ATF oil-resistant surface-expandable motor slot insulating material and preparation method thereof

Abstract

The invention discloses an ATF oil-resistant surface-expandable motor slot insulating material and a preparation method thereof, and belongs to the technical field of electrical insulating materials. The insulating material is of a three-layer sandwich structure, the middle layer is made of a polymer film, and the two edge layers are made of expandable resin. The expandable resin comprises modified epoxy resin, a curing agent, an accelerant, a foaming agent and toughened resin. The ATF oil-resistant and surface-expandable motor slot insulating material which has the functions of an insulating material and impregnating varnish is prepared by coating the expandable resin on the two surfaces of the film, and the material can be expanded and cured in a motor stator slot under a certain temperature condition so as to bond a coil and a stator slot wall and further fill a trace gap in the stator slot, so that the stability of the motor slot is improved. The impregnating varnish is used for replacing an impregnating varnish process, so that the motor stator insulation treatment process is simplified, the production cost is greatly reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrical insulation materials, and in particular to an ATF oil-resistant, surface expandable motor slot insulation material and a preparation method thereof. Background Art

[0002] In the field of motor manufacturing, ABA-type three-layer composite structure electrical soft composite materials are widely used as motor stator slot insulation materials, where A is polyester fiber non-woven fabric or polyaramid fiber paper, and B is polyester film or polyimide film. The three-layer material is made into a soft composite material by coating an adhesive on the surface of the film and curing it at high temperature.

[0003] When using soft composite materials, motor manufacturers use automatic paper machines to bend the soft composite materials into shape and embed them into the motor stator slots. Based on this, there will be slight gaps between the soft composite materials and the stator slot walls, as well as the enameled wires. In order to improve the overall insulation of the motor, motor manufacturers often use impregnation varnish to fill the gaps in the motor stator slots. Accompanied by the use of a large amount of impregnation varnish and a more complex heat treatment process, this treatment method has a high production cost and low production efficiency. In addition, with the rapid development of new energy vehicles, the shipment volume of drive motors has also soared, and the ATF oil resistance of the motor slot insulation material has also become an important indicator for evaluating its comprehensive performance. Summary of the invention

[0004] The object of the present invention is to provide an ATF oil-resistant, surface expandable motor slot insulating material and a preparation method thereof, wherein the motor slot insulating material can replace the use of impregnation varnish to solve the high cost and low efficiency problems caused by the use of impregnation varnish in motor factories.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] An ATF oil-resistant, surface expandable motor slot insulation material, which has a three-layer sandwich structure, wherein the material of the middle layer is a polymer film, and the materials of the two edge layers are both expandable resins;

[0007] The expandable resin comprises the following components in parts by weight:

[0008] 100 parts of modified epoxy resin, 5 to 10 parts of curing agent, 0.1 to 0.2 parts of accelerator, 7 to 15 parts of foaming agent and 10 to 20 parts of toughening resin.

[0009] In the present invention, by coating expandable resin on both sides of the film, an ATF oil-resistant, surface expandable motor slot insulating material having both the functions of an insulating material and an impregnating varnish can be obtained. Due to the addition of a foaming agent and the like, the material can expand and solidify in the motor stator slot under certain temperature conditions to bond the coil to the stator slot wall and further fill the tiny gaps in the stator slot. In this way, the impregnating varnish can be replaced, and no impregnating varnish process is required in the subsequent process, thereby simplifying the motor stator insulation treatment process, greatly reducing the production cost and improving the production efficiency.

[0010] Preferably, the polymer film layer is any one of a polyethylene terephthalate film, a polyethylene naphthalate film, a polyimide film, a polyphenylene sulfide film, and a polyetheretherketone film.

[0011] Preferably, the thickness of the middle layer is 50 μm to 350 μm, preferably 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 175 μm, 180 μm, 200 μm or 250 μm; the thickness of each edge layer is 40 to 60 μm.

[0012] Preferably, the modified epoxy resin is a polyurethane grafted modified epoxy resin.

[0013] Preferably, the curing agent is any one of dicyandiamide, boron trifluoride-ethylamine complex, and diaminodiphenyl sulfone.

[0014] Preferably, the accelerator is any one of 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-p-nitrophenyl-1,1-dimethylurea, N-(3,4-dichlorophenyl)-N,N′-diphenylurea, 4-phenyl-1,1-dimethylaminourea, 1-carboximidazole, 2-methylimidazole, triphenylphosphine, and tricyclohexaphosphine.

[0015] Preferably, the foaming agent is a physically expanded microsphere, such as distilled water and white carbon black as the water phase, acrylonitrile, azobisisobutyronitrile, n-pentane, methyl methacrylate, ethylene glycol dimethacrylate, etc. as the oil phase, homogenized with a high shear emulsifier under ice cooling conditions, then heated in a high-pressure closed reactor for a certain period of time, and finally filtered, centrifuged, washed, dried, and sieved to obtain the physically expanded microsphere.

[0016] Preferably, the toughening resin is a polyester resin or a polyurethane resin.

[0017] In addition, to achieve the above-mentioned purpose, the present invention also provides a method for preparing an ATF oil-resistant, surface-expandable motor slot insulating material, comprising the following steps:

[0018] S1: adding modified epoxy resin to solvent A, dissolving and stirring evenly, then adding curing agent, accelerator, foaming agent and stirring at high speed to make them dispersed evenly, to obtain mixed system A; adding toughening resin to solvent B, dissolving and stirring evenly, to obtain mixed system B; finally, mixing the mixed system A and the mixed system B and stirring at high speed to make them dispersed evenly, to obtain expandable resin dispersion;

[0019] S2 On the coating equipment, the polymer film is placed at an unwinding station, and passes through a glue tank containing the expandable resin dispersion, a coating head, and then through a segmented drying tunnel to dry out the solvent A and solvent B, and finally is rolled up at a winding station to obtain an ATF oil-resistant, surface expandable motor slot insulation material.

[0020] Wherein, when preparing the expandable resin dispersion, the weight parts of each component are as follows:

[0021] 100 parts of modified epoxy resin, 5-10 parts of curing agent, 0.1-0.2 parts of accelerator, 7-15 parts of foaming agent, 42-54 parts of solvent A, 10-20 parts of toughening resin, 40-60 parts of solvent B.

[0022] Preferably, the solvent A is any one of acetone, toluene, xylene, butanone, and dichloromethane; the solvent B is any one of acetone, toluene, butanone, and ethyl acetate.

[0023] Preferably, the length of the drying tunnel of the coating equipment is 20m; the drying tunnel temperature is: 80℃~85℃ in the first section, 90℃~95℃ in the second section, 95℃~100℃ in the third section, 100℃~105℃ in the fourth section, and 95℃~100℃ in the fifth section; the line speed is 3~5m / min.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention coats expandable resin on both sides of a film to obtain an ATF oil-resistant, surface expandable motor slot insulating material having both the functions of an insulating material and an impregnating varnish. The material can expand and solidify in the motor stator slot under certain temperature conditions to bond the coil to the stator slot wall and further fill the tiny gap in the stator slot, thereby replacing the use of an impregnating varnish process, simplifying the motor stator insulation treatment process, greatly reducing production costs and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : Schematic diagram of the structure of slot insulation material for motors resistant to ATF oil and with expandable surface;

[0027] Figure 2 : Changes in tensile shear strength of ATF oil-resistant, surface expandable motor slot insulation material after being resistant to ATF oil. DETAILED DESCRIPTION

[0028] Example 1

[0029] S1: adding 100 parts of polyurethane modified epoxy resin to 42 parts of acetone, dissolving and stirring evenly, then adding 5 parts of dicyandiamide, 0.1 parts of 3-phenyl-1,1-dimethylurea, and 8 parts of physical expansion microspheres and stirring at high speed to disperse them evenly, to obtain a mixed system A; adding 20 parts of polyester resin to 50 parts of toluene, dissolving and stirring evenly, to obtain a mixed system B; finally, mixing the mixed system A with the mixed system B and stirring at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0030] S2 On the coating equipment, the polymer film is placed in the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 80℃ for the first section, 95℃ for the second section, 100℃ for the third section, 105℃ for the fourth section, and 100℃ for the fifth section; the line speed is 5m / min. Finally, it is rolled into a roll at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0031] The motor slot insulation material is a three-layer sandwich structure. Figure 1 As shown, the material of the middle layer is a polymer film, and the materials of the two edge layers are expandable resins; the thickness of the middle layer is 100 μm; and the thickness of each edge layer is 50 μm.

[0032] Example 2

[0033] S1: adding 100 parts of polyurethane modified epoxy resin to 50 parts of toluene, dissolving and stirring evenly, then adding 5.5 parts of dicyandiamide, 0.2 parts of 3-(4-chlorophenyl)-1,1-dimethylurea, and 10 parts of physical expansion microspheres and stirring at high speed to disperse them evenly, to obtain a mixed system A; adding 18 parts of polyester resin to 45 parts of toluene, dissolving and stirring evenly, to obtain a mixed system B; finally, mixing the mixed system A with the mixed system B and stirring at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0034] S2 On the coating equipment, the polymer film is placed at the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 80°C for the first section, 92°C for the second section, 96°C for the third section, 105°C for the fourth section, and 100°C for the fifth section; the line speed is 4m / min. Finally, it is rolled up at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0035] The motor slot insulation material is a three-layer sandwich structure, the middle layer is made of polymer film, and the two edge layers are made of expandable resin; the middle layer is 100 μm thick; and each edge layer is 50 μm thick.

[0036] Example 3

[0037] S1: adding 100 parts of polyurethane modified epoxy resin to 52 parts of toluene, dissolving and stirring evenly, then adding 10 parts of boron trifluoride-ethylamine complex, 0.2 parts of 3-phenyl-1,1-dimethylurea, and 14 parts of physical expansion microspheres and stirring at high speed to disperse them evenly, to obtain a mixed system A; adding 15 parts of polyester resin to 55 parts of acetone, dissolving and stirring evenly, to obtain a mixed system B; finally, mixing the mixed system A with the mixed system B and stirring at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0038] S2 On the coating equipment, the polymer film is placed at the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 85°C for the first section, 90°C for the second section, 100°C for the third section, 105°C for the fourth section, and 100°C for the fifth section; the line speed is 5m / min. Finally, it is rolled up at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0039] The motor slot insulation material is a three-layer sandwich structure, the middle layer is made of polymer film, and the two edge layers are made of expandable resin; the middle layer is 100 μm thick; and each edge layer is 50 μm thick.

[0040] Example 4

[0041] S1: adding 100 parts of polyurethane modified epoxy resin to 42 parts of acetone, dissolving and stirring evenly, then adding 5 parts of dicyandiamide, 0.1 parts of 3-phenyl-1,1-dimethylurea, and 8 parts of physical expansion microspheres and stirring at high speed to disperse them evenly, to obtain a mixed system A; adding 20 parts of polyester resin to 50 parts of toluene, dissolving and stirring evenly, to obtain a mixed system B; finally, mixing the mixed system A with the mixed system B and stirring at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0042] S2 On the coating equipment, the polymer film is placed in the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 80℃ for the first section, 95℃ for the second section, 100℃ for the third section, 105℃ for the fourth section, and 100℃ for the fifth section; the line speed is 5m / min. Finally, it is rolled into a roll at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0043] The motor slot insulation material is a three-layer sandwich structure. Figure 1 As shown, the material of the middle layer is a polymer film, and the materials of the two edge layers are expandable resins; the thickness of the middle layer is 150 μm; and the thickness of each edge layer is 40 μm.

[0044] Comparative Example 1

[0045] S1: Add 100 parts of bisphenol A epoxy resin E-12 to 42 parts of acetone, dissolve and stir evenly, then add 3 parts of dicyandiamide, 0.1 parts of 3-phenyl-1,1-dimethylurea, and 8 parts of physical expansion microspheres and stir at high speed to disperse them evenly, to obtain a mixed system A; add 20 parts of polyester resin to 50 parts of toluene, dissolve and stir evenly, to obtain a mixed system B; finally, mix the mixed system A and the mixed system B and stir at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0046] S2 On the coating equipment, the polymer film is placed in the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 80℃ for the first section, 95℃ for the second section, 100℃ for the third section, 105℃ for the fourth section, and 100℃ for the fifth section; the line speed is 5m / min. Finally, it is rolled into a roll at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0047] The motor slot insulation material is a three-layer sandwich structure. Figure 1 As shown, the material of the middle layer is a polymer film, and the materials of the two edge layers are expandable resins; the thickness of the middle layer is 100 μm; and the thickness of each edge layer is 50 μm.

[0048] Comparative Example 2

[0049] S1: adding 100 parts of polyurethane modified epoxy resin to 42 parts of acetone, dissolving and stirring evenly, then adding 5 parts of dicyandiamide, 0.1 parts of 3-phenyl-1,1-dimethylurea, and 8 parts of physical expansion microspheres and stirring at high speed to disperse them evenly, to obtain an expandable resin dispersion;

[0050] S2 On the coating equipment, the polymer film is placed in the unwinding station, and passes through the glue tank containing the expandable resin dispersion, the coating head, and then through the segmented drying tunnel to dry out the solvent A and solvent B, wherein the coating equipment drying tunnel length is 20m; the drying tunnel temperature is: 80℃ for the first section, 95℃ for the second section, 100℃ for the third section, 105℃ for the fourth section, and 100℃ for the fifth section; the line speed is 5m / min. Finally, it is rolled into a roll at the winding station to obtain the ATF oil-resistant, surface expandable motor slot insulation material.

[0051] The motor slot insulation material is a three-layer sandwich structure. Figure 1 As shown, the material of the middle layer is a polymer film, and the materials of the two edge layers are expandable resins; the thickness of the middle layer is 100 μm; and the thickness of each edge layer is 50 μm.

[0052] It is worth mentioning that:

[0053] The physically expanded microspheres used in Examples 1-4 and Comparative Examples 1-3 are the same, and are commercially available or prepared by the following method:

[0054] The physically expanded microspheres are prepared by using distilled water and white carbon black as the aqueous phase and any one or more of acrylonitrile, azobisisobutyronitrile, n-pentane, methyl methacrylate, ethylene glycol dimethacrylate, etc. as the oil phase, homogenizing with a high shear emulsifier under ice cooling conditions, then heating in a high-pressure closed reactor for a certain period of time, and finally filtering, centrifuging, washing, drying, and sieving.

[0055] The polyurethane modified epoxy resins in Examples 1-4 and Comparative Example 2 are purchased commercially, or prepared by the following method: polyether diol PPG and TDI are used to prepare a polyether polyurethane prepolymer under the action of a catalyst, and then reacted with bisphenol-A epoxy resin E-51 to prepare the prepolymer.

[0056] Experimental example

[0057] 1. Treat ATF oil-resistant, surface expandable motor slot insulation material under certain temperature and time conditions, and test its thickness change. The results are shown in Table 1.

[0058] Table 1:

[0059]

[0060]

[0061] It can be seen from Table 1 that the slot insulating materials prepared in Examples 1-4 have good expansion ratios and are adjustable; Comparative Example 1 does not use the polyurethane modified epoxy resin of the present invention, and Comparative Example 2 does not add polyester resin to the raw materials. The expansion ratios of the insulating materials prepared by the two are worse than that of the present invention.

[0062] 2. Test on the change of tensile shear strength of ATF oil-resistant and surface expandable motor slot insulation materials after ATF oil resistance. The results are as follows Figure 2 shown.

[0063] Test method description:

[0064] 2.1 Sample processing: Cut the sample into several 10mm*10mm blocks, place them between the overlapping parts of two aluminum sheets, and fix them with a clamp. Treat the aluminum sheets according to the processing conditions in Table 1, and cool them for use after completion; clean the stainless steel tank, put the cooled aluminum sheets in, add a certain amount of ATF oil to completely immerse the aluminum sheets, seal the stainless steel tank and install a breathable valve, and finally put the stainless steel tank into a high and low temperature wet heat box. The temperature setting conditions are: 155℃, 40h as the high temperature section processing conditions, -45℃, 8h as the low temperature section processing conditions, and one high temperature section plus one low temperature section as one cycle, and the conversion time between high and low temperatures is less than 1h. Open the tank and take samples at the end of the 2nd, 4th, and 8th operation cycles.

[0065] 2.2 Tensile shear test: Use a tensile testing machine to test the tensile shear strength according to standard JB / T10942, and take the median value as the test result.

[0066] pass Figure 2 It can be seen that the motor slot insulation material made by using polyurethane modified epoxy resin and polyester resin has good ATF oil resistance.

Claims

1. An ATF oil-resistant, surface expandable motor slot insulating material, characterized in that: It is a three-layer sandwich structure, the middle layer is made of polymer film, and the two edge layers are made of expandable resin; The expandable resin comprises the following components in parts by weight: 100 parts of modified epoxy resin, 5 to 10 parts of curing agent, 0.1 to 0.2 parts of accelerator, 7 to 15 parts of foaming agent and 10 to 20 parts of toughening resin.

2. The ATF oil-resistant, surface expandable motor slot insulating material according to claim 1, characterized in that: The polymer film layer is any one of polyethylene terephthalate film, polyethylene naphthalate film, polyimide film, polyphenylene sulfide film and polyetheretherketone film.

3. The ATF oil-resistant, surface expandable motor slot insulating material according to claim 1, characterized in that: The thickness of the middle layer is 50 μm to 350 μm; the thickness of each edge layer is 40 to 60 μm.

4. The ATF oil-resistant, surface expandable motor slot insulating material according to claim 1, characterized in that: The modified epoxy resin is polyurethane modified epoxy resin.

5. The ATF oil-resistant, surface expandable motor slot insulating material according to claim 1, characterized in that: The curing agent is any one of dicyandiamide, boron trifluoride-ethylamine complex and diaminodiphenyl sulfone.

6. The ATF oil-resistant, surface expandable motor slot insulating material according to claim 1, characterized in that: The foaming agent is physically expanded microspheres.

7. The ATF oil-resistant, surface-expandable motor slot insulating material according to claim 1, wherein the toughening resin is a polyester resin or a polyurethane resin.

8. The method for preparing an ATF oil-resistant, surface expandable motor slot insulating material according to any one of claims 1 to 7, characterized in that: The steps include: S1: adding modified epoxy resin to solvent A, dissolving and stirring evenly, then adding curing agent, accelerator, foaming agent and stirring at high speed to make them dispersed evenly, to obtain mixed system A; adding toughening resin to solvent B, dissolving and stirring evenly, to obtain mixed system B; finally, mixing the mixed system A and the mixed system B and stirring at high speed to make them dispersed evenly, to obtain expandable resin dispersion; S2 On the coating equipment, the polymer film is placed at an unwinding station, and passes through a glue tank containing the expandable resin dispersion, a coating head, and then through a segmented drying tunnel to dry out the solvent A and solvent B, and finally is rolled up at a winding station to obtain an ATF oil-resistant, surface expandable motor slot insulation material.

9. The method for preparing an ATF oil-resistant, surface expandable motor slot insulating material according to claim 8, characterized in that: The solvent A is any one of acetone, toluene, xylene, butanone, and dichloromethane; the solvent B is any one of acetone, toluene, butanone, and ethyl acetate.

10. The method for preparing an ATF oil-resistant, surface expandable motor slot insulating material according to claim 8, characterized in that: The length of the drying tunnel of the coating equipment is 20m; the temperature of the drying tunnel is: 80℃~85℃ in the first section, 90℃~95℃ in the second section, 95℃~100℃ in the third section, 100℃~105℃ in the fourth section, and 95℃~100℃ in the fifth section; the line speed is 3~5m / min.

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