Polyamide Microcapsule Shell Stability in Surfactant Bases

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Solution Overview

Problem

The perfumery industry faces challenges in maintaining the stability of odoriferous compounds due to their volatility, particularly 'top-notes,' which require effective delivery systems like microcapsules that can withstand aggressive surfactant detergents in personal and household cleansers without degrading.

Innovation Solution

A process for preparing polyamide core-shell microcapsules by reacting an acyl chloride with an amino-compound through interfacial polymerization, forming a stable oil-in-water emulsion, and curing to create a slurry that encapsulates hydrophobic materials like perfumes, ensuring stability in challenging bases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If polyurea and polyurethane-based microcapsules are used for long-lasting olfactory effect, then olfactory performance is improved, but stability in challenging bases with aggressive surfactant detergents deteriorates

Engineering Contradiction:
Improveolfactory effect durationVSAvoidstability in challenging bases
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the microcapsule shell by using polyamide formed from acyl chloride and amino compound, replacing conventional polyurea/polyurethane compositions. This parameter change in material chemistry provides both durability and resistance to aggressive surfactant detergents in challenging bases

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite microcapsule structure with a polyamide shell that combines the desirable properties of durability and surfactant resistance. The specific composite formulation using acyl chloride and amino compound produces a shell material that maintains structural integrity in challenging bases while providing long-lasting olfactory delivery

Inventive Principle:
Principle #40Composite materials

2Reliability

If microcapsules are designed for stability in aggressive surfactant detergents, then stability in challenging bases is improved, but hydrophobic material delivery performance deteriorates

Engineering Contradiction:
Improvestability in challenging basesVSAvoidhydrophobic material delivery
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention applies local quality by creating a polyamide shell with specific localized properties that balance stability and delivery. The shell composition is tailored to provide surfactant resistance while maintaining appropriate permeability and structural characteristics for effective hydrophobic material delivery to the fragrance base

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes delivery performance by adjusting parameters of the polyamide shell formation through controlled interfacial polymerization. The curing step and specific monomer ratios are tuned to create a shell with optimal density and porosity characteristics that enable effective fragrance delivery while maintaining stability

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 produces microcapsules that provide a long-lasting olfactory effect and maintain stability in consumer product bases, effectively delivering hydrophobic materials like perfumes, enhancing the perfumery performance and longevity.

Implementation Method 1

reacting an acyl chloride with an amino-compound through interfacial polymerization

Methodology Applied
Scientific EffectInterfacial polymerization: Chemical Bonding

Implementation Method 2

Dispersing the oil phase obtained in step a) into a water phase comprising optionally an amino compound A or a base to form an oil-in-water emulsion

Methodology Applied
Scientific EffectEmulsion: Emulsion

Data Source

PatentUS20220055006A1Process for preparing polyamide microcapsules
Publication Date: 2022.02.24 FIRMENICH SA

AI summary

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