Toagosei Annual R&D Report “TREND” – Issue No. 21

Silsesquioxane is a siloxane-based compound with the composition formula (RSiO1.5)n, and it is regarded as an intermediate between silicone (R2SiO) and silica (SiO2).
It therefore has both inorganic features, such as heat resistance and hardness, and organic features, such as flexibility and solubility in organic solvents.

We have been developing the SQ Series of silsesquioxane derivatives, which have radically polymerizable acryloyl (AC) and methacryloyl (MAC) groups, and cationically polymerizable oxetanyl (OX) groups as crosslinking groups1-6). With the recent advances in electronic devices, heat resistance requirements for materials used in this field are becoming increasingly stringent. The SQ Series is used as a heatresistant binder for inorganic fillers and as a material for imparting heat resistance to organic materials, and has received favorable evaluations. This article describes the development of the SQ Series for heat-resistant applications and introduces the latest topics on the protective coating agent for spacecraft developed jointly with the Japan Aerospace Exploration Agency (hereinafter “JAXA”).