Cationic Polyurea Microcapsules for Perfume Retention
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Solution Overview
Problem
Existing perfume delivery systems, such as multicore capsules, fail to effectively retain and stabilize perfumes due to insufficient cross-linking and stability in consumer product bases, particularly in cationic environments.
Innovation Solution
Development of cationic polyurea or polyurethane microcapsules with a tightly cross-linked structure, capable of encapsulating both hydrophilic and hydrophobic ingredients, featuring permanent cationic charges covalently linked to the capsule wall, which enhances retention and stability in various consumer product bases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multicore capsules with coacervate complex walls are used, then capsule flexibility is improved, but perfume retention becomes insufficient
Solution Approach 1:
The invention uses a composite capsule wall structure combining polyurea or polyurethane base material with grafted cationic functional groups. This composite approach provides both the mechanical flexibility of polymer matrices and the enhanced perfume retention through tight cross-linking and electrostatic interactions, resolving the contradiction between flexibility and retention.
Solution Approach 2:
The invention modifies the chemical parameters of the capsule wall by introducing permanent cationic charges through grafting functional groups (such as quaternary ammonium groups) onto the polyurea/polyurethane matrix. This parameter change enables tight cross-linking and improves perfume retention while maintaining capsule flexibility through controlled grafting density and polymer structure.
2Ease of manufacture
If capsules with non-cationic walls are used, then manufacturing simplicity is maintained, but dispersion and deposition performance deteriorate
Solution Approach 1:
The invention changes the surface charge parameter of the capsule wall by grafting cationic functional groups onto the polyurea or polyurethane matrix. This modification improves dispersion in aqueous media and deposition on negatively charged surfaces (such as skin or textiles) without fundamentally altering the manufacturing process, as the grafting occurs during the existing capsule formation steps.
3Stability of the object's composition
If capsules without permanent cationic charges are used, then chemical stability is maintained, but stability in chemically aggressive environments deteriorates
Solution Approach 1:
The invention creates a composite wall structure where cationic functional groups are covalently grafted onto the polyurea/polyurethane matrix. This composite structure provides chemical stability through the robust polymer backbone while the grafted cationic groups offer enhanced stability in chemically aggressive environments through strong electrostatic interactions and resistance to anionic compounds.
Solution Approach 2:
The invention incorporates permanent cationic charges into the capsule wall structure during the manufacturing process, before the capsules are exposed to chemically aggressive environments. This preliminary action ensures that the cationic groups are already in place to provide stability and protection when the capsules encounter detergents, fabric softeners, or other challenging formulations.
4Ease of manufacture
If loosely cross-linked capsule walls are used, then manufacturing ease is improved, but perfume retention becomes insufficient
Solution Approach 1:
The invention changes the cross-linking density parameter of the capsule wall by introducing permanent cationic groups that form tight cross-linked structures through electrostatic interactions and covalent bonding. This increases perfume retention while maintaining manufacturing ease, as the tight cross-linking occurs automatically during the capsule formation process through the chemistry of the grafted functional groups.
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 microcapsules provide improved deposition and long-lasting fragrance release, maintaining perfume stability and intensity even in chemically aggressive environments, such as detergents and fabric softeners, with controlled release characteristics.
Implementation Method 1
reacting at least one polyisocyanate with at least one organic compound comprising a permanent quaternary ammonium group and a primary amine or hydroxyl group
Implementation Method 2
tightly cross-linked polyurea or polyurethane wall
Implementation Method 3
microcapsules having an aqueous inner phase and an oily inner phase
Implementation Method 4
very efficient in retaining perfuming ingredients
Implementation Method 5
bearing permanent cationic charges with a high charge density and therefore of having an improved deposition on the surface on which they are applied
Implementation Method 6
form an emulsion of an aqueous phase in the product obtained by such reaction
Implementation Method 7
the product resulting from said reaction has a structure of a tenside bearing permanent cationic charges
Data Source
AI summary
The present invention relates to a process for producing perfume-containing microcapsules having both an aqueous inner phase and an oily inner phase, which can be used in home or personal care products, as well as to the process for producing these microcapsules and the consumer products comprising them.