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Liquid crystalline polyester and process for producing same

A technology of liquid crystal polyester and manufacturing method, which is applied in the direction of liquid crystal materials, chemical instruments and methods, etc., can solve the problems of polymer randomness reduction, dimensional stability and insufficient fluidity, etc., and achieve excellent heat resistance and fluidity Excellent performance and low anisotropy

Inactive Publication Date: 2015-04-29
TORAY IND INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in Patent Documents 3 to 6, solid-phase polymerization is performed to increase the molecular weight, and the randomness of the polymer decreases, resulting in insufficient dimensional stability and fluidity.

Method used

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  • Liquid crystalline polyester and process for producing same
  • Liquid crystalline polyester and process for producing same
  • Liquid crystalline polyester and process for producing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0120] Add 724.5 g (3.85 moles) of 2-hydroxy-6-naphthoic acid, 478.6 g (2.57 moles) of 4,4'-dihydroxybiphenyl, 2,6-naphthalenedi Formic acid 555.6g (2.57 mol), sodium acetate 0.32g (0.02% by weight) and acetic anhydride 1010.7g (relative to all the phenolic hydroxyl groups in the system are 1.10 equivalents), under nitrogen atmosphere, while stirring, react at 145°C for 2 After 1 hour, the temperature was raised to 365° C. over 4 hours (this temperature refers to the highest attained temperature during melt polymerization. The same applies to A-2 to A-24, B-1, C-1, 2, and C7 to 10 below). Then, it was kept at 365° C. for 1.5 hours, decompressed to 133 Pa over 1.0 hour, and the reaction was continued for 60 minutes, and the polycondensation was terminated when the torque reached 22 kg·cm. Then pressurize in the reaction vessel to 0.1MPa, through the die head ( ) The polymer is discharged in the form of strands and cut into pellets with a cutting machine.

[0121] The Tm (mel...

Embodiment 2

[0125] The same operation as above-mentioned A-1 was carried out except that the melt polymerization temperature was 370° C. and the polycondensation was terminated when the torque reached 20 kg·cm.

[0126] The Tm (melting point of the liquid crystal polyester) of the liquid crystal polyester (A-2) was 345°C.

[0127] Using a Gaohua rheometer (hole 0.5φ×10mm), the melt viscosity measured under the conditions of temperature 365° C. and shear rate 1000 / s is 20 Pa·s.

[0128] The number average molecular weight measured by GPC-LS (pentafluorophenol / chloroform=50 / 50 mixed solvent, 80 degreeC) was 12600.

Embodiment 3

[0130] The same operation as above A-1 was carried out except that the melt polymerization temperature was 375° C. and the polycondensation was terminated when the torque reached 18 kg·cm.

[0131] The Tm (melting point of the liquid crystal polyester) of the liquid crystal polyester (A-3) was 345°C.

[0132] Using a Gaohua rheometer (hole 0.5φ×10mm), the melt viscosity measured under the conditions of temperature 365° C. and shear rate 1000 / s is 20 Pa·s.

[0133] The number average molecular weight measured by GPC-LS (pentafluorophenol / chloroform=50 / 50 mixed solvent, 80 degreeC) was 12600.

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Abstract

Provided is a liquid crystalline polyester which has a specifically high fluidity ,a low anisotropy ,a high toughness, a low gas property, an excellent heat resistance and a high dielectric breakdown resistance. A liquid crystalline polyester comprising 38 to 74 mol% of structural unit(s) obtained from a hydroxycarboxylic acid, 31 to 13 mol% of a structural unit obtained from 4,4'-dihydroxybiphenyl and 31 to 13 mol% of a structural unit obtained from 2,6-naphthalenedicarboxylic acid (100 mol% in total), characterized in that the hydroxycarboxylic acid structural units comprise a structural unit obtained from 2-hydroxy-6-naphthoic acid in an amount of 89 mol% or more and the average sequence length of the structural unit obtained from 2-hydroxy-6-naphthoic acid is 0.1 to 1.

Description

technical field [0001] The present invention relates to a technology for controlling the average chain length of structural units obtained from aromatic hydroxycarboxylic acids of highly heat-resistant liquid crystal polyesters to an extremely short range of 0.1 to 1, and liquid crystal polyesters obtained by the technology and compositions thereof , Shaped products made from them. Background technique [0002] Liquid crystal polyesters are used in the electrical and electronic fields because of their excellent heat resistance, fluidity, dimensional stability, and flame retardancy. In recent years, the demand for liquid crystalline polyesters has increased, and in particular, the demand for highly heat-resistant liquid crystalline polyesters called Type I, which exhibits a heat distortion temperature of 300° C. or higher, has increased. For liquid crystal polyesters, liquid crystal polyesters having structural units obtained from p-hydroxybenzoic acid or 2-hydroxy-6-naphtho...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G63/60C08G63/78C08L67/04
CPCC08G63/605C08G63/78C08L67/00C08L2205/02C09K19/3809C08L2666/18C08G63/60C08J5/00C08L67/04C09K2323/00
Inventor 大里惠子立川浩司梅津秀之
Owner TORAY IND INC