n-Hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles and method for preparing the same

Abstract

The present invention discloses a n - hexyl 2-(4 - N,N - diethylamino - 2 - hydroxybenzoyl)benzoate (DHHB) particle and a preparation method thereof. The DHHB particle has a median particle size D50 in the range of 100 - 900 μm, a maximum particle size D98 in the range of 300 - 1000 μm, and a particle size distribution width from a minimum particle size D5 of not less than 100 μm to the maximum particle size D98. The DHHB particle with certain particle size characteristics itself has unexpected transportability. On this basis, during its pipeline transportation and reprocessing, most problems such as blockage, material hardening and accumulation can be solved.

Description

Technical Field

[0001] The present invention relates to n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate, and more specifically, to a particle of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate and a method for preparing the particle of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate. Background Art

[0002] n-Hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate (DiethylaminoHydroxybenzoyl Hexyl Benzoate), namely DHHB, has a molecular formula of C 24 H 32 NO4, which is one of the most classic derivatives of dibenzoylmethane. It was first developed by BASF and marketed under the trade name Uvinul A Plus. It has the maximum ultraviolet absorption rate at a wavelength of 354 nanometers and has excellent compatibility and light stability with other sunscreen agents and cosmetic ingredients.

[0003] In the cosmetics industry, DHHB is most widely used. Typically, it is produced by raw material manufacturers and then packaged in tons or small packages of dozens of kilograms according to the needs of cosmetics manufacturers. Traditional production methods mostly use manual packaging. In addition, the particle size characteristics of ultraviolet absorbers have a great impact on their applications and properties. To meet the diverse usage requirements of different industries, purchasing manufacturers of raw materials also mostly need to perform secondary processing on particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate through various technological processes. The traditional method is also to directly pour it into the processing kettle after manually opening the box. The biggest drawbacks of the above are high manual labor intensity, high incidence of occupational diseases, serious environmental pollution, and low operation accuracy. With the strengthening of environmental protection awareness and health awareness, traditional production methods are gradually abandoned or even forced to change, otherwise enterprises will face forced production stoppage.

[0004] Based on the above, emerging technologies have emerged, and the most typical one is the application of a new powder (granular) conveying method to the transfer, transportation (such as packaging and transportation), reprocessing process (such as particle crushing), and production process (such as raw material feeding in cosmetics production) of products. The pipeline conveying method mainly based on air flow (suction type, pressure type, and flow type by adjusting the gas pressure in the conveying pipeline) is a typical representative of the new powder (granular) conveying method and is the most widely used. During transportation, the powder (granules) is pumped into the pipeline together with the two-phase fluidization of solid air, and the material is transported in the conveying pipeline by the power of the gas. The basic requirements are: 1) being able to transport stably without clogging the pipeline; 2) maximizing the application degree of the gas used for transportation to minimize the transportation cost; and more ideally, 3) having a high controllability of the conveying speed, and being able to control the conveying speed with high precision and high response speed when changing the transportation speed. In order to transport stably, generally, it is necessary to increase the gas flow rate (transportation speed) used for transportation and appropriately reduce the solid / gas ratio (powder amount) / gas amount). However, in this case, the gas flow rate increases relative to the powder to be transported, resulting in a substantial increase in the transportation cost. And once clogging occurs at this time, continuously increasing the positive pressure under the action of the large air flow may make the plug in the clogged pipeline tighter. Therefore, researchers have made a lot of contributions and achieved certain results, including improvements at the device level (for example, a pneumatic conveying pipeline clogging dredging system is disclosed in Patent Application Document 1) and explorations at the operation principle method level (for example, a powder conveying device and a powder conveying method are disclosed in Patent Application Document 2), and trying to increase the solid-gas ratio as much as possible within the range of meeting the conveying function. When there is a risk of clogging in the transportation pipeline due to various problems or environmental changes, the gas flow rate is increased in time through the device to solve the occurrence of clogging. However, the above methods have certain difficulties in practice. The main reason is that it is necessary to continuously measure the original pressure of the conveying pipe and the pressures at each port to obtain the required air transmission state, and the relationship between the pressure loss and the solid-gas ratio will also be affected by the changes of the device itself, resulting in difficulty in measuring the accuracy of the results and low accuracy.

[0005] Based on this, there are still many problems with the above new powder (granular) conveying method, resulting in a lack of ideal devices and usage effects. And the problems existing in the previous powder (granular) conveying will inevitably affect the subsequent usage and processing quality of the products, such as poor processing performance in packaging and transportation, raw material feeding in the production process, and reprocessing.

[0006] Patent Application Document 1: Patent Application No.: 201810336872.3, Title: A Pneumatic Conveying Pipeline Clogging Dredging System and Method.

[0007] Patent Application Document 2: Patent Application No.: JP2018222120, Title: Powder Conveying Device and Powder Conveying Method. Summary of the Invention

[0008] 1. Problem to be Solved

[0009] The object of the present invention is to achieve a better practical use purpose and solve the problem of poor performance of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles during use or processing (for example, during re-grinding, mixing, and delivery processes, mixing, transfer, and transportation during cosmetic production, and these problems encountered in other possible fields); the present invention provides the following technical solutions.

[0010] 2. Technical Solutions

[0011] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0012] 1. A n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particle, wherein the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particle has a measured

[0013] a. Median particle size D50 in the range of 100 - 900 μm;

[0014] b. Maximum particle size D98 in the range of 300 - 1000 μm; and

[0015] c. Width difference (which can also be referred to as particle size distribution) from the minimum particle size D5 not less than 100 μm to the maximum particle size D98;

[0016] D98 is the particle size corresponding to 98% in the particle size cumulative distribution (0 to 100%);

[0017] D5 is the particle size corresponding to 5% in the particle size cumulative distribution (0 to 100%);

[0018] D50 is the particle size corresponding to 50% in the particle size cumulative distribution (0 to 100%).

[0019] 1.1. The maximum particle size D98 is any value in the range of 300 - 1000 μm; preferably, the maximum particle size D98 is any value in the range of 400 - 1000 μm; more preferably, the maximum particle size D98 is any value in the range of 800 - 1000 μm.

[0020] 1.2. Further, the width difference from the minimum particle size D5 to the maximum particle size D98 is not higher than 900 μm.

[0021] 1.3. Further, the width difference from the minimum particle size D5 to the maximum particle size D98 is not less than 300 μm, preferably not less than 500 μm; more preferably not less than 800 μm.

[0022] 1.4. Further, the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have an effective span of not less than 1, preferably not less than 3;

[0023] The calculation method of the span size is as follows:

[0024]

[0025] Wherein,

[0026] Span is the span of the particle swarm;

[0027] D98 is the particle size corresponding to 98% in the particle size cumulative distribution (0 to 100%);

[0028] D5 is the particle size corresponding to 5% in the particle size cumulative distribution (0 to 100%);

[0029] D50 is the particle size corresponding to 50% in the particle size cumulative distribution (0 to 100%).

[0030] 1.5. Further, the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have a span of not more than 5.

[0031] 1.6. Further, the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have a total weight, and in the direction from the minimum particle size D5 to the maximum particle size D98, there is an effective width formed by the particle size distribution of the particles from the minimum particle size D5 to the maximum particle size D98. The effective width sequentially includes three adjacent but non-overlapping regions: the first, the second, and the third; and,

[0032] The particle size distribution width of the second region accounts for at least 20% of the effective width;

[0033] The sum of the particle weights in the second region does not exceed 80% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

[0034] 1.7. Further, the sum of the weights of the particles in the second region is not less than 50% of the total weight of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles; preferably, the sum of the weights of the particles in the second region is not less than 70% of the total weight of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles.

[0035] 1.8. Further, the ratio of the particle size distribution width of the second region to the effective width is not higher than 60%; preferably, the ratio of the particle size distribution width of the second region to the effective width is not higher than 50%.

[0036] 1.9. Further, the ratio of the particle size distribution width of the second region to the effective width is not less than 30%; preferably, the ratio of the particle size distribution width of the second region to the particle size distribution width is not less than 40%.

[0037] 1.10. Further, the sum of the weights of the particles contained in the first region is not less than 5% of the total weight of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles.

[0038] 1.11. Further, the sum of the weights of the particles contained in the third region is not less than 5% of the total weight of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles; preferably not less than 10%.

[0039] 1.12. Further, the ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is 0.3 to 2; preferably 0.5 to 1.5.

[0040] 1.13. Further, the ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is 1 ± 0.2.

[0041] 2. A method for preparing 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles,

[0042] comprising the following steps:

[0043] A. Providing a raw material of 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoic acid n-hexyl ester particles with an initial amount; the particle size distribution of the particle raw material has an effective width (PDI-0) formed by the minimum particle size D5 to the maximum particle size D98; the effective width corresponds to a particle size distribution width difference of not less than 100 μm and not higher than 900 μm.

[0044] B. Divide the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles with the initial amount into a first group, a second group, and a third group; wherein,

[0045] The maximum particle size D98 of the first group is not greater than the minimum particle size D5 of the second group, and the maximum particle size D98 of the second group is not greater than the minimum particle size D5 of the third group;

[0046] And there is an effective width (PDI-1) formed from the minimum particle size D5 to the maximum particle size D98 in the particle size distribution of the second group, and the size of the PDI-1 is 20% to 60% of the PDI-0;

[0047] C. Adjust the weight ratio of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles contained in the first and third groups to 0.3 to 2;

[0048] D. Re-mix the above first group, second group, and third group to form the final 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles.

[0049] 2.1. Further, the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particle raw material with the initial amount has a maximum particle size D98 in the range of 300 to 1000 μm.

[0050] 2.2. Further, after adjustment, the sum of the weights of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles contained in the second group is 50% to 80% of the total weight of the formed final 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles.

[0051] 2.3. Further, adjust the weight ratio of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles contained in the first and third groups to 0.5 to 1.5.

[0052] 2.4. Further, the size of the PDI-1 is 40% to 50% of the PDI-0.

[0053] 2.5. Further, after adjustment, the sum of the weights of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles contained in the second group is 70% to 80% of the total weight of the formed final 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles.

[0054] 2.6. Further, adjust the weight ratio of the coarse particle groups of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate in the first and third groups to be 1 ± 0.2.

[0055] 2.6. Further, the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have:

[0056] a. A median particle size D50 in the range of 100 - 900 μm;

[0057] b. A maximum particle size D98 in the range of 300 - 1000 μm; and

[0058] c. A width difference from the minimum particle size D5 of not less than 100 μm to the maximum particle size D98;

[0059] D98 is the particle size corresponding to 98% in the particle size cumulative distribution (0 to 100%);

[0060] D5 is the particle size corresponding to 5% in the particle size cumulative distribution (0 to 100%);

[0061] D50 is the particle size corresponding to 50% in the particle size cumulative distribution (0 to 100%). Description of the Drawings

[0062] Figure 1-1 Composition diagram of Sample 1 in Example 2 of the present invention;

[0063] Figure 1-2 Particle size distribution diagram of Sample 1 in Example 2 of the present invention;

[0064] Figure 2-1 Composition diagram of Sample 2 in Example 2 of the present invention;

[0065] Figure 2-2 Particle size distribution diagram of Sample 2 in Example 2 of the present invention;

[0066] Figure 3-1 Composition diagram of Sample 3 in Example 2 of the present invention;

[0067] Figure 3-2 Particle size distribution diagram of Sample 3 in Example 2 of the present invention;

[0068] Figure 4-1 Composition diagram of Sample 4 in Example 2 of the present invention;

[0069] Figure 4-2 Particle size distribution diagram of Sample 4 in Example 2 of the present invention.

[0070] Definition Explanation

[0071] Unless otherwise defined, all technical and scientific terms used in this invention have the same meanings as commonly understood by those skilled in the technical field to which this invention belongs; the term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0072] In this invention, for those not specified in the examples, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0073] As used herein, the term "about" is used to provide flexibility and imprecision associated with a given term, measurement, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0074] As used herein, the term "median particle size D50", where "median particle size" is also known as "midpoint particle size", and "D50" can also be expressed as "Dv50" or "d(0.5)", represents the particle size corresponding to when the cumulative particle size distribution percentage (which can also be called the cumulative particle size distribution percentage) of a sample reaches 50%. Further, its physical meaning is that 50% of the particles have a size greater than it, and 50% of the particles have a size less than it.

[0075] As used herein, the term "maximum particle size D98", where "D98" can also be expressed as "Dv98" or "d(0.98)", represents the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 98%. Its physical meaning is that 2% of the particles have a size greater than it, and 98% of the particles have a size less than it.

[0076] As used herein, the term "minimum particle size D5", where "D5" can also be expressed as "Dv5" or "d(0.05)", represents the particle size corresponding to when the cumulative particle size distribution percentage of a sample reaches 5%. Its physical meaning is that 95% of the particles have a size greater than it, and 5% of the particles have a size less than it.

[0077] As used herein, the term "effective width" (referred to as PDI) can also be referred to as "effective particle size width" or "particle size width" or "particle size distribution width" or "effective particle size width" or "particle size width" or "particle size distribution width", and specifically represents the absolute difference (width difference) between the particle size corresponding to a certain value (Dmin) of the cumulative particle size distribution percentage of a sample and the particle size corresponding to another value (Dmax) of the cumulative particle size distribution percentage of the sample. For example, PDI-0 in the present application refers to the absolute difference (width difference) formed between the particle size corresponding to the cumulative particle size distribution percentage of 5% and the particle size corresponding to the cumulative particle size distribution percentage of 98% of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particle raw material with an initial amount used in the preparation method. Another example is that PDI-1 in the present application refers to the absolute difference (width difference) formed between the particle size corresponding to the cumulative particle size distribution percentage of 5% and the particle size corresponding to the cumulative particle size distribution percentage of 98% of the second group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles in the preparation method.

[0078] As used herein, the term "Span" can also be referred to as the dispersion degree of the particle size distribution and is used to evaluate the uniformity of the particle size. The calculation method of the size of the Span is as follows:

[0079]

[0080] Wherein,

[0081] Span is the distance between particle sizes of the particle group;

[0082] D98 is the particle size corresponding to 98% in the cumulative particle size distribution (0 to 100%);

[0083] D5 is the particle size corresponding to 5% in the cumulative particle size distribution (0 to 100%);

[0084] D50 is the particle size corresponding to 50% in the cumulative particle size distribution (0 to 100%).

[0085] It is well known to those skilled in the art that various methods, such as laser analysis, sieving, sedimentation, and ultrasound, can be used for particle size analysis. Furthermore, even with sieving, even when using the same instrument and measurement conditions, different batches of samples can exhibit subtle differences in particle size distribution, leading to subtle differences in measurement results. These differences are generally acceptable to those skilled in the art. Those skilled in the art know that, when the instrument is the same and the test conditions are fixed, although the particle size distribution behavior of the particles will be relatively fixed in theory, in fact, it is only relatively fixed within a range with the measurement results; for example, for the same batch of samples, using the same vibrating screen and measurement conditions (the same quartering sampling, the sampling volume each time is kept as the same as possible, the vibrating screen time is the same, etc.), after multiple measurements, the theoretical median particle size D50 should be 380-400μm, but the actual test results are 365μm or 370μm or 410μm or 420μm, etc., that is to say, if there is an error of less than 5% between the theoretical value and the actual test result, these are generally acceptable to those skilled in the art, and these difference results should also be regarded as the scope of protection of the present invention. Similarly, for the same batch of samples, using the same vibrating screen machine and measurement conditions (same quartering sampling, consistent sampling volume each time, same vibrating time, etc.), after multiple measurements, if the corresponding mass of each layer of sieve surface at the same level in different measurements is within 5%, this is generally acceptable to those skilled in the art, and these discrepancies should also be considered within the scope of protection of the present invention. Furthermore, if the final difference between the sum of the mass of each layer of sieve surface and the mass of the original sample does not exceed 2%, this is also generally acceptable to those skilled in the art, and these discrepancies should also be considered within the scope of protection of the present invention.

[0086] In order to obtain a large amount of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with an initial quantity, the crude n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles formed by purchase or crystallization can be used as raw materials. After preliminary refinement treatment (such as crushing, or screening, crushing, screening treatment), a particle group is obtained. Based on this, before any further processing (such as sorting) is carried out, this particle group can be called a particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate with an initial quantity. It should be noted that the methods, steps, and parameters of the refinement treatment need not be overly rigid, as long as large particles can be decomposed into small particles. Of course, if different groups of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with specific sizes and specific quantities are required, the methods, steps, and parameters of the refinement treatment (such as crushing, or screening, crushing, screening treatment) used can be adjusted through any known existing means to achieve the corresponding purpose, and / or the corresponding purpose can be achieved through repeated means.

[0087] As used herein, the terms "fluidizability (performance)", "flowability (performance)", "processability (performance)", and "transportability (performance)" refer to the same concept, which is the ability to make particles flow better so that they can be more easily operated, processed, and transported; "fluidization aid means", "flow aid means", and "transport aid means" refer to additional methods or means adopted for fluidized beds and / or particles to improve the fluidization performance and processability of fine powders.

[0088] Description of specific implementation manners

[0089] As described above, the combination of the new powder (granular) transportation method with product transfer, transportation (such as bulk transportation, production feeding), and reprocessing (such as particle crushing) has become a trend. Therefore, problems existing in the early-stage powder (granular) transportation are bound to affect the subsequent use and processing quality of the product. During transportation, the powder (granules) are pumped into the pipeline together through the two-phase fluidization of solids and air. The basic requirements are 1) stable transportation without clogging the pipeline, and 2) having the highest possible solid-gas ratio to minimize transportation costs, which is still a major problem in current practice. At the same time, based on the foregoing, it can be seen that existing research mainly focuses on the equipment and method levels, often neglecting the product itself.

[0090] However, the present invention starts from the properties of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles. During the inventors' research, it was found that the characteristics of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles during pipeline transportation would affect their adhesion and blockage in the pipeline system. Under the condition of the same gas flow rate, the product throughput can be increased, and the frequency of blockage can still be kept from increasing. Traditionally, it is considered that particles with too small or too large particle sizes need to be separated before transportation. The reason is that the closer the particle size is to being uniform, the more likely the material will advance in a suspended state during pipeline transportation, presenting a "uniform state". At this time, larger particles cannot obtain enough power and lose their suspension ability, stagnating at the bottom of the pipe and gradually accumulating. For smaller particles, although they can obtain enough power to generate a faster speed, when the fast small particles collide with large particles, their speed will drop suddenly, and subsequent continuous pursuit collisions will occur, gradually forming a group of particles with slow speed, which accumulates and causes blockage. However, in actual operation practice, the removal amount of DHHB particles during the screening process often exceeds 30 wt%, which means that only less than 70 wt% of the amount can be used as "qualified" transportation materials for subsequent cosmetic production, processing and other steps in a single process. Although the 30 wt% removed can be returned to the previous initial stage for recycling, it is still a huge economic investment for real process applications. In addition, it was found during the research that the higher the air flow rate in the pipeline, the more the material will rub in the pipeline, resulting in the generation of serpentine or whiskers in the material, and the quality of the material will decline.

[0091] Based on this, the inventors have long been aware of and continuously and actively sought solutions: It was found during the research that for DHHB with a micron-level particle size, making the transported DHHB particles have a certain particle size distribution width, that is, in addition to particles with a relatively moderate particle size, there are also a considerable amount of small-particle-size particles and large-particle-size particles, which can produce an effect that can significantly improve the transportability while avoiding dust generation, blockage, and enhancing wettability; The possible reason is that although "particle agglomeration" is a common feature of powder products, especially smaller particles tend to adhere to larger particles, different products have different properties (such as surface charge between particles, van der Waals force, electrostatic attraction, etc.). Smaller DHHB particles adhere to larger DHHB particles, and under the action of an air flow at a certain speed, the power provided by the air flow can instead produce a moderate counteraction against the adhesion force between small-particle-size particles and large-particle-size particles. Under such an overall effect, these small-particle-size particles can instead play the role of "power rollers", accompanying and assisting the larger DHHB particles to move forward in the pipeline together, different from the traditional concept that the narrower and more uniform the particle size distribution is, the more beneficial it is for transportation and processing.

[0092] More precisely, the "n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles" of the present invention can also be regarded as a "particle group composed of numerous individual n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles". This embodiment embodies a specific idea of the technical solution of the present invention, which is as follows:

[0093] A. Provide a raw material of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with an initial amount; there is an effective width (PDI-0) formed by the minimum particle size D5 to the maximum particle size D98 in the particle size distribution of the particle raw material; the effective width corresponds to a particle size distribution width difference of not less than 100 μm and not more than 900 μm; the raw material of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with the initial amount has a maximum particle size D98 in the range of 300-1000 μm.

[0094] B. Divide the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with the initial amount into a first group, a second group and a third group; among them,

[0095] the maximum particle size D98 of the first group is not greater than the minimum particle size D5 of the second group, and the maximum particle size D98 of the second group is not greater than the minimum particle size D5 of the third group;

[0096] and there is an effective width (PDI-1) formed by the minimum particle size D5 to the maximum particle size D98 in the particle size distribution of the second group, and the size of the PDI-1 is at least 20% (±5%) of the PDI-0;

[0097] C. Adjust the weight ratio of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the first and third groups to 0.3-2;

[0098] D. Re-mix the above first group, second group and third group to form the final n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

[0099] As Figure 1-2As shown, a specific particle size distribution example of the coarse particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate prepared by the method disclosed above is given. Some parts also represent the typical characteristics of the product to be protected by the present invention. Specifically, in some embodiments, a. the median particle size D50 in the range of 100-900 μm; b. the maximum particle size D98 in the range of 300-1000 μm; and c. the width difference between the minimum particle size D5 not less than 100 μm and the maximum particle size D98 (which can also be called the particle size distribution);

[0100] In the above preparation method, among the particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate in the first group and the particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate in the third group, the fine particles will preferentially adhere to the large particles, forming a temporary particle group in a "loose" state. Under the action of this particle group, the distance between the particles is increased, resulting in a significant reduction in the force between the particles. At the same time, another function of adding fine particles is to act as a "roller" between the large particles, thereby reducing the friction between the particles. In addition, it should be noted that during the merging process, the moisture content of the particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate needs to be controlled below 10% to achieve the above purpose.

[0101] In another embodiment, for the method of preparing the DHHB particles protected by the present application, in step C, it is necessary to ensure that the sum of the weights of the particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate contained in the second group is 45%-85% of the total weight of the finally formed particles of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate, more preferably 50-80%, and most preferably 70-80%; in terms of the range, the value of the sum of the weights of the particles contained in the second region in the total weight of the particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate can be any value taken from any of the following numerical ranges: 50-80%, 50-75%, 50-70%, 50-65%, 50-60%, 50-55%, 60-80%, 60-75%, 60-70%, 60-65%, 70-80%, 70-75%.

[0102] In addition, for the method of preparing the DHHB particles protected by the present application, in step B, it is necessary to ensure that the size of PDI-1 is 15-65% of PDI-0, preferably 40-50%; in terms of the range, the numerical value of PDI-1 / PDI-0 can be any value taken from any of the following numerical ranges: 15-65%, 20-60%, 20-55%, 20-50%, 30-60%, 30-55%, 30-50%, 40-60%, 40-55%, 40-50%.

[0103] In addition, for the method of preparing the DHHB particles protected by the present application, in step C, it is necessary to adjust the weight ratio of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles contained in the first and third groups to 0.5 (±0.1)-1.5 (±0.1), preferably 1±0.2. In terms of the range, the numerical value of the weight ratio of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester coarse particle groups in the first and third groups can be any value taken from any of the following numerical ranges: 0.4-1.6, 0.4-1.5, 0.4-1.2, 0.4-1, 0.4-0.8, 0.4-0.5, 0.5-1.6, 0.5-1.5, 0.5-1.2, 0.5-1, 0.5-0.8, 0.8-1.6, 0.8-1.5, 0.8-1.2, 0.8-1, 1-1.6, 1-1.5, 1-1.2, 1.2-1.6, 1.2-1.5, 1.5-1.6.

[0104] The maximum particle size D98 of the DHHB particles prepared by the above method is any value within the range of 300 to 1000 μm; preferably, the maximum particle size D98 is any value within the range of 400 to 1000 μm; more preferably, the maximum particle size D98 is any value within the range of 800 to 1000 μm. In terms of the range, the value of the maximum particle size D98 can be any value taken from any of the following value ranges: 300 to 1000 μm, 300 to 900 μm, 300 to 800 μm, 300 to 700 μm, 300 to 600 μm, 300 to 500 μm, 300 to 400 μm, 400 to 1000 μm, 400 to 900 μm, 400 to 800 μm, 400 to 700 μm, 400 to 600 μm, 400 to 500 μm, 500 to 1000 μm, 500 to 900 μm, 500 to 800 μm, 500 to 700 μm, 500 to 600 μm, 600 to 1000 μm, 600 to 900 μm, 600 to 800 μm, 600 to 700 μm, 700 to 1000 μm, 700 to 900 μm, 700 to 800 μm, 800 to 1000 μm, 800 to 900 μm, 900 to 1000 μm.

[0105] Instead of being restricted by the traditional requirement of being "narrow", the particle size distribution width from the minimum particle size D5 to the maximum particle size D98 is not limited in this invention. The particle size distribution width of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles from the minimum particle size D5 to the maximum particle size D98 is any value within the range of 100 to 900 μm. Preferably, the particle size distribution width from the minimum particle size D5 to the maximum particle size D98 is any value within the range of 500 to 900 μm; more preferably, the particle size distribution width from the minimum particle size D5 to the maximum particle size D98 is any value within the range of 800 to 900 μm. In some embodiments, the numerical value of the particle size distribution width from the minimum particle size D5 to the maximum particle size D98 can be any value taken from any of the following ranges of values: 100 - 900 μm, 100 - 800 μm, 100 - 700 μm, 100 - 600 μm, 100 - 500 μm, 100 - 400 μm, 100 - 300 μm, 100 - 200 μm, 200 - 900 μm, 200 - 800 μm, 200 - 700 μm, 200 - 600 μm, 200 - 500 μm, 200 - 400 μm, 200 - 300 μm, 300 - 900 μm, 300 - 800 μm, 300 - 700 μm, 300 - 600 μm, 300 - 500 μm, 300 - 400 μm, 400 - 900 μm, 400 - 800 μm, 400 - 700 μm, 400 - 600 μm, 400 - 500 μm, 500 - 900 μm, 500 - 800 μm, 500 - 700 μm, 500 - 600 μm, 600 - 900 μm, 600 - 800 μm, 600 - 700 μm, 700 - 900 μm, 700 - 800 μm, 800 - 900 μm.

[0106] In this invention, another typical characteristic of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate coarse particles is that they have an effective diameter ratio of not less than 1 and not more than 5; in some embodiments, the numerical value of the diameter ratio can be any value taken from any of the following ranges of values: 1 - 5, 1 - 4.5, 1 - 4, 1 - 3.5, 1 - 3, 1 - 2.5, 1 - 2, 1 - 1.5, 2 - 2.5, 2 - 3, 2 - 3.5, 2 - 4, 2 - 4.5, 2 - 5, 3 - 3.5, 3 - 4, 3 - 4.5, 3 - 5, 4 - 5.

[0107] Such as Figure 2-2As shown, more typical features of the product to be protected by the present invention are given. In the direction from the minimum particle size D5 to the maximum particle size D98, there is an effective width formed by the minimum particle size D5 to the maximum particle size D98 in the particle size distribution of the particles. The effective width sequentially includes three adjacent but non-overlapping regions: the first, the second, and the third. And, the width of the second region accounts for at least 20% of the effective width; the sum of the particle weights in the second region does not exceed 80% of the total weight of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles. It is necessary to ensure that the particle content in the second region is the largest, and at the same time, the particle content ratios in the first and third regions are the most critical. In addition to the foregoing reasons, other mechanisms such as the destruction of liquid bridges between particles, the loss of surface charge, or the bond saturation caused by additives may also contribute to the reduction of the force between large particles. Therefore, even a very small addition amount of small particles may greatly improve the controllability of the overall transportability of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles. Especially when air jet milling is carried out, the flexible controllability of the overall transportability of the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles can be achieved by regulating the air flow rate. The inventors found in the research that under the foregoing particle size conditions, the addition ratio (weight ratio) of small particles (the first region) should be lower than that of large particles (the second and third regions), and the most preferred addition ratio of small particles is close to that of large particles.

[0108] Specifically regarding the weight percentages of the first, second, and third regions, the sum of the weights of the particles contained in the first region of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles of the present invention accounts for no less than 5% of the total weight of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles; the sum of the weights of the particles contained in the third region accounts for no less than 5% of the total weight of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles; meanwhile, the key point of the present invention is that the ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is not less than 0.3 and not more than 2. In certain embodiments, the numerical value of the ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region can be any value taken from any of the following ranges of numerical values: 0.3 - 2, 0.3 - 1.8, 0.3 - 1.5, 0.3 - 1.2, 0.3 - 1, 0.3 - 0.8, 0.3 - 0.5, 0.5 - 2, 0.5 - 1.8, 0.5 - 1.5, 0.5 - 1.2, 0.5 - 1, 0.5 - 0.8, 0.8 - 2, 0.8 - 1.8, 0.8 - 1.5, 0.8 - 1.2, 0.8 - 1, 1 - 2, 1 - 1.8, 1 - 1.5, 1 - 1.2, 1.2 - 2, 1.2 - 1.8, 1.2 - 1.5, 1.5 - 2, 1.5 - 1.8, 1.8 - 2.

[0109] Regarding the second region, the sum of the weights of the particles contained in the second region accounts for 20 - 80% of the total weight of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles. In certain embodiments, the numerical value of the sum of the weights of the particles contained in the second region accounting for the total weight of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles can be any value taken from any of the following ranges of numerical values: 50 - 80%, 50 - 75%, 5 / 0 - 70%, 50 - 65%, 50 - 60%, 50 - 55%, 60 - 80%, 60 - 75%, 60 - 70%, 60 - 65%, 70 - 80%, 70 - 75%.

[0110] In addition, the ratio of the particle size distribution width of the second region to the effective width of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles is 20-60%. In certain embodiments, the numerical value of the ratio of the region width of the second region to the particle size distribution width can be any value taken from any of the following ranges of values: 20-60%, 20-55%, 20-50%, 30-60%, 30-55%, 30-50%, 40-60%, 40-55%, 40-50%.

[0111] |Particle Size Analysis|

[0112] 1. Experimental equipment: balance, standard sieve, sieve shaker.

[0113] 2. Experimental operation

[0114] (1) Mix the dried sample materials evenly, reduce the sample by quartering, and weigh 200 grams of the sample.

[0115] (2) Stack the standard sieves in the order of decreasing pore size, install the sieve bottom, pour the weighed sample into the top sieve, add the sieve cover, and install on the sieve shaker.

[0116] (3) Start the sieve shaker, shake for 3 minutes, and remove the sieves.

[0117] (4) Weigh the sample masses on each sieve and in the chassis respectively, and record the data.

[0118] (5) Finally, check the difference between the total mass of each sieve surface and the original sample mass. If the error exceeds 2%, the experiment needs to be repeated.

[0119] It should be noted that as is well known to those skilled in the art, due to the problem of sieve pore size, that is, because the wire thickness used in weaving the sieve mesh is different, the standards in different countries are also different. Currently, there are three standards in the United States, the United Kingdom, and Japan. Among them, the standards in the United States and the United Kingdom are similar, and the Japanese standard is quite different. The US standard is adopted in this article. The corresponding relationship between the sieve mesh number and the particle size is as follows:

[0120]

[0121]

[0122] The present invention will be further described below in conjunction with specific embodiments :

[0123] Example 1: Taking Sample 2 as an example, this embodiment schematically shows a method for preparing a particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate protected by the present invention.

[0124] First, based on the purchased 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles, a batch of original 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles was obtained after simple crushing and screening, and then they were processed as follows:

[0125] The first step: Screen using 300-mesh and 16-mesh sieves respectively to obtain the "2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particle raw materials with an initial amount" (total 210.36 Kg) described in the technical solution of the present invention. The particle raw materials have a maximum particle size D98 of about 900 μm.

[0126] The second step: First, screen the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles with an initial amount using a 200-mesh sieve to obtain the first group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles (screenings 32 Kg);

[0127] Then, screen the 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles on the screenings using a 32-mesh sieve to obtain the second group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles (screenings 151.33 Kg); After testing, the PDI-1 value is about 375.

[0128] The remainder is the third group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles (screenings 22.21 Kg)

[0129] The third step: Adjust the amount of the first group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles to 22 Kg. At this time, the ratio of the amount of the first group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles to the amount of the third group of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles is close to 1, more specifically 0.99.

[0130] The fourth step: Combine the obtained first group with the second group and the third group to form the final 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particle group as shown in Figure 2-2 the different regions and their weight ratio distributions within the effective width of the particle size distribution (D5-D98). As described before, the D5 and D98 of this particle size distribution can be determined using an instrument.

[0131] It should be noted that, in order to achieve the best effect, in this embodiment, the amount of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles in the first group is reduced to be equivalent to that in the third group. In fact, it is also possible to choose not to make any changes or to increase the amount of 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particles in the third group.

[0132] Example 2: This embodiment shows several final formed 2-(4-N,N-diethylamino-2-hydroxybenzoyl) benzoic acid n-hexyl ester particle groups among the many technical solutions protected by the present invention, where:

[0133] The particle size distribution diagram of Sample 1 is as shown in Figure 1-2 shown, and the regional composition diagram of Sample 1 is as shown in Figure 1-1 shown;

[0134] The particle size distribution diagram of Sample 2 is as shown in Figure 2-2 shown, and the regional composition diagram of Sample 2 is as shown in Figure 2-1 shown;

[0135] The particle size distribution diagram of Sample 3 is as shown in Figure 3-2 shown, and the regional composition diagram of Sample 3 is as shown in Figure 3-1 shown;

[0136] The particle size distribution diagram of Sample 4 is as shown in Figure 4-2 shown, and the regional composition diagram of Sample 4 is as shown in Figure 4-1 shown. [[ID=,33]]

[0137] The specific particle size characteristics are shown in Table 1 and Table 2.

[0138] Table 1

[0139]

[0140] Table 2

[0141]

[0142] Remarks: D98 is the particle size corresponding to 98% in the particle size cumulative distribution (0 to 100%);

[0143] D5 is the particle size corresponding to 5% in the particle size cumulative distribution (0 to 100%);

[0144] D50 is the particle size corresponding to 50% in the particle size cumulative distribution (0 to 100%);

[0145] Span is the dispersion degree, specifically

[0146] PDI-0 refers to the absolute difference (width difference) formed between the particle size corresponding to when the cumulative particle size distribution percentage of the finally formed n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles reaches 5% and the particle size corresponding to when the cumulative particle size distribution percentage reaches 98%;

[0147] PDI-1 refers to the absolute difference (width difference) formed between the particle size corresponding to when the cumulative particle size distribution percentage of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles in the second region (second group) reaches 5% and the particle size corresponding to when the cumulative particle size distribution percentage reaches 98%;

[0148] wt% refers to the weight ratio percentage, wt% 第一区域 refers to the percentage of the weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles in the first region in the total weight, wt% 第二区域 refers to the percentage of the weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles in the second region in the total weight, wt% 第三区域 refers to the percentage of the weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles in the third region in the total weight;

[0149] L(t%) = PDI-1 / PDI-0.

[0150] Example 3: To demonstrate the advantages obtained from the embodiments of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles protected by the present invention. Using air as the carrier gas and an air compressor as the conveying gas source (the gas flow rate is 30 m 3 / h), an experiment is carried out using a stainless steel pipe with an inner diameter of 15 mm. The gas flow rate is controlled and measured by a gas mass flow controller, the mass of the solid material is measured by a weighing sensor, and the pressure along the horizontal stainless steel pipe is measured by 3 pressure sensors with an interval of 1 m and a range of 400 kPa. The critical state value of the pneumatic conveying blockage of the conveying capacity when different n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles are pneumatically conveyed is studied; by detecting the pressure signal on the horizontal pipe, the maximum conveying capacity when reaching the blockage critical state is obtained, as shown in Table 3 specifically.

[0151] Table 3

[0152] Sample Critical state value of material conveying volume blockage (Kg / h) 1***** 836 2* 1760 3** 1208 4** 1344 Second region in Sample 2* 729

[0153] Note: * represents the conveyability of the corresponding sample. The more *, the less the amount that can be conveyed within an acceptable range during the conveying process, and the higher the frequency of blockage occurrence. Each * represents an approximate 5% increase in the blockage probability.

[0154] The following conclusions can be drawn from the above table

[0155] 1) The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles protected by the present invention have a certain particle size distribution width. Small particle size particles (the first region) and large particle size particles (the third region) coexist, and the conveying amount is increased during pneumatic conveying with the assistance of air flow;

[0156] 2) Under the foregoing particle size conditions, the proportion of particle content in the first and third regions is the most critical. The addition proportion (weight ratio) of small particle size particles (the first region) should not be higher than that of large particle size particles (the third region). The best effect is achieved when the addition proportion of small particle size particles is close to that of large particle size particles.

[0157] 3) At the same time, under the foregoing particle size conditions, the weight percentage in the second region is also very critical. On the premise of ensuring a certain amount of particle content in the first and third regions, the larger the content ratio in the second region, the better the conveyability.

[0158] The above description is only regarded as an illustration of specific implementation manners. Those of ordinary skill in the art and those who manufacture or use the present invention will think of changes to the present invention. Therefore, it should be understood that the implementation manners shown in the drawings and described above are only for illustrative purposes and are not intended to limit the scope of the present invention.

Claims

1. A n - hexyl 2-(4 - N,N - diethylamino - 2 - hydroxybenzoyl) benzoate particle, characterized in that: The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have: a. A median particle size D50 in the range of 100 to 900 μm; b. A maximum particle size D98 in the range of 300 to 1000 μm; And c. A width difference from the minimum particle size D5 of not less than 100 μm to the maximum particle size D98; D98 is the particle size corresponding to 98% in the particle size cumulative distribution (0 to 100%); D5 is the particle size corresponding to 5% in the particle size cumulative distribution (0 to 100%); D50 is the particle size corresponding to 50% in the particle size cumulative distribution (0 to 100%); The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have a total weight, and in the direction from the minimum particle size D5 to the maximum particle size D98, there is an effective width (PDI-0) formed by the minimum particle size D5 to the maximum particle size D98 for the particle size distribution of the particles. The effective width sequentially includes a first region, a second region, and a third region, and these three regions are adjacent but do not overlap; wherein, the sum of the particle weights included in the first region is not less than 5% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles, and the sum of the particle weights in the second region accounts for 20 to 80% of the total weight of the n-hexyl ​ ​ 2. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 1, characterized in that: ​ 3. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 1, characterized in that: ​ 4. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 1, characterized in that: ​ 5. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 1, characterized in that: ​ 6. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 1 to 5, characterized in that: ​ ​ ​ is the radial distance of the particle swarm; ​ ​ D50 is the particle size corresponding to 50% in the cumulative particle size distribution (0 to 100%).

7. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 6, characterized in that: The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have an effective diameter distance of not less than 3.

8. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 6, characterized in that: The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles have a diameter distance of not more than 5.

9. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 1 to 5 and 7 to 8, characterized in that: The sum of the weights of the particles in the second region is not less than 50% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

10. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 1 to 5 and 7 to 8, characterized in that: The sum of the weights of the particles in the second region is not less than 70% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

11. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 1 to 5 and 7 to 8, characterized in that: The size of the PDI-1 is 20 to 50% of the PDI-0.

12. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 1 to 5, 7 to 8, characterized in that: The size of the PDI-1 is 40 to 50% of the PDI-0.

13. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 9, characterized in that: The sum of the weights of the particles contained in the third region is not less than 5% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

14. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 10, characterized in that: The sum of the weights of the particles contained in the third region is not less than 5% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

15. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 11, characterized in that: The sum of the weights of the particles contained in the third region is not less than 5% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

16. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 12, characterized in that: The sum of the weights of the particles contained in the third region is not less than 5% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

17. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 9, characterized in that: The sum of the weights of the particles contained in the third region is not less than 10% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

18. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 10, characterized in that: The sum of the weights of the particles contained in the third region is not less than 10% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

19. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 11, characterized in that: The sum of the weights of the particles contained in the third region is not less than 10% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

20. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 12, characterized in that: The sum of the weights of the particles contained in the third region is not less than 10% of the total weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

21. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 13 to 20, characterized in that: The ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is 0.3 to 1.

22. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 13 to 20, characterized in that: The ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is 0.5 to 1.

23. The n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to any one of claims 13 to 20, characterized in that: The ratio of the weight of the particles contained in the first region to the weight of the particles contained in the third region is 0.8 to 1.

24. A method for preparing n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles as described in any one of claims 1 to 23, characterized in that: Comprising the following steps: A. Provide a starting amount of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particle raw materials; the particle size distribution of the particle raw materials has an effective width (PDI-0) formed by the minimum particle size D5 to the maximum particle size D98; the effective width corresponds to a particle size distribution width difference of not less than 100 μm and not more than 900 μm. B. Divide the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles with the starting amount into a first group, a second group, and a third group; where the maximum particle size D98 of the first group is not greater than the minimum particle size D5 of the second group, and the maximum particle size D98 of the second group is not greater than the minimum particle size D5 of the third group; and the particle size distribution of the second group has an effective width (PDI-1) formed by the minimum particle size D5 to the maximum particle size D98, and the size of PDI-1 is 20% to 60% of the size of PDI-0; C. Adjust the weight ratio of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the first group to the weight of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the third group to be 0.3 to 2; D. Re-mix the above first group, second group, and third group to form the final n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

25. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 24, characterized in that: The starting amount of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particle raw materials has a maximum particle size D98 in the range of 300 to 1000 μm.

26. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 25, characterized in that: After adjustment, the sum of the weights of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the second group is 50% to 80% of the total weight of the formed final n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

27. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 26, characterized in that: Adjust the weight ratio of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the first and third groups to be 0.4 to 1.

28. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 25, characterized in that: The size of PDI-1 is 40% to 50% of PDI-0.

29. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 26, characterized in that: After adjustment, the sum of the weights of the n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles contained in the second group is 70% to 80% of the total weight of the formed final n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles.

30. The preparation method of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate particles according to claim 27, characterized in that: Adjust the weight ratio of the coarse particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate in the first group to the weight of the coarse particle group of n-hexyl 2-(4-N,N-diethylamino-2-hydroxybenzoyl)benzoate in the third group to be 0.5 to 1.

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