Patent GB-440983-A (GB)
Title: Colouring matters
IPC: C09B67/28
Filed: 1934-06-08
Abstract: Stable colloidal solutions of vat dyestuffs applicable for colouring textiles, paper and rubber, are obtained by treating the dyestuffs or their leuco compounds with a solution in alkali (not carried beyond the protalbinic and lysalbinic acid stage) of wool or gluten, the resulting solution, if it contains leuco compound, being treated with an oxidizing agent.  The formation of the leuco compound and the solution of the wool or gluten in alkali may be performed in a single operation, or wool, dyed with the vat dyestuff, may be dissolved in alkali at or below 40 DEG  C.  The following examples are specified: (1) Botany wool slubbing is dissolved by immersion for 24 hours with occasional stirring in a 5 per cent sodium hydroxide solution at 16--20 DEG  C. and aqueous solutions of sulphuric acid, sodium hydroxide and glucose are stirred in; the solution is then added to an aqueous solution at 50 DEG  C. containing Caledon blue RC, sodium hydroxide and sodium hydrosulphite, and the mixed solution is allowed to stand for some hours, during which it undergoes air oxidation; cotton immersed in the resulting solution and dried is evenly tinted. (2) Cross-bred wool slubbing, vat dyed with Caledon blue GCP, is dissolved by immersion for 18 hours in an 8 per cent sodium hydroxide solution at 16--18 DEG  C. with final stirring for 1 hour at 40--50 DEG  C.; a small quantity of the wetting agent "Perminal" (Registered Trade Mark) W is finally added.  (3) Cross-bred wool slubbing, vat dyed with Durindone red 3B is dissolved as in (2); the solution may be mixed with a rubber latex emulsion for the preparation of a coloured rubber.  (4) Caledon blue GC is dissolved in a sodium hydrosulphite solution containing gluten dissolved in sodium hydroxide and the solution is allowed to undergo air oxidation. (5) Wool slubbing, vat dyed with Caledon gold orange G, is dissolved in an 8 per cent sodium hydroxide solution.  (6) Durindone blue 4BC is mixed with a solution of wool in a 5 per cent sodium hydroxide solution and vatted for 1 hour at 60 DEG  C. by addition of sodium hydroxide and sodium hydrosulphite; the liquor is then neutralized with dilute sulphuric acid and agitated whereupon more acid is added and the colloidal vat dye gel is filtered off, washed and pasted with sodium hydroxide solution; the product is suitable for colouring paper pulp in the beater and disperses readily in water to a colloidal solution suitable for padding cotton or linen cloth; alternatively, the slightly acidified liquor may be agitated with sodium hydroxide solution to obtain a solution suitable for tinting cotton or linen. Specifications 889/00, [Class 2], and 425,689 are referred to.ALSO:Stable colloidal solutions of vat dyestuffs, suitable for colouring rubber, are obtained by treating the dyestuffs or their leuco compounds with a solution in alkali (not carried beyond the protalbinic and lysalbinic acid stage) of wool or gluten, the resulting solution, if it contains leuco compound, being treated with an oxidizing agent.  The formation of the leuco compound and the solution of the wool or gluten in alkali may be performed in a single operation, or wool, dyed with the vat dyestuff, may be dissolved in alkali at or below 40 DEG  C.  The following examples are specified: (1) botany wool slubbing is dissolved by immersion for 24 hours with occasional stirring in a 5 per cent sodium hydroxide solution at 16-20 DEG  C. and aqueous solutions of sulphuric acid, sodium hydroxide and glucose are stirred in; the solution is then added to an aqueous solution at 50 DEG  C. containing Caledon blue RC, sodium hydroxide and sodium hydrosulphite and the mixed solution is allowed to stand for some hours during which it undergoes air oxidation; (2) cross-bred wool slubbing, vat dyed with Caledon blue GCP, is dissolved by immersion for 18 hours in an 8 per cent sodium hydroxide solution at 16-18 DEG  C. with final stirring for 1 hour at 40-50 DEG C.; a small quantity of "Perminal" (Registered Trade Mark) W is finally added; (3) cross-bred wool slubbing, vat dyed with Durindone red 3B is dissolved as in (2); the solution may be mixed with a rubber latex emulsion for the preparation of a coloured rubber; (4) Caledon blue GC is dissolved in a sodium hydrosulphite solution containing gluten dissolved in sodium hydroxide and the solution is allowed to undergo air oxidation; (5) wool slubbing, vat dyed with Caledon gold orange G, is dissolved in an 8 per cent sodium hydroxide solution; (6) Durindone blue 4BC is mixed with a solution of wool in a 5 per cent sodium hydroxide solution and vatted for 1 hour at 60 DEG  C. by addition of sodium hydroxide and sodium hydrosulphite; the liquor is then neutralized with dilute sulphuric acid and agitated, whereupon more acid is added and the colloidal vat dye gel is filtered off, washed and pasted with sodium hydroxide solution; alternatively, the slightly acidified liquor may be agitated with sodium hydroxide solution.