Inkjet Recording Method Using Pre-Processing Fluid

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Solution Overview

Problem

Aqueous inkjet inks struggle to penetrate recording media with coated layers, leading to beading and bronzing issues, particularly when viewed from certain angles, due to the ink's inability to uniformly spread and adhere, resulting in poor image quality and gloss.

Innovation Solution

The method involves applying a pre-processing fluid containing a quaternary salt of an adduct of alkyl amine·epichlorohydrine and a nonion-based surfactant to the recording medium, followed by drying, which enhances ink permeation and leveling, reducing bronzing and improving image gloss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If aqueous ink is jetted onto recording media with coated layers, then image formation is achieved, but droplets unify on the surface leading to beading and bronzing

Engineering Contradiction:

Improveimage qualityVSAvoidbeading and bronzing

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A pretreatment liquid is applied to the recording medium before inkjet recording to modify the surface properties. This preliminary action enables aqueous ink to properly penetrate and spread on coated recording media, preventing beading and bronzing while maintaining image quality

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pretreatment liquid acts as an intermediary substance between the aqueous ink and the coated recording medium. It modifies the surface energy and porosity of the coated layer, allowing the ink to penetrate uniformly without unifying on the surface, thus eliminating beading and bronzing effects

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If bronzing resistance agents are added to aqueous ink, then bronzing is reduced, but ink penetration and uniformity on coated surfaces remain problematic

Engineering Contradiction:

ImprovebronzingVSAvoidink penetration uniformity

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

Instead of adding multiple chemical agents to the ink, the invention applies a pretreatment liquid to the recording medium beforehand. This preliminary modification of the surface properties enables uniform ink penetration without requiring complex ink formulations, thus maintaining ink uniformity while reducing bronzing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention extracts the bronzing prevention function from the ink formulation itself and transfers it to a separate pretreatment liquid applied to the recording medium. This separation simplifies the ink composition while effectively preventing bronzing and improving penetration uniformity

Inventive Principle:

Principle #2Taking out (Extraction)

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 approach effectively reduces bronzing and non-uniformity, enhancing image quality by ensuring better ink penetration and retention on coated surfaces, thereby maintaining image gloss and density.

Implementation Method 1

the pre-processing fluid contains a hydrosoluble organic solvent, a flocculating agent formed of a quaternary salt of an adduct of alkyl amine·epichlorohydrine represented by the following chemical formula 1, and a nonion-based surfactant represented by the following chemical formula 2

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 2

drying the pre-processing fluid

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2886358B1Inkjet recording method and inkjet recording device

Publication Date: 2017.08.30 RICOH CO LTD

Figure 1~2

AI summary

An inkjet recording method includes imparting a pre-processing fluid to a coated layer provided on at least one surface of the substrate of a recording medium, drying the pre-processing fluid, and forming an image on the recording medium by ejecting an aqueous ink thereon. The pre-processing fluid contains a hydrosoluble organic solvent, a flocculating agent formed of a quaternary salt of an adduct of alkyl amine-epichlorohydrine represented by the following chemical formula 1, and a nonion-based surfactant represented by the following chemical formula 2, Chemical formula 1 R-O-(CH2CH2O)x-(CH2C(CH3)CH20)y-H (2) Chemical formula 2 wherein the aqueous ink comprises a colorant, a hydrosoluble organic solvent, and a fluorine-containing surfactant represented by the following chemical formula 3 or 4: C6F13-CH2CH2O(CH2CH2O)nH (3) Chemical formula 3 CnF2n+1-CH2CH(OH)CH2-O-(CH2CH2O)a-Y (4) Chemical formula 4