| 摘要 |
1,145,133. Treating microcapsules. NATIONAL CASH REGISTER CO. 22 Sept., 1967 [17 Oct., 1966], No. 43158/67. Heading B8C. The permeability to water of microcapsule walls is reduced by establishing an agitated aqueous system of microcapsules having waterswollen, hydrophilic polymer walls at least partly composed of polypeptide material and introducing into the system an aqueous solution of a simple salt of uranium or vanadium or of a double salt containing divalent uranium or vanadium. A plasticizer, e.g. a plant gum, sugar, polyhydric alcohol or highly polar hydrophilic solvent e.g. phthalonitrile, acetamide, formamide, DMSO or dimethyl formamide, may be included in the capsule walls either during the capsule manufacture, during the above-described treatment or subsequently. Specified polymeric materials are gelatin, collagen and derivatives thereof and zein. Suitable salts are uranyl and vanadyl nitrate, acetate, sulphate and halides, and ammonium uranyl carbonate. |
