Expired Canadian patentCanada
Ascorbic acid ethers and their production
CA 1236461 A · Owner: Takeda Chemical Industries, Ltd. · Inventors: Terao, Shinji; Hirata, Minoru
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, An ascorbic acid derivative of the formula: wherein R1 is an organic residue having a molecular weight of from 58 to 400 is novel compound and is useful as antioxidant agent for food.
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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 May 10, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 10, 2005.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 18, 1984
GrantedMay 10, 1988
Term endedMay 10, 2005
Patent numberCA 1236461 A
Classification (IPC)C07D307/62 +2 more
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.