First, he must assign the patent to the company. Second, no one should "get" x% equity. Everyone should vest over time (e.g., 48 months with a one year cliff). Third, if he is being paid, you and anyone else should be paid for their work too. He might argue that his work is worth more than yours, but he cannot argue yours is worthless.
Patent assignment is non-negotiable. If your company does not own it's strategic IP, what can it be worth? You could soften on my second point about vesting. In order words, he gets faster vesting or some part up front because he developed IP before the company began.
Regarding compensation, you should argue that work is work, and everyone should be paid. But what you want is for no one to be paid. It's just a bad idea for founders to take compensation in the earliest stages.
He might be the kind of person who think it best to start any negotiation with an extreme position, or he may just be some combination of naive and unreasonable. You will find out when you push back.