Process for making acid activated bleaching earth using high susceptibility source clay and novel bleaching earth product
CA 2015256 C · Owner: Taylor, Dennis R. · Inventors: Ungermann, Charles B.; Taylor, Dennis R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making acid-activated bleaching earth from certain naturally occurring mixtures of calcium bentonite and attapulgite clay. The process involves treating such clay with low levels of activating acid which are mixed with the dried and ground clay, or spray dried from slurries containing he clay-acid mixture. Advantages include: lower acid costs/unit mass of clay treated, lower production costs (no washing filtering, or waste treatment steps) and environmental soundness (no harmful environmental waste products are produced).
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 April 24, 1990 and granted December 3, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 2012.
- 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.