| 摘要 |
A process for the preparation of large-particle, aqueous plastic dispersions by emulsion polymerization of free- radical polymerizable monomers is disclosed. The process is car- ried out in a system which controls the particle size and comprises an anionic emulsifier, an essentially non-branched, nonionic, water-soluble polymer auxiliary, which is added before the polymerization, and alkali metal and/or ammonium ions not bonded to emulsifier. The polymer auxiliary is an essentially non- branched polyethylene oxide having a AB block structure, where A is a hydrophobic radical comprising 15 to 70 C atoms and B is a non-branched hydrophilic radical comprising at least 50 ethylene oxide units. The polymer auxiliary can be prepared reproducibly in respect of its agglomerating effect. The plastic dispersion prepared according to the process of the invention are character- ized by a narrow, monomodal distribution of particle size. Depending on the monomers used, these dispersions are useful, for example, as coating materials or binders.
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