Silsesquioxane Hard Coating for Foldable Glass
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultrathin glass technologies lack a single hard coating that effectively enhances impact resistance, transparency, and durability while maintaining flexibility, and existing solutions require adhesive layers, which are not sufficient for practical applications in flexible electronic displays.
Innovation Solution
A single-layer hard coating composed of silsesquioxane with a silicon-oxygen core framework directly bonded to the ultrathin tempered glass substrate, providing a surface hardness of at least 7H, hydrophobic properties, and improved impact resistance without the need for an adhesive layer, achieved through chemical tempering and specific molecular weight ranges of the silsesquioxane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a protective hard coating is applied to ultra-thin glass, then impact resistance and surface hardness are improved, but transparency and flexibility deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the coating material by using silsesquioxane with specific molecular weight ranges (1,000-30,000) and controlled cross-linking density. This allows achieving high surface hardness (7H-9H) while maintaining transparency (≥98%) by optimizing the balance between coating density and light transmission properties.
Solution Approach 2:
The patent creates a composite hard coating system combining silsesquoxane core framework with organic functional groups (acrylate, epoxy, silane). This composite structure provides both the hardness needed for impact resistance and the optical clarity required for display applications, achieving a synergistic effect that neither component could achieve alone.
2Strength
If a protective hard coating is applied to ultra-thin glass, then surface hardness and scratch resistance are improved, but device complexity increases due to additional adhesive layers
Solution Approach 1:
The patent merges the protective hard coating function and the adhesion function into a single integrated layer. The silsesquoxane-based coating directly bonds to the ultra-thin glass substrate through chemical bonding mechanisms, eliminating the need for separate adhesive layers while maintaining strong attachment and high surface hardness (7H-9H).
Solution Approach 2:
The single hard coating layer performs multiple functions simultaneously: it provides surface hardness and scratch resistance, ensures strong adhesion to the glass substrate, maintains optical transparency, and offers impact protection. This multi-functional design simplifies the overall structure by replacing multiple specialized layers with one universal coating.
3Strength
If existing hard coating materials are used, then some protective properties are achieved, but bending durability and flexibility are insufficient
Solution Approach 1:
The patent employs a thin film hard coating approach where the silsesquoxane-based coating is applied as a thin layer that can flex with the ultra-thin glass substrate during bending. The controlled molecular weight and cross-linking density ensure the coating remains flexible enough to accommodate bending stresses while maintaining its protective hardness properties.
Solution Approach 2:
The patent optimizes the coating's mechanical parameters by controlling the silsesquoxane molecular weight (1,000-30,000) and cross-linking density to achieve an optimal balance between hardness and flexibility. This parameter optimization allows the coating to withstand repeated bending cycles (≥200,000 cycles) without cracking or delaminating while maintaining surface hardness ≥7H.
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 solution significantly enhances the impact resistance and transparency of ultrathin glass, with a maximum pen drop height at least four times greater than uncoated glass, maintaining high transparency and flexibility, and withstanding extensive bending cycles and abrasion.
Implementation Method 1
a single-layer hard coating bonded to the first and/or second surface of the ultrathin tempered glass foldable substrate without an adhesive layer. The hard coating includes at least one silsesquoxane having a silicon-oxygen core framework directly bonded to the ultrathin tempered glass foldable substrate
Implementation Method 2
the ultrathin chemically-tempered foldable glass substrate is chemically tempered through surface ion exchange
Implementation Method 3
The hard coating has a surface hardness of at least 7H surface hardness and has a hydrophobic surface with a water contact angle of at least 100°
Data Source
AI summary
A foldable ultrathin glass article includes an ultrathin chemically-tempered foldable glass substrate having a thickness of approximately 100 microns or less and a compressive surface stress of at least 100 MPa. A single-layer hard coating is bonded to the first and/or second surface of the ultrathin tempered glass foldable substrate without an adhesive layer. The hard coating includes at least one silsesquioxane having a silicon-oxygen core framework directly bonded to the ultrathin tempered glass foldable substrate. The impact resistance defined by a maximum pen drop height without glass failure is at least four times greater than the ultrathin tempered glass foldable substrate without the hard coating. The hard coating has a surface hardness of at least 7H surface hardness and has a hydrophobic surface with a water contact angle of at least 100°. The coating has a transparency of at least 98 percent compared to uncoated substrates.