Patent GB-777063-A (GB)
Title: Improvements in or relating to phosphorus- and metal-containing corrosion inhibitors
Inventor: AGIUS PETER JOSEPH VERMONT JAM
IPC: C07F9/04
Filed: 1954-10-18
Abstract: Oil-soluble corrosion-inhibiting metal salts are obtained by phosphosulphurizing a mineral hydrocarbon oil and neutralizing the product by reacting with a compound containing aluminium, calcium, magnesium, tin or zinc.  Alternatively, the metal salts may be obtained by neutralizing the phosphosulphurized mineral oil with a basic oxide or hydroxide, e.g. sodium hydroxide, and subjecting the neutralized product to double decomposition with a salt of aluminium, calcium, magnesium, tin or zinc, e.g. a naphthenate of the metal, whereby an oil-soluble metal salt of the said metal is obtained.  The mineral hydrocarbon oil should preferably have a molecular weight between 200 and 5000 and is preferably a distillate oil or a residual fuel oil particularly a residual fuel oil of the type used in gas turbines.  The phosphosulphurization may be effected by heating the hydrocarbon oil, e.g. at 30-250 DEG  C., with a phosphorus sulphide, preferably phosphorus pentasulphide, or with an elemental mixture of phosphorus and sulphur.  The phosphosulphurized product may be neutralized by reacting with an oxide or hydroxide of the desired metal or by reacting with a salt of the metal, e.g. a salt of a weak acid such as a carbonate, bicarbonate, or acetate, or a salt of a volatile acid such as a chloride.  In an example a mineral hydrocarbon oil of viscosity 170 S.U.S. at 210 DEG  F. is reacted with phosphorus pentasulphide at 225 DEG  C. and the acid product is filtered and then further reacted at 160 DEG  C. with magnesia to yield the magnesium salt.  According to the Provisional Specification any hydrocarbon oil may be used in the phosphosulphurization including the synthetic hydrocarbons obtained from the Fischer-Tropsch process.  Specifications 705,176 and 734,231, [both in Group XII], are referred to.ALSO:A residual fuel oil composition comprises a residual fuel oil, particularly a gas turbine residual fuel oil and an oil-soluble corrosion-inhibiting metal salt obtained by phosphosulphurizing a mineral hydrocarbon oil and either neutralizing the product by reacting with a compound containing aluminium, calcium, magnesium, tin or zinc or neutralizing the phosphosulphurized product with a basic oxide or hydroxide and subjecting the neutralized product to double decomposition with a salt of aluminium, calcium, magnesium, tin or zinc to form the oil-soluble metal salt (see Group IV(b)).  The mineral oil should preferably have a molecular weight between 200 and 5,000 and may be a distillate oil or the residual fuel oil itself.  In an example for the production of the metal salt a mineral hydrocarbon oil of viscosity 170 S.U.S. at 210 DEG F. is reacted with phosphorus pentasulphide at 225 DEG C. and the acid product is filtered and then reacted with magnesia. According to the Provisional Specification any hydrocarbon oil may be used for the phosphosulphurization including the synthetic hydrocarbons obtained from the Fischer-Tropsch process. Specifications 705,176 and 734,231 [Group XII] are referred to.