Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
  • C23F11/10—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using organic inhibitors
  • C23F11/167—Phosphorus-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
  • C23F11/18—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using inorganic inhibitors

Definitions

• Polyphosphates are not as efficient as chromates and they are unstable in a cooling water environment, decomposing by hydrolysis to ortho and pyrophosphates, often causing sludge and deposits.
• Orthophosphates are not as efficient as chromates and if they are not controlled properly they can also form sludge and deposits.
• organophosphonates provide some corrosion protection, they are not nearly as efficient as chromates.
• Organic phosphonocarboxylic acids or phosphinocarboxylic acids have been disclosed as useful to prevent calcium and other scale deposits and to prevent corrosion of iron in circulating water systems. Such compounds are disclosed in U.S. patents 3,933,427, 4,042,324 and 4,159,946. Examples of compounds disclosed in U.S. 3,933,427 are phosphonosuccinic acid and 2-phosphonobutane-1,2,4-­tricarboxylic acid; in U.S. 4,042,324 are disclosed carboxymethane-phosphonic acid and 1-carboxypropane-2-­phosphonic acid; in U.S.
• 4,052,160 are disclosed compounds such as 2-phosphonoacetic, 2-phosphono­propionic, 2,3-di-phosphonopropionic, 2,4-diphos­phonobutyric and 2-phosphonomethylacrylic acids; and in U.S. 4,159,946 are disclosed the telomeric products of the reaction of acrylic acid and hypophosphorous acid and the products of acrylic acid and butyl hypophosphite; and in U.S. 4,606,890 are disclosed 2-­hydroxyphosphonoacetic acid employed in combination with certain metal ions, e.g. zinc, cadmium, manganous, ferrous and chromium which are said to be synergistic in preventing corrosion.
• certain metal ions e.g. zinc, cadmium, manganous, ferrous and chromium
• 3,933,427 are said to provide improved corrosion inhibition when zinc salts, e.g. zinc sulfate or phosphate, are added to the aqueous system containing the phosphonocarboxylic or phosphinocarboxylic compound.
• zinc salts e.g. zinc sulfate or phosphate
• U.S. patent 4,640,818 discloses the combination of a manganese compound with an aminophosphonic acid derivative as an inhibitor of metal corrosion in water systems.
• the invention is an improved process for inhibiting corrosion of metals in water conducting systems. It comprises employing a composition useful for inhibiting metal corrosion in water conducting systems which comprises;
• synergistic combinations comprising manganese compounds together with organic phosphonocarboxylic or phosphinocarboxylic acid derivatives or their salts, provide metal corrosion protection comparable to chromates.
• the various organic phosphonocarboxylic or phosphinocarboxylic acid derivatives tested alone in water do not provide this level of protection.
• the corrosion protection of metals provided by an organic phosphonocarboxylic or phosphinocarboxylic acid compound is enhanced by the addition of a manganese compound which provides a source of manganese ion.
• organic phosphonocarboxylic or phosphinocarboxylic acid derivatives useful in the practice of the present invention as shown by the above formulae are known compounds.
• alkenyl and alkynyl refer to both straight and branched-chain hydrocarbon moieties having either their respective double or triple bond(s) and from 2 to 4 carbon atoms.
• alkyl refers to both straight and branched-chain hydrocarbon having from 1 to 18 carbon atoms.
• cycloalkyl refers to a saturated hydrocarbon having a cyclic structure and from to 5 to 12 carbon atoms.
• aryl refers to an aromatic hydrocarbon having from 6 to 12 carbon atoms.
• aralkyl is an C1-C4 alkyl substituted aryl.
• Representative compounds of formula (1) are: ⁇ -methylphosphonosuccinic acid; phosphonosuccinic acid; 1-phosphonopropane-2,3-dicarboxylic acid; and 2-­phosphonobutanetricarboxylic acid(1,2,4).
• the preparation of such phosphonocarboxylic acids has been described, e.g. in German Offenlegungsschrift No. 2,015,068.
• formula (2) is compounds such as carboxymethanephosphonic acid; 1-carboxy­ethan-1-phosphonic acid; 1-carboxyethane-2-phosphonic acid; 2-carboxypropane-3-phosphonic acid; 1-carboxy­propane-2-phosphonic acid and methyl(carboxyethyl)­phosphonic acid. These compounds are prepared by methods known in the art, e.g. U.S. Patent 4,052,160.
• telomers of formula (3) are provided by reacting an unsaturated acid of the formula or a salt thereof, wherein R2 ⁇ is defined as before, with a compound of the formula wherein R1 ⁇ is defined as before, and R3 ⁇ is hydrogen, a straight or branched chain alkyl group having from 1 to 18 carbon atoms, a cycloalkyl residue of 5 to 12 carbon atoms, a phenyl or benzyl moiety, or OX wherein X is defined as before.
• manganese compounds which may be employed as a source of manganese ion are, for example, MnO, MnO2, MnCl2 ⁇ 4H2O, KMnO4, Mn(CH3COO)2 ⁇ 4H2O and the like.
• the manganese compound can be added simultaneously with the phosphorous-containing carboxylic acid derivative or may be added separately to the water.
• the manganese can be complexed by the phosphorous-containing carboxylic acid compound prior to adding to the water.
• Preferred is a composition in which the weight ratio of phosphorous-containing carboxylic acid derivative to manganese is at least about 2 to 1.
• organic phosphonocarboxylic or phosphinocarboxylic acid derivatives described herein and salts thereof are considered equivalent.
• the salts referred to are the acid addition salts of those bases which will form a salt with at least one acid group of the subject derivatives.
• Suitable bases include, for example, ammonia, the alkali metal and alkaline earth metal hydroxides, carbonates, and bicarbonates such as sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, sodium bicarbonate, magnesium carbonate and the like.
• These salts may be prepared by treating the organic phosphonocarboxylic or phosphinocarboxylic acid derivative having at least one acid group with an appropriate base.
• the preferred quantity of the organic phosphonocarboxylic or phosphinocarboxylic acid derivatives to inhibit corrosion of either copper or iron containing metal alloys in water conducting systems is from 1 to 150 ppm acid or equivalent.
• the operable amounts are from 0.5 to 200 ppm.
• the addition of manganese compounds to these phosphorous containing carboxylic acid derivatives in such water conducting systems has an unexpected enhancement on corrosion inhibition.
• the present invention is the use of this composition to inhibit corrosion.
• the manganese compound usually is employed in an amount to provide from 0.5 to 30 ppm manganese by weight in the aqueous solution. Preferred amounts provide from 0.1 to 10 ppm.
• Water level in the tank was automatically controlled by a gravity feed system and heat was added to the water by electric immersion heaters.
• the water temperature was measured by a platinum RTD (resistance thermal device) and controlled at 125°F (51.7°C) by an "on/off" controller which provided power to the immersion heaters.
• the pH of the water was adjusted to pH 8.0 by addition of caustic (50%) and was automatically maintained at 8.0 by a controller which feeds HCl (1% aq. solution) to the tank in response to an increase in pH.
• the 2-phosphonobutanetricarboxylic acid was introduced to two separate tanks to a concentration of 150 ppm.
• Manganese as MnCl2 ⁇ 4H2O was added to one of these tanks to a concentration of 7.5 ppm Mn.
• the pH of each tank was controlled at 8.0, using dilute HCl.
• Carbon steel electrodes (1018) which were cleaned with 1:1 HCl and sanded with 320 grade sandpaper to remove all surface oxides were attached to the electrode corrosion probes and immersed in the tanks.
• the instantaneous corrosion rates were monitored using a potentiostatic corrosion rate instrument.
• the experiments were conducted for a period of five days, at which time, the concentration of salts in the baths were approximately four times those of the feed water. At the end of this time, the final average corrosion rates were found to be 1.0 mpy (0.025 mm/y) (mils per year) in the tank with manganese and 2.5 mpy (0.061 mm/y) in

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Citations (5)

• 1988
  • 1988-03-08 EP EP88301999A patent/EP0283191A3/de not_active Withdrawn
  • 1988-03-11 NO NO881091A patent/NO881091L/no unknown
  • 1988-03-11 FI FI881163A patent/FI881163A/fi not_active IP Right Cessation
  • 1988-03-11 ZA ZA881767A patent/ZA881767B/xx unknown
  • 1988-03-15 DK DK141388A patent/DK141388A/da not_active Application Discontinuation
  • 1988-03-17 AU AU13212/88A patent/AU1321288A/en not_active Abandoned
  • 1988-03-18 JP JP63065586A patent/JPS63259086A/ja active Pending
  • 1988-03-19 KR KR1019880002927A patent/KR880011376A/ko not_active Application Discontinuation

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