| 摘要 |
PURPOSE:To obtain a magnetic recording medium having high smoothness by immersing a base plate consisting of a high polymer molding into a solvent which dissolves the oligomer cintained in the base plate then taking out the base plate, subjecting the same to a heating treatment below the melting and decomposing temp. and cleaning away the oligomer depositing on the surface. CONSTITUTION:A base plate 41 consisting of a high polymer molding such as a polyethylene terephthalate film or the like is immersed in a solvent which can dissolve the oligomer contained therein, by which the base plate is precleaned. For example, a polyetheylene terephthalate base plate (abbreviated as PET) is immersed in acetone and oligomer is removed by prewashing and thereafter the base plate is kept put in a thermostatic chamber for about 1hr at 180 deg.C to deposite the internal oligomer. The base plate is then cleaned again by the acetone to dissolve the oligomer away. The base plate is cleaned with alcohol to remove the acetone and thereafter gaseous N2 is blown thereto to remove the alchol. A magnetic layer is coated or deposited by vacuum evaporation on such base body. Not only the deposition of the oligomer by the effect of heat during formation of the magnetic layer but also the deposition after production are thus obviated by two stages of oligomer removal. The smooth magnetic recording medium having an excellent electromagnetic converting characteristic and durability is obtd.
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