Permanent magnet ferrite and method for producing the same

Abstract

The application discloses a permanent magnet ferrite, relates to the field of ferrite, and is prepared from the following components in parts by weight: 68-80 parts of powdered ferrite; 12-18 parts of attapulgite; 1-2 parts of silane coupling agent; 6-8 parts of plasticizer; 10-15 parts of binder; 5-8 parts of dispersing agent; and 35-45 parts of solvent. The silane coupling agent is added to water, the attapulgite is added, and the temperature is raised to 50 DEG C; the powdered ferrite is added, and the temperature is raised to 80 DEG C; the mixing time is 10-20 min; filtration and drying are carried out to obtain a powdered mixture; the powdered mixture, the plasticizer, the binder and the dispersing agent are added to the solvent, and ball milling is carried out for 5-8 h to obtain a slurry; the slurry is made into a sheet through casting, and sintering is carried out to obtain the permanent magnet ferrite. The magnetic permeability of the permanent magnet ferrite prepared according to the formula and the preparation method is greatly improved, and the crack resistance and the bending strength are also greatly improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of permanent ferrite, in particular to a permanent ferrite and a preparation method of the permanent ferrite. BACKGROUND

[0002] Ferrite sheet is a common ferrite, which is often applied in some places with high requirements for ferrite volume, such as in mobile phones; however, the ferrite sheet is more prone to cracking due to the thin thickness. There are some additives such as organic polymers added in the market to improve the toughness of the ferrite, but the magnetic permeability of the ferrite is affected. Therefore, it is necessary to study a ferrite with high magnetic permeability and high toughness. SUMMARY

[0003] In order to solve at least one of the above technical problems, a ferrite with high magnetic permeability and high toughness is developed, and the application provides a permanent ferrite and a preparation method thereof.

[0004] In one aspect, the application provides a permanent ferrite prepared from the following components in parts by weight:

[0005] 68-80 parts of powdery ferrite;

[0006] 12-18 parts of attapulgite;

[0007] 1-2 parts of silane coupling agent;

[0008] 6-8 parts of plasticizer;

[0009] 10-15 parts of binder;

[0010] 5-8 parts of dispersant;

[0011] 35-45 parts of solvent.

[0012] Optionally, the application provides a permanent ferrite prepared from the following components in parts by weight:

[0013] 70-76 parts of powdery ferrite;

[0014] 14-16 parts of attapulgite;

[0015] 1.2-1.8 parts of silane coupling agent;

[0016] 7 parts of plasticizer;

[0017] 12 parts of binder;

[0018] 6-7 parts of dispersant;

[0019] 35-40 parts of solvent.

[0020] Optionally, the powdery ferrite adopts BaMnMgAl x Fe 16-x O 27 (0≤x<1);the particle size of the attapulgite is 200 mesh.

[0021] Optionally, the silane coupling agent adopts one or more combinations of A151, A171 and A172.

[0022] Optionally, the plasticizer adopts TOP; the binder adopts one or more of silicone resin, phenolic resin and polyamide resin; the dispersant adopts sodium polyacrylate, polyethylene imine or methylene acrylamide; the solvent is obtained by mixing ethyl acetate and isopropyl alcohol at a weight ratio of 3:1.

[0023] In a second aspect, the application further provides a preparation method of the above permanent ferrite, comprising the following steps:

[0024] S1, adding the silane coupling agent into water, mixing uniformly, then adding the attapulgite, mixing uniformly and heating to 50℃, adding the powdery ferrite for mixing, and heating to 80℃, the mixing time is 10-20min, filtering and drying to obtain a powdery mixture;

[0025] S2, adding the powdery mixture, the plasticizer, the binder and the dispersant into the solvent, mixing uniformly, ball milling for 5-8h to obtain a slurry;

[0026] S3, the slurry is made into a sheet by a flow casting method, then sintering and forming to obtain the permanent ferrite.

[0027] In a third aspect, the application provides an application of the above permanent ferrite in the field of mobile phones.

[0028] In summary, the application at least includes the following beneficial technical effects:

[0029] The real part of the complex permeability of the permanent ferrite prepared according to the formula and the preparation method of the application is all above 670, the imaginary part of the complex permeability is all below 10, the permeability is greatly improved, and the crack resistance and the bending strength are also greatly improved. DETAILED DESCRIPTION

[0030] The application will be further described in detail below in combination with examples.

[0031] In the following examples of the application, the main raw materials are all purchased from commercially available products if no special instructions are given.

[0032] Powdery ferrite: BaMnMgAl x Fe 16-x O 27(0≤x<1);

[0033] Attapulgite: particle size of 200 mesh;

[0034] Silane coupling agent: one or more of A151, A171 and A172, and A171 is exemplarily used in the following examples;

[0035] Plasticizer: TOP;

[0036] Binder: one or more of silicone resin, phenolic resin and polyamide resin, and silicone resin is exemplarily used in the following examples;

[0037] Dispersant: sodium polyacrylate, polyethylene imine or methylene acrylic amine, and sodium polyacrylate is exemplarily used in the following examples;

[0038] Solvent: ethyl acetate and isopropyl alcohol are mixed in a weight ratio of 3:1. Specific embodiment

[0040] Example 1

[0041] The permanent magnet ferrite prepared in this example is prepared from the following components in parts by weight: powdered ferrite 68 parts; attapulgite 18 parts; silane coupling agent 2 parts; plasticizer 6 parts; binder 10 parts; dispersant 5 parts; solvent 35 parts.

[0042] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, and the powdered ferrite is added for mixing, and heated to 80°C, the mixing time is 20 min, filtered and dried to obtain a powdered mixture;

[0043] The powdered mixture, plasticizer, binder and dispersant are added to the solvent, mixed uniformly, and ball milled for 5 h to obtain a slurry;

[0044] The slurry is made into a sheet by a flow casting method, and then sintered and formed to obtain a 5 mm thick permanent magnet ferrite.

[0045] Example 2

[0046] The permanent magnet ferrite prepared in this example is prepared from the following components in parts by weight: powdered ferrite 70 parts; attapulgite 16 parts; silane coupling agent 1.5 parts; plasticizer 7 parts; binder 12 parts; dispersant 6 parts; solvent 35 parts.

[0047] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, and the powdered ferrite is added for mixing, and heated to 80°C, the mixing time is 20 min, filtered and dried to obtain a powdered mixture;

[0048] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 6h to obtain a slurry;

[0049] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0050] Example 3

[0051] The permanent magnet ferrite prepared in this example is prepared from the following components by weight fraction: powder ferrite 72 parts; attapulgite 16 parts; silane coupling agent 1.8 parts; plasticizer 7 parts; binder 12 parts; dispersant 6 parts; solvent 40 parts.

[0052] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50℃, the powder ferrite is added and mixed, and heated to 80℃, the mixing time is 18min, filtered and dried to obtain a powder mixture;

[0053] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 6h to obtain a slurry;

[0054] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0055] Example 4

[0056] The permanent magnet ferrite prepared in this example is prepared from the following components by weight fraction: powder ferrite 74 parts; attapulgite 14 parts; silane coupling agent 1.2 parts; plasticizer 7 parts; binder 12 parts; dispersant 7 parts; solvent 40 parts.

[0057] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50℃, the powder ferrite is added and mixed, and heated to 80℃, the mixing time is 12min, filtered and dried to obtain a powder mixture;

[0058] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 6h to obtain a slurry;

[0059] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0060] Example 5

[0061] The permanent magnet ferrite prepared in the embodiment is prepared from the following components in parts by weight: powdered ferrite 76 parts; attapulgite 14 parts; silane coupling agent 1.5 parts; plasticizer 7 parts; binder 12 parts; dispersant 7 parts; solvent 40 parts.

[0062] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, the powdered ferrite is added and mixed, and heated to 80°C, the mixing time is 15 min, filtered and dried to obtain a powdered mixture;

[0063] The powdered mixture, plasticizer, binder and dispersant are added to the solvent, mixed uniformly, ball-milled for 7 h to obtain a slurry;

[0064] The slurry is made into a sheet by a flow casting method, and then sintered and formed to obtain a 5 mm thick permanent magnet ferrite.

[0065] Example 6

[0066] The permanent magnet ferrite prepared in the embodiment is prepared from the following components in parts by weight: powdered ferrite 78 parts; attapulgite 12 parts; silane coupling agent 1 part; plasticizer 8 parts; binder 15 parts; dispersant 8 parts; solvent 45 parts.

[0067] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, the powdered ferrite is added and mixed, and heated to 80°C, the mixing time is 10 min, filtered and dried to obtain a powdered mixture;

[0068] The powdered mixture, plasticizer, binder and dispersant are added to the solvent, mixed uniformly, ball-milled for 8 h to obtain a slurry;

[0069] The slurry is made into a sheet by a flow casting method, and then sintered and formed to obtain a 5 mm thick permanent magnet ferrite.

[0070] Example 7

[0071] The permanent magnet ferrite prepared in the embodiment is prepared from the following components in parts by weight: powdered ferrite 80 parts; attapulgite 12 parts; silane coupling agent 1 part; plasticizer 8 parts; binder 15 parts; dispersant 8 parts; solvent 45 parts.

[0072] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, the powdered ferrite is added and mixed, and heated to 80°C, the mixing time is 10 min, filtered and dried to obtain a powdered mixture;

[0073] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 8h to obtain a slurry;

[0074] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0075] Comparative Example 1

[0076] The permanent magnet ferrite prepared in the present comparative example is prepared from the following components by weight fraction: powder ferrite 74 parts; attapulgite 0 parts; silane coupling agent 1.2 parts; plasticizer 7 parts; binder 12 parts; dispersant 7 parts; solvent 40 parts. The difference between the present comparative example and Example 4 is that the present comparative example does not add attapulgite.

[0077] The silane coupling agent is added into water, mixed with the powder ferrite, and heated to 80℃, the mixing time is 12min, filtered and dried to obtain a powder mixture;

[0078] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 7h to obtain a slurry;

[0079] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0080] Comparative Example 2

[0081] The permanent magnet ferrite prepared in the present comparative example is prepared from the following components by weight fraction: powder ferrite 74 parts; attapulgite 10 parts; silane coupling agent 1.2 parts; plasticizer 7 parts; binder 12 parts; dispersant 7 parts; solvent 40 parts. The difference between the present comparative example and Example 4 is that the present comparative example adds attapulgite in an amount of 10 parts.

[0082] The silane coupling agent is added into water, mixed uniformly, then the attapulgite is added, mixed uniformly and heated to 50℃, the powder ferrite is added and mixed, and heated to 80℃, the mixing time is 12min, filtered and dried to obtain a powder mixture;

[0083] The powder mixture, plasticizer, binder and dispersant are added into the solvent, mixed uniformly, ball-milled for 7h to obtain a slurry;

[0084] The slurry is made into a sheet by a flow casting method, and then sintered to form a permanent magnet ferrite with a thickness of 5mm.

[0085] Comparative Example 3

[0086] The permanent magnet ferrite prepared in the present comparative example is prepared from the following components by weight fraction: powdered ferrite 74 parts; attapulgite 20 parts; silane coupling agent 1.2 parts; plasticizer 7 parts; binder 12 parts; dispersant 7 parts; solvent 40 parts. The present comparative example differs from example 4 in that the present comparative example has an added amount of attapulgite of 20 parts.

[0087] The silane coupling agent is added to water, mixed uniformly, and then the attapulgite is added, mixed uniformly and heated to 50°C, the powdered ferrite is added and mixed, and heated to 80°C, the mixing time is 12 min, filtered and dried to obtain a powdered mixture;

[0088] The powdered mixture, plasticizer, binder and dispersant are added to the solvent, mixed uniformly, ball milled for 7 h to obtain a slurry;

[0089] The slurry is made into a sheet by a flow casting method, and then sintered and formed to obtain a 5 mm thick permanent magnet ferrite.

[0090] An E4991A radio frequency impedance analyzer produced by Agilent Company of the United States is used to test the complex permeability; the experimental test frequency is 1.25 MHz. A ZHVST-10F indentation hardness test analysis system is used to test the crack resistance of the material. A WDW-5 microcomputer controlled electronic universal testing machine is used to test the bending strength of the material. A HVS-5F digital display Vickers hardness tester is used to test the Vickers hardness of the material. The test results are shown in Table 1.

[0091] Table 1 Test performance results of examples 1-7 and comparative examples 1-3

[0092]

[0093]

[0094] As can be seen from examples 1-7, comparative example 1 and Table 1, the real part of the complex permeability of the permanent magnet ferrite prepared according to the formulation and preparation method of the present application is all above 670, and the imaginary part of the complex permeability is all below 10; compared with the real part of 645 and the imaginary part of 10.78 of the permanent magnet ferrite in comparative example 1 without adding attapulgite, the permeability is greatly improved, and the crack resistance and bending strength are also greatly improved. Therefore, it can be seen that the addition of attapulgite has a great influence on the permeability, crack resistance and bending strength of the permanent magnet ferrite.

[0095] From Examples 1-7, Comparative Examples 2-3 and Table 1, it can be seen that the addition amount of palygorskite and the addition amount of other components have a great influence on the comprehensive performance of the permanent magnet ferrite. When the permanent magnet ferrite is prepared according to the following components by weight fraction, the comprehensive performance of the permanent magnet ferrite is better. Powdered ferrite 70-76 parts; palygorskite 14-16 parts; silane coupling agent 1.2-1.8 parts; plasticizer 7 parts; binder 12 parts; dispersant 6-7 parts; solvent 35-40 parts.

[0096] Comparing Example 4 with Comparative Examples 2-3, it can be seen that when the addition amount of palygorskite is increased to more than 20 parts by weight or less than 10 parts by weight under the formula of Example 4, the magnetic permeability, crack resistance, bending strength and Vickers hardness of the permanent magnet ferrite have different degrees of decline, the comprehensive performance is decreased, and especially the magnetic permeability, crack resistance and bending strength have a large decrease.

[0097] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made on the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A permanent magnet ferrite, characterized by, It is prepared by the following components by weight parts: Powdered ferrite 68~80 parts; Palygorskite 12~18 parts; Silane coupling agent 1~2 parts; Plasticizer 6~8 parts; Binder 10~15 parts; Dispersant 5~8 parts; Solvent 35~45 parts; The powder ferrite adopts BaMnMgAl x Fe 16-x O 27 (0≤x<1); the particle size of the attapulgite is 200 meshes; The preparation method of the permanent magnet ferrite, comprising the following steps: S1, the silane coupling agent is added to the water, mixed uniformly, then the palygorskite is added, mixed uniformly and heated to 50 DEG C, the powdered ferrite is added and mixed, and heated to 80 DEG C, the mixing time is 10~20 min, filtered and dried to obtain a powder mixture; S2, the powder mixture, plasticizer, binder and dispersant are added to the solvent, mixed uniformly, ball milled for 5~8 h, to obtain a slurry; S3, the slurry is made into a sheet by flow casting, then sintered and formed to obtain a permanent magnet ferrite; The application of the permanent magnet ferrite in the field of mobile phones.

2. The permanent ferrite magnet according to claim 1, characterized by It is prepared by the following components by weight parts: Powdered ferrite 70~76 parts; Palygorskite 14~16 parts; Silane coupling agent 1.2~1.8 parts; Plasticizer 7 parts; Binder 12 parts; Dispersant 6~7 parts; Solvent 35~40 parts.

3. The permanent ferrite magnet according to claim 1, characterized by The silane coupling agent uses one or more combinations of A151, A171 and A172.

4. The permanent ferrite magnet of claim 1, wherein, The plasticizer uses TOP; the binder uses one or more of siloxane resin, phenolic resin and polyamide resin; the dispersant uses polyacrylic acid sodium, polyethylene imine or methylene acrylic amine; the solvent is obtained by mixing ethyl acetate and isopropyl alcohol according to a weight ratio of 3:1.

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