GB457283A - Improvements in or relating to the colouration of textile materials containing cellulose esters - Google Patents

Abstract

Cellulose esters, dyeing; printing.--Pattern effects are produced upon a textile fabric containing a cellulose ester by applying thereto in a pattern a colouring matter or a component convertible into a colouring matter, having little or no affinity for the cellulose ester but good affinity for cellulose, before or after saponifying the cellulose ester in a pattern coinciding in part only with the pattern in which the colouring matter is applied or the component is applied and developed. The locally saponified fabric may be obtained by the local application of a saponifying agent thereto or by the use of intermittently saponified filaments or yarns therein. As colouring matters or components may be used, for example, direct cotton dyestuffs, chrome mordant printing colours, e.g. Chromazurine DN or G, the sodium salts of enolic coupling components for azo dyes, such as b -naphthol, pyrazolones, arylides of 2 - 3-oxynaphthoic acid and diacylacetyl derivatives of aromatic diamines, and sulphuric or other esters of leuco vat dyes, e.g. those of the Indigosol series. Dyestuffs having affinity for cellulose esters but not for cellulose may be incorporated in the colouring matter compositions. Oxidizing agents, e.g. sodium nitrite or aluminium chlorate may be present in compositions containing the esters of leuco vat dyestuffs together with ammonia or alkali to prevent premature oxidation, in which case oxidation catalysts, e.g. a copper salt or a vanadate, may be preliminarily applied to the fabric. Further effects may be obtained by preliminarily printing with a mechanical or other, e.g. a hydrosulphite, resist. The following examples are specified. (1) A cellulose acetate woven fabric is printed in a bold design with an aqueous saponifying composition containing caustic soda, British gum and glycerol, dried, washed with dilute acid, washed free from acid, again dried, overprinted in a small design with an aqueous composition containing Indigosol yellow HCG, Indigosol printing blue IGG, thiodiglycol, ammonia, gum tragacanth and sodium nitrite, again dried, developed in dilute sulphuric acid at 60 DEG C., washed, soaped, washed and dried; the saponified areas of the Indigosol print are deeply and the unsaponified areas faintly coloured; (2) A fabric having a weft of cellulose acetate and a warp of intermittently saponified cellulose acetate is impregnated with an aqueous solution containing ammonium vanadate and tartaric acid, dried, printed with an aqueous composition containing Indigosol golden yellow IGK, gum tragacanth, tartaric acid and aluminium chlorate, dried, hung in the air for about a day, washed and dried; the saponified and unsaponified areas of the print are coloured strongly and faintly respectively.