Purification method of electronic-grade nonionic surfactant

Abstract

The invention provides a purification method of a universal electronic-grade nonionic surfactant. Specifically, an industrial-grade nonionic surfactant (hereinafter referred to as OPn for short) with high impurity content is dissolved, impurity salt doped in the industrial-grade nonionic surfactant is removed through two-stage resin, and finally, the electronic-grade OPn is obtained through normal-temperature reduced-pressure solvent separation. The method can be used for preparing the high-purity electronic-grade OPn with metal ions lower than 1ppb and main component content higher than 99%, and the method is simple and easy to operate, recyclable in solvent, low in cost, green in process and low in energy consumption, and can meet the purity requirement of wet electronic chemicals in a high-end semiconductor manufacturing process.

Description

Technical Field

[0001] The present invention relates to a method for producing electronic-grade chemicals, in particular to a method for purifying a universal electronic-grade nonionic surfactant. Background Art

[0002] Surfactants are important additives because they can effectively reduce surface tension and improve the wettability and dispersibility of materials. They are widely used in formulated wet electronic chemicals for many key processes such as cleaning, etching, polishing, packaging and testing of semiconductor wafers. They can greatly improve production efficiency and product quality and are an indispensable part of the semiconductor industry chain. Among them, non-ionic surfactants are non-ionized and highly stable in aqueous solution, are not easily affected by the presence of strong electrolytes, inorganic salts and acids and alkalis, and are both water-soluble and oil-soluble. They are used in a large proportion. However, since the production raw materials and environmental cleanliness do not meet the requirements of the semiconductor industry, the impurity content of industrial-grade OPn salts is relatively high and is no longer suitable for high-end manufacturing. Summary of the Invention

[0003] To solve this problem, the present invention provides a method for purifying a universal electronic-grade non-ionic surfactant. Through simple two-stage ion exchange and negative pressure separation, high-purity electronic-grade OPn with metal ion content less than 1 ppb and main component content greater than 99.0% can be prepared.

[0004] Specifically, the present invention provides a method for purifying a general-purpose electronic-grade nonionic surfactant, the preparation method comprising the following steps: Step 1: Mix industrial grade OPn with solvent and fully dissolve and mix evenly; Step 2: Pass the solution through the primary resin at a certain rate to remove most of the metal and positively charged cationic impurities; Step 3: The initially purified solution is then passed through a secondary resin to remove the remaining trace anionic and cationic impurities to obtain an ultra-high-purity electronic-grade OPn solution; Step 4: Finally, the electronic-grade OPn solution is subjected to reduced pressure at room temperature to separate the solvent to obtain electronic-grade OPn.

[0005] The nonionic surfactant (OPn) in step 1 includes fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty acid polyoxyethylene esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, etc. with different chain lengths.

[0006] The solvent in step 1 includes a neutral or weak acid, a weak base, a low-boiling-point substance that does not react with the solute and does not catalyze the reaction of the solute, such as any one of pure water, ethanol, isopropanol, NMP, and DMSO.

[0007] It is worth noting that although only the above-mentioned solvents are listed in this case, other low-boiling-point substances that are neutral, weakly acidic, or weakly alkaline and do not react with the solute or catalyze the solute reaction and are compatible with the selected OPn can be used. In terms of selection, the main ingredient in the formulated product to which the OPn is added is the best solvent.

[0008] The primary resin in step 2 is an H-type strongly acidic cationic resin, preferably including any one of AmberLite™ HPR1300H, AmberLite™ HPR1600 H, AmberLite™ HPR2000H, AmberLite™ HPR252H, and LEWATIT® MonoPlus S108H.

[0009] The column flow rate in step 2 is 0-60 Bv / h, that is, any value between 0-60 Bv / h, preferably any one of 1 Bv / h, 20 Bv / h, 30 Bv / h, and 60 Bv / h.

[0010] It's worth noting that when performing ion exchange in a resin column, if the rate is too high, the ion exchange will not be thorough, affecting quality. A slower rate improves product quality, but too slow a rate can affect production efficiency. Therefore, while the lower limit of the column rate in this case is 0, it's recommended to maintain the highest possible column rate while ensuring output quality.

[0011] The secondary resin in step 3 is a polishing mixed bed resin, preferably: AmberTec™ UP6060, AmberTec™ MR-450 UPW, LEWATIT® UltraPure 1292, LEWATIT® UltraPure 1296.

[0012] The column flow rate in step 3 is 0-30 Bv / h, that is, any value between 0-30 Bv / h, preferably any one of 1 Bv / h, 10 Bv / h, 20 Bv / h, and 30 Bv / h.

[0013] The temperature in step 4 is 15-35°C, preferably any one of 15°C, 25°C, and 35°C.

[0014] It is worth noting that during the solvent separation process, the higher the temperature, the higher the separation efficiency. However, some OPn will slightly decompose above 40°C. To avoid affecting the quality of the product, this case chose a safer upper separation temperature limit of 35°C. When the temperature is extremely low, the solution and solute can also be separated, but the separation is not thorough enough and takes a very long time, so it is not recommended.

[0015] The pressure in step 4 is -0.3 to -0.1 MPa, preferably any one of -0.1 MPa, -0.2 MPa, and -0.3 MPa.

[0016] It should be noted that during the solvent separation process, the higher the negative pressure value, the higher the separation efficiency. When the negative pressure value is too high, it will not affect the product quality, but the energy consumption will be large and the material requirements of the equipment will be higher, which is not economical and not recommended. When the negative pressure value is extremely low or even when there is no negative pressure, the solution and solute can be separated, but the separation is not thorough and takes a very long time, so it is not recommended.

[0017] Another point worth noting is that two stages of resin were used to purify the material in this case. The first stage was an H-type strong acidic cationic resin, and the second stage was a polishing mixed bed resin. The first stage resin can effectively remove most of the positively charged cationic impurities, but there are still a small amount of positively charged ions that are not easily replaced by H ion exchange and negatively charged ion clusters after the coupling of metal ions and anions. In this case, a single cationic resin cannot effectively remove them. When using the second stage mixed bed resin, with the presence of both H ions and OH ions, the pH environment of the ion exchange is milder, the exchange process is faster, and the positive and negative charged ions and ion clusters can be effectively exchanged more thoroughly. DETAILED DESCRIPTION

[0018] The following is a description of the purification method of the electronic-grade nonionic surfactant of the present invention by way of specific examples: Among the resins described in the examples, LEWATIT® MonoPlus S108H, LEWATIT® UltraPure 1292, and LEWATIT® UltraPure 1296 are from Lanxess. AmberLite™ HPR1300H, AmberLite™ HPR1600 H, AmberLite™ HPR2000H, AmberLite™ HPR252H, AmberTec™ UP6060, and AmberTec™ MR-450 UPW are from DuPont.

[0019] The resins described in the comparative examples: AmberLite™ HPR8300 H (weakly acidic cationic resin), AmberLite™ HPR1300 Na (Na strongly acidic cationic resin), AmberLite™ HPR4200 OH (strongly base anionic resin), and AmberLite™ HPR2000H (H strongly acidic cationic resin) are all DuPont brands.

[0020] In the embodiments and comparative examples, AOE10 and AOE20 are fatty alcohol polyoxyethylene ethers with a degree of polymerization of 10 and 20; APEO8 and APEO16 are octylphenol polyoxyethylene ethers with a degree of polymerization of 8 and 16; OP10 is dodecylphenol polyoxyethylene ether with a polyoxyethylene chain length of 10; LAE-2 is polyoxyethylene laurate-2; and AC-1805 is polyoxyethylene octadecylamine.

[0021] Examples 1-9 Step 1: Mix industrial grade OPn with solvent, fully dissolve and mix evenly. Specific solvents and OPn are shown in Table 1. Step 2: Pass the solution through the primary resin at a certain rate to remove most metals and positively charged cationic impurities. The resin model and column flow rate are shown in Table 1. Step 3: The initially purified solution is then passed through a secondary resin to remove the remaining trace anionic and cationic impurities to obtain an ultra-high-purity electronic-grade OPn solution. The resin model and column flow rate are shown in Table 1. Step 4: Finally, the electronic-grade OPn solution is subjected to reduced pressure at room temperature to separate the solvent to obtain electronic-grade OPn. The temperature and pressure are shown in Table 1.

[0022] The electronic-grade OPn product prepared under the above conditions has a metal purity of less than 1 ppb and a main component content of greater than 99%. Specific data are shown in Table 2.

[0023] Comparative Example 1 Based on Example 1, the primary resin in step 2 was replaced with H-type weakly acidic cationic resin AmberLite™ HPR8300 H. Other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements for electronic-grade OPn. Specific data are shown in Table 2.

[0024] Comparative Example 2 Based on Example 1, the primary resin in step 2 was replaced with the Na-type strongly acidic cationic resin AmberLite™ HPR1300 Na. Other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements for electronic-grade OPn. Specific data are shown in Table 2.

[0025] Comparative Example 3 Based on Example 1, the secondary resin in step 3 was replaced with H-type strongly acidic cationic resin AmberLite™ HPR2000H, while other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements for electronic-grade OPn. Specific data are shown in Table 2.

[0026] Comparative Example 4 Based on Example 1, the secondary resin in step 3 was replaced with the OH-type strongly basic anionic resin AmberLite™ HPR4200 OH. Other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements for electronic-grade OPn. Specific data are shown in Table 2.

[0027] Comparative Example 5 Based on Example 1, the column flow rate of the primary resin tower in step 2 was adjusted to 65 Bv / h, while other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements of electronic-grade OPn. Specific data are shown in Table 2.

[0028] Comparative Example 6 Based on Example 1, the column flow rate of the secondary resin tower in step 3 was adjusted to 35 Bv / h, while other conditions remained unchanged. The OPn product prepared under these conditions had a metal content greater than 1 ppb, which did not meet the requirements of electronic-grade OPn. Specific data are shown in Table 2.

[0029] Comparative Example 7 Based on Example 1, the separation temperature in step 4 was adjusted to 10° C., while other conditions remained unchanged. The OPn product prepared under these conditions had a main component content of less than 99%, which did not meet the requirements of electronic-grade OPn. Specific data are shown in Table 2.

[0030] Comparative Example 8 Based on Example 1, the separation pressure in step 4 was adjusted to -0.05 MPa, and other conditions remained unchanged. The OPn product prepared under these conditions had a main component content of less than 99%, which did not meet the requirements of electronic-grade OPn. Specific data are shown in Table 2.

[0031] Table 1

[0032] Table 2 .

Claims

1. A method for purifying an electronic grade nonionic surfactant, characterized in that: The following steps are involved: Step 1: Mix the industrial-grade nonionic surfactant OPn with the solvent and fully dissolve it; Step 2: The solution from step 1 is passed through a primary resin at a certain rate to remove most of the metal and positively charged cationic impurities; Step 3: The initially purified solution is then passed through a secondary resin to remove the remaining trace anionic and cationic impurities to obtain an ultra-high-purity electronic-grade OPn solution; Step 4: Finally, the electronic-grade OPn solution is subjected to reduced pressure at room temperature to separate the solvent to obtain electronic-grade OPn.

2. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The nonionic surfactant in step 1 includes any one of fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty acid polyoxyethylene esters, polyoxyethylene alkylamines, and polyoxyethylene alkylamides with different chain lengths.

3. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The solvent in step 1 includes any one of pure water, ethanol, isopropanol, NMP, and DMSO.

4. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The primary resin in step 2 is an H-type strongly acidic cationic resin, including any one of AmberLite™ HPR1300H, AmberLite™ HPR1600H, AmberLite™ HPR2000H, AmberLite™ HPR252H, and LEWATIT® MonoPlus S108H.

5. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The column flow rate in step 2 is 0-60 Bv / h, preferably any one of 1 Bv / h, 20 Bv / h, 30 Bv / h, and 60 Bv / h.

6. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The secondary resin in step 3 is a polishing mixed bed resin, including any one of AmberTec™ UP6060, AmberTec™ MR-450 UPW, LEWATIT® UltraPure 1292, and LEWATIT® UltraPure 1296.

7. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The column flow rate in step 3 is 0-30 Bv / h, preferably any one of 1 Bv / h, 10 Bv / h, 20 Bv / h, and 30 Bv / h.

8. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The temperature in step 4 is 15-35°C, preferably any one of 15°C, 25°C, and 35°C.

9. The method for purifying an electronic-grade nonionic surfactant according to claim 1, wherein The pressure in step 4 is -0.3 to -0.1 MPa, preferably any one of -0.1 MPa, -0.2 MPa, and -0.3 MPa.

10. The electronic-grade nonionic surfactant obtained by the purification method according to any one of claims 1 to 9, characterized in that: The metal content has dropped to below 1ppb, and the main component content is higher than 99.0%.

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