# US 12,215,272 B2 · Heat transfer fluids and corrosion inhibitor formulations for use thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,272 B2 - Document ID: US12215272B2 - Status: Granted - Kind: B2 - Application number: 17/437,217 - Filed: 2020-03-06 - Published: 2022-06-02 - Granted: 2025-02-04 - Earliest claimed: 2019-03-08 - Assignees: Prestone Products Corporation - Applicants: Prestone Products Corporation - Inventors: Bo Yang; Peter M. Woyciesjes - Web page: https://patentgrep.com/patent/US12215272B2 ## CPC - C09K 5/20: Antifreeze additives therefor, e.g. for radiator liquids (for application to surfaces C09K3/18; inhibiting corrosion by liquids C23F11/00) - C09K 5/10: Liquid materials - C09K 15/30: containing heterocyclic ring with at least one nitrogen atom as ring member - C23F 11/10: using organic inhibitors - C23F 11/149: {Heterocyclic compounds containing nitrogen as hetero atom} - H01M 8/04029: Heat exchange using liquids - H01M 8/04701: Temperature - Y02E 60/50: Fuel cells - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Heat transfer fluid concentrates include: (a) a freezing point depressant; and (b) a non-ionic surfactant comprising (i) a corrosion inhibitor for copper and copper alloys and (ii) a polyalkylene glycol. A conductivity of the heat transfer fluid concentrate is less than or equal to about 100 S/cm. Ready-to-use heat transfer fluids and methods for preventing corrosion in heat transfer systems are described. ## Claims ### Claim 1 A heat transfer fluid concentrate comprising: a freezing point depressant; and a non-ionic surfactant comprising (i) a corrosion inhibitor for copper and copper alloys and (ii) a polyalkylene glycol; wherein a conductivity of the heat transfer fluid concentrate is less than or equal to about 100 μS/cm and wherein the heat transfer fluid concentrate is free of siloxane-polyether copolymers. ### Claim 2 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the conductivity of the heat transfer fluid concentrate is less than or equal to about 25 μS/cm. ### Claim 3 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the conductivity of the heat transfer fluid concentrate is less than or equal to about 10 μS/cm. ### Claim 4 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the freezing point depressant comprises an alcohol. ### Claim 5 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the freezing point depressant comprises ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, or a combination thereof. ### Claim 6 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the freezing point depressant is present in an amount of about 10 wt. % to about 99.85 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 7 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the freezing point depressant is present in an amount of about 30 wt. % to about 99.5 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 8 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the freezing point depressant is present in an amount of about 40 wt. % to about 99 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 9 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the corrosion inhibitor for copper and copper alloys comprises an azole compound. ### Claim 10 (depends on 9) The heat transfer fluid concentrate of claim 9 wherein the azole compound is selected from the group consisting of an optionally substituted benzotriazole, an optionally substituted tolyltriazole, an optionally substituted C2-C20 alkyl benzotriazole, an optionally substituted mercaptobenzothiazole, an optionally substituted thiazole, an optionally substituted imidazole, an optionally substituted benzimidazole, an optionally substituted indazole, an optionally substituted tetrazole, and a combination thereof. ### Claim 11 (depends on 10) The heat transfer fluid concentrate of claim 10 wherein the optionally substituted C2-C20 alkyl benzotriazole comprises a methyl benzotriazole, a butyl benzotriazole, or a combination thereof. ### Claim 12 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the corrosion inhibitor for copper and copper alloys is present in an amount of about 0.01 wt. % to about 4 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 13 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the polyalkylene glycol comprises a polyethylene glycol, a polypropylene glycol, a methoxypolyethylene glycol, or a combination thereof. ### Claim 14 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the non-ionic surfactant is present in an amount of about 0.001 wt. % to about 2 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 15 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the non-ionic surfactant is present in an amount of about 0.005 wt. % to about 1 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 16 (depends on 1) The heat transfer fluid concentrate of claim 1 wherein the non-ionic surfactant is present in an amount of about 0.01 wt. % to about 0.5 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 17 (depends on 1) The heat transfer fluid concentrate of claim 1 further comprising an additional non-ionic surfactant. ### Claim 18 (depends on 17) The heat transfer fluid concentrate of claim 17 wherein the additional non-ionic surfactant is selected from the group consisting of a sorbitan fatty acid ester, an alkoxylated alcohol, a polyalkylene glycol ester, a copolymer of ethylene oxide and propylene oxide, a polyoxyalkylene derivative of a sorbitan fatty acid ester, and a combination thereof. ### Claim 19 (depends on 18) The heat transfer fluid concentrate of claim 18 wherein the alkoxylated alcohol has a formula RO(CH2CH2O)j(CH2CH2CH2O)kH, wherein R is a C4-C25 linear primary alcohol, j is an integer from 0 to 15, k is an integer from 0 to 15, and j+k is an integer greater than or equal to 1. ### Claim 20 (depends on 19) The heat transfer fluid concentrate of claim 19 wherein R is a C6-C15 linear primary alcohol. ### Claim 21 (depends on 18) The heat transfer fluid concentrate of claim 18 wherein the alkoxylated alcohol comprises an ethoxylated alcohol, a propoxylated alcohol, or a combination thereof. ### Claim 22 (depends on 21) The heat transfer fluid concentrate of claim 21 wherein the ethoxylated alcohol has a formula RO(CH2CH2O)nH, wherein R is a is a C4-C25 linear primary alcohol, and n is an integer from 1 to 15. ### Claim 23 (depends on 22) The heat transfer fluid concentrate of claim 22 wherein R is a C6-C15 linear primary alcohol. ### Claim 24 (depends on 21) The heat transfer fluid concentrate of claim 21 wherein the propoxylated alcohol has a formula RO(CH2CH2CH2O)mH, wherein R is a C4-C25 linear primary alcohol, and m is an integer from 1 to 15. ### Claim 25 (depends on 24) The heat transfer fluid concentrate of claim 24 wherein R is a C6-C15 linear primary alcohol. ### Claim 26 (depends on 18) The heat transfer fluid concentrate of claim 18 wherein the alkoxylated alcohol is present in an amount of about 0.001 wt. % to about 1 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 27 (depends on 17) The heat transfer fluid concentrate of claim 17 wherein the additional non-ionic surfactant comprises a sorbitan fatty acid ester and an alkoxylated alcohol. ### Claim 28 (depends on 1) The heat transfer fluid concentrate of claim 1 further comprising a low-conductivity corrosion inhibitor selected from the group consisting of a colloidal silica, an amine salt of a cyclohexenic carboxylate, an amine compound, or a combination thereof. ### Claim 29 (depends on 1) The heat transfer fluid concentrate of claim 1 further comprising water. ### Claim 30 (depends on 29) The heat transfer fluid concentrate of claim 29 wherein the water is deionized water, demineralized water, softened water, or a combination thereof. ### Claim 31 (depends on 29) The heat transfer fluid concentrate of claim 29 wherein the water is present in an amount of about 0.1 wt. % to about 90 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 32 (depends on 29) The heat transfer fluid concentrate of claim 29 wherein the water is present in an amount of about 0.5 wt. % to about 70 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 33 (depends on 29) The heat transfer fluid concentrate of claim 29 wherein the water is present in an amount of about 1 wt. % to about 60 wt. % based on a total weight of the heat transfer fluid concentrate. ### Claim 34 (depends on 1) The heat transfer fluid of claim 1 further comprising an additional component selected from the group consisting of a C1-C20 tetraalkylorthosilicate ester, a colorant, a wetting agent, a biocide, an antifoaming agent, a surfactant, an additional corrosion inhibitor, a non-ionic dispersant, and a combination thereof. ### Claim 35 A heat transfer fluid comprising: water; a freezing point depressant in an amount of about 10 wt. % to about 99.85 wt. % based on a total weight of the heat transfer fluid; a non-ionic surfactant in an amount of about 0.001 wt. % to about 2 wt. % based on a total weight of the heat transfer fluid, the non-ionic surfactant comprising (i) an azole compound and (ii) a polyalkylene glycol; wherein a conductivity of the heat transfer fluid concentrate is less than or equal to about 50 μS/cm and wherein the heat transfer fluid concentrate is free of siloxane-polyether copolymers. ### Claim 36 (depends on 35) The heat transfer fluid of claim 35 wherein the freezing point depressant comprises ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, or a combination thereof. ### Claim 37 (depends on 35) The heat transfer fluid concentrate of claim 35 wherein the polyalkylene glycol comprises a polyethylene glycol, a polypropylene glycol, a methoxypolyethylene glycol, or a combination thereof. ### Claim 38 (depends on 35) The heat transfer fluid of claim 35 wherein the azole compound is selected from the group consisting of an optionally substituted benzotriazole, an optionally substituted tolyltriazole, an optionally substituted C2-C20 alkyl benzotriazole, an optionally substituted mercaptobenzothiazole, an optionally substituted thiazole, an optionally substituted imidazole, an optionally substituted benzimidazole, an optionally substituted indazole, an optionally substituted tetrazole, and a combination thereof. ### Claim 39 (depends on 35) The heat transfer fluid of claim 35 further comprising an additional non-ionic surfactant is selected from the group consisting of a sorbitan fatty acid ester, an alkoxylated alcohol, a polyalkylene glycol ester, a copolymer of ethylene oxide and propylene oxide, a polyoxyalkylene derivative of a sorbitan fatty acid ester, and a combination thereof. ### Claim 40 (depends on 35) The heat transfer fluid of claim 35 further comprising a low-conductivity corrosion inhibitor selected from the group consisting of a colloidal silica, an amine salt of a cyclohexenic carboxylate, an amine compound, or a combination thereof. ### Claim 41 (depends on 35) The heat transfer fluid of claim 35 further comprising an additional component selected from the group consisting of a C1-C20 tetraalkylorthosilicate ester, a colorant, a wetting agent, a biocide, an antifoaming agent, a surfactant, an additional corrosion inhibitor, a non-ionic dispersant, and a combination thereof. ### Claim 42 A method of preventing corrosion in a heat transfer system, the method comprising: contacting at least a portion of the heat transfer system with a heat transfer fluid; wherein the heat transfer fluid comprises: a freezing point depressant; water; and a non-ionic surfactant comprising (i) a corrosion inhibitor for copper and copper alloys and (ii) a polyalkylene glycol; wherein a conductivity of the heat transfer fluid is less than or equal to about 100 μS/cm and wherein the heat transfer fluid concentrate is free of siloxane-polyether copolymers. ### Claim 43 (depends on 42) The method of claim 42 wherein the heat transfer system comprises a component comprising carbon steel, aluminum, aluminum alloy, magnesium, magnesium alloy, yellow metal, or a combination thereof. ### Claim 44 (depends on 42) The method of claim 42 wherein the heat transfer system comprises a component comprising magnesium, magnesium alloy, or a combination thereof. ### Claim 45 (depends on 42) The method of claim 42 wherein the heat transfer system comprises a fuel cell.