A process for stabilising particulate alkali metal percarbonate involves coating it with an aqueous solution, preferably concentrated, of a non-reducing oligomeric saccharide, preferably sucrose and especially together with an inorganic salt co-coating agent. The preferred co-coating agents are alkali metal silicate, sulphate, carbonate and carbonate chloride. Coated percarbonate is provided having an excellent combination of solubility, and stability, even with low amounts of coating agent.
A bleaching detergent formulation comprising the components of: (A) particles comprising 0.01 to 50% by weight, based on the particles, of a compound represented by formula (I): ##STR1## wherein R.sup.1 represents a straight-chain alkylene or alkenylene group having 2 to 8 carbon atoms, a cycloalkylene or cycloalkenylene group having 3 to 8 carbon atoms or a phenylene group; R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, each represent a methylene group, a straight-chain alkylene or alkenylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 8 carbon atoms or a phenylene group; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may each have a substituent or substituents selected from an alkyl, alkenyl, alkynyl, alkoxy or halogenated alkyl group having up to 8 carbon atoms, a cycloalkyl or cycloalkenyl group having 3 to 8 carbon atoms, an aryl group, an aryl group having a straight-chain alkyl group having 1 to 18 carbon atoms, a hydroxyl group, a phenoxy group, a halogen atom, an amino group, a sulfuric acid radical, a sulfo group, a nitro group, and a carboxyl group; M represents a metal selected from transition metals having a I, II, III, IV, V, VI, VII or VIII-valent oxidized state; and X represents a counter ion in equilibrium with the compound's charges on a stoichiometric basis; and (B) a percarbonate.
The invention relates to a process for the production, by fluid-bed spray granulation, of granular sodium percarbonate having a low TAM value. According to the invention, in the fluid-bed spray granulation, an Mg compound in a quantity of 50 to 2,000 ppm, in particular 100 to 1,000 ppm, or/and a complexing agent from among the hydroxycarboxylic acids, aminocarboxylic acids, aminophosphonic acids and phosphonocarboxylic acids, hydroxyphosphonic acids and their alkali metal salts, ammonium salts or Mg salts, in a quantity of 50 to 2,000 ppm, in particular 200 to 1,000 ppm, are added as stabilisers to the soda solution and/or H.sub.2O.sub.2 solution. Preferably a combination of an Mg compound in a quantity of 100 to 1,000 ppm Mg.sup.2+ and waterglass in a quantity of 0.1 to 1 wt. %, in particular 0.1 to 0.5 wt. %, is used, and in this case granules having a TAM value of about or below 6 .mu.W/g and simultaneously a short dissolving time, are obtainable.
