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. 31, 1978
Filed:
Mar. 25, 1976
Barret Broyde, Decatur, GA (US);
Judith Archer Delles, Duluth, GA (US);
Steven Forrest North, Chamblee, GA (US);
Western Electric Company, Inc., New York, NY (US);
Abstract
Recompoundable polyvinyl chloride suitable to be recompounded for reuse, for example, in cable and wire production is recovered from a scrap material which includes plasticized polyvinyl chloride. A charge of plasticized polyvinyl chloride scrap material is treated with a solvent such as methyl ethyl ketone, tetrahydrofuran, cyclohexanone or dimethyl formamide to form a solvent mixture with one component thereof being a solvent solution of dissolved vinyl chloride polymer and plasticizers. The mixture is heated and agitated and scrap metal and other gross solids, if present, are removed. Then the solvent mixture is treated with an acid which advantageously causes a flocculation of suspended insolubles such as pigments and fillers. Except when using cyclohexanone as the solvent, the treatment with the acid must be accomplished, unexpectedly, in the presence of an additional flocculating agent such as a cellulose acetate which is soluble in the solution and which is insolubilized by the acid on refluxing. Recompoundable polyvinyl chloride is precipitated out by a non-solvent for the polyvinyl chloride which is miscible with the solvent in substantially all proportions, which will dissolve the plasticizer. The solvent and the non-solvent are removed from the plasticizer and are recovered separately by fractional distillation, for example.