No Umberto, it is not possible to disable the ability to comment on your father's Facebook account. There are some parental controls and default privacy settings for teenagers aged 13 - 18, but they are intended more to protect the minor from the community, not the other way around. [ Facebook Parental Controls guide (Virgin Media) ]
If Facebook is being accessed through a web browser, you could install a browser extension such as uBlock Origin and use that to transparently remove the "commenting elements" from all Facebook pages. See my solution on this forum for removing "Google Login" prompts. That solution could be adapted to remove Facebook commenting elements from the browser.