Sodium hypochlorite stabilizer, preparation method and use method thereof, and stable sodium hypochlorite solution

Abstract

The invention relates to the technical field of chemical preparations, in particular to a sodium hypochlorite stabilizer, a preparation method and a use method thereof and a stable sodium hypochlorite solution. The sodium hypochlorite stabilizer is prepared from the following components in percentage by mass: 2.5 to 3.5 percent of sodium diethylenetriamine pentaacetate, 2.5 to 3.5 percent of disodium ethylene diamine tetraacetate, 1.0 to 1.25 percent of sodium silicate, 3.5 to 5.0 percent of sodium bicarbonate, 2.5 to 3.0 percent of sodium chloride and the balance of water. The stable sodium hypochlorite solution prepared by adopting the sodium hypochlorite stabilizer disclosed by the invention is higher in stability and longer in validity period.

Description

Technical Field

[0001] The invention relates to the technical field of chemical preparations, and in particular to a sodium hypochlorite stabilizer, a preparation method and a use method thereof, and a stable sodium hypochlorite solution. Background Art

[0002] According to GB / T 36758-2018 "Hygiene Requirements for Chlorine-Containing Disinfectants", the shelf life of sodium hypochlorite / hypochlorous acid disinfectants without stabilizers is at least 3 months. During the shelf life of liquid chlorine-containing disinfectants, the effective chlorine content of the product shall not be lower than the lower limit of the labeled value, and the shelf life of the product shall not be less than 6 months. Currently, the actual shelf life of commercially available sodium hypochlorite solutions is often only 3-6 months, and consumers expect it to be valid for 12 months.

[0003] Due to the presence of hypochlorite structure in sodium hypochlorite solution, its own stability is poor. Natural decomposition, hydrolysis, acidolysis, disproportionation reaction, catalytic decomposition, etc. will occur during storage, resulting in a decrease in the effective chlorine content, affecting the disinfection effect.

[0004] The decomposition reaction rate of sodium hypochlorite solution is affected by the concentration, pH value, temperature and metal ions of the solution. The higher the concentration of the solution, the faster the decomposition rate; the increase of pH value, the lower the redox potential, the weaker the oxidizing property of the solution and the lower the decomposition rate; the increase of temperature will accelerate the decomposition rate of sodium hypochlorite solution, and the decomposition is relatively slow at room temperature; the Fe in the metal ions 3+ , Fe 2+ , Mn 2+ It has a catalytic effect on the decomposition of sodium hypochlorite and has a great influence on the stability of sodium hypochlorite.

[0005] Current research generally adopts the addition of mixed phosphonates, sodium phosphates, sodium silicates and surfactants to improve the stability of sodium hypochlorite solutions. However, the above methods do not fundamentally change the law of spontaneous decomposition reaction of sodium hypochlorite solutions, and it is difficult to ensure the shelf life of sodium hypochlorite solutions.

[0006] Chinese patent publication number CN105961382A discloses a stabilizer for sodium hypochlorite, wherein the stabilizer for sodium hypochlorite includes 5-15wt% sodium sulfamate, 0.6-1.5wt% sodium silicate, 1-3wt% sodium bicarbonate and the balance of deionized water. Although the stabilizer increases the difficulty of decomposition of sodium hypochlorite in a hot environment to a certain extent, the content loss of sodium hypochlorite is more than 10% when placed at 54°C for 14 days, and the content loss needs to be further reduced to extend the shelf life.

[0007] Chinese patent publication number CN106915726A discloses a stabilizer for sodium hypochlorite solution, which includes the following components calculated by mass percentage: 0.01-1% disodium ethylenediaminetetraacetate, 0.5-2% boron nitride, 0.1-2% potassium chloride, 0.01-1% stannous chloride, 0.5-2% sodium chloride and 0.1-2% sodium silicate, and the balance is deionized water. The stabilizer allows the storage period of the sodium hypochlorite solution to reach about 200 days at 25°C, but the storage period still needs to be further extended.

[0008] Therefore, it is very necessary to develop a sodium hypochlorite stabilizer and a preparation method and a use method thereof, and a stable sodium hypochlorite solution that can solve the above-mentioned technical problems. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a stable sodium hypochlorite solution with higher stability and longer validity period, a sodium hypochlorite stabilizer and a preparation method and a use method thereof.

[0010] The present invention is achieved through the following technical solutions:

[0011] The present invention provides a sodium hypochlorite stabilizer, which comprises the following components in terms of mass percentage:

[0012] Sodium diethylenetriaminepentaacetate 2.5%-3.5%

[0013] Disodium ethylenediaminetetraacetate (EDTA-2Na) 2.5%-3.5%

[0014] Sodium silicate 1.0-1.25%

[0015] Sodium bicarbonate 3.5%-5.0%

[0016] Sodium chloride 2.5-3.0%

[0017] Water balance.

[0018] In some embodiments of the present invention, the sodium hypochlorite stabilizer comprises the following components in terms of mass percentage:

[0019] Sodium diethylenetriaminepentaacetate 2.5%-3.0%

[0020] Disodium EDTA 2.5%-3.0%

[0021] Sodium silicate 1.0-1.25%

[0022] Sodium bicarbonate 4.0%-5.0%

[0023] Sodium chloride 2.5-3.0%

[0024] Water balance.

[0025] The present invention also relates to a method for preparing the above-mentioned sodium hypochlorite stabilizer, comprising the following steps:

[0026] Add sodium diethylenetriamine pentaacetate, disodium ethylenediaminetetraacetate, sodium silicate, sodium bicarbonate and sodium chloride to water in sequence and dissolve them completely. Adjust the pH to obtain the product.

[0027] In some embodiments of the invention, the pH is adjusted to 7.5-8.5.

[0028] In some embodiments of the invention, sodium hydroxide is used to adjust the pH.

[0029] The present invention also relates to a stable sodium hypochlorite solution, comprising an industrial sodium hypochlorite solution and a sodium hypochlorite stabilizer. The sodium hypochlorite stabilizer is the above-mentioned sodium hypochlorite stabilizer or the sodium hypochlorite stabilizer prepared by the above-mentioned preparation method.

[0030] In some embodiments of the present invention, the effective chlorine content in the industrial sodium hypochlorite solution is 10%.

[0031] In some embodiments of the present invention, the stabilized sodium hypochlorite solution is composed of the following components: 4%-6% sodium hypochlorite stabilizer, 40-60% industrial sodium hypochlorite solution, and the balance is water.

[0032] The present invention also relates to a method for using a sodium hypochlorite stabilizer, wherein the sodium hypochlorite stabilizer is the above-mentioned sodium hypochlorite stabilizer or the sodium hypochlorite stabilizer prepared by the above-mentioned preparation method, comprising the following steps:

[0033] Adjust the pH value of industrial sodium hypochlorite solution to 12.0-13.0, add sodium hypochlorite stabilizer and water, stir evenly, and obtain the product.

[0034] In some embodiments of the present invention, an industrial sodium hypochlorite solution is diluted with water in a volume ratio of 5:4, the pH is adjusted to 12.0-13.0, a sodium hypochlorite stabilizer is added, the remaining water is added, and the mixture is stirred evenly to obtain the product.

[0035] In some embodiments of the invention, sodium hydroxide is used to adjust the pH.

[0036] The beneficial effects of the present invention are:

[0037] The invention adopts diethylenetriaminepentaacetic acid and EDTA-2Na to compound, thereby improving the stability of sodium hypochlorite and extending the validity period of the sodium hypochlorite solution to more than 1 year.

[0038] The present invention also uses sodium silicate and sodium bicarbonate to form a "water glass"-like film, forming a protective film around the sodium hypochlorite molecules, which can effectively slow down the redox reaction of the sodium hypochlorite solution. At the same time, sodium chloride is added to inhibit the decomposition reaction, further improving the stability of the sodium hypochlorite and extending the shelf life of the sodium hypochlorite solution. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

[0040] The sodium hypochlorite stabilizer formulations of the embodiments and comparative examples are shown in Table 1.

[0041] Table 1 Sodium hypochlorite stabilizer formulations for various embodiments and comparative examples

[0042]

[0043] Note: The mixed phosphonates in Table 1 were purchased from Italmatch UK Ltd., model DEQUEST 6004.

[0044] Preparation process of sodium hypochlorite stabilizer: Add sodium diethylenetriamine pentaacetate, EDTA-2Na, sodium silicate, sodium bicarbonate and sodium chloride to water in sequence, shake well and dissolve completely, and adjust the pH to 8.0 with sodium hydroxide.

[0045] Application Examples

[0046] The stabilized sodium hypochlorite solution is composed of the following components by mass percentage: 4% of the sodium hypochlorite stabilizer of each embodiment or comparative example, 50% of industrial sodium hypochlorite solution (with an effective chlorine content of 10%), and the balance of water.

[0047] Among them, the formula without adding sodium hypochlorite stabilizer was used as an application control example.

[0048] Preparation process: Dilute industrial sodium hypochlorite solution and water in a volume ratio of 5:4, adjust the pH to 12.5 with sodium hydroxide, then add sodium hypochlorite stabilizer in proportion, make up the remaining water, and stir evenly.

[0049] Test Case

[0050] The evaluation of the results of the accelerated test method is that the effective component decrease rate exceeds 10% and is not in compliance with the requirements. After being stored at 54°C for 14 days, if the bactericidal effective component decreases by ≤10%, the storage validity period can be set as 1 year. The test results of the average degradation rate of effective chlorine in the stable sodium hypochlorite solution of each application example and the application control example are shown in Table 2.

[0051] Table 2 Degradation rate test results of each application example and application control example

[0052]

[0053] Two commercially available sodium hypochlorite stabilizers were prepared according to the preparation process of the application example of the present invention, and the test results of the average degradation rate of effective chlorine are shown in Table 3. Among them, the commercially available stabilizer comparison sample 1 is DEQUEST6004 of Italmatch UK Ltd., and the main component is mixed organic phosphonates; the commercially available stabilizer comparison sample 2 is the sodium hypochlorite stabilizer of Shandong Aokai Chemical Co., Ltd., and the main component is mixed inorganic salts.

[0054] Table 3 Degradation rate test results of two commercially available sodium hypochlorite stabilizers

[0055]

[0056] It can be seen from Table 2 that, compared with Example 1, under the same conditions, Comparative Examples 1-3 contain diethylenetriaminepentaacetic acid and EDTA-2Na, and have obvious synergistic effects, which can effectively slow down the decomposition of the sodium hypochlorite solution.

[0057] Compared with Example 1, under the same conditions, the "water glass"-like film formed by the composite of sodium silicate and sodium bicarbonate forms a protective film around the sodium hypochlorite molecules, which can effectively slow down the redox reaction of the sodium hypochlorite solution and thus reduce the decomposition rate of the solution.

[0058] Comparative Example 7 Compared with Example 1, under the same conditions, the mechanism of the effect of an appropriate amount of sodium chloride on the stability of the sodium hypochlorite solution should be that the presence of sodium chloride promotes the decomposition of sodium hypochlorite in the reverse direction, thereby making the sodium hypochlorite solution stable.

[0059] Compared with Example 1, under the same conditions, the sodium hypochlorite solution without stabilizer degrades significantly.

[0060] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A sodium hypochlorite stabilizer, characterized in that According to mass percentage, it includes the following components: Sodium diethylenetriaminepentaacetate 2.5-3.5% Disodium EDTA 2.5-3.5% Sodium silicate 1.0-1.25% Sodium bicarbonate 3.5-5.0% Sodium chloride 2.5-3.0% Water balance.

2. The sodium hypochlorite stabilizer according to claim 1, characterized in that According to mass percentage, it includes the following components: Sodium diethylenetriaminepentaacetate 2.5%-3.0% Disodium EDTA 2.5%-3.0% Sodium silicate 1.0-1.25% Sodium bicarbonate 4.0%-5.0% Sodium chloride 2.5-3.0% Water balance.

3. The preparation method of the sodium hypochlorite stabilizer according to claim 1 or 2, characterized in that: The steps include: Add sodium diethylenetriamine pentaacetate, disodium ethylenediaminetetraacetate, sodium silicate, sodium bicarbonate and sodium chloride to water in sequence and dissolve them completely. Adjust the pH to obtain the product.

4. The preparation method according to claim 3, characterized in that: Adjust pH to 7.5-8.

5.

5. The preparation method according to claim 3, characterized in that: The pH was adjusted with sodium hydroxide.

6. A stable sodium hypochlorite solution, characterized in that: The invention comprises an industrial sodium hypochlorite solution and a sodium hypochlorite stabilizer, wherein the sodium hypochlorite stabilizer is the sodium hypochlorite stabilizer described in any one of claims 1 to 2 or the sodium hypochlorite stabilizer prepared by the preparation method described in any one of claims 3 to 5.

7. The stable sodium hypochlorite solution according to claim 6, characterized in that The effective chlorine content in the industrial sodium hypochlorite solution is 10%.

8. The stable sodium hypochlorite solution according to claim 6, characterized in that Calculated by mass percentage, the composition is as follows: 4%-6% sodium hypochlorite stabilizer, 40%-60% industrial sodium hypochlorite solution, and the balance is water.

9. A method for using a sodium hypochlorite stabilizer, wherein the sodium hypochlorite stabilizer is the sodium hypochlorite stabilizer according to any one of claims 1 to 2 or the sodium hypochlorite stabilizer prepared by the preparation method according to any one of claims 3 to 5, characterized in that: The steps include: Adjust the pH value of industrial sodium hypochlorite solution to 12.0-13.0, add sodium hypochlorite stabilizer and water, stir evenly, and obtain the product.

10. The method of use according to claim 9, characterized in that: The pH was adjusted with sodium hydroxide.

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