Crystalline Polyester Toner Resin Fixation
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Solution Overview
Problem
Existing electrostatic image developing toner technologies face challenges in achieving a balance between low-temperature fixability, hot offset resistance, and image gloss suppression, with existing methods failing to effectively reduce fixing temperature dependency of glossiness.
Innovation Solution
The use of a binder resin containing a crystalline polyester resin and an amorphous resin, with specific thermal properties such as Tm1 between 60-80°C, Tf1/2 between 95-125°C, and a ΔH2/ΔH1 ratio between 0.65-0.95, to enhance low-temperature fixability, hot offset resistance, and reduce glossiness while minimizing fixing temperature dependency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester resin and amorphous resin are used in combination to achieve low temperature fixability, then low temperature fixability is improved, but hot offset resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the melting point (Tm1: 60-80°C) and softening temperature (Tf1/2: 95-125°C) of the binder resin, along with the specific relationship between endothermic quantities (ΔH2/ΔH1: 0.65-0.95). These parameter optimizations enable the resin to melt at low temperatures for fixation while maintaining sufficient viscosity at higher temperatures to prevent hot offset.
Solution Approach 2:
The patent uses a composite binder resin system combining crystalline polyester resin and amorphous resin in specific proportions. This composite material structure allows the crystalline portion to provide low-temperature melting behavior while the amorphous portion maintains viscosity at higher temperatures, simultaneously achieving low temperature fixability and hot offset resistance.
2Temperature
If a crystalline polyester resin and amorphous resin are used in combination to achieve low temperature fixability, then low temperature fixability is improved, but image gloss suppression deteriorates
Solution Approach 1:
The patent optimizes the softening temperature (Tf1/2: 95-125°C) and endothermic quantity ratio (ΔH2/ΔH1: 0.65-0.95) to control the melting behavior and viscosity changes during fixation. These parameter controls enable the toner to form a matte surface structure that suppresses image gloss while achieving low temperature fixation.
3Use of energy by stationary object
If the fixing temperature is reduced to improve low temperature fixability, then energy consumption is reduced, but glossiness control deteriorates due to fixing temperature dependency
Solution Approach 1:
The patent introduces the parameter ΔH2/ΔH1 (ratio of endothermic quantities in first and second heating processes) and constrains it to 0.65-0.95, along with Tf1/2 (95-125°C). These parameter optimizations reduce the glossiness of fixed images and minimize fixing temperature dependency, allowing stable gloss control at reduced fixing temperatures.
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 proposed solution effectively improves low-temperature fixability, hot offset resistance, and suppresses image gloss, while maintaining a low fixing temperature dependency of glossiness, thereby addressing the limitations of existing technologies.
Implementation Method 1
when a temperature in the temperature history at the time of fixing exceeds the melting point of the crystalline polyester resin, a crystalline portion is melted
Implementation Method 2
an endothermic peak derived from the crystalline polyester resin in a first heating process is defined as Tm1, an endothermic quantity based on the endothermic peak in the first heating process is defined as ΔH1
Data Source
AI summary
An electrostatic image developing toner includes: a binder resin containing a crystalline polyester resin and an amorphous resin, wherein when, in differential scanning calorimetry of the toner according to ASTM D3418-8, a temperature of an endothermic peak derived from the crystalline polyester resin in a first heating process is defined as Tm1 (° C.), an endothermic quantity based on the endothermic peak in the first heating process is defined as ΔH1 (J/g), an endothermic quantity based on the endothermic peak in a second heating process is defined as ΔH2 (J/g), and a softening temperature is defined as Tf1/2 (° C.), Tm1 is 60 to 80° C., Tf1/2 is 95 to 125° C., and ΔH1 and ΔH2 satisfy the relationship represented by the following Formula (1) and (2):[Math. 1]0.65≦ΔH2/ΔH1≦0.95 (1)205−(1.4×Tm1)<Tf1/2≦220−(1.4×Tm1) (2).