Polyurea Microcapsule Wall Composition for Fragrance Stability
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Solution Overview
Problem
The perfumery industry faces challenges in maintaining the stability and olfactive performance of polyurea microcapsules, especially when incorporated into surfactant-based products like detergents and fabric softeners, which are aggressive environments that lead to rapid loss of fragrance due to volatility, particularly of 'top-notes'.
Innovation Solution
A process involving a mixture of aliphatic and aromatic polyisocyanates in specific molar ratios, combined with a polyamine, to form a polyurea wall around perfumes, enhancing stability and controlled release in consumer products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If polyurea microcapsules are incorporated into surfactant-based products like detergents and fabric softeners, then the product functionality is enhanced, but the stability of the microcapsules deteriorates due to aggressive conditions
Solution Approach 1:
The patent changes the chemical composition parameters of the polyurea wall by using specific ratios of aliphatic to aromatic polyisocyanates (from 90:10 to 10:90), which modifies the wall's properties to resist surfactant aggression while maintaining encapsulation functionality
Solution Approach 2:
The patent creates a composite polyurea wall structure combining two different polyisocyanate types (aliphatic and aromatic) with complementary properties, where the aliphatic component provides stability and the aromatic component provides strength and controlled release characteristics
2Reliability
If the polyurea wall is made more stable to resist surfactants, then the storage stability improves, but the olfactive performance deteriorates due to reduced fragrance release
Solution Approach 1:
The patent adjusts the polyisocyanate composition ratio to optimize the balance between wall stability and fragrance release, where higher aromatic content enhances stability while maintaining adequate olfactive performance through controlled diffusion
Solution Approach 2:
The patent creates different functional zones within the polyurea wall structure, where the composite composition provides varying local properties that simultaneously resist surfactant penetration and allow controlled fragrance diffusion to the surface
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 resulting microcapsules exhibit improved stability and prolonged fragrance release, maintaining perfume intensity and longevity even in aggressive product bases, such as detergents and fabric softeners, while maintaining a strong olfactive performance.
Implementation Method 1
Polyurea capsules, formed by polymerisation between a polyisocyanate and a polyamine
Data Source
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AI summary
The present invention relates to a process for producing perfume-containing microcapsules with a polyurea wall that can be used in home or personal care products, as well as to the microcapsules themselves and consumer products comprising these microcapsules. The process of the invention uses a combination of aromatic and aliphatic polyisocyanates in specific relative concentrations.