Radiation-Curable Inkjet Ink Gellant Ester Composition

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Solution Overview

Problem

Radiation-curable gelling inkjet inks used in scanning ink jet printing often exhibit visible boundaries between swaths, which affects print quality due to the gelling agent's viscosity increase upon cooling.

Innovation Solution

A radiation-curable inkjet ink composition comprising a gellant ester compound derived from a condensation product of a compound with multiple hydroxyl or carboxylic acid functional groups and a gel accelerator, such as dimethyldioctadecylammonium chloride, to control viscosity and prevent blooming, thereby reducing swath boundary visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a gellant is added to radiation-curable inkjet ink composition to control droplet spreading and prevent color bleeding, then viscosity increase upon cooling is achieved, but visible swath boundaries appear in scanning ink jet printing

Engineering Contradiction:
Improvedroplet spreading controlVSAvoidswath boundary visibility
Core Design Contradiction:
Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent changes the chemical parameters of the gellant by specifying it must be an ester compound formed from a polyol (compound A) and a fatty acid (compound B). This specific chemical composition achieves the desired viscosity increase upon cooling while preventing swath boundary visibility through optimized molecular structure and interaction properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink composition by combining the radiation-curable medium with a specifically formulated gellant (ester compound) and gel accelerator. This composite approach allows the gellant to provide viscosity control without causing the harmful swath boundary effect, as the ester compound integrates smoothly with the ink formulation.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If a gellant is used to increase viscosity upon cooling for adequate droplet spreading control, then color bleeding is prevented, but swath boundary visibility increases in printed images

Engineering Contradiction:
Improveviscosity stability upon coolingVSAvoidprint quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent optimizes the gelation kinetics by introducing a gel accelerator (compound according to formula I with specific structural features). This accelerator modifies the rate and manner of viscosity increase upon cooling, allowing the ink to maintain stability while avoiding the formation of visible swath boundaries through controlled gelation dynamics.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the gelling speed is increased to improve print quality and reduce swath boundary visibility, then print quality improves, but the gelling agent may migrate to the surface causing blooming

Engineering Contradiction:
Improveprint qualityVSAvoidgelling agent distribution
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent specifies that the gel accelerator must have a particular molecular structure (formula I with defined R groups) to achieve optimal gelation speed. This structural parameter control ensures rapid gelation for high print quality while the molecular design prevents excessive surface migration and blooming by balancing gelation kinetics with molecular 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 achieves high gelling speed and improved print quality with reduced swath boundary visibility, maintaining gloss and preventing unwanted surface migration of the gelling agent.

Implementation Method 1

These inks are typically jetted at elevated temperatures. Phase change inks may become solid or semi-solid upon cooling down on a recording medium, e.g. a sheet of paper. As a result, spread of a droplet of ink on the recording medium may be decreased and color bleeding may be prevented.

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

The ink composition achieves high gelling speed and improved print quality with reduced swath boundary visibility, maintaining gloss and preventing unwanted surface migration of the gelling agent.

Methodology Applied
Scientific EffectGel formation: Gel

Implementation Method 3

A radiation-curable component is a component that may react (e.g. polymerize) under influence of suitable radiation, such as electromagnetic radiation, e.g. ultraviolet (UV) radiation.

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3249020B1Ink jet ink composition
Publication Date: 2020.08.26 CANON PRODN PRINTING HLDG BV
  • EP3249020B1 patent drawingFigure 1A~1B
  • EP3249020B1 patent drawingFigure 2~3

AI summary

The present invention relates to a radiation curable ink composition comprising a gellant and a gel accelerator. The present invention further relates to an ink set comprising such ink composition. The present invention further relates to a method for making such ink composition and a printing method using such ink composition.