GB1339256A - Activators for peroxy compounds - Google Patents

Abstract

1339256 Bleaching oils and fats HENKEL & CIE GmbH 30 July 1971 [31 July 1970] 35853/71 Heading C5C [Also in Divisions A5-A6 D1-D2 and C6-C7] Oils, fats and waxes are bleached using a peroxy-compound activated by the addition of a 1,4-diacylated 2,5-diketopiperazine activator having the Formula I in which R 1 and R 2 are preferably the same and each represent a hydrocarbon group having 1 to 8 carbons which may be substituted and R 3 and R 4 are preferably the same and each represent a hydrocarbon group having 1 to 3 carbons which may be substituted. Preferred groups R 1 , R 2 are methyl ethyl, n- or isopropyl, phenyl, tolyl or xylyl residues, optionally substituted by C 1-3 alkoxy, halogen, nitro, or cyano groups. Preferred groups R 3 , R 4 are methyl or ethyl residues, optionally substituted by hydroxyl, halogen, nitro, cyano, methoxy or ethoxy groups. Specified peroxy-compounds include hydrogen peroxide, addition products of hydrogen peroxide and urea or melamine, peroxyhydrates such as perborates, percarbonates, persilicates and perortho-, perpyro- and perpoly-phosphates, and salts of peroxymono- or peroxydisulphuric acid. The activator and peroxy compound may be formulated as a bleaching and/or oxidizing liquid, which may also contain anionic, cationic, non- ionic or amphoteric detergents, alkaline substances and complex forming substances for binding water hardening substances and heavy metal ions. The liquid preferably has a ratio of 0À5-6 acyl residues per active oxygen atom, and may be used at a pH from 7-13. Bleaching may be effected at ambient or elevated temperatures, or in two stages at different temperatures. Examples describe the activation of perborate in the presence of sodium pyrophosphate with 1,4-diacetyl-2,5-diketo piperazine, 1,4-dipropionyl-2,5-diketo piperazine or 3,6-dimethyl-1,4-diacetyl-2,5-diketo piperazine, and the activation of hydrogen peroxide with the first two activators.