A low-agglomerated spherical aluminum nitride powder and a method for preparing the same

Abstract

A kind of low agglomeration aluminum nitride powder preparation method, comprising the following steps: S1: 50-60 parts of aluminum nitrate nine water, 60-80 parts of film-forming solution and 20-30 parts of glucose monohydrate are mixed uniformly, after stirring 1-2h, it is poured into polytetrafluoroethylene dish at room temperature 25 ℃ and is stationary 4-6h, and crosslinked film is obtained;S2: the crosslinked film obtained in step S1 is burned at 300-400 ℃ for 30-40 min in argon environment, calcined at 800-900 ℃ for 1-2h in ammonia environment, then at 900-1000 ℃, heat preservation 1-2h, finally at 1200-1400 ℃, calcined 1-2h, and aluminum nitride powder is obtained.The low agglomeration spherical aluminum nitride powder machine preparation method of the application, the particle size of the prepared aluminum nitride powder is fine, the agglomeration rate is low, the conversion rate is high and the specific surface area is large.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of materials, in particular to a low-agglomeration spherical aluminum nitride powder and a preparation method thereof. BACKGROUND

[0002] Aluminum nitride is a new type of functional ceramic material, which has good thermal conductivity, reliable electrical insulation, low dielectric loss and dielectric constant, and a thermal expansion coefficient close to silicon, and a series of excellent properties, and is considered as an ideal material for high-integration semiconductor substrates and electronic device packaging.

[0003] The preparation and performance of aluminum nitride ceramic are obviously affected by factors such as powder purity, particle size, sintering performance, etc., therefore, the preparation of aluminum nitride powder with excellent performance is very important. At present, the preparation methods of aluminum nitride powder mainly include aluminum powder direct nitriding method and alumina carbon thermal reduction method, but the prepared aluminum nitride powder has low purity and is easy to agglomerate. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a low-agglomeration spherical aluminum nitride powder and a preparation method thereof, which has fine particle size, high conversion rate and low agglomeration rate.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme:

[0006] A low-agglomeration aluminum nitride powder preparation method, comprising the following steps:

[0007] S1: uniformly mix 50-60 parts by weight of aluminum nitrate nonahydrate, 60-80 parts of a film-forming solution and 20-30 parts of glucose monohydrate, stir for 1-2 h, then pour into a polytetrafluoroethylene dish at room temperature 25℃ and stand for 4-6 h to obtain a cross-linked film;

[0008] S2: burn the cross-linked film obtained in step S1 at 300-400℃ for 30-40 min in an argon environment, then calcine at 800-900℃ for 1-2 h in an ammonia environment, then heat at 900-1000℃ for 1-2 h, and finally calcine at 1200-1400℃ for 1-2 h to obtain aluminum nitride powder.

[0009] Preferably, the flow rate of the argon is 1000-1200 ml / min, and the flow rate of the ammonia is 1000-1200 ml / min.

[0010] Preferably, the preparation method of the film-forming solution in step S1 is specifically:

[0011] S11: prepare a chitosan solution and a gelatin solution;

[0012] S12: mixing the chitosan solution and the gelatin solution, stirring for 1-2h, to obtain the film-forming solution.

[0013] Preferably, the weight ratio of the chitosan solution and the gelatin solution is 1:1.

[0014] Preferably, the preparation method of the chitosan solution in step S11 is as follows:

[0015] Mixing polyvinyl alcohol and 50% chitosan glacial acetic acid solution, stirring for 1-2h, to obtain the chitosan solution.

[0016] Preferably, the weight ratio of the polyvinyl alcohol and the chitosan glacial acetic acid solution is 1:2.

[0017] Preferably, the preparation method of the gelatin solution in step S11 is as follows:

[0018] S21: preparing a swelling gel solution and a transglutaminase solution;

[0019] S22: mixing the swelling gel solution and the transglutaminase solution according to a weight ratio of 1:1, stirring for 1-2h, to obtain the gelatin solution.

[0020] Preferably, the preparation method of the swelling gel solution in step S21 is as follows:

[0021] Mixing gelatin and distilled water according to a weight ratio of 1:5, stirring for 30-40min at 60-65℃, to obtain the swelling gel solution.

[0022] Preferably, the preparation method of the transglutaminase solution in step S21 is as follows:

[0023] Mixing transglutaminase, polylactic acid-glycolic acid copolymer and distilled water according to a weight ratio of 3:1:10, stirring for 1-2h at 20-25℃, to obtain the transglutaminase solution.

[0024] An aluminum nitride powder prepared by the sintering method.

[0025] The transglutaminase solution of the present application forms a dense spiral structure of gelatin by blending of polymers, cross-linking with a swelling glue solution, increasing the cross section of gelatin, promoting the internal structure of the blend to be more ordered, thus aluminum nitrate and glucose are attached to the surface of the blend and also embedded in the internal structure, and through non-covalent interaction (hydrogen bond, etc.) and covalent interaction (covalent bond), finally through the interaction of gelatin and chitosan, transglutaminase and chitosan to promote the occurrence of self-assembly behavior, the complex embedded spiral network structure is formed between the side chain of the transglutaminase solution and the gelatin, so that the aluminum nitrate and glucose are locked in the network structure and on the surface, and the dispersion is improved.

[0026] In addition, the good network structure of the present application increases the contact area with ammonia and nitrogen, and through three-stage heating calcination, ammonia and nitrogen can fully react with the components in the network structure and on the surface, thereby improving the conversion ratio, particle size uniformity and low agglomeration of AlN. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. In addition, it is particularly pointed out that the raw materials and equipment of the present application can be obtained from the market, and will not be listed one by one. Among them, the raw materials of the present application can be obtained from the market and are well known to those skilled in the art.

[0028] Embodiment 1:

[0029] A low-agglomerated aluminum nitride powder preparation method, comprising the following steps:

[0030] S1: 60 parts by weight of aluminum nitrate nonahydrate, 80 parts of film-forming solution and 30 parts of glucose monohydrate are uniformly mixed, stirred for 2h, then poured into a polytetrafluoroethylene dish at room temperature 25℃ and left for 6h to obtain a cross-linked film;

[0031] S2: the cross-linked film obtained in step S1 is burned at 400℃ for 40min in an argon environment with a flow rate of 1200ml / min, then calcined at 900℃ for 2h in an ammonia environment with a flow rate of 1200ml / min, then heated at 1000℃ for 2h, and finally calcined at 1400℃ for 2h to obtain aluminum nitride powder.

[0032] In step S1, the preparation method of the film-forming solution is as follows:

[0033] S11: prepare a chitosan solution:

[0034] The polyvinyl alcohol and the 50% by mass chitosan glacial acetic acid solution are mixed in a ratio of 1:2 by weight, and stirred for 2 hours to obtain a chitosan solution;

[0035] A gelatin solution is prepared:

[0036] S21: A swelling gel solution is prepared: the gelatin and distilled water are mixed in a ratio of 1:5 by weight, and stirred at 65°C for 40 minutes to obtain a swelling gel solution;

[0037] A transglutaminase solution is prepared: the transglutaminase, polylactic acid-glycolic acid copolymer and distilled water are mixed in a ratio of 3:1:10 by weight, and stirred at 25°C for 2 hours to obtain a transglutaminase solution;

[0038] S22: The swelling gel solution and the transglutaminase solution are mixed in a ratio of 1:1 by weight, and stirred for 2 hours to obtain a gelatin solution;

[0039] S12: The chitosan solution and the gelatin solution are mixed in a ratio of 1:1 by weight, and stirred for 2 hours to obtain a film-forming solution.

[0040] An aluminum nitride powder is prepared by the sintering method.

[0041] Example 2:

[0042] A method for preparing a low-agglomerated aluminum nitride powder includes the following steps:

[0043] S1: 50 parts by weight of aluminum nitrate nonahydrate, 60 parts of a film-forming solution and 20 parts of dextrose monohydrate are uniformly mixed, stirred for 1 hour, and then poured into a polytetrafluoroethylene dish at room temperature of 25°C and left to stand for 4 hours to obtain a crosslinked film;

[0044] S2: The crosslinked film obtained in step S1 is burned at 300°C for 30 minutes in an argon gas environment with a flow rate of 1000 ml / min, calcined at 800°C for 1 hour in an ammonia gas environment with a flow rate of 1000 ml / min, then calcined at 900°C for 1 hour, and finally calcined at 1200°C for 1 hour to obtain an aluminum nitride powder.

[0045] The preparation method of the film-forming solution in step S1 is specifically:

[0046] S11: A chitosan solution is prepared:

[0047] The polyvinyl alcohol and the 50% by mass chitosan glacial acetic acid solution are mixed in a ratio of 1:2 by weight, and stirred for 1 hour to obtain a chitosan solution;

[0048] A gelatin solution is prepared:

[0049] S21: preparing a swelling gel solution: mixing gelatin and distilled water in a proportion of 1:5 by weight, stirring at 60℃ for 30 min, to obtain a swelling gel solution;

[0050] S31: preparing a transglutaminase solution: mixing transglutaminase, polylactic acid-glycolic acid copolymer and distilled water in a proportion of 3:1:10 by weight, stirring at 20℃ for 1 h, to obtain a transglutaminase solution;

[0051] S22: mixing the swelling gel solution and the transglutaminase solution in a proportion of 1:1 by weight, stirring for 1 h, to obtain a gelatin solution;

[0052] S12: mixing the chitosan solution and the gelatin solution in a proportion of 1:1 by weight, stirring for 1 h, to obtain a film-forming solution.

[0053] An aluminum nitride powder prepared by the sintering method.

[0054] Example 3:

[0055] A method for preparing a low-agglomerated aluminum nitride powder, comprising the following steps:

[0056] S1: mixing 55 parts by weight of aluminum nitrate nonahydrate, 70 parts of the film-forming solution and 25 parts of glucose monohydrate uniformly, stirring for 1.5 h, then pouring into a polytetrafluoroethylene dish at room temperature 25℃ and standing for 5 h, to obtain a crosslinked film;

[0057] S2: burning the crosslinked film obtained in step S1 at 350℃ for 35 min in an argon environment with a flow rate of 1100 ml / min, then calcining at 850℃ for 1.5 h in an ammonia environment with a flow rate of 1100 ml / min, then at 950℃ for 1.5 h, and finally at 1300℃ for 1.5 h, to obtain an aluminum nitride powder.

[0058] The preparation method of the film-forming solution in step S1 is specifically as follows:

[0059] S11: preparing a chitosan solution:

[0060] Mixing polyvinyl alcohol and chitosan acetic acid solution with a mass fraction of 50% in a proportion of 1:2 by weight, stirring for 1.5 h, to obtain a chitosan solution;

[0061] Preparation of a gelatin solution:

[0062] S21: preparing a swelling gel solution: mixing gelatin and distilled water in a proportion of 1:5 by weight, stirring at 62℃ for 35 min, to obtain a swelling gel solution;

[0063] Preparation of transglutaminase solution: transglutaminase, polylactic acid-glycolic acid copolymer and distilled water are mixed in a ratio of 3:1:10 by weight, stirred at 23 DEG C for 1.5 h, and transglutaminase solution is obtained;

[0064] S22: The swelling glue solution and the transglutaminase solution are mixed in a ratio of 1:1 by weight, stirred for 1.5 h, and the gelatin solution is obtained;

[0065] S12: The chitosan solution and the gelatin solution are mixed in a ratio of 1:1 by weight, stirred for 1.5 h, and the film-forming solution is obtained.

[0066] An aluminum nitride powder prepared by the sintering method.

[0067] Comparative Example 1:

[0068] Comparative Example 1 and Example 1 have substantially the same components, except that the film-forming solution is not modified, specifically:

[0069] A low-agglomerated aluminum nitride powder preparation method, comprising the following steps:

[0070] S1: 60 parts of aluminum nitrate nonahydrate, 80 parts of the film-forming solution and 30 parts of glucose monohydrate are mixed uniformly, stirred for 2 h, poured into a polytetrafluoroethylene dish at room temperature 25 DEG C and placed for 6 h, and a cross-linked film is obtained;

[0071] S2: The cross-linked film obtained in step S1 is burned at 400 DEG C for 40 min in an argon environment with a flow rate of 1200 ml / min, calcined at 900 DEG C for 2 h in an ammonia environment with a flow rate of 1200 ml / min, then heat treated at 1000 DEG C for 2 h, and finally calcined at 1400 DEG C for 2 h, and an aluminum nitride powder is obtained.

[0072] The preparation method of the film-forming solution in step S1 is specifically:

[0073] The gelatin and distilled water are mixed in a ratio of 1:5 by weight, stirred at 65 DEG C for 40 min, and the film-forming solution is obtained;

[0074] An aluminum nitride powder prepared by the sintering method.

[0075] The performance of Example 1 to Example 3, Comparative Example 1 and commercially available aluminum nitride powder of Ningxia Aisenada New Material Technology Co., Ltd. is tested, and the test results are shown in Table 1.

[0076] Table 1 Test data of Example 1-3, commercially available aluminum nitride powder and Comparative Example 1

[0077] Test item Example 1 Example 2 Example 3 Comparative Example 1 Commercially available aluminum nitride powder Average particle diameter (um) 12 12 13 37 26 Specific surface area (m 2 / g) 15.2 16.1 15.8 7.9 17.61 AlN conversion rate % 100 100 100 89.2 100

[0078] As can be seen from the above table, the aluminum nitride powder obtained in Examples 1 to 3 has a small average particle size, a low agglomeration rate, a high conversion rate, and a large specific surface area.

[0079] The foregoing description of the disclosed embodiments enables a person skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a low-agglomerated aluminum nitride powder, characterized by comprising the steps of: The method comprises the following steps: ​ S1: 50-60 parts by weight of aluminum nitrate nine water, 60-80 parts of film-forming solution and 20-30 parts of glucose monohydrate are uniformly mixed, stirred for 1-2 h, then poured into a polytetrafluoroethylene dish at room temperature 25℃ and left to stand for 4-6 h to obtain a cross-linked film; S2: the cross-linked film obtained in step S1 is burned at 300-400℃ for 30-40 min in an argon environment, calcined at 800-900℃ for 1-2 h in an ammonia environment, then heat treated at 900-1000℃ for 1-2 h, and finally calcined at 1200-1400℃ for 1-2 h to obtain aluminum nitride powder; The preparation method of the film-forming solution in step S1 is specifically as follows: S11: prepare a chitosan solution and a gelatin solution; S12: mix the chitosan solution and the gelatin solution, and stir for 1-2 h to obtain the film-forming solution; The preparation method of the gelatin solution in step S11 is specifically as follows: S21: prepare a swellable glue solution and a transglutaminase solution; S22: mix the swellable glue solution and the transglutaminase solution according to a weight ratio of 1:1, and stir for 1-2 h to obtain the gelatin solution.

2. The method of claim 1, wherein the low-agglomerated aluminum nitride powder is prepared by the steps of: preparing a mixture of aluminum and nitrogen by mixing aluminum powder and nitrogen gas; and heating the mixture to a temperature of 1,000°C or higher in a vacuum or an inert gas atmosphere. The flow rate of the argon is 1000-1200 ml / min, and the flow rate of the ammonia is 1000-1200 ml / min.

3. The method for preparing low-agglomeration aluminum nitride powder as described in claim 1, characterized in that, The weight ratio of the chitosan solution and the gelatin solution is 1:

1.

4. The method for preparing low-agglomeration aluminum nitride powder as described in claim 1, characterized in that, The preparation method of the chitosan solution in step S11 is specifically as follows: Mix polyvinyl alcohol and 50% chitosan glacial acetic acid solution according to a weight ratio of 1:2, and stir for 1-2 h to obtain the chitosan solution.

5. The method of claim 4, wherein the aluminum nitride powder has a bulk density of 0.4 to 0.6 g / cm3. The weight ratio of the polyvinyl alcohol and the chitosan glacial acetic acid solution is 1:

2.

6. The method for preparing low-agglomeration aluminum nitride powder as described in claim 1, characterized in that, The preparation method of the swellable glue solution in step S21 is specifically as follows: Mix gelatin and distilled water according to a weight ratio of 1:5, and stir at 60-65℃ for 30-40 min to obtain the swellable glue solution.

7. The method of claim 6, wherein the aluminum nitride powder has a bulk density of at least 0.4 g / cm3. The preparation method of the transglutaminase solution in step S21 is specifically as follows: Mix transglutaminase, polylactic acid-glycolic acid copolymer and distilled water according to a weight ratio of 3:1:10, and stir at 20-25℃ for 1-2 h to obtain the transglutaminase solution.