Core-Shell Microcapsules for Surfactant-Stable Fragrance Delivery

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Solution Overview

Problem

The perfumery industry faces challenges with the rapid loss of olfactive benefit due to the volatility of odoriferous compounds, particularly top-notes, and the instability of microcapsules in aggressive surfactant-based consumer products.

Innovation Solution

A process for preparing core-shell microcapsules by reacting a monomer with modified starch in the presence of chitosan during interfacial polymerization, using a limited amount of monomer to enhance stability and delivery of active ingredients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If microcapsules are used to protect and release volatile odoriferous compounds, then olfactive performance is improved, but stability in aggressive surfactant-based consumer products deteriorates

Engineering Contradiction:
Improveolfactive performanceVSAvoidstability in aggressive surfactant-based consumer products
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention uses a composite shell structure made of polyurea or polyurethane formed by interfacial polymerization between a polyisocyanate monomer and a polyol containing hydrophilic groups. This composite material provides both the protective encapsulation needed for olfactive performance and the chemical resistance required for stability in aggressive surfactant-based consumer products.

Inventive Principle:
Principle #40Composite materials

2Duration of action of moving object

If polyurea and polyurethane-based microcapsules are used, then long lasting olfactory effect is achieved, but stability in challenging bases with high levels of aggressive surfactant detergents deteriorates

Engineering Contradiction:
Improvelong lasting olfactory effectVSAvoidstability in challenging bases
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The invention modifies the chemical composition parameters of the shell material by incorporating polyols with specific hydrophilic groups (such as carboxylic acid, hydroxyl, or amine groups) into the polyurea or polyurethane matrix. This parameter change enhances the shell's resistance to aggressive surfactants while maintaining the prolonged release characteristics necessary for long-lasting olfactory effect.

Inventive Principle:
Principle #35Parameter changes

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 improved stability in challenging bases and effective delivery of active ingredients, maintaining olfactive performance.

Implementation Method 1

reacting a monomer with modified starch in presence of chitosan during the interfacial polymerization

Methodology Applied
Scientific EffectInterfacial polymerization: Chemical Bonding

Implementation Method 2

the specific combination between chitosan and modified starch allowed obtaining microcapsules with the desired stability in challenging bases

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 3

reacting a monomer with modified starch during the interfacial polymerization

Methodology Applied
Scientific EffectPolymerization: Chemical Bonding

Data Source

PatentUS20260097380A1Process for the preparation of microcapsules
Publication Date: 2026.04.09 FIRMENICH SA

AI summary

Described herein are a new process for the preparation of microcapsules, and microcapsules obtainable by this process. Perfuming compositions and consumer products including the microcapsules, in particular perfumed consumer products in the form of home care or personal care products, are also described.