Heat transfer fluids and corrosion inhibitor formulations for use thereof
View Patent ↗Disclosed herein is a heat transfer fluid concentrate comprising: greater than or equal to 90 weight percent of a freezing point depressant; 16 to 80 ppm of magnesium ions; an azole compound; an inorganic phosphate; a carboxylate; and an acrylate based polymer, wherein the heat transfer fluid concentrate has a pH of 7-9.5 and the weight ratio of acrylate based polymer to magnesium ions is 1 to 25. The heat transfer fluid concentrate can be used to make a heat transfer fluid.
1. A heat transfer fluid concentrate comprising:
greater than 90 weight percent of a freezing point depressant;
16 to 80 ppm of magnesium ions;
an azole compound;
an inorganic phosphate;
a carboxylate; and
an acrylate based polymer,
wherein the heat transfer fluid concentrate has a pH of 7 to 9.5 and is free of silicate, borate, and amines, and
wherein the weight ratio of acrylate based polymer to magnesium ions is 1 to 25.
2. The heat transfer fluid concentrate of claim 1 , further comprising calcium ions.
3. The heat transfer fluid concentrate of claim 1 , further comprising 50 to 2000 ppm lithium ions.
4. The heat transfer fluid concentrate of claim 1 , further comprising calcium ions and 50 to 2000 ppm lithium ions.
5. The heat transfer fluid concentrate of claim 1 , wherein the acrylate based polymer comprises a phosphinopolyacrylate.
6. The heat transfer fluid concentrate of claim 1 , further comprising one or more additional corrosion inhibitors selected from the group consisting of nitrites, molybdates, and salts thereof.
7. A heat transfer fluid comprising:
less than 90 weight percent of a freezing point depressant;
2 to 60 ppm of magnesium ions;
an azole compound;
an inorganic phosphate;
a carboxylate;
greater than 0.5 ppm of calcium ions; and
an acrylate based polymer,
wherein the heat transfer fluid has a pH of 7 to 9.5 and is free of silicate, borate, and amines, and
wherein and the weight ratio of acrylate based polymer to magnesium ions is 1 to 25.
8. The heat transfer fluid of claim 7 , wherein the heat transfer fluid comprises less than 60 ppm calcium ions.
9. The heat transfer fluid of claim 7 , wherein the heat transfer fluid comprises less than 40 ppm calcium ions.
10. The heat transfer fluid of claim 7 , further comprising 20 to 1800 ppm lithium ions.
11. The heat transfer fluid of claim 7 , wherein the acrylate based polymer comprises a phosphinopolyacrylate.
12. The heat transfer fluid of claim 7 , further comprising one or more additional corrosion inhibitors selected from the group consisting of nitrites, molybdates, and salts thereof.