| 摘要 |
Aqueous coating compositions are produced by treating a polyol having at least 3 hydroxy-groups and a molecular weight of at least 500 successively with (a) a drying oil fatty acid and (b) a maleinized fatty acid and partially or completely neutralizing the product with a base. Polyols specified include: a copolymer of styrene and allyl alcohol, and epoxy-resins, e.g. an epochlorohydrin/bisphenol A adduct. Drying oil fatty acids specified include those of linseed oil, soya bean oil, dehydrated castor oil and tall oil. 2 moles per mole of polyol may be used at 350-450 DEG F. Maleinized fatty acids specified include maleinized tall oil, and linseed oil. This treatment may be at 200-260 DEG F. for a sufficient time that half the maleic acid carboxyl groups are reacted. The neutralization may be at room temperature. Bases specified are ammonia, triethylamine, diethanolamine and diethylethanolamine. The base may be added in aqueous solution or dispersion which may contain an organic solvent, e.g. ethylene glycol monobutyl ether. The product may be diluted to a coating composition with water or organic solvents, e.g. hexanol, octanol, hexamethylene glycol and ethylene glycol monobutyl ether. The coating composition may also contain a drier, e.g. cobalt naphthenate in ethanol, and a filler or pigment, e.g. Fe2O3, rutile TiO2, barytes, carbon black or fibrous talc. It may be converted to a baking enamel by adding 5-100% of an aminoplast resin, e.g. a melamine-form-aldehyde resin and 0.01-2% of a catalyst therefore. In examples, the esterification is carried out in toluene or xylene solution. Potassium tripolyphosphate is used as a dispersing agent. In Example VIII the polyol is an acrylic copolymer of methyl methacrylate, butyl methacrylate, glycidyl methacrylate, thiophenol, and azodi-isobutyronitrile prepared by heating the reactants in isopropanol containing toluol. |
