Method of preventing polymer scale deposition during polymerization
CA 2011524 C · Owner: Shin-Etsu Chemical Co. Ltd. · Inventors: Kaneko, Ichiro; Ueno, Susumu; Shimizu, Toshihide
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of preventing polymer scale deposition in a polymerization vessel during polymerization of a monomer having an ethylenically double bond, wherein said polymerization is carried out in a polymerization vessel of which the inner wall has been previously coated with a coating solution containing, (A) a tannin and, (B) a water-soluble polymeric compound followed by, drying to form a coating; a scale preventive agent comprising the components (A) and (B); and a polymerization vessel having said coating an the inner wall thereof. Polymer scale deposition on the inner wall etc. of the, polymerization vessel can be effectively prevented.
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 March 1, 1990 and granted September 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 1, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 2012.
- 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.