| 摘要 |
PURPOSE:To prevent the sedimentation of silica by improving the dispersion properties and stability with time of silica slurry used as a coating fluid for a recording medium, and to facilitate coating work, particularly continuous coating work onto the surface of the recording medium. CONSTITUTION:5-30wt.% porous silica powder as sedimentating porous silica gel preferably having mean particle size of 2-15mum, an aqueous group solvent, a binder, in which the weight ratio of porous silica powder to the binder is 15:0.5-15:5, and polyalkylene polyamine, preferably polyethylene imine at 0.005-0.1wt.% to porous silica powder are compounded. |
