Battery separator
CA 1233621 A · Owner: Ppg Industries, Inc. · Inventors: Krivak, Thomas G.; Longhini, David A.; Johnson, Harlan B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Precipitated amorphous silica useful for reinforcing microporous battery separators is prepared by establishing an aqueous solution of alkali metal silicate having an alkali metal oxide concentration of from 5.6 to 7.2 and a temperature of from 190 to 198°F.; adding from 2 to 5 times the amount of alkali metal silicate simultaneously with acidifying agent to the solution while maintaining the initial alkali metal oxide concentration therein substantially constant; reducing the pH of the resulting slurry to from 8 to 9; ageing the slurry at precipitation temperatures for from 15 to 90 minutes; reducing the pH of the aged slurry to from 4.0 to 4.7 and then recovering and drying the …
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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 March 8, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 8, 2005.
- 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.