Infrared Transmitting Ink Composition for Bezel Pattern

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Solution Overview

Problem

Existing ink compositions for display devices, particularly black inks containing carbon black, require post-process removal of alignment marks and destruction of samples to detect pressure marks, and suffer from poor storage stability, curing sensitivity, and adhesion to substrates, hindering the inkjet process.

Innovation Solution

An infrared transmitting ink composition for inkjet using lactam black or perylene black pigment, combined with a dispersant, epoxy compound, oxetane compound, photopolymerization initiator, and organic solvent, allowing non-destructive inspection of alignment marks and pressure marks using an infrared camera, while improving storage stability, curing sensitivity, and adhesion to substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If carbon black ink is used for printing bezel patterns, then the ink provides good coverage and hiding power, but alignment marks cannot be detected and pressure marks require destructive inspection

Engineering Contradiction:
Improveinfrared transmittanceVSAvoidalignment mark detection
Core Design Contradiction:
Illumination intensityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent changes the optical properties of the ink by replacing carbon black with infrared-transparent pigments (lactam black or perylene black). This allows the ink to appear black to the human eye while being transparent to infrared radiation, enabling alignment marks to be detected through the printed layer using infrared cameras without requiring removal or destructive inspection.

Inventive Principle:
Principle #32Color changes

2Reliability

If conventional ink compositions are used, then the ink can be printed on the substrate, but the ink shows poor storage stability and requires post-process heat treatment for adhesion

Engineering Contradiction:
Improvestorage stabilityVSAvoidadhesion to substrate
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent creates a composite ink formulation combining infrared-transparent pigments (lactam black or perylene black) with specific polymers (epoxy compound and oxetane compound) and photopolymerization initiators. This composite material provides both excellent storage stability and strong adhesion to substrates through photopolymerization curing, eliminating the need for post-process heat treatment while maintaining black appearance and infrared transparency.

Inventive Principle:
Principle #40Composite materials

3Strength

If the ink provides good adhesion to substrate, then the bezel pattern remains stable, but the curing sensitivity is poor and requires extended curing time

Engineering Contradiction:
Improveadhesion to substrateVSAvoidcuring time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The patent optimizes the chemical composition parameters of the ink, specifically incorporating photopolymerization initiators that respond to UV or visible light, along with epoxy and oxetane compounds. This formulation enables rapid photopolymerization curing with high curing sensitivity, achieving strong adhesion to substrates in reduced time compared to conventional heat-cured inks, while maintaining excellent storage stability and infrared transparency.

Inventive Principle:
Principle #35Parameter changes

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

Enables non-destructive inspection of alignment and pressure marks, enhances storage stability, curing sensitivity, and adhesion to substrates, improving the overall performance of the inkjet process and reworkability of display panels.

Implementation Method 1

a photopolymerization initiator; curing the bezel pattern by irradiation with radiation

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS10934443B2Infrared transmitting ink composition for ink jet, method for forming bezel pattern by using same, bezel pattern formed thereby, and display substrate comprising same
Publication Date: 2021.03.02 LG CHEM LTD

AI summary

Disclosed are an infrared transmitting ink composition for an ink jet, a method for forming a bezel pattern by using the same, a bezel pattern formed thereby, and a display substrate comprising the same, wherein the infrared transmitting ink composition enables the check of align markers through an infrared camera and the detection of pressure marks through non-destructive inspection even after the bezel pattern is printed on the display substrate, has excellent storage stability, curing sensitivity, and adhesion with a basic material, and can improve an ink jet process performance. The infrared transmitting ink composition for an ink jet comprises: a lactam black pigment, a perylene black pigment, or a combination thereof; a dispersant; an epoxy compound; an oxetane compound; a photo-polymerization initiator; and an organic solvent.