That’s plainly rude and won’t help

If it is rude in your culture, you should find the appropriate way of expression

“I really need to focus on my work and be silent for a few hours a day. I’d be happy to chat on a coffee break, but I need to have some quiet time please”

But that won’t help either, because it makes too many words. By far.

It is essential to stay absolutely focused in such cases. You want something, so you say what you want, and nothing else. And then silence.

Silence is your goal.

Nothing about what you yourself are doing, only what you want the other one to do. Nothing about coffee and nothing about last year’s vacation on that beautiful island in the sun with the bowling club and how drunk they all were… The barest minimum is the right amount of politeness.