Resin composition fixing material for automobile rotating motor and preparation method of resin composition fixing material

Abstract

The invention relates to the field of motor materials, in particular to a resin composition fixing material for an automobile rotating motor and a preparation method of the resin composition fixing material for the automobile rotating motor, in the application, a combination of o-cresol type epoxy resin and DCPD type epoxy resin is selected, and a combination of linear phenolic resin and polyamide is used during curing. The formed fixing material has good oil immersion resistance.

Description

Technical Field

[0001] The present application relates to the field of motor materials, and in particular to a resin composition fixing material for an automobile rotating motor and a preparation method thereof. Background Art

[0002] In the assembly of automotive motors, the rotor and magnetic steel need to be bonded and fixed. Due to the particularity of the automotive processing environment, high requirements are placed on many properties of the bonding area, such as reliability, heat resistance, and flame retardancy, in order to achieve a more stable fixing structure between the rotor and the magnetic steel.

[0003] The use of adhesive resin to fix the rotor is a new type of fixation method, which is still in the preliminary research stage. It has the advantages of excellent processing performance, good bonding performance, and simple construction process, but its properties also need to be improved. For example, thermosetting resins such as phenolic resin and epoxy resin can be used to fix the rotor.

[0004] In the process of using resin for fixing, the defects of the resin's oil resistance will be highlighted in long-term use. Since the motor rotor will be in the oil environment for a long time, its strength and hardness will be significantly lost after long-term oil immersion, which will reduce the reliability of the motor. Summary of the invention

[0005] In order to improve the oil immersion resistance of the resin material so that it can be better adapted to the use in the field of motor rotor fixation, the present application provides a resin composition fixing material for an automotive rotating motor.

[0006] First, the present application provides a resin composition fixing material for an automotive rotating electrical machine, which is used to fix a magnet inserted into a rotor core hole with a rotor, and contains the following components in 100 parts by mass:

[0007] Epoxy resin, the epoxy resin is used as a thermosetting material, and its mass parts are 5 to 15 parts;

[0008] A curing agent, the curing agent is used for catalytic curing of epoxy resin to form a bonding system; the curing agent is composed of linear phenolic resin and polyamide; the mass of the linear phenolic resin is 0.3 to 0.6 times the mass of the epoxy resin, and the mass of the polyamide is 0.1 to 0.3 times the mass of the epoxy resin;

[0009] Accelerator used to adjust the curing rate of epoxy resin: 0.1-1 part;

[0010] Coupling agent used for coupling reaction between organic system and inorganic system: 0.2-1 part;

[0011] Inorganic flame retardant: 8-16 parts;

[0012] Other additives: 0.1-5 parts;

[0013] The flow regulator is used to adjust the epoxy resin at a curing temperature and an injection pressure of 70 kgf / cm 2 The flow length is not less than 24 inches in the state, and the mass of the flow regulator is 0.1 to 3 parts;

[0014] Filling: remainder;

[0015] The filler is any number of silicon dioxide, aluminum oxide, and inorganic fiber, and the motor rotor fixing material has an elastic strength of not less than 110 mPa and an elastic modulus of not less than 13800 mPa after curing;

[0016] The epoxy resin is a combination of an o-cresol epoxy resin and a DCPD epoxy resin, wherein the mass ratio of the o-cresol epoxy resin to the DCPD epoxy resin is 5 to 20:1;

[0017] In the epoxy resin raw material, the total amount of potassium ions, iron ions, sulfate ions, chloride ions and sodium ions is not higher than 350 ppm.

[0018] In the above scheme, a combination of o-cresol epoxy resin and DCPD epoxy resin is used, wherein the DCPD epoxy resin has lower dilution performance and elasticity. The two together provide strong barrier properties while also having good processability. A certain amount of non-aromatic ring structure is utilized to improve the toughness and bonding properties of the system, so that the system can better balance oil immersion resistance and bonding properties.

[0019] On the above basis, a linear phenolic resin system is used for curing, and a good curing system can be formed within this range, and the phenolic resin itself can produce good sealing in the system by utilizing the arrangement of its molecular chains, thereby improving the overall oil resistance, and thus having a good application prospect in the field of motor rotor binders. At the same time, a small amount of polyamide is added as a curing system. The alternating structure of soft and hard segments formed by polyamide can, on the one hand, improve the crosslinking degree of the system during curing, so that it can better form a closed grid structure, and on the other hand, it also helps to provide certain buffering properties, further improving the oil immersion resistance of the system as a whole. Wherein, the amine value of the polyamide is preferably 200-240 mgKOH / g, which can provide better reaction performance.

[0020] Preferably, the flow regulator comprises silicone oil and fumed silica, the mass of the silicone oil is 0.1 to 1 part; the mass of the fumed silica is 0.1 to 1 part.

[0021] The above two components can adjust the fluidity of the system, thereby optimizing the leveling performance of the motor rotor fixing material and reducing the spreading and flying materials during processing. In addition, silicone oil can reduce the stress of epoxy resin during the curing process, thereby reducing its shrinkage during the curing process, improving the stability of the motor rotor after bonding and the internal strength of the adhesive. At the same time, by adding a small amount of fumed silica, a more uniform curing system can be formed, while improving the reaction performance of the system. By utilizing the high specific surface area performance of fumed silica, a multi-centered grid system can be formed in the system, further suppressing the influence of oil immersion on the system.

[0022] Preferably, the silicone oil is epoxy silicone oil, and the viscosity of the silicone oil is 2400-4000 mm 2 / s.

[0023] In the above scheme, the use of epoxy silicone oil can utilize silicone oil to improve the coupling performance in the system, enhance the overall cohesion and strength of the material. After forming a coupling system, the barrier performance of the material is stronger, which can better block the penetration of hydrocarbon substances such as gasoline and engine oil, and further improve the oil immersion resistance of the system.

[0024] Preferably, the filler is silicon dioxide, and the silicon dioxide is a combination of crystalline silicon dioxide fine powder and fused silicon dioxide fine powder, and the mass ratio of the crystalline silicon dioxide fine powder to the fused silicon dioxide fine powder is 3:1 to 1:3.

[0025] The above adjustments can improve the mechanical properties of the system and make the system have good thermal conductivity.

[0026] Preferably, the coupling agent is a combination of an epoxy silane coupling agent and a mercapto silane coupling agent, which is used to improve the bonding strength of the fixing material, and the mass ratio of the epoxy silane coupling agent to the mercapto silane coupling agent is 1.5 to 3:1.

[0027] In this scheme, epoxy coupling agent and mercapto coupling agent are used in combination, wherein the mercapto coupling agent provides better reactivity with epoxy groups, while the epoxy silane coupling agent has better reactivity with hydroxyl groups in phenolic resin, so that better bonding strength can be formed in the system and its adhesion performance to metal materials can be improved.

[0028] Preferably, it also includes an MBS toughening agent, and the mass portion of the toughening agent is 0.1 to 1 part.

[0029] Toughening agents can improve the impact resistance of the system, reduce the brittleness of the system, and make it more resistant to vibration and impact during use.

[0030] Preferably, the invention further comprises 2 to 4 parts by weight of ethylene-vinyl alcohol copolymer. More preferably, in the ethylene-vinyl alcohol copolymer, the molar ratio of vinyl alcohol segments is 20 to 24%.

[0031] Ethylene-vinyl alcohol copolymer can produce a blending effect with the phenolic resin curing system to form a system with good barrier properties. Since polyamide participates in the reaction as a curing agent, the ethylene-vinyl alcohol system can further form a homogeneous phase with the phenolic system, thereby improving the overall sealing performance.

[0032] In addition, the present application also relates to a method for preparing the resin composition fixing material for fixing the magnets of the rotor core of the above-mentioned automobile rotating electrical machine. The above-mentioned materials are mixed and then cured in a mold at a curing temperature of 160 to 200°C.

[0033] In summary, the present application provides a motor rotor fixing material with good oil immersion resistance, which can maintain the mechanical properties of the system without obvious changes for a long time in the environment of gasoline and engine oil, thereby improving the durability of the automobile motor rotor and reducing safety hazards. DETAILED DESCRIPTION

[0034] The technical solution of the present application is now further described through the following specific implementation methods.

[0035] The following embodiments all involve a motor rotor fixing material with good oil immersion resistance. The temperature of the oil pressure molding machine is set to 175°C. After the temperature is reached, the components of each embodiment are mixed and injected into a special bonding mold through the injection hole of the press. After injection molding, the mold is demolded and the sample is placed in an oven at 175°C for curing for 6 hours.

[0036] The samples obtained from the above experiments are judged by the following experimental data to measure their performance.

[0037] 1. Magnet bonding: After forming in the mold, a universal testing machine is used to perform a tensile test to determine the bonding performance between the material and the magnet in the mold.

[0038] 2. Oil immersion resistance: Place the sample in commercially available engine oil and measure its initial and 2000h bending strength and elastic modulus.

[0039] 3. The contents of potassium ion, iron ion, sulfate ion, chloride ion and sodium ion were determined by IPC-MS. In the following examples, the total amount of ions was not higher than 350 ppm unless otherwise specified.

[0040] 4. Processing performance: Take 30 grams of sample and measure it with a resin transfer injection molding machine using a spiral flow metal mold. The injection pressure is 70kgf / cm 2The mold temperature is 175±1℃, and the flash and flow length are measured. The higher the flow length, the better the flow performance, and the lower the flash, the better the processability.

[0041] 5. Thermal conductivity: Refer to GB / T 1449 standard for thermal conductivity test of fiber reinforced plastics.

[0042] Example 1. The purpose of this example is to study the combination of different epoxy resins and curing agents, and to study their adhesion to magnets and their resistance to oil immersion. Specifically, in this example, the masses of curing agents and epoxy resins selected by different experimental groups per 100 parts by mass of material are shown in Table 1.

[0043]

[0044] In this embodiment, the total mass of the o-cresol epoxy resin and the DCPD epoxy resin is fixed to 10 parts, wherein the o-cresol epoxy resin is CNE195LL and the DCPD epoxy resin is HP7200. The mass of the curing agent is fixed to 7 parts, wherein the linear phenolic resin is PF8011 and the polyamide is polyamide 651, and the amine value thereof is 400-450 mg / KOH / g.

[0045] In addition, in this embodiment, in every 100 parts by mass of raw materials, the other components are as follows:

[0046] Accelerator: TPP accelerator is selected, with a mass percentage of 0.2 parts;

[0047] Coupling agent: a combination of KH560 (i.e. epoxy coupling agent) and KH590 (i.e. mercapto coupling agent), wherein the mass portion of KH560 is 0.5 parts and the mass portion of KH590 is 0.25 parts;

[0048] Inorganic flame retardant, aluminum hydroxide is selected, the weight part is 10 parts;

[0049] The remaining additives include 0.2 parts of carbon black as a colorant and 0.5 parts of wax powder as a release agent;

[0050] Flow regulator, which contains 0.5 parts of epoxy silicone oil (viscosity 3959mm at 25°C) 2 / s), 0.5 parts of fumed silica;

[0051] Including MBS toughening agent, 0.5 parts by mass;

[0052] The balance is filler: a combination of crystalline silica powder and fused silica powder is selected, wherein the mass parts of crystalline silica powder are 35 parts, and the mass parts of fused silica powder are 34.85 parts;

[0053] After preparation, the total amount of potassium ion, iron ion, sulfate ion, chloride ion and sodium ion is not higher than 350 ppm.

[0054] In addition, the mass of the accelerator can be adjusted between 0.1 and 1 parts to control the overall gelation time to be approximately within the range of 15 to 30 seconds. In addition to colorants and demolding machines, other additives and other components can be added. The overall mass should not exceed 5% of the total mass.

[0055] The above experimental groups were subjected to experiments and the results were shown in Table 2.

[0056] It can be seen from the above experiments that the overall bonding performance of the magnet is met, but by adjusting the ratio of epoxy resin and curing agent, better oil immersion resistance can be achieved. On the whole, when the mass ratio of o-cresol epoxy resin and DCPD epoxy resin is controlled in the range of 5 to 20:1, it has better oil immersion resistance, and the overall elastic strength and elastic modulus are good. In addition, increasing the amount of DCPD added can also help improve the bonding performance, but when the amount added is too large, the oil immersion resistance of the system will deteriorate, and the flash overflow phenomenon will be more significantly improved. In the selection of curing agent, the addition of a small amount of polyamide obviously helps to improve the oil immersion resistance of the system, but too much addition will also cause the system to have an excessive amount, which will also cause the bonding of the system to deteriorate, and the flash overflow will increase.

[0057]

[0058] Example 2: The purpose of this example is to adjust the addition amount and ratio of the two coupling agents based on Example 1-1, and verify the bonding performance and oil immersion resistance of the system, and the results are shown in Table 3. It should be noted that in this example and the following examples, during the mass adjustment process, the mass of the filler is increased or decreased when the mass of the coupling agent is increased or decreased, so that the total mass remains unchanged.

[0059]

[0060] From the experimental data in the above table, it can be seen that the combination of epoxy silane coupling agent and mercapto silane coupling agent has better overall bonding strength and stronger oil immersion resistance, and the best ratio is 1.5 to 3:1, which has the best overall effect.

[0061] Example 3: Based on Example 1-1, this example further adjusts the type and quality of silicone oil and the quality of gas silicone. The processing performance test results are shown in Table 4.

[0062]

[0063] Among them, silicone oils with different numbers are as follows:

[0064] A1: Epoxy silicone oil, viscosity 3959mm 2 / s.

[0065] A2: Epoxy silicone oil, viscosity 5021mm 2 / s.

[0066] A3: Epoxy silicone oil, viscosity 2485mm 2 / s.

[0067] A4: Epoxy silicone oil, viscosity 1170mm 2 / s.

[0068] B1: Methoxy silicone oil, viscosity 2777mm 2 / s.

[0069] B2: Methoxy silicone oil, viscosity 2245mm 2 / s.

[0070] B3: Methoxy silicone oil, viscosity 3630mm 2 / s.

[0071] The above viscosity data is obtained by laboratory measurement at 25°C.

[0072] Through the above experimental results, it can be seen that in this application, the addition of gas silicone and silicone oil has a significant effect on the fluidity of the system, among which the addition of gas silicone can also improve the oil resistance of the system as a whole, and compared with methoxy silicone oil, the addition of silicone oil containing epoxy groups can further improve the oil resistance of the system. However, excessive addition of silicone oil will also lead to a certain decrease in the strength and modulus of the system, and excessive addition of gas silicone will lead to a significant decrease in fluidity.

[0073] Example 4: Based on Example 1-1, this example further adds ethylene-vinyl alcohol copolymer, wherein the amount of ethylene-vinyl alcohol copolymer used, the molar ratio of vinyl alcohol chain segments and the experimental results are shown in Table 5.

[0074]

[0075] From the above experimental data, it can be seen that after adding ethylene-vinyl alcohol, the oil immersion resistance of the system can be further improved. After 2000h of oil immersion, the loss of elastic strength and elastic modulus is small. Among them, ethylene-vinyl alcohol copolymer can be obtained by hydrolysis of ethylene-vinyl acetate copolymer. When the molar ratio of its vinyl alcohol chain segment is in the range of 20-24%, the overall mechanical properties are the best. This may be related to the fact that the side chain has a large steric hindrance in the system, which affects the density of the system. Specifically, a low molar ratio of vinyl alcohol chain segment will lead to an insignificant improvement in the sealing of the system. A small amount of addition has no obvious effect on the oil immersion resistance of the system. On the contrary, a high molar ratio of vinyl alcohol chain segment will have an adverse effect on the strength of the system, and will greatly increase the elastic modulus, resulting in insufficient toughness of the system and reduced elastic strength.

[0076] Example 5, based on Example 1-1, the ratio of the two silicas in the filler is further adjusted. The relationship between the mass ratio of the two silicas and the final thermal conductivity and mechanical properties of the material is shown in Table 6.

[0077]

[0078] It can be seen from the above experiments that the combination of the two fillers can significantly improve the thermal conductivity and mechanical properties. Overall, when the mass ratio of crystalline silica powder to molten silica powder is 3:1 to 1:3, it can better balance the elastic strength and thermal conductivity.

[0079] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A resin composition fixing material for an automotive rotating electrical machine, which is used to fix a magnet inserted into a rotor core hole and a rotor, characterized in that: Each 100 parts by mass contains the following components: Epoxy resin, the epoxy resin is used as a thermosetting material, and its mass parts are 5 to 15 parts; A curing agent, the curing agent is used for catalytic curing of epoxy resin to form a bonding system; the curing agent is composed of linear phenolic resin and polyamide; the mass of the linear phenolic resin is 0.3 to 0.6 times the mass of the epoxy resin, and the mass of the polyamide is 0.1 to 0.3 times the mass of the epoxy resin; Accelerator used to adjust the curing rate of epoxy resin: 0.1-1 part; Coupling agent used for coupling reaction between organic system and inorganic system: 0.2-1 part; Inorganic flame retardant: 8-16 parts; Other additives: 0.1-5 parts; The flow regulator is used to adjust the epoxy resin at a curing temperature and an injection pressure of 70 kgf / cm 2 The flow length is not less than 24 inches in the state, and the mass of the flow regulator is 0.1 to 3 parts; Filling: remainder; The filler is any number of silica, alumina, and inorganic fibers, and the motor rotor fixing material has an elastic strength of not less than 110 MPa and an elastic modulus of not less than 13800 MPa after curing; The epoxy resin is a combination of an o-cresol epoxy resin and a DCPD epoxy resin, wherein the mass ratio of the o-cresol epoxy resin to the DCPD epoxy resin is 5 to 20:1; In the epoxy resin raw material, the total amount of potassium ions, iron ions, sulfate ions, chloride ions and sodium ions is not higher than 350 ppm.

2. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: The flow regulator comprises silicone oil and fumed silica, wherein the mass of the silicone oil is 0.1 to 1 part; the mass of the fumed silica is 0.1 to 1 part.

3. The resin composition fixing material for an automotive rotating electrical machine according to claim 2, characterized in that: The silicone oil is epoxy silicone oil, and the viscosity of the silicone oil is 2400-4000 mm 2 / s.

4. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: The filler is silicon dioxide, and the silicon dioxide is a combination of crystalline silicon dioxide fine powder and fused silicon dioxide fine powder. The mass ratio of the crystalline silicon dioxide fine powder to the fused silicon dioxide fine powder is 3:1 to 1:

3.

5. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: The coupling agent is a combination of an epoxy silane coupling agent and a mercapto silane coupling agent, and is used to improve the bonding strength of the fixing material. The mass ratio of the epoxy silane coupling agent to the mercapto silane coupling agent is 1.5 to 3:

1.

6. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: It also includes an MBS toughening agent, the mass portion of the toughening agent is 0.1 to 1 part.

7. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: The invention also includes 2 to 4 parts by weight of ethylene-vinyl alcohol copolymer for improving sealing performance.

8. The resin composition fixing material for an automotive rotating electrical machine according to claim 7, characterized in that: In the ethylene-vinyl alcohol copolymer, the molar ratio of vinyl alcohol chain segments is 20-24%.

9. The resin composition fixing material for an automotive rotating electrical machine according to claim 1, characterized in that: The amine value of the polyamide is 400-450 mgKOH / g.

10. The method for preparing a resin composition fixing material for an automotive rotating electrical machine according to any one of claims 1 to 9, characterized in that: After the above materials are mixed, they are cured in a mold at a curing temperature of 160-200°C.

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