MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To improve both the adhesive force between a nonmagnetic supporter and a magnetic layer as well as the durability for a magnetic recording medium containing a magnetic layer consisiting mainly of magnetic particles and a binder hardened by an electronic beam on a nonmagnetic supporter, by limiting the 10-point average roughness Rz for the surface of the nonmagnetic supporter. CONSTITUTION:A magnetic recording medium is obtained by forming a magnetic layer 2 on a single or both sides of a nonmagnetic supporter 1 which underwent the surface treatment within an Rz range of 0.05-0.25mum (preferably 0.1-0.15mum). The upper limit of the Rz is mainly decided by the electromagnetic conversion characteristics. In this case, (b) is approximately equal to (a+Rz+Rz') and the R'z is set at about 0.25mum with a floppy disk. Furthermore the R'z is decided mainly by the dispersing state and the polishing state of the magnetic coating material. The thickness of the layer 2 is decided preferably at 1.0-1.5mum in relation to the electromagnetic conversion characteristics. The lower limit value of the Rz is set at 0.05mum where the effect is obtained from improvement of the adhesive force. It is needed to give flaws evenly to the surface of the supporter 1 with a desired Rz by means of a polishing machine before the magnetic coating material is applied in order to give a desired Rz to the surface of the supporter 1.