Cross-linked Polymeric Toner Additive for Flow and Charge
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Solution Overview
Problem
Current toner compositions face challenges such as poor toner flow, toner blocking, and high costs due to the use of additives like titania, which also pose regulatory and certification issues. Additionally, there is a need for improved emulsion aggregation toners that maintain performance without titania.
Innovation Solution
A toner composition is developed with a parent toner particle comprising resin, optional colorant, and wax, and a surface additive formulation that includes medium silica, large cross-linked organic polymeric additive, and positive charging surface additives. This formulation provides improved flow, charge, and cleanability while reducing or eliminating titania.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If titania is used as a surface additive in toner compositions, then flow and charging performance is improved, but cost increases and regulatory/certification issues arise
Solution Approach 1:
The patent removes titania from the toner composition and replaces it with alternative surface additives including medium silica (30-50 nm), large cross-linked organic polymeric additive (75-120 nm), and positive charging surface additives (titanium dioxide at reduced levels or non-titanium dioxide alternatives). This extraction of the problematic material while maintaining functional performance directly addresses the regulatory and certification issues.
Solution Approach 2:
The patent changes the particle size parameters of the surface additives, using medium silica at 30-50 nanometers and large cross-linked organic polymeric additive at 75-120 nanometers, along with adjusted surface area coverage percentages. These parameter changes enable the formulation to achieve required flow and charging characteristics without relying on conventional titania.
2Productivity
If conventional surface additives are used to improve toner flow, then flow characteristics are enhanced, but toner blocking occurs
Solution Approach 1:
The patent segments the surface additive function into multiple components: medium silica (40-100% surface area coverage) for flow, large cross-linked organic polymeric additive (5-29% surface area coverage) for blocking prevention, and positive charging surface additive for charge distribution. This segmentation allows each component to address specific issues without causing others.
Solution Approach 2:
The patent creates a composite surface additive system combining inorganic medium silica with organic cross-linked polymeric additive and metal oxide or alternative metal oxide positive charging additive. This composite formulation synergistically improves flow while preventing blocking through the combined properties of the different materials.
3Reliability
If high concentrations of surface additives are applied to improve performance, then flow and charge characteristics are enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent specifies precise parameter ranges for particle sizes (medium silica: 30-50 nm, large cross-linked organic polymeric additive: 75-120 nm, small silica: 8-16 nm) and surface area coverage percentages (medium silica: 40-100%, large cross-linked organic polymeric additive: 5-29%, small silica: 0-75%). These controlled parameter changes simplify the formulation process while achieving desired performance.
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 composition achieves enhanced performance characteristics such as improved flow, charge distribution, and photoreceptor cleanability, while reducing costs and addressing regulatory concerns by minimizing or eliminating titania.
Implementation Method 1
the at least one medium silica provided at a surface area coverage of 40 to 100 percent of the parent toner particle surface area
Implementation Method 2
at least one large cross-linked organic polymeric additive having an average primary particle diameter of 75 to 120 nanometers
Implementation Method 3
at least one positive charging surface additive, wherein the at least one positive charging surface additive is; (a) a titanium dioxide surface additive
Implementation Method 4
the parent toner particles further contain a small silica having an average primary particle diameter of 8 to 16 nanometers, the small silica present at a surface area coverage of 5 to 75 percent
Data Source
AI summary
A toner including a parent toner particle comprising at least one resin, in combination with an optional colorant, and an optional wax; and a surface additive formulation comprising at least one medium silica surface additive; at least one large cross-linked organic polymeric additive; at least one positive charging surface additive, wherein the at least one positive charging surface additive is (a) a titanium dioxide surface additive; and wherein the parent toner particles further contain a small silica; or (b) a non-titanium dioxide positive charging metal oxide surface additive; and wherein the parent toner particles further optionally contain a small silica; and wherein a total surface area coverage of all of the surface additives combined is 100 to 140 percent of the parent toner particle surface area.