Process for the preparation of grafted polymers of improved colour
CA 2000507 C · Owner: Du Pont Canada Inc. · Inventors: Mitchell, David John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the catalytic grafting of an ethylenically unsaturated monomer onto a copolymer in the presence of a catalyst is disclosed. The monomer is a selected from the group consisting of ethylenically unsaturated carboxylic acids anhydrides esters and other derivatives thereof. The copolymer is selected from the group consisting of copolymers of ethylene with at least one monomer selected from the group consisting of vinyl alkylates, carbon monoxide, acrylic acid methacrylic, acid, acrylate esters and methacrylate esters and, mixtures thereof, and ionomers of such copolymers. The catalyst is comprised of a mixture of (a) water and (b) at least one phosphorus-containing compound …
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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 October 11, 1989 and granted July 6, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 11, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 11, 2011.
- 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.