Plasma-Curable Offset Ink for Substrate Protection

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Solution Overview

Problem

The existing plasma drying methods for offset printing, particularly using remote-type plasma generators, face challenges such as insufficient drying due to reduced plasma reactivity and potential substrate damage, while direct-type plasma generators offer rapid drying but risk substrate damage during irradiation.

Innovation Solution

A plasma-curable ink composition containing a pigment, binder resin, and specific ingredients like castor oil, polymerized oil, and alkyd resins with an acid value of 10 mg KOH/g or more, which enhances polymerization reaction rates when irradiated with plasma, allowing for sufficient drying even with remote-type plasma generators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If direct-type plasma generator is used for ink drying, then drying speed is improved, but substrate damage occurs

Engineering Contradiction:
Improvedrying speedVSAvoidsubstrate damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a remote-type plasma generator as an intermediary device that generates plasma at a distance from the substrate. The plasma is generated in a discharge space separated from the substrate by a gap, allowing the plasma to act on the ink without directly contacting or excessively heating the substrate, thus preventing substrate damage while maintaining drying effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies preliminary action by using a corona treatment unit or plasma treatment unit before the main drying process to prepare the substrate surface. This preliminary treatment activates the surface and removes contaminants, creating optimal conditions for subsequent ink adhesion and drying without requiring intense direct plasma exposure that could damage the substrate

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If remote-type plasma generator is used for ink drying, then substrate damage is reduced, but drying effectiveness decreases due to reduced plasma reactivity

Engineering Contradiction:
Improvesubstrate damageVSAvoiddrying effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes plasma generation parameters by using a corona discharge mechanism instead of conventional plasma arcs. The corona discharge produces a distributed, low-temperature plasma field with sufficient reactivity for ink drying. Additionally, the patent optimizes the gap distance between the plasma generator and substrate, and adjusts plasma power levels to maintain effective drying while preventing substrate damage

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite approach by combining multiple treatment mechanisms: corona discharge for plasma generation, oxidation for ink component breakdown, and controlled heating for evaporation. This composite method leverages the synergistic effects of different mechanisms to achieve effective drying with reduced substrate damage compared to single-mechanism approaches

Inventive Principle:
Principle #40Composite materials

3Object-generated harmful factors

If oxidative polymerization is used for ink drying, then environmental load is reduced, but drying time increases

Engineering Contradiction:
Improveenvironmental loadVSAvoiddrying time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent replaces the slow chemical oxidation process with a plasma-based physical-chemical treatment. The plasma provides highly reactive species including oxygen radicals, ozone, and excited molecular states that can rapidly oxidize and polymerize ink components. This substitution reduces drying time from hours (conventional oxidation) to seconds or minutes while maintaining low environmental impact by avoiding VOC emissions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses plasma-generated strong oxidants including ozone (O3), oxygen radicals (O2•-), and atomic oxygen to accelerate the oxidation of ink components. These highly reactive species break down complex organic molecules in the ink much faster than atmospheric oxygen alone, achieving rapid drying while still being an environmentally friendly process that doesn't release harmful VOCs into the atmosphere

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

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 rapid and effective curing of the ink on the surface, ensuring a tack-free state without damaging the substrate, as it exhibits high reactivity with plasma generated by both direct and remote-type generators, reducing the risk of substrate damage and environmental concerns.

Implementation Method 1

an ink composition for offset printing, containing a pigment, a binder resin, and at least one specific ingredient selected from the group consisting of castor oil, polymerized oil, and alkyd resins having an acid value of 10 mg KOH/g or more

Methodology Applied
Scientific EffectPolymerization:

Implementation Method 2

irradiating the printed substrate with plasma to cure and fix the ink composition on the substrate

Methodology Applied
Scientific EffectPlasma irradiation: Plasma

Implementation Method 3

The ingredients containing the specific ingredient can be polymerized into a high molecular weight product through irradiation with plasma

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS11597847B2Plasma-curable offset printing ink composition, method for producing printed matter using same, and printing method
Publication Date: 2023.03.07 SAKATA INX

AI summary

A plasma-curable ink composition for offset printing having high reactivity with plasma and capable of being hardened into a sufficiently dried state even in the use of plasma generated by a remote-type plasma generator, and a method for producing printed matter and a method for printing information using the same. The plasma-curable ink composition for offset printing comprises a pigment, a binder resin, and at least one specific ingredient selected from the group consisting of castor oil, polymerized oil, and alkyd resins having an acid value of 10 mg KOH/g or more.