Water-redispersible powders of film-forming polymers having a core/shell structure
CA 2220011 C · Owner: Rhone-Poulenc Chimie · Inventors: Richard, Joel; Bett, William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A water-redispersible powder based on substantially water-insoluble film-forming polymers prepared by the aqueous emulsion polymerisation of ethylenically unsaturated monomers with a core/shell structure comprising a hydrophobic polymeric core with a glass transition temperature (Tg) of -30-25 DEG C preferably -10-20 DEG C; and a shell attached to the core by covalent bonds resulting from the reaction of a grafting agent for grafting the shell onto the remaining ethylenically unsaturated linkages in the core. Said shell is prepared by emulsion polymerisation on the core particles of a monomer mixture comprising at least one monomer selected from styrene or a C1-12 alkyl acrylate or …
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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 May 31, 1996 and granted January 15, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 31, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 31, 2018.
- 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.