초록 ▼

The present invention provides heavy duty long life corrosion inhibition formulations and compositions for inhibiting mineral scale and the corrosion of metals particularly the cavitation corrosion of aluminum in the presence of aqueous liquids. The combination of a mixture of polymeric polycarboxyl

The present invention provides heavy duty long life corrosion inhibition formulations and compositions for inhibiting mineral scale and the corrosion of metals particularly the cavitation corrosion of aluminum in the presence of aqueous liquids. The combination of a mixture of polymeric polycarboxylates, azoles, molybdenum, and a combination of nitrite and nitrate salts, phosphates, stabilized silicates and transition metal compounds 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. The addition of selected polymeric polycarboxylates not only significantly reduces glycol based coolant cavitation erosion-corrosion, heat rejecting aluminum corrosion, and hard water precipitates and scale, it has been discovered that polymeric polycarboxylates in combination with siloxane stabilized silicates enhance secondary silicate stabilization leading to improvement in aluminum corrosion protection and coolant life when utilized with selected amounts of the above-identified additives. The formulations are particularly suitable for diesel engine applications.

대표청구항 ▼

[ We claim:] [1.]1. A corrosion inhibiting antifreeze/coolant solution for inhibiting the corrosion of metals and inhibiting mineral scale based on 100 parts by weight of said glycol-based solution, comprising:a polymeric polycarboxylate in the amount of from about 0.001 to about 10.0 percent by wei

[ We claim:] [1.]1. A corrosion inhibiting antifreeze/coolant solution for inhibiting the corrosion of metals and inhibiting mineral scale based on 100 parts by weight of said glycol-based solution, comprising:a polymeric polycarboxylate in the amount of from about 0.001 to about 10.0 percent by weight selected from the group consisting of a polyacrylic acid or sodium salt thereof having a molecular weight (GPC M.sub.w) of from between 300 to 12,000;a nitrate salt which is at least one selected from the group consisting of sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, lithium nitrate and combinations thereof in an amount of about 0.001 to about 10.0 percent by weight;a nitrite salt which is at least one selected from the group consisting of sodium nitrite, potassium nitrite, magnesium nitrite, calcium nitrite, lithium nitrite and combinations thereof in an amount of about 0.001 to about 10.0 percent by weight;an azole compound in an amount of about 0.001 to about 10.0 percent by weight;a stabilized silicate copolymer in an amount of about 0.001 to about 10.0 percent by weight;a phosphate compound which is selected from the group consisting of dipotassium phosphate, disodium phosphate, monopotassium phosphate, tripotassium phosphate, monosodium phosphate, trisodium phosphate, and mixtures thereof in an amount of about 0.001 to about 10.0 percent by weight;a transition metal compound selected from the group consisting of disodium salt dihydrate of molybdic acid, molybdenum trioxide, silicoheteropolymolybdates and/or phosphoroheteropolymolybdates, sodium molybdate, potassium molybdate, lithium molybdate, ammonium molybdate, ammonium dimolybdate, and ammonium heptamolybdate in an amount of about 0.001 to about 10.0 percent by weight; anda glycol compound selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol and combinations thereof.