Patent GB-914410-A (GB)
Title: A process for coating surfaces
IPC: B05D7/26
Filed: 1959-08-17
Abstract: Room-temperature-vulcanizable silicone compounds are bonded to surfaces by first applying to the surface a liquid comprising a silane of the general formula RSi(OZ)3 where R is a phenyl radical or an aliphatic hydrocarbon radical containing less than 4 carbon atoms and each Z is an acyl radical containing less than 4 carbon atoms, or a partial hydrolysate of such a silane, and allowing this coating to dry, then applying the silicone compound to the primed surface.  R may be a phenyl, methyl, ethyl, propyl or vinyl radical and Z a formyl, acetyl or propionyl group.  More than one kind of acyloxy radical may be attached to any silicon atom, e.g. the compound CH3Si(OOCH)(OOCCH3)2 may be used, and mixtures of such compounds may also be used.  The partial hydrolysates usable are di- and tri-siloxanes containing Si-O-Si linkages, and compounds in which all the acyloxy groups on some of the Si atoms have been removed, to form branched-chain siloxanes.  Suitable room-temperature-vulcanizable silicone compositions include (1) an acid-free diorganopolysiloxane, a silicate and a metal salt of a carboxylic acid; (2) a diorganopolysiloxane containing silicon-bonded hydroxyl groups, "Cellosolve" (Registered Trade Mark) silicates and metal salts of carboxylic acids; (3) diacyloxy end-blocked diorganopolysiloxanes; (4) an organohydrogenpolysiloxane, a diorganopolysiloxane containing at least 2 SiOH groups per molecule and a metal salt of a carboxylic acid; (5) a diorganopolysiloxane containing silicon-bonded hydroxyl groups and silicon-bonded hydrogen atoms, and a stannous salt of a carboxylic acid with or without additional hydroxylated compounds; (6) an acid-free diorganopolysiloxane, an alkylpolysilicate, and a condensation product of an aldehyde and an amine; or (7) silicones employing the reaction of a silicone-bonded hydrogen and a silicon-bonded alkenyl group in the presence of a platinum catalyst. In examples, a silicone composition containing dimethyl polysiloxanes, diatomaceous earth, iron oxide, tetra-n-propyl orthosilicate and dibutyl tin dilaurate is bonded to aluminium, steel, brick, glass and tile surfaces by the primers of the invention.  Surfaces of brass, masonry and ceramic may also be coated.  The primer may be applied by brushing, dipping or spraying the silane by itself or in solution.  Specifications 764,246, 804,199, 844,128, 862,576 and 867,619 are referred to.ALSO:Room-temperature-vulcanizable silicon compounds are bonded to surfaces by first applying to the surface a liquid comprising a silane of the general formula R Si (OZ)3 where R is a phenyl radical or an aliphatic hydrocarbon radical containing less than 4 carbon atoms and each Z is an acyl radical containing less than 4 carbon atoms, or a partial hydrolysate of such a silane, and allowing this coating to dry, then applying the silicone compound to the primed surface.  R may be a phenyl, methyl, ethyl, propyl or vinyl radical and Z a formyl, acetyl or propionyl group.  More than one kind of acyloxy radical may be attached to any silicon atom, e.g. the compound CH3 Si (OOCH)(OOCCH3)2 may be used, and mixtures of such compounds may also be used.  The partial hydrolysates usable are di- and tri-siloxanes containing Si-O-Si linkages, and compounds in which all the acyloxy groups on some of the Si atoms have been removed, to form branched-chain siloxanes.  Suitable room-temperature-vulcanizable silicone compositions include (1) an acid-free diorganopolysiloxane, a silicate and a metal salt of a carboxylic acid; (2) a diorganopolysiloxane containing silicon-bonded hydroxyl groups, "Cellosolve" (Registered Trade Mark) silicates and metal salts of carboxylic acids; (3) diacyloxy end-blocked diorganopolysiloxanes; (4) an organohydrogenpolysiloxane, a diorganopolysiloxane containing at least 2 SiOH groups per molecule and a metal salt of a carboxylic acid; (5) a diorganopolysiloxane containing silicon-bonded hydroxyl groups and silicon-bonded hydrogen atoms, and a stannous salt of a carboxylic acid with or without additional hydroxylated compounds; (6) an acid-free diorganopolysiloxane, an alkylpolysilicate, and a condensation product of an aldehyde and an amine; or (7) silicones employing the reaction of a silicone-bonded hydrogen and a silicon-bonded alkenyl group in the presence of a platinum catalyst.  In examples, a silicone composition containing dimethyl polysiloxanes, diatomaceous earth, iron oxide, tetra-n-propyl orthosilicate and dibutyl tin dilaurate is bonded to aluminium, steel, brick, glass and tile surfaces by the primers of the invention.  Surfaces of brass, masonry and ceramic may also be coated.  The primer may be applied by brushing, dipping or spraying the silane by itself or in solution. Specifications 764,246, 804,199, 844,128, 862,576 and 867,619 are referred to.