Chemically Prepared Toner with Size Limiting Binders
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Solution Overview
Problem
Conventional methods for producing small particle size toners are limited by mechanical extrusion and grinding techniques, which are not effective in achieving the high resolution required for color laser printers, and are sensitive to temperature changes, leading to particle size instability during the fusing process.
Innovation Solution
A chemical toner preparation method using a latex copolymer with a methacrylic acid ester moiety, specifically lauryl methacrylate, and a polymeric alkylene glycol ether surfactant, which allows for stable aggregation and minimal particle size growth regardless of temperature, resulting in non-spherical particles that prevent filming on developer components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical extrusion and grinding techniques are used to produce small particle size toners, then manufacturing simplicity is maintained, but particle size control precision and resolution are insufficient
Solution Approach 1:
The patent replaces mechanical extrusion and grinding techniques with a chemical process (emulsion aggregation). The chemical toner preparation method uses polymerization reactions and controlled aggregation to achieve precise particle size distribution, substituting mechanical force with chemical bonding mechanisms to form toner particles of desired dimensions.
Solution Approach 2:
The patent employs parameter changes by controlling reaction conditions such as monomer composition, initiator concentration, temperature, and pH levels during the chemical process. By adjusting these parameters, the particle size and distribution can be precisely controlled, achieving high resolution toners that mechanical methods cannot produce.
2Manufacturing precision
If conventional chemical toner preparation methods are used, then particle size can be adjusted, but particle size growth occurs during heating and fusing process
Solution Approach 1:
The patent applies preliminary anti-action by incorporating specific binder resins and surfactants before the heating process that prevent particle aggregation and growth during subsequent thermal treatment. The pre-formed emulsion structure and protective agents counteract the tendency for particle coalescence during fusing, maintaining particle size stability.
Solution Approach 2:
The patent uses composite materials comprising specific binder resins (such as polyesters, polyamides, or acrylics) combined with surfactants and pigment dispersions. This composite formulation creates a stable emulsion that resists particle growth during heating, as the binder resin matrix maintains particle separation and prevents uncontrolled aggregation.
3Ease of operation
If spherical toner particles are produced, then flowability is improved, but tendency to fuse and film on photoconductor increases
Solution Approach 1:
The patent employs asymmetry by producing non-spherical toner particles with irregular shapes or asymmetric surface features. This asymmetric morphology reduces the tendency for particles to align and fuse together on the photoconductor surface during the fusing process, while still maintaining adequate flowability through controlled particle size distribution and surface properties.
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 method achieves stable and narrow particle size distributions, preventing particle growth during heating and fusing, and improves print quality by reducing the tendency of toner particles to fuse or film, enhancing the ease of cleaning and manufacturability.
Implementation Method 1
The mixture is flocculated by addition of an inorganic salt, or an acid. The conversion of sub-micron particles of latex, pigment, and wax to micron(s) size aggregates is then increased by heating the mixture to a desired particle size.
Implementation Method 2
the particles are eventually heated at temperatures (above the softening temperature of the latex) to fuse and form a spherical or nearly spherical particle
Data Source
AI summary
Chemically prepared toner is manufactured by aggregation in which the binder resin is a latex copolymer having a methacrylic acid ester of long chain, saturated alkyl, which may be lauryl methacrylate. This binder resin has a small amount by weight of acrylic acid component and has other nonionic components, which may be styrene and butyl acrylate moieties. Aggregation is carried out in an aqueous medium, which may have organic solvent components. The aggregation is then heated, and because of the selection of the binder resin to have the long chain ester, the heating step has minimal effect on particle size.