Patent GB-899394-A (GB)
Title: Coating composition for a fluidized bed
IPC: C09D5/46
Filed: 1960-03-11
Abstract: A composition for use in the fluidized bed coating process comprises an intimate mixture of a resinous coating material having a particle size between 40 mesh (0,42 mm. sieve opening) and 325 mesh (0,044 mm. sieve opening) and a second material having an average particle size less than 5 microns in diameter and present in an amount equal to between 0,5% to 10% by weight of the first material.  The resinous coating material may be thermoplastic, e.g. polyethylene, nylon, polyvinyl chloride, or vinyl chloride copolymers, or thermosetting, e.g. epoxy resins. Plasticizers and other usual additives may be present.  The second material acts primarily to assist fluidization, and it may or may not be resinous; a preferred material is "paste grade" polyvinyl chloride.  Other materials may have secondary functions such as inhibiting excessive flow in the coatings, as with calcium carbonate, magnesium oxide, aluminium silicate, calcium metasilicate, barium sulphate, and aluminium oxide; promoting flow, as with silicone resins; or pigmentation, as with zinc oxide, zinc sulphide, titanium dioxide, lithopone, chromic oxide, iron oxides and metallic pigments.  Example 15 describes the coating of an aluminium rod with a mixture of an epoxy resin and dicyandiamide, both of particle size between 70 and 325 mesh, with silica of particle size less than 5 microns.  Other examples describe: (1) a plasticized polyvinyl chloride composition mixed with paste grade polyvinyl chloride powder (2) a plasticized mixture of copolymers of vinyl chloride and vinyl acetate and of vinyl chloride and vinylidene chloride, powdered and mixed with paste grade p.v.c.; (8) powdered polyethylene mixed with paste grade p.v.c.; (11) powdered nylon mixed with paste grade p.v.c.ALSO:A composition for use in the fluidized bed coating process comprises an intimate mixture of a resinous coating material having a particle size between 40 mesh (0,42 mm. sieve opening) and 325 mesh (0,044 mm. sieve opening) and a second material having an average particle size less than 5 microns in diameter and present in an amount equal to between 0,5% to 10% by weight of the first material.  The resinous coating material may be thermoplastic, e.g. polyethylene, nylon, polyvinyl chloride, or vinyl chloride copolymers, or thermosetting, e.g. epoxy resins. Plasticizers and other usual additives may be present.  The second material acts primarily to assist fluidization, and it may or may not be resinous; a preferred material is "paste grade" polyvinyl chloride.  Other materials may have secondary functions such as inhibiting excessive flow in the coatings, as with calcium carbonate, magnesium oxide, aluminium silicate, calcium metasilicate, barium sulphate, and aluminium oxide; promoting flow, as with silicone resins; or pigmentation, as with zinc oxide, zinc sulphide, titanium dioxide, lithopone, chromic oxide, iron oxides and metallic pigments. Example 15 describes the coating of an aluminium rod with a mixture of an epoxy resin and dicyandiamide, both of particle size between 70 and 325 mesh, with silica of particle size less than 5 microns. Other examples describe: (1) a plasticized polyvinyl chloride composition mixed with paste grade polyvinyl chloride powder (2) a plasticized mixture of copolymers of vinyl chloride and vinyl acetate and of vinyl chloride and vinylidene chloride, powdered and mixed with paste grade p.v.c.; (8) powdered polyethylene mixed with paste grade p.v.c.; (11) powdered nylon mixed with paste grade p.v.c. Other specified ingredients of the exemplary compositions are epoxidized soya acids; dipropylene glycol dibenzoate; a proprietary barium cadmium soap; titanium dioxide; n-octyl-n-decyl phthalate; and chlorinated wax.