Patent GB-678155-A (GB)
Title: New or improved process for the treatment of textile fibres
IPC: D06M11/56
Filed: 1948-04-08
Abstract: Normally produced completely coagulated non-hollow viscose rayon fibres are treated (in order to generate internal cavities) successively in either order with an aqueous solution of hydrogen peroxide and with an aqueous solution of a substance capable of reacting with hydrogen peroxide with liberation of gaseous oxygen or of promoting catalytically the decomposition of hydrogen peroxide with liberation of gaseous oxygen.  The shape, size and distribution of the oxygen bubbles thereby formed in the fibres may be controlled by regulating the concentrations and temperatures of the treating solutions and particularly by the presence in the solutions of compounds which per se do not promote the decomposition of the peroxide.  Simultaneously with the formation of microscopic hollow spaces or cavities in the fibres there may be effected in these cavities, for the purpose of delustring the fibres, precipitation of a finely-divided insoluble substance formed by the interaction of two water-soluble re-agents of which one is present in the hydrogen peroxide solution and the other in the solution of the substance used to decompose the peroxide.  In an example viscose rayon fabric is steeped in a saturated solution of barium chloride containing 2 gms. potassium permanganate per litre and centrifuged.  The fabric is then drawn through a solution of 150 gms. sodium sulphate, 150 gms. magnesium sulphate and 500 c.c. of 30 per cent hydrogen peroxide in 500 c.c. of water, the fabric to bath ratio being 1 : 20.  The fabric is then washed and dried.  The treatment is said to improve the thermal insulation of the materials and their handle and permeability to dyes and finishing solutions without appreciable decrease in tensile strength.  The specific volume of the materials is also said to be increased and their lustre subdued.  Drawings of microphotographs of viscose rayon fibres, both treated and untreated, and graphs showing the surface roughness of treated and untreated fibres are furnished. Specifications 244,446 and 299,710, [both in Class 2 (ii)], are referred to.ALSO:Textiles composed of normally produced completely coagulated non-hollow viscose rayon fibres are treated (in order to generate internal cavities) successively in either order with an aqueous solution of hydrogen peroxide and with an aqueous solution of a substance capable of reacting with hydrogen peroxide with liberation of gaseous oxygen or of promoting catalytically the decomposition of hydrogen peroxide with liberation of gaseous oxygen.  The shape, size and distribution of the oxygen bubbles thereby formed in the fibres may be controlled by regulating the concentrations and temperatures of the treating solutions and particularly by the presence in the solutions of compounds which per se do not promote the decomposition of the peroxide. Simultaneously with the formation of microscopic hollow spaces or cavities in the fibres there may be effected in these cavities, for the purpose of delustring the fibres, precipitation of a finely-divided insoluble substance formed by the interaction of two water-soluble reagents, of which one is present in the hydrogen peroxide solution and the other in the solution of the p  substance used to decompose the peroxide. Fabrics may be treated uniformly or in parts only, so as to produce pattern effects.  In an example, viscose rayon fabric is steeped in a saturated solution of barium chloride containing 2 gms. potassium permanganate per litre and centrifuged.  The fabric is then drawn through a solution of 150 gms. sodium sulphate, 150 gms. magnesium sulphate and 500 c.c. of 30 per cent hydrogen peroxide in 500 c.c. of water, the fabric to bath ratio being 1 : 20.  The fabric is then washed and dried.  The treatment is said to improve the thermal insulation of the materials and their handle and permeability to dyes and finishing solutions without appreciable decrease in tensile strength.  The specific volume of the materials is also said to be increased and their lustre subdued. Drawings of microphotographs of viscose rayon fibres, both treated and untreated, and graphs showing the surface roughness of treated and untreated fibres are furnished. Specifications 244,446 and 299,710, [both in Class 2 (ii)], are referred to.