Dyeing Method for Waterless Lithographic Plates
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Solution Overview
Problem
Existing dyeing solutions for lithographic printing plates suffer from dye concentration decreases and unevenness, particularly in waterless offset lithographic printing, leading to poor plate inspection characteristics during bulk processing.
Innovation Solution
A dyeing method using a solution comprising a dye, an anionic surface active agent with a linear alkyl group, and an organic solvent, where the anionic surface active agent is represented by a specific formula and the solvent has a solubility parameter difference of less than 5 with a polymer compound, ensuring stable dye concentration and reduced unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional dyeing solution is used for bulk processing, then the dyeing process can be performed, but the dye concentration decreases due to sludge generation and foaming
Solution Approach 1:
The patent changes the chemical parameters of the dyeing solution by specifying precise concentration ranges: dye (0.01-5 mass%), anionic surface active agent (0.01-2 mass%), and solvent (95-99.9 mass%). This parameter optimization prevents sludge generation and foaming while maintaining stable dye concentration during bulk processing
Solution Approach 2:
The anionic surface active agent acts as an intermediary substance that mediates between the dye and the printing plate. It prevents direct aggregation of dye molecules into sludge and suppresses foaming, thereby maintaining stable dye concentration throughout the bulk processing operation
2Object-generated harmful factors
If a dyeing solution with anionic surface active agent is used, then foaming is suppressed, but dyeing unevenness occurs in some parts of the plate
Solution Approach 1:
The patent optimizes the concentration parameter of the anionic surface active agent to a specific range (0.01-2 mass%) and specifies the solvent composition (95-99.9 mass%). This parameter precision ensures uniform dye distribution while suppressing foaming, eliminating dyeing unevenness
Solution Approach 2:
The patent ensures uniform dyeing across the entire plate surface by optimizing the local distribution of dyeing solution components. The specific composition ratios ensure that the dyeing solution uniformly penetrates different regions of the printing plate, achieving consistent dyeing quality throughout
3Quantity of substance
If a water-insoluble organic solvent is contained in the dyeing solution, then the dye concentration is maintained, but sludge composed mainly of dye is generated
Solution Approach 1:
The anionic surface active agent serves as an intermediary that prevents dye molecules from aggregating and forming sludge. It maintains dye concentration while ensuring the dye remains in solution form, preventing sludge generation even when using water-insoluble organic solvents
Solution Approach 2:
The patent specifies precise concentration parameters: dye (0.01-5 mass%), anionic surface active agent (0.01-2 mass%), and solvent (95-99.9 mass%). This parameter optimization ensures the dyeing solution maintains stable dye concentration while preventing sludge formation through proper solubility control
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 provides stable plate inspection characteristics with minimal dye concentration decrease and unevenness, even during bulk processing, by optimizing the solubility parameters and composition of the dyeing solution.
Implementation Method 1
a dyeing solution for lithographic printing plates comprising (a) dye, (b) an anionic surface active agent, and (c) an organic solvent
Implementation Method 2
the SP value of the organic solvent, denoted by α, and the SP value of the polymer compound, denoted by β, hold the following relation: |β-α|
Data Source
AI summary
The invention provides a dyeing solution for lithographic printing plates and a dyeing method for waterless lithographic printing plates that show stable plate inspection characteristics with little decrease in dye concentration and less dyeing unevenness even when used for bulk plate processing. The dyeing method for waterless lithographic printing plates is designed so that when used to dye an image area formed on a waterless lithographic printing plate with a dyeing solution containing an organic solvent, the relation of |β-α| < 5 (cal/cm3)1/2 is held wherein β is the SP value of the polymer compound included in the image area and α is the SP value of the organic solvent. The dyeing solution for lithographic printing plates contains (a) a dye, (b) a specific anionic surface active agent, and (c) an organic solvent containing at least one selected from ethers and alcohols.