Patent GB-467704-A (GB)
Title: Improvements in or relating to the production of artificial filaments, threads, films, and the like
IPC: D01F4/00
Filed: 1935-10-22
Abstract: Artificial filaments, threads, or films are obtained by extruding a solution of a vegetable globular protein which has been degenerated or denatured and dissolved in an aqueous solution of urea, thiourea, methylurea, other substituted urea or thiourea compounds, sodium thiocyanate, sodium salicylate, formamide, acetamide, or urethane or other lower alkyl ester of aminoformic acid.  These solvents dissolve and degenerate or denature the protein.  The solutions are extruded into a diluent or other regenerating medium.  The filaments or films obtained, show in many cases a b -keratin structure when examined by X-rays.  The protein used may be a globulin such as edestin, ground-nut, soya-bean, or castor-bean globulin.  Protective colloids or dispersing agents may be present in the protein solutions.  The solutions may be rendered more stable and the viscosity may be controlled by adding a small proportion of glyoxal polymer, formaldehyde, benzaldehyde, ethylene oxide, glycide, salicylic acid, gelatin, acetophenone, triacetin, sorbitol, glycerol, poly-glycols, glucose, triethanolamine, and, if not already present, thiourea. These additional substances may also be added to the coagulating bath or to a subsequent treatment bath.  If desired, the protein may be denatured or degenerated before the process of solution, but in such a case the use of a protective colloid or dispersing agent may be necessary to effect solution. Round, elliptical, solid, or tubular filaments may be obtained, or the products may be in the form of thin sheets.  The diluent or regenerating medium may be water, dilute aqueous solutions of ammonium sulphate, sodium sulphate or sulphite, or other liquid. Preferably, small quantities of sulphuric or acetic acid, zinc chloride, glycerol, or sorbitol, are added to the regenerating liquid.  The products may be strengthened by immersion in solutions of formaldehyde, dichromate, chrome alum, potash alum, aluminium sulphate or chloride, tannin, or picric acid.  The softness may be enhanced by treatment with solutions of waxes in oils or alcohol.  The filaments may be under tension during treatment and drying.  In an example, ground-nut seed globulin, urea, thiourea, and sorbitol are ground together and then mixed with a solution of gelatine, glyoxal polymer, and water, until dissolved.  The solution is filtered, centrifuged, ripened, and extruded into a warm solution of ammonium sulphate, zinc chloride, sulphuric acid, glycerol and water.  The filaments obtained are treated with a solution of glycerol or sorbitol in water, and then with a solution of formaldehyde.  They may also be treated with a dilute solution of urea and with a solution of paraffin wax in olive oil.  In another example formaldehyde, glycerol, and castor-seed globulin are ground to a cream with water.  Urea is added with stirring until dispersion of the protein is obtained. The solution is filtered, centrifuged, ripened, and then extruded into a solution of sodium sulphite, glacial acetic acid, formaldehyde, and water.ALSO:Dispersions of vegetable globular proteins in aqueous solutions of urea, thiourea, methylurea, other substituted urea or thiourea compounds, sodium thiocyanate, sodium salicylate, formamide, acetamide, or urethane or other lower alkyl ester of aminoformic acid, are rendered more stable by the addition of glyoxal polymer, formaldehyde, benzaldehyde, ethylene oxide, glycide, salicylic acid, gelatin, acetophenone, triacetin, sorbitol, glycerol, polyglycols, glucose, triethanol-amine, or, if not already present, thiourea.  Premature precipitation or gelling is thus avoided.  Other protective colloids or stabilizing agents may be added.  The solvents employed have a degenerating or denaturing effect on the globular proteins dispersed therein.  If desired, the protein may be degenerated or denatured before dissolution. In an example, ground-nut seed globulin, urea, thiourea, and sorbitol are ground together and then mixed with a solution of gelatin, glyoxal polymer, and water, stirring being continued until dispersion is complete or almost complete.  The solution is filtered, centrifuged, ripened, and extruded to form filaments or films.  In another example, castorseed globulin is ground to a cream with water, formaldehyde, and glycerol.  Urea is added slowly, with stirring until dispersion of the protein is effected. Other globular proteins specified are edestin, and soya-bean globulin.