GB583850A - Manufacture of polymers and interpolymers of ethylene - Google Patents

Abstract

Ethylene is polymerized by subjection to elevated temperatures and pressures in the presence of oxygen or a per-compound and, if desired, a liquid medium, in a tubular converter. Suitable per-compounds are hydrogen peroxide, persuccinic acid, lauroyl, tetralin, urea, butyryl, acetyl, acetobenzoyl and diethyl peroxides, peracetic acid, alkali metal, alkaline earth metal and ammonium persulphates, perborates and percarbonates. The liquid medium may be water, benzene, toluene, chlorobenzene, isooctane, methanol or ethanol. The process may be used for interpolymerizing ethylene with propylene, isobutylene, styrene, vinyl formate, acetate and isobutyrate, acrylic, methacrylic, itaconic, citraconic, crotonic, maleic and fumaric acids, their esters, acid halides, amides and anhydrides, vinyl and vinylidene chlorides, vinyl cyanide, N-vinyl amides, vinyl ethers, divinyl formal, divinyl butyral and methyl vinyl ketone. The process is preferably carried out continuously with the liquid in turbulent flow through the converter, which may be tilted at an angle to the horizontal, so that the point of admission is at a lower level than the point of exit. In examples, the converter is a stainless steel tube 40 feet long and of 3/16 " internal diameter. A draw-off valve at the exit leads down to a separator from which gas and liquid are continuously withdrawn and the solid present removed hourly. The gas is returned to the inlet with make-up ethylene through an electrically-heated draw-off valve. The process is also applicable to the production of telomers as described in Specifications 572,810, 581,899, 582,663, 583,118 and 583,181.