| 摘要 |
PURPOSE:To improve the writing and erasing properties of the titled material by providing with a hydrophilic colloidal layer which contains a prescribed amount of a mat agent having a prescribed particle size, and has a prescribed range of center line average roughness of the surface in the titled material, and also a prescribed range of surface tension on the titled material, respectively. CONSTITUTION:The hydrophilic colloidal layer contg. at least one layer of the mat agent is formed on a supporting body by applying it thereon, and the surface of the titled material at the side of applying the hydrophilic colloidal layer is specified so as to have the center line average roughness of 0.15-0.85mum. And, the hydrophilic colloidal layer is specified so as to contain <=5wt.% the mat agent having more than 6mum the particle size based on the total weight of the mat agent, and have the surface tension of a coating solution of 28-38dyne/cm in the hydrophilic colloidal layer positioned at the most upper layer thereof. The mat agent is exemplified by a fine particle of insoluble org. or inorg. compd. The surface tension of said coating solution is controlled by the kinds and the amount of a surfactant added to the coating solution. |
