| 摘要 |
<p>There is disclosed a process for making vinyl polymer particles that are spherical, highly porous and of uniform size with substantially no polymer buildup on the reactor surfaces. A dispersion or emulsion is first formed with high agitation comprised of an aqueous medium containing a water-insoluble suspending or dispersing agent, the monomer or monomers to be polymerized, a monomer-soluble free radical yielding catalyst, and a surfactant or surfactant system. The dispersion is neutralized with an alkali and then polymerized with stirring to a conversion of about 10% to about 30% and then continuing the reaction to completion with increased stirring, the stirring in both instances being no greater than that used in making the dispersion or emulsion. The dispersing agent employed comprises an unneutralized crosslinked interpolymer of one or more carboxylic acid monomers with a polyunsaturated compound having a plurality of terminally unsaturated polymerizable groups.</p> |
