EP0225051A1 - The treatment of aqueous systems - Google Patents
The treatment of aqueous systems Download PDFInfo
- Publication number
- EP0225051A1 EP0225051A1 EP86308419A EP86308419A EP0225051A1 EP 0225051 A1 EP0225051 A1 EP 0225051A1 EP 86308419 A EP86308419 A EP 86308419A EP 86308419 A EP86308419 A EP 86308419A EP 0225051 A1 EP0225051 A1 EP 0225051A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- zinc
- acid
- chelant
- carboxylic acid
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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
Definitions
- the present invention relates to the treatment of aqueous systems and, more particularly, to reducing or eliminating corrosion in aqueous systems.
- inorganic salts such as nitrites and chromates, inorganic mono and polyphosphates, certain water soluble polymers including naturally occurring materials such as lignins and starches as well as synthetic materials such as polyacrylates, as well as organic phosphonates.
- zinc salts for this purpose. Indeed, it is known to use zinc salts in combination with organic type corrosion inhibitors, principally organic phosphonates and polyacrylates.
- a method of treating an aqueous system which comprises adding thereto a zinc salt, a chelant and either a product containing at least one phosphorus-containing acid group and at least one carboxylic acid group or an acrylic, vinyl or allyl carboxylic acid polymer.
- any water soluble zinc salt can be used in the present invention.
- Typical salts which can be used include zinc sulphate, zinc chloride, zinc nitrate and zinc acetate, zinc sulphate monohydrate and zinc chloride being particularly preferred.
- the third component used in the present invention will, in general, be a phosphonate.
- the materials used contain at least two acid groups, one of which is a phosphonate group and the other is a carboxylic acid group, at least the two said acid groups being attached to carbon atoms.
- Preferred phosphonates include hydroxy phosphonoacetic acid and 2-phosphono butane-1,2,4-tricarboxylic acid, the latter being particularly preferred.
- these preferred phosphonates possess the general formula wherein R is hydrogen, alkyl, alkenyl or alkynyl having up to 4 carbon atoms; phenyl; cycloalkyl having 3 to 6 carbon atoms; benzyl; phenethyl or wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R''' is carboxyl or phosphonate.
- polymeric material and, in particular, carboxylic acid polymers which contain a chain phosphorus atom which forms part of an acid group.
- the molecular weight of such polymers is relatively low, generally below 5,000, the preferred molecular weight being from 250 to 750, especially about 500.
- a particularly suitable polymer is that sold as "Belclene 500" by Ciba-Geigy.
- a synergistic effect although most pronounced when the phosphorus containing materials are used, can also be obtained when a polycarboxylic acid is used, typically one having a molecular weight from 1,000 to 5,000.
- Such polymers may be derived from acrylic, vinyl or allyl carboxylic monomers, typically acrylic, methacrylic, maleic, fumaric, itaconic, crotonic or cinnamic acid alone or with a suitable comonomer.
- Such comonomers include acrylamide, (meth)acrylate esters or hydroxy esters e.g.
- chelants which can be used in the method of the present invention are generally compounds with a nitrogen ligand which are effective chelants for iron. Usually, these chelants will also possess a carboxylic acid group.
- a preferred group of chelants possesses the formula R3 - - - CR2 where R1 is hydrogen, hydroxyethyl or carboxymethyl, preferably carboxymethyl, R2 is hydrogen, hydroxyphenyl, preferably ortho-hydroxyphenyl, which is optionally methyl or sulphonic acid substituted, or carboxyl, R4 is hydrogen or carboxyl, where R1, R2 and R4 are as defined above and X is -(CH2)2- or - (CH2)3 -.
- the phenyl groups may be substituted, if desired, preferably by one or more halogen atoms.
- the chelant is to be used in aqueous systems which possess a high pH and a relatively high temperature it is preferred that at least one of R1, R2 and R3 contains a hydroxyl group.
- the most preferred chelants possess a nitrogen ligand, a carboxylic acid group and a hydroxyl group.
- Preferred chelants for use in the present invention include N,N'-di(-2-hydroxybenzyl-)trimethylenediamine-N,N'-diacetic acid, N,N'ethylene-bis-[2-(2-hydroxy-4-methyl-phenyl)-glycine], ethylenediamine N,N'-bis-[2-hydroxyphenylacetic acid] and N,N-di(2-hydroxy-5-sulphonic acid benzyl)glycine which is especially preferred not only on account of its effectiveness but also on account of its excellent solubility properties which faciliate the formulation of compositions, as well as N,N-di(2-hydroxyethyl) glycine, N-hydroxyethyl N,N' ,N'-ethylenediamine triacetic acid and 2-hydroxyethyl iminodiacetic acid.
- Ethylenediamine tetraacetic acid and diethylene triamine pentaacetic acid can also be mentioned although they are less preferred since they do not contain
- the present invention also provides a composition suitable for addition to an aqueous system which comprises a water soluble zinc salt, a product containing at least one phosphorus containing acid group and at least one carboxylic acid group or an acrylic, vinyl or allyl carboxylic acid polymer, and a chelant. In such a situation, it may be desirable to add further quantities of chelant as required.
- the composition will be an aqueous formulation containing, generally, 1% to 2% by weight of zinc salt (as zinc), 4% to 10% by weight of the phophorus containing material or polymer and 1% to 25% by weight, especially about 5% by weight, of the chelant.
- zinc salt as zinc
- 4% to 10% by weight of the phophorus containing material or polymer 1% to 25% by weight, especially about 5% by weight, of the chelant.
- a further surprising feature of the present invention is that the presence of the combination of chelant and phosphorus containing compound and/or acrylic vinyl or allyl carboxylic acid polymer enables one to reduce the amount of zinc salt. It is usual in the art to employ amounts of the order of 2 to 5ppm zinc. However, with ever increasing restrictions on concentrations of zinc in discharges there is a constant demand to reduce the amounts of zinc used. It has been found that by using the additional ingredients it is possible to reduce the amount of zinc to, say, about 1ppm for comparable effectiveness. In such circumstances it is preferred to employ about 4ppm of the phosphorus compound and about 2.5 to 5ppm of chelant. If, on the other hand, one uses 2.5ppm of zinc then it is preferred to use about 10ppm of phosphorus compound and about 5ppm of chelant.
- the combination of the present invention together with other ingredients including phosphates, biocides, yellow metal corrosion inhibitors such as benzotriazole and tolyltriazole as well as other polymers which act as dispersants such as polyacrylic acid, polymaleic acid and copolymers of maleic acid with styrene sulphonic acid.
- dispersants especially a copolymer of methacrylic acid and acrylamide is particularly advantageous, especially one in which the mole ratio is about 1:3, and further enhances the corrosion protection given by the three component system.
- the molecular weight of the homopolymers will be 1,000 to 10,000 while that of the copolymers will be 1,000 to 50,000.
- test were carried out on a laboratory scale recirculating rig consisting of a plastic vessel holding 8 litres of water and connected by tubing to a circulating pump the water passing from the pump through a glass rack holding the metal test coupons ('line') and returning to the plastic vessel. Any evaporation was made up by the addition of de-ionised water. Metal test coupons were also suspended in the plastic vessel ('Pond'). The corrosion rate was calculated from the weight of metal lost during test. The water temperature was maintained by means of a heater/thermostat arrangement.
- Examples 15 - 34 were carried out at 54°C.
- test conditions were as follows: System Water : 160ppm Calcium hardness 50ppm Magnesium hardness 200ppm 'M' Alkalinity Water Temperature (Pond) : 50°C pH : 8.8 Flow Rate through heat exchanger : 0.3 ft/sec Flow Rate through coupon chamber : 1.5 ft/sec Heat flux on exchanger : 75 kj/m ⁇ 2/sec ⁇ 1 Duration of test : 14 days Initial passivation : 3 x normal maintenance dose, allowed to decay from start of test.
- Example 42 in relation to Example 43 shows the effect of using Chelant 2 in enabling one to reduce the concentration of zinc/phosphate.
Abstract
Description
- The present invention relates to the treatment of aqueous systems and, more particularly, to reducing or eliminating corrosion in aqueous systems.
- Many different types of material have been employed to prevent or inhibit corrosion in aqueous systems. These include inorganic salts such as nitrites and chromates, inorganic mono and polyphosphates, certain water soluble polymers including naturally occurring materials such as lignins and starches as well as synthetic materials such as polyacrylates, as well as organic phosphonates. In addition, it is well known to use zinc salts for this purpose. Indeed, it is known to use zinc salts in combination with organic type corrosion inhibitors, principally organic phosphonates and polyacrylates.
- The use of zinc salts enables one to passivate corrosion of the metal in contact with the system. It is generally believed that localised high concentrations of hydroxide ions arise at sites of corrosion on the metal surface because, due to the galvanic cell effect, oxygen present in the water is reduced to hydroxide ions at the cathodic sites. These hydroxide ions then react with zinc ions of the zinc salt to give zinc hydroxide which in turn yields a protective film on the metal surface.
- While this passivation system works reasonably satisfactorily in some aqueous media it is known that the use of zinc salts, with or without the organic type corrosion inhibitor, is ineffective when the pH of the system is high, for example at pH from 8.2 to 9.0. Such a pH can be present when the water is hard, or is otherwise alkaline ie of low hardness and high alkalinity as can be the case with base exchanged water. Under such circumstances, the zinc hydroxide preciptates prematurely in the system water and therefore does not form a protective film over the metal. Thus in such systems the zinc actually becomes a foulant of the system. Similar problems arise when the temperature of the aqueous system is raised, for example to at least 40°C as can occur when the aqueous system is used as cooling water which comes into contact with hot metal surfaces.
- It has now surprisingly been found, according to the present invention, that more effective corrosion inhibition can be obtained when a zinc salt is used together with a class of phosphonate or similar material and, in addition, a chelant. It has been found that this combination is capable of being effective under a combination of severe pH and temperature conditions. It is considerably more effective than existing zinc/organic products on pre-corroded mild steel surfaces since the combination is capable of stifling existing corrosion as well as enabling much faster passivation of the rusty surface to be brought about. Thus the combination, as well as inhibiting corrosion, also acts as an on line cleaning agent by removing old rust.
- According to the present invention there is provided a method of treating an aqueous system which comprises adding thereto a zinc salt, a chelant and either a product containing at least one phosphorus-containing acid group and at least one carboxylic acid group or an acrylic, vinyl or allyl carboxylic acid polymer.
- Generally, any water soluble zinc salt can be used in the present invention. Typical salts which can be used include zinc sulphate, zinc chloride, zinc nitrate and zinc acetate, zinc sulphate monohydrate and zinc chloride being particularly preferred.
- The third component used in the present invention will, in general, be a phosphonate. Preferably, the materials used contain at least two acid groups, one of which is a phosphonate group and the other is a carboxylic acid group, at least the two said acid groups being attached to carbon atoms.
- Preferred phosphonates include hydroxy phosphonoacetic acid and 2-phosphono butane-1,2,4-tricarboxylic acid, the latter being particularly preferred. Thus these preferred phosphonates possess the general formula
wherein R' is hydrogen, alkyl having 1 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R''' is carboxyl or phosphonate. - It is also possible to employ as the third component in the method a polymeric material and, in particular, carboxylic acid polymers which contain a chain phosphorus atom which forms part of an acid group. Thus these polymeric materials are preferably phosphino polycarboxylic acids, typically those having the formula
- The molecular weight of such polymers is relatively low, generally below 5,000, the preferred molecular weight being from 250 to 750, especially about 500. A particularly suitable polymer is that sold as "Belclene 500" by Ciba-Geigy.
- It has also been found that a synergistic effect, although most pronounced when the phosphorus containing materials are used, can also be obtained when a polycarboxylic acid is used, typically one having a molecular weight from 1,000 to 5,000. Such polymers may be derived from acrylic, vinyl or allyl carboxylic monomers, typically acrylic, methacrylic, maleic, fumaric, itaconic, crotonic or cinnamic acid alone or with a suitable comonomer. Such comonomers include acrylamide, (meth)acrylate esters or hydroxy esters e.g. hydroxypropyl esters, vinyl pyrrolidone, vinyl acetate, acrylonitrine, vinyl methyl ether, 2-acrylamido-2-methyl-propane sulphonic acid, vinyl or allyl sulphonic acid and styrene sulphonic acid as well as cationic monomers such as diallyl dimethyl ammonium chloride, dimethylamino ethylacrylate or methacrylate, optionally quaternised with, for example, dimethyl sulphate or methyl chloride.
The chelants which can be used in the method of the present invention are generally compounds with a nitrogen ligand which are effective chelants for iron. Usually, these chelants will also possess a carboxylic acid group. A preferred group of chelants possesses the formula
R³ - - - CR²
where R¹ is hydrogen, hydroxyethyl or carboxymethyl, preferably carboxymethyl, R² is hydrogen, hydroxyphenyl, preferably ortho-hydroxyphenyl, which is optionally methyl or sulphonic acid substituted, or carboxyl, R⁴ is hydrogen or carboxyl,
where R¹, R² and R⁴ are as defined above and
X is -(CH₂)₂- or - (CH₂)₃ -. The phenyl groups may be substituted, if desired, preferably by one or more halogen atoms. - If the chelant is to be used in aqueous systems which possess a high pH and a relatively high temperature it is preferred that at least one of R¹, R² and R³ contains a hydroxyl group. Thus the most preferred chelants possess a nitrogen ligand, a carboxylic acid group and a hydroxyl group.
- Preferred chelants for use in the present invention include N,N'-di(-2-hydroxybenzyl-)trimethylenediamine-N,N'-diacetic acid, N,N'ethylene-bis-[2-(2-hydroxy-4-methyl-phenyl)-glycine], ethylenediamine N,N'-bis-[2-hydroxyphenylacetic acid] and N,N-di(2-hydroxy-5-sulphonic acid benzyl)glycine which is especially preferred not only on account of its effectiveness but also on account of its excellent solubility properties which faciliate the formulation of compositions, as well as N,N-di(2-hydroxyethyl) glycine, N-hydroxyethyl N,N' ,N'-ethylenediamine triacetic acid and 2-hydroxyethyl iminodiacetic acid. Ethylenediamine tetraacetic acid and diethylene triamine pentaacetic acid can also be mentioned although they are less preferred since they do not contain a hydroxyl group (other than as part of the carboxylic acid groups).
- In general, from 1 to 10 parts by weight of chelant and from 4 to 6 parts by weight of the phosphorus containing compound are employed to 1 part of the zinc salt. While in certain circumstances it may be desirable to add the individual components separately, in other situations it will be convenient to add the components together in the form of a composition. Accordingly, the present invention also provides a composition suitable for addition to an aqueous system which comprises a water soluble zinc salt, a product containing at least one phosphorus containing acid group and at least one carboxylic acid group or an acrylic, vinyl or allyl carboxylic acid polymer, and a chelant. In such a situation, it may be desirable to add further quantities of chelant as required. Typically, the composition will be an aqueous formulation containing, generally, 1% to 2% by weight of zinc salt (as zinc), 4% to 10% by weight of the phophorus containing material or polymer and 1% to 25% by weight, especially about 5% by weight, of the chelant.
- A further surprising feature of the present invention is that the presence of the combination of chelant and phosphorus containing compound and/or acrylic vinyl or allyl carboxylic acid polymer enables one to reduce the amount of zinc salt. It is usual in the art to employ amounts of the order of 2 to 5ppm zinc. However, with ever increasing restrictions on concentrations of zinc in discharges there is a constant demand to reduce the amounts of zinc used. It has been found that by using the additional ingredients it is possible to reduce the amount of zinc to, say, about 1ppm for comparable effectiveness. In such circumstances it is preferred to employ about 4ppm of the phosphorus compound and about 2.5 to 5ppm of chelant. If, on the other hand, one uses 2.5ppm of zinc then it is preferred to use about 10ppm of phosphorus compound and about 5ppm of chelant.
- It is also possible to use the combination of the present invention together with other ingredients including phosphates, biocides, yellow metal corrosion inhibitors such as benzotriazole and tolyltriazole as well as other polymers which act as dispersants such as polyacrylic acid, polymaleic acid and copolymers of maleic acid with styrene sulphonic acid. In particular, it has been found that the use of certain dispersants, especially a copolymer of methacrylic acid and acrylamide is particularly advantageous, especially one in which the mole ratio is about 1:3, and further enhances the corrosion protection given by the three component system. In general the molecular weight of the homopolymers will be 1,000 to 10,000 while that of the copolymers will be 1,000 to 50,000.
- The use of a phosphate is particularly noteworthy since zinc phosphate is effective in low water hardness systems because the zinc phophate itself gives protection. By using the chelant and phosphorus containing compound as well it is possible, as previously discussed, to use significantly lower quantities of zinc.
- The following Examples further illustrate the present invention.
- In these Examples tests were carried out on a laboratory scale recirculating rig consisting of a plastic vessel holding 8 litres of water and connected by tubing to a circulating pump the water passing from the pump through a glass rack holding the metal test coupons ('line') and returning to the plastic vessel. Any evaporation was made up by the addition of de-ionised water. Metal test coupons were also suspended in the plastic vessel ('Pond'). The corrosion rate was calculated from the weight of metal lost during test. The water temperature was maintained by means of a heater/thermostat arrangement. The conditions of the test were as follows:
System Water : 150ppm Ca hardness/150ppm 'M' Alkalinity
Water pH : 8.8
Water Temperature : 54°C or 40°C (as stated)
Flow Rate: Line : 2 ft/sec
Pond : 0.2 ft/sec
Duration of Test : 3 days
Initial Passivation : 1 day at 3 times normal maintenance dose. -
- Examples 1 - 14 illustrate:
- i) The blend of zinc/chelant/phosphonate is superior to zinc/phosphonate or zinc/chelant.
- ii) The preferred chelants are Chelants 1, 2,3 and 9.
- iii) Phosphonate 1 gives significantly better results than comparative Phosphonate 2.
-
- Chelant 1 = N, N'-di(-2 hydroxybenzyl trimethylenediamine-N,N'-diacetic acid
- Chelant 2 = N,N' Ethylene-bis- [2(2-hydroxy-4 methyl-phenyl) - glycine]
- Chelant 3 = Ethylenediamine N, N'bis-[2 hydroxyl phenyl acetic acid]
- Chelant 4 = Ethylenediamine tetraacetic acid.
- Chelant 5 = N,N-di (2 hydroxy ethyl) glycine.
- Chelant 6 = N-Hydroxyethyl,N,N' Ethylenediamine triacetic acid.
- Chelant 7 = 2-hydroxyethyl iminodiacetic acid.
- Chelant 8 = Diethylene triamine penta acetic acid.
- Chelant 9 = N,N-di(2 hydroxy -5-sulphonic acid benzyl) glycine
- Phosphonate 1 = 2-Phosphonobutane 1,2,4 tricarboxylic acid.
- Phosphonate 2 = Hydroxy ethylidene di-phosphonic acid.
- Phosphonate 3 = Hydroxy phosphonoacetic acid.
- Phosphino 1 = Phosphino polyacrylic acid, M.Wt. approx 500 (sold commercially as "Belclene 500" Ciba Geigy).
- Polymer 1 = Copolymer of methacrylic acid/acrylamide, mole ratio 1:3, M.Wt. 35,000.
- Polymer 2 = Polyacrylic acid, M.Wt.1000.
- Polymer 3 = Polyacrylic acid, M.Wt.4500.
- Examples 15 - 34 indicate:
- i) The excellent corrosion inhibiting properties of the zinc/chelant/phosphonate combinations are maintained at the higher test temperature; this is less marked with Chelant 8 which does not contain a hydroxy group (Example 32). The excellent corrosion inhibition is also maintained when the phosphonate is replaced by the phosphino-polycarboxylic acid in the 3 component combination.
- ii) The presence of Polymer 1, (Example 20), enhances the corrosion protection conferred by the 4 component blend over that given by the corresponding 3 component blend, (Example 19), without polymer.
- iii) The improvement brought about by the presence of the chelant with the zinc/polyacrylic acid combination.
- These Examples illustrate the effect of longer term tests. These were carried out on a laboratory scale simulated open, evaporative, recirculating cooling water system incorporating mild steel heat exchanger together with feed and bleed facilities which enable the system to run at a given concentration factor throughout the 14 day test. The test conditions were as follows:
System Water : 160ppm Calcium hardness
50ppm Magnesium hardness
200ppm 'M' Alkalinity
Water Temperature (Pond) : 50°C
pH : 8.8
Flow Rate through heat exchanger : 0.3 ft/sec
Flow Rate through coupon chamber : 1.5 ft/sec
Heat flux on exchanger : 75 kj/m⁻²/sec⁻¹
Duration of test : 14 days
Initial passivation : 3 x normal maintenance dose, allowed to decay from start of test. - It was noticed that when Chelant 2 was in use (Examples 35 to 38), the corrosion which initiated on the heat exchanger was rapidly stifled whereas in Examples 40 corrosion spread throughout the test. Chelant 4 was largely ineffective; in fact, the results indicate aggression. This shows that this chelant is unsuitable where there is a heat exchanger giving a high surface temperature.
- Example 42 in relation to Example 43 shows the effect of using Chelant 2 in enabling one to reduce the concentration of zinc/phosphate.
Claims (17)
wherein R' is hydrogen, alkyl having 2 to 4 carbon atoms or carboxyl, R" is hydrogen or methyl and R''' is carboxyl or phosphonate.
R³ - - - R²
where R¹ is hydrogen, hydroxyethyl or carboxymethyl, R² is hydrogen, hydroxyphenyl, which is optionally methyl or sulphonic acid substituted, or carboxyl, R⁴ is hydrogen or carboxyl,
where R¹, R² and R⁴ are as defined above and X is -(CH₂)- or -(CH₂)₃-; the phenyl groups being optionally further substituted by one or more halogen atoms.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT86308419T ATE72678T1 (en) | 1985-10-29 | 1986-10-29 | TREATMENT OF AQUEOUS SYSTEMS. |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08526590A GB2184109A (en) | 1985-10-29 | 1985-10-29 | The treatment of aqueous systems |
GB8526590 | 1985-10-29 | ||
GB8623464 | 1986-09-30 | ||
GB08623464A GB2183624A (en) | 1985-10-29 | 1986-09-30 | Anti-corrosion treatment of aqueous systems |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0225051A1 true EP0225051A1 (en) | 1987-06-10 |
EP0225051B1 EP0225051B1 (en) | 1992-02-19 |
Family
ID=26289944
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP86308419A Expired EP0225051B1 (en) | 1985-10-29 | 1986-10-29 | The treatment of aqueous systems |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0225051B1 (en) |
AT (1) | ATE72678T1 (en) |
AU (1) | AU6456486A (en) |
CA (1) | CA1332138C (en) |
DE (1) | DE3683928D1 (en) |
ES (1) | ES2038595T3 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0277412A1 (en) * | 1987-01-23 | 1988-08-10 | W.R. Grace & Co.-Conn. | Inhibiting corrosion of iron base metals |
EP0311192A1 (en) * | 1987-10-05 | 1989-04-12 | Calgon Corporation | Method of controlling corrosion at high pH |
EP0364030A1 (en) * | 1988-10-11 | 1990-04-18 | Calgon Corporation | Synergistic compositions and method for inhibiting carbon steel corrosion in aqueous systems |
US5171477A (en) * | 1991-05-31 | 1992-12-15 | W. R. Grace & Co.-Conn. | Corrosion inhibition in chelant solutions |
ES2059273A1 (en) * | 1993-02-09 | 1994-11-01 | Miret Lab | Dispersant compositions which inhibit scaling and/or corrosion in industrial water circuits |
EP0714859A3 (en) * | 1994-11-29 | 1997-05-07 | Betz Europ Inc | Methods for controlling scale formation in aqueous systems |
WO2000039359A1 (en) * | 1998-12-29 | 2000-07-06 | Calgon Corporation | Corrosion inhibitor compositions and methods to control metal corrosion in brine systems |
US8513176B2 (en) | 2006-08-02 | 2013-08-20 | Ch2O Incorporated | Disinfecting and mineral deposit eliminating composition and methods |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110158094A (en) * | 2019-07-11 | 2019-08-23 | 北京中天兰清环境科技有限公司 | A kind of formula and preparation method of the without phosphorus carbon steel corrosion inhibitor of composite efficient |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3669901A (en) * | 1970-10-22 | 1972-06-13 | William Bruce Murray | Corrosion inhibitor composition containing zinc, sulfamate, and phosphate ions |
US3794603A (en) * | 1972-01-17 | 1974-02-26 | Sherwin Williams Co | Zn++-benzotriazole-h2so4 corrosioninhibitor |
DE2338352A1 (en) * | 1972-08-02 | 1974-02-28 | Applied Chem Pty Ltd | CORROSION PROTECTION AGENT FOR INHIBITING WATER CORROSION |
AT332699B (en) * | 1973-06-30 | 1976-10-11 | Bayer Ag | MEANS TO PREVENT CORROSION AND STONE SETTING IN WATER-BASED SYSTEMS |
DE2635295A1 (en) * | 1975-08-05 | 1977-02-24 | M & T Chemicals Inc | PROCESS AND COMPOSITION FOR THE REMOVAL OF NICKEL, NICKEL / IRON AND NICKEL / IRON / COBALT COATING FROM METAL SUBSTRATES |
US4018701A (en) * | 1975-07-31 | 1977-04-19 | Calgon Corporation | Phosphorous acid and zinc corrosion inhibiting compositions and methods for using same |
EP0006065A2 (en) * | 1978-06-05 | 1979-12-12 | Calgon Corporation | Composition and method for inhibiting corrosion |
DE3314008A1 (en) * | 1982-04-20 | 1983-10-20 | Dearborn Chemicals Ltd., Widnes, Cheshire | METHOD FOR ANTI-CORROSION IN AQUEOUS SYSTEMS, THEREFORE SUITABLE COMPOSITION AND THE USE THEREOF |
-
1986
- 1986-10-27 CA CA000521449A patent/CA1332138C/en not_active Expired - Lifetime
- 1986-10-29 DE DE8686308419T patent/DE3683928D1/en not_active Expired - Lifetime
- 1986-10-29 ES ES198686308419T patent/ES2038595T3/en not_active Expired - Lifetime
- 1986-10-29 AU AU64564/86A patent/AU6456486A/en not_active Abandoned
- 1986-10-29 EP EP86308419A patent/EP0225051B1/en not_active Expired
- 1986-10-29 AT AT86308419T patent/ATE72678T1/en active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3669901A (en) * | 1970-10-22 | 1972-06-13 | William Bruce Murray | Corrosion inhibitor composition containing zinc, sulfamate, and phosphate ions |
US3794603A (en) * | 1972-01-17 | 1974-02-26 | Sherwin Williams Co | Zn++-benzotriazole-h2so4 corrosioninhibitor |
DE2338352A1 (en) * | 1972-08-02 | 1974-02-28 | Applied Chem Pty Ltd | CORROSION PROTECTION AGENT FOR INHIBITING WATER CORROSION |
AT332699B (en) * | 1973-06-30 | 1976-10-11 | Bayer Ag | MEANS TO PREVENT CORROSION AND STONE SETTING IN WATER-BASED SYSTEMS |
US4018701A (en) * | 1975-07-31 | 1977-04-19 | Calgon Corporation | Phosphorous acid and zinc corrosion inhibiting compositions and methods for using same |
DE2635295A1 (en) * | 1975-08-05 | 1977-02-24 | M & T Chemicals Inc | PROCESS AND COMPOSITION FOR THE REMOVAL OF NICKEL, NICKEL / IRON AND NICKEL / IRON / COBALT COATING FROM METAL SUBSTRATES |
EP0006065A2 (en) * | 1978-06-05 | 1979-12-12 | Calgon Corporation | Composition and method for inhibiting corrosion |
DE3314008A1 (en) * | 1982-04-20 | 1983-10-20 | Dearborn Chemicals Ltd., Widnes, Cheshire | METHOD FOR ANTI-CORROSION IN AQUEOUS SYSTEMS, THEREFORE SUITABLE COMPOSITION AND THE USE THEREOF |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0277412A1 (en) * | 1987-01-23 | 1988-08-10 | W.R. Grace & Co.-Conn. | Inhibiting corrosion of iron base metals |
EP0311192A1 (en) * | 1987-10-05 | 1989-04-12 | Calgon Corporation | Method of controlling corrosion at high pH |
AU619764B2 (en) * | 1987-10-05 | 1992-02-06 | Calgon Corporation | Method of controlling corrosion at high ph |
EP0364030A1 (en) * | 1988-10-11 | 1990-04-18 | Calgon Corporation | Synergistic compositions and method for inhibiting carbon steel corrosion in aqueous systems |
US5171477A (en) * | 1991-05-31 | 1992-12-15 | W. R. Grace & Co.-Conn. | Corrosion inhibition in chelant solutions |
ES2059273A1 (en) * | 1993-02-09 | 1994-11-01 | Miret Lab | Dispersant compositions which inhibit scaling and/or corrosion in industrial water circuits |
EP0714859A3 (en) * | 1994-11-29 | 1997-05-07 | Betz Europ Inc | Methods for controlling scale formation in aqueous systems |
WO2000039359A1 (en) * | 1998-12-29 | 2000-07-06 | Calgon Corporation | Corrosion inhibitor compositions and methods to control metal corrosion in brine systems |
US8513176B2 (en) | 2006-08-02 | 2013-08-20 | Ch2O Incorporated | Disinfecting and mineral deposit eliminating composition and methods |
Also Published As
Publication number | Publication date |
---|---|
AU6456486A (en) | 1987-04-30 |
DE3683928D1 (en) | 1992-03-26 |
CA1332138C (en) | 1994-09-27 |
ES2038595T3 (en) | 1993-08-01 |
ATE72678T1 (en) | 1992-03-15 |
EP0225051B1 (en) | 1992-02-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0544345B1 (en) | Corrosion and/or scale inhibition | |
US4689200A (en) | Systems inhibited against corrosion and/or scale deposition | |
US4663053A (en) | Method for inhibiting corrosion and deposition in aqueous systems | |
US4497713A (en) | Method of inhibiting corrosion and deposition in aqueous systems | |
US5183590A (en) | Corrosion inhibitors | |
US5076951A (en) | Antifreeze compositions | |
US4557896A (en) | Treatment of aqueous systems | |
US4692315A (en) | Method of inhibiting corrosion in aqueous systems | |
KR20010101740A (en) | Scale and/or Corrosion Inhibiting Composition | |
US4664884A (en) | Corrosion inhibitor | |
EP0225051B1 (en) | The treatment of aqueous systems | |
US5093005A (en) | Method for controlling scale | |
US4298568A (en) | Method and composition for inhibiting corrosion of nonferrous metals in contact with water | |
US4778655A (en) | Treatment of aqueous systems | |
EP0396243A1 (en) | The inhibition of corrosion in aqueous systems | |
CA2087393A1 (en) | Corrosion inhibiting compositions | |
US5229030A (en) | Corrosion inhibition | |
CA2388502C (en) | All-organic corrosion inhibitor composition and uses thereof | |
US5002697A (en) | Molybdate-containing corrosion inhibitors | |
US4806310A (en) | Corrosion inhibitor | |
GB2118159A (en) | The treatment of aqueous systems | |
CA1162726A (en) | Prevention of corrosion in aqueous systems | |
EP0786018B1 (en) | Corrosion inhibiting compositions |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE ES FR GB IT LI LU NL SE |
|
17P | Request for examination filed |
Effective date: 19870602 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: W.R. GRACE & CO.-CONN. (A CONNECTICUT CORP.) |
|
17Q | First examination report despatched |
Effective date: 19881104 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE ES FR GB IT LI LU NL SE |
|
REF | Corresponds to: |
Ref document number: 72678 Country of ref document: AT Date of ref document: 19920315 Kind code of ref document: T |
|
REF | Corresponds to: |
Ref document number: 3683928 Country of ref document: DE Date of ref document: 19920326 |
|
ITF | It: translation for a ep patent filed |
Owner name: MODIANO & ASSOCIATI S.R.L. |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2038595 Country of ref document: ES Kind code of ref document: T3 |
|
EPTA | Lu: last paid annual fee | ||
EAL | Se: european patent in force in sweden |
Ref document number: 86308419.0 |
|
NLS | Nl: assignments of ep-patents |
Owner name: BETZDEARBORN INC. |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PUE Owner name: W. R. GRACE & CO.-CONN. (A CONNECTICUT CORP.) -DAN |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732E |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: PC2A |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20001009 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20001010 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 20001011 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: LU Payment date: 20001020 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20001023 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20001025 Year of fee payment: 15 Ref country code: ES Payment date: 20001025 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 20001026 Year of fee payment: 15 Ref country code: CH Payment date: 20001026 Year of fee payment: 15 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 20001215 Year of fee payment: 15 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011029 Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011029 Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011029 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011030 Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011030 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011031 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011031 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20011031 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
BERE | Be: lapsed |
Owner name: BETZDEARBORN INC. Effective date: 20011031 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020501 |
|
EUG | Se: european patent has lapsed |
Ref document number: 86308419.0 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20011029 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020628 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 20020501 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20020702 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20021113 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20051029 |