Dyeing leather with water-insoluble sulphur dyes
CA 2061632 A1 · Owner: Schlosser, Lothar · Inventors: Mast, Jan-Hilbert; Kruse, Hubert; Bauer, Wolfgang,
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for dyeing leather by the exhaust method using a water-insoluble sulphur dye in dispersed form is disclosed. The process is carried out under the dyeing conditions which are customary for the known exhaust dyeing process involving watersoluble leather dyes. The sulphur dyes in dispersed form may be combined with a dispersion of an inorganic or organic pigment and/or with a water-soluble acid or direct dye. The process is suitable for all kinds of leather and is characterized by the deep penetration of colour and high colour strength combined with good fastness properties. The process is also free of some disadvantages of similar existing processes such as low substan-, tivity, …
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 February 21, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 21, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 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.