PROCEDE POUR OBTENIR DES TETRAPOLYMERES OLEFINIQUES

摘要

1412519 Elastomeric tetrapolymers SNAMPROGETTI SpA 11 June 1973 [21 June 1972] 27779/73 Heading C3P A vulcanizable copolymer comprises units of (a) ethylene, (b) anα-mono-olefin containing at least 3 carbon atoms, (c) a compound containing at least two carbon-carbon double bonds, no two such double bonds being conjugated, and (d) a polycyclic polyene containing one non-aromatic hydrocarbon ring having an endomethylene bridge and preferably a double bond, and a second non-aromatic hydrocarbon ring othocondensed with the first which contains a conjugated diene system including the carbon atoms common to the two rings. The copolymer may be prepared using a catalyst comprising a compound of a transition metal of groups IV-VIII and a reducing aluminium compound, monomers (c) and (d) preferably being added in portions during the course of the reaction to maintain constant concentrations. It may be vulcanized by conventional methods or covulcanized with a diene polymer or copolymer elastomer. In examples (b) is propylene, (c) is endo and/or exo dicyclopentadiene, hexa - 1,4 - diene, 4 - vinylcyclohexene, cycloocta - 1,5 - diene, or mixed dimerization and addition products of butadiene and cyclopentadiene, (d) is dehydrodicyclopentadiene or its 1- or 2-methyl derivative (various other suitable monomers being mentioned), and the catalyst comprises Et 2 AlCl and vanadium trisacetylacetonate; a small amount of pyridine is also added.