Patent GB-692478-A (GB)
Title: A process for the treatment of keratinous materials and production of articles from the treated materials
Inventor: ALEXANDER PETER
IPC: C08L89/00
Filed: 1949-09-15
Abstract: Films, fibres and other shaped articles are formed from oxidized protein prepared by treating keratin or a keratin-containing material at a temperature below 100 DEG  C. with an aqueous solution of a saturated peraliphatic acid having not more than 4 carbon atoms and dissolving the whole or a part of the oxidized protein in a solvent which is a hydrotropic substance selected from dilute alkalis, preferably dilute ammonia, solutions of cuprammonium compounds; copper ethylene diamine, phenol or resorcinol containing water, phosphoric acid, and their aqueous solutions; aqueous solutions of sodium oleate; concentrated aqueous solutions of lithium halides, lithium thiocyanate, zinc chloride, urea and substituted ureas, e.g. guanidine (see Group IV (b)).  The oxidized protein may be precipitated from the extract solutions by extrusion into aqueous solutions of acids, salts, alcohols or ketones and sometimes merely on dilution with water; alternatively, the solid protein may be recovered by evaporating the solutions.  The still soluble precipitated protein may be insolubilized by cross-linking, e.g. with formaldehyde or heavy metal salts.  The solutions of oxidized protein in ammonia may be cast and the ammonia allowed to evaporate to form films or may be spun into a vacuum or hot air to evaporate aqueous ammonia and form fibres.  The oxidized protein precipitated from ammonia solution resembles a -keratin; if such protein is then extruded from a volatile non-aqueous solvent containing little or no water, e.g. formic acid, then the protein resembles b -keratin. Accordingly, fibres having the structure of wool are obtained by spinning an aqueous ammonia solution of the oxidized protein into an aqueous coagulating bath containing sodium sulphate, drying the fibres and passing them rapidly through formic acid, then drying and finally hardening with formaldehyde.  The solid protein may be dissolved in liquid ammonia and fibres obtained by spinning the solution into air.  In example 7, merino wool is oxidized with aqueous peracetic acid and extracted with aqueous ammonia; the extract is acidified, the precipitated oxidized protein recovered and ground in aqueous ammonia forming a 15 per cent solution which is extruded into an aqueous coagulating bath containing sodium and (magnesium sulphates and some "Fixanol" (Registered Trade Mark) and the resulting white fibres are insolubilized by treatment with formaldehyde contained in a bath of the composition of the coagulating bath.  Other examples describe the preparation of solutions of oxidized proteins, obtained from botany wool or cow's horn shavings and per-acetic, -propionic or-n butyric acid, in various of the above-mentioned hydrotropic solvents.ALSO:Oxidized proteins are prepared by reacting keratin or a keratin-containing material at a temperature below 100 DEG  C. with an aqueous solution of a saturated per-aliphatic acid having less than 4 carbon atoms and dissolving the whole or part of the oxidized protein in a solvent which is a hydrotropic substance selected from dilute alkalis, especially dilute ammonia, solutions of cuprammonium compounds, copper ethylene diamine, phenol or resorcinol containing water, phosphoric acids, and their aqueous p  solutions; aqueous solutions of sodium oleate; concentrated solutions of lithium halides, lithium thiocyanate, zinc chloride, urea and substituted urea derivatives, e.g. guanidine.  To facilitate the solution of the oxidized proteins, wetting agents such as fatty sulphonates may be used.  Preferably aqueous per-acetic acid solutions are employed; the acid may be neutralized but pH values of between 4 and 7 are preferred.  The per-acid solutions may be the mixture thereof with the parent acid obtained by reacting the latter with hydrogen peroxide.  The extracted oxidized protein may be recovered by extruding the hydrotropic solvent solutions into aqueous solutions of acids, salts, alcohols or ketones and sometimes merely by diluting with water; alternatively the solutions may be allowed to evaporate. The precipitated protein may be insolubilized by means of cross-linking, e.g. with formaldehyde or heavy metal salts.  The precipitated protein is soluble in liquid ammonia and formic acid.  The production of fibres, films and other shaped articles is described (see Group IV (a)).  The oxidized protein may also be used as a foodstuff.  In typical examples: (1) botany wool is suspended in 45 per cent aqueous per-acetic acid for 1 hour at 22 DEG  C., whereupon the oxidized wool is filtered off and dissolved in N/100 ammonia; (3) botany wool is suspended in aqueous per-propionic acid at room temperature for 2 hours, and then removed and dissolved in 0.2 N ammonia; (4) as in (3) but using per-n-butyric acid; (8) fine cow's horn shavings are stirred in aqueous acetic acid-peracetic acid solution at room temperature and then dissolved in 0.2 N ammonia; (13) wool is oxidized as in (8) and then dissolved in various of the above-mentioned hydrotropic solvents including 5 per cent aqueous sodium bicarbonate, cuprammonium hydroxide, and 100 per cent lithium bromide.