Improvements in and relating to stoving

摘要

Coating means comprise water-soluble binders prepared by converting to ammonium salts the reaction products of water-insoluble polymers containing primary hydroxyl groups and having OH values of at least 100 with 0.2 to 0.75 mol of a dicarboxylic acid anhydride or 0.1 to 0.375 mol of a tricarboxylic acid anhydride per hydroxyl equivalent. The polymers may be copolymers of allyl alcohol, methallyl alcohol, 1-butene-4-ol, o -hydroxy-alkyl acrylates or methacrylates, or monoacrylates or monomethacrylates of polyhydric alcohols, with vinyl esters, acrylic, methacrylic, maleic, fumaric, aconitic and itaconic esters, acrylonitrile, acrylamide and N-substituted acrylamides, acrylonitrile, styrene, vinyl toluene and vinyl ether; reduction products of polymers containing carboxyl or carboxylic acid ester groups; products obtained by adding water to 1,2-polymers of butadiene; and polyethers obtained by ring opening of compounds of formula where R is hydrogen, hydroxyl, halogen, cyanide or an organic residue such as alkoxy or acyloxy, optionally together with hydroxyl free derivatives of trimethylene oxide, propylene oxide, epichlorohydrin, tetrahydrofuran or trioxymethylene. Internal plasticizers may be present, e.g. octyl methacrylate, dodecyl acrylate, vinyl palmitate, octadecyl vinyl ether or dibutyl maleate in the unsaturated alcohol polymers, and long chain alkyl substituted alkylene oxides, vinyl isobutyl ether or vinyl ethers of polyunsaturated fatty alcohols such as reduced linseed oil fatty acids. The unsaturated alcohol polymers may be prepared by conventional radical polymerization, and the polyethers by polymerization in inert organic solvents in the presence of Friedel-Crafts or strong acid catalysts, many suitable catalysts being listed. The hydroxyl containing polymers may be reacted with the anhydride, many examples of which are listed, in an inert organic solvent and optionally in the presence of a tertiary amine catalyst; and the products converted to salts by ammonia, volatile amines, alkanolamines or quaternary ammonium bases. The compositions may also comprise aminoplast precondensates, pigments, levelling agents, e.g. glycol half esters and half ethers, butanols and cyclohexanol, and hardening catalysts, e.g. p-toluene sulphonic acid and naphthenates; and may be applied to substrates, e.g. of metal, from aqueous media, and the coatings cured by stoving. Examples describe the reaction of (1) an allyl alcohol/vinyl acetate/methyl acrylate copolymer with maleic anhydride and ammonia, (2) a styrene/allyl alcohol copolymer with maleic anhydride and ammonia, (3) a styrene/allyl alcohol copolymer with succinic anhydride and ammonia, (4) an allyl alcohol/vinyl acetate/ethyl acrylate copolymer with phthalic anhydride and ammonia; (5) the copolymerization of the methacrylic acid ester of 2,2-dimethyl-4-hydroxymethyldioxolane-1,3 and ethyl acrylate in toluene in the presence of azodiisobutyronitrile and reaction of the product with maleic anhydride and ammonia; (6) the copolymerization of allyl alcohol and ethyl acrylate in the presence of di-t.-butyl-peroxide and reaction of the product with maleic anhydride and ammonia; (7) the copolymerization of allyl alcohol, ethyl acrylate and styrene in the presence of di-t.-butyl peroxide and reaction of the product with maleic anhydride and ammonia; (8) the copolymerization of allyl alcohol and butyl acrylate in the presence of di-t.-butyl peroxide and reaction of the product with maleic anhydride and triethylamine; (9) the polymerization of 3 - hydroxymethyl - 3 - ethyltrimethylene oxide in benzene in the presence of boron trifluoride diethyl etherate and reaction of the product with maleic anhydride and ammonia; (10) the reaction product of a copolymer of 3-hydroxy-methyl-3-ethyltrimethylene oxide and vinyl ethers of unsaturated alcohols, prepared from linseed oil fatty acids, with maleic anhydride and ammonia; and (11) the copolymerization of the monomers specified in (10) in benzene in the presence of boron trifluoride diethyl etherate and reaction of the product with maleic anhydride and ammonia.ALSO:Metals may be coated with aqueous coating compositions comprising binders prepared by converting to ammonium salts the reaction products of water-insoluble polymers containing primary hydroxyl groups and having OH values of at least 100 with 0.2 to 0.75 mol of a dicarboxylic acid anhydride or 0.1 to .375 mol of a tricarboxylic acid anhydride per hydroxyl equivalent, and the coatings cured by stoving. The polymers may be polymers of unsaturated alcohols such as allyl alcohol, reduction products of polymers containing carboxylic acid or carboxylic acid ester groups, products obtained by adding water to 1, 2-polymers of butadiene, or polymers of substituted hydroxymethyl trimethylene oxides. The compositions may also comprise aminoplast precondensates, pigments, leveling agents, e.g. glycol half ethers and half esters, butanols and cyclohexanol, and curing catalysts, e.g.p toluene sulphonic acid and naphthenates. Examples describe the coating by dipping of iron sheets with aqueous solutions of ammonium salts of (1) and allyl alcohol/vinyl acetate/methyl acrylate copolymer reacted with maleic anhydride, (2) a styrene/allyl alcohol copolymer reacted with maleic anhydride, (3) a styrene/allyl alcohol copolymer reacted with succinic anhydride, (4) an allyl alcohol/vinyl acetate/ethyl acrylate copolymer reacted with phthalic anhydride, (5) an ethyl acrylate/2, 2-dimethyl-4-hydroxymethyldioxolane 1, 3 methacrylic ester copolymer reacted with maleic anhydride, (6) an allyl alcohol/ethyl acrylate coplymer reacted with maleic anhydride, (9) poly 3-hydroxymethyl-3-ethyltrimethylene oxide reacted with maleic anhydride, and (11) a copolymer of 3-hydroxymethyl-3-ethyltrimethylene oxide and vinyl ethers of unsaturated alcohols derived from linseed oil fatty acids reacted with maleic anhydride; of metal sheets with aqueous solutions of ammonium salts of (7) an allyl alcohol/ethyl acrylate/styrene copolymer reacted with maleic anhydride, and (10) a reaction product as in (11); and of phosphated iron sheets with a triethylamine salt of (8) an allyl alcohol/butyl acrylate reacted with maleic anhydride.