Patent GB-858022-A (GB)
Title: Improvements in and relating to the treatment of textile materials
Inventor: EVANS JOHN GWYNANT
IPC: D06M13/236
Filed: 1957-11-05
Abstract: A process for imparting oleophobic and hydrophobic properties to fibrous material comprises applying thereto a fluorocarbon compound which is oleophobic and forms a film, and a finishing substance having the property of reducing the swelling power in water of hydrophilic fibres.  Specific fluorocarbons referred to are fluorinated carboxylic acids, e.g. perfluorodecanoic acid, chromium co-ordination complexes of such acids, e.g. of the type (CF3(CF2)nCOOCr2OH)4, and polymers of fluoroalkyl esters of acrylic acids.  These chemicals may be applied in aqueous or aqueous alcoholic solutions, an aqueous dispersion, or in an organic solvent, and may be applied before, simultaneously with, or after the finishing substances.  The following finishing substances are referred to: cross-linking agents, e.g. aldehydes (formaldehyde or glyoxal); methylol derivatives of triazones, e.g. dimethylol derivatives of methyl, ethyl or hydroxyethyl tetrahydros-triazone; resinous bodies, especially precondensates, e.g. reaction products of aldehydes with amino-containing compounds, e.g. urea, ethylene urea, or melamine, or the methyl and other ethers of such products; other precondensates mentioned are alkyd or modified alkyd resins, keto-aldehyde precondensates, epoxy resins or their partial polymeric products, e.g. the reaction products of epichlorhydrin and diphenylol propane; and polyfunctional isocyanates of which many examples are given.  Thermoplastic resin binders. e.g. polyvinyl acetate may be combined with the fluorinated organic chemical.  Fibrous materials which may be treated are woven and knitted fabrics, yarns, scrubbings, rovings, non-woven fabrics, felts and paper and the fibres may be natural or synthetic.  Nine examples are given in which fabrics are impregnated with the fluorocarbon with and without the finishing substances, and the impregnated areas subjected to oilrepellency and water-repellency tests (which are described) before and after washing.  Proportions of the chemicals employed in the impregnating steps are given in each example.  Sodium lauryl sulphate or sodium acetate may be mixed with the fluorinated organic chemical and isocyanate finishers mentioned in the examples are:-metatoluylene di-isocyanate, hexamethylene di-isocyanate and p, p1, p11-tri-isocyanato triphenyl methane.  Zinc nitrate and phosphoric acid are included in the impregnants in two of the examples.  Organic solvents for the finishing substances which may be diluted with water, include 2 methyl 2 amino propanol hydrochloride, methylene chloride and ethyl acetate.  Water repellants may be included e.g. the chromium complex of stearic or methacrylic acid, or the silicones.  The Provisional Specification refers to tetrakis hydroxymethyl phosphonium chloride as a precondensate, especially for flame-resistance, and the reaction products of polyfunctional isocyanates with ethylene imine, and NaH SO3 addition compounds of the isocyanates. Specifications 740,267, 761,985, 764,313 and 764,314 are referred to.