New carbonaceous pigments are obtainable by pyrolysis of substrates coated with one or more metal oxides and colloidal organic particles, and opt. with an organosilane, at temps. above 700 degrees C in the absence of O2. Also claimed is a process for producing the pigments, comprising adding a hydrolysable metal salt soln. and an aq. organic colloid soln. simultaneously but separately to an aq. substrate suspension while adding a base or acid to adjust the pH to a value at which the metal salt is hydrolysed; opt. adding an organosilane and/or an aq. organic colloid soln.; separating, washing and drying the coated substrate; and calcining the substrate at a temp. above 700 degrees C in the absence of O2. Also claimed is the use of carbonaceous pigments in formulations such as paints, lacquers, printing inks, plastics and cosmetics. Pref. the substrate is a flaked material, esp. mica (opt. coated with metal oxide) or glass, silica or ceramic flakes. The colloidal organic particles comprise starch, cellulose, gelatin or their derivs. The organosilane is of formula Y(CH3)nSi(X)3, where Y = NH2, vinyl, methacryloyloxy, 2,3-epoxypropoxy, NHCH2CH2NH2, SH, Cl or 2-imidazolin-2-yl; X = 1-6C alkoxy, Cl or acetoxy; and n = 0-3. The metal salt is a Ti salt or trivalent Ce salt.
展开▼
