Aqueous Inkjet Ink Heating for High-Hiding White Images
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Solution Overview
Problem
Inkjet recording methods face challenges in achieving high concealing properties while using aqueous inks with excellent settlement resistance, as larger titanium oxide particles tend to settle, leading to decreased contrast ratios due to scattering intensity, and smaller particles result in insufficient scattering for concealing properties.
Innovation Solution
An inkjet recording method involving an ink application step followed by a heating step where the recording medium is heated to a temperature equal to or higher than the glass transition or melting point of a first resin particle, with the resin particle having an average primary particle size of 150 nm or less, allowing the resin to melt and generate holes, enhancing scattering and concealing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If larger titanium oxide particles are used to enhance concealing property, then scattering intensity increases, but settling velocity increases causing particles to settle more easily
Solution Approach 1:
The patent changes the particle size parameter from conventional larger particles (300 nm or more) to smaller particles (150 nm or less), which fundamentally alters both the scattering characteristics and settling behavior. This parameter change allows achieving concealing properties through different mechanisms while eliminating the settling problem associated with larger particles.
Solution Approach 2:
The patent uses a composite ink formulation combining smaller titanium oxide particles with specific resin components (urethane resin and carboxyl group-containing polymer). This composite approach creates a synergistic effect where the resin matrix provides both binding functionality and enhanced scattering capability, allowing smaller particles to achieve the concealing properties previously requiring larger particles.
2Reliability
If smaller titanium oxide particles are used to reduce settling velocity, then settlement resistance improves, but scattering intensity decreases leading to insufficient concealing property
Solution Approach 1:
The patent employs a composite material system where smaller titanium oxide particles are combined with specific resin components (urethane resin and carboxyl group-containing polymer). The resin matrix provides binding functionality while also contributing to light scattering, compensating for the reduced scattering capability of smaller particles and achieving sufficient concealing properties.
Solution Approach 2:
The patent changes the particle size parameter to 150 nm or less, which fundamentally alters the scattering characteristics. By using such small particles, the patent achieves settlement resistance while relying on alternative mechanisms (resin matrix scattering and refractive index differences) to provide the necessary concealing properties.
3Illumination intensity
If titanium oxide content is increased to enhance whiteness and concealing property, then image quality improves, but settling velocity increases causing particles to settle
Solution Approach 1:
The patent changes the particle size parameter to 150 nm or less, which fundamentally alters the settling behavior. Smaller particles have significantly lower settling velocities, allowing higher titanium oxide content to be maintained in the ink formulation without causing premature settling, thereby achieving both enhanced whiteness and settlement resistance.
Solution Approach 2:
The patent uses a composite ink formulation with specific resin components (urethane resin and carboxyl group-containing polymer) that work synergistically with smaller titanium oxide particles. This composite approach enables higher pigment loading while maintaining stability, as the resin matrix provides both binding and steric stabilization against settling.
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 achieves images with excellent concealing properties by reducing settling velocity and utilizing refractive index differences between the binder and holes formed by melted resin, without relying on 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 TM (° C.) of the first resin particle... melt the first resin particle
Implementation Method 2
in the heating step, the recording medium is heated to melt the first resin particle and to generate a hole
Implementation Method 3
an ink application step of applying the aqueous ink to the recording medium
Data Source
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.