| 摘要 |
Aqueous binder formulations, particularly for the production of storing enamels, comprise (1) 10 to 50% by weight of at least one water-soluble or water-dilutable aminoplast precondensate, and (2) 50 to 90% by weight of at least one ammonium and/or amine, salt of a copolymer from (a) 50 to 90% by weight of one or more acrylic or methacrylic esters of monohydric non-polymerizable alcohols, (b) 5 to 30% by weight of at least one ethylenically unsaturated mono- or di-carboxylic acid, (c) 2 to 20% by weight of one or more acrylic or methacrylic monoesters of polyhydric non-polymerizable alcohols, and (d) optionally up to 15% by weight of other monomeric copolymerizable compounds. Aminoplast precondensates (1) specified are those of formaldehyde with urea, thiourea, melamine, benzoguanamine, o-phenylene-bis- (2, 4-diamino-1, 3, 5-triazine), amelline, guanidine, dicyandiamide, glyoxalureines, N, N1-dimethyl urea, including condensates in which the methylol groups have been etherified, e.g. with methanol. Monomers (2) specified are (a) acrylic and methacrylic esters of methyl, ethyl, propyl, isopropyl, butyl 2-ethylhexyl and cyclohexyl alcohols, (b) acrylic, methacrylic, maleic and fumaric acids, (c) acrylic and methacrylic monoesters of 1, 2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-propanediol, isomeric butanediols, pentanediols and hexanediols, and pentaerythritol, and (d) acrylonitrile, vinyl ethers, esters, amines and sulphones, vinyl and vinylidene halides, acrylamide, methacrylamide, styrene, alpha-methyl styrene, and N-vinyl sulphamides. Amines which may be used to form the salts of the copolymers are alkylamines, hydroxy-alkylamines, diamine and morpholines. The binders are used in aqueous vehicles which may also contain organic liquids, e.g. ethanol, glycol monoacetate, glycols, dimethyl formamide and diacetone alcohol, and pigments, e.g. iron oxide, titanium dioxide, slate powder and talc. The resulting compositions are applied to substrates and rendered hard and water-resistant by heating. The preparation of copolymers (2) is described by a process in which a mixture containing monomers, buten-1-ol-3, as a regulator, azodiisobutyronitrile and acetone is added gradually to boiling dioxane or ethanol, and after polymerization the solvent is distilled off and the residue is treated with ammonia and/or an amine. Specified copolymers prepared by this method are those of butyl acrylate, acrylic acid and butanediol monoacrylate with, as optional additional monomers, (a) styrene, (b) acrylonitrile and (c) acrylonitrile and acrylamide, and also a copolymer of butyl acrylate, acrylic acid and 1,4-pentanediol monoacrylate.ALSO:Surfaces of wood, metal, plastic and ceramic are coated by spraying, brushing, curtain coating, roller coating, flushing, dipping, or impregnating with an aqueous composition comprising (1) a water-soluble or water-dilutable aminoplast condensate, and (2) an ammonium and/or amine salt of a copolymer of (a) an acrylic or methacrylic ester of a monohydric alcohol, (b) an ethylenic mono- or di-carboxylic acid, (c) an acrylic or methacrylic monoester of a polyhydric alcohol, and (d) optionally other monomers (see Division C3), and then stoving the coating to render it hard and water-resistant. The compositions may also contain organic solvents and pigments, e.g. titanium dioxide, iron oxide, slate dust and talc. The examples describe the application to iron sheets of aqueous pigmented compositions comprising (1) a melamine/formaldehyde or o-phenylene-bis-(2,4-diamino)-1,3,5-triazine-urea/formaldehyde condensate, and (2) copolymers of butyl acrylate acrylic acid and butanediol monoacrylate (or pentanediol monoacrylate), with styrene, acrylonitrile and acrylamide as optional monomers, followed by stoving at 120-150 DEG C. In one Example (2) the resulting coating is overcoated with an alkyd/urea resin and the whole assembly is further stoved at 120 DEG C. |
