Purification of hydroquinone
CA 1060050 A · Owner: Goodyear Tire And Rubber Company (The) · Inventors: Slam, Thomas J.; Sturm, Budd H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed the method of preparing photographic grade hydroquinone from technical grade hydroquinone which consists of treating a a solution of the technical grade hydroquinone in the presence of a palladium catalyst with hydrogen while ?he hydroquinone solution is at a pH between about 3 and about 6.
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
- Granted August 7, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 7, 1996.
- 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.