Patent GB-239470-A (GB)
Title: Improvements relating to the dyeing or colouring of products or articles made with cellulose acetate
IPC: C09B51/00
Filed: 1924-04-04
Abstract: Aqueous suspensions of unsulphonated nitrodiarylamines (other than 2 : 4-dinitrodiarylamines) containing or not containing chlorine, hydroxyl or amino groups, or other substituents, for use in dyeing or printing cellulose acetate, may be prepared (1) by finely grinding the dyestuffs and suspending them in acid or alkaline aqueous baths or pastes, to which may be added protective colloids such as glue, starch, gums &c., or (2) by dissolving the dyestuffs in an organic solvent and pouring the solution into water, which may contain a protective colloid.  In an example a paste of 4 : 41-dichlor-2-nitrodiphenylamine or 4 : 41-dinitro-21-hydroxydiphenylamine is ground in a mill and diluted with water containing glue or gelatine and dextrin.  Other examples of bodies which may be so dispersed are 4 - nitrodiphenylamine, 4-nitrophenyl-41-tolyl-amine, 4-chlor-2-nitrodiphenylamine, 4-nitro-41-chlordiphenylamine, 4-chlor-2-nitro-41-aminodiphenylamine, 4-chlor-2-nitro-41-methoxydiphenylamine, 4-chlor-2-nitro-41-hydroxydiphenylamine, 4-chlor-2-nitro-31-aminodiphenylamine, 4-41-dinitrodiphenylamine, 4-41-dinitro-31-hydroxydiphenylamine, 4-nitrophenyl-41-nitro-21-tolylamine, and 2-41-dinitrodiphenylamine. Specifications 219,349, 224,925, and 237,943 are referred to.ALSO:Threads, films, fabrics or other products made of or containing cellulose acetate are dyed, printed or stencilled by means of unsulphonated diarylamines (other than 2 : 4-dinitrodiarylamines) containing or not containing hydroxy, chlor, amino or other substituents applied in aqueous solutions or suspensions or by any method other than that claimed in Specification 237,943.  The dyestuffs may be finely ground and suspended in acid or alkaline aqueous baths or pastes, to which may be added protective colloids such as glue, starch, gums &c. or, they may be dissolved in an organic solvent and poured into the dyebath which may contain a protective colloid.  In examples, a paste of 4 : 41-dichlor-2-nitrodiphenylamine or 4 : 41-dinitro-21-hydroxydiphenylamine is ground in a mill and diluted with water containing glue or gelatine and dextrin, the resulting dyebaths producing golden yellow shades on knitted cellulose acetate fabrics.  Other examples of suitable dyestuffs are 4-nitrodiphenylamine, 4-nitrophenyl-41-tolylamine, 4-chlor-2-nitrodiphenylamine, 4-nitro-41-chlordiphenylamine, 4-chlor-2-nitro-41-aminodiphenylamine, 4-chlor-2-nitro-41-methoxydiphenylamine, 4 - chlor - 2 - nitro - 41 - hydroxydiphenylamino, 4-chlor-2-nitro-31-amino-diphenylamine, 4 : 41 - dinitrodiphenylamine, 4 : 41-dinitro-31-hydroxydiphenylamine, 4-nitrophenyl-41-nitro-21-tolylamine and 2 : 41-dinitrodiphenylamine. The process may be applied to mixed goods with for example cotton or other cellulose fibres or wool, silk, &c., and since these fibres are coloured only slightly, if at all, resist, differential or solid effects may be obtained, or if desired dyes or colours for the non-acetate portion may be applied either simultaneously or separately. Specifications 219,349 and 224,925 also are referred to.