Patent GB-539442-A (GB)
Title: Manufacture of artificial filaments, films, sponges and similar structures
IPC: D01F1/10
Filed: 1940-03-08
Abstract: 539,442. Artificial silk, films &c. ; cellulosic and synthetic resin compositions dyeing processes. DU PONT DE NEMOURS & CO., E. I. March 8, 1940, No. 4339. Convention date, March 9, 1939. [Classes 2 (ii), 2 (iii) and 15 (ii)] Artificial films, filaments, caps, bands, sponges, and like structures of improved affinity for dyestuffs are obtained by incorporating with artificial film-forming organic compositions a proportion of a synthetic linear polyamide in the form of discrete particles, and bringing the composition into the appropriate shape. Alternatively, the polyamide may be so chosen that it is dissolved in the film-forming composition provided that it is capable of being deposited in the form of discrete particles during the setting of the shaped structures. The film-forming substance may be a cellulose derivative such as an ester or ether or a synthetic resin such as polyvinyl chloride, chlorinated polyvinyl chloride, polyvinyl acetate, or methyl methacrylate. Cellulose solutions from which cellulose is regenerated, e.g. viscose or cuprammonium cellulose solutions may be used. The process results in products with good affinity for direct dyes, acid wool dyes, developed-colour dyes (diazo dyes), chrome dyes, vat dyes, basic dyes, basic anthraquinone dyes, dyes such as 4-nitro-4<SP>1</SP>-amino-azobenzene, and dyes of the type 1-amino-4-arylamino anthraquinone-2-sulphonic acid. The dyeing process may be facilitated by including in the dye bath a small amount of solvent or swelling agent for the film-forming material. The filaments and yarns produced by the process may be mixed with wool, cotton, and other fibres and dyed in even shades. The synthetic linear polyamides used may be obtained from monoamino-carboxylic acids or from diamines and dibasic carboxylic acids. In these polyamides the amide groups form a recurring part of the main chain of atoms in the molecule. In an example a suitable polyamide is obtained by heating the monomeric salt of hexamethylene diamine and adipic acid with water for two hours at 225 C. The reaction product is cooled, solidified, and ground. In another example, hexamethylene diamine and adipic acid dissolved in cresol are heated in an atmosphere of nitrogen for several hours at 200 C., and the product is then poured into ethyl acetate to precipitate the polyamide which is soluble in phenol and in formic or acetic acid. Interpolymers of hexamethylene diammonium adipate and decamethylene diammonium sebacate, interpolymers derived from a diamine, a glycol, and a dibasic acid, polyamides obtained from diglycolic or adipic acid and diethylene triamine, and polyamides from tartaric acid or maleic acid and hexamethylene diamine may be used. The polyamides may be of sufficiently low molecular weight to have an intrinsic viscosity not greater than 0.6. They may be of lower molecular weight than those which are capable of forming filaments. The polymerization may be retarded and controlled by adjusting the amount of water present in the reaction vessel, or by using an excess of diamine or dicarboxylic acid. In an example, a slurry of a polyamine, water, and " Monopole " oil (Registered Trade Mark) is mixed with a viscose spinning solution. The yarns obtained are dyed with a solution containing Alizarin Sky Blue B, Glauber's salt, and acetic acid. In another example the viscose spinning solution treated as before is spun into a solution of ammonium sulphate and the filaments are regenerated in a bath of hot glycerine. In another example, an interpolymer obtained from hexamethylene - diammonium adipate and decamethylene diammonium sebacate is added to a solution containing a vinyl chloride-methyl methacrylate interpolymer, chloroform and methanol. The solution is poured on to a heated glass surface and baked at 130 C. The thin film obtained is'then stripped from the glass. An aqueous slurry of a polyamide is mixed with a cellulose acetate spinning solution which is then made into filaments by an electrical spinning process. Specifications 419,736, 461,236, 461,237, and 474,999 are referred to.