Hooker Chemicals & Plastics Corporation

Occidental Chemical Corporation

Gilbert Witschard

Victor A Pattison

Anthony L Lemper

A polymer blend capable of being molded to an impact resistant, substantially transparent or translucent article which comprises a vinyl halide homopolymer or copolymer, a conventional impact resistance enhancing polymer agent for polyvinyl halide wherein the monomer units consist essentially of methyl methacrylate, 1,3-butadiene and styrene residues and a thermoplastic block elastomer wherein the essential and predominant monomer units are the residue of a mono-alkenyl aromatic hydrocarbon and the residue of an alkadiene hydrocarbon. The thermoplastic elastomer is normally incompatible with the vinyl halide polymer or copolymer. The vinyl halide polymer or copolymer constitutes the major proportion of said blend and the block and methacrylate polymers together constitute a minor proportion of the composition. The weight ratio of block polymer to methacrylate polymer is about 1:5 to about 5:1.

Vinyl halide polymer blends of enhanced impact resistance

A polymer blend capable of being molded to an impact resistant, article which comprises a vinyl halide homopolymer or copolymer, a conventional impact resistant enhancing polymer agent for polyvinyl halide wherein the monomer units consist essentially of acrylonitrile, 1,3-butadiene and styrene residues and a thermoplastic block elastomer wherein the essential and predominant monomer units are the residue of a mono-alkenyl aromatic hydrocarbon and the residue of an alkadiene hydrocarbon. The thermoplastic elastomer is normally incompatible with the vinyl halide polymer or copolymer. The vinyl halide polymer or copolymer constitutes the major proportion of said blend and the block and methacrylate polymers together constitute a minor proportion of the composition. The weight ratio of block polymer to acrylonitrile-butadiene-styrene polymer is preferably about 1:5 to about 5:1. Preferably an acrylonitrile-butadiene-styrene polymer having about the same refractive index as that of the vinyl halide resin is employed to obtain a substantially transparent or transluscent molded article.

Mixtures of vinyl halide-graft-polyolefin polymer compositions with a minor proportion of a monoalkenyl arene-hydrocarbon alkadiene block thermoplastic elastomer which are capable of being molded to impact-resistant articles exhibit enhancement of low temperature impact resistance on ageing.

Polymer compositions having enhanced low temprature impact resistance on

An improved polyvinyl halide or a polyvinyl halide copolymer containing up to 50 percent of a comonomer can be obtained by post polymerizing in a single stage or two-stage bulk process in contact with a base polymer, the same or different monomer as the monomer used to form the base polymer. Compositions produced by the process of the invention are useful in making films, coated fabrics and molded objects. The liquid phase post polymerization process of the invention is applicable to base polymers in powder form prepared by emulsion, suspension and bulk polymerization processes. The base polymer can be present in a polymerization mixture in which only a partial amount of monomer has been converted to base polymer such as in a two-stage polymerization process or the base polymer can be used in dry, solid form. Polymers of the invention have improved bulk density and reduced plasticizer uptake and can be used to prepare fabric coatings. Copolymers prepared by the novel post-polymerization process of the invention which show increased impact strength in addition to improved bulk density and reduced plasticizer uptake are useful in the preparation of molding compounds. In the bulk polymerization process of the invention, the addition of the same monomer or monomers or a different monomer or monomers subsequent to the partial conversion by a two-stage bulk process of polymerization of the vinyl halide monomer or monomers or vinyl halide monomer and comonomer, results in higher yield than can be obtained in the same reaction vessel as compred with a usual two-stage bulk polymerization process. In the two-stage bulk polymerization process of the invention, the use of small amounts of a hydrocarbon rubber dissolved or dispersed in the monomer effectively prevents reactor fouling during polymerization. Where desired, a small particle size product can be obtained by incorporating in the first stage of a two-stage bulk polymerization process either an inert finely divided additive, a surfactant, a mixture thereof, or a polyolefin.

Post bulk polymerization process for polyvinyl halide and composition

An improved polyvinyl halide or a vinyl halide copolymer containing up to 50 percent of a comonomer can be obtained by post polymerizing in a single stage or two-stage bulk process in contact with a base polymer, the same or different monomer as the monomer used to form the base polymer. Compositions produced by the process of the invention are useful in making films, coated fabrics and molded objects. The liquid phase post polymerization process of the invention is applicable to base polymers in powder form prepared by emulsion, suspension and bulk polymerization processes. The base polymer can be present in a polymerization mixture in which only a partial amount of monomer has been converted to base polymer such as in a two-stage polymerization process or the base polymer can be used in dry, solid form. Polymers of the invention have improved bulk density and reduced plasticizer uptake and can be used to prepare fabric coatings. Copolymers prepared by the novel post-polymerization process of the invention which show increased impact strength in addition to improved bulk density and reduced plasticizer uptake are useful in the preparation of molding compounds. In the bulk polymerization process of the invention, the addition of the same monomer or monomers or a different monomer or monomers subsequent to the partial conversion by a two-stage bulk process of polymerization of the vinyl halide monomer or monomers or vinyl halide monomer and comonomer, results in higher yield than can be obtained in the same reaction vessel as compared with a usual two-stage bulk polymerization process. In the two-stage bulk polymerization process of the invention, optional addition of small amounts of a hydrocarbon rubber dissolved or dispersed in the monomer to the second reaction stage effectively prevents reactor fouling during polymerization. Optional second stage addition of a small amount of a surfactant beneficially diminishes the porosity of the polymer product. A small particle size product can be obtained by incorporating in the first stage of a two-stage bulk polymerization process either an inert finely divided additive, a surfactant, a mixture thereof, or a polyolefin.

Vinyl halide homopolymers, copolymers and graft polymers of substantially lower molecular weight are obtained when polymerization is carried out in the presence of an organotin mercaptide ester and an organic azo initiator. The products are faster fusing and have lower melt viscosities than corresponding polymers of the same molecular weight prepared by high temperature molecular weight reduction methods. The low molecular weight and excellent fusion characteristics of the products render these polymers particularly useful in molding, extrusion, and coating applications.

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Grand Island, NY, United States of America

Gilbert Witschard