JPH032953B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to aqueous or partially aqueous systems, in particular for the prevention of corrosion of contacting metals and/or for the prevention of scale deposits due to metal corrosion. West German Published Patent No. 2310450 describes the formula (wherein R is an alkyl residue having 1 to 4 carbon atoms and X is hydrogen or a hydroxyl group) are described.
The above compounds and their water-soluble salts are known to be useful as complexing agents for polyvalent metal ions. It is also known that said compounds are suitable for use as corrosion or scaling inhibitors for cooling water. DE 2310450 describes the prior art and distinguishes it from it in the following points: Reference is made to German Patent No. 1045373, which states that the use of methylene diphosphonic acid as a good complexing agent for calcium is disclosed. The patent states that if one phosphonic acid group is replaced by a carboxylic acid group, the unfavorable eutrophic (bionutrient) properties are reduced, but the complexing properties of the resulting phosphonoacetic acid are also substantially reduced. Are listed. In order to simultaneously maintain good complexing properties and reduce eutrophic properties, West German Published Patent No.
2310450 requires that one of the protons of the methylene group of phosphonoacetic acid be substituted with an alkyl group having 1 to 4 carbon atoms, and the second proton is optionally substituted with a hydroxyl group. It teaches that it is good. In apparent contrast to the teachings of the above prior art, the inventors have surprisingly found that 2-hydroxy-2
It has been found that by using an aqueous system containing 2-hydroxyphosphonoacetic acid instead of phosphonopropionic acid, much improved metal corrosion protection and/or scaling prevention is achieved.
Additionally, 2-hydroxyphosphonoacetic acid can be used in only partially aqueous systems, such as aqueous machining fluids.
Provides corrosion resistance with antifreeze, water/glycol hydraulic fluids, and water-based surface coatings such as water-based emulsion paints and water-based powder paints for metals. According to the invention, an aqueous or partially aqueous system for the prevention of corrosion and/or scale deposition due to corrosion of metals in contact, in particular ferrous metals, comprising:
The system has a formula An aqueous or partially aqueous system is provided in which 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof is added. 2-Hydroxyphosphonoacetic acid is a known compound, already disclosed in US Pat. No. 3,032,500 and more recently in European Patent Application No. 0050792. The compound can be obtained by a known method, for example, by reacting orthophosphorous acid, a salt thereof, or a solution thereof, or phosphorus trichloride with glyoxylic acid, a salt thereof, or a solution thereof. 2-Hydroxyphosphonoacetic acid can be used as the free acid or for example with alkali metals, alkaline earth metals, ammonia or (selectively substituted with 1 to 6 hydroxyl groups) 1 to 20, preferably 1 to 12 It can be used as a water-soluble salt or partial salt of an alkylamine containing 5 carbon atoms. Suitable examples include lithium, sodium, potassium, calcium, strontium, magnesium, ammonia, methylamine, ethylamine,
Mention may be made of the salts of n-propylamine, trimethylamine, triethylamine, n-butylamine, n-hexylamine, octylamine, ethanolamine, diethanolamine, triethanolamine or morpholine. 2-2 in an aqueous system to prevent metal corrosion and/or scale deposits from that system.
0.1-50000 ppm of hydroxyphosphonoacetic acid is added. In practice, the amount of 2-hydroxyphosphonoacetic acid added to the aqueous system being treated will vary depending on the function the 2-hydroxyphosphonoacetic acid is required to perform. For anti-corrosion protection treatment, and optionally simultaneous anti-scaling treatment, the amount of 2-hydroxyphosphonoacetic acid added to the aqueous system may range from 0.1 to 50000 ppm (i.e. 0.00001 to 5.0 ppm) to the aqueous system. (% by weight) is appropriate;
A range of 1 to 500 ppm (ie 0.0001 to 0.05% by weight) is preferred. For scale prevention only, the amount of 2-hydroxyphosphonoacetic acid used may suitably range from 1 to 200 ppm, preferably from 1 to 30 ppm, based on the aqueous system. Aqueous systems treated in accordance with the present invention that are particularly relevant for simultaneous corrosion protection and scaling control include cooling water systems, steam generation systems, seawater evaporators, hydrostatic cookers, gas scrubbing systems, and For corrosion protection treatments only, particularly relevant aqueous systems include aqueous machining fluid formulations (e.g. boring, milling, reaming, broaching, drawing, turning). ,
Cutting, sawing, crushing, and thread-cutting
aqueous scouring systems, aqueous glycol antifreeze systems, water/glycol hydraulic fluids, and water-based polymer surface coatings. The system can be mentioned. Compounds of the formula may be used alone or in conjunction with other compounds known to be useful in treating aqueous systems. For the treatment of systems that are completely aqueous, such as cooling water systems, steam generation systems, seawater evaporator systems, hydrostatic cookers, and complete circulation heating systems, additionally corrosion inhibitors, such as water-soluble zinc salts; phosphates. ; polyphosphates; phosphonic acids and their salts, such as acetodiphosphonic acid, nitrilotrismethylenephosphonic acid and methylaminodimethylenephosphonic acid; other phosphonocarboxylic acids and their salts, such as the compounds described in DE 2632774;
2-phosphonobutane-1,2,-4-tricarboxylic acid and the compounds described in British Patent No. 1572406;
Chromates, such as sodium chromate; nitrates, such as sodium nitrate; nitrites, such as sodium nitrate; benzotriazole, bis-benzotriazole or copper-depleting benzotriazole or tritriazole derivatives; N-acylsarcosine; N-acyliminodiacetic acid; ethanol amines; fatty amines; and polycarboxylic acids, such as polymaleic acid and polyacrylic acid, as well as their alkali metal salts, copolymers of maleic anhydride, copolymers of acrylic acid, and polymaleic acid, polyacrylic acid, and copolymers thereof, respectively. Substituted derivatives can be used. Furthermore, in completely aqueous systems, compounds of the formula may further contain dispersants and/or threshold agents, such as polymerized acrylic acids (or salts thereof), phosphinopolecarboxylic acids (as described in British Patent No. 1458235). , as claimed), hydrolyzed polyacrylonitrile, polymerized methacrylic acid and its salts, polyacrylamide and copolymers with acrylic acid and methacrylic acid, ligninsulfonic acid and its salts, tannins, naphthalenesulfonic acid/formaldehyde condensation products, starch and its derivatives,
and cellulose. Specific examples of threshold agents used include 2-phosphonobutane-1,2,4-tricarboxylic acid, acetodiphosphonic acid, hydrolyzed polymaleic anhydride and its salts, alkylphosphonic acids, 1- Mention may be made of aminoalkyl-1,1-diphosphonic acids and their salts, and alkali metal polyphosphates. Precipitating agents such as alkali metal orthophosphates and carbonates; oxygen scavengers such as alkali metal sulphites and hydrazine; sequestering agents such as nitrilotriacetic acid and its salts; siloxanes such as polydimethylsiloxane, distearyl sebaamide, Distearyl adipamide and related products derived from ethylene oxide and/or propylene oxide condensates; in addition antifoams such as fatty alcohols such as caprylic alcohol and its ethylene oxide condensates; and biocides such as amines. , quaternary ammonium compounds, chlorophenols, sulfur-containing compounds such as sulfones, methylene bisthiocyanates and carbamates, isothiazolones, brominated propionamides, triazines,
Phosphonium compounds, chlorine and chlorine releasing agents and organometallic compounds such as tributyltin oxide can be used. If the system being treated according to the invention is not completely aqueous, for example in the case of aqueous machining fluid formulations, water-dilutable cutting or grinding fluids can be used. The aqueous machining fluid formulations of the invention include, for example, metal working formulations.
can be given. “Metal work” means “reaming,
broaching, drawing, spinning,
Cutting, crushing, boring, milling, turning (tur
-ning), meaning "sawing, uncut shaping or rolling". Examples of water-dilutable cutting or grinding fluids incorporating corrosion inhibiting compounds of the formula include (a) one or more corrosion inhibitors used at a dilution of 1:50 to 1:100 and commonly used as grinding fluids; and optionally one or more anti-wear additives; (b) used at a dilution of 1:20 to 1:40 for cutting operations and 1:60 to 1:80 for grinding; (c) Similar to (b) but with 10-20% oil plus water diluted product to make it translucent (d) a semi-synthetic cutting fluid containing sufficient emulsifiers to and (e) an emulsifiable mineral oil concentrate that is diluted typically 1:10 to 1:50 with water to give a white opaque emulsion; and (e) a similar product to (d) containing less oil and more emulsifier. 1:50~1:
diluted to 100 to yield a translucent emulsion;
Mixtures of sodium nitrite and triethanolamine have been used for corrosion protection in metal work, but there are toxicity problems due to the risk of forming, for example, N-nitrosamines. Because of this, and because some countries have legal regulations regarding effluents, alternatives to the use of sodium nitrite are required. For partially aqueous systems where the aqueous system component is an aqueous machining fluid formulation, the compounds of the formula may be used alone or mixed with other additives, such as further known corrosion inhibitors and/or extreme pressure additives. It may also be used as In addition to compounds of formula, examples of other corrosion inhibitors used in these aqueous systems include the following groups:
(a) an organic acid, its ester or ammonium;
Amines, alkanolamines and metal salts, such as benzoic acid, p-t-butylbenzoic acid, disodium sebacate, triethanolamine laurate, isononanoic acid, triethanolamine salt of (p-toluenesulfonamidocaproic acid), sodium (b) Nitrogen-containing substances such as the following types, namely fatty acid alkanolamides; imidazolines, such as 1-hydroxyethyl-2-oleyl-imidazoline; oxazolines; triazoles, such as benzotriazole; ethanolamines; fatty amines; and inorganic salts, such as sodium nitrate; (c) phosphorus-containing substances such as the following types of amine phosphates, phosphonic acids or inorganic salts, such as sodium dihydrogen phosphate or zinc phosphate; and (d ) Mention may be made of the following types of sulfur-containing compounds: sodium, calcium or barium petroleum sulfonates, or heterocyclic compounds, such as sodium mercaptobenzothiazole. Nitrogen-containing substances are preferred, especially triethanolamine. Examples of extreme pressure additives that can be present in the system of the invention include sulfur- and/or phosphorus- and/or halogen-containing substances such as sulfurized whale oil, sulfurized fats, tritolyl phosphates, chlorinated paraffins. Alternatively, ethoxylated phosphate esters can be mentioned. When triethanolamine is present in the aqueous system treated according to the invention, it is present in a proportion such that the ratio of compound of formula to triethanolamine ranges from 2:1 to 1:20. is preferable. Partially aqueous systems treated by the method of the invention may be aqueous surface coating compositions, such as primer emulsion paints and aqueous powder coatings for metal supports. The aqueous surface coating composition may be a paint, such as a styrene-acrylic copolymer emulsion paint, a resin, a latex, or other waterborne polymeric surface coating system. Sodium nitrite and sodium benzoate have been used to prevent flash rusting in water-based primer paints, but are not commercially available due to toxicity issues and emulsion stability issues at the high ionic concentrations used. The top tends to be further away from sodium nitrate and sodium benzoate. In the aqueous surface coating compositions treated according to the invention, the compounds of the formula may be used alone or in admixture with other additives such as known corrosion inhibitors, biocides, emulsifiers and/or pigments. May be used. Further known corrosion inhibitors which may be used include, for example, those of groups (a), (b), (c) and (d) mentioned above. In addition to compounds of the formula, examples of biocides that can be used in these aqueous systems include phenols and alkyl and halogenated phenols such as pentachlorophenol,
o-phenylphenol, o-phenoxyphenol and chlorinated o-phenoxyphenol, and salicidanilide, diamine, triazine,
and organometallic compounds such as organomercury compounds and organotin compounds. In addition to compounds of the formula, examples of pigments that can be used in these aqueous systems include organic pigments such as titanium dioxide, zinc chromate, iron oxides, and phthalocyanines. The invention is further illustrated by the following examples.
Parts and percentages in the examples are by weight. A production example of the 2-hydroxyphosphonoacetic acid active ingredient used in Application Examples 2 to 6 below is shown below. Example 1 (A) 16.3 parts (0.11 mol) of 50% aqueous glyoxylic acid
and 8.2 parts (0.1 mol) of O-phosphorous acid were heated at 98 to 100° C. for 24 hours with stirring to obtain 24.5 parts of a 60% aqueous solution of 2-hydroxyphosphonoacetic acid. (B) 150 parts of the 60% aqueous solution of 2-hydroxyphosphonoacetic acid obtained in Example 1A was added under reduced pressure (20 mbar).
Evaporation to give 104 parts of a viscous brown oil. The oil was then crystallized. The crude crystal was then ground with acetone to remove impurities. The resulting pale yellow crystals of 2-hydroxyphosphonoacetic acid were separated, washed with acetone, and dried. The obtained crystalline 2-hydroxyphosphonoacetic acid was then recrystallized from water to obtain pure 2-hydroxyphosphonoacetic acid as white crystals with a melting point of 165-167°C. ³¹ P-NMR δ=-14ppm (relative to external H ₃ PO ₄ ); ¹ H-NMR P- CH δ=4.24ppm ^J P-CH=18Hz IR COOH: 1745cm ^-1 , P=O: 1200cm ^-1 conducted Example 2 The anticorrosion activity of the active compound of the formula was determined by an aerated solution bottle test with the following composition: 20 g CaSO ₄ 2H ₂ O 15 g MgSO ₄ ·7H ₂ O 4.6 g NaHCO ₃ 7.7 g CaCl ₂ ·6H ₂ O Experiments were conducted using standard corrosion water consisting of 205 liters of distilled water in the following manner. Rub a mild steel coupon (5cm x 2.5cm) with a pumice stone,
It was immersed in hydrochloric acid for 1 minute, then washed, dried and weighed. Standard corrosion water 200 with combination of additives in desired proportions
Dissolved in ml. Two steel coupons were suspended in the solution and the whole was stored in a sealed bottle in a thermostat at 40°C. During the storage period, air was passed through the solution at a rate of 500 ml/min, the air passage being interrupted by a steel coupon, and the water lost by evaporation was replaced with distilled water. After 64 hours, the steel coupons were removed, rubbed without pumice, immersed for 1 minute in hydrochloric acid anti-corrosion with the addition of 1% by weight hexamine, then washed, dried and weighed again. There must be a certain amount of weight loss. A blank test, ie, an immersion test of mild steel specimens in test water in the absence of anything that could act as a corrosion inhibitor, was conducted in parallel with each series of tests. Although corrosion rates are calculated in milligram weight loss/q. decimeters per day (mdd), for convenience the results are expressed as percentage protection, which percentage protection is defined as follows. That is, protection percentage % = Corrosion rate of blank test (mdd) - Corrosion rate of sample (mdd) / Corrosion rate of blank test (mdd) x
100 Hydroxyphosphonoacetic acid obtained in Example 1 (A) was added to 100 ppm, 90 ppm, 80 ppm, 70 ppm, respectively.
Table 1 shows the results of a series of tests conducted using 60ppm, 50ppm and 40ppm.

[Table] The results in Table 1 demonstrate the effective mild steel corrosion inhibiting properties of hydroxyphosphonoacetic acid. Example 3 The corrosion resistance of the aqueous cutting fluid composition of the present invention was evaluated by the following method, namely Institute of Petroleum Test 287.
Evaluation was made using a modified method. A 1% aqueous solution of the compound under test was prepared containing enough triethanolamine (TEA) to bring the PH value to 9. The solutions were further diluted 2x, 4x, 8x and 16x and each of these solutions was contacted with cast iron chips as described in the IP287 test method.
The test was conducted using deionized water and IP287 hard water. Visual evaluation of the condition of metal chips after exposure was performed according to the following guidelines. Rust level evaluation grade : No rust 0 5 or less small spots T (trace) The obtained results are as listed in Table 2.
Figure 2 shows the corrosion inhibitory activity of compounds of formula in aqueous liquid compositions.

[Table] *〓Dilution %〓 is the concentration percentage of only the compound.
The dilution ratio is the ratio of triethanolamine + compound to water.
Example 4 The effectiveness of compounds of formula in preventing flash lasting is demonstrated by the following method. Typical primer styrene-acrylic copolymer emulsion paint is applied using a high-speed stirrer.
It was manufactured according to the following formulation. O-Zinc phosphate 190 parts Titanium dioxide RCR-2 58 parts Modocol EK-600 (registered trademark) (4% in water) (polyacrylate) 64 parts Vinapol 1640 (registered trademark) (5% in water) (potassium polymethacrylate - vinyl Products Limited) 36 parts Ammonia (0.880) 10 parts Water 92 parts Vinacryl M 175 (registered trademark) (Styrene/acrylic copolymer - vinyl) 549 parts Acticide MPM (registered trademark) (Organic mercury compound - Thor) Chemical Limited) 1 part 1000 parts Aqueous mixture of the compound of formula obtained in Example 1(A) and triethanolamine (compound of formula:
TEA:water weight ratio = 3:48:2) was incorporated into a 100 g aliquot of the primer with stirring to obtain concentrations of 500, 250 and 100 ppm of the compound of formula. A control containing no anticorrosion agent is shown for reference. Blast clean the paint sample in advance and clean it with Sa3.
Duplicate test specimens (15.24 cm x 10.16 cm) were brushed. Once the first coating was applied to the surface of the panel and dry, a second coating was applied to half of the panel (brushing perpendicular to the direction of brushing of the first coating). Dry the painted panels in a controlled atmosphere (20°C, relative humidity 60%).
Next, a visual evaluation of flash lasting was performed. The flash lasting was evaluated visually and according to the number and nature of the rust spots on a numerical scale from 0 to 5, where 0 = no flash lasting and 5 = severe flash lasting. Summer. The results obtained are shown in Table 3.

【table】

[Table] The results in Table 3 show that the emulsion paint containing 2-hydroxyphosphonoacetic acid has superior corrosion protection compared to the control paint. Examples 5 and 6 Threshold Testing on Calcium Carbonate The following solutions (a), (b) and (c) were prepared. (a) Calcium nitrate solution 1470 g of calcium nitrate tetrahydrate was dissolved in deionized water and the solution was made up to 1. (b) Sodium carbonate solution Dissolve 0.646 g of sodium carbonate in deionized water,
The solution was designated as 1. (c) Solution of 2-hydroxy-phosphonoacetic acid 2-hydroxy-phosphonoacetic acid obtained in Example 1(A) or 1(B)
Phosphonoacetic acid was dissolved in water to give a solution containing 1000 ppm of active ingredient. 50ml of calcium nitrate solution was placed in a 120g glass bottle with screw cap. This solution is added to each final volume (100 ml) of the test solution (e.g. 1.0 ml of 0.1% of solution (c) will result in a concentration of 10 ppm of 2-hydroxy-phosphonoacetic acid in the test solution).
5ppm, 7.5ppm or 10ppm 2-hydroxy-
Add a volume of solution (c) to give the concentration of phosphonoacetic acid. Add 50 ml of solution (b) and shake the mixture. The test solution was stored in a constant temperature bath at 25°C for 24 hours. Remove 25 ml of test solution and mix with Patton and
Reader reagent [2-hydroxy-1-(2'-hydroxy-4'-sulfo-1'-naphthylazo)-3-naphthoic acid] was added followed by two pellets of sodium hydroxide. The resulting solution was titrated with a standard 0.01M solution of ethylenediaminetetraacetic acid disodium salt. As shown in Table 4 below, the above experimental results are shown as % prevention of calcium carbonate precipitation with respect to the blank titration (that is, when 2-hydroxyphosphonoacetic acid is not contained). % Prevention = (Titration - Blank Titration) / (7.78 - Blank Titration) x 100 7.78 is the maximum possible titration for 100% prevention.

[Table] Example 7 The simultaneous scale and corrosion prevention properties of the present invention were evaluated in evaporative cooling water rigs by the following method. The standard method of rig operation is to concentrate the water to the desired degree. Once concentrated, the pre-weighed corrosion coupons and heat exchanger were placed into the rig and the inhibitor was added. A passivating dose of scale/corrosion inhibitor was added into the feed water for 3 days. Thereafter, the amount of inhibitor added was reduced to the maintenance dose level over 2 days. Once the inhibitor dosage reached the desired maintenance level, sufficient scale/corrosion inhibitor was added to the feed water to maintain that level for 10 days. The corrosion rate was then calculated as the weight loss of the metal coupon, and the scale deposition rate was measured as the weight gain of the heat exchanger. Standard working parameters of evaporative cooling water rig: System capacity 20 Flow rate 15/min Flow rate 0.3 m/sec System temperature 40°C Heat exchanger temperature difference ΔT 2°C Half-life (approximately) 30 hours Typical analysis example of used water: PH 8.9 PA (*) 120ppm (as CaCO ₃ ) TA (*) 470ppm (as CaCO ₃ ) TH (*) 450ppm (as CaCO ³ ) Cl 75ppm Cl ^-

【table】 *PA stands for "phenolic alkalinity". TA stands for “total alkalinity”; TH stands for "total hardness".

Claims (1)

[Claims] 1 formula An aqueous or partially aqueous system comprising 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof represented by: 2. The system according to claim 1 for preventing corrosion and/or scale deposition of metals in contact. 3. A system according to claim 2 for corrosion protection and optionally scale deposition protection, in which the proportion of the compound of the formula is from 1 to 500 ppm in the system. 4 Compounds of formula 1 to 1 to the system
The system according to claim 3, wherein the amount is 100 ppm. 5. A scale deposition prevention system according to claim 2, wherein the compound of the formula is present in an amount of 1 to 200 ppm relative to the system. 6 Compounds of formula 1 to 1 to the system
The system according to claim 5, wherein the amount is 30 ppm. 7 formula A method using an aqueous or partially aqueous system comprising 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof represented by A method for simultaneously preventing corrosion and scale deposition, characterized in that it is a gas scrubbing system or a complete circulation heating system. 8 formula A method using an aqueous or partially aqueous system comprising 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof represented by A corrosion prevention method characterized in that the system is a water/glycol hydrostatic solution or a water-based coating composition. 9. The method of claim 8, wherein the aqueous machining fluid formulation is a water dilutable cutting or grinding fluid. 10 formula A method using an aqueous system consisting of 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof represented by a gas scrubbing system or a full circulation heating system, and the compound of the formula as well as other corrosion inhibitors, dispersing and/or ultimate agents,
A method for preventing corrosion and/or scale deposition, which comprises using in combination one or more of a settling agent, an oxygen scavenger, a sequestering agent, an antifoaming agent, and a biocide. 11 formula a partially aqueous system comprising from 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof, wherein the system is an aqueous machining fluid formulation, and together with other compounds of formula 1. A method for preventing corrosion and/or scale deposition, characterized in that one or more of corrosion inhibitors and/or extreme pressure additives are used in combination. 12. The method of claim 11, wherein the other corrosion inhibitor is triethanolamine. 13. The method of claim 12, wherein triethanolamine is present in an amount such that the ratio of compound of formula to triethanolamine is from 2:1 to 1:20. 14 formula A partially aqueous surface coating composition comprising 0.1 to 50,000 ppm of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof represented by the formula: and one of a corrosion inhibitor, a biocide, an emulsifier, and/or a pigment together with the compound of the formula. A method for preventing corrosion and/or scale deposition, characterized in that a method for preventing corrosion and/or scale deposition is used in combination. 15 Preventing corrosion of metals in contact with the system, characterized in that it consists of (a) an aqueous system, (b) a small proportion of 2-hydroxyphosphonoacetic acid or a water-soluble salt thereof, and optionally (c) triethanolamine. water-based system.