Loading patent…
AssigneeWestern Electric Company, Inc.
InventorsBarret Broyde, Judith Archer Delles, Steven Forrest North
Estimating the term…
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.
A process for recovering a reusable essentially pure vinyl chloride polymer resin from a polymer mixture which comprises plasticized polyvinyl chloride and insoluble particulate additives, which includes the steps of:
A method of separating metal, polyvinyl chloride and plasticizer from scrap conductor scrap material and plasticized polyvinyl chloride which also includes insoluble particulate matter comprising pigments and fillers, comprising the steps of:
A method of separating fillers, metal salts, and insoluble pigments from a vinyl chloride polymer scrap material, which includes:
A method of recovering an essentially pure plasticized polyvinyl chloride resin from a polyvinyl chloride scrap material, which includes the step of:
Dependencies are inferred from the claim text.