COATED ALUMINUM ALLOY PLATE FOR RECORDING MEDIUM CASSETTE SHUTTER AND RECORDING MEDIUM CASSETTE SHUTTER CONSISTING OF THIS COATED ALUMINUM ALLOY PLATE

摘要

PURPOSE: To obtain a coated aluminum alloy plate for shutter for recording medium cassette which is free from tacky adhesion to polyethylen recording film even if this film is preserved over a long period of time under a pressure in a housing case of a recording medium cassette. CONSTITUTION: Solid particles are dispersed into the coating film of the aluminum alloy plate formed with this coating film and the surface roughness of the coating film is >=0.2μm in center line average height Ra and >=1.0μm Rp. A range of 0.2 to 1.0μm Ra and 1.0 to 10.0μm Rp is more preferable. An Al-Mg alloy plate contg. 3 to 6% Mg as an essential alloy component is adequately used as the aluminum alloy plate.