Purification process of electronic grade p-toluenesulfonic acid

Abstract

The invention discloses an electronic grade p-toluenesulfonic acid purification process, which comprises: S10, introducing a p-toluenesulfonic acid crude product into pure water, and carrying out heating dissolution to obtain a crude product solution; s20, adding the first acid except the p-toluenesulfonic acid into the crude product solution according to a preset proportion, and uniformly mixing; s30, cooling the mixed system obtained in the step S20, and separating out p-toluenesulfonic acid; and S40, carrying out solid-liquid separation to obtain an electronic-grade p-toluenesulfonic acid finished product. According to the purification process of the electronic grade p-toluenesulfonic acid, the steps of water dissolving, heating, first acid adding and cooling precipitation are adopted in sequence, so that metal ions in the p-toluenesulfonic acid are effectively reduced, and the metal ion impurity content of the finished product p-toluenesulfonic acid meets the requirements of an advanced process; the purification yield is improved, the purification energy consumption and cost of p-toluenesulfonic acid are reduced, and the amount of waste liquid generated by purification and the treatment cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of electronic chemical production, and in particular to a purification process of electronic-grade p-toluenesulfonic acid. Background Art

[0002] p-Toluenesulfonic acid is widely used in the synthesis of medicines, pesticides, stabilizers for polymerization reactions, and catalysts for organic synthesis (esters, etc.). It is used as an intermediate and resin curing agent for medicines and coatings, and is also used as an electroplating intermediate. In the semiconductor field, photoresist is a key material used in the semiconductor manufacturing process, and its function is to form the required circuit pattern on the silicon wafer. As a component of photoresist, p-toluenesulfonic acid can improve the stability of photoresist, thereby affecting the manufacturing quality of semiconductor devices. With the continuous improvement of semiconductor process technology, the requirements for raw materials are also increasing. The requirements for single metal ions in solid raw materials in advanced processes are generally less than 100ppb.

[0003] CN115772101A describes a method for producing electronic-grade p-toluenesulfonic acid, which uses highly purified toluene as a production raw material to synthesize electronic-grade p-toluenesulfonic acid. In the prior art, the purification of p-toluenesulfonic acid mainly uses water as a recrystallization solvent, but water recrystallization has the following defects: first, the solubility of p-toluenesulfonic acid in water is 67g / 100ml (25±2℃), and the purification yield is relatively low, generally less than 30%, while taking energy consumption into consideration; second, the use of water as a purification solvent has a general effect on the removal of metal ions. Based on the p-toluenesulfonic acid crude raw material with a single metal ion content of up to 4000-5000ppb, the reduction in metal ion content caused by a single water recrystallization is relatively small. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a purification process for electronic grade p-toluenesulfonic acid, so as to effectively improve the removal efficiency and yield of metal ions in p-toluenesulfonic acid.

[0005] In order to achieve the above technical effects, the technical solution of the present invention is: a purification process of electronic grade p-toluenesulfonic acid, comprising the following steps: S10: introducing the crude p-toluenesulfonic acid into pure water, heating and dissolving it to obtain a crude product solution; S20: adding the first acid other than p-toluenesulfonic acid to the crude product solution in a predetermined ratio and mixing them uniformly; S30: cooling the mixture obtained in S20 to precipitate p-toluenesulfonic acid; S40: solid-liquid separation to obtain electronic grade p-toluenesulfonic acid product.

[0006] A preferred technical solution is that the first acid is an inorganic acid and an organic acid containing a carboxyl group and / or a sulfonic acid group; further, in S20, the first acid is at least one selected from hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, mellitic acid, nitrogen-sulfuric acid, trifluoromethanesulfonic acid, trichloroacetic acid, and trinitrobenzenesulfonic acid; further, in S20, the first acid is trifluoromethanesulfonic acid or nitric acid.

[0007] The preferred technical solution is that the mass ratio of the crude p-toluenesulfonic acid to pure water in S10 is (2-7):1, which can be specifically selected as 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1 point values ​​or interval values ​​with any two point values ​​as the maximum and minimum values. Further, the mass ratio of the crude p-toluenesulfonic acid to pure water in S10 is (3.5-7):1; further, the acid is hydrochloric acid, sulfuric acid, hydrofluoric acid, mellitic acid, nitrogen-sulfuric acid, trifluoromethanesulfonic acid, trichloroacetic acid, trinitrobenzenesulfonic acid, and the mass ratio of the crude p-toluenesulfonic acid to pure water in S10 is (2-5.5):1.

[0008] The preferred technical solution is that the mass ratio of pure water in S10 to the first acid in S20 is 1: (0.2-3.5). Further, the specific values ​​can be 1: 0.2, 1: 0.5, 1: 0.7, 1: 1, 1: 1.2, 1: 1.5, 1: 1.7, 1: 2, 1: 2.2, 1: 2.5, 1: 2.7, 1: 3, 1: 3.2, 1: 3.5 or an interval value with any two points as the maximum and minimum values. When the first acid is nitric acid, the mass ratio of pure water in S10 to the first acid in S20 is preferably 1: (0.3-3), and more preferably 1: (0.3-2.5).

[0009] The preferred technical solution is that the crude p-toluenesulfonic acid and pure water in S10 are heated to 50-90°C; further, the crude p-toluenesulfonic acid and pure water in S10 are heated to 55-80°C; further, the crude p-toluenesulfonic acid and pure water in S10 are heated to 58-72°C.

[0010] The heating temperature is related to the acid. Further, when the acid is hydrochloric acid, nitric acid, or trifluoromethanesulfonic acid, the crude p-toluenesulfonic acid and pure water in S10 are heated to 58-67°C; when the acid is mellitic acid, the crude p-toluenesulfonic acid and pure water in S10 are heated to 63-72°C.

[0011] A preferred technical solution is that the mixture in S30 is cooled to 10-40°C; further, the mixture in S30 is cooled to 20-35°C; further, the mixture in S30 is cooled to 25-35°C.

[0012] The preferred technical solution is that between S10 and S20, S11 is also included: keeping the crude solution warm for 20 to 300 minutes; further, the keeping time is 20 to 120 minutes; further, the keeping time is 20 to 60 minutes.

[0013] A preferred technical solution is that the solid-liquid separation in S4 is centrifugal separation.

[0014] The preferred technical solution is that the centrifugal separation step includes the following steps: S401: introducing the material obtained in S30 into a centrifugal device and centrifuging at a first speed until no liquid is separated from the p-toluenesulfonic acid solid; S402: the centrifugal device is switched to a second speed for centrifugation until no liquid is separated from the p-toluenesulfonic acid solid, thereby obtaining a solid p-toluenesulfonic acid product; The first rotation speed is lower than the second rotation speed.

[0015] A preferred technical solution is that the second rotation speed is 250-350 r / min.

[0016] The advantages and beneficial effects of the present invention are: The purification process of electronic-grade p-toluenesulfonic acid adopts the steps of water dissolution, heating, adding the first acid, and cooling and precipitation in sequence, which effectively reduces the metal ions in the p-toluenesulfonic acid, so that the metal ion impurity content of the finished p-toluenesulfonic acid meets the requirements of advanced processes; Improve the purification yield, reduce the purification energy consumption and cost of p-toluenesulfonic acid, and reduce the amount of waste liquid and treatment costs generated by purification. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0018] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0019] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0020] Pure water and primary acid It is understandable that, as raw materials for processing p-toluenesulfonic acid, the content of metal ions in pure water and the first acid must be controlled to be small. The lower the content of metal ions in the raw materials, the better the purification effect of p-toluenesulfonic acid; for example, electronic grade first acid is used as raw material.

[0021] First Acid The first acid can be selected from inorganic acids and organic acids except p-toluenesulfonic acid, and is further preferably an inorganic acid and an organic acid containing a carboxyl group and / or a sulfonic acid group. The selection range includes but is not limited to hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, mellitic acid, nitrosulfuric acid, trifluoromethanesulfonic acid, trichloroacetic acid, and trinitrobenzenesulfonic acid.

[0022] Solid-liquid separation and p-toluenesulfonic acid finished product The purpose of solid-liquid separation is to separate the solid and liquid of p-toluenesulfonic acid as much as possible. After solid-liquid separation, the finished p-toluenesulfonic acid product is not dried, otherwise it will easily cause the product to turn yellow.

[0023] The raw materials used in the embodiment are as follows: Crude p-toluenesulfonic acid: The maximum content of a single metal ion is 4000-5000ppb; Pure water; First acid (UPS grade / G3 grade, single metal ion content ≤1ppb): hydrochloric acid, mellitic acid, nitric acid, trifluoromethanesulfonic acid.

[0024] 1. Purification of crude p-toluenesulfonic acid by different first acids Example 1

[0025] Example 1 The purification process of electronic grade p-toluenesulfonic acid is carried out in the following steps: S10: introducing crude p-toluenesulfonic acid into pure water, with the mass ratio of crude p-toluenesulfonic acid to pure water being 3:1, heating to 60° C., until the crude p-toluenesulfonic acid is completely dissolved, to obtain a crude solution; S11: The crude product solution is kept at the temperature of S10 for 30 min; S20: adding the hydrochloric acid solution to the crude product solution in a predetermined ratio until the mass ratio of water to hydrochloric acid (HCl) is 1:1, mixing evenly, and a small amount of p-toluenesulfonic acid precipitates; S30: cooling the mixture obtained in S20 to 30° C. until the amount of precipitated toluenesulfonic acid no longer increases significantly; S40: centrifugally separate the acid solution and the precipitated p-toluenesulfonic acid, introduce the material obtained in S30 into a centrifugal device, and centrifuge at a speed of 100 r / min until no liquid is separated from the p-toluenesulfonic acid solid; then switch the centrifugal device to a speed of 200 r / min and centrifuge until no liquid is separated from the p-toluenesulfonic acid solid; finally switch the centrifugal device to a speed of 300 r / min and centrifuge until no liquid is separated from the p-toluenesulfonic acid solid, thereby obtaining an electronic grade p-toluenesulfonic acid product.

[0026] Example 2

[0027] The purification steps are based on Example 1, except that the mass ratio of p-toluenesulfonic acid: water: trifluoromethanesulfonic acid in Example 2 is 3:1:2.

[0028] Example 3

[0029] The purification steps are based on Example 1, except that the mass ratio of p-toluenesulfonic acid: water: mellitic acid in Example 3 is 5:1:2, and the aqueous solution is heated to 70°C.

[0030] Example 4

[0031] The purification steps are based on Example 1, except that the mass ratio of p-toluenesulfonic acid: water: nitric acid in Example 4 is 5:1:1.

[0032] Comparative Example Example 1 The purification process of p-toluenesulfonic acid is carried out in the following steps: S10': introducing crude p-toluenesulfonic acid into pure water, the mass ratio of crude p-toluenesulfonic acid to pure water being 3:1, heating to 60°C, the crude p-toluenesulfonic acid is completely dissolved, and a crude solution is obtained; S11': the crude product solution is kept at the temperature of S10' for 30 min; S20': cooling the crude product solution obtained in S11' to 30° C. until the amount of precipitated toluenesulfonic acid no longer increases significantly; S30': The mixture obtained in S20' is centrifuged in the same manner as in Example 1, and the solid-liquid separation is performed by centrifugation to obtain the finished p-toluenesulfonic acid product.

[0033] The p-toluenesulfonic acid finished products of the embodiments and comparative examples were subjected to the following tests and evaluations: 1. Use ICP-MS to detect the following main metal ions: Na, Mg, Al, K, Ca, Fe, Zn, Cu, Ni; 2. Weigh the mass of the finished p-toluenesulfonic acid product, calculate the percentage of the mass of the finished p-toluenesulfonic acid product to the mass of the crude p-toluenesulfonic acid, and calculate it as the yield.

[0034] The individual metal ion contents and yields of the toluenesulfonic acid products of Examples 1-4 and Comparative Example 1 are shown in the following table:

[0035] Compared with the pure water recrystallization in the comparative example, the hydrochloric acid in Example 1, the trifluoromethanesulfonic acid in Example 2, the mellitic acid in Example 3 and the nitric acid in Example 4 are all beneficial to improving the removal effect and yield of metal ions in p-toluenesulfonic acid. Among them, the trifluoromethanesulfonic acid in Example 2 has the best removal effect on metal ions, which meets the metal ion impurity requirements of higher-level semiconductor processes.

[0036] 2. Purification of crude p-toluenesulfonic acid by nitric acid of different concentrations Example 5

[0037] The purification steps are based on Example 4, except that the mass ratio of p-toluenesulfonic acid: water (pure water, the same below): nitric acid in Example 5 is 5:1:2.

[0038] Example 6

[0039] The purification steps are based on Example 4, except that the mass ratio of p-toluenesulfonic acid: water: nitric acid in Example 6 is 5: 1: 0.5.

[0040] The individual metal ion contents and yields of the finished toluenesulfonic acid products of Example 4-6 are shown in the table below:

[0041] Based on the same nitric acid, Examples 4-6 show that based on the same amount of pure water, the higher the content of the first acid in the p-toluenesulfonic acid precipitation system, the more beneficial it is to the removal of metal ions; the larger the total amount of pure water and the first acid, the lower the yield, but the better the removal effect of metal ions.

[0042] Therefore, on the basis that the finished product of Example 6 reaches the qualified requirements of p-toluenesulfonic acid, the mass ratio of p-toluenesulfonic acid: water: nitric acid in Example 6 is selected, and the amount of nitric acid is small to obtain a higher yield.

[0043] 3. Insulation Steps in the Purification Process Example 7

[0044] The purification steps are based on Example 4, except that Example 7 only includes S10, S20, S30, S40, and does not include the S11 insulation step.

[0045] After testing, the single metal ion content of the p-toluenesulfonic acid product of Example 7 was <120 ppb, and the yield was 92%.

[0046] Comparison between Example 4 and Example 7: The S11 heat preservation step promotes the metal ions to enter and become free in the pure water, thereby reducing the probability of the metal ions adhering to the surface of the p-toluenesulfonic acid precipitate.

[0047] 4. Solid-Liquid Separation Steps in the Purification Process Example 8

[0048] The purification steps are based on those of Example 4, except that the solid-liquid separation in Example 8 uses vacuum filtration using a yarn core funnel.

[0049] After testing, the single metal ion content of the p-toluenesulfonic acid product of Example 8 was <200 ppb, and the yield was 106%.

[0050] Comparison between Example 4 and Example 8: Suction filtration cannot completely remove the p-toluenesulfonic acid solution, so metal ions will still remain in the p-toluenesulfonic acid, and the metal ion content will be relatively high during detection. At the same time, due to the presence of the acid solution, the yield exceeds 100%.

[0051] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A purification process for electronic grade p-toluenesulfonic acid, characterized in that: The following steps are involved: S10: introducing the crude p-toluenesulfonic acid into pure water, heating and dissolving it to obtain a crude product solution; S20: adding the first acid other than p-toluenesulfonic acid to the crude product solution in a predetermined ratio and mixing them uniformly; S30: cooling the mixed system obtained in S20 to precipitate p-toluenesulfonic acid; S40: solid-liquid separation to obtain electronic grade p-toluenesulfonic acid product.

2. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: The first acid is an inorganic acid and an organic acid containing a carboxyl group and / or a sulfonic acid group; further, the first acid in S20 is at least one selected from hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, mellitic acid, nitrosulfuric acid, trifluoromethanesulfonic acid, trichloroacetic acid, and trinitrobenzenesulfonic acid; further, the first acid in S20 is trifluoromethanesulfonic acid or nitric acid.

3. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: The mass ratio of the crude p-toluenesulfonic acid to pure water in S10 is (2-7):

1.

4. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: The mass ratio of pure water in S10 to the first acid in S20 is 1:(0.2-3.5).

5. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: In S10, the crude p-toluenesulfonic acid and pure water are heated to 50-90°C; further, the crude p-toluenesulfonic acid and pure water are heated to 55-80°C; further, the crude p-toluenesulfonic acid and pure water are heated to 58-72°C in S10.

6. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: In S30, the mixed system is cooled to 10-40°C; further, in S30, the mixed system is cooled to 20-35°C.

7. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: The step between S10 and S20 also includes S11: keeping the crude product solution warm for 20 to 300 minutes.

8. The purification process of electronic grade p-toluenesulfonic acid according to claim 4, characterized in that: The solid-liquid separation in S4 is centrifugal separation.

9. The purification process of electronic grade p-toluenesulfonic acid according to claim 8, characterized in that: The centrifugal separation step comprises the following steps: S401: introducing the material obtained in S30 into a centrifugal device and centrifuging at a first speed until no liquid is separated from the p-toluenesulfonic acid solid; S402: the centrifugal device is switched to a second speed for centrifugation until no liquid is separated from the p-toluenesulfonic acid solid, thereby obtaining a solid p-toluenesulfonic acid product; The first rotation speed is lower than the second rotation speed.

10. The purification process of electronic grade p-toluenesulfonic acid according to claim 1, characterized in that: The second rotation speed is 250-350 r / min.

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