| 摘要 |
PURPOSE:To enhance electromagnetic conversion characteristics, abrasion resistance, antistatic properties, and light shading property, by incorporating a ferromagnetic powder, and at least 0.1-20wt% titanium monoxide having 0.01-5mum average particle diameter based on the ferromagnetic powder in a magnetic layer. CONSTITUTION:A mixture of 100pts.wt. Co-contg. gamma-Fe2O3 having 20m<2>/g specific surface area, 10pts.wt. vinyl alcohol copolymer, 1pt.wt. lecithin, 300pts.wt. solvent mixture, 1pt.wt. higher fatty acid ester, and 80pts.wt. TiO having about 0.05mum average particle diameter is intermixed and dispersed in a sand mill for about 20hr, about 50pts.wt. polyisocyanate is added to it, and a video magnetic tape is obtained by using this coating material obtained. On the other hand, magnetic tapes are prepared by using a coating material obtd. by substituting Tio with 8pts.wt. Cr2O3 having 0.5mum average particle diameter in said coating material, and 8pts.wt. carbon black having 0.01mum average particle diameter, and the characteristics of these 3 magnetic tapes were measured and compared. As a result, the former product using TiO was found superior in all the characteristics of electromagnetic conversion characteristics (S/N ratio), still characteristics (abrasion resistance), antistatic properties (traveling stability), further, light shading property (prevention of misoperation of tape end detection mechanism), etc. |
