Polyurea and polyurea-epoxy microcapsules
CA 1300987 C · Owner: Chao, Hung-Ya · Inventors: Chao, Hung-Ya
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for the production of microcapsules by the use of hydrogen transfer polymerization in the presence of a mixture of emulsifiers including either an aqueous solution of a sodium salt of naphthalene-sulfonic acidformaldehyde condensate or diphenyloxide disulfonate with a polyvinyl alcohol. The process is particularly useful for the production of microcapsules containing a colorless dye intermediate used in carbonless copy paper (CCP) applications.
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 19, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 19, 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.