| 摘要 |
PROBLEM TO BE SOLVED: To prevent deformation of a nonmagnetic support elution of the component by heat or cracking in a film forming process and to obtain a record medium having excellent characteristics at a low cost by forming a base coating layer comprising a polyamide imide resin on a nonmagnetic support and forming a ferromagnetic metal thin film by vacuum film forming method thereon. SOLUTION: When a polyamide imide resin is applied as a base coating layer on a nonmagnetic support, the coating liquid is prepared to have 0.5 to 10 wt.% concn. by using a general solvent containing no fluorine. such as 1/1 mixture solvent ofγ-butyrolactone/cyclohexanone, 1/1 mixture solvent of tetrahydrofuran/cyclohexanone, 1/1 mixture solvent of ethanol/toluene, 1/1 mixture solvent of dioxane/cyclopentanone, tetrahydrofuran or N-methylpyrrolide. The coating liquid is applied by wire bar method, gravure method, spray method, dip coating method or spin coating method to form a film having 0.05 to 0.8μm thickness after being dried.
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