wherein Ra is a monovalent hydrocarbon group having at least 2 carbon atoms, Rb is {TAIL ~ an alkyl group} having 1 to 4 carbon atoms, Rc to Re are each independently an aryl group having {HEAD ~ 6 to 25 carbon atoms}, an alkyl group having 1 to 20 carbon atoms or a monovalent hydrocarbon group having at least 2 carbon atoms, o is 3 to 6, p is 1 to 3, and q is 1 to 10 
wherein Ra is a monovalent hydrocarbon group having at least 2 carbon atoms , Rb is { TAIL ~ an alkyl group } having 1 to 4 carbon atoms , Rc to Re are each independently an aryl group having { HEAD ~ 6 to 25 carbon atoms } , an alkyl group having 1 to 20 carbon atoms or a monovalent hydrocarbon group having at least 2 carbon atoms , o is 3 to 6 , p is 1 to 3 , and q is 1 to 10
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH