Extended engine coolant lifetime through polymeric polycarboxylate secondary silicate stabilization

An 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 which is at least one selected from the group consisting of (i) a polyacrylic acid, (ii) a sodium salt of a polyacrylic acid, and (iii) a combination thereof, in an amount of from about 0.001 to 10.0 percent by weight;
• a nitrate salt selected from the group consisting of sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, lithium nitrate and combinations thereof in an amount of about 0.10 to about 10.0 percent by weight;
• an azole compound selected from the group consisting of sodium mercaptobenzothiazole, sodium tolytriazole, water-soluble triazoles, pyrazoles, imidazoles, isooxazoles, isothiazoles, thiazoles, thiadiazole, 1, 2, 3-benzotriazole, 1,2,3-tolyltriazole, sodium 2-mercaptobenzothiazole, and sodium 2-mercaptobenzisidazole in an amount of about 0.01 to about 10.0 percent by weight;
• a silicone-silicate copolymer in an amount of about 0.1 to about 10.0 percent by weight;
• a phosphate salt 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 from about 0.1 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;
• and
• a 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 making up the balance of the solution.