Patent GB-896376-A (GB)
Title: Partial esters of aliphatic substituted succinic acids and rust inhibiting compositions containing the same
IPC: C10L1/198
Filed: 1958-08-18
Abstract: Rust-inhibiting compositions comprise a petroleum hydrocarbon having dissolved therein a partial ester of the general formula R11(OH)x-y (-O.CO.CHR1.CHR.COOH)y in which R11 is the residue of a polyhydric alcohol R11(OH)x, one of R and R1 is hydrogen and the other is a C8-18 alkyl or alkenyl group, x is 2, 3 or 4 and y is an integer which is at least 2 but otherwise may be equal to or less than x, the polyhydric alcohol having a carbon chain which may be interrupted by an oxygen, sulphur or tertiary nitrogen atom.  The polyhydric alcohol may be a diol, a polyoxyalkylene glycol, glycinol, erythritol, pentaerythritol, castor oil, a triol, a hydroxycarboxylic acid ester of a polyhydric alcohol, a bis-(hydroxy alkyl) sulphide or an N-alkyl or N-alkylol di-alkylol amine; the substituent in the acid radical may be n-octenyl, n-dodecenyl, n-hexadecenyl, n-octadecenyl, or branched dodecenyl or the corresponding alkyl groups.  Numerous partial esters are described.  The hydrocarbon oil may be a petroleum base such as motor or aviation gasoline, jet fuel, turbine oil, a mineral lubricating oil, or a leaded fuel such as a gasoline containing lead naphthenate.ALSO:The invention comprises partial esters of a substituted succinic acid and a polyhydric alcohol having the general formula R11(OH)x-y (-O.CO.CHR1.CHR.COOH)y in which R11 is the residue of a polyhydric alcohol R11(OH)x, one of the symbols R and R1 is hydrogen and the other a C8-18 alkyl or alkenyl group, x is 2, 3 or 4 and y is an integer which is at least 2 but may otherwise be equal to or less than x, the polyhydric alcohol having a carbon chain which may be interrupted by an oxygen, sulphur or tertiary nitrogen atom.  The partial esters may be prepared by heating, at a temperature below that at which water is eliminated, a mono C8-18 alkyl- or alkenyl-substituted succinic anhydride with a polyhydric alcohol R11(OH)x, at least two molar proportions of anhydride being provided for each molar proportion of polyhydric alcohol.  The alcohol may be a polyol, an ether thereof, an ester of a polyol with a hydroxycarboxylic acid, a polyhydroxy aliphatic sulphide or a polyhydroxy tertiary amine.  Reaction is generally effected at 95 DEG C.-100 DEG C., in the presence if desired of a solvent boiling above 100 DEG C.  Saturated alkyl-succinic esters may also be obtained by catalytic hydrogenation of the corresponding alkenyl-succinic esters. The esters have rust-inhibiting properties (see Group III).  Examples describe partial esters from (1) branched dodecenyl-succinic anhydride (2 moles) and many diols (1 mole) including ethane-, propane-, butane-, pentane-, hexane- and heptane-diols and isomers thereof, e.g. neopentyl glycol, di- and tri-ethylene glycols, polyethylene glycol 400, polypropylene glycol 425, phenyl ethane diol, a decane diol, 2 : 21-di-hydroxyethyl sulphide, and butene-diol; (2) the same anhydride and a butane-triol, castor oil, triethanolamine, glycerol and pentaerythritol, generally with full esterification of the polyol; (3) n-octenyl-, n-dodecenyl-, n-hexadecenyl or n-octadecenyl succinic anhydride (2 moles) and methyl pentane diol or a butane diol (1 mole); the use of the corresponding alkyl succinic anhydride is mentioned.  C8-18 alkenyl succinic anhydrides are prepared by reacting maleic anhydride with a C8-18 mono-olefin, followed by catalytic hydrogenation if the corresponding C8-18 alkyl succinic anhydride is required.