ydrocarbon group; and s is an integer of 1 to 5; and when s is 2 or more, respective R3 s or R4 s may be the same or different from each other, and the diamine containing a diaminopolysiloxane is represented by the formula (III): ##STR17## wherein R5 and R6 each represent a divalent hydrocarbon group having 1 to 3 carbon atoms, R7 and R8 each represent a monovalent hydrocarbon group having 1 to 3