Lithographic Printing Ink Surface Tension Control
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Solution Overview
Problem
Lithographic printing faces challenges in achieving high gloss for multi-color prints and scumming resistance due to insufficient ink aggregation force under high shear conditions, which leads to printing defects and reduced gloss.
Innovation Solution
A method involving the use of lithographic printing inks with controlled surface tension differences between black, cyan, and magenta inks, ensuring a maximum difference of 3.5 mN/m, along with specific resin and surfactant compositions to enhance wettability and aggregation force, thereby improving print gloss and scumming resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resin concentration in ink is increased to enhance aggregation force and suppress scumming, then scumming resistance is improved, but adhesion property onto printing plate deteriorates and fluidity of ink decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the ink by introducing specific low molecular weight compounds (carboxylic acid esters with 8-12 carbon atoms) and controlling resin concentration within a specific range (10-30 mass%). This allows the ink to achieve both high aggregation force for scumming resistance and sufficient adhesion to the printing plate, resolving the contradiction between these two properties.
Solution Approach 2:
The patent creates a composite ink formulation combining multiple components: pigments, resins (10-30 mass%), low molecular weight carboxylic acid esters (1-10 mass%), and other additives. This composite structure provides both the aggregation force needed for scumming resistance and the adhesion properties required for proper printing plate bonding.
2Reliability
If resin concentration in ink is increased to enhance aggregation force, then scumming resistance is improved, but fluidity of ink decreases causing surface irregularities
Solution Approach 1:
The patent introduces low molecular weight carboxylic acid esters (8-12 carbon atoms) as a specific additive that modifies the ink's rheological properties. This allows the ink to maintain high fluidity for smooth surface transfer while simultaneously providing sufficient aggregation force to prevent scumming, effectively resolving the contradiction between these two properties.
Solution Approach 2:
The low molecular weight carboxylic acid esters are specifically targeted to improve local properties of the ink - enhancing fluidity and surface smoothness where needed while maintaining aggregation force through the resin component. This localized quality enhancement resolves the contradiction between fluidity and scumming resistance.
3Illumination intensity
If low molecular-weight compounds such as phthalic acid ester, adipic acid ester, and sebacic acid ester are used as gloss enhancers, then gloss of printed part is improved, but transferability deteriorates due to evaporation under high shear conditions
Solution Approach 1:
The patent changes the molecular weight parameter of the carboxylic acid ester component, specifying compounds with 8-12 carbon atoms. This parameter optimization provides the right balance: sufficient molecular weight to prevent evaporation under high shear printing conditions (maintaining transferability) while still providing gloss enhancement functionality. The patent also controls the concentration range (1-10 mass%) to achieve both gloss and transferability.
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 method effectively achieves high gloss for both single-color and multi-color prints while preventing scumming, ensuring improved print quality and surface smoothness.
Implementation Method 1
a difference in surface tension between the inks to be coated on a substrate is at most equal to 3.5 mN/m
Implementation Method 2
use of lithographic printing ink which contains no volatile component and is cured instantly upon active energy ray irradiation
Data Source
AI summary
To provide is a manufacturing method for obtaining printed material in which, in lithographic printing, a printed part where multiple colors are superimposed on each other has a high gloss, and also a lithographic printing ink set. The method for manufacturing printed material according to the present invention includes a step of coating at least black ink for lithographic printing, cyan ink for lithographic printing, magenta ink for lithographic printing, and yellow ink for lithographic printing on a substrate, in which a difference in surface tension between the inks to be coated on a substrate is at most equal to 3.5 mN/m. The lithographic printing ink set according to the present invention is a lithographic printing ink set including at least black ink, cyan ink, magenta ink, and yellow ink, in which a difference in surface tension between the inks included in the lithographic printing ink set is at most equal to 3.5 mN/m.