Processing aid for polyvinyl chloride
CA 1056540 A · Owner: Stauffer Chemical Company · Inventors: Wei, Chung H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A process is disclosed for preparing a polyacrylatemodified polyvinyl chloride processing aid for polyvinyl chloride by sequentially polymerizing the vinyl chloride and the desired acrylate ester monomer. Thus a conventional vinyl, chloride suspension polymerization is conducted and at about 60-80% of its completion a minor proportion of a methyl methacrylate-ethyl acrylate mixture is added and polymerization is resumed so that the mixture forms a copolymer with residual vinyl chloride monomer. An additional minor portion of methyl methacrylate-ethyl acrylate is then added to graft polymerize onto the copolymer. The polyacrylate-modified PVC thereby recovered is …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 12, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 12, 1996.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.