Sulfo-group-containing heat-resistant high-molecular material and a preparation process thereof
CA 2033174 C · Owner: Mitsui Mining Co. Ltd. · Inventors: Sakata, Koji; Sakawaki, Kouji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed herein is a sulfo-group-containing heat-resistant high-molecular material containing sulfo groups in an amount of not less than 1 wt.$ in terms of sulfur content and having an ammonia adsorptivity of not less than 10 mg/g, formed by heat-treating at a temperature of 250 - 500°C a starting composition composed mainly of a sulfo-group-containing aromatic high-molecular compound which comprises unit constituents of an aromatic sulfonic acid compound or a salt thereof and is soluble in aqueous solvents, and a preparation process thereof.
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 May 21, 1990 and granted August 17, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 21, 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.