There is no built-in capability of
Update: There is a capability
create_posts but it's not well publicised and also has issues surrounding it which I'm afraid I don't have time to look into at the moment.
There are already answers that might help:
publish_posts. You need to turn this off for those users. Removing this capability doesn't prevent a user or role from writing a draft post, but it does prevent them from publishing it, so it won't be seen outside the admin.
Currently (WP 4.6) posts have these capabilities associated with them:
You probably want to disallow the
*_private_* capabilities for anyone but Admins too.