Patent GB-1162851-A (GB)
Title: Improvements in and relating to the Manufacture of Simulated Leather
Inventor: HAMANO TATSUJI
IPC: D04H1/48
Filed: 1967-01-03
Abstract: 1,162,851. Making leather-like material; yarns. ICHIKAWA WOOLEN TEXTILE CO. Ltd. 8 June, 1967 [3 Jan., 1967], No. 303/67. Headings D1P and D1W. Leather-like material is produced by weaving a fabric of single or multi-layer consisting of slivers and/or soft twist yarns (i.e. yarns having a twist constant of 2 or less), forming an assembly by superimposing a fibre batt or batts on the fabric, the slivers, yarns and batt or bats being admixtures of synthetic and/or natural fibres with two or more kinds of heat shrinkable synthetic fibres varying in shrinkage percentage, subjecting the assembly to needle punching and heat shrinking and then applying thereto a resin to effect binding and filling. The batt or batts may be superimposed on the fabric in a manner such that the fibres of the batt or batts are in the direction diagonal to those of the fabric and needle punching effected with the needles in the direction perpendicular and/or off-perpendicular to the surface, the subsequent heat shrinking being effected by treatment with hot water at 80- 100C, steam at 100-180C or dry heat at 120- 230C. The slivers, soft twist yarns and batts may be made from filaments, staple fibres or crimped fibres made from a polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, polypropylene, polyethylene or polyurea cotton, wool, silk, acetate rayon or viscose rayon. The resin treatment may be effected in two steps, the first step comprising applying to the assembly by dipping or spraying an emulsion or solution of a copolymer of acrylonitrile and butadiene containing carboxyl groups, a nylon resin, an acrylic resin or a urethane resin and then heating at 120-160C under a pressure of 1-10 Kg/cm<SP>2</SP>, and the second step comprising dipping the assembly in a solution of a synthetic resin e.g. a urethane resin in an organic solvent e.g. dimethyl formamide, acetone, methyl ethyl ketone or toluene containing an organic compound, which is a non-solvent for the resin and has a boiling point higher than that of the organic solvent, e.g. polyethylene glycol or polypropylene glycol, pressing out excess solution and treating the assembly with a coagulating liquid, e.g. water or methanol, which is soluble in the organic solvent so that the resin is rapidly and evenly deposited in the assembly. The resulting material may then be subjected to slicing and/or buffing. In assemblies containing polyvinyl alcohol, polyacrylonitrile, urethane or acetate rayon fibres these fibres may be dissolved out if the subsequent treatments involved treatment with water, dimethyl formamide or acetone, and low melting point polyethylene fibres may be softened during subsequent heat treatments. To prevent breakage of yarns while passing through a weaving machine fibres 10-20 cm in length may 'be mixed with those less than 10 cm in length so that the fibres of 10-20 cm constitute 10-40% by weight of the fibres. Soft twist yarns whose twist constant is 1 or less are preferably brought together in parallel, twisted together with, or coiled around continuous yarns such as multifilaments or monofilaments prior to use, the continuous yarns optionally being subsequently removed.