The catch-all statement seems pretty clear -- they own it (unless you dispute it in a court of law -- but who will invest in your thing in the meantime ?).
Now, perhaps they are benevolent and are willing to allow you do your thing in the spare time. But, if you really think there is money to be made, spend some money on actual legal advice.
Btw, if I were your boss and would read this message I would be kinda conflictual about granting you an exception from the contract for another reason: you seem to over-work yourself. Now, when you hire somebody for a full-time job you assume a given productivity. If the person is spending another 6-8 hours a day doing his side project until he's about to collapse -- how much productivity is the company losing ? Just another angle to look at it.
My day job is not suffering in the least. I have to provide for my family, and I make sure to clearly separate the two. I take pride in what I do. I think my boss would agree, so I'm not worried there.
If you have a good relationship with your boss and your work is not influenced by your side-project by all means talk directly to him/her. Nothing like having actual management support to get things moving quickly.
Now, perhaps they are benevolent and are willing to allow you do your thing in the spare time. But, if you really think there is money to be made, spend some money on actual legal advice.
Btw, if I were your boss and would read this message I would be kinda conflictual about granting you an exception from the contract for another reason: you seem to over-work yourself. Now, when you hire somebody for a full-time job you assume a given productivity. If the person is spending another 6-8 hours a day doing his side project until he's about to collapse -- how much productivity is the company losing ? Just another angle to look at it.