Insulating coating rubber for motor

Abstract

The invention belongs to the technical field of adhesives, and particularly relates to a motor insulation coating adhesive. The coating is prepared from the following components in parts by weight: 15 to 30 parts of epoxy resin, 2 to 20 parts of toughened modified epoxy resin, 0 to 12 parts of epoxy diluent, 0.1 to 18 parts of curing agent, 40 to 70 parts of inorganic filler, 0.1 to 1.5 parts of pigment, 0 to 3 parts of thickening agent, 0 to 10 parts of unsaturated oligomer, 0 to 15 parts of unsaturated monomer, 0 to 3 parts of adhesion promoter, 0.5 to 2 parts of curing accelerator, 0 to 1 part of coupling agent and 0 to 0.5 part of defoaming agent. Wherein the epoxy resin is one or more of aliphatic epoxy resin, alicyclic epoxy resin, aromatic epoxy resin, naphthalene ring epoxy resin or high-functional-group epoxy resin with functionality of 3 or 4. The motor insulation coating rubber provided by the invention has good insulation performance, and still keeps volume resistivity gt in a high-temperature working environment (gt, 160 DEG C); in addition, the coating has the characteristics of high adhesive force, high reliability, high toughness and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and particularly relates to a motor insulation coating adhesive. Background Art

[0002] Under the trend of globalization, the energy-related strategies and policies of various countries involve energy strategy adjustment, energy structure transformation, energy system optimization, and energy conservation and emission reduction actions. The ESG evaluation system centered on the three aspects of environment, society, and corporate governance covers thousands of companies globally to evaluate whether the enterprise products, performance, business models, etc. are consistent with the sustainable development goals. Against this background, the green energy advantages shown by hybrid electric vehicles and electric vehicles are gradually becoming obvious. Among them, in terms of vehicle motors, in order to achieve higher output power and lower energy consumption, how to reduce weight, reduce size, increase the coil slot fill factor while reducing iron loss and copper loss to further improve the motor performance has become the goal pursued by people.

[0003] A relatively common stator slot structure is that the coil coated with enameled wire paint is isolated from the teeth by insulating paper, and the small gap between the insulating paper and the coil is fixed by impregnating low-viscosity varnish to manufacture the stator structure. In this traditional structure, the enameled wire paint, impregnating varnish, and insulating paper together provide excellent insulation protection performance. And the enameled wire paint formed according to the NEMA MW1000 standard can provide reliable insulation under various motor operating conditions by virtue of its own material and thickness. Therefore, the slot and turn insulation protection functions of the insulating paper and the impregnating varnish overlap. The reason is that the repeated use of various different forms of insulating materials is related to the product design and the traditional stator forming process. In order to shorten the production cycle of the stator, the silicon steel sheet coil is fixed after being quickly punched and stacked to the designed height / weight. There are burrs microscopically on its teeth. Therefore, another important function of the insulating paper is to prevent the enameled wire paint from being scratched by the burrs during the wire insertion process, which may affect the insulation performance. After the wire insertion, the air in the slot has a low thermal conductivity. By impregnating the impregnating varnish, not only can the enameled wire be firmly fixed to the stator, but also a thermal conductivity ten times more than that of air can be provided to reduce the copper loss. However, the thermal conductivity of the low-viscosity impregnating varnish itself is not high. The heat of the winding is transferred to the insulating paper through the impregnating varnish, then to the stator, and finally cooled by the cooling oil, which is inefficient. Therefore, if the cooling oil can directly dissipate heat from the coil heat source through heat convection, the copper loss can be greatly reduced and the motor efficiency can be improved to achieve a new motor design with high power and low energy consumption.

[0004] In the prior art, there are various solutions to improve the inefficient heat conduction and dissipation at multiple interfaces in traditional stator designs. For example, by combining the coil and the iron core and then performing resin molding uniformly, the heat dissipation effects of the low thermal conductivity of the porous insulating paper and the high interfacial thermal resistance with the stator teeth are improved, and at the same time, the in-slot structure for insulation and fixation is realized. There are also those who take a different approach, assembling three-dimensional phase change heat pipes to the outer shell, bonding the evaporation section to the stator winding, and evenly transferring the heat to the outer shell to achieve natural air cooling, forced air cooling, or forced water cooling. Among them, resin molding is the most direct and common optimization method.

[0005] Epoxy resin is one of the most widely used matrix resins in composite materials at present, with excellent comprehensive physical properties, such as high mechanical strength, excellent electrical insulation, and corrosion resistance, etc., which basically meet the performance requirements of the insulation materials in the motor stator slots. However, the cured substance of conventional epoxy resin is hard and brittle, has a large cohesive force, and has a certain shrinkage; at the same time, due to the structural characteristics, the cured epoxy resin still has a certain polarity (dielectric constant > 3.5 @ 1MHz, room temperature), and its insulation performance is average at high temperatures. Usually, a large amount of fillers are added to improve it, but a large amount of fillers will significantly affect the toughness of the resin; moreover, during the processing, storage, and use processes, epoxy resin and its products will age due to the action of various environmental factors such as light and heat, resulting in changes in their structure and performance, and even losing their excellent use value.

[0006] Therefore, studying a technology that can effectively improve problems such as the low insulation, low toughness, and certain shrinkage rate of epoxy resin is the key means to optimize the performance of the motor. Summary of the Invention

[0007] To solve the above problems, the invention object of the present application is to provide a motor insulation coating adhesive, which not only has good insulation performance and can effectively replace the use of insulating paper, and still maintains a volume resistivity > 10 14 Ω·cm even in a high-temperature working environment (>160°C), but also has characteristics such as high adhesion, high reliability, and high toughness, can effectively cope with the inherent modal deformation and high and low temperature difference thermal deformation during the use of the motor, has high dimensional stability and uniformity, and can provide more cooling oil channels compared with flexible insulating paper materials; in addition, this coating adhesive has high wettability and bonding strength to the motor silicon steel sheet, can reduce the thermal resistance with the inner wall of the stator slot, and has high compatibility with the cooling oil. When applied to the motor, it will provide a reliable in-slot sealing structure, realize the direct heat dissipation of the cooling oil to the winding heat source in a heat convection manner, and meet the design requirements of the motor for size reduction, weight reduction, low energy consumption, and high efficiency.

[0008] To achieve the above object, the present invention provides the following technical solutions: The motor insulation coating adhesive in the present invention is composed of the following components and their weight parts by weight: 15 - 30 parts of epoxy resin, 2 - 20 parts of toughened modified epoxy resin, 0 - 12 parts of epoxy diluent, 0.1 - 18 parts of curing agent, 40 - 70 parts of inorganic filler, 0.1 - 1.5 parts of pigment, 0 - 3 parts of thickener, 0 - 10 parts of unsaturated oligomer, 0 - 15 parts of unsaturated monomer, 0 - 3 parts of adhesion promoter, 0.5 - 2 parts of curing accelerator, 0 - 1 part of coupling agent, 0 - 0.5 part of defoaming agent; Among them, the epoxy resin is one or more of aliphatic epoxy resin, alicyclic epoxy resin, aromatic epoxy resin, naphthalene ring epoxy resin or high-functional group epoxy resin with a functionality of 3 or 4, and the viscosity is 1000 mPa·s - 200000 mPa·s.

[0009] Furthermore, the epoxy resin is one or more of NPEL-128, NPEL-128E, Epo Tohto ZX1059, JER 828US, EPICLON EXA-830LVP, EPICLON EXA 830 CRP, EPICLON 850 CRP, EPICLON HP-4032D, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-6000, EPICLON HP-6000L, EPICLON HP-9500, Araldite® MY 0500, Araldite® MY 0510, Tactix® 742, Sumitomo ELM-100, Sumitomo ELM-100H, Araldite® MY 0600, Araldite® MY 720, Araldite® MY 721, Araldite® MY 725, Sumitomo ELM-434, Sumitomo ELM-434L.

[0010] Furthermore, the toughened modified epoxy resin is one or more of MX125, MX-134, MX-135, MX139, MX153, MX154, MX960, MX965 of KANEKA Corporation, Acryset BPF 307, Acryset BPA 328 of Nippon Shokubai Co., Ltd., AER9000 of Asahi Kasei Corporation, EXA-4850-150, EXA-4860 of DIC Corporation.

[0011] Further, the epoxy diluent is one or more of ED509S, Denacol EX 146, ZL-649S, Araldite DY3601, and Heloxy 65, and has a viscosity of 100 mPa·s - 1000 mPa·s.

[0012] Further, the curing agent is one or more of acid anhydride-based, imidazole-based, dicyandiamide (DICY)-based, and peroxide-based curing agents.

[0013] Further, the inorganic filler is one or more of spherical / spherical-like silica powder, alumina, aluminum nitride, boron nitride, calcium carbonate, titanium dioxide, and talc.

[0014] Further, the pigment is one or more of Cabot Mogul L, Orion Lamp Black 101, Stan tone 90EPX04, Raven 1020, and Sudan Black B.

[0015] Further, the thickener is one or more of Cabot TS720, TS530, TS610, Wacker aerosil H15, H17, H18, H20, H30, H2000, and Tokuyama aerosil MT-10, MT-10C, DM-10, DM-10C, DM-30.

[0016] Further, the unsaturated oligomer is one or more of polyurethane (meth)acrylate, epoxy (meth)acrylate, aminated (meth)acrylate, multi-functional dendritic (meth)acrylate, aromatic maleimide, and cyanate ester; The unsaturated monomer is maleimide, (meth)acrylic acid (ester), or cyanate ester having an aliphatic, aromatic, naphthalene ring, isocyanurate, or isopentanediol structure.

[0017] Further, the adhesion promoter is one or more of P-1M, P-2M of Kyoeisha Chemical Co., Ltd., or quaternary ammonium salt-51, 2-methacryloyloxyethyl phosphorylcholine (MPC); The curing accelerator is one or more of DABCO T-12, Borchi® Kat 320, Kat 22, Kat 24, HX-3721, HX-3742, HX-3088, HX-3921HP, HX3932HP, HXA3792 of Asahi Kasei Corporation, and UR200, UR300, UR400, UR500, UR700, UR800, URAcc13, URAcc57 of the DYHARD series of AlzChem Corporation; The coupling agent is one or more of A-187 and A-186 of Momentive, KBM-502, KBM-503, KH-550, KH-560, KH-580, KH-540, KBM-602 and KBM-603 of Shin-Etsu, and Z-6011 and Z-6040 of Dow Corning; The defoaming agent is one or more of BYK-333, Croda Hypermer KD-1 and Allnex PC1344.

[0018] Based on the above technical solutions, the present invention has the following technical effects: 1. The motor insulation coating adhesive provided by the present invention uses aliphatic epoxy resin, alicyclic epoxy resin, aromatic epoxy resin, naphthalene ring epoxy resin or high-functional epoxy resin with a functionality of 3 or 4 as the main resin. It not only has good insulation performance and can effectively replace the use of insulating paper, but also maintains a volume resistivity > 10 14 Ω·cm even in a high-temperature working environment (>160 °C). Moreover, it can effectively increase the crosslinking density after curing of the material and the glass transition temperature of the system, thereby improving the heat resistance performance of the material and effectively coping with the inherent modal deformation and high and low temperature difference thermal deformation during the use of the motor, ensuring high reliability within the working temperature range of the motor.

[0019] 2. The motor insulation coating adhesive provided by the present invention has no small molecule release during the curing process, high dimensional stability, high uniformity and small internal stress. It not only has the characteristics of high adhesion, high reliability, low thermal expansion coefficient and volume shrinkage rate, but also can provide more cooling oil channels compared with flexible insulating paper materials.

[0020] 3. The motor insulation coating adhesive provided by the present invention adds toughened modified epoxy resin and epoxy diluent. It not only has high wettability and bonding strength to the motor silicon steel sheet, can reduce the thermal resistance with the inner wall of the stator slot, and has high compatibility with the cooling oil, but also when applied to the motor, it will provide a reliable in-slot sealing structure to realize direct heat dissipation of the cooling oil to the winding heat source in a heat convection manner, meeting the design requirements of reducing the size, weight, low energy consumption and high efficiency of the motor.

[0021] 4. The motor insulation coating adhesive provided by the present invention increases the toughness of the material by adding inorganic fillers and appropriately adding unsaturated monomers and unsaturated oligomers to further cope with the inherent modal deformation and high and low temperature difference thermal deformation during the use of the motor.

[0022] 5. The motor insulation coating adhesive provided by the present invention adds a thickening agent to adjust the viscosity of the material, enabling the material to be a low-viscosity liquid at room temperature with good fluidity. It can fill the inner wall of the stator slot under a relatively low injection pressure, meeting the design of a thickness of 100um - 500um, resulting in a small clamping force required during the molding process of the motor-coated stator and a small deformation of the laminated stator. Detailed Embodiments

[0023] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. Preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0024] Before further describing various embodiments of the compounds / compositions and methods of the present disclosure in more detail through exemplary descriptions, examples, and results, it should be understood that the embodiments of the present disclosure are not limited in application to the details of the methods and compositions described below. The descriptions provided herein are for illustrative purposes only and are not to be construed in a limiting sense. The inventive concept of the present disclosure can have other embodiments or can be practiced or implemented in various ways. Therefore, the language used herein is intended to give the broadest scope and meaning; and the embodiments are intended to be exemplary and not exhaustive and are not intended to limit the present disclosure to these specific embodiments. Moreover, it should be understood that the wording and terms used herein are for descriptive purposes and should not be considered restrictive unless otherwise stated. In addition, in the following detailed description, many specific details are listed to provide a more thorough understanding of the present disclosure.

[0025] However, it is obvious to those of ordinary skill in the art that the embodiments of the present disclosure can be practiced without these specific details. In other cases, features well known to those of ordinary skill in the art are not described in detail to avoid unnecessary complex descriptions. It is intended that all alternatives, substitutions, modifications, and equivalents obvious to those of ordinary skill in the art are included within the scope of the present disclosure. According to the present disclosure, all compounds / compositions and their preparation methods, applications, and uses disclosed herein can be prepared and implemented without undue experimentation.

[0026] Therefore, although the compounds / compositions and methods of the present disclosure have been described according to specific embodiments, it is obvious to those skilled in the art that changes can be made to the formulations, compounds or compositions, and / or methods and the steps or the order of steps of the methods described herein without departing from the spirit and scope of the inventive concept of the present disclosure.

[0027] As used herein, any reference to "an embodiment" or "embodiments" means that the particular elements, features, structures, or characteristics described in connection with that embodiment are included in at least one embodiment. The phrase "in one embodiment" that appears multiple times in the specification does not necessarily refer to the same embodiment.

[0028] Unless otherwise defined herein, scientific and technical terms used in connection with the present disclosure shall have the meanings commonly understood by one of ordinary skill in the art. Further, unless the context otherwise requires, singular terms shall include the plural and plural terms shall include the singular.

[0029] The present invention provides a motor insulation coating adhesive, which is composed of the following components and their weight parts by weight: 15 - 30 parts of epoxy resin, 2 - 20 parts of toughened modified epoxy resin, 0 - 12 parts of epoxy diluent, 0.1 - 18 parts of curing agent, 40 - 70 parts of inorganic filler, 0.1 - 1.5 parts of pigment, 0 - 3 parts of thickener, 0 - 10 parts of unsaturated oligomer, 0 - 15 parts of unsaturated monomer, 0 - 3 parts of adhesion promoter, 0.5 - 2 parts of curing accelerator, 0 - 1 part of coupling agent, 0 - 0.5 part of defoaming agent; wherein, the epoxy resin is one or more of aliphatic epoxy resin, alicyclic epoxy resin, aromatic epoxy resin, naphthalene ring epoxy resin or high-functional epoxy resin with a functionality of 3 or 4, and the viscosity is 1000 mPa·s - 200000 mPa·s.

[0030] Furthermore, the epoxy resin is one or more of NPEL-128, NPEL-128E, Epo Tohto ZX1059, JER 828 US, EPICLON EXA-830LVP, EPICLON EXA 830 CRP, EPICLON 850 CRP, EPICLON HP-4032D, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-6000, EPICLON HP-6000L, EPICLON HP-9500, Araldite® MY 0500, Araldite® MY 0510, Tactix® 742, Sumitomo ELM-100, Sumitomo ELM-100H, Araldite® MY 0600, Araldite® MY 720, Araldite® MY 721, Araldite® MY 725, Sumitomo ELM-434, Sumitomo ELM-434L. Preferably, the epoxy resin is a naphthalene ring epoxy resin or a high-functional epoxy resin with a functionality of 3 or 4. More preferably, the epoxy resin is preferably one or more of Araldite® MY 0500, Araldite® MY 0510, Tactix® 742, Sumitomo ELM-100, Sumitomo ELM-100H, Araldite® MY 0600, Araldite® MY 720, Araldite® MY 721, Araldite® MY 725, Sumitomo ELM-434, Sumitomo ELM-434L. The addition of naphthalene ring epoxy resin or high-functional epoxy resin can effectively increase the crosslinking density after curing of the material, increase the glass transition temperature Tg of the system, and improve the heat resistance of the material.

[0031] Furthermore, the toughened and modified epoxy resin is one or more of MX125, MX-134, MX-135, MX139, MX153, MX154, MX960, MX965 of KANEKA Corporation, Acryset BPF 307, Acryset BPA 328 of Nippon Shokubai Co., Ltd., AER9000 of Asahi Kasei Corporation, EXA-4850-150, EXA-4860 of DIC Corporation. Introducing epoxy resins with core-shell structured rubber particles or flexible chain segments can not only improve the toughness and adhesion of the material, but also not reduce the heat resistance of the material, and can greatly improve the reliability of bonded components.

[0032] Furthermore, the epoxy diluent is one or more of ED509S, Denacol EX 146, ZL-649S, Araldite DY 3601, Heloxy 65, and the viscosity is 100 mPa·s - 1000 mPa·s; the addition of the epoxy diluent can effectively reduce the viscosity of the material, improve the wettability and adhesion of the material.

[0033] Furthermore, the curing agent is one or more of acid anhydride type, imidazole type, dicyandiamide type (DICY), peroxide type curing agents; the curing agent is preferably one or more of RIKACID HH, RIKACID MH-700, RIKACID MH-700G, HN-2000, HN-2000NT, HN-2200, HN-5500, HN-07000, HN-7000A, Curezol2E4MZ, Curezol 2E4MZ-CNde, Curezol 2P4MZ, Curezol 1B2MZ, Curezol 2PHZ, Curezol 2PHZS, Curezol 2MZAzine, Dyhard 100 series, Dicyanex 1400 series, BPO (benzoyl peroxide), CHP (cumene hydroperoxide) of Hitachi.

[0034] Furthermore, the inorganic filler is one or more of spherical / spherical-like silica powder, alumina, aluminum nitride, boron nitride, calcium carbonate, titanium dioxide, talc powder; the addition of the inorganic filler can effectively increase the thermal conductivity of the material after curing, reduce the curing shrinkage rate and thermal expansion coefficient of the material. The pigment is one or more of Cabot Mogul L, Orion Lamp Black 101, Stantone 90 EPX04, Raven 1020, Sudan Black B. The thickener is one or more of Cabot TS720, TS530, TS610, Wacker aerosil H15, H17, H18, H20, H30, H2000, Tokuyama aerosil MT-10, MT-10C, DM-10, DM-10C, DM-30; the addition of the thickener can effectively adjust the viscosity of the material, making the material suitable for injection and injection molding processes.

[0035] Furthermore, the unsaturated oligomer is one or more of polyurethane (meth)acrylate, epoxy (meth)acrylate, aminated (meth)acrylate, multi-functional dendritic (meth)acrylate, aromatic maleimide, cyanate ester; preferably, the unsaturated oligomer is one or more of BMA-200, BR704P, BR970, BR991, BR471, BR741, BR7432GB, BR744P, XR-741MS, BDT-1015, BDT-1006, BDT-4330, MCURE100, MCURE201, MCURE203, MCURE300NS, Compimide 353A, Compimide 796, Compimide P500, Compimide 200, Compimide 1224L60, PFB-401 of Shandong Shengquan, Primaset PT-30 of Arxada AG, HTM-100; the addition of the unsaturated oligomer can increase the toughness of the material system and improve the temperature change resistance and reliability of the material. The unsaturated monomer is maleimide, (meth)acrylic acid (ester), cyanate ester with an aliphatic, aromatic, naphthalene ring, isocyanurate or isopentanediol structure; preferably, the unsaturated monomer is one or more of CD590, SR339NS, SR9087, SR228NS, SR349NS, SR340NS, SR423NS, SR101, SR150, SR348NS, SR540, SR9011, SR833NS, SR368NS, SR368DNS, SR9054, SR533NS, FA512AS, FA512MT, FA512M, Kerimid series (such as Kerimid 601, etc.), Compimide series (such as Compimide MDAB, Compimide TDAB, Compimide TM123, Compimide TM124, etc.), PFB002, PFB201, PFB301 of Shandong Shengquan; the addition of the rigid structure unsaturated monomer can generate rigid molecular chain segments during the curing process of the material, improve the glass transition temperature Tg of the material system, and enhance the heat resistance of the material.

[0036] Furthermore, the adhesion promoter is one or more of P-1M, P-2M of KYOEISHA CHEMICAL, quaternary ammonium salt-51, 2-methacryloyloxyethyl phosphorylcholine (MPC); a small molecule or oligomer with polar groups such as carboxyl, hydroxyl, amino, and phosphate ester groups, or a small molecule or oligomer that can react with the system to form the above polar groups, which can form an effective electrostatic adsorption with the metal substrate of the silicon steel sheet, improving the wettability and adhesion of the mixture to the substrate. The curing promoter is one or more of DABCO T-12, Borchi® Kat 320, Kat 22, Kat 24, HX-3721, HX-3742, HX-3088, HX-3921HP, HX3932HP, HXA3792 of Asahi Kasei Corporation, and UR200, UR300, UR400, UR500, UR700, UR800, URAcc13, URAcc57 of the DYHARD series of AlzChem Corporation; all are curing promoters that can react at relatively low temperatures to further reduce the curing temperature. The coupling agent is one or more of A-187, A-186 of Momentive, KBM-502, KBM-503, KH-550, KH-560, KH-580, KH-540, KBM-602, KBM-603 of Shin-Etsu, and Z-6011, Z-6040 of Dow Corning; the defoaming agent is one or more of BYK-333, BYK-3500, Croda Hypermer KD-1, Allnex PC1344.

[0037] Table 1 Component and Component Weight Parts Table of Examples 1-8

[0038] The preparation method of the motor insulation coating adhesive of the above embodiments includes the following steps: S01. Add epoxy resin and toughened modified epoxy resin into a reaction vessel, heat to 80°C, with a dispersion disk at 1200 rpm and the scraping edge adjusted to 45 rpm, stir for 30 min until uniform, then cool to room temperature, and subsequently maintain the temperature at 15°C - 30°C; if the component contains a defoaming agent, add it into the reaction vessel together. S02. Add the coupling agent and pigment, with a dispersion disk at 1000 rpm and the scraping edge at 45 rpm, stir for 30 min until uniform. S03. Add inorganic filler, first open the scraping edge to 30 rpm, and after the material is completely stirred and infiltrated, open the dispersion disk to 1500 rpm and the scraping edge to 30 rpm, stir for 60 min until uniform, and perform the operation of stopping the machine to scrape the edge during this period. S04. Add a thickening agent. First, set the scraping edge speed to 30 rpm. After the materials are completely stirred and wetted, set the dispersing disk speed to 1500 rpm, the scraping edge speed to 30 rpm, and stir for 60 min until uniform. During this period, perform the operation of scraping the edge while stopping the machine. S05. Add a curing agent. Set the dispersing disk speed to 1000 rpm, the scraping edge speed to 45 rpm, turn on the vacuum, and the required vacuum degree is not lower than -0.98 Mpa. Stir for 45 min until uniform. S06. Add a curing accelerator. Set the dispersing disk speed to 1000 rpm, the scraping edge speed to 45 rpm, turn on the vacuum, and the required vacuum degree is not lower than -0.98 Mpa. Stir for 30 min until uniform. Keep the temperature at 15°C ≤ temperature ≤ 20°C to obtain the motor insulation coating glue.

[0039] If the components in the example contain unsaturated monomers and unsaturated oligomers, add part of the unsaturated monomers together with the coupling agent and pigment to the reaction vessel and stir. The remaining unsaturated monomers and unsaturated oligomers are stirred together at 90°C and a dispersing disk speed of 1000 rpm for 4 h until the materials are completely mixed and uniform, and then added to the main materials.

[0040] The unsaturated oligomers are also divided into two parts. One part is stirred together with the unsaturated monomers at 90°C and a dispersing disk speed of 1000 rpm for 4 h until the materials are completely mixed and uniform, and then added to the main materials before step S03. The other part is added to the main materials before step S05. Set the dispersing disk speed to 1000 rpm, the scraping edge speed to 45 rpm, and stir for 30 min until uniform.

[0041] Table 2 Component and component weight parts table of Comparative Examples 1-8

[0042] Referring to the preparation method in the example, replace the bisphenol A (F) epoxy resin in the comparative examples in Table 2 with the corresponding epoxy resin in Table 1 to prepare adhesives respectively.

[0043] Test example: Cure the adhesives prepared in Examples 1-3, 5-6 and Comparative Examples 1-3, 5-6 in an oven at 160°C for 1 h; cure the adhesives prepared in Examples 4, 7-8 and Comparative Examples 4, 7-8 in an oven at 160°C for 15 min + 210°C for 45 min.

[0044] 1. Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) Refer to ASTM E831-05 standard. The TA TMA thermomechanical analyzer, model Q400, is selected for the equipment. The sample size is a cylinder with a diameter of 3 mm and a height of 3 - 5 mm. The test temperature range is -60 °C to 250 °C, and the heating rate is 10 °C / min.

[0045] 2. Storage modulus Refer to ASTM E1640-04 standard. The TA DMA dynamic thermomechanical analyzer, model Q800, is selected for the equipment. The sample size is 3 mm × 5 mm × 21 mm. The single-cantilever measurement mode is selected. The test temperature range is -65 °C to 250 °C, and the heating rate is 5 °C / min.

[0046] 3. Shearing force Select the Dage 4000 thrust machine and a 3 mm × 3 mm × 1 mm stainless steel SUS304 sample block. The base material is selected as silicon steel sheet. Dip the stainless steel SUS304 sample block in glue and stick it on the silicon steel sheet, and then cure the sample according to the aforementioned curing conditions. After curing is completed, select a shearing rate of 500 um / s for the thrust test. 4. Impact strength Refer to the ISO 180:2019 test standard for the notched Izod impact strength. Sample length: 21 mm, width: 5 mm, thickness: 5 mm, nominal energy: 2.75 J.

[0047] 5. Volume resistivity Refer to ASTM D257-05 test standard. The sample size is 100 mm × 100 mm × 0.3 mm, and the test temperature is 160 °C.

[0048] 6. Curing volume shrinkage rate Cure the adhesives prepared in Examples 1 - 3, 5 - 6 and Comparative Examples 1 - 3, 5 - 6 in an oven at 160 °C for 1 h; cure the adhesives prepared in Examples 4, 7 - 8 and Comparative Examples 4, 7 - 8 in an oven at 160 °C for 15 min + 210 °C for 45 min.

[0049] The curing volume shrinkage rate is calculated using the ratio of the volume difference before and after curing of the resin system to the volume before curing, or it can also be expressed as the percentage of the ratio of the density difference before and after curing of the resin system to the density after curing. Curing volume shrinkage rate = (1 – ρbefore / ρafter) × 100%.

[0050] Using the above test methods, the glass transition temperature (Tg), coefficient of thermal expansion (CTE), storage modulus, shearing force, impact strength, curing volume shrinkage rate and other parameters of the coating adhesives in Examples 1 - 8 and the adhesives in Comparative Examples 1 - 8 are measured as shown in Table 3.

[0051] Table 3 Performance Parameter Table of the Coated Rubber in Examples 1-8 and the Adhesives in Comparative Examples 1-8

[0052] As can be seen from Table 3, the motor insulation coated rubber in Examples 1-8 has the following advantages compared with the adhesives in Comparative Examples 1-8: (1) The motor insulation coated rubber in Examples 1-8 has good insulation performance and can effectively replace the use of insulating paper. Even in a high-temperature working environment (>160 °C), the volume resistivity still remains >10 14 Ω·cm; (2) The motor insulation coated rubber in Examples 1-8 not only has a high glass transition temperature, which can effectively improve the heat resistance of the motor insulation coated rubber, but also can effectively increase the toughness and reliability of the system. The difference in impact strength between the corresponding examples and comparative examples can reach 3.2 KJ / m 2 or more.

[0053] (3) For the motor insulation coated rubber in Examples 1-8, the volume shrinkage rate and thermal expansion coefficient after material curing decrease significantly, which can effectively ensure that the toughness of the material is not deteriorated.

[0054] (4) For the motor insulation coated rubber in Examples 1-8, the shear force on silicon steel after material curing > 25 MPa, which significantly improves the adhesion compared with traditional EMC / solid electronic plastic encapsulants and can effectively ensure the sealing of the material.

[0055] The above content is only an example and explanation of the structure of the present invention. Its description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these obvious replacement forms all belong to the protection scope of the present invention.

Claims

1. A motor insulation coating adhesive, characterized in that, By weight parts, it consists of the following components and their weight parts: 15 - 30 parts of epoxy resin, 2 - 20 parts of toughened and modified epoxy resin, 0 - 12 parts of epoxy diluent, 0.1 - 18 parts of curing agent, 40 - 70 parts of inorganic filler, 0.1 - 1.5 parts of pigment, 0 - 3 parts of thickener, 0 - 10 parts of unsaturated oligomer, 0 - 15 parts of unsaturated monomer, 0 - 3 parts of adhesion promoter, 0.5 - 2 parts of curing accelerator, 0 - 1 part of coupling agent, 0 - 0.5 part of defoamer; Among them, the epoxy resin is one or more of aliphatic epoxy resin, alicyclic epoxy resin, aromatic epoxy resin, naphthalene ring epoxy resin or high-functional group epoxy resin with a functionality of 3 or 4, and the viscosity is 1000 mPa·s - 200000 mPa·s.

2. The motor insulation coating adhesive according to claim 1, characterized in that, The epoxy resin is one or more of NPEL-128, NPEL-128E, Epo Tohto ZX1059, JER 828 US, EPICLON EXA-830LVP, EPICLON EXA 830 CRP, EPICLON 850 CRP, EPICLON HP-4032D, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-6000, EPICLON HP-6000L, EPICLON HP-9500, Araldite® MY 0500, Araldite® MY 0510, Tactix® 742, Sumitomo ELM-100, Sumitomo ELM-100H, Araldite® MY 0600, Araldite® MY 720, Araldite® MY 721, Araldite® MY 725, Sumitomo ELM-434, Sumitomo ELM-434L.

3. The motor insulation coating adhesive according to claim 1, wherein, The toughened and modified epoxy resin is one or more of MX125, MX-134, MX-135, MX139, MX153, MX154, MX960, MX965 of KANEKA Corporation, Acryset BPF 307, Acryset BPA 328 of Nippon Shokubai Co., Ltd., AER9000 of Asahi Kasei Corporation, EXA-4850-150, EXA-4860 of DIC Corporation.

4. The motor insulation coating adhesive according to claim 1, characterized in that, The epoxy diluent is one or more of ED509S, Denacol EX 146, ZL-649S, Araldite DY 3601, Heloxy 65, and the viscosity is 100 mPa·s - 1000 mPa·s.

5. The motor insulation coating adhesive according to claim 1, characterized in that, The curing agent is one or more of acid anhydride type, imidazole type, dicyandiamide type (DICY), peroxide type curing agents.

6. The motor insulation coating adhesive according to claim 1, characterized in that, The inorganic filler is one or more of spherical / spherical-like silica powder, alumina, aluminum nitride, boron nitride, calcium carbonate, titanium dioxide, and talc powder.

7. The motor insulation coating adhesive according to claim 1, characterized in that, The pigment is one or more of Cabot Mogul L, Orion Lamp Black 101, Stan tone 90 EPX04, Raven 1020, and Sudan Black B.

8. The motor insulation coating adhesive according to claim 1, wherein The thickener is one or more of Cabot TS720, TS530, TS610, Wacker aerosil H15, H17, H18, H20, H30, H2000, Tokuyama aerosil MT-10, MT-10C, DM-10, DM-10C, DM-30.

9. The motor insulation coating adhesive according to claim 1, characterized in that The unsaturated oligomer is one or more of polyurethane (meth)acrylate, epoxy (meth)acrylate, aminated (meth)acrylate, multi-functional dendritic (meth)acrylate, aromatic maleimide, and cyanate ester; The unsaturated monomer is maleimide, (meth)acrylic acid (ester), or cyanate ester with an aliphatic, aromatic, naphthalene ring, isocyanurate, or isopentyl glycol structure.

10. The motor insulation coating adhesive according to claim 1, characterized in that, The adhesion promoter is one or more of P-1M, P-2M from Kyoeisha Chemical Co., Ltd., or quaternary ammonium salt-51, 2-methacryloyloxyethyl phosphorylcholine (MPC); The curing accelerator is one or more of DABCO T-12, Borchi® Kat 320, Kat 22, Kat 24, HX-3721, HX-3742, HX-3088, HX-3921HP, HX3932HP, HXA3792 from Asahi Kasei Corporation, and UR200, UR300, UR400, UR500, UR700, UR800, URAcc13, URAcc57 of the DYHARD series from AlzChem GmbH; The coupling agent is one or more of A-187, A-186 from Momentive, KBM-502, KBM-503, KH-550, KH-560, KH-580, KH-540, KBM-602, KBM-603 from Shin-Etsu, and Z-6011, Z-6040 from Dow Corning; The defoamer is one or more of BYK-333, Croda Hypermer KD-1, and Allnex PC1344.

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