Patent Yard Sign in
Expired Canadian patentCanada

Transparent non-vitreous ceramic particulate

CA 1269216 C · Owner: Minnesota Mining And Manufacturing Company · Inventors: Lange, Roger W.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

Abstract of the Disclosure, Solid, transparent non-vitreous, ceramic, particles useful as lens elements in retroreflective pavement markings characterized by having: A. at least one metal oxide phase; and B. an average minimum dimension of more than 125 micrometers. These particles are formed by various sol gel techniques, one example of which is the chemical gelation of titania sols by first mixing with glacial acetic acid then with ammonium acetate, followed by formation of microspheres in 2-ethylhexanol. Microspheres of this ceramic composition can have relatively large diameters (e.g. over 200-1000 micrometers) making them quite useful as retroreflective lens elements in pavement …

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 May 22, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 22, 2007.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 17, 1985
GrantedMay 22, 1990
Term endedMay 22, 2007
Patent numberCA 1269216 C
Classification (IPC)C04B35/48 +2 more

Timeline

Timeline From CIPO dates

19861989199219951998200120042007Application filedJuly 17, 1985Patent grantedMay 22, 1990Term endedMay 22, 2007

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.