Inkjet Cleaning Liquid Hansen Solubility Parameter

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Solution Overview

Problem

Aqueous inks used on non-permeable recording media often adhere to recording heads, causing stability issues due to the presence of resin, and existing cleaning liquids are insufficient in removing the ink, leading to degradation of discharging stability.

Innovation Solution

A cleaning liquid comprising water and a first organic solvent with a Hansen solubility parameter of 10.0 (cal/cm^3) or less, combined with a polysiloxane surfactant having an HLB value of 8 or less, effectively disperses polyurethane resin particles, enhancing cleaning power and restoring discharging stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an ink contains a resin to secure fixability on a non-permeable recording medium, then the fixability is improved, but the ink adheres to a recording head, aggregates, and dries during continuous recording, which degrades discharging stability

Engineering Contradiction:
ImprovefixabilityVSAvoiddischarging stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts the harmful adhesive component (resin) from the ink formulation by using a pigment-based ink without resin binder, thereby eliminating the aggregation and clogging issues while maintaining fixability through the pigment particles themselves

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters of the ink by replacing resin-based binders with pigment particles and adjusting the solvent system to achieve both fixability and discharging stability simultaneously

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a cleaning liquid is used to remove ink from a recording head, then the discharging stability is improved, but typical cleaning liquids are not sufficient to remove the ink firmly adhering to the recording head

Engineering Contradiction:
Improvedischarging stabilityVSAvoidcleaning effectiveness
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent optimizes the cleaning liquid composition by adjusting the Hansen solubility parameters to match the ink components, using specific ratios of water, organic solvents, and surfactants to achieve effective removal of adhered ink

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite cleaning liquid system combining multiple components (water, organic solvents like alcohols or ketones, and surfactants) that work synergistically to remove firmly adhered ink from recording heads

Inventive Principle:
Principle #40Composite materials

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 significantly improves the cleaning power and discharging stability by effectively removing ink from recording heads, ensuring reliable inkjet printing operations.

Implementation Method 1

A liquid mixture of the water and the first organic solvent has a Hansen solubility parameter including a hydrogen bond term of 10.0 (cal/cm³

Methodology Applied
Scientific EffectSolvation: Solvation

Data Source

PatentEP3336151B2Set of ink and cleaning liquid, inkjet printing method, and inkjet printing device
Publication Date: 2023.11.08 RICOH CO LTD
  • EP3336151B2 patent drawingFigure 1~2
  • EP3336151B2 patent drawingFigure 3
  • EP3336151B2 patent drawingFigure 4

AI summary

A set includes an ink and a cleaning liquid, wherein the cleaning liquid includes water and a first organic solvent, wherein a liquid mixture of the water and the first organic solvent has a Hansen solubility parameter including a hydrogen bond term of 10.0 (cal/cm3)1/2 or less, wherein the ink includes water, a second organic solvent, a polyurethane resin particle, and a polysiloxane surfactant having an HLB value of 8 or less, wherein the polyurethane resin particle accounts for 5 percent by mass or more of a total amount of the ink.