Patent Yard Sign in
Expired Canadian patentCanada

Surface lubricants for recording surface

CA 1311049 C · Owner: Frew, Duncan W. · Inventors: Braitberg, Michael; Frew, Duncan W.; Shadwick, Robert P.

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

Magnetic recording media wherein the record surface is coated with an isocyanate lubricant (and preferably, a supercoat of like lubricant) such, lubrication being adapted to inhibit spin-off and like depletion, despite frequent head contact while, exhibiting good durability, wear resistance and recording characteristics over extended life (computer applications). M-199

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 December 1, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 1, 2009.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 21, 1987
GrantedDecember 1, 1992
Term endedDecember 1, 2009
Patent numberCA 1311049 C
Classification (IPC)G11B5/72 +1 more

Timeline

Timeline From CIPO dates

19881991199419972000200320062009Application filedAug 21, 1987Patent grantedDec 1, 1992Term endedDec 1, 2009

Sources & verification

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