Patent GB-564131-A (GB)
Title: Improvements in and relating to the production of differential dyeing effects on fabrics
IPC: D06P3/00
Filed: 1943-03-10
Abstract: Differential dyeing effects are produced on textile fabrics, e.g. of cotton, wool, regenerated cellulose, cellulose acetate, casein, vinyon or nylon fibres, by (a) uniform impregnation with a solution or suspension of a non-volatile dyestuff having at most a low affinity for the material, followed by evaporation of the liquid more rapidly from predetermined portions of the fabric than from the remaining portions, or (b) uniform impregnation with a solution or suspension of resin-forming compounds capable of modifying the dyeing properties of the material, followed by evaporation of the liquid more rapidly from predetermined portions of the fabric than from the remaining portions, heating to form the resin, and dyeing.  The process is applicable for colouring one side of the fabric differently from the other or for producing p  differently coloured areas on the same side.  In examples: (1) a tubular knit viscose fabric is padded with a cold aqueous solution containing cyanamide and formaldehyde adjusted to a pH of 6.0 by means of caustic soda, and with an addition of ammonium thiocyanate, and squeezed, whereupon air at 60-70 DEG  C. is blown through the tube and the fabric is heated for 3 minutes at 148 DEG  C. to form the resin, scoured in an aqueous solution at 40 DEG  C. containing Lissapol (Registered Trade Mark) LS and ammonia and dyed by entering it into a cold aqueous solution containing Azo geranine 2GS and formic acid, raising the temperature in 1/2 hour to 95 DEG  C. and so maintaining for 3/4 hour; a heavier shade is obtained on the inner than on the outer side of the tube; (2) a woven fabric of viscose staple fibre is steeped in a cold aqueous solution containing cyanamide, formaldehyde, caustic soda and ammonium thiocyanate and squeezed, where-upon air at 60-70 DEG  C. is blown against one side of the fabric, which is then scoured in an aqueous solution of soap at 40 DEG  C. and dyed as in (1) to obtain a heavier shade on the side upon which the hot air impinged; (3) a similar fabric is steeped in a cold aqueous solution containing (a) dicyandiamide and formaldehyde, with addition of caustic soda to adjust the pH to 6.0 followed by addition of ammonium thiocyanate, or (b) guanidine carbonate and formaldehyde, with an addition of hydrochloric acid to adjust the pH to 7.0, or (c) ethylene diamine and formaldehyde, with an addition of hydrochloric acid to adjust the pH to 7.0, squeezed and dried by blowing hot air against one side, whereupon the fabric is heated for 15 minutes at 140 DEG  C. to form the resin, scoured in an aqueous soap solution at 40 DEG  C. and dyed as in (1) with the use as dyestuff of Alizarine brilliant green G in an acetic acid bath; in each case a heavier shade is obtained on the side upon which the hot air impinged; (4) a similar fabric is padded with a cold aqueous solution of Chlorazol fast orange AG, squeezed and dried by blowing hot air against one side; (5) a cotton fabric is padded with a cold aqueous solution of Indigosol blue IBC, squeezed and dried by passage over a blast of hot air, whereupon the dyeing is developed in an aqueous solution at 25 DEG  C. containing sulphuric acid, sodium nitrite and sodium chloride, washed free from acid and treated with an aqueous soap solution at 90 DEG  C.; (6) a fabric of viscose staple fibre is padded with a cold aqueous suspension of Caledon green RCS, squeezed and dried by blowing hot air against one side, whereupon the dyeing is developed by steeping in an aqueous solution at 60 DEG  C. containing caustic soda, sodium hydrosulphite and sodium chloride, squeezing, placing in cold water, again squeezing, treating with an aqueous solution at 60 DEG  C. containing sodium percarbonate and treating with an aqueous soap solution at 90 DEG  C.; (7) a sateen fabric of cellulose acetate artificial silk is padded with a cold aqueous-alcoholic solution of Indigosol blue IBC, squeezed and dried by blowing hot air against one side, whereupon dyeing is developed by immersing in a cold aqueous solution containing sulphuric acid, sodium nitrite and sodium chloride, rinsing and treating with an aqueous soap solution; (8) a wool-casein fibre mixed fabric is padded with a cold aqueous solution of Chlorazol dark green PL, squeezed and dried by blowing hot air against one side; (9) a woollen fabric is padded with a cold aqueous suspension of Monastral fast blue BS, squeezed and dried by blowing hot air against one side; (10) a woollen fabric is padded with a cold aqueous solution containing Azo geranine 2GS and ammonium sulphate, squeezed and dried by blowing hot air against one side.