Initiator suspensions, their preparation and use

摘要

A process for the preparation of an aqueous suspension of a solid free-radical forming initiator, a plant for the preparation, an initiator suspension and use of the suspension in polymerization of ethylenically unsaturated monomers. The process for the preparation of the suspension comprises the steps of: (a) heating the initiator to its melting point; (b) finely dividing the initiator in water while it is in a molten state; (c) rapid cooling so that the initiator is in a molten state for a period of time which is less than about 5 minutes. The initiator suspension has very small particles and a narrow particle size distribution whereby at least 50% by weight of the particles are smaller than 5 mu m and at least 90% by weight of the particles are smaller than 10 mu m.