In general this invention relates to an antifreeze composition that can be used
in the cooling systems of internal combustion engines, for example, in heavy-duty
diesel engines, light duty trucks and cars. The antifreeze composition can be added
to water or other suitable liquid coolant in the cooling system, to lower the freezing
point temperature of the coolant and inhibit corrosion of metallic components associated
with the cooling system. The antifreeze composition is particularly well suited,
although not exclusively, for use with hard water. The antifreeze composition includes
an organic acid component comprising adipic acid and at least one of benzoic acid
and one or more C9-C12 dicarboxylic acid—or salts of
these acids. The antifreeze composition also includes other anti-corrosive additive,
for example, molybdate, nitrite, nitrate silicate azoles and a variety of buffer agents.
