Polyorganosilsesquioxane Hard Coat Film Surface Hardness
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Solution Overview
Problem
Cage-type silsesquioxanes used in hard coat films lack sufficient hardness, limiting their application, and increasing the thickness or using multifunctional UV-curable acrylic monomers leads to cure shrinkage and poor flexibility.
Innovation Solution
A polyorganosilsesquioxane with a specific compositional formula containing a cage silsesquioxane structure, analyzed using liquid chromatography-evaporative light scattering detection, providing a high surface hardness and flexibility while maintaining heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cage-type silsesquioxane is used as hard coat material, then heat resistance and optical properties are improved, but surface hardness is insufficient
Solution Approach 1:
The patent changes the chemical structure parameters of silsesquioxane by introducing specific organic functional groups (epoxy, carboxylic acid, hydroxyl, amine, or isocyanate groups) and controlling the ratio of T8 to T10 cage structures. This structural parameter modification enables the material to achieve both high heat resistance and sufficient surface hardness simultaneously.
Solution Approach 2:
The patent creates a composite material system combining modified silsesquoxane with polyols or other curing agents. The resulting cured product integrates the heat resistance of silsesquioxane with the mechanical properties of the composite system, achieving both high heat resistance and surface hardness.
2Strength
If multifunctional UV-curable acrylic monomer is used to increase hardness, then surface hardness is improved, but cure shrinkage increases causing poor flexibility
Solution Approach 1:
The patent changes from UV-curable acrylic monomers to silsesquoxane-based materials with controlled molecular structure. By adjusting the T8/T10 ratio and introducing specific functional groups, the material achieves high surface hardness without the excessive cure shrinkage that would compromise flexibility.
3Strength
If thickness of hard coat layer is increased to achieve higher hardness, then surface hardness is improved, but flexibility deteriorates due to greater cure shrinkage
Solution Approach 1:
The patent changes the chemical composition and crosslinking mechanism of the hard coat material. The modified silsesquoxane system achieves high surface hardness through controlled crosslinking density and functional group selection, allowing sufficient hardness at optimal thickness without the flexibility loss associated with increased thickness in conventional systems.
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 polyorganosilsesquioxane achieves a high surface hardness and flexibility in hard coat films, suitable for applications requiring both properties, and can be used in adhesive compositions for high heat resistance and flexibility.
Implementation Method 1
Polyorganosilsesquoxanes (silsesquioxanes) are network polymers or polyhedral clusters obtained by hydrolyzing trifunctional silanes
Implementation Method 2
a curable composition containing the polyorganosilsesquoxane and a cured product of the curable composition
Data Source
AI summary
Provided is a polyorganosilsesquioxane that is suitable as a material for a hard coat film or an adhesive, the polyorganosilsesquioxane being capable of forming a cured product having a high surface hardness and flexibility while having a high heat resistance or the like. The polyorganosilsesquioxane contains a cage-type silsesquioxane represented by Compositional Formula (1). When the polyorganosilsesquioxane is analyzed using a liquid chromatography-evaporative light scattering detector, a peak area % of the cage-type silsesquioxane represented by Compositional Formula (1) is 5% or greater with respect to a peak area of all components detected.[R1SiO3/2]8[R1SiO2/2(ORc)]1 Formula (1)