Color-Changing (Meth)acrylate Compositions for Cure Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing acrylate polymer compositions lack reliable methods to indicate curing degree, suffer from dye-induced curing inhibition, and have unstable color changes, making it difficult to ensure proper coverage and detect uncured/cured films non-destructively.

Innovation Solution

A color changeable (meth)acrylate composition comprising a (meth)acrylate monomer, (meth)acrylate terminated resin, photoinitiator, and benzopyranone derivatives as dye, which provides noticeable color change and stable chromaticity before and after curing, enabling non-destructive detection of curing degree and film presence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If plenty of dye is added to achieve good indication property, then color change visibility is improved, but curing inhibition increases

Engineering Contradiction:

Improvecolor change visibilityVSAvoidcuring inhibition

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the dye by selecting specific benzopyranone derivatives with particular molecular structures and substituents. This allows achieving good color change visibility while maintaining reliable curing performance, as the specific dye molecules are designed to not interfere with the photopolymerization process

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a small amount of specifically designed dye (13-150 ppm) that serves its indication function effectively without requiring large quantities. The dye is present in such low concentrations that it does not cause curing inhibition, yet still provides sufficient color change for detection

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Illumination intensity

If anthraquinone and/or xanthene dyes are used to indicate curing, then color change is achieved, but photobleaching occurs making reliable indication unavailable

Engineering Contradiction:

Improvecolor changeVSAvoidphotobleaching

Core Design Contradiction:

Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent replaces unstable dyes (anthraquinone and xanthene) with benzopyranone derivatives that have superior photostability. The new dye class maintains color change capability while resisting photobleaching, providing reliable long-term indication of curing status

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical structure parameter of the dye from anthraquinone/xanthene classes to benzopyranone derivative class. This structural change fundamentally improves photostability while preserving the necessary color change property for curing indication

Inventive Principle:

Principle #35Parameter changes

3Reliability

If no color change indicator is added, then curing inhibition and photobleaching are avoided, but detection of curing degree becomes impossible

Engineering Contradiction:

Improvecuring inhibition avoidanceVSAvoidcuring degree detection

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces a color-changing indicator (benzopyranone derivative) that provides visible color change upon curing, enabling non-destructive detection of curing degree. The dye is specifically selected to change color in the visible range, making curing status easily detectable

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The patent replaces complex mechanical or electrical detection systems with a simple optical color change indicator. The curing status is detected through visual or optical measurement of color change, which is simpler, cheaper, and non-destructive compared to other detection methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 composition achieves strong cured products with noticeable color change, ensuring accurate detection of curing status and film presence, and stable visibility enhancement, facilitating proper coating coverage.

Implementation Method 1

In luminous radiation curing process, the curing speed is usually a function of the luminous energy intensity, the luminous energy density and film thickness

Methodology Applied

Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

However, anthraquinone and/or xanthene dyes exhibit an inherent photobleaching property, and do not therefore provide a reliable indication that curing degree

Methodology Applied

Scientific EffectPhotobleaching: Photo-oxidation

Data Source

PatentUS20250297072A1Color changeable (METH)acrylate compositions and methods of using the same

Publication Date: 2025.09.25 HENKEL KGAA

AI summary

Curable compositions for use in or as adhesives, sealants and/or coatings are disclosed herein. The compositions include a (meth)acrylate monomer, a (meth)acrylate terminated resin, an effective amount of a photoinitiator together with a dye substantially dissolved in the system which imparts good dyeing property in the (meth)acrylate composition. Upon curing, a resultant cured composition has a stable second color and obvious color change. The invention also relates to a method of detecting curing degree of the polymerization of the compositions.