Method for dyeing nylon filaments
CA 2109935 C · Owner: Gillette Canada Inc. · Inventors: Suhonen, Christopher H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for dyeing nylon filaments for use in wear-indicating toothbrushes includes immersing a batch of a first nylon filament for between 10 minutes and 80 minutes in an aqueous solution containing between 0.01% and 0.19% weight to volume of Indigotine dye, said solution having a pH between 1 and 7 and having a temperature between 50°C and 90°C the dye, penetrating into the filament to color an outer cross-sectional region and not penetrating into an inner cross-sectional region of the filament; removing the batch of the first nylon filament from the solution and repeating the, steps for a batch of a second nylon filament reusing the same, 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
- Filed June 2, 1992 and granted January 25, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 2014.
- 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.