JPS63259086A - Corrosion prevention of water system using organophosphorus derivative containing carboxyl group - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION One of the primary concerns in water engineering is the corrosion of metals in both treated and untreated cooling water systems. Corrosion of metals commonly used in water systems, such as steel, aluminum, brass and copper, is primarily due to dissolved oxygen and carbon dioxide. Substances such as sodium sulfite and hydrazine that remove oxygen are uneconomical and technically unsatisfactory. Therefore, Zn, chromates, molybdates, polyphosphates, orthophosphates and organophosphonates are added to cooling water to form a protective film on metal surfaces. Chromate is an excellent corrosion inhibitor. However, this is often environmentally undesirable due to its known toxicity. Zn
They are also environmentally problematic and also produce orthophosphates, hydroxides, carbonates and products of low solubility, forming sludge and deposits that promote corrosion.

Polyphosphates have no chromate effect and are unstable in cooling water environments, decomposing hydrolytically to ortho- and pyrophosphates, often producing sludge and precipitates. Orthophosphates are also not as effective as chromates and can form sludge and precipitates if not well controlled. Although organophosphonates exhibit some corrosion protection, chromates are not as effective.

Organic phosphonocarboxylic acids or phosphinocarboxylate salts are known to be useful in preventing calcium and other scale deposits and preventing corrosion of iron in circulating water systems.

These compounds are disclosed in U.S. Patent No. 3.933,4
27.4.042,324 and 4,159.948.

For example, the compounds disclosed in U.S. Patent No. 3,933,427 include phosphonosuccinic acid and 2-phosphonobutane-
1,2,4-) carboxylic acid; US patent N
(In R 4,042,324, carboxymethane-phosphonic acid and 1-carboxypropane-2-phosphonic acid; in U.S. Pat. No. 4,052,160,
2-phosphonoacetic acid, 2-phosphonopropionic acid, 2.3
-di-phosphonopropionic acid, 2,4-diphosphonobutyric acid, 2-phosphonomethylacrylic acid, etc.; US Pat. No. 4,159;94B discloses acrylic acid and hypophosphorous acid. Telomer reactants with acids and products of acrylic acid with butyl hypophosphite are disclosed; and U.S. Pat. metal,
For example, 2-hydroxyphosphonoacetic acid is disclosed for use in combination with ions such as zinc, cadmium, manganese, iron and chromium. US Patent No. 3.933
．． The compounds described in No. 427 are said to provide excellent corrosion protection when zinc salts, such as zinc sulfate or zinc phosphate, are added to water systems containing phosphonocarboxylic acids or phosphinocarboxylic acid compounds.

US Patent No. 4,640,818 discloses the combination of manganese compounds and aminophosphonic acid derivatives as metal corrosion inhibitors in water systems.

It has now been discovered that the combination of manganese compounds and such phosphonocarboxylic acids or phosphinocarboxylic acid compounds can provide improved metal corrosion protection in water systems.

The present invention is an improved method for preventing metal corrosion in water treatment systems. That is, this means that (A) the compound is; , a cycloalkyl or aralkyl group, or a group in which R1 is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a carboxyl group; R2 is hydrogen or methyl; and R3 is a carboxyl group. or [wherein R1, R2, R3 and R4 are independently hydrogen or an alkyl group having 1 to 4 carbon atoms; R5
is hydrogen, an OH group, or an alkyl group having 1 to 3 carbon atoms; and n is 0 or 1]; or, [wherein R2 is hydrogen or a methyl or ethyl group;
is hydrogen, a straight-chain or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aryl group, an aralkyl group, the general formula: (wherein R2 is the above-mentioned and n0m is a positive integer of 100, or a group having -OX residue (X is hydrogen or an alkyl group having 1 to 4 carbon atoms); and R1 is 10X group ( in a water treatment system comprising: (B) a manganese compound capable of providing manganese ions; and (B) a manganese compound capable of providing manganese ions. It consists of using compositions useful for preventing metal corrosion.

Surprisingly, it has now been found that a synergistic combination of manganese compounds and organic phosphonocarboxylic acids or phosphinocarboxylic acid derivatives or salts thereof provides metal corrosion protection comparable to chromates. It was released. Various organic phosphonocarboxylic acids or phosphinocarboxylic acids tested alone in water do not exhibit this level of protection. However, the corrosion protection of metals provided by organic phosphonocarboxylic acids or phosphinocarboxylic acid compounds is improved by the addition of manganese compounds that provide a source of manganese ions.

The organic phosphonocarboxylic acids or phosphinocarboxylic acid derivatives shown in the above formulas useful in the practice of this invention are known compounds.

"Alkenyl" and "alkynyl" as used herein refer to straight and branched chain hydrocarbon radicals each having either a double or triple bond and having from 2 to 4 carbon atoms. It means both.

"Alkyl" means both straight and branched chain hydrocarbons having 1 to 18 carbon atoms.

“Cycloalkyl 0 has a cyclic structure and 5 to 1
means a saturated hydrocarbon having 2 carbon atoms.

"Aryl" means an aromatic hydrocarbon having 6 to 12 carbon atoms. “Aralkil” means Cl-
04 alkyl-substituted aryl.

Representative compounds of general formula (1) include α-methylphosphonosuccinic acid; phosphonosuccinic acid; 1-phosphono-propane-2,3-dicarboxylic acid; and 2-phosphonobutanetricarboxylic acid (1,2,4 ). For the production of these phosphonocarboxylic acids, for example, Off'
enlegungsschriftk2,015.06
8.

Representative compounds of general formula (2) include, for example, carboxymethanephosphonic acid; 1-carboxy-ethane-1-phosphonic acid; 1-carboxyethane-2-phosphonic acid; 2-carboxypropane-3-phosphonic acid: 1 -carboxybroban-2-phosphonic acid and methyl(carboxyethyl)phosphinic acid. These compounds are made by methods known in the literature, eg US Patent No. 4.052.160.

A typical telomer of general formula (3) has the general formula: (wherein,
(R2 is as defined above) or a salt thereof; and the general formula;
linear or branched alkyl radicals of ~18 carbon atoms, cycloalkyl residues of 5 to 12 carbon atoms, phenyl or benzyl radicals, or 0X (where X is as defined above); provided by the reaction of

Representative suitable manganese compounds used as a source of manganese ions include, for example, M n O.

M n O21M n Cj! 2-4 H20,K
M n O4.

Mn(CH3COO)2.4H20, etc. The manganese compound can be added together with the phosphorus-containing carboxylic acid derivative or separately to the water. On the other hand, manganese can also be complexed with a phosphorus-containing carboxylic acid compound before being added to the water. Compositions in which the weight ratio of phosphorus-containing carboxylic acid derivative to manganese is at least approximately 2:1 are preferred.

For purposes of this invention, the effective organic phosphonocarboxylic acids or phosphinocarboxylic acid derivatives and salts thereof described herein are considered equivalent. Salts are acid addition salts of these bases forming salts with at least one acid of these derivatives. Suitable bases are, for example, ammonia, alkali metal and alkaline earth metal hydroxides, carbonates and bicarbonates, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium carbonate, sodium bicarbonate, carbonate. Magnesium, etc.

These salts can be made by reacting an organic-phosphonocarboxylic acid or phosphinocarboxylic acid derivative having at least one acid group with a suitable base.

The preferred amount of organic phosphonocarboxylic acid or phosphinocarboxylic acid derivative for corrosion prevention of alloys containing copper or iron in water treatment systems is 1 to 150 ppm.
acid or equivalent. The amount that can be manipulated is 0.5 to 200
It is ppIM. In such water treatment systems,
The addition of manganese compounds to these phosphorus-containing carboxylic acid derivatives has an unexpected effect on corrosion protection. The invention further relates to the use of this composition for corrosion protection. The amount of the manganese compound used is such that the amount of manganese is 0.5 to 30 ppm by weight in the aqueous solution.

A suitable amount is 0.1-1Oppm.

The following examples illustrate the invention.

Example 1 This example demonstrates the improved corrosion protection of 1018 carbon steel by manganese and 2-phosphonobutanetricarboxylic acid.

An 8I tank was filled with tap water having the following composition.

Conductivity (umhos/cn+) 750.0 Alkalinity (ppm as Ca COs) 120.0
Total hardness (ppm as Ca COa) 178
．． 0Ca hardness (ppn+ as Ca COs)
138.0Fe (ppm)
0.28S O,i-(ppm)
85.0CI2″″ (pl
)it) 126.0p11
7.4 Air is pumped through a glass tube inserted from one end of the tank to the bottom at a rate of 10 standard ft3/llr (S CF H
). This air blowing was done to circulate the water and provide oxygen to the water to help steam.

The water volume in the tank was automatically controlled by a gravity feed system and heated by an electric immersion heater. Water temperature is measured by a platinum RTD (resistance thermometer) and an “on/off” controller that provides power to the immersion heater.
The temperature was controlled at 125'F (51.7°C). The pH of the water was adjusted to ptrg,o by the addition of caustic (50%) and automatically increased to 8.0 by a controller that supplied HCN (1% aqueous solution) to the tank as the pH increased.
was held at

2-phosphonobutanetricarboxylic acid was added to two separate tanks at a concentration of 150 ppm. Also M n C1
Manganese as 2.4H20 was added to one of these tanks at a concentration of 7.5ppa+M1. pH of both tanks
was controlled to 8.0 using dilute HCl. 1:
Carbon steel electrodes cleaned with IHCR and polished with 320 grade sandpaper to remove all surface oxides (1
018) was attached to an electrode corrosion probe and immersed in a tank. The instantaneous corrosion rate was measured using a potential corrosion rate meter.

The test was conducted over five days, and at that time the salt concentration in the bath was approximately four times the concentration in the water used. The final average corrosion rate after completion is 1.0IIlpy in the manganese-added tank.
(nil per year), and was 2.4 mpy in a manganese-free tank.

Two other tanks were tested under the same conditions, one with manganese (same raw material) alone and the other without any additives. The average instantaneous corrosion rate of each tank after 5 days was lO,oIIIpy.

Examples 2 and 3 Two commercially available phosphinocarboxylic acid polymers were tested on carbon steel as in Example 1 in combination with manganese. The same manganese raw material was used. The final average instantaneous corrosion rate (after 5 days) is shown in the table below: Example Commercial product "MH" + Corrosion rate N
a (conc, ppm) (1)I)I
I) (may)2 (a) Be1spers
e 161 (100) None 18.02 (b)
Be1sperse 161 (100) 5
4.03 (a) Be1clene 500
(100) None IB, 03 (b) Be
1clene 500 (100) 5 7.6
*Be1sperse 181 is a phosphinocarboxylic acid polymer from Ciba-Geigy containing phosphonate and acrylate functional groups. Ba1clean
500 is a phosphinocarboxylic acid polymer manufactured by Ciba-Gelgy.

Manual continuation supplementary text Bottle... June 1, 1986

Claims (1)

[Claims] 1. (a) The compound has (1) ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R is a hydrogen atom, an alkyl having 1 to 4 carbon atoms, each of which is ~ Alkenyl or alkynyl group, aryl, cycloalkyl or aralkyl group having ~4 carbon atoms, or ▲ Numerical formula, chemical formula, table, etc. ▼ (where R_1 is hydrogen, 1 to 4 carbon atoms) R_2 is hydrogen or methyl; and R_3 is a carboxyl group]; or (2) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, the substituted R_1, R_2, R_3 and R_4 are independently hydrogen or an alkyl group having 1 to 4 carbon atoms; R_5 is hydrogen, an OH group or an alkyl group having 1 to 3 carbon atoms; and n is 0 or 1 ]
; or (3) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_2 is hydrogen, methyl or ethyl group;
R is hydrogen, a straight or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aryl group, an aralkyl group, an -OX residue (X is hydrogen or Alkyl group having 1 to 4 carbon atoms) Or general formula: ▲ Numerical formula, chemical formula, table, etc. and R_1 is -O
a phosphorus-containing carboxylic acid compound corresponding to at least one of the following, or a salt thereof, and (b) a manganese compound capable of providing manganese ions. A composition useful for preventing metal corrosion in water treatment systems. 2. The composition according to claim 1, wherein the phosphorus-containing carboxylic acid compound corresponds to general formula (1). 3. The composition according to claim 2, wherein R is hydrogen. 4. The composition according to claim 2, wherein R in the general formula is ▲a mathematical formula, a chemical formula, a table, etc.▼, and R_3 is a carboxyl group. 5. The composition of claim 4, wherein each of R_1 and R_2 is hydrogen. 6. The composition according to claim 1, wherein the phosphorus-containing carboxylic acid compound corresponds to general formula (2). 7. The composition according to claim 1, wherein the phosphorus-containing carboxylic acid compound corresponds to general formula (3). 8. The composition according to any one of claims 1 to 5, wherein manganese is chelated with an organic phosphorus-containing carboxylic acid compound. 9. The composition according to claim 1 or 6, wherein manganese is chelated with a phosphorus-containing carboxylic acid compound. 10. A method for preventing metal corrosion in a water treatment system comprising providing the water with a composition as defined in any one of claims 1 to 9.