Process for producing a superabsorbent polymer
CA 2068948 A1 · Owner: Johnson, Thomas C. · Inventors: Johnson, Thomas C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention provides an improved process for producing a superabsorbent polymer with reduced residual monomer content which comprises partially drying a crosslinked, partially neutralized polymer gel then, raising the temperature of the gel using microwave radiation in the absence of circulating air and thereafter completing the drying. 39,497-F
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 19, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 19, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 19, 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.