摘要 |
A process for the preparation of rigid beads, of cross-linked polyester resin which beads may be solid or vesiculated, by forming an oil-in-water or a water-in-oil-in-water emulsion in which the oil phase contains an unsaturated polyester resin and an unsaturated organic monomer to provide said cross-linking and thereafter heating the emulsion to a temperature of at least 45 DEG C. before initiating polymerization of the oil phase by the introduction into the system of a polymerization initiator, and promoter system, if the latter is not already present in the emulsion. |