Patent ID: 6258471
Filing Date: 2001-07-10
Classification: G11B,Y10T

Abstract:
An anhysteretic master recording medium comprising a support having disposed thereon a coating composition at a dry thickness of from 2 to about 3 microns and having a coercivity of at least 2000 Oe; said composition comprising from about 59 to about 69% of a magnetic pigment, from about 2.9 to about 6.9% of an abrasive powder, from 1 to about 5.5% of a colloidal inorganic powder, from about 2.9 to about 4.5% of a wetting agent, from about 0.7 to about 3.1% of a lubricant, from about 14.1 to about 35.6% of a binder, at least 85% of which is a polyurethane and from 0.05 to about 15% of which is a polyisocyanate crosslinking agent, wherein all percentages are by weight based on the total weight of the coating composition, except the polyurethane and crosslinking agent which are percent by weight of the binder.