Patents are wonderful things. In order to get a patent, the inventor must disclose how to make the invention. It is perfectly legal to use this information as a starting point for your own formulation, as long as you don't try to sell something that's too close to the original. US Patent 5,422,026, "Phosphate-Free Antifreeze Formulation," J. P Greaney, June 6,1995 might be a good start for you. Go to the USPTO web site and look it up. Typically, most patents have formulations listed last.