Hindered amines are known as additives for electret filters, but the mechanism of their actions has not been fully clarified yet. In this study, blend films of negatively charged polyester doped with positively charged hindered amines were prepared as a model for an electret filter, and their triboelectric charging behaviors were investigated. The results showed that the positive and negative charges were almost equal and the difference between them was the largest when the doping level of hindered amines was 10∼20wt%, thus producing the largest internal electric field. The doping was also found to significantly reduce the film's sensitivity to moisture in the ambient atmosphere. Thus, it is suggested mechanistically that the use of hindered amines has the effect of increasing the internal electric field and stabilizing the tribocharges by reducing the effect of ambient moisture, improving aerosol particles capture performances.

Decorative technology is a technology to decorate surfaces in order to enhance the value (product appeal) of an object. Each decorative technology has its own characteristics, such as design expression, and it is necessary to select the most appropriate technology for each application. From now on, market needs are increasing not only for appearance, but also for integration with functions, environmental friendliness, and small-lot, diversified products, and decorative technologies are required to evolve to meet these needs and to add more value. This paper provides an overview of decorative technology in general and introduces some of the trends.

Future decorative technologies are expected to be “function-integrated,” “environment-responsive,” and “small-lot, multi-variety” and to add more value. In this paper, we pick up “tactile sensation,” “design/antimicrobial properties,” “anti-reflection,” “simplification of plating process,” “environmentally friendly materials,” “dry decoration,” and “on-demand foil decoration” as examples of these latest technologies, and introduce them individually in detail.

Inkjet-based printing applications in industrial printing have been applied in various fields, and are also being expanded into the fields of decoration for outer walls as building materials and tiles. Ricoh has a lineup of inkjet heads (MH series) for industrial inkjet printing including decorative printers. These heads have applicability to a wide range of inks, high durability and high reliability, and high-viscosity liquids can be ejected by the heater installed in the heads. Therefore, it is suitable for ejecting UV ink widely used in decorative printers. In addition, we have developed inkjet heads with ink circulation, enabling stable ejection of water-based ink and functional ink that are easy to dry and settle.

Ricoh Digital Painting Co., Ltd. has contributed to society by developing valve jet technology and system products that utilize it. Compared to general inkjet technology, this technology can fly a liquid with higher viscosity farther, which is a key technology for realizing digital painting.

In this paper, we first explain the auto body printer, which is a direct decoration system for large vehicles. In particular, the valve jet head configuration, printing method, dedicated ink, maintenance mechanism, and unevenness tracking mechanism, which are characteristic technologies for realizing direct decoration to large vehicle, will be described in detail. After that, we introduce the features of other system products using valve jet technology, such as LPG cylinder printers, seamless cylinder printers, tire printers, and bottle printers.

Since ancient times, raden made from shell and Tamamushi Shirine using jewel beetle wings have been known as gorgeous decorations that uses structural color. Even in modern times, structural color decoration attract attention in high-value industrial products. In addition, inkjet has high digital on-demand characteristics which can be used for high-mix low-volume production. We have developed a structural color inkjet printing technology. This decoration method does not use pigments or dyes. It develops fine structure, that reflects specific wavelength of light on a substrate by printing. As a result, it is possible to give a special effect, that the color changes depending on the background color and the observation angle.

Currently, many of the 236 items that are considered to be traditional Japanese crafts are a combination of metal and lacquer, such as Nanbu Tekki, and these products are also familiar to us. Therefore, when examining the history of the combination of metal and lacquer, it is found from the analysis result¹⁾ that the armor was already painted with black lacquer in the Kofun period 1600 years ago. In addition, Suenaga²⁾ and Kobayashi³⁾ applied the lacquer applied to the armor of the Kofun period after binding it with a strap, and the drying method is the same as normal lacquer. It is said that it is due. However, although lacquer does not adhere to metal unless it is baked and dried, if it is baked and dried after binding with a string such as deer leather, the leather string will deteriorate due to heat, so there is a trade-off between workability and corrosion resistance of leather binding. It turns off. Therefore, in order to determine the truth of these, we conducted a study this time. As a result, the surface performance was overwhelmingly higher when it was baked and dried, and the remnants of it were glimpsed in the dents of the armor. In addition, as a result of non-destructive color measurement of the black lacquer armor using a spectrocolorimeter, a profile of spectral reflectance with characteristics derived from seizure was obtained. Furthermore, it was found that there is a possibility that the baking and drying method can be adopted without thermally deteriorating the strap by switching the lacquering process and the leather binding process. From these facts, in order to ease the trade-off between workability and corrosion resistance of leather binding, the baking lacquer technique was adopted at the part molding stage, which is the opposite of the established theory, and then it is possible that leather binding may be performed.