ENVELOPE-COVERED SODIUM PERCARBONATE PARTICLES, METHOD FOR THEIR PREPARING, THEIR APPLICATION IF DETERGENT COMPOSITION AND DETERGENT COMPOSITION CONTAINING THEREOF Russian patent published in 2004 - IPC

FIELD: chemical industry, detergents. SUBSTANCE: envelope-covered sodium percarbonate particles are prepared by mixing sodium percarbonate particles not covered by envelope with solution containing mixture of solutions of alkaline metal carbonate and silicate. The mole ratio SiO₂/Na₂O in alkaline metal silicate = from 1 to 4. Mixing is carried out in mixer at temperature from room temperature to 50 C to obtain moist envelope-covered particles. Prepared particles are removed from mixer and dried in drier with fluidized bed using hot air flow at 50-90 C. Envelope-covered particles comprise a core prepared of sodium percarbonate and envelope comprising at least 40 and not above 70 weight % of alkaline metal carbonate, at least 30 and not above 60 weight % of alkaline metal silicate and less 5 weight % if sulfate, borate and magnesium compounds. Envelope represents a homogenous dispersion of alkaline metal carbonate or silicate, Envelope part is from 1 to 5 weight % of envelope-covered sodium percarbonate. The content of active oxygen is 12-15 weight %, volume density is 0.9-1.2 g/cm³, absorbing moist index is 10-100 g/kg, dissolving time is 0.5-3 min., abrasion index is from 0.5-5%, thermostability is 0.1-12 mcWt, mean particles size is 500-900 mcm, surface area is 2-6 m²/kg. Detergent compositions containing particles as bleach component can comprise zeolite or non-zeolite component. Invention can be used in producing detergent compositions. EFFECT: improved preparing, valuable properties of particles. 11 cl, 1 tbl, 1 ex