GB354773A - Improvements in and relating to the art of discharge or reserve printing - Google Patents

Abstract

Esters of reduced quinones, such as anthraquinones, benzoquinones, and vat dyes, including indigoid dyes, containing azo linkages, particularly those described in Specifications 333,506, [Class 15 (ii), Dyeing, Processes &c. for], and 333,507, [Class 2 (iii), Dyes &c.], are discharged or resisted on textile fabrics by printing the fabrics with an alkali applied in a suitable medium, followed by steaming. The discharge pastes may be applied to materials which have been dyed with colours not discharged under the conditions of the process in conjunction with the dischargeable colours, or they may contain non-dischargeable dyes, such as enolic sulphuric esters of vat dyes or azo dyes other than those derived from esters of reduced quinones. In examples, (1) a ground coloured with the dye obtained by coupling the diazotized sulphuric ester salt of 2-aminoanthrahydroquinone with the anilide of 2 : 3-oxynaphthoic acid is discharged white by printing with a paste containing British gum and caustic soda and steaming, (2) a cloth printed with the dye obtained by coupling the diazotized sulphuric ester salt of 2-aminoanthrahydroquinone with the o-anisidide of 2 : 3-oxynaphthoic acid is cross-printed with a paste containing caustic soda, glycerine and British gum, dried, steamed and developed by passing through sodium nitrite solution and through dilute hydrochloric acid, (3) a cloth is printed with a resist paste containing china clay, caustic soda and British gum, dried, cross-printed with a paste containing the dye referred to in example 2, British gum and glycerine, steamed and developed as in example 2, (4) cloth dyed with Solazol red 2B and developed is printed with a paste containing Chlorazol fast yellow BS, glycerine, gum tragacanth and potassium carbonate and steamed to obtain a yellow discharge on a red ground, (5) a blue discharge is obtained by using Chlorazol sky blue FFS and proceeding as in example 4, with the exception that Resist salt L is added to the discharge paste, (6) cloth dyed with Solazol red 2B is printed with a paste containing Katanol O, potassium carbonate and British gum, dried, steamed, acidified and dyed with a basic dye, such as Victoria blue RS or Malachite green, and (7) cloth is dyed with a mixture of Solazol red 2B and Soledon jade green, developed with acid ferric chloride, printed with a paste containing British gum and caustic soda, steamed, rinsed and soaped; a bright green discharge on a chocolate ground is obtained.