Patent GB-351400-A (GB)
Title: A process for dyeing loaded silk
Filed: 1930-03-15
Abstract: Acid wool dyes, dyeing with; azo dyes.-Loaded silk is dyed by treatment in a neutral or fatty soap bath with a metal compound of an azo dyestuff derived from an o-oxydiazo or o-carboxydiazo component and an aminonaphtholsulphonic acid such as the 2 : 5 : 7-, 1 : 8 : 4-, or 2 : 8 : 6- acids, or an N-derivative thereof (including derivatives in which the nitrogen of the amino group forms part of an azo group), or with a further conversion product of a reduced monoazo dyestuff containing chromium obtainable from diazotized 5-nitro-2-aminophenol and an aryl-2 : 5 : 7-acid (preferably coupled alkaline).  Such reduced monoazo dyestuffs containing chromium are obtainable by reducing the chromium compound of the dyestuff or by chroming the dyestuff in presence of a reducing agent such as sodium sulphide as described in Specification 295,594, [Class 2 (iii), Dyes &c.], and the further conversion products are obtained therefrom either by treatment with phosgene to form urea derivatives or by diazotization and coupling with a component such as 1-phenyl-3-methyl-5-pyrazolone, naphtholsulphonic acids, aminonaphtholsulphonic acids, salicylic acid, or 1 : 8-dioxynaphthalene-3 : 6-disulphonic acid; if the coupling component contains groups capable of combining with metals the dyestuff may be further treated with agents yielding metals.  In examples of the dyeing process loaded silk is entered at 60 DEG  C. into (1) a sodium sulphate bath and (2) a bath containing Marseilles soap and sodium sulphate, the bath in each case being heated gradually to 80-85 DEG C. and maintained at that temperature for 3/4 -1 hour.  A table is given showing the shades obtained on loaded silk with various copper, chromium, and copper and chromium compounds of the following dyestuffs:-2-aminophenol-4 : 6-disulphonic acid --> (alkaline) 2 : 5 : 7-acid, 5-nitro-2-aminophenol or anthranilic acid --> (alkaline) phenyl - 2 : 5 : 7 - acid, 4 - chloro - 2 - aminophenol --> (alkaline) acetyl-2 : 5 : 7-acid, 4 - 6-dichloro-2-aminophenol or 5-nitro - 2 - aminophenol --> (alkaline) benzoyl-2 : 5 : 7-acid, 2-aminophenol 4 - sulphamide (2 mols.) \sQ (alkaline) 2 : 21 - dinaphthylamine - 5 : 51-dioxy-7 : 71-disulphonic acid or the urea of 2 : 5 : 7-acid, 2-aminophenol-4 : 6-disulphonic acid --> (alkaline) 2 : 5 : 7-acid (acid) \sM 4-chloro - 2 - aminophenol, 4 - chloro - 2 - aminophenol --> (alkaline) 2 : 5 : 7-acid --> (acid) 2 : 5 : 7 - acid (alkaline) \sM 4-chloro-2-aminophenol.  As diazo components are also specified 5-nitro-4-chloro - 2 -aminophenol, 4-chloro-2-aminophenol-6-sulphonic acid, 4-nitro-2-aminophenol-6-sulphonic acid, 6 - nitro - 2 - aminophenol - 4 -sulphonic acid, picramic acid, p-aminosalicylic acid (for use in disazo and polyazo dyestuffs containing also an o-oxydiazo or o-carboxydiazo component), and as coupling components 21-methoxy phenyl-2 : 5 : 7-acid, 21-ethoxyphenyl-2 : 5 : 7-acid, 21-methoxy-41 - methylphenyl - 2 : 5 : 7 - acid, 21 : 41 - dichlorobenzoyl-2 : 5 : 7-acid, 31-nitrobenzoyl-2 : 5 : 7-acid, benzoyl-2 : 8 : 6 - acid, benzoyl - 1 : 8 : 4 - acid, and acetyl-2 : 8 : 6-acid.  The 21-methoxyphenyl, 21-ethoxyphenyl, and 21-methoxy-41-methylphenyl derivatives of 2 : 5 : 7-acid are obtained by heating 2 : 5 : 7-acid with o-anisidine o-phenetidine, and 1-amino-2-methoxy-4-methyl-benzene respectively in presence of sodium bisulphite.  21 : 41-Dichlorobenzoyl-2 : 5 : 7-acid is obtained by heating 2 : 5 : 7-acid with 2 : 4-dichlorobenzoyl chloride at 30-40 DEG  C. in presence of sodium acetate.