The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 30, 1979
Filed:
Jun. 29, 1977
Anthony L Lemper, Tonawanda, NY (US);
Gilbert Witschard, Grand Island, NY (US);
Victor A Pattison, Clarence Center, NY (US);
Hooker Chemicals & Plastics Corp., Niagara Falls, NY (US);
Abstract
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.