Minnesota Mining and Manufacturing Company

Imation Corporation

Douglas G Pedrotty

Brenda L Renalls

Nang T Tran

Bruce H Edwards

David J Owen

Brian D Brong

Roger J Mandt

John F Donlon

John F Donlan

A method for producing a magnetic recording medium includes heat-curing a coated substrate to cure a non-magnetic back coat on the substrate and to cure a magnetic front coat on the substrate, and calendering the heat-cured coated substrate to produce the magnetic recording medium. The calendering optionally is off-line calendering during which the substrate passes between opposed, generally non-compliant rolls. Other methods, and magnetic recording media produced by the disclosed methods, also are disclosed.

Heat curing and subsequent calendering to produce magnetic recording media

A magnetic recording medium has a biaxially-oriented polyester film base which includes carbon black beads having a median diameter from 50 to 500 nm and is substantially free from beads or agglomerates more than 5 micrometers in diameter. The beads provide opacity such as is often required of the flexible recording disk of a diskette. The film base may be either a single layer, throughout which the beads are uniformly dispersed, or it may be multi-layer, e.g., a central layer containing the carbon black beads and two surface layers which are free from the beads.

Opaque polyester film containing fine carbon black particles

Magnetic recording medium having opaque polyester film base

Growing community of inventors

Baldwin, WI, United States of America

Douglas G Pedrotty