Toner Block Polymer Low-Temperature Fixability Offset Prevention
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Solution Overview
Problem
Current toners face challenges with low-temperature fixability and durability, leading to image defects and offset issues in multifunction copiers and printers, especially under diverse environmental conditions and during continuous high-speed printing.
Innovation Solution
A toner formulation incorporating a binder resin with a styrene acrylic resin and a block polymer, featuring a polyester segment and a vinyl polymer segment, with a specific melting point, solubility parameter value, and molecular weight range, which enhances low-temperature fixability and durability while maintaining favorable charging characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the softening point of the toner is lowered by using crystalline resin to improve low-temperature fixability, then low-temperature fixability is improved, but offset phenomenon occurs where crystalline resin adheres to fixing members and re-transfers to next transfer material
Solution Approach 1:
The patent uses a composite binder resin system comprising both crystalline resin and amorphous resin. The crystalline resin provides low-temperature fixability through its sharp melt property, while the amorphous resin suppresses offset phenomenon by providing viscosity control and preventing adhesion to fixing members. This composite approach allows the toner to achieve both low-temperature fixability and stable fixing performance without the harmful offset effects of pure crystalline resin.
2Productivity
If conventional toner is used for continuous high-speed printing over long periods, then productivity is maintained, but toner melt-adheres to developing device causing image defects due to inadequate durability
Solution Approach 1:
The patent employs a composite binder resin system where the crystalline resin component provides sharp melt properties for efficient fixation at lower temperatures, while the amorphous resin component ensures long-term durability and prevents toner adhesion to the developing device during continuous high-speed printing operations. This combination resolves the contradiction between maintaining productivity and ensuring durability over extended periods.
Solution Approach 2:
The patent optimizes the melting point and viscosity characteristics of the binder resin by carefully selecting the types and proportions of crystalline and amorphous resins. This parameter optimization allows the toner to maintain stable charging characteristics and prevent melt-adhesion during continuous high-speed printing, thereby improving both productivity and durability simultaneously.
3Use of energy by stationary object
If heating temperature of fixing members is lowered to save energy, then energy consumption is reduced, but low-temperature fixability of toner deteriorates
Solution Approach 1:
The patent modifies the thermal parameters of the toner by incorporating crystalline resin with a sharp melt property and controlled melting point. This allows the toner to undergo phase change at lower temperatures, enabling effective fixation at reduced heating temperatures. Consequently, the fixing members can operate at lower temperatures to save energy while still achieving adequate 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 superior low-temperature fixability, wide fixation temperature range, and improved durability and charging performance, reducing image defects and offset issues even in high-temperature, high-humidity environments.
Implementation Method 1
the melting point (Tm) of the block polymer is 55° C. to 90° C.
Implementation Method 2
a binder resin containing a styrene acrylic resin and a block polymer
Implementation Method 3
fixing the toner image on the transfer material by a fixing method using heat and pressure
Data Source
AI summary
The present invention relates to a toner having a toner particle containing a binder resin containing a styrene acrylic resin and a block polymer, wherein the block polymer has a polyester segment and a vinyl polymer segment and has a melting point of 55° C. to 90° C., the polyester segment has a specific structure and a solubility parameter (SP) value of 9.40 to 9.85, and the vinyl polymer segment has a weight-average molecular weight (Mw) of 4000 to 15000.