Planographic Printing Plate Precursor Solubility Discrimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Positive-working planographic printing plates for infrared lasers face issues with insufficient solubility discrimination between unexposed and exposed regions, leading to problems like over-development and reduced scratch resistance due to unstable adhesion and surface changes during handling.
Innovation Solution
A method involving a planographic printing plate precursor with a multilayer structure, where the outermost recording layer contains a water-insoluble and alkali-soluble polymer compound with a fluoroalkyl or siloxane structure, and an alkali developer with specific ammonium salt compounds to enhance solubility differences and scratch resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a positive-working planographic printing plate precursor uses an infrared absorbing agent as a dissolution inhibiting agent, then the unexposed region dissolves resistance is improved, but the solubility discrimination between unexposed and exposed regions becomes insufficient
Solution Approach 1:
The patent changes the chemical parameters of the binder resin by specifying particular compounds (polyvinyl alcohol with saponified groups 80-99 mol%, carboxymethyl cellulose with degree of substitution 0.7-1.3, or starch with degree of substitution 0.7-1.3) and controlling their molecular weights and compositions. This enables sufficient solubility discrimination while maintaining dissolution resistance in the unexposed region.
Solution Approach 2:
The patent uses composite binder resin systems combining multiple polysaccharide or polyvinyl alcohol-based resins with specific molecular weights and substitution degrees. This composite approach allows optimization of both dissolution resistance and solubility discrimination by leveraging the complementary properties of different resin components.
2Reliability
If the binder resin has high solubility in alkali developer to ensure exposed region dissolves, then the dissolution property of exposed region is improved, but the state before development becomes unstable
Solution Approach 1:
The patent carefully controls the molecular weight, substitution degree, and chemical composition parameters of the binder resin to achieve an optimal balance. The specified ranges (e.g., saponified groups 80-99 mol%, degree of substitution 0.7-1.3) ensure the resin remains stable before development while dissolving adequately in the exposed region.
Solution Approach 2:
The patent creates local differences in resin properties through the interaction between the infrared absorbing agent and binder resin in the unexposed region, while the exposed region undergoes thermal changes that alter solubility locally. This allows differentiated dissolution behavior without compromising overall compositional stability.
3Strength
If the recording layer adhesion to support is increased, then the scratch resistance of unexposed region is improved, but the adhesion property at interface becomes unstable
Solution Approach 1:
The patent optimizes the chemical composition parameters of the binder resin, specifically using polysaccharides or polyvinyl alcohol with controlled molecular weights and substitution degrees. This creates stable adhesion at the recording layer-support interface while maintaining scratch resistance in the unexposed region.
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 achieves improved solubility discrimination and scratch resistance in the formed image region, ensuring better durability and image reproducibility by stabilizing the solubility differences between unexposed and exposed areas.
Implementation Method 1
an infrared absorbing agent that absorbs light and generates heat (that is, an IR dye)
Implementation Method 2
an infrared absorbing agent that absorbs light and generates heat
Implementation Method 3
the exposed region dissolves in an alkaline developer and a planographic printing plate is formed
Data Source
AI summary
A method for producing a planographic printing plate is provided, which includes: subjecting a planographic printing plate precursor to image-wise exposure, wherein the precursor includes plural recording layers at least one of which contains (A) an infrared absorbing agent on a support, the upper recording layer contains (B) a water-insoluble and alkali-soluble polymer compound having a repeating unit containing a fluoroalkyl group or a siloxane structure; and developing the precursor using an alkali developer containing (C)an ammonium salt compound of Formulae (C-1) to (C-3), wherein R1 represents a methyl group or an ethyl group, R2 and R3 represent a hydrocarbon group having 3 to 20 carbon atoms, R4 represents a hydrocarbon group, A represents an atomic group which forms a nitrogen-containing aliphatic ring with N+, B represents an atomic group which forms a nitrogen-containing aromatic ring with N+, and X−represents a counter anion.