Heat transfer fluid compositions for cooling systems containing magnesium or magnesium alloys
View Patent ↗In one embodiment, a corrosion inhibiting composition is formed by combining: (a) an inorganic phosphate; (b) a water soluble polyelectrolyte polymer dispersant; (c) a tri or tetracarboxylic acid; and (d) at least one additional component comprising at least one of a C 4 -C 22 aliphatic or aromatic mono- or dicarboxylic acid, a silicate and at least one of a silicone or a silicate stabilizing siloxane compound, and mixtures thereof. Also disclosed are heat transfer fluids that include about 5% to about 99% by weight of freezing point-depressing agent; about 1% to about 95% by weight of water; and the disclosed corrosion inhibitor composition. A method of reducing corrosion in a heat transfer system containing one or more components that contain magnesium or a magnesium alloy requires that the system and the magnesium containing components be in contact with the disclosed heat transfer fluid.
1. A corrosion inhibiting composition formed by combining components comprising:
(a) an inorganic phosphate;
(b) a water soluble polyelectrolyte polymer dispersant;
(c) a tri or tetracarboxylic acid; and
(d) at least one additional component comprising at least one selected from the group consisting of a C 4 -C 22 aliphatic or aromatic mono- or dicarboxylic acid; a silicate and at least one of a silicone or a silicate stabilizing siloxane compound; and combinations comprising at least one of the foregoing;
wherein the tri- or tetracarboxylic acid (c) comprises a C 4 to C 20 aliphatic tetra-carboxylic acid where the carboxylic groups are located at 1, 2, 3, 4 positions, a C 3 to C 24 aliphatic tricarboxylic acid or the corresponding anhydrides without or with at least one additional hydroxyl group in an aliphatic chain.
2. The corrosion inhibiting composition of claim 1 further comprising a pH adjusting agent.
3. The corrosion inhibiting composition of claim 1 wherein component (d) further comprises one or more members selected from the group consisting of a C 4 -C 22 aliphatic or aromatic mono- or dicarboxylic acid, a fluoride, spiculisporic acid, a molybdate, an azole compound, a phosphonate, a phosphinate, an amine salt, a borate and combinations comprising at least one of the foregoing.
4. The corrosion inhibiting composition of claim 1 , further comprising at least one metal ion selected from the group consisting of calcium, magnesium, strontium, zinc and combinations thereof.
5. The corrosion inhibiting composition of claim 1 , wherein the water soluble polyelectrolyte polymer dispersant (b) is at least one of an acrylic acid or methacrylic acid based homopolymer, copolymer, terpolymer, or quadpolymer, or the water soluble salts thereof; an acrylamide based homopolymer, copolymer, terpolymer or quadpolymer, or the water soluble salts thereof; a maleic acid or a maleic anhydride based homopolymer, copolymer, terpolymer, or quadpolymer, or the water soluble salts thereof; vinylpyrrolidone based homopolymers or copolymers; alkylene oxide based copolymers or terpolymers; or a combination comprising one or more of the foregoing.
6. The corrosion inhibiting composition of claim 1 , wherein the water soluble polyelectrolyte polymer dispersant (b) comprises at least 5 mole % of mer units selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, 4-methyl-4 penenoic acid, maleic acid, maleic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, bicycle[2,2,2]-5-octene-2,3-dicarboxylic anhydride, 3-methyl-1,2,6-tetrahydrophthalic anhydride, 2-methyl-1,3,6-tetrahydrophthalic anhydride, itaconic acid, mesaconic acid, methylenemalonic acid, fumaric acid, citraconic acid, 2-acrylamido-2-methylpropanesulfonic acid, 3-allyloxy-2-hydroxy propane sulfonic acid, allyl phosphonic acid, allyloxybenzenesulfonic acid, 2-hydroxy-3-(2-propenyloxy)propanesulfonic acid, allylsulfonic acid, acrylamidomethyl propane sulfonic acids, methallyl sulfonic acid, isopro-phenylsulfonic acid, vinylphosphonic acid, styrenesulfonic acid, vinylsulfonic acid, aspartic acid, hydroxamic acid, adipic acid, and the alkali metal or ammonium salts thereof; methyl acrylate, ethyl acrylate, butyl acrylate, n-hexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-butylaminoethyl methacrylate, diethylaminoethyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, tertiary butylacrylate, polyethyleneglycol monomethacrylate, phosphoethyl methacrylate, and vinyl acetate; acrylamide (or 2-propenamide), methacrylamide, ethyl acrylamide, propyl acrylamide, N-t-butylacrylamide, tertiary butyl methacrylamide, tertiary octyl acrylamide, N-methylacrylamide, N,N-dimethylacrylamide (or N,N-dimethyl-2-propenamide), dimethylaminopropyl methacrylamide, cyclohexyl acrylamide, benzyl methacrylamide, vinyl acetamide, sulfomethylacrylamide, sulfoethylacrylamide, 2-hydroxy-3-sulfopropyl acrylamide, sulfophenylacrylamide, N-vinyl formamide, N-vinyl acetamide, 2-hydroxy-3-sulfopropyl acrylamide, N-vinyl pyrrolidone (a cyclic amide), 2-vinylpyridene, 4-vinylpyridenem and carboxymethylacrylamide; maleic anhydride (or 2,5-furandione) and succinic anhydride; acrylonitrile and methacrylonitrile; acrylamidopropyltrimethylammonium chloride, diallyldimethylammonium chloride, and methacrylamidopropyltrimethylammonium chloride; 1,2-dihydroxy-3-butene, allyl alcohol, ethylene glycoldiacrylate, 2-ethyl-oxazoline, diethylenetriamine, ethylene oxide, propylene oxide, ammonia, styrene, ethylene diamine, dimethylamine, diallyl phthalate, polyethylene glycol monomethacrylate, sodium styrene sulfonate, an alkoxylated allyl alcohol sulfonate or mixtures thereof.
7. The corrosion inhibiting composition of claim 1 , wherein the a tri- or tetracarboxylic acid (c) comprises 1,2,3,4-butane tetracarboxylic acid, 1,2,3,4-pentane tetracarboxylic acid, 1,2,3,4-hexane tetracarboxylic acid, or the corresponding anhydrides without or with at least one additional hydroxyl group in the aliphatic chains.
8. The corrosion inhibiting composition of claim 7 wherein the tri- or tetracarboxylic acid (c) comprises at least one of the group consisting of citric acid, 3-hydroxy-1,3,4-alkane tricarboxylic acid, 2-(2-carboxyethyl)-3-decyl maleic anhydride, cyclohexenoic tricarboxylic acids, and combinations thereof.
9. The corrosion inhibiting composition of claim 1 , wherein the at least one additional component (d) comprises a silicate and at least one of a silicone or a silicate stabilizing siloxane compound.
10. The corrosion inhibiting composition of claim 9 wherein the at least one additional component (d) further comprises an azole compound.
11. The corrosion inhibiting composition of claim 1 , wherein the at least one additional component (d) comprises a C 6 -C 24 aliphatic or aromatic mono- or di-carboxylic acid.
12. The corrosion inhibiting composition of claim 11 wherein the at least one additional component (d) further comprises an azole compound and a water soluable molybate salt.
13. The corrosion inhibiting composition of claim 2 , wherein the at least one additional component (d) further comprises an amine salt of cyclohexenoic carboxylate compounds derived from tall oil fatty acids.
14. A heat transfer fluid formed from a combination of components comprising:
about 5% to about 99% by weight of freezing point-depressing agent;
about 1% to about 95% by weight of water; and
the corrosion inhibitor composition of claim 1 .
15. A method of reducing corrosion in heat transfer system comprising magnesium or a magnesium alloy-containing component, the method comprising contacting the component with the heat transfer fluid of claim 14 .