Continental Oil Company

Conoco Inc.

Dean R Weimer

Albert M Durr, Jr

Charles M Starks

John R Dodd

Kenneth D Freshour

E Flynt Kennedy

An improvement in the method of terminating the preparation of vinyl halide-containing polymers is disclosed. The improvement comprises injecting into the polymerization reactor at the desired level of conversion a free radical inhibitor obtained by the alkylation of p-methoxyphenol with nonene. The free radical inhibitor also functions as an antioxidant in the polymer product.

Termination of vinyl halide polymerization

Butylation of a mixture of xylenols and trimethylphenols gives a product which is suitable for use as a stabilizer for polyvinyl chloride. The material can be added to the reactor during polymerization as a shortstopper and retain effectiveness as a stabilizer in the finished polymer.

Chemicals for termination of polyvinylchloride polymerizations

Butylation of a mixture of xylenols and trimethylphenols gives a product which is suitable for use as a stabilizer for polyvinyl chloride. The material can be added to the reactor during polymerization as a short-stopper and retain effectiveness as a stabilizer in the finished polymer.

Chemicals for treatment of PVC

Polymer buildup in polymerization reactions during vinyl chloride polymerizations is greatly reduced by applying a water dispersion of alumina and oxalyl bis(benzylidenehydrazide) (OABH) to the reactor surfaces exposed to the polymerization medium prior to carrying out the polymerization. Long term effects of the buildup preventor can be obtained by applying a caustic wash to the reactor walls, prior to applying the oxalyl bis(benzylidenehydrazide) and alumina dispersion. The effect of the OABH/alumina and caustic is synergistic since the preventative effect is greater than either material used alone.

Prevention of PVC polymer buildup in polymerization reactors using

A method for preventing polymer buildup in the polymerization reactor during the suspension polymerization of vinyl chloride monomer to form polyvinyl chloride polymer and copolymers, the method comprising coating reactor surfaces in contact with the reaction medium with a material selected from the group consisting of alumina, dithiooxamide, and mixtures of these prior to carrying out this polymerization.

Method for reducing PVC polymer buildup in polymerization reactors

Reducing PVC polymer buildup in polymerization reactors with

A method for improving the water-dispersibility of alpha alumina monohydrate containing up to about 86 weight percent Al.sub.2 O.sub.3 wherein the method comprises mixing with the alpha alumina monohydrate from about 0.1 to about 50 weight percent based on the weight of the alumina of a salt compound selected from the group consisting of salts having the general formula MX wherein M is a polyvalent metal cation constituent for which the solubility product, K.sub.SP, of the corresponding metal hydroxide is less than 10.sup.-20, and X is an anion constituent derived from a monovalent acid having an ionization constant, K.sub.A, greater than 10.sup.+1 and phosphorus dichloride, phosphorus trichloride, phosphorus pentachloride, phosphorus tribromide, phosphorus pentabromide and antimony pentachloride.

Method for increasing the water dispersibility of alpha alumina

Polymer deposit or build-up on the interior surfaces of a polymerization vessel during polymerization of monoethylenically unsaturated monomers in aqueous dispersion may be inhibited by adding certain heterocyclic compounds to the dispersion prior to polymerization.

Technique for reducing polymer deposit during polymerization in aqueous

The viscosity of anionic surfactant slurries is increased by admixing with such slurries an effective amount of a viscosity increasing additive selected from the group consisting of dialkyl ethers wherein the alkyl radicals of said ethers contain from 2 to 5 carbon atoms, alkoxyethoxyethanols wherein the alkyl radical contains from 2 to 6 carbon atoms, and tertiary amines wherein the alkyl radical contains from 2 to 4 carbon atoms.

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Ponca City, OK, United States of America

Dean R Weimer