Crystallization method and application of benzotriazole compound

Abstract

The invention discloses a crystallization method and device of a benzotriazole compound. The crystallization method comprises the following steps: mixing a reaction solution containing the benzotriazole compound with a crystallization solvent in a jet mixer, and crystallizing the mixed material flow in a crystallization kettle. Compared with the prior art, the method has the advantages that the product yield is higher, the mixing temperature of the reaction liquid and the crystallization solvent is obviously reduced, the crystallization time is shortened, the process flow is short, and qualified benzotriazole products with narrower particle size distribution, larger specific surface area, higher purity and lower solvent residue can be directly obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemical products, and specifically relates to a crystallization method of a benzotriazole compound and application thereof. Background Art

[0002] UV absorber UV-360 (2,2'-methylene-bis(4-tert-octyl-6-benzotriazolyl)phenol) is a light stabilizer that does not change color, is non-polluting, is resistant to water extraction, does not volatilize at processing temperatures, and has light and heat stability. Its structural formula is:

[0003]

[0004] UV-360 is widely used in polypropylene (PP) and polyethylene (PE); it is also suitable for polystyrene, ABS resin, polyvinyl chloride (PVC), nylon, polyurethane, etc. It has a synergistic effect when used with light stabilizers. UV-360 is insoluble in water, soluble in ester and benzene solvents, and has high thermal stability. In the cosmetics industry, UV-360 can provide the widest range of ultraviolet protection as a broad-spectrum sunscreen. Because cosmetics are in direct contact with the human body, higher requirements are placed on product quality: higher purity, smaller particle size, and especially stricter requirements on solvent residues.

[0005] Regarding the preparation of UV360, the existing technology mainly focuses on the synthesis method of the substance, and there is little research on its crystallization. For example, CN113999182A and US4937348A mainly use the intermittent cooling of mixed solvents to obtain the product. For products in the cosmetics industry or high-end industries, in order to ensure that the residual solvent meets the quality requirements, the conventional crystallization process generally first makes large crystal particles and then crushes the material. This crystallization process is cumbersome, time-consuming and costly. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a semi-continuous collision jet crystallization method, in which the reaction solution and the crystallization solvent are added to a jet mixer, and then enter an intermittent crystallization kettle for cooling and crystallization to obtain the final product. This method can directly obtain a product with higher yield, narrower particle size distribution, larger specific surface area, higher purity and lower solvent residue.

[0007] According to a first aspect of the present invention, a method for crystallizing a benzotriazole compound is provided, the method comprising mixing a reaction solution containing the benzotriazole compound with a crystallization solvent in a jet mixer, and then crystallizing the mixed stream in a crystallization kettle.

[0008] In some embodiments, the feed weight ratio of the reaction solution to the crystallization solvent is (0.5-5): 1, preferably (1-2): 1. In some specific embodiments, the feed weight ratio of the reaction solution to the crystallization solvent is 0.5: 1, 1: 1, 1.2: 1, 1.5: 1, 1.8: 1, 2: 1, 3: 1, 4: 1, 5: 1 or any value therebetween.

[0009] In some embodiments, the crystallization solvent comprises a C1-C3 alcohol compound, such as methanol, ethanol or propanol. In some preferred embodiments, the crystallization solvent is ethanol.

[0010] In some embodiments, the mixing temperature is 25-60° C., preferably 30-50° C. In some specific embodiments, the mixing temperature is 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 60° C. or any value therebetween.

[0011] In some embodiments, the mixing time is 0.5-5 h, preferably 1-1.5 h. In some specific embodiments, the mixing time is 0.5 h, 1 h, 1.5 h, 2 h, 3 h, 4 h, 5 h or any value therebetween.

[0012] In some embodiments, the crystallization is cooling crystallization.

[0013] In some preferred embodiments, the temperature of the crystallization is reduced from 25-60°C to 10-20°C, for example, to 10°C, 12°C, 14°C, 16°C, 18°C, 20°C or any value therebetween. In some preferred embodiments, the temperature of the crystallization is reduced from 30-50°C to 10-20°C.

[0014] In some embodiments, the crystallization time is 0.5-5h, preferably 1-2h. In some specific embodiments, the mixing time is 0.5h, 1h, 1.5h, 2h, 3h, 4h, 5h or any value therebetween.

[0015] In some embodiments, the jet mixer adopts a corrugated plate structure. Jet refers to liquid ejected from a nozzle or orifice, breaking away from the constraints of a solid boundary and diffusing in a liquid or gas.

[0016] In some embodiments, the crystallization kettle is an indirect crystallization kettle. Intermittent crystallization belongs to a single-tank periodic batch operation, which is a device that intermittently adds materials and operates.

[0017] In some embodiments, the crystallization method further comprises washing and drying the crystallized product.

[0018] In some embodiments, the solvent used for washing includes a C1-C3 alcohol compound, such as methanol, ethanol or propanol. In some preferred embodiments, the solvent used for washing is ethanol.

[0019] In some embodiments, the washing solvent is the same as the crystallization solvent.

[0020] In some embodiments, the washing is performed more than 2 times, preferably 2-4 times.

[0021] In some embodiments, the benzotriazole compound is selected from the compound of the structure shown in Formula I,

[0022]

[0023] Wherein, R1, R3, R5, R7 are each independently selected from hydrogen or C1-C3 alkyl, R4 is selected from C1-C3 alkylene, and R2 and R6 are selected from C4-C10 straight chain or branched chain alkyl.

[0024] In some embodiments, R1, R3, R5, and R7 are each independently selected from hydrogen, methyl, ethyl, or propyl, preferably hydrogen.

[0025] In some embodiments, R4 is selected from methylene, ethylene or propylene, preferably methylene.

[0026] In some embodiments, R2 and R6 are each independently selected from C6-C10 branched alkyl groups, for example, secondary hexyl, tertiary hexyl, isohexyl, secondary heptyl, tertiary heptyl, isoheptyl, secondary octyl, tertiary octyl, isooctyl, secondary nonyl, tertiary nonyl, isononyl, secondary decyl, tertiary decyl or isodecyl.

[0027] In some embodiments, the benzotriazole compound is selected from the compound of the structure shown in Formula II, namely 2,2'-methylene-bis(4-tert-octyl-6-benzotriazole)phenol, also known as ultraviolet absorber UV-360,

[0028]

[0029] According to a second aspect of the present invention, there is provided an apparatus for the crystallization method described in the first aspect, comprising a jet mixer and a crystallization kettle connected to each other, wherein the jet mixer is connected to a reaction liquid feed pipeline and a crystallization solvent feed pipeline, and the crystallization kettle is connected to a discharge pipeline.

[0030] In some embodiments, the jet mixer adopts a corrugated plate structure.

[0031] In some embodiments, the crystallization reactor is an indirect crystallization reactor.

[0032] According to a third aspect of the present invention, there is provided a product containing a benzotriazole compound, which is obtained by using the crystallization method described in the first aspect or the device described in the second aspect.

[0033] In some embodiments, the median particle size of the benzotriazole compound is 20-50 μm, preferably 20-30 μm.

[0034] In some embodiments, the purity of the benzotriazole compound is ≥98%, preferably ≥99%.

[0035] In some embodiments, the yield of the benzotriazole compound is ≥94%, preferably ≥96%.

[0036] In some embodiments, the residual solvent in the preparation is ≤500 ppm, preferably ≤300 ppm, more preferably 200-250 ppm.

[0037] According to a fourth aspect of the present invention, there is provided use of the crystallization method described in the first aspect or the device described in the second aspect in the production of benzotriazole compounds.

[0038] In some embodiments, the crystallization method or apparatus is used for the production of benzotriazole compounds in the cosmetics industry.

[0039] In some embodiments, the benzotriazole compound is selected from the compound of the structure shown in Formula II,

[0040]

[0041] Wherein, R1, R3, R5, R7 are each independently selected from hydrogen or C1-C3 alkyl, R4 is selected from C1-C3 alkylene, and R2 and R6 are selected from C4-C10 straight chain or branched chain alkyl.

[0042] In some embodiments, R1, R3, R5, and R7 are each independently selected from hydrogen, methyl, ethyl, or propyl, preferably hydrogen.

[0043] In some embodiments, R4 is selected from methylene, ethylene or propylene, preferably methylene.

[0044] In some embodiments, R2 and R6 are each independently selected from C6-C10 branched alkyl groups, for example, secondary hexyl, tertiary hexyl, isohexyl, secondary heptyl, tertiary heptyl, isoheptyl, secondary octyl, tertiary octyl, isooctyl, secondary nonyl, tertiary nonyl, isononyl, secondary decyl, tertiary decyl or isodecyl.

[0045] In some embodiments, the benzotriazole compound is selected from the compound of the structure shown in Formula II, namely 2,2'-methylene-bis(4-tert-octyl-6-benzotriazole)phenol, also known as ultraviolet absorber UV-360,

[0046]

[0047] In the production of benzotriazole compounds, the crystallization method of the present invention can achieve a single crystallization to obtain a product with higher yield, larger specific surface area, higher purity and lower solvent residue, which is applied in the cosmetics industry with a short process flow and lower cost. The process flow of the present invention is shortened, material loss is reduced, and the yield of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic diagram of a crystallization method according to some embodiments of the present invention is shown. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0050] The present invention relates to a crystallization method of a benzotriazole compound and a device used for the crystallization method. Figure 1 shown.

[0051] In some embodiments, the crystallization method of the present invention comprises the following steps:

[0052] (1) Mixing: feeding the reaction solution containing the benzotriazole compound and the crystallization solvent into a jet mixer respectively; controlling the temperature of the jet mixer to be 25-60° C. (preferably 30-50° C.), and fully mixing the reaction solution and ethanol in the mixer;

[0053] (2) Crystallization and aging: The reaction solution is fully mixed in the jet mixer and enters the crystallization kettle for crystallization and aging;

[0054] (3) Filtration and washing: Filter and wash the filter cake to obtain a crystalline product.

[0055] In some embodiments, in step (1), the weight ratio of the reaction solution to the crystallization solvent feed is (0.5-5):1, preferably 1-2:1, for example 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1.

[0056] In some embodiments, in step (2), the crystallization temperature is controlled to drop from 25-60°C (preferably from 30-50°C) to 10-20°C, and the crystallization time is 0.5-5h, preferably 1-2h.

[0057] In some embodiments, in step (1), the crystallization solvent comprises a C1-C3 alcohol compound, such as methanol, ethanol or propanol, preferably ethanol.

[0058] In some embodiments, the washing solvent in step (3) is the same as the crystallization solvent; in order to improve product purity and reduce solvent residue, the washing is performed twice.

[0059] In some embodiments, the jet mixer has a corrugated plate structure.

[0060] The reagents and / or materials used in the following examples are commercially available or can be synthesized by known methods.

[0061] The UV360 reaction solutions used in the following comparative examples and embodiments are all obtained by the following steps:

[0062] (1) Add 5g of paraformaldehyde, 80g of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and 25g of diethylamine into a four-necked bottle, and start heating after the addition is complete. Keep the temperature at 130-140°C for 2h. Then add 3g of sodium hydroxide, slowly raise the temperature to 180-190°C for 4h, and then add 100g of toluene solvent;

[0063] (2) The pH of the reaction solution was adjusted to neutral using glacial acetic acid, and the solution was washed with 100 ml of water to obtain a UV-360 reaction solution.

[0064] Comparative Example 1

[0065] Step 1: Add 180g of UV360 reaction solution (including 100g of toluene, 80g of UV360 reaction product and reaction impurities) and 100g of ethanol into a four-necked bottle in sequence. Start stirring and heat to about 75°C to dissolve.

[0066] Step 2: Control the material to precipitate slowly by cooling, wherein the total cooling time is divided into three steps: keep the precipitation point at about 70°C for 3 hours, cool from 70°C to 40°C for 6 hours, and from 40°C to 20°C for about 4 hours. The total cooling time is 13 hours to cool to 20°C.

[0067] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to obtain a UV360 dry product.

[0068] Step 4: Use a grinder to crush the UV360 dry product to obtain the UV360 finished product.

[0069] The experimental conditions were repeated for a total of five groups, and the average yield reached 94.68%.

[0070] Example 1

[0071] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer, control the addition rate so that the addition is completed within 1-1.5h, control the temperature of the jet mixer to 40°C, and take a total of 1h to enter the four-necked bottle through the jet mixer.

[0072] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0073] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0074] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.59%.

[0075] Example 2

[0076] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer. Control the addition rate so that the addition is completed within 1-1.5h. Control the temperature of the jet mixer to 50°C. It takes a total of 1h to enter the four-necked bottle through the jet mixer.

[0077] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0078] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0079] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.13%.

[0080] Example 3

[0081] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer, control the addition rate so that the addition is completed within 1-1.5h, control the temperature of the jet mixer to 40°C, and take a total of 1h to enter the four-necked bottle through the jet mixer.

[0082] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 10°C.

[0083] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0084] The experimental conditions were repeated for a total of five groups, and the average yield reached 97.06%.

[0085] Example 4

[0086] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (180g) into a jet mixer. Control the addition rate so that the addition is completed within 1-1.5h. Control the temperature of the jet mixer to 40°C. It takes a total of 1h to enter the four-necked bottle through the jet mixer.

[0087] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0088] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0089] The experimental conditions were repeated for a total of five groups, and the average yield reached 95.43%.

[0090] Example 5

[0091] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (270g) into a jet mixer. Control the addition rate so that the addition is completed within 1-1.5h. Control the temperature of the jet mixer to 40°C. It takes a total of 1h to enter the four-necked bottle through the jet mixer.

[0092] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0093] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0094] The experimental conditions were repeated for a total of five groups, and the average yield reached 94.86%.

[0095] Example 6

[0096] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer, control the addition rate so that the addition is completed within 1-1.5h, control the temperature of the jet mixer to 20°C, and take a total of 1h to enter the four-necked bottle through the jet mixer.

[0097] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0098] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0099] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.38%.

[0100] Example 7

[0101] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer. Control the addition rate so that the addition is completed within 1-1.5h. Control the temperature of the jet mixer to 55°C. It takes a total of 1h to enter the four-necked bottle through the jet mixer.

[0102] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0103] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0104] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.54%.

[0105] Example 8

[0106] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer, control the addition rate so that the addition is completed within 1-1.5h, control the temperature of the jet mixer to 40°C, and take a total of 1h to enter the four-necked bottle through the jet mixer.

[0107] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and precipitate it. It takes a total of 0.5 h to cool to 20°C.

[0108] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0109] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.04%.

[0110] Example 9

[0111] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and ethanol (100g) into a jet mixer, control the addition rate so that the addition is completed within 1-1.5h, control the temperature of the jet mixer to 40°C, and take a total of 1h to enter the four-necked bottle through the jet mixer.

[0112] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 4 hours to cool down to 20°C.

[0113] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0114] The experimental conditions were repeated for a total of five groups, and the average yield reached 96.49%.

[0115] Example 10

[0116] Step 1: Add 180g of UV360 reaction solution (containing 100g of toluene, 80g of UV360 product and reaction impurities) and methanol (100g) into a jet mixer. Control the addition rate so that the addition is completed within 1-1.5h. Control the temperature of the jet mixer to 40°C. It takes a total of 1h to enter the four-necked bottle through the jet mixer.

[0117] Step 2: Slowly cool the crystallized liquid in the four-necked bottle and let it precipitate. It takes a total of 2 hours to cool down to 20°C.

[0118] Step 3: The obtained crystal solution is then filtered using a Buchner funnel, and the filter cake is washed twice with 160 ml of ethanol. The washed filter cake is dried to directly obtain the UV360 finished product.

[0119] The experimental conditions were repeated for a total of five groups, and the average yield reached 95.81%.

[0120] Test Case

[0121] 1. Detection of solvent residues

[0122] Weigh 400-500 mg of the sample (record the exact value) into a 25 mL volumetric flask, add 4 mL of dichloromethane to dissolve it, then add methanol to make up to volume and shake well, let it stand for 5 minutes, take the upper layer solution and filter it for sampling, after sampling, record the peak area and sample weight of the target peak, and bring it into the calibration curve to calculate the solvent content. The detection conditions are shown in Table 1 below.

[0123] Table 1

[0124] 2. Detection of particle size or specific surface area

[0125] Instrument: Dandong Better Laser Particle Size Analyzer

[0126] Instrument parameters: speed 800, no ultrasound, medium: water

[0127] Dispersant: Tween 80

[0128] Weigh 0.5-1.0g of sample into a beaker and add water to dissolve it. During the dissolution process, add dispersant Tween 80 to evenly disperse the sample in the water. Then turn on the instrument. When the instrument is ready, use a rubber-tipped dropper to add the dispersed sample into the sample pool. The refractive index of the instrument is in the green area. When the refractive index stabilizes in the green area, the instrument starts automatic detection.

[0129] 3. Purity testing

[0130] The purity was tested according to the test conditions shown in Table 2 below.

[0131] Table 2

[0132]

[0133] The test results of the solvent residue, medium particle size, purity and yield of UV-360 prepared in each embodiment and comparative example are shown in Table 3 below.

[0134] Table 3

[0135] Residual solvent, ppm Median particle size, μm purity,% Yield, % Comparative Example 1 450 26.58 99.09 94.68 Example 1 204 28.45 99.86 96.59 Example 2 198 25.97 99.67 96.13 Example 3 207 24.78 99.87 97.06 Example 4 275 24.96 99.78 95.43 Example 5 261 22.84 99.89 94.86 Example 6 489 20.18 98.43 96.38 Example 7 275 49.53 99.82 96.54 Example 8 248 23.84 99.28 96.04 Example 9 209 29.14 99.72 96.49 Example 10 297 34.82 99.04 95.81

[0136] It can be seen from the results of Comparative Example 1 and the embodiment above and Table 3 that compared with the process flow, the equipment required, and the conditions for crystallization control adopted by the method of Comparative Example 1, they are more complicated. The crystallization method of the present application can achieve a UV360 product that passes the quality inspection in one crystallization, has a higher product yield, and significantly reduces the temperature of the mixture of the reaction solution and the crystallization solvent, while shortening the crystallization time, with a short process flow and lower cost.

[0137] It can be further seen from the results of the various embodiments and Table 3 that in the crystallization method of the present application, by controlling the mixing ratio of the reaction solution and ethanol, the mixing temperature, and the crystallization temperature within a specific range, a product with a smaller particle size, higher purity, and lower solvent residue can be obtained.

[0138] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A crystallization method for a benzotriazole compound, the crystallization method comprising mixing a reaction solution containing the benzotriazole compound with a crystallization solvent in a jet mixer, and then crystallizing the mixed stream in a crystallization kettle.

2. The crystallization method according to claim 1, characterized in that The feed weight ratio of the reaction solution to the crystallization solvent is (0.5-5):1, preferably (1-2):1; Preferably, the crystallization solvent comprises a C1-C3 alcohol compound, more preferably ethanol.

3. The crystallization method according to claim 1 or 2, characterized in that The mixing temperature is 25-60°C, preferably 30-50°C; and / or The mixing time is 0.5-5h, preferably 1-1.5h.

4. The crystallization method according to any one of claims 1 to 3, characterized in that The crystallization is cooling crystallization; Preferably, the crystallization temperature is reduced from 25-60°C to 10-20°C, preferably from 30-50°C to 10-20°C; Preferably, the crystallization time is 0.5-5h, preferably 1-2h.

5. The crystallization method according to any one of claims 1 to 4, characterized in that The jet mixer adopts a corrugated plate structure; and / or The crystallization kettle is an indirect crystallization kettle.

6. The crystallization method according to any one of claims 1 to 5, characterized in that The crystallization method further comprises washing and drying the crystallized product; Preferably, the solvent used for washing comprises a C1-C3 alcohol compound, preferably ethanol; More preferably, the solvent used in the washing is the same as the crystallization solvent; More preferably, the washing is performed more than 2 times, preferably 2-4 times.

7. The crystallization method according to any one of claims 1 to 6, characterized in that The benzotriazole compound is selected from the compounds of the structure shown in Formula I, wherein R1, R3, R5, and R7 are each independently selected from hydrogen or C1-C3 alkyl, R4 is selected from C1-C3 alkylene, and R2 and R6 are selected from C4-C10 straight or branched chain alkyl; Preferably, the benzotriazole compound is selected from the compound having the structure shown in Formula II, 8. A device for the crystallization method according to any one of claims 1 to 7, comprising a jet mixer and a crystallization kettle connected to each other, the jet mixer being connected to a reaction liquid feed pipeline and a crystallization solvent feed pipeline, and the crystallization kettle being connected to a discharge pipeline; Preferably, the jet mixer adopts a corrugated plate structure; Preferably, the crystallization kettle is an indirect crystallization kettle.

9. A product containing a benzotriazole compound, obtained by the crystallization method according to any one of claims 1 to 7 or the device according to claim 8, which satisfies one or more of the following (a) to (d): (a) the benzotriazole compound has a median particle size of 20-50 μm, preferably 20-30 μm; (b) the purity of the benzotriazole compound is ≥98%, preferably ≥99%; (c) the yield of the benzotriazole compound is ≥94%, preferably ≥96%; (d) The residual solvent in the product is ≤500 ppm, preferably ≤300 ppm.

10. Use of the crystallization method according to any one of claims 1 to 7 or the device according to claim 8 in the production of benzotriazole compounds, in particular in the production of benzotriazole compounds in the cosmetics industry; Preferably, the benzotriazole compound is selected from the compound having the structure shown in Formula II, in, R1, R3, R5, R7 are each independently selected from hydrogen or C1-C3 alkyl, R4 is selected from C1-C3 alkylene, R2 and R6 are each independently selected from C4-C10 straight or branched alkyl; More preferably, the benzotriazole compound is selected from the compound having the structure shown in Formula II,

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