CA1089315A - Synergistic compositions for corrosion and scale control - Google Patents
Synergistic compositions for corrosion and scale controlInfo
- Publication number
- CA1089315A CA1089315A CA296,315A CA296315A CA1089315A CA 1089315 A CA1089315 A CA 1089315A CA 296315 A CA296315 A CA 296315A CA 1089315 A CA1089315 A CA 1089315A
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- CA
- Canada
- Prior art keywords
- water
- composition
- acid
- systems
- poly
- 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.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
- C02F5/14—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus
- C02F5/145—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus combined with inorganic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
- C02F5/14—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F9/00—Compounds containing elements of Groups 5 or 15 of the Periodic System
- C07F9/02—Phosphorus compounds
- C07F9/28—Phosphorus compounds with one or more P—C bonds
- C07F9/38—Phosphonic acids RP(=O)(OH)2; Thiophosphonic acids, i.e. RP(=X)(XH)2 (X = S, Se)
- C07F9/3804—Phosphonic acids RP(=O)(OH)2; Thiophosphonic acids, i.e. RP(=X)(XH)2 (X = S, Se) not used, see subgroups
- C07F9/3839—Polyphosphonic acids
- C07F9/3873—Polyphosphonic acids containing nitrogen substituent, e.g. N.....H or N-hydrocarbon group which can be substituted by halogen or nitro(so), N.....O, N.....S, N.....C(=X)- (X =O, S), N.....N, N...C(=X)...N (X =O, S)
-
- 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
Abstract
SYNERGISTIC COMPOSITIONS FOR CORROSION AND SCALE CONTROL
Abstract of the Disclosure Dimethylaminomethylenebis(phosphonic acid) is prepared by reacting dimethylformamide with phosphorous trichloride and treating the reaction mixture with alcohols or glycols and water. The phosphonic acid is combined with water soluble carboxylic acid polymers for use as a corrosion and scale inhibitor in aqueous systems. These compositions may also be combined with phosphorous acid and water soluble zinc salts.
Abstract of the Disclosure Dimethylaminomethylenebis(phosphonic acid) is prepared by reacting dimethylformamide with phosphorous trichloride and treating the reaction mixture with alcohols or glycols and water. The phosphonic acid is combined with water soluble carboxylic acid polymers for use as a corrosion and scale inhibitor in aqueous systems. These compositions may also be combined with phosphorous acid and water soluble zinc salts.
Description
This invention rela~es to compositions, methods of preparing the : compositions, and methods of using the compositions for inhibiting the corrosion of metal parts in contact with aqueous systems, for inhibiting 10 the deposition of scale and sludge on the heat transfer surfaces of- ¦
cooling water systems and boilers, said compositions comprising dimethyl-aminomethylenebis(phosphonic acid) or water soluble salts thereof, a water soluble polymer having a linear hydrocarbon structure and containing in a side chain carboxylic acid groups or carboxylic acid salt groups 15 with a molecular weight of between 200 and lO0,000 with one or more of the following:
A. Water ~
B. An aqueous solution of phosphorous acid or alkali metal salts thereof C. An aqueous solution of water soluble zinc salts : It i8 well known that the operation of commercial and indu6trial cooling systems is adversely affected by a number of diferent factors. Of these adverse factors, corrosion of metallic parts coming into contact with the water is probably one of the most serlou~. If not jcon~rDllod, co sion ca~e~ che rapld de~eriDration oE the =etallic , ~ I
~, , . ~, ~ . , ,..... . ~ .
: - - . :,: .: . : : ; -- . :
~: , -: - ...... - . . : -: , .
~ 9315 materials of construction used in cooling towers and associated equipment such as pumps, pipelines and valves, causing major losses in overall efficiency of the cooling systems. While control of bleedoff, pH, and other operating variables is helpful in reducing corrosion, chemical treat-ment of the water is generally the most effective and economical means of minimizing this problem, particularly where conservation of water by means of recycling is -necessary or desired.
Cooling water systems are also subject to formation of scale deposits. Scaling can occur when the concentration of a dissolved substance in a cooling water becomes greater than its solubility in the water. It can especially be a problem with a substance that has an inverse solubility curve, that is, a material whose solubility goes down as the temperature goes up. Since water temperatures at or near heat-transfer surfaces are greater than temperatures in the bulk of the system, the solubility of such materials is less in these regions. Consequently, they tend to precipitate and form scales that reduce heat-transfer ; -efficiency.
One principal scale-forming material encountered in .: .
cooling water systems is calcium carbonate formed by the decomposition of calaium bicarbonate. This compound not ;~ only has an inverse solubility curve, but its solubility is much lower in most typical cooling waters than almost all other potential scale-formers that might be present in I ,~
these waters. Of course, calcium carbonate is soluble in acidic solutions, and as the pH of a cooling water is lowered, scale generally becomes less of a problem. However, most cooling waters are kept on the alkaline side to reduce corrosion, and thus calcium carbonate scaling remains as a ~-potential problem. Calcium sulfate, calcium phosphate, , ~ :
3 3 ~ 5 barium sulfate, and ferric hydroxide can also cause scale.
Thus, to be a broadly useful composition, a scale control product must be capable of controlling different scale types.
Waterside problems encountered in boilers and steam systems include the formation of scale and other deposits, corrosion, and foam. Scale and other deposits on heat-transfer surfaces can cause loss in the thermal efficiency of the boiler and can make the temperature of the boiler --metal increase. Under scaling conditions, temperatures may go high enough to lead to failure of the metal due to overheating. Corrosion in boilers and steam systems also causes failure of boiler metal and damage to steam and condensate lines.
The principal source of deposits in boilers is -~
dissolved mineral matter in the boiler feedwater. The term ;~ -"scale" is generally used for deposits that adhere to boiler surfaces exposed to the water, while nonadherent deposits are called "sludge" or "mud." Scale causes more difficulty because the sludge can be purged from the system with the blowdown or can be easily washed out, but scale can normally ~; only be removed by mechanical or chemical cleaning of the boiler.
In natural, untreated water the main sources of scale and sludge are calcium carbonate, calcium sulfate, magnesium hydroxide, and silica. The most common type of scale in boilers is probably calcium carbonate, but the most trouble-some is usually calcium sulfate. The latter causes more difficulties because its solubility decreases more rapidly with increasing temperatures than does that of other su~stan~
ces, and the scale it forms is hard, dense, and difficult to remove. On the other hand, calcium carbonatP tends to form -~
sludge more than scale, and the calcium carbonate scales that do form are generally softer and easier to remove.
Magnesium hydroxide precipitates are not very adherent and tend to form sludges rather than scales.
It is an object of this invention to provide a stable liquid corrosion inhibiting and deposit control product.
More specifically, it is an object to prepare a synergistic -composition containing a bisphosphonic acid and a polycar-boxylic acid which performs for scale control in the threshold range far better than would be expected from the performance of either class of compound alone. It is a further objective of this invention to provide a process for corrosion inhibi- ~
tion and deposit control in cooling water systems. ~-Further objectives will be evident to those skilled in the art.
All of the compositions of this invention contain dimethylaminomethylenebis (phosphonlc acid) or water soluble salts thereof. This compound has the following structure:
OH
O _ P - OH
CH3 ~ I ~
N C - H -CH3 ~
O - P - OH
OH
The two phosphonic acid groups on the molecule provide acid hydrogens which can be converted to alkali metal, alkaline - .
ea~rth metal and ammonium salts. -~ :
The water soluble polymer also contained in all of ~'~ the compositions is a linear hydrocarbon structure with side chain carboxylic acid groups and is exemplified ~y the -following structure:
. -.
.
', , ' . . , ' ' ' : ' ' ': . ' ~ ' .
- 1~`85~315 ~:
.
¦ H R~ I
.1 1 ,:
- r c c - ~ ". .
R C _ ¦
I . '''.'~
OH _ n where R is hydrogen or -COOH and R' is hydrogen or methyl.
These polymers may be obtained from acrylic acid or metha-crylic acid. Polymers of maleic anhydride can be prepared -and the anhydride group hydrolyzed with water to provide carboxylic acid groups. Acrylonitrile and acrylamide polymers may also be hydrolyzed with hot alkaline solutions to elimi-nate ammonia and form carboxylic acid salts. Copolymers of all of the monomers listed may also be prepared and these copolymers may be hydrolyzed to the carboxylic acid groups if the anhydride, amide, or nitrile groups are contained in the copolymer. These polymers may be utilized as the free ?
acid or as water soluble salts such as the alkali metal and alkaline earth metal salts. The polymers used in this invention are com~ercially available or methods for their preparation are well known in the art.
The phosphorous acid utilized in these compositions j .
may be anhydrous or a~ueouo solutions containing 50 to 75 percent of the acid.
~4~ Water soluble 2inc salts which may be utilized include .
zinc acetate, zinc chloride, zinc nitrate, and zinc sulfate.
The preparation of dimethylaminomethylenebis (phosphonic acid) has been described in U.S. 3,846,42a, ~; ~ November S, 1974. Dimethylformamide was reacted ~ith phosphorous trichloride and then a large excess of ~ater was added. Alternatively, a mixture of phosphorou~ acid and -phosphorous trichloride is reacted with dimethylformamide.
In some examples, solvents such as carbon tetrachloride and ~` dioxane are used in the reaction. The yields ~ased on the ~, .
.
,, , . , - ~ ... .
~ 9315 amount of phosphorous trichloride used vary from 22 to 76 percent. The process described has a number of disadvantages:
1. Even when a solvent is used, ~he products are pasty or solid and impossible to handle in commercial processes.
cooling water systems and boilers, said compositions comprising dimethyl-aminomethylenebis(phosphonic acid) or water soluble salts thereof, a water soluble polymer having a linear hydrocarbon structure and containing in a side chain carboxylic acid groups or carboxylic acid salt groups 15 with a molecular weight of between 200 and lO0,000 with one or more of the following:
A. Water ~
B. An aqueous solution of phosphorous acid or alkali metal salts thereof C. An aqueous solution of water soluble zinc salts : It i8 well known that the operation of commercial and indu6trial cooling systems is adversely affected by a number of diferent factors. Of these adverse factors, corrosion of metallic parts coming into contact with the water is probably one of the most serlou~. If not jcon~rDllod, co sion ca~e~ che rapld de~eriDration oE the =etallic , ~ I
~, , . ~, ~ . , ,..... . ~ .
: - - . :,: .: . : : ; -- . :
~: , -: - ...... - . . : -: , .
~ 9315 materials of construction used in cooling towers and associated equipment such as pumps, pipelines and valves, causing major losses in overall efficiency of the cooling systems. While control of bleedoff, pH, and other operating variables is helpful in reducing corrosion, chemical treat-ment of the water is generally the most effective and economical means of minimizing this problem, particularly where conservation of water by means of recycling is -necessary or desired.
Cooling water systems are also subject to formation of scale deposits. Scaling can occur when the concentration of a dissolved substance in a cooling water becomes greater than its solubility in the water. It can especially be a problem with a substance that has an inverse solubility curve, that is, a material whose solubility goes down as the temperature goes up. Since water temperatures at or near heat-transfer surfaces are greater than temperatures in the bulk of the system, the solubility of such materials is less in these regions. Consequently, they tend to precipitate and form scales that reduce heat-transfer ; -efficiency.
One principal scale-forming material encountered in .: .
cooling water systems is calcium carbonate formed by the decomposition of calaium bicarbonate. This compound not ;~ only has an inverse solubility curve, but its solubility is much lower in most typical cooling waters than almost all other potential scale-formers that might be present in I ,~
these waters. Of course, calcium carbonate is soluble in acidic solutions, and as the pH of a cooling water is lowered, scale generally becomes less of a problem. However, most cooling waters are kept on the alkaline side to reduce corrosion, and thus calcium carbonate scaling remains as a ~-potential problem. Calcium sulfate, calcium phosphate, , ~ :
3 3 ~ 5 barium sulfate, and ferric hydroxide can also cause scale.
Thus, to be a broadly useful composition, a scale control product must be capable of controlling different scale types.
Waterside problems encountered in boilers and steam systems include the formation of scale and other deposits, corrosion, and foam. Scale and other deposits on heat-transfer surfaces can cause loss in the thermal efficiency of the boiler and can make the temperature of the boiler --metal increase. Under scaling conditions, temperatures may go high enough to lead to failure of the metal due to overheating. Corrosion in boilers and steam systems also causes failure of boiler metal and damage to steam and condensate lines.
The principal source of deposits in boilers is -~
dissolved mineral matter in the boiler feedwater. The term ;~ -"scale" is generally used for deposits that adhere to boiler surfaces exposed to the water, while nonadherent deposits are called "sludge" or "mud." Scale causes more difficulty because the sludge can be purged from the system with the blowdown or can be easily washed out, but scale can normally ~; only be removed by mechanical or chemical cleaning of the boiler.
In natural, untreated water the main sources of scale and sludge are calcium carbonate, calcium sulfate, magnesium hydroxide, and silica. The most common type of scale in boilers is probably calcium carbonate, but the most trouble-some is usually calcium sulfate. The latter causes more difficulties because its solubility decreases more rapidly with increasing temperatures than does that of other su~stan~
ces, and the scale it forms is hard, dense, and difficult to remove. On the other hand, calcium carbonatP tends to form -~
sludge more than scale, and the calcium carbonate scales that do form are generally softer and easier to remove.
Magnesium hydroxide precipitates are not very adherent and tend to form sludges rather than scales.
It is an object of this invention to provide a stable liquid corrosion inhibiting and deposit control product.
More specifically, it is an object to prepare a synergistic -composition containing a bisphosphonic acid and a polycar-boxylic acid which performs for scale control in the threshold range far better than would be expected from the performance of either class of compound alone. It is a further objective of this invention to provide a process for corrosion inhibi- ~
tion and deposit control in cooling water systems. ~-Further objectives will be evident to those skilled in the art.
All of the compositions of this invention contain dimethylaminomethylenebis (phosphonlc acid) or water soluble salts thereof. This compound has the following structure:
OH
O _ P - OH
CH3 ~ I ~
N C - H -CH3 ~
O - P - OH
OH
The two phosphonic acid groups on the molecule provide acid hydrogens which can be converted to alkali metal, alkaline - .
ea~rth metal and ammonium salts. -~ :
The water soluble polymer also contained in all of ~'~ the compositions is a linear hydrocarbon structure with side chain carboxylic acid groups and is exemplified ~y the -following structure:
. -.
.
', , ' . . , ' ' ' : ' ' ': . ' ~ ' .
- 1~`85~315 ~:
.
¦ H R~ I
.1 1 ,:
- r c c - ~ ". .
R C _ ¦
I . '''.'~
OH _ n where R is hydrogen or -COOH and R' is hydrogen or methyl.
These polymers may be obtained from acrylic acid or metha-crylic acid. Polymers of maleic anhydride can be prepared -and the anhydride group hydrolyzed with water to provide carboxylic acid groups. Acrylonitrile and acrylamide polymers may also be hydrolyzed with hot alkaline solutions to elimi-nate ammonia and form carboxylic acid salts. Copolymers of all of the monomers listed may also be prepared and these copolymers may be hydrolyzed to the carboxylic acid groups if the anhydride, amide, or nitrile groups are contained in the copolymer. These polymers may be utilized as the free ?
acid or as water soluble salts such as the alkali metal and alkaline earth metal salts. The polymers used in this invention are com~ercially available or methods for their preparation are well known in the art.
The phosphorous acid utilized in these compositions j .
may be anhydrous or a~ueouo solutions containing 50 to 75 percent of the acid.
~4~ Water soluble 2inc salts which may be utilized include .
zinc acetate, zinc chloride, zinc nitrate, and zinc sulfate.
The preparation of dimethylaminomethylenebis (phosphonic acid) has been described in U.S. 3,846,42a, ~; ~ November S, 1974. Dimethylformamide was reacted ~ith phosphorous trichloride and then a large excess of ~ater was added. Alternatively, a mixture of phosphorou~ acid and -phosphorous trichloride is reacted with dimethylformamide.
In some examples, solvents such as carbon tetrachloride and ~` dioxane are used in the reaction. The yields ~ased on the ~, .
.
,, , . , - ~ ... .
~ 9315 amount of phosphorous trichloride used vary from 22 to 76 percent. The process described has a number of disadvantages:
1. Even when a solvent is used, ~he products are pasty or solid and impossible to handle in commercial processes.
2. If a water soluble solvent is used, distillation must be used to isolate the product.
3. Hydrolysis converts every atom of chlorine in the phosphorous trichloride to hydrochloric acid which is so irritating and so toxic that it must also be isolated or neutralized with alkali.
4~ The best yield reported is only 76 percent.
In this invention we have reacted dimethylformamîde with phosphorous trichloride and about two-thirds the stoichiometric amount of an alcohol or glycol. The reaction was completed utilizing hydrolysis with water. ~e were surprised that the evolution of hydrogen chloride was greatly reduced and that alcohols and glycols could be converted in high yield to alkyl chlorides and to dichloroalkanes. The yields of dimethylamlnomethylenebis~phosphonic acid) based on the weight of phosphorous trichloride used were essentially quantitative in many instances. Although the stoichiometry is not completely understood, the overall reaction may be characterized by the equation CH3 O C,H3 N - C -H + 2PC13 + H2O + 4ROHr ~ N -C - H ~ 2HC1 ~ 4 RCl - When a solvent is re~uired, the alkyl halide ~RCl) or dichloroalkane that is being formed may be added to the mixture when the dimethylformamide and phosphorous trichloride are 'i reacted.
Alcohols and glycol~ suitable for the preparation of dimethylaminomethylenebisCphosphonic acid) and the corres-ponding alkyl chlorides and dichloroalkanes include, but are ..
.
.... . . .
.
l('~B~315 not limited to methanol, ethanol, l-propanol, 2-propanol, l-butanol, isobutanol, sec-butanol, tert-butanol, amyl alcohols, longer chain alcohols with C6 to C18 alkyl groups, ethylene glycol, propylene glycol, butylene glycols, diethylene glycol and triethylene glycol.
The advantages of producing dimethylaminomethylenebis (phosphonic acid) by the process of this invention are:
1. Very high yields based on the amount of phosphorous trichloride used are obtained.
2. The toxic and polluting hydrogen chloride is reduced.
3. Valuable chloroalkanes and dichloroalkanes are simul-taneously produced with the dimethylaminomethylenebis (phosphonic acid).
4. A wide variety of alcohols and glycols are suitable in the process.
In this invention we have reacted dimethylformamîde with phosphorous trichloride and about two-thirds the stoichiometric amount of an alcohol or glycol. The reaction was completed utilizing hydrolysis with water. ~e were surprised that the evolution of hydrogen chloride was greatly reduced and that alcohols and glycols could be converted in high yield to alkyl chlorides and to dichloroalkanes. The yields of dimethylamlnomethylenebis~phosphonic acid) based on the weight of phosphorous trichloride used were essentially quantitative in many instances. Although the stoichiometry is not completely understood, the overall reaction may be characterized by the equation CH3 O C,H3 N - C -H + 2PC13 + H2O + 4ROHr ~ N -C - H ~ 2HC1 ~ 4 RCl - When a solvent is re~uired, the alkyl halide ~RCl) or dichloroalkane that is being formed may be added to the mixture when the dimethylformamide and phosphorous trichloride are 'i reacted.
Alcohols and glycol~ suitable for the preparation of dimethylaminomethylenebisCphosphonic acid) and the corres-ponding alkyl chlorides and dichloroalkanes include, but are ..
.
.... . . .
.
l('~B~315 not limited to methanol, ethanol, l-propanol, 2-propanol, l-butanol, isobutanol, sec-butanol, tert-butanol, amyl alcohols, longer chain alcohols with C6 to C18 alkyl groups, ethylene glycol, propylene glycol, butylene glycols, diethylene glycol and triethylene glycol.
The advantages of producing dimethylaminomethylenebis (phosphonic acid) by the process of this invention are:
1. Very high yields based on the amount of phosphorous trichloride used are obtained.
2. The toxic and polluting hydrogen chloride is reduced.
3. Valuable chloroalkanes and dichloroalkanes are simul-taneously produced with the dimethylaminomethylenebis (phosphonic acid).
4. A wide variety of alcohols and glycols are suitable in the process.
5. Pasty or solid intermediates are eliminated which makes the process useful at commercial scale.
The examples of this invention describe several ' ; experiments in which dimethylaminomethylene~is (phosphonic acid) was prepared in good yield using several different glycols and alcohols.
~ ~ The dimethylaminomethylenebis(phosphonic acid) is ,~ usually isolated as an aqueous solution, but it aan also be obtained as a crystalline solid. Aqueous solutions of the ; phosphonic acid or salts of the phosphonic acid can be mixed with solutions of the polymers in water to prepare the ~ composition of this invention. Phosphorous acid, alkali metal `-~ phosphites, and water-soluble zinc salts may then be added to the aqueous solutions in varying amounts to prepare the additional compositions described in this invention. When zinc salts are used in the compositions of this invention, it is necessary to decrease the pH of the preparation by addition of the appropriate level of phosphorous acid or another mineral -;
~' :~ .
acid to prevent separation of complex zinc salts.
The use of dimethylaminomethylenebis(phosphonic acid) and its alkali metal and ammonium salts for the inhibition of precipitation of insoluble salts from aqueous solutions has been described in U.S. 3,957,160, May 18, 1976. This invention claims that the compound is effective at a molar ratio of 5 X 10 4 to 5 X 10 2 mols per mol of precipitable salt cation. For dimethylaminomethylenebis(phosphonic acid) these values correspond to ratios of 0.27 to 27 parts of the phosphonic acid per 100 parts of calcium.
Polyacrylic acid, other carboxylic acid polymers and salts of the polymers are also known to be effective in preventing the precipitation of alkaline earth metal salts and iron salts from aqueous solution.
; Neither the dimethylaminomethylenebis(phosphonic acid) ;-nor the polymeric carboxylic acids are completely satisfactory as water treatment chemicals. The phosphonic acid is most -effective in preventing the precipitation of calcium carbonate, but it is much less effective with regard to precipitation of ~ -calcium sulfate, calcium acid phosphate, barium sulfate, and ferric hydroxide. The polymeric carboxylic acids are not effective as corrosion inhibitors and the literature does not ~,, - --have any statements concerning corrosion inhibiting properties of the dimethylaminomethylenebis(phosphonic aci~.
We have found that the compositions of this invention can be manufactured efficiently and that these compositions -~
will provide effective corrosion inhibition of metal parts in ~ ~ -contact with aqueous systems. Surprisingly, these compositions -~
are more effective in preventing the precipitation of metal salts from aqueous solutions than would be expected from the . .
combinations of the individual products included in the , compositions. This synergism is particularly noted when the compositions are used for scale control at threshold treatment : -.' ~ .
.
levels.
In order to demonstrate the scale inhibiting properties of the compositions of this invention, we have used anti-precipitation tests with super-saturated solutions of calcium carbonate, calcium sulfate, calcium acid phosphate, barium sulfate, and ferric hydroxide. The most convenient test methods are related to the demonstration of a "threshold effect," which is defined as a stabilization of super-saturated solutions of scale forming salts by less than stoichiometric concentrations of the anti-precipitants. The mechanism of this effect currently postulates that the anti-precipitant is adsorbed on the growth site of the scalent crystallite during the process of crystallization. This adsorption alters the ~-~
growth pattern so that the resultant scalent crystals are formed more slowly and are highly distorted. The retardance of crystal growth rate lowers the amount of solid scalent deposited on surfaces. In addition, the distortion of the crystal structure usually gives the scalent solid a different adherence characteristic and the surfaces then have a decreased amount of scale accumulation. ! ' This invention is further illustrated by the following specific but non-limiting examples.
l .
j~ A reaction flask was charged with 200 grams of bis ,i~ (2-chloroethyl) ether and 36.5 grams of dimethylformamide and the mixture was treated with lla grams of phosphorous trich-loride added dropwise at such a rate that the reaction lj :
~; ~ temperature was maintained between 20 and 45 C. After one j, : :
1~ hour agitation at this temperature, the reaction was treated ,~
with 63.6 grams of diethylene glycol which was added at such ` a rate that the reaction temperature did not exceed 45 C.
, .;., .
Agitation was continued for two hours at 30 to 45 C after the addition was complete. The reaction was warmed slowly to _ g _ .
, .............
-70 C and maintained at this temperature for sixteen hours.
Twenty grams of water were then added slowly while the temperature was allowed to increase to 95 to 100 C. The mixture was agitated for thirty minutes, after which, an additional charge of 100 grams of water was made. Once again, the reaction was maintained at 95 to 100 C for thirty minutes before being cooled to 60 C and separated in a separatory funnel. The lower aqueous layer was steam distilled to remove bis(2-~hloroethyl)ether and treated with acetone to precipitate 72.1 grams (76 percent yield~ of dimethylaminomethylenebis (phosphonic acid)monohydrate. The bis(2-chloroethyl~ether removed by steam distillation was combined with the organic layer and a total yield of 283.2 grams (97 percent) was obtained.
ExAMæLE 2 A reaction flask was charged with 1200 grams of bis ~;-(2-chloroethyl~ ether and 220 grams of dimethylformamide and j the mixture was treated with 660 grams of phosphorous trich-`I loride added at such a rate that the reaction temperature was ~ -maintained between 20 and 45 C. After one hour of agitation at this temperature, the flask was charged with 490 grams of -diethylene glycol which was added at such a rate that the ; temperature did not exceed 45 C. The flask contents were i ~ .
agitated at 20 to 25 C for sixteen hours and than trans~erred to a glass-lined, steel autoclave. The autoclave was heated ;
at 15~ to 165 C for twelve hours and a pressure of 50 pounds per square inch was observed. After cooling and venting, the autoclave contents were treated with 18Q grams of water and the temperature was allowed to rise to 90 to 95 C. Agitation at this temperature was continued for thirty minutes and then 1500 grams of additional water were added. The reaction -~ -mixture was agitated for eight hours and then separated in a separatory funnel. Analysis of the aqueous layer indicated -- 10 `' :
:, " . , . . , , - , . . .. .
that a yield of 494.6 grams (94.1 percent) of dimethylamino-methylenebis(phosphonic acid) had been obtained. The yield of bis(2-chloroethyl~ether in excess of that added in the beginning of the reaction was 553.6 grams (83.8 percent~.
EXAMPLE 3.
The procedure of Example 1 was followed except that the dimethylaminomethylenebis(phosphonic acid) in the aqueous solution was determined by titration. A yield of 89.3 percent was obtained. The yield of the bis(2-chloroethyl)ether in excess of that used as solvent was 92.1 percent.
EXAMPLE 4.
The procedure of Example 1 was followed except that ethylene dichloride was used in place of bis(2-chloroethyl) ether and ethylene glycol ~37.2 grams) was used in place of diethylene glycol. The yield of ethylene dichloride in excess of that used as solvent was 5Q.8 percent and the yield of dimethylaminomethylenebis~phosphonic acid) was 87.7 percent.
EXAMPLE 5.
The procedure of Example 1 was followed except that ethylene dichloride was used in place of ~is~2-chloroethyl~
ether and n-butyl alcohol t88 8 grams~ was used in place of ;~ diethylene glycol. The yield of n-butyl chloride was 39.2 percent and the yield of dimethylaminomethylenebis~phosphonic acid~ was 75.5 percent.
EXAMPLE 6.
The procedure of Example 1 was followed except that n-dodecyl chloride was used in place of bis(2-chloroethyl) , ether and n-dodecyl alcohol (224 grams~ was used in place of diethylene glycol. The yield of dodecyl chloride in excess of that used as solvent was 82 percent and the yield of dimethylaminomethylenebis~phosphonic acid~ was 56.q percent.
EXAMPLE 7.
~composition containin~ 15 percerlt of dimet-' ' " , ~
l~B5~315 hylaminomethylenebis(phosphonic acid) and 15 percent of poly (acrylic acid) in water was prepared by mixing 47.5 grams of an aqueous solution containing 31.6 percent of the trisodium salt of dimethylaminomethylenebis~phosphonic acid), 35.2 grams of an aqueous solution containing 42.6 percent of poly(acrylic acid)(molecular weight--3000), and 17.3 grams of water.
EXAMP~E 8 The solutions of dimethylaminomethylenebis(phosphonic ; acid) and poly~acrylic acid) referred to in Example 7 were used to prepare two formulations. The first contained 17.0 percent each of the phosphonate and polymer and the second solution contained 20.0 percent of the phosphonate and 13.0 percent of the polymer. Each of these solutions was then mixed with an aqueous solution containing 70 percent of phosphorous acid to prepare the following compositions~
Number Phosphonate Polymer Phosphorous acid PercentPercent Percent 8A 16.2 16.2 3.5 ;
A, 8B 15.3 15 3 7 Q
8C 14.4 14 4 10 5 8D 19.0 12.4 3.5 8E 18.0 11.7 7 0 ,~ 8F 17.0 11.0 10 5 , ~ A composition was prepared using a 31.Q percent ?~ ~ solution of the trisodium salt of dimethylaminomethylene~is ;~ (phosphonic acid~, a 45.6 percent solution of poly(acrylic acid) with a molecular weight of 3300-3500, 70 percent phosphorous acid, 50 percent sodium hydroxide and water to provide the following concentrations:
Phosphonate 16.5 percent Poly~acrylic acid~ 11.0 percent Phosphorous acid 6.0 percent Sodium hydroxide 5.5 percent The corrosion inhibiting properties of solutions of this composition with zinc chloride were determined in .
~931S
Example 11.
EXAMP~E 10 One hundred grams of a solution containing 20 percent -of the trisodium salt of dimethylaminomethylenebis(phosphonic acid) and 13 percent of 3300-3500 molecular weight poly(acrylic acid) were mixed with 15 grams of 37 percent hydrochloric acid and 40 grams of a 50 percent solution of zinc chloride. The corrosion inhibiting results using this compositions are included in Example 11.
; This example illustrates the corrosion-inhibiting -properties of the compositions. The test apparatus included a sump, a flow circuit, a circulating pump, and a heater. A
test fluid was prepared to approximate a moderately hard well water concentrated 4 times which did not come in contact with any metal except for test coupons placed within the circuit --in a manner simulating flow, impingement, and sump conditions.
The test coupons were 1010 mild steel, and the circulating solution had a calcium hardness of CaCO3 of 270 parts~per million, a magneæîum hardness~ as CaCO3 of 170 parts per million, , ~
chloride as NaCl of 5Q0 parts per millions, and sulfate as -Na2SO4 of 624 parts per million.
The temperature during the test was maintained at about ~ 55 C, and the pH varied from 7 to 9. The test ~luid wa9 ;~ circulated continuously through the system containing the ~ coupons for a period of seven days. The steel coupons were ., ~ .
removed and examined or scale. No significant amount of scale was observed on any of the coupons protected by the compositions of this invention. The coupons were then cleaned and weighed ~ .
and the corrosion rates calculated as mils per year. One mil - ~ per year loss is equal to a volume decrease of 0.001 inch per year or Q.0254 millimeter per year. The corrosion rates are included in Table 1.
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Table 1 Corrosion test results using the compositions of Examples 7, 8, 9, and 10 Corrosion inhibiting Active Zinc* Corrosion rate in c_mposition ingredient added _ mils per year Example No. Parts per million Current Impingement Sump ; 8D 35 - 20 33 31 9 33~5 3.411 23 9 9 33.5 6.7 4 3 4 9 33.5 10.1 3 3 3 9 33.5 13.4 2 3 2 5.4 1.527 112 41 I0 10.7 3.110 6 8 lQ 16.0 4.6 9 24 14 ~0 21.3 6.2 2 2 31.9 9.3 2 2 2 Control - - 56 186 44 30 *The compositions of Example 10 contained zinc in the concent- -rated formulations.
The results of these tests clearly demonstrate that 1 : .
compositions of this invention have excellent corrosion inhibiting properties when tested against steel coupons in a very aggressive aqueous system.
, ~ The compositions of this example were tested as scale 1~::
~ inhibiting preparations in Examples 13-17.
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Table 2 Trisodium salt of dimethylamino-methylenebis(phos- Poly(acrylic acid) Phosphoric Phosphorous phonic acid) Mol Wt = 3000-5000 acid acid Percent Percent Percent Percent (Based on total of active materials) Compositions of this invention included in Table 2 were compared for inhibition of calcium carbonate with the trisodium salt of dimethylaminomethylenebis(phosphonic acid) and poly(acrylic acid). The test was conducted by adding to a bottle 100 milli-~ liter8 of 0.04 percent solution of calcium hydroxide freshly I prepared from recently boiled demineralized water. The composi-tions being tested were added to provide the calculated concen-tration desired. Then, 100 milliliters of a 0.05 percent solution of sodium bicarbonate prepared from recently boiled demineralized -, ;. ~ : -`~ ~ water was added to the bottle. The final volume was adjusted to , ~ :
220 milliliters and the solutions were allowed to stand for 18 hours at room temperature. The contents of the bottles were filtered through Whatman No. 4 filter paper, and the filtered -solutions were analyzed for calcium content using an atomic ; , , . . ,............. . , . :.................. - ~ ' :
- ' : . , - ~8~315 absorption instrument or an EDTA titration procedure. The concentration was 98 parts per million calcium which is equivalent to 245 parts per million of calcium carbonate. ~' The percentage inhibition of precipitation was calculated by dividing the calcium content of the filtrate by 98 and ~' mul~iplying by lQQ. The results obtained are included in Table 3. ' The results of these tests show that dimethylamino- -, methylenebis(phosphonic acid)(A) and poly(acrylic acid)(B) will inhibit the precipitation of calcium carbonate. When ' the two are combined in various proportions (C, D, E, F), ' ' the antiprecipitant properties are maintained and the results with F actually indicate that the overall effectiveness is better than that expected from the combination (synergism).
When the phosphonate and poly(,acrylic acid) are combined with phosphoric acid (G and H), the antiprecipitant property is greatly decreased. However, combinations with phosphorous acid (,I and J) maintain the high level of antiprecipitant effee,t -, and the corrosion inhibiting property of the composition con-,~ 20 taining phosphorous acid was demonstrated in Example 11. The startling difference observed with compositions containing -~ phosphoric and phosphorous acids is completæly unexpected ~ ; because of the similarity of the two acids and the relative ; lack of information in the literature concerning the use of ', phosphorous acid in water treatment chemical compositions.
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'' ' ~able 3 Results of antiprecipitation tests with calcium carbonate Composition ConcentrationA B C D E F G H I J
Parts per millionPercent inhibition
The examples of this invention describe several ' ; experiments in which dimethylaminomethylene~is (phosphonic acid) was prepared in good yield using several different glycols and alcohols.
~ ~ The dimethylaminomethylenebis(phosphonic acid) is ,~ usually isolated as an aqueous solution, but it aan also be obtained as a crystalline solid. Aqueous solutions of the ; phosphonic acid or salts of the phosphonic acid can be mixed with solutions of the polymers in water to prepare the ~ composition of this invention. Phosphorous acid, alkali metal `-~ phosphites, and water-soluble zinc salts may then be added to the aqueous solutions in varying amounts to prepare the additional compositions described in this invention. When zinc salts are used in the compositions of this invention, it is necessary to decrease the pH of the preparation by addition of the appropriate level of phosphorous acid or another mineral -;
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acid to prevent separation of complex zinc salts.
The use of dimethylaminomethylenebis(phosphonic acid) and its alkali metal and ammonium salts for the inhibition of precipitation of insoluble salts from aqueous solutions has been described in U.S. 3,957,160, May 18, 1976. This invention claims that the compound is effective at a molar ratio of 5 X 10 4 to 5 X 10 2 mols per mol of precipitable salt cation. For dimethylaminomethylenebis(phosphonic acid) these values correspond to ratios of 0.27 to 27 parts of the phosphonic acid per 100 parts of calcium.
Polyacrylic acid, other carboxylic acid polymers and salts of the polymers are also known to be effective in preventing the precipitation of alkaline earth metal salts and iron salts from aqueous solution.
; Neither the dimethylaminomethylenebis(phosphonic acid) ;-nor the polymeric carboxylic acids are completely satisfactory as water treatment chemicals. The phosphonic acid is most -effective in preventing the precipitation of calcium carbonate, but it is much less effective with regard to precipitation of ~ -calcium sulfate, calcium acid phosphate, barium sulfate, and ferric hydroxide. The polymeric carboxylic acids are not effective as corrosion inhibitors and the literature does not ~,, - --have any statements concerning corrosion inhibiting properties of the dimethylaminomethylenebis(phosphonic aci~.
We have found that the compositions of this invention can be manufactured efficiently and that these compositions -~
will provide effective corrosion inhibition of metal parts in ~ ~ -contact with aqueous systems. Surprisingly, these compositions -~
are more effective in preventing the precipitation of metal salts from aqueous solutions than would be expected from the . .
combinations of the individual products included in the , compositions. This synergism is particularly noted when the compositions are used for scale control at threshold treatment : -.' ~ .
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levels.
In order to demonstrate the scale inhibiting properties of the compositions of this invention, we have used anti-precipitation tests with super-saturated solutions of calcium carbonate, calcium sulfate, calcium acid phosphate, barium sulfate, and ferric hydroxide. The most convenient test methods are related to the demonstration of a "threshold effect," which is defined as a stabilization of super-saturated solutions of scale forming salts by less than stoichiometric concentrations of the anti-precipitants. The mechanism of this effect currently postulates that the anti-precipitant is adsorbed on the growth site of the scalent crystallite during the process of crystallization. This adsorption alters the ~-~
growth pattern so that the resultant scalent crystals are formed more slowly and are highly distorted. The retardance of crystal growth rate lowers the amount of solid scalent deposited on surfaces. In addition, the distortion of the crystal structure usually gives the scalent solid a different adherence characteristic and the surfaces then have a decreased amount of scale accumulation. ! ' This invention is further illustrated by the following specific but non-limiting examples.
l .
j~ A reaction flask was charged with 200 grams of bis ,i~ (2-chloroethyl) ether and 36.5 grams of dimethylformamide and the mixture was treated with lla grams of phosphorous trich-loride added dropwise at such a rate that the reaction lj :
~; ~ temperature was maintained between 20 and 45 C. After one j, : :
1~ hour agitation at this temperature, the reaction was treated ,~
with 63.6 grams of diethylene glycol which was added at such ` a rate that the reaction temperature did not exceed 45 C.
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Agitation was continued for two hours at 30 to 45 C after the addition was complete. The reaction was warmed slowly to _ g _ .
, .............
-70 C and maintained at this temperature for sixteen hours.
Twenty grams of water were then added slowly while the temperature was allowed to increase to 95 to 100 C. The mixture was agitated for thirty minutes, after which, an additional charge of 100 grams of water was made. Once again, the reaction was maintained at 95 to 100 C for thirty minutes before being cooled to 60 C and separated in a separatory funnel. The lower aqueous layer was steam distilled to remove bis(2-~hloroethyl)ether and treated with acetone to precipitate 72.1 grams (76 percent yield~ of dimethylaminomethylenebis (phosphonic acid)monohydrate. The bis(2-chloroethyl~ether removed by steam distillation was combined with the organic layer and a total yield of 283.2 grams (97 percent) was obtained.
ExAMæLE 2 A reaction flask was charged with 1200 grams of bis ~;-(2-chloroethyl~ ether and 220 grams of dimethylformamide and j the mixture was treated with 660 grams of phosphorous trich-`I loride added at such a rate that the reaction temperature was ~ -maintained between 20 and 45 C. After one hour of agitation at this temperature, the flask was charged with 490 grams of -diethylene glycol which was added at such a rate that the ; temperature did not exceed 45 C. The flask contents were i ~ .
agitated at 20 to 25 C for sixteen hours and than trans~erred to a glass-lined, steel autoclave. The autoclave was heated ;
at 15~ to 165 C for twelve hours and a pressure of 50 pounds per square inch was observed. After cooling and venting, the autoclave contents were treated with 18Q grams of water and the temperature was allowed to rise to 90 to 95 C. Agitation at this temperature was continued for thirty minutes and then 1500 grams of additional water were added. The reaction -~ -mixture was agitated for eight hours and then separated in a separatory funnel. Analysis of the aqueous layer indicated -- 10 `' :
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that a yield of 494.6 grams (94.1 percent) of dimethylamino-methylenebis(phosphonic acid) had been obtained. The yield of bis(2-chloroethyl~ether in excess of that added in the beginning of the reaction was 553.6 grams (83.8 percent~.
EXAMPLE 3.
The procedure of Example 1 was followed except that the dimethylaminomethylenebis(phosphonic acid) in the aqueous solution was determined by titration. A yield of 89.3 percent was obtained. The yield of the bis(2-chloroethyl)ether in excess of that used as solvent was 92.1 percent.
EXAMPLE 4.
The procedure of Example 1 was followed except that ethylene dichloride was used in place of bis(2-chloroethyl) ether and ethylene glycol ~37.2 grams) was used in place of diethylene glycol. The yield of ethylene dichloride in excess of that used as solvent was 5Q.8 percent and the yield of dimethylaminomethylenebis~phosphonic acid) was 87.7 percent.
EXAMPLE 5.
The procedure of Example 1 was followed except that ethylene dichloride was used in place of ~is~2-chloroethyl~
ether and n-butyl alcohol t88 8 grams~ was used in place of ;~ diethylene glycol. The yield of n-butyl chloride was 39.2 percent and the yield of dimethylaminomethylenebis~phosphonic acid~ was 75.5 percent.
EXAMPLE 6.
The procedure of Example 1 was followed except that n-dodecyl chloride was used in place of bis(2-chloroethyl) , ether and n-dodecyl alcohol (224 grams~ was used in place of diethylene glycol. The yield of dodecyl chloride in excess of that used as solvent was 82 percent and the yield of dimethylaminomethylenebis~phosphonic acid~ was 56.q percent.
EXAMPLE 7.
~composition containin~ 15 percerlt of dimet-' ' " , ~
l~B5~315 hylaminomethylenebis(phosphonic acid) and 15 percent of poly (acrylic acid) in water was prepared by mixing 47.5 grams of an aqueous solution containing 31.6 percent of the trisodium salt of dimethylaminomethylenebis~phosphonic acid), 35.2 grams of an aqueous solution containing 42.6 percent of poly(acrylic acid)(molecular weight--3000), and 17.3 grams of water.
EXAMP~E 8 The solutions of dimethylaminomethylenebis(phosphonic ; acid) and poly~acrylic acid) referred to in Example 7 were used to prepare two formulations. The first contained 17.0 percent each of the phosphonate and polymer and the second solution contained 20.0 percent of the phosphonate and 13.0 percent of the polymer. Each of these solutions was then mixed with an aqueous solution containing 70 percent of phosphorous acid to prepare the following compositions~
Number Phosphonate Polymer Phosphorous acid PercentPercent Percent 8A 16.2 16.2 3.5 ;
A, 8B 15.3 15 3 7 Q
8C 14.4 14 4 10 5 8D 19.0 12.4 3.5 8E 18.0 11.7 7 0 ,~ 8F 17.0 11.0 10 5 , ~ A composition was prepared using a 31.Q percent ?~ ~ solution of the trisodium salt of dimethylaminomethylene~is ;~ (phosphonic acid~, a 45.6 percent solution of poly(acrylic acid) with a molecular weight of 3300-3500, 70 percent phosphorous acid, 50 percent sodium hydroxide and water to provide the following concentrations:
Phosphonate 16.5 percent Poly~acrylic acid~ 11.0 percent Phosphorous acid 6.0 percent Sodium hydroxide 5.5 percent The corrosion inhibiting properties of solutions of this composition with zinc chloride were determined in .
~931S
Example 11.
EXAMP~E 10 One hundred grams of a solution containing 20 percent -of the trisodium salt of dimethylaminomethylenebis(phosphonic acid) and 13 percent of 3300-3500 molecular weight poly(acrylic acid) were mixed with 15 grams of 37 percent hydrochloric acid and 40 grams of a 50 percent solution of zinc chloride. The corrosion inhibiting results using this compositions are included in Example 11.
; This example illustrates the corrosion-inhibiting -properties of the compositions. The test apparatus included a sump, a flow circuit, a circulating pump, and a heater. A
test fluid was prepared to approximate a moderately hard well water concentrated 4 times which did not come in contact with any metal except for test coupons placed within the circuit --in a manner simulating flow, impingement, and sump conditions.
The test coupons were 1010 mild steel, and the circulating solution had a calcium hardness of CaCO3 of 270 parts~per million, a magneæîum hardness~ as CaCO3 of 170 parts per million, , ~
chloride as NaCl of 5Q0 parts per millions, and sulfate as -Na2SO4 of 624 parts per million.
The temperature during the test was maintained at about ~ 55 C, and the pH varied from 7 to 9. The test ~luid wa9 ;~ circulated continuously through the system containing the ~ coupons for a period of seven days. The steel coupons were ., ~ .
removed and examined or scale. No significant amount of scale was observed on any of the coupons protected by the compositions of this invention. The coupons were then cleaned and weighed ~ .
and the corrosion rates calculated as mils per year. One mil - ~ per year loss is equal to a volume decrease of 0.001 inch per year or Q.0254 millimeter per year. The corrosion rates are included in Table 1.
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l(?B931S
Table 1 Corrosion test results using the compositions of Examples 7, 8, 9, and 10 Corrosion inhibiting Active Zinc* Corrosion rate in c_mposition ingredient added _ mils per year Example No. Parts per million Current Impingement Sump ; 8D 35 - 20 33 31 9 33~5 3.411 23 9 9 33.5 6.7 4 3 4 9 33.5 10.1 3 3 3 9 33.5 13.4 2 3 2 5.4 1.527 112 41 I0 10.7 3.110 6 8 lQ 16.0 4.6 9 24 14 ~0 21.3 6.2 2 2 31.9 9.3 2 2 2 Control - - 56 186 44 30 *The compositions of Example 10 contained zinc in the concent- -rated formulations.
The results of these tests clearly demonstrate that 1 : .
compositions of this invention have excellent corrosion inhibiting properties when tested against steel coupons in a very aggressive aqueous system.
, ~ The compositions of this example were tested as scale 1~::
~ inhibiting preparations in Examples 13-17.
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Table 2 Trisodium salt of dimethylamino-methylenebis(phos- Poly(acrylic acid) Phosphoric Phosphorous phonic acid) Mol Wt = 3000-5000 acid acid Percent Percent Percent Percent (Based on total of active materials) Compositions of this invention included in Table 2 were compared for inhibition of calcium carbonate with the trisodium salt of dimethylaminomethylenebis(phosphonic acid) and poly(acrylic acid). The test was conducted by adding to a bottle 100 milli-~ liter8 of 0.04 percent solution of calcium hydroxide freshly I prepared from recently boiled demineralized water. The composi-tions being tested were added to provide the calculated concen-tration desired. Then, 100 milliliters of a 0.05 percent solution of sodium bicarbonate prepared from recently boiled demineralized -, ;. ~ : -`~ ~ water was added to the bottle. The final volume was adjusted to , ~ :
220 milliliters and the solutions were allowed to stand for 18 hours at room temperature. The contents of the bottles were filtered through Whatman No. 4 filter paper, and the filtered -solutions were analyzed for calcium content using an atomic ; , , . . ,............. . , . :.................. - ~ ' :
- ' : . , - ~8~315 absorption instrument or an EDTA titration procedure. The concentration was 98 parts per million calcium which is equivalent to 245 parts per million of calcium carbonate. ~' The percentage inhibition of precipitation was calculated by dividing the calcium content of the filtrate by 98 and ~' mul~iplying by lQQ. The results obtained are included in Table 3. ' The results of these tests show that dimethylamino- -, methylenebis(phosphonic acid)(A) and poly(acrylic acid)(B) will inhibit the precipitation of calcium carbonate. When ' the two are combined in various proportions (C, D, E, F), ' ' the antiprecipitant properties are maintained and the results with F actually indicate that the overall effectiveness is better than that expected from the combination (synergism).
When the phosphonate and poly(,acrylic acid) are combined with phosphoric acid (G and H), the antiprecipitant property is greatly decreased. However, combinations with phosphorous acid (,I and J) maintain the high level of antiprecipitant effee,t -, and the corrosion inhibiting property of the composition con-,~ 20 taining phosphorous acid was demonstrated in Example 11. The startling difference observed with compositions containing -~ phosphoric and phosphorous acids is completæly unexpected ~ ; because of the similarity of the two acids and the relative ; lack of information in the literature concerning the use of ', phosphorous acid in water treatment chemical compositions.
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'' ' ~able 3 Results of antiprecipitation tests with calcium carbonate Composition ConcentrationA B C D E F G H I J
Parts per millionPercent inhibition
6 98 97 85 85 82 98 53 40 90 92
7 94 95 85 85 85 99 - - 92 97
8 99 97 85 83 88 96 54 42 92 97 The compositions included in Table 2 were tested for inhibition of calcium sulfate scale. This test was conducted by mixing in a bottle 10 milliliters of a solution containing -162.9 grams of calcium chloride per liter of solution (prepared with deionized water~ and the desired volume of inhibitor stock solution to provide the desired concentration ~ 20 in a final total volume of 175 milliliters. The pH was then "~ adjusted with dilute HCl or dilute NaOH solutions to 7Ø
Twenty-five milliliters of Na2SO4 solution containing 83.45 ` grams of Na2SO4 per liter of solution was added to the bottle.
The final volume was adjusted to 175 milliliters if ~ necessary and the bottle was shaken on a gyratory shaker table -=~ at room temperature for 18 hours. Each bottle contained }0,000 parts per million of calcium sulfate.
After shaking, the contents of the bottles were filtered through Whatman No. 4 filter paper and the filtrates were ana~yzed for calcium content using an atomic absorption spec-trophotometer or an EDTA titration procedure. It was necessary to dilute the filtrate before analysis if the calcium content was high. The percentage inhibition of precipitation was calculated by dividing the calcium content of the filtrate by 2940 and multiplying by 100. The results are included in Table 4.
The results included in Table 4 show that the trisodium ~-salt of dimethylaminomethylenebis(phosphonic acid)(A) is not ~ ~ -an effective control agent for calcium sulfate. Although poly(acrylic acid) was consistent, it did not inhibit precipi- ^
tation of calcium sulfate by as much as 70 percent at 10 parts per million. When various combinations of the phosphonic acid and polymer were used (C, D, E, F, K, L), excellent inhibition was obtained in every case. For example, composition D gave 97 percent inhibition of the calcium sulfate at one part per million. All of the combinations were much more -effective than would have been expected from the test results ; with either component, and there is no doubt that synergism was demonstrated in these tests.
Table 4 Results of antiprecipitation tests with calcium sulfate Composition Concentration A B C D E F K L
20Parts per million Percent inhibition - 62 -- 97 -- -- -- -- ~-,~
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Twenty-five milliliters of Na2SO4 solution containing 83.45 ` grams of Na2SO4 per liter of solution was added to the bottle.
The final volume was adjusted to 175 milliliters if ~ necessary and the bottle was shaken on a gyratory shaker table -=~ at room temperature for 18 hours. Each bottle contained }0,000 parts per million of calcium sulfate.
After shaking, the contents of the bottles were filtered through Whatman No. 4 filter paper and the filtrates were ana~yzed for calcium content using an atomic absorption spec-trophotometer or an EDTA titration procedure. It was necessary to dilute the filtrate before analysis if the calcium content was high. The percentage inhibition of precipitation was calculated by dividing the calcium content of the filtrate by 2940 and multiplying by 100. The results are included in Table 4.
The results included in Table 4 show that the trisodium ~-salt of dimethylaminomethylenebis(phosphonic acid)(A) is not ~ ~ -an effective control agent for calcium sulfate. Although poly(acrylic acid) was consistent, it did not inhibit precipi- ^
tation of calcium sulfate by as much as 70 percent at 10 parts per million. When various combinations of the phosphonic acid and polymer were used (C, D, E, F, K, L), excellent inhibition was obtained in every case. For example, composition D gave 97 percent inhibition of the calcium sulfate at one part per million. All of the combinations were much more -effective than would have been expected from the test results ; with either component, and there is no doubt that synergism was demonstrated in these tests.
Table 4 Results of antiprecipitation tests with calcium sulfate Composition Concentration A B C D E F K L
20Parts per million Percent inhibition - 62 -- 97 -- -- -- -- ~-,~
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9 14 66 93 94 89 100 100 100 The compositions included in Table 2 were tested for inhibition of barium sulfate scale. The same procedure as . . ~
~ 931S
that described in Example 13 was used except that the concentration of barium sulfate present was 255 parts per million. The barium solution used contained 5.35 grams of BaC12 2H2O per liter of solution and the sulfate solution contained 1.24 grams of Na2SO4 per liter of solution. After filtration, the solutions were analyzed for barium using atomic absorption spectrophotometry. The results of the tests are included in Table 5.
The results from the table show that the trisodium sale of dimethylaminomethylenebis(phosphonic acid)(A) is not a good inhibitor for barium sulfate precipitation but that poly(acrylic acid) is a good inhibitor. Combinations of the two materials (C, D, E, F) show intermediate effectiveness.
However, the outstanding feature of Table 5 is related to the excellent and unexpected results obtained when phosphorous acid is added to the combination of the phosphonic acid and poly(acrylic acid)~M). Composition M gave 75 percent inhibition ~ -at a concentration as low as 3 parts per million and 100 percent at 6 parts per million.
Table 5 Results of antiprecipitation tests with barium sulfate Composition Concentration A B C D E F M
Parts per million Percent inhibition .
Solution M contained 50 percent of trisodium dimethyl-aminomethylenebisphosphonate, 32 percent of poly(acrylic acid) and 18 percent of phosphorous acid on a 100 percent active basis ~-as described in Table 2.
The compositions included in Table 2 were tested for inhibition of calcium acid phosphate precipitation. The same procedure as that described in Example 13 was used except that the concentration of calcium acid phosphate (CaHPO4) present was 300 parts per million. The calcium solution contained 4.89 grams of CaC12 per liter of solution and the phosphate solution contained 4.70 grams of Na2HPO4 7H2O per liter of solution.
The filtered solutions were analyzed by an EDTA titration pro- -cedure. The results of these tests are included in Table 6.
Poly(acrylic acid)~B) is a good inhibitor of CaHPO4 but the trisodium salt of dimethylaminomethylenebis(phosphonic acid) is only fair in effectiveness. Combinations of the two materials (C, D, E) provided good inhibition of CaHPO4 at intermediate concentrations and Composition E was even more effective than would be expected from combination of the two materials.
Table 6 Results of antiprecipitation tests with calcium acid phosphate Composition oncentration A B C D E
Parts per million Percent inhibition .,~ .
- ~ , , Inhibition of ferric hydroxide precipitation by compositions included in Table 2 were evaluated. A solution containing 14.5 grams of ferric chloride (FeC13) per liter of solution was diluted 1 to 50 with deionized water. One hundred milliliters of the dilute solution were mixed with stock solu-tions of compositions A, B, and D. The volume was made to 200 milliliters, and the pH was adjusted to 9.0 with sodium hydro-xide solution. The bottles were allowed to stand for 24 hours and were observed for presence of a brown-orange precipitate of ferric hydroxide. Concentrations of 20 parts per million of A and B were required to inhibit precipitation but only 15 parts per million of composition D were required to inhibit precipi-tation of the ferric hydroxide.
A composition similar to Composition D in Table 2 was prepared by mixing a solution of dimethylaminomethylenebis (phosphonic acid~ and a aolution of a polymer prepared by ~ polymerizing acrylonitrile and hydrolyzing the polymer with '~ 20 sodium hydroxide to a mixture of aodium polyacrylate and poly-acrylamide. The solution was formulated so that approximately equal amounts of the phosphonic acid and polymer were present.
~ Thiscomposition was effective as an antiprecipitant and as a r ~ corro~ion inhibitor.
! ~ EXAMPLE 19 A composition similar to Composition D in Table 2 was prepared by mixing a solution of dimethylaminomethylenebis (phosphonic acid~ and a solution of a polymer prepared by polymerizing maleic anhydride and su~sequently hydrolyzing the anhydride group to carboxylic acid groups with sodium hydroxide. The molecular weight of the polymer was in the range of 800 to 2QOQ. The solution was formulated so that approximately equal amounts of the phosphonic acid and polymer were present. This composition was effective as an antipreci~
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~ 93~5pitant and as a corrosion inhibitor.
A composition was prepared from an aqueous solution of the trisodium salt of dimethylaminomethylenebis(phosphonic acid), an aqueous solution of poly(acrylic acid) having a mole-cular weight of 4000, an aqueous solution containing 70 percent phosphorous acid, an aqueous solution containing 50 percent sodium hydroxide, and water. The concentration present was : -17 percent of the trisodium salt of dimethylaminomethylenebis (phosphonic acid), 11 peraent of poly(acrylic acid), 6 percent of phosphorous acid, and 5.5 percent of sodium hydroxide. This composition was effective as an antiprecipitant and as a. . .
corrosion inhibitor. ~ .
EXAMPLE 21 ~.
A corrosion and scale inhibiting composition was prepared by mixing 100 grams of an aqueous solution containing ~:
20 percent of the trisodium salt of dimethylaminomethylenebis (phosphonic acid) and 13 percent of poly(acrylic acid) having ; a molecular weight of 3200, 15 grams of 35 percent hydrochloric ~.
: 20 acid, and 50 grams of an aqueous solution containing 50 percent ~: of zinc chloride.
~- ~ EXAMPLE 22 A corro~ion and scale inhibiting composition was prepared by mixing 100 grams of an aqueous solution containing 18 percent of the trisodium salt of dimethylaminomethylenebis (phos.phonic acid), 11.7 percent of poly(acrylic acid~ having . a molecular weight of 3200, and 7 percent of phosphorous acid, 25~grams of 37 percent hydrochloric acid solution, and --50 grams of an aqueous solution containing 50 percent of zinc chloride.
While particular embodiments of the invention have been described, it will be understood., of course, that the invention is not limited thereto since many modifications may be made; and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the spirit and scope of the invention. ~
The invention having thus been described, what is .
claimed and desired to be secured by Letters Patent is: :
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~ 931S
that described in Example 13 was used except that the concentration of barium sulfate present was 255 parts per million. The barium solution used contained 5.35 grams of BaC12 2H2O per liter of solution and the sulfate solution contained 1.24 grams of Na2SO4 per liter of solution. After filtration, the solutions were analyzed for barium using atomic absorption spectrophotometry. The results of the tests are included in Table 5.
The results from the table show that the trisodium sale of dimethylaminomethylenebis(phosphonic acid)(A) is not a good inhibitor for barium sulfate precipitation but that poly(acrylic acid) is a good inhibitor. Combinations of the two materials (C, D, E, F) show intermediate effectiveness.
However, the outstanding feature of Table 5 is related to the excellent and unexpected results obtained when phosphorous acid is added to the combination of the phosphonic acid and poly(acrylic acid)~M). Composition M gave 75 percent inhibition ~ -at a concentration as low as 3 parts per million and 100 percent at 6 parts per million.
Table 5 Results of antiprecipitation tests with barium sulfate Composition Concentration A B C D E F M
Parts per million Percent inhibition .
Solution M contained 50 percent of trisodium dimethyl-aminomethylenebisphosphonate, 32 percent of poly(acrylic acid) and 18 percent of phosphorous acid on a 100 percent active basis ~-as described in Table 2.
The compositions included in Table 2 were tested for inhibition of calcium acid phosphate precipitation. The same procedure as that described in Example 13 was used except that the concentration of calcium acid phosphate (CaHPO4) present was 300 parts per million. The calcium solution contained 4.89 grams of CaC12 per liter of solution and the phosphate solution contained 4.70 grams of Na2HPO4 7H2O per liter of solution.
The filtered solutions were analyzed by an EDTA titration pro- -cedure. The results of these tests are included in Table 6.
Poly(acrylic acid)~B) is a good inhibitor of CaHPO4 but the trisodium salt of dimethylaminomethylenebis(phosphonic acid) is only fair in effectiveness. Combinations of the two materials (C, D, E) provided good inhibition of CaHPO4 at intermediate concentrations and Composition E was even more effective than would be expected from combination of the two materials.
Table 6 Results of antiprecipitation tests with calcium acid phosphate Composition oncentration A B C D E
Parts per million Percent inhibition .,~ .
- ~ , , Inhibition of ferric hydroxide precipitation by compositions included in Table 2 were evaluated. A solution containing 14.5 grams of ferric chloride (FeC13) per liter of solution was diluted 1 to 50 with deionized water. One hundred milliliters of the dilute solution were mixed with stock solu-tions of compositions A, B, and D. The volume was made to 200 milliliters, and the pH was adjusted to 9.0 with sodium hydro-xide solution. The bottles were allowed to stand for 24 hours and were observed for presence of a brown-orange precipitate of ferric hydroxide. Concentrations of 20 parts per million of A and B were required to inhibit precipitation but only 15 parts per million of composition D were required to inhibit precipi-tation of the ferric hydroxide.
A composition similar to Composition D in Table 2 was prepared by mixing a solution of dimethylaminomethylenebis (phosphonic acid~ and a aolution of a polymer prepared by ~ polymerizing acrylonitrile and hydrolyzing the polymer with '~ 20 sodium hydroxide to a mixture of aodium polyacrylate and poly-acrylamide. The solution was formulated so that approximately equal amounts of the phosphonic acid and polymer were present.
~ Thiscomposition was effective as an antiprecipitant and as a r ~ corro~ion inhibitor.
! ~ EXAMPLE 19 A composition similar to Composition D in Table 2 was prepared by mixing a solution of dimethylaminomethylenebis (phosphonic acid~ and a solution of a polymer prepared by polymerizing maleic anhydride and su~sequently hydrolyzing the anhydride group to carboxylic acid groups with sodium hydroxide. The molecular weight of the polymer was in the range of 800 to 2QOQ. The solution was formulated so that approximately equal amounts of the phosphonic acid and polymer were present. This composition was effective as an antipreci~
:., .. .. . . .
.. ~ .
~ 93~5pitant and as a corrosion inhibitor.
A composition was prepared from an aqueous solution of the trisodium salt of dimethylaminomethylenebis(phosphonic acid), an aqueous solution of poly(acrylic acid) having a mole-cular weight of 4000, an aqueous solution containing 70 percent phosphorous acid, an aqueous solution containing 50 percent sodium hydroxide, and water. The concentration present was : -17 percent of the trisodium salt of dimethylaminomethylenebis (phosphonic acid), 11 peraent of poly(acrylic acid), 6 percent of phosphorous acid, and 5.5 percent of sodium hydroxide. This composition was effective as an antiprecipitant and as a. . .
corrosion inhibitor. ~ .
EXAMPLE 21 ~.
A corrosion and scale inhibiting composition was prepared by mixing 100 grams of an aqueous solution containing ~:
20 percent of the trisodium salt of dimethylaminomethylenebis (phosphonic acid) and 13 percent of poly(acrylic acid) having ; a molecular weight of 3200, 15 grams of 35 percent hydrochloric ~.
: 20 acid, and 50 grams of an aqueous solution containing 50 percent ~: of zinc chloride.
~- ~ EXAMPLE 22 A corro~ion and scale inhibiting composition was prepared by mixing 100 grams of an aqueous solution containing 18 percent of the trisodium salt of dimethylaminomethylenebis (phos.phonic acid), 11.7 percent of poly(acrylic acid~ having . a molecular weight of 3200, and 7 percent of phosphorous acid, 25~grams of 37 percent hydrochloric acid solution, and --50 grams of an aqueous solution containing 50 percent of zinc chloride.
While particular embodiments of the invention have been described, it will be understood., of course, that the invention is not limited thereto since many modifications may be made; and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the spirit and scope of the invention. ~
The invention having thus been described, what is .
claimed and desired to be secured by Letters Patent is: :
.,,':
.
: . , ,, :,.. ~... . . .
-: ::
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A corrosion and scale inhibiting composition consisting essentially of on a weight basis: about 10 to about 90% dimethylaminomethylenebis-(phosphonic acid) or a water-soluble salt thereof, a water-soluble polymer having a linear hydrocarbon structure with side chain carboxylic groups exemplified by the structure:
wherein R is hydrogen or -COOH and R' is hydrogen or methyl in an amount varying from about 10 to about 90% and one or more of the following:
A. Water B. about 0 to 25% of an aqueous solution of phosphorous acid or an alkali metal salt thereof, or C. about 1.5 to about 13.5% of an aqueous solution of a water soluble zinc salt.
wherein R is hydrogen or -COOH and R' is hydrogen or methyl in an amount varying from about 10 to about 90% and one or more of the following:
A. Water B. about 0 to 25% of an aqueous solution of phosphorous acid or an alkali metal salt thereof, or C. about 1.5 to about 13.5% of an aqueous solution of a water soluble zinc salt.
2. The compositions of Claim 1 wherein the water soluble polymer is poly(acrylic acid).
3. The composition of Claim 1 wherein the water soluble polymer is poly(methacrylic acid).
4. The composition of Claim 1 wherein the water soluble polymer is hydrolyzed poly(maleic anhydride).
5. The composition of Claim 1 wherein the water soluble polymer is hydrolyzed polyacrylonitrile.
6. The composition of Claim 1 wherein the water soluble polymer is hydrolyzed polyacrylamide.
7. The composition of Claim 1 wherein the dimethylamino-methylenebis-(phosphonic acid) and water soluble polymer are dissolved in water.
8. The composition of Claim 1 wherein the dimethylamino-methylenebis(phosphonic acid) and water soluble polymer are combined with aqueous phosphorous acid.
9. The composition of Claim 1 wherein the dimethylamino-methylenebis(phosphonic acid) and water soluble polymer are combined with aqueous zinc chloride and hydrochloric acid.
10. The composition of Claim 1 wherein the dimethylamino-methylenebis(phosphonic acid) and water soluble polymer are combined with phosphorous acid, zinc chloride, hydrochloric acid, and water.
11. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems an effective amount of the composition in Claim 1.
12. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems from 0.5 to 1000 parts per million of the com-position of Claim 1.
13. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems an effective amount of the composition in Claim 1 wherein the water soluble polymer is poly(acrylic acid).
14. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems an effective amount of the composition of Claim 1 wherein the water soluble polymer is poly(acrylic acid) and the composition contains phosphorous acid.
15. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems an effective amount of the composition of Claim 1 wherein the water soluble polymer is poly(acrylic acid) and the composition contains zinc chloride.
16. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems an effective amount of the composition of Claim 1 wherein the water soluble polymer is poly(acrylic acid) and the composition contains phosphorous acid, zinc chloride, and hydrochloric acid.
17. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems from 0.5 to 1000 parts per million of the composition of Claim 1 comprising dimethylaminomethylenebis (phosphonic acid), poly(acrylic acid), and water.
18. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems from 0.5 to 1000 parts per million of the composition of Claim 1 comprising dimethylaminomethylenebis (phosphonic acid), poly(acrylic acid), phosphorous acid, and water.
19. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems from 0.5 to 1000 parts per million of the composition of Claim 1 comprising dimethylaminomethylenebis (phosphonic acid), poly(acrylic acid), zinc chloride, hydrochloric acid, and water.
20. A process for inhibiting corrosion and scaling of metal surfaces in water systems comprising adding to water in said systems from 0.5 to 1000 parts per million of the composition of Claim 1 comprising dimethylaminomethylenebis (phosphonic acid), poly(acrylic acid), phosphorous acid, zinc chloride, hydrochloric acid, and water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US845,011 | 1977-10-25 | ||
| US05/845,011 US4163733A (en) | 1977-10-25 | 1977-10-25 | Synergistic compositions for corrosion and scale control |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1089315A true CA1089315A (en) | 1980-11-11 |
Family
ID=25294194
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA296,315A Expired CA1089315A (en) | 1977-10-25 | 1978-02-06 | Synergistic compositions for corrosion and scale control |
Country Status (18)
| Country | Link |
|---|---|
| US (2) | US4163733A (en) |
| JP (2) | JPS5495648A (en) |
| AR (1) | AR217676A1 (en) |
| AU (1) | AU518434B2 (en) |
| BE (1) | BE863904A (en) |
| BR (1) | BR7806956A (en) |
| CA (1) | CA1089315A (en) |
| DE (1) | DE2807222B2 (en) |
| ES (1) | ES467263A1 (en) |
| FR (2) | FR2407253A1 (en) |
| GB (1) | GB1590510A (en) |
| IT (1) | IT1102471B (en) |
| MX (1) | MX149051A (en) |
| NL (1) | NL175440C (en) |
| NO (1) | NO780906L (en) |
| NZ (1) | NZ186474A (en) |
| SE (1) | SE444003B (en) |
| ZA (1) | ZA781847B (en) |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2838437A1 (en) * | 1978-09-02 | 1980-03-20 | Benckiser Gmbh Joh A | N, N'-DIALKYL-UREIDOMETHANE DIPHOSPHONIC ACID, THEIR PRODUCTION AND USE |
| US4411865A (en) * | 1979-04-05 | 1983-10-25 | Betz Laboratories, Inc. | Method of corrosion inhibition in aqueous mediums |
| US4279758A (en) * | 1979-07-19 | 1981-07-21 | Joh. A. Benckiser Gmbh | Process for inhibiting the formation of mineral deposits from a water using N-N-dialkylureidomethane diphosphonic acids |
| US4303568A (en) * | 1979-12-10 | 1981-12-01 | Betz Laboratories, Inc. | Corrosion inhibition treatments and method |
| DE3047107A1 (en) * | 1980-12-13 | 1982-07-29 | Hoechst Ag, 6000 Frankfurt | METHOD FOR PRODUCING 1-AMINO-ALKANE-1,1-DIPHOSPHONIC ACIDS |
| US4414126A (en) * | 1981-10-22 | 1983-11-08 | Basf Wyandotte Corporation | Aqueous compositions containing corrosion inhibitors for high lead solder |
| US4457847B2 (en) * | 1981-11-05 | 1996-12-31 | Nalco Chemical Co | Carboxylate polymers for internal scale control agents in boiler systems |
| EP0089189B1 (en) * | 1982-03-11 | 1986-06-11 | Calgon Corporation | A calcium carbonate, magnesium hydroxide and calcium sulfate hemihydrate scale inhibitor |
| US4714564A (en) * | 1982-04-21 | 1987-12-22 | The United States Of America As Represented By The Secretary Of The Air Force | High performance multifunctional corrosion inhibitors especially for combining at 20 to 50 weight percent with soap or paint |
| GB8309573D0 (en) * | 1983-04-08 | 1983-05-11 | Ciba Geigy Ag | Water treatment composition |
| US4642194A (en) * | 1985-09-16 | 1987-02-10 | Nalco Chemical Company | Method for prevention of phosphonate decomposition by chlorine |
| US4711724A (en) * | 1985-09-16 | 1987-12-08 | Nalco Chemical Company | Method for prevention of phosphonate decomposition by chlorine |
| DE3545909A1 (en) * | 1985-12-23 | 1987-06-25 | Henkel Kgaa | SILICATE- AND MAGNESIUM-FREE ACTIVE SUBSTANCE MIXTURES |
| US4959075A (en) * | 1985-12-23 | 1990-09-25 | Henkel Kommanditgesellschaft Auf Aktien | Silicate- and magnesium-free stabilizer hydrogen peroxide mixtures for bleaching processes |
| US4904413A (en) * | 1986-03-26 | 1990-02-27 | Nalco Chemical Company | Cooling water corrosion control method and composition |
| US4717542A (en) * | 1987-01-23 | 1988-01-05 | W. R. Grace & Co. | Inhibiting corrosion of iron base metals |
| US5068059A (en) * | 1990-01-16 | 1991-11-26 | Drew Chemical Corporation | Corrosion inhibitor |
| DE4006849C2 (en) * | 1990-03-05 | 1999-01-28 | Brigitte Mendel Fa | Method for marking partial stacks contained in a stack from a certain number of punched-out film blanks and device for carrying out the method |
| US5089150A (en) * | 1990-05-29 | 1992-02-18 | Mobil Oil Corporation | Method of increasing retention of scale inhibitors in subterranean formations |
| US5019651A (en) * | 1990-06-20 | 1991-05-28 | Merck & Co., Inc. | Process for preparing 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid (ABP) or salts thereof |
| US5292449A (en) * | 1992-11-24 | 1994-03-08 | Akzo Nv | Scale inhibiting composition |
| CA2197267C (en) * | 1997-02-11 | 2000-02-08 | Yong Tao | Process for the production of 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid or salts thereof |
| US6585933B1 (en) | 1999-05-03 | 2003-07-01 | Betzdearborn, Inc. | Method and composition for inhibiting corrosion in aqueous systems |
| EP1482897A2 (en) * | 2002-02-19 | 2004-12-08 | Ilex Products, Inc. | Aminodiphosphonate apolipoprotein e modulators |
| CN103819506A (en) * | 2014-03-12 | 2014-05-28 | 山东省泰和水处理有限公司 | Preparation method of scale and corrosion inhibitor for circulating cooling water in oil refinery |
| CN104086007A (en) * | 2014-07-31 | 2014-10-08 | 威海翔宇环保科技有限公司 | Corrosion and scale inhibitor for heat supply network |
| DE102018119835A1 (en) | 2018-08-15 | 2020-02-20 | Chemische Fabrik Budenheim Kg | Polymer composition with phosphonate flame retardant |
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|---|---|---|---|---|
| US2763200A (en) * | 1953-08-21 | 1956-09-18 | Charles R Kittler | Charcoal barbecue |
| DE1302557B (en) * | 1963-04-09 | 1971-08-26 | ||
| US3505238A (en) * | 1965-03-29 | 1970-04-07 | Calgon C0Rp | Methods and compositions for inhibiting scale in saline water evaporators |
| IL30533A (en) * | 1967-09-01 | 1972-01-27 | Bayer Ag | Thiol-or thionothiol-phosphoric or-phosphonic acid esters |
| 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 |
| DE1806594C3 (en) * | 1968-11-02 | 1979-05-03 | Joh. A. Benckiser Gmbh, 6700 Ludwigshafen | Use of a mixture of aminoalkylenephosphonic acid and polymeric compounds to prevent stone-forming deposits in aqueous systems |
| DE1958123C3 (en) * | 1969-11-19 | 1978-09-28 | Henkel Kgaa, 4000 Duesseldorf | Process for the preparation of 1-aminoalkane-1,1-diphosphonic acids or their salts |
| DE2022777A1 (en) * | 1970-05-09 | 1971-11-25 | Henkel & Cie Gmbh | Aluminium protection in alkali solutions using-1-aminoalkane - -1,1-diphosphonic acid corrosion inhibitors |
| US3669673A (en) * | 1970-10-23 | 1972-06-13 | Rca Corp | Recording of a continuous tone focused image on a diffraction grating |
| DE2104476C2 (en) * | 1971-02-01 | 1983-12-01 | Henkel KGaA, 4000 Düsseldorf | Process for preventing precipitation in water or aqueous solutions |
| US3821335A (en) * | 1971-02-04 | 1974-06-28 | Swift & Co | Aminomethylphosphonates |
| US3963636A (en) * | 1972-12-04 | 1976-06-15 | Ciba-Geigy Corporation | Treatment of water or aqueous systems |
| GB1374270A (en) * | 1971-12-10 | 1974-11-20 | Ciba Geigy Ag | Polymaleic anhydride compositions and their use |
| DE2306069A1 (en) * | 1973-02-08 | 1974-08-22 | Henkel & Cie Gmbh | Detergents having low phosphorus content - for washing natural and synthetic textiles and contg. carboxylate surfactant component and org. complexing salts for calcium ions |
| US3890228A (en) * | 1973-04-13 | 1975-06-17 | Chemed Corp | Polyacrylate-polyphosphonic acid treatment in aqueous systems |
| US3885914A (en) * | 1973-06-04 | 1975-05-27 | Calgon Corp | Polymer-zinc corrosion inhibiting method |
| US3975160A (en) * | 1974-07-29 | 1976-08-17 | Milton Roy Company | Colorimetric analyzer |
| US4018701A (en) * | 1975-07-31 | 1977-04-19 | Calgon Corporation | Phosphorous acid and zinc corrosion inhibiting compositions and methods for using same |
| US4029696A (en) * | 1976-04-09 | 1977-06-14 | Benckiser-Knapsack Gmbh | N-hydroxy alkane amino alkane diphosphonic acids, process of producing same, and compositions for and method of using same |
-
1977
- 1977-10-25 US US05/845,011 patent/US4163733A/en not_active Expired - Lifetime
-
1978
- 1978-01-31 SE SE7801154A patent/SE444003B/en not_active IP Right Cessation
- 1978-02-06 CA CA296,315A patent/CA1089315A/en not_active Expired
- 1978-02-08 US US05/875,964 patent/US4157364A/en not_active Expired - Lifetime
- 1978-02-13 BE BE185118A patent/BE863904A/en not_active IP Right Cessation
- 1978-02-13 AR AR271093A patent/AR217676A1/en active
- 1978-02-14 AU AU33284/78A patent/AU518434B2/en not_active Expired
- 1978-02-14 NZ NZ186474A patent/NZ186474A/en unknown
- 1978-02-20 DE DE2807222A patent/DE2807222B2/en not_active Ceased
- 1978-02-23 ES ES467263A patent/ES467263A1/en not_active Expired
- 1978-02-28 FR FR7805776A patent/FR2407253A1/en active Granted
- 1978-03-01 MX MX172612A patent/MX149051A/en unknown
- 1978-03-14 NO NO780906A patent/NO780906L/en unknown
- 1978-03-29 NL NLAANVRAGE7803311,A patent/NL175440C/en not_active IP Right Cessation
- 1978-03-31 ZA ZA00781847A patent/ZA781847B/en unknown
- 1978-04-06 IT IT48768/78A patent/IT1102471B/en active
- 1978-05-22 GB GB21014/78A patent/GB1590510A/en not_active Expired
- 1978-10-20 BR BR7806956A patent/BR7806956A/en unknown
- 1978-10-25 JP JP13146778A patent/JPS5495648A/en active Granted
- 1978-11-23 FR FR7833054A patent/FR2407217B3/fr not_active Expired
-
1979
- 1979-01-24 JP JP698879A patent/JPS54160317A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE2807222B2 (en) | 1980-05-22 |
| BR7806956A (en) | 1979-07-10 |
| SE444003B (en) | 1986-03-17 |
| NO780906L (en) | 1979-04-26 |
| BE863904A (en) | 1978-05-29 |
| MX149051A (en) | 1983-08-15 |
| JPS54160317A (en) | 1979-12-19 |
| AU3328478A (en) | 1979-08-23 |
| IT1102471B (en) | 1985-10-07 |
| JPS5444694B2 (en) | 1979-12-27 |
| US4157364A (en) | 1979-06-05 |
| JPS5495648A (en) | 1979-07-28 |
| GB1590510A (en) | 1981-06-03 |
| AU518434B2 (en) | 1981-10-01 |
| NL175440B (en) | 1984-06-01 |
| DE2807222A1 (en) | 1979-04-26 |
| FR2407253A1 (en) | 1979-05-25 |
| IT7848766A0 (en) | 1978-04-06 |
| NZ186474A (en) | 1979-08-31 |
| FR2407253B1 (en) | 1983-02-25 |
| NL175440C (en) | 1984-11-01 |
| SE7801154L (en) | 1979-04-26 |
| US4163733A (en) | 1979-08-07 |
| NL7803311A (en) | 1979-04-27 |
| AR217676A1 (en) | 1980-04-15 |
| FR2407217B3 (en) | 1980-06-20 |
| JPS5726675B2 (en) | 1982-06-05 |
| FR2407217A1 (en) | 1979-05-25 |
| ZA781847B (en) | 1979-03-28 |
| ES467263A1 (en) | 1978-10-16 |
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