Polyol composition, polyurethane pouring sealant and preparation method and application thereof

Abstract

The invention belongs to the technical field of electronic pouring sealants, and particularly relates to a polyol composition, a polyurethane pouring sealant and a preparation method and application thereof. The polyol composition with a synergistic effect is prepared by ingeniously fusing the non-modified castor oil polyol, the modified castor oil polyol and the epoxy modified polyol. Wherein the non-modified castor oil polyol and the modified castor oil polyol are complementarily matched, so that the internal compatibility of the colloid is remarkably enhanced, the structure of the colloid is optimized, and the toughness, the adhesion, the weather resistance and the defoaming performance of the colloid are greatly improved. Meanwhile, due to the addition of the epoxy modified polyol, the crosslinking density is improved, the mechanical property is further enhanced, the weather resistance and transparency are further optimized, and precipitation of colloid components is effectively avoided. Therefore, the polyurethane pouring sealant prepared from the polyol composition has excellent toughness, weather resistance, adhesion, transparency and defoaming performance, and is beneficial to promoting the development of industries such as electronics, new energy and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic potting adhesives, and more specifically, relates to a polyol composition, a polyurethane potting adhesive, and a preparation method and application thereof. Background Art

[0002] During the manufacturing process of traditional washing machines, smart water meters, smart toilets and other household appliances, polyurethane potting glue is generally used to seal the circuits for protection to achieve the effects of dust-proof, corrosion-proof, moisture-proof and earthquake-resistant, thereby effectively extending the service life of home appliances.

[0003] However, the current polyurethane potting glue still faces multiple challenges in its application. First, its lack of transparency leads to limited light penetration, which in turn increases the difficulty of maintenance and inspection. Secondly, in a high temperature environment, the polyurethane potting glue is easy to soften, thus affecting its sealing performance. In addition, bubbles are easily generated during the potting process, which not only further weakens its sealing performance, but also damages the appearance quality of the product. Furthermore, insufficient toughness makes the polyurethane potting glue easy to break when facing external impact or vibration. It is particularly critical that poor bonding performance will directly lead to a decrease in the stability of electronic components, thereby affecting the heat dissipation effect, safety and overall service life. Finally, the polyurethane potting glue is also prone to discoloration during long-term use, which not only affects the appearance, but also the problem of insufficient hardness will make it easier to wear under the action of external forces, thereby further shortening the service life. To solve the above problems, Chinese patent application CN117801764A prepared a high-performance polyurethane potting glue by using sorbitol-based polyether polyols, castor oil polyols and epoxy-modified polyols, which performs well in hardness and moisture and heat resistance. However, although the patent application has improved the performance of polyurethane potting adhesive to a certain extent, the problems of low transparency, easy generation of bubbles, insufficient toughness, poor bonding performance 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 prior art polyurethane potting glue, such as low transparency, easy generation of bubbles, insufficient toughness, poor bonding performance and easy discoloration, and provide a polyol composition.

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

[0006] Another object of the present invention is to provide a method for preparing the polyurethane potting adhesive.

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

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] The invention protects a polyol composition, which comprises the following raw materials by weight: 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 the present invention is usually used as the main component of the potting glue, constructs a basic framework and provides key functional characteristics. As the main body, it gives the potting glue good adhesion, mechanical strength after curing, weather resistance and transparency, etc. In addition, the synergistic effect of the various components in the polyol composition significantly enhances the toughness, chemical corrosion resistance and environmental aging resistance of the potting glue. In particular, as a base resin, non-modified castor oil polyol forms a close synergistic effect with modified castor oil polyol by virtue of its excellent compatibility, which not only significantly improves the toughness, weather resistance and defoaming of the potting glue, but also greatly enhances the mechanical properties of the potting glue by introducing epoxy-modified polyols, and further optimizes weather resistance and transparency, effectively preventing the precipitation of colloidal components. The synergistic effect of these three components realizes mutual enhancement and complementarity in performance, so that the potting glue can still maintain its stability and reliability under harsh conditions, and provides long-term and effective protection and support for electronic components.

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

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

[0013] Furthermore, the hydroxyl value of the modified castor oil polyol is 180 to 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] The present invention protects a polyurethane potting adhesive, characterized in that it comprises a component A and a component B;

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

[0018] The B component includes: 40-50 parts of isocyanate, 20-30 parts of flame retardant, and 20-30 parts of plasticizer;

[0019] The polyurethane potting adhesive does not contain fillers.

[0020] Component A and component B together constitute a high-performance polyurethane potting compound, each of which plays an indispensable role. As the main body of the potting compound, component A constructs the basic framework and provides key functional properties including good adhesion, mechanical strength after curing, weather resistance and transparency. At the same time, the synergistic effect of the various components in component A significantly enhances the toughness, chemical corrosion resistance and environmental aging resistance of the potting compound. Component B significantly improves the flame retardant properties of the potting compound by adding flame retardants, ensuring its safety and reliability; and further improves the flexibility and processing performance of the potting compound by optimizing the selection of plasticizers. In summary, the synergistic effect of components A and B constructs a polyurethane potting compound with high toughness, high adhesion and excellent processing performance.

[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 defoaming agent is a silicone defoaming agent and / or a non-silicon defoaming agent.

[0023] Furthermore, the defoaming agent 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 an organic tin catalyst, an organic bismuth catalyst, an organic zinc catalyst, and an organic amine catalyst.

[0025] Furthermore, the catalyst is an organotin catalyst, because it has excellent comprehensive performance and relatively low cost.

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

[0027] Furthermore, 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 tolylene diphenyl phosphate.

[0031] The present invention provides a method for preparing the polyurethane potting adhesive, comprising the following steps:

[0032] S1. The dehydrated polyol composition obtained above, the plasticizer, the defoamer and the catalyst are mixed to obtain a mixture of component A;

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

[0034] S3. The component A mixture obtained in step S1 and the component B mixture obtained in step S2 are mixed evenly, degassed, and cured at room temperature to obtain the polyurethane potting adhesive.

[0035] The present invention prepares a mixture of component A and component B respectively, mixes the two, and successfully prepares a polyurethane potting glue through a degassing and curing process. This preparation process not only ensures the uniformity and stability of the potting glue, but also gives it excellent performance. In terms of mechanical properties, its hardness, tensile strength and other indicators are all excellent; in terms of transparency and weather resistance, even after rigorous aging tests (such as double 85 tests), the potting glue can still maintain high transparency and is not easy to yellow and precipitate; in terms of bonding performance, its shear strength is excellent; at the same time, it also has good defoaming performance, ensuring the flatness and sealing effect of the surface of the potting glue.

[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 stirring mixing.

[0039] Furthermore, the stirring and mixing condition is 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] Furthermore, in step S3, the mass ratio of the component A mixture to the component B mixture is 1:(0.8-1.2).

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

[0044] The present invention protects the use of the polyurethane potting adhesive in preparing electrical appliance potting adhesive.

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

[0046] The present invention prepares a synergistic polyol composition by ingeniously fusing non-modified castor oil polyol, modified castor oil polyol and epoxy-modified polyol. Wherein, the complementary collocation of non-modified castor oil polyol and modified castor oil polyol not only significantly enhances the compatibility inside the colloid, optimizes the colloid structure, but also greatly improves its toughness, adhesion, weather resistance and defoaming performance. At the same time, the addition of epoxy-modified polyol improves its cross-linking density, and then enhances its mechanical properties, further optimizes weather resistance and transparency, and effectively avoids the precipitation of colloid components. Therefore, the polyurethane potting glue prepared by the polyol composition has excellent toughness, weather resistance, adhesion, transparency and defoaming performance, which is conducive to promoting the development of industries such as electronics and new energy. DETAILED DESCRIPTION

[0047] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

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

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

[0050] Modified castor oil polyol: H-368 purchased from Ito Oil Manufacturing Co., Ltd. (hydroxyl value 180KOH / g), X368 purchased from Fucheng County 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 Haierma Technology Co., Ltd.;

[0053] Polyether polyol: polyoxypropylene 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] Defoaming agent: BYK-088 was purchased from BYK, Germany;

[0057] Catalyst: Dibutyltin dilaurate was purchased from Guangzhou Haoyi New Materials 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. 60 parts of refined non-modified 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 were mixed in a high-speed machine and stirred at 300 rpm / min for 15 min until a uniform state, followed by vacuum dehydration at 120° C. for 3 h to obtain a mixture of component A;

[0062] S2. 25 parts of DOA and 30 parts of triethyl phosphate (TEP) were heated to 120°C for vacuum dehydration for 2h, then cooled to 60°C, and then 45 parts of 4,4-diphenylmethane diisocyanate were added and mixed uniformly to obtain a mixture of component B;

[0063] S3. The component A mixture obtained in step S1 and the component B mixture obtained in step S2 are mixed evenly in a mass ratio of 1:1, and then subjected to vacuum degassing treatment, and then cured at room temperature for 48 hours to obtain a polyurethane potting adhesive.

[0064] Example 2 Preparation of a polyurethane potting compound

[0065] The difference from Example 1 is that in step S1, the amount of non-modified castor oil polyol is changed from 60 parts to 70 parts, and the amount 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 those 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 non-modified 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 those 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 modified castor oil polyol H-368 is changed from 20 parts to 10 parts, and the number of epoxy modified polyether polyol HM-2210 is changed from 15 parts to 25 parts; in step S2, the number of 4,4-diphenylmethane diisocyanate is changed from 45 parts to 47 parts, and the number of plasticizer DOA is changed from 25 parts to 23 parts.

[0072] The other steps and conditions are the same as those 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 by food grade unmodified castor oil polyol.

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

[0076] Example 6 Preparation of a polyurethane potting compound

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

[0078] The other steps and conditions are the same as those 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 added amount of modified castor oil polyol is 80 parts.

[0081] The other steps and conditions are the same as those 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 added amount of refined grade non-modified castor oil polyol is 80 parts.

[0084] The other steps and conditions are the same as those 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 grade non-modified 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 those 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 those 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 added amount of epoxy-modified polyether polyol HM-2210 is 35 parts.

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

[0103] Comparative Example 9 Preparation of a polyurethane potting adhesive

[0104] The difference from Example 1 is that in step S1, the amount of refined grade non-modified 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.

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

[0106] Experimental example: Characterization of mechanical properties, weather resistance and appearance properties of polyurethane potting glue

[0107] 1. Experimental Methods

[0108] (1) Appearance test: A mixture of component A and a mixture of component B in a mass ratio of 1:1 were stirred to obtain 50 g of glue, and then the glue was poured into a 100 mL plastic cup and subjected to vacuum degassing treatment. Finally, the appearance of the glue after curing was observed.

[0109] (2) Hardness test: The potting glue obtained in the above-mentioned embodiments and comparative examples was tested using a hardness tester according to the national standard GB / T531.2-2009 of the People's Republic of China.

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

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

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

[0113] (6) Double 85 test: The potting glue obtained in the above embodiments and comparative examples was placed in a constant temperature box at 85°C and relative humidity of 85%, set up a sensor test device, and left to stand for 1000 hours to observe the changes in its appearance.

[0114] 2. Experimental results

[0115] Table 1 Mechanical properties, bonding properties, weather resistance and appearance performance tests of polyurethane potting glue

[0116]

[0117]

[0118] As can be seen from Table 1, the results of Example 1 and Comparative Example 1 show that when non-modified castor oil polyol is not added and all 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 the problem of increased number of 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 all 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 the mechanical properties and weather resistance.

[0120] The results of Example 1 and Comparative Examples 3-4 show that when polyether polyols are used to replace non-modified or modified castor oil polyols, a series of performance changes are observed. First, the shear strength of the aluminum material is greatly reduced, and this change is not directly related to the tensile strength. Secondly, the number of bubbles increases and the pore size becomes larger. More seriously, the sample using polyether polyols to replace non-modified castor oil will also have oil leakage after undergoing the double 85 test. These performance changes jointly affect the bonding performance, sealing performance and appearance performance of the potting compound.

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

[0122] The results of Example 1 and Comparative Examples 7 to 8 show that when epoxy resin (E51, E44) is used to replace epoxy-modified polyols, the hardness, shear strength and tensile strength decrease due to viscosity increase and compatibility issues with the castor oil system, which directly affects the expression of bonding properties and mechanical properties.

[0123] The results of Example 1 and Comparative Examples 9 to 10 show that when the addition amount of unmodified castor oil polyol or modified castor oil polyol is too much or too little, it may lead to an increase in the number of bubbles, 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 glue formula of the present application, non-modified castor oil polyol as the base resin, with its excellent compatibility, forms a close synergistic effect with modified castor oil polyol, this combination not only significantly improves the toughness, weather resistance and defoaming of the potting glue, but also by ingeniously introducing epoxy modified polyols, greatly enhancing the mechanical properties of the potting glue, and further optimizing the weather resistance and transparency. The synergistic effect of these three components not only strengthens the toughness (hardness ≥ 44, tensile strength > 0.5), adhesion (shear strength > 0.3), weather resistance (tensile strength > 0.48 after double 85 test), transparency (light yellow transparent, and the color only slightly turns yellow after double 85 test) and defoaming (bubble diameter < 1mm, and the number of bubbles < 50) of the potting glue, but also realizes the mutual enhancement and complementarity of performance as a whole, and optimizes the comprehensive performance. This synergistic effect ensures that the potting glue can still maintain its stability and reliability in harsh environments, providing long-term 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 equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A polyol composition, characterized in that The raw materials are as follows, calculated by weight: 60-70 parts of unmodified castor oil polyol, 10-20 parts of modified castor oil polyol and 5-25 parts of epoxy modified polyol.

2. The polyol composition according to claim 1, characterized in that: The hydroxyl value of the non-modified castor oil polyol is 155-170 KOH / g.

3. The polyol composition according to claim 1, characterized in that: The hydroxyl value of the modified castor oil polyol is 180 to 220 KOH / g.

4. The polyol composition according to claim 1, characterized in that: The epoxy-modified polyol includes one or more of epoxy-modified polyether polyol, epoxy-modified polyester polyol and epoxy-modified polylactic acid polyol.

5. A polyurethane potting adhesive, characterized in that: It includes component A and component B; Wherein, the component A comprises, by weight: the polyol composition according to any one of claims 1 to 4, 4 to 10 parts of a plasticizer, 0.2 to 0.3 parts of a defoamer, and 0.05 to 0.1 parts of a catalyst; The B component includes: 40-50 parts of isocyanate, 20-30 parts of flame retardant, and 20-30 parts of plasticizer; The polyurethane potting adhesive does not contain fillers.

6. The polyurethane potting adhesive according to claim 5, 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.

7. The polyurethane potting adhesive according to claim 5, characterized in that: The isocyanate includes one or more of 2,4-toluene diisocyanate, 2,4-diphenylmethane diisocyanate, and 4,4-diphenylmethane diisocyanate.

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

9. The method for preparing the polyurethane potting adhesive according to any one of claims 5 to 8, characterized in that: The following steps are involved: S1. The dehydrated polyol composition according to any one of claims 1 to 4, a plasticizer, a defoamer, and a catalyst are mixed to obtain a mixture of component A; S2. The dehydrated plasticizer and flame retardant are mixed with isocyanate to obtain a mixture of component B; S3. The component A mixture obtained in step S1 and the component B mixture obtained in step S2 are mixed evenly, degassed, and cured at room temperature to obtain the polyurethane potting adhesive.

10. Use of the polyol composition according to any one of claims 1 to 4 or the polyurethane potting adhesive according to any one of claims 5 to 8 in the preparation of electrical appliance coating adhesive.

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