GB598914A - Methylpentadiene polymers and process for their production - Google Patents

Abstract

High molecular weight solid linear polymers are produced by copolymerising a mixture of two or more methyl pentadienes-1.3 directly or in solution in an inert organic liquid with a Friedel-Crafts catalyst below 0 DEG C., preferably below -50 DEG C. Mixtures of 2-methyl-, 3-methyl-and 4-methyl-pentadienes may be used, the preferred mixture being obtained by dehydration of 2-methyl-2.4-pentandiol. Copolymerisation may be carried out in the presence of inhibitors, e.g. tert. butyl catechol. Inert organic liquids suitable are ethane, propane, the butanes, the pentanes, ethylene, propylene, the butylenes, the pentylenes, butadiene, isoprene, and methyl, ethyl and propyl chlorides. The preferred catalysts are stannic and aluminium chlorides, and preferably they are used in solution in an inert solvent, e.g. methyl or ethyl chloride or 2.4-dimethylsulpholane. The copolymers may be non-elastic, rubbery or tacky and may be compounded with modifying substances and also vulcanised. Suitable plasticisers are dibutyl and dioctyl phthalates, tricresyl phosphate, triacetin, tetralin, soft coal tar, coal tar oils, cumar resins, soft factice, wool grease, stearic and lauric acids and waxes. Anti-oxidants, vulcanising agents and accelerators are listed. Specified fillers include carbon black, e.g. hard channel black, silica, alumina, iron oxide, barytes, titanium dioxide, zinc oxide and lithopone. The copolymers may be compounded with other synthetic and natural rubber-like materials and resins, cellulose derivatives and protein plastics. Adhesive compositions are obtained by compounding the copolymers with one or more solvents and/or plasticisers; suitable solvents are hexane, pentane, isooctane, gasoline, high-aromatic petroleum fractions, cyclohexane, methylcyclohexane, chloroform, ethylene dichloride, trichlorethane, trichloroethylene, monochlorbenzene and toluene, dichlorpentanes, o-dichlorobenzene, 1.2.3-trichlorobutane, benzene, toluene, benzyl alcohol, phenyl ethyl alcohol, dibenzyl ether, phenyl ethyl ether, dioxane, dioxolane, methyl dioxolane, methyl cellosolve acetate, methyl, ethyl, isopropyl and butyl acetates, ethyl oxalate, ethyl acetoacetate, benzyl benzoate, acetone, methy ethyl ketone, diisopropyl ketone and methyl isobutyl ketone. To increase viscosity the copolymers may be added to natural and synthetic lubricating oils, greases and waxes. Specification 569,071 is referred to.