Polyol composition, polyurethane potting adhesive, and preparation method and application thereof

Abstract

This invention belongs to the field of electronic potting compound technology, specifically relating to a polyol composition, a polyurethane potting compound, its preparation method, and its application. This invention cleverly blends unmodified castor oil polyol, modified castor oil polyol, and epoxy-modified polyol to prepare a polyol composition with synergistic effects. The complementary combination of the unmodified and modified castor oil polyols not only significantly enhances the compatibility within the colloid and optimizes its structure, but also greatly improves its toughness, adhesion, weather resistance, and defoaming properties. Simultaneously, the addition of the epoxy-modified polyol increases its crosslinking density, thereby enhancing its mechanical properties and further optimizing weather resistance and transparency, effectively preventing the precipitation of colloidal components. Therefore, the polyurethane potting compound prepared using this polyol composition possesses excellent toughness, weather resistance, adhesion, transparency, and defoaming properties, which is beneficial for promoting the development of industries such as electronics and new energy.

Description

Technical Field

[0001] This invention belongs to the field of electronic potting compound technology. More specifically, it relates to a polyol composition, a polyurethane potting compound, its preparation method, and its application. Background Technology

[0002] Traditional washing machines, smart water meters, smart toilets and other household appliances generally use polyurethane potting compound to encapsulate and protect the circuitry during the manufacturing process, in order to achieve dustproof, corrosion-proof, moisture-proof and shockproof effects, thereby effectively extending the service life of the appliances.

[0003] However, polyurethane potting compounds currently face multiple challenges in application. First, their insufficient transparency limits light penetration, increasing the difficulty of maintenance and inspection. Second, polyurethane potting compounds soften easily at high temperatures, affecting their sealing performance. Furthermore, air bubbles are easily generated during potting, further weakening the sealing performance and damaging the product's appearance. Third, insufficient toughness makes polyurethane potting compounds prone to breakage under impact or vibration. Crucially, poor adhesion directly leads to decreased stability of electronic components, affecting heat dissipation, safety, and overall lifespan. Finally, polyurethane potting compounds are prone to discoloration over long-term use, affecting not only aesthetics but also, due to insufficient hardness, making them more susceptible to wear under external forces, further shortening their lifespan. To address these issues, Chinese patent application CN117801764A developed a high-performance polyurethane potting compound using sorbitol-based polyether polyol, castor oil polyol, and epoxy-modified polyol. This potting compound exhibits excellent performance in terms of hardness and resistance to damp heat. However, although the patent application has improved the performance of polyurethane potting compound to some extent, problems such as low transparency, easy formation of bubbles, insufficient toughness, poor adhesion, and easy discoloration still need to be further solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the existing polyurethane potting compound, such as low transparency, easy generation of bubbles, insufficient toughness, poor adhesion and easy discoloration, and to provide a polyol composition.

[0005] Another object of the present invention is to protect a polyurethane potting compound.

[0006] Another object of the present invention is to protect the preparation method of the above-mentioned polyurethane potting compound.

[0007] Another object of the present invention is to protect the use of the above-mentioned polyol composition or the above-mentioned polyurethane potting compound in the preparation of electrical coating adhesives.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution:

[0009] This invention protects a polyol composition comprising, by weight, the following raw materials: 60-70 parts of unmodified castor oil polyol, 10-20 parts of modified castor oil polyol, and 5-25 parts of epoxy-modified polyol.

[0010] The polyol composition of this invention typically serves as the main component of potting compounds, constructing a fundamental framework and providing key functional properties. As the main component, it imparts excellent adhesion, cured mechanical strength, weather resistance, and transparency to the potting compound. Furthermore, the synergistic effect of multiple components in the polyol composition significantly enhances the potting compound's toughness, chemical resistance, and environmental aging resistance. In particular, the unmodified castor oil polyol, as the base resin, exhibits excellent compatibility and forms a close synergistic effect with the modified castor oil polyol. This not only significantly improves the potting compound's toughness, weather resistance, and defoaming properties but also, through the introduction of epoxy-modified polyols, greatly enhances the mechanical properties of the potting compound and further optimizes weather resistance and transparency, effectively preventing the precipitation of colloidal components. The synergistic effect of these three components achieves mutual enhancement and complementarity in performance, enabling the potting compound to maintain its stability and reliability even in harsh environments, providing long-lasting and effective protection and support for electronic components.

[0011] Furthermore, the hydroxyl value of the unmodified castor oil polyol is 155-170 KOH / g.

[0012] Furthermore, the unmodified castor oil polyol includes one or more of extra virgin castor oil, refined castor oil, and food-grade castor oil.

[0013] Furthermore, the modified castor oil polyol has a hydroxyl value of 180–220 KOH / g.

[0014] Furthermore, the epoxy-modified polyol is a polyol with epoxy groups.

[0015] Furthermore, the epoxy-modified polyol includes one or more of epoxy-modified polyether polyol, epoxy-modified polyester polyol, and epoxy-modified polylactic acid polyol.

[0016] This invention protects a polyurethane potting compound, characterized in that it comprises component A and component B;

[0017] Wherein, by weight, component A comprises: the polyol composition obtained above, 4-10 parts of plasticizer, 0.2-0.3 parts of defoamer, and 0.05-0.1 parts of catalyst;

[0018] Component B comprises: 40-50 parts isocyanate, 20-30 parts flame retardant, and 20-30 parts plasticizer;

[0019] The polyurethane potting compound contains no fillers.

[0020] Component A and Component B together constitute the high-performance polyurethane potting compound, each playing an indispensable role. Component A, as the main component of the potting compound, constructs the basic framework and provides key functional properties including good adhesion, cured mechanical strength, weather resistance, and transparency. Simultaneously, the synergistic effect of various components in Component A significantly enhances the potting compound's toughness, chemical resistance, and environmental aging resistance. Component B, through the addition of flame retardants, significantly improves the flame retardant properties of the potting compound, ensuring its safety and reliability; and through the optimized selection of plasticizers, it further improves the flexibility and processability of the potting compound. In summary, the synergistic effect of Components A and B creates a polyurethane potting compound that combines high toughness, high adhesion, and excellent processability.

[0021] Further, the plasticizer includes one or more of dimethyl phthalate, diisooctyl phthalate, dihexyl phthalate, diisodecyl phthalate, diisononyl phthalate, dibutyl sebacate, dioctyl sebacate, and dioctyl adipate (DOA).

[0022] Furthermore, the defoamer is a silicone-based defoamer and / or a non-silicone-based defoamer.

[0023] Furthermore, the defoamer includes one or more of BYK-088, BYK-A500, BYK-A535, BYK-A550, and BYK-A555.

[0024] Furthermore, the catalyst includes one or more of the following: organotin catalysts, organobismuth catalysts, organozinc catalysts, and organoamine catalysts.

[0025] Furthermore, the catalyst is an organotin catalyst, chosen because of its excellent overall performance and relatively low cost.

[0026] Preferably, the organotin catalyst includes one or more of dibutyltin dilaurate, dimethyltin dinecapate, and dibutyltin diacetate.

[0027] Further, the isocyanate includes one or more of 2,4-toluene diisocyanate, 2,4-diphenylmethane diisocyanate, and 4,4-diphenylmethane diisocyanate.

[0028] Furthermore, the flame retardant is an aliphatic phosphate flame retardant and / or an aromatic phosphate flame retardant.

[0029] Furthermore, the flame retardant is an aliphatic phosphate flame retardant.

[0030] Preferably, the aliphatic phosphate flame retardant includes one or more of triethyl phosphate, tricresyl phosphate, and diphenyl toluene phosphate.

[0031] This invention protects a method for preparing the above-mentioned polyurethane potting compound, comprising the following steps:

[0032] S1. Mix the above-obtained polyol composition, plasticizer, defoamer, and catalyst after dehydration treatment to obtain component A mixture;

[0033] S2. The dehydrated plasticizer and flame retardant are mixed with isocyanate to obtain component B mixture;

[0034] S3. After mixing the A component mixture obtained in step S1 with the B component mixture obtained in step S2, remove the bubbles and cure at room temperature to obtain the polyurethane potting compound.

[0035] This invention successfully prepares a polyurethane potting compound by separately preparing a mixture of components A and B, mixing them, and then subjecting them to a defoaming and curing process. This preparation process not only ensures the uniformity and stability of the potting compound but also endows it with excellent performance. In terms of mechanical properties, its hardness and tensile strength are excellent; in terms of transparency and weather resistance, even after rigorous aging tests (such as the double 85 test), the potting compound maintains high transparency and is not prone to yellowing or exudation; in terms of adhesive properties, its shear strength is excellent; at the same time, it also has good defoaming properties, ensuring the smoothness of the potting compound surface and the sealing effect.

[0036] Furthermore, in step S1, the temperature of the dehydration treatment is 100–120°C.

[0037] Furthermore, in step S1, the dehydration treatment time is 2 to 3 hours.

[0038] Furthermore, in step S1, the mixing is agitation.

[0039] Furthermore, the mixing conditions are as follows: stirring at 200–300 rpm / min for 10–20 min.

[0040] Furthermore, in step S2, the temperature of the dehydration treatment is 100–120°C.

[0041] Furthermore, in step S2, the dehydration treatment time is 1 to 2 hours.

[0042] Further, in step S3, the mass ratio of the A component mixture to the B component mixture is 1:(0.8~1.2).

[0043] Furthermore, in step S3, the curing time is 24 to 48 hours.

[0044] This invention protects the use of the above-mentioned polyurethane potting compound in the preparation of electrical potting compounds.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] This invention prepares a synergistic polyol composition by cleverly fusing unmodified castor oil polyol, modified castor oil polyol, and epoxy-modified polyol. The complementary combination of the unmodified and modified castor oil polyols significantly enhances the compatibility within the colloid, optimizes its structure, and greatly improves its toughness, adhesion, weather resistance, and defoaming properties. Simultaneously, the addition of the epoxy-modified polyol increases its crosslinking density, thereby enhancing its mechanical properties and further optimizing weather resistance and transparency, effectively preventing the precipitation of colloidal components. Therefore, the polyurethane potting compound prepared using this polyol composition possesses excellent toughness, weather resistance, adhesion, transparency, and defoaming properties, which is beneficial for promoting the development of industries such as electronics and new energy. Detailed Implementation

[0047] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0048] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0049] Unmodified castor oil polyols (hydroxyl value 155-170 KOH / g): Food-grade unmodified castor oil polyols and refined-grade unmodified castor oil polyols were purchased from Fucheng Huanyu Oils Co., Ltd.

[0050] Modified castor oil polyols: H-368 was purchased from Ito Oil Co., Ltd. (hydroxyl value 180KOH / g), and X368 was purchased from Fucheng Huanyu Oil Co., Ltd. (hydroxyl value 220KOH / g);

[0051] Epoxy-modified polyol: Epoxy-modified polyether polyol HM-2210 was purchased from Shanghai Yinman Chemical.

[0052] Epoxidized soybean oil: 13150 was purchased from Herma Technology Co., Ltd.

[0053] Polyether polyol: Polypropylene oxide triol (molecular weight 1000) was purchased from Wanhua Chemical;

[0054] Epoxy resins: E51 and E44 were purchased from Nan Ya Epoxy Resin Co., Ltd.

[0055] Plasticizer: Dioctyl adipate (DOA) was purchased from Shandong Shengfan Chemical Co., Ltd.;

[0056] Defoamer: BYK-088, purchased from BYK GmbH, Germany;

[0057] Catalyst: Dibutyltin dilaurate was purchased from Guangzhou Haoyi New Material Technology Co., Ltd.

[0058] Isocyanate: 4,4-diphenylmethane diisocyanate was purchased from Wanhua Chemical.

[0059] Flame retardant: Triethyl phosphate (TEP) was purchased from Shandong Ruixing Flame Retardant Technology Co., Ltd.

[0060] Example 1: Preparation of a polyurethane potting compound

[0061] S1. Mix 60 parts of refined unmodified castor oil polyol, 20 parts of modified castor oil polyol H-368, 15 parts of epoxy modified polyether polyol HM-2210, 4.7 parts of dioctyl adipate (DOA), 0.1 parts of dibutyltin dilaurate, and 0.2 parts of defoamer BYK-088 in a high-speed mixer and stir at 300 rpm / min for 15 min until homogeneous. Then, dehydrate under vacuum at 120℃ for 3 h to obtain component A mixture.

[0062] S2. Heat 25 parts of DOA and 30 parts of triethyl phosphate (TEP) to 120°C and dehydrate under vacuum for 2 hours, then cool to 60°C and add 45 parts of 4,4-diphenylmethane diisocyanate and mix evenly to obtain component B mixture;

[0063] S3. Mix the A component mixture obtained in step S1 and the B component mixture obtained in step S2 at a mass ratio of 1:1, then perform vacuum degassing treatment, and then cure at room temperature for 48 hours to obtain polyurethane potting compound.

[0064] Example 2: Preparation of a polyurethane potting compound

[0065] The difference from Example 1 is that in step S1, the number of parts of unmodified castor oil polyol is changed from 60 parts to 70 parts, and the number of parts of modified castor oil polyol H-368 is changed from 20 parts to 10 parts.

[0066] The other steps and conditions are the same as in Example 1.

[0067] Example 3: Preparation of a polyurethane potting compound

[0068] The difference from Example 1 is that in step S1, the number of parts of unmodified castor oil polyol is changed from 60 parts to 70 parts, and the number of parts of epoxy modified polyether polyol HM-2210 is changed from 15 parts to 5 parts; in step S2, the number of parts of 4,4-diphenylmethane diisocyanate is changed from 45 parts to 42 parts, and the number of parts of plasticizer DOA is changed from 25 parts to 28 parts.

[0069] The other steps and conditions are the same as in Example 1.

[0070] Example 4: Preparation of a polyurethane potting compound

[0071] The difference from Example 1 is that in step S1, the number of parts of modified castor oil polyol H-368 is changed from 20 parts to 10 parts, and the number of parts of epoxy modified polyether polyol HM-2210 is changed from 15 parts to 25 parts; in step S2, the number of parts of 4,4-diphenylmethane diisocyanate is changed from 45 parts to 47 parts, and the number of parts of plasticizer DOA is changed from 25 parts to 23 parts.

[0072] The other steps and conditions are the same as in Example 1.

[0073] Example 5: Preparation of a polyurethane potting compound

[0074] The difference from Example 1 is that in step S1, the refined grade unmodified castor oil polyol is replaced with food grade unmodified castor oil polyol.

[0075] The other steps and conditions are the same as in Example 1.

[0076] Example 6: Preparation of a polyurethane potting compound

[0077] The difference from Example 1 is that in step S1, modified castor oil polyol H-368 is replaced with modified castor oil polyol X368.

[0078] The other steps and conditions are the same as in Example 1.

[0079] Comparative Example 1: Preparation of a polyurethane potting compound

[0080] The difference from Example 1 is that in step S1, no unmodified castor oil polyol is added, and the amount of modified castor oil polyol added is 80 parts.

[0081] The other steps and conditions are the same as in Example 1.

[0082] Comparative Example 2: Preparation of a polyurethane potting compound

[0083] The difference from Example 1 is that in step S1, no modified castor oil polyol is added, and the amount of refined unmodified castor oil polyol added is 80 parts.

[0084] The other steps and conditions are the same as in Example 1.

[0085] Comparative Example 3: Preparation of a polyurethane potting compound

[0086] The difference from Example 1 is that in step S1, the refined unmodified castor oil polyol is replaced by an equal amount (60 parts) of polyoxypropylene triol (molecular weight 1000).

[0087] The other steps and conditions are the same as in Example 1.

[0088] Comparative Example 4: Preparation of a polyurethane potting compound

[0089] The difference from Example 1 is that in step S1, the modified castor oil polyol is replaced by an equal amount (20 parts) of polyoxypropylene triol (molecular weight 1000).

[0090] The other steps and conditions are the same as in Example 1.

[0091] Comparative Example 5: Preparation of a polyurethane potting compound

[0092] The difference from Example 1 is that in step S1, no modified castor oil polyol is added, and the amount of epoxy modified polyether polyol HM-2210 added is 35 parts.

[0093] The other steps and conditions are the same as in Example 1.

[0094] Comparative Example 6: Preparation of a polyurethane potting compound

[0095] The difference from Example 1 is that in step S1, the modified castor oil polyol is replaced by an equal amount (20 parts) of epoxidized soybean oil 13150.

[0096] The other steps and conditions are the same as in Example 1.

[0097] Comparative Example 7: Preparation of a polyurethane potting compound

[0098] The difference from Example 1 is that in step S1, the epoxy-modified polyether polyol HM-2210 is replaced by an equal amount (15 parts) of epoxy resin E51.

[0099] The other steps and conditions are the same as in Example 1.

[0100] Comparative Example 8: Preparation of a polyurethane potting compound

[0101] The difference from Example 1 is that in step S1, the epoxy-modified polyether polyol HM-2210 is replaced by an equal amount (15 parts) of epoxy resin E44.

[0102] The other steps and conditions are the same as in Example 1.

[0103] Comparative Example 9: Preparation of a polyurethane potting compound

[0104] The difference from Example 1 is that in step S1, the amount of refined unmodified castor oil polyol added is changed from 60 parts to 50 parts, and the amount of modified castor oil polyol added is changed from 20 parts to 30 parts. Comparative Example 10: Preparation of a polyurethane potting compound.

[0105] The difference from Example 1 is that in step S1, the amount of refined unmodified castor oil polyol added is changed from 60 parts to 75 parts, and the amount of modified castor oil polyol added is changed from 20 parts to 5 parts.

[0106] Characterization of mechanical properties, weather resistance, and appearance properties of polyurethane potting compounds in experimental examples.

[0107] 1. Experimental Methods

[0108] (1) Appearance test: Mix the A component mixture and the B component mixture in a mass ratio of 1:1 to obtain 50g of glue. Then pour the glue into a 100mL plastic cup and perform vacuum degassing treatment. Finally, observe the appearance after curing.

[0109] (2) Hardness test: The potting compounds obtained in the above embodiments and comparative examples were tested using a hardness tester in accordance with the People's Republic of China National Standard GB / T531.2-2009.

[0110] (3) Defoaming test: Mix the A component mixture and the B component mixture at a mass ratio of 1:1 to obtain 50g of glue. Then pour the glue into a 100mL plastic cup and observe the internal bubbles after curing.

[0111] (4) Shear strength test: According to the People's Republic of China National Standard GB / T7124-2008, the polyurethane potting compound prepared in the above examples and comparative examples was used to make a standard shear part of 3003 aluminum material with a thickness of 0.2 mm. After curing for 7 days, the tensile strength was tested.

[0112] (5) Tensile strength test: According to the People's Republic of China National Standard GB / T 528-2009, the potting compounds obtained in the above embodiments and comparative examples were cured in a 200*200*4mm mold for 7 days, and then the tensile strength was tested after cutting with a Type I dumbbell-shaped cutter.

[0113] (6) Double 85 test: The potting compounds obtained from the above embodiments and comparative examples were placed in a constant temperature chamber at 85°C and 85% relative humidity, and a sensing test device was set up. After standing for 1000 hours, the appearance changes were observed.

[0114] 2. Experimental Results

[0115] Table 1. Mechanical properties, adhesive properties, weather resistance, and appearance properties of polyurethane potting compounds.

[0116]

[0117]

[0118] As shown in Table 1, the results of Example 1 and Comparative Example 1 indicate that when no unmodified castor oil polyol is added and only modified castor oil polyol is used, although the shear strength and tensile strength of the potting compound can be improved to a certain extent, it also causes an increase in the number of air bubbles, thereby affecting the sealing performance and appearance performance of the potting compound.

[0119] The results of Example 1 and Comparative Example 2 show that when no modified castor oil polyol is added and only unmodified castor oil polyol is used, although the number of bubbles is significantly reduced, the shear strength and tensile strength are greatly reduced, resulting in damage to mechanical properties and weather resistance.

[0120] The results of Examples 1 and Comparative Examples 3-4 show that a series of performance changes are observed when polyether polyols are used to replace unmodified or modified castor oil polyols. First, the shear strength of the aluminum material decreases significantly, a change not directly related to tensile strength. Second, the number of bubbles increases and the pore size becomes larger. More seriously, samples using polyether polyols instead of unmodified castor oil exhibit oil seepage after undergoing the double 85 test. These performance changes collectively affect the adhesive properties, sealing properties, and appearance properties of the potting compound.

[0121] The results of Example 1 and Comparative Examples 5-6 show that when epoxy-modified polyol or epoxidized soybean oil is used to replace modified castor oil polyol, the shear strength decreases significantly. Furthermore, the sample using epoxidized soybean oil to replace modified castor oil polyol exhibits severe yellowing after undergoing the double 85 test, which affects its adhesive properties, weather resistance, and appearance.

[0122] The results of Example 1 and Comparative Examples 7-8 show that when epoxy resins (E51, E44) are used to replace epoxy-modified polyols, the viscosity increases and compatibility with the castor oil system leads to a decrease in hardness, shear strength, and tensile strength, which directly affects the expression of adhesive performance and mechanical properties.

[0123] The results of Example 1 and Comparative Examples 9-10 indicate that when the amount of unmodified castor oil polyol or modified castor oil polyol added is too much or too little, the number of air bubbles may increase, thereby affecting the sealing performance and appearance performance of the potting compound; or it may have an adverse effect on the shear strength and tensile strength.

[0124] In summary, in the potting compound formulation of this application, the unmodified castor oil polyol, as the base resin, exhibits excellent compatibility and forms a close synergistic effect with the modified castor oil polyol. This combination not only significantly improves the toughness, weather resistance, and defoaming properties of the potting compound, but also greatly enhances its mechanical properties and further optimizes its weather resistance and transparency through the ingenious introduction of epoxy-modified polyol. The synergistic effect of these three components not only individually strengthens the potting compound's toughness (hardness ≥44, tensile strength >0.5), adhesion (shear strength >0.3), weather resistance (tensile strength >0.48 after double 85 testing), transparency (pale yellow transparent, with only slight yellowing after double 85 testing), and defoaming properties (bubble diameter <1mm, and number of bubbles <50), but also achieves mutual enhancement and complementarity of overall performance, optimizing comprehensive performance. This synergistic effect ensures that the potting compound maintains its stability and reliability even in harsh environments, providing long-lasting and effective support and protection for electronic components.

[0125] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A polyurethane potting compound, characterized in that, Includes component A and component B; Wherein, by weight, component A comprises: a polyol composition, 4-10 parts of plasticizer, 0.2-0.3 parts of defoamer, and 0.05-0.1 parts of catalyst; Component B comprises: 40-50 parts isocyanate, 20-30 parts flame retardant, and 20-30 parts plasticizer; The polyurethane potting compound contains no fillers; The polyol composition comprises, by weight, the following raw materials: 60-70 parts of unmodified castor oil polyol, 10-20 parts of modified castor oil polyol, and 5-25 parts of epoxy-modified polyol. The modified castor oil polyol is H-368 or X368; The epoxy-modified polyol is epoxy-modified polyether polyol HM-2210.

2. The polyurethane potting compound according to claim 1, characterized in that, The hydroxyl value of the unmodified castor oil polyol is 155~170 KOH / g.

3. The polyurethane potting compound according to claim 1, characterized in that, The plasticizer includes one or more of dimethyl phthalate, diisooctyl phthalate, dihexyl phthalate, diisodecyl phthalate, diisononyl phthalate, dibutyl sebacate, dioctyl sebacate, and dioctyl adipate.

4. The polyurethane potting compound according to claim 1, characterized in that, The isocyanate includes one or more of 2,4-toluene diisocyanate, 2,4-diphenylmethane diisocyanate, and 4,4-diphenylmethane diisocyanate.

5. The polyurethane potting compound according to claim 1, characterized in that, The flame retardant is an aliphatic phosphate flame retardant and / or an aromatic phosphate flame retardant.

6. A method for preparing the polyurethane potting compound according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Mix the dehydrated polyol composition, plasticizer, defoamer, and catalyst to obtain component A mixture; S2. The dehydrated plasticizer and flame retardant are mixed with isocyanate to obtain component B mixture; S3. After mixing the A component mixture obtained in step S1 with the B component mixture obtained in step S2, remove the bubbles and cure at room temperature to obtain the polyurethane potting compound.

7. The use of the polyurethane potting compound according to any one of claims 1 to 5 in the preparation of electrical coating adhesives.

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