Patent GB-497397-A (GB)
Title: Improvements in or relating to the colouration of textile materials
IPC: D06P5/15
Filed: 1937-06-16
Abstract: An aqueous liquor, for the after-treatment of discharge printed textile materials, contains an oxidizing agent and a finely dispersed solid adsorbent, e.g. a hydroxide of magnesium, aluminium, zinc, cadmium or beryllium or fuller's earth, infusorial earth, china clay, silica, bentonite or animal charcoal.  A preferred adsorbent is magnesium hydroxide formed by precipitation in presence of a protective colloid or dispersing agent, such as a sulphuric ester of a higher fatty alcohol, a polyether alcohol or the sodium salt of a condensation product of a higher fatty acid with a hydroxy- or amino-alkyl sulphonic acid.ALSO:Cellulose esters or ethers, dyeing; printing.-To lessen or eliminate the discolouration of white or coloured discharge effects produced upon dyed cellulose ester or ether materials the discharged materials are subjected to the action of an aqueous liquid containing an oxidizing agent and a finely divided solid adsorbent.  Specified oxidizing agents are sodium perborate, hydrogen peroxide and ammonium persulphate and specified solid adsorbents are hydroxides of magnesium, aluminium, zinc cadmium or beryllium, fuller's earth, infusorial earth, colloidal china clay, finely divided silica, bentonite and animal charcoal.  A preferred adsorbent is magnesium hydroxide formed by precipitation in presence of a protective colloid or dispersing agent such as a sulphuric ester of a higher fatty alcohol, a polyether alcohol or the sodium salt of a condensation product of a higher fatty acid with a hydroxy- or amino-alkylsulphonic acid.  Alternatively, there may be used an oxidizing agent, such as magnesium or zinc peroxide, which yields a solid adsorbent under the conditions of the treatment.  In examples: (1) a cellulose acetate cr<\>zepe fabric, dyed with Celliton discharge blue 3R, is printed in separate patterns with aqueous discharge pastes containing (a) zinc formaldehydesulphoxylate, thiodiglycol, and gum tragon, and (b) the same with addition of Indigosol pink IR, the printed fabric is aged, steamed, hung in the air, treated with an aqueous solution containing sodium bichromate and sulphuric acid, rinsed, treated with an aqueous dispersion of magnesium hydroxide in the form of a liquor at 85 DEG  C. prepared from magnesium sulphate, caustic soda, sodium carbonate, sodium perborate sodium sulphate and "Gardinol" (Registered Trade Mark) R and water, washed and dried to obtain a clear white and a bright pink pattern on a blue ground; (2) a cr<\>zepe fabric having a cellulose acetate warp and a viscose weft is shrunk, scoured, partially saponified, dyed a navy shade with Diazamine blue BR and Chlorazol black BH, diazotized and developed with b -naphthol and printed with an aqueous paste containing zinc formaldehydesulphoxylate, Glyecine A and gum tragon and the printed fabric is dried, aged, washed, treated with an aqueous dispersion of magnesium hydroxide as in (1), rinsed and dried to obtain a white discharge on a navy ground; (3) a similar fabric is shrunk, scoured, partially saponified, dyed a black shade with Chlorazol black BH and Diazophenyl orange R, diazotized and developed with b -naphthol, printed with an aqueous paste containing formosul, diethylene glycol and gum tragon, dried, aged, washed and treated with a magnesium hydroxide dispersion as in (1) to obtain a white discharge on a black ground.