Controlled release microcapsules
AssigneeEncapsys, LLC
InventorsLinsheng Feng, Todd Arlin Schwantes, Robert Stanley Bobnock, Nianxi Yan
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Abstract
A method of forming microcapsules having improved physical properties and release control as well as the microcapsules formed by the process wherein the capsule wall is formed by the concurrent polymerization of monomers, oligomer and/or prepolymers on the inside of the capsule wall and different monomers, oligomers and/or prepolymers on the exterior of the capsule wall as it forms.
Claims49
Microcapsules formed in an oil-in-water or water-in-oil microencapsulation process wherein the shell wall is formed from an oil phase (meth)acrylate polymer wall forming composition and from an aqueous phase (meth)acrylate polymer wall forming composition wherein said oil phase (meth)acrylate wall forming composition comprises the combination of either (A) (a) at least one oil soluble or dispersible amine (meth)acrylate, (b) at least one oil soluble or dispersible acidic (meth)acrylate or at least one oil soluble or dispersible simple acid or both, and (c) at least one oil soluble or dispersible multifunctional (meth)acrylate monomer or oligomer or (B) (a) at least one oil soluble or dispersible acidic (meth)acrylate, (b) at least one oil soluble or dispersible simple base, and (c) at least one oil soluble or dispersible multifunctional (meth)acrylate monomer or oligomer, or (C) one or more oil soluble or dispersible mono-, di- or multi-functional (meth)acrylate monomers or oligomers and said aqueous phase (meth)acrylate polymer wall forming composition comprises at least one water soluble or dispersible (meth)acrylate monomer and/or oligomer wherein the shell wall is as a result of the concurrent or sequential polymerization of the wall forming compositions at the interface of the oil and aqueous phases.
A method of making microcapsules whose shell wall comprises on one surface a first (meth)acrylate polymer and on its other surface a second (meth)acrylate polymer, said first (meth)acrylate polymer derived from an aqueous phase (meth)acrylate polymer wall forming composition and said second (meth)acrylic polymer derived from an oil phase first (meth)acrylate polymer wall forming composition, and an intermediate region comprising an interpenetrating network and/or copolymer of the two wall forming compositions, said method comprising:
- (i) forming an oil-in-water or a water-in-oil emulsion of the two (meth)acrylate polymer wall forming compositions,
- (ii) subjecting the emulsion to conditions for concurrently, at last in part, polymerizing the wall forming materials of each of the oil phase and water phase, and
- (iii) allowing the reaction to continue until the microcapsules of desired wall thickness are attained.
Dependencies are inferred from the claim text.