| 摘要 |
1,237,498. Microcapsules. FUJI PHOTO FILM CO. Ltd. 30 May, 1969 [4 June, 1968], No. 27629/69. Heading B8C. Microcapsules are made by dissolving a hydrophobic, film-forming polymer in a lowboiling liquid which is a good solvent therefor, mixing the solution with a liquid to be encapsulated which is a poor solvent for the polymer, is water-insoluble, is compatible with the good solvent, and has a higher boiling point and may contain suspended solid, emulsifying the resulting mixture in an aqueous medium at a temperature below the boiling point of the low-boiling solvent and heating the emulsion to a temperature below the boiling point of the high-boiling liquid but above that of the low-boiling liquid. The polymer. may be one of a wide..range of synthetic resins such as a phenolic resin, a melamine, urea, epoxy, furan, xylene, alkyd, acrylic, silicone &c. resin, a vinyl polymer, a polyolefin, polycarbonate, polyether or cellulose resin. " Suitable high .boiling liquids are oils of all types and suitable low-boiling liquids are organic solvents such as CH 2 Cl 2 , CS 2 , CHCl 3 , acetone, benzene, ketones, ethers and alkanes. |
