Toner Binder Resin Cross-Linking for Offset Resistance
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Solution Overview
Problem
Existing electrophotographic toners face challenges in achieving both high-temperature offset resistance and mechanical strength while maintaining low-temperature fixability, with previous solutions either compromising on mechanical strength or experiencing high-temperature offset issues.
Innovation Solution
A toner comprising a binder resin of non-crystalline polyester resin, crystalline polyester resin, and acryl resin with a cross-link structure, where the acryl resin has a cross-link site derived from a specific cross-linking agent, allowing for enhanced compatibility and reaction progress, resulting in improved mechanical strength and high-temperature offset resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester resin is used to lower the melting point or fusion viscosity for achieving low-temperature fixability, then low-temperature fixability is improved, but mechanical strength (stress resistance) and high-temperature off-set resistance are lowered
Solution Approach 1:
The patent uses a composite binder resin system comprising three components: crystalline polyester resin (provides low-temperature fixability through low melting point), non-crystalline polyester resin (provides mechanical strength through high glass transition temperature), and acryl resin with cross-link structure (provides high-temperature off-set resistance through elastic recovery). This composite material approach allows simultaneous achievement of low-temperature fixability and high mechanical strength that cannot be obtained with single resin systems.
2Object-affected harmful factors
If an acryl resin with cross-link structure is used to achieve high-temperature off-set resistance, then high-temperature off-set resistance is improved, but mechanical strength is reduced resulting in fragile toner and image defects
Solution Approach 1:
The patent carefully controls the cross-linking degree of the acryl resin by adjusting the cross-linking agent content to 1-10 parts by mass per 100 parts of acryl resin. This parameter optimization ensures sufficient cross-linking for high-temperature off-set resistance while preventing excessive cross-linking that would cause brittleness. The patent also specifies the cross-linking structure type (divinylbenzene or polyfunctional meth)acrylate) to balance elasticity and strength.
3Object-affected harmful factors
If divinylbenzene cross-linking agent is used to form acryl resin with cross-link structure, then high-temperature off-set resistance is achieved, but mechanical strength is low resulting in fragile toner
Solution Approach 1:
The patent specifies precise compositional parameters for the acryl resin system: total content of 5-50 parts by mass per 100 parts of binder resin, cross-linking agent content of 1-10 parts by mass per 100 parts of acryl resin, and controlled gel fraction of 5-60%. These parameter controls ensure optimal balance between cross-linking density (for off-set resistance) and mechanical integrity (to prevent fragility).
Solution Approach 2:
The patent combines acryl resin with cross-link structure with non-crystalline polyester resin in a composite binder system. The non-crystalline polyester resin acts as a matrix that provides mechanical strength and flexibility, while the cross-linked acryl resin provides elastic recovery for off-set resistance. This composite approach mitigates the fragility issue of highly cross-linked acryl resin alone.
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 enhanced image quality with superior mechanical strength and high-temperature offset resistance while maintaining low-temperature fixability, attributed to the specific cross-linking agent's long chain portion providing flexibility and improved resin affinity.
Implementation Method 1
an acryl resin having a cross-link structure, and the acryl resin having a cross-link structure having a cross-link site derived from a crosslinking agent
Implementation Method 2
lowering the melting point or fusion viscosity of a binder resin by use of a crystalline polyester resin
Implementation Method 3
a polymerization toner comprised of multi-layered resin particles formed of layers of a crystalline polyester resin, a non-crystalline polyester resin and a crystalline polyester resin
Data Source
AI summary
A toner comprising toner particles containing a binder resin comprising a crystalline polyester resin, a non-crystalline polyester resin and an acryl resin having a cross-link structure, and the acryl resin having a cross-link structure has a cross-link site derived from a crosslinking agent represented by the following formula (1):CH2═CR1—C(═O)O—Z—OC(═O)—CR2═CH2 Formula (1)wherein R1 and R2 are each a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, and Z is a hydrocarbon group of 2 to 90 carbon atoms, provided that the hydrocarbon group may include an ether linkage, an ester linkage, a heterocyclic ring or a substituent.