Purified Polyurea Capsules Controlled Release
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Solution Overview
Problem
Polyurea or polyurethane microcapsules have not been effectively applied for release of benefit agents in laundry, washing, cleaning, surface care, and personal care products, where quicker and easier release, and controlled permeability are desired, due to their high mechanical strength and limited application in these fields.
Innovation Solution
A purified polyurea capsule composition is developed by preparing an oil phase with an active material and polyisocyanate, emulsifying it into an aqueous phase containing a polyamine or polyol, adding a cross-linking agent, and curing the mixture, followed by washing to achieve a neutral pH, which results in a composition suitable for personal care products and fine fragrances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyurea or polyurethane microcapsules are used for encapsulation, then mechanical strength and durability are improved, but release speed and ease of application deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the capsule wall by using polyurea formed from polyisocyanate and polyamine, and by controlling the cross-linking density and wall thickness, to achieve a balance between mechanical strength and release speed suitable for personal care applications
Solution Approach 2:
The patent uses composite capsule wall structures combining polyurea with cross-linking agents to create a material that provides both adequate mechanical strength for handling and controlled permeability for fragrance release in laundry and personal care products
2Strength
If polyurea or polyurethane microcapsules are used for encapsulation, then mechanical strength is improved, but capsule wall permeability and controlled release are worsened
Solution Approach 1:
The patent adjusts the permeability parameter by controlling the cross-linking degree and wall composition of the polyurea capsules, enabling tailored release profiles that maintain mechanical integrity while allowing controlled fragrance diffusion for various personal care applications
Solution Approach 2:
The patent creates localized variations in capsule wall properties through controlled cross-linking and wall thickness variations, allowing different regions of the capsule wall to have different permeability characteristics to optimize both strength and controlled release
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 purified polyurea capsules provide a controlled release of active materials, enhancing fragrance intensity and stability, suitable for hydroalcoholic mediums and leave-on personal care applications, with improved consumer benefits and storage stability.
Implementation Method 1
the polycondensation reaction will take place. Thus, the small droplets of the water-immiscible phase will be surrounded by the microcapsule wall formed by polycondensation of the isocyanate and the polyalcohol or polyamine as starting materials
Implementation Method 2
adding at least one cross-linking agent to the fragrance emulsion to form a capsule slurry; curing the capsule slurry
Data Source
AI summary
Purified polyurea capsules that encapsulate active materials for use in personal care, fine fragrance, or deodorant products are provided as are methods for producing the same.