| 摘要 |
Textile fibres are bleached by treating them with an aqueous solution containing a peroxy compound and a di-carboxylic acid anhydride at least one hydrogen atom of which is substituted by an electronegative group, e.g. a No2-, Cl-, Br-, HSO3- or Na So3- group. The peroxy compound may be a monohydrated or tetrahydrated perborate, a percarbonate, a perpyrophosphate, urea peroxyhydrate, hydrogen peroxide or a mineral or organic peroxide. Suitable substituted dicarboxylic acid anhydrides are 3-introphthelic acid anhydride, 4-intro phthalic acid anhydride and 4-chlorophthalic acid anhydride and mixtures thereof. The bleaching solution, which may contain the peroxy compound in a concentration such that the bath has an active oxygen content of 20-500 mg of active oxygen per litre, is preferably adjusted to a pH of 7-11 and maintained at a temperature of 30 DEG -80 DEG C. The solution may contain 0.4-2 molecules of substituted dicarboxylic acid anhydride per molecule of peroxy compound. Specification 550,490 is referred to. |
