| 摘要 |
PURPOSE:To safely obtain the titled powder useful in cosmetics and in frontier technologies such as electronic components and ceramics, by cooling an emulsion obtained by subjecting a thermoplastic resin containing a uniformly dispersed inorganic substance to a specified treatment. CONSTITUTION:An emulsion is obtained by melting with agitation under heat and pressure a thermoplastic resin formed by uniformly mixing 100pts.wt. thermoplastic resin such as PE, PS or a styrene/acrylic copolymer with 1-20pts.wt. inorganic substance (except carbon black) such as a finely powdered metal, ZnO or Al2O3 in 50-3,000pts.wt. water as a medium in the presence of 3-60pts. wt. ethylene oxide/propylene oxide copolymer of formula I (wherein x is 2-250, y is 10-90 and z is 2-150) and, optionally, 1-20pts.wt. ethylene/acrylic acid copolymer of formula II. This emulsion is cooled to a temperature lower than the softening temperature of said inorganic-containing thermoplastic resin to obtain the titled exactly spherical fine powder of an average particle diameter <=50mu. |
