Toner Composition for Uniform Melting and Low-Energy Fixing
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Solution Overview
Problem
Existing toners face challenges in achieving both low-energy fixing in high-speed systems and maintaining heat-resistant storability while ensuring satisfactory developing performance, as they often experience issues with uniform melting and hot offset phenomena due to compatibility problems between crystalline and binder resins.
Innovation Solution
A toner composition featuring a binder resin with a styrene-acrylic resin and a block or graft polymer crystalline resin, where the crystalline segment and amorphous segment have a specific mass ratio, and the MDSC measurement indicates a low percentage of reversing heat flow, ensuring compatibility and uniform melting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester is used to achieve low-temperature fixability, then the toner softens at lower temperatures, but during high-speed fixing the crystalline polyester and toner binder do not melt uniformly causing hot offset phenomenon
Solution Approach 1:
The invention uses a composite binder resin system comprising a styrene-acrylic resin and a specific crystalline resin (block polymer or graft polymer with crystalline and amorphous segments). This composite structure allows the crystalline segment to provide sharp melt at low temperature while the amorphous segment ensures uniform melting behavior, preventing hot offset during high-speed fixing.
Solution Approach 2:
The invention specifies precise parameter ranges: the mass ratio of crystalline to amorphous segments is controlled at 30:70 to 90:10, and the endothermic peak temperature is maintained at 55.0°C to 90.0°C. These parameter optimizations ensure uniform melting while maintaining low-temperature fixability, resolving the contradiction between sharp melt and uniform melting.
2Temperature
If a block polymer with crystalline polyester bonded to incompatible amorphous polymer is used, then low-temperature fixability is achieved, but the crystalline polyester is present at the toner surface making it difficult to speed up the development system
Solution Approach 1:
The invention changes the compositional parameters by using a crystalline resin where the amorphous segment is substantially compatible with the styrene-acrylic binder resin. This compatibility parameter adjustment prevents crystalline polyester from segregating to the toner surface, enabling high-speed development while maintaining low-temperature fixability.
3Stability of the object's composition
If another resin is made the main component with added block polymer, then compatibility issues arise, but satisfactory low-temperature fixability cannot be achieved
Solution Approach 1:
The invention optimizes the compositional parameters by making the styrene-acrylic resin the main component and carefully controlling the ratio and structure of the crystalline resin additive. The amorphous segment of the crystalline resin is selected to be substantially compatible with the styrene-acrylic resin, ensuring both good compatibility and satisfactory low-temperature fixability.
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 satisfactory heat-resistant storability and developing performance with low-energy fixing in high-speed systems, preventing hot offset and ensuring uniform melting, thus improving image quality and fixability.
Implementation Method 1
the toner readily collapses during fixing due to liquefaction of the crystalline polyester
Implementation Method 2
in a total heat flow of the binder resin obtained by measuring the binder resin with a temperature-modulated differential scanning calorimeter (MDSC)
Data Source
AI summary
A toner containing a toner particle containing a binder resin, wherein the binder resin contains a styrene-acrylic resin and a crystalline resin, and the crystalline resin is a block polymer or a graft polymer in which the mass ratio between the crystalline segment and an amorphous segment is 30:70 to 90:10, and wherein, in the total heat flow measured for the binder resin by a temperature-modulated differential scanning calorimeter, the peak temperature of an endothermic peak is from 55.0° C. to 90.0° C., and the percentage of the endothermic quantity of the endothermic peak in the reversing heat flow with respect to the endothermic quantity of the endothermic peak in the total heat flow is from 0.0% to 35.0%.