Boron-based delay composition and preparation thereof

Abstract

The application discloses a boron-based delay composition and a preparation method thereof. The boron-based delay composition provided by the application has high delay precision and good thermal stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of energetic materials, and in particular relates to a boron-based delay spray and its preparation. Background Art

[0002] Delay charge is a substance that utilizes a specifically formulated, stable combustion reaction to achieve time control. Delay charge is widely used in civilian applications both domestically and internationally. By optimizing its formulation, burning rate modifier, and preparation process, the delay accuracy and burning rate stability of products such as electric detonators can be improved. Delay accuracy refers to the accuracy of a delay charge's delay time and is a key metric for evaluating its performance. For example, Patent Document 1 discloses the addition of negative thermal conductivity materials, such as aluminum nitride, to a tungsten-based delay charge to enhance both accuracy and temperature response.

[0003] Boron-based delay agents are composed of two components: boron powder and barium chromate. They are excellent millisecond-level delay agents. According to existing research, for boron-based delay agents, the delay accuracy is related to formulation factors such as boron content and particle size, but the influence of external conditions such as ambient temperature cannot be ignored. As the ambient temperature rises, the number of activated molecules inside the delay agent increases, the burning rate of the delay agent accelerates, and the delay accuracy decreases. For example, non-patent document 1 discloses that by changing the thickness and material of the delay agent shell, the law of delay agent accuracy and wall thickness is explored to improve the accuracy of boron-based delay agents. For another example, patent document 2 discloses that based on the microfluidic principle, delay agent composite particles are prepared by using a micro-droplet template confinement assisted self-assembly method to improve the delay accuracy.

[0004] Furthermore, to reduce the impact of temperature effects on delay accuracy, diatomaceous earth is a common additive used in delay agents. Diatomaceous earth has a low thermal conductivity and a porous structure, making it an excellent thermal insulator. Furthermore, it does not participate in the combustion reaction within the delay agent, making it a common additive. However, according to literature, such as Non-Patent Document 2, the optimal addition of diatomaceous earth to improve the temperature effect of delay agents is 10%. Furthermore, the silica in diatomaceous earth is amorphous, mixing with the delay agent components and filling the gaps between the particles, making uniform and directional heat transfer difficult. While it does not participate in the delay agent combustion reaction, it does affect heat transfer stability. Therefore, it is necessary to find an additive with a fixed structure.

[0005] In summary, the above methods inevitably make the structure or preparation process of the extension piece complicated, or the amount of additives added is too much, which makes it difficult to meet actual use needs.

[0006] Non-patent literature 1: Chang Shenglu, Chen Shixiong, et al., Effect of tube material and size on low burning rate boron-based delay charge[J]. Explosive Materials, 2016, 45(6);

[0007] Non-patent document two: Wang Zhixin, Li Guoxin, et al. Study on the effect of combustion temperature of tungsten-based delay composition [J]. Initiating explosive, 2008, 2;

[0008] Patent document one: CN201910212243.4, a low-temperature sensitive high-precision tungsten-based delay composition formula, application date 2019.03.20;

[0009] Patent document two: CN202211268029.9, preparation method of delay composition based on microdroplet template limited auxiliary self-assembly, application date 2022.10.17. SUMMARY

[0010] 1. Problem to be solved

[0011] The purpose of the present application is to improve the delay precision of the delay composition and its preparation.

[0012] 2. Technical solution

[0013] In order to solve the above problems, the technical solution adopted by the present application is as follows:

[0014] The present application provides a boron-based delay composition, which comprises a base drug and an additive.

[0015] The additive comprises attapulgite powder.

[0016] The additive amount of attapulgite powder is 1-5% of the mass of the base drug.

[0017] As described herein, the "additive amount of attapulgite powder" will affect the delay time precision of the delay composition. Based on this, if the additive amount of attapulgite powder is too much (>5%), it will affect the combustion process of the delay composition, and instead make its precision worse; if the additive amount of attapulgite powder is too little (<1%), it will result in that the improvement effect of the additive is not obvious.

[0018] As described herein, the "mesh size of attapulgite powder" will also affect the delay time precision of the delay composition. Based on this, according to any embodiment of the first aspect of the present application, the mesh size of attapulgite powder is 1000-2000 mesh.

[0019] According to any embodiment of the first aspect of the present application, the additive amount of attapulgite powder is preferably 1-4% of the mass of the base drug; the additive amount of attapulgite powder is further preferably 2-4% of the mass of the base drug; the additive amount of attapulgite powder is further preferably 2.5-3.5% of the mass of the base drug.

[0020] According to any embodiment of the first aspect of the present application, the average particle size of the base drug is 1-10 μm.

[0021] The average particle size of the base drug as described herein also affects the precision of the delay time, and thus, the precision of the delay time of the delay drug is reduced regardless of whether the average particle size of the base drug is too large (> 10 μm) or too small (< 10 μm).

[0022] The boron-based delay drug according to any one of the embodiments of the first aspect of the present application, wherein the base drug comprises boron powder and barium chromate; and wherein the boron powder is monomer boron.

[0023] The boron-based delay drug according to any one of the embodiments of the first aspect of the present application, wherein the mass ratio of the boron powder to the barium chromate is (8-13):(87-92).

[0024] The boron-based delay drug according to any one of the embodiments of the first aspect of the present application, wherein the average particle size of the boron powder is 1-10 μm.

[0025] The boron-based delay drug according to any one of the embodiments of the first aspect of the present application, wherein the average particle size of the barium chromate is 1-10 μm.

[0026] The use of the attapulgite powder as a raw material for the boron-based delay drug according to the second aspect of the present application, wherein the mesh size of the attapulgite powder is 1000-2000 mesh.

[0027] The average particle size of the attapulgite powder as described herein is too large (> 2000) or too small (< 1000), which adversely affects the precision of the delay time of the delay drug.

[0028] The use of the attapulgite powder as a raw material for the boron-based delay drug according to any one of the embodiments of the second aspect of the present application, wherein the boron-based delay drug comprises a base drug, and the amount of the attapulgite powder added is 1-5% of the mass of the base drug.

[0029] The use of the attapulgite powder as a raw material for the boron-based delay drug according to any one of the embodiments of the second aspect of the present application, wherein the amount of the attapulgite powder added is preferably 1-4% of the mass of the base drug; the amount of the attapulgite powder added is further preferably 2-4% of the mass of the base drug; and the amount of the attapulgite powder added is further preferably 2.5-3.5% of the mass of the base drug.

[0030] The use of the attapulgite powder as a raw material for the boron-based delay drug according to any one of the embodiments of the second aspect of the present application, wherein the base drug comprises boron powder and barium chromate; and wherein the boron powder is monomer boron.

[0031] The use of the attapulgite powder as a raw material for the boron-based delay drug according to any one of the embodiments of the second aspect of the present application, wherein the mass ratio of the boron powder to the barium chromate is (8-13):(87-92).

[0032] The use of the attapulgite powder according to any of the embodiments of the second aspect of the present application as a raw material of a boron-based delay composition, wherein the average particle size of the attapulgite powder is 1-10 μm.

[0033] The use of the attapulgite powder according to any of the embodiments of the second aspect of the present application as a raw material of a boron-based delay composition, wherein the average particle size of the barium chromate is 1-10 μm.

[0034] The third aspect of the present application provides a detonator containing the boron-based delay composition according to any of the embodiments of the first aspect of the present application.

[0035] The fourth aspect of the present application provides an explosive device containing the boron-based delay composition according to any of the embodiments of the first aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 TG-DSC curves of Example 4 and Comparative Example 1; wherein (A) is a DSC curve; (B) is a TG curve;

[0037] Figure 2 SEM image of the attapulgite powder used;

[0038] Figure 3 Precision change of the attapulgite powder with different addition amounts at normal temperature (25°C) and high temperature (65°C).

[0039] ADVANTAGEOUS EFFECTS

[0040] (1) The boron-based delay composition provided by the present application has high delay precision.

[0041] (2) The boron-based delay composition provided by the present application has good thermal stability.

[0042] It is found in the research that the diatomite commonly used as a raw material of a delay composition contains amorphous silicon dioxide, which is difficult to uniformly and directionally transfer heat when mixed with delay composition components and filled in the gaps between the particles, and although it does not participate in the combustion reaction of the delay composition, it will adversely affect the heat transfer stability.

[0043] The attapulgite powder used in the present application has a unique layered and stacked structure, and thus has strong stability in addition to the heat insulation property. The silicon dioxide in the attapulgite is in the form of continuous two-dimensional silicon-oxygen tetrahedral sheets, and between any two silicon-oxygen tetrahedral sheets, active oxygen is opposite to active oxygen, and inert oxygen is opposite to inert oxygen, and the active oxygen and OH - are closely packed, and cations are filled in the octahedral voids formed by the active oxygen and OH - constituting octahedral sheets (bands) extending in one dimension. Thus, the attapulgite crystal and the pore channel are in a three-dimensional structure, which can ensure the stability of the heat transfer process.

[0044] (3) The boron-based delay composition provided by the present application, the added amount of attapulgite powder is not more than 5%, and the effective regulation of combustion can be realized at a lower mass fraction. DETAILED DESCRIPTION

[0045] The present disclosure can be more easily understood and further advantages and benefits can be obtained by reference to the following description and examples in conjunction with the accompanying drawings in which all figures are schematic, like elements are referred to with like reference numerals, and in which: It should be understood that the present disclosure is not limited to the specific products, methods, conditions or parameters described and / or shown herein, unless otherwise specified. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless otherwise specified.

[0046] It has to be noted that, as used herein, the terms "preferably", "further preferably", "particularly", "more particularly", "especially" and "more especially" are used to describe a particularly advantageous feature of the application, but not to limit it. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless otherwise specified.

[0047] It has to be noted that, as used herein, the terms "preferably", "further preferably", "particularly", "more particularly", "especially" and "more especially" are used to describe a particularly advantageous feature of the application, but not to limit it. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless otherwise specified.

[0048] Unless otherwise indicated, it is to be understood that each individual element in a list and each combination of individual elements in a list is to be construed as a separate embodiment. For example, a list of embodiments recited as "A, B, or C" is to be construed as including the embodiments of "A," "B," "C," "A or B," "A or C," "B or C," or "A, B, or C."

[0049] In this article, the endpoints of the disclosed scope and any value are not limited to the accurate scope or value, and these scopes or values ​​should be understood as comprising values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Unless the context clearly indicates otherwise, the singular forms "one", "a kind of" and "described" as used herein include singular and plural indicators. The numerical ranges described by endpoints are included in all numerical values ​​and fractions within the corresponding range, and the described endpoints, unless the context clearly indicates otherwise.

[0050] Reference herein to "a substance" is a reference to at least one of that substance and its equivalents.

[0051] In this paper, accuracy is defined as:

[0052] Where v1 is the maximum value of the burning rate at that temperature, v2 is the minimum value of the burning rate at that temperature, and v is the average value of the burning rate at that temperature.

[0053] When items are described by using the conjunction terms "... and / or..." etc., the description should be understood to include any one and all combinations of one or more of the associated listed items.

[0054] In general, the use of the term "about" indicates an approximate value that can vary depending on the desired properties obtained by the disclosed subject matter and will be interpreted in a context-dependent manner based on function. Therefore, one of ordinary skill in the art will be able to interpret a certain degree of difference on a case-by-case basis. In some cases, the number of important figures used when expressing a particular value can be a representative technique for determining the difference allowed by the term "about". In other cases, a gradient in a range of values ​​can be used to determine the range of differences allowed by the term "about". Further, all ranges in this disclosure are inclusive and combinable, and reference to a value stated in a range includes every value within that range.

[0055] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; and the terms used herein include any and all combinations of one or more of the associated listed items.

[0056] The present invention is described below by means of specific examples to make the technical solution of the present invention easier to understand and grasp, but the present invention is not limited thereto, and the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, they do not impose any restrictions on the present invention, and those skilled in the art may make some non-essential improvements and adjustments based on the contents of the present invention, which all fall within the scope of protection of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the scope of protection of the present invention. The experimental methods described in the following examples, unless otherwise specified, are all conventional methods; the reagents and materials, unless otherwise specified, can all be obtained from commercial channels. Specific embodiments

[0058] In the following examples, for the preparation of the delay agent base, a hand mixing and sieving method was adopted. 5 g of boron powder and 45 g of barium chromate were weighed and mixed on paper. After being observed to be uniform with the naked eye, the mixture was passed through a 100-mesh sieve three or more times. After sieving and mixing, it was placed in an oven and dried at 45°C for several hours. After being taken out, it was placed in an antistatic bag for use.

[0059] The boron powder used was purchased from Nanjing University of Science and Technology Science and Technology Chemical Co., Ltd., with an average particle size of 1 μm.

[0060] The barium chromate used was purchased from Nanjing University of Science and Technology Science and Technology Chemical Co., Ltd., with an average particle size of 1 μm.

[0061] In addition, the SEM images of the attapulgite powder used are as follows: Figure 2 As shown: purchased from Meishibo Company, the mesh size is 1000 / mesh;

[0062] Define precision as:

[0063]

[0064] Among them, v1 is the maximum value of the burning rate at this temperature, v2 is the minimum value of the burning rate at this temperature, and v is the average value of the burning rate at this temperature. The temperatures in the experiment are room temperature (25°C) and high temperature (65°C), respectively.

[0065] Example 1

[0066] Add 1% by weight of attapulgite powder to the base compound. After hand-mixing until the color is uniform, pass through a 100-mesh sieve three or more times. After sieving, place in an oven and dry at 45°C for several hours. Remove and store in an antistatic bag for later use. The mold used for pressing the compound is stainless steel, and the tube shell is made of 2A12 aluminum alloy. Specifications: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay agent is pressed in three batches, each containing 90mg. The input and output terminals contain 60mg each of red zirconium and lead ignition powder.

[0067] Example 2

[0068] Add 3% by mass of attapulgite powder to the base compound. After hand-mixing until the color is uniform, pass through a 100-mesh sieve three or more times. After sieving, place in an oven and dry at 45°C for several hours. Remove and store in an antistatic bag for later use. The mold used for pressing the compound is stainless steel, and the tube shell is made of 2A12 aluminum alloy. Specifications: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay agent is pressed in three batches, each containing 90mg. The input and output terminals contain 60mg each of red zirconium and lead ignition powder.

[0069] Example 3

[0070] Add 4% by mass of attapulgite powder to the base compound. After hand-mixing until the color is uniform, pass through a 100-mesh sieve three or more times. After sieving, place in an oven and dry at 45°C for several hours. Remove and store in an antistatic bag for later use. The mold used for pressing the compound is stainless steel, and the tube shell is made of 2A12 aluminum alloy. Specifications: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay agent is pressed in three batches, each containing 90mg. The input and output terminals contain 60mg each of red zirconium and lead ignition powder.

[0071] Example 4

[0072] Add 5% by mass of attapulgite powder to the base compound. After hand-mixing until the color is uniform, pass through a 100-mesh sieve three or more times. After sieving, place in an oven and dry at 45°C for several hours. Remove and store in an antistatic bag for later use. The mold used for pressing the compound is stainless steel, and the tube shell is made of 2A12 aluminum alloy. Specifications: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay agent is pressed in three batches, each containing 90mg. The input and output terminals contain 60mg each of red zirconium and lead ignition powder.

[0073] Comparative Example 1

[0074] This comparative example is basically the same as Example 4, except that attapulgite powder is not added.

[0075] Combine Figure 1 As can be seen from Figure (B), the thermogravimetric curves did not change much before and after the addition of attapulgite. Figure 1 As can be seen from Figure (A), the peak temperature of DSC is delayed to a certain extent; this shows that the addition of attapulgite powder is of great help in improving the thermal stability of the delay spray.

[0076] Comparative Example 2

[0077] The comparative example is basically the same as example 4, the only difference is that the attapulgite powder is replaced by diatomite (purchased from Nanjing University of Technology Science and Technology Chemical Co., Ltd., the average particle size is 1 um), and the addition amount of diatomite is also 5% by mass as in example 4. After the delay incendiary test, the delay precision of the delay incendiary prepared by the comparative example is shown in Table 1.

[0078] Comparative example 3

[0079] The comparative example is basically the same as example 4, the only difference is that the attapulgite powder is replaced by diatomite (purchased from Nanjing University of Technology Science and Technology Chemical Co., Ltd., the average particle size is 1 um), and the addition amount of diatomite is also 5% by mass as in example 4. After the delay incendiary test, the delay precision of the delay incendiary prepared by the comparative example is shown in Table 1.

[0080] Comparative example 4

[0081] The comparative example is basically the same as example 4, the only difference is that the attapulgite powder is replaced by diatomite (purchased from Nanjing University of Technology Science and Technology Chemical Co., Ltd., the average particle size is 1 um), and the addition amount of diatomite is also 5% by mass as in example 4. After the delay incendiary test, the delay precision of the delay incendiary prepared by the comparative example is shown in Table 1.

[0082] In the base incendiary, 6% by mass of attapulgite powder is added, and after hand mixing to uniform color, it is sieved through a 100 mesh screen more than three times, and then sieved and placed in an oven at 45°C for several hours. After taking out, it is placed in an anti-static bag for use. The mold used for pressing the incendiary is a stainless steel mold, the tube shell material is 2A12 aluminum alloy, and the specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay incendiary is divided into three layers, and one layer is 90mg, and the output and input end is zirconium and lead dinitrate ignition incendiary, each 60mg.

[0083] Based on the above, the delay incendiary prepared by examples 1-4 and comparative examples 1-4 is subjected to a delay incendiary speed test, and the delay precision of the delay incendiary obtained is shown in Table 1.

[0084] Table 1 Performance test of delay incendiary

[0085]

[0086] Based on Table 1, it can be seen that:

[0087] (1) It can be seen from any one of examples 1-4 and comparative example 4 that within a certain range (1-5wt%), as the amount of attapulgite powder added increases, the delay time precision of the delay incendiary improves, but when the addition amount of the attapulgite powder is too much (>5%, such as 6%), it will affect the burning process of the delay incendiary, and instead make the precision worse.

[0088] (2) It can be seen from example 4, comparative example 2 or 3 that compared with diatomite, the attapulgite powder used in the present application can effectively improve the delay precision of the delay incendiary under the condition of less dosage.

[0089] (3) Through Example 4 and Comparative Example 1, combined with Figure 1 (B) It can be seen that the thermogravimetric (TG) curve does not change much before and after adding attapulgite powder. Figure 1 (A) It can be seen that the peak temperature of the scanning calorimetry (DSC) curve is delayed to a certain extent after the addition of attapulgite powder, which indicates that the thermal stability of the delayed drug is greatly improved after the addition of attapulgite powder.

[0090] (4) Combination Figure 3 It can be seen that the boron-based delay agent provided by the present invention has good delay time accuracy regardless of room temperature (25°C) or high temperature (65°C), especially when the addition amount of attapulgite powder is within the range of 1-5% of the base agent mass.

Claims

1. A boron-based delay spray, characterized in that: The boron-based delay agent includes a base agent and additives; The additive includes attapulgite powder; The addition amount of the attapulgite powder is 1-5% of the mass of the base drug.

2. The boron-based delay agent according to claim 1, characterized in that: The mesh size of the attapulgite powder is 1000-2000 mesh.

3. The boron-based delay agent according to claim 1, characterized in that: The average particle size of the base drug is 1-10 μm.

4. The boron-based delay spray according to any one of claims 1 to 3, characterized in that: The base drug includes boron powder and barium chromate.

5. The boron-based delay agent according to claim 4, characterized in that: The mass ratio of the boron powder to barium chromate is (8-13): (87-92).

6. Use of attapulgite powder as a raw material for a boron-based delay spray, characterized in that: The mesh size of the attapulgite powder is 1000-2000 mesh; The boron-based delay agent includes a base agent, and the added amount of the attapulgite powder is 1-5% of the mass of the base agent.

7. Use of the attapulgite powder as a raw material for a boron-based delay spray according to claim 6, characterized in that: The base drug includes boron powder and barium chromate; The mass ratio of the boron powder to barium chromate is (8-13): (87-92).

8. Use of the attapulgite powder as a raw material for a boron-based delay spray according to claim 7, characterized in that: The average particle size of the boron powder is 1-10 μm; The average particle size of the barium chromate is 1-10 μm.

9. A detonator or blasting material comprising the boron-based delay charge according to any one of claims 1 to 5.

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