Abstract: A method for dimerization of olefins containing 2 to 4 carbon atoms, wherein at least one of said olefins is mixed, in a medium of hydrocarbon or halogenated hydrocarbon solvents at a temperature ranging from 0.degree. to 100.degree. C under a pressure of from 1 to 40 atm with a two-component catalyst consisting of:(1) a complex of a nickel salt with a tertiary phosphine or tertiary phosphite;(2) an organoaluminum compound comprising a natural or synthetic carbochain rubber, swellable in said solvents, containing 2 to 50 mol. % of AlRX units, wherein R is an alkyl with at most 8 carbon atoms, X is a halogen; atomic ratio Al/Ni being varied within the range of from 1 to 100.The catalyst employed in the method according to the present invention features high stability (retaining its original activity for a long time); it is not crushed and can be readily regenerated.

Abstract: A method for dimerization of olefins with a number of carbon atoms of at most 10 which comprises intermixing, in a medium of solvents selected from the group consisting of hydrocarbon solvents and halogenated hydrocarbon solvents at a temperature ranging from -20.degree. to +100.degree. C under a pressure of from 1 to 45 atm, of at least one of said olefines with a two-component catalyst consisting of an organoaluminum compound of the formula R.sub.n AlX.sub.3-n, wherein R is an alkyl with a number of carbon atoms of at most 8, X is a halogen, n = 1 or 2, and a graft-copolymer, swellable in said solvents, of a rubber selected from the group consisting of natural, synthetic carbo-chain and vinyl-containing siloxane rubbers, with vinylpyridine; said copolymer containing 0.5 to 40% by weight of polyvinylpyridine fragments complexed with a nickel salt; molar ratio between said organoaluminum compound and said nickel salt ranging from 1:1 to 100:1.

Abstract: The method of dimerization of olefins having from 2 to 4 carbon atoms consists in that at least one said olefin is mixed, in a medium of hydrocarbon or halogenated hydrocarbon solvents at a temperature of from 0.degree. to 100.degree. C and a pressure from 1 to 40 atmospheres, with a catalyst, which is a graft copolymer of a natural or a synthetic carbon-chain rubber with vinylpyridine; said copolymer swells in said solvents and contains from 0.5 to 40 per cent of fragments of polyvinylpyridine that are complexed with a nickel salt, and contains also from 2 to 50 mole per cent of -AIRX- units, where R is an alkyl having not more than 8 carbon atoms, and X is a halogen, the aluminum atom being bound with the main chain of the copolymer through the carbon atom. The atom ratio of Al/Ni is from 1 to 20.Said catalyst is characterized by high stability and preserves it initial activity for a long period of time. It is not crushed in the process and is easy to recover.