| 摘要 |
1,105,847. Making microcapsules. NATIONAL CASH REGISTER CO. 21 Feb. 1967 [30 March, 1966], No. 8103/67. Heading B8C. The walls of microcapsules, of hydrophilic polymeric material, are rendered non-sticky by treatment with a cationic surfactant after they have been separated as a liquid slurry from the aqueous sol in which they were formed. The walls may be of gelatine hardened by a crosslinking compound such as glutaraldehyde or formaldehyde. The surfactant may be a primary amine acetate or a quaternary amine salt, or surfactants of both these classes may be applied simultaneously or successively. Suitable surfactants are hydrogenated tallow furfuryl amine acetate, trimethyl arachidyl behenyl quaternary, or dimethyl di-hydrogenated tallow quaternary. The surfactant may be applied in aqueous solution, or in an organic solvent such as petroleum distillate, and the capsules are subsequently spray dried or dried by hot air. The core of the capsules may be toluene, or other solid, liquid or gas. |
