| 摘要 |
A coating composition comprises a polymer of methyl methacrylate having a relative viscosity of 1.117 to 1.196 inclusive and a solvent therefor. The polymer may be polymethyl methacrylate or a copolymer of methyl methacrylate with acrylic or methacrylic acid, an acrylate or methacrylate, vinyl acetate, acrylonitrile or styrene. Relative viscosity is measured using ethylidene dichloride as solvent, and the above figures correspond to molecular weights of 55,000 to 105,000. The solvent may be acetone, ethyl acetate, ethylene glycol monoethyl ether, benzene, toluene or xylene; non-solvents, such as alcohols and aliphatic hydrocarbons, may be included. The composition may include a plasticizer such as dibutyl, benzyl butyl, 2-ethyl hexyl benzyl, dicyclohexyl, diallyl, dibenzyl or di (methyl-cyclohexyl) phthalate, triphenyl or tricresyl phosphate, mixed benzoic and fatty oil acid esters of pentaerythritol, poly (propylene adipate) or diethylene glycol dibenzoate, tetrabutylthiodisuccinate, butyl phthalyl butyl glycolate, acetyl tributyl citrate, dibenzyl sebacate, toluene ethyl sulphonamide and the di 2-ethyl hexyl ester of hexamethylene diphthalate. Pigments such as titanium dioxide, phthalocyanine green, milori blue, carbon black, Prussian blue, Chinese blue, phthalocyanine blues, metal oxides, hydroxides, sulphides, sulphates, silicates and chromates, organic maroons, aluminium flake, bronze powders, pearl essence and fillers or extenders such as talc, barytes, china clay and diatomaceous earth may be incorporated. The composition may also contain other film-forming materials such as cellulose nitrate, alkyd resins and polymers of acrylates and methacrylates other than methyl methacrylate. Specification 763,158 is referred to. |
