Modified polyether polyol, method for preparing the same, polyurethane adhesive, method for preparing the same and application thereof

Abstract

The application belongs to the technical field of polyurethane adhesive materials, and particularly relates to a modified polyether polyol and a preparation method thereof, a polyurethane adhesive and a preparation method and application thereof. The preparation raw material of the modified polyether polyol comprises the following raw materials in parts by weight: 120-300 parts of high-functionality monomers, 30-150 parts of small-molecule polyols, and 1150 parts of alkylene oxides. The modified polyether polyol provided by the application has both structural properties and functional properties.

Description

Technical Field

[0001] This invention belongs to the technical field of polyurethane adhesive materials, specifically relating to a modified polyether polyol and its preparation method, a polyurethane adhesive and its preparation method and application. Background Technology

[0002] Polyurethane adhesives are organic polymer materials, hailed as the fifth largest plastic, and are widely used in many sectors of the national economy due to their excellent performance. Application areas include light industry, chemical industry, electronics, textiles, medical, construction, and automotive. Polyurethane adhesives are characterized by high strength, strong wear resistance, low-temperature resistance, oil resistance, and chemical corrosion resistance. Since their introduction in the 1930s, they have been widely used in various fields. However, with the expansion of polyurethane adhesive applications, their poor heat resistance has become increasingly prominent. Existing polyurethane adhesives have relatively poor heat resistance and low thermal decomposition temperatures, which greatly limits their application range. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a modified polyether polyol and its preparation method, a polyurethane adhesive and its preparation method, and its applications. This addresses at least one aspect of solving the above-mentioned technical problems.

[0004] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a raw material for preparing a modified polyether polyol comprising the following parts by weight: 120-300 parts high-functionality monomers, 30-150 parts small molecule polyols, and 1150 parts epoxides; The modified polyether polyol has a hydroxyl value of 340 mg / KOH to 360 mg / KOH.

[0005] Secondly, the present invention provides a method for preparing the above-mentioned modified polyether polyol, comprising the following steps: High-functionality monomers and small-molecule polyols are mixed to obtain a polyhydroxy mixed alcohol system; The polyhydroxy mixed alcohol system is polymerized with epoxide alkane, and after dehydration, modified polyether polyol is obtained.

[0006] Thirdly, the present invention provides a polyurethane adhesive, the raw materials of which include the above-mentioned modified polyether polyol.

[0007] Fourthly, the present invention provides a method for preparing the above-mentioned polyurethane adhesive, comprising the following steps: Polyurethane prepolymer, thixotropic agent and filler are mixed and emulsified to obtain polyurethane adhesive; The raw materials for preparing the polyurethane prepolymer include high molecular weight polyols, modified resins, isocyanates, adhesive catalysts, and silane coupling agents.

[0008] Fifthly, the present invention provides an application of the above-mentioned polyurethane adhesive in the field of automotive adhesives.

[0009] The modified polyether polyol provided by this invention has at least the following beneficial technical effects compared with the prior art: The modified polyether polyol provided by this invention possesses both structural and functional properties, with a hydroxyl value of 340 mg / KOH to 360 mg / KOH, a viscosity of 1500 mPa·s to 4000 mPa·s / 25℃, and a functionality of 4 to 5.

[0010] The method for preparing modified polyether polyols provided by this invention has at least the following beneficial technical effects compared with the prior art: The method for preparing modified polyether polyols provided by this invention involves mixing high-functionality monomers and small-molecule polyols to form a homogeneous, moderately reactive multi-hydroxyl mixed alcohol system; and polymerization reaction to polymerize the mixed alcohol system with epoxide alkane to obtain modified polyether polyols. The modified polyether polyols have the advantages of low temperature sensitivity and high temperature resistance. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described and illustrated below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0012] Obviously, the following description is merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0013] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand the invention and is not intended to limit the subject matter of the claims.

[0014] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present invention can be combined with each other to form new technical solutions.

[0015] Modified polyether polyols The first aspect of this invention provides a modified polyether polyol, the raw materials of which include the following parts by weight: 120-300 parts high-functionality monomers, 30-150 parts small molecule polyols, and 1150 parts epoxides; The modified polyether polyol has a hydroxyl value of 340 mg / KOH to 360 mg / KOH.

[0016] The modified polyether polyol provided in this invention combines highly cross-linked, high-functionality monomer macromolecules with low-functionality small polyol molecules in its raw materials. The highly cross-linked portion increases rigidity to stabilize the foam structure; the low-cross-linked long-chain structure counteracts intermolecular stress, preventing breakage in environments with drastic temperature changes. The modified polyether polyol prepared from the above raw materials maintains excellent high-temperature resistance and dimensional stability during foaming, while also exhibiting a certain degree of flexibility. The modified polyether polyol provided in this invention possesses both structural and functional properties, with a hydroxyl value of 340 mg / KOH to 360 mg / KOH, a viscosity of 1500 mPa·s to 4000 mPa·s / 25℃, and a functionality of 4 to 5.

[0017] In some embodiments, the high-functionality monomer includes at least one of sucrose, sorbitol, xylitol, and tetraethylenepentamine.

[0018] In some embodiments, the small molecule polyol includes at least one of glycerol, triethylene glycol, diethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, and ethylene glycol.

[0019] In some embodiments, alkyl epoxides include propylene oxide.

[0020] In some embodiments, the modified polyether polyol has the following structural formula:

[0021] Where n ranges from 5 to 55, and m ranges from 65 to 135.

[0022] In some specific embodiments, n ranges from 5 to 15, and m ranges from 65 to 75.

[0023] In some specific embodiments, n ranges from 10 to 20, and m ranges from 120 to 130.

[0024] In some specific embodiments, n ranges from 30 to 40, and m ranges from 120 to 130.

[0025] In some specific embodiments, n ranges from 45 to 55, and m ranges from 125 to 135.

[0026] Preparation method of modified polyether polyol A second aspect of the present invention provides a method for preparing the above-mentioned modified polyether polyol, comprising the following steps: S10. High-functionality monomers and small-molecule polyols are mixed to obtain a polyhydroxy mixed alcohol system.

[0027] S20. A polyhydroxy mixed alcohol system is polymerized with epoxide alkane, and after dehydration, a modified polyether polyol is obtained.

[0028] The method for preparing modified polyether polyols provided in this invention involves mixing high-functionality monomers and small-molecule polyols to form a homogeneous, moderately reactive multi-hydroxyl mixed alcohol system; and polymerization reaction to polymerize the mixed alcohol system with epoxide alkane to obtain modified polyether polyols. The modified polyether polyols have the advantages of low temperature sensitivity and high temperature resistance.

[0029] In some embodiments, the mixing process in step S10 above includes the following steps: S101. High-functionality monomers, small-molecule polyols and base catalysts are mixed at 100℃~105℃.

[0030] In some embodiments, during the mixing process in step S101 above, the moisture content of the mixture is controlled to be below 0.1%. In this case, it is possible to avoid the consumption of catalyst by trace amounts of water and its reaction with propylene oxide to generate unwanted monofunctional byproducts (propylene glycol), which would lead to a reduction in the molecular weight distribution width and functionality of the product.

[0031] In some embodiments, the alkaline catalyst in step S10 above includes potassium hydroxide.

[0032] In some embodiments, in step S10 above, the amount of alkaline catalyst added is 0.2% to 0.3% of the total mass of the raw materials for preparing 100 parts of modified polyether polyol.

[0033] In some embodiments, in step S20 above, the polymerization reaction includes the following steps: S201. The polyhydroxy mixed alcohol system is aged after being mixed with epoxide alkane at 90℃~130℃.

[0034] In some embodiments, in step S201 above, the mixing pressure is 0.1 MPa to 0.4 MPa.

[0035] In some embodiments, the curing time in step S201 is 2h to 3h.

[0036] In some embodiments, the polymerization reaction further includes the following steps in step S20 above: S202. Remove impurities from the matured product.

[0037] The above-mentioned impurity removal process mainly removes unreacted epoxides.

[0038] In some embodiments, in step S202 above, the impurity removal process includes the following steps: S2021. Remove impurities under pressure of -0.08MPa to -0.09MPa.

[0039] In some embodiments, in step S2021 above, the temperature for removing impurities is 100°C to 140°C.

[0040] In some embodiments, the time for impurity removal in step S2021 is 1h to 2h.

[0041] In some embodiments, in step S20 above, dehydration includes the following steps: S203. At 75℃~85℃, the crude product obtained from the polymerization reaction, phosphoric acid and water are stirred and mixed, and then mixed with the adsorbent to obtain a mixture.

[0042] S204. The mixture is vacuum dehydrated at 100℃~110℃ until the moisture content of the mixture is less than 0.1%.

[0043] In some embodiments, in step S203 above, the time for stirring and mixing the crude product, phosphoric acid, and water is 1h to 2h.

[0044] In some embodiments, in step S203 above, the amount of phosphoric acid added is 0.7% to 0.8% of the total mass of the raw materials for preparing the modified polyether polyol.

[0045] In some embodiments, in step S203 above, the mass fraction of phosphoric acid is 10% to 15%.

[0046] In some embodiments, in step S203 above, the amount of water added is 5% to 6% of the total mass of the raw materials for preparing the modified polyether polyol.

[0047] In some embodiments, in step S203 above, the adsorbent includes magnesium silicate.

[0048] In some embodiments, in step S203 above, the amount of adsorbent added is 0.15% to 0.2% of the total mass of the raw materials for preparing the modified polyether polyol.

[0049] In some embodiments, in step S203 above, the pressure of vacuum dehydration is -0.08MPa to -0.09MPa.

[0050] In some embodiments, in step S203 above, the vacuum dehydration time is 3h to 5h.

[0051] Polyurethane adhesives A third aspect of this invention provides a polyurethane adhesive comprising the following raw materials in parts by weight: 65 parts high molecular weight polyol, 10 to 15 parts modified resin, 10 to 20 parts isocyanate, 0.5 to 1 part adhesive catalyst, 0.5 to 1 part silane coupling agent, 5 to 10 parts thixotropic agent, 60 to 70 parts filler; Among them, the high molecular weight polyols include at least one of polyether polyols and the modified polyether polyols mentioned above.

[0052] In some embodiments, the modified resin includes bisphenol A polyoxypropylene ether.

[0053] In some embodiments, the average molecular weight of bisphenol A polyoxypropylene ether is 400-600.

[0054] In some embodiments, the isocyanate includes diphenylmethane diisocyanate.

[0055] In some embodiments, the isocyanate index in diphenylmethane diisocyanate is 1.2 to 1.8.

[0056] In some embodiments, the adhesive catalyst includes at least one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, and dibutyltin diacetate.

[0057] In some embodiments, the silane coupling agent includes 3-glycidyl etheroxypropyltrimethoxysilane (KH560).

[0058] In some embodiments, the thixotropic agent includes at least one of fumed silica, organobentonite, and polyamide wax.

[0059] In some embodiments, fumed silica is provided by Hubei Huifu Nanomaterials Co., Ltd.

[0060] In some embodiments, the organic bentonite is provided by Hebei Hengyue Mineral Products Co., Ltd.

[0061] In some embodiments, the polyamide wax is provided by Zhejiang Fenghong New Material Co., Ltd.

[0062] In some embodiments, the filler includes at least one of aluminum hydroxide, calcium carbonate, silica powder, talc powder, and mica powder.

[0063] In some embodiments, aluminum hydroxide is provided by Zibo Yideye New Material Technology Co., Ltd.

[0064] In some embodiments, calcium carbonate is provided by Jiangxi Hengshengtai New Materials Co., Ltd.

[0065] In some embodiments, the silicon micropowder is provided by Foshan Orite New Material Technology Co., Ltd.

[0066] In some embodiments, the talc powder is provided by Laizhou Shengkai Talc Co., Ltd.

[0067] In some embodiments, the mica powder is provided by Hebei Hengyue Mineral Products Co., Ltd.

[0068] Preparation methods for polyurethane adhesives A fourth aspect of this invention provides a method for preparing the above-mentioned polyurethane adhesive, comprising the following steps: s10. Polyurethane prepolymer, thixotropic agent and filler are mixed and emulsified to obtain polyurethane adhesive; The raw materials for preparing polyurethane prepolymers include high molecular weight polyols, modified resins, isocyanates, adhesive catalysts, and silane coupling agents.

[0069] In some embodiments, in step s10 above, the preparation of the polyurethane prepolymer includes the following steps: s101. Polymer polyol, modified resin, adhesive catalyst and silane coupling agent are mixed and dehydrated under vacuum, and then reacted with isocyanate.

[0070] In some embodiments, in step s101 above, the temperature of the vacuum dehydration treatment is 110°C to 120°C.

[0071] In some embodiments, in step s101 above, the vacuum dehydration treatment time is 2h~3h.

[0072] In some embodiments, in step s101 above, the temperature of the mixing reaction is 60°C to 80°C.

[0073] In some embodiments, the mixing reaction time in step s101 above is 40 min to 60 min.

[0074] In some embodiments, in step s10 above, the mixing emulsification includes the following steps: s102. Disperse and emulsify the polyurethane prepolymer, thixotropic agent, and filler at a stirring speed of 200 rpm.

[0075] The following description, in conjunction with specific embodiments, provides further details.

[0076] Example 1 Example 1 provides a modified polyether polyol with the following structural formula: ; The value of m is between 5 and 15, and the value of n is between 65 and 75.

[0077] It consists of the following raw materials in parts by weight: 250 parts sucrose, 100 parts glycerol and 1150 parts propylene oxide.

[0078] This embodiment also provides a method for preparing the above-mentioned modified polyether polyol, the steps of which are as follows: E10. Mixing treatment: Sucrose, glycerol and 4.5 parts by weight of potassium hydroxide (alkali catalyst) are mixed and then vacuum dehydrated at 100°C to control the moisture content of the mixture to be less than 0.1% to obtain a polyhydroxy mixed alcohol system.

[0079] E20. Polymerization reaction: E201. The polyhydroxy mixed alcohol system was mixed with epoxy alkane at 102℃±2℃ and then aged for 3h under a pressure of less than 0.4MPa. E202. The matured product was subjected to a pressure of -0.08MPa to -0.09MPa and a temperature of 112℃±2℃ for 1 hour to remove unreacted propylene oxide monomers.

[0080] E30. Dehydration: E301. At 80℃±5℃, the crude product obtained from the polymerization reaction, phosphoric acid and water are stirred and mixed for 1 hour, and then mixed with magnesium silicate to obtain a mixture; Of these, phosphoric acid accounts for 10.57 parts by weight, water accounts for 75 parts by weight, and magnesium silicate accounts for 2.25 parts by weight.

[0081] E302. At 105℃±5℃, the mixture is vacuum dehydrated for 4 hours under a vacuum of -0.08MPa to -0.09MPa until the moisture content of the mixture is less than 0.1%, to obtain modified polyether polyol.

[0082] Example 2 Example 2 provides a modified polyether polyol with the following structural formula: ; The value of m is between 10 and 20, and the value of n is between 120 and 130.

[0083] It consists of the following raw materials in parts by weight: 120 parts sucrose, 30 parts glycerol and 1150 parts propylene oxide.

[0084] This embodiment also provides a method for preparing the above-mentioned modified polyether polyol, the steps of which are basically the same as those in Example 1.

[0085] Example 3 Example 3 provides a modified polyether polyol with the following structural formula: ; The value of m is between 30 and 40, and the value of n is between 120 and 130.

[0086] It consists of the following raw materials in parts by weight: 150 parts sucrose, 50 parts glycerol and 1150 parts propylene oxide.

[0087] This embodiment also provides a method for preparing the above-mentioned modified polyether polyol, the steps of which are basically the same as those in Example 1.

[0088] Example 4 Example 4 provides a modified polyether polyol with the following structural formula: ; The value of m is between 45 and 55, and the value of n is between 125 and 135.

[0089] It consists of the following raw materials in parts by weight: 300 parts sucrose, 150 parts glycerol and 1150 parts propylene oxide.

[0090] This embodiment also provides a method for preparing the above-mentioned modified polyether polyol, the steps of which are basically the same as those in Example 1.

[0091] Comparative Example 1 Comparative Example 1 provides a sucrose polyether polyol, purchased from Jurong Ningwu New Materials Co., Ltd.

[0092] Example 5 Example 5 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 1, 12 parts of bisphenol A polyoxypropylene ether, 15 parts of diphenylmethane diisocyanate, 0.8 parts of dibutyltin dilaurate, 0.8 parts of KH-560, 7 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 500. In diphenylmethane diisocyanate, the isocyanate index is 1.5.

[0093] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are as follows: e10. Preparation of polyurethane prepolymer: The modified polyether polyol, bisphenol A polyoxypropylene ether, dibutyltin dilaurate and KH-560 provided in Example 1 were mixed and dehydrated under vacuum, and then reacted with diphenylmethane diisocyanate. The vacuum dehydration process was carried out at a temperature of 115℃ for 2 hours. The temperature for the mixed reaction was 70℃ and the time was 50 min.

[0094] e20. Mixed emulsion The polyurethane prepolymer, thixotropic agent, and filler were dispersed and emulsified at a stirring speed of 1400 rpm to obtain a polyurethane adhesive.

[0095] Example 6 Example 6 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 1, 10 parts of bisphenol A polyoxypropylene ether, 10 parts of diphenylmethane diisocyanate, 0.5 parts of dibutyltin dilaurate, 0.5 parts of KH-560, 5 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 400. In diphenylmethane diisocyanate, the isocyanate index is 1.2.

[0096] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0097] Example 7 Example 7 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 1, 15 parts of bisphenol A polyoxypropylene ether, 20 parts of diphenylmethane diisocyanate, 1 part of dibutyltin dilaurate, 1 part of KH-560, 10 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 600. In diphenylmethane diisocyanate, the isocyanate index is 1.8.

[0098] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0099] Example 8 Example 8 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 2, 12 parts of bisphenol A polyoxypropylene ether, 15 parts of diphenylmethane diisocyanate, 0.8 parts of dibutyltin dilaurate, 0.8 parts of KH-560, 7 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 500. In diphenylmethane diisocyanate, the isocyanate index is 1.5.

[0100] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0101] Example 9 Example 9 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 3, 12 parts of bisphenol A polyoxypropylene ether, 15 parts of diphenylmethane diisocyanate, 0.8 parts of dibutyltin dilaurate, 0.8 parts of KH-560, 7 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 500. In diphenylmethane diisocyanate, the isocyanate index is 1.5.

[0102] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0103] Example 10 Example 10 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Example 4, 12 parts of bisphenol A polyoxypropylene ether, 15 parts of diphenylmethane diisocyanate, 0.8 parts of dibutyltin dilaurate, 0.8 parts of KH-560, 7 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 500. In diphenylmethane diisocyanate, the isocyanate index is 1.5.

[0104] This embodiment also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0105] Comparative Example 2 Comparative Example 2 provides a polyurethane adhesive, which is composed of the following components in parts by weight: 65 parts of the modified polyether polyol provided in Comparative Example 1, 12 parts of bisphenol A polyoxypropylene ether, 15 parts of diphenylmethane diisocyanate, 0.8 parts of dibutyltin dilaurate, 0.8 parts of KH-560, 7 parts of fumed silica, and 65 parts of aluminum hydroxide. The average molecular weight of bisphenol A polyoxypropylene ether is 500. In diphenylmethane diisocyanate, the isocyanate index is 1.5.

[0106] This comparative example also provides a method for preparing the above-mentioned polyurethane adhesive, the steps of which are basically the same as those in Example 5.

[0107] To verify the advancements of the modified polyether polyol and its preparation method, and the polyurethane adhesive and its preparation method provided in the embodiments of the present invention, the polyurethane adhesives obtained in Examples 5-10 and Comparative Example 2 were cured under standard conditions (23±2℃, 50±5% RH) for 7 days, and their hardness, density, shear strength, and elongation at break were tested. After further damp heat aging (85℃, 85% RH) for 7 days, their hardness, density, shear strength, and elongation at break were tested again. The performance was tested according to the testing standards shown in Table 1, and the results are shown in Table 2 below.

[0108]

[0109] Table 2

[0110] From the table above, at least the following conclusions can be drawn: The hardness and density of the polyurethane structural adhesives obtained in each embodiment and comparative example were all within the specified range. The polyurethane structural adhesive of Example 5 exhibited the best shear strength and elongation at break after hygrothermal aging. This indicates that using sucrose (8 hydroxyl groups) and glycerol (3 hydroxyl groups) as initiators, and modifying them with propylene oxide under an alkaline catalyst, ultimately synthesizes a polyether polyol with high functionality and a high hydroxyl value, which can provide a rigid network structure with high strength and high modulus. Compared to Example 3, using ordinary commercial sucrose as a substitute resulted in poor hygrothermal stability and low mechanical properties after aging, similar to Example 1. Compared to Example 2, adjusting the ratio of sucrose to glycerol resulted in a lower hardness of the colloid obtained in Example 1, which is closely related to the functionality and hydroxyl value of the synthesized polyol. Higher polyol functionality leads to greater crosslinking density, resulting in higher hardness and tensile strength of the cured adhesive layer. Conversely, excessively low functionality (e.g., 2-functionality) easily forms a linear structure, resulting in a more flexible adhesive layer with lower hardness. A higher hydroxyl value indicates a smaller molecular weight and a higher content of active hydroxyl groups in the polyol, resulting in a denser distribution of crosslinking points and higher hardness of the adhesive layer after the reaction. Conversely, a low hydroxyl value indicates a larger molecular weight, insufficient crosslinking density, and lower hardness. It should be noted that this invention is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this invention are included within the technical scope of this invention. Furthermore, various modifications to the embodiments that can be conceived by those skilled in the art, and other ways of constructing embodiments by combining some of the constituent elements, without departing from the spirit of this invention, are also included within the scope of this invention.

Claims

1. A modified polyether polyol, characterized in that, The raw materials for preparing the modified polyether polyol include the following parts by weight: 120-300 parts high-functionality monomers, 30-150 parts small molecule polyols, and 1150 parts epoxides; The modified polyether polyol has a hydroxyl value of 340 mg / KOH to 360 mg / KOH.

2. The modified polyether polyol according to claim 1, characterized in that, It satisfies at least one of the following characteristics (1) to (3): (1) The high-functionality monomer includes at least one of sucrose, sorbitol, xylitol, and tetraethylenepentamine; (2) The small molecule polyol includes at least one of glycerol, triethylene glycol, diethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol, and ethylene glycol; (3) The epoxide hydrocarbons include propylene oxide.

3. The modified polyether polyol according to claim 1 or 2, characterized in that, It satisfies at least one of the following characteristics (1) to (2): (1) The viscosity of the modified polyether polyol is 1500 mPa·s to 4000 mPa·s at 25°C; (2) The functionality of the modified polyether polyol is 4 to 5.

4. A method for preparing the modified polyether polyol according to any one of claims 1 to 3, characterized in that, Includes the following steps: High-functionality monomers and small-molecule polyols are mixed to obtain a polyhydroxy mixed alcohol system; The polyhydroxy mixed alcohol system is polymerized with epoxide alkane, and after dehydration, modified polyether polyol is obtained.

5. The method for preparing the modified polyether polyol according to claim 4, characterized in that, It satisfies at least one of the following characteristics (1) to (3): (1) The mixing process includes the following steps: High-functionality monomers, small-molecule polyols, and base catalysts are mixed at 100℃~105℃; (2) The polymerization reaction includes the following steps: The polyhydroxy mixed alcohol system was aged after being mixed with epoxy alkane at 90℃~130℃; (3) The dehydration includes the following steps: At 75℃~85℃, the crude product obtained from the polymerization reaction, phosphoric acid and water are stirred and mixed, and then mixed with the adsorbent to obtain a mixture. The mixture is vacuum dehydrated at 100℃~110℃ until the moisture content of the mixture is less than 0.1%.

6. The method for preparing the modified polyether polyol according to claim 5, characterized in that, It satisfies at least one of the following characteristics (1) to (3): (1) In the hybrid processing, at least one of the following features 1) to 2) is satisfied: 1) The alkaline catalyst includes potassium hydroxide; 2) The amount of the alkaline catalyst added is 0.2% to 0.3% of the total mass of the raw materials for preparing 100 parts of modified polyether polyol; (2) The polymerization reaction satisfies at least one of the following characteristics 1) to 6): 1) The mixing pressure is 0.1 MPa to 0.4 MPa; 2) The maturation time is 2 to 3 hours; 3) The polymerization reaction further includes the following steps: The matured product is then purified to remove impurities. 4) The impurity removal process includes the following steps: Impurity removal under pressures of -0.08 MPa to -0.09 MPa; 5) The temperature for impurity removal is 100℃~140℃; 6) The impurity removal time is 1 to 2 hours; (3) The dehydration process satisfies at least one of the following characteristics 1) to 7): 1) The crude product, phosphoric acid, and water should be mixed for 1 to 2 hours; 2) The amount of phosphoric acid added is 0.7%~0.8% of the total mass of the raw materials for preparing the modified polyether polyol; 3) The mass fraction of phosphoric acid is 10%~15%; 3) The amount of water added is 5% to 6% of the total mass of the raw materials for preparing the modified polyether polyol; 4) The adsorbent includes magnesium silicate; 5) The amount of adsorbent added is 0.15%~0.2% of the total mass of the raw materials for preparing the modified polyether polyol; 6) The pressure for vacuum dehydration is -0.08MPa to -0.09MPa; 7) The vacuum dehydration time is 3h~5h.

7. A polyurethane adhesive, characterized in that, The raw materials for preparation include the modified polyether polyol as described in any one of claims 1 to 3.

8. The polyurethane adhesive according to claim 7, characterized in that, It satisfies at least one of the following characteristics (1) to (9): (1) The polyurethane adhesive comprises the following raw materials in parts by weight: 60-70 parts of the modified polyether polyol, 10-15 parts of the modified resin, 10-20 parts of the isocyanate, 0.5-1 part of the adhesive catalyst, 0.5-1 part of the silane coupling agent, 5-10 parts of the thixotropic agent, and 60-70 parts of the filler. (2) Modified resins include bisphenol A polyoxypropylene ether; (3) The average molecular weight of bisphenol A polyoxypropylene ether is 400~600; (4) Isocyanates include diphenylmethane diisocyanate; (5) In diphenylmethane diisocyanate, the isocyanate index is 1.2~1.8; (6) The adhesive catalyst includes at least one of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, and dibutyltin diacetate; (7) Silane coupling agents include 3-glycidyl etheroxypropyltrimethoxysilane; (8) The thixotropic agent includes at least one of fumed silica, organobentonite, and polyamide wax; (9) The filler includes at least one of aluminum hydroxide, calcium carbonate, silica powder, talc powder and mica powder.

9. A method for preparing a polyurethane adhesive as described in claim 7 or 8, characterized in that, Includes the following steps: Polyurethane prepolymer, thixotropic agent and filler are mixed and emulsified to obtain polyurethane adhesive; The raw materials for preparing the polyurethane prepolymer include high molecular weight polyols, modified resins, isocyanates, adhesive catalysts, and silane coupling agents.

10. The application of a polyurethane adhesive as described in claim 7 or 8 in the field of automotive adhesives.

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