JPS6053050B2 - Method for manufacturing polyester elastomer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyester elastomers.

More specifically, the present invention aims to provide a method for producing a polyester elastomer with a high degree of polymerization in a short period of time. Conventionally, natural rubber, vinyl-based synthetic rubber, polyurethane, and the like have been widely used as elastomers, but aromatic polyester-based elastomers have recently attracted attention because of their excellent bending fatigue resistance and low-temperature properties. Polyester elastomers can be obtained by polycondensation using specific catalysts such as terephthalic acid, tetramethylene glycol, polyethylene glycol, dl 1 1 ゛, and ethane compounds. (Unexamined Japanese Patent Publication No. 4)
7-25295). However, polycondensation of polyester elastomers is more difficult than polycondensation of aromatic polyesters, which have no elasticity, and not only is the polycondensation rate slow, but simply extending the reaction time can actually reduce the degree of polymerization due to thermal decomposition. A decrease is observed, making it difficult to obtain a polyester elastomer with a high degree of polymerization. On the other hand, the mechanical properties of polyester elastomers, particularly the breaking strength and tear strength, are greatly affected by the degree of polymerization, and there is a demand for the production of polyester elastomers with a high degree of polymerization in order to improve these properties.

In response to such a demand, the present inventor conducted extensive research on a method for producing a highly polymerized polyester elastomer in a short period of time. By using it together with carboxylate,
The inventors discovered that a polyester elastomer with a high degree of polymerization can be produced in a short period of time, and arrived at the present invention. That is, the present invention provides (a) dicarboxylic acid and/or its ester-forming derivative, (b) tetramethylene glycol and/or its ester-forming derivative, and (c) an average molecular weight of 50
0-5000 polyoxyalkylene glycol and/or
or the production of a polyester elastomer characterized in that a lithium carboxylate and an organic titanate ester or a titanium carboxylate are used together as a polycondensation catalyst when producing a polyester elastomer by reacting an ester-forming derivative thereof. It's a method.

The aromatic dicarboxylic acids used as the component (a) include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid,
! 5-naphthalene dicarboxylic acid, diphenyl-4,4″
-dicarboxylic acid, 3,3″-dimethyldiphenyl-4,
Examples include 4''-dicarboxylic acid, 4,4-diphenylsulfonedicarboxylic acid, and 4,4''-diphenoxyethanedicarboxylic acid.

As with aromatic dicarboxylic acids, their ester-forming derivatives can also be used.

Such ester-forming derivatives include methyl ester,
Examples include lower alkyl esters such as ethyl ester, substituted aliphatic esters such as 2-hydroxyethyl ester, aryl esters such as phenyl ester, carbonic acid esters, and acid halides. These aromatic dicarboxylic acids and/or their ester-forming derivatives may be used alone or in combination of two or more. Further, the aromatic dicarboxylic acid or its ester-forming derivative may be used in combination with a small amount of other dicarboxylic acid or its ester-forming derivative.

The Zika. Examples of the rubonic acid include aliphatic and alicyclic dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and decahydronaphthalene-2,6-dicarboxylic acid. In the present invention, it is preferable that 60% or more of the aromatic dicarboxylic acid or its ester-forming derivative as component (a) is occupied by one type of aromatic dicarboxylic acid component.

Similar to tetramethylene glycol, its ester-forming derivative can also be used as the (oral) component.

Examples of such ester-forming derivatives include monoesters and diesters with monocarboxylic acids. These may be used alone or in combination of two or more. Also,(
A small amount of other low molecular weight glycols may be used in combination with the component.

The low molecular weight glycols include ethylene glycol,
Preferred examples include aliphatic glycols such as tetramethylene glycol and hexamethylene glycol, but 4
,4-bis-β-hydroxyethoxybisphenol A
Glycols having an aromatic group such as l4,4''-bis-β-hydroxyethoxydiphenylsulfone and the like and glycols having an alicyclic group such as cyclohexanedimethanol are also included. Used as a (mouth) component The molecular weight of the low molecular weight glycol is preferably 400 or less.The component (c) has an average molecular weight of 500 to 500.
5000 polyoxyalkylene glycol is used.

The average molecular weight of the polyoxyalkylene glycol is 50
If the average molecular weight is less than 0, the resulting polyester will have insufficient elasticity, and if the average molecular weight is more than 5,000, it will be difficult to copolymerize into the polyester and will tend to become a mere blend, which is not preferred. The polyoxyalkylene glycols include polyoxyethylene glycol, polyoxypropylene glycol, poly1,2-butylene ether glycol, polyoxytetramethylene glycol, polyoxypentamethylene glycol, polyoxyhexamethylene glycol, polyoxyheptamethylene glycol, Examples include polyoxyoctamethylene glycol and polyoxynonamethylene glycol. Among these, polyoxytetramethylene glycol is particularly preferred. The polyoxyalkylene glycol may not only be non-copolymerized but also random or block copolymerized. An ethylene oxide/propylene oxide copolymer is exemplified as a typical copolymer. The polyoxyalkylene glycols may be used alone or in combination of two or more.

Similar to the above-mentioned polyoxyalkylene glycol, its ester-forming derivative can also be used. Examples of such ester-forming derivatives include monoesters and diesters with monocarboxylic acids. The above component (c) is such that its polyoxyalkylene component is 10% in the polyester produced.
It is preferable to use it so that it accounts for 9 to 11%, particularly 20 to 7% of the heel weight.

The polyoxyalkylene component referred to herein refers to a polyoxyalkylene moiety composed only of repeating units of the polyoxyalkylene glycol or its ester-forming derivative. In the present invention, a preferred method for producing a polyester elastomer by reacting the three components is to react a lower alkyl ester of an aromatic dicarboxylic acid with a polyoxyalkylene glycol and an excess of tetramethylene glycol in the presence of a catalyst.
(1) Heating at a temperature of C and at the same time distilling off the methanol produced by the transesterification reaction, first forming a low polymer, and then heating and stirring this low polymer at a temperature of 220 to 2600 C under high vacuum. Then, polycondensation is carried out while distilling off excess tetramethylene glycol to obtain a polyester elastomer with a high degree of polymerization. The low polymer can also be obtained by an esterification reaction between an aromatic dicarboxylic acid and polyoxyalkylene glycol and tetramethylene glycol.

In addition, a method of producing a high polymerization degree polyester by reacting and polycondensing a low polymer of an aromatic dicarboxylic acid component and a tetramethylene glycol component obtained by transesterification or esterification reaction with polyoxyalkylene glycol is also used. It's good to wear.

In the present invention, a lithium compound and a titanium compound are used together as a catalyst for the polycondensation reaction.

As a result, a highly polymerized polyester elastomer exhibiting superior effects and excellent color tone can be obtained in a short time compared to when these compounds are used alone. The carboxylate of lithium is preferably one that is soluble in the reactant, and examples thereof include lithium acetate, lithium citrate, lithium oxalate, and lithium benzoate.

Among these, lithium acetate, lithium oxalate, and lithium benzoate are particularly preferred. Examples of organic titanate esters include tetraalkyl titanates (eg, tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, etc.), and examples of titanium carboxylates include potassium titanium oxalate and potassium titanium tartrate.

The amount of lithium carboxylate used is 0.001 based on the aromatic dicarboxylic acid component of the polyester elastomer.
-1 mol%, preferably 0.005-0.5 mol%, and the amount of organic titanate or titanium carboxylate used is 0.001-1 mol% based on the aromatic dicarboxylic acid component of the polyester elastomer. 1 mol%, preferably 0.005 to 0.5 mol%.

The ratio of lithium carboxylate to organic titanate ester or titanium carboxylate is preferably 0.1 to 10 times, more preferably 0.5 to 10 times, the ratio of metallic lithium to metallic titanium. Naturally, the lithium carboxylate, organic titanate ester, or titanium carboxylate can also be used as a catalyst for the transesterification reaction and esterification reaction.

In the present invention, various stabilizers (oxidation stabilizers, heat stabilizers, light stabilizers, etc.), pigments, glass fibers, other reinforcing agents, inorganic fillers (e.g. carbon black, alumina, silica gel, clay, etc.) are used. Additives can be used as needed. As the stabilizer, for example, 4,4″-bis(2,6-di-tert-butyl-4-hydroxyphenol)
Phenol derivatives such as N,N5-bis(β-naphthyl)P-phenylenediamine, etc.;
Examples include compounds such as substituted benzophenones and benzotriazoles. Hereinafter, the present invention will be explained in detail with reference to Examples.

The reduced viscosity ηSp/C shown in the examples is polymer 1200.
m91 to orthochlorophenol 1001rL1 10
The value was measured at 35°C after dissolving in 0C for 1 hour. Further, in the examples, 1 part represents a part by weight, and the oxidation point was measured using a penetrometer at a heating rate of 1° C./min. Example 1 33.5 parts of dimethyl terephthalate was placed in a reactor equipped with a rectification column.
Tetramethylene glycol feather J part average molecular weight 2000f
) 65 parts of polyoxytetramethylene glycol, 0.1 part of pentaerythritol, and as catalysts) 0.012 parts of lithium acetate and 0.0 part of titanium tetraptoxide.
18 parts of methanol were charged and heated to 170 to 220C to distill out 95% of the theoretical amount of methanol.

The obtained reaction product was transferred to a polymerization vessel equipped with a stirrer and heated to 40
℃, one powder is reacted at normal pressure, then three powders are reacted in a weak vacuum of about 20 mRHy, and further 0.1 to 0.3? Hf
The reduced viscosity of the polymer after 2 hours of reaction under high vacuum was 2.45. The reduced viscosity of the polymer after 3 hours was 2.87. Example 2 The same procedure as in Example 1 was carried out except that 0.12 parts of lithium benzoate was used instead of lithium acetate.

The reduced viscosity of the polymer after 2 hours of reaction under high vacuum is 2.
51, and the reduced viscosity of the polymer at 3 hours is 2.93.
It was hot. Comparative example 1
** Polycondensation was carried out in the same manner as in Example 1, except that only part 0 of titanium tetrabutoxide was used as a catalyst.

The reduced viscosity of the polymer after 2 hours of reaction under high vacuum is 1.
The reduced viscosity of the polymer at 3 hours to 4 was 1.70. Example 3 Example 1 except that 0.01 Bm of potassium titanium oxalate dihydrate was used instead of titanium tetrabutoxide.
The reduced viscosity of the polymer after 2 hours of reaction under high vacuum was 2.33, and the reduced viscosity of the polymer after 3 hours was 2.75.

Claims (1)

[Claims] 1 (a) aromatic dicarboxylic acid and/or its ester-forming derivative; (b) tetramethylene glycol and/or its ester-forming derivative; and (c) polyoxyalkylene glycol with an average molecular weight of 500 to 5,000 and/or its ester. A method for producing a polyester elastomer, which comprises using a lithium carboxylate salt and an organic titanate ester or a titanium carboxylate salt together as a polymerization catalyst when producing a polyester elastomer by reacting a forming derivative.