Highly adhesive electrically insulating polyolefin hot melt adhesive and method for its preparation

Abstract

The application discloses a kind of high bonding electric insulating polyolefin hot melt adhesive and preparation method thereof, it is related to hot melt adhesive technical field.The high bonding electric insulating polyolefin hot melt adhesive prepared by the application includes modified phenolic resin and crosslinking metallocene polyethylene, the modified phenolic resin is prepared by the reaction of polymeric isomerous decanol and polyethylene glycol derivative, the polymeric isomerous decanol is prepared by the reaction of polymeric rosin epoxy resin and isomerous decanol polyoxyethylene ether, the polymeric rosin epoxy resin is prepared by the reaction of polymeric rosin and epoxide chloropropane, the polyethylene glycol derivative is prepared by the reaction of aldehyde group polyethylene glycol and amino polyoxyethylene ether;Crosslinking metallocene polyethylene is prepared by the crosslinking of metallocene polyethylene, modified nanometer silicon dioxide and crosslinking agent, the modified nanometer silicon dioxide is prepared by the reaction of vinyl tris (2-methoxy ethoxy) silane and nanometer silicon dioxide, improve electric insulating property, also make hot melt adhesive still can maintain good stability and strength under high temperature environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot melt adhesive, in particular to a high-bonding and electrically insulating polyolefin hot melt adhesive and a preparation method thereof. BACKGROUND

[0002] At present, the sealing of heat exchangers of household room air conditioners in the domestic and foreign air conditioning industry is generally sealed by sealant, sponge, plastic sealing strip, EVA hot melt adhesive and other materials. Due to the influence of material performance and production process control, the product quality and performance are affected to varying degrees, which has puzzled the development of the industry. Polyolefin hot melt adhesive is a new type of adhesive widely used in packaging, automobile, electronics, furniture and other industries. It is a synthetic resin mainly composed of polyolefin. When it encounters high temperature, it begins to melt into a liquid. When it returns to normal temperature, it returns to solid. The silane modified polyolefin in the glue begins to crosslink with the moisture in the air to solidify.

[0003] However, the polyolefin hot melt adhesive currently used still has defects in terms of bonding and electrical insulation, and therefore the present application studies and prepares a polyolefin hot melt adhesive with high bonding and excellent electrical insulation to solve the above problems. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a high-bonding and electrically insulating polyolefin hot melt adhesive and a preparation method thereof.

[0005] A technical solution proposed by the present application to solve the above technical problem is: a high-bonding and electrically insulating polyolefin hot melt adhesive, comprising modified phenolic resin, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax; the modified phenolic resin is prepared by reacting polymeric isomerized decaol with polyethylene glycol derivative; the cross-linked metallocene polyethylene is prepared by cross-linking metallocene polyethylene, modified nano-silicon dioxide and cross-linking agent; the cross-linking agent is vinyl silane polymer.

[0006] Preferably, the polymeric isomerized decaol is prepared by reacting polymeric rosin-based epoxy resin with isomerized decaol polyoxyethylene ether; the polymeric rosin-based epoxy resin is prepared by reacting polymeric rosin with epoxy chloropropane; the polyethylene glycol derivative is prepared by reacting aldehyde-based polyethylene glycol with amino polyoxyethylene ether.

[0007] Preferably, the modified nano-silicon dioxide is prepared by reacting vinyl tri(2-methoxyethoxy) silane with nano-silicon dioxide; the vinyl silane polymer is prepared by reacting trimethylolpropane monoallyl ether with 3-epoxypropoxypropylmethyl dimethoxysilane.

[0008] Preferably, the synthetic wax is one of polyethylene wax, polypropylene wax and Fischer-Tropsch wax; the antioxidant is antioxidant 1010; the filler is one of calcium carbonate, silicon dioxide or kaolin.

[0009] Preferably, the preparation method of the high-adhesion electrically insulating polyolefin hot melt adhesive includes the following specific steps:

[0010] S1. Aldehyde-based polyethylene glycol, amino polyoxyethylene ether, and anhydrous ethanol are mixed in a mass ratio of 1:1.4 to 1.8:1. The pH is adjusted to 4 to 6 with acetic acid at a mass fraction of 0.6 to 2%. The mixture is reacted at room temperature for 2 to 4 hours. Sodium borohydride, a reducing agent, is added at a mass ratio of 0.5 to 0.6 times that of aldehyde-based polyethylene glycol. The reaction is continued for 50 to 60 minutes. The mixture is dialyzed with deionized water for 24 to 48 hours, with the deionized water being replaced every 6 to 8 hours. The mixture is then freeze-dried at -40 to -60°C to obtain the polyethylene glycol derivative.

[0011] S2. Under a nitrogen atmosphere, polymerized rosin-based epoxy resin, isomeric decaol polyoxyethylene ether, and catalyst potassium hydroxide are mixed in a mass ratio of 20:1-3:0.02-0.04, heated to 90-110°C, and reacted for 2-4 hours. The pH was adjusted to 8-9 with sodium hydroxide, the temperature was raised to 140-160°C, the pressure was adjusted to 0.2-0.3 MPa, and the reaction was continued for 3-6 hours. The mixture was then dehydrated under vacuum to obtain polymerized isomeric decaol.

[0012] S3. Mix polymeric isomeric decaol, polyethylene glycol derivative and oxalic acid in a mass ratio of 100:26-30:0.05-0.1, heat to 98-105℃, react for 2-4 hours, adjust the pH to 0.5-1.5 with 5-10% sulfuric acid, dehydrate under reduced pressure at 140-160℃, and then add hexamethylenetetramine, a curing agent, in 0.08-0.12 times the mass of polymeric isomeric decaol to obtain modified phenolic resin;

[0013] S4. Metallocene polyethylene, modified nano-silica, crosslinking agent, dicumyl peroxide and antioxidant 1010 are mixed in a mass ratio of 100:5~15:3~7:0.1~0.3:0.2~0.6, and extruded in a twin-screw extruder at a temperature of 160~180℃ for 2~5 min and a speed of 200~300 rpm. After vacuum dehydration, the mixture is then heat-treated at 120~150℃ for 1~2 h to obtain crosslinked metallocene polyethylene.

[0014] S5. Under a nitrogen atmosphere, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax are mixed, heated to 150-160℃, stirred at 100-200 rpm for 1-2 hours, cooled to 125-135℃, and modified phenolic resin is added. The mass ratio of cross-linked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 20-30:15-20:3-7:1-2:8-12:10-12. Vacuum dehydration is performed to obtain a high-adhesion electrically insulating polyolefin hot melt adhesive.

[0015] Preferably, in step S1 above, the preparation method of amino polyoxyethylene ether is as follows: dimethylaminoethanol, ethylene oxide and sodium hydroxide catalyst are mixed in a mass ratio of 3:42-45:0.03-0.05, heated to 80-85°C, pressure 0.6-0.7 MPa, reacted for 3-4 hours, pH adjusted to 6.8-7.2 with acetic acid, then precipitated with diethyl ether at 0-4°C, filtered, washed with diethyl ether 3-5 times, and vacuum dried at 40-50°C to obtain amino polyoxyethylene ether.

[0016] Preferably, in step S1 above, the preparation method of aldehyde-based polyethylene glycol is as follows: under a nitrogen atmosphere, polyethylene glycol with a molecular weight of 1000-5000 Da, terephthalaldehyde, sodium periodate, catalyst 4-dimethylaminopyridine and N,N-dimethylformamide are mixed in a mass ratio of 2:1:0.02:0.08-0.09:6-8, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added dropwise at a rate of 1-3 ml / min at a mass ratio of 1.1-1.3 times that of polyethylene glycol. After reacting at room temperature for 12-24 h, the mixture is distilled under reduced pressure, dissolved in dichloromethane, precipitated with petroleum ether and diethyl ether in a volume ratio of 3-5:1, and dried under vacuum at 60-70 °C to obtain aldehyde-based polyethylene glycol.

[0017] Preferably, in step S2 above, the preparation method of the polymerized rosin-based epoxy resin is as follows: polymerized rosin, epichlorohydrin, and toluene are mixed in a mass ratio of 10:7 to 11:7 to 11, stirred evenly, and then 0.05 to 0.07 times the mass of polymerized rosin is added as a catalyst, tetramethylammonium chloride. The mixture is heated to 100 to 110°C and reacted for 3 to 6 hours. Then, 0.01 to 0.03 times the mass of polymerized rosin is added as sodium hydroxide. The mixture is cooled to 60 to 70°C and reacted for 2 to 5 hours. Then, 4 to 8 times the mass of polymerized rosin and 0.01 to 0.02 times the mass of polymerized rosin as sodium hydroxide are added, and the reaction continues for 3 to 4 hours. The mixture is then distilled under reduced pressure and dried under vacuum at 60 to 70°C to obtain the polymerized rosin-based epoxy resin.

[0018] Preferably, in step S4 above, the modified nano-silica is prepared as follows: under a nitrogen atmosphere, nano-silica, vinyltris(2-methoxyethoxy)silane and anhydrous ethanol are mixed at a mass ratio of 1:0.3-0.5:9-11, the pH is adjusted to 3.5-4.5 with acetic acid at a mass fraction of 0.6-2%, the mixture is heated to 60-70°C and refluxed for 32-42 hours, centrifuged and washed 3-5 times with anhydrous ethanol, and then vacuum dried at 60-70°C to obtain modified nano-silica.

[0019] Preferably, in step S4 above, the crosslinking agent is prepared by mixing trimethylolpropane monoallyl ether and 3-epoxypropoxypropylmethyldimethoxysilane at a mass ratio of 5:3-6 under a nitrogen atmosphere, heating to 90-110°C, adding tetrabutyl titanate catalyst at 0.01-0.03 times the mass of trimethylolpropane monoallyl ether, reacting for 2-4 hours, cooling to 55-58°C, terminating the reaction with methanol, and dehydrating under vacuum to obtain a vinylsilane polymer, which is the crosslinking agent.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] The high-adhesion, electrically insulating polyolefin hot melt adhesive prepared by this invention comprises modified phenolic resin and cross-linked metallocene polyethylene;

[0022] Modified phenolic resin is prepared by reacting polymerized isomeric decaol with polyethylene glycol derivatives. Polymeric isomeric decaol is prepared by reacting polymerized rosin-based epoxy resin with isomeric decaol polyoxyethylene ether. Polymeric rosin-based epoxy resin is prepared by reacting polymerized rosin with epichlorohydrin. Polyethylene glycol derivatives are prepared by reacting aldehyde-based polyethylene glycol with amino polyoxyethylene ethers. By improving the hydrophobicity and compatibility with polyolefins through the long-chain alkyl groups of isomeric decaol polyoxyethylene ethers, the hydrophobicity of the material is enhanced, thereby ensuring good wetting and strong adhesion of the hot melt adhesive on various polar substrates. The polyoxyethylene ether segments in the polyethylene glycol derivatives further enhance the wetting ability of the colloid to the substrate, reduce interfacial defects, and effectively improve the bonding strength.

[0023] Crosslinked metallocene polyethylene is prepared by crosslinking metallocene polyethylene, modified nano-silica, and a crosslinking agent. The modified nano-silica is prepared by reacting vinyltris(2-methoxyethoxy)silane with nano-silica. The crosslinking agent is a vinyl silane polymer, which is prepared by reacting trimethylolpropane monoallyl ether with 3-epoxypropoxypropylmethyldimethoxysilane. The vinyl silane polymer crosslinks with metallocene polyethylene on one hand and reacts with modified nano-silica on the other, forming a covalent crosslinked network. The crosslinking agent effectively connects metallocene polyethylene and modified nano-silica, forming a tightly connected network structure. While improving electrical insulation performance, it also enables the hot melt adhesive to maintain good stability and strength at high temperatures. Detailed Implementation

[0024] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those skilled in the art. CAS9003-35-4

[0025] The phenolic resin used in Comparative Example 3 of this invention was purchased from Shenzhen Yoshida Chemical Co., Ltd., model BF01; the metallocene polyethylene was purchased from Nanjing Praxair Trading Co., Ltd.

[0026] To more clearly illustrate the method provided by the present invention, the following examples are provided for detailed explanation. The test methods for various indicators of the high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples are as follows:

[0027] Mechanical properties: The high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples were subjected to tensile strength tests in accordance with GB / T1040.2.

[0028] Bond strength: The high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples were tested for melt viscosity in accordance with HG / T3660.

[0029] Electrical insulation: The volume resistivity of the high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples was tested in accordance with GB / T1410.

[0030] Stability: The high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples were tested for heat distortion temperature in accordance with GB / T1634.2.

[0031] Example 1

[0032] The method for preparing the high-adhesion electrically insulating polyolefin hot melt adhesive in this embodiment is as follows:

[0033] S1. Under a nitrogen atmosphere, polyethylene glycol (molecular weight 1000 Da), terephthalaldehyde, sodium periodate, catalyst 4-dimethylaminopyridine, and N,N-dimethylformamide were mixed in a mass ratio of 2:1:0.02:0.08:6. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.1 times the mass of polyethylene glycol) was added dropwise at a rate of 1 ml / min. After reacting at room temperature for 12 h, the mixture was distilled under reduced pressure, dissolved in dichloromethane, precipitated with petroleum ether and diethyl ether in a volume ratio of 3:1, and dried under vacuum at 60 °C to obtain aldehyde-based polyethylene glycol. Dimethylaminoethanol, ethylene oxide, and catalyst sodium hydroxide were mixed in a mass ratio of 3:42... Mix 0.03g of aldehyde polyethylene glycol, amino polyoxyethylene ether and anhydrous ethanol at a mass ratio of 1:1.4:1, adjust the pH to 4 with 0.6% acetic acid, react at room temperature for 2 hours, add sodium borohydride reducing agent at 0.5 times the mass of aldehyde polyethylene glycol, continue the reaction for 50 minutes, dialyze with deionized water for 24 hours, change the deionized water every 6 hours, freeze dry at -40℃ to obtain polyethylene glycol derivative;

[0034] S2. Polymerized rosin, epichlorohydrin, and toluene are mixed in a mass ratio of 10:7:7. After stirring evenly, 0.05 times the mass of the polymerized rosin is added to the catalyst tetramethylammonium chloride. The mixture is heated to 100°C and reacted for 3 hours. Then, 0.01 times the mass of the polymerized rosin is added to the sodium hydroxide mixture. The mixture is cooled to 60°C and reacted for 2 hours. Next, 4 times the mass of the polymerized rosin and 0.01 times the mass of the polymerized rosin to the toluene mixture and sodium hydroxide mixture are added. The mixture is reacted for another 3 hours. The mixture is then distilled under reduced pressure and dried under vacuum at 60°C to obtain polymerized rosin-based epoxy resin. Under a nitrogen atmosphere, polymerized rosin-based epoxy resin, isomeric decaol polyoxyethylene ether, and catalyst potassium hydroxide are mixed in a mass ratio of 20:1:0.02. The mixture is heated to 90°C and reacted for 2 hours. The pH is adjusted to 8 with sodium hydroxide. The mixture is then heated to 140°C, the pressure is adjusted to 0.2 MPa, and the mixture is reacted for another 3 hours. The mixture is then dehydrated under vacuum to obtain polymerized isomeric decaol.

[0035] S3. Polymeric isodecyl alcohol, polyethylene glycol derivative and oxalic acid are mixed in a mass ratio of 100:26:0.05, heated to 98℃ and reacted for 2 hours. The pH is adjusted to 0.5 with 5% sulfuric acid, dehydrated under reduced pressure at 140℃, and then 0.08 times the mass of polymeric isodecyl alcohol as a curing agent hexamethylenetetramine is added to obtain modified phenolic resin.

[0036] S4. Under a nitrogen atmosphere, trimethylolpropane monoallyl ether and 3-epoxypropoxypropylmethyldimethoxysilane were mixed at a mass ratio of 5:3, heated to 90°C, and tetrabutyl titanate catalyst (0.01 times the mass of trimethylolpropane monoallyl ether) was added. The reaction was carried out for 2 hours, cooled to 55°C, and the reaction was terminated with methanol. The mixture was then dehydrated under vacuum to obtain a vinyl silane polymer, which is the crosslinking agent. Under a nitrogen atmosphere, nano-silica, vinyltris(2-methoxyethoxy)silane, and anhydrous ethanol were mixed at a mass ratio of 1:0.3:9, and the mixture was dehydrated using mass fraction... The pH was adjusted to 3.5 with 0.6% acetic acid, and the mixture was refluxed at 60°C for 32 hours. After centrifugation and washing three times with anhydrous ethanol, the mixture was vacuum dried at 60°C to obtain modified nano-silica. Metallocene polyethylene, modified nano-silica, crosslinking agent, dicumyl peroxide, and antioxidant 1010 were mixed in a mass ratio of 100:5:3:0.1:0.2 and extruded in a twin-screw extruder at 160°C for 2 minutes and 200 rpm. After vacuum dehydration, the mixture was heat-treated at 120°C for 1 hour to obtain crosslinked metallocene polyethylene.

[0037] S5. Under a nitrogen atmosphere, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax are mixed, heated to 150°C, stirred at 100 rpm for 1 hour, cooled to 125°C, and modified phenolic resin is added. The mass ratio of cross-linked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 20:15:3:1:8:10. Vacuum dehydration is performed to obtain a high-adhesion electrically insulating polyolefin hot melt adhesive.

[0038] Example 2

[0039] The method for preparing the high-adhesion electrically insulating polyolefin hot melt adhesive in this embodiment is as follows:

[0040] S1. Under a nitrogen atmosphere, polyethylene glycol (4000 Da), terephthalaldehyde, sodium periodate, catalyst 4-dimethylaminopyridine, and N,N-dimethylformamide were mixed in a mass ratio of 2:1:0.02:0.085:7. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.2 times the mass of polyethylene glycol) was added dropwise at a rate of 2 ml / min. After reacting at room temperature for 18 h, the mixture was distilled under reduced pressure, dissolved in dichloromethane, precipitated with petroleum ether and diethyl ether in a volume ratio of 3–5:1, and dried under vacuum at 65 °C to obtain aldehyde-based polyethylene glycol. Dimethylaminoethanol, ethylene oxide, and catalyst sodium hydroxide were mixed in a mass ratio of 3:44... Mix 0.04g of aldehyde polyethylene glycol, heat to 83℃, and pressurize to 0.65MPa. React for 3.5h. Adjust the pH to 7.0 with acetic acid, then precipitate with ether at 2℃, filter, wash 4 times with ether, and dry under vacuum at 45℃ to obtain amino polyoxyethylene ether. Mix aldehyde polyethylene glycol, amino polyoxyethylene ether, and anhydrous ethanol in a mass ratio of 1:1.6:1. Adjust the pH to 5 with 1.3% acetic acid and react at room temperature for 3h. Add sodium borohydride, a reducing agent, at 0.55 times the mass of aldehyde polyethylene glycol, and continue the reaction for 55min. Dialyze with deionized water for 36h, changing the deionized water every 7h. Freeze dry at -50℃ to obtain polyethylene glycol derivative.

[0041] S2. Polymerized rosin, epichlorohydrin, and toluene were mixed in a mass ratio of 10:9:10. After stirring evenly, 0.06 times the mass of the polymerized rosin was added to the catalyst tetramethylammonium chloride. The mixture was heated to 105°C and reacted for 4 hours. Then, 0.02 times the mass of the polymerized rosin was added to the sodium hydroxide mixture. The mixture was cooled to 65°C and reacted for 4 hours. Then, 6 times the mass of the polymerized rosin and 0.015 times the mass of the polymerized rosin to the toluene mixture and the sodium hydroxide mixture were added. The mixture was reacted for another 3.5 hours. The mixture was then distilled under reduced pressure and dried under vacuum at 65°C to obtain polymerized rosin-based epoxy resin. Under a nitrogen atmosphere, polymerized rosin-based epoxy resin, isomeric decaol polyoxyethylene ether, and catalyst potassium hydroxide were mixed in a mass ratio of 20:2:0.03. The mixture was heated to 100°C and reacted for 3 hours. The pH was adjusted to 8.5 with sodium hydroxide. The mixture was then heated to 150°C and the pressure was adjusted to 0.25 MPa. The mixture was reacted for another 4 hours and then dehydrated under vacuum to obtain polymerized isomeric decaol.

[0042] S3. Mix polymeric isomeric decaol, polyethylene glycol derivative and oxalic acid in a mass ratio of 100:28:0.08, heat to 102℃, react for 3 hours, adjust the pH to 1.0 with 8% sulfuric acid, dehydrate under reduced pressure at 150℃, and then add hexamethylenetetramine, a curing agent, at 0.1 times the mass of polymeric isomeric decaol to obtain modified phenolic resin.

[0043] S4. Under a nitrogen atmosphere, trimethylolpropane monoallyl ether and 3-epoxypropoxypropylmethyldimethoxysilane were mixed at a mass ratio of 5:5, heated to 100°C, and tetrabutyl titanate catalyst (0.02 times the mass of trimethylolpropane monoallyl ether) was added. The reaction was carried out for 3 hours, cooled to 56°C, and the reaction was terminated with methanol. The mixture was then dehydrated under vacuum to obtain a vinyl silane polymer, which is the crosslinking agent. Under a nitrogen atmosphere, nano-silica, vinyltris(2-methoxyethoxy)silane, and anhydrous ethanol were mixed at a mass ratio of 1:0.4:10, and a mass fraction of... The pH was adjusted to 4.0 with 1.3% acetic acid, and the mixture was refluxed at 65°C for 37 h. After centrifugation and washing four times with anhydrous ethanol, the mixture was vacuum dried at 65°C to obtain modified nano-silica. Metallocene polyethylene, modified nano-silica, crosslinking agent, dicumyl peroxide, and antioxidant 1010 were mixed in a mass ratio of 100:10:5:0.2:0.4 and extruded in a twin-screw extruder at 170°C for 4 min at 250 rpm. After vacuum dehydration, the mixture was heat-treated at 135°C for 1.5 h to obtain crosslinked metallocene polyethylene.

[0044] S5. Under a nitrogen atmosphere, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax are mixed, heated to 155℃, stirred at 150 rpm for 1.5 h, cooled to 130℃, and modified phenolic resin is added. The mass ratio of cross-linked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 25:17:5:1.5:10:11. Vacuum dehydration is performed to obtain a high-adhesion electrically insulating polyolefin hot melt adhesive.

[0045] Example 3

[0046] The method for preparing the high-adhesion electrically insulating polyolefin hot melt adhesive in this embodiment is as follows:

[0047] S1. Under a nitrogen atmosphere, polyethylene glycol (molecular weight 5000 Da), terephthalaldehyde, sodium periodate, catalyst 4-dimethylaminopyridine, and N,N-dimethylformamide were mixed in a mass ratio of 2:1:0.02:0.09:8. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.3 times the mass of polyethylene glycol) was added dropwise at a rate of 3 ml / min. After reacting at room temperature for 24 h, the mixture was distilled under reduced pressure, dissolved in dichloromethane, precipitated with petroleum ether and diethyl ether in a volume ratio of 5:1, and dried under vacuum at 70 °C to obtain aldehyde-based polyethylene glycol. Dimethylaminoethanol, ethylene oxide, and catalyst sodium hydroxide were mixed in a mass ratio of 3:4... Mix 45:0.05, heat to 85℃, pressure 0.7MPa, react for 4h, adjust pH to 7.2 with acetic acid, precipitate with ether at 4℃, filter, wash 5 times with ether, and vacuum dry at 50℃ to obtain amino polyoxyethylene ether. Mix aldehyde polyethylene glycol, amino polyoxyethylene ether and anhydrous ethanol at a mass ratio of 1:1.8:1, adjust pH to 6 with 2% acetic acid, react at room temperature for 4h, add sodium borohydride reducing agent at 0.6 times the mass of aldehyde polyethylene glycol, continue reaction for 60min, dialyze with deionized water for 48h, change deionized water every 8h, freeze dry at -60℃ to obtain polyethylene glycol derivative;

[0048] S2. Polymerized rosin, epichlorohydrin, and toluene were mixed in a mass ratio of 10:11:11. After stirring evenly, 0.07 times the mass of the polymerized rosin was added to the catalyst tetramethylammonium chloride. The mixture was heated to 110°C and reacted for 6 hours. Then, 0.03 times the mass of the polymerized rosin was added to the sodium hydroxide mixture. The mixture was cooled to 70°C and reacted for 5 hours. Then, 8 times the mass of the polymerized rosin and 0.02 times the mass of the polymerized rosin to the toluene mixture and the sodium hydroxide mixture were added. The mixture was reacted for another 4 hours. The mixture was then distilled under reduced pressure and dried under vacuum at 70°C to obtain polymerized rosin-based epoxy resin. Under a nitrogen atmosphere, polymerized rosin-based epoxy resin, isomeric decaol polyoxyethylene ether, and catalyst potassium hydroxide were mixed in a mass ratio of 20:3:0.04. The mixture was heated to 110°C and reacted for 4 hours. The pH was adjusted to 9 with sodium hydroxide. The mixture was then heated to 160°C and the pressure was adjusted to 0.3 MPa. The mixture was reacted for another 6 hours and then dehydrated under vacuum to obtain polymerized isomeric decaol.

[0049] S3. Polymeric isodecyl alcohol, polyethylene glycol derivative and oxalic acid are mixed in a mass ratio of 100:30:0.1, heated to 105℃ and reacted for 4 hours. The pH is adjusted to 1.5 with 10% sulfuric acid, dehydrated under reduced pressure at 160℃, and then 0.12 times the mass of polymeric isodecyl alcohol as a curing agent is added to obtain modified phenolic resin.

[0050] S4. Under a nitrogen atmosphere, trimethylolpropane monoallyl ether and 3-epoxypropoxypropylmethyldimethoxysilane were mixed at a mass ratio of 5:6, heated to 110°C, and tetrabutyl titanate catalyst (0.03 times the mass of trimethylolpropane monoallyl ether) was added. The reaction was carried out for 4 hours, cooled to 58°C, and the reaction was terminated with methanol. The mixture was then dehydrated under vacuum to obtain a vinyl silane polymer, which is the crosslinking agent. Under a nitrogen atmosphere, nano-silica, vinyltris(2-methoxyethoxy)silane, and anhydrous ethanol were mixed at a mass ratio of 1:0.5:11, and the mixture was dehydrated by mass fractionation. The pH was adjusted to 4.5 with 2% acetic acid, and the mixture was refluxed at 70°C for 42 hours. After centrifugation and washing five times with anhydrous ethanol, the mixture was vacuum dried at 70°C to obtain modified nano-silica. Metallocene polyethylene, modified nano-silica, crosslinking agent, dicumyl peroxide, and antioxidant 1010 were mixed in a mass ratio of 100:15:7:0.3:0.6 and extruded in a twin-screw extruder at 180°C for 5 minutes and 300 rpm. After vacuum dehydration, the mixture was heat-treated at 150°C for 2 hours to obtain crosslinked metallocene polyethylene.

[0051] S5. Under a nitrogen atmosphere, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax are mixed, heated to 160℃, stirred at 200 rpm for 2 hours, cooled to 135℃, and modified phenolic resin is added. The mass ratio of cross-linked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 30:20:7:2:12:12. Vacuum dehydration is performed to obtain a high-adhesion electrically insulating polyolefin hot melt adhesive.

[0052] Comparative Example 1

[0053] The preparation method of Comparative Example 1 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the modified phenolic resin is prepared by reacting isomeric deca-ol polyoxyethylene ether with a polyethylene glycol derivative.

[0054] Comparative Example 2

[0055] The preparation method of Comparative Example 2 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the modified phenolic resin is prepared by reacting isomeric decaol with aldehyde polyethylene glycol.

[0056] Comparative Example 3

[0057] The preparation method of Comparative Example 3 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the prepared high-adhesion electrically insulating polyolefin hot melt adhesive includes phenolic resin and cross-linked metallocene polyethylene.

[0058] Comparative Example 4

[0059] The preparation method of Comparative Example 4 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the crosslinked metallocene polyethylene is prepared by reacting metallocene polyethylene with modified nano-silica.

[0060] Comparative Example 5

[0061] The preparation method of Comparative Example 5 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the crosslinked metallocene polyethylene is obtained by crosslinking metallocene polyethylene with a crosslinking agent.

[0062] Comparative Example 6

[0063] The preparation method of Comparative Example 6 is the same as that of Example 2. The difference between this high-adhesion electrically insulating polyolefin hot melt adhesive and Example 2 is that the prepared high-adhesion electrically insulating polyolefin hot melt adhesive includes modified phenolic resin and metallocene polyethylene.

[0064] Example of effect

[0065] Table 1 below shows the performance test results of the high-adhesion electrically insulating polyolefin hot melt adhesives prepared in the examples and comparative examples;

[0066] Table 1

[0067]

[0068] As can be seen from the performance data comparison in Table 1, the high-adhesion electrically insulating polyolefin hot melt adhesive prepared by the present invention not only has excellent mechanical and adhesive properties, but also electrical insulation and high-temperature stability.

[0069] A comparison of the experimental data from Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 reveals that the long-chain alkyl groups of the isomeric deca-ol polyoxyethylene ether enhance the hydrophobicity and compatibility with polyolefins of the material, thereby ensuring good wetting and strong adhesion of the hot melt adhesive on various polar substrates. Furthermore, the polyoxyethylene ether segments in the polyethylene glycol derivative further enhance the wetting ability of the colloid on the substrate, reduce interfacial defects, and effectively improve the bonding strength.

[0070] A comparison of the experimental data from Examples 1, 2, and 3 and Comparative Examples 4, 5, and 6 reveals that the vinyl silane polymer crosslinks with metallocene polyethylene on one hand and reacts with modified nano-silica on the other, forming a covalent crosslinked network. The crosslinking agent effectively connects the metallocene polyethylene and the modified nano-silica, forming a tightly connected network structure. This improves the electrical insulation performance while also enabling the hot melt adhesive to maintain good stability and strength at high temperatures.

[0071] Obviously, the above embodiments are merely examples to clearly illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, these obvious variations or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. A high-adhesion, electrically insulating polyolefin hot melt adhesive, characterized in that, The product comprises modified phenolic resin, crosslinked metallocene polyethylene, polybutadiene, antioxidants, fillers, and synthetic waxes; the modified phenolic resin is prepared by reacting polymerized isomeric decaols with polyethylene glycol derivatives; the crosslinked metallocene polyethylene is prepared by crosslinking metallocene polyethylene, modified nano-silica, and a crosslinking agent; the crosslinking agent is a vinyl silane polymer; the polymerized isomeric decaol is prepared by reacting polymerized rosin-based epoxy resin with isomeric decaol polyoxyethylene ether; the polymerized rosin-based epoxy resin is prepared by reacting polymerized rosin with epichlorohydrin; the polyethylene glycol... The alcohol derivative is prepared by reacting aldehyde-based polyethylene glycol with amino polyoxyethylene ether; the modified nano silica is prepared by reacting vinyltris(2-methoxyethoxy)silane with nano silica; the vinyl silane polymer is prepared by reacting trimethylolpropane monoallyl ether with 3-epoxypropoxypropylmethyldimethoxysilane; the mass ratio of the crosslinked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 20~30:15~20:3~7:1~2:8~12:10~12.

2. The high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 1, characterized in that, The synthetic wax is one of polyethylene wax, polypropylene wax, and Fischer-Tropsch wax; the antioxidant is antioxidant 1010; and the filler is one of calcium carbonate, silica, or kaolin.

3. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 1, characterized in that, The specific steps include the following: S1. Aldehyde-based polyethylene glycol, amino polyoxyethylene ether, and anhydrous ethanol are mixed in a mass ratio of 1:1.4 to 1.8:

1. The pH is adjusted to 4 to 6 with acetic acid (0.6% to 2% by mass). The mixture is reacted at room temperature for 2 to 4 hours. Sodium borohydride, a reducing agent, is added at 0.5 to 0.6 times the mass of aldehyde-based polyethylene glycol. The reaction is continued for 50 to 60 minutes. The mixture is dialyzed with deionized water for 24 to 48 hours, with the deionized water replaced every 6 to 8 hours. The mixture is then freeze-dried at -40 to -60°C to obtain the polyethylene glycol derivative. S2. Under a nitrogen atmosphere, polymerized rosin-based epoxy resin, isomeric decaol polyoxyethylene ether, and catalyst potassium hydroxide are mixed in a mass ratio of 20:1~3:0.02~0.04, heated to 90~110℃, reacted for 2~4h, the pH was adjusted to 8~9 with sodium hydroxide, the temperature was raised to 140~160℃, the pressure was adjusted to 0.2~0.3MPa, and the reaction was continued for 3~6h. The mixture was then dehydrated under vacuum to obtain polymerized isomeric decaol. S3. Mix polymeric isomeric decaol, polyethylene glycol derivative and oxalic acid in a mass ratio of 100:26~30:0.05~0.1, heat to 98~105℃, react for 2~4h, adjust the pH to 0.5~1.5 with 5~10% sulfuric acid, dehydrate under reduced pressure at 140~160℃, and then add hexamethylenetetramine, a curing agent, in 0.08~0.12 times the mass of polymeric isomeric decaol to obtain modified phenolic resin; S4. Metallocene polyethylene, modified nano-silica, crosslinking agent, dicumyl peroxide and antioxidant 1010 are mixed in a mass ratio of 100:5~15:3~7:0.1~0.3:0.2~0.6, and extruded in a twin-screw extruder at a temperature of 160~180℃ for 2~5 min and a speed of 200~300 rpm. After vacuum dehydration, the mixture is then heat-treated at 120~150℃ for 1~2 h to obtain crosslinked metallocene polyethylene. S5. Under a nitrogen atmosphere, cross-linked metallocene polyethylene, polybutadiene, antioxidant, filler and synthetic wax are mixed, heated to 150~160℃, stirred at 100~200rpm for 1~2h, cooled to 125~135℃, and modified phenolic resin is added. The mass ratio of cross-linked metallocene polyethylene, modified phenolic resin, polybutadiene, antioxidant, filler and synthetic wax is 20~30:15~20:3~7:1~2:8~12:10~12. Vacuum dehydration is performed to obtain a high-adhesion electrically insulating polyolefin hot melt adhesive.

4. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 3, characterized in that, In step S1 above, the preparation method of amino polyoxyethylene ether is as follows: dimethylaminoethanol, ethylene oxide and sodium hydroxide catalyst are mixed in a mass ratio of 3:42~45:0.03~0.05, heated to 80~85℃, pressure of 0.6~0.7MPa, reacted for 3~4h, pH adjusted to 6.8~7.2 with acetic acid, then precipitated with diethyl ether at 0~4℃, filtered, washed with diethyl ether 3~5 times, and vacuum dried at 40~50℃ to obtain amino polyoxyethylene ether.

5. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 3, characterized in that, In step S1 above, the preparation method of aldehyde-based polyethylene glycol is as follows: under a nitrogen atmosphere, polyethylene glycol with a molecular weight of 1000~5000 Da, terephthalaldehyde, sodium periodate, catalyst 4-dimethylaminopyridine and N,N-dimethylformamide are mixed in a mass ratio of 2:1:0.02:0.08~0.09:6~8. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added dropwise at a rate of 1~3 ml / min at a mass ratio of 1.1~1.3 times that of polyethylene glycol. After reacting at room temperature for 12~24 h, the mixture is distilled under reduced pressure, dissolved in dichloromethane, precipitated with petroleum ether and diethyl ether in a volume ratio of 3~5:1, and dried under vacuum at 60~70 °C to obtain aldehyde-based polyethylene glycol.

6. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 3, characterized in that, In step S2 above, the preparation method of polymerized rosin-based epoxy resin is as follows: polymerized rosin, epichlorohydrin, and toluene are mixed in a mass ratio of 10:7~11:7~11, stirred evenly, and then 0.05~0.07 times the mass of polymerized rosin is added as a catalyst, tetramethylammonium chloride. The mixture is heated to 100~110℃ and reacted for 3~6 hours. Then, 0.01~0.03 times the mass of polymerized rosin is added as sodium hydroxide. The mixture is cooled to 60~70℃ and reacted for 2~5 hours. Then, 4~8 times the mass of polymerized rosin and 0.01~0.02 times the mass of polymerized rosin as sodium hydroxide are added, and the reaction continues for 3~4 hours. The mixture is then distilled under reduced pressure and dried under vacuum at 60~70℃ to obtain polymerized rosin-based epoxy resin.

7. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 3, characterized in that, In step S4 above, the modified nano-silica is prepared as follows: under a nitrogen atmosphere, nano-silica, vinyltris(2-methoxyethoxy)silane and anhydrous ethanol are mixed at a mass ratio of 1:0.3~0.5:9~11, the pH is adjusted to 3.5~4.5 with acetic acid at a mass fraction of 0.6~2%, the mixture is heated to 60~70℃ and refluxed for 32~42h, centrifuged and washed 3~5 times with anhydrous ethanol, and then vacuum dried at 60~70℃ to obtain modified nano-silica.

8. The method for preparing a high-adhesion, electrically insulating polyolefin hot melt adhesive according to claim 3, characterized in that, In step S4 above, the crosslinking agent is prepared as follows: under a nitrogen atmosphere, trimethylolpropane monoallyl ether and 3-epoxypropoxypropylmethyldimethoxysilane are mixed at a mass ratio of 5:3~6, heated to 90~110℃, and tetrabutyl titanate catalyst (0.01~0.03 times the mass of trimethylolpropane monoallyl ether) is added. The mixture is reacted for 2~4 hours, cooled to 55~58℃, and the reaction is terminated with methanol. The mixture is then dehydrated under vacuum to obtain a vinyl silane polymer, which is the crosslinking agent.

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