Articles having hydrophilic surfaces and methods of preparing them

摘要

The surface of an article is rendered hydrophilic by applying thereto a silane of the formula CH2=CH.SiR3, wherein R is an alkoxy or aryloxy radical or a halogen atom, and acrylic or methacrylic acid or a water-soluble salt thereof, acrylamide or methacrylamide, and copolymerizing these reactants (see Group IV(a)). The silane and acrylic compound may be applied to the surface either simultaneously or successively and then copolymerized. In Examples (1) a zinc plate, (2) an aluminium p roller, (4) a copper plate, and (5) an aluminium sheet, are coated as above. Other metals specified are tin, lead, chromium, steel, magnesium and anodized aluminium.ALSO:A copolymer is formed in situ, as a hydrophilic coating on the surface of a roller or other article (see Groups III and VIII), by copolymerizing acrylic acid, methacrylic acid, a water-soluble salt of these acids, acrylamide or methacrylamide, and a silane of the formula CH2 = CHSiR3, wherein R is an alkoxy or aryloxy radical or a halogen atom. The silane and acrylic compound may be simultaneously applied to the surface as a mixture in a solvent and then co-polymerized. Preferably the silane (in solution in e.g. toluene, benzene, xylene, pentane, hexane, heptane, octane, carbon tetrachloride or chloroform with or without a condensation catalyst, e.g. ethanolamine) is first applied to the surface and heat is applied to remove solvent and promote formation of a polysiloxane through hydrolysis by surface and/or atmospheric moisture; the acrylic compound is then applied as a solution in e.g. benzene, toluene, xylene, pyridine, petroleum ether, methanol, ethanol, butanol, monoalkylethers of ethylene glycol, chloroform or carbon tetrachloride, together with a polymerization catalyst, e.g. benzoyl, acetyl, urea- or hydrogenperoxide, cumene hydroperoxide or potassium persulphate, and the assembly is then heated at 120 DEG -300 DEG C. for from 10 minutes to 12 hours. Examples are given.