MONOCARBOXYLIC ACID BASED ANTIFREEZE COMPOSITION FOR DIESEL ENGINES

摘要

The present invention relates to an acid based antifreeze coolant formulatio n for heavy duty applications such as for diesel engines which may be used for inhibition and prevention erosion and corrosion of aluminum and the corrosio n of other metals exposed to an aqueous liquid in automotive coolant systems. The formulation further inhibits mineral scale. It may be packaged as an ethylene glycol based additive for use in new engines or in a concentrated inhibition package as an additive as for reinhibition of used coolant. The combination of a mixture of ethylene or propylene glycol, a monobasic aliphatic organic acid, azoles, low levels of molybdates, a combination of nitrite and/or nitrate salts, polyvinylpyrrolidone, a hydroxide salt, silicates and/or siloxane stabilized silicates with transition metal compoun ds provide a synergistic protective effect against the cavitation corrosion of aluminum in aqueous liquids reducing the corrosion rate and is effective at relatively low concentrations and varying pH ranges.