JPH03269015A - Polyester copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer suitable as molded articles such as tubes, hoses, belts, packings, electric wires, sporting goods and parts of automobile, having excellent heat resistance and rubber elasticity, by reacting a liquid crystal polyester with a lactone. CONSTITUTION:A liquid crystal polyester (e.g. one obtained by reacting an aromatic dicarboxylic acid such as isophthalic acid with an aromatic dihydroxy compound such as resorcin) is reacted with a lactone (e.g. epsilon-caprolactone) to give the objective copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyester copolymer having rubber elasticity, and more particularly to a lactone-polyester block copolymer having excellent heat resistance.

(Prior art) As a method for producing a lactone-polyester block copolymer having rubber elasticity, there is a method in which a crystalline aromatic polyester and lactone are reacted in a uniform molten state (Japanese Patent Publication No. 48-4116). ) and (2) a method in which lactones are polymerized in the presence of a crystalline aromatic polyester while the polyester is in a solid phase (Japanese Patent Publication No. 52-49037).

In the above method (■), a transesterification reaction occurs between the polyester block and the polylactone block during the reaction between the crystalline aromatic polyester and the lactone, and as a result, the length of each block becomes shorter, resulting in a copolymer. The disadvantage is that the melting point of the copolymer decreases and the heat resistance of the copolymer decreases.

The above method (2) can overcome the disadvantage of lowering the melting point mentioned in (2), but has the disadvantage that the reaction takes a long time.

(Problems to be Solved by the Invention) The present invention has been made in order to eliminate each of the above-mentioned drawbacks, and its objectives are to provide excellent heat resistance and rubber elasticity, and a relatively short reaction time. The purpose of the present invention is to provide a polyester copolymer that can be obtained in a short time.

(Means for Solving the Problems) The polyester copolymer of the present invention is obtained by reacting (1) liquid crystal polyester and (b) lactones, and thereby can be used for the above purpose of the present invention. Liquid crystalline polyester can be obtained by copolymerizing an aromatic dicarboxylic acid and an aromatic dihydroxy compound, or by copolymerizing an aromatic hydroxyl carboxylic acid, or by copolymerizing an aromatic dicarboxylic acid, an aromatic dihydroxy compound, and an aromatic hydroxyl carboxylic acid. It can be obtained by copolymerizing.

Aromatic dihydroxy compounds used as constituent components of liquid crystalline polyester include resorcinol, 4-acetylresorcinol, hydroquinone, chlorohydroquinone,
Promohydroquinone, methylhydroquinone, phenylhydroquinone (2,S-dihydroxybiphenyl), methoxyhydroquinone, phenoxyhydroquinone, 4,4'-dihydroxybiphenyl, 3,3'-diphenyl-4,4°-dihydroxybiphenyl, 4.
4'-dihydroxydiphenyl ether, 4,4°-dihydroxydiphenyl sulfide, 4,4°-dihydroxydiphenyl sulfone, 3.3°-diphenyl-4
, 4′-dihydroxydiphenylsulfone, 4.4′-
Dihydroxybenzophenone, 4,4-dihydroxydiphenylmethane, bisphenol A, 1,1-di(
Examples include 4-hydroxyphenyl)cyclohexane, 1,2-bis(4-hydroxyphenoxy)ethane, 1,4-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene. Among these aromatic dihydroxy compounds, those capable of producing highly crystalline liquid crystalline polyesters include nohydroquinone, 4,4'-dihydroxybiphenyl, 4,4-dihydroxydiphenyl ether, and 4,4°-dihydroxydiphenyl sulfide. be.

Aromatic dicarboxylic acids include isophthalic acid, metal group of 5-sulfoisophthalic acid, terephthalic acid, 4.4'-dicarboxybiphenyl, 4.4'-dicarboxydiphenyl ether, 4.4'-dicarboxydiphenyl sulfide, 4.4°-dihydroxydiphenylsulfone, 3,3°-dicarboxybenzophenone, 4.4°-
Examples include dicarboxybenzophenone, 1,2-bis(4-carpoxyphenoxy)ethane, 1,4-dicarboxynaphthalene, and 2,6-dicarboxynaphthalene. Among these aromatic dicarboxylic acids, those from which highly crystalline liquid crystalline polyester can be obtained include terephthalic acid, 4,4'-dicarboxybiphenyl, 4
．． 4'-dicarboxydiphenyl ether, 4.4'-
Dicarboxydiphenyl sulfide, 4.4°-dicarboxybenzophenone, 1.2-bis(4-carboxyphenoxy)ethane, 2. There is todicarboxynaphthalene.

Examples of the aromatic hydroxycarboxylic acids include salicylic acid, metahydroxybenzoic acid, p-hydroxybenzoic acid,
3-chloro-4-hydroxybenzoic acid, 3-bromo-4
-Hydroxybenzoic acid, 3-methyl-4-human o4cyan 1B, Kaoru L 3-phenyl-4-hydroxybenzoic acid,
Examples include 3-methoxy-4-hydroxybenzoic acid, 4-hydroxy-4°-carboxybiphenyl, and 2-hydroxy-6-carboxynaphthalene. Among these aromatic hydroxycarboxylic acids, those from which highly crystalline liquid crystalline polyesters can be obtained include p-hydroxybenzoic acid and 4-hydroxy-4°-carboxydiphenyl.

In particular, liquid crystalline polyesters which are copolymers with p-hydroxybenzoic acid and whose main constituent units are repeating units whose general formula is represented by formula (1), and repeating units whose general formula is represented by formula (2) A copolymer having this unit as a main constituent unit is preferred.

Here, R1 is an aliphatic group or a divalent aromatic group containing at least one carbon six-membered ring, and examples thereof include the following.

-C1ltCH1-.

-0-@-(+- 1・(Concubine... (2) The above lactones have 4 or more carbon atoms in the ring. Preferred lactones have 5- to 8-membered rings. These are ring lactones, such as ε-caprolactone, δ-valerolactone, γ-butyrolactone, enantolactone, cabryrolactone, etc.These may be used alone or in combination with 2fi or more. good.

The composition ratio of the above liquid crystal polyester (a) and lactones (b) is determined from the viewpoint of elastic properties of the obtained polyester copolymer, liquid crystal polyester/lactones = 30/70 to 80.
/20 (weight ratio) is preferable, more preferably 30/
70 to 70/30 (weight ratio).

The above liquid crystal polyester and lactones may be reacted by heating and melting them in a solvent-free system, or by reacting them in a solvent system in which both can be dissolved.

When the reaction is carried out in a solvent-free system, the reaction can be carried out at an appropriate temperature. This temperature varies depending on the type of liquid crystal polyester used and the composition ratio with lactones, etc.
Generally, a temperature range of 180 to 300°C is preferred. If the reaction temperature is less than 180°C, it is difficult for the liquid crystal polyester to dissolve uniformly in the lactones, and if it exceeds 300°C, thermal decomposition or undesirable side reactions occur.

Preferably, a catalyst is used to accelerate the reaction.

As the catalyst, a catalyst generally used for polyester polymerization may be used. This catalyst includes lithium, sodium, potassium, cesium, magnesium, calcium,
Metals such as barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, manganese, their organometallic compounds, organic acid salts, alkoxides, metal oxides, etc. It will be done. Particularly preferred catalysts include:
diacyl stannous, tetraacyl stannous, dibutyltin dilaurate, tin dioctanoate, tin tetraacetate, triisobutylaluminum,
Examples include tetrabutyl titanium, tetrabutyl titanate, germanium dioxide, and antimony dioxide. Two or more of these catalysts may be used in combination.

Furthermore, in order to efficiently distill off water and the like produced as by-products during the polymerization and obtain a high molecular weight copolymer, it is preferable to reduce the pressure of the reaction system to 1 Hg or less in the late stage of the polymerization.

(Example) Hereinafter, the present invention will be explained in detail based on examples.

Tip JLfLL Internal volume I with stirring blade, gas inlet and distillation port
250 g of Rodlan LC-3000 (manufactured by Unitika) as a liquid crystal polymer was placed in a L glass flask.

250 g of ε-caprolactone, 0.4 g of tetrabutyl titanate as a catalyst and 1.3.5-trimethyl-2,4,6-tris(3,5-di-butyl-4-hydroxybenzyl)benzene as a heat stabilizer. 0 g was charged, and after purging the inside of the flask with nitrogen, it was heated to 270° C. in an oil bath while stirring. A homogeneous and viscous liquid was produced in the reaction system. After reacting for 2 hours under a nitrogen stream, the gas inlet was connected to a vacuum pump, and the reaction was further carried out for 1 hour under reduced pressure of 1 tOrr or less. The melting point of the obtained polymer was 197°C. The polymer also had good rubber elasticity.

In a flask similar to that used in Example 1, 350 g of Rodlan LC-3000 (manufactured by Unitika) as a liquid crystal polymer was added.
150 g of ε-caprolactone, 0.4 g of tetrabutyl titanate as a catalyst and 1.3.5- as a heat stabilizer.
After charging 1.0 g of trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene and purging the inside of the flask with nitrogen, the temperature was raised to 270°C in an oil bath while stirring. Heated. A homogeneous and viscous liquid was produced in the reaction system. After reacting for 2 hours under a nitrogen stream, connect the gas inlet to a vacuum pump and incubate at 1 torr.
The reaction was further carried out for 1 hour under reduced pressure below r. The melting point of the obtained polymer was 205°C. The polymer also had good rubber elasticity.

(Effects of the Invention) The composition of the polyester copolymer of the present invention is as described above, and since it can be reacted in a uniformly melted state, productivity is not reduced; It does not deteriorate and has excellent heat resistance. Such polyester copolymers can be used as thermoplastic ester elastomers with excellent heat resistance and rubber elasticity, and are used, for example, in the molding of tubes, hoses, belts, packing, electric wires, sporting goods, automobile parts, etc. It can be suitably used for products.

that's all

Claims (1)

[Claims] 1. A polyester copolymer obtained by reacting (a) a liquid crystal polyester and (b) a lactone.