Ink Set Cleaning Liquid Conductivity and HLB Control

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Solution Overview

Problem

Inkjet printing faces issues with jetting faults and clogging due to the aggregation of components in the inkjet head, which can lead to insufficient cleaning and reduced printing quality, especially when using aqueous inks.

Innovation Solution

An ink set comprising an inkjet pretreatment liquid with an aggregating agent, an inkjet ink, and a cleaning liquid that includes water, a water-soluble organic solvent, a surfactant with an HLB value of 10 or more, and a metal salt, with a conductivity of 0.10 to 3.0 mS/cm at 5°C, enhancing the dispersion and stability of the aggregating agent and preventing aggregation of ink components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cleaning liquid is used to clean the inkjet head, then jetting faults and clogging are reduced, but insufficient cleaning and foreign matter formation occur with conventional cleaning liquids

Engineering Contradiction:
Improvejetting stabilityVSAvoidforeign matter formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The cleaning liquid's conductivity is precisely controlled within 0.10 to 3.0 mS/cm at 5°C, and the surfactant's HLB value is set to 10 or more. These parameter optimizations enable the cleaning liquid to effectively dissolve aggregating agents and ink components while preventing foreign matter formation, resolving the contradiction between cleaning effectiveness and foreign matter generation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The cleaning liquid comprises a composite formulation containing water, water-soluble organic solvent, surfactant with HLB≥10, and metal salt A. This composite composition synergistically provides both strong cleaning capability for jetting faults and prevents foreign matter formation through balanced chemical properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the cleaning liquid has high polarity to dissolve aggregating agents, then cleaning effectiveness improves, but surfactant precipitation occurs reducing storage stability

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidstorage stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The surfactant's HLB value is optimized to 10 or more, which maintains sufficient polarity for effective dissolution of aggregating agents while preventing surfactant precipitation. This parameter optimization resolves the contradiction between cleaning effectiveness and storage stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The cleaning liquid is designed with specific local chemical properties: metal salt A is selected to provide targeted ionic strength that enhances aggregating agent dissolution without triggering surfactant precipitation, creating localized optimal conditions for both cleaning and stability.

Inventive Principle:
Principle #3Local quality

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 provides excellent cleaning effects for both the pretreatment liquid and ink, reducing foreign matter formation and clogging, thereby ensuring stable jetting and improved printing quality by maintaining high polarity and preventing surfactant precipitation, which enhances storage stability and cleaning properties.

Implementation Method 1

a surfactant with an HLB value of 10 or more

Methodology Applied
Scientific EffectSurfactant: Surfactant

Implementation Method 2

a surfactant with an HLB value of 10 or more, and has a conductivity of 0.10 to 3.0 mS/cm at 5° C.

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

a cleaning liquid that contains water, a water-soluble organic solvent, a surfactant with an HLB value of 10 or more, and a metal salt A, and has a conductivity of 0.10 to 3.0 mS/cm at 5° C.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

an inkjet pretreatment liquid containing an aggregating agent

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentUS20240110074A1Ink set
Publication Date: 2024.04.04 RISO KAGAKU CORP

AI summary

Disclosed is an ink set including: an inkjet pretreatment liquid containing an aggregating agent; an inkjet ink; and a cleaning liquid that contains water, a water-soluble organic solvent, a surfactant with an HLB value of 10 or more, and a metal salt A, and has a conductivity of 0.10 to 3.0 mS/cm at 5° C. A method for producing a printed textile item is also disclosed.