Patent GB-550489-A (GB)
Title: Improvements in and relating to the production of synthetic filaments, films and the like
IPC: D06M15/17
Filed: 1941-07-04
Abstract: 550,489. Artificial filaments, films etc.; treating textiles with liquids ; coated fabrics. IMPERIAL CHEMICAL INDUSTRIES, Ltd. (Du Pont de Nemours & Co., E. 1.). July 4, 1941, No. 8447. [Classes 2 (ii) and 15 (ii)] [Also in Group VII]] Synthetic linear polymer structures, capable of being permanently elongated by cold drawing or cold rolling, are coated with a filmforming substance which is not capable of cold drawing or rolling or is not capable of being permanently elongated by cold drawing or rolling to the same extent as the synthetic linear polymer, and the coated structures are then cold drawn or cold rolled. The effects produced are determined by the coating substance employed. If polyamide fibres are coated with rubber and then cold drawn, they subsequently become curled or coiled due to contraction of the rubber. If the fibres or films are coated with a film of resinous or other material incapable of being temporarily or permanently stretched and are then cold drawn, the coating usually cracks leaving the surface roughened by the adhering particles, shreds, or scales. Materials applied in this way may modify the dyeing properties of the fibres or act as delustrants or give the fibre a woolly appearance. Particles of the polymer from which the fibre is made together with a binder may be applied to the fibre to yield a roughened surface when the fibre is subsequently cold drawn. ]n an example, a smooth undrawn polyhexamethylene adipamide filament is coated with a film of cellulose acetate from a chloroform solution. The filament is cold drawn 400 per cent. before all the solvent has evaporated from the coating. The coating breaks up into small areas and imparts a roughened surface. In another example, the filaments are coated with pigment-size particles of a polymer of lower molecular weight by passing them through an aqueous suspension of the particles. They are dried and bak ed and then cold drawn. A partially drawn yarn of polydecamethylene adipamide is dipped in a suspension of titanium dioxide pigment in an aqueous solution of partially de-acetylated chitin, centrifuged, and dried. 1t is then colddrawn. A filament of polyhexamethylene adipamide is coated with polymerized methyl methacrylate in solution in alcohol and toluene. A second coating is applied and then the fila. ment is cold drawn. A beady surface appearance is obtained. A filament of polyhexamethylene adipamide is coated with vulcanized rubber latex and cold drawn. The filament becomes curled or crinkled. The process is applicable to filaments, bristles, yarns, fabrics, sheeting; films, or ribbons. Instead of polyamide mater ials, the process may be applied to other linear condensation polymers such as polyesters, polyethers, polyacetals, or ester-amide interpolymers, or to other linear polymers such as polyethylenes, polystyrene, polyvinyl chloride, polyacrylic and polymethacrylic acid deriva. tives. As coating material there may be used synthetic resins, cellulose esters or ethers, natural or synthetic rubbers, e.g. polymerized butadiene or chlor-butadiene, or synthetic linear condensation polymers. The roughened surface effects facilitate the spinning of the fibres into yarns. The fibres may be mixed with silk, wool, cotton, or other yarns. The coatings may contain dyes, bronze powder, or coloured pigments. Novel effects may be obtained by dyeing the polymer fibres before coating and drawing. The fibres are suitable for use in the production of draperies, decorated fabrics, pile fabrics, upholstery goods, woven or knitted wear. Specifications 461,236, 461,237 and 471,590 are referred to.