| 摘要 |
PURPOSE:To increase heat resistance, water resistance and oil resistance by covering a core material consisting of hollow silicic fine particles and a hydrophobic liquid material with a wall film constituted of urea resin or melamine resin and forming a capsule body. CONSTITUTION:Hollow silicic particles with surfaces wetted with a hydrophobic material are dispersed in a prepolymer prepared by methylol formation or urea or melamine and formaldehyde. A capsule body constituted of hollow silicic particles and the hydrophobic material as a core material and urea resin or melamine resin as a film material by forming a urea resin or melamine resin wall and covering the surfaces of hollow silicic fine particles and the hydrophobic liquid material with said wall is manufactured. As for the hollow silicic fine particles, the fine particles prepared by melting and crushing sodium silicate, borax and a foaming agent and then expanding the same under heating or the like are used. |
