MXPA98005251A - Method to prevent the formation of incrustation in metal surfaces in contact with water industr - Google Patents

Abstract

Methods for preventing corrosion and deposition of scale in aqueous media are described. The methods use water soluble polymers having derivatized amide functionality bound or sloped, for inhibition of scale.

Description

METHOD TO PREVENT THE FORMATION OF INCRUSTATIONS IN METAL SURFACES IN CONTACT WITH INDUSTRIAL WATER CfiMEQJ2í Methods for preventing corrosion and deposition of scale in aqueous media are described. The methods use water soluble polymers having derivatized or bound amide functionalities for inhibition of scale. fi-? rrTF. rcg ™ - Tift TMVBMPT? M The use of water which contains certain inorganic impurities, and the production and processing of mixtures of water and crude oil containing such impurities, is plagued by the precipitation of these impurities with subsequent formation of scale. In the case of water which contains these pollutants, the effects of the incrustation formation generally are due to the reduction of the capacity of the well or receptacles and ducts used to store and transport the contaminated water. In the case of conduits, the flow impedance is an obvious consequence. However, many problems occur with REF: 27587 consequences equal in specific uses of contaminated water. For example, the incrustation formed on surfaces of storage containers and transport lines to process water can generate losses and these large masses of deposit are dragged and transported by the water processing to damage and cover equipment through which the water passes, for example tubes, valves, filters and sieves. In addition, these crystalline deposits may appear, and impair the final product which is derived from the process, for example, paper formed from an aqueous slurry of pulp. In addition, when contaminated water is involved in the heat exchange process, either as a "hot" or "cold" medium, the scale will form on heat exchange surfaces which are in contact with the water. Such incrustation formation forms an insulating or thermal opacifying barrier which damages the heat transfer efficiency and at the same time prevents the flow through the system. Although calcium sulfate and calcium carbonate are the main contributors in the formation of scale, other alkaline earth metal salts and > aluminum silicates are also the aggressors, for example magnesium carbonate, barium sulfate, aluminum silicates provided by sediments or silts of type bentonite, ilitic, kaolinitic, etc.

Most industrial waters contain alkaline earth metal cations such as calcium, barium, magnesium, etc., and various anions such as bicarbonate, carbonate, sulfate, oxalate, phosphate, silicate, fluoride, etc. When the combinations of these anions and cations are present in concentrations which exceed the solubility of their reaction products, they precipitate out until these solubility product concentrations are no longer exceeded. For example, when the calcium ion and carbonate ion concentrations exceed the solubility of the calcium carbonate reaction products, a solid phase of calcium carbonate will be formed. Calcium carbonate is the most common form of encrustation. The concentrations of the solubility product are exceeded for various reasons such as partial evaporation of the aqueous phase, change in pH, pressure and temperature and the introduction of additional ions which form insoluble compounds with the ions that are already present in the solution. Since these reaction products precipitate on surfaces of the water transport system, they form scale or deposits. This accumulation prevents the effective transfer of heat, interferes with the flow of fluids, facilitates corrosive processes and harbors bacteria. This incrustation is a costly problem in many industrial water systems, which causes delays and suspensions for cleaning and removal. The deposits of encrustation are generated and spread mainly by means of crystalline growth, and consequently several approaches to reduce the development of scale include the inhibition of crystal growth, crystal growth modification and dispersion of the encrusting minerals. Many other industrial waters, although they do not form incrustation, tend to be corrosive. Such waters, when in contact with various metal surfaces such as ferrous metals, aluminum, copper and their alloys, tend to corrode one or more metals or alloys. Various compounds have been suggested to solve these problems. Such materials are low molecular weight polyacrylic acid polymers. Corrosive waters of this type are usually acidic and are commonly found in closed recirculation systems. Many compounds have been added to these industrial waters in an attempt to avoid or reduce fouling and corrosion. One such class of materials are the well-known organophosphonates which are illustrated by the hydroxyethylidene phosphonic acid (HEDP) and phosphonobutanetricarboxylic acid (PBTC) compounds. Another group of active inhibitors of the incrustation and corrosion are the monosodic phosphinicobis (succinic acids) which are described in the North American patent number 4,088,678. Polymeric treatments have been described in U.S. Patent Nos. 4,680,339; 4,731,419; 4,885,345 and 5,084,520. The utility for the treatments have been described as dispersants in water treatment, scale inhibitors in industrial and natural waters, flocculants, coagulants and thickeners. In addition, methods for controlling the calcium oxalate scale with an effective amount of a water-soluble (meth) acrylic / allyl ether copolymer have been described in U.S. Patent No. 4,872,995. In US Pat. No. 4,933,090 a method for controlling silica / silicate deposition including calcium and magnesium silicate by addition of phosphonate and a water soluble terpolymer of an unsaturated carboxylic acid monomer, an unsaturated sulfonic compound and a unsaturated polyalkylene oxide. In US Pat. No. 4,818,506 acrylate / acrylamide copolymers have been described as useful for the inhibition of gypsum scale in flue gas desulfurization processes.

In U.S. Patent No. 5,049,310, a method for inhibiting the formation of phosphonate scale and the corrosion of iron containing solid surfaces in contact with industrial waters with a water-soluble zinc stabilizer polymer is disclosed. In U.S. Patent No. 4,999,161 a method for preventing condensate corrosion in heaters or boilers is disclosed which comprises treating the condensate with a water soluble polymer composition comprising an acrylic acid polymer containing acrylic acid groups in the form of amides of a primary or secondary amine aliphatic and soluble in water. However, there is still a need for polymeric treatments which provide increased efficiency against corrosion, and scale control.

BRIEF DESCRIPTION OF THE IA -VENTION Methods for preventing corrosion and deposition of scale in aqueous media are described. The methods use water soluble polymers having derivatized or bound amide functionalities to inhibit fouling.

DESCRIPTION OF THE INVENTION The invention is a method for preventing the formation of scale on metal surfaces in contact with industrial scale-forming water within an industrial system which comprises the step of treating the water with an effective scale-inhibiting amount of a water-soluble polymer that has distributed "meric" (constitutive) units repeated and distributed, represented by the formula wherein R1 is selected from the group consisting of hydrogen and Cx-C3 alkyl; p and q are integers of 1 to 10; R2 and R3 are selected from the group consisting of hydrogen and alkyl of Cj.-C3; Het1 and Het2 are selected from the group consisting of oxygen and nitrogen; R 4 is selected from the group consisting of hydrogen and C 1 Ca 2 alkyl; R5 and R6 are selected from the group consisting of hydrogen, carboxylate, alkyl of and a cycloalkyl group of 3 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring. For any embodiment of this invention, industrial water may be cooling water. In addition, the scale can be selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, calcium sulfate, barium sulfate, clay, magnesium phosphate-sediment, magnesium carbonate and calcium carbonate. Any form of the polymers of this invention is also active against scale caused by the calcium and magnesium salts of HEDP and the calcium and magnesium salts of PBTC. In addition, the cooling water may contain a biocide, corrosion inhibitors or other scale inhibitors. Industrial water can be industrial process water selected from the group consisting of water from mining processes, pulp and paper process water and water from oil field processes. The invention is also a method for preventing scale formation on metal surfaces in contact with industrial scale forming water within an industrial system which comprises the step of treating the water with an effective scaling inhibiting amount of a water soluble polymer. that has: A) a unit of the formula wherein R1 is selected from the group consisting of hydrogen and Cx-C3 alkyl; p and q are integers from 1 to 10; R2 and R3 are selected from the group consisting of hydrogen and CJ.-C3 alkyl; Het1 and Het2 are selected from the group consisting of oxygen and nitrogen; R4 is selected from the group consisting of hydrogen and CJ.-C20 alkyl; R5 and R6 are selected from the group consisting of hydrogen, carboxylate, alkyl of Cj.-C3 and a cycloalkyl group of 3 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring; and B) a metric unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamidemethacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-terbu and lacrylamide, butoxymethyl and lacrylate, N, N-dimethylacrylamide, sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof. For any of the I-III structures, the salts of the comonomers will also have utility. A specific applicable polymer is identified as one in which p = 1; q = 1; R1, R2, R3, R4, R5 and R6 are hydrogen; and Het1 and Het2 are oxygen in formula I of step A; and the mer units of step B are acrylic acid and acrylamide for the water soluble polymer. Another useful polymer is one in which p = 1; q = 1; R1, R2, R3, R4, R5 and R6 are hydrogen; and Het1 and Het2 are oxygen in formula I of step A; and the mer units of step B are acrylic acid for the water soluble polymer. Another useful additional polymer is one in which p = 1; q = 1; R1, R2, R3, R4, R5 and R6 are hydrogen; and Het1 and Het2 are oxygen in formula I of step A; and the mer units of step B are acrylic acid and acrylamide for the water soluble polymer. In addition, where p = 1; q = 1; Het1 is nitrogen, Het2 is oxygen and R1, R2, R3, R4, R5 and R6 are hydrogen in formula I of step A; and the mer units of step B are acrylic acid, it is also a useful water soluble polymer. Where p = 1; q = 1; Het1 is nitrogen, Het2 is oxygen and R1, R2, R3, R4, R5 and R6 are hydrogen in formula I of step A; and the iron units of stage B are maleic acid and acrylic acid, is another applicable polymer, soluble in water. The invention is also mentioned to prevent the formation of scale on metal surfaces in contact with industrial scale-forming water which comprises the step of treating the water with an effective scale-inhibiting amount of a water-soluble polymer containing distributed repeat mineral units. of the formula wherein R1 is selected from the group consisting of hydrogen and alkyl groups of p is an integer from 0 to 50; R2 is selected from the group consisting of hydrogen and alkyl groups of R5 and R6 are selected from groups consisting of hydrogen, carboxylates, alkyl groups of Cj.-C3 and a cycloalkyl group of 3 to 6 carbon atoms formed by the linking of R5 and R6 as a ring, with the proviso that, when p is 0, R2 is not hydrogen. The invention is also a method for preventing scale formation on metal surfaces in contact with industrial scale forming water within an industrial system which comprises the step of treating the water with an effective scaling inhibiting amount of a water soluble polymer. that has: A) a unit of the formula NH H3CCHCH2 (OCHRiCH2) pOR II wherein R1 is selected from the group consisting of hydrogen and alkyl groups of C ^^, p is an integer from 0 to 50; R2 is selected from the group consisting of hydrogen and Ci-C alkyl groups; R5 and R6 are selected from groups consisting of hydrogen, carboxylates, CX-C3 alkyl groups and a cycloalkyl group of 3 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring, with the proviso that, when p is 0, R2 is not hydrogen; and B) a mill unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-tert-butylacrylamide, butoxymethylacrylamide, N, N-dimethylacrylamide, acid sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof. For the practice of this invention, p can be an integer from 10 to 25, R1 can be selected from the group consisting of hydrogen and methyl groups, R2 can be a methyl group; R5 can be hydrogen and R6 can be hydrogen, and the mer units of step B can be acrylic acid. Additionally, p is an integer from 10 to 25, R1 may be selected from the group consisting of hydrogen and methyl groups, R2 may be a methyl group, R5 and R6 may be hydrogen, and the mer units of step B may be acidic. acrylic and acrylamide. In addition, another useful polymer is one in which p is an integer from 10 to 25, R1 is selected from the group consisting of hydrogen and methyl groups, R2 is a methyl group, R5 is hydrogen and R6 is hydrogen, and the units The drugs of stage B are maleic acid and acrylic acid. Another aspect of this invention is a method for preventing scale formation on metal surfaces in contact with industrial scale forming water within an industrial system which comprises the step of treating the water with an effective scale inhibitor amount of a soluble polymer. in water that has distributed repeated units of the formula wherein R1 is selected from the group consisting of hydrogen and alkyl of p is an integer from 1 to 10; R4 is selected from the group consisting of Cj-Cg alkyl groups, alkyl ether groups and morpholino groups; R5 and R6 are selected from the group consisting of hydrogen, carboxylate, alkyl of and a cycloalkyl group of 1 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring. Another aspect of this invention is a method for preventing scale formation on metal surfaces in contact with industrial scale forming water within an industrial system which comprises the step of treating the water with an effective scale inhibitor amount of a soluble polymer. in water that has: a) units of the formula wherein R1 is selected from the group consisting of hydrogen and alkyl of CS.-C3; p is an integer from 1 to 10; R4 is selected from the group consisting of alkyl groups of alkyl ether groups of Cj_-C6 and morpholino groups; R 5 and R 6 are selected from the group consisting of hydrogen, carboxylate, alkyl of 0, 3 and a cycloalkyl group of 1 to 6 carbon atoms formed by the attachment of R 5 and R 6 as a ring; and B) a mill unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-tert-butylacrylamide, butoxymethylacrylamide, N, N-dimethylacrylamide, acid sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof. For practicing the method described above, a useful polymer is one in which R1, R5 and R6 are hydrogen, p is 2 and R4 is a morpholino group in formula III of step A, and the units of mire of step B They are acrylic acid and acrylamide. Another example of a useful polymer is one in which R1, R5 and R6 are hydrogen, p is 2 and R4 is a morpholino group in formula III of step A and the mer units of step B are acrylic acid for the polymer soluble in water. Another additional useful polymer is one in which R1, R5 and R6 are hydrogen, p is 2 and R4 is a morpholino group in formula III of step A and the mer units of step B are acrylamide acid for the polymer soluble in Water. In addition, wherein R1, R5 and R6 are hydrogen, p ßß 3 and R4 are a methoxy group in 1 * formula III of step A: and the units of step B are acrylic acid and acrylamide; wherein R1, R5 and R6 are hydrogen, p is 3 and R4 is a methoxy group in formula III of step A; and the mer units of step B are acrylic acid; wherein R1, R5 and R6 are hydrogen, p is 3 and R4 is a methoxy group in formula III of step A; and the mer units of step B are maleic acid and acrylic acid, are all examples of applicable water-soluble polymers. The polymers described herein for the practice of this invention may vary in molecular weight from about 1,000 to about 1,000,000. Preferably, the molecular weight will be between about 5,000 and about 100,000. For the polymers defined herein, the mineral units defined by the formulas I-III will vary between 1 and 75% of the total number of polymer units in the polymer. Preferably, the units defined as formulas I-III will be 5-50% of the total number of units in the polymer. The polymer classes described herein contain amide mer units which are functionalized with linked or pendant groups. These bonded groups confer favorable polymer properties for use as scale inhibitors. The polymers can be produced by polymerization using specific monomers, such as those that can be produced by the copolymerization of acrylic acid with an N-methoxypropyl acrylamide, methoxyethoxyacrylate, methoxyethoxy oxalate or N-methoxypropyl acrylate comonomer. The polymer produced in this way can contain a hydrophilic backbone with attached groups. Alternatively, groups attached in the polymer can be introduced after the polymerization. For example, polyacrylic acid can be amidated with an ethoxylated / propoxylated amine, such as those available from Texaco under the trade name of the Jeffamine series, to produce a polymer with a hydrophilic backbone and ethyleneoxy / propyleneoxy linked groups. During the amidation process, the cyclic imide structures can be formed between two adjacent carboxylate or carboxamide units of the polymer backbone. These imide structures are not expected to have adverse effects on the performance of the polymers. Typical metal surfaces in water cooling systems which can be subjected to corrosion or scale deposition are made of stainless steel, medium steel and copper alloys such as bronze, among others.

The polymers can be effective against other types of scale including magnesium silicate, calcium sulfate, barium sulfate and calcium oxalate. Polymers are also effective in extremely hard water. The polymers can be used in conjunction with other treatments, for example biocides, other corrosion inhibitors of ferrous metals, yellow metal corrosion inhibitors, scale inhibitors, dispersants and additives. Such a combination can exert a synergistic effect in terms of corrosion inhibitors, scale inhibitors, dispersion capacity and bacteria control. Examples of biocides which can be used together with the polymers include: stabilized bleach, chlorine and hypobromite, bromine (oxidizing biocides). In addition, non-oxidizing biocides such as glutaraldehyde, isothiazolones (mixtures of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one), bleach stabilized with sulfamic acid and bromine stabilized with sulfamic acid. Additionally, polymers can be used in conjunction with other corrosion and scale inhibitors.

Therefore, the polymers can be effective in combination with other inhibitors such as acid (HEDP), 2-phosphonobutane-1, 2,4-tricarboxylic acid (PBTC), 2-hydroxyethylimine N-oxide bis (methylene phosphonic acid) ( EBO), methylene diphosphonic acid (MDP), hexamethylenediamine-N, N, N ', N' -tetra (methylene phosphonic acid), amino and tris (methylene phosphonic acid) and inorganic phosphorus-containing substances such as orthophosphates, pyrophosphates, polyphosphates; hydroxycarboxylic acids and their salts such as gluconic acids; glucaric acid; Zn2 +, Ce2 +, Mo062", W042" and nitrites. The polymers can also be used effectively together with other polymeric treatment agents, for example anionic polymers of less than 200,000 molecular weight. Such polymers include acrylic, methacrylic or maleic acid containing homopolymers, copolymers or terpolymers. Examples of yellow metal corrosion inhibitors that can be used in combination with the polymers include benzotriazole, tolyltriazole, mercaptobenzothiazole and other azole compounds. Examples of other scale inhibitors that may be used in conjunction with the polymers include polyacrylates, polymethacrylates, copolymers of acrylic acid and methacrylate, copolymers of acrylic acid and acrylamide, poly (maleic acid) copolymers of acrylic acid and maleic acid, polyesters, polyaspartic acid, functionalized polyaspartic acid, terpolymers of acrylic acid and copolymers of acrylamide / sulfonatylated acrylamide, HEDP (1-hydroxyethylidene-1, diphosphonic acid), PBTC (2-phosphonobutane-1,2,4-tricarboxylic acid), and AMP (amino tri (methylene phosphonic acid)) To treat a water cooling system, the compounds can be added to the cooling tower vessel or in any other place where a good mixing can be obtained in a short period. used in the present term "system" is defined as any industrial process which uses water. The system may contain mainly aqueous fluids, or mainly non-aqueous fluids, but it must also contain water. Such systems are found in industrial processes which use cooling water towers or boilers. For example, the food processing industry is an industry which requires such a system. The polymers can be added to the industrial fouling or corrosion-forming process water in an amount from about 0.5 ppm to about 500 ppm. Preferably, the polymers can be added in an amount from about 2 ppm to about 100 ppm. More preferably, the polymers can be added in an amount from about 5 ppm to about 50 ppm. The following examples are presented to describe the preferred embodiments and utilities of the invention and does not mean that they limit the invention, unless otherwise indicated in the claims appended hereto.

Example 1 The polymer synthesis of ammonium acrylate / N- (hydroxyethoxy) ethylacrylamide is carried out with the following reagents in the following amounts: Reagent Amount (g) Poly (AA), 25.6% by weight, in water 100.00 Aminoethoxyethanol 11.92 Ammonium hydroxide, 29% by weight 2.51 To prepare the polymer, poly (AA) (25.6 weight percent solution of poly (acrylic acid), pH = 3.8, 16,000 of P.M.) is placed in a beaker, which is cooled using an ice bath. Aminoethoxyethanol (available from Huntsman Petrochemical Co., Houston, Texas) is added dropwise to the poly (acrylic acid) / water solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. Aqueous caustic is added to adjust the pH to about 5. Subsequently the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then slowly heated to 160 ° C (or less as the case may be) and kept at this temperature for 8 hours (or more, as the case may be). Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR.

The content of N- (hydroxyethoxy) ethylacrylamide is 21 mol%, based on the total moles of the polymer units, which represents the secondary amide and imide units. The molecular weight of the polymer is 24,000.

Example 2 The synthesis of a terpolymer of ammonium acrylate / acrylamide / N- (hydroxyethoxy) ethylacrylamide is carried out in the following manner, with the reagents in the amounts indicated below: Reagent Amount (g) Poly (NH4AA / AcAm), polymer solution 50/50% moles, 38.2% by weight 300.00 Aminoethoxyethanol 114.00 To prepare the polymer, poly (NH4AA (AcAm) (50/50 mol% ammonium acrylate / acrylamide copolymer, 38. 2 percent by weight, pH = 5.5, 33,000 of P.M.) is placed in a beaker, which is cooled using an ice bath. Aminoethoxyethanol (available from Huntsman Petrochemical Co., Houston, Texas) is added dropwise to the above water solution, vigorous stirring (pH = 10.1). Subsequently, the solution is stirred for another 15 minutes. Then, the reaction mixture is transferred to a 600 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 14 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N- (hydroxyethoxy) ethylacrylamide is 33.3 mol%, based on the total moles of the polymer units in the polymer. The molecular weight of the polymer is 35,000 and a molar ratio of N- (hydroxyethoxy) ethylacrylamide / acrylic acid / acrylamide of about 33/41/26.

Example 3 The synthesis of a sodium acrylate / acrylamide / N- (hydroxyethoxy) ethylacrylamide terpolymer is carried out in the following manner, with the reagents in the amounts indicated below: Reagent Amount (g) Poly (NaAA / AcAm), polymer solution 50/50 mol%, 32.0% by weight 100.00 Aminoethoxyethanol 32.00 Sulfuric acid (95%) 11.5 To prepare the polymer, poly (NaAA (AcAm) (copolymer 50/50 mole% sodium acrylate / acrylamide, 32.0 weight percent, pH = 5.2, 11,000 MW) is placed in a beaker, which is cool down using an ice bath Aminoethoxyethanol (available from Huntsman Petrochemical Co., Houston, Texas) is added in the above water solution, with vigorous agitation. Subsequently, the solution is stirred for another 15 minutes. Sulfuric acid is added to use the pH at approximately 5.6. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 12 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N- (hydroxyethoxy) ethylacrylamide is 33 mol%, based on the total moles of the polymer units in the polymer. The molecular ratio is approximately 42/22/33 acrylic acid / acrylamide (which includes the 3% imide mineral units) / N- (hydroxyethoxy) -ethylacrylamide (which includes the imide mineral units). The product polymer has a molecular weight of 12,000.

Example 4 The synthesis of a sodium acrylate / acrylamide / N-methoxypropyl acrylamide terpolymer is carried out in the following manner, with the reagents in the amounts indicated below: Reagent Amount (g) Poly (NaAA / AcAm), polymer solution 50/50 mol%, 32.0% by weight 100.00 Methoxypropylamine 23.32 Sulfuric acid (95%) 11.23 To prepare the polymer, poly (NaAA (AcAm) (50/50 mol%, 32.0% by weight, pH = 5.2, 11,000 MW) is placed in a beaker, which is cooled using an ice bath. drop methoxypropylamine (available from Aldrich Chemical Co., Milwaukee, Wl) into the above water solution with vigorous stirring, then stir the solution for another 15 minutes, sulfuric acid is added to adjust the pH to approximately 5.6 Thereafter, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi).

Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 12 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N-methoxypropyl acrylamide is 34.2 mol%, based on the total moles of the polymer units in the polymer. The molecular ratio of the product is about 41/17/34 which represents acrylic acid / acrylamide (which includes 6% imide mineral units) / methoxypropyl acrylamide (which includes the imide mineral units). The molecular weight of the product is 11,000.

Example 5 The synthesis of a sodium acrylate / acrylamide / N-hydroxy (ethylamino) -ethylacrylamide terpolymer is carried out in the following manner, with the reagents in the amounts indicated below: REAGENT QUANTITY (g) Poly (NaAA / AcAm), polymer solution 50/50 mol%, 24.0% by weight 80.00 (Aminoethylamino) ethanol 19.02 Sulfuric acid (95%) 12.23 To prepare the polymer, poly (NaAA (AcAm) (50/50 mol% 24.0% by weight, pH = 3.5, 15,000 PM) is placed in a beaker, which is cooled using an ice bath. dropwise (aminoethylamino) ethanol (available from Aldrich Chemical Co., Milwaukee, Wl) in the above aqueous solution, with vigorous stirring, then the solution is stirred for another 15 minutes.Sulfuric acid is added to adjust the pH to about 5.6 Then the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi), then the reactor is assembled and purged with nitrogen for about 60 minutes. Subsequently, the Parr reactor is heated slowly to 138 ° C and maintained at this temperature for 14 hours, after which the reactor is cooled to room temperature and the pressure is released, the product is subsequently transferred for storage. The product is confirmed by 13 C NMR. The content of N-hydroxy (ethylamino) ethylacrylamide is 46 mol%, based on the total moles of polymer units in the polymer, which represent the secondary amide and imide mineral units. The molecular proportion of the product is about 46/51/3 of N-hydroxy (ethylamino) ethylacrylamide / acrylic acid / acrylamide. The product polymer has a molecular weight of 15,000.

Example 6 The synthesis of a terpolymer of acrylic acid / acrylamide / N- (hydroxyethoxy) ethylacrylamide is carried out in the following manner, with the reagents in the amounts indicated below: Reagent Amount (a) Poly (AcAm), 50% by weight 50.00 Aminoethoxyethanol 12.9 Deionized water 50.0 Sulfuric acid (95%) 6.1 To prepare the polymer, poly (AcAm) is placed (50% by weight, available from Aldrich Chemical Co., 10,000 P.M.) in a beaker, which is cooled using an ice bath. Aminoethoxyethanol (available from Huntsman Petrochemical Co., in Houston, Texas) is added dropwise in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. Sulfuric acid is added to adjust the pH to approximately 5.6. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 14 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR.

The content of N- (hydroxyethoxy) ethylacrylamide is 19.6 mole%, based on the total moles of the polymer units in the polymer. The molar proportion of the product is approximately 32/44/20 which represents acrylic acid / acrylamide / N- (hydroxyethoxy) ethylacrylamide.

Example 7 The synthesis of the ammonium acrylate / N-methoxypropyl acrylamide copolymer is carried out in the following manner, with the reagents in the amounts indicated below: To prepare the polymer, poly (AA) is placed (32.0% by weight, pH = 3.3, 15,000 of P.M.) in a beaker, which is cooled using an ice bath.

Drops methoxypropylamine (available from Aldrich) Chem. Co., in Milwaukee, Wl) in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. Aqueous caustic is added to adjust the pH to about 5. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). The reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 160 ° C and maintained at this temperature for 8 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N-methoxypropyl acrylamide is 22.4 mol%, based on the total moles of the polymer units, which represents both amide and imide units. The molecular weight of the polymer is 15,000.

Example 8 The synthesis of the acrylic acid / acrylamide / N-methoxypropyl acrylamide terpolymer is carried out in the following manner, with the reagents in the amounts indicated below: To prepare the polymer, poly (AcAm) is placed (50.0% by weight, available from Aldrich Chemical, Co., 10,000 P.M.) in a beaker, which is cooled using an ice bath. Methoxypropylamine (available from Aldrich Chemical Co., in Milwaukee, Wl) in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred during others minutes. Aqueous caustic is added to adjust the pH to approximately 5.6. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 12 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N-methoxypropyl acrylamide is 20.3 mol%, based on the total moles of the polymer units, which represents both the secondary amide and imide units. The molar ratio of the product is approximately 33.8 / 45/20 which represents acrylic acid / acrylamide / N- (methoxypropyl) acrylamide. The molecular weight of the polymer is 18,500.

Example 9 The synthesis of a terpolymer of acrylic acid / acrylamide / N-methoxyethylacrylamide is carried out in the following manner, with the reagents in the amounts indicated below: To prepare the polymer, poly (A / AcAm) (31.4% by weight, 11,000 of P.M.) is placed in a beaker, which is cooled using an ice bath. Methoxyethylamine (available from Aldrich Chemical Co., Milwaukee, Wl) is added dropwise in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. The pH of the reaction mixture is measured using pH strips moistened in water. Aqueous caustic is added to adjust the pH to approximately 5.6. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 12 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N-methoxypropylacrylamide is 40.8 mole%, based on the total moles of the polymer units, which represents both secondary amide and imide units. The molar ratio of the product is about 40/14/41 which represents acrylic acid / acrylamide / N- (methoxypropyl) acrylamide. The molecular weight of the polymer is 11,000.

Example 10 The synthesis of a sodium acrylate / acrylamide / N-alkoxylated acrylamide copolymer is carried out in the following manner, with the reagents in the amounts indicated below: To prepare the polymer, poly (A / AcAm) is placed (43.8% by weight, pH = 4.0, 18,000 of P.M.) in a beaker, which is cooled using an ice bath. Jeffamine M-1000 (available from Texaco Chemical Co.) is added dropwise in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. Aqueous caustic is added to adjust the pH to approximately 6.9. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Then the reactor is assembled and purged with nitrogen for about 60 minutes. The Parr reactor is then heated slowly to 150 ° C and maintained at this temperature for 5 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage.

Example 11 The synthesis of a sodium acrylate / N-hydroxy (ethylamino) ethylacrylamide terpolymer is carried out in the following manner, with the reagents in the amounts indicated below: Reagent Amount (g) Poly (AA), 27.0% by weight, in water 100.00 (Aminoethylamino) ethanol 12.89 Sulfuric acid (95%) 0.6 To prepare the polymer, poly (A A) (27.0% by weight, pH = 3.4, 17,000 of P.M.) is placed in a beaker, which is cooled using an ice bath.

It is added dropwise (aminoethylamino) ethanol (available from Aldrich Chem. Co., in Milwaukee, Wl) in the above aqueous solution, with vigorous stirring. Subsequently, the solution is stirred for another 15 minutes. Sulfuric acid is added to adjust the pH to approximately 5.6. Then, the reaction mixture is transferred to a 300 ml Parr reactor with a nominal pressure of at least 56 kg / cm2 (800 psi). Subsequently, the reactor is assembled and purged with nitrogen for approximately 60 minutes. The Parr reactor is then heated slowly to 138 ° C and maintained at this temperature for 14 hours. Subsequently, the reactor is cooled to room temperature and the pressure is released. The product is subsequently transferred for storage. The formation of the product is confirmed by 13 C NMR. The content of N-hydroxy (ethylamino) ethylacrylamide is 30 mol%, based on the total moles of polymer units in the polymer, which represent both amide and secondary imide units. The molar ratio of the product is approximately 70/30 which represents acrylic acid / N- (hydroxyethylamino) ethylacrylamide. The molecular weight of the polymer product is 32,000.

Example 12 The activity of the polymers for inhibition of calcium phosphate incrustation was evaluated in the following manner.

A concentrated acid solution is prepared which contains calcium chloride, magnesium sulfate and phosphoric acid. The aliquots of this concentrated solution are transferred to flasks so that upon dilution, the final calcium concentration is 750 to 1500 ppm as CaCO3. Iron or aluminum is added in tests of Ca of 750 ppm. The appropriate volume of inhibitor is added to provide 20 ppm of polymer for the tests of Ca at 1500 ppm, 25 ppm of polymer for the iron tests and 30 ppm of polymer for the aluminum tests. DI water is added, and the flasks are heated to 70 ° C in a water bath. Stirring is maintained at 250 rpm with stirring bars of 2.54 cm (1") .After the solutions are at temperature, the pH is adjusted to 8.5.The pH is frequently checked to maintain it at 8.5. They are taken after 4 hours, then 100 ml of solution are taken and boiled for 10 minutes in a covered flask, the volume is brought back to 100 ml with DI water, and the filtered samples are taken again. standard determines the concentration of orthophosphate in the samples.The percent of phosphate is reported as 100 * P (filtered) / P (not filtered) .When no polymer is added, 4.6% filterable phosphate is added.

Percent inhibition numbers greater than 80% indicate exceptional dispersing activity. The polymers which disperse the phosphate in this test are observed to avoid calcium phosphate incrustation in recirculating cooling water systems under similar high voltage conditions. Numbers less than about 40% indicate poor dispersing activity. Such polymers may or may not work under more moderate conditions (softer cooling water) but allow scaling to form under high voltage conditions. Polymers with intermediate activity are good dispersants for low voltage conditions, but will lose activity at higher voltages.

TABLE I Calcium phosphate dispersion test - high voltage conditions 1 - . 1 - treatm ento 1, p AAAcAm your ona 2 = polymer prepared according to the procedure similar to example 10; 10/40/50 molar ratio of Jeffamine / AA / cAm, 60,000 of P.M. 3 = polymer prepared according to a procedure similar to example 10, molar ratio 20/40/40 of Jeffamine / AA / AcAm, 10,000 of P.M. 4 = polymer prepared according to a procedure similar to example 10, molar ratio 40/40/20 of Jeffamine / AA / AcAm, 20,000 of P.M. 5 = polymer prepared according to a procedure similar to example 3. 6 = polymer prepared according to a procedure similar to example 1. 7 = polymer prepared according to a procedure similar to example 2; molar ratio of 33/41/26 of EEE / AA / AcArn. 8 = polymer prepared according to a procedure similar to example 4; molar ratio 34/41/17 of MOPA / AA / AcAm 9 = polymer prepared according to a procedure similar to example 5; molar ratio of 51/46/3 of AA / AEAE / AcAm 10 = polymer prepared according to a similar procedure to Example 9. 11 = conventional treatment 2. p (AA / AcAm) available from Nalco Chemical Co., Naperville, IL.

Example 13 The following test procedure was used with respect to the dispersion capacity to obtain the results shown in Table II. Prepare 200 ml of a test solution containing 20 ppm of a polymer dispersant and 20 ppm of PBTC dissolved in distilled water. Subsequently, the test solution is added to a 250 ml Erlenmeyer flask with magnetic stirring at 40 ° C. Hardness and m-alkalinity are added to the solution for seven minutes to obtain a final solution composition (ppm as Ca C03) of 700 ppm Ca2 +, 350 ppm of Mg2 + and 700 ppm of C032. "As the calcium carbonate precipitation proceeds, the particle monitoring responds to the fraction of calcium carbonate particles greater than 0.5 micrometers in diameter. calcium carbonate, lower is the agglomerate fraction of large particles.The test solutions that work best are indicated by (1) minor particle monitoring intensities, and (2) maximum intensity reached in longer times (60 minute limit). Examples 1 and 7 are the dispersants that work best to avoid the agglomeration of calcium carbonate particle evidenced by: (1) the smallest particle monitoring intensity and (2) that requires longer times to get your response maximum of the signal Traditional dispersants (polyacrylic acid) provide improved dispersion capacity on the target, but they do not work also like the mentioned examples.

TABLE II 1 = 20 ppm of PBTC 2 = polymer prepared according to "the procedure of Example 1. 3 = polymer prepared according to the procedure of Example 7. Changes can be made in the composition, operation and arrangement of the method of the present invention , described herein, without departing from the concept and scope of the invention as defined in the following claims.It is noted that in relation to this date, the best method known by the applicant to carry out the practice mentioned, is the conventional for the manuf ß ^ ra of the objects to which it refers The invention having been described as above, is claimed as property contained in the following:

Claims (26)

1. A method for preventing the formation of scale on metal surfaces in contact with industrial scale-forming water within an industrial system, the method is characterized in that it comprises the step of treating the water with an effective scale-inhibiting amount of a water-soluble polymer. that has distributed repeated mineral units, represented by the formula wherein R1 is selected from the group consisting of hydrogen and alkyl of p and q are integers of 1 to 10; R2 and R3 are selected from the group consisting of hydrogen and alkyl of Cj.-C3; Het1 and Het2 are selected from the group consisting of oxygen and nitrogen; R 4 is selected from the group consisting of hydrogen and C-L-Ca alkyl; R5 and R6 are selected from the group consisting of hydrogen, carboxylate, alkyl of -C-, and a cycloalkyl group of 3 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring.

The method according to claim 1, characterized in that it further comprises a mill unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-terbutylacrylamide , butoxymethylacrylamide, N, N-dimethylacrylamide, sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof.

3. The method according to any of claims 1 or 2, characterized in that the industrial water is cooling water.

The method according to any of claims 1 or 2, characterized in that the scale is selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, calcium sulfate, sulfate of barium, clay, sediment or silt, magnesium carbonate, magnesium phosphate and calcium carbonate.

The method according to claim 3, characterized in that the cooling water contains treatment chemicals that are selected from biocides, corrosion inhibitors and other scale inhibitors.

The method according to claim 3, characterized in that the industrial water is industrial process water that is selected from the group consisting of mining processing water, pulp and paper processing water and oilfield processing water.

7. The method according to claim 2, characterized in that p = 1; q = 1; R1, R2, R3, R4, R5 and R6 are hydrogen; and Het1 and Het2 are oxygen in formula I; and the mineral units are selected from acrylic acid and acrylamide or mixtures thereof for the water soluble polymer; maleic acid and acrylic acid for the water soluble polymer; or p = 1, q = 1, Het1 is nitrogen, Het2 is oxygen and R1, R2, R3, R4, R5 and R6 are hydrogen in the formula I; and the mer units are acrylic acid and acrylamide for the water soluble polymer, or p = 1; q = 1, Het1 is nitrogen, Het2 is oxygen and R1, R2, R3, R4, R5 and R6 are hydrogen in the formula I; and the mer units are acrylic acid for the water soluble polymer, or p = 1; q = 1, Het1 is nitrogen, Het2 is oxygen and R1, R2, R3, R4, R5 and R6 are hydrogen in the formula I; and the mer units are maleic acid and acrylic acid for the water soluble polymer.

8. A method for preventing the formation of scale on metal surfaces in contact with industrial scale-forming water within an industrial system, the method is characterized in that it comprises the step of treating the water with an effective inhibiting amount of a soluble polymer scale. in water that has distributed repeated units of the formula wherein R1 is selected from the group consisting of hydrogen and alkyl groups of p is an integer from 0 to 50; R2 is selected from the group consisting of hydrogen and C3-C20 alkyl groups; R5 and R6 are selected from groups consisting of hydrogen, carboxylates, alkyl groups of ^^ 3 and a cycloalkyl group of 3 to 6 carbon atoms formed by the union of R5 and R6 as a ring, with the proviso that, when p is 0, R2 is not hydrogen.

The method according to claim 10, characterized in that it also contains a mill unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-tert-butylacrylamide , butoxymethylacrylamide, N, N-dimethylacrylamide, sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof.

10. The method according to any of claims 8 or 9, characterized in that the industrial water is cooling water.

The method according to claim 8, characterized in that the scale is selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, calcium sulfate, barium sulfate, clay , sediment or silt, magnesium phosphate, magnesium carbonate and calcium carbonate.

The method according to claim 10, characterized in that the cooling water contains treatment chemicals that are selected from biocides, corrosion inhibitors and other scale inhibitors.

The method according to claim 8, characterized in that the industrial water is industrial process water which is selected from the group consisting of mining processing water, pulp and paper processing water and oilfield processing water.

The method according to claim 11, characterized in that when p is an integer from 10 to 25, R1 is selected from the group consisting of hydrogen and methyl groups, R2 is a methyl group, R5 is hydrogen and R6 is hydrogen , and the units are acrylic acid, or when p is an integer from 10 to 25, R1 is selected from the group consisting of hydrogen and methyl groups, R2 is a methyl group, R5 is hydrogen and R6 is hydrogen, and units are acrylic acid and acrylamide, or when p is an integer from 10 to 25, R1 is selected from the group consisting of hydrogen and methyl groups, R2 is a methyl group, R5 is hydrogen and R6 is hydrogen, and the units Meric acids are maleic acid and acrylic acid.

The method according to claim 11, characterized in that the scale is selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, calcium sulfate, barium sulfate, clay , sediment or silt, magnesium phosphate, magnesium carbonate and calcium carbonate.

The method according to claim 9, characterized in that the industrial water is industrial process water which is selected from the group consisting of mining processing water, pulp and paper processing water, and oilfield processing water.

17. A method for preventing the formation of scale on metal surfaces in contact with industrial scale-forming water within an industrial system, the method is characterized in that it comprises the step of treating the water with an effective inhibiting amount of scale of a polymer. soluble in water containing distributed multiple units of the formula wherein R 1 is selected from the group consisting of hydrogen and C 1 -C 6 alkyl, - p is an integer from 1 to 10; R 4 is selected from the group consisting of alkyl groups of alkyl ether groups of and morpholino groups; R5 and R6 are selected from the group consisting of hydrogen, carboxylate, alkyl of and a cycloalkyl group of 1 to 6 carbon atoms formed by the attachment of R5 and R6 as a ring.

The method according to claim 17, characterized in that it further comprises a mill unit selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, itaconic acid, vinylsulfonic acid, styrene sulfonate, N-tert-butylacrylamide , butoxymethylacrylamide, N, N-dimethylacrylamide, sodium acrylamidomethylpropanesulfonic acid, vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, maleic acid and combinations thereof.

19. The method according to any of claims 17 or 8, characterized in that the industrial water is cooling water.

The method according to claim 17, characterized in that the scale is selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, barium sulfate, clay, sediment or silt. , magnesium phosphate, magnesium carbonate and calcium carbonate.

The method according to claim 19, characterized in that the cooling water contains other treatments that are selected from biocides, corrosion inhibitors and other scale inhibitors.

The method according to claim 17, characterized in that the industrial water is industrial process water which is selected from the group consisting of mining processing water, pulp and paper processing water, and oilfield processing water.

23. The method according to claim 18, characterized in that the scale is selected from the group consisting of calcium phosphate, zinc phosphate, (hydr) iron oxide, aluminum hydroxide, barium sulfate, clay, sediment or silt, phosphate of magnesium, magnesium carbonate and calcium carbonate.

24. The method according to claim 19, characterized in that the cooling water contains treatment chemicals that are selected from biocides, corrosion inhibitors and other scale inhibitors.

25. The method according to claim 18, characterized in that the industrial water is industrial process water which is selected from the group consisting of mining processing water, - pulp and paper processing water, and oilfield processing water. .

26. The method according to claim 18, characterized in that R1, R5 and R6 are hydrogen, p is 2 and R4 is a morpholino group in the formula III; and the mer units are acrylic acid and acrylamide for the water-soluble polymer, or when R1, Rs and R6 are hydrogen, p is 2 and R4 is a morpholino group in formula III; and the faecal units are acrylic acid for the water-soluble polymer, wherein R1 and R6 are hydrogen, p is 2 and R4 is a morpholino group in formula III; and the mer units are acrylic acid and maleic acid for the water-soluble polymer, or when R1, R5 and R6 are hydrogen, p is 3 and R4 is a methoxy group in the formula III; and the acrylic acid and acrylamide acidic units for the water soluble polymer, or when R1, R5 and R6 are hydrogen, p is 3 and R4 is a methoxy group in the formula III; and the mer units are acrylic acid for the water soluble polymer, or when R1, R5 and R6 are hydrogen, p is 3 and R4 is a methoxy group in the formula III; and the mer units are maleic acid and acrylic acid for the water soluble polymer.