Polyurea Microcapsule Wall Tuning for Controlled Fragrance Release
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Solution Overview
Problem
Current polyurea and polyurethane microcapsules are not suitable for applications in laundry, personal care, and cleaning products due to their high mechanical strength and complex release mechanisms, which are not desirable for quicker and easier release of benefit agents on surfaces.
Innovation Solution
The development of polyurea or polyurethane microcapsules with specific formulations using isocyanates, polyamines, and surfactants to create encapsulated fragrances with controlled release profiles, suitable for use in rinse-off products such as shampoos, detergents, and conditioners, where the wall polymer level and fragrance oil composition are optimized for enhanced stability and fragrance delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyurea or polyurethane microcapsules are used for rugged applications with high mechanical strength, then the microcapsules can protect agrochemicals and provide slow time-release, but they are not suitable for laundry and personal care applications where quicker and easier release is desired
Solution Approach 1:
The patent modifies the capsule wall composition by using specific isocyanate indices (1.7-2.3) and controlling the ratio of polyfunctional alcohol to diamine (0.8-1.2), along with adding chain extenders and crosslinking agents, to create walls with optimized mechanical properties that allow easier release while maintaining sufficient strength for consumer product applications
2Duration of action of stationary object
If polyurea or polyurethane microcapsules are used for slow time-release applications, then the agents are released over an extended period, but the release mechanism is too complex and slow for laundry and personal care products
Solution Approach 1:
The patent optimizes the polycondensation reaction parameters including isocyanate index (1.7-2.3), molar ratios of reactants (0.8-1.2), and adds chain extenders and crosslinking agents to create capsule walls with controlled permeability that enable faster release kinetics suitable for rinse-off products while maintaining adequate duration for consumer benefit
3Reliability
If polyurea or polyurethane microcapsules are used for rugged applications, then the microcapsules have high mechanical strength and slow release properties, but they lack the precise control over capsule wall permeability needed for desired release profiles in consumer products
Solution Approach 1:
The patent creates composite capsule walls by combining polyfunctional isocyanates with polyfunctional alcohols and diamines, adding chain extenders and crosslinking agents to form a multi-component polymer system that provides both mechanical integrity and tunable permeability properties for controlled release in consumer products
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 encapsulated fragrances demonstrate improved stability and fragrance delivery, with increased intensity and longevity on surfaces, even after extended storage, offering enhanced consumer benefits without mechanical perturbation.
Implementation Method 1
the polycondensation reaction will take place. Thus, the small droplets of the water-immiscible phase will be surrounded by the microcapsule 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 of, and to stabilise, the emulsion
Implementation Method 3
Suitable emulsifiers are often utilized to aid in the preparation of, and to stabilise, the emulsion
Data Source
AI summary
The invention relates to products for washing and cleaning and/or care and protection of animate or inanimate surfaces that comprise micro-encapsulated benefit agents. The invention also relates to polyurethane and polyurea microcapsules.