the invention relates to a novel fluorine - containing copolymer which comprises 25 - 75 mol % of chlorotrifluoroethylene , 10 - 70 mol % of a vinyl or isopropenyl ester of fatty acid and 3 - 40 mol % of allylglycidyl ether and may optionally comprise additional comonomer such as an acrylate . this copolymer possesses favorable properties characteristic of fluororesins , is soluble in various organic solvents and is curable with a compound having a functional group that reacts with epoxy group . a coating liquid using this copolymer gives a hard , stable and transparent coating film on either metal surface or glass surface .