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US 8,013,081 B2Granted
Method for preparing polymer particles
AssigneeValspar Sourcing, Inc.
InventorsMartin Peter Joseph Heuts, Archie W. Garner
Life of this patent
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Abstract
A polymer particle (10) useful for opacifying includes a polymer core (12) and a polymer sheath (16) surrounding the polymer core (12). The polymer core (12) is produced by polymerizing the polymer sheath (16) around the polymer core (12) in an emulsion. After at least a portion of the polymer core (12) is formed, a non-homopolymerizing monomer is added to the emulsion.
Claims15
A method for preparing emulsion polymer particles useful for opacifying, the method comprising:
- polymerizing a first portion of a polymer sheath around a swellable polymer core in an emulsion;
- treating the polymer core with a swelling agent to swell the polymer core;
- adding non-homopolymerizing monomers to the emulsion containing the polymer core to retard or interrupt the polymerization of the polymer sheath;
- after adding the non-homopolymerizing monomers, adding free monomers to the emulsion that are capable of copolymerizing with the non-homopolymerizing monomers;
- and
- polymerizing the added free monomers and the non-homopolymerizing monomers to form a second portion of the polymer sheath.
3 more elements
A method for preparing emulsion opacifying polymer particles, the method comprising:
- emulsion polymerizing a polymer core;
- exposing the polymer core to a supply of free monomers to polymerize a first portion of a polymer sheath around the polymer core;
- after polymerizing the first portion of the polymer sheath, exposing the polymer core to an amount of a swelling agent sufficient to swell the polymer core;
- adding non-homopolymerizing monomers to retard or interrupt the polymerization of the first portion of the polymer sheath;
- and then
- polymerizing additional free monomers and the non-homopolymerizing monomers into a second portion of the polymer sheath.
3 more elements
Dependencies are inferred from the claim text.