Toner with Low Modulus Convex Portions for Filming Suppression
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Solution Overview
Problem
Existing toners for developing electrostatic latent images face challenges with filming due to mechanical stress, which affects image quality and low temperature fixing performance, and struggle to maintain fluidity while suppressing filming.
Innovation Solution
A toner with a convex portion on its surface, where the convex portion is formed from a resin with a low Young's modulus, specifically a vinyl modified polyester resin, and has a controlled average length and covering percentage to reduce attachment to carriers and maintain low temperature fixing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a convex portion is formed on the toner surface to reduce filming, then filming is suppressed, but low temperature fixing performance deteriorates when using hard resin with high Young's modulus
Solution Approach 1:
The invention changes the key parameter of Young's modulus from high to low (specifically ER(1)/ER(2) within 1.05 to 1.40). By using soft resin with low Young's modulus for the convex portion, the toner maintains its spherical shape and low temperature fixing performance while still suppressing filming through the convex structure.
Solution Approach 2:
The invention uses a composite resin structure where the convex portion is made from resin (2) with low Young's modulus, different from the base resin (1). This composite approach allows the convex portion to provide filming suppression while the soft material composition maintains low temperature fixing performance.
2Object-generated harmful factors
If the covering percentage of convex portion is increased to suppress filming, then filming is reduced, but fluidity deteriorates
Solution Approach 1:
The invention optimizes the covering percentage parameter to within 30% to 70%, which is a specific range that balances filming suppression and fluidity maintenance. This parameter optimization ensures adequate convex portion coverage for filming prevention while leaving enough smooth surface area for good fluidity.
3Strength
If styrene type resin is used for the convex portion to improve hardness, then mechanical strength is increased, but low temperature fixing performance deteriorates
Solution Approach 1:
The invention changes the material composition parameter by selecting resin (2) with low Young's modulus and appropriate glass transition temperature, specifically excluding styrene type resin. This material selection ensures the convex portion has sufficient mechanical strength while maintaining low temperature fixing performance through the soft resin composition.
Data Source
AI summary
According to one implementation, a toner includes a toner mother particle and a convex portion on a surface of the toner mother particle. The toner mother particle includes at least a resin (1). The convex portion is formed from a resin particle including at least a resin (2). An average value of a length of a long side of the convex portion is within a range of 0.1 to 0.5 μm. A ratio between a Young's modulus of a non-convex portion of the toner mother particle (ER (1)) and a Young's modulus of a convex portion of the toner mother particle (ER (2)) is a value (ER (1)/ER (2)) within the range of 1.2 to 2.0.