Patent ID: 7964002

Claim:
A composition comprising (a) biodiesel fuel and (b) an antioxidizing effective amount of a mixture of (i) at least one aromatic diamine selected from the group consisting of N-(1,4-dimethylbutyl)-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, and N,N′-di-sec-butyl-p-phenylenediamine and (ii) at least one sterically hindered phenol selected from the group consisting of 2,4-di-methyl-6-tert-butyl phenol, 2-methyl-6-tert-butyl phenol, 2,6-di-tert-butyl-4-methyl phenol, and 1,2,3-trihydroxybenzene wherein the ratio of aromatic amine to hindered phenol is about 1:1 by weight.