Patent GB-1482652-A (GB)
Title: Articles coated with cured fluorocarbon polymer compositions
IPC: A47J36/02
Filed: 1974-10-11
Abstract: 1482652 Coated products E I DU PONT DE NEMOURS & CO 11 Oct 1974 [12 Oct 1973] 44147/74 Heading B2E An article bearing (a) a primer coating which comprises a fluorocarbon polymer, overlaid with (b) a cured topcoat obtained from a composition which comprises (i) a fluorocarbon polymer which is a polymer of hydrocarbon monomer(s) completely substituted with fluorine atoms or a combination of fluorine atoms and chlorine atoms, (ii) a polymer of monethylenically unsaturated monomer(s) which depolymerises and whose depolymerisation products vapourise at a temperature of from 150‹C below the fusion temperature of the fluorocarbon polymer to the decomposition temperature of the fluorocarbon polymer, (iii) a liquid carrier, b(i) is preferably polytetrafluoroethylene and b(ii) may be a polymer of an ethylenically unsaturated monomer(s) which contain at least one monoethylenically unsaturated acid or acid anhydride unit. b(i) may be in an amount of 25-95% by weight, based on the weight of b(i) and b(ii) and b(ii) in an amount of 75-5% by weight, based on the weight of b(i) and b(ii). b(ii) may comprise an alkyl acrylate or alkyl methacrylate wherein the alkyl group contains 1 to 8 carbon atoms, styrene, α-methylstyrene, vinyltoluene, a glycidyl ester of up to 14 carbon atoms copolymerised with acrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride; b(ii) is preferably methylmethacrylate / 2-ethylhexyacrylate / methacrylic acid terpolymer, methylmethacrylate/ ethylacrylate/acrylic acid terpolymer, n-butylacrylate or i-butyl acrylate/methylmethacrylate/glycidyl ester/acrylic acid quadripolymer, styrene/methylmethacrylate/glycidyl ester/ acrylic acid quadripolymer wherein said glycidyl ester has the formula wherein R 1  is CH 3 , R 2  and R 3  are alkyl, and R 1 , R 2 , R 3  contain 7 to 9 carbon atoms. (a) may be a polymer of hydrocarbon monomer(s) completely substituted with fluorine atoms or a combination of fluorine and chlorine atoms. (a) may also comprise a siliceous material, preferably derived from colloidal silica sol which has a silica content of 30% by weight and a pH of 9.0 at 25‹C, whose particles have been surface modified with aluminium, have a size of 13 to 14 millimicrons and a specific surface area of 210 to 230 square metres per gramme. (a) which is preferably polytetrafluoroethylene, may comprise 90 to 30% by weight of the fluorocarbon polymer, and 10 to 70 % by weight of the siliceous material. The article is preferably metal cook-ware.  In the Examples; (a) is (2) polytetrafluoroethylene, colloidal silica, 'Triton' X-100, toluene, butyl 'Carbitol', silicone (60% solids in xylene), titanium dioxide, channel black; (b) is (1) (2) polyetetrafluoroethylene, methylmethacrylate / ethylacrylate / methacrylic acid terpolymer, triethanolamine, oleic acid, toluene, butyl 'Carbitol', water, channel black, sodium polynaphthalene sulphonate, aluminium silicate. The article is a fritcovered pan, and the layer thickness of (a) is 0.2-0.6 mil and of (b) is 0.8 to 1 mil. (The words 'Triton' and 'Carbitol' are registered Trade Marks).