CN102153212A - Composite corrosion and scale inhibitor containing benzotriazole - Google Patents

Abstract

The invention discloses a composite corrosion and scale inhibitor containing benzotriazole. The corrosion and scale inhibitor consists of maleic acid compound, acrylic acid terpolymer, zinc salt, gluconate, sulfamic acid compound and benzotriazole The benzotriazole compound corrosion and scale inhibitor of the present invention has a wide application range and can be used for corrosion and scale inhibition treatment of carbon steel, copper and copper alloy equipment. The benzotriazole composite corrosion and scale inhibitor of the present invention is a completely phosphorus-free formula, and the treated external drainage will not cause eutrophication pollution caused by phosphorus to the water body, and is an environmentally friendly product; the benzotriazole compound of the present invention There is no need to pre-coat the equipment before using the triazole composite corrosion and scale inhibitor. It can be operated at room temperature, and the treatment effect is stable. The annual corrosion rate of carbon steel is lower than ^0.0240mm . It has good corrosion and scale inhibition effects and economic and environmental benefits.

Description

Composite corrosion and scale inhibitor containing benzotriazole

technical field

The invention relates to a phosphorus-free, biodegradable, high-efficiency, environment-friendly corrosion and scale inhibitor for industrial circulating cooling water treatment systems, in particular to a benzotriazole-containing composite corrosion and scale inhibitor.

Background technique

The economic loss caused by metal corrosion to the development of the national economy accounts for about 1.5-4.2% of the national economic output value. Metal corrosion problems pervade all fields of the national economy, from daily life to industrial and agricultural production, from cutting-edge technology to national defense industry , wherever metal materials are used, corrosion problems exist to varying degrees. It brings huge economic losses to people, causes catastrophic accidents, and consumes precious energy and resources. In order to minimize the loss caused by corrosion, corrosion researchers have developed and developed many anti-corrosion measures, and the application of organic corrosion and scale inhibitors is one of the most extensive and effective means.

The molecules of organic corrosion and scale inhibitors are usually composed of polar groups centered on atoms such as O, N, S, and P with relatively high electronegativity, and non-polar groups composed of C and H atoms. Polar groups are adsorbed on the metal surface to change the structure of the electric double layer and increase the activation energy of metal ionization; non-polar groups are far away from the metal surface to form a hydrophobic protective film, and the two work together to inhibit the corrosion of the metal. With the strengthening of environmental and safety awareness, environmental load must be considered in the research and development of corrosion inhibitors, which requires us to design new and efficient corrosion and scale inhibitors that meet environmental requirements, and develop synergistic technologies for corrosion and scale inhibitors . In recent years, triazole compounds have attracted increasing attention due to their special molecular structure and excellent corrosion and scale inhibition properties. Quraishi and Bentiss conducted systematic research on multi-unit triazole compounds and found that triazole compounds have the characteristics of wide temperature range and environmental friendliness. Therefore, there is a great way to develop high-efficiency corrosion and scale inhibitors compounded with triazole compounds.

Contents of the invention

The purpose of the present invention is to provide a composite corrosion and scale inhibitor containing benzotriazole, which can be used in industrial circulating cooling water systems, improve the water saving rate of industrial water, reduce the amount of sewage discharge, and overcome the impact of phosphorus-containing corrosion and scale inhibitors on the environment. secondary pollution.

The compound corrosion and scale inhibitor containing benzotriazole provided by the invention comprises maleic acid compound, acrylic acid terpolymer, zinc salt, gluconate, sulfamic acid compound, benzotriazole and distilled water; The mass percentage of composite corrosion and scale inhibitors is: polymaleate 20%-25%, acrylic acid terpolymer 12%-18%, zinc salt 10%-15%, gluconate 15%-20%, 1%-2% of sulfamic acid compound, 0.5%-1% of benzotriazole, and the rest is distilled water.

Wherein, the maleic acid compound is selected from one or more mixtures of styrene maleic acid, dimethyl maleic anhydride, hydrolyzed polymaleic acid, and maleic anhydride grafted polyethylene.

The acrylic acid terpolymer is selected from acrylic acid-2-acrylamide-2 methylpropanesulfonic acid, acrylic acid-acrylate-sulfonate terpolymer, styrene-maleic anhydride-acrylic acid lauryl terpolymer Copolymer, acrylic acid-AMPS-hydroxypropyl acrylate terpolymer, or a mixture of two or more.

The zinc salt is selected from one or a mixture of zinc nitrate, zinc sulfate, zinc molybdate, zinc borate and zinc chloride.

The gluconate is selected from one or a mixture of potassium gluconate, sodium gluconate, D-sodium gluconate, D-potassium gluconate, zinc gluconate and manganese gluconate.

The sulfamic acid compound is selected from one or a mixture of ammonium sulfamate, sodium p-aminobenzenesulfonate, and sulfamic acid.

The preparation method of the benzotriazole-containing composite corrosion and scale inhibitor of the present invention: take each material according to the composition mass percentage, and then distilled water, maleic acid compound, acrylic acid terpolymer, zinc salt, gluconic acid Add the salt, sulfamic acid compound and benzotriazole into the container in sequence according to the above, and stir at room temperature for 1 hour to obtain the product.

The preferred technical solution of the present invention is: a composite corrosion and scale inhibitor containing benzotriazole for use in industrial cooling water systems, characterized in that the composition of the composite corrosion and scale inhibitor is: maleic acid compound 20 %～25%, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 12%～18%, zinc nitrate or zinc sulfate 10%～15%, gluconate 15%～20%, sulfamic acid 1% ～2%, benzotriazole 0.5%～1%, the rest is distilled water, wherein the maleic acid compound is selected from hydrolyzed polymaleic acid or styrene maleic acid, and the gluconate is D- Sodium gluconate or potassium gluconate.

According to the above preferred technical solution: in the benzotriazole-containing composite corrosion and scale inhibitor, the polymaleic acid compound is hydrolyzed polymaleic acid, and its mass percentage concentration is 21%-23%.

According to the above preferred technical scheme, in the benzotriazole-containing composite corrosion and scale inhibitor, the mass percent concentration of the acrylic acid-2-acrylamide-2-methylpropanesulfonic acid is 13% to 16% .

According to the above preferred technical solution: in the benzotriazole-containing composite corrosion and scale inhibitor, the mass percentage concentration of the zinc nitrate or zinc sulfate is 12%-15%.

According to the above preferred technical solution: in the benzotriazole-containing composite corrosion and scale inhibitor, the mass percent concentration of the gluconate is 16%-19%.

According to the above preferred technical solution: in the benzotriazole-containing composite corrosion and scale inhibitor, the mass percent concentration of the sulfamic acid is 1.2-1.8%.

According to the above preferred technical scheme: the preparation method of the benzotriazole-containing composite corrosion and scale inhibitor is characterized in that: each material is taken according to the mass percentage of the composition, and then distilled water, maleic acid compound, acrylic acid -2-acrylamide-2-methylpropanesulfonic acid, zinc nitrate or zinc sulfate, gluconate, sulfamic acid and benzotriazole are added to the container in sequence according to the above order, and stirred at room temperature for 1 hour to obtain product.

The application of the benzotriazole-containing composite corrosion and scale inhibitor of the present invention is suitable for the industrial cooling water circulation system of carbon steel, copper and copper alloy equipment, and the alkalinity is lower than 7.0mmol.L ^-1 and the hardness is lower than 8.0 mmol.L ^-1 , C(Ca ²⁺ ) less than 400mg.L ^-1 , C(Cl ^- ) less than 800mg.L ^-1 , conductance below 2400us.cm ^-1 for direct treatment of industrial cooling circulating water, put into Add benzotriazole compound corrosion and scale inhibitor, the dosage is 20mg.L ^-1 ~50mg.L ^-1 .

The present invention has the following characteristics:

1. The formula of the benzotriazole-containing composite corrosion and scale inhibitor of the present invention does not contain phosphorus at all, which avoids the possibility of calcium phosphate scale, so there is no need to consider the performance of calcium phosphate inhibition, and it is not easy to cause damage due to phosphorus discharge. The resulting eutrophication of the water body is an environmentally friendly product.

2. This composite corrosion and scale inhibitor contains benzotriazole. The benzotriazole in the formula contains a delocalized electron π bond, which strengthens the adsorption of metals with a planar adsorption configuration, which is beneficial to increase the corrosion resistance and scale inhibitor. The coverage of corrosion and scale inhibitors on the metal surface and the formation of multi-layer adsorption on the surface.

3. The raw materials of the benzotriazole-containing composite corrosion and scale inhibitor have a wide range of sources, and the preparation process of the corrosion and scale inhibitor is simple, the investment in equipment is low, and the equipment does not need to be pre-coated before the agent is used.

4. In this compound corrosion and scale inhibitor containing benzotriazole, the selected sodium D-gluconate is a polyhydroxy hydroxy acid corrosion inhibitor, which has a good complexing effect on Fe ²⁺ and other metals. The composite corrosion and scale inhibitor contains groups such as -CONH ₂ and sulfonic acid groups. Under the synergy and dispersion of these groups, the corrosion current in the system is reduced, the galvanic effect on the metal surface is blocked, and the corrosion rate is reduced. The corrosion rate plays a role in protecting the metal surface.

5. This benzotriazole-containing composite corrosion and scale inhibitor has a wide range of applications, and can be used for corrosion and scale inhibition of carbon steel, copper and copper alloy equipment.

Specific implementation plan:

The composition and application effect of the benzotriazole-containing composite corrosion and scale inhibitor of the present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited to the scope of the examples.

The medicines used in the following examples are commercially available products or routine laboratory medicines.

Example 1

To prepare a composite corrosion and scale inhibitor containing benzotriazole, the materials are taken according to the following mass percentages: hydrolyzed polymaleic acid or styrene maleic acid 20% to 25%, acrylic acid-2-acrylamide-2- Methylpropanesulfonic acid 12%-18%, zinc nitrate or zinc sulfate 10%-15%, D-sodium gluconate or potassium gluconate 15%-20%, sulfamic acid 1%-2%, benzotriazepam 0.5% to 1% azole, the rest is distilled water; then distilled water, hydrolyzed polymaleic acid or styrene maleic acid, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid, zinc nitrate or zinc sulfate, D- Add sodium gluconate or potassium gluconate, sulfamic acid and benzotriazole into the container in sequence according to the above, and stir at room temperature for 1 hour to obtain the product.

Example 2

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 21g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 16g, Zn( NO ₃ ) ₂ .6H ₂ O 14g, D-sodium gluconate 16, sulfamic acid 1.8g, benzotriazole 0.5g, and the rest is distilled water, add them in turn to a clean and dry beaker, stir well to get the product .

Example 3

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 22g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 15g, Zn( NO ₃ ) ₂ .6H ₂ O 13g, D-sodium gluconate 17g, sulfamic acid 1.7g, benzotriazole 0.6g, and the rest are distilled water, add them in turn to a clean and dry beaker, stir well to get the product .

Example 4

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 23g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 14g, Zn( NO ₃ ) ₂ .6H ₂ O 12g, D-sodium gluconate 18g, sulfamic acid 1.6g, benzotriazole 0.7g, and the rest are distilled water, add them in turn to a clean and dry beaker, stir well to get the product .

Example 5

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 21g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 16g, ZnSO ₄ Add 14g of 7H ₂ O, 19g of sodium D-gluconate, 1.2g of sulfamic acid, 0.5g of benzotriazole, and the rest in distilled water into a clean and dry beaker, and stir evenly to obtain the product.

Example 6

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 22g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 13g, ZnSO ₄ Add 13g of 7H ₂ O, 16g of sodium D-gluconate, 1.5g of sulfamic acid, 0.6g of benzotriazole, and the rest in distilled water into a clean and dry beaker, and stir evenly to obtain the product.

Example 7

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 23g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 14g, ZnSO ₄ Add 12g of 7H ₂ O, 17g of sodium D-gluconate, 1.4g of sulfamic acid, 0.7g of benzotriazole, and the rest in distilled water into a clean and dry beaker, and stir evenly to obtain the product.

Example 8

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 21g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 15g, Zn( NO ₃ ) ₂ .6H ₂ O 14g, D-sodium gluconate 18g, sulfamic acid 1.3g, benzotriazole 0.5g, and the rest are distilled water, add them in turn to a clean and dry beaker, stir well to get the product .

Example 9

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 22g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 16g, ZnSO ₄ Add 13g of 7H ₂ O, 19g of sodium D-gluconate, 1.2g of sulfamic acid, 0.6g of benzotriazole, and the rest in distilled water into a clean and dry beaker, and stir evenly to obtain the product.

Example 10

Prepare 100g of benzotriazole-containing composite corrosion and scale inhibitors, preparation process: get 50% hydrolyzed polymaleic acid 23g, 30% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid 15g, Zn( NO ₃ ) ₂ .6H ₂ O 12g, D-sodium gluconate 18g, sulfamic acid 1.3g, benzotriazole 0.7g, and the rest are distilled water, add them in turn to a clean and dry beaker, stir well to get the product .

Example 11

Application Effect Test of Composite Corrosion and Scale Inhibitor Containing Benzotriazole Prepared in Example 2-10

The water used in this experiment is the circulating cooling water of the enterprise. The corrosion rate of A3 carbon steel in the cooling circulating water is measured by the weight loss method of the rotating hanging plate. Preparation of composite corrosion and scale inhibitors containing benzotriazole.

Experimental water quality indicators:

Static scale inhibition test: The test temperature is 45°C, and at the same time, 0.5Lmin ^-1 of nitrogen gas is passed into the bottom of the container, and the test is stopped when the concentration ratio is 6 times. Calculation formula of resistance to calcium carbonate rate η _k :

η _k = (C ₂ -C ₁ )/(K×C ₀ -C ₁ )×100%

In the formula: C ₂ is the measured Ca ²⁺ mass concentration after adding the drug, mg.L ^-1 ; C ₁ is the measured Ca ²⁺ mass concentration without adding the drug, mg.L ^-1 ; C ₀ is the measured Ca 2+ mass concentration without adding the drug Initial Ca ²⁺ mass concentration, mg.L ^-1 ; K is the concentration multiple under the measurement conditions of C ₂ and C ₁ .

Rotating coupon corrosion test: The test equipment is assembled according to HG/T2159-91 standard. Experimental conditions: ①Constant temperature 45±1℃; ②Rotational speed 75r.min ^-1 ; ③Experiment period 72h. The test coupon adopts Type I test piece of HG/T 3523-2008 "Technical Conditions for Standard Corrosion Test Specimen of Cooling Water Chemical Treatment". The material is A3 carbon steel sheet, the size is 50mm×25mm×2mm, and the area of the test piece is 28cm ² . The formula for calculating the annual corrosion rate (mm·a ^-1 ) is as follows:

K _a =87600(m ₀ -m)/spt

In the formula: K _a is the annual corrosion rate, mm.a ^-1 ; m ₀ is the mass of the test piece before the experiment, g; m is the mass of the test piece after the experiment, g; s is the surface area of the test piece, cm ² ; ρ is Density of test piece, g.cm ^-3 ; t is test time, h.

The experimental test data is shown in the table below:

Example Drug dosage mg.L ^-1 Annual corrosion rate mm.a ^-1 Calcium carbonate resistance rate% Example 2 30 0.0227 98.8% Example 3 30 0.0199 98.5% Example 4 30 0.0213 98.3% Example 5 30 0.0234 99.2% Example 6 30 0.0212 98.7% Example 7 30 00214 98.2% Example 8 30 0.0224 99.3%

Example 9 30 0.0226 98.8% Example 10 30 0.0205 98.2% Blank 0 0.5621 ---

The results show that the annual corrosion rate is lower than 0.0240 mm.a ^-1 and the calcium carbonate inhibition rate is over 98.2% after using the benzotriazole-containing composite corrosion and scale inhibitor of the present invention.

Claims (8)

1. one kind contains the benzotriazole composite slow-corrosion scale resistor, be used for industrial cooling circulating water system, it is characterized in that, this composite slow-corrosion scale resistor is formed mass percent: maleinization compound 20%～25%, vinylformic acid-2-acrylamide-2-methyl propane sulfonic acid 12%～18%, zinc nitrate or zinc sulfate 10%～15%, gluconate 15%～20%, thionamic acid 1%～2%, benzotriazole 0.5%～1%, all the other are distilled water, and wherein said maleinization compound is selected from hydrolyzed polymaleic anhydride or styrene maleic acid, and described gluconate is maltonic acid sodium or maltonic acid potassium.

2. the benzotriazole composite slow-corrosion scale resistor that contains according to claim 1 is characterized in that described polymaleic acid compound is a hydrolyzed polymaleic anhydride, and its mass percent concentration is 21%～23%.

3. the benzotriazole composite slow-corrosion scale resistor that contains according to claim 1 is characterized in that, the mass percent concentration of described vinylformic acid-2-acrylamide-2-methyl propane sulfonic acid is 13%～16%.

4. the benzotriazole composite slow-corrosion scale resistor that contains according to claim 1 is characterized in that the mass percent concentration of described zinc nitrate or zinc sulfate is 12%～15%.

5. the benzotriazole composite slow-corrosion scale resistor that contains according to claim 1 is characterized in that the mass percent concentration of described gluconate is 16%～19%.

6. the benzotriazole composite slow-corrosion scale resistor that contains according to claim 1 is characterized in that the mass percent concentration of described thionamic acid is 1.2～1.8%.

7. the described preparation method who contains the benzotriazole composite slow-corrosion scale resistor of claim 1, it is characterized in that: get each material by described composition mass percent, then with distilled water, maleinization compound, vinylformic acid-2-acrylamide-2-methyl propane sulfonic acid, zinc nitrate or zinc sulfate, gluconate, thionamic acid and benzotriazole, add in the container successively by said sequence, stir 1h at normal temperatures, promptly get product.

8. the described application that contains the benzotriazole composite slow-corrosion scale resistor of claim 1 is characterized in that, is applicable to the industrial colling recycle system of carbon steel, copper and copper alloy equipment, and basicity is lower than 7.0mmol.L ^-1, hardness is lower than 8.0mmol.L ^-1, C (Ca ²⁺) be lower than 400mg.L ^-1, pH=7.5～9.2, C (Cl ^-) be lower than 800mg.L ^-1, electricity is led at 2400 μ s.cm ^-1Following industrial cooling circulating water is directly handled, and benzotriazole composite slow-corrosion scale resistor, dosage are 20mg.L ^-1～50mg.L ^-1