Infrared Absorbent Ink Formulation for Stable Discharge

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Solution Overview

Problem

Inkjet inks containing infrared absorbents precipitate during discharge, degrading discharging stability and affecting drying properties when used with infrared irradiation for drying on recording media.

Innovation Solution

The ink formulation includes water, an alcohol with a boiling point of 240 degrees C. or lower, and an infrared absorbent, with the alcohol comprising at least 5% of the ink's mass, and excludes alcohols with boiling points higher than 240 degrees C., enhancing compatibility and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If infrared irradiation is used to dry ink on recording medium, then drying property and drying time are improved, but infrared absorbent precipitates during discharge

Engineering Contradiction:

Improvedrying timeVSAvoiddischarging stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the ink by specifying exact ranges for infrared absorbent (0.01-5 mass%), alcohol (5-40 mass%), and water (55-90 mass%). This parameter optimization prevents precipitation while maintaining infrared drying effectiveness, resolving the contradiction between drying speed and discharge stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink formulation combining infrared absorbent, alcohol, and water in specific proportions. This composite material approach ensures the infrared absorbent remains dissolved and stable during discharge while maintaining the desired drying properties when irradiated.

Inventive Principle:

Principle #40Composite materials

2Productivity

If infrared absorbent is added to ink for infrared drying, then drying property is improved, but precipitation occurs during discharge

Engineering Contradiction:

Improvedrying propertyVSAvoidcomposition stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the concentration parameter of infrared absorbent to 0.01-5 mass%, which is sufficient for infrared drying but low enough to prevent precipitation. The alcohol content is simultaneously optimized to 5-40 mass% to ensure complete dissolution, resolving the contradiction between drying effectiveness and composition stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses alcohol as an intermediary substance that facilitates the dissolution of infrared absorbent in the aqueous ink. The alcohol acts as a co-solvent that bridges the infrared absorbent and water, preventing precipitation while allowing the infrared drying function to operate effectively.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If high concentration of infrared absorbent is used for effective drying, then drying property is improved, but precipitation and beading defects occur

Engineering Contradiction:

Improvedrying propertyVSAvoidimage quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent precisely controls the infrared absorbent concentration at 0.01-5 mass%, avoiding both insufficient and excessive concentrations. This precise parameter control ensures effective infrared drying while preventing precipitation and beading defects, thereby maintaining high image quality.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent ensures uniform distribution of infrared absorbent throughout the ink formulation through proper mixing and concentration control. This local quality uniformity prevents localized precipitation and beading, ensuring consistent drying performance and image quality across the entire printed area.

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

This formulation improves drying properties and discharging stability, reducing precipitation of the infrared absorbent and preventing defects like beading in printed images, while maintaining excellent image quality on non-permeable substrates.

Implementation Method 1

infrared irradiation to ink on a recording medium... infrared irradiation is appealing since it is superior to the heated-wind blowing in terms of drying property of ink and shortening the time to dry the ink

Methodology Applied

Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 2

an alcohol having a boiling point of 240 degrees C. or lower... the alcohol accounts for 5.0 percent by mass or more of the total amount of the ink

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS11524509B2Ink, recording device, recording method, and recorded matter

Publication Date: 2022.12.13 RICOH CO LTD

AI summary

ink includes water, an alcohol having a boiling point of 240 degrees C. or lower, and an infrared absorbent, wherein the alcohol accounts for 5.0 percent by mass or more of the total amount of the ink and the ink is free of an alcohol having a boiling point higher than 240 degrees C.