Resist composition
CA 2000552 A1 · Owner: Uetani, Yasunori · Inventors: Uetani, Yasunori; Nakanishi, Hirotoshi; Oi, Fumio
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 comprises an alkali-soluble resin and, as a sensitizer a quinone diazide, sulfonic acid ester of a phenol compound wherein, (a) a pattern area corresponding to the quinone diazide sulfonic acid diester of the phenol compound having not less than three hydroxyl groups is not less than 40 % of all pattern areas corresponding to the sensitizer in a HPLC pattern measured with a primary detector using IR light having the wavelength of 254 nm, and, (b) a pattern area corresponding to the complete ester of the phenol compound having not less than two hydroxyl groups with the quinone diazide sulfonic acid is not less than 5 % and less than 60 % of all pattern …
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 October 12, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 12, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 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.