Process for preparing polymer emulsion particles having pores
CA 2006736 A1 · Owner: Mitsui Toatsu Chemicals, Inc. · Inventors: Hoshino, Futoshi; Nakano, Makoto; Yanagihara, Takeshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract:, A process for preparing polymer emulsion particles having pores therein, an outside diameter D of 0.1 to 5.0 µ, an inside diameter d of 0.05 to 4.0 µ and a, ratio (d/D) of 0.1 to 0.9 in dry condition comprising, the steps of forming core-shell emulsion particles from specific monomers by two-emulsion polymerizations and, swelling the core of the particles with water by hydrolyzing the vinyl acetate part of polymer (A) thereby, inducing the hydroxyl groups therein e.g. using an, acidic material or a basic material at 50 to 100°C. The particles when use as a pigment in coating compositions provide excellent converage rate, brightness gloss and, water resistance.
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 27, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 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.