Toner Binder Resin Low-Temperature Fixing and Anti-Offset
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Solution Overview
Problem
Conventional toners face challenges in achieving excellent low-temperature fixing property, anti-offset property, durability, pulverizability, and storage stability, especially in high-speed and energy-saving image forming systems, where they often result in image degradation and increased odor.
Innovation Solution
A toner formulation incorporating a binder resin comprising a (meth)acrylic acid-modified rosin derived polyester resin (A) with a softening point of 80°C to 120°C and a purified rosin derived polyester resin (B) with a softening point of 120°C to 160°C, where resin (A) contains 65 mol% or more of 1,2-propanediol and resin (B) contains 70 mol% or more of 1,2-propanediol and 1,3-propanediol, enhancing low-temperature fixing and anti-offset properties while maintaining thermal resistance and storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional toners are used in high-speed and energy-saving image forming systems, then productivity is improved, but image quality deteriorates and odor increases
Solution Approach 1:
The patent changes the chemical parameters of the binder resin by specifying precise compositional ratios (65-85 mass% of polyester resin with 1,2-propanediol and 15-35 mass% of polyester resin with mixed propanediols) and softening point ranges (80-120°C and 120-160°C). This parameter optimization enables the toner to achieve both high-speed fixing and excellent image quality without degradation or odor issues.
Solution Approach 2:
The patent uses a composite binder resin system combining two different polyester resins with complementary properties. The first resin (lower softening point) provides low-temperature fixing capability for energy saving, while the second resin (higher softening point) ensures thermal resistance and storage stability. This composite structure resolves the contradiction between speed and quality.
2Use of energy by moving object
If low-temperature fixing is achieved, then energy consumption is reduced, but anti-offset property deteriorates
Solution Approach 1:
The patent optimizes the softening point parameters of the binder resin components to specific ranges (80-120°C and 120-160°C) that enable low-temperature fixing while maintaining adequate anti-offset performance. The precise control of 1,2-propanediol content (65-85 mass%) further fine-tunes the thermal properties to balance energy efficiency and reliability.
Solution Approach 2:
The composite resin system combines a lower softening point resin (for low-temperature fixing and energy savings) with a higher softening point resin (for thermal resistance and anti-offset property). This material composition allows the toner to fix at lower temperatures without sacrificing anti-offset reliability.
3Volume of moving object
If the image forming apparatus is made compact, then size is reduced, but stability of each unit deteriorates
Solution Approach 1:
The patent changes the material parameters of the toner, specifically the binder resin composition and softening points, to enhance toner durability and stability. This allows compact apparatus design where each unit undergoes repeated charging, exposing, developing, and transferring cycles without degradation, thus maintaining reliability despite reduced size.
4Productivity
If toner is used for long-term printing, then productivity is maintained, but image quality deteriorates due to color tone variations
Solution Approach 1:
The patent specifies precise compositional parameters for the binder resin, including the ratio of 1,2-propanediol to other diols (65-85 mass%), and softening point ranges (80-120°C and 120-160°C). These parameter controls ensure toner stability during repeated use, preventing color tone variations and maintaining consistent image quality over long printing periods.
Solution Approach 2:
The composite polyester resin system provides balanced thermal and chemical stability for long-term use. The combination of resins with different softening points ensures that the toner maintains its properties through multiple charging, exposing, developing, and transferring cycles, preventing degradation and color shifts during continuous printing.
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 toner achieves high-quality image formation over long periods without color tone variations, ensuring durability and reduced odor, while maintaining excellent fixing properties at low temperatures and high speeds.
Implementation Method 1
a polyester resin (A) which has a polyester unit obtained by polycondensation of an alcohol component and a carboxylic acid component
Implementation Method 2
a fixing unit configured to fix the image on the recording medium
Implementation Method 3
the polyester resin (A) with a softening point of 80°C to 120°C and a polyester resin (B) with a softening point of 120°C to 160°C
Data Source
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AI summary
An image forming apparatus including a charging unit, an exposing unit, a developing unit, a transferring unit, and a fixing unit. A toner containing a colorant and a binder resin which contains a polyester resin (A) and a polyester resin (B) having a softening point 10°C or more higher than that of the polyester resin (A); the polyester resin (A) is a (meth)acrylic acid-modified rosin derived resin having a polyester unit obtained by polycondensation of an alcohol component, which contains 65 mol% or more of 1,2-propanediol in a dihydric alcohol component, and a carboxylic acid component containing a (meth)acrylic acid-modified rosin; the polyester resin (B) is a purified rosin derived resin having a polyester unit obtained by polycondenstation of an alcohol component, which contains a total of 70 mol% or more of 1,2-propanediol and 1,3-propanediol in a dihydric alcohol component, and a carboxylic acid component containing purified rosin.