Brown stain suppressing phenol free and chlorinated hydrocarbon free photoresist stripper
CA 1215614 A · Owner: Allied Corporation · Inventors: Thomas, Evan G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Stripping solution compositions which avoid the problem known as "brown staining" are provided. Relevant stripping solutions are those that are free from phenol and chlorinated hydrocarbon compounds and comprise a surfactant alkylarylsulfonic acid having 12-20 carbons, a hydrotropic aromatic sulfonic acid haviny 6-9 carbons and a halogen-free aromatic hydrocarbon solvent with a boiling point above 150°C. To suppress brown staining, a water soluble sulfone is incorporated into the stripping solution. The stripping compositions effectively remove organic polymeric substances from inorganic substrates and are substantially clear water rinsable.
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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
- Granted December 23, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 23, 2003.
- 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.