Toner with Controlled Viscoelasticity for Fixing and Offset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current toners face challenges in achieving good low-temperature fixability, shelf stability, hot offset resistance, and maintaining image glossiness, with existing solutions either compromising on hot offset resistance or image glossiness.
Innovation Solution
A toner composition with specific viscoelastic properties, including a glass transition temperature between 50°C and 90°C, a loss tangent of 1.70 or less at the glass transition temperature, and a storage elastic modulus less than 56000 Pa at a certain temperature range, incorporating a binder resin, colorant, softening agent, and charge control agent, is developed to address these issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the content of vinyl resin in the binder resin is increased to improve low-temperature fixability, then low-temperature fixability is improved, but hot offset resistance decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the glass transition temperature (Tg) of the binder resin to be within 50°C to 90°C and the loss tangent (tan δ) at Tg to be 1.70 or less. This optimization of viscoelastic parameters allows the toner to achieve good low-temperature fixability while maintaining excellent hot offset resistance, resolving the contradiction between these two properties.
Solution Approach 2:
The patent uses a composite binder resin system comprising a polyester resin and a vinyl resin in specific proportions (polyester resin 85-95 parts, vinyl resin 5-15 parts). This composite approach allows the toner to benefit from both the low-temperature fixability of vinyl resin and the hot offset resistance of polyester resin, achieving both properties simultaneously.
2Reliability
If fine particles are dispersed in the toner to improve hot offset resistance, then hot offset resistance is improved, but blocking during toner storage occurs
Solution Approach 1:
The patent optimizes the viscoelastic parameters of the binder resin, specifically setting the glass transition temperature (Tg) between 50°C and 90°C and the loss tangent (tan δ) at Tg to 1.70 or less. This parameter optimization prevents blocking during storage while maintaining hot offset resistance, eliminating the need for fine particle additives that cause blocking.
3Stability of the object's composition
If the binder resin composition is adjusted to improve shelf stability, then shelf stability is improved, but image glossiness decreases
Solution Approach 1:
The patent optimizes the viscoelastic properties of the binder resin by controlling the glass transition temperature (Tg) to be between 50°C and 90°C and the loss tangent (tan δ) at Tg to be 1.70 or less. This parameter optimization achieves both good shelf stability and maintained image glossiness, resolving the contradiction between storage stability and image quality.
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 excellent low-temperature fixability, shelf stability, and hot offset resistance while preventing a decrease in image glossiness, balancing these properties effectively.
Implementation Method 1
a glass transition temperature (Tg) specified from a temperature dependence curve of a loss tangent (tan δ) obtained by dynamic viscoelastic measurement of the toner, is 50° C. or more and less than 90° C.
Implementation Method 2
the loss tangent (tan δ) at the glass transition temperature (Tg) is 1.70 or less; in a temperature range of 90° C. or more and 160° C. or less, a lowest temperature (Ta) with a loss tangent of 1.50 is more than 95° C. and less than 145° C.; and a storage elastic modulus (G′) at the lowest temperature (Ta) is less than 56000 Pa
Data Source
AI summary
Provided is toner which has good low-temperature fixability, shelf stability and hot offset resistance, and which suppresses a decrease in glossiness of an image. The toner comprising colored resin particles containing a binder resin, a colorant, a softening agent and a charge control agent, and an external additive, wherein a glass transition temperature (Tg) specified from a temperature dependence curve of a loss tangent (tan δ) obtained by dynamic viscoelastic measurement of the toner, is 50° C. or more and less than 90° C.; the loss tangent (tan δ) at the glass transition temperature (Tg) is 1.70 or less; in a temperature range of 90° C. or more and 160° C. or less, a lowest temperature (Ta) with a loss tangent of 1.50 is more than 95° C. and less than 145° C.; and a storage elastic modulus (G′) at the lowest temperature (Ta) is less than 56000 Pa.