Silica Adsorbed Tertiary Amine Electrophotographic Surface Layer

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Solution Overview

Problem

Existing electrophotographic photosensitive members face challenges in maintaining mechanical durability and preventing image deletion, particularly when using tertiary amine compounds or antioxidants, which can degrade potential stability and curing processes.

Innovation Solution

Incorporating silica particles with a specific surface area and pore diameter range, along with a compound-A such as a tertiary amine or urea compound adsorbed onto the silica particles, into the surface layer to enhance mechanical durability and suppress image deletion without impairing potential stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a tertiary amine compound or antioxidant is added to suppress image deletion, then the effect of suppressing image deletion is improved, but potential stability and curing are insufficient, causing mechanical durability to decrease

Engineering Contradiction:
Improveimage deletionVSAvoidmechanical durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses silica particles as an intermediary carrier to deliver the tertiary amine compound or antioxidant to the surface layer. The silica particles have a specific surface area of 100-500 m²/g and pore diameter of 0.003-0.02 μm, allowing the compound to be adsorbed and gradually released. This mediator approach enables the suppression of image deletion while maintaining potential stability and mechanical durability, as the compound is delivered in a controlled manner rather than being directly incorporated into the resin.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies the tertiary amine compound or antioxidant locally to the surface layer through adsorption on silica particles, rather than uniformly throughout the entire electrophotographic photosensitive member. The surface layer contains 0.01-5% by weight of the compound relative to the silica particle weight, creating a localized concentration that effectively suppresses image deletion at the surface while maintaining overall potential stability and curing properties of the bulk material.

Inventive Principle:
Principle #3Local quality

2Duration of action of stationary object

If the wear resistance of the layer is enhanced to extend lifetime, then the lifetime is improved, but image deletion occurs due to blurring of electrostatic latent image

Engineering Contradiction:
ImprovelifetimeVSAvoidimage deletion
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The silica particles serve as a mediator that allows the release of tertiary amine compound or antioxidant during the wear process. As the surface layer experiences wear over extended use, the silica particles gradually release the compound to neutralize discharge products, thereby suppressing image deletion while maintaining the mechanical durability needed for extended lifetime.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The silica particles are pre-loaded with the tertiary amine compound or antioxidant during manufacturing, creating a reservoir that acts in advance during subsequent use. This preliminary incorporation ensures that the compound is available to suppress image deletion from the beginning of extended use, preventing the blurring of electrostatic latent images that would otherwise occur with enhanced wear resistance.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a curable protective layer is introduced to extend lifetime, then the mechanical durability is improved, but image deletion occurs due to discharge products changing surface properties

Engineering Contradiction:
Improvemechanical durabilityVSAvoidimage deletion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite surface layer combining silica particles with tertiary amine compound or antioxidant within a curable resin matrix. This composite structure provides the mechanical durability of the curable protective layer while the silica-adsorbed compound counteracts the image deletion caused by discharge products, achieving both enhanced lifetime and suppressed image deletion through material composition.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The tertiary amine compound or antioxidant, delivered via silica particles, acts as an intermediary between the curable protective layer and the discharge products. It neutralizes the harmful effects of discharge products on the surface properties, allowing the curable layer to provide mechanical durability without causing image deletion.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 proposed solution effectively improves mechanical durability and suppresses image deletion, maintaining high performance even in high-output speed copiers or printers over extended periods, while ensuring sufficient potential stability.

Implementation Method 1

silica particles with a specific surface area and pore diameter range, along with a compound-A such as a tertiary amine or urea compound adsorbed onto the silica particles

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2720087B1Electrophotographic photosensitive member, production method for electrophotographic photosensitive member, process cartridge and electrophotographic apparatus, and particle having compound adsorbed thereto
Publication Date: 2016.07.20 CANON KK
  • EP2720087B1 patent drawingFigure 1A~1B
  • EP2720087B1 patent drawingFigure 2
  • EP2720087B1 patent drawing

AI summary

Provided is an electrophotographic photosensitive member including a surface layer containing particles which include: silica particles; and a compound-A adsorbed to each of the silica particles, in which the silica particles have a volume average particle diameter of 0.1 µm or more and 4 µm or less, and a specific surface area of 400 m2/g or more and 1000 m2/g or less, the compound-A is a tertiary amine compound and/or a urea compound, and the compound-A has a molecular weight of 150 or more and 550 or less.