Process for making polypropylene graft copolymers containing anhydride groups
CA 2245386 C · Owner: Syed, Abuzar · Inventors: Syed, Abuzar; Denicola, Anthony J. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A graft copolymer containing anhydride groups is made by (1) making a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto polymerized monomers selected from the group consisting of (a) at least one acrylic acid substituted with a 1-3 C alkyl group and (b) a mixture of at least one of these substituted acrylic acids and a vinyl compound capable of copolymerizing therewith, wherein the total amount of polymerized monomers is about 20 parts toabout 240 parts per hundred parts of the propylene polymer material and the amount of the substituted acrylic acid is 60 mole % or more of the polymerized monomers and (2), heating the graft copolymer to …
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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
- Filed August 20, 1998 and granted July 8, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 20, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 20, 2020.
- 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
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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.