PURPOSE: To provide satisfactory stability in traveling and satisfactory video characteristics and to improve the adhesive strength of a back coat layer to its base, by forming the back coat layer contg. barium sulfate of 0.01W0.1μm average grain size on the rear side of the base having a magnetic layer on the principal side.
CONSTITUTION: Barium sulfate is well dispersible in a binder incorporated in a back coat layer, and barium sulfae of ≤0.1μm small average grain size can be easily manufactued. A back coat layer contg. the barium sulfate has very fine surface unevenness and produces a favorable effect on the stability of a cassette tape in traveling and video characteristics. When the grain size is <0.01μm, it is difficult to form the fine surface unevenness, so the preferred grain size is ≥0.01μm. Since barium sulfate with about 3 Mohs' hardness is relatively soft, it does not damage the guide of a cassette VTR, etc., and the back coat layer has high adhesive strength to its base and does not cause stripping during use.
MATSUURA TAKESHI
MORIOKA AKIRA
TAKAHIRA YOSHIYUKI
WATAYA SEIJI
HITACHI MAXELL
| JPS4849518A | 1973-07-12 | |||
| JPS4911305A | 1974-01-31 | |||
| JPS50147306A | 1975-11-26 | |||
| JPS50147307A | 1975-11-26 |
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