Polymer scale preventive agent, polymerization vessel effective in preventing polymer scale deposition, and process of producing polymer using said vessel
CA 2079064 A1 · Owner: Usuki, Masahiro · Inventors: Ueno, Susumu; Usuki, Masahiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polymer scale preventive agent Polymerization, vessel effective in preventing polymer scale deposition, and Process of producing polymer using said vessel, A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising:, (A) at least one compound selected from the group consisting of diaminobenzenes and diaminonaphthalenes (B) a hydroxynaphthoquinone, and, (C) an acid. The polymerization vessel having a coating comprising the polymer scale preventive agent on its inner wall, etc. is effective in preventing deposition of polymer scale, and the polymeric product has a high whiteness and is of high quality.
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 September 24, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 24, 2014.
- 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.