Patent GB-683382-A (GB)
Title: Improvements in or relating to liquid synthetic copolymers
IPC: H01B3/44
Filed: 1948-01-12
Abstract: An unsaturated linear oily copolymer of olefines and diolefines of an average m.w. between 1200 and 4200, an iodine number between 20 and 70 and a solidifying point below -40 DEG  C. is made by polymerizing a mixture of olefines containing 0.5 to 10 per cent by weight of di-olefines at a temperature between 0 DEG  and 100 DEG  C. in the presence of an alkane diluent and a Friedel-Craft type catalyst.  The olefines may be ethylene, propylene, isobutylene, amylene and mixtures.  The diolefins which may be obtained as by-products in a petroleum cracking processes may be butadiene-1,3, butadiene - 1,2, beta - methyl butadiene - 1,3, alpha - methyl butadiene - 1,3, diisopropenyl, 1,1,3 - trimethylbutadiene - 1,3, pentadiene - 1,4, hexadiene - 1,5, 2,5 - dimethyl hexadiene - 1,5, 1,1,5 - trimethyl hexadiene - 1,5, octadiene - 1,4, and mixtures.  Specified alkanes are n-butane, iso-butane, propane, pentane, hexane, octane and mixtures. Catalysts mentioned are aluminium chloride, boron trifluoride, alumina-silica compounds and boron trifluoride in the presence of alumina.  The copolymers alone or admixed with a refined mineral oil are used as electrical insulating oils, e.g. in capacitors.ALSO:An unsaturated linear oily copolymer of olefines and diolefines of an average M.W. between 1200 and 4200, an iodine number between 20 and 70 and a solidifying point below -40 DEG  C. is made by polymerizing a mixture of olefines containing 0.5 to 10 per cent by weight of diolefines at a temperature between 0 DEG  and 100 DEG C. in the presence of an alkane diluent and a Friedel-Craft type of catalyst.  The olefines may be ethylene propylene, isobutylene, amylene, and mixtures.  The diolefines which may be obtained as by products in a petroleum cracking process, may be butadiene-1,3, butadiene-1,2, beta-methyl butadiene-1,3, alpha methyl butadiene-1,3, diisopropenyl, 1,1,3-trimethylbutadiene-1,3, pentadiene-1,4, hexadiene-1,5, octadiene-1,4, and mixtures. Specified alkanes are n-butane, iso-butane, propane, pentane, hexane, octane and mixtures. Catalysts mentioned are aluminium chloride, boron trifluoride, alumina-silica compounds and boron trifluoride in the presence of alumina.  The copolymers alone or admixed with a refined mineral oil are used as electrical insulating oils, e.g. in capacitors.ALSO:A lubricating oil suitable for electrical insulation purposes e.g. capacitors consists of, or comprises an unsaturated linear oily copolymer of an olefine and 0.5 to 10 per cent by weight of a diolefine (see Group IV (a)) of average M.W. between 1,200 and 4,200, an iodine number between 20 and 70, and a solidifying point below -40 DEG C.  The copolymer may be admixed with a refined mineral oil.  The olefine may be ethylene, propylene, isobutylene, amylene and mixtures.  Specified diolefines, which may be obtained as a byeproduct in a petroleum cracking process, are butadiene 1-3, butadiene-1-2, betamethyl butadiene-1-3, alpha methyl butadiene-1, 3, diisopropenyl, 1, 1, 3-trimethylbutadiene-1, 3, pentadiene-1, 4, hexadiene-1, 5, octadiene-1, 4, and mixtures.