Patent GB-403966-A (GB)
Title: Treatment of textile and other materials made of or containing cellulose esters
IPC: D06M11/38
Filed: 1932-06-04
Abstract: Materials consisting of or containing cellulose esters are improved in their resistance to hot ironing or like operations by subjecting the ester to surface saponification, and thereafter incorporating in the surface layer a substance which melts, if at all, at a high temperature only, that is, at a temperature above 300 DEG  C.  The saponification may be effected in such a way as to lead to a loss in weight of 4--8 per cent.  The incorporation of substances having a high melting point in the saponified layer may be effected with aqueous solutions of the desired substance, applied by padding, spraying, or like treatments, the material being afterwards dried. When the substance to be incorporated is insoluble or difficulty soluble, a mixture of aqueous solutions of reagents yielding the desired compound by interaction on the material may be employed.  The compounds which may be incorporated are preferably inorganic salts, and include borates, phosphates, sulphates, and fluorides or other halides.  Mixtures of two or more compounds, such as alkali metal salts of the foregoing types, for example, a mixture of sodium fluoride and borax may be used. Other suitable compounds are aluminium acetate, magnesium sulphate or chloride, potassium sulphate, potash alum, potassium magnesium chloride, sodium sulphate, and sodium silico fluoride.  Compounds having a fire-proofing character may be used, or may be admixed with other substances to be incorporated.  Examples of such compounds are halides, borates, or phosphates of ammonia or other volatile bases or mixtures of such compounds.  Insoluble compounds which may be incorporated are the insoluble salts of aluminium, magnesium, calcium, borium, strontium, tin, or other metals with boric, phosphoric, sulphuric oxalic, or other acids. Such substances are applied directly to the materials in the form of colloidal solutions or dispensions, as in the case of silica or alumina.  Preferably the insoluble compounds are incorporated by treatment with the requisite reagents in successive baths, magnesium or zinc ammonium phosphate being incorporated, for example, by successive baths of a soluble magnesium or zinc salt and a sodium phosphate solution containing ammonia.  Tin compounds may be applied by padding with stannic chloride and fixing with sodium phosphate.  When tin or like weighting metal salts are employed, any substantial swelling of the cellulose ester should be obviated, substances which repress swelling, such as sodium chloride or other alkali metal salts or substantially neutral salts yielding anions of the same kind being employed, for example, to effect this purpose. The quantity of substance of high melting point incorporated may be sufficient to make up for the loss in weight due to saponification. The incorporation treatment may be effected after all other aqueous treatments, such as dyeing or softening treatments, or may be combined with a final aqueous treatment, for example, treatment with a suphonated oil or the like.  Cellulose esters specified, which the materials treated may comprise, are cellulose acetate, formate, propionate, and butyrate, and mixed esters such as cellulose nitroacetate or acetate-butyrate.  Textile and also other materials, such as films, foils, ribbon or the like may be treated.  Examples are given, in one of which a sulphonated higher fatty alcohol is added as a wetting-out agent to a treatment bath of sodium fluoride and borax.  Specifications 304,596, 309,377, 314,446, 314,447, 316,521, 318,468, 319,420, 330,950, [all in Class 2 (ii), Cellulose &c.], and 351,417 are referred to.