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EP0238728B1 - Korrosionsinhibition Zusammensetzungen - Google Patents

Korrosionsinhibition Zusammensetzungen Download PDF

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Publication number
EP0238728B1
EP0238728B1 EP86118127A EP86118127A EP0238728B1 EP 0238728 B1 EP0238728 B1 EP 0238728B1 EP 86118127 A EP86118127 A EP 86118127A EP 86118127 A EP86118127 A EP 86118127A EP 0238728 B1 EP0238728 B1 EP 0238728B1
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Prior art keywords
acid
weight
corrosion
polymer
composition according
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Expired - Lifetime
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EP86118127A
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English (en)
French (fr)
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EP0238728A1 (de
Inventor
John E. Hoots
Donald A. Johnson
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ChampionX LLC
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Nalco Chemical Co
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    • 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

Definitions

  • the invention concerns the use of a composition for inhibiting in industrial cooling waters which contain hardness and have a pH of at least 8, which composition comprises a water-soluble organic phosphonate capable of inhibiting corrosion in an aqueous alkaline environment and a co- or terpolymer of acrylic acid and t-butyl acrylamide.
  • Phosphonates refers to organic materials containing one or more -POsH 2 groups and salts thereof.
  • Phosphonates particularly useful in this invention include i-hydroxy-i, i-ethane diphosphonic acid (HEDP), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), amino-tris-methylenephosphonic acid (AMP), and their salts.
  • HEDP i-hydroxy-i, i-ethane diphosphonic acid
  • PBTC 2-phosphonobutane-1,2,4-tricarboxylic acid
  • AMP amino-tris-methylenephosphonic acid
  • Corrosion occurs when metals are oxidized to their respective ions and/or insoluble salts.
  • corrosion of metallic iron can involve conversion to soluble iron in a 2+ or 3+ oxidation state or insoluble iron oxides and hydroxides.
  • corrosion has a dual nature in that a portion of the metal surface is removed, while the formation of insoluble salts contributes to the buildup of deposits. Losses of metal cause deterioration of the structural integrity of the system. Eventually leakage between the water system and process streams can occur.
  • Inhibition of metal corrosion by oxygenated waters typically involves the formation of protective barriers on the metal surface. These barriers prevent oxygen from reaching the metal surface and causing metal oxidation.
  • a chemical additive In order to function as a corrosion inhibitor, a chemical additive must facilitate this process such that an oxygen-impermeable barrier is formed and maintained. This can be done by interaction with either the cathodic or anodic half-cell reaction.
  • Inhibitors can interact with the anodic reaction 1 by causing the resultant Fe 2 + to form an impermeable barrier, stifling further corrosion. This can be accomplished by including ingredients in the inhibitor compound which: react directly with Fe 2+ causing it to precipitate; facilitate the oxidation of Fe 2+ to Fe 3 +, compounds of which are typically less soluble; or promote the formation of insoluble Fe 3+ compounds.
  • Reaction (2) represents the half-cell in which oxygen is reduced during the corrosion process.
  • the product of this reaction is the hydroxyl (OH-) ion. Because of hydroxyl production, the pH at the surface of metals undergoing oxygen-mediated corrosion is generally much higher than that of the surrounding medium. Many compounds are less soluble at elevated pH's. These compounds can precipitate at corrosion cathodes and act as effective inhibitors of corrosion if their precipitated form is impervious to oxygen and is electrically nonconductive.
  • Corrosion inhibitors function by creating an environment in which the corrosion process induces inhibitive reactions on the metal surface.
  • the components of the composition must not precipitate under the conditions in the bulk medium.
  • Inhibitors which effectively inhibit this precipitation by kinetic inhibition have been extensively described in the literature.
  • An example of this art is US-A 3 880 765 which teaches the use of polymers for prevention of calcium carbonate prepitation.
  • Corrosion inhibition can be achieved by a combination of the use of inhibitors and modification of the chemistry of the medium.
  • US-A 4 547 740 teaches a method of corrosion inhibition relying on operation under conditions of high pH and alkalinity. This method does not rely on the use of inorganic phosphates, giving a more desirable product from an environmental impact point of view.
  • Said copolymers in connection with threshold inhibition of salt-forming scales and dispersion of particulate matter find usage as scale inhibitors - but not as corrosion inhibitors.
  • FR-A 1 598 419 The subject matter of FR-A 1 598 419 is the inhibition of scale formation and corrosion by using a water-soluble polymer and a phsophonate, with a considerable amount of homopolymers and copolymers being stated for the water soluble polymer. Despite that enormous number of polymer classes the copolymers of acrylic acid with the specifically substituted acrylamide according to the invention cannot be seen from this cited reference.
  • composition for inhibiting corrosion in industrial cooling waters which contain hardness and have a pH of at least 8 which composition comprises:
  • any water-soluble phosphonate may be used that is capable of providing corrosion inhibition in alkaline systems. See US-A 4 303 568 which lists a number of representative phosphonates.
  • the organo-phosphonic acid compounds are those having a c-P bond, i.e.,
  • R is lower alkyl having from 1 to 6 carbon atoms, e.g., methyl, ethyl, butyl, propyl, isopropyl, pentyl, isopentyl and hexyl; substituted lower alkyl of from 1 to 6 carbon atoms, e.g., hydroxyl and amino- substituted alkyls; a mononuclear aromatic (aryl) radical, e.g., phenyl, benzene, as a substituted mononuclear aromatic compound, e.g., hydroxyl, amino, lower alkyl substituted aromatic, e.g., benzyl phosphonic acid; and M is a water-soluble cation, e.g., sodium, potassium, ammonium, lithium, or hydrogen.
  • R 1 is an alkylene having from 1 to 12 carbon atoms or a substituted alkylene having from 1 to 12 carbon atoms, e.g., hydroxyl, amino substituted alkylenes, and M is as earlier defined above.
  • R 2 is a lower alkylene having from 1 to 4 carbon atoms, or an amine or hydroxy substituted lower alkylene
  • R 3 is [R 2 -P0 3 M 2] H, OH, amino, substiuted amino, an alkyl having from 1 to 6 carbon atoms, a substituted alkyl of from 1 to 6 carbon atoms (e.g., OH, NH 2 substituted) a mononuclear aromatic radical and a substituted) a mononuclear aromatic radical (e.g., OH, NH 2 substituted);
  • R 4 is R 3 or the group represented by the formula
  • R 5 and R 6 ar each hydrogen, lower alkyl of from 1 to 6 carbon atoms, a substituted lower alkyl (e.g., CH, NH 2 substituted), hydrogen, hydroxyl, amino group, substituted amino group, a mononuclear aromatic radical, and a substituted mononuclear aromatic radical (e.g., OH and amine substituted);
  • R is Rs, Rs, or the group R 2 -PO 3 M 2 (R 2 is as defined above); n is 1 to 15; y is 1 to 14; and M is as earlier defined.
  • Preferred phosphonates are the two compounds:
  • additives such as tolytriazole may be utilized.
  • Tolytriazole is effective in the reduction of copper substrate corrosion.
  • Suitable acrylic acids for purposes herein are generally defined as monounsaturated monocarboxylic acids containing 3 or 4 carbon atoms. Specific examples of such acids include acrylic and methacrylic acids, with acrylic acid being preferred.
  • comonomers can be used with an acrylic acid and tert.butyl acrylamide provided that such additional comonomers do not deleteriously affect the desired properties.
  • additional comonomers examples include acrylic acid and tert.butyl acrylamide, acrylamide and methacrylamide, acrylonitrile, vinyl esters.
  • the acrylic acid units in the copolymer can be in the acid form or in a neutralized form where the hydrogen of the carboxyl group is replaced with an alkali metal, alkaline earth metal, or an ammonium cation, depending on the neutralizing medium.
  • the copolymers can be neutralized with a strong alkali, such as sodium hydroxide, in which instance, the hydrogen or the carboxyl group of the acrylic acid units will be replaced with sodium. With the use of an amine neutralizing agent, the hydrogen will be replaced with an ammonium group.
  • Useful copolymers include copolymers that are unneutralized, partially neutralized, and completely neutralized.
  • the copolymer is preferably formed in a high yield ranging from 50% to 99% by weight of the comonomers.
  • polymers of the type described above may be modified by incorporating into their structure up to 30% by weight of a termonomer which contains: a non-ionic or anionic polar group from the group selected perferably consisting of amido, lower alkyl ester, and maleic acid salt groups.
  • a termonomer which contains: a non-ionic or anionic polar group from the group selected perferably consisting of amido, lower alkyl ester, and maleic acid salt groups.
  • Examples of preferred monomers that may be polymerized to form terpolymers are acrylamide, methyl, or ethyl acrylate, maleic anhydride.
  • Other polar monomers that may be used are, for example, vinyl acetate, acrylonitrile, the various vinyl ketones, and vinyl ethers.
  • Illustrative of these monomers are the compounds: vinyl pyrrolidone, methyl vinyl ether, methacrylonitrile, allyl alcohol, methyl methacrylate, beta-diethylaminoethyl methacrylate, vinyl trimethylacetate, methyl isobutyrate, cyclohexyl methacrylate, vinyl laurate, vinyl stearate, N-vinyl imides, N-vinyl lactams, diethylene glycol dimethacrylate, diallylmaleate, allyl methacrylate, diallyl phthalate, and diallyl adipate.
  • the polymers formed may have weight average molecular weight in the range of 1,000 to 50,000, and preferably 2,000 to 30,000, as determined of known gel permeation chromatography using polystyrene of known molecular weight as a reference material.
  • the acid numbers of the copolymers formed may range from 310 to 740, corresponding to a weight fraction of from 40% to 95% by weight of monomer units having COOH groups.
  • the preferred polymers have more than 50% by weight of free carboxyl groups and an acid number in the range from 390 to 700.
  • Polymer Composition Nos. 1-12 are unneutralized copolymers of acrylic acid and t-butylacrylamide (t-BAm).
  • Polymer Composition No. 5 Polymer Composition No. 6, and Polymer Composition Nos. 7-12 are terpolymers which respectively contain the additional mer units of ethyl acrylate (EA), acrylamide (Am), and methacrylic acid (MAA).
  • EA ethyl acrylate
  • Am acrylamide
  • MAA methacrylic acid
  • the copolymers composed of acrylic acid and t-butyl acrylamide contains between 50 to 90% by weight of acrylic acid and from 50-10% by weight of t-butyl acrylamide.
  • the acrylic acid is present in a weight percent amount ranging between 70-90 with the t-butyl acrylamide being present at between 30-10.
  • the acrylic acid is present in a weight percent amount ranging between 80-90 with the t-butyl acrylamide being present at between 20-10.
  • the terpolymers are within the following weight percent composition ranges:
  • the aqueous system is dosed based on active ingredients to provide thereto on a weight basis from between 5-50 ppm, preferably 8 to 40 ppm and most preferably 15-30 ppm of Compositions 1 and 2 previously described.
  • compositions When the compositions are first added it is beneficial if they are dosed on the side to control the corrosion and to begin forming protective films. After a week or so the dosages can be diminished until an optimum maintenance dosage is established.
  • the systems treated are industrial recirculating and once through cooling waters that either due to their natural make-up or by pH adjustment have a pH of at least 8.
  • the pH of the systems are within the range of 8-9.5 and are most often within the range of 8.5-9.2.
  • These systems are characterized as containing at least 10 ppm of calcium ion and are considered to be corrosive to ferrous metals as well as non-ferrous with which they come in contact.
  • the mixture was cooled in an ice-bath and then basified by slow addition of approximately 22 grams of aqueous sodium hydroxide (50 wt%) to the vigorously stirred solution. During the addition of base, the solution's temperature was maintained below (130 ° F) 55 ° C. The pH was adjusted to 13 with 4.7 grams of a 50 weight percent of a sodium tolyltriazole solution. Finally, sufficient softened water to produce 100 grams of product were added. The cooling bath was removed and the solution stirred until ambient temperature was reached.
  • aqueous sodium hydroxide 50 wt%
  • the stock solutions were added to attain 360 ppm Ca2+, 10 ppm inhibitor, 5.6 ppm Dequest and 8 ppm PBS-AM in the final 500 ml test volume.
  • the pH was adjusted to 9.2 using aqueous sodium hydroxide.
  • test samples The pH of the test samples was manually adjusted at 15 minute intervals during the first hour and at 1 hour intervals, subsequently. A 4 hour test durating was sufficient for these precipitation reactions to stabilize. Finally, a portion of each test solution was passed through cellulose acetate/nitrate Millipore filter (type HA, 0.45 ⁇ m). Both filtered and unfiltered aliquots were spectrophotometrically analyzed for total phosphate content. To study particle size effects, an additional sample was passed through a 0.10 Il m Millipore filter (type VC). The % inhibition was determined by a following formula: In calcium phosphonate inhibition tests, polymer performance versus precipitated particle size was examined and the results are presented in Table B.
  • the calcium phosphonate "inhibition" process involves minimizing particle growth. Maintaining scale particles at an extremely small size and mass may ultimately prove to be a pivotal factor in determining polymer performance.
  • filters with mean pore sizes of 0.10 and 0.45 ⁇ m differences in polymer performance were readily observed.
  • Versa TL-4 the low molecular weight copolymer of sulfonated styrene and maleic acid
  • Polymer Composition Nos. 1 and 5 exhibited very good inhibition (0.45 ⁇ m filter), but performance decreased rapidly when the filter pore size was reduced to 0.10 ⁇ m.
  • Polymer Composition No. 11 exhibited the best overall performance in both bench-top and PCT tests.
  • the pilot cooling tower test is a dynamic test which simulates many features present in an industrial recirculating cooling water system.
  • the general test method is described in the article "Smail-Scale Short-Term Methods of Evaluating Cooling Water Treatments ... Are They Worthwhile?", by D.T. Reed and R. Nass, Minutes of the 36th Annual Meeting of the INTERNATIONAL WATER CONFERENCE, Pitts- burgh, Pennsylvania, November 4-6, 1975.
  • Tolytriazole is explained inhackh's Chemical Dictionary, Fourth Edition, page 91 (CF. benzotriazole) and is employed as a corrosion inhibitor for copper and copper alloy surfaces in contact with water when it is used it is applied to the system at a dosage ranging between 1-20 ppm by weight.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Preventing Corrosion Or Incrustation Of Metals (AREA)
  • Magnetic Heads (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Prevention Of Electric Corrosion (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Claims (7)

1. Verwendung eines Korrosions-Inhibitors für harte industrielle Kühlwässer mit einem pH-Wert von zumindest 8 aus:
A. einem wasserlöslichen organischen Phosphonat zur Verhinderung der Korrosion in wässrig alkalischem Milieu und
B. einem wasserlöslichen, nicht vernetzten statistischen Copolymeren von 50 bis 90 Gew.-Teilen Acrylsäure-Einheiten und 50 bis 10 Gew.-Teilen substituierter Acrylamid-Einheiten, bezogen auf insgesamt 100 Gew.-Teile polymerisierte Monomere, wobei das Polymere ein mittleres Molekulargewicht (Gewichtsmittel) von 1000 bis 50 000 und eine Säurezahl von 310 bis 740 besitzt und die polymerisierten Einheiten der Acrylsäure und des substituierten Acrylamids durch folgende Formel dargestellt werden können:
Figure imgb0020
worin m 10 bis 700 und n 0,1 bis 350 ist unter Berücksichtigung der Molekulargewichtsbegrenzung, R und R1 Wasserstoff oder Methyl,
X Wasserstoff, Natrium, Kalium, Calcium, Ammonium oder Magnesium ist
und das Gewichtsverhältnis Polymer:Phosphonat 0,2:1 bis 2:1 beträgt.
2. Verwendung des Korrosions-Inhibitors nach Anspruch 1, wobei das Phosphonat ein Gemisch von 2-Phosphonobutan-1,2,4-tricarbonsäure und 1-Hydroxyethan-1,1-diphosphonsäure ist.
3. Verwendung des Korrosions-Inhibitors nach Anspruch 1 oder 2, wobei das statistische Polymere weiter charakterisiert ist durch einen Gehalt bis zu 30 Gew.-% eines Termonomeren, welches anionische oder nicht anionische Gruppen enthält.
4. Verwendung des Korrosions-Inhibitors nach Anspruch 3, wobei das Polymere ein Terpolymer von Acrylsäure, Methacrylsäure und tert.-Butylacrylamid ist und das Phosphonat 1-Hydroxyethan-1.1-diphosphonsäure und/oder 2-Phosphonobutan-1,2,4-tricarbonsäure ist.
5. Verwendung des Korrosions-Inhibitors nach Anspruch 3, wobei das Terpolymer ein mittleres Molekulargewicht (Gewichtsmittel) von 9000 bis 30 000 hat. -
6. Verwendung des Korrosions-Inhibitors nach Anspruch 1 bis 5, der zusätzlich Tolyltriazol als korrosionsinhibierende Substanz enthält.
7. Verwendung des Korrosions-Inhibitors nach Anspruch 1 bis 6 für die verbesserte Leistung von Phosphonat-Korrosionsinhibitoren in wässrigen Systemen enthaltend Härtebildner mit einem pH-Wert von zumindest 8 durch eine Dosis von 5 bis 50 ppm, vorzugsweise 8 bis 30 ppm Korrosions-Inhibitor.
EP86118127A 1986-03-26 1986-12-30 Korrosionsinhibition Zusammensetzungen Expired - Lifetime EP0238728B1 (de)

Applications Claiming Priority (2)

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US84441586A 1986-03-26 1986-03-26
US844415 1986-03-26

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EP0238728B1 true EP0238728B1 (de) 1990-08-29

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EP (1) EP0238728B1 (de)
JP (1) JPS62270786A (de)
CN (1) CN1019989C (de)
AT (1) ATE56051T1 (de)
AU (1) AU593082B2 (de)
BR (1) BR8701331A (de)
CA (1) CA1329474C (de)
DE (1) DE3673809D1 (de)
DK (1) DK169709B1 (de)
ES (1) ES2016796B3 (de)
FI (1) FI871242A (de)
GR (1) GR3001105T3 (de)
MX (1) MX173411B (de)
PT (1) PT84551B (de)
TR (1) TR24741A (de)
ZA (1) ZA872236B (de)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4717542A (en) * 1987-01-23 1988-01-05 W. R. Grace & Co. Inhibiting corrosion of iron base metals
WO1989007633A1 (en) * 1988-02-18 1989-08-24 John Kenneth Bethune Absorbent polymer compositions
CN1034738C (zh) * 1993-03-27 1997-04-30 云浮硫铁矿企业集团公司 一个防护剂组合物
GB9505675D0 (en) * 1995-03-21 1995-05-10 Diversey Corp Cleaning compositions
CA2599940C (en) * 2005-03-04 2011-11-29 The Procter & Gamble Company Automatic dishwashing composition with corrosion inhibitors
CN101368091B (zh) * 2007-08-16 2012-01-11 中国石油天然气集团公司 一种油井水泥缓凝剂
CN101560022B (zh) * 2009-05-26 2011-05-11 西安协力动力科技有限公司 复合缓蚀阻垢剂
US11085118B2 (en) 2016-04-14 2021-08-10 Nch Corporation Composition and method for inhibiting corrosion and scale
US10351453B2 (en) * 2016-04-14 2019-07-16 Nch Corporation Composition and method for inhibiting corrosion

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1208827A (en) * 1968-02-23 1970-10-14 Grace W R & Co Composition and process for inhibiting scaling and/or corrosion in cooling water systems and for stabilizing phosphate solutions
DE2333353C2 (de) * 1973-06-30 1983-05-19 Bayer Ag, 5090 Leverkusen Verfahren zur Verhinderung von Korrosion in wasserführenden Systemen und Korrosionsschutzmittel zur Durchführung des Verfahrens
US4317744A (en) * 1979-04-25 1982-03-02 Drew Chemical Corporation Corrosion inhibitor
GB2124607B (en) * 1982-07-16 1986-02-05 Katayama Chemical Works Co Scale-inhibiting agent
US4566973A (en) * 1984-08-06 1986-01-28 The B. F. Goodrich Company Scale inhibition in water systems
GB2168359B (en) * 1984-11-08 1988-05-05 Grace W R & Co A method of inhibiting corrosion in aqueous systems
US4650591A (en) * 1985-08-29 1987-03-17 Calgon Corporation Acrylic acid/2-acrylamido-2-methylpropylsulfonic acid/2-acrylamido-2-methylpropyl phosphonic acid polymers as scale and corrosion inhibitors
US4752443A (en) * 1986-05-09 1988-06-21 Nalco Chemical Company Cooling water corrosion inhibition method

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AU593082B2 (en) 1990-02-01
DK150787A (da) 1987-09-27
DE3673809D1 (de) 1990-10-04
EP0238728A1 (de) 1987-09-30
DK169709B1 (da) 1995-01-16
JPS62270786A (ja) 1987-11-25
GR3001105T3 (en) 1992-05-12
ATE56051T1 (de) 1990-09-15
PT84551B (pt) 1989-11-10
JPH0146593B2 (de) 1989-10-09
ES2016796B3 (es) 1990-12-01
MX5678A (es) 1993-09-01
TR24741A (tr) 1992-03-06
CN87102313A (zh) 1988-02-24
CN1019989C (zh) 1993-03-03
MX173411B (es) 1994-03-02
PT84551A (en) 1987-04-01
FI871242A (fi) 1987-09-27
AU7063287A (en) 1987-10-01
DK150787D0 (da) 1987-03-25
ZA872236B (en) 1987-11-25
FI871242A0 (fi) 1987-03-20
BR8701331A (pt) 1988-01-05
CA1329474C (en) 1994-05-17

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