METHOD OF PREPARING ATMOSPHERE-RESISTANT PIGMENT FROM TITANITE CONCENTRATE Russian patent published in 2004 - IPC

FIELD: varnish-and-paint industry.

SUBSTANCE: titanite concentrate with Fe₂O₃ content no more than 1.5% is subjected to heat treatment at 400^оС for 40 min and a modifier is added, namely mixture of (i) particles containing 5-30% silicic acid gel calcined at 800-900^оС and coated with 1-5% cobalt phosphate with (ii) particles containing, dried at 100-120^оС, mixture of 35-45% aluminum triphosphate and 20-30% silicic acid gel coated with 10-20% cobalt phosphate. Modifier can further be supplemented with 1-3% powdered daylight fluorescent organic pigment (Belofor) to transform absorbed light portion into visible emission. Material is subjected to dry ultrafine grinding to achieve particle size below 10 mcm. Pigment shows whiteness 87-96 rel. units., oil capacity 20-24 g/100g, yellowness 10-18 rel units, light resistance (4 h) 0.25-0.3 rel units, stratification resistance of paint 6 months. Lacquer containing prepared from the pigment was tested in artificial weather apparatus and was not changed in its color and smoothness after 500 h.

EFFECT: improved performance characteristics.

2 cl, 2 tbl, 6 ex