Full Idea
Kripke and Putnam made unsubstantiated claims, indeed false claims, to the effect that the theory of direct reference has nontrivial essentialist import.
Gist of Idea
Kripke and Putnam made false claims that direct reference implies essentialism
Source
Nathan Salmon (Reference and Essence: seven appendices [2005], Pref to Exp Ed)
Book Reference
Salmon,Nathan: 'Reference and Essence (2nd ed)' [Prometheus 2005], p.-1
A Reaction
Kripke made very few claims, and is probably innocent of the charge. Most people agree with Salmon that you can't derive metaphysics from a theory of reference.