Polymeric Capsules With Uniform Fracture Strength for Active Retention

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Solution Overview

Problem

Existing encapsulation technologies face challenges in maintaining complete retention of the encapsulated active within the capsule throughout the supply chain until a controlled or triggered release is applied, leading to inefficiencies and potential loss of the core material.

Innovation Solution

The development of capsules with a polymeric shell surrounding a core, characterized by a narrow distribution of capsule size and fracture strength, achieved through a membrane emulsification process that forms droplets with a polymer precursor migrating to the interface to form the shell, resulting in a high core-to-shell ratio and controlled release properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional encapsulation methods are used, then the capsule can be formed with a polymeric shell, but the capsule size distribution becomes broad and fracture strength varies widely, leading to incomplete retention of the encapsulated active throughout the supply chain

Engineering Contradiction:
Improveretention of encapsulated activeVSAvoidcapsule size distribution and fracture strength uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling the membrane emulsification process parameters (flow rate, pressure differential, membrane pore size) to produce capsules with narrow size distribution (CV < 30%) and uniform fracture strength (delta fracture strength percentage within 15-230%). This ensures reliable retention of the encapsulated active throughout the supply chain while maintaining manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional mechanical encapsulation methods with a membrane emulsification process that uses controlled fluid dynamics and pressure differentials to form capsules with uniform properties. This substitution enables precise control over capsule size distribution and fracture strength, resolving the contradiction between reliability and manufacturing precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If the polymeric shell is made thicker to improve mechanical resistance, then the capsule strength increases, but the amount of polymeric material needed increases, raising costs and environmental impact

Engineering Contradiction:
Improvemechanical resistance of capsuleVSAvoidamount of polymeric material
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent optimizes the shell thickness parameter to achieve the minimum necessary for mechanical resistance while minimizing polymeric material usage. By controlling the membrane emulsification process and polymer precursor migration, the patent creates shells with uniform thickness that provide adequate strength without excessive material consumption, thereby reducing costs and environmental impact.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures where the polymeric shell is formed through controlled polymerization of precursors that migrate to the interface. This creates an optimized shell composition and structure that maximizes mechanical resistance while minimizing the total amount of polymeric material required, addressing both strength and material efficiency.

Inventive Principle:
Principle #40Composite materials

3Loss of substance

If the polymeric shell is made thinner to reduce material usage, then the amount of polymeric material decreases, but the mechanical resistance and stability of the capsule deteriorates

Engineering Contradiction:
Improveamount of polymeric materialVSAvoidmechanical resistance of capsule
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The patent precisely controls the shell thickness parameter through membrane emulsification to achieve an optimal balance between material efficiency and mechanical resistance. By optimizing process parameters such as flow rate, pressure differential, and membrane properties, the patent creates thin yet sufficiently strong shells that minimize polymeric material usage while maintaining the necessary mechanical resistance and stability.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If the membrane emulsification process is optimized for narrow capsule size distribution, then manufacturing precision improves, but the process complexity and device requirements increase

Engineering Contradiction:
Improvecapsule size distribution uniformityVSAvoidmembrane emulsification process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a membrane as an intermediary component in the emulsification process. This membrane acts as a mediator that controls droplet formation and capsule size distribution through its pore structure and mechanical properties. By using the membrane as an intermediary, the patent achieves narrow size distribution (CV < 30%) without requiring complex multi-stage processing equipment, thus managing device complexity while improving manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 capsules ensure uniform and timely release of the benefit agent, reducing the amount of polymeric material needed, thereby lowering costs and environmental impact while maintaining stability and mechanical resistance.

Implementation Method 1

exposing the dispersion of droplets of disperse phase in the continuous phase under conditions sufficient to initiate polymerization of the polymer precursor within the droplets of disperse phase

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

The polymer precursor becomes insoluble in the disperse phase and migrates to the interface between the disperse phase and the continuous phase

Methodology Applied
Scientific EffectInterface migration:

Implementation Method 3

passing the disperse phase through a plurality of holes in a membrane, from a first side of the membrane to a second side of the membrane and into the continuous phase, while the continuous phase is flowed across the second side of the membrane and the membrane is mechanically moved

Methodology Applied
Scientific EffectMechanical dispersion:

Data Source

PatentEP3955900B1Polymeric capsules
Publication Date: 2025.07.23 PROCTER & GAMBLE CO
  • EP3955900B1 patent drawingFigure 1
  • EP3955900B1 patent drawingFigure 2
  • EP3955900B1 patent drawingFigure 3A~3B

AI summary

A population of capsules can include a plurality of capsules, the capsules can include a core including a benefit agent, and a polymeric shell surrounding the core. The population of capsules can have a delta fracture strength percentage of about 15% to about 230% and a shell thickness of about 20 nm to about 400 nm.