Process for the preparation of polyurea greases
CA 2078724 A1 · Owner: Perrey, Hermann · Inventors: Lehmann, Bernhard; Rasp, Christian; Perrey, Hermann
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of polyurea greases A b s t r a c t, The invention relates to a new three-part process which, can also be employed on a large industrial scale for the, preparation of polyurea lubricating greases which is, characterised, (a) in that polyureas which carry oleophilic groups are prepared by reaction of diisocyanates with amines either in the absence of a solvent on a reaction screw at 80-120°C, preferably at 85-95°C (variant, A) or in a toluene medium at 20-80°C preferably at, 30-60°C, (variant B), (b) in that after complete reaction, the polyureas prepared according to (a) are ground in the solid dry state to give powders (at least 70% by weight of the powder …
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 September 21, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 21, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 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.