Polymer-Encapsulated TiO2 for Low Sheen Paint Opacity

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Solution Overview

Problem

Low sheen paints with existing matting agents face issues of uncontrolled light scattering, graying, loss of film integrity, and burnish resistance, while also lacking effective opacity and color intensity.

Innovation Solution

An aqueous paint composition comprising 11-35% polymeric duller particles and 25-70% titanium dioxide particles, where 50-100% of the titanium dioxide particles are encapsulated by polymer shells, providing controlled gloss and opacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If matting agents (dullers) are added to reduce gloss, then gloss control is improved, but light scattering increases causing graying and loss of color intensity

Engineering Contradiction:
Improvegloss controlVSAvoidlight scattering
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The patent encapsulates titanium dioxide particles within polymeric particle shells, creating a nested structure where one particle type is contained within another. This nesting allows the TiO2 to provide opacity while the polymeric shell controls gloss, preventing uncontrolled light scattering that would cause graying.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent creates a composite particle system combining inorganic titanium dioxide particles with organic polymeric particles. This composite structure integrates the high opacity of TiO2 with the gloss-controlling properties of the polymeric shell, achieving both opacity and controlled sheen without the harmful light scattering effects of conventional dullers.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If duller particles are added to control gloss, then gloss reduction is achieved, but film integrity is disrupted leading to loss of water and abrasion resistance

Engineering Contradiction:
ImproveglossVSAvoidfilm integrity
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The composite structure of polymeric shells encapsulating TiO2 particles creates a more compatible interface with the paint film matrix. The polymeric material integrates better with organic binders than inorganic dullers, maintaining film integrity while providing gloss control.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies gloss control functionality at the particle level through the polymeric shell, allowing the bulk film matrix to maintain its integrity and protective properties. The local modification of particle surfaces with polymeric material prevents disruption of the overall film structure.

Inventive Principle:
Principle #3Local quality

3Illumination intensity

If conventional dullers are used to reduce gloss, then sheen control is improved, but burnish resistance is lost due to polishing after rubbing

Engineering Contradiction:
ImprovesheenVSAvoidburnish resistance
Core Design Contradiction:
Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The composite particle with polymeric shell provides a more durable surface that resists polishing. The polymeric material in the shell can be formulated to have appropriate hardness and friction characteristics that prevent burnish, maintaining gloss control over time.

Inventive Principle:
Principle #40Composite materials

4Quantity of substance

If titanium dioxide particles are added for opacity, then opacity is improved, but gloss control is reduced due to light scattering

Engineering Contradiction:
ImproveopacityVSAvoidgloss control
Core Design Contradiction:
Quantity of substanceVSIllumination intensity

Solution Approach 1:

By nesting TiO2 particles within polymeric shells, the patent achieves a separation of functions: the TiO2 core provides opacity through light scattering, while the polymeric shell provides gloss control through surface roughness. The nested structure prevents the uncontrolled light scattering that would otherwise compromise gloss.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 paint composition achieves controlled gloss, enhanced opacity, and improved stain resistance, maintaining film integrity and preventing burnish, while maintaining color intensity.

Implementation Method 1

matting agents, also known as dullers... function by roughening the surface of the film

Methodology Applied
Scientific EffectSurface roughening:

Implementation Method 2

Such uncontrolled interaction of light with the duller particles can cause graying, haziness, cloudiness, loss of color intensity

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 3

from 50% to 100% of the titanium dioxide particles are encapsulated by (co)polymeric particles

Methodology Applied
Scientific EffectEncapsulation: Physical Containment

Data Source

PatentUS11498992B2Low sheen paint composition with effective opacity
Publication Date: 2022.11.15 ROHM & HAAS CO

AI summary

The present invention provides an aqueous paint composition comprising by dry weight based on total dry weight of the pigment composition, from 11% to 35% of a polymeric duller of (co)polymeric particles having an average diameter of from 1 to 20 μm, and from 25% to 70% of titanium dioxide particles; wherein from 50% to 100% of the titanium dioxide particles are encapsulated by polymer shell of (co)polymeric particles.