Abstract: A polymer nucleating agent is composed of inorganic particles carrying an anchor layer capable of bonding to an organic acid, such as alumina-coated silica particles, and having a surface coating of a substituted or unsubstituted benzoic acid compound.

Abstract: A hydrophilic powder such as silica, adapted for dispersion in organic solvents and polymers, is provided with a coating over the outer surface of the powder particles to modify the surface characteristic from polar to non-polar or organophilic, whereby the thus coated powder is readily dispersible without agglomeration or enlargement of the powder particles. Preferred are nano-sized powders.

Abstract: Hollow microspheres of reduced surface energy and reactivity and of improved packing and sphericity are prepared by simultaneously forming said microspheres and reacting them with an 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, penetrates and reacts to form a shell consisting of a silicate, polysalt and the organosilicon compound. 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.