AQUEOUS DISPERSION OF MULTISTAGE POLYMER PARTICLES

    公开(公告)号:US20200071558A1

    公开(公告)日:2020-03-05

    申请号:US16556572

    申请日:2019-08-30

    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 Tg hydrophobic monomer; and wherein the second phase second polymer comprises at least 80 percent structural units of styrene. The high Tg hydrophobic 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 TiO2. 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

    公开(公告)号:US20200071439A1

    公开(公告)日:2020-03-05

    申请号:US16556607

    申请日:2019-08-30

    Abstract: 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 Tg hydrophobic monomer and/or the first monomers comprise a high Tg hydrophobic monomer, and the second monomers comprise at least 80 percent styrene. The high Tg hydrophobic 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 TiO2. The particles exhibit excellent collapse resistance and unusually low dry bulk density, and do not require acrylonitrile to achieve this desired combination of properties.

    CONTROLLED PARTICLE SIZE DISTRIBUTION
    147.
    发明申请

    公开(公告)号:US20200048386A1

    公开(公告)日:2020-02-13

    申请号:US16342355

    申请日:2017-11-06

    Abstract: Provided is a method of making a collection of polymer beads comprising (a1) forming a first collection of monomer droplets in an aqueous medium in a container, wherein the first collection of monomer droplets has volume-average diameter DAV1 and has uniformity coefficient less than 1.3; (a2) forming a second collection of monomer droplets in the aqueous medium in the container, wherein the second collection of monomer droplets has volume-average diameter DAV2 and has uniformity coefficient less than 1.3, wherein DAV1 and DAV2 differ by 10 μm or more; wherein either step (a1) and step (a2) are performed simultaneously; or step (a2) is performed after step (a1), while the first collection of monomer droplets remains in the container; or a combination thereof; and (b) after steps (a1) and (a2), polymerizing the monomer droplets by suspension polymerization to form the polymer beads.

    AQUEOUS DISPERSION OF MUTLISTAGE POLYMER PARTICLES

    公开(公告)号:US20200024458A1

    公开(公告)日:2020-01-23

    申请号:US16511061

    申请日:2019-07-15

    Abstract: The present invention relates to a composition comprising an aqueous dispersion of multistage polymer particles with a first phase comprising structural units of a carboxylic acid monomer and a nonionic ethylenically unsaturated monomer; and a second phase with a calculated Tg of less than 50° C. and comprising a mixture of polymers which together comprise structural units of styrene or methyl methacrylate or both; structural units of one or of n-butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, or n-butyl methacrylate; and structural units of a carboxylic acid monomer. The composition is useful as an open time additive in coatings formulations.

    PROCESS FOR PREPARING AN AQUEOUS DISPERSION OF MULTISTAGE POLYMER PARTICLES

    公开(公告)号:US20200024440A1

    公开(公告)日:2020-01-23

    申请号:US16511069

    申请日:2019-07-15

    Abstract: The present invention relates to a process for preparing an aqueous dispersion of neutralized multistage polymer particles comprising the steps of:1) contacting under emulsion polymerization conditions a) a aqueous dispersion of first polymer particles comprising structural units of a carboxylic acid monomer, and structural units of a nonionic monomer with b) first monomers comprising styrene or methyl methacrylate or a combination thereof, and a carboxylic acid monomer; to form an aqueous dispersion of 2-stage polymer particles; then2) contacting under emulsion polymerization conditions the aqueous dispersion of first multistage polymer particles with second monomers comprising a) methyl methacrylate; b) n-butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, or n-butyl methacrylate, or a combination thereof; c) a carboxylic acid monomer; and d) less than 20 weight percent styrene, to form an unneutralized aqueous dispersion of 3-stage polymer particles; then3) neutralizing the unneutralized aqueous dispersion of 3-stage polymer particles with a base to form an aqueous dispersion of neutralized 3-stage polymer particles, wherein the first and second monomers form a shell having a calculated Tg of less than 50° C.The process of the present invention is useful in preparing a composition that is useful as an open time additive in coatings formulations.

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