Method for cold-milling cellulose derivatives
CA 1067055 A · Owner: Hoechst Aktiengesellschaft · Inventors: Kostrzewa, Michael; Holst, Arno; Buchberger, Gerhard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to an improvement in the method for the cold-milling of a cellulose derivative in which the cellulose deriva-, tive is cooled by means of liquid nitrogen until it becomes brittle and the thus cooled cellulose derivative is milled in a mill the improve-, ment comprising cold-milling a cellulose derivative which is soluble or swellable in water and has a water content of between 40 and 150 per cent by weight, based on its dry weight and which is, at 20°C, able to absorb, during swelling more than 150 per cent by weight of, water based on its dry weight.
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
- Granted November 27, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 27, 1996.
- 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.