T.B.
I feel it would be perfectly acceptable to state on the invite that the event is for adults only and before you state this, you better be sure that no exceptions will be made for others who do have well mannered children. If you don't want the unruly children there, then make it known that NO CHILDREN are allowed by stating, "For adults only." I have children and I would not be offended to know in advance that my kiddos are not welcome. It would give me time to find suitable care for them while I am attending the event.