Multifunctional (meth)acrylate polysaccharide microcapsules
AssigneeEncapsys, LLC
InventorStephen Marc Baumler
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Abstract
The invention describes a core shell microcapsule wherein the capsule shell is an interfacial copolymer formed of a modified polysaccharide free radical cross-linked with a multifunctional (meth)acrylate. The polysaccharide is hydrophobically modified with an adduct containing at least one unsaturated bond. The modification imparts hydrophobic character to the polysaccharide to act as an emulsifier, driving the modified polysaccharide to an oil-water interface of an encapsulation emulsion described, and creates an active bonding site for free-radical polymerization between the polysaccharide and multifunctional (meth)acrylate, thereby forming a microcapsule shell surrounding the core material.
Claims25
A microcapsule comprising a core material and a shell encapsulating the core material, wherein the shell comprises a free radical addition product of a multifunctional (meth)acrylate cross-linked with a hydrophobically modified polysaccharide wherein the polysaccharide is characterized as having hydroxy groups of which from 0.5 up to 40 mole percent of the hydroxy groups of the polysaccharide are substituted with a hydrophobizing agent containing from 1 to 200 carbons.
A process of forming a population of microcapsules, the microcapsules comprising a core material and a shell encapsulating the core material, the shell of the microcapsules formed by an interfacial reaction between a multifunctional (meth)acrylate dispersed in an oil phase, and a polysaccharide dispersed in a water phase, the process comprising:
- a. dispersing one or more in oil phases a first initiator, a core material, and a multifunctional (meth)acrylate monomer, prepolymer or oligomer;
- b. dispersing in a water phase the polysaccharide, and an optional second initiator;
- c. emulsifying the one or more oil phases into the water phase under high shear agitation to form an oil-in-water emulsion comprising droplets of the core material and oil phase monomer, prepolymer or oligomer dispersed in the water phase;
- d. and activating the initiator or initiators by heat or actinic radiation to react the multifunctional (meth)acrylate monomer, prepolymer or oligomer, and polysaccharide by free radical addition polymerization, thereby forming a polymer shell surrounding the droplets of the emulsion.
A process of forming a population of microcapsules, the microcapsules comprising a core material and a shell encapsulating the core material, the shell of the microcapsules formed by an interfacial reaction between a multifunctional (meth)acrylate dispersed in an oil phase, and a polysaccharide dispersed in a water phase, the process comprising:
- a. dispersing one or more in oil phases a first initiator, a core material, and a multifunctional (meth)acrylate monomer, prepolymer or oligomer;
- b. dispersing in a water phase the polysaccharide, and an optional second initiator;
- c. emulsifying the one or more oil phases into the water phase under high shear agitation to form an oil-in-water emulsion comprising droplets of the core material and oil phase monomer dispersed in the water phase;
- d. and activating the initiator or initiators by heat or actinic radiation to react the multifunctional (meth)acrylate monomer, prepolymer or oligomer, and polysaccharide by free radical addition polymerization, thereby forming a polymer shell surrounding the droplets of the emulsion, wherein the polysaccharide is of Formula I
- wherein n1 is an integer from 1 to 1,000, wherein x is a terminal hydrogen or repeating glucose unit of Formula I from 1 to 50 units, and wherein each A are independently a terminal hydrogen, or an adduct selected from the group consisting of Formula II, Formula III, Formula IV, Formula V, and Formula VI,
- wherein each R1 are independently a terminal hydrogen, alkyl or alkenyl, from 1 to 20 carbons, each R2 are independently an alkyl, alkenyl, alkoxy, from 1 to 20 carbons or hydroxy, each R3 are independently a terminal hydrogen, alkyl or alkenyl, from 1 to 20 carbons, R4 is an alkyl or alkenyl, from 1 to 20 carbons, R5 is a terminal hydrogen, alkyl, alkenyl, from 1 to 20 carbons, or polyoxyethylene, from 1 to 40 carbons, R6 is a terminal hydrogen, a hydroxy, an alkoxy, alkyl, alkenyl, alkanol or alkylamine, from 1 to 20 carbons, and R7 is a terminal hydrogen, (meth)acrylate, alkyl, alkenyl, alkynyl, amine, amide, arenyl, carboxylate, disulfide, ester, ether, epoxide, isocyanate, or sulfide, from 1 to 20 carbons, and n2 is an integer from 1 to 1,000.
Dependencies are inferred from the claim text.