Patent GB-360938-A (GB)
Title: Improvements in the treatment of textiles made of or containing organic derivatives of cellulose
IPC: D06M11/155
Filed: 1930-07-14
Abstract: Carbonizing processes; cellulose esters or ethers, dyeing; printing.--Textile materials made of or containing organic esters or ethers of cellulose are treated to render at least a part of the cellulose derivative removable by the application of an organic liquid together with an inorganic salt having a solvent or swelling action upon the cellulose derivative.  Preferably the organic liquid is also a swelling agent for the cellulose derivative.  Specified liquids are diacetone alcohol, acetic acid, phenol, benzyl alcohol and cyclohexanol.  When the liquid is of low boiling-point it is advantageous to add a substance of high boiling-point having a solvent action on the cellulose derivative, e.g. triacetin. Specified inorganic salts are sodium, potassium and calcium thiocyanates, and zinc chloride.  The treatment may be effected by printing, stencilling, padding or immersion methods and parts of the material may have a resist applied thereto to prevent the carbonizing action.  The treated material is subsequently dried, e.g. at 100-100 DEG  C., whereafter the carbonized portions are removed, e.g. by brushing.  The invention is applicable inter alia to the removal of fibres of organic derivatives of cellulose from admixture with other fibres in waste materials, the production of gauzes from fabrics comprising organic derivatives of cellulose and other fibres, the removal of a backing consisting of an organic derivative of cellulose from an embroidery, and the production of pattern effects, especially upon pile fabrics.  Thus pattern effects may be obtained by the application by printing or stencilling of a 50 per cent solution of calcium thiocyanate in methylated spirit containing 5 per cent of olive oil soap to the back of a velvet having a cellulose acetate pile upon a backing of cotton, regenerated cellulose or silk, with subsequent heating and brushing as above.  When the liquid is applied to the pile the latter may be treated locally with resists.  To obtain coloured effects the pile and the backing may at any stage be printed or otherwise coloured with dyestuffs appropriate to the respective fibres.  The following examples are specified: (1) A solution of calcium thiocyanate in an equal weight of acetone is printed or otherwise applied upon the back of a scoured fabric having a pile of cellulose acetate yarn and a cotton backing, the material is then dried at 100-110 DEG  C., the treated pile is removed immediately by brushing, and the material is again scoured; discolouration produced by contact with iron may be removed by treatment with sulphur dioxide or other bleaching agent.  (2) The solution in (1) is replaced by one of 50 parts by weight of ammonium thiocyanate in 50 parts of acetone with addition of 5 parts of diacetone alcohol.  (3) The solution in (1) is replaced by one of 100 parts by weight of calcium thiocyanate in 100 parts of methylated spirit with addition of 1 part of olive oil soap.  Specification 302,592, [Class 42 (i), Fabrics, Finishing &c.], is referred to.