Patent GB-762228-A (GB)
Title: Improvements in and relating to corrosion inhibitors and application thereof
IPC: C10L1/222
Filed: 1954-05-11
Abstract: A solution in a hydrocarbon of a salt of a polycarboxylic acid containing at least 6 carbon atoms and an alkylene polyamine having at least 1 hydrogen atom on each nitrogen atom, said salt containing at least 20 carbon atoms, is used to inhibit corrosion of metals in presence of water.  The hydrocarbon solvent may itself be an oil or other hydrocarbon which is being processed or stored and from which the water is separating or has separated. Alkylene polyamines used to form salts include ethylene, propylene up to hexylene diamine and homologues, as well as diethylene (propylene or butylene) triamine, triethylene (propylene or butylene) tetramine and tetraethylene (or butylene) pentamine. Hydrocarbon substituents on the nitrogen include aryl, aralkyl, alkaryl and cycloalkyl.  The preferred polyamines have the formula R-NH-R1-NHR11 where R and R11 are hydrogen or alkyl, at least one being alkyl, preferably of at least 6 and especially 10 or more carbon atoms, and R1 is an alkylene radical, preferably of 3 or more carbon atoms.  Thus, propylene diamines having a substituent alkyl group derived from lauric or coconut or soya oil acid and particularly from tallow acids, the last being available as "Duomeen T" (Registered Trade Mark), are preferred.  Polycarboxylic acids used for forming the amine salts include di-, tri- and tetracarboxylic, examples being given. Preferred acids are the mixed dibasic acids of 35-50 carbon atoms such as commercial linoleic acid dimer or "VR-1 Acid". Neutral acid or basic salts are prepared by mixing the appropriate amounts of amine and acid at ordinary or elevated temperature up to about 93 DEG  C., a solvent being added if desired. The salt is used in a concentration of about 0.0001-5 per cent by weight of the hydrocarbon which may be paraffinic, olefinic, naphthenic or aromatic.  In examples, a neutral salt of "Duomeen T" and "VR-1 Acid" is prepared and the anti-corrosive effect when added to fuel oil or naphtha containing water and in contact with steel strip is illustrated.  Comparative tests using "Duomeen T" itself and its dioleate are given.  The use of the basic salt of "VR-1 Acid" in kerosene and of the azelaic acid salt of lauryl-1,4-butylene diamine in cracked gasoline is also illustrated.ALSO:Corrosion of metals in presence of water is inhibited by contacting with a solution in a hydrocarbon of a salt of a polycarboxylic acid containing at least 6 carbon atoms and an alkylene polyamine having at least 1 hydrogen atom on each nitrogen atom, said salt containing at least 20 carbon atoms.  The hydrocarbon solvent may be gasoline, kerosene, fuel oil, crude oil or lubricating oil which is being processed or stored and from which the water is separating or has separated.  Alkylene polyamines used to form salts include ethylene diamine and homologues up to hexylene diamine, as well as di-ethylene (or propylene or - butylene) triamine, tri - ethylene (or-propylene or n-butylene) tetramine and tetra-ethylene (or - butylene) pentamine.  Hydrocarbon substituents on the nitrogen include aryl, aralkyl, alkaryl and cycloalkyl.  The preferred polyamines have the formula R-NH-R1-NHR11 where R and R11 are hydrogen or alkyl, at least one being alkyl, preferably of at least 6 and especially 10 or more carbon atoms, and R1 is an alkylene radical, preferably of 3 or more carbon atoms. Thus, propylene diamines having a substituent alkyl group derived from lauric or coconut or soya oil acid and particularly from tallow acids, the last being available as "Duomeen T" (the word "Duomeen" is a Registered Trade Mark), are preferred. Polycarboxylic acids used for forming the amine salts include di-, tri-, and tetra-carboxylic acids, examples being given. Preferred acids are the mixed dibasic acids of 35-50 carbon atoms such as commercial linoleic acid dimer or "VR-1 Acid."  Neutral, acid or basic salts may be employed.  The salt is used in a concentration of about 0.0001-5 per cent by weight of the hydrocarbon.  In examples a neutral salt of "Duomeen T" and "VR-1 Acid" is prepared and the anti-corrosive effect when added to fuel oil or naphtha containing water and in contact with steel strip is illustrated.  Comparative tests using "Duomeen T" itself and dioleate are given.  The use of the basic salt of "VR-1 Acid" in kerosene and the azelaic acid salt of lauryl-1, 4-butylene diamine in cracked gasoline is also illustrated.