COATED ALKALI METAL PEROXOSALTS AND METHOD OF PREPARING THEREOF Russian patent published in 1999 - IPC

FIELD: chemical industry, more particularly preparation of detergents and bleaching agents. SUBSTANCE: alkali metal, more particularly sodium peroxocarbonate, peroxopyrophosphate, peroxotripolyphosphate and/or peroxomonosulphate particles are treated with coating agent, e.g. aqueous solution or suspension of lactabionic acid, salt and/or derivative thereof. Particles thus treated are dried to residual water content of not higher than 0.6 wt %. Coating material further comprises mixtures of sodium or potassium sulfates or chlorides, boric acid and/or salts thereof. Molar ratio of acid to mixture of sulfates or chlorides is from 1:1 to 10:1, weight ratio to mixture of boric acid and/or salts thereof calculated for boron is from 10:1 to 1:3. This coating constitutes at least 80% of weight the entire coating, the remainder being auxiliary substances, such as sodium polyphosphates, polycarboxylates, silicates, phosphonic acids and salts thereof, and magnesium sulphates. Coating constitutes 2-10% of weight of particles. Stability of coated particles at 105 C after 2 h is 9-18%. 100% of particles are completely dissolved after 3 min. EFFECT: improved properties of detergents and bleaching agents. 24 cl, 5 ex, 4 tbl