| abstract |
A liquid-crystalline polyester for film having small linear expansibility and high flexibility is provided. The polyester may have structural units —O—Ar1-CO—, —NH—Ar2-X—, —CO—Ar3-CO— and —CO—Ar4-Z-Ar5-CO— wherein Ar1 represents 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene, Ar2 represents 1,4-phenylene or 1,3-phenylene, X represents —O— or —NH—, Ar3 represents 1,4-phenylene, 1,3-phenylene or 2,6-naphthylene, Ar4 and Ar5 independently represent 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene, and Z represents —O—, —SO 2 — or —CO—, in which the amount of monomer (1) is 30-80% by mol, the amount of monomer (2) is 10-35% by mol, the total amount of monomers (3) and (4) is 10-35% by mol and the amount of monomer (4) is 1% by mol or larger. |