Patent GB-633160-A (GB)
Title: New colouring process to give patterned or differential colour effects
IPC: D06P5/00
Filed: 1947-07-10
Abstract: Differential colour effects are obtained on textiles and paper by using a dyestuff containing one or more quaternary ammonium, ternary sulphonium or isothiouronium salt groups, each of which is attached via a methylene linkage to an aromatic nucleus, which nucleus remains as part of the dyestuff molecule when fixed.  The manufacture of such dyestuffs is described in Specifications 576,234, 576,270, 587,636 and 613,980.  The effects may be produced either by local application of the dyestuffs or by padding on a material which has been treated locally with chemical or mechanical resists; in the latter case, other dyestuffs (e.g. substantive, vat, azoic) may be incorporated with the resists, giving two or more coloured effects.  The "onium" dyestuffs may be applied locally by spraying, painting, or preferably printing by the hand block, screen or roller techniques, and may be applied alongisde other dyestuffs.  The "onium" dyestuffs are preferably applied in aqueous solution or as a paste with a weakly acidic substance, e.g. formic, acetic, mono-, di-and tri-chloracetic, diglycollic, citric, lactic, tartaric, maleic and oxalic acids, sodium and potassium bicarbonates and sodium dihydrogen phosphate. After treatment, the dyestuffs are preferably fixed by application of an alkaline substance, or alternatively by incorporating with the dyestuff a substance which changes from weakly acid to weakly alkaline on steaming, e.g. sodium acetate, borate and trichlor-acetate, trisodium phosphate and disodium hydrogen phosphate.  The resists may be mechanical, such as wax or zinc oxide, or chemical, such as acids which prevent fixation of the "onium" dyestuff, reducing agents which destroy the colour, or compounds which precipitate the dyestuff in an insoluble form, e.g. thiocyanate.  Typical methods of application with other dyestuffs are: (1) mixing the "onium" dyestuff with a soluble or dispersed cellulose acetate dyestuff; (2) printing alongside a vat dyestuff, aniline black or azoic component mixture or sulphuric ester of a leuco vat dyestuff; (3) padding with an alkaline coupling component and printing with an "onium" dyestuff and diazo compound together or successively; this may be followed by application of a resist and then a further diazo compound or aniline black mixture; (4) printing in succession with an "onium" dyestuff, a resist, a vat dyestuff plus a resist, padding with a leuco vat dyestuff and developing; (5) padding with a coupling component, printing successively with a resist and a diazo compound and padding with an "onium" dyestuff; (6) printing with azoic or vatting combination and a wax resist and padding with an "onium" dyestuff.  Materials which may be so treated include cotton, viscose, cuprammonium and acetate rayon, nylon, silk chlorinated wool, linen and jute.  Examples are given of some of the above-described processes.  Typical dyestuffs used can be obtained by reacting: (1) bis-(chloromethyl)-acedianthrone with pyridine; (2) di-(chloromethyl)-4 : 41-di-(6 - methyl - benzthiazyl - 2) - azobenzene with pyridine; (3) copper tri-(chloromethyl)-phthalocyanine with tetramethyl thiourea. Specification 482,184 also is referred to.