Patent GB-738065-A (GB)
Title: Chromium complexes of fluorocarbon acids
IPC: C07F11/00
Filed: 1953-07-20
Abstract: Water-insoluble, green-coloured, chlorine-free, tacky, liquid, co-ordination complexes of trivalent chromium and a perfluoroalkyl monocarboxylic acid of 4-12 C atoms in the molecule, which have two acid groups per atom of chromium, and ammoniated derivatives thereof and polymers of both the ammoniated and unammoniated complexes are used directly or in solutions for treating textiles to, e.g., render them water- or oil-proof and to improve their tensile strength. Un-polymerized complexes may be applied directly or in solution, the coating being formed on subsequent heating of the material.  During the heating monomers are polymerized, the polymer product forming the coating. Polymerized complexes, obtained by heating the monomers, may be dissolved in a solvent and the solution thus obtained applied to the material to leave a coating of polymer product on evaporation of the solvent.  Highly polymerized products are soluble only in highly fluorinated solvents but a preferred "heat-advanced" partially polymerized product is obtained by heating the monomer to such an extent that although insoluble in normal alcohols and acetone it is soluble in isopropanol.  Solutions of this partially polymerized product in isopropanol are used for coating fabrics, a final heating to remove solvent and effect further polymerization being necessary. Isopropanol solutions preferably contain 5-15 grams of complex per litre.  When using an ammoniated complex or an un-ammoniated complex made in the presence of isopropanol (c.f. Group IV (b)) the isopropanol solution may contain water. Materials specified for treatment are cotton, wool, silk, acetate and viscose rayons, nylon, "Orlon" (Registered Trade Mark) and glass fibres.  When treating cotton a preliminary swelling of the fibres by steaming or kier-boiling is preferred.  Specification 712,784 is referred to.ALSO:The invention comprises polymers of water-insoluble, green-coloured, chlorine-free, tacky, liquid, co-ordination complexes of trivalent chromium and a perfluoroalkyl monocarboxylic acid of 4-12 C atoms per molecule, which have two acid groups per atom of chromium, and ammoniated derivatives thereof.  The unpolymerized unammoniated complex (see Group IV (b)) is made by reacting a chlorine-free, soluble, colloidal compound containing trivalent chromium with the perfluoroalkyl monocarboxylic acid in the presence of a hydroxylated compound. The product is ammoniated by treatment with ammonia.  The unammoniated polymers are formed on heating the monomer or on allowing the latter to stand.  Ammoniated polymers are obtained by treating unammoniated polymers with ammonia whilst dissolved in a solvent or by heating an ammoniated monomer.  The polymers may also be obtained on driving off the solvent from a solution of the unpolymerized complex in a suitable solvent with subsequent heating if necessary and therefore may be used to form films and in coating textiles and other materials (see Groups IV (c) and VIII).  Highly polymerized products are soluble in highly fluorinated solvents only but a preferred "heat-advanced" partially polymerized product is obtained by heating the unammoniated monomer to such an extent that although insoluble in normal alcohols and acetone it is soluble in isopropanol.  This partially polymerized product may be completely polymerized on further heating. Isopropanol solutions of the polymers may be incorporated in lacquers and enamels, e.g. a melamine type enamel, to provide coating compositions.  In an example a polymer is formed from perfluorocaprylic acid and chromium trioxide. Perfluoro-butyric and pentanoic acids are also mentioned. Specification 712,784, [Group IV (b)], is referred to.ALSO:The invention comprises a water-insoluble green-coloured, chlorine-free, tacky, liquid, coordination complex of trivalent chromium and a perfluoroalkyl monocarboxylic acid having 4-12 C atoms in the molecule, the complex having two acid groups for each atom of chromium and an ammoniated derivative of the complex. The unammoniated complex is made by reacting a chlorine-free, soluble, colloidal compound containing trivalent chromium with the perfluoroalkyl monocarboxylic acid in the presence of a hydroxylated compound.  Hexavalent chromium compounds, e.g. CrO3, may be used in an aqueous reaction mixture, being reduced in situ to the trivalent form by means of a reducing agent such as methanol or isopropanol. Water and the reducing alcohols or solvents are mentioned as hydroxylated compounds.  The reaction is preferably effected at an elevated temperature in an aqueous medium.  Other media, e.g. carbon tetrachloride and methanol, may be used.  Chromic acetate and hydroxide are specified trivalent chromium compounds.  The product is a liquid mixture of unpolymerized chromium-complex molecules and polymers thereof, continued heating increasing the degree of polymerization, (c.f. Group IV (a)).  The complexes are ammoniated in their liquid state or dissolved in a solvent such as isopropanol or a fluorinated solvent by passing anhydrous gaseous ammonia therethrough, the colour changing from green to purple. In an example a complex is formed by treating perfluorocaprylic acid under reflux with chromium trioxide in a mol. ratio of 2 : 1 in aqueous methanol solution.  In place of methanol as reducing agent the following may be used: ethanol, isopropanol, glycerol, diethylene glycol, sugar, acetone, formaldehyde, phenol, hydroquinone and sodium bisulphite. Perfluoro-butyric and -pentanoic acids are also mentioned. Specification 712,784 is referred to.