METHOD OF DYEING MINERAL CRUMB Russian patent published in 2004 - IPC

FIELD: manufacture of building materials. SUBSTANCE: objective of invention is to provide method for dyeing stone or shale mineral crumb (grit) used in manufacture of colored decorative coatings, which method would allow formation of strong coating from a crumb fraction 0.1-3 mm and would not require complex equipment. For that objective, mineral crumb is treated such that its surface is covered by colorant envelope after the stirring of crumb with a colorant in rotary-drum mixer. The colorant is a suspension of pigments in polymethylphenylsiloxane varnish. Crumb is first added into mixer, which is then evacuated to residual pressure 450-500 mm Hg, after which colorant is introduced, the total is stirred during 10 min, mixer is further evacuated to residual pressure 45-50 mm Hg and heated, while being periodically stirred. EFFECT: facilitated process and increased coating adhesion. 3 cl, 1 dwg, 2 ex