Patent GB-1019466-A (GB)
Title: Curable halocarbon polymers and process for preparation of same
IPC: C08F214/24
Filed: 1963-12-13
Abstract: Copolymers of chlorotrifluoroethylene and acrylic acid or anhydride containing a high proportion of chlorotrifluoroethylene units are prepared by reacting the monomers in the presence of a free radical polymerization initiator while maintaining the amount of monomeric chlorotrifluoroethylene at 90 mol. per cent or more of the unreacted monomers. The polymerization may be affected batchwise, semi - continuously or continuously in the presence of solvents, e.g. acetone, and the reaction terminated (batch process) or further monomer added (semi-continuous process) after a monomer conversion of 1 to 10%.  The catalyst may be azobisisobutyronitrile, benzoyl peroxide or glutaric acid peroxide.  The polymers may contain 50 to 96 mol. per cent of chlorotrifluoroethylene units and may be cured by heating with polyepoxides, optionally in the presence of accelerators such as tertiary amines. Specified polyepoxides are diepoxybutane, diglycidyl ether, diglycidyl ether of ethylene glycol epoxidized polybutadienes, Bisphenol A/epichlorhydrin condensates, epoxyethyl 3,4-epoxycyclohexane, 3,4 - epoxy - 6 - methylcyclohexylmethyl - 3,4 - epoxy - 6 - methylcyclohexane carboxylate, bis (3,4 - epoxy - 6 - methylcyclohexylmethyl) adipate, resorcinol diglycidyl ether, epoxy novolaks, epoxidized linseed oil, epoxidized soya bean oil, and 2-ethylhexyl epoxy tallate.  The copolymers may be used as moulding compounds, and for coating and casting films from solvents such as tetrahydrofuran, dioxane and dimethyl formamide. Examples describe the preparation of chloro-trifluoroethylene-acrylic acid copolymers and the curing thereof with (1) and (3) 3,4:epoxy-6 -methylcyclohexylmethyl - 3,4 - epoxy - 6 - methylcyclohexane carboxylate; and (4) epoxidized polybutadiene, epoxidized linseed oil, resorcinol diglycidyl ether, an epoxy novolak an a Bisphenol A/epichlorhydrin condensate.ALSO:Substrates may be coated with compositions comprising organic solvents, a copolymer of chlorotrifluoroethylene and acrylic acid or anhydride, a polyepoxide and optionally a cure accelerator for the reaction between the copolymer and the polyepoxide. Specified substrates are glass slides, polytetrafluoroethylene coated steel panels and regenerated cellulose film.  Specified solvents are tetrahydrofuran, dioxane and dimethyl formamide. Specified polyepoxides are diepoxybutane, diglycidyl ether, diglycidyl ether of ethylene glycol, epoxidized polybutadienes, Bisphenol A/epichlorhydrin condensates, epoxyethyl-3,4-epoxycyclohexane, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane carboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, resorcinol diglycidyl ether, epoxy novolaks, epoxidized linseed oil, epoxidized soya bean oil and 2-ethylhexyl epoxytallate.  In examples, (1) steel panels, glass slides and regenerated cellulose film and (3) steel panels and glass slides are coated with compositions comprising chlorotrifluoroethylene/acrylic acid copolymers, 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexane carboxylate, tetrahydrofuran and toluene; and (4) glass slides are coated with compositions comprising chlorotrifluoroethylene copolymers, tetrahydrofuran and toluene together with epoxidized polybutadiene, epoxidized linseed oil, resorcinol diglycidyl ether, an epoxy novolak and a Bisphenol A/epichlorhydrin condensate.