Electrophotographic Photoconductor Abrasion Resistance
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Solution Overview
Problem
Conventional electrophotographic photoconductors face challenges in achieving long-term durability, high sensitivity, and stable electric characteristics due to issues with abrasion resistance, filming, and variations in image quality, particularly in environments with varying temperatures and usage conditions.
Innovation Solution
The development of an electrophotographic photoconductor with a charge transport layer containing a specific hole transport material, resin binder, electron transport material, and inorganic oxide at predetermined mass ratios, along with a charge generation layer using titanyl phthalocyanine with specific heat characteristics, to enhance mechanical strength and maintain sensitivity and retention rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polycarbonate resin structures are used to improve durability, then abrasion resistance is enhanced, but compatibility with charge transport agents decreases and electric characteristics become unstable in long-term use
Solution Approach 1:
The patent uses a composite resin system combining polycarbonate (PC) and polyurethane (PU) in specific ratios (PC content: 20-80 mass%, PU content: 80-20 mass%). This composite structure provides both the abrasion resistance of polycarbonate and the flexibility/electrical stability of polyurethane, resolving the contradiction between durability and electric characteristic stability.
Solution Approach 2:
The patent specifies precise compositional parameters (PC/PU ratio, molecular weight ranges, glass transition temperatures) to optimize the balance between abrasion resistance and electric stability. By controlling these parameters within specific ranges, the invention achieves both high durability and stable electric characteristics in long-term use.
2Illumination intensity
If polycarbonate resin with bulky structure is used, then transparency in exposure is improved, but spaces between polymers allow penetration of discharge substances and foreign objects, reducing durability
Solution Approach 1:
The patent combines polycarbonate (providing transparency) with polyurethane (providing durability and flexibility) in a composite structure. The PU component fills the spaces between PC polymer chains, preventing penetration of discharge substances while maintaining the transparency provided by the PC matrix.
Solution Approach 2:
The invention creates different local properties within the resin system: polycarbonate regions provide transparency and rigidity, while polyurethane regions provide flexibility and barrier properties. This local differentiation allows the material to simultaneously achieve high transparency and durability.
3Strength
If filler particles are added to improve abrasion resistance, then durability increases, but aggregation of particles occurs during coating liquid production, affecting photoconductor characteristics
Solution Approach 1:
The patent uses a composite PC-PU resin system that inherently provides abrasion resistance without requiring filler particles. The synergistic interaction between PC and PU molecules creates a durable matrix that resists wear while maintaining homogeneous structure during coating, avoiding aggregation issues.
4Device complexity
If conventional single-layer photosensitive layer is used, then structure simplicity is maintained, but both charge generation function and charge transport function cannot be sufficiently achieved
Solution Approach 1:
The patent divides the photosensitive layer into two distinct functional layers: a charge generation layer (containing titanyl phthalocyanine) and a charge transport layer (containing the PC-PU resin system). This segmentation allows each layer to be optimized for its specific function while working together as an integrated system.
Solution Approach 2:
The charge transport layer uses a multi-functional PC-PU resin system that simultaneously provides charge transport, mechanical durability, flexibility, and resistance to filming. This multi-functionality reduces the need for additional layers or components, maintaining relative structural simplicity while achieving high performance.
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 provides improved mechanical strength, high sensitivity, and stable electric characteristics over long-term use, while preventing filming and maintaining image quality, even after repeated printing.
Implementation Method 1
a charge transport layer disposed on the charge generation layer and containing a hole transport material
Implementation Method 2
an electron transport material having a mass denoted by c
Implementation Method 3
the charge generation material contains titanyl phthalocyanine
Implementation Method 4
a photosensitive layer having a photoconduction function
Data Source
AI summary
Provided are an electrophotographic photoconductor being resistant to abrasion even in long-term use, having highly sensitive electric characteristics, being capable of maintaining a high retention rate, and being capable of providing a stable image without filming, a method of manufacturing the same, and an electrophotographic device. The photoconductor includes an electroconductive substrate (1), a charge generation layer (3), and a charge transport layer (4); the charge transport layer contains a hole transport material, a resin binder, an electron transport material, and an inorganic oxide; the charge generation layer contains a charge generation material; the masses of the hole transport material, the resin binder, the electron transport material, and the inorganic oxide in the charge transport layer respectively denoted by a to d satisfy 1.5≤b/a≤5.7, 0.005≤c/a≤0.35, 0.05≤d/a≤0.70, a≥c+d, and c/d≥0.01; the hole transport material contains a compound expressed by formula (A-1); and the charge generation material contains titanyl phthalocyanine having an exothermic peak at 251±5° C., a half-value width of the exothermic peak equal to or less than 15° C., and a heating value equal to or greater than 1.0 mJ/mg when a temperature rise condition is 20° C./min in differential scanning calorimetry, and having an X-ray diffraction peak at 27.2±0.3°.