NZ207345A - Scale and corrosion inhibiting mixtures - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £07345 207345 Priority Date(s): .7.(CWTSf^ Complete Specification Filed: ^ .rDoT.^^. Class: .co^p.5>.|.iQ,i?-.,a,- ..CQft3P.itt-.lQ?!- Publication Oate: ... 5 P.O. Journal, No: AM 5 NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION SYNERGISTIC SCALE AND CORROSION INHIBITING ADMIXTURES CONTAINING CARBOXYLIC ACID/SULFONIC ACID POLYMERS X / We, CALGON CORPORATION, a corporation duly organized and existing under the laws of the State of Delaware, United States of America, of Route 60-Campbell's Run Road, Robinson Township, State of Pennsylvania, United States of America, hereby declare the invention for which W we pray that a patent maybe granted toaH0£/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- 1 (followed by la) y ZU/J43 "SYNERGISTIC SCALE AND CORROSION INHIBITING ADMIXTURES CONTAINING CARBOXYLIC ACID/ SULFONIC ACID POLYMERS" Background of the Invention U.S. Patent 3,928,196 discloses the use of a 5 copolymer of -2-acrylamido-2-methylpropylsulfonic acid and acrylic acid in inhibiting scale. The instant invention is directed to a synergistic admixture of a water-soluble polymer comprising a carboxylic acid and a sulfonic acid or their salts, 1° including the copolymer of U.S. Patent 3,928,196, in combination with at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphorates, phosphates, polyphosphates, metal salts and sulfonates.

Most industrial waters contain alkaline earth metal cations, such as calcium, barium, magnesium, etc. and several anions such as bicarbonate, carbonate, sulfate, oxalate, phosphate, silicate, fluoride, etc. When combinations of these anions and cations are present in concentrations which exceed the solubility of their reaction products, precipitates form until these product solubility concentrations are no longer exceeded. For example, when the concentrations of calcium ion and carbonate ion exceed the solubility of the ^calcium carbonate reaction products, a solid phase of calcium carbonate will form.

Solubility product concentrations are exceeded for various reasons, such as partial evaporation of the water phase, change in pH, pressure or temperature, and the introduction of additional ions which form insoluble compounds with the ions already present in the solution.

As these reaction products precipitate on surfaces of the water carrying system, they form scale or deposits. This accumulation prevents effective heat transfer, interferes with fluid flow, facilitates corrosive processes, and harbors bacteria. This scale is an expensive problem in many industrial water systems causing delays and shutdowns for cleaning and removal.

Scale-forming compounds can be prevented from precipitating by inactivating their cations with chelating or sequestering agents, so that the solubility of their reaction products is not exceeded. Generally, this requires as much chelating or sequestering agent as cation, since chelation is a stoichiometric reaction, and these amounts are not always desirable or economical. 207345 Almost 50 years ago, it was discovered that certain inorganic polyphosphates would prevent such precipitation when added in amounts far less than the concentrations needed for sequestering or 5 chelating. By polyphosphates, we mean phosphates having a molar ratio of metal oxide5p2°5 between 1:1 and 2:1. —-x ^ When a precipitation inhibitor is present in a potentially scale-forming system at a markedly lower 10 concentration than that required for sequestering (stoichiometric) the scale-forming cation, it is ^ said to be present in "threshold" amounts. See for — example. Hatch and Rice, "Industrial Engineering Chemistry", Vol. 31, pages 51 to 53 (Jan. 1939); 15 Reitemeier and Buehrer, "Journal of Physical Chemistry", Vol. 44, No. 5, pages 535 to 536 (May 1940); Fink and Richardson, U.S. Patent 2,358,222; and Hatch, U.S. Patent 2,539,305.

Generally, sequestering takes place at a weight 20 ratio of threshold active compound greater than scale-forming cation components. Threshold inhibition generally takes place at a weight ratio of threshold active compound to scale-forming cation components of less than about 0.5:1.0.

Certain water soluble polymers, including groups derived from acrylamide and acrylic acid have been used to condition water containing scale-forming compounds. As for example, see U.S. Patents 2,783,200; 3,514,476; 2,980,610; 3,285,886; 30 3,463,730 and 3,518,204. £. sj* Description of the Invention The instant invention is directed to an admixture comprising: (a) a water-soluble polymer having a weight average malecular weight of less than 2^5,000, a^dfc^erminjed by loW ^ngl^ laser; light scattering, comprising an unsaturated rtiono-carboxylic acid ^nd an 10 unsaturated sulfonic ^cid selected- from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-mpthylpropyl-sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxy-propyl 20 sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof,, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from 25 the group consisting of water-soluble polycarboxylates, phosphonates, organic phosphates, organic polyphosphates, metal salts and sulfonates.

The instant invention is also directed to a method of inhibiting the precipitation of scale-forming salts in an agueous system, comprising 207345 -5- Cki35€J^ adding to the,system at least 0.1 mg/1 of an admixture oft (a) a water-soluble polymer having a weight average molecular weight of 5 loss th^n 2^^000, as determine^ by low angle laser light scattering, >otoirtprising a«i unsaturated ""l carboxylftc acid selected from the group consisting of acrylic acid, 1° methacrylic acid, a-halo acrylic acidr maleic acid or anhydride, itaconic acid or anhydride, vinyl ^ acetic acid, allyl acetic acid, '■w fumaric-acid, fi-carboxyethyl 15 acrylate/ their salts, and mixtures thereof, and an unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 20 2-methacrylamido-2-methylpropyl- sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 25 3-methacrylamido-2-hydroxy-propyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphonates, phosphates, polyphosphates, metal salts and 35 sulfonates. 207345 The instant invention is also directed to a method of inhibiting the corrosion of metal in an aqueous system comprisng adding to the system at least 0.1 mg/1 of an admixture of: (a) a water-soluble polymer having a weight average molecular weight of l^ss than 25,000, as determined by low angle laser lig£t scatter jjig, comprising an unsaturated mono-carboxylic acid and an unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl-sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxy-propyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphorates, organic phosphates, organic polyphosphates, metal salts and sulfonates.

The instant invention is also directed to a method of inhibiting the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an ^queous system, comprising adding to the system at least 0.1 mg/1 of a water-soluble polymer having a weight average molecular weight of less than 25^000, as determii^d by low angle laser ^Light scattering,"comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a weight ratio of 1:20 to 20:1 and a phosphonate.

The phrase "inhibiting the precipitation" is meant to include threshold inhibition, dispersion, solubilization, or particle size reduction.

The phrase "scale-forming salts" is meant to include any of the scale-forming salts, including, but not limited to, calcium carbonate, calcium sulfate, calcium phosphate, calcium phosphonate (including calcium hydroxyethylidene diphosphonic acid), calcium oxalate, calcium fluoride, barium sulfate and magnesium salts.

The phrase "aqueous system" is meant to include any system containing water? including, but not limited to, cooling water, boiler water, desalination, gas scrubbers, blast furnaces, sewage sludge thermal conditioning equipment, reverse osmosis, sugar evaporators, paper processing, mining circuits and the like.

The carboxylic acid/sulfonic acid polymer was also found to be effective in inhibiting insoluble alluvial deposition, metal oxide and metal hydroxide deposition, especially in combination with a phosphonate. Alluvial deposits include silts; clays; particulate material extracted from the air. dcWiA' such as dust; and the like. Any metal oxide or metal hydroxide may be used. Examples of metal oxides are iron oxide and chromus oxide. An example of a metal hydroxide is zinc hydroxide.

Any unsaturated carboxylic acid or its salt may be used to prepare the polymer (a). Examples include acrylic acid/ methacrylic acid, a-halo acrylic acid, maleic acid, itaconic acid/ vinyl acetic acid, allyl acetic acid, fumaric acid, B-carboxyethyl acrylate, their salts and mixturess thereof. The preferred carboxylic acids are acrylic ac: d methacrylic acid.

Any unsaturated sulfonic acid or its salt may be used in producing the polymer (a). Examples include 2-acrylamido-2-n»ethylpropylsulfonic acid, 2-methacrylamido-2-methylpropylsulfonic acid, vinyl sulfonic acid, sulfo alkyl acrylate or methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxy propyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof. The preferred sulfonic acid is 2-acrylamido-2-methylpropylsulfonic acid.

Polymer (a) may be prepared from more than two monomers. Monomers other than carboxylic and sulfonic acids or their salts may be present in the polymer. Mixtures of the polymers may be used.

The weight ratio of carboxylic acid to sulfonic acid should be 1:20 to 20:1, preferably 1:10 to 10:1, most preferably 4:1 to 1:4.

Any water-soluble polycarboxylate may be used as component (b). Examples include polymers derived from homo- and/or copolymers (including terpolymers, CteT>56Tfcr tetra-, etc.) of acrylic acid, methacrylic acid, vinyl acetic acid, allyl acetic acid, fumaric acid, phosphinocarboxylic acid, maleic acid or anhydride, itaconic acid, a-halo acrylic acid and B-carboxyethyl acrylate.

Any water-soluble phosphonate may be used as component (b). Examples include 2-phosphono-l ,2,4-tricarboxybutane, amino tri(methylene phosphonic acid), hydroxyethylidene diphosphonic acid, phosphonosuccinic acid, benzene phosphonic acid, 2-aminoethyl phosphonic acid, polyamino phosphonates and the like. Additional phosphonates are identified in U.S. Patent 3,837,803, which is hereby incorporated by reference. The preferred phosphonates are 2-phosphono-l,2,4-tricarboxybutane, amino tri(methylene phosphonic acid) and hydroxyethylidene diphosphonic acid.

Any water-soluble phosphate may be used as component (b). Examples include orthophosphate; condensed phosphates, such as sodium hexametaphosphate; phosphate esters; organophosphate esters, such as the lower alkyl mono-, di- and trialkyl phosphates. The alkyl group is selected from to C4 and may be branched or unbranched. The alkyl group may be substituted with hydroxy, amino, halide, sulfate or sulfonate, alone or in combination; and molecularly dehydrated phosphates.

Any water-soluble metal salt may be used as component (b). Examples include water-soluble salts of zinc, molybdenum, chromate and sodium silicate and mixtures thereof. The combination of zinc and 2 ""7345 - 10 - Vg/Tr3^6^ chromate were found especially effective. The polymer stabilizes the zinc ion and prevents its precipitation at high pH.

Any water-soluble sulfonate-containing polymer may be used as component (b). Examples include homo- and/or copolymers of 2-acrylamido-2-methylpropylsulfonic acid, 2-methacrylamido-2-methylpropylsulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, sulfo alkyl acrylate or methacrylate, allyl or methallyl sulfonic acid, sulfonic acid acrylate, 3-methacrylamido-2-hydroxy propyl sulfonic acid, their salts and mixtures thereof.

It is possible that the carboxylic acid, from which the polycarboxylate used as component (b) is prepared, is the same carboxylic acid used to prepare the polymer of component (a). However, the carboxylic acid used to prepare component (b) is not polymerized with the same sulfonic acid as (a). The same is true with regards to the sulfonate.

The weight ratio of component (a) to component (b) is preferably 1:50 to 50:1, more preferably 1:10 to 10:1.

It is preferred that component (a) be a copolymer.

The carboxylic acid/sulfonic acid polymer was found, in addition, to enhance the effectiveness of the water-soluble polycarboxylates, phosphonates, polyphosphates, phosphates, metal salts and sulfonates. 207345 Calcium phosphate scale is a particular problem at a pH of 7 to 9. The admixtures of the instant invention were surprisingly found to be effective at a pH 7 to 9 and at temperatures ranging from 0 to 80°C. The admixtures of the instant invention are, of course, effective over a broad pH range (e.g. less than 7 and to some extent, greater than 9) * The admixture is used at a minimum dosage of 0.1 10 mg/1 in inhibiting scale and corrosion, preferably in a dosage of 1 to 100 mg/1, most preferably 1 to ^ 15 mg/1. o It is preferred that component (a) have a weight average molecular weight of less than 25,000, 15 preferably less than 15,000, most preferably less than 10,000, as determined by low angle laser light scattering.

The admixture was found to be synergistic in that the admixture inhibited scale and corrosion to 20 a greater extent than expected.

Examples The following abbreviations and product names are used in the Examples and are defined as indicated: AA/AMPS = copolymer of acrylic acid and 2-acrylamido-2-methylpropyl sulfonic acid having a weight average molecular weight of about 8200, as determined by low angle laser light scattering.

CL361S = an aqueous solution of alkyl phenoxy poly(ethyleneoxy) ethanols and propylene oxide terminated ethylene oxide adduct, available from Calgon Corporation.

PMA = polymaleic acid, MWT = 1300, as determined by light scattering, 70 percent active.

HEDP = hydroxyethylidene diphosphonic acid.

PBS-AM = 2-phosphono-l,2,4-tricarboxybutane, manufactured by Mobay Chemical Corporation.

Natrol 42 = a solution of a 60/40 copolymer of acrylic acid and 2-hydroxypropyl acrylate, manufactured by National Starch Corporation.

Belclene 500 = phosphinocarboxylic acid, manufactured by Ciba Geigy.

Versa TL-3 = copolymer of maleic anhydride and sulfonated styrene, manufactured by National Starch Corporation.

Versa TL-70 = sulfonated polystyrene, manufactured by National Starch Corporation.

PAA = polyacrylic acid, MWT 4700, as determined by light scattering.

PolyAMPS = polyacrylamido methyl propyl sulfonic acid.

AMP = amino tri(methylene phosphonic acid). 207345 - 13 - ctOSTWA- Zn++ = zinc ion added as zinc dissolved in hydrochloric acid. The concentration reported is solely zinc ion. -2 CrOg = chromate ion added as potassium dichromate. The concentration reported is solely chromate ion.

P-35 = copolymer of 40 percent acrylamide and 60 percent acrylate, MWT 7500, manufactured by American Cyanamid.

PolyDMDAAC = polydimethyldiallyl ammonium chloridef MWT 130,000, as determined by light scattering. -2 MoO^ = molybdate ion added as sodium molybdate. The concentration reported is solely molybdate ion. -3 PO^ = phosphate ion added as potassium dihydrogen phosphate. The concentration reported is solely phosphate ion.

AA/AS = copolymer of acrylic acid and allyl sulfonic acid.

Examples 1 through 65: Synergism between copolymers of carboxylic acids and sulfonic acids and other building blocks were screened for threshold inhibition of calcium carbonate, calcium sulfate and calcium phosphate. Stagnant flask tests were used with solutions stored for 24 hours at constant temperature. The standard test conditions used were as follows: % J e O # 3 Calcium, mg/1 Bicarbonate, mg/1 Sulfate, mg/1 Phosphate, mg/1 pH Temperature,°C Calcium Carbonate 200 600 8.0-8.2 65 Calcium Sulfate 2000 4800 ?.0 65 Calcium Phosphate 200 4 8.5 60 Four flasks were used for each test; one for a 10 control (no inhibitor), one with the copolymer alone, one with the other inhibitor alone, and the last with both inhibitors. For all inhibitors, a level of inhibitor was picked which by itself would give 0 to 50 percent inhibition as determined by the 15 following equation: Percent Inhibition = St - s( si - s( x 100 where: Sj = level of test specie initially? S = c test; and S test.

S = level of test specie at end of control c ST = level of test specie at end of inhibitor Calcium was used as the test specie in the 25 calcium carbonate and calcium sulfate tests, and phosphate was the test specie in the calcium phosphate test. Synergism was determined by comparing the percent inhibition obtained using both inhibitors, each at the same level as used alone. 207345 - 15 - ^1^5 with the sum of the inhibition obtained using the inhibitors alone. The results are summarized in Tables I, II and III.

Examples 66 through 85: Synergism data on the inhibition of iron oxide deposition by a combination of the copolymer and other building blocks was determined by zeta potential measurements. The test solution consisted of 500 mg/1 iron oxide (Fe203) and 0.01M sodium nitrate (for ionic strength) at pH 7.1 to 7.2. Caustic was used to adjust the pH. The test solutions were treated with 1.0 mg/1 of the copolymer and the various building blocks, alone or with a combination of 0.5 mg/1 of the copolymer of and 0.5 mg/1 of the other building block. The pH of the test solution was readjusted to 7.1 to 7.2, if necessary.

The change in zeta potential of the control (without inhibitor) with the inhibited solutions was determined. Synergism was noted when that change was greater in the solutions treated by the combination of building blocks than with the building blocks alone. The results are summarized in Table IV.

Examples 86 through 104: The synergistic effects of the AA/AMPS copolymer and other building blocks for corrosion inhibition were determined in eight liter test cells using synthetic four-cycle Pittsburgh water at pH 7.5. The tests were run for 7 days at a constant temperature of 50°C. Two steel test coupons (1 ? 16 inch x 2 inches) were suspended on glass rods in each test cell. The test solution was constantly agitated by a submersible pump and air was constantly bubbled through the solution to keep it saturated.

The various test solutions were treated with the AA/AMPS copolymer and the other building blocks, alone or with a combination of the copolymer and another building block. Synergism was determined by comparing the corrosion rates obtained on the test coupons from the cells containing the individual inhibitors with those from the cell containing the combination of inhibitors. The results are summarized in Table V.

Example 105: The effect of the AA/AMPS copolymer in inhibiting the precipitation of calcium HEDP (hydroxyethylidene diphosphonic acidf a common scale inhibitor) precipitation was tested using synthetic four-cycle Pittsburgh water at pH 8.5. The tests were run for the number of days indicated at a constant temperature of 50°C. Thirty mg/1 of HEDP was added. Fifty-three percent of the HEDP remained in solution in the absence of the copolymer. The turbidity was also measured and found to be 9 NTU. Ninety percent remained in solution when 15 mg/1, active, of a 60/40 AA/AMPS copolymer was added and the turbidity was 1.5 NTU.

The effect of the 60/40 AA/AMPS copolymer in preventing calcium HEDP precipitation in industrial water was tested at pH 8.5 at a constant temperature of 50°C. The results are summarized in Table VI. 2^7345 Example 106: Forty grams of zinc ion were added to 8 liters of Pittsburgh tap water which had been concentrated 4 times. Ten experiments were run, five without additive and five with 10 mg/1 of 60/40 AA/AMPS. The temperature of the test solutions was maintained at 50°C. The pH of the five solutins without additive was 7.0, 7.5, 8.0, 8.5 and 9.0, respectively. The pH of the five additive-containing solutions was likewise 7.0, 7.5, 8.0, 8.5 and 9.0, respectively. Samples were taken after one and three days from each of the solutions. The samples were filtered and the zinc ion concentration determined by atomic adsorption spectrometry. The results are summarized in Table VII.

Both solutions at pH 9 contained 0.25 mg/1 AMP to prevent any CaCO^ precipitation and interference at the high pH with the zinc data.

Example 107: 3.1 grams of CrO« in 500 ml of distilled water +3 was reduced to Cr with 25 ml of NaHSO^. The pH was adjusted to 11 and the solution was stirred for 45 minutes. 20 ml of the mixture was added to 25 180 ml of Pittsburgh tap water which had been concentrated 4 times. The solution was split in two samples. 15 mg/1 of active of 60/40 AA/AMPS was added to one of the samples. The two samples were shaken. In the sample without the additive, the 30 precipitate settled after 5 minutes, while the sample containing the additive retained a blue turbidity and precipitate took much longer to 18 settle. The effect was quantified using a Brinkmann colorimeter at 450 nm. The sample with no additive had a 69.1 percent change in transmittance after 7 minutes, while the sample with additive had only a 3.7 percent change in transmittance.

Example 108: C The change in percent transmittance of iron oxide-containing BOF water and various dispersants was determined using the fiber optics probe from a Brinkmann PC/1000 colorimeter. The percent dispersant effectiveness was calculated from the following: A % transmittance with dispersant 100 1- A % transmittance without dispersant The iron oxide-containing BOF water was an industrial steel water sample characterized as follows: Ion Total (mg/1) Dissolved (mg/1) CO3 HC03 Cl" SiO2 SOf Orthophosphate Polyphosphate Organic Phosphate Fluoride Iron Calcium Magnesium Suspended Solids 24 >968 110 1.5 200 <0.05 <0.1 <0.1 32 855 560 152 <0.05 19 34 3500 * 3.5% 207345 The percent dispersion effectiveness of various concentrations of additive to disperse iron oxide in BOF scrubber water at a pH of 8.8 is summarized in Table VIII.

Example 109 (Polyphosphate Stabilization): The ability of 60/40 AA/AMPS to stabilize polyphosphate (hexametaphosphate) was determined by measuring the reversion of polyphosphate to 10 orthophosphate. 250 mg/1 HCOj was added to 8 liters of water characterized as follows: Ion mg/1 Ca++ 400 Mg++ 48 SO| 788 CI" 708 HCO3 250 which had been concentrated 4 times. The pH was 8.5 and the temperature was 50°C. After 7 days, using 10 mg/1 hexametaphosphate (9.0 mg/1 P04), there was 0.433 mg/1 total P04 still in solution. After 7 days, using 10 mg/1 hexametaphosphate and 10 mg/1 60/40 AA/AMPS, there was 8.95 mg/1 total P04 still in solution. - 20 - GsX3StflV ttBEI CMO5 TnhlMtim 200 wg/1 QI++, 600 Mg/1 HDDg, pH 8.0-8.2, 65%, 24 Houra * Cksncomt Oonoec- M- taunt Inhibi n™nmr# tennt Mdbl- taaeat ftXCCBt Actual A + B Actual -— ■ - « Pnwrlp Jk imve) tion B ■3lw) tlcn X+B UttOBtJ 1 60/40 AA/AMPS 0.5 34 Qrtfco Xbcaffccte 2.0 34 68 95 427 2 /60 AA/AMPS 0.5 ORto IU»iiiatE 2.0 28 33 60 +27 3 60/40 AA/AWS 0.5 34 Qi~361S ' .0 0 34 46 +12 4 60/40 M/AMPS 0.5 34 Bft 0 J. 12 46 52 60/40 AA/AMPS 0.5 34 BEEP 0.06 23 57 60 +3 6 80/20 AA/AWS 0.5 70 OCtho fto^h«tE 2.0 28 98 98 o 7 60/40 AA/UffS 0.5 34 IBS-AM 0.2 54 52 -2 8 60/40 AA/AMPS 0.5 34 Nitrol 42 0.5 34 68 *6 -2 9 .60/40 AA/NffS 0.5 34 Btlcleoe 500 0.25 39 73 68 -5 v 60/40 AA/AMPS 0.5 34 Versa IL-70 .0 Ifi 50 42 -8 11 60/40 AA/AtfS 0.5 34 MyAtfS .0 4 38 -13 12 60/40 AA/AMPS 0.5 34 BAA 0.5 52 82 65 -17 13 60/40 AA/AMS 0.5 34 Sorftig Hexa-■eta Rwqhate 0.2 37 71 52 -19 14 60/40 AA/AMPS 0.5 34 Verai W-3 .0 37 71 50 -21 60/40 AA/AMPS 0.5 34 AMP oa 64 .42 -22 16 60/40 AA/MffS 0.5 34 P-35 1.0 68 102 69 -33 17 60/40 AA/AMPS 0.5 34 Italy MMAC .0 28 62 14 -48 18 70/30 AA/AS 1.0 62 (hrtto Ibcafhate 2.0 28 90 77 -43 21 TT Gtfo4Udtaltlon 2000 mg/1 CS++, 4800 mg/190^2, |B 7.0, «5%, 24 Hours rwmrwmtl- tacaot WitM— K[/l . Rercent TnMM-tlcc ltaosnt ^X^BCQBQ A + B taoaat Artrl A + B Acbal - ffnwrtp A ac&ve) Hirf ■C&w) CFfercent) 19 60/40 AA/AWS 1.0 16.7 AW 1.0 .3 22.0 45.6 +23.6 60/40 AA/AWS 1.0 16.7 Rft 1.0 47.4 64.1 85.1 +21.0 21 60/40 AA/AWS 1.0 16.7 IBS-AM 1.0 .3 22.0 36.8 +14.8 22 60/40 AA/AWS 1.0 16.7 Belcla* 500 1.0 8.6 .5 38.6 +13 J. 23 60/40 AA/AWS 1.0 16.7 BAA 0.5 .5 27.2 36.0 •18.8 24 60/40 AA/AWS 1.0 16.7 HEP 1.0 4.4 21.1 26.3 45.2 /80 AA/AWS 1.5 7.0 AW 1.0 2.0 9.0 13.0 +4.0 26 60/40 AA/AWS 1.0 11.0 MS 2.0 16.0 27.0 31.0 44.0 27 60/40 AA/AWS 1.0 16.7 Nttrol 42 0.5 8.8 .5 28.9 +3.4 28 /80 AA/AWS 1.5 7.0 m. 1.0 18.0 .0 27.0 +2.0 29 *80/20 AA/AWS 1.5 .0 AW 1.0 2.0 27.0 28.0 +1.0 X 60/40 AA/AWS 1.0 16.7 Ortho IboqfaaCe 1.0 4.4 21 J. 21.1 0 3a 60/40 AA/AWS 1.0 16.7 Scxiiun Hexa-aeta Hwsiiiate 1.0 3.5 .2 .2 0 32 60/40 AA/AWS 1.0 16.7 CL-361 1.0 3.5 .2 19.3 -0.9 33 60/40 AA/AWS 1.0 16.7 VemTb-70 1.0 7.0 23.7 21.1 -2.6 34 60/40 AA/AWS 1.0 16.7 ttewaJL-3 1.0 .3 22.0 19.3 -2.7 60/40 AA/AWS 1.0 U.0 Italy AWS 4.0 .0 16.0 13.0 -3.0 36 80/20 AA/AWS 1.5 .0 mk 1.0 18.0 43.0 36.0 -7.0 37 60/40 AA/AWS 1.0 16.7 Poly DOMC 1.0 .3 22.0 8.8 -13.2 38 Versa TL-3 50.0 28 AW 2.0 42 70 3L -39 39 70/30 AA/AS 2.0 14 AW 2.0 42 56 100 444 40 70/30 AA/AS 2.0 14 m. 1.0 16 12 46 +14 "Stace the CtSQt jrirthitinn curve la -vcxy Btaep, experimental varl ■noe la quite large • 22 - numn Ck/fc}* TrMhltion 200 ag/1 CH++, 4 wg/1 Rf3, jB 8.5, 60%, 24 Boun tntioi fexceot tratirki ftarit Bsceat tacent Actual - &&> MliM-ttng TrMM-tdflQ EnopLe A 2&e) rAi+BT' A+B \IWOBKC/ 41 60/40 AA/AWS 1.5 Veraa 3L-3 4.0 40 97 457 42 60/40 AA/AWS 1.5 VnalLrTO .0 36 56 100 444 43 60/40 AA/AWS 1.5 23 m. 1.5 53 95 442 44 60/40 AA/AWS 1.5 16 P-35 .0 31 47 8L 434 45 80/20 AA/AWS 1.5 6 BAA 1.5 13 19 45 4-26 46 80/20 AA/AWS 1.5 6 WeraaTL-3 4.0 57 63 86 4-23 47 60/40 AA/AWS 1.5 23 IWA 1.5 53 75 4-22 48 60/40 AA/AWS 1.5 23 Natrol 42 3.0 54 77 95 438 49 60/40 AA/VfS 1.5 23 BrIcIa* 500 .0 44 67 76 49 50 /80 AA/JWS 1.5 IB Veraa Qi-3 4.0 SI 75 77 42 51 ' 60/40 AA/AWS 1.5 14 Baly XMMAC 1.5 19 19 o 52 /B0 AA/AWS 1.5 18 BAA 1.5 "13 3L 31 0 53 60/40 AA/AWS 1.5 myites .0 34 54 -4 54 60/40 AA/AWS 1.5 26 Oi-3SL .0 3L 22 55 60/40 AA/AWS 1.5 26 Dloctyl Sulfo Sucdaate .0 3L 13 -18 56 60/40 AA/AWS 1.5 23 AMP 1.5 28 51 27 -24 57 60/40 AA/AWS 1.5 14 ne_Aii RSrnrl 1.5 29 43 18 -25 58 60/40 AA/AWS 1.5 23 ■eta HiwtiaLe 1.5 43 -2B 59 60/40 AA/AWS 1.5 23 HEH> 1.5 53 19 -34 60 Veraa E>3 .0 19 Versa 1L-70 39 58 63 45 61 70/30 AA/AS .0 Versa TL-70 39 59 -39 62 Vtersa H/-3 .0 19 BAA 1.5 39 19 -20 63 70/30 AA/AS .0 BAA 1.5 40 -10 64 Verm Dr-3 .0 19 MS .0 24 43 86 443 65 70/30 AA/AS .0 M5 .0 24 44 72 4-28 •31* M/AWS CtfQ& jms tested each tiw a un»iliu> test wi conducted. Hie testing w cmfictri over a Kvenl-mk period. 81nae the ObFC^ lrMMtlm curw la wry steep, espexiaental wrl/nrr la quite large. 2 07345 TtMZ IV fcjP3 SOO mg/1 BbjOj, .OIM NMO3, pB 7.10-7.16 nrwrmnf- £BKple A A Zeta rh^mnt- A Zeta A + B A Zeta *sr » wnrtM 66 60/40 AA/AWS nran 31 37 X 67 60/40 M/4WS fflp 32 34 X 68 60/40 M/ttCS 50 Mrs 48 49 69 60/40 AA/AMPS 50 P-35 49 50 70 60/40 AA/JWS 50 Nrtrol 42 54 47 71 60/40 AA/AMPS 50 Belclene 500 49 47 72 60/40 AA/AMPS BAA 24 28 73 60/40 AA/AWS 50 Woctyl 9ulfo Sucdaate 5 45 74 60/40 AA/AWS B& 26 75 . 60/40 AA/AWS 50 Or361S 1 44 76 60/40 AA/AWS (50) Versa Hr70 28 (40) 77 60/40 AA/AMPS 50 ftvHiw ■eta Bmsphatf 41 40 78 60/40 AA/AWS 50 JQJ3 42 79 60/40 M/AWS 50 Vena Hr-3 49 39 80 60/40 AA/AMPS AMP 26 23 81 60/40 AA/AWS 50 DBMC 26 82 Versa Ur-3 23 IBM' HI racmn 26 X 83 70/30 AA/AS 22 PBS-AM 26 51 X 84 Versa Hr-3 23 SEP 26 60 * 85 70/30 AA/AS 22 SEP 26 24 •Hie M/AWS ^ seta potntlal for ItejOa Aifted during tie ■gwi—n — tlon. Tbe aeta pnfwiHa] for M/iMRTw assamed far each eoacle. AcIm of iron artrte la belleml to lie the cue of tbe aeta potential ddft. 2073> amy Steel CDROBten TnMMflcn 4 Cycle Kttriurgi tkter, 50%, jfl 7.2 i. 7ft^ anBcIe Ocapcoeat A & Cbrro-■lan Bate Ocanoant B OODOBD- K Ctaro-dm Bate ■py ftwinim Bate *r, Pyirmtg" 86 KUdc Bsfc 74.0 87 60/40 AA/AlffS 49.0 2b++ 23.9 31.5 88 60/40 AA/AMPS 75 J. &++ 23.9 12.9 X 89 60/40 AA/AtffS 55.6 i» 32.9 24.4 X 90 60/40 AA/tfffS 75 J.

AMP 32.9 .0 X 91 60/40 AA/AfffS 55.6 HOT .9 23.9 X 92 60/40 AA/AMPS 75 .1 HEDP .9 6.0 * 93 60/40 AA/AMPS 55.6 SwHiw Hexa-meta Tbcmfrmte 19.4 22.6 94 60/40 AA/AMPS 75 .1 Boa- ■ts mipiira 19.4 .8 X 95 60/40 AA/AMPS 75 20a KJ53 3.6 2.7 X 96 60/40 AA/AMPS 75 .1 CrC£2 0.5 2.0 97 60/40 AA/AMPS 75 J.

HS-AM 41.8 6.9 X 98 60/40 AA/MffS 75 .1 MS? 62.4 8.4 ssar X 99 60/40 AA/AMPS 100 8.7 tatxol 42 100 8.0 .4 100 60/40 AA/AMPS 100 8.7 m. 100 28.9 27.2 101 60/40 AA/AWS 100 8.7 BAA 100 .1 7 J.

X 102 60/40 MAMS 100 8.7 /10/55 M/ OOAAC/AM 100 67.0 38.5 103 60/40 M/«ffS 100 8.7 BddneSOO 100 27.6 2B.2 104 60/40 M/AWS XOO 8.7 RjljDDAAC 100 43.5 49.0 2073 (oyrs&szx tazv Stael Qaao&Sm tidMtiaa 4 Cycle Pittsburg Ifeter, 50%, jB 7.5, 7 D«y» Garment QgpDO^ Cbrro-■jen Kate Brit Inn S£ OKXD-aloa tate OiimiflQ Bite TSt . taenia 86 KLafc Blxk 74.0 87 60/40 AA/AMPS 49.0 &++ 23.9 31.5 86 60/40 M/AMPS 75 J. 2tf4+ 23.9 12.9 X 89 60/40 M/AWS 55.6 Atff 32.9 24.4 X 90 60/40 M/AMPS 75 J.

AW 32.9 .0 X 91 60/40 AA/AWS 55.6 BEEP .9 23.9 x 92 60/40 M/AMPS 75 .1 BEEP .9 6.0 X 93 60/40 M/AMPS 55.6 firvtiiw Tim ■eta fhcaifaate 19.4 22.6 94 60/40 M/AMPS 75 fiwHiwi J. '■eta IhoqfaBte 19.4 .8 X 95 60/40 AA/AWS 75 .1 sqj3 3.6 2.7 X ' 96 60/40 AA/AMPS 75 .1 CrCg2 0.5 2.0 97 60/40 AA/IWS 75 J.

HE-AM 4L.8 6.9 * :■? 96 60/40 AA/AMPS 75 .1 MdQ«2 62.4 8.4 ssar 99 60/40 AA/AWS 100 8.7 Nrtrol 42 100 8.0 .4 100 60/40 AA/AMPS 100 8.7 BK 100 28.9 27.2 ia 60/40 AA/AWS 100 8.7 SftA 100 ioa 7J.

X 102 60/40 AA/AWS 100 8.7 /10/55 AA/ DOMC/AM 100 67.0 36.5 103 60/40 AA/AWS 100 8.7 Belclcne 500 100 27.6 28.2 104 60/40 AA/AMPS 100 8.7 BalyMMAC 100 433 49.0 V.

TABt£ VI Calcltin ftiosphate Inhibition — Industrial WaterV Condition OTU NoMdltlw 10 3 wfjl HOT / 10^/1 180-233 30 pg/1 HHF / 50Jg/1 W>-233 1.5 Itafaldlty rained constant for at lent three weeks 1-310 ng/l calcltn ton, 76 ne/1 aagneslua Ion. 960 wfJl chlorides, 4800 n^l sulfate Ion, nitrate ion, 60 n*7l sllTra, U «r/1 nrthopnosffate.

Initial KJ^Level Final P0£JLevel GoBHDtS 11 After 7 toys 14 4 (3 Pty, 1 KEEP) After 7 Hays 41 40 (17.5 FO4, 22 HOT) After 5 Etays TABLE VII Initial Zinc Concentration 5 ng/1 in 4 Cycle Plttsburtfi Mster1; 50°C Zlnc«S2£St2S2? (bb/1) Zinc Ccmcentration (■g/l) with Without Addltlw 10 */l 60/40 M/SffS CbpolyBer jgH TMyi Uay 7 —^ uayi— 7.0 4.1 4.5 4.5 4.8 7.5 3.8 4.4 4.8 5.42 8.0 0.90 0.65 4.6 4.7 8.5 0.30 0.25 4.5 4.9 9.0 0.25 0.30 4.6 4.6 ^ 5^1 hoo^ 24 >te++' 328 ^ ^ 70 ^ Q" Values sli#itly elevated ahov^ 5 mg/1 dun to a ronrant rating effect Tue to solution fvaporatlnri. 207345 - 27 - G=2n&81tf ^ ZABL£ VTTT w' _ Active Percent *»■*■»»-. ""by1- jgSSSL £ 80 8 90 _ n tig 60/40 M/AMB and HHP n 60/40 A/CwTS and HHP 2 60/40 M/aSI mi HBP 3 J* J 300 207,345 28

Claims (9)

WHAT WE CLAIM IS:

1. A synergistic scale and corrosion inhibiting admixture comprising: (a) a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl-sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxy-propyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphonates, organic phosphates, organic polyphosphates, metal salts and sulfonates.

2. The admixture of Claim 1, wherein said unsaturated mono-carboxylic acid is selected from the group consisting of acrylic acid, methacrylic acid, a-halo acrylic acid, vinyl acetic acid, allyl acetic acid, 3-carboxyethyl acrylate, their salts, and mixtures thereof.

3. The admixture of Claim 1, wherein said component (b)" is selected from the group consisting of polyacrylic acid, hydroxyethylidene diphosphonic acid, amino tri-(methylene phosphonic acid), polymaleic an unsaturated mono-carboxylic acid and an unsaturated sulfonic acid selected from the group 207345 - 29 - anhydride, zinc chloride, sodium polystyrene sulfonate, a copolymer of maleic anhydride and sulfonated styrene, a copolymer of acrylamide and acrylate, and mixtures thereof.

4. A method of inhibiting the precipitation of scale-forming salts in an aqueous system, comprising adding to the system at least 0.1 mg/1 of a synergistic scale and corrosion inhibiting admixture of: (a) a water-soluble polymer having a weight average molecular weight of less than 25,000 as determined by low angle laser light scattering, comprising an unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid, a-halo acrylic acid, maleic acid or anhydride, itaconic acid or anhydride, vinyl acetic acid, allyl acetic acid, fumaric acid, 3-carboxyethyl acrylate, their salts, and mixtures thereof, and an unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl-sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxy-propyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphonates, phosphates, polyphosphates, metal salts and sulfonates. N A* °A L. 207345 - 30 -

5. The method of Claim 4 wherein said component (b) is selected from the group consisting of polyacrylic acid, hydroxyethylidene diphosphonic acid, phosphinocarboxylic acid, amino tri(methylene phosphonic acid), polymaleic anhydride, zinc chloride, sodium orthophosphate, sodium polystyrene sulfonate, a copolymer of maleic anhydride and sulfonated styrene, a copolymer of acrylamide and acrylate, and mixtures thereof.

6. A method of inhibiting the corrosion of metal in an aqueous system, comprising adding to the system at least 0.1 mg/1 of a synergistic scale and corrosion inhibiting admixture of: (a) a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising an unsaturated mono-carboxylic acid and an unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl-sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, sulfoalkyl acrylate, sulfoalkyl methacrylate, allyl sulfonic acid, methallyl sulfonic acid, 3-methacrylamido-2-hydroxypropyl sulfonic acid, sulfonic acid acrylate, their salts and mixtures thereof, having a weight ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, - phosphonates, organic phosphates, organic, polyphosphates, metal salts and sulfonates.

7. The method of Claim 6, wherein said carboxylic acid is selected from the iz \\-6MAR19S7 \.'i> o group consisting of acrylic acid, methacrylic acid and the said sulfonic acid is selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, alkyl sulfonic acid and their salts.

8. A method of inhibiting the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an aqueous system, comprising adding to the system at least 0.1 mg/1 of a synergistic scale and corrosion inhibiting admixture of a water soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a weight ratio of 1:20 to 20:1 and a phosphonate.

9. The method of Claim 8, wherein said metal oxide is selected from the group consisting of zinc oxide, chromous oxide and mixtures thereof, said metal hydroxide is zinc hydroxide, and said phosphonate is selected from the group consisting of hydroxyethylidene diphosphonic acid, amino tri(methylene phosphonic acid), a carboxyl phosphonate, and mixtures thereof. 207345 - 31 - ****** ) THIS Stk DAY OF A. J. PARK S SON p£R A' S. AGENTS FOR THE APPLICANTS- 10^7 r H 6MAR"87 i . <v;' c.-