METHOD FOR THE PRODUCTION OF PVC PARTICLES

摘要

Production of polyvinyl chloride (PVC) particles with a narrow size distribution in the range 10-50 (10-30) micron, comprises: (1) a first stage in which a vinyl monomer(s) is polymerised to form a polymer/oligomer seed particle in the range 1-10 micron; then (2) a second stage in which another vinyl monomer(s) is swelled into the polymer/oligomer seed particles and polymerisation takes place in such a way that they grow into polymer particles of the desired size. Also claimed are: (1) use of spherical PVC particles so produced as viscosity reducers in other polymer systems or in liquids where other polymer systems are not present, as fillers in columns for separation purposes or as basic particles for further chemical modification; (2) a PVC mixture for plastisol purposes containing such spherical PVC particles, standard paste PVC, 0-100 parts by weight (pts.wt.) plasticiser, 0.1-10 pts.wt. thermostabiliser and 0-100 pts.wt. other standard additives for PVC-based products; and (3) the spherical PVC particles produced by the process.