US 12,240,957 B2
Method for fabricating impermeable porous particles
Kevin D. Lofftus, Fairport, NY (US); John Leonard Muehlbauer, Stafford, NY (US); and Mridula Nair, Penfield, NY (US)
Assigned to EASTMAN KODAK COMPANY, Rochester, NY (US)
Filed by Eastman Kodak Company, Rochester, NY (US)
Filed on Dec. 8, 2021, as Appl. No. 17/545,079.
Claims priority of provisional application 63/126,633, filed on Dec. 17, 2020.
Prior Publication US 2022/0195138 A1, Jun. 23, 2022
Int. Cl. C08J 3/12 (2006.01); C08J 9/28 (2006.01); C08J 9/36 (2006.01); C08K 7/22 (2006.01); C09D 5/02 (2006.01); C09D 5/30 (2006.01); C09D 7/40 (2018.01); C09D 7/41 (2018.01); C09D 7/65 (2018.01); C09D 11/023 (2014.01); C09D 11/037 (2014.01); C09D 11/106 (2014.01); C09D 11/107 (2014.01); C09D 133/04 (2006.01)
CPC C08J 9/365 (2013.01) [C08J 3/126 (2013.01); C08J 9/286 (2013.01); C09D 5/022 (2013.01); C09D 5/30 (2013.01); C09D 7/41 (2018.01); C09D 7/65 (2018.01); C09D 7/70 (2018.01); C09D 11/023 (2013.01); C09D 11/037 (2013.01); C09D 11/107 (2013.01); C09D 133/04 (2013.01); C08J 2201/0544 (2013.01)] 5 Claims
 
1. A method for preparing core/shell particles comprising:
a) forming a suspension of ethylenically unsaturated monomer droplets containing one or more monomers and a porogen in an aqueous medium containing a first stabilizer, a polymerization initiator, and a promoter species, wherein at least one of the one or more monomers is a cross-linking monomer, and wherein the first stabilizer is an inorganic colloid;
b) polymerizing the one or more monomers to form core/shell particles comprising a porous core of a porous polymer and an impermeable polymeric shell having a shell thickness of at least 5 nm, and having the first stabilizer disposed thereon;
c) removing the porogen; and
d) removing the first stabilizer that is disposed on the impermeable polymeric shell of the core/shell particles; and optionally
e) forming a film-forming latex coating over the core/shell particles after removing the first stabilizer,
wherein the porogen includes two or more solvents, and one of the solvents has a greater miscibility in water than the one or more other solvents.