Polyurea Capsule Stability via Amine Stabilizers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyurea or polyurethane capsules face issues such as low olfactory intensity, low stability, and high toxicity, and have challenges with deposition to target surfaces, particularly in applications like laundry, cleaning, and personal care where quicker and easier release or less mechanical strength is desired.
Innovation Solution
A capsule composition is developed with an oil core containing a fragrance, flavor, or malodor counteractant, encapsulated by a polyurea or polyurethane wall, stabilized with a multi-functional amine or amino acid, and optionally including a polymer mixture for enhanced stability and controlled release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyurea or polyurethane capsules are used for rugged applications requiring high mechanical strength, then capsule strength is improved, but stability and olfactory intensity deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the capsule wall by using polyisocyanate and polyol/polyamine in specific molar ratios (1:1 to 4:1), and by controlling the molecular weight and functionality of the polymers used. This optimization of parameters achieves both high strength and improved stability, resolving the contradiction between strength and reliability.
Solution Approach 2:
The patent creates composite capsule wall materials by combining polyisocyanate with polyol or polyamine to form polyurethane or polyurea polymers. The composite structure integrates the strength properties of polyisocyanate with the stability properties of polyol/polyamine, achieving both high strength and reliability simultaneously.
2Strength
If polyurea or polyurethane capsules are used for rugged applications, then mechanical strength is improved, but olfactory intensity deteriorates
Solution Approach 1:
The patent optimizes the wall thickness and porosity parameters of the capsule by controlling the polymerization conditions and monomer ratios. This allows the capsule wall to be thin enough to permit fragrance diffusion (maintaining olfactory intensity) while still providing sufficient mechanical strength through the optimized polymer composition.
Solution Approach 2:
The patent creates porous capsule wall structures that allow fragrance molecules to diffuse through the wall while maintaining mechanical integrity. The porous structure increases the surface area for fragrance release, improving olfactory intensity, while the polymer matrix maintains the necessary strength.
3Strength
If polyurea or polyurethane capsules are used for rugged applications, then mechanical strength is improved, but toxicity increases
Solution Approach 1:
The patent changes the chemical parameters by selecting specific polyisocyanates and polyols/polyamines that result in lower toxicity upon degradation. The controlled polymerization and specific monomer selection produce capsule walls that are mechanically strong but less toxic to the environment and human health.
Solution Approach 2:
The patent converts the potential harm of polyisocyanate residues into a benefit by using excess polyol or polyamine to react with and neutralize unreacted isocyanate groups. This transforms a harmful residual into a stable, less toxic end group, reducing overall toxicity while maintaining strength.
4Strength
If polyurea or polyurethane capsules are used for rugged applications, then mechanical strength is improved, but deposition to target surfaces deteriorates
Solution Approach 1:
The patent changes the surface property parameters of the capsule by adjusting the polymer composition and adding surface-active agents. This modifies the surface energy and wettability of the capsule, enabling better deposition on target surfaces like fabrics while maintaining the core mechanical strength through the optimized polymer matrix.
Solution Approach 2:
The patent introduces surface-active intermediaries (surfactants or polymer additives) that mediate between the hydrophobic capsule surface and the target substrate. These intermediaries improve wetting and adhesion properties, facilitating deposition while the core capsule structure maintains its mechanical strength.
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 capsule composition provides improved stability, controlled release, and increased olfactory intensity, making it suitable for various consumer products like fabric softeners, while reducing toxicity and improving deposition on surfaces.
Implementation Method 1
the polycondensation reaction will take place. Thus, the small droplets of the oil phase will be surrounded by the capsule wall formed by polycondensation of the isocyanate and the polyalcohol or polyamine as starting materials.
Implementation Method 2
Suitable emulsifiers are often utilized to aid in the preparation and stabilization of the emulsion.
Data Source
AI summary
A capsule composition containing a capsule and a stabilizing agent. The capsule has an oil core containing an active material and a capsule wall encapsulating the oil core. The active material is a fragrance, a flavor, a malodor counteractant, or a combination thereof. The wall is formed of polyurea or polyurethane. The capsule composition has 20 ppm or greater of the stabilizing agent, which is a multi-functional amine, an amino acid, a polymer mixture, or a combination thereof. Also disclosed is a consumer product containing this capsule composition.