JPH082948B2 - polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel polyester.

More specifically, the present invention relates to a polyester having excellent characteristics, which is suitable for use in the fields of polyurethane, paints / adhesives, polyamide elastomers, polyester elastomers and the like.

[Conventional technology]

Polyethylene alcohol, diethylene glycol, propylene glycol, neopentyl glycol, 1, used as raw materials for polyhydric alcohols used in the production of polyester polyols whose molecular ends are hydroxyl groups, which have been conventionally used in the fields of polyurethane, coatings, adhesives, etc. 4-Butanediol, 1,6-hexanediol, trimethylolpropane, glycerin and the like have been commonly used. A polyester polyol having a hydroxyl group as a functional group has been industrially produced by mixing one or more of these polyhydric alcohols with a polybasic acid or an anhydride thereof or an ester thereof to carry out an esterification reaction or a transesterification reaction. . Among these polyester polyols, polybasic acids are used in combination with aromatic dicarboxylic acids such as phthalic anhydride, isophthalic acid, and terephthalic acid, and aliphatic dicarboxylic acids such as adipic acid, and esterified with polyhydric alcohols having a valence of 3 or more. The polyester polyol obtained by the reaction is widely used in the fields of paints and adhesives.

Further, a polyester polyol synthesized from adipic acid or the like and a dihydric or trihydric polyhydric alcohol is used in an extremely wide range of applications such as elastomers, adhesives, foams and coatings in the polyurethane field by reacting with diisocyanate. There is.

Further, a polyester having a carboxyl group at its molecular end is also used for applications such as a polyamide elastomer having excellent heat resistance by reacting with a diisocyanate.

[Problems to be solved by the invention]

However, the hydrolysis resistance of conventional polyurethanes, paints, adhesives, polyamide elastomers, etc. obtained from polyester polyols or polyesters whose molecular ends are carboxyl groups is poor. As a result, the surfaces of products from these become tacky or cracked in a relatively short period of time. In order to improve the hydrolysis resistance, it is effective to reduce the ester group concentration of the polyester. Therefore, the use of polyesters derived from high carbon number glycols and dicarboxylic acids gives favorable results. However, although polyurethanes, paints, adhesives, polyamide elastomers, etc. obtained using such polyesters have improved hydrolysis resistance, they have a large tendency to crystallize, and such polyurethanes are
If left in a low temperature atmosphere such as 20 ° C, the cold resistance and low temperature characteristics represented by bending resistance, flexibility, low temperature adhesiveness, etc. are significantly deteriorated. Therefore, there is a big problem in applying such polyester to polyurethane.

It has been conventionally known to use glycols having an alkyl side chain such as neopentyl glycol, propylene glycol, 2-methyl-1,3 propanediol and 1,3-butylene glycol in order to suppress crystallization of polyester. However, when it is used in applications such as polyurethane in the form of a copolyester made of a mixture of these glycols and glycols having no side chains having a large number of carbon atoms, hydrolysis resistance, flexibility and low temperature properties are deteriorated. It was impossible to impart the non-crystallinity without using it.

The object of the present invention is to provide a novel polyester capable of imparting excellent hydrolysis resistance, cold resistance and low temperature characteristics to elastomers, paints, adhesives, binders, foams, leather, elastic fibers and the like when used for these purposes. To do.

[Means for solving problems]

In order to achieve the above object, the inventors of the present invention have made extensive studies, and as a diol component, 2-methyl-1,8-octanediol or a mixture thereof with 1,9-nonanediol is mainly used. When the obtained polyester was applied to the above-mentioned applications, it was found that amorphous property is effectively imparted, low-temperature characteristics and flexibility are excellent, and hydrolysis resistance is highly secured, and the present invention is completed. It came to do.

That is, the present invention essentially comprises the following repeating unit (I)
And (II) and the unit (I) / (II) molar ratio is 5 /
A polyester characterized by having a molecular weight of 95 to 100/0 and a molecular weight of 300 to 30,000.

[In the formula, R ₁ and R ₂ are the same or different and each have 2 to 2 carbon atoms.
20 alkyl groups, cycloalkyl groups, aryl groups, or (X represents O, S, SO ₂ , alkylidene having 2 to 8 carbon atoms, alkylene having 1 to 2 carbon atoms) and at least one group selected from the group consisting of the following. In the polyester of the present invention, the repeating unit (I) / (II) has a molar ratio of 5/95 to 100/0, preferably 10 /
It is important to be in the range of 90 to 100/0, and more preferably 10/90 to 90/10.

When the molar ratio of the repeating unit (I) / (II) is less than 5/95, the crystallinity of the polyester is too large, and when it is suitable for applications such as polyurethane, cold resistance, low temperature characteristics and flexibility are extremely poor. Become.

The polyester of the present invention includes 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3- Methyl-1,5-pentanediol, 1,10-
A small amount of a bifunctional or higher functional diol such as decanediol, trimethylolpropane, or glycerin may be contained, but these other diols are preferably used in an amount of less than 50 mol% in the diol component.

The dicarboxylic acid component used for producing the polyester of the present invention is preferably an aliphatic, alicyclic or aromatic dicarboxylic acid having 4 to 12 carbon atoms. Of these, aliphatic dicarboxylic acids are preferred.

Examples of the aliphatic dicarboxylic acid include glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, etc., and the cycloaliphatic dicarboxylic acid includes cyclohexanedicarboxylic acid, and examples of the aromatic dicarboxylic acid. Examples thereof include phthalic acid, terephthalic acid, isophthalic acid and the like.

Among the aliphatic dicarboxylic acids, use of adipic acid, azelaic acid, or sebacic acid is preferable in order to obtain polyurethane and the like having particularly excellent hydrolysis resistance, low-temperature characteristics, cold resistance, and flexibility. These dicarboxylic acids may be used alone or in combination of two or more.

There is no particular limitation on the method for producing the polyester of the present invention, and known polyester condensation means can be applied. That is, diol and dicarboxylic acid are charged at a desired ratio for esterification or transesterification, and the reaction product thus obtained is further subjected to polycondensation reaction at high temperature and high vacuum in the presence of a polycondensation catalyst. Polyesters of desired molecular weight can be produced. It is desirable that the molecular weight is in the range of 300 to 30,000, preferably 600 to 20,000, but it must be set to an appropriate molecular weight depending on the application.

If the molecular weight is less than 300, cold resistance, low temperature characteristics and flexibility will be poor, and if it exceeds 30,000, mechanical performance will be poor.
The polyester of the present invention needs to have a hydroxyl group at the molecular end when used for applications such as polyurethane, and needs to have a carboxyl group at the molecular end when applied to applications such as polyamide elastomers. It goes without saying that whether the terminal is a hydroxyl group or the terminal is a carboxyl terminal can be changed depending on the charged molar ratio of the diol and the dicarboxylic acid.

Furthermore, the number of hydroxyl groups or carboxyl groups present in the polyester varies depending on the application, and cannot be generally stated, but
It is in the range of 2 or more, especially 2 to 3, per molecule that can be used for most applications.

As the polycondensation catalyst used in the production of polyester, a wide range of catalysts can be used, but titanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, dititanium compounds, etc. Tin compounds such as -n-butyltin oxide, di-n-butyltin dilaurate and dibutyltin diacetate, magnesium,
Examples thereof include combinations of acetates such as calcium and zinc with antimony oxide or the above titanium compounds. These catalysts are 5ppm based on the total polyester produced.
It is preferably used in the range of up to 500 ppm.

The polyester thus obtained is excellent in hydrolysis resistance, low temperature characteristics, cold resistance, flexibility and mechanical properties when used in the fields of polyurethane, paints / adhesives and polyamide elastomers, polyester elastomers, etc. It is a new high-performance material that can provide performance and can be expected to be applied to various other uses.

Hereinafter, the present invention will be described in more detail with reference to Examples.

In the Reference Examples, the hydrolysis resistance of polyurethane and polyamide elastomer was evaluated by subjecting a polyurethane and polyamide elastomer film having a thickness of 60μ to a hydrolysis acceleration test in hot water at 100 ° C for 1 week.
The retention rate of the logarithmic viscosity measured by re-dissolving in F (dimethylformamide) was also evaluated. For low-temperature flexibility, a test piece was made from 0.2 mm thick polyurethane and polyamide elastomer film, and a direct-reading dynamic viscoelasticity measuring instrument Vibron Model DDV-II (110H manufactured by Toyo Sokki Co., Ltd.
It was evaluated by measuring T _α according to Z), further applying a solution of polyurethane and polyamide elastomer on the artificial leather substrate and drying, and measuring flex resistance at −20 ° C. The bending resistance was measured using a bending tester with a stroke width (3 cm at the longest, 1 cm at the shortest) and a bending frequency of 8600 times / hour. When there is no change after 100,000 times, it is indicated by O, when it is slightly scratched, it is indicated by Δ, and when it is scratched so that the substrate can be seen, it is indicated by X. Those having a low T _α and good low-temperature flexibility can achieve both low-temperature flexibility and non-crystallization.

 The average molecular weight was determined from the acid value or hydroxyl value.

The compounds used are indicated by abbreviations, and the relationship between abbreviations and compounds is as follows.

[Example] Example 1 One reactor was purged with nitrogen, and then 146 g of adipic acid, 100 g of 2-methyl-1,8-octanediol, and 1,9-nonanediol.
100 g was charged, and the produced water was distilled while the temperature was raised from 150 ° C. to 210 ° C. over 1 hour. After distilling about 35g of water,
Add 60 mg of tetraisopropyl titanate, 150 mmHg-1
While reducing the pressure to 00 mmHg, the water that was still generated was distilled off. About 1g of water was distilled out, and the acid value dropped to 0.3KOHmg / g, then 0.5m
The pressure was reduced to mHg, and 16.5 g of excess glycol was distilled off. As a result, a polyester having hydroxyl groups of 56 KOHmg / g, an acid value of 0.20 KOHmg / g and a number average molecular weight of about 2,000 was obtained.
This polyester had a paste form at room temperature and a viscosity at 75 ° C. of about 600 centipoise.

Also, ¹ H nuclear magnetic resonance spectrum was measured in a heavy chloroform solvent, and 2-methyl-polyester in the polyester was compared with hexamethyldisiloxane (HMS) as a reference compound.
Hydrogen of methyl group of 1,8-octanediol is 0.9ppm, 2
-Methyl-1,8-octadiol and 1,9-nonanediol the hydrogen of the methylene group adjacent to the oxygen atom is 4.1 ppm,
2.2 ppm of hydrogen in methylene adjacent to C = O of adipic acid
A resonance peak is shown in FIG.
When the molar ratio of 1,8-octanediol residue, 1,9-nonanediol residue and adipic acid residue was calculated, it was 0.58 / 0.57 / 1.
The value was 00, which was close to the calculated value of 0.575 / 0.575 / 1.00 from the composition of feed. This copolyester is referred to as Sample A.

Examples 2 to 6 and Comparative Examples 1 to 6 Polyester B having hydroxyl groups at both ends having the compositions shown in Table 1
F and G to K were synthesized in the same manner as in Example 1. Table 1 shows the structure and properties.

Reference Examples 1 to 11 Polyurethanes were produced using the polyester polyols (AK) obtained in Examples 1 to 6 and Comparative Examples 1 to 5, and various performances were compared.

That is, 0.1 mol (200 g) of polyester polyol,
0.4 mol (36 g) of 1,4-butanediol and 0.5 mol (125 g) of 4,4'-diphenylmethane diisocyanate were reacted in DMF at 75 ° C under a nitrogen stream, and a 30% solution of 1,500 poises of polyurethane solution Got Various performances of the polyurethane thus obtained were examined. Table 2 shows the results.

As is clear from Table 2, the polyurethane using the polyester of the present invention was excellent in all properties such as hydrolysis resistance, low temperature characteristics, cold resistance and flexibility.

Example 7 1 After replacing the reactor with nitrogen, adipic acid 167 g, 2-methyl-1,8-octanediol 80 g, 1,9-nonanediol 8
Esterification was carried out by charging 0 g and heating the temperature from 150 ° C to 210 ° C over 3 hours while distilling off the produced water. Then, the pressure in the system was gradually reduced to catch up the reaction, and the reaction was terminated when the terminal hydroxyl groups were almost eliminated. as a result,
A polyester having a hydroxyl value of 0.1 KOHmg / g, an acid value of 57 KOHmg / g and an average molecular weight of about 2,000 was obtained.

Also, ¹ H nuclear magnetic resonance spectrum was measured in a heavy chloroform solvent, and 2-methyl-polyester in the polyester was compared with hexamethyldisiloxane (HMS) as a reference compound.
Hydrogen of methyl group of 1,8-octanediol is 0.8ppm, 2
-Methyl-1,8-octanediol and 1,9-nonanediol have 3.9 pp of hydrogen in the methylene group adjacent to the oxygen atom.
m, hydrogen of methylene adjacent to C = O of adipic acid is 2.2
Resonance peaks are shown at ppm, and the moles of 2-methyl-1,8-octanediol residue, 1,9-nonanediol residue and adipic acid residue are calculated from these integrated values to be 0.5 / 0.5 / 1.15.
The value was exactly the same as the calculated value of 0.5 / 0.5 / 1.15 from the composition. This polyester having carboxyl groups at both ends is designated as sample L.

Examples 8 to 9 and Comparative Examples 6 to 8 Polyesters M to Q having carboxyl groups at both ends having the compositions shown in Table 3 were synthesized in the same manner as in Example 7. Table 3 shows the structure and properties.

Reference Examples 12 to 17 Polyamide elastomers were produced using the polyesters (L to Q) having terminal carboxyl groups obtained in Examples 7 to 9 and Comparative Examples 6 to 8, and various performances were compared.

That is, 0.1 mol (200 g) of polyester with carboxyl groups at both ends, 0.3 mol (56.4 g) of azelaic acid and 4,
0.4 mol of 4'-diphenylmethane diisocyanate (100
g) was added to tetramethylene sulfone under a nitrogen stream and 1,3-dimethylphosphorene-1-oxide was added as a catalyst, and the mixture was reacted at 180 ° C. for 6 hours to give a polyamide elastomer solution of 1,000 poise as a 30% solution. . Various performances of the polyamide elastomer thus obtained were investigated. The results are shown in Table 4.

As is clear from Table 4, the polyamide elastomer using the copolyester of the present invention has hydrolysis resistance,
It was excellent in all properties such as low temperature characteristics, cold resistance, and flexibility.

[Effects of the Invention] The polyester of the present invention is extremely excellent in hydrolysis resistance, low temperature characteristics, cold resistance, when applied to elastomers such as polyurethane and adhesives as is clear from the examples.
It is a new material that can give flex resistance.

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Claims (3)

[Claims] 1. It consists essentially of the following repeating units (I) and (II) and has a molar ratio of units (I) / (II) of 5/95 to.
Polyester characterized by 100/0 and molecular weight of 300-30,000. [In the formula, R ₁ and R ₂ are the same or different and each have 2 to 20 carbon atoms.
Alkyl group, cycloalkyl group, aryl group, or (X represents at least one group selected from the group consisting of O, S, SO ₂ , alkylidene having 2 to 8 carbon atoms, and alkylene having 1 to 2 carbon atoms). 2. The polyester according to claim 1, wherein the molecular terminal is a hydroxyl group. 3. The polyester according to claim 1, wherein the molecular terminal is a carboxyl group.