Boron delay powder and preparation thereof

Abstract

The invention discloses a boron-based delay powder and preparation thereof, and the boron-based delay powder taking attapulgite powder as one of raw materials is high in delay precision and good in thermal stability.

Description

Technical Field

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

[0002] Delay charge is a substance that uses a specific formula of stable combustion reaction to achieve time control. Delay charge is widely used in the civilian field at home and abroad. By optimizing the formula, burning rate regulator and preparation process of delay charge, the delay accuracy and burning rate stability of electric detonators can be improved. Delay accuracy refers to the accuracy of the delay time of delay charge, which is an important indicator for evaluating the performance of delay charge. For example, Patent Document 1 discloses that negative thermal conductivity materials such as aluminum nitride are added to tungsten-based delay charge to achieve improved accuracy and temperature effect.

[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 studies, 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, a delay agent composite particle is prepared by using a micro-droplet template confinement-assisted self-assembly method to improve the delay accuracy.

[0004] In addition, in order to reduce the influence of temperature effect on delay accuracy, diatomaceous earth is a more commonly used additive in delay medicine. It has a small thermal conductivity and a porous structure, and can be used as a good thermal insulation material. It does not participate in the combustion reaction in the delay medicine, so it is often used as a delay medicine additive. However, according to literature records, such as the record in non-patent literature 2, the best addition amount of diatomaceous earth to improve the temperature effect of delay medicine is 10%, and the silicon dioxide in diatomaceous earth is amorphous. It is mixed with the delay medicine components and filled in the gaps between the particles, which makes it difficult to carry out uniform and directional heat transfer. Although it does not participate in the combustion reaction of the delay medicine, it affects the heat transfer stability. Therefore, it is necessary to find an additive with a fixed structure.

[0005] In summary, the above methods inevitably make the delay part structure or preparation process complicated, or too much additive is added, which is difficult to meet the 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 literature 2: Wang Zhixin, Li Guoxin, et al., Study on the combustion temperature effect of tungsten-based delayed combustion [J]. Initiators, 2008, 2;

[0008] Patent document 1: CN201910212243.4, a low-temperature sensitive and high-precision tungsten-based delay medicine formula, application date 2019.03.20;

[0009] Patent document 2: CN202211268029.9, a method for preparing delayed-release drugs based on microdroplet template confinement-assisted self-assembly, application date 2022.10.17. Summary of the invention

[0010] 1. Problem to be solved

[0011] The invention aims to improve the prescription of a delay medicine with high delay accuracy and its preparation.

[0012] 2. Technical solution

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

[0014] The first aspect of the present invention provides a boron-based delay agent, including a base agent and an additive;

[0015] The additive includes attapulgite powder;

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

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

[0018] As described herein, the "mesh size of the attapulgite powder" will also affect the delay time accuracy of the delay agent. Based on this, according to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the mesh size of the attapulgite powder is 1000-2000 mesh.

[0019] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the added amount of the attapulgite powder is preferably 1-4% of the mass of the base medicine; the added amount of the attapulgite powder is further preferably 2-4% of the mass of the base medicine; the added amount of the attapulgite powder is further preferably 2.5-3.5% of the mass of the base medicine.

[0020] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the average particle size of the base agent is 1 to 10 μm.

[0021] As described herein, the "average particle size of the base drug" will also affect the delay time accuracy. Based on this, whether the average particle size of the base drug is too large (>10μm) or too small (<10μm), the delay time accuracy of the delay drug will be reduced.

[0022] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the base agent includes boron powder and barium chromate; wherein the boron powder is monomeric boron.

[0023] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the mass ratio of the boron powder to barium chromate is (8-13):(87-92).

[0024] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the average particle size of the boron powder is 1 to 10 μm.

[0025] According to the boron-based delay agent described in any embodiment of the first aspect of the present invention, the average particle size of the barium chromate is 1 to 10 μm.

[0026] The second aspect of the present invention provides the use of attapulgite powder as a raw material for a boron-based delay agent, wherein the attapulgite powder has a mesh size of 1000 to 2000 meshes.

[0027] As mentioned herein, whether the "mesh size of attapulgite powder" is too large (>2000) or too small (<1000), the delay time accuracy of the delay medicine will be adversely affected.

[0028] According to the use of the attapulgite powder as a raw material of a boron-based delay agent according to any embodiment of the second aspect of the present invention, the boron-based delay agent comprises a base agent, and the addition amount of the attapulgite powder is 1-5% of the mass of the base agent.

[0029] According to any embodiment of the second aspect of the present invention, for the use of the attapulgite powder as a raw material for a boron-based delay agent, the added amount of the attapulgite powder is preferably 1-4% of the mass of the base drug; the added amount of the attapulgite powder is further preferably 2-4% of the mass of the base drug; the added amount of the attapulgite powder is further preferably 2.5-3.5% of the mass of the base drug.

[0030] According to the use of the attapulgite powder as a raw material for a boron-based delay agent according to any embodiment of the second aspect of the present invention, the base agent comprises boron powder and barium chromate; wherein the boron powder is monomeric boron.

[0031] According to the use of the attapulgite powder as a raw material for a boron-based delay agent according to any embodiment of the second aspect of the present invention, the mass ratio of the boron powder to barium chromate is (8-13):(87-92).

[0032] According to the use of the attapulgite powder as a raw material for a boron-based delay agent according to any embodiment of the second aspect of the present invention, the average particle size of the boron powder is 1 to 10 μm.

[0033] According to the use of the attapulgite powder as a raw material for a boron-based delay agent as described in any embodiment of the second aspect of the present invention, the average particle size of the barium chromate is 1 to 10 μm.

[0034] A third aspect of the present invention provides a detonator, wherein the detonator contains the boron-based delay agent described in any embodiment of the first aspect of the present invention.

[0035] A fourth aspect of the present invention provides a blasting material, wherein the blasting material contains the boron-based delay charge described in any embodiment of the first aspect of the present invention. BRIEF DESCRIPTION OF THE 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 is the SEM image of the attapulgite powder used;

[0038] Figure 3 The precision changes of attapulgite powder with different addition amounts at room temperature (25℃) and high temperature (65℃).

[0039] Beneficial Effects

[0040] (1) The boron-based delay agent provided by the present invention has high delay accuracy.

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

[0042] The study found that diatomite, which is often used as a raw material for delay medicine, contains amorphous silicon dioxide, which causes it to mix with the delay medicine components and fill the gaps between particles, making it difficult to conduct uniform and directional heat transfer. Although it does not participate in the delay medicine combustion reaction, it will have an adverse effect on the heat transfer stability:

[0043] The attapulgite powder used in the present invention has a unique layered stacking structure, so it has strong stability in addition to heat insulation properties. The silicon dioxide in the attapulgite is a continuous two-dimensional silicon-oxygen tetrahedron sheet. Between any two silicon-oxygen tetrahedron sheets, active oxygen is opposite to active oxygen, inert oxygen is opposite to inert oxygen, and active oxygen is opposite to OH. - Tightly packed, cations fill the active oxygen and OH - In the octahedral voids, one-dimensional infinitely extended octahedral sheets (belts) are formed. Therefore, both the attapulgite crystals and the pores have a three-dimensional structure, which can ensure the stability of the heat transfer process.

[0044] (3) In the boron-based delay agent provided by the present invention, the addition amount of attapulgite powder does not exceed 5%, and effective regulation of combustion can be achieved with a lower mass fraction. DETAILED DESCRIPTION

[0045] The present disclosure may be more easily understood by reference to the following description in conjunction with the accompanying drawings and examples, all of which constitute a part of the present disclosure. It should be understood that the present disclosure is not limited to the specific products, methods, conditions or parameters described and / or shown herein. Further, the terms used herein are only used for the purpose of describing specific embodiments by way of example and are not intended to be limiting unless otherwise stated.

[0046] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. It should be understood that the scope of protection of the present invention is not limited to the specific specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are for describing specific specific embodiments and are not intended to limit the scope of protection of the present invention. In the following specific embodiments, if the experimental methods of specific conditions are not indicated, they are generally in accordance with the conventional methods and conditions of molecular biology within the art, and such techniques and conditions are fully explained in the literature.

[0047] It should also be understood that, for the sake of clarity, certain features of the present disclosure may be described herein in the context of separate embodiments, but may also be provided in combination with each other in a single embodiment. That is, unless clearly incompatible or specifically not included, each separate embodiment is considered to be combinable with any other embodiment, and the combination is considered to represent another different embodiment. Conversely, for the sake of simplicity, the various features of the present disclosure described in the context of a single embodiment may also be provided individually or in any sub-combination. Finally, although a particular embodiment may be described as part of a series of steps or part of a more general structure, each step or substructure itself may also be considered to be an independent embodiment.

[0048] Unless otherwise indicated, it should be understood that each individual element in a list and each combination of individual elements in the list will be interpreted as a different embodiment. For example, a list of embodiments represented as "A, B, or C" should be interpreted to include embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B, or C".

[0049] In this article, the endpoints and any value of the disclosed scope are not limited to the accurate scope or value, and these scopes or values ​​should be understood to include 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 form "one", "a kind of" and "described" as used herein include singular and plural indicators. The numerical range described by the endpoint is included in all numerical values ​​and fractions within the corresponding range, and the described endpoint, unless the context clearly indicates otherwise.

[0050] In this document, reference 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] 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.

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

[0054] In general, the use of the term "about" indicates an approximate value that may 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 significant 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 the values ​​stated in the range includes each value within the range.

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

[0056] The present invention is described below by specific embodiments 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 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 some non-essential improvements and adjustments made by technicians in this field based on the content of the present invention belong to the protection scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should belong to the protection scope of the present invention. The experimental methods described in the following embodiments, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be obtained from commercial channels. Specific embodiments

[0058] In the following examples, for the preparation of the delay drug 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 by naked eye, they were sieved through a 100-mesh sieve for more than three times. After sieving and mixing, they were placed in an oven and dried at 45°C for several hours. After being taken out, they were put into an antistatic bag for standby 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 um.

[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 um.

[0061] In addition, the SEM image of the attapulgite powder used is 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% mass fraction of attapulgite powder to the base medicine, mix it by hand until the color is uniform, pass it through a 100-mesh screen for more than three times, put it in an oven after sieving and drying it at 45℃ for several hours, take it out and put it in an anti-static bag for use. The mold used for pressing medicine is a stainless steel mold, and the tube shell material is 2A12 aluminum alloy. The specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay medicine is divided into three medicines, one medicine is 90mg, and the output and input ends are zirconium lead red ignition powder, each 60mg.

[0067] Example 2

[0068] Add 3% mass fraction of attapulgite powder to the base medicine, mix it by hand until the color is uniform, pass it through a 100-mesh screen for more than three times, put it in an oven after sieving and drying it at 45℃ for several hours, take it out and put it in an anti-static bag for use. The mold used for pressing medicine is a stainless steel mold, and the tube shell material is 2A12 aluminum alloy. The specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay medicine is divided into three medicines, one medicine is 90mg, and the output and input ends are zirconium lead red ignition powder, each 60mg.

[0069] Example 3

[0070] Add 4% mass fraction of attapulgite powder to the base medicine, mix it by hand until the color is uniform, pass it through a 100-mesh screen for more than three times, put it into an oven after sieving and drying it at 45℃ for several hours, take it out and put it into an anti-static bag for use. The mold used for pressing medicine is a stainless steel mold, and the tube shell material is 2A12 aluminum alloy. The specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay medicine is divided into three medicines, one medicine is 90mg, and the output and input ends are zirconium lead red ignition powder, each 60mg.

[0071] Example 4

[0072] Add 5% mass fraction of attapulgite powder to the base medicine, mix it by hand until the color is uniform, pass it through a 100-mesh screen for more than three times, put it into an oven after sieving and drying it at 45℃ for several hours, take it out and put it into an anti-static bag for use. The mold used for pressing medicine is a stainless steel mold, and the tube shell material is 2A12 aluminum alloy. The specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay medicine is divided into three medicines, one medicine is 90mg, and the output and input ends are zirconium lead red ignition powder, each 60mg.

[0073] Comparative Example 1

[0074] This comparative example is basically the same as Example 4, except that attapulgite powder is no longer added.

[0075] Combination Figure 1 As can be seen from Figure (B), the thermogravimetric curve does 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 indicates that the addition of attapulgite powder is of great help in improving the thermal stability of the delay agent.

[0076] Comparative Example 2

[0077] This comparative example is basically the same as Example 4, except that the attapulgite powder is replaced with diatomaceous earth (purchased from Nanjing University of Science and Technology Science and Technology Chemical Co., Ltd., with an average particle size of 1 um), and the amount of diatomaceous earth added is also 5% by mass as in Example 4. After the delaying agent burning rate test, the delaying accuracy of the delaying agent prepared in this comparative example is shown in Table 1.

[0078] Comparative Example 3

[0079] This comparative example is basically the same as Example 4, except that the attapulgite powder is replaced with diatomaceous earth (purchased from Nanjing University of Science and Technology Science and Technology Chemical Co., Ltd., with an average particle size of 1 um), and the amount of diatomaceous earth added (by mass) is 10%. After the delay agent burning rate test, the delay accuracy of the delay agent prepared in this comparative example is shown in Table 1.

[0080] Comparative Example 4

[0081] This comparative example is basically the same as Example 4, except that the added amount (by mass) of attapulgite powder is 6%.

[0082] Add 6% mass fraction of attapulgite powder to the base medicine, mix it by hand until the color is uniform, pass it through a 100-mesh screen for more than three times, put it into an oven after sieving and drying it at 45℃ for several hours, take it out and put it into an anti-static bag for use. The mold used for pressing medicine is a stainless steel mold, and the tube shell material is 2A12 aluminum alloy. The specifications are: inner diameter 3.50mm, outer diameter 6.5mm, length 16.5mm. The delay medicine is divided into three medicines, one medicine is 90mg, and the output and input ends are zirconium lead red ignition powder, each 60mg.

[0083] In summary, the delay charge prepared by Examples 1 to 4 and Comparative Examples 1 to 4 was subjected to a delay charge burning rate test, and the delay accuracy of the delay charge obtained is shown in Table 1.

[0084] Table 1 Performance test of delay medicine

[0085]

[0086] Based on Table 1, we can see that:

[0087] (1) It can be seen from any one of Examples 1 to 4 and Comparative Example 4 that, within a certain range (1 to 5 wt%), as the amount of attapulgite powder added increases, the delay time accuracy of the delay agent is improved. However, when the amount of attapulgite powder added is too much (>5%, for example, 6%), it will affect the combustion process of the delay agent and make its accuracy worse.

[0088] (2) It can be seen from Example 4 and Comparative Example 2 or 3 that, compared with diatomaceous earth, the attapulgite powder used in the present invention can effectively improve the delay accuracy of the delay agent with a smaller 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 agent, characterized in that: The boron-based delay agent includes a base agent and an additive; The additive includes attapulgite powder; The added 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 meshes.

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

4. The boron-based delay agent according to claim 1, characterized in that: The base drug includes boron powder and barium chromate.

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

7. The use of the attapulgite powder as a raw material for a boron-based delay agent according to claim 6, characterized in that: The boron-based delay agent comprises a base agent, and the added amount of the attapulgite powder is 1-5% of the mass of the base agent.

8. The use of the attapulgite powder as a raw material for a boron-based delay agent 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).

9. The use of the attapulgite powder as a raw material for a boron-based delay agent according to claim 6, characterized in that: The average particle size of the boron powder is 1 to 10 μm; The average particle size of the barium chromate is 1 to 10 μm.

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

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