Browse Prior Art Database

Chromium Dioxide Magnetic Media

IP.com Disclosure Number: IPCOM000053056D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Haines, RS: AUTHOR

Abstract

A room temperature curable magnetic ink, which includes CrO(2) particle is made from urethane, a polyfunctional isocyanate crosslinking agent and CrO(2) particles. This ink is then used to coat a non-magnetic substrate to form magnetic recording media. Preferably, the CrO(2) particles, prior to mixing, are not stabilized in that their magnetic properties would be subject to change with humidity were it not for the following procedure. Stabilized particles can be used if desired.

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Chromium Dioxide Magnetic Media

A room temperature curable magnetic ink, which includes CrO(2) particle is made from urethane, a polyfunctional isocyanate crosslinking agent and CrO(2) particles. This ink is then used to coat a non-magnetic substrate to form magnetic recording media. Preferably, the CrO(2) particles, prior to mixing, are not stabilized in that their magnetic properties would be subject to change with humidity were it not for the following procedure. Stabilized particles can be used if desired.

When a solvent solution of an isocyanate crosslinking agent, such as the MONDUR* MRS brand, is slurried with unstabilized CrO(2) particles, the isocyanate reacts with the surface of the CrO(2) particles at room temperature. This reaction results in CrO(2) particles which are stabilized; i.e. their magnetic property is no longer subject to variation with changes in humidity. Urethane polymer is then added to the slurry, and comprises the ink"s binder constituent. The ink is now cast as a thin film on a support film to form magnetic recording media. Cross-linking of this cast film occurs at room temperature, thus eliminating adverse effects such as media heat distortion which can occur during high temperature curing. * Trademark of Mobay Chemical Co.

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