Patent GB-1409327-A (GB)
Title: Process for treating surfaces
IPC: D06M101/16
Filed: 1973-01-10
Abstract: 1409327 Coated polymers DOW CORNING LTD 10 Jan 1973 1329/73 Heading B2E [Also in Division C3] The surface of leather or a solid natural or synthetic organic polymer containing less than 12% by weight of hydroxyl radicals and having at least one carbon to hydrogen bond and/or olefinically-unsaturated linkage, is treated with an organopolysiloxane having in the molecule at least one unit of the general formula: and at least one unit of the general formula: wherein each R and each R" represents a hydrogen atom or a monovalent hydrocarbon or halogenated hydrocarbon radical of less than 19 carbon atoms, R' represents a divalent aliphatic radical of 1 to 12 carbon atoms and composed of carbon, hydrogen and optionally oxygen and sulphur, any oxygen being present in the form of ether linkages, in groups or in groups and any sulphur being present as sulphide-CSC-groups, a is 0, 1 or 2 and b is 1, 2 or 3, there being present in the organopolysiloxane at least one mol percent of (A) units and exposing the applied organopolysiloxane to high energy radiation, ultra violet light and/ or a temperature in excess of 18C. The R and R" radicals may be alkyl or cycloalkyl, such as methyl, ethyl, propyl, octadecyl and cyclohexyl, alkenyl radicals such as vinyl and allyl, aryl, aralkyl and alkaryl radicals and halogenated hydrocarbon radicals such as chloromethyl, bromophenyl and 3, 3, 3-trifluoropropyl. Numerous suitable examples of divalent aliphatic radicals R' are given. The organopolysiloxanes may range in molecular weight from a disiloxane comprising one unit of each specified type in which a is 2 and b is 3, to high molecular weight polymers containing many of the organosiloxane units. The organopolysiloxane may have a linear configuration and consist of one or more units (A) in which a is 1 end-stopped with units (B) wherein b is is 3. In addition to the units (A) and (B) the organopolysiloxane may contain up to 10 mol percent of tetra-functional, that is, SiO 2  units. A relatively high proportion, i.e. more than about 70 mol percent of (A) units may be present. Preferably the organopolysiloxanes have molecular weights of 1000-1000000. It is preferred that at least 50% of the total R and R" substituents in the organopolysiloxane are methyl radicals. Polymer surfaces which may be treated are, for example, polyethylene, polypropylene, ethylene-propylene copolymers, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polymethyl methacrylate, polyethyl acrylate, polyacrylonitrile, polystyrene, natural rubber, polybutadiene, polyisoprene, polychloroprene, acrylonitrile-butadienestyrene copolymers, styrene-butadiene copolymers, polyethylene terephthalate, polyamides, acrylic resins, epoxy resins, phenol-formaldehyde resins, urea-formaldehyde resins, and cellulose acetate. The compositions may be applied by flooding, brushing, spraying or immersion and the organopolysiloxane may be applied as an organic solvent solution or aqueous immersion. Suitable solvents are benzene, toluene, pentane, white spirit, diethyl ether, acetone or mixtures of these. It may also be applied as a liquid without dilution. Suitable high energy ionising radiation is X-rays, gamma rays and accelerated electrons.