Negative-Working Imageable Elements Moisture Stability

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Solution Overview

Problem

Negative-working imageable elements on sulfuric acid-anodized aluminum substrates exhibit variability in on-press developability and printing quality, particularly in humid environments, leading to background staining issues.

Innovation Solution

A method involving a single-layer imageable element with a free radically polymerizable component, an initiator composition, a radiation absorbing compound, and a polymeric binder with poly(alkylene glycol) side chains, enclosed in a water-impermeable sheet material to inhibit moisture transfer, allowing for improved developability and storage stability without a preheat step.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If negative-working imageable elements are used on sulfuric acid-anodized aluminum substrates, then manufacturing precision and imaging performance are improved, but background staining occurs in humid environments leading to reduced reliability

Engineering Contradiction:

Improveimaging performanceVSAvoidstorage stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

A polymeric binder comprising a polymer backbone to which is directly or indirectly linked poly(alkylene glycol) side chains serves as an intermediary between the sulfuric acid-anodized aluminum substrate and the radiation-sensitive composition. This polymeric binder prevents direct harmful interaction between moisture and the anodized substrate, eliminating background staining while maintaining imaging performance

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical composition parameters of the binder system by specifying a polymeric binder with poly(alkylene glycol) side chains. This parameter change in the binder chemistry provides resistance to moisture-induced background staining, improving storage stability in humid environments

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional multi-layer positive-working imageable elements are used, then storage stability is maintained, but developability variability and background staining occur in humid conditions

Engineering Contradiction:

Improvestorage stabilityVSAvoiddevelopability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The polymeric binder with poly(alkylene glycol) side chains acts as a protective intermediary layer that prevents moisture from reaching the anodized substrate and causing background staining, while still allowing proper development to occur

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The polymeric binder forms a thin film structure that provides protection against moisture penetration while maintaining the necessary properties for imaging and development operations

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of operation

If elements are stored in humid environments, then accessibility and ease of operation are improved, but background staining increases reducing image quality

Engineering Contradiction:

ImproveaccessibilityVSAvoidimage quality

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The invention converts the potentially harmful effect of humidity into a beneficial situation by using the polymeric binder with poly(alkylene glycol) side chains that specifically resists moisture-induced background staining, allowing elements to be stored and handled in humid environments without quality degradation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 enhances the developability and storage stability of negative-working imageable elements, reducing background staining and eliminating the need for a preheat step, thereby improving image quality and reducing energy costs.

Implementation Method 1

an initiator composition capable of generating free radicals sufficient to initiate polymerization of the free radically polymerizable component upon exposure to imaging radiation

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a radiation absorbing compound

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentUS7175969B1Method of preparing negative-working radiation-sensitive elements

Publication Date: 2007.02.13 EASTMAN KODAK CO

AI summary

A method of preparing negative-working, single-layer imageable elements improves their storage stability in a humid environment. The method includes enclosing the coated imageable elements in a water-impermeable sheet material that substantially inhibits the transfer of moisture to and from the imageable element. Such imageable elements include a radiation-sensitive composition that includes a radically polymerizable component, an initiator composition to provide radicals upon exposure to imaging radiation, a radiation absorbing compound, and a polymeric binder having poly(alkylene glycol) side chains.