Color developer for pressure sensitive recording paper
CA 2005249 A1 · Owner: Tokunaga, Yukio · Inventors: Saeki, Yukio; Tokunaga, Yukio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A color developer for pressure-sensitive recording paper is produced by admixing components comprising: (A) 100 parts by weight of a polyvalent metal salt of a co-condensation product of a substituted salicylic acid, an aromatic hydrocarbon and an aldehyde. Such a co-condensation product is obtained by reacting: (a) a substituted salicylic acid, (b) one or more aromatic hydrocarbons having 4 to 9 carbon atoms, and, (c) an aldehyde of 1 to 8 carbon atoms in the presence of an acidic catalyst; and (B) 5 to 200 parts by weight of one or more members selected from the group consisting of petroleum resins, terpene resins, modified terpene resins coumarone resins and modified coumarone resins. …
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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
- Filed December 12, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 12, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 12, 2011.
- 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.