Rohm and Haas Company

Dow Global Technolgoies LLC

Michael W Leonard

James Keith Bardman

David Goodro Kelly

James Charles Bohling

Wei Gao

Michael L Jackson

Qing Zhang

Robert Kooy

Takumi Kitagawa

Andrew J Swartz

Ikuo Asato

Jeff Makarewicz

Nobuhiro Mori

Blake Burich

Manabu Ozawa

Toru Tanaka

David G Kelly

The present invention relates to a composition comprising an aqueous dispersion of multistage polymer particles comprising a first and a second phase, wherein the first phase comprises structural units of a carboxylic acid monomer or a salt thereof, and a nonionic ethylenically unsaturated monomer; and wherein the second phase comprises a first and second polymer, wherein the first phase or the second phase first polymer or both comprise structural units of a high Thydrophobic monomer; and wherein the second phase second polymer comprises at least 80 percent structural units of styrene. The high Thydrophobic monomer is defined as being one or more of the following monomers: cyclohexyl methacrylate, isobornyl methacrylate, 4-t-butyl methacrylate, t-butylstyrene, or n-butyl methacrylate. The multistage polymer particles are useful as opaque polymers, which are used in pigmented coating formulations to reduce the load of TiO. The particles exhibit excellent collapse resistance and unusually low dry bulk density, and do not require acrylonitrile to achieve this desired combination of properties.

Aqueous dispersion of multistage polymer particles

The present invention relates to a method of preparing an aqueous dispersion of multistage polymer particles comprising contacting under emulsion polymerization conditions and in a staged fashion an aqueous dispersion of carboxylic acid functionalized core polymer particles with first monomers and second monomers. The core comprises structural units of a high Thydrophobic monomer and/or the first monomers comprise a high Thydrophobic monomer, and the second monomers comprise at least 80 percent styrene. The high Thydrophobic monomer is cyclohexyl methacrylate, isobornyl methacrylate, 4-t-butyl methacrylate, t-butylstyrene, or n-butyl methacrylate, or a combination thereof. The multistage polymer particles are useful as opaque polymers, which are used in pigmented coating formulations to reduce the load of TiO. The particles exhibit excellent collapse resistance and unusually low dry bulk density, and do not require acrylonitrile to achieve this desired combination of properties.

Method for preparing an aqueous dispersion of multistage polymer particles

The present invention relates to opaque polymers functionalized with phosphorus acid groups, composites of TiOparticles and the opaque polymers, and methods for their preparation. The composites are useful in coatings formulations and have been shown to exhibit improved hiding benefits in coated substrates over compositions containing non-functionalized opaque polymer and TiO.

Phosphorus acid functionalized opaque polymer

A coating composition particularly suitable for coating poly(phenylene oxide) comprises aqueous medium-dispersed particles of: A) between about 30 and about 35 wt %, of a first styrene-acrylic polymer formed of monomers, between about 50 and about 80 mole % of which monomers are styrene or substituted styrene monomers, between about 2 and about 15 mole percent of which monomers are acrylonitrile, and between about 18 and about 48 mole percent of which are acrylic monomers, said first styrene-acrylic polymer having an acid number of about 15 or below; B) between about 30 and 35 wt %, of an acrylic second polymer formed of monomers, at least about 90 mole percent of which monomers are acrylate monomers, balance other &agr;, &bgr;-ethylenically unsaturated monomers, said acrylic second polymer having an acid number between 0 and about 25; and C) between about 30 and about 40 wt % of an acrylic-urethane hybrid polymer.

One component waterborne coating with improved chemical resistance

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Collegeville, PA, United States of America

Michael W Leonard