GB648715A - Manufacture of ester-like derivatives of ortho:ortho-dioxy-monoazo-dyestuffs - Google Patents

Abstract

Ester-like derivatives of o : o1-dihydroxymonoazo dyestuffs containing a single sulphonic acid group are manufactured by treating the dyestuffs, in an aqueous alkaline medium, with organic acylating agents which contain as the sole acylating group a functionally converted carboxyl group and which are otherwise free from groups imparting solubility and substituents convertible into such groups by hydrolysis. As starting materials may be employed any monosulphonated monoazo dyestuffs containing the grouping <FORM:0648715/IV (c)/1> and especially those containing at least once the residue of a component of the benzene or naphthalene series, obtainable by coupling the diazo compound of an o-aminophenol or o-aminonaphthol, which may contain further substituents (e.g. halogen atoms or nitro, alkyl, alkoxy or sulphonic acid amide groups) with a component coupling in vicinal position to a phenolic or enolic hydroxy group, e.g. hydroxybenzenes, 8-hydroxyquinolines or especially hydroxynaphthalenes coupling in o-position to the hydroxy group, acetoacetic arylides, 2 : 4-dihydroxyquinoline, or pyrazolones, especially 1-aryl-3-methyl-5-pyrazolones. Specified components are those enumerated in Specification 636,681 and additionally in that Specification as open to inspection under Sect. 91. Suitable acylating agents are those referred to in the said Specification, and the products may be used for the purposes therein described. In dyeing by the single bath chroming process it s sometimes advantageous to add a wetting or dispersing agent, which may be ionogenic or preferably non-ionogenic, e.g. a polyglycol ether of a fatty alcohol of high molecular weight. Examples describe esterifications in aqueous solutions of sodium acetate and caustic soda, or caustic soda alone, or sodium carbonate, and the dyeing of wool with certain of the products. Specification 380,431 also is referred to. The Specification as open to inspection under Sect. 91 comprises also the treatment of other o : o1-dihydroxymonoazo dyestuffs, and the use of other acylating agents, maleic and terephthalic anhydrides being additionally specified. This subject-matter does not appear in the Specification as accepted.