Inkjet-Printable Adhesive Composition for Foldable Displays

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Solution Overview

Problem

The production of foldable displays is hindered by the need for precise cutting of optically clear adhesives (OCAs) to fit films accurately, leading to increased production costs and complexity.

Innovation Solution

A composition comprising a first monomer with a hydroxy group, a second monomer without a hydroxy group, a third monomer with a terminal heterocyclic group, a fourth monomer with an alkylene glycol group, an oligomer, a silane coupling agent, and a photoinitiator, which can be inkjet-printed at room temperature, forming a polymer with suitable modulus values for adhesion and flexibility, eliminating the need for precise cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If optically clear adhesive is precisely cut to fit films accurately, then adhesion performance is improved, but production cost increases

Engineering Contradiction:
Improveadhesive fitting precisionVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical cutting system with an inkjet printing system that applies adhesive in liquid form directly to the film. This substitution eliminates the need for precise mechanical cutting while maintaining adhesion performance, as the liquid adhesive can be precisely deposited and conforms to the film surface.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state of the adhesive from solid (requiring cutting) to liquid (suitable for inkjet printing). The composition is formulated with specific viscosity parameters (5-50 cP at room temperature) that enable inkjet deposition. This parameter change allows the adhesive to be applied in a more flexible and cost-effective manner while maintaining precise application.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If optically clear adhesive is precisely cut to fit films accurately, then adhesion performance is improved, but production complexity increases

Engineering Contradiction:
Improveadhesive fitting precisionVSAvoidproduction process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical cutting operations with a simpler inkjet printing process. The liquid adhesive composition can be directly deposited onto the film without requiring precise mechanical cutting, thereby reducing production process complexity while maintaining adhesion performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The adhesive composition is pre-formulated with specific viscosity and compositional parameters that enable direct inkjet printing application. This preliminary preparation of the adhesive in liquid form eliminates the need for subsequent cutting operations, simplifying the overall production process.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If adhesive viscosity is reduced for inkjet printing, then ease of application is improved, but adhesion strength may deteriorate

Engineering Contradiction:
Improveinkjet printing applicabilityVSAvoidadhesion strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent optimizes the viscosity parameter to a specific range (5-50 cP at room temperature) that balances inkjet printability with adhesion strength. This parameter optimization ensures the adhesive flows sufficiently for inkjet deposition while maintaining adequate bonding strength after curing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive composition is formulated as a complex mixture of multiple components including monomers (first monomer with hydroxy group, second monomer without hydroxy group, third monomer with terminal heterocyclic group, fourth monomer with alkylene glycol group), oligomer, silane coupling agent, and photoinitiator. This composite formulation achieves the desired balance between low viscosity for inkjet printing and high adhesion strength after polymerization.

Inventive Principle:
Principle #40Composite materials

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 cost-effective and precise application of the adhesive, maintaining high adherence performance and reliability in various temperature and humidity environments, enhancing the folding reliability of foldable displays.

Implementation Method 1

a photoinitiator, wherein the composition has a viscosity of 5 centipoise to 50 centipoise at room temperature. The composition provides a capability for application by inkjet-printing at about room temperature.

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a silane coupling agent

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentUS20230357557A1Composition, polymer prepared therefrom, and electronic apparatus including the same
Publication Date: 2023.11.09 SAMSUNG DISPLAY CO LTD

AI summary

A composition including a first monomer including a hydroxy group, a second monomer that does not include a hydroxy group, a third monomer including a terminal heterocyclic group, a fourth monomer including an alkylene glycol, an oligomer, a silane coupling agent, and a photoinitiator. The composition has a viscosity of 5 centipoise to 50 centipoise at about room temperature.