Patent ID: 8057695

Claim:
A method for increasing the thermal stability of an antifreeze composition which does not contain glycol, the method comprises the step of adding to a freezing point depressant matrix a corrosion inhibitor system comprising: a) 0.01 to 10 wt. % of at least a branched organic acid (C5-C16) or alkali- or amino salt of a branched organic acid (C5-C16); and b) 0.01 to 10 wt % of i) an aliphatic mono acid (C5-C12) or alkali- or amino salt of an aliphatic mono acid (C5-C12); or ii) an aromatic organic acid (C7-C18) or alkali- or amino salt of an aromatic organic acid (C7-C18); iii) a substituted aromatic organic acid (C7-C18) or alkali- or amino salt of a substituted aromatic organic acid, and wherein the freezing point depressant matrix comprises at least one of potassium acetate, potassium formate, potassium formate, potassium propionate, dipotassium adipinate, and mixtures thereof.