In this report, a test method for estimating the life expectancy of an optical media storing digital information has been discussed. A rewritable DVD (Digital Versatile Disc) in the market was examined by an accelerated life test based on the effects of temperature and relative humidity (RH). The evaluation item is BER (Byte Error Rate) as the performance of operation signal. The conditions of the accelerated test for life expectancy were (a) 80°C, 85%RH and 70°C, 85%RH, (b) 80°C, 85%RH and 80°C, 70%RH and then the characteristics of archival (readout) performance was evaluated as a reliability condition. It was experimentally clarified that life expectancy of a rewritable DVD media depends on the RH stress condition of accelerated life test, and it is necessary to examine the life expectancy with high reliability by using the acceleration model (so-called Eyring acceleration model) where both the temperature and RH stress conditions are considered.
The 7th group in the Technical Committee of the Imaging Society of Japan has been discussing the future of electronic newspapers as one of promising applications of electronic paper. This paper summarizes the opinions of the members through the discussion. It is indicated that newspapers exhibit a double-faced nature, “easy reading” whereas “deliberate reading,” and that because most of the problems with current newspapers are due to the integration of news and paper, they can be solved once electronic paper emerges. In addition, the essence of newspaper in comparison with other information media is discussed. Moreover required features for electronic paper to be used as electronic newspapers are listed and an anticipated roadmap is presented.
The properties sought for the toners used in printers and copiers will be the properties that support low energy usage and an increase in printing speed. Historically, for toner resin this has been the molecular weight distribution. In recent years with the demand for color toners, this field has expanded to include the new technology known as polymerized toner. Mitsui Chemicals enters this field and responds to market needs with a toner resin utilizing our original technology.
Toner pigments must satisfy coloristic requirements such as hue, tinctorial color strength, and transparency; also they must exhibit good heat resistance and light fastness. In addition, toner pigments must meet tribo-electric requirements. Furthermore, chemical toners require specific compatibility in each chemical process. Chemically-identical pigments can show different properties depending on the production process. Through specialized and optimized synthesis/kneading/milling processes, toner pigments are specified in terms of particle shape, particle size distribution, surface character, impurities, crystallinity, etc. Micro-reactor technology could be a breakthrough for toner pigment development in the near future.
Carbon black is generally used as the black pigment for the electron photograph toner. Safety for the human body is especially required to carbon black for toner, and it is necessary to reduce an amount of polycyclic aromatic hydrocarbon (PAH) that exists in the carbon black surface. To reduce an amount of PAH is difficult for large particle diameter carbon black. Image density, color tone, electric conductivity, and blow-off charge characteristic are demanded in carbon black. I explained how the carbon black characteristic relates to the characteristics of this demand characteristics and introduced MITSUBISHI CARBON BLACK for toner at last.
Recently, the engineered magnetite particle is used for the composition material of magnetic toner. Characteristics required for this use have magnetics, pigment performance, electric resistivity, dispersibility, surface characteristics, etc. Various functions have been given to the magnetite against such a demand. As an example, there are control of the magnetism by control of a particle size or shape, control of magnetism or heat-resisting property by addition of a zinc, control of the residual magnetization by addition of a silicon, the complementary color by addition of carbon black, a raise in resistance by addition of an aluminum, control ion electric resistivity by the electrolyte removal on the surface of a particle, acid-proof improvement by titanium treatment, etc. From now on, a magnetite needs to attain the further advanced features, and it is required to make it satisfied to substance regulation.
Charge control agent (CCA) is one of materials for toner of electophotography. The role of CCA is to improve toner's tribocharging characteristics and is necessary for electrophotography. Though inflluence of CCA in toners on their tribocharging characteristics is not enough explained theoretically, tribocharge of CCA is enough useful for electrophotography. In future we have to understand the function of CCA in toner from various standpoints to development new high performance CCA.
The addition volume of external additive is very small to the toner, but it is necessary to set up the toner formulation. An inorganic fine particle is generally used as an external additive. Production process and character of inorganic fine particle is described. Additionally, “Tribo electro static charge” and “Flowability” is introduced with some specific data.
Because of stability for getting tribo-electricity against toner easily, dual component system is especially used for high speed and high image quality—oriented systems such as Multi-Function Printer, Office Use Printer, and On Demand Printing. And recently, based on demand for color documentation and net-working system in offices, full color printer market are growing, resulting in rapid increase of dual component development system machines due to it's high reliability. Carrier is composed of core having magnetization and resin layer coated on the core surface. By properties of core and resin layer, tribo-electricity and efficiency as an electrode are controlled. Future potential of carrier particle for dual component system, through study of current carriers, future carrier design and subjects, is discussed in this report.