Process for the manufacture of membrane-covered fertilizer granules
CA 2115998 C · Owner: Wegener, Holger · Inventors: Kloth, Bernhard; Wehr, Peter; Kohl, Wilhelm
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Described is a process for the manufacture of membranecovered fertilizer granules by coating the granules with films of a mixture of a polyisocyanate and a polyol the, coating compound being applied in proportions such that each film has a thickness of 10 to 30 µm, preferably 15 to 20 µm. The granular fertilizer manufactured in this way has the advantage that it initially emphasizes nitrogen release and subsequently potassium release.
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 August 18, 1992 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 18, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 18, 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.