Optical Multilayer Window Film for Scratch Resistance and Flexibility

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Tempered glass used in display devices is heavy, vulnerable to external shock, and unsuitable for flexible or foldable applications, lacking the combined characteristics of being unbreakable and bendable.

Innovation Solution

An optical multilayer structure comprising a substrate layer, a hard coating layer, a low-reflective adhesion reinforcement layer with a siloxane-based compound, and a water repellent layer with an alkoxysilane-based compound containing a fluorine atom, designed to provide low reflectance, high wear resistance, and a high water contact angle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If tempered glass is used as a window cover for display protection, then scratch resistance and strength are improved, but weight increases and flexibility is lost

Engineering Contradiction:

Improvescratch resistanceVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces rigid tempered glass with a flexible polymer film structure consisting of multiple functional layers including a hard coating layer, low-reflective adhesion reinforcement layer, and water repellent layer. This flexible film structure achieves the required scratch resistance and protective functions while enabling bendability and significantly reducing weight compared to glass solutions.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The invention employs a composite multilayer structure where each layer serves a specific function: the hard coating layer provides scratch resistance, the low-reflective adhesion reinforcement layer enhances bonding and reduces reflection, and the water repellent layer provides water resistance. This composite approach achieves the combined properties of strength, flexibility, and optical performance that single-material solutions cannot provide.

Inventive Principle:

Principle #40Composite materials

2Strength

If tempered glass is used as a window cover, then scratch resistance is improved, but adaptability to flexible and foldable applications deteriorates

Engineering Contradiction:

Improvescratch resistanceVSAvoidflexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The patent employs a flexible polymer film structure consisting of multiple functional layers that can be bent and folded without breaking. The hard coating layer provides scratch resistance while the flexible substrate and other functional layers maintain bendability, enabling the window cover to adapt to flexible and foldable display applications.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The invention creates a dynamic structure that can transition from a flat state to a bent or folded state. The flexible film construction allows the window cover to adapt its shape dynamically according to the display device configuration, maintaining protective functions throughout the range of motion.

Inventive Principle:

Principle #15Dynamics

3Strength

If a hard coating layer is applied to provide scratch resistance, then wear resistance is improved, but water contact angle and adhesion may deteriorate

Engineering Contradiction:

Improvewear resistanceVSAvoidwater contact angle

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies different functional properties to different layers: the hard coating layer provides wear resistance, while the water repellent layer applied on top provides high water contact angle. Each layer is optimized for its specific function, allowing the overall structure to achieve both wear resistance and water repellency without compromise.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention uses a composite multilayer structure where the hard coating layer and water repellent layer work together. The hard coating layer provides mechanical durability while the water repellent layer provides hydrophobicity, achieving a combination of properties that neither layer could provide alone.

Inventive Principle:

Principle #40Composite materials

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 multilayer structure offers improved flexibility, scratch resistance, and water repellency, making it suitable for flexible display devices while maintaining optical clarity and reducing weight.

Implementation Method 1

a low-reflective adhesion reinforcement layer which is formed on the hard coating layer and comprises a siloxane-based compound

Methodology Applied

Scientific EffectOptical interference: Interference

Implementation Method 2

a water repellent layer which is formed on the low-reflective adhesion reinforcement layer and comprises an alkoxysilane-based compound containing a fluorine atom

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentUS12473411B2Optical multilayer structure, method of manufacturing the same and window cover film comprising the same

Publication Date: 2025.11.18 SK INNOVATION CO LTD

AI summary

An optical multilayer structure including a hard coating layer, a low-reflective adhesion reinforcement layer, and a water repellent layer on a substrate layer. The optical multilayer structure includes a structure in which a hard coating layer, a low-reflective adhesion reinforcement layer including a siloxane-based compound, and a water repellent layer including an alkoxysilane-based compound containing a fluorine atom are laminated on a substrate layer, thereby having high wear resistance and water contact angle simultaneously.