Microcapsules having acrylic polymeric shells and methods of making same
AssigneeMicrotek Laboratories, Inc.
InventorsTeresa T. Virgallito, Carl M. Lentz, David R. Virgallito, Dale E. Work
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Abstract
Microcapsules are described that include a hydrophobic core material within an acrylic polymeric shell that was polymerized from a monomeric blend that includes a mono-functional acrylic monomer as less than 25% by weight of the monomeric blend and a hyperbranched polyester acrylic oligomer as the balance of the monomeric blend, and methods of making the same. The methods include a two-stage polymerization process where the monomeric blend is polymerized with an azo-initiator in a first stage polymerization reaction and is subsequently further polymerized with a water soluble initiator in a second stage polymerization reaction.
Claims20
A method for producing microcapsules, the method comprising:
- emulsion polymerizing, in a first stage, an organic phase comprising core material and acrylic monomers as wall material, the wall material being polymerized with an azo-initiator thereby forming a polymerized intermediate in capsule form;
- and
- polymerizing further, in a second stage, the polymerized intermediate by addition of a water soluble initiator to form microcapsules.
A microcapsule comprising:
- a hydrophobic core material within an acrylic polymeric shell;
- wherein the acrylic polymeric shell was polymerized from a monomeric blend comprising:
- a mono-functional acrylic monomer comprising less than 25% by weight of the monomeric blend;
- and
- a hyperbranched polyester acrylic oligomer as the balance of the monomeric blend.
Dependencies are inferred from the claim text.