Quantum Dot Print Material Two-Stage Curing

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Solution Overview

Problem

Existing inkjet printing technologies face challenges in precisely depositing and curing quantum dot materials on substrates, particularly in achieving uniform polymerization and retaining the initial mass of the print material after curing.

Innovation Solution

A print material comprising a vinylic monomer, a polyfunctional monomer, scattering particles, quantum dots, and two polymerization initiators with different decomposition rates is used. During a first curing process, the first polymerization initiator with a higher decomposition rate initiates photo-polymerization, while in a second curing process, the second initiator with a higher decomposition rate drives thermal polymerization, ensuring thorough curing and mass retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single polymerization initiator is used, then the curing process is simple, but uniform polymerization and mass retention cannot be achieved

Engineering Contradiction:

Improveuniform polymerization and mass retentionVSAvoidcuring process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the polymerization initiation function into two separate initiators: a photoinitiator for photo-polymerization and a thermal initiator for thermal polymerization. This segmentation allows each initiator to be optimized for its specific activation method, enabling uniform polymerization and mass retention while maintaining process simplicity through separate, well-defined curing steps.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a preliminary photo-polymerization step using the photoinitiator before the final thermal polymerization step. This preliminary action pre-polymerizes the composition to a sufficient degree, reducing volatile content and preparing the material for complete curing, which ultimately achieves uniform polymerization and mass retention.

Inventive Principle:

Principle #10Preliminary action

2Loss of substance

If photo-polymerization is used first, then volatile content is reduced, but complete curing requires additional thermal processing

Engineering Contradiction:

Improvevolatile content reductionVSAvoidcuring process time

Core Design Contradiction:

Loss of substanceVSProductivity

Solution Approach 1:

The patent implements a continuous two-stage curing process where photo-polymerization immediately precedes thermal polymerization without interruption. The photoinitiator begins polymerization upon UV exposure, reducing volatiles, and the thermal initiator completes the curing process subsequently. This continuous action achieves both volatile reduction and complete curing efficiently.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If thermal polymerization is used alone, then complete curing is achieved, but mass loss occurs due to volatile content

Engineering Contradiction:

Improvecomplete curingVSAvoidmass retention

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent uses photo-polymerization as a preliminary step before thermal polymerization. This preliminary action pre-polymerizes the composition, significantly reducing volatile content and preventing mass loss during the subsequent thermal curing process, while ensuring complete curing is still achieved.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the curing process into two distinct stages: photo-polymerization to reduce volatiles and prevent mass loss, followed by thermal polymerization to achieve complete curing. This segmentation allows each process to be optimized for its specific function, achieving both complete curing and mass retention.

Inventive Principle:

Principle #1Segmentation

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

This approach allows for precise deposition and effective curing of quantum dot materials, ensuring at least 85% retention of the initial mass of the print material and achieving uniform polymerization, thereby enhancing the performance and reliability of quantum dot-based displays.

Implementation Method 1

during a first curing process comprising a photo-initiated polymerization process using a radiation wavelength less than 400 nm the first polymerization initiator has a higher decomposition rate than the second polymerization initiator

Methodology Applied

Scientific EffectPhoto-initiated decomposition: Photopolymerisation

Implementation Method 2

during a second curing process free of activating radiation the second polymerization initiator has a higher decomposition rate than the first polymerization initiator

Methodology Applied

Scientific EffectThermal decomposition: Thermolysis

Data Source

PatentUS20250115776A1Quantum dot material and method of curing

Publication Date: 2025.04.10 KATEEVA INC

AI summary

Print materials described herein include a first polymerization initiator comprising an initiator material having a thermal decomposition rate and a peak photo-initiated decomposition rate, wherein the thermal dissociation rate is higher than the peak photo-initiated decomposition rate; a vinylic monomer; a polyfunctional monomer; scattering particles; and quantum dots. Methods of making a quantum dot material using such print materials, and of incorporating into light emitting devices, are also described.