UV-Curable Ink Composition for Foldable Display Bezel Patterns
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Solution Overview
Problem
Foldable display devices require a bezel pattern with low thickness and excellent light-shielding properties to prevent panel pattern visibility and light leakage, while also needing a cost-effective single-layer printing process for the bezel formation.
Innovation Solution
A film printable ultraviolet curable ink composition comprising a black pigment, dispersant, alicyclic epoxy compound, oxetane compound, photosensitizer, and photopolymerization initiator, with specific weight ratios and content percentages, is used to form a bezel pattern through single-layer printing and UV curing, ensuring low thickness and high light-shielding properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the bezel thickness is increased to improve light-shielding properties, then light leakage is prevented, but the bezel step becomes visually recognizable and bubbles form during OCA attachment
Solution Approach 1:
The invention changes the chemical composition parameters of the ink, specifically using a photopolymerization initiator with maximum absorption wavelength of 380 nm or more and adjusting the photosensitizer to photopolymerization initiator weight ratio to 1:1 to 1:4, enabling effective curing at low UV doses and forming thin bezels with sufficient light-shielding properties without visible steps
Solution Approach 2:
The invention uses a composite ink system combining black pigment, photopolymerization initiator, and photosensitizer that work synergistically to achieve both light-shielding function and thin profile, where the composite formulation enables effective UV curing at low doses while maintaining adequate light blocking
2Object-affected harmful factors
If multi-layer printing is used to achieve high light-shielding properties, then light leakage is prevented, but process complexity and costs increase
Solution Approach 1:
The invention merges the light-shielding function and UV-curable properties into a single ink layer formulation, combining black pigment for light blocking with optimized photopolymerization components, allowing one-layer printing to achieve both adequate light shielding and thin profile without requiring multiple printing layers
Solution Approach 2:
The single-layer ink composition performs multiple functions simultaneously: it provides light-shielding properties through black pigment, forms a thin uniform layer through proper rheology, and cures effectively at low UV dose through the optimized photopolymerization system, eliminating the need for separate printing steps
3Reliability
If high UV dose is applied to cure thick bezel patterns, then complete curing is achieved, but surface wrinkles form and film damage occurs
Solution Approach 1:
The invention changes the UV curing parameters by using a photopolymerization initiator system with photosensitizer that absorbs at 380 nm or more and has specific weight ratios, enabling complete curing at low UV doses (100-500 mJ/cm²) and preventing surface wrinkles and film damage that occur with high UV dose exposure
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 enables the formation of a bezel pattern with excellent light-shielding and adhesion properties, suitable for foldable display devices, achieving low UV dose curing and maintaining inkjet processability without surface wrinkles or pattern visibility issues.
Implementation Method 1
an ultraviolet curable ink composition for forming a bezel pattern of a display substrate, comprising a black pigment, a dispersant, an alicyclic epoxy compound, an oxetane compound, a photosensitizer, a photopolymerization initiator, and an organic solvent
Data Source
AI summary
An ultraviolet curable ink composition for forming a bezel pattern of a foldable display substrate, methods of using the same, a bezel pattern formed from the same, and a foldable display substrate include the bezel pattern are disclosed herein. In some embodiments, an ultraviolet curable ink composition includes a black pigment, a dispersant, an alicyclic epoxy compound, an oxetane compound, a photosensitizer, a photopolymerization initiator, and an organic solvent, wherein a weight ratio of the photosensitizer to the photopolymerization initiator is 1:1 to 1:2, and a sum of the amounts of the photosensitizer and the photopolymerization initiator is 13 to 21 parts by weight based on 100 parts by weight of a sum of the amounts of the alicyclic epoxy compound and the oxetane compound. The ink composition is capable of forming a bezel pattern having a diminished thickness and excellent light blocking properties.