Bonded magnet composition and preparation method and application thereof

Abstract

The invention discloses a bonded magnet composition and a preparation method and application thereof. The composite material is prepared by co-extruding the following raw materials in percentage by weight, the magnetic material is prepared from the following components in percentage by weight: 80 to 95 percent of magnetic powder, 3 to 15 percent of monocarboxyl-terminated nylon 12 oligomer, 1 to 12 percent of multi-arm polyether amine, 0.05 to 0.5 percent of catalyst, 0.1 to 0.5 percent of lubricant and 0.1 to 0.5 percent of antioxidant. The composition formula provided by the invention contains the low-viscosity monocarboxyl-terminated nylon 12 oligomer, so that the dispersity of the magnetic powder is improved, a certain amount of multi-arm polyether amine is compounded, and amidation reaction of amino and carboxyl can be carried out in the raw material co-extrusion process; therefore, the bonded magnet composition which is filled with high magnetic powder and has excellent magnetic performance and impact performance is comprehensively obtained, and is suitable for manufacturing various magnetic electronic components with high requirements on the bonded magnet composition.

Description

Technical Field

[0001] The present invention relates to a magnetic material, and more particularly to a bonded magnet composition, a preparation method thereof and an application thereof. Background Art

[0002] A bonded magnet is a composite permanent magnet material made by uniformly mixing magnetic powder with a plastic resin, rubber or a low-melting-point metal, and then by methods such as extrusion molding, compression molding or injection molding. Among them, a bonded magnet prepared with a plastic resin as a binder (especially nylon 12 as a binder) has a simple molding process, high production efficiency and low cost. In recent years, the market has expanded extremely fast, showing good development prospects.

[0003] Two main indicators for measuring the performance of injection-molded ferrite are magnetic properties and fluidity. Generally speaking, the higher the filling amount of magnetic powder, the better the magnetic properties of the molded device obtained. However, with the increase in the content of magnetic powder, it will inevitably lead to a decrease in the amount of binder used, thereby reducing fluidity, deteriorating processing performance, and the magnetic powder is prone to agglomeration, and the magnetic properties and impact properties of the molded device will also deteriorate.

[0004] Patent JP1998172820A discloses a composition composed of a mixture of magnetic powder and a modified polyamide. By compounding nylons with different molecular weights and additionally adding an acidic organophosphorus compound, it is claimed that a resin-bonded magnet composition with excellent moldability (melt fluidity) and mechanical strength can be obtained. However, when the content of low-molecular-weight nylon is too high, the mechanical properties are inevitably poor, and when the content of high-molecular-weight nylon is too high, the moldability (melt fluidity) is inevitably poor. This method cannot fundamentally solve the problem that it is difficult to balance moldability and mechanical strength. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a bonded magnet composition, a preparation method thereof and an application thereof.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The present invention first provides a bonded magnet composition, which is obtained by co-extrusion of substances containing the following raw materials in weight percentages;

[0008] Magnetic powder 80-95%,

[0009] Monocarboxyl-terminated nylon 12 oligomer 3-15%,

[0010] Multi-arm polyetheramine 1-12%,

[0011] Catalyst 0.05-0.5%,

[0012] Lubricant 0.1-0.5%,

[0013] Antioxidant: 0.1 - 0.5%.

[0014] In some preferred examples, the magnetic powder is a ferrite magnetic powder surface - modified by a coupling agent; the coupling agent with an amphoteric structure can improve the affinity between the magnetic powder and the resin system, and the conventional modification of the magnetic powder by the coupling agent is a general treatment method.

[0015] Preferably, the content of the coupling agent for modification in the magnetic powder is 0.1 - 3 wt%, preferably 0.3 - 0.5 wt%;

[0016] Preferably, the coupling agent is selected from at least one of silane coupling agents, phthalate coupling agents, and phosphate coupling agents;

[0017] Preferably, the ferrite magnetic powder is selected from at least one of Sr - based ferrite magnetic powder, Ba - based ferrite magnetic powder, anisotropic NdFeB magnetic powder, isotropic NdFeB magnetic powder, SmFeN magnetic powder, and samarium - cobalt magnetic powder.

[0018] In some preferred examples, the number - average molecular weight of the mono - carboxyl - terminated nylon 12 oligomer is 1500 - 10000, preferably 3000 - 5000, and the terminal carboxyl group content is 0.1 - 0.67 mmol / g, preferably 0.3 - 0.4 mmol / g. The nylon 12 oligomer meeting the above requirements of the number - average molecular weight has the characteristic of lower viscosity, which is beneficial to improving the dispersibility of a high - content magnetic powder in the system and maintaining good fluidity.

[0019] In some preferred examples, the number - average molecular weight of the multi - arm polyetheramine is 2000 - 16000, preferably 8000 - 10000;

[0020] Preferably, the multi - arm polyetheramine is obtained by the reaction of a polybasic acid branching agent and a polyetheramine, wherein the polybasic acid branching agent is preferably selected from one or more of 1,3,5 - benzenetricarboxylic acid, 1,2,3,5 - benzenetetracarboxylic acid, benzene pentacarboxylic acid, benzene hexacarboxylic acid, 1,3,5 - cyclohexanetricarboxylic acid, 1,2,4,5 - cyclohexanetetracarboxylic acid, and 1,2,3,4,5,6 - cyclohexanehexacarboxylic acid.

[0021] In some preferred examples, the catalyst is one or more of phosphoric acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, and calcium hypophosphite;

[0022] Preferably, the lubricant is one or more of zinc stearate, calcium stearate, ethylene bis - stearamide (EBS), oleic acid amide, erucic acid amide, silicone oil, and paraffin wax;

[0023] Preferably, the antioxidant is one or more of antioxidant 1098, antioxidant 1010, antioxidant 168, and antioxidant H10.

[0024] Secondly, the present invention also provides a method for preparing the bonded magnet composition as described above, which includes reactive extrusion, granulation after mixing magnetic powder, mono-carboxyl-terminated nylon 12 oligomer, multi-arm polyetheramine, catalyst, lubricant, and antioxidant to obtain the bonded magnet composition;

[0025] Preferably, the extrusion temperature is 220 - 280 °C, and the screw speed is 80 - 120 rpm.

[0026] In some preferred examples, the surface modification method of the magnetic powder is to drop the coupling agent into the ferrite magnetic powder after preparing it into a solution, and mix and process for 20 - 30 min. For example, isopropanol can be used as the solvent, and the solution concentration is, for example, 0.1 - 1 g / ml.

[0027] In some preferred examples, the preparation method of the mono-carboxyl-terminated nylon 12 oligomer is as follows:

[0028] Add laurolactam and mono-carboxyl type capping agent into water, first carry out ring-opening polymerization reaction, and then vacuum polycondensation to obtain the product;

[0029] Preferably, the mono-carboxyl type capping agent is selected from one or more of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, dodecanoic acid, benzoic acid, and its dosage is preferably 0.5 - 15 wt% of the weight of laurolactam;

[0030] Preferably, the water is ultrapure water, and the addition amount is 5 - 15% of the weight of laurolactam;

[0031] Preferably, the reaction temperature of the ring-opening polymerization is 260 - 290 °C, and the reaction time is 3 - 5 h;

[0032] Preferably, the reaction temperature of the vacuum polycondensation is 220 - 240 °C, the reaction time is 0.5 - 1 h, and preferably the vacuum is pumped to -85 kPa to -95 kPa.

[0033] In some preferred examples, the preparation method of the multi-arm polyetheramine is as follows:

[0034] Mix polyetheramine and polybasic acid branching agent, then heat up to 200 - 220 °C, react for 30 - 60 min, and then pump vacuum to -85 kPA to -95 kPa and continue to react for 60 - 180 min;

[0035] Preferably, the raw materials are in a molar ratio of the terminal amino group of polyetheramine to the carboxyl group of the polybasic acid branching agent of (1.5 - 2.5):1.

[0036] Preferably, the number average molecular weight of the polyetheramine is 200 - 4000.

[0037] Herein, the present invention also provides an application of the bonded magnet composition as described above or the bonded magnet composition prepared by the method as described above in electronic components.

[0038] The composition formula provided by the present invention contains a low-viscosity mono-carboxyl-terminated nylon 12 oligomer, which is beneficial to improving the dispersibility of magnetic powder. After compounding with a certain amount of multi-arm polyetheramine, amidation reaction between amino group and carboxyl group can occur during the co-extrusion process of raw materials, so as to comprehensively obtain a bonded magnet composition with high magnetic powder filling, excellent magnetic properties and impact properties, which is suitable for manufacturing various magnetic electronic components with high requirements for this. Specific Embodiments

[0039] The present invention will be further described below through specific examples. The examples described in the present invention are only for the illustration of the present invention and do not limit the scope of the present invention.

[0040] The main analysis and testing methods involved in the following examples of the present invention are as follows:

[0041] (1) Number-average molecular weight test: It is tested through a gel permeation chromatography (GPC) system, and the equipment model is WATERS1515;

[0042] (2) Terminal carboxyl group content test: It is tested through potentiometric titration method (Metrohm 848 automatic potentiometric titrator);

[0043] (3) Melt viscosity test: It is tested by using an AR 1500EX (TA Instrument) type rheometer in a constant shear mode. The test temperature is 200 °C, the shear rate is 1 s -1 , and the strain is 1%, under nitrogen atmosphere protection.

[0044] (4) Charpy impact strength at room temperature: It is tested with reference to the method in ISO 179;

[0045] (5) Magnetic property test: The composition granule material is injection-molded by using an injection molding machine, and magnetized by applying an orientation magnetic field (the orientation magnetic field strength is 1.10 MA / m). The remanence (Br), intrinsic coercivity (H cj ) and maximum magnetic energy product (BH) max of the bonded magnet are measured by using an FD-BH-I hysteresis loop tester (Shanghai Fudan Tianxin Science and Education Instrument Co., Ltd.).

[0046] Unless otherwise specified, the raw materials used can be obtained from general commercial channels.

[0047]

Preparation Example 1

[0048] Add 2 kg of dodecanolactam (Evonik Specialty Chemicals), 13 g of acetic acid (Aladdin Reagent), and 400 g of ultrapure water into the reaction kettle in sequence, replace the nitrogen three times, heat up to 280 °C and hold for 5 h to complete the ring-opening reaction; slowly release the pressure to 10 kPa at a rate of -2 kPa / s, cool down to 240 °C while releasing the pressure, then evacuate to -95 kPa and react for 1 h to complete the melt polycondensation. Stop evacuating, add nitrogen to 10 kPa for discharging, cooling, pelletizing, and drying to obtain a monocarboxyl-terminated nylon 12 oligomer (PA12-1). The number-average molecular weight of the tested product is 9281, the terminal carboxyl content is 0.108 mmol / g, and the melt viscosity is 8.0 Pa·s.

[0049] Add 2 kg of dodecanolactam (Evonik Specialty Chemicals), 90 g of n-heptanoic acid (Aladdin Reagent), and 100 g of ultrapure water into the reaction kettle in sequence, replace the nitrogen three times, heat up to 280 °C and hold for 5 h to complete the ring-opening reaction; slowly release the pressure to 10 kPa at a rate of -2 kPa / s, cool down to 220 °C while releasing the pressure, then evacuate to -95 kPa and react for 0.5 h to complete the melt polycondensation. Stop evacuating, add nitrogen to 5 kPa for discharging, cooling, pelletizing, and drying to obtain a monocarboxyl-terminated nylon 12 oligomer (PA12-2). The number-average molecular weight of the tested product is 3005, the terminal carboxyl content is 0.333 mmol / g, and the melt viscosity is 2.5 Pa·s.

[0050] Add 2 kg of dodecanolactam (Evonik Specialty Chemicals), 300 g of dodecanoic acid (Aladdin Reagent), and 200 g of ultrapure water into the reaction kettle in sequence, replace the nitrogen three times, heat up to 280 °C and hold for 5 h to complete the ring-opening reaction; slowly release the pressure to 10 kPa at a rate of -2 kPa / s, cool down to 220 °C while releasing the pressure, then evacuate to -95 kPa and react for 0.5 h to complete the melt polycondensation. Stop evacuating, add nitrogen to 4 kPa for discharging, cooling, pelletizing, and drying to obtain a monocarboxyl-terminated nylon 12 oligomer (PA12-3). The number-average molecular weight of the tested product is 1518, the terminal carboxyl content is 0.659 mmol / g, and the melt viscosity is 1.2 Pa·s.

[0051] Add 2 kg of dodecanolactam (Evonik Specialty Chemicals), 40 g of benzoic acid (Aladdin Reagent), and 200 g of ultrapure water into the reaction kettle in sequence, replace the nitrogen three times, heat up to 280 °C and hold for 5 h to complete the ring-opening reaction; slowly release the pressure to 10 kPa at a rate of -2 kPa / s, cool down to 220 °C while releasing the pressure, then evacuate to -95 kPa and react for 1 h to complete the melt polycondensation. Stop evacuating, add nitrogen to 8 kPa for discharging, cooling, pelletizing, and drying to obtain a monocarboxyl-terminated nylon 12 oligomer (PA12-4). The number-average molecular weight of the tested product is 6210, the terminal carboxyl content is 0.161 mmol / g, and the melt viscosity is 6.0 Pa·s.

[0052]

Preparation Example 2

[0053] Add 2000 g of polyetheramine JEFFAMINE D-400 (Huntsman) and 269.9 g of 1,2,3,4,5,6-cyclohexanehexacarboxylic acid (Aladdin reagent) to the reaction kettle, heat up to 200 °C and react for 30 min; evacuate to -90 kPa and continue to react for 60 min. After the reaction is completed, stop evacuating, stop stirring and add nitrogen to 3 kPa for discharging, cooling, pelletizing and drying to obtain multi-arm polyetheramine (PEA-1). The number-average molecular weight of the tested product is 2820.

[0054] Add 2000 g of polyetheramine JEFFAMINE D-900 (Huntsman) and 132.5 g of pentacarboxylic acid (Aladdin reagent) to the reaction kettle, heat up to 220 °C and react for 30 min; evacuate to -90 kPa and continue to react for 120 min. After the reaction is completed, stop evacuating, stop stirring and add nitrogen to 5 kPa for discharging, cooling, pelletizing and drying to obtain multi-arm polyetheramine (PEA-2). The number-average molecular weight of the tested product is 4708.

[0055] Add 2000 g of polyetheramine JEFFAMINE D-2003 (Huntsman) and 65.1 g of 1,2,4,5-cyclohexanetetracarboxylic acid (Aladdin reagent) to the reaction kettle, heat up to 220 °C and react for 60 min; evacuate to -90 kPa and continue to react for 180 min. After the reaction is completed, stop evacuating, stop stirring and add nitrogen to 8 kPa for discharging, cooling, pelletizing and drying to obtain multi-arm polyetheramine (PEA-3). The number-average molecular weight of the tested product is 8188.

[0056] Add 2000 g of polyetheramine JEFFAMINE T-5000 (Huntsman) and 28.0 g of 1,3,5-benzenetricarboxylic acid (Aladdin reagent) to the reaction kettle, heat up to 220 °C and react for 60 min; evacuate to -90 kPa and continue to react for 180 min. After the reaction is completed, stop evacuating, stop stirring and add nitrogen to 10 kPa for discharging, cooling, pelletizing and drying to obtain multi-arm polyetheramine (PEA-4). The number-average molecular weight of the tested product is 15156.

[0057]

Example 1

[0058] Prepare raw materials according to the following formula by weight:

[0059] Magnetic powder, 4530 g,

[0060] PA12-1, 500 g,

[0061] PEA-3, 110 g,

[0062] Phosphoric acid, 25 g,

[0063] EBS, 15 g,

[0064] Antioxidant 1098, 7.5 g, Antioxidant 168, 7.5 g.

[0065] Among them, the magnetic powder is Sr-based ferrite magnetic powder surface-modified by silane coupling agent KH550, and the preparation method is as follows: Add 15 g of silane coupling agent KH550 to 15 g of isopropanol to prepare a solution. Put 4500 g of Sr-based ferrite magnetic powder (Zhongrui Magnetic Industry Co., Ltd., Gangcheng District, Laiwu City) into a high-speed mixer, start stirring, dropwise add the aforementioned solution and carry out a blending treatment for 30 min.

[0066] After preparing the above raw materials, mix them in a high-speed mixer for 30 min, and then send them to a reactive extrusion extruder with a length-diameter ratio of 68 (three sets of vacuum exhaust systems are installed at the length-diameter ratios of 35, 50, and 65 of the extruder) for melt extrusion, water cooling, pelletizing, and drying to obtain a bonded magnet composition (PA12-F-1). The vacuum pumping rates of the three sets of vacuum exhaust systems are 0.8 L / min, 0.5 L / min, and 0.5 L / min in sequence. The temperature from the feeding section to the first set of vacuum exhaust systems is set at 220 - 260 °C, the temperature from the first set of vacuum exhaust systems to the die head is set at 260 - 280 °C, and the screw speed is 100 rpm.

[0067]

Example 2

[0068] Prepare raw materials according to the following formula by weight:

[0069] Magnetic powder, 4780 g,

[0070] PA12-2, 500 g,

[0071] PEA-1, 78 g,

[0072] Hypophosphorous acid, 25 g,

[0073] EBS, 15 g,

[0074] Antioxidant 1098, 7.5 g, Antioxidant 168, 7.5 g.

[0075] Among them, the magnetic powder is Sr-based ferrite magnetic powder surface-modified by silane coupling agent KH570, and the preparation method is as follows: Add 15 g of silane coupling agent KH570 to 15 g of isopropanol to prepare a solution. Put 4750 g of Ba-based ferrite magnetic powder (Shanghai Biosciences Co., Ltd.) into a high-speed mixer, start stirring, dropwise add the aforementioned solution and carry out a blending treatment for 30 min.

[0076] After preparing the above raw materials, mix them in a high-speed mixer for 30 min, and then send them into a reactive extrusion extruder with a length-diameter ratio of 68 (three sets of vacuum exhaust systems are installed at the length-diameter ratios of 35, 50, and 65 of the extruder) for melt extrusion, water cooling, pelletizing, and drying to obtain a bonded magnet composition (PA12-F-2). The vacuum pumping rates of the three sets of vacuum exhaust systems are 0.8 L / min, 0.5 L / min, and 0.5 L / min in sequence. The temperature from the feeding section to the first set of vacuum exhaust system is set at 220-260 °C, the temperature from the first set of vacuum exhaust system to the die head is set at 260-280 °C, and the screw speed is 120 rpm.

[0077]

Example 3

[0078] Prepare raw materials according to the following formula by weight:

[0079] Magnetic powder, 4530 g,

[0080] PA12-3, 500 g,

[0081] PEA-2, 310 g,

[0082] Sodium hypophosphite, 25 g,

[0083] EBS, 15 g,

[0084] Antioxidant 1098, 10 g; Antioxidant 168, 5 g.

[0085] Among them, the magnetic powder is Sr-based ferrite magnetic powder surface-modified by titanate GR-101. The preparation method is as follows: Add 15 g of titanate GR-101 to 15 g of isopropanol to prepare a solution. Put 4500 g of SmFeN magnetic powder (Junci Technology) into a high-speed mixer, start stirring, dropwise add the aforementioned solution, and carry out a blending treatment for 30 min.

[0086] After preparing the above raw materials, mix them in a high-speed mixer for 30 min, and then send them into a reactive extrusion extruder with a length-diameter ratio of 68 (three sets of vacuum exhaust systems are installed at the length-diameter ratios of 35, 50, and 65 of the extruder) for melt extrusion, water cooling, pelletizing, and drying to obtain a bonded magnet composition (PA12-F-3). The vacuum pumping rates of the three sets of vacuum exhaust systems are 0.8 L / min, 0.5 L / min, and 0.5 L / min in sequence. The temperature from the feeding section to the first set of vacuum exhaust system is set at 220-260 °C, the temperature from the first set of vacuum exhaust system to the die head is set at 260-280 °C, and the screw speed is 110 rpm.

[0087]

Example 4

[0088] Prepare raw materials according to the following formula by weight:

[0089] Magnetic powder, 4280 g,

[0090] PA12 - 4, 750 g,

[0091] PEA - 4, 610.1 g,

[0092] Potassium hypophosphite, 25 g,

[0093] Oleamide, 15 g,

[0094] Antioxidant 1098, 7.5 g, Antioxidant 168, 7.5 g.

[0095] Among them, the magnetic powder is Sr - based ferrite magnetic powder surface - modified by titanate GR - 105. The preparation method is as follows: Add 15 g of titanate GR - 105 into 15 g of isopropanol to prepare a solution. Put 4250 g of samarium - cobalt magnetic powder (Guangdong Hengyi Electromechanical Technology Co., Ltd.) into a high - speed mixer, start stirring, and drop the aforementioned solution and carry out a co - mixing treatment for 30 min.

[0096] After preparing the above raw materials, mix them in a high - speed mixer for 30 min, and then send them into a reactive extrusion extruder with a length - to - diameter ratio of 68 (there are three sets of vacuum exhaust systems installed at the positions of the extruder with length - to - diameter ratios of 35, 50, and 65) for melt extrusion, water cooling, pelletizing, and drying to obtain a bonded magnet composition (PA12 - F - 3). The vacuum pumping rates of the three sets of vacuum exhaust systems are 0.8 L / min, 0.5 L / min, and 0.5 L / min in sequence. The temperature from the feeding section to the first set of vacuum exhaust system is set at 220 - 260 °C, the temperature from the first set of vacuum exhaust system to the die head is set at 260 - 280 °C, and the screw speed is 100 rpm.

[0097]

Example 5

[0098] According to the weight parts, prepare raw materials according to the following formula:

[0099] Magnetic powder, 4580 g,

[0100] PA12 - 2, 500 g,

[0101] PEA - 3, 340 g,

[0102] Phosphoric acid, 25 g,

[0103] Zinc stearate, 15 g,

[0104] Antioxidant 1098, 5 g, Antioxidant 168, 10 g.

[0105] Among them, the magnetic powder is Sr-based ferrite magnetic powder surface-modified with silane coupling agent KH550. The preparation method is as follows: Add 15 g of silane coupling agent KH550 to 15 g of isopropanol to prepare a solution. Put 4500 g of Sr-based ferrite magnetic powder (Zhongrui Magnetic Industry Co., Ltd., Gangcheng District, Laiwu City) into a high-speed mixer, start stirring, dropwise add the aforementioned solution and carry out blending treatment for 30 min.

[0106] After preparing the above raw materials, mix them in a high-speed mixer for 30 min, and then send them into a reactive extrusion extruder with a length-diameter ratio of 68 (there are three sets of vacuum exhaust systems installed at the length-diameter ratios of 35, 50, and 65 of the extruder) for melt extrusion, water cooling, pelletizing, and drying to obtain a bonded magnet composition (PA12-F-3). The vacuum pumping rates of the three sets of vacuum exhaust systems are 0.8 L / min, 0.5 L / min, and 0.5 L / min in sequence. The temperature from the feeding section to the first set of vacuum exhaust systems is set at 220 - 260 °C, the temperature from the first set of vacuum exhaust systems to the die head is set at 260 - 280 °C, and the screw speed is 80 rpm.

[0107]

Comparative Example 1

[0108] Prepare a bonded magnet composition according to the same formula and method as in Example 1, denoted as PA12-F-D1. The difference is only that PA12-1 is replaced with an equal amount of nylon 12 resin 3012u (number-average molecular weight 15540, terminal carboxyl group content 0.064 mmol / g, melt viscosity 10 Pa·s).

[0109]

Comparative Example 2

[0110] Prepare a bonded magnet composition according to the same formula and method as in Example 1, denoted as PA12-F-D2. The difference is only that PA12-1 is replaced with an equal amount of nylon 12 resin 3012u (number-average molecular weight 15540, terminal carboxyl group content 0.064 mmol / g, melt viscosity 10 Pa·s), and PEA-3 is not added.

[0111] Perform the performance tests in Table 1 on the bonded magnet compositions provided in each example and comparative example. The results are as follows:

[0112] Table 1. Performance test results

[0113]

[0114]

[0115] The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A bonded magnet composition, characterized in that: It is prepared by co-extrusion of the following raw materials in weight percentage: Magnetic powder 80-95%, Monocarboxyl terminated nylon 12 oligomer 3-15%, Multi-arm polyetheramine 1-12%, Catalyst 0.05-0.5%, Lubricant 0.1-0.5%, Antioxidant 0.1-0.5%.

2. The bonded magnet composition according to claim 1, characterized in that The magnetic powder is ferrite magnetic powder surface-modified by a coupling agent; Preferably, the content of the coupling agent for modification in the magnetic powder is 0.1-3wt%, preferably 0.3-0.5wt%; Preferably, the coupling agent is selected from at least one of a silane coupling agent, a phthalate coupling agent, and a phosphate coupling agent; Preferably, the ferrite magnetic powder is selected from at least one of Sr-based ferrite magnetic powder, Ba-based ferrite magnetic powder, anisotropic NdFeB magnetic powder, homotropic NdFeB magnetic powder, SmFeN magnetic powder, and samarium cobalt magnetic powder.

3. The bonded magnet composition according to claim 1, characterized in that: The number average molecular weight of the monocarboxyl-terminated nylon 12 oligomer is 1500-10000, preferably 3000-5000, and the terminal carboxyl content is 0.1-0.67 mmol / g, preferably 0.3-0.4 mmol / g.

4. The bonded magnet composition according to any one of claims 1 to 3, characterized in that: The number average molecular weight of the multi-arm polyetheramine is 2000-16000, preferably 8000-10000; Preferably, the multi-arm polyetheramine is obtained by reacting a polyacid branching agent and a polyetheramine, wherein the polyacid branching agent is preferably selected from one or more of 1,3,5-benzenetricarboxylic acid, 1,2,3,5-benzenetetracarboxylic acid, benzene pentacarboxylic acid, benzene hexacarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 1,2,3,4,5,6-cyclohexanehexacarboxylic acid.

5. The bonded magnet composition according to any one of claims 1 to 4, characterized in that: The catalyst is one or more of phosphoric acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, and calcium hypophosphite; Preferably, the lubricant is one or more of zinc stearate, calcium stearate, ethylene bis stearamide, oleamide, erucamide, silicone oil, and paraffin; Preferably, the antioxidant is one or more of antioxidant 1098, antioxidant 1010, antioxidant 168, and antioxidant H10.

6. A method for preparing a bonded magnet composition according to any one of claims 1 to 5, characterized in that: The magnetic powder, monocarboxyl-terminated nylon 12 oligomer, multi-arm polyether amine, catalyst, lubricant and antioxidant are mixed and reactively extruded and granulated to obtain a bonded magnet composition; Preferably, the extrusion temperature is 220-280°C and the screw speed is 80-120 rpm.

7. The method for preparing a bonded magnet composition according to claim 6, characterized in that: The surface modification method of the magnetic powder is to prepare a coupling agent into a solution, drip it into the ferrite magnetic powder, and mix it for 20-30 minutes.

8. The method for preparing a bonded magnet composition according to claim 6, characterized in that: The preparation method of the monocarboxyl terminated nylon 12 oligomer is as follows: Add laurolactam and a monocarboxyl end-capping agent into water, first perform a ring-opening polymerization reaction, and then perform vacuum polycondensation to obtain the product; Preferably, the monocarboxyl end-capping agent is selected from one or more of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, and benzoic acid, and its usage is preferably 0.5-15wt% of the weight of laurolactam; Preferably, the reaction temperature of the ring-opening polymerization is 260-290° C., and the reaction time is 3-5 h; Preferably, the reaction temperature of the vacuum polycondensation is 220-240° C., and the reaction time is 0.5-1 h.

9. The method for preparing a bonded magnet composition according to any one of claims 6 to 8, characterized in that: The preparation method of the multi-arm polyetheramine is: Mix the polyetheramine and the polyacid branching agent, heat to 200-220°C, react for 30-60 minutes, and then evacuate to -85kPA to -95kPa and continue to react for 60-180 minutes; Preferably, the molar ratio of the terminal amino group of the polyetheramine to the carboxyl group of the polyacid branching agent is (1.5-2.5):

1.

10. Use of the bonded magnet composition according to any one of claims 1 to 5 or the bonded magnet composition obtained by the method according to any one of claims 6 to 9 in electronic components.

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