1. Product Overview

The light, which has a shorter wavelength than visible light (light that can be seen by the human eye), is called ultraviolet (UV) light, and is classified into UV-A (320-400 nm), UV-B (280-320 nm), and UV-C (100-280 nm) according to its wavelength. The UV-C light has a strong germicidal effect. With the recent global spread of COVID-19, surface sterilization, water sterilization, and air sterilization products using UV-C, which is considered to be effective in sterilizing and inactivating viruses, have been seen in various situations.

This product is a coating material that can efficiently reflect the wavelength of 250-280 nm, which is considered to be the most effective wavelength of UV-C for virus inactivation, thus shortening the time required for sterilization and disinfection of novel coronaviruses and other viruses. This product is a highly reflective material that focuses on UV-C, which is said to be effective in sterilizing and inactivating the novel coronavirus.

Fig.1 External view of Hi-UVC

2. Product Description

• High reflectivity in the UV-C wavelength band

In order to achieve high reflective performance in the UV-C band, we examined the combination of filler particle sizes that can be highly filled, and optimized blending ratio of fillers with high specific surface area and low specific surface area. As a result, as shown in Figure 2, the reflective performance at wavelengths of 250-280 nm was approximately twice that of an aluminum substrate.

Fig. 2 Reflectance spectral characteristics in the UV-C band

Durability for use with high power light

Since this product contains silicone material, the generation of low-molecular siloxane during use has been an issue. However, by improving the manufacturing method and other factors, we have succeeded in reducing cyclic siloxane with a low boiling point, which has been a problem in contact failure of electronic components, to below the lower limit of analysis. This minimizes the degradation of reflectance in the heat resistance test, UV-light resistance test, and constant temperature and humidity test, and improves the reliability in long-term use (Figure 3).

Fig.3 Environment test result

Application to complex uneven surfaces

This product is a coating material and can be used with coating methods such as screen printing, spray coating, and dipping coating. Therefore, the coating can be applied not only to flat substrates but also to complex uneven and curved surface as shown in Figure 4. It is also possible to coat resin substrates.

Fig.4 Hi-UVC applied to a curved surface

3. Sales Result

The product is currently being evaluated by more than 50 customers for use in industrial water treatment and water treatment equipment for aquaculture. In addition, mass production has begun as a reflective material for COB substrates of UVC-LEDs.

4. Summary

This product is a coating material that reflects the UV-C band, which is effective in sterilizing and inactivating novel coronaviruses, with high efficiency. In the future, as the development of UVC-LEDs progresses and inexpensive high-brightness light sources enter the market, we expect that this product will be widely used in various applications, contributing to the improvement of light use efficiency and energy conservation.

Okamoto Glass Co., Ltd.
Corporate Member，380, Toyofuta, Kashiwa, Chiba, 270-0872, Japan