In the commercial printing market, being able to print on for many types of paper is required as well as offset printing. In particular, embossed paper, which has a unique texture, is used for the cover of printed material, so there is a need to be able to print on it. Ricoh launched the Ricoh Pro C5110S/C5100S in June 2013 and made it possible to print on embossed paper with the AC (Alternating Current) transfer technology and the elastic fusing belt.  We increased the number of types of embossed paper that can be printed on and also improved the image quality by developing a new AC transfer technology and optimizing the elastic fusing belt technology. In this paper, we report on our improvement of the printing technology for embossed paper, which was mainly due to the new AC transfer technology and the elastic fusing belt.

View full abstract

The performance of top-gate organic field-effect transistors (OFETs) based on 2,7-dioctyl [1] benzothieno [3,2-b] [1] benzothiophene (C₈-BTBT) using halogen-free organic solvents for forming semiconductor layers has been investigated to reduce the impacts on environment in the solution process. Top-gate FETs where C₈-BTBT thin films processed by spin coating from non-halogen solvents onto cross-linked poly (4-vinylphenol) layers exhibit high field-effect mobility of 4cm²V^-1s^-1 and good subthreshold characteristics, which are comparable to those of devices processed from a halogen solvent of chlorobenzene.

View full abstract

Objects of which color we recognize gold/silver can only be measured as yellow/gray by using a colorimeter. We focused on why we can distinguish gold/silver color as a different category from yellow/gray. We also focused on why we can distinguish silver color as a different category from a simple mirror. We have performed following experiments : evaluation of dependence of gold/silver color recognition to lighting conditions, evaluation of recognition transition from mirror to silver/gold when applying various disturbance or distortion on a flat mirror surface. Our experimental results suggested that frosted or deformed surface reflection of ambience was necessary for gold/silver color recognition.

View full abstract

There are many methods to modify the surface of particles, e.g., chemical, physical, and mechanical treatments;in addition, according to the different properties of materials (organic/inorganic) and the processes used (wet/dry), these methods become more diversified. Among these methods, surface modification based on externally adding ultrafine particles to resin particles—i.e. forming toner composites—is carried out mainly by mechanical treatment. The external additives are used to control particle adhesion, flowability, and so forth. It is known that these properties strongly depend on the type of the external additives and its treatment conditions. The techniques for surface modification and the formation of composite particles are summarized in this article. Then, experimental methods to detect slight differences in the aforementioned properties and to allow a multifaceted evaluation are described, where statistical distributions or profiles of the data are used for the evaluation instead of average or representative values. The airflow method is specifically introduced to evaluate the adhesive properties. The effects of the state of the external additives, the initial charge of the particles, and the external electric field on particle adhesion are demonstrated;in addition, the results of the distribution of adhesive strength between the toner and carrier are provided. The vibrating tube method is introduced to evaluate flowability, showing that the flowability profile varies according to the size of the external additives, their amount, the treatment condition, and the shape of the resin particles.

View full abstract

The external additive is one of the key materials to design the toner formulation. With the ever increasing diversity of requirements and technical complexity of today's toner industry, we have developed a broad line-up of AEROSIL^® and AEROXIDE^® products. Production process, character of inorganic fine particle and technical trend are described in this article based on AEROSIL^® and AEROXIDE^® products. In addition, newly developed sub-micron silica produced by the fumed and hybrid process is introduced. A unique feature of these large-particle additives is that they can be broadly hydrophobized. Tribo-electrostatic charge (T-ESC) stability under an extended activation period and SEM images of these large-particle additives on the toner are also described.

View full abstract

Fumed silica can be used for additives to improve the toner fluidity. Triboelectric charge of toner is also affected by surface characters of the fumed silica. Therefore, it is important to study on the relationship between chemical structures of the silica surface and its property.  In this review, we describe some measurement methods to estimate silanol groups on the silica surface, and demonstrate the difference of silanol density between before and after various surface modification of fumed silica. We also show the bonding strength between the silica surface and treatment reagents by using pyrolysis GC-MS, and reveal the bonding characters of polydimethylsiloxane on the silica surface by using solid state NMR.

View full abstract

These days, electrophotographic color copying machine and color printers have become popular for office use. Further to some commercial printing market, the electrophotographic system has been supplied in association with the trend of high definition. With this recent tendency, color toner is in widespread use and its particle size is getting smaller, and the surface processed titanium dioxide products are used increasingly as external additives as is the case of silica. Ultra-fine titanium dioxide treated with organic surface processing can be effective to improve electrostatic charge control, environmental stability and flowability of toner as an external additive. This paper is introducing production method of titanium dioxide external additive and the function related to the difference in surface processing and particle diameter as an external additive.

View full abstract

The toner which has been use for electrophotography is generally made up of plastic resin, colorant, wax, charge control agents and external additive. ‘Two-component developer' is charged with mixing toner and carrier. The material exists on toner surface has a major influence on its functions. So, even if it's added a small amount, the external additive exists on toner surface works well. It makes improvement for charge amount, fluidity and cleaning capability. Acrylic particles which represented polymer particles are insulating material. It's easy modifying diameter of particles and introducing a functional group also. So we can say it' s a suitable material as external additive. In this article, we describe characteristics about the polymeric particle as the external additive for toner.

View full abstract

The silica fine particles are produced by the sol gel method, and discusses characteristic when it is applied as synthetic method and the additive for toner. The sol gel silica fine particles perform hydrolysis, polycondensation by an ammonia catalyst in solution using tetraalkoxysilane.  The characteristics as the additive for toner, in addition to the the highly hydrophobic in spherical, as compared with other silica, environmental electrostatic charge properties, admix property, and is excellent in rising characteristics of the electrostatic charge, and describes their characteristics, and in the future outlook also I described.

View full abstract

Metallic soaps are the materials that consist of two moieties, one is non-polar group of hydrocarbon and the other is polar group of metal and carboxylic group.  Fine particle metallic soaps are the world's first novel materials that have been successfully produced using Jet Mixing method based on the conventional technology results in even smaller particle size of metallic soap that further creates specifically narrow particle size distribution (average particle size;0.3∼3μm) as well as thin and smooth particle configuration.  In the paper, we give an explanation on Jet Mixing method and characteristic high fluidity and charge behavior in the toner model of adding them in poly methyl methacrylate resin.

View full abstract