Patent GB-1005207-A (GB)
Title: Process for inhibiting the corrosion of metals and compositions for use therein
IPC: C23F11/10
Filed: 1961-11-29
Abstract: An inhibited alcohol composition comprising an alcohol, a silicon-free inorganic basic buffer and, as a corrosion inhibitor, a water- and alcohol-soluble organosiloxane polymer containing silicon-bonded <FORM:1005207/C4-C5/1> radicals, wherein M is a cation that imparts water and alcohol solubility to the siloxane, a is the valency of M and R is a divalent hydrocarbon radical (see Division C3), is used in coding systems of internal combustion engines.  The compositions include concentrates or antifreezes which contain from 0 to 10 parts (by weight) of water per 100 parts of alcohol, and coolants which contain from 30 to 900 parts of water per 100 parts of alcohol, and the buffer and inhibitor are each used in amount of 0.1 to 10 parts per 100 parts of alcohol or aqueous liquid respectively in the antifreeze or coolant.  The compositions can also be used as heat transfer media and hydraulic fluids.ALSO:The corrosion of metals below sodium in the electromotive series that come into contact with aqueous liquids, is inhibited by adding to the liquid a silicon-free inorganic basic buffer and an inhibiting amount of a certain organopolysiloxane or one or more reactants capable of forming the siloxane in situ (see Division C3).  The aqueous liquids disclosed are aqueous alcohol solutions for use as anti-freeze or coolant compositions in internal combustion engine cooling systems composed of iron, copper, brass and other alloys.  Other liquids mentioned are pure water, refrigerating solutions, corrosive well and river water and solutions containing specific organic compounds. The process is also applicable to preventing the corrosion of metals that are cleaned by corrosive solutions or that are used in cooling coils, boilers, refrigeration and air conditioning equipment, heat exchange tubes, storage tanks for liquids, pipes, solvent containers tank cars and ballast tanks containing sea water.ALSO:An inhibited alcohol composition comprises an alcohol, a silicon-free inorganic basic buffer and, as an inhibitor, a water- and alcohol-soluble siloxane composed of units of the formula <FORM:1005207/C3/1> with or without units of the formula <FORM:1005207/C3/2> wherein M is an inorganic or organic cation that imparts water and alcohol solubility to the siloxane, a is the valency of M, R is a divalent hydrocarbon radical of at least 2 C atoms and may contain a [M1/a OOC-] substituent group, R1 is a monovalent hydrocarbon radical (saturated or unsaturated, R11 is an aminohydrocarbon or R1 radical, b is 1, 2 or 3, c is 0, 1 or 2, b+c is 1, 2 or 3 and e is 1, 2 or 3.  If desired, the siloxane may be formed in situ from the corresponding silane or silanes, and the buffer may also be formed in situ.  The compositions include concentrates of antifreezes which contain from 0 to 10 parts (by weight) of water per 100 parts of alcohol, and coolants which contain from 30 to 900 parts of water per 100 parts of alcohol, and the inhibitor and buffer are each used in amount of 0.1 to 10 parts per 100 parts of alcohol or aqueous liquid respectively in the antifreeze or coolant.  Buffers specified are sodium and potassium carbonates, sodium phosphate, molybdate, phosphomolybdate, phosphotungstate, meta-arsenite and tungstate, lithium molybdate and borate, ammonium monohydrogen phosphate, and sodium, potassium and calcium meta- and tetra-borates.  The compositions can also be used as heat transfer media and hydraulic fluids.  Examples are given.