Aqueous Inkjet Ink Heating for Concealing and Settlement Resistance

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Solution Overview

Problem

The settling velocity of titanium oxide particles in aqueous inks is high due to their larger particle size, leading to a trade-off between image contrast and concealing properties, as smaller particles result in reduced scattering intensity.

Innovation Solution

An ink jet recording method using an aqueous ink containing particles with an average primary particle size of 150 nm or less, combined with a heating step to melt a first resin particle and generate holes, allowing for excellent settlement resistance and concealing properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If titanium oxide particles with larger particle size are used to enhance concealing property and whiteness, then the concealing property is improved, but the particles settle more easily in the ink

Engineering Contradiction:
Improveconcealing propertyVSAvoidsettlement resistance
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent changes the particle size parameter of titanium oxide to 150 nm or less, which fundamentally alters the settling behavior while maintaining optical properties. This parameter change resolves the contradiction by using nanoscale particles that resist settling due to Brownian motion while still providing adequate concealing property.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink system combining titanium oxide particles with specific resins and surfactants. This composite formulation stabilizes the nanoscale particles in the ink, preventing aggregation and settling while maintaining the concealing property provided by the titanium oxide.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If titanium oxide particles with smaller particle size are used to reduce settling velocity, then settlement resistance is improved, but the scattering intensity decreases and contrast ratio decreases

Engineering Contradiction:
Improvesettlement resistanceVSAvoidcontrast ratio
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The patent optimizes the particle size parameter to 150 nm or less, which is small enough to resist settling through Brownian motion but large enough to maintain adequate light scattering. This precise parameter control resolves the contradiction between settlement resistance and contrast ratio.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses nanoscale titanium oxide particles that replicate the light-scattering functionality of larger particles at a much smaller size, achieving both settlement resistance and adequate contrast ratio through the nanoscale dimension.

Inventive Principle:
Principle #26Copying

3Illumination intensity

If the content of titanium oxide is increased to enhance concealing property, then the concealing property is improved, but the particles settle more easily

Engineering Contradiction:
Improveconcealing propertyVSAvoidsettlement resistance
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent changes the particle size parameter to nanoscale (150 nm or less), which allows for higher particle concentrations without increased settling. The nanoscale dimension enables Brownian motion to counteract gravitational settling, allowing adequate concealing property with maintained stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent formulates a composite ink with nanoscale titanium oxide particles combined with specific resins and surfactants that stabilize high particle concentrations. This composite system enables adequate concealing property through higher particle content while preventing settling through the stabilizing formulation.

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 method enables recording of images with high concealing properties while maintaining excellent settlement resistance, without the need for components that easily settle, such as large titanium oxide particles.

Implementation Method 1

heating the recording medium applied with the aqueous ink to a temperature that is equal to or higher than the glass transition temperature Tg (°C) or melting point T M (°C) of the first resin particle and is less than the glass transition temperature Tg (°C) or melting point T M (°C) of the particle, wherein the particle has an average primary particle size D P0 (nm) of 150 nm or less, and in the heating step, the recording medium is heated to melt the first resin particle and to generate a hole

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

heating the recording medium applied with the aqueous ink to a temperature that is equal to or higher than the glass transition temperature Tg (°C) or melting point T M (°C) of the first resin particle and is less than the glass transition temperature Tg (°C) or melting point T M (°C) of the particle

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

aqueous ink containing a particle and a first resin particle

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP4696519A1Inkjet recording method, inkjet recording device, and aqueous ink
Publication Date: 2026.02.18 CANON KK
  • EP4696519A1 patent drawingFigure 1~2
  • EP4696519A1 patent drawingFigure 3~4
  • EP4696519A1 patent drawing

AI summary

An ink jet recording method records an image on a recording medium using an aqueous ink containing a particle and a first resin particle. The method includes an ink application step of applying an aqueous ink to a recording medium and a heating step of heating the recording medium applied with the aqueous ink to a temperature that is equal to or higher than the glass transition temperature Tg (°C) or melting point TM (°C) of the first resin particle and is less than the glass transition temperature Tg (°C) or melting point TM (°C) of the particle. The particle has an average primary particle size DP0 (nm) of 150 nm or less, and in the heating step, the recording medium is heated to melt the first resin particle and to generate holes.