Process for the production of heat resistant methacrylic resin
CA 1238139 A · Owner: Sumitomo Chemical Co. Ltd. · Inventors: Iijima, Susumu; Yuyama, Masahiro; Kato, Yasuyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
1-, Abstract:, The invention provides an improved process for the production of a methacrylic polymer having good heat resistance. The process comprises radical-polymerizing a monomer or monomer mixture consisting of 80 to 100% by weight of methyl methacrylate and 0 to 20% by weight of a copolymerizable vinyl monomer in the presence of a polymerization initiator and one or more specific chain transfer agents selected from, (A) 2-mercaptoethyl alkanecarboxylate of the formula: (1), wherein R is an alkyl group having 4 to 12 carbon atoms and, (B) alkyl 3-mercaptopropionate of the formula: (2), wherein R is an alkyl group having 4 to 18 carbon atoms. The methacrylic resin prepared by this …
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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 14, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 14, 2005.
- 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.