I don't have as much time as West Coast Sign Guy to respond (no offense) but I will offer this. You can manage a successful business and still have time for your family. I do it every day and neither my kids nor my wife feel neglected. It is a matter of balance with a strong emphasis on time management.
Do what you can do until 5 pm and go home. Spend quality time with your kids and pick up where you left off after the kids are in bed. It is important to understand that if you HAVE to work do it at home as much as possible. Just being there is better then being absent. They all understand that the bills have to be paid and they know who the bread winner in the family is (whether it be husband, wife or both).
The key is to be available and take time out when needed to be "there" for them and have the sense to step into the 21st century and embrace technology for your best hope at creating a balanced life for yourself.
Regards,
Bryan