Patent GB-1236128-A (GB)
Title: Coating composition
IPC: C08F20/34
Filed: 1969-07-17
Abstract: 1,236,128. Acrylic coatings. E.I. DU PONT DE NEMOURS & CO. 17 July, 1969 [23 Aug., 1968], No. 35987/69. Heading 2BE. [Also in Division C3] Coating compositions, which are suitable for use as exterior finishes or refinishes for automobiles and trucks, comprise from 5- 45% by weight of a film-forming material in solution in a volatile organic liquid which includes at least one solvent for the filmforming material, said film-forming material consisting of (a) from 40-60% by weight of an acrylic oxazoline polymer consisting of (1) 30-70% (by weight of the polymer) of methyl methacrylate units, (2) less than 35% of units of an ester of an α, #-olefinically unsaturated monocarboxylic acid and a saturated aliphatic monohydric alcohol containing from 2 to 12 carbon atoms, (3) less than 10% of acrylonitrile units and (4) 15-35% of units of a compound of the formula: where R 5 -CO- is a saturated or unsaturated fatty acid acyl radical containing 4-22 carbon atoms, R 6  is H, C 1 -C 4  alkyl or -CH 2 -O-OC-R 5 , R 7  is H or C 1 -C 4  alkyl and R 8  is the residue obtained by removing the carboxyl group and α-carbon atom from a C 4 -C 22  saturated or unsaturated fatty acid; (b) from 60-40% by weight of cellulose acetate butyrate of specified viscosity and having a butyryl content of 30-55% by weight; and (c) from 0-10% by weight of an organic monomeric plasticiser and/or polymeric plasticiser. In a modification, the polymer (a) includes up to 15% by weight of styrene units as a partial or total substitution for the units of the α, #-olefinically unsaturated monocarboxylic acid ester. The compositions preferably also include a pigment in a pigment volume concentration of 0.1- 20.0%. Preferred as the ester component (2) of the polymer are alkyl acrylates and methacrylates. Component (4) of the polymer is preferably the oxazoline compound obtained by reacting 1 mole of tris (hydroxymethyl) aminomethane with 3 moles of tall oil fatty acid, and reacting the product with formaldehyde. Suitable as plasticisers (c) are phthalate esters, particularly butyl cyclohexyl phthalate, phosphate esters, benzoic acid/fatty oil acid esters of pentaerythritol, diethylene glycol dibenzoate, tetrabutylthiodisuccinate, butyl, glycolate, acetyltributyl citrate, dibenzyl sebacate, N-ethyl-toluene sulphonamide, epoxidised soya bean oil, oil-free and oil-modified alkyds and polyesters, and polyalkylene and polyarylene adipate esters. Suitable solvents and diluents include toluene, xylene, butyl acetate, acetone, methyl isobutyl ketone, methyl ethyl ketone, butyl alcohol and ethylene glycol monoethyl ether acetate. Pigments which may be used include metal oxides, e.g. titanium dioxide or zinc oxide, metal hydroxides, metal flakes, chromates, sulphides, sulphates, carbonates, carbon black, silica, talc, china clay, organic dyes, lead and iron blues, and organic reds and maroons. The compositions can be applied to various substrates, e.g. wood, glass or metal, by the usual methods, such as spraying, dipping, flour-coating and brushing, and the coatings can be air-dried or baked, e.g. at 125-175C. In an Example, coatings are sprayed onto steel panels which have previously been (a) primed, (b) coated with acrylic lacquer or (c) coated with pigmented nitrocellulose lacquer.