Novel petroleum resin formed by a catalyst system containing (a) organoaluminum compound and (b) alkyl halide or hydrogen halide as cocatalyst

摘要

A petroleum resin produced by copolymerizing a monomer composition comprising (1) a mixture of 20 to 80 parts by weight of a so- called spent C.sub.4 - or C.sub.5 -fraction obtained by removing most of the dienic constituents from a fraction mainly of four or five carbon atoms formed in petroleum cracking and 80 to 20 parts by weight of styrene and/or a styrene derivative, and (2) 0.5 to 10 parts by weight of divinylbenzene for 100 parts by weight of the monomeric constituents contained in said mixture (1), with a catalyst system comprising an organoaluminum compound represented by the general formula AlR.sub.n X. sub.3.sub.-n (wherein R is an alkyl group having 1 to 4 carbon atoms, X is a halogen atom, and n is a positive number from 1 to 2) as main catalyst and an alkyl halide or a hydrogen halide as co-catalyst in a hydrocarbon solvent at a temperature of 0° to 60° C.