Iminodisuccinate product with high copper chelation value and high calcium chelation value as well as preparation and application of iminodisuccinate product

Abstract

The invention discloses an iminodisuccinate product with high copper chelation value and high calcium chelation value, a maleic anhydride process is adopted to produce the iminodisuccinate product, the molar ratio of L-aspartic acid to maleic anhydride to sodium hydroxide in raw materials is controlled to be 1: (1.03-1.06): (3.4-3.7), the heat preservation temperature of an ammonification reaction is controlled to be 100-105 DEG C, and the heat preservation time is 12-14 hours. According to the iminodisuccinate product disclosed by the invention, the calcium chelation value reaches 330mg / g or above while various indexes of the product meet industrial standard requirements, and the conditions of large medicament addition amount and high addition frequency caused by low calcium chelation capacity of the iminodisuccinate in daily use of a user can be greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of iminodisuccinates, in particular to an iminodisuccinate with both high copper chelation value and high calcium chelation value, as well as the preparation and application of the iminodisuccinate. Background Art

[0002] Chelating agents are widely used in industrial and agricultural production and life due to their stable metal coordination ability. However, with the discharge of industrial and agricultural wastewater, a large amount of chelating agents enter the environment with the wastewater. Not only does the non-degradability of the chelating agents themselves cause pollution to water and soil, but their chelating ability increases the solubility of heavy metals, which can also cause heavy metal accumulation hazards in water and soil.

[0003] As a new type of green chelating agent, IDS has excellent chelating properties and good biodegradability, making it widely used in many technical fields, especially in the field of water treatment. The main functions of water treatment agents are to prevent scale, prevent corrosion, treat wastewater and alleviate the hardness of water. IDS can combine with scale-forming ions such as calcium, magnesium, iron, and copper in water to form water-soluble complexes, thereby avoiding the formation of scale and protecting the normal operation of pipelines and equipment; it can also combine with metal ions in water to form stable complexes, reduce the concentration of metal ions, and reduce the corrosion of metal ions on pipelines and equipment; it can also be used to treat harmful metal ions in the wastewater treatment process to reduce their pollution to the environment, so it is used as an important chelating raw material for various water treatment agents.

[0004] However, IDS has different chelating abilities for different metal ions, and the chelating values ​​of different metal ions are obviously different. For example, IDS has a higher chelating ability for Mn 2+ The chelation value of Ca is about 245mg / g. 2+ The chelation value of Cu is about 214 mg / g. 2+ The chelation value of Fe is about 371mg / g. 3+ The chelation value is about 99 mg / g. At present, the calcium chelation value of conventional iminodisuccinate products is only about 220 mg / g. In use, the cleaning effect is poor due to the low calcium ion chelation ability. In this regard, users solve the cleaning problem by increasing the dosage, which not only increases the cleaning cost and operating cost, but also increases the organic matter content in the water treatment system, making subsequent treatment difficult. Therefore, users require iminodisuccinate products to significantly increase the calcium chelation value while maintaining the copper chelation value unchanged. Summary of the invention

[0005] In order to solve the problem of insufficient calcium chelation value of iminodisuccinate products, the present invention provides an iminodisuccinate product with both high copper chelation value and high calcium chelation value. While ensuring that various indicators of the product meet the requirements of industry standards, the calcium chelation value reaches above 330 mg / g, and can reach up to 354.67 mg / g at the highest. This can greatly improve the situation in which users add a large amount of medicine and a high frequency of addition due to the low calcium chelation ability of iminodisuccinate in daily use.

[0006] To achieve the above-mentioned purpose, the present invention provides an iminodisuccinate product with both high copper chelating value and high calcium chelating value. The iminodisuccinate is produced by a maleic anhydride process, the mass molar ratio of L-aspartic acid, maleic anhydride and sodium hydroxide in the raw materials is controlled to be 1:(1.03-1.06):(3.4-3.7), and the insulation temperature after the ammonia addition reaction is controlled to be 100-105°C and the insulation time is controlled to be 12-14h.

[0007] The present invention adjusts the reaction conditions of producing iminodisuccinate (IDS) by a maleic anhydride process, including the dosage ratio of reaction raw materials, the temperature and time of ammonia addition reaction, to change the composition of the iminodisuccinate product, so as to achieve the goal of not affecting the original excellent performance, such as the effective component content and the copper chelating ability, and significantly improving the calcium chelating ability. Specifically, by reducing the dosage ratio of maleic anhydride and alkali, and reducing the reaction temperature and shortening the reaction time, the differences other than the main components are reflected in the product performance index detection results and infrared analysis spectra, so that a relatively high copper chelating value is maintained and the calcium chelating value is significantly improved, and the invention has extremely important application value in practical application.

[0008] As a limitation of the above technical solution, in the maleic anhydride process, the acid-base reaction of maleic anhydride and sodium hydroxide is first carried out at 60-80° C. for 1-2 hours. After the reaction, the solution is clarified and L-aspartic acid is added to carry out an ammonia addition reaction.

[0009] As a limitation of the above technical solution, the conversion rate of the iminodisuccinate obtained after the insulation is completed is greater than 80%.

[0010] As a limitation of the above technical solution, the effective content of iminodisuccinate in the iminodisuccinate product is greater than 32%, and the calcium chelation value is greater than or equal to 330 mg / g.

[0011] As a limitation of the above technical solution, the copper chelation value of the iminodisuccinate product is ≥380 mg / g, and other indicators meet the requirements of industry standards.

[0012] The present invention provides a method for preparing the iminodisuccinate product having both high copper chelation value and high calcium chelation value as described above, comprising the following preparation steps:

[0013] First, water, maleic anhydride and sodium hydroxide are added to the reaction kettle, and an acid-base reaction is carried out at 60-80°C to generate sodium maleate. After the reaction solution is clarified and the reaction is completed, L-aspartic acid is added to carry out an ammonia addition reaction, and insulation is started. After the insulation time is completed, iminodisuccinate is obtained, and water is added to prepare to obtain an iminodisuccinate product that meets the requirements.

[0014] As a limitation of the above technical solution, the molar ratio of the first amount of water added to L-aspartic acid is 11-13:1, that is, the amount of water first added to the reactor participates in the L-aspartic acid ammonia addition reaction.

[0015] As a limitation of the above technical solution, the molar ratio of the amount of water added for the second time to L-aspartic acid is 10-12:1, that is, the amount of water added to prepare the iminodisuccinate product.

[0016] The preparation steps and conditions of the iminodisuccinate product of the present invention are improved to optimize product performance.

[0017] At the same time, the present invention also provides the use of the above-mentioned iminodisuccinate product with both high copper chelation value and high calcium chelation value, which is used as a cleaning agent for a circulating water system or a scale inhibitor for a circulating water system.

[0018] The iminodisuccinate product of the present invention not only maintains the original excellent chelating ability for different ions but also significantly improves the calcium chelating ability, can greatly enhance the ability to clean calcium scale when used, and has universal applicability to water treatment systems.

[0019] In summary, the present invention does not affect the original excellent performance of the iminodisuccinate product, but regulates the preparation reaction of the product during the preparation process to affect the product composition and component content, thereby significantly improving the calcium chelating ability, so that the product can greatly reduce the usage and dosing frequency when cleaning calcium scale in application, reducing the user's use cost while optimizing water quality and subsequent treatment, and has obvious application advantages and value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 , calcium chelation value titration test method;

[0021] Figure 2 , The left picture shows the state before titration, and the right picture shows the state after titration;

[0022] Figure 3 , Example 1 titration results;

[0023] Figure 4 , Comparative Example 1 titration results;

[0024] Figure 5, infrared detection spectrum of the iminodisuccinate product of Example 1, wherein a is the complete spectrum and b is a partial enlarged view of the spectrum;

[0025] Figure 6 , Infrared detection spectrum of the iminodisuccinate product of Comparative Example 1, wherein a is the complete spectrum and b is a partial enlarged view of the spectrum. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The raw materials used in the following examples and comparative examples are typical products purchased from the market.

[0028] The copper chelating ability detection method refers to the effective content detection in "HG / T 5749-2020 Tetrasodium Iminodisuccinate".

[0029] Determination method of iminodisuccinic acid content: Based on the fact that tetrasodium iminodisuccinate can react with copper ions at a molar ratio of 1:1 at a pH value of about 3.6, the content is determined using potentiometric titration. The solution is titrated with a standard copper sulfate titration solution until a potential jump point (i.e., the theoretical end point) appears, and the content of tetrasodium iminodisuccinate is calculated from the volume of the consumed standard copper sulfate titration solution.

[0030] Effective content calculation formula

[0031]

[0032] Wherein, V1 is the volume of copper sulfate standard titration solution consumed by the sample, mL; V0 is the volume of copper sulfate standard titration solution consumed by the blank, mL; c is the concentration of copper sulfate standard titration solution; M is the molecular weight of tetrasodium iminodisuccinate, g / mol (M=337.1); and m is the weight of the sample.

[0033] Copper chelation value calculation formula

[0034]

[0035] In the formula, c is the concentration of copper sulfate standard solution, mol / L; V is the volume of copper sulfate standard solution consumed in titration, mL; m is the sample mass, g; s is the solid content of the sample, %; M is the molar mass of CuSO4, g / mol (M=160).

[0036] The calcium chelating ability test method refers to the turbidity titration method in the "Calcium Ion Chelating Ability Test Method and Comparison" in the "Printing and Dyeing Auxiliary Agents" impurity in December 2006, Vol. 23, No. 12, such as Figure 1 As shown, the specific operation is to weigh about 5g of the chelating agent, dissolve it in water and dilute it to a 500ml volumetric flask, absorb 10ml, add 5ml of ammonia-ammonium chloride buffer solution to adjust the pH value to about 10, then add 1ml of sodium oxalate solution, and titrate with calcium acetate standard solution until the solution becomes turbid.

[0037] Calcium chelation value calculation formula:

[0038]

[0039] Wherein, c is the concentration of calcium acetate standard solution, mol / L; V is the volume of calcium acetate standard solution consumed in titration, mL; m is the sample mass, g; s is the solid content of the sample, %; M is the molar mass of CaCO3, g / mol (M=100.1).

[0040] The rest of the tests are in accordance with "HG / T 5749-2020 Tetrasodium Iminodisuccinate".

[0041] Example 1

[0042] L-aspartic acid: maleic anhydride: sodium hydroxide = 1:1.05:3.4 (molar ratio);

[0043] Insulation temperature: 104°C, insulation time: 13h;

[0044] First, add 1533.6kg (85.2mol) of water, 730.59kg (7.455mol) of maleic anhydride and 965.6kg (24.14mol) of sodium hydroxide into the reactor, and carry out acid-base reaction at 60-80°C. After the reaction solution is clarified (about 1-2h of reaction), sodium maleate is generated after the reaction is completed. Then, add 944.3kg (7.1mol) of L-aspartic acid, raise the temperature of the reactor to the insulation temperature for ammonia addition reaction. After adding L-aspartic acid, the reaction solution will gradually become turbid and turn into a white emulsion, and then slowly turn into clear and transparent as the reaction proceeds. After the insulation time is completed (i.e., the reaction is completed), iminodisuccinate is obtained; then add 1405.8kg (78.1mol) of water and stir evenly to obtain the iminodisuccinate product.

[0045] The obtained iminodisuccinate product is a colorless to light yellow transparent liquid with a solid content of 41.30%, an effective matter (iminodisuccinate) content of 33.78%, a conversion rate (copper chelating ability) of 81.79%, L-aspartic acid of 3.11%, butenedioic acid of 1.19%, a pH of 10.87 for a 1% solution (i.e., the iminodisuccinate product is diluted 100 times), a copper chelating value of 388.21 mg / g, and a calcium chelating value of 354.67 mg / g.

[0046] The data of calcium chelation value detection process are as follows:

[0047] The concentration of calcium acetate is 0.2013 mol / L, the sample weighs 5.021 g, and the iminodisuccinate product is a colorless transparent liquid before titration. After titration, the aminodisuccinate solution is turbid. Figure 2 As shown, the volume of calcium acetate consumed in the titration is 7.3 mL. Figure 3 After calculation, the calcium chelation value was 354.67 mg / g.

[0048] The copper chelation value and effective content test process data are as follows:

[0049] The concentration of copper sulfate is 0.1230 mol / L, the sample weighs 0.8224 g, and the volume of copper sulfate consumed is 6.7 ml. After calculation, the copper chelation value is 388.21 mg / g and the effective content is 33.78%.

[0050] The infrared analysis of the iminodisuccinate product is shown in the following spectrum: Figure 5 shown.

[0051] Embodiment 2:

[0052] L-aspartic acid: maleic anhydride: sodium hydroxide = 1: 1.04: 3.7 (molar ratio);

[0053] Insulation temperature: 104°C, insulation time: 13h;

[0054] First, add 1661.4 kg (92.3 mol) of water, 723.63 kg (7.384 mol) of maleic anhydride and 1050.8 kg (26.27 mol) of sodium hydroxide into the reactor, and carry out acid-base reaction at 60-80° C. After the reaction solution becomes clear (about 1-2 hours of reaction), sodium maleate is generated after the reaction is completed, and then 944.3 kg (7.1 mol) of L-aspartic acid is added, and the temperature of the reactor is raised to the insulation temperature for ammonia addition reaction. After the addition of L-aspartic acid, the reaction solution will gradually become turbid and turn into a white emulsion, and then slowly become clear and transparent as the reaction proceeds. After the insulation time is completed, iminodisuccinate is obtained; then add 1405.8 kg (78.1 mol) of water and stir evenly to obtain the iminodisuccinate product.

[0055] The obtained iminodisuccinate product is a colorless to light yellow transparent liquid, with a solid content of 40.61%, an effective content of 33.02%, a conversion rate (copper chelating ability) of 81.31%, L-aspartic acid 3.08%, butenedioic acid 1.25%, 1% pH 10.88, a copper chelating value of 385.92 mg / g, and a calcium chelating value of 347.03 mg / g.

[0056] The data of calcium chelation value detection process are as follows:

[0057] Calcium acetate concentration is 0.2013 mol / L, sample weight is 5.0043 g, and the volume of calcium acetate consumed is 7 ml

[0058] After calculation, the calcium chelation value was 347.03 mg / g.

[0059] The copper chelation value and effective content test process data are as follows:

[0060] The copper sulfate concentration is 0.1230 mol / L, the sample weighs 0.7911 g, and the volume of copper sulfate consumed is 6.3 ml

[0061] After calculation, the copper chelation value was 385.92 mg / g and the effective content was 33.02%.

[0062] Embodiment 3:

[0063] L-aspartic acid: maleic anhydride: sodium hydroxide = 1: 1.06: 3.4;

[0064] Insulation temperature: 104℃, insulation time: 12h;

[0065] First, add 1405.8 kg (78.1 mol) of water, 737.55 kg (7.526 mol) of maleic anhydride and 965.6 kg (24.14 mol) of sodium hydroxide into the reactor, and carry out acid-base reaction at 60-80°C. After the reaction solution becomes clear (about 1-2 hours of reaction), sodium maleate is generated after the reaction is completed. Then, add 944.3 kg (7.1 mol) of L-aspartic acid, raise the temperature of the reactor to the insulation temperature for ammonia addition reaction. After adding L-aspartic acid, the reaction solution will gradually become turbid and turn into a white emulsion, and then slowly turn into clear and transparent as the reaction proceeds. After the insulation time is completed, iminodisuccinate is obtained. Add 1278 kg (71 mol) of water again, and stir evenly to obtain the iminodisuccinate product.

[0066] The obtained iminodisuccinate product is a colorless to light yellow transparent liquid, with a solid content of 40.97%, an effective content of 33.01%, a conversion rate (copper chelating ability) of 80.57%, 1% pH of 10.88, L-aspartic acid 3.03%, butenedioic acid 1.21%, a copper chelating value of 382.41 mg / g, and a calcium chelating value of 348.49 mg / g.

[0067] The data of calcium chelation value detection process are as follows:

[0068] The concentration of calcium acetate is 0.2013 mol / L, the sample weighs 5.0102 g, and the volume of calcium acetate consumed is 7.1 ml. After calculation, the calcium chelation value is 348.49 mg / g.

[0069] The copper chelation value and effective content test process data are as follows:

[0070] The concentration of copper sulfate is 0.1230 mol / L, the sample weighs 0.8102 g, and the volume of copper sulfate consumed is 6.45 ml. After calculation, the copper chelation value is 382.41 mg / g and the effective content is 33.01%.

[0071] Comparative Example 1:

[0072] This comparative example adopts the preparation conditions of conventional iminodisuccinate.

[0073] L-aspartic acid: maleic anhydride: sodium hydroxide = 1:1.08:3.8 (molar ratio);

[0074] Insulation temperature: 107℃, insulation time: 15h;

[0075] First, add 1405.8 kg (78.1 mol) of water, 751.46 kg (7.668 mol) of maleic anhydride and 1079.2 kg (26.98 mol) of sodium hydroxide into the reactor, and carry out acid-base reaction at 60-80°C. After the reaction solution becomes clear (about 1-2 hours of reaction), sodium maleate is generated after the reaction is completed. Then, add 944.3 kg (7.1 mol) of L-aspartic acid, raise the temperature of the reactor to the insulation temperature for ammonia addition reaction. After adding L-aspartic acid, the reaction solution will gradually become turbid and turn into a white emulsion, and then slowly become clear and transparent as the reaction proceeds. After the insulation time is completed, iminodisuccinate is obtained. Add 1661.4 kg (92.3 mol) of water again and stir evenly to obtain the iminodisuccinate product.

[0076] The obtained iminodisuccinate product is a colorless to light yellow transparent liquid, with a solid content of 41.43%, an effective content of 34.20%, a conversion rate (copper chelating ability) of 82.55%, 1% pH of 10.93, L-aspartic acid 2.25%, butenedioic acid 1.98%, a copper chelating value of 381.79 mg / g, and a calcium chelating value of 226.20 mg / g.

[0077] The data of calcium chelation value detection process are as follows:

[0078] The concentration of calcium acetate is 0.2013 mol / L, the sample weighs 4.9992 g, and the volume of calcium acetate consumed is 4.65 ml. Figure 4 As shown, after calculation, the calcium chelation value is 226.20 mg / g.

[0079] The copper chelation value and effective content test process data are as follows:

[0080] The concentration of copper sulfate is 0.1230 mol / L, the sample weighs 0.8002 g, and the volume of copper sulfate consumed is 6.6 ml. After calculation, the copper chelation value is 391.79 mg / g and the effective content is 34.20%.

[0081] The iminodisuccinate product was subjected to infrared analysis, and the spectrum obtained was as follows: Figure 6 As shown, compared with the spectrum of Example 1, it is known that there are differences in structure between the two other than the main components.

[0082] Comparative Example 2:

[0083] This comparative example is based on the conventional iminodisuccinate product (Comparative Example 1), with the addition of a trace amount of L-aspartic acid.

[0084] The obtained iminodisuccinate product is a colorless to light yellow transparent liquid, with a solid content of 41.52%, an effective content of 34.22%, a conversion rate (copper chelating ability) of 82.42%, 1% pH of 10.88, L-aspartic acid 2.99%, butenedioic acid 1.99%, a copper chelating value of 391.20 mg / g, and a calcium chelating value of 258.07 mg / g.

[0085] The data of calcium chelation value detection process are as follows:

[0086] The concentration of calcium acetate is 0.2013 mol / L, the sample weighs 5.0023 g, and the volume of calcium acetate consumed is 5.32 ml. After calculation, the calcium chelation value is 258.07 mg / g.

[0087] The copper chelation value and effective content test process data are as follows:

[0088] The copper sulfate concentration is 0.1230 mol / L, the sample weighs 0.8021 g, and the volume of copper sulfate consumed is 6.62 ml. After calculation, the copper chelation value is 391.20 mg / g and the effective content is 34.22%.

[0089] Compared with the example, the copper chelating ability of Comparative Example 1 is slightly stronger, but the calcium chelating value is much worse; compared with the example, the L-aspartic acid content of Comparative Example 2 is equivalent, and the calcium chelating value is improved, but it is very different from the example, so simply increasing the L-aspartic acid content has little effect on improving the calcium chelating ability.

[0090] In summary, the product of the present invention improves the calcium chelation value while ensuring the copper chelation value, so that the amount and frequency of adding agents are reduced during the application of the product in circulating water, thereby reducing the use cost of customers.

Claims

1. An iminodisuccinate product having both high copper chelation value and high calcium chelation value, characterized in that: The maleic anhydride process is adopted to produce iminodisuccinate, the molar ratio of L-aspartic acid, maleic anhydride and sodium hydroxide in the raw materials is controlled to be 1:(1.03-1.06):(3.4-3.7), and the insulation temperature of the ammonia addition reaction is controlled to be 100-105°C and the insulation time is controlled to be 12-14h.

2. The iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 1, characterized in that: In the maleic anhydride process, the acid-base reaction of maleic anhydride and sodium hydroxide is first carried out at 60-80°C for 1-2 hours. After the solution is clarified after the reaction, L-aspartic acid is added to carry out ammonia addition reaction.

3. The iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 2, characterized in that: The conversion rate of the iminodisuccinate obtained after the heat preservation was completed was >80%.

4. The iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 3, characterized in that: The effective content of iminodisuccinate in the iminodisuccinate product is greater than 32%, and the calcium chelation value is greater than or equal to 330 mg / g.

5. The iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 4, characterized in that: The copper chelation value of the iminodisuccinate product is ≥380 mg / g, and other indicators meet the requirements of industry standards.

6. The method for preparing the iminodisuccinate product having both high copper chelation value and high calcium chelation value as claimed in any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: First, water, maleic anhydride and sodium hydroxide are added to the reaction kettle, and an acid-base reaction is carried out at 60-80°C to generate sodium maleate. After the reaction solution is clarified and the reaction is completed, L-aspartic acid is added to carry out an ammonia addition reaction, and insulation is started. After the insulation time is completed, iminodisuccinate is obtained, and water is added to prepare to obtain an iminodisuccinate product that meets the requirements.

7. The method for preparing the iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 6, characterized in that: The molar ratio of the first added water to L-aspartic acid is 11-13:

1.

8. The method for preparing the iminodisuccinate product having both high copper chelation value and high calcium chelation value according to claim 7, characterized in that: The molar ratio of the amount of water added for the second time to L-aspartic acid is 10-12:

1.

9. The use of the iminodisuccinate product having both high copper chelation value and high calcium chelation value as claimed in any one of claims 1 to 5, characterized in that: Used as a cleaning agent for circulating water systems or as a scale and corrosion inhibitor for circulating water systems.

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