Surface modified microcapsules
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Solution Overview
Problem
Existing microcapsules face issues such as low deposition onto solid surfaces, low olfactory intensity, and low stability, making them unsuitable for applications in consumer products like laundry, washing, and personal care.
Innovation Solution
Chemically modify microcapsules by forming a covalent bond between a deposition agent with reactive groups and the microcapsule wall, using polymers like polyurea or polyethyleneimine, to enhance deposition and olfactory intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional polyurea or polyurethane microcapsules are used, then the microcapsule structure is simple and easy to manufacture, but the deposition onto solid surfaces is low
Solution Approach 1:
The patent modifies the surface properties of microcapsules by changing chemical parameters - specifically by incorporating cationic polymers or surface-modified microcapsules with positive charge. This parameter change enables electrostatic attraction to negatively charged surfaces (skin, hair, fabric), dramatically improving deposition from less than 5% to over 50% on target surfaces.
Solution Approach 2:
The patent creates composite microcapsule structures by combining conventional polyurea/polyurethane core materials with cationic polymer coatings or surface modifications. This composite approach maintains the structural integrity and fragrance delivery function of the original microcapsules while adding surface charge properties for enhanced deposition.
2Quantity of substance
If conventional microcapsules are used, then the manufacturing process is simple, but the olfactory intensity is low
Solution Approach 1:
The patent applies preliminary surface modification to microcapsules during or after the manufacturing process. By pre-coating microcapsules with cationic polymers or incorporating surface-active agents during synthesis, the microcapsules are prepared in advance to have enhanced adhesion and fragrance release properties, achieving high olfactory intensity without requiring complex post-processing.
3Reliability
If conventional microcapsules are used, then the formulation is simple and stable, but the stability on surfaces is low
Solution Approach 1:
The patent changes the surface charge parameter of microcapsules from neutral or negative to positive by incorporating cationic polymers. This parameter change provides electrostatic stabilization on surfaces, preventing microcapsules from detaching or aggregating, thereby significantly improving stability on skin, hair, and fabric surfaces.
4Reliability
If grafting microcapsules onto fibers is done as in U.S. Pat. No. 8,586,143, then permanent attachment to textiles is achieved, but the method is unsuitable for skin and hair deposition applications
Solution Approach 1:
The patent develops a universal deposition mechanism based on electrostatic attraction that works across multiple surface types (skin, hair, fabric, hard surfaces) rather than being specific to textile fibers only. The cationic surface modification provides a general-purpose adhesion strategy applicable to wash-off and leave-on consumer products for various applications.
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 surface-modified microcapsules exhibit high deposition and stability on surfaces like skin, hair, and fabric, suitable for various consumer products, including shampoos, conditioners, and fabric softeners, with improved fragrance release.
Implementation Method 1
forming a covalent bond between the primary or secondary amine group and the reactive group to graft the deposition agent to the encapsulating polymer on the outer surface of the microcapsule wall
Data Source
AI summary
A method of preparing a microcapsule composition include the steps of: (a) providing a microcapsule formed of an encapsulating polymer having a primary or secondary amine group, (b) providing a deposition agent having a reactive group, and (c) forming a covalent bond between the primary or secondary amine group and the reactive group to graft the deposition agent to the encapsulating polymer. Also disclosed are consumer products containing these microcapsules.