Curable Composition for Crack-Resistant Cured Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing curable compositions used to form cured films lack followability to deformation of base materials while maintaining strength, leading to cracking issues during cutting processes, especially when multiple base materials are stacked and cut.
Innovation Solution
A curable composition comprising a polymerizable compound with a specific ratio of monofunctional and polyfunctional components, where the monofunctional compound has a melting point of 25° C. or less and the polyfunctional compound is present in higher quantities, is cured by irradiation with active rays to achieve a cured film with enhanced flexibility and strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a curable composition is designed to increase followability to deformation of base material, then the cured film becomes more flexible and less likely to break during folding, but the cured film becomes more prone to cracking during cutting processes
Solution Approach 1:
The patent changes the chemical composition parameters of the curable composition by specifying precise ratios of monofunctional to polyfunctional polymerizable compounds (1:4 to 1:1 by mass), and controlling the glass transition temperature range (−50°C to 0°C). These parameter changes enable the cured film to achieve both flexibility for followability and strength for crack resistance during cutting.
Solution Approach 2:
The patent creates a composite curable composition system combining monofunctional polymerizable compounds (providing flexibility) with polyfunctional polymerizable compounds (providing strength). This composite approach allows the cured film to exhibit both followability to base material deformation and resistance to cracking during cutting processes.
2Strength
If a curable composition is designed to maintain high strength of cured film, then the cured film resists breaking during folding, but the cured film becomes less adaptable to deformation of base material
Solution Approach 1:
The patent adjusts the glass transition temperature parameter to a specific range (−50°C to 0°C) and controls the functional group ratio to achieve optimal balance between strength and flexibility, resolving the contradiction between maintaining high strength and achieving good followability.
Solution Approach 2:
The patent uses a composite system of monofunctional and polyfunctional polymerizable compounds where the monofunctional component provides flexibility for followability while the polyfunctional component provides strength, achieving both properties simultaneously in the cured film.
3Adaptability or versatility
If a cured film is formed with high flexibility to improve followability, then the film can deform with the base material, but cracking occurs more frequently in the vicinity of cut portions
Solution Approach 1:
The patent optimizes the glass transition temperature to (−50°C to 0°C) and controls the monofunctional to polyfunctional compound ratio to achieve a balance where the cured film has sufficient flexibility to follow base material deformation while maintaining enough strength to resist cracking during cutting operations.
Solution Approach 2:
The composite curable composition combining flexible monofunctional compounds with stronger polyfunctional compounds creates a cured film that exhibits both followability and crack resistance, eliminating the harmful cracking effect while maintaining flexibility.
4Strength
If a curable composition uses monofunctional monomers with high glass transition temperature to maintain strength, then the cured film has high strength, but the cured film has poor followability to deformation
Solution Approach 1:
The patent changes the glass transition temperature parameter from high values to a specific range (−50°C to 0°C) and controls the functional group ratio, enabling the cured film to achieve both strength and followability by optimizing these chemical parameters.
Solution Approach 2:
Instead of using high Tg monomers for strength, the patent inverts the approach by using low Tg monomers (−50°C to 0°C) combined with polyfunctional compounds, achieving strength through crosslinking density rather than monomer rigidity, thus obtaining both strength and flexibility.
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 resulting cured film exhibits improved followability to base material deformation, reduced cracking during cutting, and consistent properties across multiple base materials when stacked and cut, while maintaining high abrasion resistance and stress relaxation properties.
Implementation Method 1
a curable composition that contains a polymerizable compound and is cured by irradiation with active rays
Data Source
AI summary
A curable composition cured by irradiation with active rays. The content of a monofunctional polymerizable compound having a melting point of 25° C. or less is 5-50% by mass; the content of a polyfunctional polymerizable compound is 50-95% by mass. When a nanoindentation evaluator is used to press an indenter into a cured film (obtained by curing a coating film with an average thickness of 8 μm by irradiation with an active ray at a cumulative light amount of 400 mJ/m2) by 100 nm in the thickness direction, P1 is a load amount required for pressing, and P2 is a load amount after the pressing is maintained for 2 seconds, the cured film satisfies conditions (1) and (2): (1) P2 is 20 μN or less, and (2) A relaxation rate determined by an expression ((P1−P2)/P1×100) is 15% or more.