Dye for coloring cigarette paper
CA 2033546 C · Owner: Mcmurtrie, Andrew · Inventors: Lauterbach, John Harvey; Mcmurtrie, Andrew; Chakraborty, Baran B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A dye for coloring cigarette paper a brown color which includes caramel as the brown coloring agent, a plasticizer to prevent the paper from becoming brittle, and water. The dye can further include carmine as a red coloring agent to change the shade and hue of the brown color of the caramel. The dye can further include a burn additive to promote the burning of the dyed paper if needed.
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 January 3, 1991 and granted February 25, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 3, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 3, 2013.
- 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.