Positive resist composition
CA 2076357 A1 · Owner: Sumitomo Chemical Co. Ltd. · Inventors: Tomioka, Jun; Kuwana, Koji; Nakanishi, Hirotoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A positive resist composition comprising an alkali-soluble resin containing a novolak resin which is obtained by a condensation reaction of a phenol compound and a carbonyl compound and has an area in a GPC pattern of a range in that a molecular weight as converted to polystyrene is not larger than 900 not exceeding 20 % of a whole pattern area excluding the unreacted phenol compound a quinone-, diazide compound and a polyphenol compound of the formula: (I), in which R1 and R2 are independently a hydrogen atom a, halogen atom, an alkyl group, an alkoxy group or a group: -OCOR3 in which R3 is an alkyl group or a phenyl group x, and y are independently an integer of 1 to 3 and m is an, …
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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 August 19, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 19, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 19, 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.