GB516929A - Manufacture and use of new azo dyes - Google Patents

Abstract

516,929. Dyes ; dyeing. ELLIS, G. H., and OLPIN, H. C. July 13, 1938, No. 20777. [Classes 2 (iii) and 15 (ii)] Azo dyes are made by coupling a diazo compound with the pyrazolone nucleus of a pyrazolone coupling component, one only of the two components containing a single hydroxyl group which is both attached directly to an alkyl group and esterified to an acid ester of a polybasic acid, and both components being free from sulphonic and carboxylic groups. The esterified hydroxyalkyl group may be derived from a hydroxyalkoxy or hydroxyalkylamino group. The polybasic acid may be. sulphuric acid or phosphoric or phosphorous acids (cf. Specification 506,262), or an acid ester of an inorganic acid containing at least two acidic hydrogen atoms, e.g., a monoalkyl ester of phosphoric acid. The diazo components are preferably of the benzene series. The dyes obtained by coupling diazo compounds of sulphato-alkoxy derivatives of anilines and their nuclear alkyl, alkoxy and halogen derivatives with 1:3-dialkyl-, 3-alkyl- and 1-aryl-3-alkyl-5- pyrazolones and 1-aryl-5-pyrazolone-3-carboxylic esters, of which the 1-aryl group, if present, is a phenyl group which may be substituted by alkyl, alkoxy and halogen from a particularly useful group, as do also the dyes made by coupling diazobenzene or its nuclear alkoxy, alkyl or halogen derivatives with a 1-aryl-3-alkyl-5-pyrazolone or a 1-aryl-5-pyr-, azolone-3-carboxylic ester group ; these two groups dye cellulose acetate in fast yellow shades. The dyes may also be obtained by esterifying the corresponding hydroxyalkylated dyes to acid esters of polybasic acids. The products are dyes for cellulose esters and ethers, and may also be used for dyeing wool, silk and other animal fibres or mixed materials containing two or more types of fibre, e.g., cellulose acetate and an animal fibre or cellulose acetate and cotton or regenerated cellulose. In examples : (1) p-hydroxyethoxyaniline is esterified with sulphuric acid, diazotized and coupled with 1-phenyl-3-methyl-5-pyrazolone, (2) -p-#-hydroxyethoxyaniline is diazotized, coupled with 1-phenyl-3-methyl-5-pyrazolone and esterified with sulphuric acid or phosphorus trichloride, (3) 1-(p-hydroxyethoxyphenyl)-3-methyl-5-pyrazolone (made by condensing p-(hydroxyethoxy)- phenylhydrazine with acetoacetic ester) is coupled with diazobenzene and esterified with sulphuric acid, and (4) cellulose acetate fabric is dyed in a bath made of p-(#-sulphatoethoxy)- benzene-azo-1-phenyl-3-methyl-5-pyrazolone in water, salt being added to assist exhaustion. .Specification 181,750, [Class 2 (iii)] also is referred to.