Photosensitive Resin Composition Low-Temperature Tapered Shape
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing photosensitive resin compositions for touch panels face challenges in forming a tapered shape at low temperatures and preventing development residue when using weak alkali developers, due to high crosslink density and excessive polymerization initiator content.
Innovation Solution
A photosensitive resin composition comprising a binder, a difunctional polymerizable monomer with a molecular weight of 500 or less, a polymerization initiator, and a black pigment, where the difunctional monomer constitutes at least 50% of the polymerizable monomer mass, and the polymerization initiator is within specific ratios to prevent development residue and enable heat sagging for shape formation at low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If ethylenically unsaturated hexafunctional bond-containing compound is used to increase crosslink density, then strength and durability are improved, but the ability to form tapered shape at low temperature deteriorates
Solution Approach 1:
The patent segments the polymerizable compound into two distinct functional components: a hexafunctional bond-containing compound (for high crosslink density and strength) and a difunctional bond-containing compound with specific molecular weight (for low-temperature tapered shape formation). This segmentation allows each component to fulfill its specific function without interfering with the other, resolving the contradiction between strength and shape formation capability.
Solution Approach 2:
The patent specifies precise parameter ranges: the difunctional bond-containing compound has a molecular weight of 500-2000 and a specific functional group ratio (0.01-0.1 mmol/g), while the hexafunctional compound content is controlled at 5-50 wt%. These parameter changes enable the composition to achieve both high crosslink density and low-temperature processability, resolving the contradiction between strength and manufacturability.
2Productivity
If polymerization initiator content is increased to improve sensitivity, then curing speed is improved, but development residue increases
Solution Approach 1:
The patent optimizes the polymerization initiator content within a specific range (1-10 wt% of total solid content) and combines it with controlled ratios of polymerizable compounds. This parameter optimization ensures sufficient curing speed while preventing excessive polymerization that would cause development residue, resolving the contradiction between productivity and quality.
3Shape
If heat treatment temperature is increased to form tapered shape, then shape formation is improved, but damage to resin base material increases
Solution Approach 1:
The patent changes the thermal parameters of the photosensitive resin composition by incorporating a difunctional bond-containing compound with molecular weight 500-2000 and specific functional group content. This modification lowers the processing temperature range, enabling tapered shape formation at 80-150°C instead of higher temperatures, thus preventing base material damage while achieving the desired shape.
4Productivity
If weak alkali developer is used to improve productivity, then development speed is improved, but development residue increases
Solution Approach 1:
The patent modifies the chemical composition parameters of the photosensitive resin to be compatible with weak alkali developers. By controlling the functional group ratio and molecular weight of the polymerizable compounds, the cured film achieves sufficient contrast and solubility characteristics that enable complete development with weak alkali solutions, resolving the contradiction between productivity and quality.
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 composition effectively prevents development residue and forms a tapered shape during low-temperature heat treatment, improving pattern linearity and edge roughness while maintaining sensitivity and optical density.
Implementation Method 1
a polymerization initiator; a step of exposing the photosensitive resin layer with a desired pattern
Implementation Method 2
a step of performing heat treatment (hereinafter, also referred to as baking) of the photosensitive resin layer to form a tapered shape
Data Source
AI summary
Provided are a photosensitive resin composition including: a binder; a polymerizable monomer; a polymerization initiator; a pigment; and a solvent, in which the polymerizable monomer includes a difunctional polymerizable monomer having a molecular weight equal to or smaller than 500, and a content of the difunctional polymerizable monomer having a molecular weight equal to or smaller than 500 is equal to or greater than 50% by mass with respect to a total mass of the polymerizable monomer, a transfer film, a decorative pattern, and a touch panel.