Photosensitive CTP Plate Wrinkle Prevention via Barrier Layer

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Solution Overview

Problem

Conventional photosensitive CTP flexographic printing original plates experience wrinkle generation, particularly under low-temperature and low-humidity conditions, due to the high flexibility of the photosensitive resin layer, which affects the barrier property and image reproducibility.

Innovation Solution

Incorporating a barrier layer composed of a polyamide resin (A) with a basic nitrogen atom and a polyamide resin (B) containing 40 to 70% alkylene glycol structural units, which prevents wrinkle generation while maintaining excellent barrier properties across various environmental conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a water-developable photosensitive resin layer with high flexibility is used, then ease of operation is improved, but wrinkle generation increases under low-temperature and low-humidity conditions

Engineering Contradiction:
Improveflexibility of photosensitive resin layerVSAvoidwrinkle generation on plate surface
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

A barrier layer is introduced as an intermediary between the photosensitive resin layer and the infrared-sensitive layer. This barrier layer prevents mass transfer and oxygen diffusion that cause polymerization inhibition, thereby eliminating wrinkle formation while preserving the flexibility and water-developability of the photosensitive resin layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer is constructed from a composite system comprising a polyamide resin and a specific plasticizer. This composite material provides both mechanical stability to prevent wrinkles and chemical barrier properties to block oxygen and mass transfer, resolving the contradiction between flexibility and wrinkle resistance.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the photosensitive resin layer is made thinner to reduce wrinkle influence, then manufacturing precision is improved, but barrier property deteriorates

Engineering Contradiction:
Improvewrinkle influence on reliefVSAvoidbarrier property against oxygen and mass transfer
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The barrier layer serves as a dedicated intermediary component that specifically addresses the barrier property requirement. It prevents oxygen diffusion and mass transfer between layers, allowing the photosensitive resin layer to be optimized for minimal wrinkle influence without compromising barrier performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer's composition is carefully controlled with specific ratios of polyamide resin to plasticizer (3:1 to 1:1 by mass), and its thickness is optimized (1-5 μm) to provide sufficient barrier properties while maintaining overall plate thinness to minimize wrinkle influence on the relief structure.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a conventional protective layer with high flexibility is used, then ease of operation is improved, but wrinkle generation increases in low-temperature environments

Engineering Contradiction:
Improveflexibility of protective layerVSAvoidwrinkle resistance under low temperature
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The barrier layer uses a composite material system of polyamide resin combined with a specific plasticizer. This composite provides the necessary flexibility for ease of operation while the plasticizer prevents the layer from becoming too soft and wrinkling under low-temperature conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The plasticizer content in the barrier layer is precisely controlled at 20-60 parts by mass per 100 parts of polyamide resin. This parameter optimization ensures the layer remains flexible enough for handling but resistant to wrinkle formation in low-temperature environments.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively prevents wrinkle formation and maintains high barrier properties throughout the year, including low-temperature and low-humidity conditions, ensuring excellent image reproducibility and durability of the printing plate.

Implementation Method 1

an infrared-sensitive layer (heat-sensitive mask layer) which is opaque to a chemical ray is formed on a photosensitive resin layer and then this infrared-sensitive layer is evaporated using an infrared laser

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

an infrared-sensitive layer (heat-sensitive mask layer) which is opaque to a chemical ray

Methodology Applied
Scientific EffectAbsorption of infrared radiation: Absorption (EM radiation)

Implementation Method 3

a photosensitive resin layer, a protective layer and the infrared-sensitive layer

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3605229B1Photosensitive CTP flexographic printing original plate
Publication Date: 2021.09.15 TOYOBO CO LTD

AI summary

The present invention aims to provide a photosensitive CTP flexographic printing original plate wherein no wrinkle is generated during handling of the CTP printing original plate against environmental changes throughout the year and barrier property is also excellent. A water-developable photosensitive CTP flexographic printing original plate which is characterized in that it comprises at least a support, a photosensitive resin layer, a barrier layer and a heat-sensitive mask layer which are sequentially layered, that the barrier layer contains a polyamide resin (A) containing a basic nitrogen atom in a molecule and a polyamide resin (B) containing 40 to 70% by mass of an alkylene glycol structural unit in a molecule, and that a content of the polyamide resin (B) to a total content of the polyamide resin (A) and the polyamide resin (B) is 25 to 52% by mass.