Patent ID: 6270566
Filing Date: 2001-08-07
Classification: C01P,C04B,C09C

Abstract:
A process for coloring inorganic building materials which comprises:(a) combining particulate inorganic building materials with microgranulates of pigments, said microgranulates(i) being substantially free of organic liquefiers;(ii) consisting essentially of one or more inorganic pigments selected from the group consisting of iron, chromium, manganese and titanium oxides, and from about 0.05 to about 1 percent (%) by weight, calculated as oxide and based on the quantity of pigment, of one or more boron, aluminum, silicon, titanium, zinc or tin compounds;(iii) having an average particle size between about 50 and 500 .mu.m; and(iv) being sufficiently unstable to shearing forces such that they break down and disperse the pigment in the building materials substantially as if the pigment was not microgranulated; and(b) mixing the combination of building materials and microgranulates thereby subjecting the combination to shearing forces which break down the microgranulates and intimately disperse the pigment throughout the building materials to impart a final color intensity to the building materials.