Dupont Canada Inc.

Ronald A Zelonka

Vaclav G Zboril

Chun Sing Wong

Daniel W Boivin

A solution polymerization process for the preparation of high molecular weight polymers selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and butene-1 is disclosed. The process comprises feeding monomer(s), coordination catalyst and inert hydrocarbon solvent to a reactor, polymerizing the monomers at a temperature of up to 320.degree. C. and a pressure of less than 25 MPa, and deactivating the catalyst in the solution so obtained. The catalyst is deactivated by sequentially admixing therewith a minor amount of dimethyl carbonate followed by a solution of a salt of an alkaline earth metal or zinc and an aliphatic monocarboxylic acid dissolved in hydrocarbon solvent. The hydrocarbon solvent and other volatile matter are then separated from the resultant solution and a composition comprising the high molecular weight polymer is recovered. The amount of dimethyl carbonate is not more than 2.5 moles, per mole of halogen plus alkyl radicals in the coordination catalyst.

Reduction of isomerization in solution process for polymerization of

A polyolefin blend comprising, in physical admixture, a major portion of particles of a polyethylene and a minor portion of particles of a composition of a thermoplastic second polymer, is disclosed. The polyethylene is selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and at least one C.sub.4 -C.sub.10 higher alpha-olefin, and the second polymer is a normally solid thermoplastic polymer having a melting point of less than 185.degree. C. and a shear viscosity that is not more than that of the polyethylene when measured at 200.degree. C. and a shear rate of 400 sec.sup.-1 with the proviso that the second polymer is not a homopolymer or copolymer derived solely from hydrocarbon alpha-olefins having 2-10 carbon atoms. Examples of second polymers are (a) homopolymers and copolymers of unsaturated hydrocarbons in which at least one monomer is other than a C.sub.2 -C.sub.10 alpha-olefin, e.g. ethylene/propylene elastomers, polystyrene and styrene/butadiene/styrene copolymers, (b) copolymers of ethylene with ethylenically unsaturated carboxylic acids and anhydrides, and esters thereof, and (c) modified polymers e.g. chlorinated polyethylene, grafted and ionomeric polymers. The composition of the second polymer contains a reactive agent that is capable of reacting with polyolefins that are in a molten state, such agents being cross-linking agents and/or modifying agents. In an alternative embodiment, the polyethylene may be more broadly defined as being a homopolymer or copolymer of hydrocarbon alpha-olefins having 2-10 carbon atoms. The blends may be used in a wide variety of processes, including blow-moulding processes, film and pipe extrusion processes, sheet thermoforming processes and rotational moulding processes.

Blends of polyolefins with polymers containing reactive agents

A continuous process for the grafting of ethylenically unsaturated monomers onto homopolymers of ethylene and copolymers of ethylene and C.sub.4 -C.sub.10 higher alpha-olefins is disclosed. The process involves feeding to an extruder an admixture comprising (i) a major portion of the above polymer of ethylene, (ii) the monomer, (iii) 25-500 ppm of an organic peroxide and (iv) a minor portion of a normally solid thermoplastic polymer having a melting point of less than 185.degree. C. and a shear viscosity at 200.degree. C. and a shear rate of 400 sec.sup.-1 that is not more than 50% of that of the polymer of ethylene. The organic peroxide is in the form of a composition with the thermoplastic polymer. The admixture is mixed in a first zone at a temperature above the melting point of the polymers for at least ten seconds but for less than 25% decomposition of the peroxide and then in a second zone for a period that is at least four times the half-life of the peroxide. A grafted polymer having a melt index that is 20-100% of that of the polymer prior to grafting is obtained. The grafted polymer may be used in a variety of end-uses, for example, the manufacture of film, moulding of articles, extrusion coating of metals and coextrusion processes.

Process for the grafting of monomers onto polyolefins

A process is disclosed for the catalytic oxidation of a cycloparaffin, e.g., cyclohexane, to partial oxidation products thereof, especially for the production of mixtures of cycloalkanols and cycloalkanones. In the process, molecular oxygen, usually in the presence of an inert gas, is introduced into the cycloparaffin at elevated pressure and a temperature of 130.degree.-180.degree. C., in the presence of an oxidation catalyst comprising a heavy metal compound along with an N-heterocyclic compound. The heavy metal of the heavy metal compound may be cobalt, vanadium, manganese, copper, iron or nickel. The heavy metal compound may have ligands of alkanoate, dialkylphosphate, dicycloalkylphosphate or alkylcycloalkylphosphate. The N-heterocyclic compound may be dipyridyl, pyrimidine, pyrazine, pyridine and pyridine substituted with --CN, --R, and/or --OR where R is alkyl. A preferred catalyst is cobalt bis[di(2-ethylhexyl)phosphate] in combination with pyridine.

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Kingston, Canada

Ronald A Zelonka