Rigid magnetic recording media coating composition
AssigneeInternational Business Machines Corporation
InventorJohn C. S. Shen
Life of this patent
Estimating the term…
Abstract
A magnetic recording coating has a high density of magnetic particles uniformly dispersed in a thermoset resin binder with the dispersion applied as a thin coating onto a rigid substrate. The thermoset resin binder comprises a phenolic, an epoxy, and a styrene allylalcohol. The curing action of this coating is initiated by blocked acid catalysts. The material can be cured at a low temperature to produce a smooth, hard coating with an improved orientation ratio and without impairing the properties of the magnetic particles.
Claims7
A rigid magnetic recording medium having finely divided magnetic particles dispersed in a mixture of phenolic-styrene allylalcohol/phenolic-epoxy thermosetting resin binder composition applied as a thin film, having a thickness of less than 40 microinches, closely adhered to a rigid non-magnetic substrate wherein the coating composition includes 50 to 80 percent by weight of magnetic particles, 20 to 50 percent by weight of binder and comprises:
- 10 to 45 parts by weight of a hard thermoset phenolic-styrene allkyalcohol resin,
- 55to 90 parts by weight of a tough thermoset phenolic-epoxy resin,
- and additives, including a blocked acid catalyst, not exceeding 10 parts by weight.
Dependencies are inferred from the claim text.