| 摘要 |
1,266,400. Microcapsules. FARBENFABRIKEN BAYER A.G. 31 Dec., 1969 [9 Jan., 1969], No. 63422/69. Heading B8C. Microcapsules compound of a core material surrounded by a complex coacervate shell are produced by preparing solutions of two watersoluble coacervatable polymers (A) and (B), polymer (A) containing acid and basic groups and polymer (B) containing carboxyl or carboxylate groups and passing one or both of them separately over a mixture of basic and acidic ion-exchangers, the core material being dispersed in either (A) or (B) either before or after treatment with the ion-exchange material or in the mixture formed subsequently. Coacervation and encapsulation is stated to occur spontaneously when the solutions are subsequently mixed. Typical of polymers of type (A) are casein, gelatine and albumin and of type (B) are copolymers of maleic anhydride with ethylene, styrene, isobutylene, vinyl ether, copolymers of acrylic or methacrylic acid with acrylamide or acrylic esters, carboxymethyl cellulose, gum arabic, alginic acid, alginates and pectins. Examples relate to the encapsulation of polybutadiene oil, lemon oil, TiO 2 in silicone oil, iron oxide and castor oil. |
