Ink Jet Ink Formulation for Light and Ozone Resistance

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Solution Overview

Problem

Conventional ink jet recording methods face challenges in achieving both high optical density and fastness properties, particularly in light resistance and ozone resistance, while maintaining intermittent ejection stability.

Innovation Solution

The development of an ink jet ink containing a specific compound represented by general formula (I), ethylene urea, and an alkanediol with 4 to 6 carbon atoms, where the mass ratios of these components are optimized to ensure effective light resistance, ozone resistance, and intermittent ejection stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional coloring materials are used to achieve high optical density, then color developing properties are improved, but light resistance and ozone resistance deteriorate

Engineering Contradiction:
Improveoptical densityVSAvoidlight resistance and ozone resistance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the chemical structure parameters of the coloring material by introducing specific substituents (electron-withdrawing groups like -NO2, -CN, -CF3 and electron-donating groups like -OH, -OCH3, -NH2) at defined positions on the naphthalene ring. This structural parameter modification enables the coloring material to simultaneously achieve high optical density and improved light/ozone resistance, resolving the contradiction between these properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink formulation combining the novel naphthalene-based coloring material with specific humectants (glycerin, ethylene glycol, propylene glycol) and surfactants. This composite approach enhances the overall stability, light resistance, and ozone resistance of the ink system while maintaining high optical density, thus resolving the contradiction between color strength and durability.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If conventional coloring materials are used to achieve high optical density, then color developing properties are improved, but image fastness deteriorates

Engineering Contradiction:
Improveoptical densityVSAvoidimage fastness
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent modifies the molecular structure parameters of the coloring material by precisely positioning electron-withdrawing and electron-donating substituents on the naphthalene ring. This structural optimization enhances both the optical density and the chemical stability of the image, thereby improving image fastness against fading and deterioration while maintaining strong color development.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If ink formulation is optimized for light resistance, then durability is improved, but intermittent ejection stability deteriorates

Engineering Contradiction:
Improvelight resistanceVSAvoidintermittent ejection stability
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent optimizes the molecular parameters of the coloring material to balance light resistance with ejection stability. The specific substituent positions and types are selected to ensure the ink maintains appropriate viscosity and flow characteristics for reliable intermittent ejection, while simultaneously providing high light resistance. The ink formulation parameters (humectant ratios, surfactant concentrations) are also adjusted to achieve this balance.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2695920B1Ink, ink cartridge and ink jet recording method
Publication Date: 2015.10.14 CANON KK
  • EP2695920B1 patent drawingFigure 1
  • EP2695920B1 patent drawingFigure 2A~2B
  • EP2695920B1 patent drawing

AI summary

The present invention provides an ink jet ink that is capable of recording an image excellent in light resistance and ozone resistance and has excellent intermittent ejection stability. The ink jet ink contains a coloring material and a water-soluble organic solvent. The coloring material contains a compound represented by the following general formula (I), the water-soluble organic solvent contains ethylene urea and an alkanediol having 4 to 6 carbon atoms, and a content A (% by mass) of the coloring material, a content B (% by mass) of the ethylene urea and a content C (% by mass) of the alkanediol having 4 to 6 carbon atoms based on a total mass of the ink satisfy relationships of 0.20 ≤ B/A ≤ 10.0 and 0.10 ≤ C/A ≤ 10.0.