New equation of penetration velocity of pigment ink-jet ink to the ink-jet media was proposed by considering the pressure loss due to cake formed by the solid contents. It was experimentally confirmed by micro drop contact angle analyzer and automatic scanning absorptometer that penetration quantity to every contact area was proportional to the square root of time in pigment ink-jet ink, and penetration velocity was evaluated by its slope. It was also confirmed that the specific resistance of cake is evaluated from the pigment ink-jet ink penetration velocity ratio to the liquid contents penetration velocity.

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The proximity theory was proposed to solve the problem of large differences between measured adhesion forces and calculated electrostatic image forces. This theory shows the fact that the electrostatic image force becomes remarkably large value when the distance between the charge on a sphere surface and its image becomes very short.
We attempted to explain the effect of silica additives based on this theory. Consequently we found that the action of silica additives to decrease the adhesion forces are performed by a spacer effect at low coverage and a uniform charge dispersion effect at high coverage.

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Microencapsulated color electrophoretic image display (MC-Color EPD) using a color filter array has attracted considerable attention as a color electronic paper display during recent years. However, improvements in the brightness and contrast ratio are desired in this system. In this study we investigated a new type of MC-Color EPD based on the electrophoretic migration of color particles in the microcapsule including insulating liquid under the influence of applied voltage. The electrophoretic colored particles which have good electrophoretic mobility and dispersion stability in the insulating liquid are synthesized by the Inverse Emulsification-Evaporation process in a one-batch system. The MC-Color EPD using electrophoretic color particles and white titanium dioxide particles exhibited a high brightness and high contrast ratio.

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The suspension polymerization toner always led a chemical toner market in both monochromatic and color machine. The shape characteristic of suspension polymerization toner is approximately spherical, come from the manufacturing method and bring a superior merit. In this paper, I look back on the history of suspension polymerization toner and survey a technical progress trend. Essentially, a toner should argue with the performance. The manufacturing method of a toner is only one of our means that there is in various ways to develop needed toner performance. The new manufacturing method and technology are developed in future, and an electrophotographic system pleased with by a user is expected.

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Developments of chemical process toners are accelerated to meet market demands for higher print quality, higher productivity, and higher reliability of color multi functional copiers and color printers. EA-HG toner has been developed to meet these market demands by improving performances of EA1 toner.
EA-HG toner has achieved expanding color Gamut by changing a color pigment used in the toner, and performing both high gloss of images and wide fusing latitude by controlling toner rheology and a toner internal wax structure. Accordingly, the EA-HG toner has achieved higher print quality and higher reliability compared to the predecessor EA1 toner, and has allowed to introduce the systems performing higher print quality and higher productivity.

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Digital Toner HD (DT-HD) is a toner for full color that evolved Digital Toner 2000 (DT-2000) produced by emulsion polymerization and coagulation method. A characteristic is that enabled that We get a high image quality by a design having the high cleaning characteristic while raising surface smoothness and spheronization degree by optimization of the shape control technique, to have achieved fixing temperature reduction of 20°C for DT-2000. The model that carried DT-HD by these innovation gets high evaluation in the market. Superior color reproductivity is high-resolution and, in bizhub PRO C6500 which makes a POD market a target, contributes to a thing corresponding to high reliability and the various paper class represented by coated paper for print, thick paper. Additionally, in bizhub C451/C550 which makes an office market a target, we contribute to the achievement of the energy-saving. Here, I comment on a characteristic of DT-HD and the technology that we developed.

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PxP toner for the monochrome digital multifunctional printers and Color PxP toner for the full color digital multifunctional printers have been developed with ester elongation polymerization. In the ester elongation polymerized toner, high durability in preserving toners as well as fusing ability at low temperature is achieved by controlling the molecular weight distribution of polyester resin and the dispersion of wax. Moderate gloss of the fixing image is achieved by the combination of the high molecular weight resin by ester elongation reaction in emulsification and the low molecular weight resin that has low melting viscosity. Compared with the conventional pulverized toner, PxP toner is able to reduce about 26% of toner consumption in printing and about 35% of CO₂ emission in production, and therefore environmental impact is decreased. This report introduces the technical characteristics and manufacturing method of the PxP toners.

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Recently various CPT (chemically produced toner) technologies have emerged as technical and economical alternatives for producing small sized toners and thus improving the performance of electro-photography. Among the CPTs, polymerized toners generally have a small particle size, a narrow size distribution, and a regular shape, and these characteristics provide better printing performance and brilliant images as compared to the conventional toner. However, the CPT technology based on polymerization method presents several difficulties such as process and equipment complexity, potential for contamination of toner particles by unreacted monomer, inflexibilityofformulation variation and so on.
We developed a novel chemical milling (CM) method of producing small toner particles, which has the advantages of the polymerization methods but are free of the above-mentioned disadvantages. The spherical toner particles produced by the chemical milling method may have the mean diameter at any value in the range of 3-15Fdm with a simple adjustment of process parameters. The particles generally have a narrow size distribution with the span (=(d₉₀-d₁₀)/d₅₀) value of as low as 0.4. Furthermore, the CM toner is able to meet most consumers' needs for electro-photography by virtue of wide range of controllability and flexibility regarding the key properties such as charging, fusing, and color reproduction.

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Hosokawa Micron Corporation has been pursuing the advanced technologies related with powder and particles and developing the business with a corporate philosophy of contribution to the industries in the world through the powder technology. The production of toner particles is also strongly connected with the powder technology for the purpose to improve the uniformity of particle size distribution and to control the particle shape. In this report are introduced the powder processing machines to do with toner production and a new technology for toner particle production developed by our Group.

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It is effective to reduce the size of toner for fine image quality on electrophotographic system. But, in general, size reduction of toner is energy intensive. In addition, the size reduction of the color toners including high content of the wax for oil-less fusing is especially hard in a dry process. The pre-con grinding method in a dry process, introduced in this paper, is that the toner granules mixed with silica are ground with the pulverizer like a jet mill and is especially suitable to produce the color toners including high content of the wax. On the other hand, the grindability of the polyester resin as toner binder, which is main components of toner and controls the productivity of the toner, is also discussed. It is proposed in this paper that both pre-con grinding method and high grindable binder should be simultaneously applied as the process of size reduction of toner for fine image quality. The two technologies are proposed in this paper to make it possible to manufacture productively the full-color toners with smaller particle size in a dry process in the near future.

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