Abstract: Dry, freely-flowing, water-insoluble but readily dispersible, solid and homogeneous silica pigment particulates essentially spheroidal in geometrical configuration and having a mean particle size in excess of 80.mu., preferably in excess of 150.mu., are prepared by atomizing to dryness a pulverulent aqueous suspension of silica having a solids contact in excess of 18%. Such silica pigment particulates, advantageously comprised of precipitated silica, are well adapted as reinforcing fillers for elastomeric matrices.

Abstract: Process for the manufacturing of silicas having a specific surface area ranging between 100 and 600 sq m/g, which does not vary upon drying, due to the action of a strong acid on an alkaline silicate, characterized by the fact that the addition of strong acid to the alkaline silicate is interrupted one to three times.

Abstract: A hydrophilic polyurethane composition comprising a reaction product of:1. 10 to 45 weight percent of an organic diisocyanate and,2. 35 to 89 weight percent of a compound containing one or two active hydrogen atoms selected from:A. 75 to 100 weight percent of a compound of the general formula:R--(O--C.sub.x H.sub.x).sub.n -OHwhereinR is hydrogen or a hydrocarbon radical containing from 1 to 20 carbon atoms;X is a number from 2 to 4;n is a number to indicate that the molecular weight is between 300 and 10,000; and,B. 0 to 25 weight percent of a diol and,3. 1 to 25 weight percent of a nitrogen-containing compound of the general formula: ##STR1## wherein R' is an alkyl radical containing from 1 to 5 carbon atoms;X.sub.1 and X.sub.2 are hydroxyalkyl or amino alkyl radicals with the proviso that the overall ratio of NCO/active H is from about 0.7 to about 1.