Patent ID: 7112640

Claim:
A fluorocopolymer which comprises: repeating units (a) based on tetrafluoroethylene and/or chlorotrifluoroethylene; repeating units (b) based on a cyclic hydrocarbon monomer, having a dicarboxylic anhydride group and an endocyclic polymerizable unsaturated group, selected from the group consisting of the following formulae (1) to (8): wherein in the formulae (2) and (5) to (8), R is a C 1-6 lower alkyl group, a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, or a halogenated alkyl group having hydrogen atoms in the above lower alkyl group substituted by halogen atoms; and repeating units (c) based on other monomer (excluding tetrafluoroethylene, chlorotrifluoroethylene and the cyclic hydrocarbon monomer); wherein the repeating units (a) are from 50 to 99.89 mol %, the repeating units (b) are from 0.01 to 5 mol %, and the repeating units (c) are from 0.1 to 49.99 mol %, based on the total molar amount of the repeating units (a), (b) and (c); and which has a volume flow rate of from 0.1 to 1,000 mm 3 /sec.