With a Premium Economy ticket you can't go to the Business Class Lounge, right?

The business class costs 2000 Euro and more is just too expensive for me, but I don't want to be squeezed into an airplane for half a day like in a sardine can either. A premium economy class ticket (to Southeast Asia) with more legroom costs from 1000 Euro I was looking at the Premium…

Can you go in and out of the Business Class Lounge at the airport as often as you like if you have a longer layover, for example, or is there a time limit?

I found a business class return flight to Thailand for 1590 euros (it normally costs 1000 euros more) with Turkish Airlines. The only catch is that there's a 20-hour layover on the outbound flight! Since I'm only allowed to enter one link, the bargain will be included in the reply in case anyone else is…