Liquid-crystalline polyester solution composition

A method for producing a liquid-crystalline polyester solution composition comprising an aprotic solvent and a liquid-crystalline polyester comprising:

• at least one of the repeating units selected from the group consisting of a repeating unit derived from aromatic diamine, a repeating unit derived from aromatic amine having a hydroxyl group, and a repeating unit derived from aromatic amino acid, wherein the at least one of the repeating units is from 10 to 35 mol % in the liquid-crystalline polyester, and
• at least one of the repeating units represented by formulae (1), (2) and (3):
• —O—Ar1—CO— (1)
• —CO—Ar2—CO— (2)
• —X—Ar3—Y (3)
• wherein Ar1 represents 1,4-phenylene, 2,6-naphthalene or 4,4′-biphenylene, Ar2 represents 1,4-phenylene 1,3-phenylene or 2,6-naphthalene, Ar3 represents 1,4-phenylene of 1,3-phenylene, X represents —NH—, and Y represents —O— or —NH—,
• wherein the content of the repeating units represented by formulae (1), (2) and (3) is 30 to 80 mol %, 35 to 10 mol % and 35 to 10 mol %, respectively, in the liquid crystalline polyester
• and the method comprising the steps of:
• acylating at least one repeating unit selected from the group consisting of a hydroxycarboxylic acid providing the repeating unit represented by formula (1), an aromatic diamine, an aromatic amine having a hydroxyl group, an aromatic acid, and a repeating unit represented by formula (3) with an excess amount of a fatty acid anhydride to obtain an acylated compound,
• transesterification of the acylated compound and an aromatic dicarboxylic acid providing the repeating unit represented by formula (2) to obtain a liquid-crystalline polyester;
• dissolving the polyester in an aprotic solvent to obtain a liquid-crystalline polyester solution composition thereof.