Patent GB-497793-A (GB)
Title: Improvements in and relating to rubber latex and to the treatment of textiles and kindred materials therewith
IPC: D06M15/693
Filed: 1937-05-27
Abstract: Textile fibres, yarns, fabrics, &c. of wool, cellulose, silk &c. are rubberized by being immersed in rubber latex which has been treated, by the addition of cationic soap solution to have a reversed or positive charge.  Woollen fibres may be oxidized or chlorinated before treatment.  In an example, 10 gals. of centrifugally concentrated latex of 60 per cent rubber content is diluted with 50 gals. of ,5N aqueous solution of ammonium hydroxide and added to 60 gals. of a 1 per cent aqueous solution of cetyl dimethyl sulphonium methyl sulphate.  Woollen fabric, scoured and treated with chlorine gas to a chlorine content of ,9 per cent is immersed in the 5 per cent latex so made for 30 mins. and on removal, rinsing and drying is found to contain between 9 and 10 per cent of rubber.  This can be vulcanized, or a vulcanized latex may be used.  In another example, 25 cc. of the 5 per cent converted latex prepared as above is diluted to 200 cc. with water containing sufficient ammonia to give a final pH of about 10.  A half-ounce hank of woollen yarn is immersed in this and kept moving, for 5-10 minutes, until all the rubber has been deposited on the wool fibres.  The treated hank is hydro-extracted and dried.  The rubber can be subsequently vulcanized or a vulcanized latex may be used.  Dyes or pigments, or waterproofing agents such as waxes, oils and fats may be incorporated in the latex.  Specification 483,496 is referred to.ALSO:Latex or other rubber dispersion is treated by having added thereto a cationic soap solution in amount sufficient to impart to the rubber particles a reversed or positive charge.  The treated latex has a proneness to deposit rubber on surfaces carrying a negative charge such as textile fibres of cellulose, wool, silk &c., asbestos, glass &c.  The cationic soap compounds consist essentially of a long-chain aliphatic residue attached to a radical capable of ionizing a solution in such a way that a positive charge is assumed by the polar end of the long-chain molecule.  The aliphatic chain may contain 8 or more carbon atoms and the ionizable radical may be represented by quaternary ammonium or phosphonium or ternary sulphonium groups in combination with a suitable anion such as a halogen ion or sulphate ion.  Typical compounds are cetyl pyridium bromide, cetyl trimethyl ammonium chloride and cetyl dimethyl sulphonium methyl sulphate.  In low concentrations these compounds act as gelling, flocculating or coagulating agents.  To form a stable latex having a reversed charge, one or more of the reagents is added in excess of the amount required for flocculation.  For deposition of rubber on to textile fibres, the pH of the treated latex should be between 8 and 10,5.  Woollen fibres to be rubberized, may be oxidized or chlorinated prior to immersion in the treated latex. In an example, 10 gals. of centrifugally concentrated latex of 60 per cent rubber content is diluted with 50 gals. of ,5N aqueous solution of ammonium hydroxide and added to 60 gals. of a 1 per cent aqueous solution of cetyl dimethyl sulphonium methyl sulphate.  Woollen fabric, scoured and treated with chlorine gas to a chlorine content of ,9 per cent is immersed in the 5 per cent latex so made for 30 mins., and on removal, rinsing and drying, is found to contain between 9 and 10 per cent of rubber. This can be vulcanized by sulphur chloride, the Peachey process or otherwise, or a vulcanized latex may be used.  In another example, 25 cc. of the 5 per cent converted latex prepared as above is diluted to 200 cc. with water containing sufficient ammonia to give a final pH of about 10. A half-ounce hank of woollen yarn is immersed in this and kept moving, for 5-10 minutes, until all the rubber has been deposited on the wool fibres.  The treated hank is hydro-extracted and dried. Vulcanization can be effected as in the first example.  Dyes or pigments, or waterproofing agents such as waxes, oils and fats may be incorporated in the latex.  Specification 483,496 is referred to.