| 摘要 |
PROBLEM TO BE SOLVED: To improve a volumetric recording density and to obtain excellent recording and reproducing characteristics by specifying the arithmetic average roughness (Ra) on the surface of a recording layer on the side to be irradiated with a beam to <=0.010μm. SOLUTION: A soln. which is prepd. by mixing Ni indoaniline dyestuff and ketone resin having a mol.wt. of 700 to 900 at a weight ratio of 80:20 and mixing this mixture at 6wt.% with a solvent. formed by mixing methyl ethyl ketone (b. p. 79.5 deg.C) and cyclohexanone (b. p. 156.5 deg.C) at a weight ratio of 60:40 is applied on a polyethylene terephthalate film having 20μm thickness by a bar coater and the coating is dried, by which the recording layer having 0.5μm thickness is formed. The coating conditions are a substrate transporting speed of 5m/min and a count #8 of a bar is used. The drying conditions are 60sec at 25 deg.C and in succession 60sec at 90 deg.C and 30% humidity. |
