KR100725948B1 - Compound for prevention of corrosion and removal of scale and composition comprising the same - Google Patents

Abstract

10-30 parts by weight of carboxylic acid-phosphoric acid condensate, 10-30 parts by weight of hydroxy polycarboxylic acid, at least one alkaline selected from NaOH, KOH, K ₂ CO ₃ , KHCO ₃ , Na ₂ CO ₃ , and NaHCO ₃ 5 to 15 parts by weight of a neutralizing agent is prepared by stirring and reacting at a temperature of 80 to 110 ° C. for 1 to 2 hours, and the compound for preventing and descaling the present invention having a pH of 1% by weight aqueous solution of 6 to 8 and containing the same The composition is excellent in corrosion prevention and descaling effect even when using less amount than conventional rust preventive agent or customs agent, does not cause secondary environmental pollution problem, and is neutral and easy to use and handle as well as metal materials such as piping after use No damage to the equipment extends the life of the equipment, and the emission control eliminates the need to shut down the unit during descaling and corrosion protection It is possible to obtain the effect of preventing the economic loss caused by the interruption of operation.

Anti-corrosion, descaling, antirust, customs, neutral, nontoxic

Description

Compound for preventing and descaling and composition containing same {Compound for prevention of corrosion and removal of scale and composition comprising the same}

1 is a photograph of a solid, high concentration composition for preventing corrosion and removing scale of the present invention prepared according to Example 5 of the present invention.

2a and 2b are photographs showing the anti-corrosion effect of the zinc alloy steel pipe (white tube) in water to which 0.05% by weight of the composition of the present invention was added for 1 month, compared with the case where the composition of the present invention was not added. .

Figure 3a and Figure 3b is a photograph showing the anti-corrosion effect before and after two days of putting an aluminum tube and a copper tube in water to which 1.0% by weight of the composition of the present invention is added, respectively.

Figures 4a and 4b is the addition of the composition of the present invention to the effect of removing the scale when the calcium (Ca) -magnesium (Mg) scale collected in the pipe for 1 month soaked in water to which 5.0% by weight of the composition of the present invention is added The picture is shown in case it is not.

5a to 5d are photographs showing the descaling effect for three days after immersing the hard silica scale in water to which 5.0 wt% of the composition of the present invention was added, as compared with the case where no composition of the present invention was added. .

6A to 6C show zinc alloy steel and goldfish in water without mixing any anti-corrosion and descaling agent, respectively, and after 24 hours, 48 hours and 72 hours, the goldfish are not dead and the zinc alloy steel is corroded. Is a picture showing.

7A to 7C show that zinc alloy steel is not corroded when 24 hours, 48 hours, and 72 hours have been added to zinc alloy steel and goldfish in water mixed with a corrosion inhibitor and scale remover of the present invention at a concentration of 0.01% by weight. Of course, goldfish is a picture that shows the living state without dying.

8A to 8C show that zinc alloy steel is not corroded when 24 hours, 48 hours, and 72 hours have elapsed after the zinc alloy steel and the goldfish are added to water mixed with the anti-corrosion and scale remover of the present invention at a concentration of 0.05% by weight. Of course, goldfish is a picture that shows the living state without dying.

9A to 9C show that zinc alloy steel is not corroded when 24 hours, 48 hours, and 72 hours have been added to zinc alloy steel and goldfish in water mixed with the anti-corrosion and scale remover of the present invention at a concentration of 0.1% by weight. Of course, goldfish is a picture that shows the living state without dying.

10A to 10C show that zinc alloy steel is not corroded when 24 hours, 48 hours, and 72 hours have elapsed after the zinc alloy steel and the goldfish are added to water mixed with the corrosion inhibitor and the scale remover of the present invention at a concentration of 0.15% by weight. Of course, goldfish is a picture that shows the living state without dying.

The present invention relates to a compound for anti-corrosion and descaling, and a composition for anti-corrosion and descaling, including the same. More particularly, excellent anti-scaling and anticorrosive effects, as well as neutral, easy to handle and do not cause water pollution. It relates to a compound for descaling and preventing corrosion and a composition comprising the same.

In order to remove scales generated inside pipes using water such as boilers, freezers, heat exchangers, and other various pipes, and to prevent corrosion and formation of scales, various chemicals such as customs and rust inhibitors are used. Strong alkaline agents with pH above 11 are used, for example, NaOH, Na ₂ SO ₄ , NaNO ₂ , Na ₃ PO ₄ , and these agents are used inside the device and drained without any additional treatment. And high acidity cause secondary water pollution problems, and strong acids below pH 2 used as descaling agents, such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, generate various toxic gases when used and Metallic corrosion caused by residual acid caused by double hassle that requires separate safety accident and neutralization treatment after use Due to the shortening of the equipment lifespan, enormous economic losses occur, and the acid wastewater is additionally treated accordingly.

In addition, customs and rust preventive chemicals currently in use should be used in large quantities, and the scale removal operation had a problem of stopping the mechanical device in operation.

And, until now, no anti-corrosive and customs chemicals have been developed which have anti-corrosion and descaling functions.

The present invention is neutral (pH = 6 to 8) in order to solve the problems of the conventional customs and rust preventive chemicals as described above, does not affect the metal material of the piping and other mechanical devices, and a small amount of high performance during machine operation It is an object of the present invention to provide a compound for corrosion prevention and descaling, which can be used by use, has no heavy metals and is neutral, and has non-toxic antirust and customs functions that do not affect the external ecosystem.

Another object of the present invention is to provide a composition for preventing corrosion and removing scale containing the compound.

Corrosion preventing and descaling compounds according to the first object of the present invention is 10 to 30 parts by weight of carboxylic acid-phosphoric acid condensate, 10 to 30 parts by weight of hydroxy polycarboxylic acid, NaOH, KOH, K ₂ CO ₃ , KHCO 5 to 15 parts by weight of at least one alkaline neutralizing agent selected from ₃ , Na ₂ CO ₃ , and NaHCO ₃ are prepared by stirring and reacting at a temperature of 80 to 110 ° C. for 1 to 2 hours, and the pH of the 1 wt% aqueous solution is 6 to 8 It is

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Preferably, the anti-corrosion and descaling compound according to the first object of the present invention is represented by the following formula (2) and the pH of the 1% aqueous solution is 6 to 8:

Wherein M ¹ to M ⁴ are each a hydroxy group or one metal selected from K, Na, preferably hydroxy or Na,

M ⁵ to M ⁷ are each hydrogen or one metal selected from K and Na, preferably hydrogen or Na.

Most preferably, the compound for preventing corrosion and descaling according to the first object of the present invention is represented by the following formula (3) and the pH of 1% aqueous solution is 6 to 8:

The anti-corrosion and descaling composition according to the second object of the present invention comprises at least one selected from 30 to 72 parts by weight and 5 to 20 parts by weight of sodium citrate, EDTA-2Na and glucose as described above. It is containing further. The amount of these can be added or subtracted depending on the type of scale and the corrosion state of the pipe to be descaled.

The composition may further comprise 10 to 50 parts by weight of water, soda citric acid, EDTA-2Na and glucose are added separately or after the preparation of the anti-corrosion and descaling compounds according to the first object of the present invention or corrosion and descaling It may be added with water in the preparation step of the compound.

The composition is further contained in nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkyl phenol ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters and sucrose fatty acid esters. It may contain one or more selected ones, and by including these surfactants, it becomes a solid phase. In addition, the nonionic surfactants are the same as those used to control the dissolution rate of the solid or jelly toilet bowl detergent, and the release rate is controlled by controlling the dissolution rate of the anti-corrosion and descaling compound of the present invention. It will play a role. Such a nonionic surfactant can be purchased, for example, under the trade name of "DO 3K" from Southeast Synthetics.

The anti-corrosion and descaling compound and the composition comprising the same according to the present invention are neutral and there is no risk of handling, and the solid phase composition having excellent descaling and anti-corrosion effect and controlled release rate is released even if a large amount is added to the feed tank once. It gradually dissolves at a constant speed by the adjustment function and exerts effect continuously for a long time, so it is possible to operate it for a long time without stopping operation for customizing boilers and other facilities with a single input. Does not cause

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the examples are provided only to aid the understanding of the present invention, and in no case should be interpreted as limiting the scope of the present invention, the protection scope of the present invention is limited only by the appended claims. .

Example 1

To 50 g of pure water, 15 g of hydroxyethylene diphosphonic acid and 20 g of hydroxypropane tricarboxylic acid were dissolved with stirring for 1 hour, 5 g of EDTA-2Na was added, 5 g of NaOH and 5 g of glucose were added, followed by stirring for 1 hour. A liquid composition for prevention and descaling was obtained.

Example 2

15 g of hydroxyethylene diphosphonic acid and 10 g of hydroxypropane tricarboxylic acid were dissolved in 50 g of pure water for 1 hour, followed by dissolving 15 g of sodium citrate and 5 g of glucose, adding 5 g of NaOH, and stirring for 1 hour to prevent light brown corrosion and A liquid composition for descaling was obtained.

Example 3

After the pure water 50g hydroxy ethylene diphosphonic acid 10g and hydroxy tri-carboxylic acid In a 20g EDTA-2Na 5g to and stirred for 1 hour to dissolve Na ₂ CO ₃ 10 g was added to dissolve and 5 g of glucose was added and stirred for 1 hour to obtain a white liquid composition for preventing corrosion and descaling.

Example 4

To the pure 50g hydroxy ethylene diphosphonic acid 10g and hydroxy tri-carboxylic acid In the 10g and citric acid soda 15g, and stirred for 1 hour and then put into glucose 5g and Na ₂ CO ₃ 10g was dissolved by stirring for 1 hour A brown anticorrosion and descaling liquid composition was obtained.

Example 5

30 g of hydroxyethylene diphosphonic acid and 20 g of hydroxypropane tricarboxylic acid were dissolved in 10 g of pure water at 80-90 ° C. for 1 hour, and then dissolved. When 25g of polyoxyethylene derivative was added, 5g of glucose was added thereto, followed by stirring and cooling for 30 minutes to obtain a highly concentrated solid composition for preventing corrosion and descaling of white color. The photograph of the obtained product is shown in FIG.

Example 6

20 g of pure water and 20 g of hydroxyethylene diphosphonic acid and 20 g of hydroxypropane tricarboxylic acid were dissolved with stirring at 80-90 ° C. for 1 hour, 10 g of sodium citrate was added thereto, and 15 g of Na ₂ CO ₃ was added thereto, at a temperature of 100-110 ° C. When reached to 20g of polyoxy ethylene derivative was added and stirred for 30 minutes and cooled to obtain a highly concentrated solid composition for preventing corrosion and descaling of white.

Example 7

To 30 g of pure water, 25 g of hydroxyethylene diphosphonic acid and 25 g of hydroxypropane tricarboxylic acid were dissolved with stirring at 80-90 ° C. for 1 hour. Then, 10 g of sodium citrate was added and 8 g of NaOH was added to reach a temperature of 100-110 ° C. When 10 g of glucose was added thereto, the mixture was stirred for 30 minutes and cooled to obtain a highly concentrated solid composition for preventing corrosion and descaling of white color.

Example 8

To 10 g of pure water, 30 g of hydroxyethylene diphosphonic acid and 30 g of hydroxypropane tricarboxylic acid were dissolved with stirring at 80-90 ° C. for 1 hour, followed by adding 10 g of EDTA-2Na and adding 12 g of NaOH to 10 g of glucose at 100-110 ° C. Then, 15 g of polyoxyethylene derivative was added thereto, followed by stirring for 30 minutes and cooling to obtain a highly concentrated solid composition for preventing corrosion and descaling of white color.

The results of comparing the anti-corrosion and descaling agent composition according to the present invention with heavy metals, descaling and anti-corrosion ability with conventional commercial products and fish (goldfish) toxicity test results are shown below.

Experimental Example 1

The results of analyzing the presence of heavy metals and toxic substances by requesting from Korea Testing and Research Institute are shown in Table 1 below.

sample Exterior pH Heavy metal content Cr Pb CD Hg Example 5 White solid 7.2 Not detected Not detected Not detected Not detected KSM 0011: 20031 (measured in w / v% aqueous solution) ICP Analysis

As described above, the anti-corrosion and descaling composition of the present invention does not contain heavy metals and other toxic substances, so it is safe for the human body and the ecosystem, and the pH is neutral, and thus there is no difficulty in handling.

Experimental Example 2

Evaluation of Scale Removal Force

* Test method (Total hardness titration method)

Calcium ion (Ca ²⁺ ) concentration: 500 mg / l as CaCO ₃ ; Magnesium ion (Mg ²⁺ ) concentration: 200 mg / l as MgCO ₃ ; 50 ml of water sample with pH = 8.0 ± 0.5 was added to the Erlenmeyer flask, and each of the descaling agents listed in Table 2 was added at the prescribed concentration, and allowed to stand at 30 ± 5 ° C for 60 minutes, followed by mixing 1-2 ml of ammonium chloride buffer. PH = 10 ~ 10.8, add 2-3 drops of EBTchrome (Erichchrome black T indicator) and shake. At this time, the solution turns red. The solution is titrated with 0.01 M EDTA (ethylene-diamine tetraacetic acid) solution until the sample solution turns blue. At this time, the total hardness (mg / l) was calculated from the consumed amount of 0.01M EDTA solution (a; ml) according to the following equation, and the Ca ⁺² and Mg ⁺² ion removal powers were calculated for each dose, and the scale removal power was evaluated. It is shown in Table 2 below.

Total hardness (ppm; mg / l) = (a) x ㅇ (sample volume, ml) / 1,000 x f

Wherein a = 0.01 M-EDTA consumption in ml and f = 1.0.

Descaling force (%) by concentration of descaling agent Descaler Concentration (ppm) 0 5 10 15 20 25 polyphosphate ¹⁾ 0 16.8 21.4 32.6 40.5 55.8 acryl polymer ²⁾ 0 18.5 22.4 36.5 42.8 56.4 PAA / MA copolymer ³⁾ 0 32.5 52.6 60.4 68.4 71.5 Example 2 0 89.5 91.2 95.4 97.5 99.7

Note: 1) Tripolysodium phosphate product from Kanto Chemical, Japan

     2) Sodium polyacrylate product of Doojin Chemical Co., Ltd. in Korea

     3) Doojin Chemical Co., Ltd. polyacrylate / maleic acid copolymer product

Referring to Table 1 above, it can be seen that the descaling ability of the anticorrosion and descaling compound-containing composition of the present invention is much superior to the conventional descaling agent, and the descaling ability is excellent even at low concentration.

Experimental Example 3

Evaluation of Corrosion Inhibition Effect

Test Method (O-Phenanthroline Absorbance Spectroscopy)

Ferric oxide ion (Fe ³⁺ ) concentration: 100 mg / l; Calcium ion (Ca ²⁺ ) concentration: 100 mg / l as CaCO ₃ ; HCO ₃ ^- Concentration: 50 mg / l as CaCO ₃ ; 50 ml of water sample with pH = 8.0 ± 0.5 was added to the Erlenmeyer flask and each corrosion inhibitor was added at the prescribed concentration. After standing at 30 ± 5 ℃ for 60 minutes, 2 ml of hydrochloric acid and 1 ml of hydroxylamine were added. Heat and concentrate until it is cooled, and then, after cooling, 10 ml of ammonium acetate buffer and 2-3 ml of o-Phenanthroline solution are added and left to develop for 15 minutes. The total amount of iron (Total-Fe) was calculated by the standard calibration curve, and the corrosion inhibitory power was calculated for each input amount, and is shown in Table 2 below.

Corrosion inhibitory power by concentration of corrosion inhibitor (%) Corrosion remover concentration (ppm) 0 10 20 30 40 50 polyphosphate ¹⁾ 0 10.4 17.8 21.5 34.2 42.6 acryl polymer ²⁾ 0 1.4 2.6 4.5 9.8 12.4 PAA / MA copolymer ³⁾ 0 10.8 18.5 26.4 35.2 47.5 Example 2 0 32.5 85.4 92.4 96.8 99.8

Note: 1) Tripolysodium phosphate product from Kanto Chemical, Japan

     2) Sodium polyacrylate product of Doojin Chemical Co., Ltd. in Korea

     3) Doojin Chemical Co., Ltd. polyacrylate / maleic acid copolymer product

Referring to Table 2 above, it can be seen that the corrosion inhibiting ability of the anticorrosive and descaling compound-containing composition of the present invention is much superior to conventional corrosion inhibitors, and the corrosion inhibiting ability is excellent even at low concentrations.

Experimental Example 4

Evaluation of corrosion protection

When the 0.05 wt% of the compound prepared in Example 1 was added to water and the zinc alloy steel pipe (white tube) was immersed in water for 1 month, respectively, and the anticorrosion effect test was performed. The results are compared with those of FIGS. 2A and 2B. The photo is shown. When the compound of the present invention is added, it can be confirmed that no corrosion occurs even after one month.

An aluminum tube and a copper tube were placed in water to which 1.0 wt% of the composition prepared in Example 6 was added, respectively. FIG. 3a and FIG. Through this, it can be seen that the composition containing the compound of the present invention has a corrosion protection effect on aluminum and copper.

Experimental Example 5

Evaluation of the Descaling Effect

When the calcium and magnesium scales were added to water and 5% of the compound prepared in Example 3 of the present invention and left unwatered for 1 month, the scale dissolution test was performed and the pictures taken of the results are shown in FIGS. 4A and 4B. Shown in

5 wt% of the composition prepared in Example 7 of the present invention was added to the water and the water was added to the hard silica scale was not observed the scale dissolution phenomenon for 3 days and the results are shown in the photographs 5a to 5d .

As can be seen from the above pictures, the scale is dissolved and removed in the water containing the compound of the present invention, but it can be seen that the scale is not dissolved at all in the other water.

Experimental Example 6

Fish Toxicity Test Results

In 500 ml of mineral water, the composition prepared in Example 2 of the present invention was added to each of the concentrations shown in Table 4 below (pH = 7.2), and then one goldfish was added. Survival was confirmed, and as a result, the photograph is shown in FIGS. 7A to 10C together with FIGS. 6A to 6C when no drug was added, and the results are summarized in Table 3 below.

Toxicity test results for fish Fish and Weight Goldfish 5.2g Goldfish 5.0 g Goldfish 5.4g Goldfish 5.2g Drug concentration (wt%) 0.01 0.05 0.1 0.15  Elapsed time (hr) 24 survival survival survival survival 48 survival survival survival survival 72 survival survival survival survival

As can be seen in Table 4 and FIGS. 6A to 10C, the anti-corrosion and descaling composition of the present invention is excellent in anti-corrosion effect even at a low concentration of 0.01 wt%, as well as at least 72 hours at a high concentration of 0.15%. In view of the fact that it is not dead, it can be seen that it is a safe substance that does not affect the ecosystem even if it is discharged without any separate wastewater treatment procedure after customs work.

As described above, the anti-corrosion and descaling compound / composition of the present invention is an environmentally friendly agent that exhibits excellent anti-corrosion and descaling effects even when using less than conventional chemicals and does not cause secondary environmental pollution problems. As it is neutral, it is easy to use and handle, and even after use, it does not damage any metal material inside the machinery and pipes, and thus prolongs the life of the equipment. There is no need to avoid the economic loss of an outage.

Claims (6)

10-30 parts by weight of carboxylic acid-phosphoric acid condensate, 10-30 parts by weight of hydroxy polycarboxylic acid, at least one alkaline selected from NaOH, KOH, K ₂ CO ₃ , KHCO ₃ , Na ₂ CO ₃ , and NaHCO ₃ 5 to 15 parts by weight of a neutralizing agent is prepared by stirring and reacting at a temperature of 80 to 110 ° C. for 1 to 2 hours, and the pH of the 1 wt% aqueous solution is 6 to 8, A compound for preventing corrosion and removing scale represented by the following Chemical Formula 2: [Formula 2]

Wherein M ¹ , M ² , M ³ and M ⁴ are each one selected from hydroxy, K and Na, M ⁵ , M ⁶ and M ⁷ are each one selected from hydrogen, K and Na. delete delete According to claim 1, Corrosion prevention and descaling compound represented by the formula (3): [Formula 3]

Anticorrosion and descaling further comprising at least 30 to 72 parts by weight and 5 to 20 parts by weight of citric acid soda, EDTA-2Na and glucose according to claim 1 or 4 Composition. The nonionic surfactant according to claim 5, wherein the polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alkyl phenol ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester and sucrose fatty acid ester are selected. The composition for preventing corrosion and descaling solid phase controlled release rate, characterized in that it further comprises.

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