| abstract |
Capsules (I) having a polyelectrolyte (PE) shell and a diameter of up to 10 (preferably to 5) Microm, are new, specifically where (I) are obtained by applying PE molecules onto template particles (II). Independent claims are included for the following: (1) the preparation of (I) (with no restriction on capsule size) by forming an aqueous dispersion of (II) having suitable size, then applying PE to (II); (2) the preparation of a coated surface by applying (I) to the surface; (3) partially crosslinked melamine-formaldehyde (MF) particles (III) having a diameter of 10 Microm or less; (4) the preparation of partially crosslinked MF particles by polycondensation of MF precondensates, where the polycondensation process is interrupted during the reaction; and (5) a method for applying multiple coating layers to (II), involving: (a) contacting (II) with a first coating material (C1) in a liquid medium, in a reaction region bounded on at least one side by a filtration membrane, to form a coating of (C1) on (II); (b) removing at least part of the reaction medium, optionally with any excess (C1), via the filtration membrane; (c) repeating steps (a) and (b), but using a second coating material (C2) instead of (C1); and (d) optionally repeating steps (a)/(b) and/or step (c). |