| 摘要 |
A process for the preparation of microcapsules by the condensation of melamine-formaldehyde resins and/or the methyl ethers thereof in water, in which the substantially water-insoluble material forming the eo=e of the capsule is dispersed, in the presence of an anionic protective colloid at pH's of from 3 to 6.5 by the formation of the microcapsules at temperatures of from 20.degree. to 50.degree.C followed by curing of the shell of the capsules at from >50.degree. to 100.degree.C, in which, prior to curing, from 10 to 200 wt% of urea, whose amino groups are optionally linked to an ethylene or propylene bridge, based on the melamine-formaldehyde resin are added, the microcapsules produced by this process and also the use thereof in a pressure-sensitive recording system. |
