GB806649A - Ethylene polymerisation - Google Patents

Abstract

Solid ethylene polymers are made by polymerizing, e.g continuously, ethylene, alone or in admixture with another copolymerizable monomer, at pressures above 500 atmospheres and above 10 DEG C. in the presence of a catalyst of the formula <FORM:0806649/IV (a)/1> wherein A, X and Y are similar or dissimilar, are alkyl, alkoxy or aryl groups, or where A may also be hydrogen, and where X and Y may together form a cycloaliphatic ring. The polymerization may be effected in the presence of chain transfer agents, e.g. hydrogen, carbon tetrachloride or chloroform, and also a diluent, e.g. pentane. The copolymerizable monomer may be vinyl acetate, allyl acetate, vinyl carbazole or carbon monoxide. The catalyst may be diisobutyryl, bistrimethylacetyl, bis-betamethoxyisobutyryl, bisdineopentylacetyl or bis - (1 - methylcyclopropylcarbonyl) peroxides and may be activated, e.g. by a tertiary amine. The Provisional Specification specifies also as catalysts bis-alpha-dichloroisobutyryl, bis-trichloracetyl and bis-alpha-methoxyisobutyryl peroxides.ALSO:Diisobutyryl, bistrimethylacetyl, bis-betamethoxyisobutyryl and bisdineopentylacetyl peroxides of the following general formula <FORM:0806649/IV (b)/1> wherein A and R may be similar or dissimilar and may be alkyl or alkoxy groups or where A may also be hydrogen, are made from isobutyryl, trimethylacetyl, betamethoxyisobutyryl and dineopentylacetyl chlorides by reacting with aqueous hydrogen peroxide in the presence of a base. In examples(1), (2) and (3) isobutyryl, trimethylacetyl and an n-pentane solution of beta-methoxyisobutyryl chlorides, respectively, are added to a cooled aqueous solution of hydrogen peroxide and sodium hydroxide. In Example (4) dineopentylacetyl chloride is refluxed with pyridine and the solution treated at 0 DEG C. with hydrogen peroxide.