Patent GB-1047099-A (GB)
Title: Copolymer compositions for sizing textile fibres
IPC: D06M15/263
Filed: 1964-12-11
Abstract: Compositions for sizing textile fibres are prepared by a process which comprises (1) emulsion copolymerizing a monomer mixture containing (a) an ethylenically unsaturated monomer, the homopolymer of which is water-insoluble and (b) an ethylenically unsaturated carboxylic acid and, if desired, (c) one or more other ethylenically unsaturated monomers, in an aqueous medium in the presence of a regulator and (2) treating the aqueous dispersion thereby obtained with a base to effect salt formation; the said monomer mixture containing from 1 to 15% by weight of component (b) and the nature and quantity of the regulator being such that, if the aqueous dispersion obtained from step (1) is adjusted to a solids content of 10% by weight and is then treated with an appropriate base to a pH of 9 to form an alkali metal or ammonium salt, the viscosity increase which results from the treatment with the base is less than twenty-fold.  Component (a) of the monomer mixture is preferably a C1- 4-alkyl ester of acrylic and/or methacrylic acid but may also be styrene, a substituted styrene, a vinyl ether or a vinyl ester; components (b) specified are acrylic and/or methacrylic acid, itaconic acid, aconitic acid, maleic acid, dimeric and trimeric methacrylic acid, and 2-methylene-5-methyl adipic acid; examples of component (c) are acrylonitrile, ethylenically unsaturated amides and derivatives thereof.  Polymerization regulators specified are n-dodecyl mercaptan, di - (isopropyloxythiocarbonyl) disulphide, diphenyl disulphide, thioglycolic acid and the 2-ethylhexyl ester thereof. The salt formed in step (2) is preferably an alkali metal or ammonium salt.  In examples, there are polymerized (i) ethylacrylate/methacrylic acid, (ii) ethylacrylate/methyl methacrylate/methacrylic acid, (iii) methylacrylate / acrylonitrile / methacrylic acid, (iv) ethylacrylate/methyl methacrylate / 2 - methylene - 5 - methyladipic acid and (v) isopropyl acrylate/acrylic acid using a sulphated nonylphenol - ethylene oxide condensation product as emulsifier and ammonium persulphate as catalyst, salt formation being effected with NaOH.ALSO:A method of sizing textile fibres, which are wholly or in part synthetic, prior to weaving comprises coating the fibres with a sizing composition prepared by (1) emulsion copolymerizing a monomer mixture containing (a) an ethylenically unsaturated monomer the homopolymer of which is water-insoluble and (b) an ethylenically unsaturated carboxylic acid and, if desired, (c) one or more other ethylenically unsaturated monomers, in an aqueous medium in the presence of a polymerization regulator (e.g. a mercaptan, disulphide, thioether, thio acid or ester thereof) and (2) treating the aqueous dispersion thereby obtained with a base (preferably of an alkali metal or ammonia) to effect salt formation; the said monomer mixture containing from 1 to 15% by weight of component (b) and the nature and quantity of the regulator being such that, if the aqueous dispersion obtained from step (1) is adjusted to a solids content of 10% by weight and is then treated with an appropriate base to a pH of 9 to form an alkalic metal or ammonium salt, the viscosity increase which results from the treatment with the base is less than twenty-fold.  The coating applied to the fibres by sizing can be readily removed from the finished fabric, after weaving, by washing with water or other aqueous cleaning liquid.  Sizing is generally effected at 50-70 DEG C. and the solids content of the sizing composition is preferably adjusted, prior to use, to less than 10% by weight.  Suitable fibres for sizing include rayon, polyacrylonitrile, polyester, polypropylene, acetate and triacetate fibres.  In examples, there are copolymerized (i) ethyl acrylate/methacrylic acid (ii) ethyl acrylate/methyl methacrylate/methacrylic acid (iii) methyl acrylate/acrylonitrile/methacrylic acid (iv) ethyl acrylate/methyl methacrylate/2-methylene-5-methyladipic acid and (v) isopropyl acrylate/acrylic acid and the dispersions of the copolymers are treated with NaOH to a pH of 9.