Patent GB-353046-A (GB)
Title: Improvements in or relating to tanning
IPC: C14C3/08
Filed: 1930-04-09
Abstract: Materials to be tanned are treated with a water soluble compound of the general formula <FORM:0353046/IV/1> in which R is a substituted or unsubstituted arylene or diarylene and R1 and R2 are substituted or unsubstituted bi- or polynuclear arylsulphone-arylamide derivatives of a chain structure in which the sulphone imide groups combining the aryl nuclei may be partly replaced by other acyl amino groups.  An example of a suitable substance is the sodium salt of bis (1 : 2 - dichlorobenzene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid which can be produced by reacting benzidine-m.m1-disulphonic acid with two molecular proportions of 3-nitrobenzene sulphochloride, reducing the condensation product and condensing the diamino compound with two molecular proportions of 1 : 2-dichlorobenzene-4-sulphochloride. The condensations may be carried out in aqueous solution or in an indifferent organic solvent.  The reduction is affected by iron dust or stannous chloride in hydrochloric acid solution.  A tanning agent of the probable structural formula shown is obtained by condensing a tetraphenyl diamino compound of formula- <FORM:0353046/IV/2> with a mixture of 1 : 2-dichlorobenzene-4-sulphochloride and 1 : 4-dichlorobenzene-2-sulphochloride. <FORM:0353046/IV/3> The following compounds of the general formula specified are also mentioned:-bis-(1 : 2-dichlorobenzene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - diamino - stilbene - disulphonic acid, bis - (1 : 2 - dichlorobenzene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl - 311 - aminobenzene - 111 - sulphonyl) - benzidine - m.m1 - disulphonic acid bis - (1 : 4 - dichlorobenzene - 2 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis-(4 - chlorobenzene - 1 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (toluene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (benzenesulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (salicylic acid - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (naphthalene - 1 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (naphthalene - 2 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (benzenesulphonyl - 41 - amino - 11 - toluene - 21 - sulphonyl) - benzidine - m.m1 - disulphonic acid, bis - (benzenesulphonyl - 41 - amino - 11 - chlorobenzene - 21 - sulphonyl) - benzidine - m.m1 - disulphoni acid, bis - (benzoic acid - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - 111.511 - naphthalenediamino - 311 - 711 - disulphonic acid, bis-(1 : 2 - dichloroben zene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl - 311 - aminobenzene - 111 - sulphonyl) - diami nostilbenedisulphonic acid, bis - (1 : 2 - dichlorbenzene - 4 - sulphonyl - 31 - aminobenzene - 11 - sulphonyl) - 211 : 611 - toluylenediamine - 411 - sulphonic acid, bis - (3 - chlorophenoxyacetyl - 31 - aminobenzene - 11 - sulphonyl) - benzidine - mm.1 - disulphonic acid.