Ink Set Fatty Acid Layer Anti-Bleeding on Low-Absorbent Media

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Solution Overview

Problem

Existing ink jet recording methods face issues with color bleeding and poor water and light fastness when using water-soluble dyes on low-absorbent recording media, particularly when combining different inks.

Innovation Solution

An ink set comprising a first ink with a fatty acid and self-dispersing pigment, a second ink with resin-dispersed pigment and no fatty acid, and optionally a third ink with self-dispersing pigment and no fatty acid, is used to prevent bleeding by forming a fatty acid layer on the recording medium, enhancing anti-bleeding effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If water-soluble dyes are used in ink jet recording, then the ink can be easily deposited on recording media, but the images show poor water fastness and light fastness

Engineering Contradiction:
Improveease of ink depositionVSAvoidwater fastness and light fastness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a binder resin as an intermediary substance that mediates between the water-soluble dye and the recording medium. The binder resin forms a film that anchors the dye particles, preventing them from dissolving or fading, thereby improving water and light fastness while maintaining ease of deposition

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The ink composition is formulated as a composite material system combining water-soluble dyes with binder resins, surfactants, and other additives. This composite approach allows the ink to simultaneously achieve easy deposition (from water solubility) and high fastness (from the binder resin matrix)

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If a single ink containing water-soluble dye is used for recording on plain paper, then the recording process is simple, but color bleeding occurs and images show poor fastness

Engineering Contradiction:
Improvesimplicity of recording processVSAvoidanti-bleeding performance and fastness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent divides the recording system into multiple segmented components: different inks are assigned to different color channels (CMYK), each with optimized compositions. This segmentation allows each ink to be tailored for specific performance characteristics while collectively achieving anti-bleeding effects through their interactions on the recording medium

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent modifies key parameters of the ink composition, specifically adjusting the molecular weight, glass transition temperature, and chemical structure of the binder resin. These parameter changes enable the resin to form a effective film that prevents bleeding while maintaining the simplicity of the recording process

Inventive Principle:
Principle #35Parameter changes

3Productivity

If inks are used for recording on low-absorbent recording media, then the recording speed can be maintained, but abnormal bleeding occurs

Engineering Contradiction:
Improverecording speedVSAvoidanti-bleeding performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The binder resin performs a preliminary action by forming a protective film on the recording medium surface before the dye fully penetrates or dries. This pre-formed film acts as a barrier that prevents abnormal bleeding, allowing the ink to be deposited at high speeds without sacrificing anti-bleeding performance

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

The ink set effectively prevents color bleeding and maintains high color developability and glossiness on low-absorbent media, even when used for high-density and high-gloss printing applications.

Implementation Method 1

by selecting inks for an ink set so that each of the inks has a specific relationship between the pigment and the presence or absence of a fatty acid... forming a fatty acid layer on the recording medium, enhancing anti-bleeding effects

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentUS9334413B2Ink set and recording method using the same
Publication Date: 2016.05.10 SEIKO EPSON CORP

AI summary

An ink set includes a first ink containing a fatty acid and a self-dispersing pigment, and at least either a second ink containing a resin-dispersed pigment and substantially no fatty acid or a third ink containing a self-dispersing pigment and substantially no fatty acid.