A method for preparing an organosilicon encapsulant and a mixing apparatus for its preparation.

Abstract

This invention relates to the field of encapsulant preparation, specifically disclosing a method for preparing an organosilicon encapsulant, comprising the following raw materials: 80-100 parts of vinyl-terminated polydimethylsiloxane, 5-15 parts of epoxy-modified hydrogen-containing mixed cyclic polymer, 10-20 parts of fumed silica, 10-25 parts of high-reinforcing filler MQ resin, 3-8 parts of crosslinking agent, 1.5-3 parts of adhesion promoter, 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of inhibitor, 1-3 parts of structure control agent, 5-15 parts of plasticizer, 1-2 parts of dehydrating agent, and 0.5-1.5 parts of antioxidant. During the encapsulant preparation process, epoxy-modified hydrogen-containing mixed cyclic polymer is added. Its cyclic structure provides high-density crosslinking points, and the three-dimensional spherical structure of MQ resin forms a "micro-region reinforcing phase" in the crosslinking network. Under the combined effect of these two components, the tear resistance of the material can be increased to 2-3 times that of traditional formulations.

Description

Technical Field

[0001] This invention relates to the field of encapsulant preparation, and more specifically to a method for preparing an organosilicon encapsulant and a mixing apparatus for its preparation. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the safety and reliability of the power battery pack, as the "heart" of the vehicle, has become a focus of industry attention. The battery pack contains a large number of cells, high-voltage connectors, and precision electronic components. It needs to be kept absolutely sealed under complex driving conditions to prevent the intrusion of external impurities such as moisture and dust, while resisting multiple stresses such as vibration, impact, and temperature changes.

[0003] As the core material for sealing the battery pack structure, sealant plays multiple key roles: first, it acts as a physical barrier to prevent the infiltration of external moisture (as required by IP67 protection level) and corrosive media; second, it strengthens the structure by improving the overall mechanical strength of the battery pack through bonding; and third, it acts as a stress buffer to absorb and disperse vibration and shock energy, protecting the internal cells.

[0004] Currently, sealants used in new energy vehicle battery packs mainly fall into three technical categories: 1. Silicone sealant: Due to its excellent high and low temperature resistance (-60-260℃), weather resistance, and electrical insulation, it has become the mainstream choice for battery pack sealing. The elastomer formed after the silicone material is cured has good shockproof and impact-resistant properties, which can effectively protect the delicate internal structure of the battery.

[0005] 2. Polyurethane sealant: It has high bonding strength and is suitable for structural bonding and vibration environments, but it is sensitive to humid heat aging, and its long-term reliability is a challenge.

[0006] 3. Epoxy resin sealant: It has high bonding strength and good chemical corrosion resistance, but after curing, it has high hardness and brittleness, making it difficult to adapt to the thermal expansion and contraction deformation of the battery pack.

[0007] Silicone sealants are one of the most widely used sealants in battery packs due to their high performance. However, they also have disadvantages, such as lower adhesive strength compared to epoxy and polyurethane sealants, and they are more prone to tearing due to high temperatures. Summary of the Invention

[0008] The present invention addresses the technical problems mentioned in the background section and proposes the following technical solutions: A method for preparing an organosilicon encapsulant includes the following raw materials: 80-100 parts of vinyl-terminated polydimethylsiloxane, 5-15 parts of epoxy-modified hydrogen-containing mixed cyclic compound, 10-20 parts of fumed silica, 10-25 parts of high-reinforcing filler MQ resin, 3-8 parts of crosslinking agent, 1.5-3 parts of adhesion promoter, 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of inhibitor, 1-3 parts of structure control agent, 5-15 parts of plasticizer, 1-2 parts of dehydrating agent, and 0.5-1.5 parts of antioxidant. The specific preparation steps are as follows: S1. Raw material pretreatment: Confirm the dryness of the raw materials. If necessary, drying treatment is required. For auxiliary materials such as fumed silica and high reinforcing filler MQ resin, place them in an oven at 120-150℃ for 4-6 hours to remove excess moisture, and then seal and cool. S2. Add 80-100 parts of vinyl-terminated polydimethylsiloxane, 5-15 parts of epoxy-modified hydrogen-containing mixed ring, 5-15 parts of plasticizer, and 1-3 parts of structure control agent into a mixing device and mix them. S3. During the stirring process, add 10-20 parts of fumed silica and 10-25 parts of MQ resin, which are high-reinforcing filler. S4. Increase the working temperature in the stirring device to 120-150℃, and continuously draw a vacuum inside the stirring device during the stirring process. S5. After vacuum dehydration is completed, stop heating and continue stirring until the temperature inside the mixing device is below 40°C. At this point, air is introduced to obtain a paste-like base material. S6. Seal the stirring device and fill it with nitrogen. Under the protection of nitrogen, add 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of inhibitor, 1.5-3 parts of adhesion promoter and 1-2 parts of dehydrating agent mixture, and 0.5-1.5 parts of antioxidant in sequence. After the additives are added, stir for 30-60 minutes and control the temperature between 25-35℃. S7. After stirring, vacuum degassing is performed. After degassing, the finished product is taken out and filtered through a filter to remove agglomerates. Finally, it is filled and stored.

[0009] Preferably, the crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.5%-1.2%.

[0010] Preferably, the adhesion promoter is an α-aminosilane coupling agent or an epoxysilane complex.

[0011] Preferably, the inhibitor is ethynylcyclohexanol.

[0012] Preferably, the structuring control agent is diphenylsilanediol.

[0013] Preferably, the interval between adding 10-20 parts of fumed silica and 10-25 parts of MQ resin with high reinforcing filler is no less than 10 minutes.

[0014] A mixing device for preparing silicone encapsulant, the mixing device being used in the mixing operation mentioned in any one or more preparation methods of claims 1-6, the mixing device comprising: a vessel body 1, a stirring structure 2, a vacuuming structure 3, a feeding structure 4, and a temperature control structure 5, the stirring device 2 comprising a stirring rod 2-1 and a stirring motor 2-2, the vacuuming structure 3 comprising a vacuum machine 3-1 and a vacuum tube 3-2, one end of the vacuum tube 3-2 being connected to the interior of the vessel body 1, and the other end of the vacuum tube 3-2 being connected to the vacuum machine 3-1, the feeding structure 4 comprising a feeding pipe 4-1, a solenoid valve 4-2, and a sealing cap 4-3, the feeding pipe 4-1 being fixed to the vessel body 1, the bottom of the feeding pipe 4-1 being connected to the interior of the vessel body 1, the solenoid valve 4-2 being installed at the bottom of the feeding pipe 4-1, and the sealing cap 4-3 being installed at the top of the feeding pipe 4-1, the temperature control structure 5 comprising a heating copper pipe 5-1 and a heat dissipation port 5-2.

[0015] The beneficial effects of this invention are: 1. By adding epoxy-modified hydrogen-containing mixed cyclic polymer and MQ resin to the production formula of silicone encapsulant, the cyclic structure in the epoxy-modified hydrogen-containing mixed cyclic polymer provides high-density cross-linking points, and the three-dimensional spherical structure of MQ resin forms a "micro-region reinforcing phase" in the cross-linking network. Under the combined effect of the two, the tear strength of the material can be increased to 2 to 3 times that of the traditional formula, and the addition of MQ value can also improve the adhesion performance of the encapsulant.

[0016] 2. The mixing device in this invention integrates a stirring structure, a vacuuming structure, a feeding structure, and a temperature control structure, which can fulfill the requirements for the mixing device in the preparation method of organosilicon encapsulant in this invention. It can complete the requirements of stirring, vacuum dehydration, feeding in a vacuum environment, and temperature control without changing the device, saving material transfer costs and avoiding accidents during the transfer process.

[0017] 3. When adding fumed silica and high-reinforcing filler MQ resin to the raw materials, the interval should be no less than 10 minutes. This interval can prevent the filler from boiling over and ensure uniform dispersion. Attached Figure Description

[0018] Figure 1 This is a flowchart of the preparation method of the present invention; Figure 2 This is a schematic diagram of the mixing device structure in this invention; Figure 3 This is a cross-sectional view of the mixing device in this invention.

[0019] In the diagram: 1. Kettle body; 2. Stirring structure; 2-1. Stirring rod; 2-2. Stirring motor; 3. Vacuuming structure; 3-1. Vacuum machine; 3-2. Vacuum tube; 4. Feeding structure; 4-1. Feeding pipe; 4-2. Solenoid valve; 4-3. Sealing cover; 5. Temperature control structure; 5-1. Heating copper tube; 5-2. Heat dissipation port. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] In the description of this invention, it should be understood that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The connection methods described by the terms "fixed connection" and "fixed arrangement" include, but are not limited to, "welding," "riveting," "adhesion," and "threaded connection." The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The terms “upper,” “lower,” “front,” “back,” “left,” “right,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0022] Example 1 A method for preparing an organosilicon encapsulant, comprising the following raw materials in the following mass ratio: 90 parts of vinyl-terminated polydimethylsiloxane, 15 parts of epoxy-modified hydrogen-containing mixed rings, 15 parts of fumed silica, 25 parts of MQ resin, 4 parts of crosslinking agent, 2.5 parts of adhesion promoter, 0.03 parts of platinum catalyst, 0.2 parts of inhibitor, 1 part of structure control agent, 8 parts of plasticizer, 1 part of dehydrating agent, and 0.5 parts of antioxidant. The cyclic structure in the epoxy-modified hydrogen-containing mixed rings provides high-density crosslinking points, and the three-dimensional spherical structure of MQ resin forms a "micro-region reinforcing phase" in the crosslinking network. Under the combined effect of the two, the tear resistance of the material can be increased to 2 to 3 times that of the traditional formulation.

[0023] To ensure the rapid and safe preparation of the anti-collision corner, a mixing device specifically designed for this preparation method is used. This mixing device includes a vessel body 1, a stirring structure 2, a vacuuming structure 3, a feeding structure 4, and a temperature control structure 5. The stirring device 2 includes a stirring rod 2-1 and a stirring motor 2-2. The vacuuming structure 3 includes a vacuum pump 3-1 and a vacuum tube 3-2. One end of the vacuum tube 3-2 is connected to the interior of the vessel body 1, and the other end is connected to the vacuum pump 3-1. The feeding structure 4 includes a feeding pipe 4-1, a solenoid valve 4-2, and a sealing cap 4-3. The feeding pipe 4-1 is fixed to the vessel body 1, and its bottom is connected to the interior of the vessel body 1. The solenoid valve 4-2 is installed at the bottom of the feeding pipe 4-1, and the sealing cap 4-3 is installed at the top of the feeding pipe 4-1. The temperature control structure 5 includes a heating copper pipe 5-1 and a heat dissipation port 5-2.

[0024] In actual operation: S1. Raw material pretreatment: Confirm the dryness of the raw materials. If necessary, drying treatment is required. For auxiliary materials such as fumed silica and high reinforcing filler MQ resin, place them in an oven at 150°C for 4 hours to remove excess moisture, and then seal and cool. S2. Add 90 parts of vinyl-terminated polydimethylsiloxane, 15 parts of epoxy-modified hydrogen-containing mixed ring, 8 parts of plasticizer, and 1 part of structure control agent into reactor 1 and stir to mix. S3. During the stirring process, 15 parts of fumed silica and 25 parts of MQ resin are sequentially added into the reactor body 1 through the feeding structure 4. S4. The working temperature inside the reactor body 1 is increased to 125°C by the temperature control structure 5. During the stirring process, the reactor body 1 is continuously vacuumed, so that the raw materials are continuously dehydrated at high temperature during the mixing process, removing moisture and low molecular weight substances from the raw materials and preventing bubbles from being generated during solidification.

[0025] S5. After vacuum dehydration is completed, stop heating and allow the vessel 1 to cool naturally. Continue stirring the raw material in the vessel 1 until the temperature inside the mixing device is below 40°C. Open the heat dissipation port 5-2 to introduce air. At this time, the raw material is in the form of a paste. S6. Seal the vessel body 1 and fill it with nitrogen. Under the protection of nitrogen, add 0.03 parts of platinum catalyst, 0.2 parts of inhibitor, 2.5 parts of adhesion promoter and 1 part of dehydrating agent mixture and 0.5 parts of antioxidant sequentially into the vessel body 1 through the feeding structure 4. During the addition of additives, first close the solenoid valve 4-2, then open the sealing cover 4-3 and pour the additives into the feeding pipe 4-1. Then close the sealing cover 4-3 and open the solenoid valve 4-2 to pour the additives in the feeding pipe 4-1 into the vessel body 1. After the additives are added, stir for 60 minutes and control the temperature between 25-35℃. S7. After stirring, the air inside the vessel is extracted by the vacuum structure 3 for vacuum degassing. After degassing, the finished product is taken out and filtered through a filter to remove agglomerates. Finally, it is filled and stored.

[0026] The properties of the silicone encapsulant prepared by this method are as follows: Example 2 The difference between this embodiment and Embodiment 1 is that the raw materials in this embodiment include: 80 parts of vinyl-terminated polydimethylsiloxane, 15 parts of epoxy-modified hydrogen-containing mixed cyclic compound, 10 parts of fumed silica, 25 parts of MQ resin, 8 parts of crosslinking agent, 3 parts of adhesion promoter, 0.05 parts of platinum catalyst, 0.2 parts of inhibitor, 1 part of structure control agent, 10 parts of plasticizer, 1 part of dehydrating agent, and 0.5 parts of antioxidant.

[0027] In actual operation: S1. Raw material pretreatment: Confirm the dryness of the raw materials. If necessary, drying treatment is required. For auxiliary materials such as fumed silica and high reinforcing filler MQ resin, place them in an oven at 120℃ for 4 hours to remove excess moisture, and then seal and cool. S2. Add 80 parts of vinyl-terminated polydimethylsiloxane, 15 parts of epoxy-modified hydrogen-containing mixed ring, 10 parts of plasticizer, and 1 part of structure control agent into reactor 1 and stir to mix. S3. During the stirring process, 10 parts of fumed silica and 25 parts of MQ resin are added sequentially into the reactor body 1 through the feeding structure 4. S4. The working temperature inside the reactor body 1 is increased to 130°C by the temperature control structure 5. During the stirring process, the reactor body 1 is continuously vacuumed, so that the raw materials are continuously dehydrated at high temperature during the mixing process, removing moisture and low molecular weight substances from the raw materials and preventing bubbles from being generated during solidification.

[0028] S5. After vacuum dehydration is completed, stop heating and allow the vessel 1 to cool naturally. Continue stirring the raw material in the vessel 1 until the temperature inside the mixing device is below 40°C. Open the heat dissipation port 5-2 to introduce air. At this time, the raw material is in the form of a paste. S6. Seal the vessel body 1 and fill it with nitrogen. Under the protection of nitrogen, add 0.05 parts of platinum catalyst, 0.2 parts of inhibitor, 3 parts of adhesion promoter and 1 part of dehydrating agent mixture and 0.5 parts of antioxidant sequentially into the vessel body 1 through the feeding structure 4. During the addition of additives, first close the solenoid valve 4-2, then open the sealing cover 4-3 and pour the additives into the feeding pipe 4-1. Then close the sealing cover 4-3 and open the solenoid valve 4-2 to pour the additives in the feeding pipe 4-1 into the vessel body 1. After the additives are added, stir for 60 minutes and control the temperature between 25-35℃. S7. After stirring, the air inside the vessel is extracted by the vacuum structure 3 for vacuum degassing. After degassing, the finished product is taken out and filtered through a filter to remove agglomerates. Finally, it is filled and stored.

[0029] The performance parameters of the silicone encapsulant prepared by the raw material ratio in this embodiment are as follows: Example 3 The difference between this embodiment and Embodiment 1 is that the raw materials in this embodiment include: 100 parts of vinyl-terminated polydimethylsiloxane, 5 parts of epoxy-modified hydrogen-containing mixed cyclic compound, 20 parts of fumed silica, 10 parts of MQ resin, 6 parts of crosslinking agent, 1.5 parts of adhesion promoter, 0.02 parts of platinum catalyst, 0.5 parts of inhibitor, 3 parts of structure control agent, 15 parts of plasticizer, 2 parts of dehydrating agent, and 1.5 parts of antioxidant.

[0030] In actual operation: S1. Raw material pretreatment: Confirm the dryness of the raw materials. If necessary, drying treatment is required. For auxiliary materials such as fumed silica and high reinforcing filler MQ resin, place them in an oven at 150°C for 4 hours to remove excess moisture, and then seal and cool. S2. Add 100 parts of vinyl-terminated polydimethylsiloxane, 5 parts of epoxy-modified hydrogen-containing mixed ring, 15 parts of plasticizer, and 3 parts of structure control agent into reactor 1 and stir to mix. S3. During the stirring process, 20 parts of fumed silica and 10 parts of MQ resin are added sequentially into the reactor body 1 through the feeding structure 4. S4. The working temperature inside the reactor body 1 is increased to 140℃ by the temperature control structure 5. During the stirring process, the reactor body 1 is continuously vacuumed, so that the raw materials are continuously dehydrated at high temperature during the mixing process, removing moisture and low molecular weight substances from the raw materials and preventing bubbles from being generated during solidification.

[0031] S5. After vacuum dehydration is completed, stop heating and allow the vessel 1 to cool naturally. Continue stirring the raw material in the vessel 1 until the temperature inside the mixing device is below 40°C. Open the heat dissipation port 5-2 to introduce air. At this time, the raw material is in the form of a paste. S6. Seal the vessel body 1 and fill it with nitrogen. Under the protection of nitrogen, add 0.02 parts of platinum catalyst, 0.5 parts of inhibitor, 1.5 parts of adhesion promoter and 2 parts of dehydrating agent mixture and 1.5 parts of antioxidant sequentially from the feeding structure 4 into the vessel body 1. During the addition of additives, first close the solenoid valve 4-2, then open the sealing cover 4-3 and pour the additives into the feeding pipe 4-1. Then close the sealing cover 4-3 and open the solenoid valve 4-2 to pour the additives in the feeding pipe 4-1 into the vessel body 1. After the additives are added, stir for 60 minutes and control the temperature between 25-35℃. S7. After stirring, the air inside the vessel is extracted by the vacuum structure 3 for vacuum degassing. After degassing, the finished product is taken out and filtered through a filter to remove agglomerates. Finally, it is filled and stored.

[0032] The performance parameters of the silicone encapsulant prepared by the raw material ratio in this embodiment are as follows: Example 4 The difference between this embodiment and the first embodiment of the rubber is that the 10-20 parts of fumed silica and the 10-25 parts of high-reinforcing filler MQ resin are added at intervals of no less than 10 minutes. This interval prevents the filler from bubbling up and ensures uniform dispersion.

[0033] The crosslinking agent mentioned in Examples 1-4 above is a hydrogen-containing silicone oil with a hydrogen content of 0.5%-1.2% by volume.

[0034] The adhesion promoters mentioned in Examples 1-4 above are α-aminosilane coupling agents.

[0035] The inhibitor mentioned in Examples 1-4 above is ethynylcyclohexanol.

[0036] The structuring control agent mentioned in Examples 1-4 above is diphenylsilanediol.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a silicone encapsulant adhesive, characterized by, Including the following raw materials: The composition includes 80-100 parts of vinyl-terminated polydimethylsiloxane, 5-15 parts of epoxy-modified hydrogen-containing mixed rings, 10-20 parts of fumed silica, 10-25 parts of high-reinforcing filler MQ resin, 3-8 parts of crosslinking agent, 1.5-3 parts of adhesion promoter, 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of inhibitor, 1-3 parts of structure control agent, 5-15 parts of plasticizer, 1-2 parts of dehydrating agent, and 0.5-1.5 parts of antioxidant. The specific preparation steps are as follows: S1. Raw material pretreatment: Confirm the dryness of the raw materials. If necessary, drying treatment is required. For auxiliary materials such as fumed silica and high reinforcing filler MQ resin, place them in an oven at 120-150℃ for 4-6 hours to remove excess moisture, and then seal and cool. S2. Add 80-100 parts of vinyl-terminated polydimethylsiloxane, 5-15 parts of epoxy-modified hydrogen-containing mixed ring, 5-15 parts of plasticizer, and 1-3 parts of structure control agent into a mixing device and mix them. S3. During the stirring process, add 10-20 parts of fumed silica and 10-25 parts of MQ resin, which are high-reinforcing filler. S4. Increase the working temperature in the stirring device to 120-150℃, and continuously draw a vacuum inside the stirring device during the stirring process. S5. After vacuum dehydration is completed, stop heating and continue stirring until the temperature inside the mixing device is below 40°C. At this point, air is introduced to obtain a paste-like base material. S6. Seal the stirring device and fill it with nitrogen. Under the protection of nitrogen, add 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of inhibitor, 1.5-3 parts of adhesion promoter and 1-2 parts of dehydrating agent mixture, and 0.5-1.5 parts of antioxidant in sequence. After the additives are added, stir for 30-60 minutes and control the temperature between 25-35℃. S7. After stirring, vacuum degassing is performed. After degassing, the finished product is taken out and filtered through a filter to remove agglomerates. Finally, it is filled and stored.

2. The method for preparing an organosilicon encapsulating adhesive according to claim 1, characterized in that, The crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.5%-1.2%.

3. The method for preparing an organosilicon encapsulating adhesive according to claim 1, characterized in that, The adhesion promoter is an α-aminosilane coupling agent or an epoxysilane complex.

4. The method for preparing an organosilicon encapsulating adhesive according to claim 1, characterized in that, The inhibitor is ethynylcyclohexanol.

5. The method for preparing an organosilicon encapsulating adhesive according to claim 1, characterized in that, The structuring control agent is diphenylsilanediol.

6. The method for preparing an organosilicon encapsulating adhesive according to claim 1, characterized in that, Add 10-20 parts of fumed silica and 10-25 parts of high-reinforcing filler MQ resin sequentially at intervals of no less than 10 minutes.

7. A mixing apparatus for preparing an organosilicon encapsulant, characterized in that, This mixing device is used for the mixing operation mentioned in any one or more preparation methods of claims 1-6. The mixing device includes: a vessel body (1), a stirring structure (2), a vacuuming structure (3), a feeding structure (4), and a temperature control structure (5). The stirring device (2) includes a stirring rod (2-1) and a stirring motor (2-2). The vacuuming structure (3) includes a vacuum machine (3-1) and a vacuum tube (3-2). One end of the vacuum tube (3-2) is connected to the inside of the vessel body (1), and the other end of the vacuum tube (3-2) is connected to a vacuum pump. The empty machine (3-1) is connected, and the feeding structure (4) includes a feeding pipe (4-1), a solenoid valve (4-2) and a sealing cover (4-3). The feeding pipe (4-1) is fixed on the vessel body (1). The bottom of the feeding pipe (4-1) is connected to the inside of the vessel body (1). The solenoid valve (4-2) is installed at the bottom of the feeding pipe (4-1). The sealing cover (4-3) is installed at the top of the feeding pipe (4-1). The temperature control structure (5) includes a heating copper pipe (5-1) and a heat dissipation port (5-2).

Images