Two-component pouring resin and pouring method of stator core

Abstract

The invention belongs to the field of pouring resin, and particularly relates to bi-component pouring resin and a pouring method of a stator iron core. The double-component casting resin provided by the invention comprises a component A and a component B, wherein the component A comprises the following components: polyethylene glycol modified bisphenol A epoxy resin, polyether hyperbranched epoxy resin, an epoxy silane coupling agent KH-560, an epoxy silane coupling agent, first silica powder and second silica powder; the component B is prepared from the following components: methyl tetrahydrophthalic anhydride, polysebacic anhydride, a boron trichloride-n-octyl dimethyl amine compound, an epoxy group silane coupling agent KH-560, an epoxy group silane coupling agent A-187, first silicon micro powder and second silicon micro powder. The double-component casting resin provided by the invention is low in initial viscosity and long in gelation time, the operability of the casting process can be effectively improved, gaps are prevented from being formed, and a casting body formed after curing has relatively good glass transition temperature, cracking resistance and mechanical strength.

Description

Technical Field

[0001] The present invention belongs to the field of casting resins, and particularly relates to a two-component casting resin and a casting method for a stator core. Background Art

[0002] The epoxy resin casting process technology is widely used in the fields of precision electronics and high-voltage electrical component manufacturing, and plays a significant role in aspects such as product sealing, insulation, corrosion prevention, wind and sand protection, and stable appearance dimensions. In high-speed maglev system equipment, core electrical and electromagnetic components such as long stators, magnetic poles, sensors, and positioning marker plates also adopt the epoxy resin casting technology, providing guarantee for the full-life service of products such as long stators and magnetic poles.

[0003] The stator core in a long stator linear motor is a core functional component that generates a magnetic field in the maglev train running track and supports the suspension, guidance, and braking of the train. Among them, the stator core is laid on the maglev track and exposed to air and rainwater. If rust occurs, it will cause induced eddy currents, resulting in heating, local melting, short circuit, and affecting the driving safety. Epoxy resin casting is usually used as a process method to prevent rust of long stator components, which can isolate air and water vapor, maintain the fixed shape of the stator core, and improve the service life of the stator core. However, during the manufacturing process of the epoxy resin casting body, quality problems such as bubbles, gaps, unqualified glass transition temperature, and cracking are extremely likely to occur, greatly affecting the service life of the stator core. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a two-component casting resin and a casting method for a stator core. The two-component casting resin provided by the present invention has a low initial viscosity and a long gel time, which can effectively improve the operability of the casting process, avoid the formation of gaps, and the casting body formed after curing has good glass transition temperature, anti-cracking performance, and mechanical strength; the casting method provided by the present invention preferably adopts a vacuum automatic pressure gel process, which can further improve the casting quality of the product and reduce the occurrence rate of bubbles.

[0005] The present invention provides a two-component casting resin, comprising a component A and a component B. The components of the component A include: 15-25 wt% of polyethylene glycol modified bisphenol A epoxy resin, 10-20 wt% of polyether hyperbranched epoxy resin, 0.5-3 wt% of epoxy group silane coupling agent KH-560, 0.1-1 wt% of epoxy group silane coupling agent A-187, 25-35 wt% of the first silica powder, and 30-40 wt% of the second silica powder; the components of the component B include: 15-20 wt% of methyltetrahydrophthalic anhydride, 10-15 wt% of polysebacic anhydride, 2-10 wt% of boron trichloride-n-octyldimethylamine complex, 0.5-3 wt% of epoxy group silane coupling agent KH-560, 0.1-1 wt% of epoxy group silane coupling agent A-187, 25-35 wt% of the first silica powder, and 35-45 wt% of the second silica powder; the D 50 particle size of the first silica powder is 1-5 μm, and the D 50 particle size of the second silica powder is 15-20 μm; the mass ratio of the component A to the component B is 1:(0.5-1).

[0006] Preferably, the number average molecular weight of the polyethylene glycol modified bisphenol A epoxy resin is ≤700, and the epoxy equivalent is 4.7-5 Eq / kg.

[0007] Preferably, the number average molecular weight of the polyether hyperbranched epoxy resin is ≤10,000, and the epoxy equivalent is 3.5-4 Eq / kg.

[0008] Preferably, the D 50 particle size of the first silica powder is 2 μm; the D 50 particle size of the second silica powder is 17 μm.

[0009] Preferably, the components of the component A include: 20 wt% of polyethylene glycol modified bisphenol A epoxy resin, 15 wt% of polyether hyperbranched epoxy resin, 1.5 wt% of epoxy group silane coupling agent KH-560, 0.5 wt% of epoxy group silane coupling agent A-187, 30 wt% of the first silica powder, and 33 wt% of the second silica powder.

[0010] Preferably, the components of the component B include: 18 wt% of methyltetrahydrophthalic anhydride, 12 wt% of polysebacic anhydride, 5 wt% of boron trichloride-n-octyldimethylamine complex, 1.5 wt% of epoxy group silane coupling agent KH-560, 0.5 wt% of epoxy group silane coupling agent A-187, 30 wt% of the first silica powder, and 38 wt% of the second silica powder.

[0011] Preferably, the mass ratio of the component A to the component B is 1:0.75.

[0012] The present invention provides a casting method for a stator core, comprising the following steps:

[0013] Mix the component A and component B of the two-component casting resin described in the above technical solution, and then cast the stator core to obtain a stator casting.

[0014] Preferably, the process adopted for casting is the vacuum automatic pressure gel process.

[0015] Preferably, it further comprises the following steps:

[0016] Perform external inspection and internal inspection on the stator casting; wherein, the items for external inspection include one or more of casting layer thickness inspection, appearance state inspection of the casting, and dimension inspection of the casting; the items for internal inspection include using X-ray to inspect whether there are defects inside the casting.

[0017] Compared with the prior art, the present invention provides a casting method for a two-component casting resin and a stator core. The two-component casting resin provided by the present invention comprises component A and component B. The components of component A include: polyethylene glycol modified bisphenol A epoxy resin 15-25 wt%, polyether hyperbranched epoxy resin 10-20 wt%, epoxy group silane coupling agent KH-560 0.5-3 wt%, epoxy group silane coupling agent A-187 0.1-1 wt%, first silicon micropowder 25-35 wt%, second silicon micropowder 30-40 wt%; the components of component B include: methyltetrahydrophthalic anhydride 15-20 wt%, polysebacic anhydride 10-15 wt%, boron trichloride-n-octyldimethylamine complex 2-10 wt%, epoxy group silane coupling agent KH-560 0.5-3 wt%, epoxy group silane coupling agent A-187 0.1-1 wt%, first silicon micropowder 25-35 wt%, second silicon micropowder 35-45 wt%; the D 50 particle size of the first silicon micropowder is 1-5 μm, and the D 50The particle size is 15 to 20 μm; the mass ratio of the component A and the component B is 1:(0.5 to 1). Through the optimized design of the composition of the casting resin, the present invention reduces the initial viscosity of the casting resin and prolongs the gel time of the casting resin, thereby effectively improving the operability of the casting process and avoiding the formation of gaps; moreover, the casting body formed after the casting resin is cured has both a high glass transition temperature, anti-cracking performance and mechanical strength. Applying it to the casting of the stator core can effectively ensure the casting quality of the stator core and improve its service life. The stator core casting method provided by the present invention includes the following steps: mixing the component A and the component B of the two-component casting resin described in the above technical solution and then casting the stator core to obtain a stator casting. The stator core casting method provided by the present invention preferably adopts a vacuum automatic pressure gel process, which can further improve the casting quality of the product, reduce the occurrence rate of bubbles, and at the same time reduce the shrinkage of the resin material. Detailed Embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] The present invention provides a two-component casting resin, including component A and component B. The components of component A include: 15 to 25 wt% of polyethylene glycol modified bisphenol A epoxy resin, 10 to 20 wt% of polyether hyperbranched epoxy resin, 0.5 to 3 wt% of epoxy group silane coupling agent KH-560, 0.1 to 1 wt% of epoxy group silane coupling agent A-187, 25 to 35 wt% of the first silica powder, and 30 to 40 wt% of the second silica powder; the components of component B include: 15 to 20 wt% of methyltetrahydrophthalic anhydride, 10 to 15 wt% of polysebacic anhydride, 2 to 10 wt% of boron trichloride-n-octyldimethylamine complex, 0.5 to 3 wt% of epoxy group silane coupling agent KH-560, 0.1 to 1 wt% of epoxy group silane coupling agent A-187, 25 to 35 wt% of the first silica powder, and 35 to 45 wt% of the second silica powder; the mass ratio of component A and component B is 1:(0.5 to 1).

[0020] In the two-component casting resin provided by the present invention, after the component A and the component B are mixed, a polymerization reaction occurs at a certain temperature, and the shrinkage rate after the reaction is low, which is suitable for casting products with a relatively large volume such as a long stator linear motor (1030×185×129 mm). The operable time is 10 to 15 minutes under the reaction condition of 140 °C, and it can quickly cover all the casting surfaces in the long stator casting mold with a relatively low viscosity.

[0021] In the two-component casting resin provided by the present invention, Component A mainly consists of polyethylene glycol-modified bisphenol A epoxy resin and polyether-based hyperbranched epoxy resin, and in the presence of epoxy-based silane coupling agents KH-560 and A-187, the first silica powder and the second silica powder are mixed; Component B mainly consists of methyltetrahydrophthalic anhydride and polysebacic anhydride, and a certain amount of boron trichloride-n-octyldimethylamine complex is added to the anhydride, and in the presence of epoxy-based silane coupling agents KH-560 and A-187, the first silica powder and the second silica powder are mixed.

[0022] In the two-component casting resin provided by the present invention, the D of the first silica powder 50 particle size is 1-5 μm, preferably 2 μm; the D of the second silica powder 50 particle size is 15-20 μm, preferably 17 μm. In the present invention, the silica powder has a small particle size and has good dispersibility under the action of epoxy-based silane coupling agents KH-560 and A-187, which can significantly reduce the internal stress generated by resin shrinkage and reduce the shrinkage rate after resin reaction.

[0023] In the two-component casting resin provided by the present invention, the polyethylene glycol-modified bisphenol A epoxy resin in Component A has good toughness, its number average molecular weight is preferably ≤700, and the epoxy equivalent is preferably 4.7-5 Eq / kg. The polyether-based hyperbranched epoxy resin in Component A is prepared by reacting hydroquinone and polyglycidyl ether under the catalysis of tetrabutylammonium hydroxide, and the number average molecular weight is preferably ≤10,000, and the epoxy equivalent is preferably 3.5-4.0 Eq / kg, which can improve the strength of the product.

[0024] In the two-component casting resin provided by the present invention, the methyltetrahydrophthalic anhydride and polysebacic anhydride in Component B act synergistically to improve the impact resistance, anti-cracking performance and heat and cold resistance of the product. The boron trichloride-n-octyldimethylamine complex in Component B is used as a catalyst for the reaction of Components A and B, which can improve the reaction activity of the resin.

[0025] In the two-component casting resin provided by the present invention, the components of Component A preferably include: 20 wt% of polyethylene glycol-modified bisphenol A epoxy resin, 15 wt% of polyether-based hyperbranched epoxy resin, 1.5 wt% of epoxy-based silane coupling agent KH-560, 0.5 wt% of epoxy-based silane coupling agent A-187, 30 wt% of the first silica powder, and 33 wt% of the second silica powder.

[0026] In the two-component casting resin provided by the present invention, the components of the B component include: methyltetrahydrophthalic anhydride 18 wt%, polysebacic anhydride 12 wt%, boron trichloride-n-octyldimethylamine complex 5 wt%, epoxy group silane coupling agent KH-560 1.5 wt%, epoxy group silane coupling agent A-187 0.5 wt%, first silicon micropowder 30 wt%, and second silicon micropowder 38 wt%.

[0027] In the two-component casting resin provided by the present invention, the mass ratio of the A component to the B component is preferably 1:0.75.

[0028] The present invention also provides a casting method for a stator core, comprising the following steps:

[0029] Mix the A component and the B component of the two-component casting resin described in the above technical solution and then cast the stator core to obtain a stator casting.

[0030] In the casting method provided by the present invention, the process adopted for casting is preferably the vacuum automatic pressure gel (VPG) process; the casting equipment adopted for casting is preferably a mold clamping machine driven by a servo hydraulic motor, and the mold clamping machine preferably has functions such as automatic or manual mold opening and closing, mold heating, mold vacuum pumping and vacuum breaking, equipment tilting for bubble removal, automatic casting, and mold hoisting.

[0031] In the casting method provided by the present invention, the specific process of casting using the vacuum automatic pressure gel process in the mold clamping machine preferably includes: First, the mold and the stator core are preheated in the vacuum chamber of the mold clamping machine. When the preheating temperature reaches the requirement, the vacuum chamber is evacuated; after the A and B components are mixed in proportion, they are vacuum stirred at a suitable temperature until there are no bubbles; the stator core casting is started, and the resin is automatically injected into the mold in a vacuum state. After the injection is completed, the resin is pressurized, and at the same time, the mold clamping machine is tilted to facilitate bubble removal. After gelling for more than half an hour, the mold is opened; after the mold is opened, the stator core is transferred to a curing furnace for curing, and then cooled with the furnace. Among them, the temperature of the preheating is preferably 120-150°C, more preferably 130-140°C; the temperature of the vacuum stirring is preferably 40-80°C, more preferably 60°C; from the preheating of the mold to the end of gelling, the temperature at the material injection port at the bottom of the mold is preferably 8-15°C higher than the temperature at the material discharge port at the upper part of the mold, more preferably 10°C higher, to facilitate the gelling and flow of the resin; the temperature of the curing is preferably 120-150°C, more preferably 135°C; the time of the curing is preferably 5-10 h, more preferably 8 h.

[0032] In the casting method provided by the present invention, after casting is completed, it is preferable to detect the obtained stator casting. In the present invention, the detection preferably includes two parts: internal detection and external detection; among them, the items of the external detection include one or more of the detection of the casting layer thickness, the detection of the appearance state of the casting, and the detection of the dimensions of the casting; the items of the internal detection include using X-ray to detect whether there are defects such as air bubbles inside the casting.

[0033] In the casting method provided by the present invention, in the external detection, the detection of the casting layer thickness is preferably carried out by a paint film thickness gauge, and the measuring range of the paint film thickness gauge is ≤3 mm; the detection of the appearance state of the casting is preferably carried out by visual inspection and assisted by a magnifying glass to observe whether there are air bubbles and cracking defects on the surface; the detection of the dimensions of the casting is preferably carried out by three-dimensional coordinates.

[0034] For the sake of clarity, the following will be described in detail through the following examples and comparative examples.

[0035] Example 1

[0036] A two-component casting resin includes component A and component B, and the mass ratio of the two is 100:75. The specific component compositions of component A and component B are shown in Table 1 and Table 2 for details.

[0037] Table 1 Component Table of Component A of the Casting Resin

[0038]

[0039] Table 2 Component Table of Component B of the Casting Resin

[0040]

[0041] Comparative Example 1

[0042] A casting resin, whose components include CY5995 epoxy resin, HY227 curing agent, and FW 12EST silica powder, and the mass ratio of CY5995, HY227, and FW 12EST is 100:100:300.

[0043] Performance Comparison between Example 1 and Comparative Example 1

[0044] The casting resin provided in Example 1 and the casting resin provided in Comparative Example 1 were subjected to performance detection, and the detection results are shown in Table 3.

[0045] Table 3 Performance Detection Results of the Casting Resins of Example 1 and Comparative Example 1

[0046]

[0047] Example 2

[0048] A casting method for a long stator core. The specific process of casting in a mold clamping machine using the vacuum automatic pressure gel process includes: First, the mold and the long stator core (1030×185×129mm) are preheated to 130 - 140°C in the vacuum chamber of the mold clamping machine. When the preheating temperature reaches the requirement, the vacuum chamber is evacuated to less than 10 mbar; After mixing the A and B components of the casting resin in Example 1 in proportion, they are vacuum stirred at 60°C until there are no bubbles; Start the casting of the stator core. The resin is automatically injected into the mold in a vacuum state. After injection, the resin is pressurized to 1.5 bar, and at the same time, the mold clamping machine is tilted to facilitate the removal of bubbles. After gelling for more than half an hour, the mold is opened; After opening the mold, the long stator core is transferred to a curing furnace for curing. It is cured at 135°C for 8 hours and then cooled with the furnace. Among them, from the preheating of the mold to the end of gelling, the temperature at the material injection port below the mold is set 10°C higher than the temperature at the material discharge port above the mold to facilitate the gelling and flow of the resin.

[0049] The long stator castings prepared by the above method are visually observed and assisted by a magnifying glass, and there are no bubble and cracking defects on the surface; The X-ray is used to inspect the inside of the long stator castings, and there are no defects such as bubbles.

[0050] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A two-component casting resin, characterized in that: The invention comprises a component A and a component B, wherein the components of the component A include: 15-25wt% of polyethylene glycol-modified bisphenol A epoxy resin, 10-20wt% of polyether hyperbranched epoxy resin, 0.5-3wt% of epoxy silane coupling agent KH-560, 0.1-1wt% of epoxy silane coupling agent A-187, 25-35wt% of first silicon micropowder, and 30-40wt% of second silicon micropowder; the components of the component B include: 15-20wt% of methyltetrahydrophthalic anhydride, 10-15wt% of polysebacic anhydride, 2-10wt% of boron trichloride-n-octyldimethylamine complex, 0.5-3wt% of epoxy silane coupling agent KH-560, 0.1-1wt% of epoxy silane coupling agent A-187, 25-35wt% of first silicon micropowder, and 35-45wt% of second silicon micropowder; the components of the component D of the first silicon micropowder include: 15-20wt% of methyltetrahydrophthalic anhydride, 10-15wt% of polysebacic anhydride, 2-10wt% of boron trichloride-n-octyldimethylamine complex, 50 The particle size is 1 to 5 μm, and the D 50 The particle size is 15 to 20 μm; the mass ratio of component A to component B is 1:(0.5 to 1).

2. The two-component casting resin according to claim 1, characterized in that The number average molecular weight of the polyethylene glycol-modified bisphenol A epoxy resin is ≤700, and the epoxy equivalent is 4.7 to 5 Eq / kg.

3. The two-component casting resin according to claim 1, characterized in that The number average molecular weight of the polyether hyperbranched epoxy resin is ≤10000, and the epoxy equivalent is 3.5 to 4 Eq / kg.

4. The two-component casting resin according to claim 1, characterized in that The D of the first silicon powder 50 The particle size is 2 μm; the D 50 The particle size is 17μm.

5. The two-component casting resin according to claim 1, characterized in that The components of the component A include: 20wt% of polyethylene glycol-modified bisphenol A epoxy resin, 15wt% of polyether hyperbranched epoxy resin, 1.5wt% of epoxy silane coupling agent KH-560, 0.5wt% of epoxy silane coupling agent A-187, 30wt% of first silicon micropowder, and 33wt% of second silicon micropowder.

6. The two-component casting resin according to claim 1, characterized in that The components of the second component include: 18wt% of methyltetrahydrophthalic anhydride, 12wt% of polysebacic anhydride, 5wt% of boron trichloride-n-octyldimethylamine complex, 1.5wt% of epoxysilane coupling agent KH-560, 0.5wt% of epoxysilane coupling agent A-187, 30wt% of first silicon micropowder, and 38wt% of second silicon micropowder.

7. The two-component casting resin according to claim 1, characterized in that The mass ratio of component A to component B is 1:0.

75.

8. A casting method for a stator core, characterized in that: The following steps are involved: The component A and the component B of the two-component casting resin according to any one of claims 1 to 7 are mixed and then cast on a stator core to obtain a stator casting.

9. The pouring method according to claim 8, characterized in that: The pouring process is a vacuum automatic pressure gel process.

10. The pouring method according to claim 8, characterized in that: The following steps are also included: The stator casting is subjected to external and internal inspections; wherein the external inspection items include one or more of the casting layer thickness inspection, casting appearance state inspection and casting size inspection; the internal inspection items include using X-rays to inspect whether there are defects inside the casting.

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