Patent GB-947764-A (GB)
Title: Preparing resins for coating
IPC: C09D5/46
Filed: 1960-02-25
Abstract: In processes for coating articles with a noncellulosic resin composition by the fluidized bed technique the resin composition is obtained in the appropriate form for such application by milling particles of the resin with particles of pigment, filler, stabilizer or combinations thereof under conditions resulting in shearing of the particles against each other to generate heat until a fused mass is obtained and then pulverising the mass to a particle size between 40 mesh (0.42 mm) and 325 mesh (0.044 mm). External heat may also be applied during the milling while pulverisation is preferably effected in the presence of liquid nitrogen at about -50 DEG F. Coating is effected by heating the article to be coated and immersing it in the fluidized bed of the resin composition while the surface temperature is sufficiently high to fuse the composition to form a coating.  In specific examples the following resin compositions are formulated under the specified conditions:-Example 1, polyvinyl chloride, epoxidised soya fatty acids, dipropylene glycol dibenzoate, titanium dioxide, barium-cadmium soap and a proprietary epoxy chelating agent; Example 2, a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinyl and vinylidene chlorides, n-octyl-n-decyl phthalate, chlorinated wax and the epoxy acids, chelating agent, soap and pigment as in Example 1; Example 3 as Example 1 except that the phthalate plasticizer of Example 2 replaced the benzoate; Example 4 a copolymer of vinyl chloride and vinyl acetate, dioctyl sebacate, stearic acid and the epoxy acids, chelating agent, soap and phthalate as above; and Example 5 a commercial epoxy resin, mica, lead-iron oxide, methylene dianiline p,p-diamino diphenyl methane and a m-phenylene diamine epoxy adduct curing agent.ALSO:In processes for coating articles with a non-cellulosic resin composition by the fluidized bed technique the resin composition is obtained in the appropriate form for such application by milling particles of the resin with particles of pigment, filler, stabilizer or combinations thereof under conditions resulting in shearing of the particles against each other to generate heat until a fused mass is obtained and then pulverizing the mass to a particle size between 40 mesh (0,42 mm.) and 325 mesh (0,044 mm.).  External heat may also be applied during the milling while pulverization is preferably effected in the presence of liquid nitrogen at about -50  DEG F.  Coating is effected by heating the article to be coated, e.g. a steel rod, and immersing it in the fluidized bed of the resin composition while the surface temperature is sufficiently high to fuse the composition to form a coating, followed by further heating.  In specific examples the following resin compositions are formulated under the specified conditions: Example 1, polyvinyl chloride, epoxidized soya fatty acids, dipropylene glycol dibenzoate, titanium dioxide, barium-cadmium soap and a proprietary epoxy chelating agent; Example 2, a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinyl and vinylidene chlorides, n-octyl-n-decyl phthalate, chlorinated wax and the epoxy acids, chelating agent, soap and pigment as in Example 1; Example 3 as Example 1 except that the phthalate plasticizer of Example 2 replaced the benzoate; Example 4, a coplymer of vinyl chloride and vinyl acetate, dioctyl sebacate, stearic acid and the epoxy acids, chelating agent, soap and phthalate as above; and Example 5, a commercial epoxy resin, mica, lead-iron oxide, methylene dianiline, p,p-diamino diphenyl methane and a m-phenylene diamine epoxy adduct curing agent.