Liquid crystal polyester and its preparation method

A technology of liquid crystal polyester and transesterification, applied in liquid crystal materials, chemical instruments and methods, etc., can solve the problems of no impact strength of liquid crystal polyester, prolonged transesterification time, etc., and achieve superior impact strength, superior heat resistance and tensile strength. The effect of tensile strength

Inactive Publication Date: 2002-03-20
SUMITOMO CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the problem of this method is that the transesterification time is extended, and coloring is caused by side reactions, and there is also a problem that the liquid crystal polyester having an aromatic skeleton obtained by this method does not have the required sufficient impact strength.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0090] Charge 1064 g (7.7 mol) p-hydroxybenzoic acid, 307 g (1.65 mol) 4,4'-dihydroxybiphenyl, 274.1 g (1.65 mol) terephthalic acid and 1235 g (12.1 mol) acetic anhydride. The reaction vessel was fully charged with nitrogen, then heated to 150° C. under nitrogen flow for 15 minutes, and the mixture was refluxed for 3 hours while maintaining the temperature.

[0091] Subsequently, 1.1 g of 1-methylimidazole was added, and then the mixture was heated to 320° C. for 2 hours and 50 minutes while distilling off by-product acetic acid and unreacted acetic anhydride. The recognition point of torque increase was considered to be complete, Remove the contents at this point. The resulting solid was cooled to room temperature and ground with a coarse grinder, then the mixture was heated from room temperature to 250°C over 1 hour and from 250°C to 335°C over 5 hours under nitrogen atmosphere and held at 335°C for 3 hours , to carry out the polymerization reaction in the solid layer. Th...

Embodiment 2～3， comparative Embodiment 1～3

[0093] The resin was obtained and its properties were measured in the same manner as in Example 1, except that the mixing ratio of the raw materials and the polymerization temperature in the solid layer were changed as shown in Table 1.

[0094] As for the obtained resin, the degree of crystallinity was measured with a polarizing microscope, and it was found to be a liquid crystalline polyester forming a melt phase having optical anisotropy similarly to Example 1.

Embodiment 4

[0096] Charge 911 g (6.6 mol) p-hydroxybenzoic acid, 409 g (2.2 mol) 4,4'-dihydroxybiphenyl, 274 g (1.65 mol) terephthalic acid, 91 g (0.55 mol) isophthalic acid and 1235 g (12.1 mol) acetic anhydride. The reaction vessel was fully charged with nitrogen, then heated to 150° C. under nitrogen flow for 15 minutes, and the mixture was refluxed for 3 hours while maintaining the temperature.

[0097] Subsequently, 1.1 g of 1-methylimidazole was added, and then the mixture was heated to 320° C. for 2 hours and 50 minutes while steaming the by-product acetic acid and unreacted acetic anhydride. remove the contents. The resulting solid was cooled to room temperature, ground with a coarse grinder, and the mixture was heated from room temperature to 250°C over 1 hour and from 250°C to 288°C over 5 hours under nitrogen atmosphere and kept at 288°C for 3 hours , to carry out the polymerization reaction in the solid layer.

[0098] Mixed glass (EFH-7501) manufactured by Central Glass wa...

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PUM

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Abstract

A method for producing a liquid crystalline polyester comprising the steps of acylating phenolic hydroxyl groups of an aromatic diol, an aromatic hydroxycarboxylic acid, or an aromatic diol and aromatichydroxycarboxylic acid with a fatty anhydride to obtain an acylated substance, and trans-esterifying said acylated substance with an aromatic dicarboxylic acid, an aromatic hydroxycarboxylic acid, or an aromatic dicarboxylic acid and aromatic hydroxycarboxylic acid, wherein the acylation, the trans-esterification, or the acylation and trans-esterification is conducted in the presence of a heterocyclic organic base compound containing two or more nitrogen atoms.

Description

field of invention [0001] The invention relates to a liquid crystal polyester and a preparation method thereof. Background of the invention [0002] Recently, liquid crystal polyesters having an aromatic ring skeleton are used as materials superior in heat resistance and tensile strength in the fields of electric and electronic fields. Liquid crystal polyesters can be prepared, for example, by adding acetic anhydride to aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and / or phenolic diols such as 4,4'-dihydroxybiphenyl On the hydroxyl group, the acylated substance is obtained by acylation of the phenolic hydroxyl group, and the acylated substance is transesterified with an aromatic dicarboxylic acid such as terephthalic acid, and other methods are used. [0003] However, in this method, the time required for acylation is long, causing a problem in yield, and there is also a problem that liquid crystal polyester having an aromatic skeleton obtained by this met...

Claims

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Application Information

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IPC IPC(8): C08G63/60
CPCC08G63/605C08G63/60
Inventor 冈本敏平川学
Owner SUMITOMO CHEM CO LTD
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