Abstract: A process for preparing microgel(s) that uses a wide range of activatable prepolymers; in the process, a polymer composition of crosslinked component A and soluble components B and C is formed from mono-olefinic and multi-olefinic monomers in the presence of catalyst and initiator; the process comprises:

Abstract: The invention provides UV-absorbing compounds of formula (I) ##STR1## and compositions, including sunscreens, containing compounds of formula (I).

Abstract: A process for the production of polymers by free radical polymerization, characterized in that there is added to the polymerization system one or more compounds of the general formula (A). ##STR1## where R.sup.1 is hydrogen or a group capable activating the vinylic carbon towards free radical addition;Y is OR.sup.2 or CH.sub.2 X(R.sup.2).sub.nwhere R.sup.2 is an optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, or optionally substituted saturated, unsaturated or aromatic, aromatic carbocyclic or heterocyclic ring;X is an element other than carbon selected from Groups IV, V, VI or VII of the Periodic Table or a group consisting of an element selected from Groups IV, V, or VI to which is attached one or more oxygen atoms; andn is a number from 0 to 3, such that the valency of the group X is satisfied and, when n is greater than 1, the groups represented by R.sup.2 may be identical or different.