Process for making structural aggregate pigments

Claim 1

A process for the manufacture of single-component and multicomponent structural aggregate pigment products from particulate matter, said particulate matter being selected from the group consisting of naturally occurring and synthetic minerals, non film forming organic emulsion polymers, latex adhesives, and color pigments treated with complex functional microgels, comprising the steps of: (a) preparing, in-situ, a subcolloidal reactive hydrosol by blending aqueous solutions, one of which contains at leas one compound selected from the group consisting of alkali-metal silicates and quaternary ammonium silicates in amounts of from 0.1% to 2.0%, by weight, and the other of which contains at least one compound selected from the group consisting of alkali-metal aluminates and alkali-metal zincates in amounts of from 0.1% to 2.0% by weight, each in an aqueous dispersion of quantitatively predominant particulate matter wherein the ratio of silicate to aluminate or zincate is from 10:1 to 1:10; (b) blending an aqueous solution containing at least one gel-setting agent selected from the group consisting of bivalent and multivalent inorganic salts in amounts of from 0.5% to 10.0%, by weight, and organic cationically-active chemical compounds with at least two reactive groups in each molecule in amounts of from 0.1% to 5.0%, by weight, with the resultant system from step (a) to crosslink the in-situ formed subcolloidal reactive hydrosol and synthesize said complex functional microgels, wherein the particulate matter flocculates instantaneously, indiscriminately and completely to form a structural aggregate pigment product; and (c) recovering said structural aggregate pigment product from step (b).