Inkjet Recording Method Using Anionic and Cationic Processing Liquids

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Solution Overview

Problem

Ink bleeding and image quality degradation occur due to diffusion of color material in ink during the drying process, and excessive condensing phenomena happen when color material and resin react with fixing solutions, leading to image shrinkage.

Innovation Solution

A recording method involving a first applying step of anionic pre-processing liquid and a second applying step of cationic reaction liquid, followed by a drying step, where the mixed liquid reacts to form a cationic condensation layer, preventing excessive condensing and enhancing image stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cationic fixing solution is applied to the medium before anionic ink is adhered, then ink bleeding is prevented, but excessive condensing occurs causing image shrinkage

Engineering Contradiction:

Improveink bleeding preventionVSAvoidimage dimension accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The fixing solution is divided into two separate applications: first an anionic fixing solution is applied, then after drying, a cationic fixing solution is applied. This segmentation prevents simultaneous reaction of both solutions that would cause excessive condensing, while still achieving the bleeding prevention effect through the cationic solution's interaction with the anionic ink.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The anionic fixing solution is applied in advance and dried before applying the cationic fixing solution. This preliminary action prepares the medium surface to receive the cationic solution without causing immediate excessive reaction, allowing controlled interaction only when needed for bleeding prevention.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If color material and resin in the ink react with the fixing solution, then ink bleeding is prevented, but the image shrinks due to excessive condensing

Engineering Contradiction:

Improveink bleeding preventionVSAvoidimage size

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The fixing process is segmented into two distinct stages: first applying and drying the anionic fixing solution, then applying the cationic fixing solution. This prevents the color material and resin from reacting with both solutions simultaneously, avoiding excessive condensing and image shrinkage while still achieving bleeding prevention through the cationic solution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The anionic fixing solution is applied and dried in advance to prepare the medium, creating a controlled surface state. The cationic fixing solution is then applied to interact with the anionic ink without causing excessive condensing, as the preliminary anionic layer moderates the reaction.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a fixing solution is applied before ink adhesion, then bleeding is prevented, but the process complexity increases

Engineering Contradiction:

Improveprinting image qualityVSAvoidprocessing steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fixing process is segmented into two separate applications using different charged solutions, which can be implemented using existing multi-color inkjet mechanisms. This segmentation maintains printing image quality while utilizing standard equipment capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixing solution system uses charged droplets that can be delivered by standard inkjet print heads, making the dual-solution approach compatible with existing printing apparatus without requiring entirely new equipment. The same print head mechanism that deposits colored ink can also deposit the charged fixing solutions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 excessive condensing and maintains high printing speed while ensuring precise image formation by fixing the color material and resin to a condensation layer, thus improving image quality and adhesion.

Implementation Method 1

causing the first processing liquid and the second processing liquid to react with each other, and generating mixed liquid

Methodology Applied

Scientific EffectChemical reaction between anionic and cationic substances: Chemical Bonding

Implementation Method 2

a first drying step of drying the mixed liquid subsequently to the second applying step

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS11065885B2Recording method, ink set, and printing apparatus

Publication Date: 2021.07.20 SEIKO EPSON CORP

AI summary

Provided is a recording method including: a first applying step of applying anionic first processing liquid on a medium; a second applying step of applying cationic second processing liquid on the medium, causing the first processing liquid and the second processing liquid to react with each other, and generating mixed liquid, subsequently to the first applying step; and a first drying step of drying the mixed liquid subsequently to the second applying step, in which the mixed liquid is cationic.