GB1474596A - Electrostatic spray coating method and powder paint composition suitable for it - Google Patents

Abstract

1474596 Production of polymer-pigment particles TEKKOSHA CO Ltd 14 May 1974 [14 May 1973 10 Sept 1973 26 Sept 1973] 21274/74 Heading C3P Spherical polymer particles have a size in the range of 30 to 250 microns, a volume intrinsic resistivity of at least 10<SP>9</SP> ohm/cm. and a bulk density of at least 0À3 g./d., said particles having pigment particles embedded therein and uniformly dispersed throughout the interior thereof, the surface of the particles being substantially free from adhering pigment particles, and the particles being produced by emulsion polymerization of (i) vinyl chloride or a C 1 to C 18 - alkyl acrylate or methacrylate, and (ii) 0 to 185 parts by weight per 100 parts of (ii) of a selected comonomer, in the presence of (iii) 0À1 to 50% by weight of (i) and (ii) of a water-insoluble pigment, (iv) 3 to 20% by weight of a watersoluble organic surfactant having a hydrophilic oleophilic balance value of at least 8, (v) a water-soluble initiator and (vi) 200 to 400% by weight based on the sum of components (i) and (ii) of an aqueous liquid medium, while simultaneously vigorously agitating the reaction mixture such that the circulation number per minute of the mixture is at least 3, wherein the circulation number per minute is equal to the integrated volume of the circulating flow of the reaction mixture per minute divided by the total volume of reaction mixture. Examples are given of the production of particles from (a) vinyl chloride, n-butyl acrylate and carbon black; (b) vinyl chloride, ethyl acrylate, lauryl methacrylate, titanium dioxide and carbon black; (c) vinyl chloride, di-n-butyl maleate, n-butyl acrylate, glycidyl methacrylate and phthalocyanine blue; (d) vinyl chloride, n-butyl acrylate and titanium dioxide; (e) vinyl chloride, acrylic acid, n-butyl acrylate, methyl methacrylate and quinacridone red; (f) vinyl chloride, methyl acrylate and Fast Yellow pigment; (g) vinyl chloride, or butyl acrylate and carbon; (h) vinyl chloride, vinyl acetate, titanium dioxide and carbon black; (i) vinyl chloride, di-n-butyl maleate and phthalocyanine blue; (j) vinyl chloride, vinyl propionate and titanium dioxide; (k) vinyl chloride, acrylic acid and quinacridone red; (1) vinyl chloride, styrene and Fast Yellow pigment; (m) ethyl acrylate, methyl methacrylate and titanium dioxide; (n) n-butyl methacrylate and carbon black; (o) ethyl methacrylate, n-butyl methacrylate, titanium dioxide and phthalocyanine blue; (p) ethyl methacrylate, n-butyl methacrylate and a yellow azo pigment; (q) as (o) except that acrylic acid is an additional monomer; (r) methyl methacrylate, lauryl methacrylate, methyl acrylate, 4-vinyl(pyridine and carbon black; (s) ethyl methacrylate, n-butyl methacrylate, titanium oxide and carbon black. The polymer/pigment powders produced are applied by electrostatic spray coating procedures to steel plates.