Patent GB-815794-A (GB)
Title: Cellulose ester textile fabrics
IPC: D06M11/38
Filed: 1956-03-29
Abstract: Textile fabric containing fibres having a basis of a cellulose triester of a fatty acid containing up to 4 carbon atoms is subjected to treatment to saponify the surfaces of said fibres while leaving the fibre interiors substantially intact. Saponification of the fibre surfaces may be effected by the action of a strong aqueous alkali, e.g. fabric containing cellulose triacetate fibres may be superficially saponified by treatment with aqueous sodium hydroxide of at least 20 per cent strength at a temperature of 20-40 DEG  C. followed by rinsing with hot or cold water to produce a thin cellulose skin on the fibre exteriors. Wetting agents, e.g. cresols, cresylic acids or alkylated-phenol-ethylene oxide condensation products, such as "Triton X-100" and "Igepal" (Registered Trade Marks), may be used to assist alkaline saponification.  The fabric may be treated prior to, simultaneously with or after the saponification to increase the crystallinity of the fibre interiors, e.g. by a heat treatment taking the form of hot air, steam, oil or molten metal, infra-red radiation, high-frequency electric heating, or passage between hot rollers or platens, the fabric being either relaxed or under tension and the treatment being at reduced, atmospheric or superatmospheric pressure.  Alternatively the heat treatment may be partially or complete substituted by subjecting the fabric to the action of a swelling agent, e.g. methylene chloride, benzene or acetone/water or acetone/alcohol mixtures.  Prior to the treatment of the fabric to increase its crystallinity and thereby its safe ironing temperature, it may be printed or dyed, which process may be preceded by or be simultaneous with the saponification treatment.  Scouring of the fabric after the heat treatment may be effected with aqueous solutions of non-ionic or anionic detergents, e.g. "Emulphor ELA-719," "Tide" (Registered Trade Marks) or "Duponol RA," to which may be added a mild stripping agent, e.g. sodium hydrosulphite.  Finishing agents which may be applied to the fabric include urea-formaldehyde, melamine-formaldehyde, reactive silicones and stearamidomethyl pyridinium chloride type resins.  The fabrics may be woven or knitted from fibres of cellulose acetate, propionate, butyrate, acetate/propionate, acetate/butyrate, or acetate/formate or blends of such fibres with other fibrous materials such as cotton, polyethylene terephthalate, polymers and copolymers of acrylonitrile, glass fibres or asbestos.  Examples are given.  Specifications 753,461, 758,442, 775,406, [Group IV (c)], 776,346, [791,391 and 791,392], [both in Group IV (c)], are referred to.ALSO:A textile fabric containing fibres having a basis of a cellulose triester of a fatty acid containing up to four carbon atoms is subjected to treatment to saponify the surfaces of said fibres while leaving the fibre interiors substantially intact. The fabric may be treated prior to, simultaneously with or subsequently to the saponification with a swelling agent or heating means or combination of both. Simultaneously with or after saponification the fabric may be dyed or printed.  In the case when dyeing and saponification are effected simultaneously a paste containing a vat dye and an alkali may be used. Alternatively the dye may be used in aqueous solution or dispersion, e.g. in the form of a paste containing a cellulose acetate disperse dye which may be applied to the fabric by padding, or as a solution in an organic solvent, e.g. ethyl alcohol.  A number of suitable dyes are specified.  Examples are given.  Specifications 753,461, 758,442, [both in Group IV (a)], 775,406, 776,346, [Group IV (a)], 791,391 and 791,392 are referred to.