JPH0393830A - Heat-resistant polyester - Google Patents

Abstract

PURPOSE:To obtain the subject polymer excellent in fluidity by copolymerization of plural structural units such as a fluorine-containing structural unit in a specified ratio. CONSTITUTION:(A) A fluorine-substituted hydroquinone constituting a structural unit of formula I (n is 1-4), (B) terephthalic acid, etc., constituting a structural unit of formula II (m is 1 or 2) and, as necessary, (C) methyl hydroquinone, isophthalic acid, etc., respectively constituting structural units of formulae III (X is formula IV, etc.) and V (Y is formula VI, etc.) are polymerized, e.g. by the melt polymerization method to obtain the objective polymer having 10-20000 poise melt viscosity and a composition in which (formula I)/(formula III) and (formula I + formula III) are (10/0)-(1/9) and equimolar to (formula II + formula V), respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heat-resistant polyester with excellent fluidity and capable of forming an anisotropic melt phase.

<Conventional technology> In recent years, the demand for higher performance plastics has been increasing, and many polymers with various new performances have been developed and put on the market. Optically anisotropic liquid crystal polymers have attracted attention because of their excellent mechanical properties.

As a polymer exhibiting an anisotropic melt phase, for example, a liquid crystal polymer obtained by copolymerizing p-hydroxybenzoic acid with polyethylene terephthalate (Japanese Patent Application Laid-open No. 72393/1983), p.
-Liquid crystalline polymer made by copolymerizing hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (Japanese Unexamined Patent Publication No. 77691/1982), p-hydroxybenzoic acid, 4.4-dihydroxybiphenyl, terephthalic acid, and isophthalic acid. Copolymerized liquid crystal polymers (JP-A-57-24407, JP-A-60-25046) are known. However, the elastic modulus of these liquid crystal polymers is not necessarily higher than that of metals (such as aluminum). It turns out that it can't be called big.

On the other hand, it is known that a liquid crystal polymer containing chlorohydroquinone and 4,4-diphenyldicarboxylic acid as its main components has a relatively high modulus of elasticity (Japanese Patent Laid-Open No. 1989-1927).
No. 25, JP-A-60-192724).

Problems to be Solved by the Invention However, this liquid crystal polymer containing chlorohydroquinone as the main component of the dihydroxy compound has the problem that the heat resistance of chlorine atoms at high temperatures is not necessarily sufficient and the polymer partially decomposes during polymerization. I understand.

Means for Solving the Problems In order to solve the above problems, the present inventors have made extensive studies and found that the following polyesters have good heat resistance at high temperatures, and have accomplished the present invention. Ta.

That is, the present invention consists of structural units selected from the following structural units (I) to (IV), and the structural units (I) and (n
) is an essential precept, and the structural unit (I
The molar ratio of >/(III) is 10/0 to 1/9, and the structural units [(I>+(III)] and [(II) +
(IV)] are substantially equimolar, and the melt viscosity is 1O
The present invention provides a heat-resistant polyester characterized by having a void of ~20,000 (measured at a liquid crystal initiation temperature of +40°C and a shear rate of 1,000 (1/sec)). However, the liquid crystal start temperature is the temperature at which the polymer begins to exhibit optical anisotropy when the polymer is heated on a hot stage while being sheared.

+O-X-O+- (I[I) (However, n in the formula is an integer of 1 to 4, m is l or/and 2. X represents 1, and Y represents 1 CH3 group.) In the heat-resistant polyester of the present invention, the above structural unit (
I> is a unit obtained by removing the hydrogen atom of the hydroxyl group from substituted fluorine hydroquinone, and the structural unit (n) is a unit obtained by removing the hydroxyl group of the carboxyl group from terephthalic acid and/or 4,4-diphenyldicarboxylic acid. be.

Structural unit (III) was derived from methylhydroquinone, chlorohydroquinone, phenylhydroquinone, t-butylhydroquinone, hydroquinone, 4.4″-dihydroxybiphenyl, 4.4-dihydroxydiphenyl ether and 2,6-dihydroxynaphthalene It is a unit obtained by removing the hydrogen atom of the hydroxyl group of a dihydroxy compound of one year or more.The structural unit (IV) is one
．． 2-bis(phenoxy)ethane-4.4-1-dicarboxylic acid, 1,2-bis(2-chlorophenyxy)ethane-
4.4 A unit obtained by removing the hydroxyl group of the carboxyl group from one or more dicarboxylic acids selected from 1-1 dicarboxylic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid. Also,'! In addition to r4 structural units (I) to (IV), p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid,
One or more aromatic hydroxycarboxylic acids selected from 3-chloro-4-hydroxybenzoic acid, 3-phenyl-4-hydroxybenzoic acid, and tetrafluoro-p-hydroxybenzoic acid may be copolymerized, and structural units other than the above structural units may be copolymerized. A small amount of dihydroxy compound, dicarboxy compound, hydroxycarboxylic acid, p-phenylenediamine, etc. may be copolymerized.

The molar ratio of these structural units (I>/(n) is 10/0
~1/9, preferably 95/5 ~ 5/5,
More preferably 95/5 to 7/3.

Further, the heat-resistant polyester having an anisotropic melt phase type used in the present invention can be produced according to the conventional polycondensation method of polyester, and there is no particular restriction, but typical production methods include the following (1) to (4) One example is the law.

(1) A method for producing a diacetylated aromatic dihydroxy compound such as fluorohydroquinone, an acetylated aromatic hydroxycarboxylic acid, and an aromatic dicarboxylic acid such as 4,4-diphenyldicarboxylic acid by deacetic acid polycondensation reaction.

(2) A method for producing an aromatic dihydroxy compound such as fluorohydroquinone, an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid such as 4.4-1-diphenyldicarboxylic acid, and acetic anhydride by deacetic acid polycondensation reaction.

(3) A method of producing by dephenolization polycondensation from an aromatic dihydroxy compound such as fluorohydroquinone, a diphenyl ester of an aromatic dicarboxylic acid such as 4.4-1-diphenyldicarboxylic acid, and a phenyl ester of an aromatic hydroxycarboxylic acid. .

(4) After reacting an aromatic dihydroxy compound such as fluorohydroquinone and an aromatic dicarboxylic acid such as 4.4-diphenyldicarboxylic acid with a desired amount of diphenyl carbonate to phenyl esterify the carboxyl group, the aromatic dihydroxy compound A method of manufacturing by adding and removing phenol polycondensation reaction.

Typical catalysts used in polycondensation reactions include metal compounds such as tin acetate, tetrabutyl titanate, lead acetate, antimony trioxide, magnesium, sodium acetate, potassium acetate, and trisodium phosphate. Effective during polycondensation.

Moreover, it is also possible to use melt polymerization and solid phase polymerization together for each of the above polycondensation methods.

That is, a polymer that has been polycondensed by melt polymerization can be made to have a higher degree of polymerization by solid phase polymerization. A wide variety of known methods can be used for solid phase polymerization.

The anisotropic melt phase formation start temperature of the heat-resistant polyester capable of forming an anisotropic melt phase used in the present invention is preferably 400°C or lower, and the melting point measured with a differential scanning calorimeter (DSC) is 200 to 450 when it can be detected. ℃ is preferable, 200~
400°C is more preferred.

The melt viscosity of the heat-resistant polyester having an anisotropic melt phase used in the present invention is 10 to 2 x 10' poise, preferably 102 to I x 10' poise. In addition,
This melt viscosity is determined at a shear rate of 1,
000 (1/sec) using a Koka type flow tester. However, the liquid crystal start temperature is increased when the temperature is increased while applying shear to the polymer on a hot stage.
This is the temperature at which the polymer begins to exhibit optical anisotropy.

The present invention will be explained below with reference to Examples.

Example ■ Fluorohydroquinone diacetate 5 in a test tube for polymerization
．． ,OOg (2.4X10-2 mol), 4.67g (1.9X10'') of 4.4-diphenyldicarboxylic acid
mole> and 2,6-naphthalene dicarboxylic acid 0.46
g (2.1xlO - 3 mol) was charged, and acetic acid depolymerization was carried out under the following conditions.

First, the reaction was carried out at 250 to 380°C for 2.9 hours in a nitrogen gas atmosphere, then the pressure was reduced to 0.8 mmHg at 380°C, and the mixture was further heated for 0.9 hours to perform a polycondensation reaction, resulting in a pale yellow color with no thermal deterioration. of polymer was obtained.

The liquid crystal initiation temperature of this volima was 304° C., and it exhibited optical anisotropy.

The theoretical structural formula of this polymer is as follows, and the elemental analysis results showed good agreement with the theoretical values.

m/n=9/1 This volima was subjected to a flow tester, and the spinning temperature was 400°C.
, spinning was performed with a spinneret hole diameter of 0.3 mmφ, and the spinneret diameter was 0.095 mmφ.
A spun yarn was obtained.

When this spun yarn was measured using a Rheovibron DDV-I[-EA manufactured by Toyo Baldwin Co., Ltd. at a frequency of 110 Hz, a temperature increase rate of 2°C/min, and a distance between chucks of 4.13 cm, the elastic modulus was 96.6 GPa. It had a high elastic modulus.

Examples 2-19 Fluorohydroquinone diacetate (I>, 2.3.
5.6-tetrafluorohydroquinone diacetate (
■>, Chlorhydroquinone diacetate (■>, Methylhydroquinone diacetate (IV), t-butylhydroquinone diacetate (V), Phenylhydroquinone diacetate (vI), Hydroquinone diacetate (VI), 4. 4-- Diacetoxybiphenyl (
■), 4.4″-diacetoxydiphenyl alcohol (I
A diacetoxy compound selected from Dicarbonate #(XII), 1,2-bis(
2-chlorophenoxy)ethane-4.4-1-dicarboxylic acid (XIII), terephthalic acid (XIV), isophthalic acid (XV), 2.6-1-naphthalenedicarboxylic acid (XVI)
), 4. 4--Dicarboxydiphenyl ether (
A dicarboxy compound selected from XVl[) and p-
Acetoxybenzoic acid (X), 2.6-acetoxynaphthoic acid (X IX'), 3-chloro-4-acetoxybenzoic acid (XX), 3-phenyl-4-acetoxybenzoic acid (XX engineering), 2.3 .5.6-tetrafluoro-
4 Acetoxybenzoic i! Acetoxycarboxylic acid consisting of I82 (XXII) was charged into a reaction vessel in the proportions shown in Table 1, and acetic acid depolymerization was carried out in the same manner as in Example 1.

Examples 2 to 19 of the present invention formed liquid crystals at 400° C. or lower, and produced strong polymers with good fluidity.

Comparative Example 1 When chlorohydroquinone diacetate was used instead of fluorohydroquinone diacetate and acetic acid depolymerization was performed under the same composition and conditions as in Example 1, it was found that the polymer became rubbery and gelled. Ta. And it was not possible to obtain spun yarn from this polymer.

Comparative Example 2 Chlorhydroquinone diacetate 12 in a test tube for polymerization
．． 6g (5.5X10"mol), 2.6-diacetoxynaphthalene 5.8g (2.4X10"mol)
, 17.3 g of 4.4-diphenyldicarboxylic acid (7
．． 1XIO-2 mol) was charged, and acetic acid depolymerization was performed under the following conditions.

First, the reaction was carried out at 250 to 370°C for 3.4 hours in a nitrogen atmosphere, and then the pressure was reduced to 0.8 Hg at 370°C, and the polycondensation reaction was carried out by heating for an additional 0.6 hours. It was found that it became rubbery and gelatinized. And it was not possible to obtain a spun yarn from this polymer.

Comparative Example 3 0.0% p-acetoxybenzoic acid was added to a polymerization test tube. '56g
(3.1XIO'mol), phenylhydroquinone diacetate 8.83g (3.3XIO-2mol),
Chlorhydroquinone diacetate 7.47g (3.
14.38 g (5.9×10 −2 mol) of 4.4-1-1 diphenyldicarboxylic acid were charged, and acetic acid depolymerization was carried out under the following conditions.

First, the reaction was carried out at 250 to 370°C for 3.3 hours in a nitrogen atmosphere, and then the pressure was reduced to 0.8 mmHg at 370°C, and the pressure was reduced to 0.1
Heat for an additional 380°C, 0.8mm} {g = 0.
When polycondensed by heating for 1 hour, the volima exhibited a heat-degraded black-green color and was impossible to spin.

Table 1 (continued) Effects of the Invention The heat-resistant polyester of the present invention is melt-formable and has excellent mechanical and thermal properties, and can be used for various purposes such as engineering plastics.

Claims (1)

[Claims] A polyester consisting of structural units selected from the following structural units (I) to (IV), containing structural units (I) and (II) as essential components, and comprising structural units (I)/( The molar ratio of III) is 10/0 to 1/9, and the structural unit [(I)+
(III)] and [(II) + (IV)] are substantially equimolar, and the melt viscosity is 10 to 20,000 poise (measured at liquid crystal start temperature +40°C and shear rate of 1000 (1/sec)). A heat-resistant polyester characterized by: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) (However, n in the formula is 1 to 4 m is an integer of 1 or/and 2.
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
Y indicates one or more groups selected from ▼There are tables, etc.▼ and ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ , ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
Indicates one or more groups selected from ▼ which includes tables, etc. and ▲ which includes mathematical formulas, chemical formulas, tables, etc. )