Preparation method of ultrahigh-purity hydroxylamine aqueous solution

Abstract

The application discloses a preparation method of ultrahigh-purity hydroxylamine aqueous solution and relates to the field of organic chemistry and chemical production. The method comprises the following steps: reacting electronic-grade hydroxylamine salt and an organic base in a proper solvent to generate hydroxylamine, then removing salt and unreacted hydroxylamine in the reaction solution through a sulfhydryl pyridine ion exchange modified membrane, and finally concentrating the solution to 50wt% ultrahigh-purity hydroxylamine aqueous solution through vacuum evaporation or multi-effect evaporation. The process has the characteristics of high efficiency, environmental protection and simple operation, effectively improves the purity, yield and separation efficiency of hydroxylamine, and meets the strict requirements of electronic-grade hydroxylamine on purity and metal ion content.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of organic chemistry and chemical production, and particularly to a preparation method of ultra-high purity hydroxylamine aqueous solution. BACKGROUND

[0002] Hydroxylamine (NH2OH) is an important chemical reagent widely used in semiconductor manufacturing, photolithography, chemical analysis, pesticide synthesis, and reduction reactions, among other fields. In particular, in the semiconductor industry, hydroxylamine, as an electronic-grade chemical, is commonly used in important processes such as the development of photoresists, cleaning, and the removal of metal layers. However, electronic-grade hydroxylamine has extremely strict requirements for metal ions, generally reaching ppb levels, to avoid adverse effects on the tiny structures in semiconductor circuits. In order to meet this high-purity requirement, effective production and purification techniques must be employed.

[0003] Currently, there are two main methods for producing electronic-grade hydroxylamine: one is the reduction method using ammonia as the raw material, and the other is the reduction method using hydroxylamine salt as the raw material. The former method uses ammonia gas and a reducing agent (such as iron powder or zinc powder) to generate hydroxylamine. Although this method has high reduction efficiency, it has problems such as the generation of multiple by-products during the reaction, harsh operating conditions, and difficulty in controlling product purity. The latter method uses electronic-grade hydroxylamine salt (such as hydroxylamine chloride or hydroxylamine sulfate) as the raw material, which is reacted with an organic base to synthesize pure hydroxylamine. This method is relatively simple in operation, and by adjusting the reaction conditions and subsequent processing, high purity of hydroxylamine can be achieved.

[0004] Currently, the process of synthesizing hydroxylamine by reacting organic base with electronic-grade hydroxylamine salt has been applied to some extent, but the existing production methods still face the following problems:

[0005] Insufficient reaction purity: Although the hydroxylamine generated by the reaction of organic base with electronic-grade hydroxylamine salt is relatively pure, a certain amount of salt and unreacted hydroxylamine may still be produced during the reaction, resulting in the purity of the final product not meeting the requirements of electronic grade.

[0006] Low impurity removal efficiency: Current conventional methods rely on precipitation, centrifugation, or simple filtration to remove salt and impurities from the reaction residue, but these methods often have low efficiency and cannot completely remove salts and other impurities during the reaction, resulting in high levels of metal ions and other contaminants in the product, which cannot meet the high-purity requirements.

[0007] Complex concentration process: The existing concentration process mainly uses evaporation to increase the concentration of hydroxylamine solution. However, due to the high volatility of hydroxylamine itself and the possibility of decomposition during evaporation, it is difficult to control the process parameters, resulting in low yield of hydroxylamine and potential impact on the purity of the final product. SUMMARY

[0008] To solve the shortcomings in the existing production process, the application provides a preparation method of ultrahigh-purity hydroxylamine aqueous solution. By reasonably selecting reaction raw materials, solvents and reaction conditions, the synthesis process of hydroxylamine is optimized, and the membrane separation technology and concentration technology are combined to successfully remove the salt and unreacted hydroxylamine generated in the reaction process.

[0009] The technical scheme is as follows:

[0010] A preparation method of ultrahigh-purity hydroxylamine aqueous solution, comprising the following steps:

[0011] Step 1: 100-200 parts of electronic-grade hydroxylamine salt and 200-500 parts of organic base are added to 150-300 parts of deionized water, and reacted under the set reaction conditions. After the reaction is completed, it is cooled to room temperature to obtain a hydroxylamine solution;

[0012] Step 2: The reaction solution is separated by a membrane separation technology, and a sulfhydryl pyridine ion exchange modified membrane is used to remove the salt and unreacted hydroxylamine in the reaction system, so as to obtain a purified hydroxylamine aqueous solution, the operating pressure is 5-10 MPa, and the operating temperature is 25-40°C;

[0013] Step 3: The separated solution is concentrated by vacuum evaporation to 50wt% ultrahigh-purity hydroxylamine aqueous solution.

[0014] In some embodiments of the application, the electronic-grade hydroxylamine salt is selected from hydroxylamine chloride, hydroxylamine sulfate and a mixture thereof.

[0015] In some embodiments of the application, the organic base is selected from triethanolamine, diethylaminoethanol and a mixture thereof.

[0016] In some embodiments of the application, the reaction temperature is 0-50°C, the reaction time is 2-3 hours, and the stirring speed is 200-500 rpm.

[0017] In some embodiments of the application, the preparation method of the sulfhydryl pyridine ion exchange modified membrane is as follows, according to the mass fraction:

[0018] Swelling: 100 parts of polystyrene membrane is immersed in 50-100 parts of dichloromethane, and swelled at room temperature for 30-60 min;

[0019] Sulfonation reaction: 5-10 parts of chlorosulfonic acid, 1-2 parts of 4-amino-3-mercaptopyridine and 0.1-0.3 parts of aluminum chloride catalyst are added to dichloromethane, and then added dropwise into the swelled membrane at 0-10°C, and reacted for 1-3 h;

[0020] Neutralization and cleaning: The membrane after the reaction is neutralized with NaOH solution, and then rinsed with deionized water until neutral to obtain the mercaptopyridine ion exchange modified membrane.

[0021] In some embodiments of the present invention, the operating flow rate of the membrane separation technology is 0.5-1.5 L / h·m. 2 .

[0022] In some embodiments of the present invention, the temperature of the reduced pressure evaporation is 50-70°C and the operating pressure is 50-200 mmHg.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1) High-purity product: Salt and impurities are effectively removed through membrane separation technology to ensure compliance with the requirements of electronic-grade hydroxylamine.

[0025] 2) High separation efficiency: By optimizing membrane separation operating conditions, impurities in the reaction solution can be removed efficiently, product purity can be improved, and adverse reactions can be reduced.

[0026] 3) Simple and efficient concentration process: Concentration methods such as vacuum evaporation or multi-effect evaporation not only effectively avoid the thermal decomposition of hydroxylamine, but also improve the concentration efficiency and ensure high yield and purity.

[0027] 4) High scalability: This method is applicable to large-scale industrial production, with low equipment investment, simple operation, and is suitable for large-scale production of electronic-grade hydroxylamine.

[0028] 5) The mercaptopyridine ion exchange modified membrane has the following beneficial effects:

[0029] High selectivity: The mercaptopyridine group has a special affinity for hydroxylamine, and achieves highly efficient and selective separation of hydroxylamine through ion exchange and coordination, significantly improving the purity of the purified hydroxylamine.

[0030] Good hydrophilicity and antifouling properties: The sulfonic acid groups and mercaptopyridine groups introduced by sulfonation increase the hydrophilicity of the membrane surface, reduce the adsorption and deposition of impurities on the membrane surface, and improve the membrane's antifouling performance and service life.

[0031] High operational stability: The modified membrane has a stable chemical structure, can be used in a wide range of pH and temperature conditions, and maintains stable performance during long-term operation, reducing the frequency and cost of membrane replacement.

[0032] Simple process: The preparation process is relatively simple, the raw material cost is low, it is easy to industrialize and apply, and it has good economic and social benefits. Detailed Implementation

[0033] 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.

[0034] Example 1

[0035] Raw material formula:

[0036] Electronic grade hydroxylamine salt (hydroxylamine chloride): 100g

[0037] Organic base (triethanolamine): 200g

[0038] Solvent (deionized water): 150g

[0039] Preparation steps:

[0040] Step 1 (Reaction Preparation):

[0041] Add 100g of hydroxylamine chloride and 120g of triethanolamine to 150g of ethanol and stir until well mixed.

[0042] Heat to 0°C, maintain stirring speed at 200 rpm, and react for 2 hours.

[0043] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0044] Step 2 (membrane separation and purification):

[0045] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0046] The operating pressure is controlled at 5 MPa, the operating temperature at 25℃, and the operating flow rate at 0.5 L / h·m. 2 .

[0047] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0048] Step 3 (Concentration under reduced pressure):

[0049] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 50℃ and the operating pressure to 50mmHg.

[0050] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0051] Preparation of mercaptopyridine ion exchange modified membrane:

[0052] Swelling: 100g of polystyrene film was immersed in 50g of dichloromethane and swelled at room temperature for 30 minutes.

[0053] Sulfonation reaction: 5g chlorosulfonic acid, 1g 4-amino-3-mercaptopyridine and 0.1g aluminum chloride were added to dichloromethane and added dropwise to the swollen membrane at 0℃, and the reaction was carried out for 1h.

[0054] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0055] Example 2

[0056] Raw material formula:

[0057] Electronic grade hydroxylamine salt (hydroxylamine sulfate): 130g

[0058] Organic base (diethylaminoethanol): 260g

[0059] Solvent (deionized water): 200g

[0060] Preparation steps:

[0061] Step 1 (Reaction Preparation):

[0062] Add 130g of hydroxylamine sulfate and 160g of diethylaminoethanol to 200g of methanol and stir until well mixed.

[0063] Heat to 20°C, maintain stirring speed at 300 rpm, and react for 2.3 hours.

[0064] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0065] Step 2 (membrane separation and purification):

[0066] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0067] The operating pressure is controlled at 6 MPa, the operating temperature at 30℃, and the operating flow rate at 0.8 L / h·m. 2 .

[0068] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0069] Step 3 (Concentration under reduced pressure):

[0070] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 55℃ and the operating pressure to 100mmHg.

[0071] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0072] Preparation of mercaptopyridine ion exchange modified membrane:

[0073] Swelling: 100g of polystyrene film was immersed in 65g of dichloromethane and swelled at room temperature for 40 minutes.

[0074] Sulfonation reaction: 7g chlorosulfonic acid, 1.3g 4-amino-3-mercaptopyridine and 0.2g aluminum chloride were added to dichloromethane and added dropwise to the swollen membrane at 5°C for 2 hours.

[0075] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0076] Example 3

[0077] Raw material formula:

[0078] Electronic grade hydroxylamine salt (hydroxylamine chloride): 170g

[0079] Organic base (diethylaminoethanol): 400g

[0080] Solvent (deionized water): 250g

[0081] Preparation steps:

[0082] Step 1 (Reaction Preparation):

[0083] Add 170g of mixed hydroxylamine salt and 200g of mixed organic base to 250g of deionized water and stir well.

[0084] Heat to 35°C, maintain stirring speed at 400 rpm, and react for 2.7 hours.

[0085] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0086] Step 2 (membrane separation and purification):

[0087] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0088] The operating pressure is controlled at 8 MPa, the operating temperature at 35℃, and the operating flow rate at 1.2 L / h·m. 2 .

[0089] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0090] Step 3 (Concentration under reduced pressure):

[0091] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 60℃ and the operating pressure to 150mmHg.

[0092] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0093] Preparation of mercaptopyridine ion exchange modified membrane:

[0094] Swelling: 100g of polystyrene film was immersed in 80g of dichloromethane and swelled at room temperature for 45 minutes.

[0095] Sulfonation reaction: 8g chlorosulfonic acid, 1.5g 4-amino-3-mercaptopyridine and 0.2g aluminum chloride were added to dichloromethane and added dropwise to the swollen membrane at 5°C for 2 hours.

[0096] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0097] Example 4

[0098] Raw material formula:

[0099] Electronic grade hydroxylamine salt (hydroxylamine sulfate): 200g

[0100] Organic base (triethanolamine): 500g

[0101] Solvent (deionized water): 300g

[0102] Preparation steps:

[0103] Step 1 (Reaction Preparation):

[0104] Add 200g of mixed hydroxylamine salt and 240g of mixed organic base to 300g of deionized water and stir well.

[0105] Heat to 45°C, maintain stirring speed at 500 rpm, and react for 3 hours.

[0106] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0107] Step 2 (membrane separation and purification):

[0108] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0109] The operating pressure is controlled at 10 MPa, the operating temperature at 40℃, and the operating flow rate at 1.5 L / h·m. 2 .

[0110] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0111] Step 3 (Concentration under reduced pressure):

[0112] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 70℃ and the operating pressure to 200mmHg.

[0113] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0114] Preparation of mercaptopyridine ion exchange modified membrane:

[0115] Swelling: 100g of polystyrene film was immersed in 100g of dichloromethane and swelled at room temperature for 60 minutes.

[0116] Sulfonation reaction: 10g chlorosulfonic acid, 2g 4-amino-3-mercaptopyridine and 0.3g aluminum chloride were added to dichloromethane and added dropwise to the swollen membrane at 10°C for 3 hours.

[0117] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0118] Comparative Example 1

[0119] Raw material formula:

[0120] Electronic grade hydroxylamine salt (hydroxylamine chloride): 100g

[0121] Organic base (triethanolamine): 200g

[0122] Solvent (deionized water): 150g

[0123] Preparation steps:

[0124] Step 1 (Reaction Preparation):

[0125] Add 100g of hydroxylamine chloride and 120g of triethanolamine to 150g of ethanol and stir until well mixed.

[0126] Heat to 0°C, maintain stirring speed at 200 rpm, and react for 2 hours.

[0127] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0128] Step 2 (membrane separation and purification):

[0129] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0130] The operating pressure is controlled at 5 MPa, the operating temperature at 25℃, and the operating flow rate at 0.5 L / h·m. 2 .

[0131] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0132] Step 3 (Concentration under reduced pressure):

[0133] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 50℃ and the operating pressure to 50mmHg.

[0134] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0135] Preparation of mercaptopyridine ion exchange modified membrane:

[0136] Swelling: 100g of polystyrene film was immersed in 50g of dichloromethane and swelled at room temperature for 30 minutes.

[0137] Sulfonation reaction: Add 5g chlorosulfonic acid and 0.1g aluminum chloride to dichloromethane, and add dropwise to the swollen membrane at 0℃, and react for 1h.

[0138] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0139] Comparative Example 2

[0140] Raw material formula:

[0141] Electronic grade hydroxylamine salt (hydroxylamine chloride): 100g

[0142] Organic base (triethanolamine): 200g

[0143] Solvent (deionized water): 150g

[0144] Preparation steps:

[0145] Step 1 (Reaction Preparation):

[0146] Add 100g of hydroxylamine chloride and 120g of triethanolamine to 150g of ethanol and stir until well mixed.

[0147] Heat to 0°C, maintain stirring speed at 200 rpm, and react for 2 hours.

[0148] After the reaction was complete, the solution was naturally cooled to room temperature to obtain a hydroxylamine solution.

[0149] Step 2 (membrane separation and purification):

[0150] The above solution was separated using a mercaptopyridine ion-exchange modified membrane.

[0151] The operating pressure is controlled at 5 MPa, the operating temperature at 25℃, and the operating flow rate at 0.5 L / h·m. 2 .

[0152] Remove the salt and unreacted hydroxylamine from the system to obtain a purified aqueous solution of hydroxylamine.

[0153] Step 3 (Concentration under reduced pressure):

[0154] The purified solution was fed into a vacuum evaporator, and the evaporation temperature was set to 50℃ and the operating pressure to 50mmHg.

[0155] The solution was concentrated to obtain an ultra-high purity hydroxylamine aqueous solution.

[0156] Preparation of mercaptopyridine ion exchange modified membrane:

[0157] Swelling: 100g of polystyrene film was immersed in 50g of dichloromethane and swelled at room temperature for 30 minutes.

[0158] Sulfonation reaction: 1g of 4-amino-3-mercaptopyridine and 0.1g of aluminum chloride were added to dichloromethane and added dropwise to the swollen membrane at 0°C for 1 hour.

[0159] Neutralization and cleaning: Neutralize the membrane with NaOH solution to pH=7, rinse 3 times with deionized water, and air dry for later use.

[0160] Test method:

[0161] 1) Hydroxylamine purity test:

[0162] Test method: The purity of hydroxylamine solution was tested by high performance liquid chromatography (HPLC). The sample was passed through a C18 reversed-phase column using methanol and water as the mobile phase, the column temperature was maintained at 30℃, and a UV detector was used with a detection wavelength of 210 nm.

[0163] 2) Metal ion content detection:

[0164] Test method: The metal ion content in the samples was detected using inductively coupled plasma mass spectrometry (ICPMS). The test equipment was a PerkinElmer ICP-MS instrument, and standard elemental analysis procedures were used.

[0165] 3) Yield testing:

[0166] Test method: The yield of hydroxylamine is calculated based on the mass of the starting materials and the final product. The final yield is calculated by measuring the change in solution concentration before and after the reaction by weighing or volume measurement, combined with the amount of product obtained after final concentration.

[0167] Test results:

[0168] Purity of hydroxylamine aqueous solution Metallic impurity content ppb Yield Example 1 50.8 1 87.7 Example 2 51.2 0.9 88.1 Example 3 51.5 0.8 88.4 Example 4 51.7 0.6 88.6 Comparative Example 1 50.0 1.5 87.4 Comparative Example 2 49.8 1.3 87.2

[0169] Therefore, the method provided by this invention can effectively improve the purity, yield and production efficiency of electronic-grade hydroxylamine, while reducing energy consumption and environmental pollution during the production process. It is an innovative process with broad application prospects.

[0170] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the content of the present invention specification, or any direct or indirect application in other related technical fields, shall also be included within the patent protection scope of the present invention.

Claims

1. A method for preparing an ultra-high purity aqueous hydroxylamine solution, characterized by, The method comprises the following steps, in terms of mass fraction: Step 1: 100-200 parts of electronic grade hydroxylamine salt and 200-500 parts of organic base are added to 150-300 parts of deionized water, and reacted under the set reaction conditions; after the reaction is completed, it is cooled to room temperature to obtain a hydroxylamine solution; Step 2: The reaction solution is separated by a membrane separation technology, and a sulfhydryl pyridine ion exchange modified membrane is used to remove salt and unreacted hydroxylamine in the reaction system, so as to obtain a purified hydroxylamine aqueous solution, the operating pressure is 5-10 MPa, and the operating temperature is 25-40℃; Step 3: The separated solution is concentrated by vacuum evaporation to obtain a 50wt% ultra-high purity hydroxylamine aqueous solution; The sulfhydryl pyridine ion exchange modified membrane is prepared by neutralization and cleaning after reaction of polystyrene membrane, chlorosulfonic acid, 4-amino-3-mercaptopyridine and aluminum chloride catalyst; The preparation method of the sulfhydryl pyridine ion exchange modified membrane is as follows, in terms of mass fraction: Swelling: 100 parts of polystyrene membrane are immersed in 50-100 parts of dichloromethane, and swelled at room temperature for 30-60 min; Sulfonation reaction: 5-10 parts of chlorosulfonic acid, 1-2 parts of 4-amino-3-mercaptopyridine and 0.1-0.3 parts of aluminum chloride catalyst are added to dichloromethane, and then added dropwise into the swelled membrane at 0-10℃, and reacted for 1-3 h; Neutralization and cleaning: the reacted membrane is neutralized with NaOH solution, and then washed with deionized water until neutral to obtain the sulfhydryl pyridine ion exchange modified membrane; The reaction temperature of step 1 is 0-50℃, the reaction time is 2-3 hours, and the stirring speed is 200-500 rpm.

2. The method for preparing an ultra-high purity hydroxylamine aqueous solution according to claim 1, characterized in that: The electronic grade hydroxylamine salt is selected from hydroxylamine chloride, hydroxylamine sulfate and mixtures thereof.

3. The method for preparing an ultra-high purity hydroxylamine aqueous solution according to claim 1, characterized in that: The organic base is selected from triethanolamine, diethylaminoethanol and mixtures thereof.

4. The method of claim 1, wherein the method is characterized by: The membrane separation technique operates at a flow rate of 0.5-1.5 L / h.m 2 .

5. The method of claim 1, wherein the method is characterized by: The temperature of the vacuum evaporation is 50-70℃, and the operating pressure is 50-200 mmHg.