Patent ID: 8039517

Claim:
A method of preparing a sol of particles suspended in an organic medium comprising the following steps: a) providing a suspension of particles in an aqueous medium; b) adding an organic liquid compatible with the aqueous medium to form an admixture wherein the concentration of particles in the admixture is less than or equal to 40 percent by weight based on the total weight of the admixture; c) maintaining the admixture at a temperature and pressure and for a time sufficient to reduce the water content to less than 30 percent by weight based on the total weight of the admixture while simultaneously adding a water-compatible organic liquid at a rate sufficient to maintain a concentration of particles in the admixture at less than or equal to 50 percent by weight based on the total weight of the admixture, wherein the water-compatible organic liquid is the same as or different from the organic liquid used in step (b); and d) adding a polysiloxane which is non-reactive with the water and the organic liquid in the admixture and, optionally, an organic liquid compatible with the liquid portion of the admixture wherein the organic liquid is the same as or different from the organic liquid used in step (c); while maintaining the admixture at a temperature and pressure and for a time sufficient to provide a sol of particles comprising 1 percent by weight or less of water based on the total weight of the admixture; and wherein step d) follows step c); and wherein the polysiloxane has at least three Si atoms and at least one of the following structural units (I): R 1 n R 2 m SiO ( 4−n−m)/2 (I) wherein each R 1 independently represents a monovalent hydrocarbon having 1 to 6 carbon atoms or a non-reactive monovalent siloxane; wherein each R 2 independently is R 3 —X, and wherein R 3 is selected from at least one of alkylene, oxyalkylene, alkylene aryl, alkenylene, oxyalkenylene, alkenylene aryl; and X represents a group having at least one reactive functional group selected from at least one of hydroxyl, carboxyl, blocked isocyanate, primary amine, secondary amine, amide, carbamate, urea, urethane, vinyl, unsaturated ester, maleimide, fumarate, onium salt, anhydride, hydroxy alkylamide, and epoxy; and 0<n<4; 0<m<4; (4−n−m)/2 equals a whole number; and 2≦(m+n)<4.