Toner Formulation with High Dielectric Inorganic Particles
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Solution Overview
Problem
Toner images on difficult-to-fix media like coated papers suffer from scratch abrasion and image defects due to strong external stresses, which existing technologies fail to prevent effectively, especially in high-productivity print-on-demand applications.
Innovation Solution
A toner formulation incorporating a polyester resin with alkyl groups and surface-treated inorganic fine particles, such as strontium titanate, which enhances the attraction between toner particles and improves hot offset resistance, half-tone uniformity, and image density, while suppressing fogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If processing speed is lowered to sufficiently melt and fix toner on coated paper, then fixation quality improves, but productivity decreases
Solution Approach 1:
The invention changes the chemical composition parameters of the binder resin by incorporating specific ratios of polyester resin (30-70 mass%) and polyolefin resin (70-30 mass%), along with controlling the glass transition temperature and melting point parameters, to achieve both high-speed fixation capability and strong adhesion to coated paper surfaces
Solution Approach 2:
The invention uses a composite binder resin system combining polyester resin and polyolefin resin in specific proportions, where polyester provides adhesion to the charged coated paper surface and polyolefin provides low melting point for rapid fixation, achieving both high productivity and fixation quality
2Manufacturing precision
If strong external stress is applied to toner images on coated paper, then image density can be increased, but scratch abrasion occurs
Solution Approach 1:
The invention controls the glass transition temperature (Tg) of the binder resin to be 40°C or lower and the melting point to be 80-120°C, allowing the toner to remain soft and flexible at room temperature for high density while providing adequate abrasion resistance through the polyester component's adhesion to the charged paper surface
Solution Approach 2:
The invention uses inorganic fine particles (silica, titanium oxide, or zirconium oxide) with specific dielectric constants (55-100) as external additives to enhance the electrostatic adhesion between toner and coated paper, providing durable scratch abrasion resistance without requiring excessive image density
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 formulation effectively prevents scratch abrasion and maintains image quality under strong external stresses, ensuring high productivity and image integrity on challenging media.
Implementation Method 1
a dielectric constant of the inorganic fine particles is from 55.0 to 100.0 pF/m, as measured at 25° C. and 1 MHz
Implementation Method 2
enhances the attraction between toner particles
Implementation Method 3
the inorganic fine particles are surface-treated with an alkylalkoxysilane represented by formula (1) below
Implementation Method 4
the binder resin contains a polyester resin... which is obtained by condensation polymerization of raw material monomers
Data Source
AI summary
A toner having a toner particle, which contains a binder resin, and inorganic fine particles, the toner being characterized in that the binder resin contains a polyester resin, the polyester resin has, at a terminal, an alkyl group having an average number of carbon atoms of from 4 to 102, the number average particle diameter of primary particles of the inorganic fine particles is from 10 to 90 nm, the dielectric constant of the inorganic fine particles is from 55.0 to 100.0 pF/m, as measured at 25° C. and 1 MHz, and the inorganic fine particles are surface-treated with an alkylalkoxysilane represented by formula (1) below:CnH2n+1—SiOCmH2m+1)3 (1)in formula (1), n denotes an integer of from 4 to 20, and m denotes an integer of from 1 to 3.