Electrically-debondable one-component polyurethane hot melt adhesive, preparation method therefor, and use thereof

Abstract

The present invention relates to the field of adhesives, and in particular to an electrically-debondable one-component polyurethane hot melt adhesive, a preparation method therefor, and a use thereof. The electrically-debondable single-component reactive polyurethane hot melt adhesive has a viscosity range of 1,000-150,000 cps at 25ºC and a bonding strength attenuation rate of 80% or more when electrifying at a voltage of 1-100 V, and the content of isocyanate groups in the electrically-debondable single-component reactive polyurethane hot melt adhesive is 5-20%. The polyurethane hot melt adhesive provided by the present invention has a low melt viscosity, can be dispensed at room temperature, exhibits a high final bonding strength, and also has a debonding function under an electrification condition and broad practical application prospects.

Description

An electrically detachable one-component polyurethane hot melt adhesive, its preparation method and application

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024114606171, filed on October 18, 2024, entitled "An electrically detachable one-component polyurethane hot melt adhesive and its preparation method and application", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention belongs to the field of adhesives, specifically relating to an electrically detachable one-component polyurethane hot melt adhesive, its preparation method, and its application. Background Technology

[0004] Reactive polyurethane hot melt adhesives are often used to bond and fix electronic components in electronic products such as smartphones, tablets, smartwatches, and TWS earphones. The electronic components bonded by reactive polyurethane hot melt adhesives are often of high value. When there are situations such as poor assembly, product after-sales repair, or recycling of valuable electronic components, it is usually necessary to disassemble the bonded parts. Therefore, the adhesive usually needs to have excellent bonding reliability while also being easy to disassemble under certain conditions.

[0005] Reactive polyurethane hot melt adhesives are mainly composed of isocyanate-terminated oligomers. The isocyanate groups in the isocyanate-terminated oligomers can react with moisture in the air. After complete curing, they can form a cross-linked chemical structure, thereby achieving high bonding strength. However, the covalent bonds formed by the reaction of isocyanate groups with moisture are irreversible, and the cross-linked structure is difficult to destroy. After complete curing, it is usually difficult to disassemble the adhesive. If it is necessary to separate the bonded materials, it is often necessary to use large external forces, high temperatures, chemical reagents, etc., and the disassembly of the adhesive may cause damage to the bonded materials, resulting in significant economic losses.

[0006] In recent years, some technologies have also been developed to add alkali metal salts and solvated matrices to polyurethane hot melt adhesives, giving them the ability to be disassembled under electrical conditions. However, while existing electrically disassembleable polyurethane hot melt adhesives possess this disassembly capability, their high melt viscosity and solid state at room temperature mean they typically require heating to above their melting temperature (usually 90℃~160℃) before extrusion. This generally necessitates the use of specialized heating and application equipment, which increases costs and significantly limits the application scenarios for these single-component polyurethane hot melt adhesives. For example, they are unsuitable for use in homes or repair shops where heating equipment is inconvenient, thus severely restricting their widespread adoption. Furthermore, existing electrically disassembleable polyurethane hot melt adhesives suffer from low final bond strength. Although they possess some electrical disassembly capability, their low final bond strength and poor reliability result in a significant performance gap compared to traditional reactive polyurethane hot melt adhesives, making it difficult to meet the performance requirements of practical applications.

[0007] In summary, there is an urgent need to develop an adhesive with low melt viscosity, capable of being dispensed at room temperature, exhibiting high final bond strength, and also possessing electrical disassembly capability to meet market application demands. Summary of the Invention

[0008] The primary objective of this invention is to provide an electrically disintegratable one-component polyurethane hot melt adhesive that has low melt viscosity, can be dispensed at room temperature, and exhibits high final bond strength.

[0009] A second objective of this invention is to provide a method for preparing the above-mentioned electrically disintegratable single-component polyurethane hot melt adhesive.

[0010] A third objective of this invention is to provide the application of the above-mentioned electrically decomposable single-component polyurethane hot melt adhesive in products requiring decomposition.

[0011] Specifically, the electrically detachable one-component reactive polyurethane hot melt adhesive provided by the present invention has a viscosity range of 1000-150000cps at 25°C and a bond strength attenuation rate of more than 80% after being energized with a voltage of 1-100V. The content of isocyanate groups in the electrically detachable one-component reactive polyurethane hot melt adhesive is 5-20%.

[0012] In a preferred embodiment, the raw materials for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive contain polyisocyanate compounds, low-viscosity polyol compounds, ionic liquids, and optional rheology modifiers, silane coupling agents, water-absorbing agents, and catalysts. The molar equivalent ratio of isocyanate groups in the polyisocyanate compounds to hydroxyl groups in the low-viscosity polyol compounds is (5-10):1. The glass transition temperature of the low-viscosity polyol compounds is below 0°C and the melting point is below 40°C.

[0013] The method for preparing electrically detachable one-component reactive polyurethane hot melt adhesive provided by the present invention includes mixing polyisocyanate compounds, low-viscosity polyol compounds, ionic liquids, and optional rheology modifiers, silane coupling agents, water absorbents, and catalysts uniformly to obtain electrically detachable one-component reactive polyurethane hot melt adhesive.

[0014] After in-depth and extensive research, the inventors of this invention discovered that the polyurethane polymers with isocyanate functional groups used in existing electrically disintegratable polyurethane hot melt adhesives are polyurethane prepolymers obtained by reacting polyol compounds with an excess of polyisocyanate compounds. In these polyisocyanate compounds, the molar equivalent ratio of isocyanate groups to hydroxyl groups in the polyol compound is typically set at (1.5–2.5):1 (i.e., the molar ratio of NCO / OH is (1.5–2.5):1). Polyurethane prepolymers prepared according to this stoichiometric relationship have low isocyanate content, large molecular weight, and strong intermolecular forces, resulting in a high melt viscosity and making them difficult to dispense at room temperature. Furthermore, some of the polyol compounds used in these isocyanate functional group polyurethane prepolymers have strong crystallinity or high glass transition temperature (Tg) at room temperature. Polyurethane prepolymers prepared by reacting room-temperature crystalline polyols or high-Tg polyols with isocyanate compounds are typically solid substances at room temperature. Therefore, the electrically disintegratable polyurethane hot melt adhesives prepared by traditional methods are usually solid at room temperature and need to be heated to above the melting point (90℃~160℃) to melt and apply. This greatly raises the barrier to entry for using such polyurethane hot melt adhesives, increases the cost of adhesive application equipment, and also increases the risk of burns to operators during the application process.

[0015] Existing electrically degradable polyurethane hot melt adhesives achieve this by adding ionic liquids or alkali metal salts and a solvating matrix. The Faraday reaction between the anions and cations in the ionic liquids or alkali metal salts under energized conditions imparts the degradability of the polyurethane hot melt adhesive. While the introduction of ionic liquids and solvating matrices facilitates electrical degradation, these liquids do not participate in the curing process. After curing, they remain in their initial low-viscosity state, negatively impacting the final adhesive strength. Furthermore, the isocyanate-terminated polyurethane prepolymers currently have a low isocyanate-to-hydroxyl equivalence (NCO / OH equivalence ratio between 1.5 and 2.5), resulting in a low isocyanate content. Consequently, these prepolymers exhibit low crosslinking density after wet curing, leading to inherently low adhesive strength. The negative effects of ionic liquids and solvating matrices further reduce this adhesive strength. Therefore, although it is possible to prepare electrically disintegratable polyurethane hot melt adhesives by adding ionic liquids or alkali metal salts in combination with solvation matrices to polyurethane hot melt adhesives, their final adhesion is still significantly lacking, which is not conducive to the application and promotion of such products.

[0016] The key to this invention lies in breaking away from the design limitation of traditional electrically disintegratable polyurethane hot melt adhesive preparation processes that set the equivalent ratio of isocyanate to hydroxyl groups between (1.5-2.5):1. It innovatively sets the equivalent ratio of isocyanate groups to hydroxyl groups within the range of (5-10):1 to control the isocyanate group content in the electrically disintegratable single-component reactive polyurethane hot melt adhesive to 5-20%. Simultaneously, it selects polyol compounds with low crystallinity and low glass transition temperature at room temperature to react with an excess of isocyanate compounds to prepare a polyurethane hot melt adhesive that is liquid at room temperature. This hot melt adhesive has a high isocyanate group content, resulting in a polyurethane prepolymer with low molecular weight, weak intermolecular chain interactions, and low melt viscosity. Furthermore, the higher isocyanate monomer content dilutes the melt viscosity of the polyurethane prepolymer, and the high isocyanate group content leads to a high crosslinking density after curing, resulting in higher adhesive strength. Meanwhile, this invention innovatively introduces ionic liquids into this liquid polyurethane hot melt adhesive. Utilizing the Faraday reaction that occurs when the ionic liquid is energized, this imparts a certain degree of electrolytic disintegration to the liquid polyurethane hot melt adhesive. Furthermore, the ionic liquid selected in this invention is a liquid substance at room temperature, which can be conveniently added directly to the polyurethane hot melt adhesive system. This effectively avoids introducing a solubilizing matrix into the adhesive system, effectively reducing the negative impact of the solubilizing matrix on the adhesive strength of the polyurethane hot melt adhesive. Simultaneously, the ionic liquid introduced into the low-viscosity polyurethane hot melt adhesive can also effectively reduce the viscosity of the polyurethane hot melt adhesive. Moreover, as mentioned above, by increasing the equivalence ratio of isocyanate groups to hydroxyl groups, this invention can result in a higher excess of isocyanate groups in the system, leading to a high crosslinking density after curing. Even when affected by the uncured ionic liquid, it can still maintain relatively high adhesive strength. Therefore, the ionic liquid introduced in this invention, on the one hand, endows the polyurethane hot melt adhesive with the function of being disassembled under electrical conditions; on the other hand, the introduced ionic liquid can also significantly reduce the melt viscosity of the polyurethane hot melt adhesive, allowing the polyurethane hot melt adhesive of this invention to be applied directly at room temperature. This greatly lowers the barrier to entry for using such electrically disassembled polyurethane hot melt adhesives, reduces the equipment costs required for applying polyurethane hot melt adhesives, and effectively avoids the risk of burns to operators during the application process. Furthermore, the polyurethane hot melt adhesive of this invention has the function of being electrically disassembled after curing, and at the same time, it has high adhesive strength before being energized, providing sufficiently excellent reliability for the product. In summary, the polyurethane hot melt adhesive provided by this invention has low melt viscosity, can be applied at room temperature, has high final adhesive strength, and also has the function of being disassembled under electrical conditions, showing broad prospects for practical applications. Detailed Implementation

[0017] The electrically detachable one-component reactive polyurethane hot melt adhesive provided by this invention has a viscosity range of 1000 to 150000 cps at 25°C, specifically 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 30000, 50000, 70000, 90000, 110000, 130000, 150000 cps or any value between them.

[0018] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by this invention exhibits a bonding strength attenuation rate of over 80% after being energized with a voltage of 1 to 100V. Specifically, it can be 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, 99%, 100%, or any value between them. The voltage required for disassembling the electrically removable single-component reactive polyurethane hot melt adhesive is preferably 1 to 100V, specifically 1V, 3V, 5V, 7V, 9V, 10V, 20V, 30V, 40V, 50V, 60V, 70V, 80V, 90V, 100V or any value between them; the required energizing time is preferably 1s to 60min, such as 1s, 2s, 15s, 30s, 40s, 50s, 1min, 5min, 10min, 15min, 20min, 30min, 40min, 50min, 60min or any value between them.

[0019] The isocyanate group content in the electrically detachable one-component reactive polyurethane hot melt adhesive provided by this invention is 5% to 20%, specifically 5%, 8%, 10%, 12%, 15%, 17%, 19%, 20%, or any value between them. In this invention, the isocyanate group content refers to the ratio of the total weight of all unreacted isocyanate functional groups in the system to the total weight of the polyurethane hot melt adhesive.

[0020] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present invention is a liquid or paste at room temperature, and has the characteristics of low melt viscosity, room temperature dispensing capability, high final bond strength, and electrical detachability.

[0021] In a preferred embodiment, the raw materials for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive contain a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optionally a rheology modifier, a silane coupling agent, a water-absorbing agent, and a catalyst. The molar equivalent ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the low-viscosity polyol compound is (5-10):1. The glass transition temperature of the low-viscosity polyol compound is below 0°C, and its melting point is below 40°C. Specifically, the molar equivalent ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the low-viscosity polyol compound can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or any value between them. The glass transition temperatures of the low-viscosity polyol compounds can specifically be 0℃, -2℃, -4℃, -6℃, -8℃, -10℃, -12℃, -14℃, -16℃, -18℃, -20℃, -22℃, -24℃, -26℃, -28℃, -30℃, -32℃, -34℃, -36℃, -38℃, -40℃, etc. The melting points of the low-viscosity polyol compounds can specifically be 40℃, 38℃, 36℃, 34℃, 32℃, 30℃, 28℃, 26℃, 24℃, 22℃, 20℃, 18℃, 16℃, 14℃, 12℃, 10℃, 8℃, 6℃, 4℃, 2℃, 0℃, -5℃, -10℃, -15℃, -20℃, -30℃, etc.

[0022] In this invention, the preferred mass ratio of the total content of the polyisocyanate compound and the low-viscosity polyol compound to the content of the ionic liquid is (5-46):1, specifically 5:1, 8:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 43:1, 46:1, or any value between them. The preferred mass ratio of the rheology modifier to the ionic liquid is (0-5):1, specifically 0, 0.1:1, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, or any value between them. The preferred mass ratio of the silane coupling agent to the ionic liquid is (0–2.5):1, specifically 0, 0.005:1, 0.01:1, 0.05:1, 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, or any value between them. The preferred mass ratio of the desiccant and catalyst content to the ionic liquid content is independently (0–1):1, specifically 0, 0.005:1, 0.01:1, 0.05:1, 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1, or any value between them.

[0023] In a preferred embodiment, based on the total weight of the raw materials for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive, the total content of the polyisocyanate compounds and low-viscosity polyol compounds is 75%–92%, such as 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, or any value between them; the content of the ionic liquid is 2%–15%, such as 2%, 5%, 8%, 10%, 12%, 15%, or any value between them; the content of the rheology modifier is 2%–10%, such as 2%, 5%, 8%, 1 ... The content of the silane coupling agent is 0.1% to 5%, such as 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any value between them; the content of the desiccant is 0.1% to 2%, such as 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, or any value between them; the content of the catalyst is 0.1% to 2%, such as 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, or any value between them.

[0024] In this invention, the polyisocyanate compound is a compound with two or more isocyanate groups at the molecular chain terminal, specifically an aromatic isocyanate and / or an aliphatic isocyanate, including but not limited to: at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated phenyldimethyl diisocyanate, 1,5-naphthalene diisocyanate, 1,5-pentane diisocyanate, 1,4-phenyl diisocyanate, phenyldimethyl diisocyanate, tetramethylxylene diisocyanate, norbornene dimethyl isocyanate, lysine diisocyanate, triphenylmethane triisocyanate, triphenyl thiophosphate triphenyl isocyanate, and 1,6,11-undecane triisocyanate.

[0025] In this invention, the number-average molecular weight of the low-viscosity polyol compound is preferably 400–6000 g / mol, such as 400, 500, 800, 1000, 1200, 1500, 1800, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000 g / mol or any value between them. The low-viscosity polyol compound can be any existing polyol compound with a glass transition temperature below 0°C and a melting point below 40°C, specific examples including but not limited to: liquid polyester polyol, liquid polyether polyol, liquid polycarbonate polyol, liquid polycaprolactone polyol, fatty acid dimer diol, castor oil derivative polyol, and at least one of hydroxyl-terminated polybutadiene polyol.

[0026] In this invention, the melting point of the ionic liquid is preferably below 25°C, such as 25°C, 23°C, 20°C, 18°C, 15°C, 13°C, 10°C, 8°C, 5°C, 2°C, 0°C, -5°C, -10°C, -15°C, -20°C, -30°C, -40°C, etc. The ionic liquid is composed of cations and anions. The cations are preferably selected from at least one of imidazole cations, pyrrole cations, quaternary ammonium salt cations, quaternary phosphate salt cations, pyrrolidine cations, and piperidine cations. The anions are preferably selected from at least one of trifluoromethanesulfonate anion, tetrafluoroborate anion, hexafluorophosphate anion, difluoromethanesulfonylimide anion, hydrogen sulfate anion, ethyl sulfate anion, and p-toluenesulfonate anion. Specific examples of the aforementioned ionic liquids may include, but are not limited to: 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-2,3-dimethylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-propyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, 1-propyl-2,3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, and 1-butyl-3-methylimidazolium bis(trifluoromethane) At least one of the following: sulfonyl bis(trifluoromethanesulfonyl)imide salt, 1,3-diethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, N-butylpyridine tetrafluoroborate, hexyltriethylammonium bis(trifluoromethanesulfonyl)imide salt, methyltrioctylphosphonium bis(trifluoromethanesulfonyl)imide salt, N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide salt, N-butyl-N-methylpyrrolidine trifluoromethanesulfonate, and N-propyl-N-methylpiperidine bis(trifluoromethanesulfonyl)imide salt.

[0027] In this invention, the rheology modifier is preferably fumed silica, and specific examples include, but are not limited to, at least one of: AEROSIL A150, AEROSIL A200, AEROSIL A300, AEROSIL A380, AEROSIL R972, AEROSIL R974, AEROSIL R202, AEROSIL R812, HDK V15, HDK N20, HDK T30, HDK T40, HDK H13L, HDK H15, HDK H15L, HDK H16, HDK H17, HDK H18, HDK H2000, HDK H20, HDK H21, HDK H30, HDK H30RM, LM-150, M-5, E-5, EH-5, TS610, TS620, TS622, TS720, TS530, and TSUBOND. The specific surface area of ​​the fumed silica is preferably 90–380 m². 2 / g, specifically 90, 100, 120, 150, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380m 2 / g or any value in between.

[0028] In this invention, specific examples of the silane coupling agent include, but are not limited to: 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane. The first of the following: methyl silane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-isocyanate propyltrimethoxysilane.

[0029] In this invention, the desiccant may be selected from at least one of molecular sieve desiccant, oxazolidine desiccant, p-methylbenzenesulfonyl isocyanate and triethyl orthoformate.

[0030] In this invention, the catalyst may be selected from at least one of dibutyltin dilaurate, stannous octoate, zinc isooctanoate, bismuth isooctanoate, triethylamine, diethylenetriamine, triethylenediamine, N-ethylmorpholine, and 2,2-dimorpholinodiethyl ether.

[0031] The method for preparing an electrically detachable one-component reactive polyurethane hot melt adhesive provided by the present invention includes uniformly mixing a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optionally a rheology modifier, a silane coupling agent, a water-absorbing agent, and a catalyst to obtain an electrically detachable one-component reactive polyurethane hot melt adhesive. The mixing method is not particularly limited, but preferably includes the following steps: S1, dehydrating the low-viscosity polyol compound, ionic liquid, rheology modifier, silane coupling agent, and water-absorbing agent to obtain a pretreated product; S2, stirring the pretreated product, the polyisocyanate compound, and the catalyst at 70–90°C for 1–5 hours to obtain the one-component reactive polyurethane hot melt adhesive.

[0032] In this invention, in step S1, the dehydration treatment conditions preferably include a temperature of 100–120°C, such as 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, or any value between them; a rotation speed of 100–200 r / min, such as 100 r / min, 110 r / min, 120 r / min, 130 r / min, 140 r / min, 150 r / min, 160 r / min, 170 r / min, 180 r / min, 190 r / min, 200 r / min, or any value between them; and a time of 1–5 h, such as 1 h, 2 h, 3 h, 4 h, 5 h, or any value between them.

[0033] The present invention also provides the application of the electrically detachable one-component reactive polyurethane hot melt adhesive in electronic product bonding.

[0034] The adhesive substrate used in the electrically detachable single-component reactive polyurethane hot melt adhesive provided by this invention is a conductive substrate.

[0035] The present invention will be described in detail below through embodiments. These embodiments are intended to explain the invention and should not be construed as limiting it. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0036] Example 1

[0037] By weight, 18.37 g (6.124 mmol) of liquid polycarbonate diol with a number-average molecular weight of 3000 (Kuraray polyol C3090; Tg = -42℃; melting point <25℃), 21.43 g (6.124 mmol) of liquid polyester diol with a number-average molecular weight of 3500 (Dynacoll 7230; Tg = -30℃; melting point <25℃), 12.25 g (6.124 mmol) of liquid polyester diol with a number-average molecular weight of 2000 (stepanpol PH-56; Tg = -15℃; melting point <25℃), 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15℃), 5.0 g of fumed silica HDK H2O, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of water-absorbing agent Additive were added. TI was heated to 110°C and vacuum dehydrated for 2 hours under stirring at 150 rpm. The mixture was then cooled to 80°C, and 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added. The mixture was reacted for 2 hours under stirring at 150 rpm, and then discharged to obtain an electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this electrically removable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0038] Example 2

[0039] By weight, 40.30 g (13.43 mmol) of liquid polyether glycol (Dow Voranol WD2130; Tg < 0 °C; melting point < 25 °C) with a number-average molecular weight of 3000, 8.96 g (4.478 mmol) of polycaprolactone glycol (PERSTORP CAPA 7201A; Tg < 0 °C; melting point = 30-35 °C) with a number-average molecular weight of 2000, 12.0 g of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (melting point = -12 °C), 6.50 g of fumed silica AEROSIL R972, 0.3 g of 3-epoxypropoxypropyltrimethoxysilane, and 0.5 g of water-absorbing agent Additive were added. The solution was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. Then, it was cooled to 80°C, and 31.34 g (125.378 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.1 g of 2,2-dimorpholinodiethyl ether were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain an electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this electrically removable one-component reactive polyurethane hot melt adhesive was 9.03%.

[0040] Example 3

[0041] By weight, 22.06 g (22.06 mmol) of liquid polyester diol with a number-average molecular weight of 1000 (Stepanpol PD-110LV; Tg = -60℃; melting point <25℃), 22.06 g (22.06 mmol) of polytetrahydrofuran ether diol with a number-average molecular weight of 1000 (purchased from PTG Corporation, Korea, brand name PTMEG-1000; Tg = -76℃; melting point = 24℃), 4.0 g of 1,3-diethylimidazolium bis(trifluoromethanesulfonyl)imide salt (melting point = 12.4℃), 3.50 g of fumed silica HDK H18, 2.1 g of 3-isocyanate propyltrimethoxysilane, and 1.5 g of water-absorbing agent Additive were added. Ti was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. The mixture was then cooled to 80°C, and 44.48 g (264.741 mmol) of hexamethylene diisocyanate (HDI) and 0.3 g of dibutyltin dilaurate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain an electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this electrically removable one-component reactive polyurethane hot melt adhesive was 18.53%.

[0042] Example 4

[0043] By weight, 33.35 g (22.06 mmol) of liquid polyester diol with a number-average molecular weight of 3500 (Hoopol-F37031; Tg = -30℃; melting point <25℃), 14.29 g (4.764 mmol) of liquid polyether diol with a number-average molecular weight of 3000 (Dow Voranol WD2130; Tg <0℃; melting point <25℃), 15.0 g of hexyltriethylammonium bis(trifluoromethanesulfonyl)imide salt (melting point = 20℃), 7.50 g of fumed silica TS610, 0.9 g of 3-aminopropyltrimethoxysilane, and 0.3 g of water-absorbing agent Additive were added. The solution was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. Then, it was cooled to 80°C, and 28.56 g (128.636 mmol) of isophorone diisocyanate (IPDI) and 0.1 g of zinc isooctanoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain an electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this electrically removable one-component reactive polyurethane hot melt adhesive was 9.60%.

[0044] Example 5

[0045] By weight, 37.51 g (18.753 mmol) of polycaprolactone diol (PLACCEL L220AL; Tg < 0℃; melting point = 0-5℃) with a number-average molecular weight of 2000, 9.38 g (9.376 mmol) of liquid polyester diol (Stepanpol PD-110LV; Tg = -60℃; melting point < 25℃) with a number-average molecular weight of 1000, 2.0 g of N-butyl-N-methylpyrrolidine difluorosulfonylimide salt (melting point = -15℃), 2.0 g of fumed silica AEROSIL R202, 2.5 g of 3-acryloyloxypropyltrimethoxysilane, and 1.3 g of water-absorbing agent Siliporite were added. SA1702 was heated to 110℃ and vacuum dehydrated for 2 hours under stirring at 150 rpm. Then, it was cooled to 80℃, and 44.22 g (168.773 mmol) of dicyclohexylmethane-4,4'-diisocyanate (HMDI) and 1.1 g of bismuth isooctanoate were added. The mixture was reacted for 2 hours under stirring at 150 rpm, and then discharged to obtain an electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this electrically removable one-component reactive polyurethane hot melt adhesive was 11.81%.

[0046] Comparative Example 1

[0047] By weight, 42.59 g (12.169 mmol) of polyester diol with a number average molecular weight of 3500 (Dynacoll 7380; melting point = 70℃), 12.17 g (6.085 mmol) of polyester diol with a number average molecular weight of 2000 (Dynacoll 7110; Tg = 10℃; melting point < 25℃), 12.17 g (6.085 mmol) of liquid polyether diol with a number average molecular weight of 2000 (Dow Voranol WD2130; Tg < 0℃; melting point < 25℃), 20.0 g of thermoplastic acrylic resin BM19 (Tg = 75℃), 0.5 g of 3-mercaptopropyltrimethoxysilane, and 0.3 g of water-absorbing agent Additive were added. The solution was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. Then, it was cooled to 80°C, and 12.17 g (48.677 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.1 g of stannous octoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain a reference one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this reference one-component reactive polyurethane hot melt adhesive was 2.56%.

[0048] Comparative Example 2

[0049] By weight, the following components were added: 39.39 g (10.504 mmol) of polyester diol with a number-average molecular weight of 3750 (Hoopol F3000; melting point = 71℃), 21.01 g (10.504 mmol) of liquid polyether diol with a number-average molecular weight of 2000 (Dow Voranol 2120; Tg < 0℃; melting point < 25℃), 17.0 g of thermoplastic acrylic resin BM751 (Tg = 49℃), 5.0 g of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (melting point = -12℃), 5.0 g of propylene carbonate, 1.2 g of 3-mercaptopropyltrimethoxysilane, and 0.7 g of water-absorbing agent Additive. The solution was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. Then, it was cooled to 80°C, and 10.50 g (42.015 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.2 g of stannous octoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain a reference electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this reference electrically removable one-component reactive polyurethane hot melt adhesive was 1.76%.

[0050] Comparative Example 3

[0051] The reactive polyurethane hot melt adhesive was prepared according to the method described in Example 1, except that the low-viscosity polyol compound used in Example 1 was replaced with a high-melting-point or high-Tg polyol, as detailed below:

[0052] By weight, the following components were added: 18.37 g (6.124 mmol) of polyester diol with a number average molecular weight of 3000 (Hoopol F-580; melting point = 50℃), 21.43 g (6.124 mmol) of polyester diol with a number average molecular weight of 3500 (Hoopol F5630; Tg = 16℃), 12.25 g (6.124 mmol) of polycarbonate diol with a number average molecular weight of 2000 (UH-CARB200; melting point = 50℃), 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15℃), 5.0 g of fumed silica HDK H2O, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of water-absorbing agent Additive. TI was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. The mixture was then cooled to 80°C, and 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain a reference electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this reference electrically removable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0053] Comparative Example 4

[0054] The electrically detachable reactive polyurethane hot melt adhesive was prepared according to the method described in Example 1, except that the molar equivalent ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the low-viscosity polyol compound in Example 1 was reduced from 7.5:1 to 2:1, as detailed below:

[0055] By weight, 25.95 g (8.65 mmol) of liquid polycarbonate diol with a number-average molecular weight of 3000 (Kuraray polyol C3090; Tg = -42℃; melting point <25℃), 30.28 g (8.65 mmol) of liquid polyester diol with a number-average molecular weight of 3500 (Dynacoll 7230; Tg = -30℃; melting point <25℃), 17.30 g (8.65 mmol) of liquid polyester diol with a number-average molecular weight of 2000 (stepanpol PH-56; Tg = -15℃; melting point <25℃), 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15℃), 5.0 g of fumed silica HDK H2O, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of water-absorbing agent Additive were added. TI was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. The mixture was then cooled to 80°C, and 12.98 g (51.90 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain a reference electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this reference electrically removable one-component reactive polyurethane hot melt adhesive was 2.18%.

[0056] Comparative Example 5

[0057] The electrically detachable reactive polyurethane hot melt adhesive was prepared according to the method described in Example 1, except that 1-ethyl-3-methylimidazolium tetrafluoroborate was removed from Example 1, as follows:

[0058] By weight, 18.37 g (6.124 mmol) of liquid polycarbonate diol with a number-average molecular weight of 3000 (Kuraray polyol C3090; Tg = -42℃; melting point <25℃), 21.43 g (6.124 mmol) of liquid polyester diol with a number-average molecular weight of 3500 (Dynacoll 7230; Tg = -30℃; melting point <25℃), 12.25 g (6.124 mmol) of liquid polyester diol with a number-average molecular weight of 2000 (stepanpol PH-56; Tg = -15℃; melting point <25℃), 5.0 g of fumed silica HDK H2O, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of water-absorbing agent Additive were added. TI was heated to 110°C and vacuum dehydrated for 2 hours with stirring at 150 rpm. The mixture was then cooled to 80°C, and 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added. The mixture was reacted for 2 hours with stirring at 150 rpm, and then discharged to obtain a reference electrically removable one-component reactive polyurethane hot melt adhesive, which was then vacuum-sealed and stored. The isocyanate group content in this reference electrically removable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0059] Test case

[0060] The samples from the examples and comparative examples were compared and tested using the following method:

[0061] (1) Viscosity at 25℃: Samples of polyurethane hot melt adhesives obtained from the above examples and comparative examples were taken into a cone-plate viscometer and the viscosity of the adhesives at 25℃ and 1 rpm was tested using the cone-plate viscometer. The results are shown in Table 1.

[0062] (2) Adhesion strength before and after energization:

[0063] Bond strength before power-on: Using a dispensing machine, the polyurethane hot melt adhesive obtained in the above embodiments and comparative examples was dispensed at room temperature (if it is solid at room temperature, the dispensing temperature was set to 110℃). A rectangular adhesive line of 25mm × 4mm was applied to the stainless steel substrate, and then the adhesive was irradiated with a 365nm UV-LED light source at 2000mJ / cm². 2 After irradiation with the required energy, another stainless steel substrate was bonded to the original stainless steel substrate. Following bonding, the sample was cured at 25°C and 50% RH for 48 hours. Then, a universal testing machine was used to run the bonded sample along the shear direction at a speed of 10 mm / min until the bond failed. The maximum force value displayed by the instrument was recorded, and the shear bond strength of the polyurethane hot melt adhesive to the stainless steel substrate before energization was calculated based on the bond area. The results are shown in Table 1.

[0064] Bonding strength after energization: Using a dispensing machine, the polyurethane hot melt adhesive obtained in the above embodiments and comparative examples was dispensed at room temperature (if it is solid at room temperature, the dispensing temperature was set to 110℃). A rectangular adhesive line of 25mm × 4mm was applied to the stainless steel substrate, and then the adhesive was irradiated with a 365nm UV-LED light source at 2000mJ / cm². 2 After irradiation with the required energy, another stainless steel substrate was bonded to the original stainless steel substrate. Following bonding, the sample was cured at 25°C and 50% RH for 48 hours. Then, the positive and negative terminals of a DC power supply were clamped to both ends of the sheared sample. A specific voltage was applied for a certain time. After energizing, the sample was removed, and a universal testing machine was used to run the bonded sample along the shear direction at a speed of 10 mm / min until the bond failed. The maximum force displayed by the instrument was recorded, and the shear bond strength of the polyurethane hot melt adhesive to the stainless steel substrate was calculated based on the bond area. The results are shown in Table 1.

[0065] (3) High temperature and high humidity resistance (double 85 aging): Using a dispensing machine, the polyurethane hot melt adhesives obtained in the above embodiments and comparative examples were dispensed at room temperature (if solid at room temperature, the dispensing temperature was set to 110℃). A rectangular adhesive line of 25mm×4mm was applied to the stainless steel substrate, and then the adhesive was irradiated with a 365nm UV-LED light source at 2000mJ / cm². 2 After irradiation with high energy, another stainless steel substrate was bonded to the original stainless steel substrate. Following bonding, the sample was cured at 25°C and 50% RH for 48 hours. The bonded sample was then placed in a high-temperature, high-humidity oven at 85°C and 85% RH for 7 days. Afterward, a universal testing machine was used to run the bonded sample along the shear direction at a speed of 10 mm / min until the bond failed. The maximum force value displayed by the instrument was recorded, and the shear bond strength of the polyurethane hot melt adhesive to the stainless steel substrate after high-temperature, high-humidity aging was calculated based on the bond area. The results are shown in Table 1.

[0066] Table 1

[0067] As shown in Table 1, the electrically removable one-component reactive polyurethane hot melt adhesive provided by this invention has a low melt viscosity at room temperature, allowing for direct dispensing at room temperature. This significantly improves upon the drawback of reactive polyurethane hot melt adhesives requiring heating for application, increasing the convenience of adhesive use and reducing the risk of burns to operators using heating equipment. Based on practical experience, a bond strength below 2.0 MPa at room temperature indicates that the polyurethane hot melt adhesive is removable; otherwise, it is not. Table 1 also shows that the reactive polyurethane hot melt adhesive provided by this invention exhibits excellent final bond strength after curing, and the bond strength decreases significantly after energization, even to the point of direct detachment, demonstrating excellent electrically removable properties. Furthermore, the electrically removable one-component reactive polyurethane hot melt adhesive provided by this invention also exhibits excellent high-temperature and high-humidity stability. In summary, the polyurethane hot melt adhesive provided by this invention has low melt viscosity, can be dispensed at room temperature, has high final bond strength, and is removable under energized conditions, making it promising for practical applications.

[0068] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An electrically detachable one-component reactive polyurethane hot-melt adhesive, characterized in that, The electrically detachable one-component reactive polyurethane hot melt adhesive has a viscosity range of 1000-150000cps at 25°C and a bond strength attenuation rate of over 80% after being energized with a voltage of 1-100V. The isocyanate group content in the electrically detachable one-component reactive polyurethane hot melt adhesive is 5-20%.

2. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The raw materials for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive contain polyisocyanate compounds, low-viscosity polyol compounds, ionic liquids, and optional rheology modifiers, silane coupling agents, water-absorbing agents, and catalysts. The molar equivalent ratio of isocyanate groups in the polyisocyanate compounds to hydroxyl groups in the low-viscosity polyol compounds is (5-10):

1. The glass transition temperature of the low-viscosity polyol compounds is below 0°C and the melting point is below 40°C.

3. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, Based on the total weight of the raw materials for preparing the electrically detachable single-component reactive polyurethane hot melt adhesive, the total content of the polyisocyanate compounds and low-viscosity polyol compounds is 75-92%, the content of the ionic liquid is 2-15%, the content of the rheology modifier is 2-10%, the content of the silane coupling agent is 0.1-5%, the content of the water absorbent is 0.1-2%, and the content of the catalyst is 0.1-2%.

4. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 2, characterized in that, The polyisocyanate compound is selected from at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated phenyldiisocyanate, 1,5-naphthalene diisocyanate, 1,5-pentane diisocyanate, 1,4-phenyl diisocyanate, phenyldiisocyanate, tetramethylxylene diisocyanate, norbornene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, triphenyl thiophosphate, and 1,6,11-undecane triisocyanate.

5. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 2, wherein The number average molecular weight of the low-viscosity polyol compound is 400-6000 g / mol; the low-viscosity polyol compound is selected from at least one of liquid polyester polyol, liquid polyether polyol, liquid polycarbonate polyol, liquid polycaprolactone polyol, fatty acid dimer diol, castor oil derivative polyol and hydroxyl-terminated polybutadiene polyol.

6. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, The melting point of the ionic liquid is below 25°C.

7. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, The ionic liquid is composed of cations and anions. The cations are selected from at least one of imidazole cations, pyrrole cations, quaternary ammonium salt cations, quaternary phosphate salt cations, pyrrolidine cations, and piperidine cations. The anions are selected from at least one of trifluoromethanesulfonate anion, tetrafluoroborate anion, hexafluorophosphate anion, difluoromethanesulfonylimide anion, hydrogen sulfate anion, ethyl sulfate anion, and p-toluenesulfonate anion.

8. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, The ionic liquid is selected from 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-2,3-dimethylimidazolium trifluoromethanesulfonate, 1-octyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-propyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, 1-propyl-2,3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide. At least one of the following: 1,3-diethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium bis(fluoromethanesulfonyl)imide salt, N-butylpyridine tetrafluoroborate, hexyltriethylammonium bis(trifluoromethanesulfonyl)imide salt, methyltrioctylphosphonium bis(trifluoromethanesulfonyl)imide salt, N-butyl-N-methylpyrrolidine bis(fluoromethanesulfonyl)imide salt, N-butyl-N-methylpyrrolidine trifluoromethanesulfonate, and N-propyl-N-methylpiperidine bis(trifluoromethanesulfonyl)imide salt.

9. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, The rheology modifier is fumed silica; The water-absorbing agent is selected from at least one of molecular sieve desiccant, oxazolidine dehydrating agent, p-methylbenzenesulfonyl isocyanate and triethyl orthoformate; The catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, zinc isooctanoate, bismuth isooctanoate, triethylamine, diethylenetriamine, triethylenediamine, N-ethylmorpholine, and 2,2-dimorpholinodiethyl ether.

10. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 2, characterized in that, The silane coupling agent is selected from 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2 At least one of the following: (-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-isocyanate propyltrimethoxysilane.

11. The process for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive of claim 1, characterized in that, The method involves uniformly mixing a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optional rheology modifiers, silane coupling agents, water-absorbing agents, and catalysts to obtain an electrically detachable one-component reactive polyurethane hot melt adhesive.

12. The method for preparing the electrically detachable single-component reactive polyurethane hot melt adhesive according to claim 11, characterized in that, The mixing step includes: S1. The low-viscosity polyol compound, ionic liquid, rheology modifier, silane coupling agent and dehydrating agent are dehydrated to obtain the pretreated product; S2. Stir the pretreated product, polyisocyanate compound and catalyst at 70-90℃ for 1-5 hours to obtain a one-component reactive polyurethane hot melt adhesive.

13. The application of the electrically detachable one-component reactive polyurethane hot melt adhesive of claim 1 in the bonding of electronic products.

Images