Glass bubbles of increased collapse strength
CA 1197103 A · Owner: Minnesota Mining And Manufacturing Company · Inventors: Howell, Peter A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Glass bubbles of increased collapse strength are prepared. The bubbles have an average particle density of 0.4 or more and are made of glass that consists essentially of SiO2 (60 - 90 weight-percent), alkali metal oxide (2-20 weight-percent), B2O3 (1-30 weight-percent) sulfur (0.005, to 0.5 weight-percent), and other conventional glassforming ingredients.
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 26, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 26, 2002.
- 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.