Open-pore molded article on polyvinyl acetals, and a process for its preparation
CA 1186450 A · Owner: Clariant Gmbh · Inventors: Pospich, Gunther; Zimmermann, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
When polyvinyl alcohol and vinyl acetate/ethylene copolymers are acetalized in an acid aqueous medium in the presence of a wetting agent, an open-pore solid foam is formed, if the reaction mixture contains gas bubbles. These gas bubbles are produced in particular, by stirring in air. The molded articles obtained are porous, and the pores are uniformly distributed. The dried molded article absorbs many times its weight of water. It is employed as a sponge for household use and in industry.
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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
- Granted April 30, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 30, 2002.
- 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.