| 摘要 |
A dispersion comprising fine porous inorganic oxide particles, e.g., silica gel particles, wherein the particles have a median particle size below three microns. The dispersed particles have a porosity after drying in which at least about 0.50 cc/g of pore volume is from pores having a pore size of 600 .ANG. or less as determined by nitrogen porosimetry. Embodiments prepared fr om silica gel have porosity after drying in which at least about 0.7 cc/g of po re volume is from pores having a diameter of 600 .ANG. or smaller. The particle s of the dispersion also can be described as having viscosity derived pore volume of at least about 0.5 cc/g. The dispersion is prepared by forming a dispersion from inorganic oxides having sufficient rigid structure to mainta in porosity after milling and drying. After the inorganic oxide is selected, it is milled to have a median particle size of 0.05 to about 3 microns. In embodiments in which stable dispersions of fine porous particles are desired without the addition of substantial amounts of dispersant, or if dispersions having a median particle size less than one micron are desired, the dispersi on is created by, for example, centrifuging the milled slurry to obtain a settl ed phase and a supernatant phase in which the median particle size is in the range of0.05 to about 1 micron. The supernatant phase is then separated from the settled phase to create the final product. |
