Societe Chimique Des Charbonnages-cdf Chimie

Societe Chimique Des Charbonnages

Genevieve Le Brasseur

Jean-Pierre Machon

Marius Hert

Jean-Claude Decroix

A modified copolymer of ethylene and of at least one .alpha.-olefin having from 3 to 12 carbon atoms, comprising from 0.5 to 10 mole percent of units derived from the .alpha.-olefin, wherein the measured limiting viscosity of the copolymer is between 1.5 and 10 times the limiting viscosity of the copolymer calculated from the molecular weight distribution of the copolymer. Process for producing these copolymers employing at least one free-radical initiator.

Modified copolymers of ethylene and .alpha.-olefins and a process for

A halogen-containing catalyst for the polymerization of ethylene or copolymerization of ethylene and .alpha.-olefins having from 3 to 8 carbon atoms and a process for their preparation. The catalyst has the general formula: M.sub.n Mg(OR).sub.2-m X.sub.m+4n, wherein M is a metal of groups IVa to VIa of the Periodic Tables, X is a halogen, R is an alkyl radical containing from 1 to 4 carbon atoms, 0&lt;m&lt;2, and 0.05&lt;n&lt;1.

Halogenated catalyst for ethylene polymerization containing a transition

An ethylene polymerization catalyst having the general formula M.sub.n Mg(OR).sub.2+4n-m X.sub.m, wherein R is an alkyl radical containing from 1 to 4 carbon atoms, M is a transition metal of groups IVa to VIa of the Periodic Table, X is a halogen, 0.05.ltoreq.n.ltoreq.0.6 and 0&lt;m&lt;n+1.

Ethylene polymerization catalyst and a process for its preparation

In purifying polyolefins obtained by suspension polymerization to remove catalyst residues therefrom, the polymer is first separated from the polymerization medium and then degassed in the absence of air. Next the degassed polymer is deactivated by suspension in a liquid medium comprising a liquid hydrocarbon, an aliphatic alcohol having 1 to 4 C atoms, and an organic chloride which is an acid chloride or an alkyl chloride, the suspension being at a temperature of +30, +65.degree. C. Finally the deactivated polymer is separated from the liquid medium and washed with an aliphatic alcohol and/or a liquid hydrocarbon.

Process for removing catalyst residues from polyolefins

Photodegradable polyethylene or polystyrene compositions of copolymers thereof containing up to 500 ppm of iron in the form of a ferrous carboxylic acid salt having a substituted alkyl chain of at least 6 carbon atoms.

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Bully les Mines, France

Genevieve Le Brasseur