Coating Thickness Indicator Using Color-Changing Dye

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Solution Overview

Problem

Existing surface coatings for metals like aluminum and titanium are costly due to waste generation and difficulty in detecting clear, transparent coatings, making quality assurance inspections challenging.

Innovation Solution

A surface coating composition that includes an alkoxyzirconium aqueous sol, an organosilane coupling agent, and a catalyst with an indicator such as Basic Blue 41, Direct Red 81, or Pyranine dye, which modifies the appearance to facilitate thickness determination and is controllable to demodify, ensuring uniform application and visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If clear transparent coating is applied to metal surface, then protective and adhesive properties are maintained, but difficulty in detecting coating thickness and uniformity increases

Engineering Contradiction:
Improveprotective and adhesive propertiesVSAvoidcoating thickness and uniformity
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies a color-changing principle by incorporating indicators that alter the coating's visual appearance based on coating thickness. The indicator changes color from blue to colorless as coating thickness increases, providing visual feedback for thickness determination and uniformity inspection while maintaining the clear transparent protective coating properties

Inventive Principle:
Principle #32Color changes

2Reliability

If chromate conversion coating is applied to reduce corrosion, then protective properties improve, but waste generation and processing costs increase

Engineering Contradiction:
Improvecorrosion protectionVSAvoidwaste generation
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces expensive chromate conversion coatings with a more economical alternative formulation based on alkoxyzirconium and organosilane that provides equivalent corrosion protection without the environmental waste issues. The indicator system is a temporary, consumable component that serves its detection purpose and then degrades or can be removed, eliminating long-term waste problems

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical composition parameters of the coating formulation, transitioning from chromate-based chemistry to alkoxyzirconium and organosilane-based chemistry. This parameter change maintains the protective function while eliminating the harmful waste generation associated with chromate processing

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If indicator is added to modify coating appearance for thickness detection, then measurement capability improves, but coating complexity increases

Engineering Contradiction:
Improvecoating thickness determinationVSAvoidcoating formulation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an indicator as an intermediary substance that mediates between the clear transparent coating and the inspection process. The indicator temporarily modifies the coating appearance to enable thickness detection, then can be removed or degraded, serving its measurement purpose without permanently complicating the coating system

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies a dynamic approach where the indicator's concentration and visual properties change over time and with coating thickness. The indicator is controllable to demodify the appearance, transitioning from a visible state during inspection to a less visible or colorless state afterward, reducing the perceived complexity

Inventive Principle:
Principle #15Dynamics

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 coating provides a visually detectable layer for consistent applications and quality assurance, reducing waste and costs while maintaining protective and adhesive properties, and can be made transparent again post-inspection.

Implementation Method 1

The zirconium is configured to chemically bond the surface

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

the indicator modifies an appearance of the coating

Methodology Applied
Scientific EffectColor modification:

Implementation Method 3

an organosilane coupling agent

Methodology Applied
Scientific EffectCoupling agent bonding: Chemical Bonding

Data Source

PatentEP1928961B1Coloured coating and formulation comprising an indicator facilitating determining the coating thickness
Publication Date: 2021.08.04 THE BOEING CO
  • EP1928961B1 patent drawingFigure 1
  • EP1928961B1 patent drawingFigure 2
  • EP1928961B1 patent drawing

AI summary

A composition for coating a surface includes a carrier and an indicator distributed throughout the carrier. The indicator is configured to modify an appearance of the coating. The indicator facilitates determining a thickness of the coating in response to the appearance of the coating.