The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 2021
Filed:
Aug. 30, 2019
Rohm and Haas Company, Collegeville, PA (US);
James K. Bardman, Green Lane, PA (US);
David G. Kelly, Ambler, PA (US);
Michael W. Leonard, Collegeville, PA (US);
Rohm and Haas Company, Collegeville, PA (US);
Abstract
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.