GB758611A - Stabilization of solutions containing peroxygen compounds - Google Patents

Abstract

Peroxygen bleaching solutions are stabilized by the incorporation of a composition comprising a water-soluble magnesium salt and a water-soluble alkalimetal phosphate, the amount of the phosphate being in the proportion of 1 to 5 parts by weight, on an anhydrous basis, for each part of magnesium salt calculated as magnesium. Aqueous solutions of sodium or hydrogen peroxide or mixtures thereof may be stabilized. The magnesium salt may be the sulphate, chloride, nitrate or acetate in anhydrous or hydrated form and the phosphate may be the tetraphosphate, pyrophosphate, tripolyphosphate, hexametaphosphate or normal orthophosphate of sodium or potassium. The bleaching solution may also comprise sodium silicate, and pH adjustments may be made with cautic soda, soda ash or an acid. Materials which may be bleached with the stabilized bleaching solutions include textile fibres and fabrics composed of cotton, regenerated cellulose, silk or synthetic fibres; wood; wood pulp and feathers. In examples, (8) regenerated cellulose filaments are formed into a loose yarn continuous with their production and are passed successively through the following stages: acid, water-wash, sulphide, wash, bleach, acid, wash, soap, dry; (9) kier-boiled and washed cloth is taken from a storage pit successively through a washer, a hot-water filled saturator, a squeezer, a first and second U-tube containing heated bleach solution, a final squeezer and a washer; (10) bleached cloth is after-treated with steam.