Abstract: Storage stable polymer-oligomer particles with a high swelling capacity are produced by means of two-stage seed polymerisation in which the mole ratio between initiator and monomer is in the range from 0.07:1 to 0.01:1. These particles are used to produce polymer particles with a narrow size distribution by seed polymerisation.

Abstract: The present invention concerns large spherical polymer particles with a narrow size distribution and a procedure for producing such particles. The procedure is characterized in that a seed polymerization is performed in which the start particles have a very high ability to absorb new monomer so that finished particles are obtained after only one stage of polymerization even if the finished particles are to be as large as in the range 10 to 100 ?m. The procedure is also characterized in that, when porous particles are produced, a porous structure can be formed in which the fraction of micropores is insignificant. Another characteristic feature of the procedure is that the size distribution of the finished particles is narrow and in some cases narrower than in the start particles.

Abstract: The present invention concerns the use of polymer particles in cleaning agents, and such cleaning agents. The polymer particles used according to the present invention are spherical and monodisperse with a particle size which may be varied within the range 10 to 50 micrometers. When all the particles are identical in size and otherwise have identical properties, all the particles will contribute equally to the abrasive effect, and the problems of phase separation phenomena in the final formulation will be reduced. Particles of this type cause no problems with scratching either. Another new and surprising feature of the present invention is that spherical monodisperse polymer particles which have a surface evenly covered with “spikes” of the same polymer material as that of the spherical particle demonstrated much improved washing results in comparison with particles which only had a normal smooth surface. The invented cleaning agents produce good washing results without scratching.

Abstract: A procedure for the production of PVC particles with a narrow size distribution in the range 10-50 &mgr;m, preferably 10-30 &mgr;m, in which, in a first stage, a vinyl monomer or a mixture of monomers is polymerised to form a polymer/oligomer seed particle in the range 1-10 &mgr;m. In a second stage, another vinyl monomer or mixture of monomers 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. It is preferable to use aromatic vinyl monomers or acrylates as the monomer in the seed particles. The seed particles in the first stage can be produced in a two-stage swelling process or by dispersion polymerisation.

Abstract: A process for preparing an aqueous emulsion with a narrow droplet size distribution of an oily material comprising one or more highly water insoluble substances, wherein the oily material is homogenized in a hydrophilic phase in which the oily material is more soluble than in water, but still so insoluble that an emulsion is formed by the homogenization, and the emulsion is subsequently diluted with a high proportion of water to form a stable emulsion of the oily material having the desired narrow size distribution. The stable emulsion may be mixed with an excess of a partly water soluble material which becomes absorbed by the droplets of the oily material. Said partly water soluble material may comprise a polymerizable monomer, and polymerization is subsequently effected to prepare a dispersion of polymer particles, and if desired, the polymer particles are recovered from said dispersion.