Fluorinated Polyether Clear Coat for Weather-Resistant Self-Cleaning

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Solution Overview

Problem

Modern automotive clear coat layers experience a reduction in self-cleanability over time due to exposure to weather, despite initial effectiveness, which affects their ability to easily wash off dirt with rain.

Innovation Solution

A clear coat coating composition with a hydroxyl-functional binder component incorporating a fluorine-containing aliphatic polyether polyol, providing a fluorine content of 0.1 to 3 wt.%, which maintains sustainable easy-to-clean properties even after long-term weather exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a clear coat layer is designed to provide initial self-cleanability through surface enrichment of hydrophobic substance, then the initial self-cleanability is improved, but the self-cleanability reduces over time during weather exposure

Engineering Contradiction:
Improveself-cleanabilityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The invention changes the chemical composition parameters of the clear coat by incorporating fluorinated polyether polyols with specific molecular structures (containing CF3 and/or CF2H groups) into the binder system. This chemical parameter modification enables the coating to maintain hydrophobic properties and self-cleanability throughout its service life, resolving the contradiction between initial effectiveness and long-term durability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite binder system combining polyester polyols, polyether polyols, and fluorinated polyether polyols in specific ratios. This composite material approach integrates multiple functional components: the polyester provides structural backbone, the polyether contributes to flexibility and weather resistance, and the fluorinated polyether delivers sustained hydrophobicity and self-cleanability, thereby maintaining performance over time

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If hydrophobic substances are enriched at the surface for easy cleaning, then ease of operation is improved, but the coating composition complexity increases

Engineering Contradiction:
Improveease of cleaningVSAvoidcoating composition complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention achieves local quality enhancement by incorporating fluorinated polyether polyols that naturally migrate to and concentrate at the coating surface, creating a hydrophobic surface layer with distinct properties from the bulk coating. This localized functional enrichment provides easy cleaning properties without requiring complex multi-component formulations or additional surface treatment steps

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fluorinated polyether polyol component performs self-service by automatically migrating to the coating surface during the curing process and forming a permanent hydrophobic layer. This self-organizing behavior eliminates the need for complex application processes, additional surface treatments, or sophisticated formulation techniques, thereby achieving ease of cleaning with relatively simple coating composition

Inventive Principle:
Principle #25Self-service

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 ensures a clear coat layer with sustained self-cleanability, maintaining its initial dirt removal efficiency throughout its service life despite exposure to sunlight and rainwater, ensuring a smooth surface and high gloss.

Implementation Method 1

a hydroxyl-functional binder component and a crosslinker component, wherein the hydroxyl-functional binder component comprises at least one hydroxyl-functional urethane component comprising at least one aliphatic polyether polyol having - OCH 2 C n F 2n-1 groups with n = 1 or 2 as a building block

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentEP2785758B1Clear coat coating composition
Publication Date: 2015.10.28 AXALTA COATING SYSTEMS IP CO LLC

AI summary

A clear coat coating composition with a resin solids content comprising a hydroxyl-functional binder component and a crosslinker component, wherein the hydroxyl-functional binder component comprises at least one hydroxyl-functional urethane component comprising at least one aliphatic polyether polyol having -OCH2CnF2n+1groups with n = 1 or 2 as a building block, and wherein said -OCH2CnF2n+1groups provide the clear coat coating composition with a fluorine content of 0.1 to 3 wt.%, calculated on the resin solids content of the clear coat coating composition.