Resins
CA 2204754 A1 · Owner: Commonwealth Scientific And Industrial Research Organisation · Inventors: Collins, Peter James; Yazaki, Yoshikazu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preparing a phenolic resin the method including a first stage in which an aldehyde compound is reacted with a phenol compound in a molar ratio of aldehyde to phenol of less than 1 in the presence of a catalyst such that the pH does not rise above about 10.5 to form an intermediate product; and a second stage in which the intermediate product is reacted with additional aldehyde compound such that the molar ratio of aldehyde to phenol is at least 1 in the presence of a strongly alkaline catalyst.
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 9, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 9, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2016.
- 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.