Patent GB-687856-A (GB)
Title: Shrinkage control of textiles
IPC: D06M15/423
Filed: 1949-12-29
Abstract: The shrinkage of textile materials consisting of natural cellulose, regenerated cellulose, or mixtures thereof with up to about 50 per cent of cellulose acetate is controlled by impregnating the material with an aqueous solution of a formaldehyde-yielding compound consisting of dimethyl hydantoin formaldehyde or preferably monomethylol dimethyl hydantoin or both compounds, said solution containing 1-7 per cent by weight of the formaldehyde-yielding compound, which gives 0.2-1.5 per cent of available formaldehyde, and containing also a non-volatile organic acid in an amount such as to give to the solution a pH of about 2-2.5, squeezing the surplus liquid from the material, drying it, baking the dried material at 120-150 DEG  C., and neutralizing and washing it to remove acid and reaction by-products.  The organic acid may be oxalic, lactic, citric or tartaric acid.  The solution may contain a small proportion of sodium sulphate or basic aluminium acetate as a buffer.  It may also contain a small proportion of a wetting agent.  In an example a cotton sheeting material and a dull filament rayon fabric respectively are desized, dried and passed through an aqueous-solution containing 25 grams dimethyl hydantoin formaldehyde, 2.5 grams of oxalic acid and 2 grams of anhydrous sodium sulphate per litre and having a pH of about 2.2.  The fabric is then squeezed to remove solution in excess of 100 per cent pick-up and dried without tension on a pin-tenter frame at about 83 DEG  C.  The dried, tentered fabric is then cured in circulating air at about 149 DEG  C. for about 2-3 minutes.  Finally, the fabric is washed with a dilute aqueous solution of sodium carbonate, soaped, rinsed, hydro-extracted and dried without tension.  In other examples, the same types of textile materials are treated in a similar manner using aqueous solutions of (1) dimethyl hydantoin formaldehyde, oxalic acid, sodium sulphate and "Igepal CTA Extra," (2) monomethylol dimethyl hydantoin and the same auxiliary agents and (3) monomethylol dimethyl hydantoin, lactic acid, sodium sulphate and "Igepal CTA Extra." U.S.A. Specifications 2,441,859, 2,484,545 and 2,541,457 are referred to.  The Specification as open to inspection under Sect. 91 comprises also the treatment of linear polyamides such as nylon or mixtures thereof with the other textile materials specified.  This subject-matter does not appear in the Specification as accepted.ALSO:The shrinkage of textile materials consisting of natural cellulose, regenerated cellulose, or mixtures thereof with up to about 50 per cent of cellulose acetate is controlled by impregnating the material with an aqueous solution of a formaldehyde-yielding compound consisting of dimethyl hydantoin formaldehyde or preferably monomethylol dimethyl hydantoin or both compounds, said solution containing 1-7 per cent by weight of the formaldehyde-yielding compound, which gives 0.2-1.5 per cent of available active formaldehyde, and containing also a non-volatile organic acid in an amount such as to give to the solution a pH of about 2-2.5, squeezing the surplus liquid from the material, drying it, baking the dried material at 120-150 DEG  C., and neutralizing and washing it to remove acid and reaction by-products.  The organic acid may be oxalic, lactic, citric or tartaric acid.  The solution may contain a small proportion of sodium sulphate or basic aluminium acetate as a buffer.  It may also contain a small proportion of a wetting agent.  In an example, a cotton sheeting material and a dull filament rayon fabric respectively are desized, dried and passed through an aqueous solution containing 25 grams dimethyl hydantoin formaldehyde, 2.5 grams of oxalic acid and 2 grams of anhydrous sodium sulphate per litre and having a pH of about 2.2.  The fabric is then squeezed to remove solution in excess of 100 per cent pick-up and dried without tension on a pin-tenter frame at about 83 DEG  C. The dried, tentered fabric is then cured in circulating air at about 149 DEG  C. for about 2-3 minutes.  Finally the fabric is washed with a dilute aqueous solution of sodium carbonate, soaped, rinsed, hydro-extracted and dried without tension.  In other examples, the same types of textile materials are treated in a similar manner using aqueous solutions of (1) dimethyl hydantoin formaldehyde, oxalic acid, sodium sulphate and "Igepal CTA Extra," (2) monomethylol dimethyl hydantoin and the same auxiliary agents, and (3) monomethyl dimethyl hydantoin, lactic acid, sodium sulphate and "Igepal CTA Extra."  U.S.A. p  Specifications 2,441,859, 2,484,545 and 2,541,457 are referred to.  The Specification as open to inspection under Sect. 91 comprises also the treatment of linear polyamides such as nylon or mixtures thereof with the other textile materials specified.  This subject-matter does not appear in the Specification as accepted.