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AssigneeRohm and Haas Company
InventorsJames C. Bohling, Ibrahim Eryazici, Philip R. Harsh, Partha S. Majumdar, Edwin A. Nungesser
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The present invention relates to composition comprising an aqueous dispersion of microspheres and a class of a nonionic polyalkylene oxide of a distyryl or tristyryl phenol or an anionic polyalkylene oxide salt of a distyryl or tristyryl phenol and a process for preparing the composition. The microspheres have an average particle size in the range of from 1 μm to 25 μm, as well as a low coefficient of variation and low gel concentration; the composition is useful in coatings applications, especially where a matte finish is desired.
A process comprising the step of contacting, under polymerization conditions and in the presence of a nonionic polyalkylene oxide of a distyryl or tristyryl phenol or an anionic polyalkylene oxide salt of a distyryl or tristyryl phenol, an aqueous dispersion of first microspheres comprising structural units of a first monoethylenically unsaturated nonionic monomer with a first stage monomer comprising from 70 to 100 weight percent of a second monoethylenically unsaturated nonionic monomer, based on the weight of first stage monomer, to grow out the first microspheres to form an aqueous dispersion of second microspheres, wherein the first microspheres have a particle size in the range of from 1 μm to 15 μm and the second microspheres have a particle size in the range of from 1.1 μm and 25 μm.
Dependencies are inferred from the claim text.