Process for improving the hydrophilicity of the substrate for a lithographic printing plate by treatment with polyvinyl phosphonic acid
CA 2172734 A1 · Owner: Wanat, Stanley F. · Inventors: King, Dennis A.; Wanat, Stanley F.; Loveland, Allen W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Provided herein a process to improve the hydrophilicity of the surface of the substrate for a lithographic printing plate. The inventive process comprises treating said surface with a solution of polyvinyl phosphonic acid which is maintained at a pH range of about 2.5 to about 6.6 at temperature range of ambient to about 212 °F for about 5-20 seconds. The process substantially reduces sensitivity to background toning, thereby substantially improving the quality of images printed from using the inventive lithographic printing plate.
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 September 27, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 27, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 27, 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.