Olefin-Polyester Toner Resin Low-Temperature Fixing
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Solution Overview
Problem
Existing electrophotographic toner technologies face challenges in achieving low-temperature fixability, chargeability, and storage stability due to the trade-offs between softening temperature, electrical resistance, and blocking characteristics, particularly when using crystalline polyester resins or olefin-based copolymers.
Innovation Solution
A toner formulation utilizing a high molecular weight olefin-based copolymer, such as ethylene-acetate ester copolymers, in combination with a crystalline polyester resin, where the olefin-based copolymer constitutes 50% or more of the resin component, with specific unit ratios and melt flow rates, enhances low-temperature fixability, chargeability, and storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester resin is used as the main binding resin to achieve low-temperature fixability, then the fixing temperature is lowered, but the electrical resistance decreases causing poor chargeability
Solution Approach 1:
The patent uses a composite resin system combining amorphous polyester resin as the main component (50-90 mass%) with crystalline polyester resin (10-50 mass%). This composite structure allows the amorphous resin to provide low glass transition temperature for low-temperature fixing while the crystalline resin maintains electrical resistance for good chargeability, resolving the contradiction between fixing temperature and chargeability
2Temperature
If the glass transition temperature of the binding resin is lowered to improve low-temperature fixability, then the fixing temperature decreases, but the storage property deteriorates causing blocking
Solution Approach 1:
The patent combines amorphous polyester resin with low glass transition temperature (below 80°C, preferably 40-70°C) for low-temperature fixability with crystalline polyester resin having sharp melt properties. The crystalline component provides thermal stability and prevents blocking during storage, while the amorphous component enables low-temperature fixing, thus resolving the contradiction between fixability and storage stability
3Reliability
If a high molecular weight olefin-based copolymer is used as the main resin to improve chargeability, then the electrical resistance increases, but the melt viscosity becomes excessively high reducing image quality
Solution Approach 1:
The patent uses amorphous polyester resin as the primary matrix material rather than high molecular weight olefin-based copolymer. The amorphous polyester provides appropriate melt viscosity for good image quality while the crystalline polyester component ensures electrical resistance and chargeability. This composite approach avoids the excessive viscosity problem of high molecular weight olefin copolymers while maintaining chargeability
4Temperature
If an ethylene-vinyl acetate copolymer is partially blended in toner to improve fixability, then the low-temperature fixability improves, but it is difficult to satisfy high-speed printing conditions
Solution Approach 1:
The patent optimizes the glass transition temperature of the amorphous polyester resin to be below 80°C (preferably 40-70°C) and controls the resin component composition to achieve rapid melting characteristics. This parameter optimization enables the toner to melt quickly at low temperatures, satisfying both low-temperature fixability and high-speed printing requirements without relying on ethylene-vinyl acetate copolymer blending
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 combination of high molecular weight olefin-based copolymers and crystalline polyester resins improves image quality, low-temperature fixability, blocking resistance, and charge retention, while maintaining high-speed printing capabilities.
Implementation Method 1
the resin component has an olefin-based copolymer and a crystalline polyester resin
Implementation Method 2
the viscosity sharply decreases when the temperature exceeds the melting point
Implementation Method 3
the crystalline polyester resin has low electrical resistance, and thus has had a problem with chargeability
Data Source
AI summary
Toner containing toner particles having a resin component, in which the resin component has an olefin-based copolymer and a crystalline polyester resin, the olefin-based copolymer has a unit Y1 represented by Formula (1) and at least one kind of unit Y2 selected from the group consisting of a unit represented by Formula (2) and a unit represented by Formula (3), a content of the olefin-based copolymer contained in the resin component is 50% by mass or more based on a total mass of the resin component, a content of the unit Y2 is 3% by mass or more and 35% by mass or less based on a total mass of the olefin-based copolymer, and a melt flow rate of the olefin-based copolymer is 30 g/10 min or less.