Toner Binder Resin Low-Temperature Fixing
Solution Overview
Problem
Conventional toner technologies face challenges in achieving low-temperature fixing while maintaining storability and image stability, as they require precise control of resin composition and molecular weight, leading to increased costs and environmental concerns, and existing combinations of crystalline and amorphous resins often result in insufficient fixing performance or image defects.
Innovation Solution
A toner formulation using a low-melting point crystalline polyester resin and an amorphous resin, with controlled thermal properties to enable fixing at lower temperatures, ensuring energy conservation and improved storage stability, where the crystalline polyester resin and amorphous resin are combined with specific ratios and structures to optimize melting points and glass transition temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the fixing temperature is reduced to save energy and shorten warm-up time, then energy consumption and warm-up time are reduced, but the glass transition point of the toner particles decreases making it difficult to preserve storability
Solution Approach 1:
The patent changes the thermal parameters of the binder resin by selecting a crystalline resin with a specific melting point range (50-80°C) and controlling the softening temperature (85-135°C) to achieve a sharp melting property. This allows the toner to maintain high glass transition point for storability while exhibiting sharp viscosity decrease at fixing temperature for low-temperature fixing
Solution Approach 2:
The patent uses a composite binder resin system combining crystalline polyester resin with specific melting point characteristics and amorphous resin components. This composite structure enables the toner to exhibit both high storage stability (through maintained glass transition point) and sharp melting behavior (through crystalline resin melting) for efficient low-temperature fixing
2Temperature
If amorphous resins are used as binder resin to enable low-temperature fixing, then fixing temperature can be reduced, but the resin composition and molecular weight must be controlled extremely precisely increasing production cost
Solution Approach 1:
The patent shifts from relying on precise molecular weight control of amorphous resins to controlling the melting point parameter of crystalline polyester resin (50-80°C) and softening temperature (85-135°C). This parameter change simplifies the manufacturing process by using commercially available resins within specified temperature ranges rather than requiring special purification processes
Solution Approach 2:
The patent employs commercially available crystalline polyester resins and amorphous resins that can be used directly without special purification or extensive molecular weight control. This approach replaces expensive specially-controlled resins with readily available materials, reducing production costs while achieving the desired sharp melting property
3Temperature
If crystalline resins are used as binder resin to improve low-temperature fixing efficiency, then fixing temperature is reduced, but fixing performance on paper is insufficient
Solution Approach 1:
The patent creates a composite binder resin system where crystalline polyester resin (providing sharp melting at 50-80°C) is combined with amorphous resin components. This composite structure ensures both low-temperature fixing capability (from crystalline melting) and adequate fixing performance on paper (from the combined resin system's adhesive properties)
Solution Approach 2:
The patent optimizes the thermal parameters by setting the softening temperature Tf1/2 in the range of 85-135°C and establishing the relationship Tf1/2≦205-(1.4×Tm1). This parameter optimization ensures the toner maintains appropriate viscosity characteristics for paper fixing while achieving low fixing temperature through the crystalline resin's sharp melting behavior
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 solution allows for efficient low-temperature fixing, enhanced toner storage life, and improved image storage stability, achieving a balance between energy conservation and performance.
Implementation Method 1
a decrease in the fixing temperature of toner is accompanied by a decrease in the glass transition point of the toner particles... it is necessary to provide the toner with a so-called sharp melting property, by which the toner retains a high glass transition point and exhibits a sharp decrease in viscosity in the high temperature range
Implementation Method 2
exhibits a sharp decrease in viscosity in the high temperature range
Implementation Method 3
a decrease in the fixing temperature of toner is accompanied by a decrease in the glass transition point of the toner particles... the toner retains a high glass transition point
Implementation Method 4
contact-heating fixing methods using, for example, a heating roll and a belt, by which images are fixed in a fixing unit... bringing the toner image face of a recording medium into contact with, while conveying it past, the heating roll or belt surface under pressure
Data Source
AI summary
A toner for developing electrostatic images, comprising a binder resin and a colorant, the binder resin including a crystalline polyester resin and an amorphous resin. When, in differential scanning calorimetry of the toner according to ASTM D3418-8, the temperature of the endothermic peak derived from the crystalline polyester resin in a first heating process is defined as Tm1 (° C.), the endothermic quantity based on the endothermic peak in the first heating process is defined as ΔH1 (mW/g), and the endothermic quantity based on the endothermic peak in a second heating process is defined as ΔH2 (mW/g), Tm1 is 50 to 80° C., and ΔH1 and ΔH2 satisfy the relationship represented by the following Formula (1). When the softening temperature of the toner is defined as Tf1/2 (° C.), Tf1/2 is 85 to 135° C. Tm1 and Tf1/2 satisfy the relationship represented by the following Formula (2):0.35≦ΔH2/ΔH1≦0.95 Formula (1)Tf1/2≦205−(1.4×Tm1) Formula (2).