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. 22, 1980
Filed:
Dec. 16, 1977
Edwin D Hornbaker, Baton Rouge, LA (US);
Adam Nugent, Jr, Baton Rouge, LA (US);
Cecil P Loechelt, Baton Rouge, LA (US);
Ethyl Corporation, Richmond, VA (US);
Abstract
An apparatus for reducing the vinyl chloride monomer content of polyvinyl chloride resins suspended as a slurry in an aqueous medium. The polyvinyl chloride-water slurry as produced in a conventional suspension resin autoclave, or a resin-water slurry prepared subsequent to suspension polymerization, is placed in a vessel and heated to a suitable temperature for removal of vinyl chloride monomer from the resin. In this operation, the polyvinyl chloride-water slurry is agitated in a vessel and steam is injected directly into the slurry to rapidly heat the slurry up to a minimum temperature of at least about 180.degree. F. The slurry is cooled immediately, or optionally it can be maintained for a period of time at the selected maximum temperature and then rapidly cooled by applying vacuum to the vessel and condensing the vapor phase removed from the vessel. Dried polyvinyl chloride resin produced by this process has been found to have a vinyl chloride monomer content below a detectable limit of 0.5 ppm.