Discoloration inhibitors for aromatic amines
CA 1264475 C · Owner: Weidig, Charles F. · Inventors: Weidig, Charles F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Substituted aromatic amines containing a discoloration inhibiting amount of a substituted phenol selected from 2,6-dialkylphenols, 2,4,6-trialkylphenols and dibenzylphenol. A method and composition are provided for inhibiting discoloration of alkylated aromatic amines and diamines. A minor portion of the substituted phenol described above is combined with a fresh water white sub-, stituted aromatic amine of structure wherein m is 1 or 2, n is 1 to 5, m + n is not greater than 6, and the R are independently selected alkyl cycloalkyl, aryl, aralkyl, or alkaryl, said amine being subject to gradual discoloration.
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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 January 16, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 16, 2007.
- 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.