Patent GB-1343226-A (GB)
Title: Ethylene copolymers
IPC: C08F234/02
Filed: 1972-02-03
Abstract: 1343226 Modifying ethylene-polyene copolymers SNAM PROGETTI SpA 3 Feb 1972 [3 Feb 1971] 5195/72 Heading C3P Copolymers of ethylene with 0À02 to 20 weight per cent of a polyene containing at least two conjugated carbon to carbon double bonds and selected from (a) polycyclic polyenes containing a hydrocarbon ring bridged by an endomethylene group and ortho condensed with another hydrocarbon ring, wherein the two carbon atoms common to the two rings belong to a conjugated diene system of which the carbon to carbon double bonds are in said other hydrocarbon ring, (b) polyenes in which the carbon to carbon double bond of an alkylidene radical is conjugated with a carbon to carbon double bond of a ring part of which is common with part of an endocyclic ring, and (c) polyenes constituted by a norbornene radical substituted either by an acyclic alkadiene radical or by a cycloalkadiene radical, the acyclic alkadiene or cycloalkadiene radical containing the conjugated carbon to carbon double bonds and being bound to the norbornene radical either directly or via a methylene bridge, are modified by treating with a cationic promoter capable of giving rise to transversal bonds by interaction of double bonds in different molecules of the copolymer. The copolymers may be prepared by copolymerization in solution at - 100 to + 100‹ C. The copolymers may also contain units of other α- olefins, e.g. propylene. Specified polyenes are 1 - isopropylidene dicyclopentadiene, dehydrodicyclopentadiene, 3<SP>1</SP>- or 41-methylcyclopentadienyl - 2 - norborn - 5 - enyl - methane, 2- (2<SP>1</SP>,4<SP>1</SP> - dimethylpenta - 1<SP>1</SP>,3<SP>1</SP> - dienyl) - norborn - 5 - ene and (2 - norborn - 5 - enyl)- [6<SP>1</SP> - (2<SP>1</SP>- or 3<SP>1 </SP>- methyl) - cyclohexa - 2<SP>1</SP>,5<SP>1</SP>- dienyl] - methane. Polymerization may be effected in hydrocarbon or chlorinated hydrocarbon solvents in a first stage in the presence of a catalyst constituted by a Group IV to VIII transition metal compound and an aluminium hydrocarbyl or Lewis base complex thereof to form a copolymer of molecular weight 500 to 50,000, and modification in a second stage by treating the copolymer with the cationic promoter. Specified promoters are Lewis acids, protonic acids and mixtures of (1) a Group II to VIII metal alkyl or alkyl halide with (2) RCl, SOCl 2 , Cl 2 , XI where X is a chlorine, bromine or iodine atom or AH where R is alkyl and A is an anion. In examples ethylene is copolymerized in heptane with (1) isopropylidene dicyclopentadiene in the presence of vanadium tetrachloride, diethyl aluminium chloride and anisole, and the product further reacted in the presence of ethyl aluminium dichloride, titanium tetrachloride, boron trifluoride etherate, stannic chloride, ferric chloride, trichloracetic acid, hydrochloric acid or sulphuric acid; with (2) dehydrodicyclopentadiene in the presence of vanadium triacetylacetonate and diethyl aluminium chloride and the product further reacted in the presence of a Lewis acid; and with (3) methylcyclopentadienyl norbornenyl methane in the presence of vanadyl tri(n-butoxide) and diethyl aluminium chloride, and the product further reacted in the presence of boron trifluoride etherate.