| 摘要 |
In dispersions of mixed oxide particles containing silicon dioxide and cationic polymer, the amount of cationic polymer can be 25% decreased by doping the silicon dioxide with 0.25 wt.% aluminum oxide without affecting the positive surface charge on the particles. A stable aqueous dispersion contains flame-hydrolytically prepared mixed oxide particles containing silicon dioxide and aluminum oxide or titanium dioxide, with a BET (Brunauer Emmett Teller) surface area between 5 and 600 m2/g, which shows a negative zeta potential, and a dissolved cationic polymer of weight average mol. wt. less than 100,000 g/mole, the dispersion having a positive zeta potential. Independent claims are also included for the following: (1) a process for preparation of the dispersion involving predispersion and final dispersion, where before predispersion the cationic polymer is included in an aqueous medium or is added during dispersion, or the mixed oxide particles and cationic polymer are added alternately; (2) a brushing on paint for formation of an ink acceptance layer using the dispersion and at least one hydrophilic binder; (3) a process for preparation of the brushing on paint by addition of the dispersion to a solution of hydrophilic binder, optionally with addition of other additives, followed by dilution to the required ratio of mixed oxide and binder and the desired total solids content; (4) an ink take up medium using a brushing on paint; and (5) a method for preparation of the ink take up medium involving application of the brushing on paint to a carrier and drying. |
