Claims
- 1. In a process for inhibiting the corrosion of metals that come in contact with an aqueous antifreeze or coolant composition, the improvement wherein said antifreeze or coolant composition consists essentially of a mixture of water and an antifreeze or coolant concentrate consisting essentially of an alcohol, a corrosion inhibitor, and at least one organic basic buffer compound wherein said alcohol is selected from the group consisting of methanol, ethanol, propanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and glycerol, wherein said corrosion inhibitor is present in an amount of about 0.1 percent to about 10 percent by weight of said alcohol and is a water-soluble and alcohol-soluble metal salt of a carboxysiloxane consisting essentially of groups represented by the formula: ##EQU2## wherein M is a cation that imparts water and alcohol solubility to the siloxane, said cation being selected from the group consisting of the sodium, potassium, lithium and rubidium cations and the tetraorgano ammonium cations, a is the valence of the cation represented by M and has a value of at least one, R is a divalent hydrocarbon group containing from 0 to 1 M.sub.1/a OOC-- groups as substituents, each M.sub.1/a OOC-- group is connected to the silicon atom through at least 2 carbon atoms of the group represented by R; R' is a monovalent hydrocarbon group, b has a value from 1 to 3 inclusive, c has a value from 0 to 2 inclusive, and (b+c) has a value from 1 to 3 inclusive, wherein said organic basic buffer is present in the amount of about 0.1 to about 1.5 percent by weight based upon the weight of said concentrate and is selected from the group consisting of orthohydroxybenzoic acid, para hydroxybenzoic acid, and mixtures thereof, and wherein said buffer serves to maintain the pH of said antifreeze or coolant above about 9 to about 11.
- 2. The process of claim 1 wherein said antifreeze or coolant composition contains about 25 percent to about 90 percent by weight of water based upon the total weight of said coolant concentrate and wherein M is an alkali metal.
- 3. The process of claims 1 or 2 wherein the alcohol of said concentrate is ethylene glycol, said corrosion inhibitor comprises 0.1 part to 99.9 parts by weight of the siloxane of formula (1) and 0.1 part to 99.9 parts by weight of the siloxane of the formula:
- R".sub.e SiO.sub.4-e/2
- wherein R" is an unsubstituted monovalent hydrocarbon group or an amino-substituted monovalent hydrocarbon group and e has a value of 1 to 3 inclusive and, as an additional component, about 25 to about 90 percent by weight of water based upon the total weight of said concentrate.
Parent Case Info
This is a division of application Ser. No. 347, filed Jan. 2, 1979.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
Country |
Parent |
347 |
Jan 1979 |
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