Improvements in the art of printing textile yarns and fabrics containing cellulose acetate

摘要

Yarns and fabrics of secondary or acetone-soluble cellulose acetate are printed with a paste containing a dyestuff as hereinafter defined, a thiocyanate and a liquid organic swelling agent, excluding the lower monohydric aliphatic alcohols. Suitable dyestuffs are those which colour the materials when the latter are immersed in a dye bath containing 10 per cent of ammonium thiocyanate and 16 per cent of ethyl lactate for 10 minutes followed by washing, soaping, rewashing and drying and, in the case of Rapidogen, Indigosol or azoic dyestuffs, the appropriate after-treatment. Many such dyestuffs are specified. The liquid organic swelling agents which may be used are ketones, esters and alcohols (other than lower monohydric aliphatic alcohols) which are liquid at ordinary temperatures, which p preferably have boiling points above 100 DEG C. and which cause swelling of secondary or acetone-soluble cellulose acetate, e.g. ethyl lactate, diacetone alcohol, methyl cyclohexanone, dimethyl phthalate or Reomal P. A typical printing paste contains 20 parts of dyestuff, 160 parts of methyl cyclohexanone, 100 parts of ammonium thiocyanate, 550 parts of British Gum (4 lbs. per gallon of water) and 170 parts of water. After drying, the printed material is preferably steamed for 15-20 minutes. Mixed yarns of cellulose acetate and viscose or cotton are dyed solid colours by means of substantive dyestuffs; mixed acetate and wool or silk are dyed solid colours by means of acid dyers; and mixed acetate and viscose are dyed solid colours by means of acid dyes in the presence of urea. Differential effects may also be obtained. In an example, the material is printed with an Indigosol dyestuff as above, dried and developed in a bath containing sodium nitrite and sulphuric acid. In a further example, material printed as above with a Rapidogen dyestuff is dried and developed in a bath containing acetic acid, formic acid and Glauber's salts. In another example, the material is printed with an azoic colour, dried and coupled with a neutralized diazotized fast colour base, e.g. Brentamine Fast Red B base. Specification 588,106 is referred to in the first and second Provisional Specifications and Specification 592,858 in the second Provisional Specification.