US 11,655,322 B2
Multiphase emulsion polymers for aqueous coating compositions containing little or no organic solvents
Wenjun Wu, Cary, NC (US)
Assigned to Arkema Inc., King of Prussia, PA (US)
Appl. No. 14/376,713
Filed by Arkema Inc., King of Prussia, PA (US)
PCT Filed Feb. 5, 2013, PCT No. PCT/US2013/024701
§ 371(c)(1), (2) Date Aug. 5, 2014,
PCT Pub. No. WO2013/119524, PCT Pub. Date Aug. 15, 2013.
Claims priority of provisional application 61/597,455, filed on Feb. 10, 2012.
Prior Publication US 2015/0031830 A1, Jan. 29, 2015
This patent is subject to a terminal disclaimer.
Int. Cl. C08F 265/02 (2006.01); C09D 151/00 (2006.01); C08L 33/12 (2006.01); C08F 265/06 (2006.01); C08L 33/14 (2006.01); C09D 133/12 (2006.01); C09D 133/14 (2006.01)
CPC C08F 265/02 (2013.01) [C08F 265/06 (2013.01); C08L 33/12 (2013.01); C08L 33/14 (2013.01); C09D 133/12 (2013.01); C09D 133/14 (2013.01); C09D 151/003 (2013.01); C08L 2205/02 (2013.01); C08L 2207/02 (2013.01)] 12 Claims
 
1. A polymer latex binder having a VOC level of less than about 50 g/L comprising a multiphase emulsion polymer in the form of latex particles, water and at least one emulsifier, said multiphase emulsion polymer comprising:
at least one soft polymer phase having a glass transition temperature of from 0 to −70° C. comprised of a soft phase polymer and at least one hard polymer phase comprised of a hard phase polymer, said multiphase emulsion polymer prepared by a multi-stage emulsion polymerization,
wherein the hard phase polymer has a glass transition temperature of from 10° C. to 100° C. which is more than 50° C. higher than that of the soft phase polymer,
wherein said multi-stage emulsion polymerization comprises the steps of forming the at least one hard polymer phase as a first stage polymer, and subsequently polymerizing the at least one soft polymer phase in the presence of the first stage polymer, and
wherein the hard phase polymer comprises: (i) copolymer of at least one C1-C4 alkyl (meth)acrylate, methacrylic acid and at least one wet adhesion monomer, or (ii) copolymer of butyl acrylate, methyl methacrylate, methacrylic acid and at least one of hydroxyethyl ethylene urea methacrylate and diacetone acrylamide,
wherein the soft polymer phase represents from 65% to 75% by weight of the multiphase emulsion polymer and the hard polymer phase represents from 25% to 35% by weight of the multiphase emulsion polymer, the total weight amount of soft polymer phase and hard polymer phase equaling 100%,
wherein the soft phase polymer is a homopolymer or copolymer formed from one or more monomers selected from the group consisting of methyl (meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and diacetone acrylamide,
wherein the multiphase emulsion polymer is in the form of latex particles, and
wherein the latex particles comprise an outer phase comprising the hard polymer phase and an inner phase comprising the soft polymer phase and have an average particle size less than 150 nm, and
the polymer latex binder has a minimum film forming temperature of less than 15° C.