Patent GB-847657-A (GB)
Title: Process for preventing corrosion, corosion inhibitors and certain mixtures containing cyclic amidines
Inventor: GROOTE MELVIN DE
IPC: C02F1/24
Filed: 1956-10-12
Abstract: Mixtures containing cyclic amidines are obtained by reacting polyalkylene amines with "blown fatty oils", i.e. blown unsaturated fatty acids and their esters with monohydric and polyhydric alcohols (esterified before or after blowing), and also polymerised unsaturated fats and oils and polymerised unsaturated fatty acids derived therefrom.  Suitable for this purpose are blown castor oil, sperm oil, cottonseed oil, corn oil, rapeseed oil and soyabean oil; blown esters of unsaturated acids with methanol, ethanol, propanol, glycol, glycerol, diglycerol, trimethylolethane, trimethylolpropane, pentaerythritol and sorbitol; esters of blown ricinoleic acid; and polymerised castor oil.  Suitable amines are ethylenediamine, diethylenetriamine and higher analogues; propylenediamine and higher analogues; trimethylenediamine; butylenediamine; N-alkyl, N-hydroxyalkyl and N-aminoalkyl derivatives of these; 2 : 4-diaminopentene; 3 : 31-iminobispropylamine; reaction products of the above with ethylene oxide, propylene oxide, butylene oxide, glycide or styrene oxide; and reaction products of mono-and poly-amines with ethylene imine or propylene imine, which may also be after-treated with alkylene oxides.  The products are imidazolines or tetrahydro-pyrimidines substituted or linked by alkyl or aminoalkyl groups, which may be further substituted according to the starting material used.  Hydroxy groups may be esterified by the acid present. The formulae of typical products are given. The reactants are heated together at 230 DEG -300 DEG  C., this being below pyrolysis temperature, and conditions should be chosen so that no cross-linking occurs which would make the products insoluble in organic solvents such as coal tar fractions, diluted if desired with alcohols, pine oil, carbon tetrachloride or glycol ethers.  The products can be converted into salts with acetic, glycollic, lactic, gluconic, propionic, diglycollic, oxydipropanoic, malonic or succinic acid. They can be further reacted with mono- or poly-epoxides, alkylene imines, or polycarboxylic acids such as diglycollic, maleic, phthalic or succinic.ALSO:Oil additives which are emulsifiers and corrosion - inhibitors comprise the cyclic amidines obtained from alkylene di- and polyamines and "blown fatty oils", i.e. blown unsaturated fatty acids and their esters with monohydric and polyhydric alcohols, polymerized unsaturated fats and oils and polymerized unsaturated fatty acids derived therefrom.  The cyclic amidines are in general complex mixtures and the formulae of typical components are mentioned.  They are particularly suitable for addition to the oil and oilbrine mixtures in oil wells and refineries, and in oil wells they help to seal the strata and prevent loss when liquid pressure is applied; in the case of oil wells they may be mixed with a gel-former, with or without finely-divided mineral particles.  The cyclic amidines are also useful in the resolution of petroleum emulsions of the water-in-oil or oil-in-water type.  The amidines can be used as such or as salts with organic acids; they can be dissolved in aromatic hydrocarbons or other tar oils, which may be diluted with alcohols, pine oil, carbon tetrachloride or glycol ethers.  They may also be added to lubricating oils and fuel oils, in the latter case in conjunction with glyoxalidine or amido-glyoxalidine if desired, and for inhibiting fogs in hydrocarbon products.  As emulsifiers the cyclic amidines may replace or supplement the mahogany petroleum sulphonates in the preparation of soluble oils or emulsifiable lubricants.  Some of the compounds dissolve in xylene to give a solution which emulsifies when shaken with water.