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Magnetic Media Composition

IP.com Disclosure Number: IPCOM000040697D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Bradshaw, RL: AUTHOR [+3]

Abstract

A magnetic coating composition for flexible media includes chromium dioxide magnetic particles, a polyester polyurethane, a crosslinking agent, a tridecyl stearate lubricant and a dispersant. The formulation can be coated onto a substrate of polyethylene terephthalate to produce a stick-free magnetic media. The magnetic media coating composition is based on chromium dioxide magnetic particles in an organic binder. The binder consists of a polyurethane resin constructed from a polyester resin and a hydroxyl-terminated chain extender which has been reacted with an aromatic diisocyanate. A polyfunctional isocyanate crosslinking agent is added together with a soybean lecithin pigment dispersing agent. The composition is coated on an organic substrate to produce the magnetic media.

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Magnetic Media Composition

A magnetic coating composition for flexible media includes chromium dioxide magnetic particles, a polyester polyurethane, a crosslinking agent, a tridecyl stearate lubricant and a dispersant. The formulation can be coated onto a substrate of polyethylene terephthalate to produce a stick-free magnetic media. The magnetic media coating composition is based on chromium dioxide magnetic particles in an organic binder. The binder consists of a polyurethane resin constructed from a polyester resin and a hydroxyl-terminated chain extender which has been reacted with an aromatic diisocyanate. A polyfunctional isocyanate crosslinking agent is added together with a soybean lecithin pigment dispersing agent. The composition is coated on an organic substrate to produce the magnetic media. The chromium dioxide particles are stabilized prior to mixing with the binder. The polymeric binder is a thermoplastic, linear polyester polyurethane having a high molecular weight. The chemical crosslinking agent is an aromatic polyfunctional isocyanate with a functionality of 2.3 and is added to the final magnetic ink prior to coating. A lubricant is incorporated in the ink formulation which is composed of fatty acid esters of tridecyl alcohol, primarily stearic and palmitic acid esters. The lecithin pigment dispersant is a complex mixture of glycerol phosphatides containing palmitic and stearic acid ester moieties. The solvents used in the creation of the formu...