Silane reactive mineral fillers

Claim 1

An organosilane modified metal silicate treated inorganic mineral composition, said composition having been produced by a process which comprises contacting a water-insoluble metal silicate treated inorganic mineral product, said product having been produced by a process which comprises (a) contacting in the presence of water, the surface of naturally occurring water-insoluble calcium carbonate with a precipitated, undried water-insoluble metal silicate salt wherein the metal of said salt is selected from the group consisting of aluminum, barium, beryllium, cadmium, calcium, cobalt, copper, iron, lead, lithium, magnesium, manganese, mercury, nickel, silver, strontium, tin, zinc, zirconium, and the rare earth metals having atomic numbers from 57 to 71 inclusive, and mixtures thereof, wherein the amount of said water-insoluble metal silicate salt employed ranges from about 0.1 parts by weight to about 20.0 parts by weight per 100 parts by weight of said water-insoluble calcium carbonate, and (b) drying said water-insoluble metal silicate salt on the surface of said water-insoluble calcium carbonate; with an organosilane coupling agent selected from the group consisting of organo-functional silanes having the formula ##STR4## wherein R which contains a carbon atom directly bonded to the Si atom of the above formula represents a functionally substituted organic radical, R' represents a radical selected from the group consisting of R and monovalent hydrocarbon radicals, a has a value of 0 or 1, and X represents a hydrolyzable group, the hydrolyzates of said silanes, the condensates of said silanes, and mixtures thereof.