Rohm and Haas Company

Dow Global Technolgoies LLC

Rohn and Haas Company

James Keith Bardman

Robert Mitchell Blankenship

Ward Thomas Brown

John Michael Friel

David Goodro Kelly

Andrew Hejl

Jonathan DeRocher

Karl Allen Bromm

Lin Wang

Kimy Yeung

Michael W Leonard

Ralph Craig Even

Antony Keith Van Dyk

Gary Robert Larson

William Christopher Finch

Michele Heffner

Wei Zhang

Kenneth Michael Donnelly

Rosemarie Palmer Lauer

David Michael Fasano

Robert Krasnansky

William Joseph Rosano

Bernhard Helmut Lieser

Yili Guo

Michael Rhodes

Mark S Frazza

Kathleen A Auld

Tomohiro Shinoda

Anthony K VanDyk

Kunihide Takarabe

Yoshio Tamura

Takayuki Sugiyama

Jonathan Derocher

David G Kelly

Michele Heffnew

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 process comprising the step of contacting an aqueous dispersion of swelled polymer particles with a rheology modifier and a binder to form a coatings composition with a VOC of less than 50 g/L. The swelled polymer particles arise from neutralization of alkali swellable polymer particles having a high acid core content and a low Tshell. The composition arising from the process of the present invention is useful for improving open time, especially for low VOC coatings applications.

Preparation of a coatings formulation with alkali swellable polymer particles

The present invention relates to a process for preparing a coatings composition with an open time additive comprising the steps of a) contacting an aqueous dispersion of alkali swellable polymer particles with a rheology modifier and a binder to form a coatings composition with a VOC of less than 50 g/L; and b) neutralizing the alkali swellable particles with a non-volatile base after or upon contact with the rheology modifier and the binder to form swelled multi-staged polymer particles; wherein the alkali swellable polymer particles comprise a shell having a Tof not greater than 25&#xb0; C. and an acid functionalized core; and wherein the core-to-shell ratio is in the range of from 1:3.2 to 1:10. The composition arising from the process of the present invention is useful for improving open time, especially for low VOC coatings applications.

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

A process for encapsulating TiOparticles by polymerizing sodium styrene sulfonate with a redox initiator system; then polymerizing a first monomer mixture comprising at least 60 wt % acrylic monomers; then polymerizing a second monomer mixture comprising at least 40 wt % vinyl ester monomers.

Method of making polymer encapsulated titanium dioxide particles

The present invention relates an aqueous dispersion of low Tpolymer encapsulating TiOparticles and a process for preparing the dispersion. The encapsulating polymer is a (meth)acrylate polymer, a styrene-acrylate copolymer, or a vinyl acetate-(meth)acrylate copolymer, or a combination thereof, and the encapsulating polymer further contains units of sodium styrene sulfonate. The present invention provides encapsulated TiOparticles with low gel that are film-forming at ambient temperatures, especially for coatings applications.

Polymer encapsulated titanium dioxide particles

A composition including a core-shell polymeric particle, the core including, when dry, at least one void and the shell including, as polymerized units, from 18% to 50%, by weight based on the weight of the shell, monomer selected from the group consisting of acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and mixtures thereof is provided. Also provided is a composition including an organic medium and a core-shell polymeric particle, the core including, when dry, at least one void and the shell having a calculated shell-organic medium interaction parameter, X&#x3e;1.15 and a method for providing opacity to a dry composition.

Core-shell polymers suitable for use in organic media

A coating containing pigment particles and a polymer matrix is provided. The coating contains pigment particles that have a scattering coefficient with a linear or quasi-linear relationship to the pigment volume concentration of those pigment particles. The coating has improved hiding and is useful as a protective coating or an aesthetic coating on an underlying substrate. Also provided are compositions useful for preparing the coating, including covalently bonded composite particles and aqueous dispersions containing composite particles. The composite particles each contain a pigment particle with a plurality of polymer particles attached by adsorption on the outer surface of the pigment particle or by covalent bonding to the pigment particle through a coupling agent. Methods to prepare the composite particles and coating compositions containing the composite particles are also provided.

Coating with improved hiding compositions prepared therewith, and processes for the preparation thereof

Composite particles

A polymeric particle including a core, a first shell, and a second shell is provided:

Core-shell polymeric particles

An aqueous dispersion of polymeric particles and process for forming thereof is provided. The particles comprise a first polymer comprising, when dry, at least one void; and, substantially encapsulating the first polymer, at least one second polymer comprising, as polymerized units, at least one ethylenically unsaturated monomer.

Aqueous dispersion of polymeric particles

An aqueous dispersion of polymeric particles, the particles including: from 5% to 80% by weight, based on the weight of the polymeric particles, of a first polymer including at least one copolymerized ethylenically unsaturated monomer; and, substantially encapsulating the first polymer, from 20% to 95% by weight, based on the weight of the polymeric particles, of a second polymer including at least one copolymerized ethylenically unsaturated monomer, the second polymer having a Tg of from &#x2212;40&#xb0; C. to 30&#xb0; C., wherein at least 90 weight % of the second polymer is formed by polymerization at a temperature of from 5&#xb0; C. to 65&#xb0; C. is provided. The invention also relates to a process for forming the aqueous dispersion of polymeric particles and an aqueous coating composition including the aqueous dispersion of polymer particles, a method for providing a coated substrate, and the coated substrate so provided.

An aqueous polymer emulsion comprising water and swollen multi-stage polymer is provided. The swollen multi-stage polymer has low dry bulk density, as measured by centrifugation. To achieve the low dry bulk density, the polymer is highly swollen in such a way that it does not subsequently collapse. The polymer is useful in paint and paper coatings.

Process for preparing polymer emulsions and polymers formed therefrom

An aqueous dispersion of polymeric particles and process for forming thereof is provided. The particles comprise a first polymer comprising, as polymerized units, at least one monoethylenically unsaturated monomer and at least one multi-ethylenically unsaturated monomer and when dry, at least one void; and at least one second polymer, substantially encapsulating the first polymer, comprising, as polymerized units, at least one ethylenically unsaturated monomer.

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Green Lane, PA, United States of America

James Keith Bardman