Patent GB-930035-A (GB)
Title: Coatings from acid-containing terpolymers and epoxy resins
IPC: C08L63/00
Filed: 1961-05-08
Abstract: A process for coating an article comprises applying to the surface thereof a solution in a blend of xylene, butanol and ethylene glycol monomethyl ether an epoxy modified terpolymer comprising from 45 to 85% by weight of a vinyl aromatic-alkyl acrylate-acrylic or methacrylic acid terpolymer containing at least 50% by weight of the vinyl aromatic compound, from 2,5 to 30% by weight of the alkyl acrylate, in which the alkyl group contains at least 6 carbon atoms and from 5 to 10% by weight of the acrylic or methacrylic acid, and correspondingly from 55 to 15% of the epoxy resin, and curing by heating or baking.  The composition may be applied by spraying, brushing or dipping.  In the examples, steel panels are sprayed with solutions in the specified solvent mixture of an epoxy resin derived from bis-phenol-A and epichlorohydrin and terpolymers derived from vinyl toluene, acrylic acid and octyl acrylate, vinyl toluene, acrylic acid and lauryl acrylate, vinyl toluene, acrylic acid and 2-ethylhexyl acrylate, vinyl toluene, methacrylic acid and octyl acrylate, styrene, acrylic acid and lauryl acrylate and vinyl toluene, decyl-octyl acrylate and acrylic acid and optionally titanium dioxide, the coated panels being air dried and oven baked.ALSO:A flexible stain and detergent resistant coating composition comprises or contains an epoxy modified terpolymer comprising from 45 to 85% by weight of a vinyl aromatic-alkyl ester of acrylic acid-acrylic or methacrylic acid terpolymer containing at least 50% by weight of the vinyl aromatic compound, from 2,5 to 30% by weight of the alkyl ester of acrylic acid in which the alkyl group contains at least 6 carbon atoms and from 5 to 10% by weight of the acrylic or methacrylic acid, in polymerized form, and correspondingly from 55 to 15% by weight of an epoxy resin, characterized in that in the terpolymer the proportion of the vinyl aromatic compound is controlled by the length of the alkyl group of the acrylic acid ester in that as the chain length of the alkyl group is increased the proportion of the vinyl aromatic compound is increased and the proportion of acrylic acid ester is decreased within the aforesaid ranges.  Specified vinyl aromatic compounds are styrene, vinyl toluene, vinyl xylene, isopropyl styrene, t-butyl styrene and ethyl vinyl benzene.  Specified acrylic acid esters are octyl, 2-ethyl hexyl, nonyl, decyl and lauryl acrylate.  The preparation of the terpolymer may be effected in an organic solvent, e.g. toluene, xylene or mineral spirits, in the presence of a catalyst, e.g. benzoyl peroxide, t-butyl peroxide, cumene peroxide, t-butyl hydroperoxide or cumene hydroperoxide.  The specified epoxy resin is a bis-phenol-A-epichlorohydrin condensate.  The epoxy resin and the terpolymer are preferably dissolved in a solvent, e.g. a xylene-butanol-ethylene glycol monomethyl ether mixture optionally with a catalyst, e.g. dodecyl trimethyl ammonium chloride. Pigments, e.g. titanium dioxide, carbon black, phthalocyanine blues and greens, organic maroons and metal oxides, hydroxides, silicates, sulphates, sulphides and chromates may be included in the compositions.  Many examples are given.