GB1059978A - High molecular weight, solid, crystalline copolymers of alpha-olefins - Google Patents

Abstract

A solid crystalline copolymer of a -monoolefins each containing at least 3 C atoms, which copolymer contains polymerized monomer segments exhibiting melting points and crystallinities characteristic of the corresponding crystalline homopolymers, is substantially free from such homopolymers, and contains less than 10% by weight of non-crystallizable amorphous polymer, is prepared by bringing the olefin mixture into contact under polymerizing conditions with a catalyst formed from (A) an aluminium dihalide RAlX2, wherein R is alkyl, aryl or aralkyl of 1 to 12 C atoms and X is Cl, Br or I, (B) a chloride, bromide or iodide of Ti, Zr, V, Cr or Mo, and (C) dimethylformamide or N,N-dimethylacetamide. The molar ratio of (A) to (B) may be within the range 1:0.5 to 1:2, the molar ratio of (A) to (C) may be within the range 1:1 to 1:0.25, the temperature of polymerization may be from 25 DEG to 100 DEG C., and the pressure may be from 15 to 1000 p.s.i.g. The process may be carried out continuously, and hydrogen or other chain transfer agent may be present. The polymerization mixture may contain 2 to 5 or more a -olefins. The polymer may be annealed before analysis. The a -olefins specified include 1-eicosene, styrene, allylbenzene, allylcyclopentane, and vinylcyclohexane. Polymerization may be effected in an inert organic solvent or in liquid monomer as sole diluent. In Example 1, propylene and 1-butene are copolymerized in presence of ethyl aluminium dichloride, dimethylformamide and TiCl3. In Example 3, propylene and styrene are copolymerized in presence of ethyl aluminium dichloride, N,N-dimethylacetamide and TiCl3. Examples 4 to 7 copolymerize propylene and 1-dodecene; 1-butene and 1-hexene; propylene, 1-butene and 1-pentene; and 1-butene and vinylcyclohexane respectively. The copolymers may be blended with high-pressure polyethylene or with other polymers or waxes.