Transfer Film for Capacitive Input Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic capacitance-type input devices face challenges in preventing air bubble incorporation and ensuring smooth lamination on base materials with elevation differences, particularly when using transfer films without a thermoplastic resin layer.
Innovation Solution
A transfer film with a temporary support and a curable transparent resin layer in direct contact, where the temporary support has a thickness of 38 μm or less, the curable transparent resin layer is 5 μm or more, and the melt viscosity at 100°C is 1.0×10³ Pa·s or more, allowing for direct contact and preventing air bubble incorporation during lamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a transfer film without a thermoplastic resin layer is used, then the structure is simplified and manufacturing is easier, but air bubbles are incorporated during lamination on base materials with elevation differences
Solution Approach 1:
The invention changes the physical parameters of the temporary support by controlling its thickness to 38 μm or less and the melt viscosity of the curable transparent resin layer to 1.0×10³ Pa·s or more at 100°C. These parameter adjustments enable the resin layer to flow and fill elevation differences during lamination without requiring a thermoplastic resin layer, thus preventing air bubble incorporation while maintaining structural simplicity.
Solution Approach 2:
The invention performs preliminary action by pre-setting the thickness and viscosity parameters before the lamination process. The temporary support is designed with specific thickness (38 μm or less) and the curable transparent resin layer is formulated with appropriate melt viscosity (1.0×10³ Pa·s or more at 100°C) in advance, enabling the material to automatically adapt to elevation differences during the lamination process without additional cushioning layers.
2Adaptability or versatility
If the temporary support thickness is reduced to 38 μm or less, then the transfer film becomes more flexible and conforms better to elevation differences, but the mechanical strength decreases
Solution Approach 1:
The invention uses a composite structure where the temporary support (thickness 38 μm or less) is combined with a curable transparent resin layer having specific melt viscosity (1.0×10³ Pa·s or more at 100°C). The composite system compensates for the reduced strength of the thin temporary support through the viscosity-controlled resin layer, which provides structural support during lamination while maintaining flexibility to conform to elevation differences.
Solution Approach 2:
The invention changes the physical state and flow characteristics of the curable transparent resin layer by controlling its melt viscosity parameter. The resin layer's viscosity (1.0×10³ Pa·s or more at 100°C) is optimized to provide sufficient structural support and strength during the lamination process, compensating for the reduced mechanical strength of the thin temporary support while maintaining the ability to conform to surface variations.
3Manufacturing precision
If the curable transparent resin layer thickness is increased to 5 μm or more, then the coverage over elevation differences is improved, but the visibility of transparent electrode patterns deteriorates
Solution Approach 1:
The invention optimizes the thickness parameter of the curable transparent resin layer to 5 μm or more, which provides sufficient coverage over elevation differences while maintaining appropriate optical properties. This parameter setting ensures uniform manufacturing precision across the surface while preserving the visibility of transparent electrode patterns through the layer.
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 effectively prevents air bubble incorporation and ensures smooth lamination on base materials with elevation differences, improving the visibility of transparent electrode patterns and maintaining favorable patterning properties.
Implementation Method 1
a melt viscosity ηc of the curable transparent resin layer measured at 100° C. is 1.0×10³ Pa·s or more
Data Source
AI summary
In a transfer film including a temporary support having a thickness of 38 μm or less; and a curable transparent resin layer disposed on the temporary support in a direct-contact manner, in which a thickness of the curable transparent resin layer is 5 μm or more, the curable transparent resin layer includes a binder polymer, a polymerizable compound, and a polymerization initiator, and a melt viscosity ηc of the curable transparent resin layer measured at 100° C. is 1.0×103 Pa·s or more, the temporary support and the curable transparent resin layer are in direct contact with each other, and it is possible to prevent the incorporation of air bubbles during lamination on base materials having an elevation difference; a method for manufacturing a laminate; a laminate; an electrostatic capacitance-type input device; and an image display device.