Non-spherical Polyurea Microcapsule Stability

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Solution Overview

Problem

Existing microcapsules for delivering benefit agents, such as perfumes, face challenges in deposition efficiency and stability, particularly in the presence of surfactants, leading to aggregation and reduced effectiveness on substrates like textiles and hair.

Innovation Solution

Development of non-spherical microcapsules with a polyurea shell comprising nanoparticles of 10 to 300 nm diameter, which improves dispersion and stability in surfactant-containing products, and optionally incorporating a deposition aid on the surface for enhanced deposition efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional spherical microcapsules are used, then the microcapsules can be easily manufactured, but they aggregate due to surface interaction and show reduced stability in surfactant-containing products

Engineering Contradiction:
Improveease of manufactureVSAvoidstability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by changing the microcapsule shape from spherical to non-spherical (rod-like, ellipsoid-like, or other non-spherical shapes). This shape modification reduces surface interaction between microcapsules, preventing aggregation and improving stability in surfactant-containing products while maintaining manufacturability through emulsion-based preparation methods

Inventive Principle:
Principle #4Asymmetry

2Productivity

If deposition aids are used to improve deposition efficiency, then the deposition efficiency improves, but the product complexity increases and may cause stability issues

Engineering Contradiction:
Improvedeposition efficiencyVSAvoidproduct complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies self-service by designing the microcapsule shell itself to possess deposition-promoting properties. The shell comprises specific polymers (acrylamide, acrylic acid, vinyl acetate, or their copolymers) that inherently enhance deposition onto substrates without requiring additional deposition aid components, thus improving deposition efficiency while maintaining product simplicity

Inventive Principle:
Principle #25Self-service

3Reliability

If non-spherical microcapsules are used, then the dispersion and stability in surfactant-containing products improves, but the manufacturing precision requirements increase

Engineering Contradiction:
ImprovestabilityVSAvoidmanufacturing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the emulsion preparation parameters to control microcapsule shape formation. By adjusting emulsification conditions, polymerization parameters, and component ratios during manufacturing, non-spherical shapes are achieved with consistent properties, meeting precision requirements while maintaining improved stability and dispersion characteristics

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 non-spherical microcapsules with a polyurea shell demonstrate improved dispersion and stability in surfactant-containing products, maintaining effectiveness and reducing aggregation, thereby enhancing the deposition efficiency of benefit agents like fragrances on various substrates.

Implementation Method 1

a shell comprising nanoparticles having a diameter of 10 to 300 nm and polyurea

Methodology Applied
Scientific EffectSteric stabilization:

Implementation Method 2

the microcapsules are well dispersed and capable of being stable in the presence of surfactant

Methodology Applied
Scientific EffectElectrostatic repulsion:

Implementation Method 3

the microcapsules may aggregate due to the surface interaction of microcapsules when they are prepared

Methodology Applied
Scientific EffectSurface interaction: Van der Waals Force

Implementation Method 4

optionally incorporating a deposition aid on the surface for enhanced deposition efficiency

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11471386B2Non-spherical microcapsule
Publication Date: 2022.10.18 CONOPCO INC

AI summary

Disclosed is a non-spherical microcapsule comprising a core comprising a benefit agent, and a shell comprising nanoparticles having a diameter of 10 to 300 nm and polyurea.