Ink Jet Recording Method Using Microcapsule Curing

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Solution Overview

Problem

Ink jet recording methods using water-based ink compositions face challenges in suppressing color bleeding due to differences in curability among ink compositions, especially when cured under the same conditions, leading to undesirable color mixing and image quality issues.

Innovation Solution

The method involves ejecting and irradiating ink compositions A and B onto a substrate, where the absorbance and microcapsule concentrations satisfy specific formulas, ensuring a controlled curing rate to minimize color bleeding. Ink composition A includes water, a coloring agent, and a photopolymerization initiator with microcapsules containing polymerizable compounds, while ink composition B has similar components and microcapsules, with specific pigment ratios and photopolymerization initiators to achieve uniform curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If water-based ink compositions with different coloring agents are used for multi-color printing, then color variety is achieved, but curability differences cause color bleeding between adjacent ink droplets

Engineering Contradiction:
Improvecolor varietyVSAvoidcolor boundary precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes the polymerizable compound content parameter in microcapsules to control curing rates. By adjusting the polymerizable compound content to specific ranges (5-20% for first ink, 10-30% for second ink), the invention achieves uniform curing across different ink compositions, preventing color bleeding while maintaining color variety

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by giving different microcapsule compositions to different ink types. Each ink composition contains microcapsules with specifically tailored polymerizable compound contents matched to that ink's absorbance characteristics, allowing each ink to cure at the same rate despite different base compositions

Inventive Principle:
Principle #3Local quality

2Speed

If the amount of photopolymerization initiator is increased to improve curability, then curing speed increases, but water-based ink viscosity increases and ejection performance deteriorates

Engineering Contradiction:
Improvecuring speedVSAvoidejection performance
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent introduces microcapsules as an intermediary carrier containing polymerizable compounds. This allows the system to achieve fast curing through photopolymerization of the microencapsulated compounds without needing to increase photopolymerization initiator concentration in the bulk water-based ink, thus maintaining low viscosity and good ejection performance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the system from relying on bulk photopolymerization initiators to using microencapsulated polymerizable compounds that polymerize upon light exposure. This parameter change enables fast curing while keeping the water-based ink composition simple and ejectable

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

This approach effectively suppresses color bleeding by ensuring uniform curing rates between ink compositions, maintaining image quality and preventing unwanted color mixing during the recording process.

Implementation Method 1

an ink jet recording method using an ink for ink jet printing, the ink being capable of being cured by irradiation with active energy rays such as ultraviolet rays

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

an absorbance ABSA of the ink composition A and an absorbance ABSB of the ink composition B satisfy a formula (1) below

Methodology Applied
Scientific EffectAbsorption of electromagnetic radiation: Absorption (EM radiation)

Data Source

PatentEP3415332B1Ink jet recording method
Publication Date: 2021.09.22 FUJIFILM CORP
  • EP3415332B1 patent drawingFigure 1
  • EP3415332B1 patent drawingFigure 2
  • EP3415332B1 patent drawingFigure 3

AI summary

An ink jet recording method has an ejection step of ejecting, onto a substrate, an ink composition A that includes water, a coloring agent, a photopolymerization initiator, and a microcapsule enclosing a polymerizable compound therein, and an ink composition B that includes water, a coloring agent, a photopolymerization initiator, and a microcapsule enclosing a polymerizable compound therein; and an irradiation step of irradiating, with light, the ink composition A and the ink composition B ejected on the substrate. An absorbance ABSA of the ink composition A and an absorbance ABSB of the ink composition B satisfy a formula (1), and a concentration MA of the microcapsule included in the ink composition A and a concentration MB of the microcapsule included in the ink composition B satisfy a formula (2). ABSA<ABSB MA<MB