GB674755A - Improvements in and relating to the production of artificial protein fibres - Google Patents

Abstract

Protein fibres soluble in dilute alkaline solutions are manufactured by extruding an alkaline protein solution into a coagulating bath containing at least one metal salt, stretching the resultant thread at least 50 per cent, but preferably 300-700 per cent, rendering the thread resistant to cold water by treatment in an aqueous bath containing a halogenated aldehyde, e.g. chloral, chloral hydrate, bromal, mono- and dichloracetaldehyde and water soluble halogen-substituted propionaldehydes such as 1 : 1-dibromopropionaldehyde, and drying the hardened thread, the entire process being effected in the absence of formaldehyde. Stretching may be effected, if desired, in two stages, inside or outside the coagulating bath or in a subsequent identical or different coagulating bath which may be heated, if desired, to 40-70 DEG C. Further stretching may also be effected after hardening. Partial hardening of the thread with the halogenated aldehyde may be effected in the coagulating or subsequent coagulating bath and later completed in the subsequent hardening bath. Treatment in the hardening bath may be effected while the thread is passed over rollers or with the thread in the relaxed condition by the procedure of Specification 565,011. The hardening bath, which may be heated to 40-70 DEG C., may also contain one or more metal salts, e.g. the sulphates of sodium or magnesium, aluminium acetate or calcium chloride. The coagulating bath may contain the sulphates of sodium, magnesium or aluminium and sodium chloride, and, if desired, an acid, e.g. sulphuric acid. Specified proteins are lactic, soya bean, peanut and castor bean proteins. The fibres may be used as a soluble yarn in the production of effect textile materials; thus they may be twisted with wool or employed as a binder for twistless yarns which after knitting or weaving into fabrics may be treated with an alkaline solution to dissolve the protein fibres. Numerous examples are given. Specifications 547,583, [Group IX], and 550,525 also are referred to.