| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to form the boundary between a lower layer and upper layer and the surface of an upper magnetic layer in a good state at the time of producing a magnetic recording medium having a lower nonmagnetic layer by a wet-on-wet coating application method. SOLUTION: The complex elastic modulus G* of a magnetic coating material for the upper layer is specified to time zero second right after initial shearing for 60 seconds is applied on the material at a strain of 1000% and an angular speed of 2πrad/sec. The ratio between the complex elastic modulus G* (0) at the strain of 1% and the angular speed of 2πrad/sec in the time zero second and the complex elastic modulus G* (120) at the strain of 1% and the angular speed of 2πrad/sec at the point of the time 120 seconds elapses from the time zero second is so set as to satisfy the conditions G* (0)/G* (120)<=3.0.
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