Polymer-Encapsulated Opacifier Dispersion for Stable Aqueous Opacity

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Solution Overview

Problem

Conventional opacifiers used in aqueous personal care compositions face issues with stability, compatibility, and water content, affecting the formulation's functionality and aesthetics, particularly in concentrated detergents or unit dose packets.

Innovation Solution

A composite opacifier dispersion is developed, comprising metal oxide particles encapsulated by a polycaprolactone polymer, with specific size ranges, to provide stable opacification comparable to styrene acrylic copolymers while reducing water content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional mixing methods are used to disperse opacifiers in plastic resins, then the mixing process is simple, but the dispersion is inconsistent and contains agglomerates

Engineering Contradiction:
Improvedispersion consistencyVSAvoidmixing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mixing process is segmented into multiple stages: pre-mixing opacifiers with compatible polymers to create master batches, then incorporating these master batches into the final plastic resin. This multi-stage segmentation allows each stage to optimize for specific dispersion requirements, eliminating agglomerates while maintaining process manageability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Opacifiers are pre-dispersed in compatible polymers to create master batches before being incorporated into the final plastic resin. This preliminary action ensures uniform distribution at a smaller scale, preventing agglomerate formation in the final product and achieving consistent dispersion.

Inventive Principle:
Principle #10Preliminary action

2Illumination intensity

If opacifiers are added to plastic resins, then opacity is improved, but yellowing occurs over time

Engineering Contradiction:
ImproveopacityVSAvoidcolor stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the opacifier system by using specific combinations of titanium dioxide, zinc oxide, and zinc sulfide in controlled ratios. These parameter changes optimize both opacity and color stability, preventing yellowing while maintaining effective light scattering properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

A composite opacifier system is created using multiple materials (titanium dioxide, zinc oxide, zinc sulfide) in specific combinations. This composite approach balances the high opacity of titanium dioxide with the color stability and UV resistance of zinc oxide and zinc sulfide, achieving both opacity and resistance to yellowing simultaneously.

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If titanium dioxide is used as opacifier, then opacity is high, but cost increases

Engineering Contradiction:
ImproveopacityVSAvoidmaterial cost
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent applies different opacifier materials to different functional requirements: titanium dioxide provides core opacity, while zinc oxide and zinc sulfide address color stability and UV resistance. This local quality assignment optimizes performance while controlling costs by not overusing expensive titanium dioxide beyond what is necessary for opacity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite opacifier system replaces some expensive titanium dioxide with more cost-effective alternatives like zinc oxide and zinc sulfide while maintaining or improving overall performance. This composite approach reduces material costs through strategic substitution of less expensive materials that provide complementary functions.

Inventive Principle:
Principle #40Composite materials

4Illumination intensity

If opacifiers are dispersed in plastic resins, then opacity is achieved, but processing difficulties arise

Engineering Contradiction:
ImproveopacityVSAvoidprocessing ease
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

Opacifiers are pre-dispersed in compatible polymers to create master batches before final compounding. This preliminary dispersion action ensures uniform distribution and reduces processing difficulties in the final product, as the opacifiers are already properly distributed and compatible with the resin matrix.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Compatible polymers serve as intermediaries between the opacifiers and the final plastic resin. These intermediary materials facilitate proper dispersion and compatibility, reducing processing difficulties by ensuring smooth integration of opacifiers into the final product matrix.

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 composite opacifier dispersion enhances the sustainability and aesthetic appeal of personal care products by maintaining formulation stability and reducing water usage, offering uniform opacity without interfering with other ingredients.

Implementation Method 1

A method for making a dispersion of an opacifier in a plastic resin is provided

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP4404905B1Composite opacifier dispersion
Publication Date: 2026.05.06 DOW GLOBAL TECHNOLOGIES LLC

AI summary

A composite opacifier dispersion is provided, comprising: a dispersion medium; a processing surfactant; and a plurality of composite opacifier particles, wherein the composite opacifier particles comprise metal oxide particles that are partially or completely encapsulated by a polycaprolactone polymer; wherein the metal oxide particles are selected from the group consisting of zinc oxide, titanium oxide and mixtures thereof; wherein the metal oxide particles have a z average particle size of > 100 nm as measured by dynamic light scattering; and wherein the composite opacifier particles have a z average particle size of > 150 nm to 2, 500 nm as measured by dynamic light scattering.