Engine antifreeze composition

Abstract

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.

Description

FIELD OF THE INVENTION [0001] In general, this invention is related to a coolant composition. More specifically, but not exclusive, this invention is directed to a coolant composition that includes anti-corrosion additives for use in combustion engines and a method of inhibiting the corrosion of components in cooling systems. BACKGROUND OF THE INVENTION [0002] Typically coolant compositions are specifically formulated with ethylene glycol or propylene glycol or their derivatives and include specific additives that inhibit and reduce corrosion of coolant systems. Specific coolant formulations are desired because with the advent of higher performance engines, particularly heavy-duty diesel engines, increasing more components of these engines are manufactured from a wide variety of materials to reduce weight and increase efficiency. Similarly, the coolant coursing through these engines contact a variety of materials. Typically additives are selected to impart particular benefits, such ...

AI Technical Summary

Benefits of technology

[0008] In still yet another form the present invention provides a method of reducing the corrosion of metal surfaces in a cooling system having a recirculating liquid coolant comprising hard water. The method comprises adding an additive to the liquid coolant. The additive can include an organic acid component or salt thereof, a anti-corrosion additive and a buffer agent. The acid component can comprise a mixture of a C4-C6 dicarboxylic acid and at least one of benzoic acid or a C9-C12 aliphatic dicarboxylic acid. The anti-corrosion additive can include molybdate, and at least one compound selected from the group consisting of: mercaptobenzothiazole, benzotriazole, tolyltriazole, nitrite, nitrate, and silicate.

Problems solved by technology

Despite the specificity which these coolant compositions are formulated, the benefits associated with many of the additives can be thwarted because a large percentage of operators include hard water in the cooling system.

In many parts of the world, there is no ready access to suitable water for use in cooling system.

These minerals may contribute to loss of efficacy and reduce the usable lifetime of the coolant composition.

This loss can be particularly detrimental to heavy duty diesel trucks that can cover over 10,000 miles a month.

An ineffective coolant composition can shorten engine life, allow internal passageways in the cooling system to clog, contribute to cylinder liner pitting and water pump cavitation all which result in costly engine overhauls.

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