| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a cage silsesquioxane, a crosslinked cage silsesquioxane, and an optical element using the same which realize high thermostability and a low coefficient of linear expansion.SOLUTION: A cage silsesquioxane is represented by the general formula (1). [In the general formula (1), R1 represents a direct coupling or a C1-C5 divalent hydrocarbon group; and R2 is selected from a hydrogen atom, a C1-C15 monovalent hydrocarbon group, a substituted C6-C15 monovalent aromatic hydrocarbon group, and an unsubstituted monovalent C6-C15 aromatic hydrocarbon group.]</p> |
