US 12,077,705 B2
Liquid crystal polyester and film comprising the same
Shinji Ohtomo, Ibaraki (JP); Shohei Azami, Ibaraki (JP); Monami Tosa, Ibaraki (JP); and Nozomi Masui, Ibaraki (JP)
Assigned to SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed by SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed on Mar. 9, 2023, as Appl. No. 18/181,288.
Claims priority of application No. 2022-041382 (JP), filed on Mar. 16, 2022; and application No. 2022-122145 (JP), filed on Jul. 29, 2022.
Prior Publication US 2023/0295512 A1, Sep. 21, 2023
Int. Cl. C09K 19/38 (2006.01)
CPC C09K 19/3809 (2013.01) [C09K 2219/03 (2013.01); C09K 2219/13 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A liquid crystal polyester comprising a repeating unit derived from an aromatic hydroxycarboxylic acid,
wherein the content of the repeating unit derived from an aromatic hydroxycarboxylic acid is 80% or more based on 100% of a total number of all repeating units of the liquid crystal polyester,
the repeating unit derived from an aromatic hydroxycarboxylic acid comprises a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2),
a ratio between the number of the repeating unit (A2) and the number of the repeating unit (A1) [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger and
a molar ratio of phenolic hydroxyl groups to the total amount of the phenolic hydroxyl groups and acetyl groups [phenolic hydroxyl groups/(the phenolic hydroxyl groups+acetyl groups)] is 0.3 or lower, as calculated by 1H-NMR,
—O—Ar11—CO—  (A1)
—O—Ar12—CO—  (A2)
wherein Ar11 represents a phenylene group, and a hydrogen atom in the phenylene group in Ar11 is optionally substituted by a halogen atom, an alkyl group or an aryl group; and Ar12 represents a naphthylene group, and a hydrogen atom in the naphthylene group in Ar12 is optionally substituted by a halogen atom, an alkyl group or an aryl group.