Crates should NOT be used for long term confinement. More than 10 hours for any dog is too long to remain in a crate without being able to relieve themself. This must be gradualy worked up to through proper training from puppy hood. I suggest placing an exercise pen around the crate. This will give him the advantage of not being shut up in the crate at an early stage for long periods of time.
Puppies urinate immediately after waking up from a nap and defecate after every meal.
At this stage they become ready to stay in their crates all day while you are at work and all night while you sleep. I keep thick layers of newspapers in the crate for the first month or so. If the puppy is fed and watered and taken outside before being crated you will have a much cleaner and happier puppy when you return home. Puppies grow very fast and usually within a month you can remove the papers from the crate and replace it with a soft rug or towel. I usually have two crates per new puppy.