Multi-Capsule Fragrance Delivery System for Surfactant Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fragrance materials in consumer products face premature release due to permeable capsule shells, especially when stored in aqueous bases with surfactants, leading to reduced effectiveness and increased costs, as existing encapsulation technologies struggle to maintain stability and desirable release profiles.
Innovation Solution
A capsule delivery system comprising multiple types of microcapsules with different wall materials, curing temperatures, and heating rates to enhance retention and stability, including melamine-formaldehyde and urea-formaldehyde capsules, which are designed to maintain fragrance release profiles and stability in consumer products for extended periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single type of capsule shell is used to encapsulate fragrance materials, then the capsule provides basic protection and delivery, but the fragrance is prematurely released when stored in aqueous bases with surfactants
Solution Approach 1:
The invention divides the capsule population into multiple segments with different wall compositions and properties. Each capsule type is formulated with specific wall materials (e.g., melamine-formaldehyde, polyurea, polyacrylamide/acrylate copolymers) and curing conditions to achieve different release profiles, collectively providing stable fragrance retention in surfactant-containing bases
Solution Approach 2:
The invention uses composite capsule walls made from multiple polymer materials with complementary properties. For example, melamine-formaldehyde provides structural integrity and chemical resistance, while polyacrylamide/acrylate copolymers provide controlled permeability. These composite structures resist surfactant penetration while allowing timed fragrance release
2Ease of manufacture
If conventional capsule shells are used in surfactant-containing bases, then the product can be manufactured with standard materials, but the active material is diffused from the core over time through leaching
Solution Approach 1:
The invention modifies key parameters of capsule wall formation, including curing temperature (e.g., 70-90°C for polyacrylamide/acrylate copolymers, higher temperatures for melamine-formaldehyde), curing time, and wall composition ratios. These parameter changes create cross-linked polymer networks with reduced surfactant permeability while maintaining manufacturability through established encapsulation processes
Solution Approach 2:
The capsule wall acts as an intermediary barrier between the fragrance core and the surfactant-containing base. The polymer matrix, particularly when cross-linked, provides a selective interface that allows controlled fragrance diffusion while blocking surfactant penetration, preventing leaching of active material
3Reliability
If higher concentrations of microcapsules are used to compensate for premature release, then fragrance delivery can be maintained initially, but product costs increase
Solution Approach 1:
The invention creates a dynamic release system where different capsule types release fragrance at different rates. Fast-release capsules provide initial fragrance impact, while slow-release capsules with enhanced surfactant resistance provide sustained delivery. This dynamic multi-rate release maintains effective fragrance levels throughout product use without requiring excessive microcapsule concentrations
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 system effectively retains fragrance materials for longer periods, maintaining stability and desirable release profiles even in surfactant-containing bases, reducing the need for higher microcapsule concentrations and extending product shelf life while ensuring consistent sensory performance.
Implementation Method 1
the capsule shell is somewhat permeable to the core contents when stored under certain conditions
Implementation Method 2
The overall leaching mechanism may be viewed as a diffusion process, with transfer occurring from the capsule core to the aqueous media
Implementation Method 3
The polymeric material is used to protect the fragrance material from evaporation, reaction, oxidation or otherwise dissipating prior to use
Data Source
AI summary
A capsule delivery system. The system has a first capsule containing a first capsule wall encapsulating a first active material and a second capsule containing a second capsule wall encapsulating a second active material. The first and second capsules differ in their wall materials, amounts of wall materials, ratios of wall materials, core modifiers, scavengers, active materials, curing temperatures, heating rates, curing times, or a combination thereof. Also provided is a consumer product containing this capsule delivery system.