Retarding depolymerization of poly(methyl methacrylate) grafted onto a propylene polymer
CA 2225141 C · Owner: Montell North America Inc. · Inventors: Becker, Ronald F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Depolymerization during melt processing of poly(methyl methacrylate) that is grafted onto a backbone of propylene polymer material is retarded by adding 0.025 parts to 5.0 parts of a hydroxylamine compound per hundred parts of the graft copolymer. The methyl methacrylate can be copolymerized with another monomer such as methyl acrylate.
Read the whole patent
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
- Filed December 18, 1997 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 18, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 18, 2019.
- 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.