Patent GB-398842-A (GB)
Title: Improvements in the colouration of materials made of or containing cellulose esters or ethers
IPC: C09B31/062
Filed: 1932-03-12
Abstract: Cellulose esters or ethers, dyeing; disazo dyes; azo dyes, forming on the materials; printing.--Materials made of or containing cellulose esters or ethers are coloured by the application in substance of disazo dyes, free from carboxylic or sulphonic groups of the type R1 - N = N - R2 - N = N - R3 - OH, in which R1, R2 and R3 are residues of the benzene series each containing a single benzene nucleus.  The residues R1, R2, R3 may be substituted, e.g. by alkyl, alkoxy or halogen groups.  The dyes are obtainable by diazotizing the appropriate aminoazo compounds and coupling with phenols, e.g. phenol itself or o- or m-cresol. Specified aminoazo compounds are those obtainable by coupling diazotized aniline, chloranilines, toluidines, xylidines, anisidines or phenetidines with middle components of the benzene series such as m-toluidine, p-xylidine or cresidine.  The dyestuff aminoazobenzene --> phenol, being resistant to the action of nitrous acid, is of value in the production of compound shades in conjunction with dyestuffs produced by azoic methods.  The use of the dyestuff p-anisidine --> p-xylidine --> o-cresol is also specified. The dyes may be applied in solution, suspension or dispersion, and specified dispersing agents for use with or without protective colloids and/or liquids, e.g. water, are sulphoaromatic fatty acid compounds (cf. Specification 242,393, [Class 15 (ii), Dyeing, Processes &c. for]), sulphoaromatic ricinoleic acid compounds (cf. Specification 273,819, [Class 15 (ii), Dyeing, Processes &c. for]), naphthenic acids or other carbocyclic compounds containing salt-forming groups or salts of such acids or compounds (cf. Specification 224,925, [Class 15 (ii), Dyeing, Processes &c. for]), sulphonated oils, e.g. sulphonated castor oil, sulphuric esters of higher aliphatic alcohols, furfural-naphthalene sulphonic acid compounds (cf. Specification 322,737, [Class 2 (iii), Dyes &c.]), resino-naphthalene sulphonic acid compounds (cf. Specification 323,788, [Clase 2 (iii), Dyes &c.]), formaldehyde naphthalene sulphonic acid compounds, alkyl-, cycloalkyl- and aralkyl-naphthalene sulphonic acids, sulphite cellulose waste liquor or its constituents or products of transformation, e.g. lignin sulphonic acid compounds, sulphonic acid compounds of mineral oils, tar oils, brown coal tar oils and the like and their products of condensation with alcohols, and sulphonic acid compounds of distillation residues of benzaldehyde.  Specified protective colloids are carbohydrates, including gums, glue, and gelatine.  The following examples are specified: (1) A cellulose acetate woven fabric is printed or stencilled with an aqueous paste containing gum arabic, diethylene glycol or alcohol and the dyestuff aminoazobenzene --> phenol, dried, steamed or aged, washed, dried and finished to obtain a golden yellow print, very fast to light.  (2) The cellulose acetate pile of a fabric having a cotton backing is dyed a reddish yellow fast to steaming in a bath containing the dyestuff o-aminoazotoluene --> p-cresol dispersed with turkey-red oil with or without an auxiliary solvent such as xylene; the backing may be dyed with a cotton dyestuff in the same or a separate bath.  (3) A cellulose acetate woven fabric, dyed navy blue with a dispersion of the dyestuff p-aminobenzeneazodimethylaniline diazotized on the fibre and developed with b -oxynaphthoic acid, is further dyed in a bath containing an aqueous paste of the dyestuff aminoazobenzene --> phenol until the colour deepens to a fine black, and is washed and dried; to obtain pattern effects the dyed fabric is printed with a paste containing decroline (Registered Trade Mark) diethylene glycol, ethyl lactate and gum arabic thickening, dried, steamed or aged, washed and finished to obtain a white discharge; a coloured discharge may be obtained by incorporating in the paste a dyestuff resistant to decroline.  Specification 219,349, [Class 15 (ii), Dyeing, Processes &c. for], also is referred to.