초록 ▼

The invention relates to a high density high energy magnetic memory card. The card is provided throughout or part of at least one of its surfaces with a recording medium which contains magnetic particles having a coercitive field higher than 4000 Oe (320 kA/m), which has no overlying layer and which

The invention relates to a high density high energy magnetic memory card. The card is provided throughout or part of at least one of its surfaces with a recording medium which contains magnetic particles having a coercitive field higher than 4000 Oe (320 kA/m), which has no overlying layer and which has a density of information higher than 5 kbits/cm2, an electric wear corresponding to an electric signal loss equal to or lower than 5% for 2000 passages, a mean arithmetic rugosity lower than 10 nm, an abrasivity lower than 600 mm

대표청구항 ▼

A magnetic memory card having at least 40 tracks/cm comprised of a 20-80 m1.5:1 and 3:1, a length of 0.1 to 0.3 m5000 Oe, a binder formed by a cross-linked three dimensional polyurethane formed from a branched polyol having a mean molecular weight of less than 4,000 and containing at least 8% by wei

A magnetic memory card having at least 40 tracks/cm comprised of a 20-80 m1.5:1 and 3:1, a length of 0.1 to 0.3 m5000 Oe, a binder formed by a cross-linked three dimensional polyurethane formed from a branched polyol having a mean molecular weight of less than 4,000 and containing at least 8% by weight OH groups and an isocyanate prepolymer containing at least three isocyanate groups, and at least one solid particulate lubricant present in an amount of less than 2 wt % based on the weight of magnetic particles, said solid particulate lubricant being tetrafluoroethylene polymer particles of which at least 99% have a size smaller than 3 m50 kbits/cm2, wear corresponding to a loss of electric signal equal to or smaller than 5% for 2000 passes, an average peak-to-valley height of less than 10 nm, an abrasive characteristic of less than 600 m1.5 m