Quite often, the phrase "x for x's sake" is used in English, and so one could describe someone as being "argumentative for argument's sake" to describe someone who is arguing for the sake of arguing. However, is there an adjective that means the same thing? For example, it could be used in the context:
I don't want to be [X], but [argument...]
... indicating that your argument is necessary and not intended to irritate.