Conductive Coating for Developing Rollers via Micro Phase Separation

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Solution Overview

Problem

Existing developing rollers require an additional intermediate layer for adhesion, which is environmentally detrimental and has poor electrical conductivity, leading to issues with surface roughness orientation and uneven toner distribution, affecting print quality.

Innovation Solution

A conductive coating comprising a methacrylic acid-acrylic ester copolymer and polyurethane dispersion that undergoes micro phase separation upon drying, eliminating the need for an intermediate layer and ensuring uniform surface roughness and chargeability without roughness orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an intermediate layer is added between the base layer and charge providing layer to improve adhesion, then adhesion is improved, but device complexity increases and environmental harm increases due to solvent use

Engineering Contradiction:
ImproveadhesionVSAvoidnumber of layers
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention combines the base layer and charge providing layer into a single integrated coating composition, eliminating the need for a separate intermediate layer. The coating contains both adhesive components (for bonding to base layer) and charge-providing components (for electrostatic function) merged into one layer, thus reducing device complexity while maintaining adhesion.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts and eliminates the harmful intermediate layer containing solvents from the roller structure. By removing this unnecessary layer, the patent reduces environmental harm while still achieving adequate adhesion through the integrated coating design that directly bonds to the base layer.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If an intermediate layer is used to improve adhesion, then adhesion is improved, but electrical conductivity deteriorates

Engineering Contradiction:
ImproveadhesionVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention merges the adhesive function and charge-providing function into a single layer. The coating composition includes adhesive resins for bonding to the base layer and conductive materials (such as carbon black or metal particles) for providing electrical conductivity and electrostatic charge, eliminating the conductivity problem of separate intermediate layers.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If a conventional coating is used, then manufacturing is simple, but surface roughness orientation occurs leading to uneven toner distribution

Engineering Contradiction:
Improvecoating applicationVSAvoidsurface roughness uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention creates local quality variations within the coating layer through phase separation. The coating composition contains components that separate into different phases during drying, creating regions with different properties. This micro-phase separation produces a surface structure with controlled roughness that prevents orientation effects while maintaining manufacturing simplicity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses a composite coating material containing multiple components with different properties (adhesive resins, charge-providing materials, and phase-separating components). This composite structure enables the coating to self-organize into a non-oriented rough surface pattern during application and drying, improving toner distribution uniformity without complicating the manufacturing process.

Inventive Principle:
Principle #40Composite materials

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 coating provides a uniform charge providing layer with improved toner transfer properties and print quality by achieving similar surface roughness in both radial and axial directions, enhancing the roller's chargeability and print quality without the need for additional layers.

Implementation Method 1

said coating comprising a conductive polymer in a matrix, said coating when dried shows good surface roughness... said coating comprising a conductive polymer in a matrix, said coating having good adherence to the base layer without the need for an additional, intermediate layer

Methodology Applied
Scientific EffectMicro phase separation:

Data Source

PatentEP2110418B1A conductive coating, a method for preparing a coating, a roller, a method for manufacturing a roller as well a use of a coating
Publication Date: 2014.05.21 TEN CATE ENBI INT
  • EP2110418B1 patent drawingFigure 1~2
  • EP2110418B1 patent drawingFigure 3~4
  • EP2110418B1 patent drawingFigure 5A~5C

AI summary

The present invention relates to a conductive coating to coat a developer, charge or transfer roller in a developing apparatus to give a charge providing layer, said coating comprising a conductive polymer in a matrix. The present invention furthermore relates to a roller for a developing apparatus comprising from the centre to the periphery a conductive mandrel, a conductive elastic base layer and a charge providing layer.