| 摘要 |
PURPOSE:To improve dispersibility, surface property, and abrasion resistance of a magnetic powder by using a binder composed of at least nitrocellulose and a urethane resin, and a magnetic layer contg. a titanate type coupling agent. CONSTITUTION:Nitrocellulose and a polyurethane resin are generally used by 10-40pts.wt., preferably, 10-25pts.wt. per 100pts.wt. magnetic powder. A titanate type coupling agent is used by 0.5-15pts.wt., preferably, 0.5-8pts.wt. Nitrocellulose is exemplified by ''Cellnova BTH1/2'' and ''Nitrocellulose SL- 1'', etc. The one having 1-1/4sec viscosity is excellent. A titanate type coupling agent having six ligands and represented by the formula: (R<1>-O-)4Ti[P (OR<2>)2OH]2 is preferable. A dispersing agent is added in the range of 1- 20pts.wt. per 100pts.wt. of said binder, and an abrasive agent is added in the range of 1- 20pts.wt. per 100pts.wt. binder, and they are dissolved in an org. solvent, and the supporting base is coated with a coating soln. contg. them. |
