Acid yellow dye and method for using same
CA 2271817 A1 · Owner: Crompton & Knowles Colors Incorporated · Inventors: Smith, Howard L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is a composition of matter useful as an acid yellow dye having formula (I) wherein: X is hydrogen or SO3-M+; M+ Na+ Li+, K+, NH4+, or , hydroxyalkylammonium of the formula H-(OCH2CH2)np NHm where n is 1 to 5, p , is 1 to 3, and p + m is 4; R1 is hydrogen a metal ion, an alkyl or C1-4, of , hydroxyalkyl of C1-4 and combinations thereof; and R2 is an unsubstituted aromatic ring or a substituted aromatic ring having at least one substituent provided that when one of the substituents is SO3-M+ X is hydrogen; and , combinations thereof. The invention also includes a process for dyeing a material with this compound and the material so dyed.
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 November 18, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 18, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 18, 2019.
- 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.