Patent GB-1119748-A (GB)
Title: Colored polymer powders
Inventor: LERMAN FRANK
IPC: C08L25/00
Filed: 1967-06-13
Abstract: Coloured spherical thermoplastic polymer powders of particle size below 1000 microns diameter are prepared by vigorously agitating a water-insoluble thermoplastic polymer, colorant and water in the presence of a water-soluble ethylene oxide/propylene oxide block copolymer at an elevated temperature above the melting-point of the polymer to produce a fine dispersion and thereafter cooling the dispersion below the melting-point of the polymer. Specified polymers are polyvinyl chloride, polyvinyl acetate, partially hydrolysed polyvinyl alcohol, polyvinyl acetal, polymethyl methacrylate, polyacrylonitrile, polymethyl acrylate, polyethyl methacrylate, vinyl chloride/vinyl acetate, ethylene/vinyl acetate, ethylene/vinyl propionate, ethylene/vinyl isobutyrate, ethylene/vinyl alcohol, ethylene/methyl acrylate, ethylene/ethyl acrylate, ethylene/ethyl methacrylate, ethylene/allyl alcohol, ethylene/allyl acetate, ethylene/allyl acetone, ethylene/allyl benzene, ethylene/allyl ether and ethylene/acrolein copolymers, polyhexamethylene adipamide, polyhexamethylene sebacamide and polycaprolactam.  Specified colorants are carbon black, phthalocyanines, fluorescent dyes, cadmium sulphide, cadmium sulphide selenide, titanium dioxide, calcined iron oxide, chromic oxide and zinc oxide. Examples describe the preparation of particulate compositions of polyethylene with carbon black, fluorescent pigments, phthalocyanine blue and titanium dioxide; of an ethylene/vinyl acetate copolymer with phthalocyanine blue; and of a styrene/methyl methacrylate with carbon black.ALSO:Fluorescent coloured spherical thermoplastic polymer powders of particle size below 1000 microns diameter are prepared by vigorously agitating a water-insoluble thermoplastic polymer, a fluorescent dye or pigment and water in the presence of a water-soluble ethylene oxide/propylene oxide block copolymer at a temperature above the melting point of the polymer to produce a fine dispersion and thereafter cooling the dispersion below the melting point of the polymer.  Specified polymers are polyvinyl chloride, polyvinyl acetate, partially hydrolysed polyvinyl alcohol, polyvinyl acetal, polymethyl methacrylate, polyacrylonitrile, polymethyl acrylate, polyethyl methacrylate, vinyl chloride/vinyl acetate, ethylene/vinyl acetate, ethylene/vinyl propionate, ethylene/vinyl isobutyrate, ethylene/vinyl alcohol, ethylene/methyl acrylate, ethylene/ethyl acrylate, ethylene/ethyl methacrylate, ethylene/allyl alcohol, ethylene/allyl acetate, ethylene/allyl acetone, ethylene/allyl benzene, ethylene/allyl ether and ethylene/acrolein copolymers, polyhexamethylene adipamide, polyhexamethylene sebacamide and polyacaprolactam.  In Example III a fluorescent red polyethylene powder is prepared by agitating polyethylene and a red orange fluorescent pigment in water containing an ethylene oxide/propylene oxide block copolymer. Uses include air dissemination studies, simulants for chemical, biological, radio-active aerosol dispersion and oceanography tracer work, signal powders, coatings for paper and textiles, dipcoating of heated metal parts and coloured or black toner or photoconductive coating in electrostatic printing processes.