Controlled release microcapsules

Patent metadata

Field	Value
Publication number	US-9714397-B2
Application number	US-201514884694-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 16, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

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.

First claim

We claim:

1. 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 (meth)acrylate polymer wall forming composition comprising a combination of (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, 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.

2. The method of claim 1 wherein the method further comprise a step of oligomerizing and/or prepolymerizing some or all of the (meth)acrylate polymer wall forming components of the oil phase composition, the aqueous phase composition or both subsequent to forming the emulsion but prior to initiating wall formation.

3. The method of claim 1 wherein the oil phase composition, the aqueous phase composition or both, prior to forming the emulsion, comprises oligomers and/or prepolymers of some or all of the (meth)acrylate polymer wall forming components thereof.

4. The method of claim 1 wherein the oil phase wall forming composition comprises (a) at least one oil soluble or dispersible amine (meth)acrylate, (b) at least one oil soluble or dispersible acidic (meth)acrylate, and (c) at least one oil soluble or dispersible multifunctional (meth)acrylate monomer or oligomer.

5. The method of claim 1 wherein the oil phase wall forming composition comprises (a) at least one oil soluble or dispersible amine (meth)acrylate, (b) at least one oil soluble or dispersible simple acid, and (c) at least one oil soluble or dispersible multifunctional (meth)acrylate monomer or oligomer.

6. The method of claim 1 wherein the oil phase wall forming composition comprises (a) at least one oil soluble or dispersible amine (meth)acrylate, (b) the combination of at least one oil soluble or dispersible acidic (meth)acrylate and at least one oil soluble or dispersible simple acid, and (c) at least one oil soluble or dispersible multifunctional (meth)acrylate monomer or oligomer.

7. The method of claim 1 wherein the aqueous phase wall forming composition comprises one or more polyethylene glycol di(meth)acrylates, ethoxylated mono- or multi-functional (meth)acrylates, and (meth)acrylate monomers and/or oligomers.

8. The method of claim 1 wherein the aqueous phase further comprises a polymeric emulsifier.

9. The method of claim 8 wherein the polymeric emulsifier is one which comes out of solution during the wall forming process and is incorporated into the shell wall.

10. The method of claim 1 wherein the wall formation is a two-step reaction process where the first reaction step comprises subjecting the emulsion to such conditions as will form prepolymers and polymers of the wall forming materials and the second reaction step comprises subjecting the emulsion to a second set of conditions which effectuates the formation of the shell wall.

11. The method of claim 1 wherein the wall formation is a three-step reaction process where the first step comprising subjecting the emulsion to such conditions as will form prepolymers and polymers of the wall forming materials, the second step comprises subjecting the emulsion to a second set of conditions which effectuates building of the shell wall and the third step comprises subjecting the emulsion to a third set of conditions, which may be merely an extension or continuation of the second set of conditions, to cross-link the polymer(s) of the shell wall.

12. The method of claim 11 wherein the third step effects the cross-linking of at least the oil phase derived (meth)acrylate polymer.

13. The method of claim 1 wherein initiation of wall formation from the oil phase and the aqueous phase is concurrent.

14. The method of claim 1 wherein initiation of the wall formation from one of the oil phase and the aqueous phase is staggered relative to the other.

15. The method of claim 14 wherein wall formation of the second wall forming composition is initiated after the shell wall is partially formed from the first wall forming material but before the shell wall is impermeable to the wall forming material of the second wall forming composition.

16. The method of claim 14 wherein wall formation of the second wall forming composition is initiated after a seed capsule is formed of the first wall forming material.

17. An oil in water or water in oil emulsion 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 (meth)acrylate polymer wall forming composition comprising a combination of (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, and an intermediate region comprising an interpenetrating network and/or copolymer of the two wall forming compositions, said method comprising:
(i) forming a first oil phase composition comprising the wall forming monomers, oligomers and/or prepolymers,
(ii) forming a second oil phase composition comprising a first initiator for effecting oligomerization and/or polymerization of the (meth)acrylate monomers/oligomers of the first oil phase composition, alone or in combination with the ingredient(s) to be encapsulated, provided that at least one of the first oil phase composition and the second oil phase composition includes at least one of the ingredients to be encapsulated,
(iii) combining and mixing the two oil phase compositions,
(iv) either
(A) subjecting the combined oil phase composition to such conditions and for such period of time as is effective for causing the oligomerization/prepolymerization of the (meth)acrylate monomers/oligomers of the combined oil phase compositions and then adding to that reaction product an excess of a first aqueous composition comprising an emulsifier suitable for emulsifying the oil phase composition in water, water, and, optionally, either (a) a second initiator, (b) an alkali or alkali salt, or (c) both, and intimately mixing/milling the same to form droplets of the combined oil phase composition dispersed in the first aqueous composition; or
(B) combining the mixture of step (iii) with an excess of a first aqueous composition comprising an emulsifier suitable for emulsifying the oil phase composition in water, water, and, optionally, either (a) a second initiator, (b) an alkali or alkali salt, or (c) both, and intimately mixing/milling the same to form droplet

Assignees

• Encapsys Llc

Inventors

• Feng Linsheng
• Schwantes Todd Arlin
• Bobnock Robert Stanley
• Yan Nianxi

Classifications

• A61K2800/412

  Microsized, i.e. having sizes between 0.1 and 100 microns · CPC title

• C11D3/505

  encapsulated or adsorbed on a carrier, e.g. zeolite or clay · CPC title

• A61Q15/00

  Anti-perspirants or body deodorants (deodorisation of air A61L9/00) · CPC title

• A61Q13/00

  Formulations or additives for perfume preparations (essential oils or perfumes per se C11B9/00) · CPC title

• C11B9/00 Primary

  Essential oils; Perfumes · CPC title