Positive resist composition
CA 2062399 A1 · Owner: Nakanishi, Hirotoshi · Inventors: Hanawa, Ryotaro; Uetani, Yasunori; Tomioka, Jun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A positive resist composition which contains in, admixture, an alkali-soluble resin and at least one quinone diazide sulfonate of a phenol compound of the formula: (I), in which R1 and R2 are independently an alkyl group an, alkoxy group, a carboxyl group or a halogen atom; R3 is a hydrogen atom, an alkyl group, an alkoxy group a carboxyl, group or a halogen atom; R4 is a hydrogen atom an alkyl, group or an aryl group; and w x, y and z are independently, 0, 1, 2 or 3 provided that the sum of w and x is at least 1 or a phenol compound of the formula:, (II) in which R5 is an alkyl group, an alkoxy group a carboxyl, group or a halogen atom; R6 is a hydrogen atom an alkyl, group, an alkoxy …
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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 March 5, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 5, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 5, 2014.
- 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.