Interpenetrating Network Microcapsule Wall for Controlled Release
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Solution Overview
Problem
Current microcapsule technologies face challenges in achieving a suitable balance of release/permeability characteristics and physical properties, particularly in applications like perfumes and fabric treatments, where controlled release and longevity are necessary, while maintaining capsule strength and integrity.
Innovation Solution
The development of novel microcapsules with a shell wall comprising a first (meth)acrylate polymer from an aqueous phase and a second (meth)acrylate polymer from an oil phase, forming an interpenetrating network, through an oil-in-water or water-in-oil emulsion process, allowing for controlled release and improved physical attributes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional microcapsule walls are made impermeable to prevent leakage, then capsule integrity is improved, but controlled release capability deteriorates
Solution Approach 1:
The patent employs porous polymer wall materials that allow controlled permeation of encapsulated contents. The porous structure enables selective passage of molecules based on size and polarity, achieving controlled release while maintaining capsule integrity through the interconnected pore network that prevents catastrophic failure.
Solution Approach 2:
The patent utilizes composite wall structures combining multiple polymer materials with different properties. This composite approach allows simultaneous achievement of mechanical strength for integrity and selective permeability for controlled release, as different polymer components contribute different functional characteristics to the wall system.
2Strength
If microcapsule walls are made strong to avoid premature fracture, then capsule integrity is improved, but ease of fracture for controlled release deteriorates
Solution Approach 1:
The patent modifies wall parameters including thickness, crosslinking density, and polymer composition to achieve optimal balance between strength and fracture ease. By controlling these parameters, the walls maintain sufficient strength for storage integrity while remaining responsive to mechanical stimuli for controlled fracture-based release.
Solution Approach 2:
The patent creates walls with dynamic mechanical properties that can transition between rigid and flexible states. This dynamic characteristic allows walls to maintain strength under normal conditions but become susceptible to controlled fracture when subjected to specific mechanical forces, enabling on-demand release.
3Duration of action of stationary object
If microcapsules are designed for slow release without fracture, then longevity is improved, but release rate control becomes more difficult
Solution Approach 1:
The porous wall structure provides inherent release control through diffusion mechanisms. The pore size distribution and connectivity naturally regulate the release rate of encapsulated contents, achieving slow release and extended longevity without requiring complex additional control mechanisms.
Solution Approach 2:
The patent implements spatial variations in wall properties such as pore density, thickness, and polymer composition across different regions of the capsule wall. This local quality differentiation enables precise control of release rates in different directions and under different conditions, managing complexity through localized property optimization rather than uniform design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The novel microcapsules exhibit enhanced release characteristics and physical properties, ensuring controlled release of contents while maintaining capsule integrity, thus addressing the limitations of existing technologies in demanding applications such as perfumes and fabric treatments.
Implementation Method 1
comprising (i) forming a first oil phase composition comprising (a) at least one oil soluble or dispersible amine (meth)acrylate, (b) at least one oil soluble or dispersible acidic (meth)acrylate alone or in combination with 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
Implementation Method 2
forming an oil-in-water or a water-in-oil emulsion of the two (meth)acrylate polymer wall forming compositions
Implementation Method 3
an intermediate region comprising an interpenetrating network and/or copolymer of the two wall forming compositions
Data Source
AI summary
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.