ES360562A1 - Treatment of inorganic substrates - Google Patents

Abstract

An inorganic substrate has bonded thereto a coating comprising a mixture of an organo siloxane, the organo group of which is bonded to the silicon thereof by a carbon to silicon bond and contains at least one functional group which is condensible with a carboxylic acid group and an ethylene copolymer containing units of the formula: in which R is hydrogen or an alkyl radical having 1-4 carbon atoms. The inorganic substrate may be treated first with the organosiloxane, dried, e.g. at a temperature above 50 C, and then treated with the ethylene copolymer in the form of a solution or dispersion, and heated, e.g. at above 50 C, to effect reaction between the copolymer and the siloxane. Alternatively the siloxane or a silane giving rise thereto on hydrolysis may be mixed with the ethylene copolymer prior to the application thereof to the inorganic substrate which is subsequently heated to a temperature above 75 C to effect reaction between the copolymer and the siloxane. The ethylene copolymer may be obtained by copolymerizing ethylene with acrylic, methacrylic, maleic, fumaric, crotonic, 2-heptenoic, 2-ethyl-2-propenoic, 2-butyl-2-propenoic or 2-phenyl-2-propenoic acid. The copolymer may also contain units derived from propylene, 1- or 2-butylene, 1,3-butadiene, 2,5 or 2,6-norbornadiene, 2-norbornene, dicyclopenta, diene, vinyl acetate, alcohol or chloride, isoprene, 2-chloroprene, alkyl acrylates or methacrylates in which the alkyl group contains 1-12 carbon atoms, styrene, [alpha]-methyl styrene, betachlorostyrene, acrylamide, methacrylamide, dimethylol acrylamide or methacrylamide, N-vinyl-2 pyrrolidone, acrylonitrile, methacrylonitrile and alkyl vinyl ethers and ketones, in which the alkyl group contains 1-6 carbon atoms. The organo siloxane may have the repeating units [X R1 SiO 3/2 ] in which R1 is a divalent saturated hydrocarbon radical containing at least 3 carbon atoms in sequence separating X from Si and X is a group condensible with a car- O # boxylic acid group, e.g. a -CH-CH-, | HN-, HS, HO or O=C=N. The inorganic substrate may be of metal, e.g. iron, steel, copper, nickel or alloys thereof or aluminium, an inorganic oxide filler, silica, sand or clay, a metal pigment, e.g. iron chromates, lead oxide, zinc oxide or titanium dioxide, inorganic fibres, e.g. graphite, glass or tungsten fibres, or glass in the form of plates or beads.