Patent GB-557783-A (GB)
Title: Improvements in or relating to the production of synthetic linear polyamide knitted goods
IPC: D04B1/26
Filed: 1942-04-29
Abstract: 557,783. Treating textiles with liquids ; sizes. DU PONT DE NEMOURS & CO., E. I. April 29, 1942, No. 5748. Convention date, May 14, 1941. [Class 15 (ii)] [Also in Group V] A film-forming solution of a protein which is, per se, substantially water-insoluble is applied as a size to a synthetic linear polyamide yarn and the sized yarn is then knitted to form sheer knit goods, especially fully-fashioned hosiery. As synthetic linear polyamides there may be used polyhexamethylene adipamide, poly - p - xylylene sebacamide, polyhexamethylene hexahydro - terephthalamide, polyhexamethylene - 4 - keto - pimelamide, polymerized 6-amino-caproic acid, and similar compounds. The protein may be a globulin which is insoluble in water but soluble in a dilute salt solution, or a prolamine which is soluble in alcohol, or a glutelin which is soluble in alkali solution, or a phosphoprotein. Serum globulin from blood, glycinin from soya beans, and edestin from hemp seed are examples of globulins. Gliadin, zein from maize, and hordein from barley, are examples of prolamines. Oryzenin from rice, and maize glutelin are examples of glutelins. Casein from milk and vitellin from egg yolk are examples of phosphoproteins. Edestan, i.e. denatured edestin and other denatured proteins may be used. The protein may be applied in aqueous or organic solutions. The composition may contain a water-soluble plasticizer for the protein, e.g. glycerol, triethylene glycol, polymerized ethylene oxide, ethanol formamide, triethanolamine or a salt thereof, or a waterinsoluble plasticizer such as di-(#-methoxyethyl) adipate, N-ethyl toluenesulphonamides, amyl benzene-sulphonamide, and dibutyl phthalate. Hardening agents for the proteins may be added to the sizing solutions or may be applied to the yarn before or after application of the size. Formaldehyde, tannic acid, tannates, aluminium acetate, and other heavy metal salts may be used as hardening agents for blood albumin, glue, gelatine, and other proteins. Hardening is preferably carried out to such an extent that though the size coating is not readily soluble in water it becomes tacky when the yarn is moistened. Lubricants, e.g. triethanolamine oleate, dodecylamine acetate, glycerol monoricinoleate, and diglycol stearate may be added to the sizing composition. The proteins may be brought into aqueous solution by using solubilizing agents such as acids, salts, or alkalies, e.g. by dissolving in dilute aqueous sodium hydroxide, ammonium hydroxide or ethylene imine. Zein may be solubilized by means of triethanolamine oleate. If a non-aqueous preparation is desired, a solution of zein in alcohol may be used. The sizing solution may be applied by immersion of the hanks or travelling yarns or by spraying or by contact of the yarns with a moistened roller. After sizing, the yarns are dried. The sized yarn is preferably wetted just before it passes through the needles to form the knitted material. In an example, a yarn of oriented polyhexamethylene adipamide is sized on a bobbin to bobbin sizing machine with a solution comprising soya bean protein, sodium carbonate, water, glycerol, and triethanolamine oleate. It is dried, coned, and knit on a fullfashioned hosiery knitting machine. In other examples, the sizing compositions comprise casein, ammonia, ethanolamine and water; zein, triethanolamine oleate, ethanol formamide, and water; casein, ethylene imine, and water; hydrochloric acid casein, sodium acetate, water, isopropanol glycolamide, and formaldehyde. Specifications 461,236, 461,237, 471,591, and 543,291 are referred to. The Specification as open to inspection under Sect. 91 comprises also the use of sizing compositions containing proteins together with natural or synthetic resins. This subject-matter does not appear in the Specification as accepted.