No. Unless you have an agreement with the buyer in which it states that you have to.
That said, if you are aware of a trademark issue when making the sale, and a problem arises for the new buyer, they might claim that you acted in bad faith and request compensation for damages and lost profits (but they would have to prove that you knew).
I have successfully helped over 300 entrepreneurs and would be happy to help you (after scheduling a call, please send me a message with all the background information so that I can prepare in advance). Good luck