Ink Composition with Density-Graded Wax Particles

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing inkjet recording technologies face challenges in achieving excellent temporal storage stability and immediate blocking resistance, particularly due to the insufficient storage stability of pigment inks and reduced rubbing resistance on various recording media.

Innovation Solution

An ink composition comprising a colorant, water, and wax particles with specific gravities differing by 0.05 to 0.15, where the mass ratio of the waxes ranges from 1:4 to 4:1, effectively suppressing wax separation and enhancing storage stability and blocking resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pigment is used for colorant, then weather resistance is improved, but storage stability deteriorates

Engineering Contradiction:
Improveweather resistanceVSAvoidstorage stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the physical state parameter of the colorant from solid pigment particles to dissolved state by using water-soluble dyes, which fundamentally alters the storage stability characteristics while maintaining weather resistance through dye selection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink formulation combining water-soluble dyes with specific additives including surfactants, humectants, and pH buffers to achieve both good storage stability and weather resistance simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If wax particles with different specific gravities are added, then blocking resistance is improved, but ink composition complexity increases

Engineering Contradiction:
Improveblocking resistanceVSAvoidink composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent optimizes the specific gravity parameter of wax particles to fall within 0.90-1.05, creating a narrow range that ensures uniform distribution and prevents separation while maintaining simple ink formulation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses wax particles with uniform specific gravity within a narrow range to ensure homogeneous distribution throughout the ink, preventing phase separation and maintaining formulation simplicity

Inventive Principle:
Principle #33Homogeneity

3Strength

If pigment particles remain on surface, then rubbing resistance deteriorates, but storage stability worsens

Engineering Contradiction:
Improverubbing resistanceVSAvoidstorage stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent uses water-soluble dyes that can be applied in aqueous form and then fixed to the recording medium, creating a copied image that resists rubbing while the aqueous vehicle maintains storage stability

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the colorant form from insoluble pigment particles to water-soluble dye molecules, which can be uniformly distributed in the aqueous ink and firmly fixed to the recording medium, improving rubbing resistance while maintaining storage stability

Inventive Principle:
Principle #35Parameter changes

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 composition exhibits improved temporal storage stability and enhanced blocking resistance immediately after image formation, maintaining ink stability while improving rubbing resistance on various recording media.

Implementation Method 1

the at least two kinds of wax comprise a first wax and a second wax, the first and second waxes having different specific gravities from each other, wherein the difference of the specific gravity of the first wax and the specific gravity of the second wax is from 0.05 to 0.15

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Data Source

PatentEP2412763B1Ink composition, ink set and image forming method
Publication Date: 2014.08.06 FUJIFILM CORP
  • EP2412763B1 patent drawingFigure 1
  • EP2412763B1 patent drawing

AI summary

The invention provides an ink composition comprising a colorant, water and wax particles, the wax particles comprising at least two kinds of wax; an ink set including the ink composition; and a method of forming an image using the ink composition.