| 摘要 |
1,129,430. Making microcapsules. NATIONAL CASH REGISTER CO. 29 June, 1967 [22 July, 1966], No. 29994/67. Heading B8C. Microcapsules are prepared by establishing an agitated coacervatable solution of wallforming polymeric material, dispersing the core material (solid or liquid) therein, and causing the co-acervate phase of wall-forming material to form in the system at a controlled rate which is substantially equal to that at which it deposits on the core material, thereby avoiding the presence of substantial amounts of undeposited coacervate phase and the " clumping " of capsules. The capsules formed are subsequently hardened by conventional procedures, either physical or chemical. Specific examples relate to the encapsulation of a solution of a dye in chlorinated biphenyl, which is dispersed in a gelatin/gum arabic solution at pH 9 to which a solution of polyvinylmethyl ether/maleic anhydride copolymer sodium salt in water/ethylmethylketone and acetic acid is gradually added to induce coacervation. Reference is also made to the encapsulation of various animal, vegetable, mineral and synthetic oils and to pharmaceuticals, e.g. riboflavin, salicylamide, tetracycline HCl, tetracycline phosphate, phenaglycodol, chlorotrianisene, cholesterol, meprobamate, erythromycin propionate, benzathine penicillin G and vitamin K. |
