Near-Infrared Absorbing Polymeric Particles for Lithographic Plates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithographic offset printing plates face issues such as tacky surfaces, phase separation, poor substrate adhesion, high laser power requirements, and limited run length due to drawbacks in materials and coatings, including poor scratch resistance and the need for overcoating or special substrate treatments.
Innovation Solution
Development of polymeric particles with a hydrophobic backbone, near-infrared absorbing segments, and transparent segments, which absorb radiation to induce coalescence and cross-linking, enhancing adhesion and scratch resistance without requiring additional overcoating or substrate treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional coating compositions are used, then the printing plate can be manufactured, but the surface becomes tacky and shows phase separation
Solution Approach 1:
The patent uses a composite coating composition containing polymeric particles with hydrophobic backbones and polar side chains, combined with specific polymer binders and near-infrared absorbers. This composite structure prevents phase separation and tackiness by creating a stable heterogeneous system where each component performs its designated function: the polymeric particles provide structural stability and adhesion, while the polar side chains ensure proper distribution and prevent aggregation.
2Ease of manufacture
If conventional polymeric particles are used, then the coating can be applied, but substrate adhesion is poor
Solution Approach 1:
The polymeric particles exhibit local quality differentiation with hydrophobic backbones providing structural integrity and polar side chains (containing carboxyl, hydroxyl, or amine groups) providing adhesion functionality. This localized functional distribution enables the particles to simultaneously maintain coating stability and achieve strong substrate adhesion through the polar groups interacting with the substrate surface.
3Manufacturing precision
If high laser power is used, then imaging can be achieved, but energy consumption increases and run length is limited
Solution Approach 1:
The patent incorporates near-infrared absorbing dyes and pigments with specific absorption maxima (700-1100 nm) that match the laser wavelength. This parameter optimization allows the coating to efficiently absorb laser energy at low power levels, converting it to heat that triggers controlled polymerization and cross-linking, thereby achieving high-quality imaging with reduced energy consumption and extended run length.
4Ease of manufacture
If conventional coatings are used, then the plate can be produced, but scratch resistance is poor requiring overcoating
Solution Approach 1:
The coating composition includes polymeric particles with polar side chains that undergo preliminary cross-linking reactions upon laser exposure, forming a pre-hardened surface layer before printing operations begin. This preliminary action creates a scratch-resistant surface that eliminates the need for additional overcoating layers, while maintaining ease of manufacture through a single-coat application process.
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 polymeric particles improve on-press development capabilities by enhancing substrate adhesion and scratch resistance, reducing the need for high laser power and overcoating, while maintaining image quality and extending run length.
Implementation Method 1
near infrared absorbing segments, which absorb radiation to induce coalescence and cross-linking
Implementation Method 2
absorb radiation to induce coalescence and cross-linking
Implementation Method 3
absorb radiation to induce coalescence and cross-linking
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
There is provided polymeric particles having a particle size between about 60 nm and about 1000 nm and comprising a polymer, the polymer comprising a hydrophobic backbone, a near infrared absorbing segment having attached thereto a near infrared absorbing chromophore having an absorption peak between about 700 nm and about 1100 nm; and a near infrared transparent segment. Method of manufacture these particles are also provided. A coating composition comprising the above-polymeric particles and a reactive iodonium oligomer is also provided. Finally, a negative-working lithographic offset printing plate comprising a substrate; a hydrophilic under layer; and a laser imageable upper layer, wherein the laser imageable upper layer comprises the above polymeric particle is also provided.