| 摘要 |
A mixture of an iso-mono-olefine and a diolefine having a conjugated system of alternate single and double bonds is polymerized at a temperature between - 50 DEG C. and - 150 DEG C. in the presence of a Friedel-Crafts catalyst, and the crude polymer is subjected to a severe milling treatment, e.g. in a Banbury mixer, at a temperature between 100 DEG and 200 DEG C. for 20 to 90 minutes. Mixtures specified are isobutylene or b - or g -amylene with butadiene, isoprene, chloroprene or cyclopentadiene. A suitable catalyst is aluminium chloride dissolved in methyl or ethyl chloride. Sulphur and vulcanization accelerators such as tetramethyl thiuram disulphide may be incorporated with the copolymer and curing effected by heating. A long list of fillers and plasticisers which may be added is given. Specifications 479,478 and 565,974 are referred to. The Specification as open to inspection under Sect. 91 comprises also the purification of the copolymers by (1) fractional separation from hot solution by cooling in stages; (2) fractional precipitation from solution and (3) selective extraction of undesired low molecular weight products. Solvents specified are ethylene dichloride, trichloroethane, chloroform, carbon tetrachloride, diisobutylene, benzene, toluene and ethyl, propyl, isopropyl and butyl ethers. Precipitants specified are alcohols and ketones. This subject-matter does not appear in the Specification as accepted.
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