GB634812A - Process for improving the properties of protein spinning products - Google Patents

Abstract

Artificial fibres, threads and the like obtained by extruding protein solutions, particularly casein solutions, are impregnated with pre-condensation products of formaldehyde and resorcin or a nuclear substitution derivative of resorcin, prepared in an acid medium, and further condensation is effected by heating the impregnated textile products. The process may be applied to threads which have already been hardened with formaldehyde. The threads are rendered resistant to hot dilute acid liquids such as acid dye baths without reduction in the flexibility. Resorcin may be added to an acid solution of formaldehyde. The solution is heated for some time, e.g. 30 mins. at 60 DEG C., and then cooled. Casein fibres are introduced into the diluted solution at room temperature. The fibres are removed from the bath, centrifuged, dried and heated to 105 DEG C. to complete the condensation. Condensation products containing 6 mols. of formaldehyde per mol. of resorcin are preferred. Specified substituted resorcins which may be used are 1-chloro-2.4-dihydroxybenzene and the corresponding methoxy and carboxy substitution products. Threads of gelatine, soya-bean protein, or pea-nut protein may also be treated. In an example, 0.5 kg. of resorcin is dissolved in 3 litres of 33 per cent formalin and the solution of pH 3.5 is heated for 30 mins. at 60 DEG C. After cooling, 37 litres of water are added. Casein fibres, previously hardened with formaldehyde are impregnated with the solution, and then centrifuged, dried at 70 DEG C., and heated to 105 DEG C. for 15 mins. In another example, an emulsion of lanoline and paraffin oil is added to the impregnating liquid. The process may be carried out continuously with the spinning process. Thus, the still wet and pre-hardened casein threads may be cut to staple fibre and spread on a conveyer belt upon which they are sprayed with a solution of the pre-condensate. Several spraying devices may be provided and the treatment may be such that fresh liquid is applied from the last spray of the series and the used liquid is supplied to the preceding spray. The material may thus be treated on the counter-current principle.ALSO:Fibres, threads, and like products obtained from protein solutions, particularly from casein solutions, are impregnated with precondensation products of formaldehyde and resorcin or a nuclear substitution derivative of resorcin, prepared in an acid medium, and further condensation is effected by heating the impregnated textile products. Threads which have already been hardened with formaldehyde may be treated. The threads are rendered resistant to hot dilute acid liquids such as acid dye baths without reduction in the flexibility. Resorcin may be added to an acid solution of formaldehyde, which is then heated, e.g. for 30 minutes at 60 DEG C. Casein threads are introduced into the cooled and diluted solution. They are then removed from the bath, centrifuged, dried, and heated to 105 DEG C. to complete the condensation. Condensation products containing 6 mols. of formaldehyde per mol of resorcin are preferred. Specified substituted resorcins which may be used are 1-chloro-2.4-dihydroxybenzene and the corresponding methoxy and carboxy substitution products. Threads of gelatine, soya-bean protein, or pea-nut protein, may also be treated. In an example, casein fibres are impregnated with an aqueous solution containing a resorcin-formaldehyde product, obtained by condensation in an acid medium, and also containing an emulsion of lanoline and paraffin oil.