Toner Particle Mechanical Strength for Cleanerless Offset
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Solution Overview
Problem
Current toner technologies face challenges in suppressing fogging and back-end offset in low-temperature, high-humidity environments, particularly in cleanerless systems, due to toner particle cracking and breakage, which affect image quality and adhesiveness.
Innovation Solution
A toner with specific characteristics, including an average circularity of at least 0.960, an onset temperature of storage elastic modulus between 50°C to 70°C, and a load range of 1.00 mN to 1.50 mN in nanoindentation measurements, is developed to enhance mechanical strength and adhesiveness, thereby preventing toner particle cracking and breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the toner is used in cleanerless systems with harder members (low-temperature, low-humidity environments), then the size of the process cartridge is reduced, but toner particle cracking and breakage occur leading to fogging
Solution Approach 1:
The patent modifies the chemical composition parameters of the binder resin, specifically using a vinyl resin with controlled glass transition temperature and incorporating polyester resin in specific ratios. These parameter changes enhance the toner's mechanical strength and elasticity, allowing it to withstand the stress of cleanerless systems without cracking or breaking, thus preventing fogging while maintaining the compact cartridge design
Solution Approach 2:
The patent creates a composite toner structure by combining vinyl resin (as the primary binder), polyester resin (for mechanical strength), and silicone wax (for flexibility and stress distribution). This composite material approach allows the toner to possess both the hardness needed for cleanerless operation and the elasticity required to prevent particle cracking and fogging
2Volume of moving object
If film fixing with small amount of heat and low pressure is used to reduce fixing unit size, then the machine size is reduced, but adequate heat transfer to toner is insufficient causing back-end offset
Solution Approach 1:
The patent adjusts the toner's melting characteristics by selecting vinyl resin with specific glass transition temperature (Tg) and incorporating polyester resin with controlled softening point. These parameter changes enable the toner to melt and adhere properly at the lower temperatures and pressures of film fixing, ensuring adequate fixing quality even in compact fixing units without causing back-end offset
Solution Approach 2:
The patent creates a layered structure within the toner particle where the vinyl resin forms the base matrix and polyester resin creates domains with different thermal properties. This local quality differentiation allows the toner to have both structural integrity and controlled melting behavior, enabling proper adhesion during film fixing with minimal heat and pressure
3Reliability
If melt viscosity of the toner is lowered to prevent back-end offset, then fixing at low pressure is improved, but cracking and breakage of toner particle occurs
Solution Approach 1:
The patent precisely controls the molecular weight and composition ratios of the vinyl resin and polyester resin to achieve optimal melt viscosity. By adjusting these parameters, the toner maintains sufficiently low viscosity for good adhesion during film fixing while retaining enough molecular strength and intermolecular forces to prevent particle cracking and breakage under mechanical stress
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 effectively suppresses fogging and back-end offset, ensuring high-quality images over long-term use in challenging environments by improving toner particle strength and adhesiveness.
Implementation Method 1
toner melting is impaired
Implementation Method 2
an onset temperature Tε (° C.) of a storage elastic modulus E′ of the toner, as determined by a powder dynamic viscoelastic measurement
Data Source
AI summary
A toner comprising a toner particle that contains a binder resin and a colorant, wherein (1) an average circularity of the toner is at least 0.960, (2) an onset temperature Tε (° C.) of a storage elastic modulus E′ of the toner, as determined by a powder dynamic viscoelastic measurement, is from 50° C. to 70° C., and (3) in a differential curve obtained by differentiation, by load, of a load-displacement curve provided by measurement of the strength of the toner by a nanoindentation procedure, with the horizontal axis being load (mN) and the vertical axis being displacement (μm), the load X that provides the maximum value in the differential curve in the load region from 0.20 mN to 2.30 mN is from 1.00 mN to 1.50 mN.