COATING COMPOSITIONS BASED ON ESTERIFIED METHYL METHACRYLATE GLYCIDYL ACRYLATE OR METHACRYLATE COPOLYMERS

摘要

1313653 Acrylic coating compositions CANADIAN INDUSTRIES Ltd 15 June 1970 [30 June 1969] 32826/69 Headings C3F C3P and C3R Coating compositions comprise an organic solvent and, as film-forming material, (1) at least 40 parts by weight of a mixture of (a) one or more copolymers of at least 75% by weight methyl methacrylate and 0À5-25% by weight glycidyl acrylate or methacrylate, esterified with an aromatic monocarboxylic acid and (b) one or more homopolymers of methyl methacrylate or copolymers of methyl methacrylate and an ethylenically unsaturated comonomer which is inert towards the esterified glycidyl moiety of the first copolymer; (2) 0-50 parts by weight of at least one compatible plasticizer; and (3) 0-35 partsby weight of cellulose acetate butyrate, the total parts by weight of filmforming material being 100. The esterified copolymer may also include units of an alkyl (meth)acrylate, vinyl acetate, acrylonitrile or styrene; these comonomers are also suitable as the comonomer component of copolymer 1(b). Examples of aromatic acids used in the esterification of copolymer 1(a) are benzoic, p-toluic, cinnamic, naphthoic, nicotinic, picolinic, quinaldinic, p - aminobenzoic, p - nitrobenzoic, p - hydroxybenzoic and p - methoxybenzoic acids. Suitable solvents include aromatic hydrocarbons, aliphatic or cycloaliphatic ketones, amyl alcohol and ethylene dichloride. Preferred plasticizers are oil-free polyesters, e.g. derived from neopentyl glycol, adipic acid, phthalic anhydride and butyl alcohol; and acidmodified and coconut oil-modified alkyd resins. Other useful plasticizers include phthalate and phosphate esters. The compositions may also include pigments, e.g. metal oxide and salt pigments, carbon black, metal flakes, and organic dyestuffs and lakes. The compositions can be applied to substrates, e.g. primed steel surfaces, and baked at 200-300‹ F.