Polyarylate Resin Binder for Photosensitive Layer Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophotographic photosensitive members face challenges in achieving optimal abrasion resistance and layer density due to limitations in the properties of binder resins used in their charge transport layers.
Innovation Solution
A polyarylate resin with specific molecular weight and composition, including repeating units derived from aromatic diols and dicarboxylic acids, is used as a binder resin to enhance the abrasion resistance and solubility of the photosensitive member, allowing for improved molecular entanglement and packability, thereby forming a high-density photosensitive layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional binder resins are used in the charge transport layer, then the photosensitive member can be manufactured with standard materials, but the abrasion resistance and layer density are insufficient
Solution Approach 1:
The patent changes the molecular weight parameter of the polyarylate resin to a specific range (10,000-80,000) to optimize both abrasion resistance and solubility. This parameter adjustment allows the resin to form a high-density layer while maintaining ease of manufacture through standard coating processes
Solution Approach 2:
The patent uses a composite binder resin system combining polyarylate resin with specific functional groups (carboxyl, hydroxyl, or amine groups) alongside hole transport materials. This composite approach enhances abrasion resistance while the functional groups improve interlayer adhesion and layer density
2Strength
If the binder resin has high molecular weight to improve abrasion resistance, then wear resistance increases, but solubility and layer formation become difficult
Solution Approach 1:
The patent precisely controls the molecular weight parameter within 10,000-80,000 to balance abrasion resistance and solubility. This optimal range ensures the resin is heavy enough for wear resistance but light enough to dissolve and form uniform layers
Solution Approach 2:
The patent introduces functional groups (carboxyl, hydroxyl, or amine) at specific locations in the polyarylate resin structure. These localized functional groups improve solubility and interlayer adhesion without compromising the overall molecular weight and abrasion resistance properties
3Manufacturing precision
If the photosensitive layer is formed with high density to improve performance, then image quality increases, but the manufacturing process becomes more complex
Solution Approach 1:
The patent adjusts the molecular weight and functional group content parameters of the binder resin to achieve high layer density through standard coating processes. The optimized resin formulation allows high density formation without requiring complex multi-step manufacturing procedures
Data Source
AI summary
An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, and a binder resin. The binder resin contains a polyarylate resin represented by general formula (1). In general formula (1), r and s each represent an integer of at least 0 and no greater than 49 and t and u represents an integer of at least 1 and no greater than 50. Furthermore, r+s+t+u=100 and r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4).