Patent GB-646450-A (GB)
Title: Process for stiffening washable fibrous textile materials and stiffening compositions therefor
IPC: D06M15/233
Filed: 1947-11-05
Abstract: Washable textile materials are stiffened by applying thereto a mixture of a water-insoluble thermoplastic polyvinyl resin, e.g. polyvinyl acetate and polystyrene, with a water-removable softener for the resin, e.g. triacetin, and then washing the stiffened material with water to remove at least the greater part of the softener, and using in the stiffening operation a mixture containing such a proportion of the softener in relation to the resin, e.g. 2 to 8 per cent, that the initial stiffness is not less than the stiffness after the washing with water and that the reduction in stiffness of the treated material after a laundering treatment is less than it would be without the addition of the softener.  The permanent stiffening effect of the thermoplastic resin may be reduced by the incorporation of dibutyl phthalate or other plasticizer not removable by washing.  The resin composition may be applied by spraying, brushing or dipping the textile material in a solution of the resin and softener in acetone, benzene, toluene, xylene or ethyl alcohol, or preferably in an aqueous emulsion containing at least 60 per cent of water. If desired, the fixation of the resin may be enhanced by a heat treatment prior to washing.  In an example a cotton tablecloth is immersed in an aqueous emulsion comprising 25 parts by weight of a 54.5 per cent polyvinyl acetate aqueous emulsion, 0.7 parts triacetin, 0.3 parts dibutyl phthalate and 74 parts water.  After squeezing and partial drying it is calendered or ironed while damp. It is then washed by overnight soaking in water at room temperature followed by agitation in a rotary washer at the boil. Specification 510,203 is referred to.ALSO:Washable fibrous textile materials are stiffened by applying thereto a mixture of a water-insoluble thermoplastic polyvinyl resin with a water-removable softener for the resin, and then washing the stiffened material with water to remove at least the greater part of the softener, and using in the stiffening operation a mixture containing such a proportion of the softener in relation to the resin that the initial stiffness is not less than the stiffness after the washing with water and that the reduction in stiffness of the treated material after a laundering treatment is less than it would be without the addition of the softener.  The washing operation may be carried out in any desired manner, e.g. soaking in cold water or agitating in hot or boiling water with or without the addition of soap, provided that the greater part of the softener is removed.  Triacetin is the preferred softener, and may be used in amounts from 2-8 per cent of the resin. It is important that the initial stiffness is not less than the stiffness after washing with water.  The permanent stiffening effect of the thermoplastic resin may be reduced by the incorporation of dibutyl phthalate or other plasticizer not removable by washing.  The resin composition may be applied by spraying, brushing or dipping the textile material in a solution of the resin and softener in a volatile organic solvent or preferably in an aqueous emulsion containing at least 60 per cent of water.  Suitable resins are polyvinyl acetate and polystyrene. Woven fabrics, partly finished articles, yarns or loose staple fibres may be treated.  If desired, the fixation of the resin may be enhanced by a heat treatment prior to washing.  In an example a cotton tablecloth is immersed in an aqueous emulsion comprising 25 parts by weight of a 54.5 per cent polyvinyl acetate aqueous p  emulsion, 0.7 parts triacetin, 0.3 parts dibutyl phthalate and 74 parts water.  After squeezing and partial drying it is calendered or ironed while damp.  It is then washed by overnight soaking in water at room temperature followed by agitation in a rotary washer at the boil.  Specification 510,203 is referred to.