Ink composition for writing board
CA 1300295 C · Owner: Toyo Soda Manufacturing Co. Ltd. · Inventors: Okuzono, Shuichi; Sakanaka, Yasuhiro; Shintani, Takashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a wipe-erasable ink composition for a writing board, which has good erasability and long-period stability. This ink composition comprises a colored polymer formed by dyeing an organic solvent-soluble resin having a sulfonic acid group or a salt thereof with a basic dye, a volatile organic solvent and as, additives, (A) a nonionic surface active agent having an HLB value of 8 to 14 and/or a cationic organic compound and (B) a slightly volatile or nonvolatile organic compound.
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 5, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 5, 2009.
- 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.