Ink for erasable script
CA 1269788 C · Owner: Shintani, Takashi · Inventors: Nakagawa, Tatsushi; Shintani, Takashi; Okuzono, Shuichi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a coloring material comprising a rubber having a sulfonic acid group or a salt thereof which is dyed with a basic dye. The coloring material is prepared by adding a solution of an alkali in an alcohol to a solution of a chlorosulfonated polyolefin in an organic solvent and then adding a basic dye to the obtained reaction liquid, or adding a basic dye to a solution of a sulfonated product of a rubber in an organic solvent, and optionally removing the solvent from the obtained solution.
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
- Granted May 29, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 29, 2007.
- 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.