JP-7857161-B2 - Method for manufacturing liquid crystalline resin

Inventors

• 川原 俊紀
• 鈴木 惠亮

Assignees

• ポリプラスチックス株式会社

Dates

Publication Date

20260512

Application Date

20220523

Claims (5)

1. A method for manufacturing liquid crystalline resin, The process involves subjecting a starting material monomer, which includes one or more selected from the group consisting of aromatic hydroxycarboxylic acids and their polymerizable derivatives, to a melt polycondensation reaction in a reaction vessel. When a melt polycondensation reaction is performed, and the melting point of the liquid crystalline resin is Tm2, A method for producing a liquid crystalline resin, comprising: melting and polycondensing raw material monomers at a final polymerization temperature within the range of Tm2 to (Tm2 + 30)°C; and maintaining the temperature of the region of the reaction vessel, including the sides and top surface of the reaction vessel that are in contact with the space above the reaction liquid surface during the melting and polycondensing reaction, within the range of (Tm2 - 40 ) to (Tm2 - 5)°C.
2. The raw material monomers are One or more selected from the group consisting of aromatic or alicyclic dicarboxylic acids and their polymerizable derivatives, One or more selected from the group consisting of aromatic or alicyclic diols, aromatic or alicyclic hydroxyamines, aromatic or alicyclic diamines, and polymerizable derivatives thereof, A method for producing a liquid crystal resin according to claim 1, further comprising:
3. A method for producing a liquid crystalline resin according to claim 1 or 2, further comprising acylation of the raw material monomer with a fatty acid anhydride before the melt polycondensation reaction.
4. A method for producing a liquid crystalline resin according to claim 1 or 2, wherein the reaction vessel includes a stirrer, a reflux column, a raw material monomer supply port, a reduced pressure line, and an outlet line.
5. The melt polycondensation reaction includes carrying out the melt polycondensation reaction while removing fatty acids by distillation. A method for producing a liquid crystalline resin according to claim 1 or 2, wherein at least a portion of the distilled fatty acids is refluxed into a polymerization vessel.

Description

This invention relates to a method for producing liquid crystalline resin. Liquid crystal resins are widely used as high-performance engineering plastics because they possess a good balance of excellent mechanical strength, heat resistance, chemical resistance, and electrical properties, as well as excellent dimensional stability. A known method for manufacturing liquid crystal resins involves acylation of the raw material monomers as needed, followed by melt polycondensation. When manufactured by batch-type continuous polymerization, sublimated monomers adhering to the polymerization vessel undergo thermal history, resulting in foreign matter with a higher melting point than the normal polymer. This foreign matter may be mixed into the polymer when the polymer is discharged from the polymerization vessel after polymerization is complete. Patent Document 1 describes maintaining the temperature of the part of the reactor in contact with the reaction space at 150 to 300°C during the polycondensation reaction when producing aromatic polymers in a batch process. Patent Document 2 describes performing polycondensation while controlling the temperature of the reaction vessel liquid surface and the part located near the reaction liquid surface above it in the range of 70 to 200°C. International Publication No. 2003/062299Japanese Patent Application Publication No. 10-7781 This is an explanatory diagram showing an example of a polymerization apparatus that can be used in the method for producing liquid crystalline resin according to this embodiment. The following describes in detail one embodiment of the present invention. However, the scope of the present invention is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the invention. Furthermore, if multiple upper and lower limits are described for a particular parameter, any combination of these upper and lower limits can be used to obtain a suitable numerical range. If a specific description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments. [Method for manufacturing liquid crystal resin] The method for producing a liquid crystalline resin according to this embodiment includes subjecting a raw material monomer, which contains one or more selected from the group consisting of aromatic hydroxycarboxylic acids and polymerizable derivatives thereof, to a melt polycondensation reaction in a reaction vessel. In one embodiment, the method for producing the liquid crystalline resin may be a method for producing liquid crystalline polyester and/or liquid crystalline polyesteramide. In another embodiment, the method for producing the liquid crystalline resin may be a method for producing all aromatic polyester and/or all aromatic polyesteramide. In one embodiment, it is preferable that the obtained liquid crystalline resin contains one or more selected from the group consisting of all aromatic polyester and all aromatic polyesteramide. (Raw material monomer) The raw material monomer comprises one or more compounds selected from the group consisting of aromatic hydroxycarboxylic acids and their polymerizable derivatives. In this disclosure, "polymerizable derivative" means a compound in which part of the molecular structure has been changed and which can be polymerized by melt polymerization. Examples include acylated compounds obtained by acyling the phenolic hydroxyl group and/or amino group with an acyling agent, acid halides obtained by halogenating the carboxyl group with a halogenating agent, acid anhydrides, alkyl esters (with about 1 to 4 carbon atoms), etc. Aromatic hydroxycarboxylic acids and their polymerizable derivatives are not particularly limited and include, for example, 4-hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA), 3-hydroxybenzoic acid, 6-hydroxy-3-naphthoic acid, 6-hydroxy-4-naphthoic acid, 4-hydroxy-4'-carboxydiphenyl ether, 2,6-dichloro-p-hydroxybenzoic acid, 2-chloro-p-hydroxybenzoic acid, 2,6-dimethyl-p-hydroxybenzoic acid, 2,6-difluoro-p-hydroxybenzoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, vanillic acid, and the like. At least one compound selected from these can be used. Among these, at least one selected from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid is preferred due to its availability. The raw material monomer is preferably further satisfied with either (1) or (2) below. (1) A compound comprising at least one compound selected from the group consisting of aromatic or alicyclic dicarboxylic acids and their polymerizable derivatives, (2) comprising at least one compound selected from the group consisting of aromatic or alicyclic dicarboxylic acids and polymerizable derivatives thereof, and at least one compound selected from the group consisting of aromatic or alicyclic diols, aromatic or alicyclic hydroxyamines, aromatic or alicyclic diamines, and polymerizable derivatives the