Preparation method of electronic grade hydroxylamine aqueous solution

Abstract

The application discloses a preparation method of electronic-grade hydroxylamine aqueous solution and relates to the field of chemical preparation. Electronic-grade ammonia water or an organic base is reacted with electronic-grade hydroxylamine salt to generate hydroxylamine aqueous solution. After the reaction, the hydroxylamine aqueous solution is separated through a POSS nano-blended modification membrane to remove salt, impurities and unreacted raw materials, so that high-purity hydroxylamine aqueous solution is obtained. The solution is concentrated to 50% hydroxylamine aqueous solution through a low-temperature vacuum concentration technology. The method can effectively remove metal ions and inorganic impurities, and ensure that the purity of the final product is high and meets the electronic-grade requirement.

Description

Technical Field

[0001] This invention relates to the field of chemical preparation, and in particular to a method for preparing an electronic-grade hydroxylamine aqueous solution. Background Technology

[0002] Hydroxylamine (NH2OH), as an important chemical intermediate, is widely used in high-tech fields such as pharmaceuticals, electronics, and metallurgy. Particularly in semiconductor manufacturing, hydroxylamine is used as a cleaning and etching solution, requiring extremely high purity; therefore, the demand for electronic-grade hydroxylamine is constantly increasing. Electronic-grade hydroxylamine has a low impurity content, and the production process must avoid introducing any impurities or byproducts that may affect product purity. To meet this requirement, developing an efficient and environmentally friendly preparation method is particularly important.

[0003] Traditional methods for preparing hydroxylamine mainly include hydrolysis, oxidation, and ammoniation.

[0004] Hydrolysis method: The earliest method for preparing hydroxylamine is through a hydrolysis reaction. This usually involves reacting amino compounds with hydrogen peroxide or sodium chloride. The reaction is relatively simple, but this method has significant limitations in obtaining high-purity hydroxylamine. It produces many byproducts and has low purity, which cannot meet the needs of high-end applications.

[0005] Oxidation method: The oxidation method is a common method in industrial production. It usually uses oxidants such as hydrogen peroxide to oxidize ammonia gas to produce hydroxylamine. Although this method can yield high-purity hydroxylamine, it produces a large amount of oxidation byproducts, such as hydrogen peroxide residue, requiring additional processing steps to remove these byproducts.

[0006] Ammoniation method: This method mainly converts other amino compounds into hydroxylamine through an ammoniation reaction. It usually requires high temperature and high pressure conditions and a complex separation process, resulting in high equipment investment and energy consumption. It is also difficult to guarantee the purity of the final product.

[0007] While the above traditional methods can synthesize hydroxylamine, they generally suffer from problems such as harsh reaction conditions, numerous impurities, and low reaction efficiency, and cannot meet the demand for high-purity electronic-grade hydroxylamine.

[0008] Electronic-grade hydroxylamine is widely used in semiconductors, optoelectronic display devices, integrated circuits, and other precision manufacturing fields. With the continuous development of electronic technology, the increasing precision of manufacturing processes demands high-purity chemicals, especially gases and solutions used in etching processes, which require extremely high purity. To avoid any impurities affecting the performance of circuits or materials, electronic-grade hydroxylamine must maintain an extremely low impurity content.

[0009] Furthermore, in these applications, hydroxylamine often needs to react with other chemicals (such as fluorides, peroxides, etc.) to form special chemical substances. Therefore, controlling the type and concentration of impurities in hydroxylamine, especially the content of inorganic impurities such as heavy metals and salts, is crucial. Summary of the Invention

[0010] This invention proposes a novel method for preparing electronic-grade hydroxylamine aqueous solution. By optimizing the reaction conditions between ammonia or organic base and electronic-grade hydroxylamine salt, and introducing efficient membrane separation and low-temperature concentration technology, this method can significantly improve the purity of the final product while ensuring high reaction efficiency.

[0011] The technical solution is as follows:

[0012] A method for preparing an electronic-grade hydroxylamine aqueous solution includes the following steps, in parts by mass:

[0013] Reaction steps: Add 100-1000 parts of electronic grade ammonia and 50-500 parts of electronic grade hydroxylamine salt to the reactor, heat and react for 1-2 hours, stirring continuously during the reaction;

[0014] Membrane separation step: The solution generated from the reaction is treated through a POSS nano-blended modified membrane at a temperature of 30-60℃; salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine;

[0015] Concentration step: The hydroxylamine aqueous solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40-60℃ and carried out under vacuum conditions to ensure that the hydroxylamine does not decompose. The concentration is carried out to a 45-60wt% hydroxylamine aqueous solution.

[0016] In some embodiments of the present invention, the metal ion content of the electronic-grade ammonia water is not higher than 1 ppb.

[0017] In some embodiments of the present invention, the electronic-grade hydroxylamine salt is hydroxylamine chloride, hydroxylamine sulfate, or a mixture thereof.

[0018] In some embodiments of the present invention, the heating reaction temperature is 0-50°C.

[0019] In some embodiments of the present invention, the stirring speed during the reaction is controlled at 200-600 rpm.

[0020] In some embodiments of the present invention, the preparation method of the POSS nanoblending modified film is as follows:

[0021] Solution preparation: Mix 100 parts of polyvinylidene fluoride (PVDF), 200-300 parts of N,N-dimethylformamide (DMF) and 10-20 parts of porogen PEG400, and stir at 60-80℃ for 4-8 hours to obtain a PVDF solution;

[0022] Co-dispersion: Add 5-15 parts of silica nanoparticles (SiO2), 1-2 parts of hydrogen-based silsesquioxane POSS (CAS: 281-50-5) and 0.05-0.1 parts of dibutyltin dilaurate to the above PVDF solution, and ultrasonically disperse at 200-400W power for 30-60 min to obtain a co-casting solution;

[0023] Phase transformation to film formation: The blend casting solution is cast into a film, which is then immersed in a water / ethanol mixed coagulation bath for 1-2 hours to complete the phase transformation and obtain a POSS nano-blended modified film.

[0024] In some embodiments of the present invention, the operating pressure of the membrane separation step is controlled at 1-5 MPa.

[0025] In some embodiments of the present invention, the pressure of the vacuum concentrator is controlled at 0.001-0.01 MPa.

[0026] In some embodiments of the present invention, the concentration time is 2-6 hours.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1) The hydrophilicity of SiO2 and the cage-like structure of POSS provide specific adsorption and permeation channels for hydroxylamine, while the porous structure also acts as a size sieving agent. Impurity content can be controlled to an extremely low range, and the product can meet electronic grade requirements.

[0029] 2) The low-temperature, low-pressure concentration process avoids thermal decomposition reactions at high temperatures, reducing energy consumption. Simultaneously, membrane separation technology improves the separation efficiency of hydroxylamine, reducing the complexity of subsequent processing steps.

[0030] 3) This process reduces reliance on traditional chemical separating agents and high-temperature heating through membrane separation technology and low-temperature concentration steps, thereby reducing the amount of harmful gases and wastewater discharged. Detailed Implementation

[0031] The features of the present invention are further illustrated below through embodiments, but the scope of protection of this patent is not limited to the embodiments.

[0032] Example 1

[0033] Raw material formula:

[0034] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 100g

[0035] Electronic grade hydroxylamine salt (hydroxylamine chloride): 50g

[0036] Preparation steps:

[0037] Reaction steps: Add 100g of electronic grade ammonia and 50g of electronic grade hydroxylamine chloride to the reactor, cool to 0℃, and react for 1 hour, stirring continuously at 200rpm during the reaction.

[0038] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 30℃ and the operating pressure at 1MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0039] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40℃ and the pressure under vacuum conditions is controlled at 0.01MPa to ensure that hydroxylamine does not decompose. After concentration for 2 hours, a 45wt% hydroxylamine aqueous solution is obtained.

[0040] Preparation of POSS nanoblend modified films:

[0041] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 200g of N,N-dimethylformamide (DMF) and 10g of porogen PEG400 were mixed and stirred at 60℃ for 4h to obtain a PVDF solution.

[0042] Co-dispersion: 5g of silica nanoparticles (SiO2), 1g of hydrogen-based silsesquioxane (POSS) and 0.05g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 200W power for 30min to obtain a co-casting solution.

[0043] Phase transformation to film formation: The blend casting solution is cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 1 hour to complete the phase transformation and obtain a POSS nano-blended modified film.

[0044] Example 2

[0045] Raw material formula:

[0046] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 400g

[0047] Electronic grade hydroxylamine salt (hydroxylamine sulfate): 200g

[0048] Preparation steps:

[0049] Reaction steps: Add 400g of electronic grade ammonia and 200g of electronic grade hydroxylamine sulfate to the reactor, heat to 20℃, and react for 1.3 hours, stirring continuously at 300rpm during the reaction.

[0050] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 40℃ and the operating pressure at 2MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0051] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 45℃ and the pressure under vacuum conditions is controlled at 0.005MPa to ensure that hydroxylamine does not decompose. Concentration is carried out for 3 hours to obtain a 50wt% hydroxylamine aqueous solution.

[0052] Preparation of POSS nanoblend modified films:

[0053] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 230g of N,N-dimethylformamide (DMF) and 13g of porogen PEG400 were mixed and stirred at 65℃ for 5h to obtain a PVDF solution.

[0054] Co-dispersion: 8g of silica nanoparticles (SiO2), 1.3g of hydrosteresilsesquioxane (POSS) and 0.07g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 250W power for 40min to obtain a co-casting solution.

[0055] Phase transformation to film formation: The blend casting solution was cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 1.3 h to complete the phase transformation and obtain the POSS nano-blended modified film.

[0056] Example 3

[0057] Raw material formula:

[0058] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 700g

[0059] Electronic grade hydroxylamine salt (hydroxylamine chloride): 350g

[0060] Preparation steps:

[0061] Reaction steps: Add 700g of electronic grade ammonia water and 350g of a mixed salt of electronic grade hydroxylamine chloride and hydroxylamine sulfate to the reactor, heat to 30℃, and react for 1.7 hours, stirring continuously at 450rpm during the reaction.

[0062] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 50℃ and the operating pressure at 4MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0063] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 55℃ and the pressure under vacuum conditions is controlled at 0.005MPa to ensure that hydroxylamine does not decompose. The concentration is carried out for 5 hours to obtain a 55wt% hydroxylamine aqueous solution.

[0064] Preparation of POSS nanoblend modified films:

[0065] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 270g of N,N-dimethylformamide (DMF) and 17g of porogen PEG400 were mixed and stirred at 70℃ for 6h to obtain a PVDF solution.

[0066] Co-dispersion: 12g of silica nanoparticles (SiO2), 1.7g of hydrogen-based silsesquioxane (POSS) and 0.09g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 350W for 50min to obtain a co-casting solution.

[0067] Phase transformation to film formation: The blend casting solution was cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 1.7 h to complete the phase transformation and obtain the POSS nano-blended modified film.

[0068] Example 4

[0069] Raw material formula:

[0070] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 1000g

[0071] Electronic grade hydroxylamine salt (hydroxylamine sulfate): 500g

[0072] Preparation steps:

[0073] Reaction steps: Add 1000g of electronic grade ammonia water and 500g of a mixed salt of electronic grade hydroxylamine chloride and hydroxylamine sulfate to the reactor, heat to 40℃, and react for 2 hours, stirring continuously at 600rpm during the reaction.

[0074] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 60℃ and the operating pressure at 5MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0075] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 60℃ and the pressure under vacuum conditions is controlled at 0.001MPa to ensure that hydroxylamine does not decompose. Concentration is carried out for 6 hours to obtain a 60wt% hydroxylamine aqueous solution.

[0076] Preparation of POSS nanoblend modified films:

[0077] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 300g of N,N-dimethylformamide (DMF) and 20g of porogen PEG400 were mixed and stirred at 80℃ for 8h to obtain a PVDF solution.

[0078] Co-dispersion: 15g of silica nanoparticles (SiO2), 2g of hydrogen-based silsesquioxane (POSS) and 0.1g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 400W power for 60min to obtain a co-casting solution.

[0079] Phase transformation to film formation: The blend casting solution was cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 2 hours to complete the phase transformation and obtain a POSS nano-blended modified film.

[0080] Comparative Example 1

[0081] Raw material formula:

[0082] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 100g

[0083] Electronic grade hydroxylamine salt (hydroxylamine chloride): 50g

[0084] Preparation steps:

[0085] Reaction steps: Add 100g of electronic grade ammonia and 50g of electronic grade hydroxylamine chloride to the reactor, cool to 0℃, and react for 1 hour, stirring continuously at 200rpm during the reaction.

[0086] Membrane separation step: The solution generated by the reaction is processed through a polyvinylidene fluoride (PVDF) membrane, with the temperature controlled at 30°C and the operating pressure at 1 MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0087] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40℃ and the pressure under vacuum conditions is controlled at 0.01MPa to ensure that hydroxylamine does not decompose. After concentration for 2 hours, a 45wt% hydroxylamine aqueous solution is obtained.

[0088] Comparative Example 2

[0089] Raw material formula:

[0090] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 100g

[0091] Electronic grade hydroxylamine salt (hydroxylamine chloride): 50g

[0092] Preparation steps:

[0093] Reaction steps: Add 100g of electronic grade ammonia and 50g of electronic grade hydroxylamine chloride to the reactor, cool to 0℃, and react for 1 hour, stirring continuously at 200rpm during the reaction.

[0094] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 30℃ and the operating pressure at 1MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0095] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40℃ and the pressure under vacuum conditions is controlled at 0.01MPa to ensure that hydroxylamine does not decompose. After concentration for 2 hours, a 45wt% hydroxylamine aqueous solution is obtained.

[0096] Preparation of POSS nanoblend modified films:

[0097] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 200g of N,N-dimethylformamide (DMF) and 10g of porogen PEG400 were mixed and stirred at 60℃ for 4h to obtain a PVDF solution.

[0098] Blending and dispersion: 5g of silica nanoparticles (SiO2) and 0.05g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 200W power for 30min to obtain a blended casting solution.

[0099] Phase transformation to film formation: The blend casting solution is cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 1 hour to complete the phase transformation and obtain a POSS nano-blended modified film.

[0100] Comparative Example 3

[0101] Raw material formula:

[0102] The electronic-grade ammonia water has a metal ion content of no more than 1 ppb: 100g

[0103] Electronic grade hydroxylamine salt (hydroxylamine chloride): 50g

[0104] Preparation steps:

[0105] Reaction steps: Add 100g of electronic grade ammonia and 50g of electronic grade hydroxylamine chloride to the reactor, cool to 0℃, and react for 1 hour, stirring continuously at 200rpm during the reaction.

[0106] Membrane separation step: The solution generated by the reaction is processed through a POSS nano-blended modified membrane, with the temperature controlled at 30℃ and the operating pressure at 1MPa; the salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine.

[0107] Concentration step: The solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40℃ and the pressure under vacuum conditions is controlled at 0.01MPa to ensure that hydroxylamine does not decompose. After concentration for 2 hours, a 45wt% hydroxylamine aqueous solution is obtained.

[0108] Preparation of POSS nanoblend modified films:

[0109] Solution preparation: 100g of polyvinylidene fluoride (PVDF), 200g of N,N-dimethylformamide (DMF) and 10g of porogen PEG400 were mixed and stirred at 60℃ for 4h to obtain a PVDF solution.

[0110] Co-dispersion: 1g of hydrosilsesquioxane (POSS) and 0.05g of dibutyltin dilaurate were added to the above PVDF solution and ultrasonically dispersed at 200W power for 30min to obtain a co-casting solution.

[0111] Phase transformation to film formation: The blend casting solution is cast into a film, and then immersed in a water / ethanol mixed coagulation bath for 1 hour to complete the phase transformation and obtain a POSS nano-blended modified film.

[0112] Test method:

[0113] 1. Purity test of hydroxylamine aqueous solution

[0114] Methods: Purity analysis was performed using gas chromatography (GC) to detect major impurities in the solution (such as ammonia, unreacted raw materials, chlorides, etc.). After pretreatment, the sample solution was quantitatively analyzed using GC to calculate the purity of hydroxylamine.

[0115] Instrumentation: Gas chromatograph (GC), equipped with chemical standards (pure hydroxylamine).

[0116] 2. Metal impurity content test

[0117] Test method: The metal ion content in the sample was detected by inductively coupled plasma mass spectrometry (ICP-MS).

[0118] Instrumentation: PerkinElmer ICP-MS instrument, using standard elemental analysis procedures.

[0119] 3. Membrane separation efficiency test

[0120] Methods: A POSS nanoblended modified membrane was used for separation. The removal rate of impurities after the reaction solution passed through the membrane was measured. The separation effect of the membrane was evaluated by comparing the impurity content of the solution before and after membrane separation.

[0121] Equipment: Membrane separation unit, combined with chemical analysis instruments to measure the impurity content in the solution.

[0122] The test results are shown in Table 1.

[0123] Table 1

[0124]

[0125] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for preparing an electronic-grade hydroxylamine aqueous solution, characterized in that, Includes the following steps, measured in parts by weight: Reaction steps: Add 100-1000 parts of electronic grade ammonia and 50-500 parts of electronic grade hydroxylamine salt to the reactor, heat and react for 1-2 hours, stirring continuously during the reaction; Membrane separation step: The solution generated from the reaction is treated through a POSS nano-blended modified membrane at a temperature of 30-60℃; salt and unreacted raw materials are removed by membrane separation to obtain an aqueous solution of hydroxylamine; Concentration step: The hydroxylamine aqueous solution after membrane separation is sent to a vacuum concentrator for concentration. The temperature is controlled at 40-60℃ and carried out under vacuum conditions to ensure that the hydroxylamine does not decompose. The concentration is carried out to a 45-60wt% hydroxylamine aqueous solution. The POSS nano-blended modified membrane is prepared by reacting polyvinylidene fluoride, porogen PEG400, silica nanoparticles, hydrogen-based silsesquioxane, and dibutyltin dilaurate to obtain a blended casting solution, followed by phase inversion to form a membrane.

2. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The metal ion content of the electronic-grade ammonia water is not higher than 1 ppb.

3. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The electronic-grade hydroxylamine salt is hydroxylamine chloride, hydroxylamine sulfate, or a mixture thereof.

4. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The temperature of the heating reaction is 0-50℃.

5. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The stirring speed during the reaction is controlled at 200-600 rpm.

6. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The preparation method of the POSS nano-blended modified film is as follows, according to parts by mass: Solution preparation: Mix 100 parts of polyvinylidene fluoride, 200-300 parts of N,N-dimethylformamide and 10-20 parts of porogen PEG400, and stir at 60-80℃ for 4-8 hours to obtain PVDF solution; Blending and dispersion: Add 5-15 parts of silica nanoparticles, 1-2 parts of hydrogen-based silsesquioxane and 0.05-0.1 parts of dibutyltin dilaurate to the above PVDF solution, and ultrasonically disperse at 200-400W power for 30-60 min to obtain a blended casting solution; Phase transformation to film formation: The blend casting solution is cast into a film, which is then immersed in a water / ethanol mixed coagulation bath for 1-2 hours to complete the phase transformation and obtain a POSS nano-blended modified film.

7. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The operating pressure of the membrane separation step is controlled at 1-5 MPa.

8. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The pressure of the vacuum concentrator is controlled at 0.001-0.01 MPa.

9. The method for preparing an electronic-grade hydroxylamine aqueous solution according to claim 1, characterized in that: The concentration time is 2-6 hours.

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