CARBON BLACK FOR COLORING CEMENT AND METHOD FOR COLORING MOLDED CEMENT ARTICLE

摘要

A carbon black for coloring cement which has been surface-treated with an aqueous solution containing humic acid dissolved therein and which has humic acid adsorbed thereon, preferably a carbon black having humic acid adsorbed thereon which is prepared by wet granulating a carbon black powder using an aqueous solution containing humic acid dissolved therein as a granulation water, followed by drying; and a method for coloring a molded article of cement using the carbon black which comprises adding an aqueous suspension of a carbon black having humic acid adsorbed thereon to a cement slurry, followed by mixing, or adding a carbon black having humic acid adsorbed thereon directly to a cement slurry, followed by mixing. The carbon black for coloring cement is excellent in dispersibility into a cement slurry and has high adhesiveness to a cement matrix, and also is excellent in coloring properties and strength properties of the resulting cement article.