Cationic Polymer Ink Fixing for Feathering and Bleeding

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Solution Overview

Problem

Existing inkjet recording methods face issues with ink fixability on plain paper, leading to problems like feathering, color bleeding, and abrasion resistance, due to the rapid agglutination of pigment and resin emulsion with polyallylamine, resulting in poor image quality and durability.

Innovation Solution

A liquid composition containing a water-soluble cationic polymer derived from epihalohydrin and amine/amide monomers, which agglutinates negatively charged particles, is applied to the recording medium, enhancing ink fixation and preventing bleeding, while a compound represented by Formula (6) improves compatibility and diffusion, ensuring better image density and coatability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an ink having low permeability is used to prevent feathering, then feathering is prevented, but the ink easily retains on the surface of the recording medium, degrading drying properties and causing color bleeding

Engineering Contradiction:

ImprovefeatheringVSAvoiddrying properties

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

A liquid composition containing a water-soluble cationic polymer and a compound of formula (6) is applied as an intermediary layer on the recording medium before applying the dispersion liquid. This intermediary composition mediates between the ink and paper, enabling controlled permeability that prevents feathering while maintaining good drying properties by facilitating proper ink penetration and fixation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If an ink having high permeability is used to prevent color bleeding, then color bleeding is prevented, but feathering occurs and the quality of the recorded matter degrades

Engineering Contradiction:

Improvecolor bleeding preventionVSAvoidfeathering

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The liquid composition serves as a mediator that controls the interaction between the dispersion liquid and recording medium. The water-soluble cationic polymer and compound of formula (6) work together to create optimal permeability conditions that prevent both feathering and color bleeding, achieving high-quality recorded matter.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If polyallylamine is used to fix the ink composition, then print bleeding and color bleeding are reduced, but the pigment and resin emulsion rapidly agglutinate, forming aggregates with small vehicle content that have poor abrasion resistance

Engineering Contradiction:

Improveprint bleeding preventionVSAvoidabrasion resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent changes the chemical parameters of the fixing composition by using a water-soluble cationic polymer obtained by polymerizing monomers containing epihalohydrin and at least one of amine and amide, along with a compound of formula (6). This parameter change modifies the agglutination behavior to prevent rapid aggregation while maintaining good abrasion resistance and print bleeding prevention.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The liquid composition is a composite material combining a water-soluble cationic polymer and a compound of formula (6). This composite structure provides synergistic effects that simultaneously achieve print bleeding prevention, good abrasion resistance, and controlled agglutination behavior.

Inventive Principle:

Principle #40Composite materials

4Reliability

If the reaction liquid has a strong effect to cause the ink to agglutinate, then color bleeding is prevented, but the diameter of each dot recorded is small, causing white-out

Engineering Contradiction:

Improvecolor bleeding preventionVSAvoiddot diameter

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent adjusts the chemical parameters of the liquid composition by selecting specific water-soluble cationic polymers and compounds of formula (6) with controlled properties. This enables moderate agglutination effect that prevents color bleeding while maintaining sufficient dot diameter to avoid white-out.

Inventive Principle:

Principle #35Parameter changes

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 solution effectively prevents feathering and color bleeding, enhances abrasion resistance, and improves drying properties, resulting in high-density images with reduced white-out and improved coatability.

Implementation Method 1

a water-soluble cationic polymer obtained by polymerizing monomers containing epihalohydrin and at least one of amine and amide... for agglutinating negatively charged particles

Methodology Applied

Scientific EffectElectrostatic attraction: Ion Repulsion/Attraction

Implementation Method 2

a compound represented by Formula (6)... the dispersion medium contained in the dispersion liquid is diffused by the action of a water-soluble cationic polymer

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentEP2606084B1Liquid composition, recording method, and recorded matter

Publication Date: 2017.10.25 RICOH CO LTD

AI summary

A liquid composition containing: a water-soluble cationic polymer obtained by polymerizing monomers containing epihalohydrin and at least one of amine and amide; and water, wherein the liquid composition is for agglutinating negatively charged particles which are dispersed in a dispersion liquid.