Automatic or semi-automatic urethane potting adhesive for electronic and electrical products and preparation method thereof

Abstract

The present application relates to the field of polyurethane potting adhesives, and in particular to an automatic or semi-automatic urethane potting adhesive for electronic and electrical products and a preparation method thereof. An automatic or semi-automatic urethane potting adhesive for electronic and electrical products comprises component A and component B, wherein component A is an isocyanate component, and component B is mainly composed of the following raw materials in percentage by mass: 10% to 50% polyether polyol, 2% to 10% chain extender, 1% to 10% silicone resin microspheres, 5% to 85% inorganic powder, 2% to 5% dewatering agent, 0.5% to 2% dispersant, and 0.001% to 0.1% catalyst. The urethane potting adhesive provided in the present application has good defoaming performance and is not demanding on vacuum degassing conditions. It has excellent electrical properties, heat resistance, bonding strength, and water resistance, and is used for automatic or semi-automatic potting of electronic and electrical products. It is particularly suitable for potting fields with complex structures, large potting depths, and difficulty in degassing.

Description

Technical Field

[0001] The present application relates to the technical field of polyurethane potting adhesives for electronic and electrical products, and in particular to an automatic or semi-automatic polyurethane potting adhesive for electronic and electrical products and a preparation method thereof. Background Art

[0002] Polyurethane electronic potting adhesives based on polyethers often exhibit mechanical bubbles that are difficult to eliminate during dispensing. Even when vacuum potting is used, secondary mechanical bubbles can form during dispensing or potting, where the adhesive comes into contact with the workpiece or encounters complex workpiece structures. With the expansion of thermally conductive adhesive applications, the high viscosity of thermally conductive adhesives due to their high content of thermally conductive powders makes degassing even more difficult. This makes it difficult to achieve a completely bubble-free state through vacuum potting. The presence of bubbles can significantly impair the electrical, mechanical, thermal conductivity, and water resistance of the adhesive layer.

[0003] Traditional polyurethane potting glue with polyether as the main material usually adds a certain amount of defoaming agent to degas or suppress foaming during the preparation of glue. However, the defoaming agent is usually incompatible with the system, and most defoaming agents contain more than 90% organic solvents. Therefore, adding defoaming agent to the potting glue will have many adverse effects, such as: (1) The odor is strong during the gluing process. For example, most silicone defoaming agents contain ketones and benzene solvents, which are harmful to the environment and human health; (2) The plasticizing effect of the solvent causes the hardness and strength of the potting glue to be significantly reduced, and at the same time absorbs The water content also increases; (3) The adhesion between the potting glue and the substrate becomes worse after curing, which makes it easy to peel off due to hot and cold shock; (4) In order to increase the defoaming property of the difficult-to-defoam system, excessive addition increases the incompatibility of the system, resulting in reduced transparency of the cured product. The surface migration of the defoamer affects the appearance of the cured product, such as pits, oil floating, gloss changes, etc., and defects such as pits and lines appear; (5) Silicone defoamers have high surface tension. Adding too much will reduce the wettability of the system with the substrate during the potting process, which is not conducive to the penetration and filling of the glue into small gaps.

[0004] Therefore, there is an urgent need to develop a polyurethane potting compound that does not rely on defoaming agents for degassing, so as to solve the problem of degassing during the potting process for complex structures or large potting depths. At the same time, the potting compound has excellent comprehensive properties such as strength, adhesion, insulation and heat resistance. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides an automatic or semi-automatic urethane potting compound for electronic and electrical products and a preparation method thereof.

[0006] In a first aspect, the present application provides an automatic or semi-automatic urethane potting compound for electronic and electrical products, which is achieved through the following technical solutions:

[0007] An automatic or semi-automatic urethane potting adhesive for electronic and electrical products comprises a component A and a component B. Component A is an isocyanate component, comprising an isocyanate component a; the isocyanate component a accounts for 20-100% of the total mass of component A; the isocyanate component a is liquefied MDI; and component B is mainly composed of the following raw materials in percentage by mass: 10% to 50% of a polyether polyol, 2% to 10% of a chain extender, 1% to 10% of silicone resin microspheres, 5% to 85% of an inorganic powder, 2% to 5% of a dehydrating agent, 0.5% to 2% of a dispersant, and 0.001% to 0.1% of a catalyst.

[0008] The present application adds 1% to 10% silicone resin microspheres to Group B. The hydroxyl groups on the silicone resin can form hydrogen bonds with the ether bonds in the polyether to improve compatibility. However, there is incompatibility between the highly polar polyether and the less polar silicone resin. Therefore, this limited compatibility is beneficial for degassing the system and ensures that the spherical silicone resin is evenly dispersed, ultimately obtaining a foam-free adhesive layer with high heat resistance, yellowing resistance, water resistance, motor performance, and bonding strength. Therefore, the polyurethane potting adhesive provided by the present application has good defoaming performance and is not demanding on vacuum degassing conditions. It has excellent electrical properties, heat resistance, bonding strength, and water resistance, and is used for automatic or semi-automatic potting of electronic and electrical products. It is particularly suitable for potting fields with complex structures, large potting depths, and difficulty in degassing.

[0009] Preferably, the component A further comprises an isocyanate component b, wherein the isocyanate component b is one or a mixture of PAPI, IPDI, and HDI; the isocyanate component a accounts for 20-100% of the total mass of the component A; the liquefied MDI is BASF MM103C or Covestro Desmodur 0129M; the PAPI is one of BASF M20S, Covestro 44V20L, and Dow PAPI20; the IPDI is one of Wanhua IPDI, Evonik IPDI, and Covestro IPDI; and the HDI is one of Wanhua HDI or Bayer HDI.

[0010] By adopting the above technical solution, the overall physical and chemical properties of this application can be guaranteed and the quality stability of products in the same batch can be guaranteed.

[0011] Preferably, the polyether polyol comprises one or a mixture of polyethers having a hydroxyl value of 20-600 mg KOH / g and a functionality of 2-8.

[0012] By adopting the above technical solution, the overall physical and chemical properties of this application can be guaranteed.

[0013] Preferably, the chain extender is a small molecule polyol, specifically including one or more combinations of diethylene glycol, tripropylene glycol, butanediol, trimethylolpropane, and pentaerythritol.

[0014] By adopting the above technical solution, the overall cross-linking degree is improved and the overall physical and chemical properties of this application are enhanced.

[0015] Preferably, the silicone resin microspheres are spherical silicone resins and spherical silicone resin modifications with an average particle size of 0.2 to 10 microns; the spherical silicone resin modifications are chemically modified silicone resin microspheres of silicone, acrylic acid, polyurethane, and polyether.

[0016] By adopting the above technical solution, the hydroxyl groups on the silicone resin microspheres can form hydrogen bonds with the ether bonds in the polyether to improve compatibility. However, there is incompatibility between the highly polar polyether and the less polar silicone resin. Therefore, this limited compatibility is beneficial to the degassing of the system and ensures the uniform dispersion of the spherical silicone resin, ultimately obtaining a foam-free adhesive layer with higher heat resistance, yellowing resistance, water resistance, motor performance and bonding strength.

[0017] Preferably, the particle size of the inorganic powder is 0.1 to 100 μm; the inorganic powder includes a mixture of at least one of unsurface-treated or surface-treated calcium carbonate, talc, mica powder, kaolin, silica powder, barium sulfate, aluminum oxide, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, silicon carbide, carbon black, and titanium dioxide; the reagent used for the surface treatment of the inorganic powder is a silane coupling agent; the specific method for the surface treatment of the inorganic powder is: spraying the silane coupling agent into the inorganic powder, and mixing it at high speed while heating it to 40-60° C. to obtain the surface-modified inorganic powder.

[0018] By adopting the above technical solution, the overall physical and chemical properties of this application can be guaranteed.

[0019] Preferably, the dehydrating agent is at least one of molecular sieve activation powder and p-toluenesulfonyl isocyanate; the molecular sieve activation powder is at least one of 3A molecular sieve powder, 4A molecular sieve powder, 5A molecular sieve powder, and 13X molecular sieve powder; and the p-toluenesulfonyl isocyanate is Bayer Additive Ti.

[0020] By adopting the above technical solution, moisture is effectively removed and the overall quality of this application is guaranteed.

[0021] Preferably, the dispersant is a mixture of high molecular weight carboxylic acid and modified polysiloxane; the mixture of high molecular weight carboxylic acid and modified polysiloxane is at least one of Hymers 904S and Merck Chemical MOK-5019; the catalyst includes one or a combination of organotin, organobismuth, and organozinc catalysts.

[0022] By adopting the above technical solution, the silicone resin microspheres and the inorganic powder can be dispersed, thereby ensuring the overall physical and chemical properties and quality of the present application.

[0023] In a second aspect, the present application provides a method for preparing an automatic or semi-automatic urethane potting compound for electronic and electrical products, which is achieved by the following technical solutions:

[0024] A method for preparing an automatic or semi-automatic urethane potting compound for electronic and electrical products comprises the following steps: preparing component A: uniformly mixing isocyanate component a and isocyanate component b, heating at 50-70° C. and vacuuming for 0.5-2 hours to obtain component A;

[0025] Component B: Heat the accurately measured polyether polyol, chain extender, and silicone resin microspheres at 80-130°C and evacuate for 1-3 hours, with a vacuum degree of -0.9 to -1.0 MPa. Cool to 50-90°C, then add the dispersant and stir evenly. Slowly add the inorganic powder and water remover in sequence while stirring. Disperse at high speed at 1500-4000 rpm for 0.5 to 2 hours. Keep warm at 80-130°C and evacuate at a vacuum degree of -0.9 to -1.0 MPa. Evacuate for 1-3 hours, cool to below 50°C, then add the catalyst, disperse and mix evenly to obtain component B.

[0026] When in use, the prepared component A and component B are mixed evenly to obtain a finished product of the urethane potting compound.

[0027] This application carries out three heat preservation processes during the preparation of component B. The first heat preservation process is 80-130℃ and vacuuming to remove moisture from the polyol. The second heat preservation process is 50-90℃ high-speed dispersion after adding inorganic powder and dehydrating agent, which slowly achieves infiltration and fusion between polyether, chain extender, dispersant, silicone resin microspheres and inorganic powder. The third heat preservation process is 80-130℃ and vacuuming to further remove moisture from the filler. The viscosity of component B of the polyurethane adhesive prepared by this method is significantly lower, which is conducive to degassing after filling, and no hard precipitation is produced during storage for 12 months. In addition, the appearance of the cured polyurethane adhesive prepared in this application is smoother and brighter.

[0028] Preferably, the preparation of component A: the isocyanate component a and the isocyanate component b are stirred and mixed at 500±50rpm, and then heated and vacuumed at 60±2℃ for 1±0.1 hours to obtain component A; component B: the accurately measured polyether polyol, chain extender, and silicone resin microspheres are heated and vacuumed at 120±5℃ for 2±0.1 hours, with a vacuum degree of -0.9 to -1.0MPa, cooled to 80±2℃, and then the dispersant is added and stirred evenly. At a stirring speed of 500±50rpm, the inorganic powder, water scavenger, and inorganic The powder is added at a rate of 10±1wt% / min, the dehydrating agent is added at a rate of 10±1wt% / min, and the mixture is dispersed at a high speed at 3000±50 rpm for 1.5±0.1 hours. The mixture is then kept at 110±2°C and vacuumed at a vacuum degree of -0.9 to -1.0MPa for 1.5±0.1 hours. The mixture is cooled to below 50±2°C, and the catalyst is added. The mixture is dispersed and mixed uniformly at 500±50rpm to obtain component B. When used, the prepared components A and B are evenly mixed to obtain a finished urethane potting compound.

[0029] By adopting the above technical solutions and optimizing the preparation parameters, the overall quality and quality stability of this application can be guaranteed.

[0030] In summary, this application has the following advantages:

[0031] 1. The polyurethane potting glue provided in this application has good defoaming performance and is not demanding on vacuum degassing conditions. It has excellent electrical properties, heat resistance, bonding strength, and water resistance, and is used for automatic or semi-automatic potting of electronic and electrical products.

[0032] 2. The cured surface of the polyurethane potting compound provided in this application is flat and smooth, and does not have the appearance defects caused by defoaming agents, such as depression, oil floating, and matting.

[0033] 3. The polyurethane potting glue provided in this application can greatly reduce or eliminate the need for defoaming agents, thereby achieving a bubble-free and seamless polyurethane adhesive layer on complex workpieces and in situations where it is difficult to cast glue. This is especially true for the casting of high-viscosity glue that is difficult to defoam. That is, it is particularly suitable for casting areas with complex structures, large casting depths, and difficulty in degassing.

[0034] 4. The polyurethane potting glue provided in this application does not have the organic solvent odor produced by the defoaming agent and is harmless to the environment and human body.

[0035] 5. The cured urethane potting compound provided in this application has good strength, strong wettability to substrates, and metal bonding strength of up to 18 MPa.

[0036] 6. The cured urethane potting compound provided in this application has excellent water resistance. In a one-day immersion test, the water absorption rate is 0.005%, and in a 30-day immersion test, the water absorption rate is less than 0.1%.

[0037] 7. The tensile strength of the cured urethane potting compound provided in this application decreases by less than 10% after high-temperature aging at 125°C for 1000 hours or double 85 test for 1000 hours.

[0038] 8. The preparation method of the urethane potting compound provided in this application is relatively simple and convenient for industrial production and promotion. DETAILED DESCRIPTION

[0039] The present application is further described in detail below with reference to comparative examples and embodiments.

[0040] Example

[0041] Example 1

[0042] The present application discloses an automatic or semi-automatic urethane potting adhesive for electronic and electrical products, comprising component A and component B, wherein component A is an isocyanate component, specifically comprising isocyanate component a and isocyanate component b, wherein isocyanate component a accounts for 20-100% of the total mass of component A, and isocyanate component a is liquefied MDI, which is BASF MM103C or Covestro Desmodur 0129M.

[0043] Isocyanate component b is one or a mixture of PAPI, IPDI, and HDI. PAPI is one of BASF M20S, Covestro 44V20L, and Dow PAPI 20. IPDI is one of Wanhua IPDI, Evonik IPDI, and Covestro IPDI. HDI is one of Wanhua HDI or Bayer HDI.

[0044] The polyether polyol includes one or a mixture of polyethers having a hydroxyl value of 20-600 mg KOH / g and a functionality of 2-8.

[0045] Component B is mainly composed of the following raw materials in percentage by mass: 10% to 50% polyether polyol, 2% to 10% chain extender, 1% to 10% silicone resin microspheres, 5% to 85% inorganic powder, 2% to 5% dehydrating agent, 0.5% to 2% dispersant, and 0.001% to 0.1% catalyst.

[0046] The polyether polyol includes one or more polyethers with a hydroxyl value of 20-600 mg KOH / g and a functionality of 2-8. The chain extender is a small molecule polyol, specifically including one or more combinations of diethylene glycol, tripropylene glycol, butanediol, trimethylolpropane, and pentaerythritol.

[0047] Silicone resin microspheres are spherical silicone resins and spherical silicone resin modifications with an average particle size of 0.2 to 10 microns. Spherical silicone resin modifications are chemically modified silicone resin microspheres made from silicone, acrylic acid, polyurethane, or polyether.

[0048] The inorganic powder has a particle size of 0.1 to 100 μm and comprises a mixture of at least one of unsurface-treated or surface-treated calcium carbonate, talc, mica powder, kaolin, silica powder, barium sulfate, aluminum oxide, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, silicon carbide, carbon black, and titanium dioxide. The surface treatment agent used for the inorganic powder is a silane coupling agent, specifically γ-aminopropyltriethoxysilane KH550. The surface treatment method comprises spraying the silane coupling agent onto the inorganic powder and then heating the mixture to 40-60°C for high-speed mixing for 0.5-2 hours to obtain the surface-modified inorganic powder.

[0049] The dehydrating agent is at least one of molecular sieve activation powder and p-toluenesulfonyl isocyanate (Bayer Additive Ti). The molecular sieve activation powder is at least one of 3A molecular sieve powder, 4A molecular sieve powder, 5A molecular sieve powder, and 13X molecular sieve powder.

[0050] The dispersant is a mixture of high molecular weight carboxylic acid and modified polysiloxane, and the mixture of high molecular weight carboxylic acid and modified polysiloxane is at least one of Hemingway 904S and Merck Chemical MOK-5019.

[0051] The catalyst includes one or a combination of organic tin, organic bismuth and organic zinc catalysts.

[0052] The specific formulas of component A and component B are as follows:

[0053] Table 1 is a table of specific formula components of component A and component B in Examples 1-6

[0054]

[0055] The calcium carbonate in Table 1 has a particle size D50 of 5 μm and was surface-modified using a silane coupling agent, KH550. Specifically, 1.5 g of the silane coupling agent was sprayed onto 100 g of the inorganic powder, heated to 50° C., and mixed at 500 rpm for 30 minutes to obtain the surface-modified calcium carbonate.

[0056] A method for preparing an automatic or semi-automatic urethane potting compound for electronic and electrical products is as follows: Preparation of component A: isocyanate component a and isocyanate component b are stirred and mixed at 500 rpm, and then heated at 60°C and vacuumed for 1 hour to obtain component A;

[0057] Component B: Heat the accurately measured polyether polyol, chain extender, and silicone resin microspheres at 120°C and evacuate for 2 hours, with a vacuum degree of -0.9 to -1.0 MPa, to remove the moisture in the polyol. After cooling to 80°C, add the dispersant and stir evenly. At a stirring speed of 500 rpm, add the inorganic powder and water remover in sequence. The addition rate of the inorganic powder is 10 wt% / min, and the addition rate of the water remover is 10 wt% / min. At 3000 rpm, high-speed dispersion is carried out for 1.5 hours to make the polyether, chain extender, dispersant, and silicone resin The microspheres and the inorganic powder are slowly infiltrated and fused, and then the temperature is kept at 110°C while vacuuming, with a vacuum degree of -0.9 to -1.0 MPa, and the vacuuming is carried out for 1.5 hours to further remove moisture from the filler. The temperature is lowered to below 50°C, and then a catalyst is added. The mixture is dispersed and mixed evenly at 500 rpm to obtain component B. The viscosity of the prepared polyurethane glue component B is significantly lower, which is conducive to degassing during glue pouring, and no hard precipitation is produced after storage for 12 months, and the appearance of the formed solid is smoother and brighter. When used, the prepared components A and B are evenly mixed to obtain a finished urethane potting glue.

[0058] Examples 2-4

[0059] The difference between Examples 2-4 and Example 1 is: see the specific formula of component A and component B in Table 1.

[0060] Example 5

[0061] The difference between Example 5 and Example 1 is that the silicone resin microspheres are modified silicone resins, and the modified silicone resins are allyl-terminated polyether (Cologne Co., Ltd., model APEG-580, hydroxyl value 90-102) and triethoxysilane TES (Jiuding Chemical) undergo an addition reaction to generate a terminal hydroxyl polyether silane coupling agent. The terminal hydroxyl polyether silane coupling agent is mixed and reacted with the spherical silicone resin to obtain the target silicone resin microspheres.

[0062] The specific preparation method of the hydroxyl-terminated polyether silane coupling agent is as follows: using triethoxysilane and allyl polyether as raw materials (relative molecular weight 600), under the conditions of n(APEG) / n(TES) being 1:1, chloroplatinic acid being a catalyst, the catalyst dosage being 15 mg / L, the reaction temperature being 70°C, and the reaction time being 4 h, the hydroxyl-terminated polyether triethoxysilane coupling agent is synthesized by hydrosilylation.

[0063] Example 6

[0064] Example 6 differs from Example 1 in that the silicone resin microspheres are modified silicone resins, which are silicone resin microspheres modified by dry-blending with γ-methacryloxypropyltrimethoxysilane. The ratio (by mass) of γ-methacryloxypropyltrimethoxysilane to silicone resin microspheres is 1:20.

[0065] Comparative Example

[0066] The difference between Comparative Example 1 and Example 1 is that conventional polyurethane glue is sourced from VEVO-CHEMIE, Germany.

[0067] The difference between Comparative Example 2 and Example 1 is that no silicone resin microspheres are added.

[0068] Performance testing

[0069] Detection method / test method

[0070] 1. Mechanical properties test: According to GB / T 1040-2006, the tensile strength and tensile fracture rate are tested.

[0071] 2. Peel strength test: Test in accordance with GB / T 7124-2008.

[0072] 3. Water resistance test: Test in accordance with GB / T 1034-2008.

[0073] 4. Weathering test: According to GB / T2423.2-2008 entry and exit test. Test conditions: After the cured urethane potting compound is aged at 125°C for 1000 hours or subjected to the double 85 test for 1000 hours, the tensile strength is tested and the retention rate and decline rate are calculated.

[0074] Data Analysis

[0075] Table 1 is the experimental test data table of Examples 1-6 and Comparative Examples 1-2

[0076]

[0077] Table 2 is the experimental test data table of Examples 1-6 and Comparative Examples 1-2

[0078]

[0079]

[0080] As can be seen from Examples 1-6 and Comparative Examples 1-2, in conjunction with Tables 1-2, the automatic or semi-automatic polyurethane potting compound prepared using the silicone resin microspheres of this application in combination with the production method provided herein exhibits excellent defoaming performance, is not demanding on vacuum degassing conditions, and exhibits excellent electrical properties, heat resistance, bond strength, and water resistance. It is suitable for automatic or semi-automatic potting of electronic and electrical products. It is particularly suitable for potting applications involving complex structures, deep potting depths, and resistance to degassing.

[0081] From Examples 1-6 and Comparative Examples 1-2 and Table 1-2, it can be seen that the defoaming performance of the automatic or semi-automatic urethane potting adhesive prepared by chemically modified silicone resin microspheres of silicone, acrylic acid, polyurethane, and polyether is improved, and the heat resistance, bonding strength, and water resistance are also improved.

[0082] In summary, this application has the following advantages:

[0083] 1. The polyurethane potting glue provided in this application has good defoaming performance and is not demanding on vacuum degassing conditions. It has excellent electrical properties, heat resistance, bonding strength, and water resistance, and is used for automatic or semi-automatic potting of electronic and electrical products.

[0084] 2. The cured surface of the polyurethane potting compound provided in this application is flat and smooth, and does not have the appearance defects caused by defoaming agents, such as depression, oil floating, and matting.

[0085] 3. The polyurethane potting glue provided in this application can greatly reduce or eliminate the need for defoaming agents, thereby achieving a bubble-free and seamless polyurethane adhesive layer on complex workpieces and in situations where it is difficult to cast glue. This is especially true for the casting of high-viscosity glue that is difficult to defoam. That is, it is particularly suitable for casting areas with complex structures, large casting depths, and difficulty in degassing.

[0086] 4. The polyurethane potting glue provided in this application does not have the organic solvent odor produced by the defoaming agent and is harmless to the environment and human body.

[0087] 5. The cured urethane potting compound provided in this application has good strength, strong wettability to substrates, and metal bonding strength of up to 18 MPa.

[0088] 6. The cured polyurethane potting compound provided in this application has excellent water resistance. In a one-day immersion test, the water absorption rate is 0.005%, and in a 30-day immersion test, the water absorption rate is less than 0.1.

[0089] 7. The tensile strength of the cured urethane potting compound provided in this application decreases by less than 10% after high-temperature aging at 125°C for 1000 hours or double 85 test for 1000 hours.

[0090] 8. The preparation method of the urethane potting compound provided in this application is relatively simple and convenient for industrial production and promotion.

[0091] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An automatic or semi-automatic polyurethane potting compound for electronic and electrical products, characterized by: The invention comprises components A and B, wherein component A is an isocyanate component, including isocyanate component a; the isocyanate component a accounts for 20-100% of the total mass of component A; the isocyanate component a is liquefied MDI; the component B is mainly composed of the following raw materials in percentage by mass: 10% to 50% of polyether polyol, 2% to 10% of chain extender, 1% to 10% of silicone resin modifier, 5% to 85% of inorganic powder, 2% to 5% of water remover, 0.5% to 2% of dispersant, and 0.001% to 0.1% of catalyst; the silicone resin modifier is silicone resin microspheres chemically modified with γ-methacryloxypropyltrimethoxysilane or a terminal hydroxyl polyether silane coupling agent; wherein the terminal hydroxyl polyether silane coupling agent is obtained by an addition reaction between an allyl-terminated polyether and triethoxysilane.

2. The automatic or semi-automatic urethane potting compound for electronic and electrical products according to claim 1, characterized in that: The component A further includes an isocyanate component b, which is one or a mixture of PAPI, IPDI, and HDI; the isocyanate component a accounts for 20-100% of the total mass of component A; the liquefied MDI is BASF MM103C or Covestro Desmodur 0129M; the PAPI is one of BASF M20S, Covestro 44V20L, and Dow PAPI 20; the IPDI is one of Wanhua IPDI, Evonik IPDI, and Covestro IPDI; and the HDI is one of Wanhua HDI or Bayer HDI.

3. The automatic or semi-automatic urethane potting compound for electronic and electrical products according to claim 1, characterized in that: The polyether polyol comprises one or a mixture of polyethers having a hydroxyl value of 20-600 mg KOH / g and a functionality of 2-8.

4. The automatic or semi-automatic urethane potting adhesive for electronic and electrical products according to claim 1, characterized in that: The chain extender is a small molecule polyol, specifically including one or more combinations of diethylene glycol, tripropylene glycol, butanediol, trimethylolpropane, and pentaerythritol.

5. The automatic or semi-automatic urethane potting adhesive for electronic and electrical products according to claim 1, characterized in that: The particle size of the inorganic powder is 0.1 to 100 μm; the inorganic powder includes a mixture of at least one of unsurface-treated or surface-treated calcium carbonate, talc, mica powder, kaolin, silica powder, barium sulfate, aluminum oxide, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, silicon carbide, carbon black, and titanium dioxide; the reagent used for the surface treatment of the inorganic powder is a silane coupling agent; the specific method for the surface treatment of the inorganic powder is: spraying the silane coupling agent into the inorganic powder, and mixing it at high speed while heating it to 40-60° C. to obtain the surface-modified inorganic powder.

6. The automatic or semi-automatic urethane potting compound for electronic and electrical products according to claim 1, characterized in that: The dehydrating agent is at least one of molecular sieve activation powder and p-toluenesulfonyl isocyanate; the molecular sieve activation powder is at least one of 3A molecular sieve powder, 4A molecular sieve powder, 5A molecular sieve powder, and 13X molecular sieve powder; the p-toluenesulfonyl isocyanate is Bayer Additive Ti.

7. The automatic or semi-automatic urethane potting adhesive for electronic and electrical products according to claim 1, characterized in that: The dispersant is a mixture of high molecular weight carboxylic acid and modified polysiloxane; the mixture of high molecular weight carboxylic acid and modified polysiloxane is at least one of Hymers 904S and Merck Chemical MOK-5019; the catalyst includes one or a combination of organic tin, organic bismuth, and organic zinc catalysts.

8. A method for preparing an automatic or semi-automatic urethane potting compound for electronic and electrical products according to any one of claims 1 to 7, characterized in that: Preparation of component A: Mix the isocyanate component a and the optional isocyanate component b, heat at 50-70°C and evacuate for 0.5-2 hours to obtain component A; Component B: Heat the accurately measured polyether polyol, chain extender, and silicone resin modifier at 80-130°C and evacuate for 1-3 hours, with a vacuum degree of -0.9 to -1.0 MPa. Cool to 50-90°C, then add the dispersant and stir evenly. Slowly add the inorganic powder and water remover in sequence while stirring, and disperse at a high speed of 1500-4000 rpm for 0.5 to 2 hours. Keep warm at 80-130°C while evacuating, with a vacuum degree of -0.9 to -1.0 MPa. Evacuate for 1-3 hours, cool to below 50°C, then add the catalyst, disperse and mix evenly to obtain component B. When in use, the prepared component A and component B are mixed evenly to obtain a finished product of the urethane potting compound.

9. The method for preparing an automatic or semi-automatic urethane potting compound for electronic and electrical products according to claim 8, characterized in that: Preparation of the A component: the isocyanate component a and the isocyanate component b are stirred and mixed at 500±50rpm, and then heated and vacuumed at 60±2℃ for 1±0.1 hours to obtain the A component; the B component: the accurately measured polyether polyol, chain extender, and silicone resin modifier are heated and vacuumed at 120±5℃ for 2±0.1 hours, with a vacuum degree of -0.9 to -1.0MPa, and then cooled to 80±2℃, and the dispersant is added and stirred evenly. At a stirring speed of 500±50rpm, the inorganic powder, the water scavenger, and the inorganic powder are added in sequence. The addition rate of the dehydrating agent is 10±1wt% / min, the addition rate of the water removing agent is 10±1wt% / min, and the mixture is dispersed at a high speed at 3000±50 rpm for 1.5±0.1 hours. The mixture is then kept at 110±2°C and vacuumed at a vacuum degree of -0.9 to -1.0MPa. The mixture is vacuumed for 1.5±0.1 hours, cooled to below 50±2°C, and the catalyst is then added. The mixture is dispersed and mixed uniformly at 500±50rpm to obtain component B. When used, the prepared components A and B are evenly mixed to obtain a finished urethane potting compound.

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