octanol, usually 1 to 1 in terms of hydrogen atoms available for reduction in the metal hydride complex compound.
The amount is 10 mol, preferably 1 to 3 mol.

In the reaction of 3-methyl-7-oxo-1-octanol with the metal hydride complex, a solvent can be used as long as it does not inhibit the reaction. Examples of usable solvents include saturated aliphatic hydrocarbons such as hexane and octane; ethers such as diethyl ether and tetrahydrofuran; and aromatic hydrocarbons such as toluene and xylene. One type of solvent may be used, or two or more types may be mixed and used. The amount of the solvent used is 3-methyl-7-oxo-1
It is usually 0.1 to 100 times the weight, preferably 1 to 20 times the weight of octanol.

The reaction between 3-methyl-7-oxo-1-octanol and a metal hydride complex is usually carried out at a temperature of -70 to 20.
It is carried out at 0 ° C, preferably at -10 to 150 ° C.

After completion of the reaction, 3-methyl-1,7-octanediol is added to the reaction mixture by adding an acid such as hydrochloric acid or acetic acid; an aqueous solution of ammonium chloride, and the like. After decomposing the complex compound, it can be isolated from the resulting mixture by a conventional method such as distillation, extraction with an organic solvent, and the like. At this time, examples of the organic solvent used for the extraction include esters such as ethyl acetate; halogenated hydrocarbons such as methylene chloride; and saturated hydrocarbons such as hexane.

The polyester provided by the present invention is:
It may contain other polyol units other than the diol unit represented by the formula (2). As such a unit of the other polyol, a unit of a low molecular weight diol is suitably used, for example, 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, 2,2-diethyl-1,3-propanediol,
Units of aliphatic diols such as -butyl-2-ethyl-1,3-propanediol; 1,4-cyclohexanediol, cyclohexanedimethanol, 3 (or 4), 8
(Or 9) -dihydroxytricyclo [5.2.1.
And a unit of an alicyclic diol such as [ ^2,6 ] decane. Among them, a unit of an aliphatic diol is preferable. These diol units may be used alone or in combination of two or more. In addition, the polyester of the present invention may include units of aromatic ring-containing diols such as 1,4-bis (β-hydroxyethoxy) benzene and bis (β-hydroxyethoxy) terephthalate as long as the gist of the invention is not impaired. It may be contained. Also, trimethylolpropane, trimethylolethane,
Glycerin, 1,2,6-hexanetriol, 1,
It may also contain units of a polyol having three or more functionalities such as 2,4-butanetriol. These equations (2)
The content of other polyol units other than the diol unit represented by is desirably less than 20 mol% based on the total amount of the polyol units constituting the polyester.

The dicarboxylic acid unit represented by the formula (3) includes units of an aliphatic dicarboxylic acid such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid; cyclohexanedicarboxylic acid And the like. Units of alicyclic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and units of aromatic dicarboxylic acids such as naphthalenedicarboxylic acid. These dicarboxylic acid units are derived from the corresponding dicarboxylic acid or its ester derivative.

These dicarboxylic acid units are appropriately selected and used according to the use of the obtained polyester.
For example, in order to obtain a polyester which gives a polyurethane having excellent flexibility (flexibility), hydrolysis resistance and low-temperature properties, use of an aliphatic dicarboxylic acid unit, in particular, adipic acid, azelaic acid or sebacic acid is preferred. preferable. These dicarboxylic acid units may be used alone or 2
A mixture of more than one species may be used. Further, a polycarboxylic acid unit having three or more functionalities may be contained.

The polyester of the present invention is 300 to 3000
It is necessary to have a number average molecular weight of 0. If the number average molecular weight is less than 300, the low-temperature properties and flexibility of the polyurethane or polyester polyamide obtained from the polyester become poor, while the number average molecular weight is 30,000.
If it is larger than this, mechanical properties such as strength and flexibility of polyurethane or polyester polyamide obtained from polyester will be poor. The number average molecular weight of the polyester is 700
It is preferably in the range of 20,000 to 20,000.

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

The number of hydroxyl groups or carboxyl groups present in the polyester varies depending on the intended use, but the number of hydroxyl groups or carboxyl groups is generally 2 or more per molecule, and more preferably 2 to 3 per molecule. If
Polyester can be used for most applications 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, 3-methyl-1,7-octanediol and dicarboxylic acid or an ester derivative thereof are charged at a predetermined ratio, and esterification or transesterification is performed.
The resulting reaction product is further subjected to a polycondensation reaction under high temperature and vacuum in the presence of a polycondensation catalyst to produce a polyester having a desired molecular weight. A wide range of polycondensation catalysts can be used for the production of polyester. Such polycondensation catalysts include, for example, titanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium; di-n-butyltin oxide, di-n-butyltin dilaurate And tin compounds such as dibutyltin diacetate; combinations of acetates such as magnesium, calcium and zinc with antimony oxide or the above titanium compounds. It is preferable to use these polycondensation catalysts in a range of 5 to 500 ppm based on the total polyester produced.

The polyester obtained according to the present invention has excellent hydrolysis resistance, does not have a tendency to crystallize, and when used as a raw material for producing paints, adhesives, polyurethanes, polyamide elastomers and polyester elastomers, Gives products with excellent hydrolysis resistance and the like. Further, the polyester obtained by the present invention is a novel high-performance material applicable to various other uses.

[0032]

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, measurement of the number average molecular weight of polyester and evaluation of hydrolysis resistance were performed by the following methods. ◎ Measurement of number average molecular weight It was calculated by calculation based on the hydroxyl value and acid value of the polyester. ◎ Evaluation of hydrolysis resistance 0.5 g of polyester was added to 10 ml of hot water at 100 ° C.
After standing for 4 days, the acid values of water and polyester were measured in accordance with JIS K1577, and the sum of both was used as an acid value as an index of hydrolysis resistance. The smaller the acid value, the better the hydrolysis resistance.

Reference Example 1 In an autoclave having an internal volume of 200 ml, 3-methyl-7 was added.
-Oxo-1-octanol 30.0 g (purity 90.2
%, 171 mmol) and 0.6 g of Raney nickel
(Water content: 50% by weight) was charged at room temperature under a nitrogen atmosphere, and then the atmosphere in the autoclave was replaced with hydrogen, and the pressure inside the autoclave was set to 7 atm (absolute pressure). The temperature in the autoclave was raised to 100 ° C., and the mixture was stirred at the same temperature for 25 hours while appropriately supplying hydrogen to the autoclave and maintaining the hydrogen pressure at 7 atm (absolute pressure). The obtained reaction mixture was analyzed by gas chromatography using an internal standard method using diethylene glycol monomethyl ether as an internal standard. As a result, the conversion of 3-methyl-7-oxo-1-octanol was 99.
It was found that the selectivity to 3-methyl-1,7-octanediol was 98.3%. After cooling the reaction mixture obtained above to room temperature, Raney nickel was removed by filtration, and the obtained filtrate was distilled under reduced pressure to give 3-methyl-1,7-octanediol (colorless liquid, boiling point 136 to 140). ° C / 2.5 mmHg)
5.8 g (161 mmol, yield: 94.2%) were obtained.
The physical properties of the obtained 3-methyl-1,7-octanediol are shown below. ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 0.90 (d, 3H), 1.19
(D, 3H) Low-resolution mass spectra (EIMS) m / z: 142 ([M-H 2 O] +)

Example 1 A reactor was charged with 438 g (3 mol) of adipic acid and 721 g (4.5 mol) of 3-methyl-1,7-octanediol prepared according to the method of Reference Example 1 and charged with nitrogen at normal pressure. The mixture was heated to 200 ° C. in an atmosphere, and an esterification reaction was performed while distilling off generated water out of the system. At the time when the amount of generated water was reduced, 15 mg of tetraisopropyl titanate was added, and 200 to 100 mm was added with a vacuum pump.
The reaction was continued while reducing the pressure to Hg, and the hydroxyl value was 56.1 KO.
A polyester having an Hmg / g, an acid value of 0.07 KOHmg / g and a number average molecular weight of 2,000 (hereinafter abbreviated as polyester A) was obtained. The hydrolysis resistance of polyester A was measured according to the method described above. Table 1 shows the results.

Examples 2 and 3 and Comparative Examples 1 and 2 The esterification reaction and the polycondensation reaction were carried out in the same manner as in Example 1 except that the diol components shown in Table 1 were used in the same mole number as in Example 1. Polyester (hereinafter, Example 2)
And the polyesters obtained in Comparative Examples 1 and 2 are referred to as polyesters D and E, respectively. Table 1 shows the physical properties of the polyesters B to E. Among the polyesters A to E, the polyesters A to C and E have 20
The liquid was a low-viscosity liquid at 20 ° C, and the polyester D was solid at 20 ° C. The hydrolysis resistance of polyesters BE was measured according to the method described above. Table 1 shows the results.

[0036]

[Table 1]

In Table 1, each component is indicated by the following abbreviations. MODO: 3-methyl-1,7-octanediol ND: 1,9-nonanediol MPD: 3-methyl-1,5-pentanediol AD: adipic acid From the results in Table 1, it is represented by the formula (1). Polyesters A to C containing repeating units and polyesters E containing no repeating units represented by the formula (1) and being liquid at 20 ° C.
It can be seen from the comparison with that that the polyester containing the repeating unit represented by the formula (1) has improved hydrolysis resistance.

Reference Example 2 100 g (0.05 mol) of each of the polyesters A to E obtained in Examples 1 to 3 and Comparative Examples 1 and 2, 9 g (0.10 mol) of 1,4-butanediol, 37.5 g (0.15 mol) of 4'-diphenylmethane diisocyanate and 340 g of dimethylformamide (DMF) were mixed and reacted at 80 ° C. for 8 hours to obtain polyurethane DM.
An F solution (nonvolatile content 30%) was obtained. The obtained polyurethane DMF solution was cast on a glass plate and dried to a thickness of 1 μm.
A 00 μm dry film was prepared. After leaving the obtained film in hot water at 100 ° C. for 14 days, the retention (%) of the intrinsic viscosity of the polyurethane constituting the film was calculated according to the following formula, and was used as an index of hydrolysis resistance. The intrinsic viscosity of the polyurethane is measured as a DMF solution, and corresponds to the molecular weight of the polyurethane. Retention of intrinsic viscosity (%) = (intrinsic viscosity after standing in hot water for 14 days) / (intrinsic viscosity before standing in hot water for 14 days) × 10
0 The results are also shown in Table 1 (the retention of the intrinsic viscosity is shown as the hydrolysis resistance of the polyurethane).

[0039]

According to the present invention, hydrolysis resistance is excellent,
A polyester that does not have a tendency to crystallize and has excellent handleability, and has excellent hydrolysis resistance when used for applications such as paints, adhesives, polyurethanes, polyamide elastomers and polyester elastomers. A new polyester is provided.

Claims (1)

[Claims] 1. The following formula (1): -O- (CH ₂ ) ₂ CH (CH ₃ )-(CH ₂ ) ₃ CH (CH ₃ ) -O-CO-R-CO- (1) , R represents at least one group selected from the group consisting of an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group and an arylene group) in an amount of 20 mol% or more, and has a number average molecular weight of 300 ~ 300
Polyester which is 00.