GB555410A - Manufacture of alcohol-soluble dyestuffs - Google Patents

Abstract

555,410. Dyes. GEIGY AKT.-GES., J. R. Jan. 20. 1942, Nos. 809 and 810. Convention dates, Jan. 22, 1941 and Nov. 27, 1941. [Class 2 (iii)] Azo dyes in the form of salts, insoluble in water but soluble in alcohol, are-obtained by precipitating by means of a: basic dyestuff, an azo dyestuff containing at least one water solubilizing acid group, and at least one hydroxyl group acylated by an arylsulphonic acid. When the azo dyestuff contains more than one water-solubilizing group, the amount of the basic dyestuff used may be reduced to about an equimolecular amount, the balance necessary for the precipitation being replaced by one or more other organic bases, e.g. aniline, toluidines, xylidines, aminodiphenyl compounds, arylguanidines and arylbiguanides. Products of a colour more closely approaching that of the acid dyestuff component may be thus obtained. Examples of the use of basic dyestuffs only as precipitating agents relate to (1) the precipitation, with Rhodamine 6G extra or Rhodamine B, of the acid azo dyestuff, benzidine-2-sulphonic acid<SP>#</SP># 1 - (4<SP>1</SP>-sulpho) phenyl - 3 - methyl - 5 - pyrazolone (1 mol.) and phenol (1 mol.), of which the phenolic group is finally esterified with ptoluenesulphonic acid chloride.; the products are suitable for colouring cellulose ester lacquers in pure brilliant shades, fast to light, (2) the precipitation with Rhodamine 6G extra, Rhodamine B or Auramine 00 of the acid azo dyestuff, 4 - amino - 2<SP>1</SP> - methyl - diphenyl ether - 2-sulphonic acid # 1 - naphthylamine - 6 - or 7 - sulphonic acid # phenol, of which the phenolic group is finally esterified as in (1), (3) the precipitation with Rhodamine B extra of the acid azo dyestuff, 4 : 4<SP>1</SP> - diaminostilbene - 2 : 21-disulphonic acid <SP>#</SP># phenol (2 mols.), of which the phenolic groups are finally esterified as in (1). A table is also given showing the shades obtainable with the products of precipitation with various basic dyestuffs, selected from those specified above and Setoflavine T, or mixtures thereof, of the following acid azo dyestuffs, viz. (a) 4 - amino - 4<SP>1</SP> - nitro diphenylamine - 2<SP>1</SP> - sulphonic acid # phenol, of which the phenolic group is finally esterified with p-toluenesulphonic acid chloride, (b) and (c), 1 : 4-diaminobenzene-2-sulphonic acid<SP>#</SP># (b) 2 : 8 : 6 - aminonaphtholsulphonic acid, (c) 2 : 8 : 3 : 6 - aminonaphthol - 3.: 6 : disulphonic acid (1 mol. coupled acid) and phenol (1 mol.), of which the phenolic group is finally esterified as in (a), (d) benzidine <SP>#</SP># 2 : 6 : 8 - naphtholdisulphonic acid (1 mol.) and phenol (1 mol.) of which the phenolic group is finally esterified as in (a), (e) 4 - amino - 4<SP>1</SP> - nitro - diphenylamine - 2 - sulphonic acid # 1 - naphthylamine - 6 - or 7 - sulphonic acid # phenol, of which the phenolic group is finally esterified as in (a), (f) 2 - amino - 2 <SP>1</SP> - methyl - diphenyl ether - 4 - sulphonic acid # 2 : 8 : 3 : 6 - aminonaphtholdisulphonic acid (coupled alkaline) # phenol, of which the phenolic group is finally esterified as in (a), (g) 4 - amino - 21 - methyl - diphenyl ether - 2 sulphonic acid # 1 - naphthylamine - 6 - or 7 - sulphonic acid # phenol, of which the phenolic group is finally esterified as in (a), (h) 2 - amino - 2<SP>1</SP> - .- methyl - diphenyl ether # 1 : 8 - dihydroxynaphthalene - 3 : 6 - disulphonic acid of which one naphtholic group is esterified with p - - toluenesulphonic acid, and (j); (i) 4 - aminophenol - 2 - sulphonic acid, (j) 2 - amino - 4 - chloro - 21 - methyl - diphenyl ether, # - naphthylamine - 6 - or - 7 - sulphonic acid # 1 - naphthylamine - 6 - or 7 - sulphonic acid# phenol, the phenolic 'group or groups being finally esterified as in (a). Examples of the replacement of part of the basic dyestuff by other amines relate to (4) the precipitation with Rhodamine 6G extra, p - toluidine and N- phenylbiguanide of the acid azo dyestuff, 4 - amino-diphenyl ether - 2 - sulphonic acid# 1 - naphthylamine - 6 - or 7 - sulphonic acid # phenol, of which the phenolic group is finally esterified with p - toluenesulphonic acid chloride, (5) the precipitation with Auramine O, Rhodamine 6G extra, p - toluidine and N - phenylbiguanide, sym.- diphenyl- or dio - tolyl-guanidine, N - cyclohexylaniline or dicyclohexylamine of the acid azo dyestuff in (1).