Ink Jet Recording Method for Resin Media Using White Ink Layer

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Solution Overview

Problem

Ink-jet printing methods struggle to prevent color migration and thermal deformation when using infrared drying on transparent resin printing media, as the resin medium absorbs infrared differently across various ink colors, leading to uneven heating and potential deformation.

Innovation Solution

An ink-jet printing method using water-based inks containing black, chromatic, and white inks with a specific organic solvent having a boiling point between 90°C and 250°C, where the inks are ejected and then covered with a white ink layer, which is subsequently dried using an infrared heater, minimizing temperature differences and preventing deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If infrared drying is used on transparent resin printing media, then drying speed is improved, but color migration and thermal deformation occur due to uneven infrared absorption across different ink colors

Engineering Contradiction:
Improvedrying speedVSAvoidcolor uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies homogeneity by forming a white solid image printing layer that provides uniform optical properties across the entire printed surface. This white layer ensures that infrared radiation is absorbed uniformly regardless of the underlying color pattern, eliminating the color-dependent absorption differences that cause thermal deformation and color migration during infrared drying.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The patent implements preliminary action by forming the white solid image printing layer before applying the colored pattern layer. This preliminary white layer acts as a uniform base that prevents subsequent color layers from causing uneven infrared absorption, thereby preventing thermal deformation and color migration during the drying process.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by stationary object

If infrared drying is used on transparent resin printing media, then drying efficiency is improved, but thermal deformation occurs due to differential heating

Engineering Contradiction:
Improvedrying efficiencyVSAvoiddimensional stability
Core Design Contradiction:
Use of energy by stationary objectVSStability of the object's composition

Solution Approach 1:

The white solid image printing layer creates a homogeneous surface with uniform infrared absorption characteristics. This uniformity ensures that infrared energy is distributed evenly across the printed material during drying, preventing localized overheating and thermal deformation while maintaining high drying efficiency.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The white solid image printing layer serves as an intermediary between the transparent resin substrate and the colored pattern layer. It mediates the infrared radiation interaction by providing a uniform absorption layer that prevents direct differential heating of the substrate and color layers, thereby maintaining dimensional stability during efficient infrared drying.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If multiple ink layers are printed on transparent resin, then image quality is improved, but uneven infrared absorption leads to thermal deformation

Engineering Contradiction:
Improveimage qualityVSAvoidthermal deformation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses a homogeneous white solid image printing layer as the foundation for the multi-layer print structure. This white layer provides uniform infrared absorption properties that counteract the uneven absorption caused by subsequent colored layers, enabling high image quality without thermal deformation during infrared drying.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The white solid image printing layer is formed in advance before the colored pattern layer is applied. This preliminary uniform layer establishes consistent infrared absorption characteristics that prevent thermal deformation caused by differential heating of subsequent color layers during the drying process.

Inventive Principle:
Principle #10Preliminary action

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 method effectively prevents color migration and deformation of the resin printing medium by ensuring uniform drying and absorption, resulting in high-quality printed materials suitable for practical applications.

Implementation Method 1

heating and drying the resulting printed material from a side of a surface of the printing medium on which the white image obtained in the step 2 is formed, using an infrared heater

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

drying the resulting printed material

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

the resin medium absorbs infrared differently across various ink colors

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Data Source

PatentEP3415333B1Ink jet recording method
Publication Date: 2020.07.29 KAO CORP
  • EP3415333B1 patent drawingFigure 1~2
  • EP3415333B1 patent drawing

AI summary

The present invention relates to an ink-jet printing method that is capable of obtaining good printed materials that are free of occurrence of color migration and deformation of a printing medium even when printed on a resin printing medium. The present invention provides an ink-jet printing method using a water-based ink containing a black ink, a chromatic ink and a white ink which each contain a pigment (A), an organic solvent (C) having a boiling point of not lower than 90°C and lower than 250°C, and water, said method including step 1 of ejecting at least one water-based ink selected from the group consisting of the black ink and the chromatic ink onto a transparent resin printing medium to print an image 1 on the printing medium; step 2 of ejecting the white ink onto the resulting image 1 to print a white image that covers the image 1 on the printing medium; and step 3 of heating and drying the resulting printed material from a side of a surface of the printing medium on which the white image is formed, using an infrared heater.