Rubber O-rings, commonly used as sealing materials for piping, containers, etc., feature high sealing performance with elastic recovery. However, the service lifetime and utility of O-rings are relatively limited when used in high-temperature and/or high-pressure extreme environments, such as in chemical plants, and power generation and oil drilling applications. This limitation in utility constrains the scope of possible applications and their inevitable frequent replacement. Furthermore, from an energy saving standpoint, the replacement of metal seals with lighter weight materials is in demand in the automotive and aerospace industries.

Based on results achieved during a national project of the New Energy and Industrial Technology Development Organization (NEDO), a long-lifetime and heat-resistant O-ring commercial product was developed. This O-ring was fabricated using inexpensive fluorinated rubber (FKM) combined with single-walled carbon nanotubes, which were mass produced by the Super-Growth method, and began sale in October 2018 by Sunarrow Limited under the brand name “SGOINT^TM”.

The properties of this SGOINT O-ring showed a 3.5-times improvement in lifetime in compression set evaluations at elevated temperatures (230 Celsius degree) than that of commercially available FKM O-rings. This result is expected to reduce the frequency of replacement and overall equipment maintenance costs. Numerous applications, including sealing materials for oil rigs, and metal seal replacements in automotive and aircraft engine peripheral parts are expected to benefit from this new product. In conclusion, this O-ring represents the world's first commercial application that uses Super-Growth single-walled carbon nanotubes (SGCNTs) mass produced by the Super-Growth method, a method developed by AIST in 2004 enabling high growth efficiency, high purity, and large-scale synthesis.