Patent GB-624733-A (GB)
Title: Process of stabilising textile material
IPC: D06M13/123
Filed: 1946-12-24
Abstract: The process of the parent Specification is modified in regard to the range of proportions of glyoxal and acidic catalyst, and the pH value of the solution with which regenerated cellulose textile material is treated and in regard to the permissible temperature and duration of the heat treatment.  The material is treated with an aqueous solution having a pH of 1.0 to 2.5 and containing the equivalent of 30-200 c.c. of 30 per cent by weight glyoxal solution and 1-20 grams of an acidic catalyst per litre, and the treated material is baked at a temperature of about 212 DEG  F. or higher until a reaction between the glyoxal and the fibres of the textile material has occurred and the material has been stabilized with respect to dimensional shrinkage and has been rendered resistant to crushing and creasing. Temperatures up to 400 DEG  F. may be used for the baking treatment and the time period may be 30-0.5 minutes.  The acid reacting catalyst may be oxalic acid, ammonium chloride, ammonium sulphate or ammonium nitrate. In an example, viscose rayon fabric is passed through a solution containing 120 c.c. of glyoxal solution (of 30 per cent glyoxal by weight) and 15 grams of oxalic acid per litre and having a pH of 1.25.  The fabric is squeezed to remove excess solution above 130 per cent pick-up and is then dried on a tenter frame at 250 DEG  F. to the dimensions of the fabric before the impregnation.  The dried, tentered fabric is then cured in circulating air at 300 DEG  F. for 5 minutes.  The treated fabric is resistant to shrinking on washing.  In another example, the catalyst is a mixture of oxalic acid and boric acid.  The material treated may be composed wholly or mainly of regenerated cellulose of the viscose, cuprammonium, or saponified cellulose acetate type.  Mixtures of regenerated cellulose and cellulose acetate fibres or yarns, or fabrics made of them, may be treated.  The materials may be bleached or dyed before or after the treatment.ALSO:The process of the parent Specification is modified as regards the range of proportions of glyoxal and acidic catalyst, and the pH value of the solution with which the regenerated cellulose textile material is treated, and as regards the permissible temperature and duration of the heat treatment.  The material is treated with an aqueous solution having a pH of 1.0 to 2.5 and containing the equivalent of 30-200 c.c. of 30 per cent by weight glyoxal solution and 1-20 grams of acidic catalyst per litre, and the treated material is baked at about 212 DEG  F. or higher until a reaction between the glyoxal and the fibres of the textile material has occurred and the material has been stabilized with respect to dimensional shrinkage and has been rendered resistant to crushing and creasing.  Temperatures up to 400 DEG  F. may be used for the baking treatment and the time period may be 30-0.5 minutes according to the temperature.  The material may be wholly or mainly of regenerated cellulose.  Mixtures of regenerated cellulose and cellulose acetate fibres or yarns, or fabrics made of them, may be treated.  The materials may be bleached or dyed before or after the treatment.  The acidic catalyst may be oxalic acid, ammonium chloride, sulphate, or nitrate.  After impregnation, the fabric may be squeezed to remove excess solution and may be dried on a tenter frame at 250 DEG  F. and maintained at the dimensions of the fabric prior to the impregnation.  The dried, tentered, fabric may be cured in air at 300 DEG  F. for 5 minutes.  A mixture of oxalic and boric acids may be used as the catalyst.