Liquid crystal polyester and its molded composition and use

A technology of molding composition and liquid crystal polyester, which is applied in the field of liquid crystal polyester and the molding composition composed of it, and can solve the problems affecting the application of liquid crystal polymer, mold filling dissatisfaction, resin fluidity, etc.

Inactive Publication Date: 2016-08-10
KINGFA SCI & TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its preparation usually adopts the high-temperature melt polymerization method, but due to the self-polymerization of monomers such as HBA and HNA or the branched cross-linking reaction of the molecular chain, the melt processability and physical properties of the final liquid crystal product are poor, especially the resin The fluidity of the liquid crystal polymer is seriously affected, which leads to the mold filling dissatisfaction during the molding process of the liquid crystal polyester molding composition, which seriously affects the application of liquid crystal polymers in thin-walled parts of electronic appliances.

Method used

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  • Liquid crystal polyester and its molded composition and use
  • Liquid crystal polyester and its molded composition and use
  • Liquid crystal polyester and its molded composition and use

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] Add the following monomer raw materials, acylating agent and catalyst to the polymerization reaction device equipped with agitator, reflux condenser, monomer feeding port, nitrogen inlet, thermometer and torque sensor.

[0064] (I) p-Hydroxybenzoic acid 1298.4 g (47 mol %) HBA

[0065] (Ⅱ) 6-hydroxy-2-naphthoic acid 112.9 g (3mol%) HNA

[0066] (Ⅲ) Terephthalic acid 731g (22mol%) TA

[0067] (IV) 99.7 g (3 mol%) IA of isophthalic acid

[0068] (Ⅴ) 4,4'-biphenol 931.1 g (25mol %) BP

[0069] Acylating agent: acetic anhydride 2041 g

[0070] Catalyst: Magnesium acetate 103 mg

[0071] After the feeding is completed, completely replace the atmosphere in the reaction vessel with nitrogen, raise the temperature of the reaction system to 140°C under the protection of nitrogen, and keep the nitrogen pressure at 0.2MPa, and maintain this temperature for 2 hours to carry out the acylation reaction; After the reaction is over, turn on the vacuum pump to reduce the pressure i...

Embodiment 2-5

[0072] Example 2-5 : According to the formula in Table 1, after the acylation reaction finishes, open the vacuum pump to decompress the pressure in the reactor to 10KPa-30KPa, and quickly discharge acetic acid and unreacted acetic anhydride molecules from the rectifying column to meet the technical requirements of rapid heating. When the amount of acetic acid received reaches more than 50% of the theoretical value, quickly raise the temperature to 210°C, maintain this reduced pressure condition and raise the temperature of the reaction system to the highest temperature of 370°C within 6 hours. During this period, acetic acid, especially phenol, etc. are continuously discharged to cause molecular chain weight. Arrangement and branched by-product small molecules, then decompressed to 60KPa in 30 minutes; All the other are the same as embodiment 1;

Embodiment 6-12

[0073] Example 6-12 : According to the formula in Table 1, after the acylation reaction finishes, open the vacuum pump to decompress the pressure in the reactor to 10KPa-30KPa, and quickly discharge acetic acid and unreacted acetic anhydride molecules from the rectifying column to meet the technical requirements of rapid heating. When the amount of acetic acid received reaches more than 50% of the theoretical value, quickly raise the temperature to 220°C, maintain this reduced pressure condition and raise the temperature of the reaction system to the highest temperature of 380°C within 6 hours, during which the continuous discharge of acetic acid, especially phenol, etc. Arrange and branched by-product small molecules, then decompress to 70KPa in 30 minutes; All the other are the same as embodiment 1; The fusing point of this liquid crystal polyester, melt viscosity, storage modulus release rate, rod-like fluid length are listed in table 1 middle.

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Abstract

The invention discloses a liquid crystal polyester and its molded composition and use. The liquid crystal polyester comprises repeated structural units [I]-[IV]. A differential scanning calorimetry (DSC) test proves that the liquid crystal polyester has a double enthalpy ratio delta H greater than or equal to 0.1 and less than or equal to 0.9 defined in the formula (1) of delta H=H(melting enthalpy)/H(crystalline enthalpy) and preferably, the double enthalpy ratio delta H is greater than or equal to 0.2 and less than or equal to 0.7. The liquid crystal polyester has a double enthalpy ratio delta H greater than or equal to 0.1 and less than or equal to 0.9. The liquid crystal polyester and the liquid crystal polyester molded composition have good fluidity and excellent melting characteristics. A small thin wall molded product has high stability and is especially suitable for a thin wall electronic product.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a liquid crystal polyester, a molding composition composed of it and its application. Background technique [0002] As a high-performance special engineering plastic, thermotropic liquid crystal polymer (TLCP) has excellent mechanical properties, good fluidity, heat resistance, chemical corrosion resistance, flame retardancy and electrical insulation properties. It is currently used in electronic appliances and small It is widely used in precision thin-walled parts and other fields. Its preparation usually adopts the high-temperature melt polymerization method, but due to the self-polymerization of monomers such as HBA and HNA or the branched cross-linking reaction of the molecular chain, the melt processability and physical properties of the final liquid crystal product are poor, especially the resin The fluidity of the liquid crystal polymer is seriously affected, resulting in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/60C08L67/00C08K7/14
Inventor 孙华伟李闻达肖中鹏宋彩飞罗德彬许柏荣易庆锋周广亮姜苏俊曹民曾祥斌蔡彤旻
Owner KINGFA SCI & TECH CO LTD
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