Can a judgment against me be vacated because it should be against my business?

First of all, you say the judgment should be against the business, not you personally.  What form of organization does the business follow?  It is true that corporations, llc's, and the like are separate legal entities, and that their owners are not, in general, personally liable for their obligations, but not all businesses are separate entities.  The owners of sole proprietorships, for example, are personally liable for their business's debts.   Perhaps more important, it si very difficult to have a judgment vacated.  You have already had your chance to raise this defense and failed to do so.  You really have no good reason; you just missed it.  It is therefore very unlikely that you will be able to have the judgment vacated.