Patent GB-592225-A (GB)
Title: Reinforced film and process of making the same
IPC: D06M15/09
Filed: 1944-08-19
Abstract: 592,225. Coated fabrics. SYLVANIA INDUSTRIAL CORPORATION. Aug. 19, 1944, No. 15874. Convention date, Aug. 20, 1943. [Class 140] A substantially transparent reinforced film is produced by coating an open mesh textile web having a substantial nap with an alkaline solution of an alkalisoluble, water - insoluble cellulose ether, ironing the treated web to lay the nap hairs and coagulating the cellulose ether to produce a continuous film with the web embedded therein. The solution may be applied to the web by immersion or other specified methods and the coated web is ironed, as by upward passage between smooth plates to spread the solution and remove excess ; after the coagulation step it is washed in water, and, preferably, dried whilst it is maintained under tension. The web may be formed of cotton, and it may first be treated with a wetting agent such as an aqueous solution of an alkali, saponin, turkey red oil or a sulphated fatty alcohol, or such agent may be added to the' cellulose ether solution. The alkali-soluble, water-insoluble cellulose ether may be an alkyl, hydroxy-alkyl, carboxy-alkyl, or alkali salt of carboxy-alkyl, cellulose ether and this is dissolved in aqueous sodium, potassium or lithium hydroxide; hydroxy ethyl cellulose ether is specified in an example. The cellulose ether solution may be thickened before application to the web by # addition of agents such as an acid, acid salt or a salt, gelatin, casein starch, gum tragacanth or water-soluble methyl cellulose and may be coloured by an alkali-soluble dye or a pigment. After application of the solution to the web, the cellulose ether may be coagulated by immersion of the treated web in an aqueous solution of an acid, such as sulphuric acid, an acid salt or a salt or by hot water or an acid gas such as sulphur dioxide. The reinforced film may be fireproofed, flameproofed, waterproofed, mildewproofed, made gas absorbent or have its flexibility increased by agents included in the cellulosic solution or applied to the film afterwards, thus a flameproofing plasticiser such as urea, amine phosphates or ethanolamine sulphamates may be used ; and an added waterproof coating may include wax, rubber, resin or synthetic resin such as ureaformaldehyde or alkyd resins which may be hardened by ammonium thiocyanate ; cellulose derivatives such as nitrocellulose, wax blending agent and plasticisers. Activated carbon may be used as gas absorbent. In the drawing, the open mesh web 10 is treated with wetting agent in bath 11, squeezed by bowls 12 and passed through the cellulosic solution in bath 17. It is then ironed as at 14 and coagulant solution is applied, first by roll 16 and secondly in the bath 18, the treated web is washed in water in baths 19 and 20, of which bath 20 may contain a plasticiser, and, finally, dried by hot air in the teater frame 21 and wound on roll 22. The Specification as open to inspection under Sect. 91 refers also to the use of cellulose solutions in cuprammonia, caustic alkali, alkaline zincate and stannate and quaternary ammonium bases in place of the cellulose ether solution ; and the use of webs of artificial fibres such as rayon, cellulose acetate rayon and nylon in addition to cotton. This subject-matter does not appear in the Specification as accepted.