Examples of a substituent for the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms represented by R3 include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; alkoxy groups having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a t-butoxy group