Production of hydrogels
CA 1211897 A · Owner: Sumitomo Chemical Company Limited · Inventors: Oonishi, Toshihiro; Oota, Masaru; Ogura, Masato
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process are provided herein for producing highly water-absorbable and water-retainable hydrogels having a large particle diameter together with a sufficient gel strength. The process involves the use of a specific dispersing agent in the water-in-oil type inverse phase suspension polymerization in an organic solvent polymerization medium of an .alpha. , .beta. -unsaturated carboxylic acid and/or its alkali metal salt in the presence or absence of a cross-linking agent. The improvement involves using a carboxyl-containing polymer having an affinity to the organic solvent which is used as the dispersing agent. Due to the high waterabsorbability and water-retainability, along with the superior …
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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 September 23, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 23, 2003.
- 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.