Fluorocarbon Silane Surface Modifier for Optical Stain Resistance

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Solution Overview

Problem

Existing stain-resistant coatings for optical members and surfaces have insufficient stain resistance and durability, making it difficult to remove fingerprints, skin oil, sweat, and cosmetics, and their effectiveness decreases over time.

Innovation Solution

A surface modifier comprising an organic silicone compound represented by General Formula (A) and/or its partial hydrolysis product, which forms a low-surface-tension treated layer that prevents dirt and moisture from adhering and allows easy removal, while maintaining optical properties and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional stain-resistant coatings are applied to optical members, then some level of stain resistance is achieved, but the stain resistance is insufficient and durability is poor

Engineering Contradiction:

Improvestain resistanceVSAvoiddurability

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent uses a composite coating system comprising a silane-based primer layer and a fluorocarbon-based topcoat layer. The silane primer provides strong adhesion to the optical member surface through hydrolysis and condensation reactions, while the fluorocarbon topcoat provides low surface energy for stain resistance. This composite structure achieves both durability through strong bonding and effective stain resistance through low surface tension.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the surface properties of optical members by controlling the chemical composition and surface energy parameters of the coating layers. By adjusting the fluorocarbon content and molecular structure in the topcoat, the surface tension is reduced to achieve excellent stain resistance. The silane crosslinking density is controlled to optimize both adhesion strength and coating flexibility for long-term durability.

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If conventional antireflection coatings are used on optical members, then optical performance is achieved, but the surface is easily stained and dirt accumulates

Engineering Contradiction:

Improveoptical performanceVSAvoidstain adhesion

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different functional properties to different layers of the coating system. The silane primer layer provides adhesion and surface preparation functions, while the fluorocarbon topcoat specifically provides low surface energy and stain resistance. This local differentiation of functional qualities allows the optical member to maintain its optical performance while gaining superior stain resistance at the surface level.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The silane-based primer layer acts as an intermediary between the optical member surface and the fluorocarbon topcoat. It provides a chemically active surface that enhances bonding to both the substrate and the topcoat, ensuring long-term durability while allowing the fluorocarbon layer to maintain its low surface tension properties for stain resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If existing stain-proofing agents are applied, then some stain resistance is obtained, but the effectiveness greatly reduces after prolonged use

Engineering Contradiction:

Improvestain resistanceVSAvoidlong-term effectiveness

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The silane primer layer is applied first to prepare the surface and create strong chemical bonds with the optical member before the fluorocarbon topcoat is applied. This preliminary action ensures that the subsequent topcoat has a stable, well-bonded foundation, preventing delamination and maintaining stain resistance over long periods. The silane hydrolysis and condensation reactions occur in advance to create a durable bonding network.

Inventive Principle:

Principle #10Preliminary action

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 treated layer effectively prevents the adhesion of stains and moisture, allowing easy wiping and maintaining high durability and optical performance, even after prolonged use.

Implementation Method 1

a surface modifier comprising an organic silicone compound represented by General Formula (A) and/or a partial hydrolysis product... forms a low-surface-tension treated layer that prevents dirt and moisture from adhering

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

General Formula (B)... X' is hydrolysable group... a partial hydrolysis product

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP1869103B1Surface modifier, article with a coated surface and method of coating

Publication Date: 2017.05.03 DAIKIN INDUSTRIES LTD

AI summary

A surface modifier comprising an organosilicone compound represented by General Formula (A) and/or General Formula (B): F-(CF2)q-(OC3F6)m-(OC2F4)n-(OCF2)o(CH2)pXX"Si(X')3-a(R1)a (A) and F-(CF2)q-(OC3F6)m-(OC2F4)n-(OCF2)o(CH2)pXX"(X')2-a(R1)aSiO(F-(CF2)q-(OC3F6)m-(OC2F4)n-(OCF2)o(CH2)pXX"(X')1-a(R1)aSiO)zF-(CF2)q-(OC3F6)m-(OC2F4)n-(OCF2)o(CH2)pXX"(X')2-a(R1)aSi (B) wherein q is an integer from 1 to 3; m, n, and o are independently integers from 0 to 200; p is 0, 1 or 2; X is oxygen or a bivalent organic spacer group: X" is a bivalent organosilicone spacer group; X' is hydrolysable group; and z is an integer from 0 to 10 when a is 0 or 1.