Polyamide Microcapsule Shells for Surfactant-Stable Perfume Release
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Solution Overview
Problem
The perfumery industry faces challenges in maintaining the stability of microcapsules containing odoriferous compounds in aggressive consumer product bases, such as high surfactant detergents, leading to rapid loss of olfactive benefit.
Innovation Solution
A process for preparing polyamide core-shell microcapsules by dissolving acyl chloride in a hydrophobic material, forming an oil phase, dispersing it in a water phase with amino compounds, and adding a stabilizer, followed by a curing step to form microcapsules with a polyamide shell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If polyurea or polyurethane microcapsules are used for long-lasting olfactory effect, then olfactory performance is improved, but stability in challenging bases with aggressive surfactants deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the shell by using polyamide formed from acyl chloride and amino compounds instead of polyurea or polyurethane, while maintaining the microcapsule structure. This parameter change in material composition provides both long-lasting olfactory effect and stability in challenging bases with surfactants
Solution Approach 2:
The patent creates a composite shell structure using polyamide formed by reaction between acyl chloride and amino compounds. This composite material combines the encapsulation properties needed for long-lasting release with chemical resistance to aggressive surfactants in consumer product bases
2Reliability
If microcapsules are designed for stability in challenging bases, then reliability is improved, but olfactive performance and active ingredient delivery deteriorate
Solution Approach 1:
The patent optimizes the shell composition parameters by controlling the types and ratios of amino compounds used in polyamide formation. This allows the shell to maintain chemical stability against surfactants while preserving permeability properties that enable effective delivery of perfume and other active ingredients
Solution Approach 2:
The patent creates different functional zones within the shell structure - the polyamide provides chemical resistance in the external environment, while the core-shell architecture maintains controlled permeability for active ingredient delivery. The stabilizer addition further enhances local stability without compromising overall delivery performance
3Device complexity
If single amino compound is used in microcapsule preparation, then process complexity is reduced, but stability in surfactant-containing bases deteriorates
Solution Approach 1:
The patent combines multiple amino compounds in the polyamide shell formation process to achieve synergistic effects. The combination of different amino compounds provides enhanced chemical resistance to surfactants while maintaining manageable process complexity through sequential addition and standard curing procedures
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 process results in microcapsules with enhanced stability in challenging bases, ensuring sustained release of the encapsulated perfume, maintaining olfactive performance.
Implementation Method 1
reacting an acyl chloride with two amino compounds during the process
Implementation Method 2
wherein a stabilizer is added in the oil phase and/or in the water phase
Implementation Method 3
Dispersing the oil phase obtained in step a) into a water phase comprising a first amino-compound to form an oil-in water emulsion
Data Source
AI summary
Described herein are a new process for the preparation of polyamide microcapsules, as well as such polyamide microcapsules. Further described are perfuming compositions and consumer products including such capsules, in particular perfumed consumer products in the form of home care or personal care products.