In situ modification of gelatin carboxyl groups
CA 2099422 A1 · Owner: Weatherill, Timothy Donald · Inventors: Weatherill, Timothy Donald
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A modified gelatin and its use in a photographic element are described whereby the pendant carboxyl groups of polypeptide chains are modified. The derivatization involves initial reaction with a carboxyl activator followed by addition of a substituted amine thereby forming an amide linkage on the polypeptide chain. The resulting gelatin and photographic elements comprising such gelatin have a decreased propensity for water absorption without the loss of sensitometric properties.
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 June 30, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 30, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 30, 2015.
- 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.