GB399040A - Improved process for the manufacture of high-percentage per compounds - Google Patents

Abstract

High-percentage organic per-compounds are obtained by treating water-free organic compounds with aqueous hydrogen peroxide in such a manner that a moist mixture is not even temporarily produced, and thereupon reducing the water content of the product, preferably immediately, or in any case before the water is fully bound, by drying in vacuo, or by passage of hot or cold air or by other means. Stabilizers may be added to either or both of the reactants, or may be formed in the mixture during reaction. Reference is made to the production of a urea per-compound. In this case, stabilizers consist of alcohol, added to the hydrogen peroxide, and solid organic acids, added to the urea. The hydrogen peroxide may be added in stages, with intermediate drying. In this modification, final drying is optional. Fresh portions of the solid reactant may be added before or after or simultaneously with the solution. This latter may be added in atomized form, preferably into the finely divided solid material falling through a sieve, or both reactants may be injected into the reaction chamber through nozzles. When heated air is used for this purpose, drying is also effected.ALSO:High-percentage peroxides, per-salts, or organic per-compounds are obtained by treating water-free metallic oxides or salts or organic compounds with aqueous hydrogen peroxide in such a manner that a moist mixture is not even temporarily produced, and thereupon reducing the water content of the product, preferably immediately, or in any case before the water is fully bound, by drying in vacuo, or by passage of hot or cold air or by other means. Stabilizers such as pyrophosphoric acid, pyrophosphates, water-glass, protalbinic acid, gum arabic, sodium chloride, boric acid and tin chloride may be added to either or both of the reactants, or may be formed in the mixture during reaction. To this end, the following combinations may be added respectively to the solid and liquid components:--magnesium chloride--water-glass, alkali stannate--sulphuric, phosphoric or hydrofluoric acid, tin fluoride-phosphoric acid. Reference is made to the production of sodium, calcium and magnesium peroxides, sodium percarbonate and perphosphate, and a urea per-compound. In this latter case, stabilizers consist of alcohol, added to the hydrogen peroxide, and solid organic acids, added to the urea. The hydrogen peroxide may be added in stages, with intermediate drying. In this modification, final drying is optional. Fresh portions of the solid reactant may be added before or after or simultaneously with the solution. This latter may be added in atomized form, preferably into the finely divided solid material falling through a sieve, or both reactants may be injected into the reaction chamber through nozzles. When heated air is used for this purpose, drying is also effected. A statement of the prior art refers to the production of percarbonates by treatment with hydrogen peroxide solution of a carbonate which has lost part of its water of crystallization, or of a mixture of anhydrous soda and powdered soda crystals. The pasty mass is freed from mother liquor and dried.