| abstract |
Hollow microspheres of reduced surface energy and reactivity are prepared by simultaneously forming said microspheres and reacting them with a organosilicon compound. The microspheres are prepared by spray drying a solution of alkali metal silicate and a "polysalt." The organosilicon is present as the microspheres are formed and react to form the surfaces of the spheres. The resulting product is more discrete, more free-flowing, has better packaging characteristics, improved packing factor and improved filler properties when compared to prior-art microspheres. |