Patent GB-291118-A (GB)
Title: Improvements in or relating to the dyeing, printing or stencilling of materials made of or containing cellulose derivatives
IPC: C09B3/06
Filed: 1926-11-23
Abstract: 291,118. Dreyfus, H. Nov. 23, 1926. Samples furnished. Anthracene, azo, nitro, and sulphuretted dyes. -Dyestuffs suitable for dyeing or otherwise colouring cellulose esters and ethers are made by introducing one or more thiocyanate, cyanate, isothiocyanate, isocyanate, or simple or aliphatically-substituted urea or thiourea groups into an aryl dye nucleus or component, thereof. Dyes of the azo, anthraquinone, nitrodiaryl, nitrodiarylamine and nitrodiarylmethane groups are specified. The thiocyanate or cyanate groups may be introduced by diazotizing the corresponding amino compound and treating with a, thiocyanate or cyanate, or by treating the hydrochloride of an amino compound with an inorganic or aliphatic thiocyanate or cyanate; in the latter case the substituted ammonium thiocyanates or cyanates obtained may be converted into the corresponding ureas or thioureas by heating. Thiocyanate groups may also be introduced by treating with a halogen in presence of a thiocyanate and may be converted into the corresponding cyanates by treating with mercuric oxide or lead acetate. Urea or thiourea derivatives may also be made by treating the corresponding cyanate or thiocyanate derivatives with ammonia or an amine, or by treating amino compounds with a urea halide or an aliphaticallysubstituted urea halide. The preparation of the following dye-stuffs, whch yield various shades of yellow and orange on cellulose acetate, is described in examples. (1) 1-Acetylamino-4-thiocyanoanthraquinone is obtained by diazotizing 1-acetyl-4-aminoanthraquinone and heating with potassium thiocyanate. (2) The thiocyanate of 1-aminoanthraquinone is made by treating the hydrochloride with potassium thiocyanate; on heating, the 1-anthraquinonylthiourea is obtained. Corresponding aliphatically-substituted thioureas may be made by using an aliphatic thiocyanate, e.g. ethyl or allyl isothiocyanate, instead of potassium thiocyanate. Two further thiocyanate groups may be introduced into compounds containing an ethylenic linkage, e.g. the allyl derivative, by treating with chlorine and a thiocyanate. The corresponding isocyanate and urea derivatives may be obtained by using a cyanate instead of a thiocyanate. (3) 2 : 4-Dinitraniline is diazotized and coupled with 5-thiocyanosalicylic acid. (4) Aniline is diazotized, coupled with a-naphthylamine, rediazotized, and coupled with o-oxyphenylurea. (5) m-Aminophenylurea is diazotized and coupled with 5-thiocyanoduct may be diazotized on the fibre and coupled with o-oxyphenylurea. (6) 2: 2<1>-Dinitrodiphenylamine is treated with sodium thiocyanate and bromine in dilute sulphuric acid, yielding probably the 4 : 4<1>-dithiocyano derivative. (7) 3 : 3<1> - dinitro-4 : 4<1>-diaminodiphenyl and 3 : 3<1>- dinitro - 4 : - 4<1> - diaminodiphenylmethane hydrochlorides are converted into the corresponding ureas by heating with potassium cyanate. Specifications 158,340, [Class 15 (ii), Dyeing, Processes &c. for], 219,349, 224,925, 227,183, 242,393, 242,711, 269,960, 273,819. 273,820, and 285,968 are referred to. o-Oxyphenylurea is made by heating o-oxyaniline hydrochloride with potassium cyanate. m-Aminophenylurea is made by heating an ethereal solution of m-nitraniline with moist cyanogen chloride and reducing the product. 5-Thiocyano-salicylic acid is made by treating salicylic acid with sodium thiocyanate and bromine.