An electrically detachable single-component polyurethane hot melt adhesive as well as a preparation method and application thereof

Abstract

The application belongs to the field of adhesives, and particularly relates to a single-component polyurethane hot melt adhesive capable of being electrically disassembled as well as a preparation method and application thereof. The single-component reactive polyurethane hot melt adhesive has a viscosity range of 1000-150000 cps at 25 DEG C and an attenuation rate of bonding strength of more than 80% after being powered at a voltage of 1-100 V, and the content of isocyanate groups in the single-component reactive polyurethane hot melt adhesive is 5-20%. The polyurethane hot melt adhesive provided by the application has low melt viscosity, can be dispensed at room temperature, has high final bonding strength, and has the function of being disassembled under the condition of power supply, and thus has a wide practical application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of adhesives, and particularly relates to a single-component polyurethane hot melt adhesive capable of being electrically disassembled, a preparation method and application thereof. BACKGROUND

[0002] In electronic products such as smart phones, tablet computers, smart watches, TWS earphones, etc., reaction type polyurethane hot melt adhesives are often used to bond and fix the parts of electronic products. The parts of electronic products bonded by reaction type polyurethane hot melt adhesives often have high value. When there are situations such as poor assembly, product after-sales repair, recycling of valuable electronic product parts, etc., the bonded parts often need to be disassembled. Therefore, the adhesive is often required to have excellent bonding reliability and easy disassembly function under certain conditions.

[0003] Reaction type polyurethane hot melt adhesives mainly use isocyanate-terminated oligomers as the main body. The isocyanate groups in the isocyanate-terminated oligomers can react with moisture in the air. After complete curing, a cross-linked chemical structure can be formed, thereby realizing high bonding strength. However, the covalent bond obtained by the reaction of isocyanate groups with moisture is irreversible, and the cross-linked structure is difficult to be destroyed. After complete curing, it is usually difficult to disassemble the adhesive. If the bonded materials need to be separated, a large external force, high temperature, chemical reagents, etc. are often required, and the bonded materials may be damaged during the disassembly of the adhesive, causing great economic losses.

[0004] In recent years, there are also technologies that add alkali metal salts and solventized matrices to polyurethane hot melt adhesives to endow the polyurethane hot melt adhesives with the function of being disassembled under the condition of being electrified. However, although the existing electrically disassemblable polyurethane hot melt adhesives have the function of being disassembled under the condition of being electrified, due to the high melt viscosity of such polyurethane hot melt adhesives, they are solid substances at room temperature, and usually need to be heated to a melt temperature (usually 90℃-160℃) or above to be extruded and applied. At this time, professional heating and application equipment is usually required, but this will not only increase the cost of using the adhesive, but also greatly limit the application scenarios of such single-component polyurethane hot melt adhesives, such as homes and repair markets where it is inconvenient to provide heating equipment, thereby greatly limiting the widespread application and promotion of such single-component polyurethane hot melt adhesives. In addition, the existing electrically disassemblable polyurethane hot melt adhesives have the defect of low final bonding strength. Although they have certain electrically disassemblable function, the final bonding strength is low, the reliability is poor, there is a large performance gap with traditional reaction type polyurethane hot melt adhesives, and it is difficult to meet the performance requirements of actual application scenarios.

[0005] In summary, there is an urgent need to develop an adhesive with low melt viscosity, which can be dispensed at room temperature, has high final bonding strength, and has the function of being electrically disassembled to meet the application requirements of the market. SUMMARY

[0006] A first object of the present application is to provide a single-component polyurethane hot melt adhesive that is electrically dismountable, has low melt viscosity, can be dispensed at room temperature, and has high final adhesive strength.

[0007] A second object of the present application is to provide a method for preparing the above-mentioned single-component polyurethane hot melt adhesive that is electrically dismountable.

[0008] A third object of the present application is to provide the use of the above-mentioned single-component polyurethane hot melt adhesive that is electrically dismountable in products that have a need for dismounting.

[0009] Specifically, the single-component reactive polyurethane hot melt adhesive that is electrically dismountable according to the present application has a viscosity in the range of 1000-150000 cps at 25°C and an attenuation rate of adhesive strength of 80% or more after being powered on at a voltage of 1-100 V, and the content of isocyanate groups in the single-component reactive polyurethane hot melt adhesive that is electrically dismountable is 5-20%.

[0010] In a preferred embodiment, the single-component reactive polyurethane hot melt adhesive that is electrically dismountable is prepared from a raw material that contains a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optionally a rheology modifier, a silane coupling agent, a water absorbent, 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, and the glass transition temperature of the low-viscosity polyol compound is 0°C or lower and the melting point is 40°C or lower.

[0011] The method for preparing the single-component reactive polyurethane hot melt adhesive that is electrically dismountable according to the present application 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 absorbent, and a catalyst to obtain the single-component reactive polyurethane hot melt adhesive that is electrically dismountable.

[0012] The inventors of the present application have found, after in-depth and extensive research, that the polyurethane polymer with isocyanate functional groups selected by the existing electrically disassemblable polyurethane hot melt adhesive is a polyurethane prepolymer obtained by reacting a polyol compound with an excess of a polyisocyanate compound. The molar equivalent ratio of isocyanate groups in the polyisocyanate compound to hydroxyl groups in the polyol compound is usually set at (1.5-2.5):1 (i.e., the molar ratio of NCO / OH is (1.5-2.5):1). According to this stoichiometric relationship, the isocyanate content of the polyurethane prepolymer prepared is low, the molecular weight of the polyurethane prepolymer is large, and the interaction force between the molecular chains is large, thereby resulting in the final polyurethane prepolymer having a relatively high melt viscosity, which is not easy to dispense at room temperature. In addition, some polyol compounds used in the polyurethane prepolymer with isocyanate functional groups have strong crystallinity or a high glass transition temperature (Tg) at room temperature. The polyurethane prepolymer prepared by reacting the room temperature crystalline polyol or high Tg polyol with the isocyanate compound is usually a solid substance at room temperature. Therefore, the currently prepared electrically disassemblable polyurethane hot melt adhesive according to the traditional method is usually a solid substance at room temperature, which needs to be heated to above the melting point (90-160°C) to melt and apply, greatly increasing the use threshold of the adhesive, increasing the cost of the adhesive equipment, and also increasing the risk of burns to the operators during the use of the adhesive.

[0013] The existing electrically disassemblable polyurethane hot melt adhesive is prepared by adding an ionic liquid or an alkali metal salt and a solvating matrix to the polyurethane hot melt adhesive, and using the Faraday reaction of the anion and the cation in the ionic liquid or the alkali metal salt under the condition of electricity to give the polyurethane hot melt adhesive a disassemblable function under the condition of electricity. The introduction of the ionic liquid, the solvating matrix and other liquid substances into the polyurethane hot melt adhesive is beneficial to the realization of the electric disassembly function, but such liquid substances cannot participate in the curing of the polyurethane hot melt adhesive, and still exist in the initial low viscosity state after the curing of the polyurethane hot melt adhesive, thus having a certain negative effect on the final adhesive strength. In addition, since the equivalent ratio of isocyanate to hydroxyl in the isocyanate-terminated polyurethane prepolymer is low (the equivalent ratio of NCO / OH is between 1.5 and 2.5), the isocyanate content of the finally prepared polyurethane prepolymer is low, and thus the crosslinking density of the polyurethane prepolymer after the final wet curing is low, resulting in a low adhesive strength of the adhesive after curing. After the negative influence of the liquid components such as the ionic liquid and the solvating matrix, the adhesive strength will be further reduced. Therefore, although the ionic liquid or the alkali metal salt combined with the solvating matrix can be added to the polyurethane hot melt adhesive to prepare an electrically disassemblable polyurethane hot melt adhesive, the final adhesive strength is still insufficient, which is not conducive to the application and promotion of such products.

[0014] The key of the present application is to break the design limitation of setting the equivalent ratio of isocyanate and hydroxyl between (1.5-2.5):1 in the preparation process of traditional electrically disassemblable polyurethane hot melt adhesive, and innovatively set the equivalent ratio of isocyanate and hydroxyl in the range of (5-10):1 to control the content of isocyanate groups in the electrically disassemblable single-component reactive polyurethane hot melt adhesive to 5-20%, and at the same time, select a polyol compound with low crystallinity and low glass transition temperature at room temperature and react with a large excess of isocyanate compound to prepare a liquid polyurethane hot melt adhesive at room temperature. The content of isocyanate groups in this hot melt adhesive is high, the molecular weight of the finally prepared polyurethane prepolymer is low, the interaction between the molecular chains is small, and the melt viscosity is low. At the same time, the relatively high content of isocyanate monomers can dilute the melt viscosity of the polyurethane prepolymer, and on the other hand, the high content of isocyanate groups can form high crosslinking density after final curing, and can form high bonding strength. At the same time, the present application innovatively introduces ionic liquid into this liquid polyurethane hot melt adhesive, which can undergo Faraday reaction after being electrified, and endows this kind of liquid polyurethane hot melt adhesive with certain electrically disassemblable performance. In addition, the ionic liquid selected by the present application is a liquid substance at room temperature, which can be very conveniently and directly added to the polyurethane hot melt adhesive system, thereby effectively avoiding the introduction of a solvated matrix into the adhesive system, and effectively reducing the negative impact of the solvated matrix on the bonding strength of the polyurethane hot melt adhesive. At the same time, the introduction of ionic liquid into the low-viscosity polyurethane hot melt adhesive can also effectively reduce the viscosity of the polyurethane hot melt adhesive. In addition, as mentioned above, by increasing the equivalent ratio of isocyanate groups and hydroxyl groups, the present application can make the excess of isocyanate groups in the system be relatively high, and the crosslinking density after curing is high, so that even affected by the uncured ionic liquid, the relatively high bonding strength can still be maintained. Therefore, the ionic liquid introduced by the present application can endow the polyurethane hot melt adhesive with the function of being disassembled under the condition of being electrified, and on the other hand, the introduction of ionic liquid can also significantly reduce the melt viscosity of the polyurethane hot melt adhesive, so that the polyurethane hot melt adhesive of the present application can be directly glued at room temperature, greatly reducing the threshold of applying this kind of electrically disassemblable polyurethane hot melt adhesive, reducing the equipment cost required for applying the polyurethane hot melt adhesive, and effectively avoiding the risk of the operator being scalded during the use of the adhesive. In addition, the polyurethane hot melt adhesive of the present application has the function of being electrically disassembled after curing, and at the same time, has high bonding strength before being electrified, which provides sufficient excellent reliability for the product. In summary, the polyurethane hot melt adhesive provided by the present application has low melt viscosity, can be dispensed at room temperature, has high final bonding strength, and at the same time has the function of being disassembled under the condition of being electrified, which has a broad practical application prospect. DETAILED DESCRIPTION

[0015] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application has a viscosity range of 1000-150000 cps at 25 DEG C, and specifically can be 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 30000, 50000, 70000, 90000, 110000, 130000, 150000 cps or any value between them.

[0016] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application has a decay rate of bonding strength of 80% or more after being powered at a voltage of 1-100 V, and specifically can be 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, 99%, 100% or any value between them. The voltage required for the electrically detachable single-component reactive polyurethane hot melt adhesive to be powered and detached is preferably 1-100 V, and specifically can be 1 V, 3 V, 5 V, 7 V, 9 V, 10 V, 20 V, 30 V, 40 V, 50 V, 60 V, 70 V, 80 V, 90 V, 100 V or any value between them; the time required for being powered is preferably 1 s-60 min, such as 1 s, 2 s, 15 s, 30 s, 40 s, 50 s, 1 min, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 60 min or any value between them.

[0017] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application has a content of isocyanate groups of 5-20%, and specifically can be 5%, 8%, 10%, 12%, 15%, 17%, 19%, 20% or any value between them. In the present application, the content of isocyanate groups 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.

[0018] The electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application is a liquid or paste at room temperature, and has the characteristics of low melt viscosity, room temperature dispensing, high final bonding strength and electrically detachable.

[0019] In a preferred embodiment, the raw materials for preparing the electrically detachable single-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 absorbent, 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, and the glass transition temperature of the low-viscosity polyol compound is 0°C or lower and the melting point is 40°C or lower. 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 therebetween. Specifically, the glass transition temperature of the low-viscosity polyol compound can be 0°C, -2°C, -4°C, -6°C, -8°C, -10°C, -12°C, -14°C, -16°C, -18°C, -20°C, -22°C, -24°C, -26°C, -28°C, -30°C, -32°C, -34°C, -36°C, -38°C, -40°C, or the like. Specifically, the melting point of the low-viscosity polyol compound can be 40°C, 38°C, 36°C, 34°C, 32°C, 30°C, 28°C, 26°C, 24°C, 22°C, 20°C, 18°C, 16°C, 14°C, 12°C, 10°C, 8°C, 6°C, 4°C, 2°C, 0°C, -5°C, -10°C, -15°C, -20°C, -30°C, or the like.

[0020] In the present application, the mass ratio of the total content of the polyisocyanate compound and the low-viscosity polyol compound to the content of the ionic liquid is preferably (5-46):1, and specifically can be 5:1, 8:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 43:1, 46:1, or any value therebetween. The mass ratio of the rheology modifier to the ionic liquid is preferably (0-5):1, and specifically can be 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 therebetween. The mass ratio of the silane coupling agent to the ionic liquid is preferably (0-2.5):1, and specifically can be 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 therebetween. The mass ratio of the content of the water absorbent and the catalyst to the content of the ionic liquid is preferably independently (0-1):1, and specifically can be 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 therebetween.

[0021] In a preferred embodiment, the total content of the polyisocyanate compound and the low viscosity polyol compound is 75 to 92%, such as 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, or any value therebetween, based on the total weight of the raw materials for preparing the electrically detachable single-component reactive polyurethane hot melt adhesive; the content of the ionic liquid is 2 to 15%, such as 2%, 5%, 8%, 10%, 12%, 15%, or any value therebetween; the content of the rheology modifier is 2 to 10%, such as 2%, 5%, 8%, 10%, or any value therebetween; 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 therebetween; the content of the water absorbing agent is 0.1 to 2%, such as 0.1%, 0.5%, 0.8%, 1%, 1.5%, 2%, or any value therebetween; and 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 therebetween.

[0022] In the present application, the polyisocyanate compound is a compound having two or more isocyanate groups at the terminal of the molecular chain, and can specifically be an aromatic isocyanate and / or an aliphatic isocyanate, and specific examples thereof include, but are 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 xylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-pentane diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, norbornane dimethylene isocyanate, lysine diisocyanate, triphenylmethane triisocyanate, thiophosphoric acid triphenyl isocyanate, and 1,6,11-undecane triisocyanate.

[0023] In the present application, the number average molecular weight of the low viscosity polyol compound is preferably 400 to 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 therebetween. The low viscosity polyol compound can be any of the various polyol compounds having a glass transition temperature of 0°C or less and a melting point of 40°C or less, specific examples of which include, but are not limited to, at least one of a liquid polyester polyol, a liquid polyether polyol, a liquid polycarbonate polyol, a liquid polycaprolactone polyol, a fatty acid dimer diol, a castor oil derivative polyol, and a hydroxyl-terminated polybutadiene polyol.

[0024] In the present application, the melting point of the ionic liquid is preferably 25°C or less, 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 a cation and an anion. The cation is preferably selected from at least one of imidazole-based cations, pyrrole-based cations, quaternary ammonium salt-based cations, quaternary phosphonium salt-based cations, pyrrolidine-based cations, and piperidine-based cations. The anion is preferably selected from at least one of triflate anions, tetrafluoroborate anions, hexafluorophosphate anions, bisfluorosulfonimide anions, hydrogen sulfate anions, ethyl sulfate-based anions, and p-toluenesulfonate anions. Specific examples of the above ionic liquid can include, but are not limited to, at least one of 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium triflate, 1-ethyl-2,3-dimethylimidazolium triflate, 1-octyl-3-methylimidazolium triflate, 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-dimethylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,3-diethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium bisfluorosulfonimide, N-butylpyridinium tetrafluoroborate, hexyltriethylammonium bis(trifluoromethanesulfonyl)imide, methyltrioctylphosphonium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidinium bisfluorosulfonimide, N-butyl-N-methylpyrrolidinium triflate, and N-propyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide.

[0025] In the present application, the rheology modifier is preferably fumed silica, specific examples of which 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 to 380 m 2 / g, specifically 90, 100, 120, 150, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380 m 2 / g, or any value therebetween.

[0026] In the present application, specific examples of the silane coupling agent include, but are not limited to, at least one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-isocyanatepropyltrimethoxysilane.

[0027] In the present application, the water absorbing agent can be selected from at least one of molecular sieve desiccant, oxazolidine water removing agent, p-toluenesulfonylisocyanate, and triethyl orthoformate.

[0028] In the present application, the catalyst can be selected from at least one of dibutyltin dilaurate, stannous octoate, zinc isooctoate, bismuth isooctoate, triethylamine, diethylenetriamine, triethylenediamine, N-ethylmorpholine, and 2,2-dimorpholinyl diethyl ether.

[0029] The application provides a preparation method of the electrically detachable single-component reactive polyurethane hot melt adhesive, which comprises uniformly mixing a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optional rheological modifiers, silane coupling agents, water absorbents and catalysts to obtain the electrically detachable single-component reactive polyurethane hot melt adhesive. The mixing mode is not particularly limited, and preferably comprises the following steps: S1, performing dehydration treatment on the low-viscosity polyol compound, the ionic liquid, the rheological modifier, the silane coupling agent and the water absorbent to obtain a pretreated product; S2, stirring and reacting the pretreated product, the polyisocyanate compound and the catalyst at 70-90 ℃ for 1-5 h to obtain the single-component reactive polyurethane hot melt adhesive.

[0030] In the present application, in step S1, the dehydration treatment is preferably performed at a temperature of 100-120 ℃, such as 100 ℃, 102 ℃, 104 ℃, 106 ℃, 108 ℃, 110 ℃, 112 ℃, 114 ℃, 116 ℃, 118 ℃, 120 ℃ or any value therebetween, at a rotating 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 therebetween, and for 1-5 h, such as 1 h, 2 h, 3 h, 4 h, 5 h or any value therebetween.

[0031] The application further provides an application of the electrically detachable single-component reactive polyurethane hot melt adhesive in electronic product bonding.

[0032] The adhesive substrate used in the electrically detachable single-component reactive polyurethane hot melt adhesive provided by the application is a substrate with electrical conductivity.

[0033] The application will be described in detail below through examples. The examples are intended to explain the application, and cannot be understood as a limitation of the application. If a specific technology or condition is not specified in the examples, the technology or condition described in the literature in the field or according to the product instruction is used. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be obtained on the market.

[0034] Example 1

[0035] 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°C; melting point < 25°C), 21.43 g (6.124 mmol) of liquid polyester diol with a number average molecular weight of 3500 (Dynacoll 7230; Tg = -30°C; melting point < 25°C), 12.25 g (6.124 mmol) of liquid polyester diol with a number average molecular weight of 2000 (stepan pol PH-56; Tg = -15°C; melting point < 25°C), 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15°C), 5.0 g of fumed silica HDK H20, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of water absorbent Additive TI were heated to 110°C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80°C, 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min before discharging to obtain an electrically dismountable one-component reactive polyurethane hot melt adhesive, which was stored in vacuum seal. The content of isocyanate groups in the electrically dismountable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0036] Example 2

[0037] By weight, 40.30 g (13.43 mmol) of liquid polyether diol with a number average molecular weight of 3000 (Dow Voranol WD2130; Tg < 0°C; melting point < 25°C), 8.96 g (4.478 mmol) of polycaprolactone diol with a number average molecular weight of 2000 (PERSTORP CAPA 7201A; Tg < 0°C; melting point = 30-35°C), 12.0 g of 1-ethyl-3-methylimidazolium triflate (melting point = -12°C), 6.50 g of fumed silica AEROSIL R972, 0.3 g of 3-glycidoxypropyltrimethoxysilane, and 0.5 g of water absorbent Additive OF were heated to 110°C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80°C, 31.34 g (125.378 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.1 g of 2,2-dimorpholinodiethylether were added, and the reaction was carried out for 2 h under stirring at 150 r / min before discharging to obtain an electrically dismountable one-component reactive polyurethane hot melt adhesive, which was stored in vacuum seal. The content of isocyanate groups in the electrically dismountable one-component reactive polyurethane hot melt adhesive was 9.03%.

[0038] Example 3

[0039] 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°C; melting point < 25°C), 22.06 g (22.06 mmol) of polytetramethylene ether glycol with a number average molecular weight of 1000 (purchased from the Korean PTG company, brand PTMEG-1000; Tg = -76°C; melting point = 24°C), 4.0 g of 1,3-diethylimidazole bis(trifluoromethanesulfonyl) imide salt (melting point = 12.4°C), 3.50 g of fumed silica HDK H18, 2.1 g of 3-isocyanate propyl trimethoxysilane, and 1.5 g of water absorption agent Additive TI, were heated to 110°C, vacuum dehydrated for 2 h under the condition of stirring at 150 r / min, then cooled to 80°C, 44.48 g (264.741 mmol) of hexamethylene diisocyanate (HDI) and 0.3 g of dibutyl tin dilaurate were added, and after reaction for 2 h under the condition of stirring at 150 r / min, the product was discharged to obtain an electrically detachable one-component reactive polyurethane hot melt adhesive, which was vacuum sealed and stored. The content of isocyanate groups in the electrically detachable one-component reactive polyurethane hot melt adhesive was 18.53%.

[0040] Example 4

[0041] By weight, 33.35 g (22.06 mmol) of liquid polyester diol with a number average molecular weight of 3500 (Hoopol-F37031; Tg = -30°C; melting point < 25°C), 14.29 g (4.764 mmol) of liquid polyether diol with a number average molecular weight of 3000 (Dow Voranol WD2130; Tg < 0°C; melting point < 25°C), 15.0 g of hexyl triethylammonium bis(trifluoromethanesulfonyl) imide salt (melting point = 20°C), 7.50 g of fumed silica TS610, 0.9 g of 3-aminopropyl trimethoxysilane, and 0.3 g of water absorption agent Additive OF were heated to 110°C, vacuum dehydrated for 2 h under the condition of stirring at 150 r / min, then cooled to 80°C, 28.56 g (128.636 mmol) of isophorone diisocyanate (IPDI) and 0.1 g of zinc isooctoate were added, and after reaction for 2 h under the condition of stirring at 150 r / min, the product was discharged to obtain an electrically detachable one-component reactive polyurethane hot melt adhesive, which was vacuum sealed and stored. The content of isocyanate groups in the electrically detachable one-component reactive polyurethane hot melt adhesive was 9.60%.

[0042] Example 5

[0043] By weight, 37.51 g (18.753 mmol) of polycaprolactone diol (Shin-Etsu PLACCEL L220AL; Tg < 0 °C; melting point = 0-5 °C), 9.38 g (9.376 mmol) of liquid polyester diol (Stepanpol PD-110LV; Tg = -60 °C; melting point < 25 °C), 2.0 g of N-butyl-N-methylpyrrolidinium bisfluorosulfonyl imide salt (melting point = -15 °C), 2.0 g of fumed silica AEROSIL R202, 2.5 g of 3-acryloxypropyltrimethoxysilane, and 1.3 g of water absorbent Siliporite SA1702 were heated to 110 °C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80 °C, 44.22 g (168.773 mmol) of dicyclohexylmethane-4,4’-diisocyanate (HMDI) and 1.1 g of bismuth isooctoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min to obtain an electrically dismountable one-component reactive polyurethane hot melt adhesive, which was vacuum-sealed and stored. The content of isocyanate groups in the electrically dismountable one-component reactive polyurethane hot melt adhesive was 11.81%.

[0044] Comparative Example 1

[0045] By weight, 42.59 g (12.169 mmol) of polyester diol (Dynacoll 7380; melting point = 70 °C), 12.17 g (6.085 mmol) of polycaprolactone diol (Dynacoll 7110; Tg = 10 °C; melting point < 25 °C), 12.17 g (6.085 mmol) of liquid polyether diol (Dow Voranol WD2130; Tg < 0 °C; melting point < 25 °C), 20.0 g of thermoplastic acrylic resin BM19 (Tg = 75 °C), 0.5 g of 3-mercaptopropyltrimethoxysilane, and 0.3 g of water absorbent Additive OF were heated to 110 °C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80 °C, 12.17 g (48.677 mmol) of diphenylmethane-4,4’-diisocyanate (MDI) and 0.1 g of stannous octoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min to obtain a reference one-component reactive polyurethane hot melt adhesive, which was vacuum-sealed and stored. The content of isocyanate groups in the reference one-component reactive polyurethane hot melt adhesive was 2.56%.

[0046] Comparative Example 2

[0047] By weight, 39.39 g (10.504 mmol) of polyester diol with number average molecular weight 3750 (Hoopol F3000; melting point = 71 °C), 21.01 g (10.504 mmol) of liquid polyether diol with number average molecular weight 2000 (Dow Voranol 2120; Tg < 0 °C; melting point < 25 °C), 17.0 g of thermoplastic acrylic resin BM751 (Tg = 49 °C), 5.0 g of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (melting point = -12 °C), 5.0 g of propylene carbonate, 1.2 g of 3-mercaptopropyltrimethoxysilane, and 0.7 g of water absorbent Additive OF were heated to 110 °C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80 °C, 10.50 g (42.015 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.2 g of stannous octoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min before discharging to obtain a reference electrically dismountable one-component reactive polyurethane hot melt adhesive, which was vacuum sealed and stored. The content of isocyanate groups in the reference electrically dismountable one-component reactive polyurethane hot melt adhesive was 1.76%.

[0048] Comparative Example 3

[0049] The reactive polyurethane hot melt adhesive was prepared in the same manner as in Example 1, except that the low-viscosity polyol compound used in Example 1 was replaced by a high-melting-point or high-Tg polyol, as follows:

[0050] By weight, 18.37 g (6.124 mmol) of polyester diol with number average molecular weight 3000 (Hoopol F-580; melting point = 50 °C), 21.43 g (6.124 mmol) of polyester diol with number average molecular weight 3500 (Hoopol F5630; Tg = 16 °C), 12.25 g (6.124 mmol) of polycarbonate diol with number average molecular weight 2000 (UH-CARB200; melting point = 50 °C), 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15 °C), 5.0 g of fumed silica HDK H20, 1.0 g of 3-mercaptopropyltrimethoxysilane, 0.2 g of water absorbent Additive TI were heated to 110 °C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80 °C, 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min before discharging to obtain a reference electrically dismountable one-component reactive polyurethane hot melt adhesive, which was vacuum sealed and stored. The content of isocyanate groups in the reference electrically dismountable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0051] Comparative Example 4

[0052] An electrically dismountable reaction type polyurethane hot melt adhesive was prepared in the same manner as 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 adjusted from 7.5:1 to 2:1, as follows:

[0053] By weight, 25.95 g (8.65 mmol) of a liquid polycarbonate diol (Kuraray polyol C3090; Tg = -42°C; melting point < 25°C) with a number average molecular weight of 3000, 30.28 g (8.65 mmol) of a liquid polyester diol (Dynacoll 7230; Tg = -30°C; melting point < 25°C) with a number average molecular weight of 3500, 17.30 g (8.65 mmol) of a liquid polyester diol (stepan pol PH-56; Tg = -15°C; melting point < 25°C) with a number average molecular weight of 2000, 7.00 g of 1-ethyl-3-methylimidazolium tetrafluoroborate (melting point = 15°C), 5.0 g of fumed silica HDK H20, 1.0 g of 3-mercaptopropyltrimethoxysilane, and 0.2 g of a water absorbent Additive TI were heated to 110°C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80°C, 12.98 g (51.90 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added, and reacted for 2 h under stirring at 150 r / min to obtain a reference electrically dismountable one-component reaction type polyurethane hot melt adhesive, which was vacuum sealed and stored. The content of isocyanate groups in the reference electrically dismountable one-component reaction type polyurethane hot melt adhesive was 2.18%.

[0054] Comparative Example 5

[0055] An electrically dismountable reaction type polyurethane hot melt adhesive was prepared in the same manner as in Example 1, except that the 1-ethyl-3-methylimidazolium tetrafluoroborate in Example 1 was removed, as follows:

[0056] 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°C; melting point < 25°C), 21.43 g (6.124 mmol) of liquid polyester diol with a number average molecular weight of 3500 (Dynacoll 7230; Tg = -30°C; melting point < 25°C), 12.25 g (6.124 mmol) of liquid polyester diol with a number average molecular weight of 2000 (stepan pol PH-56; Tg = -15°C; melting point < 25°C), 5.0 g of fumed silica HDK H20, 1.0 g of 3-mercaptopropyl trimethoxysilane, and 0.2 g of water absorbent Additive TI were heated to 110°C, vacuum dehydrated for 2 h under stirring at 150 r / min, then cooled to 80°C, 34.45 g (137.786 mmol) of diphenylmethane-4,4'-diisocyanate (MDI) and 0.3 g of stannous octoate were added, and the reaction was carried out for 2 h under stirring at 150 r / min, and then the product was discharged to obtain a reference electrically dismountable one-component reactive polyurethane hot melt adhesive, which was stored in vacuum seal. The content of isocyanate groups in the reference electrically dismountable one-component reactive polyurethane hot melt adhesive was 10.03%.

[0057] Test Example

[0058] The samples of the examples and the comparative examples were tested by the following method:

[0059] (1) Viscosity at 25°C: The polyurethane hot melt adhesive samples obtained in the above examples and comparative examples were sampled into a cone and plate viscometer, and the viscosity of the adhesive at 25°C and 1 rpm was tested by using the cone and plate viscometer. The results are shown in Table 1.

[0060] (2) Adhesion strength before and after power on:

[0061] Adhesion strength before power on: The polyurethane hot melt adhesives obtained in the above examples and comparative examples were dispensed at room temperature by using a dispensing machine (if it is solid at room temperature, the dispensing temperature was set to 110°C), a 25 mm x 4 mm rectangular glue line was coated on a stainless steel substrate, then a 365 nm UV-LED light source was used to irradiate the glue with an energy of 2000 mJ / cm 2 After the irradiation, another stainless steel substrate was attached to the stainless steel substrate, and after the attachment, the sample was cured in an environment of 25°C and 50% RH for 48 h, and then a universal material testing machine was used to run the prepared adhesive sample to adhesive failure along the shear direction at a speed of 10 mm / min, and the maximum force value displayed by the instrument was recorded. The shear adhesion strength of the polyurethane hot melt adhesive to the stainless steel substrate before power on was calculated in combination with the adhesive area. The results are shown in Table 1.

[0062] Adhesion strength after power on: the polyurethane hot melt adhesive obtained in each of the above examples and comparative examples was dispensed at room temperature using a dispenser (if it is solid at room temperature, the dispensing temperature was set to 110°C), a 25 mm x 4 mm rectangular glue line was coated on a stainless steel substrate, then a 365 nm UV-LED light source was used to irradiate the glue with an energy of 2000 mJ / cm 2 After the irradiation was completed, another stainless steel substrate was attached to the stainless steel substrate, after the attachment was completed, the sample was cured in an environment of 25°C, 50% RH for 48 h, then the positive and negative leads of the direct current power supply were clamped at both ends of the sheared sample, under a certain voltage, the power was turned on for a certain time, after the power was turned on, the sheared sample was removed, the universal material testing machine was used to run the prepared adhesive sample along the shearing direction at a speed of 10 mm / min until the adhesive sample failed, the maximum force value displayed by the instrument was recorded, and the shear adhesion strength of the polyurethane hot melt adhesive to the stainless steel substrate after power on was calculated in combination with the adhesive area. The results are shown in Table 1.

[0063] (3) High temperature and high humidity resistance (double 85 aging): the polyurethane hot melt adhesive obtained in each of the above examples and comparative examples was dispensed at room temperature using a dispenser (if it is solid at room temperature, the dispensing temperature was set to 110°C), a 25 mm x 4 mm rectangular glue line was coated on a stainless steel substrate, then a 365 nm UV-LED light source was used to irradiate the glue with an energy of 2000 mJ / cm 2 After the irradiation was completed, another stainless steel substrate was attached to the stainless steel substrate, after the attachment was completed, the sample was cured in an environment of 25°C, 50% RH for 48 h, then the prepared adhesive sample was placed in a high temperature and high humidity oven at 85°C, 85% RH for 7 days, then the universal material testing machine was used to run the adhesive sample along the shearing direction at a speed of 10 mm / min until the adhesive sample failed, the maximum force value displayed by the instrument was recorded, and the shear adhesion strength of the polyurethane hot melt adhesive to the stainless steel substrate after high temperature and high humidity aging was calculated. The results are shown in Table 1.

[0064] Table 1

[0065]

[0066] As can be seen from the results in Table 1, the electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application has a low melt viscosity at room temperature, can be directly dispensing at room temperature, significantly improves the defect that the reactive polyurethane hot melt adhesive needs to be applied with heating, increases the convenience of use of the adhesive, and reduces the risk of being scalded in the process of using the heating equipment by the operator. According to practical experience, the adhesive strength at room temperature below 2.0 MPa indicates that the polyurethane hot melt adhesive has detachability, and otherwise does not have detachability. As can be seen from the results in Table 1, the reactive polyurethane hot melt adhesive provided by the present application has excellent final adhesive strength after curing, and the adhesive strength can be significantly attenuated after being powered on, and even can be directly detached, and has excellent electrically detachable performance. In addition, the electrically detachable single-component reactive polyurethane hot melt adhesive provided by the present application also has excellent high-temperature and high-humidity stability. In summary, the polyurethane hot melt adhesive provided by the present application has low melt viscosity, can be dispensing at room temperature, has high final adhesive strength, and at the same time has detachable function under the condition of being powered on, and has broad practical application prospect.

[0067] Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present application, and those of ordinary skill in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments without departing from the principles and purposes of the present application within the scope of the present application.

Claims

1. An electrically detachable one-component reactive polyurethane hot-melt adhesive, characterized in that, The electrically detachable single-component reactive polyurethane hot melt adhesive has a viscosity range of 1000-150000 cps at 25℃ and an adhesion strength attenuation rate of 80% or more after power supply at a voltage of 1-100 V, and the content of isocyanate groups in the electrically detachable single-component reactive polyurethane hot melt adhesive is 8-20%; the preparation raw materials of the electrically detachable single-component reactive polyurethane hot melt adhesive contain a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optionally a rheological modifier, a silane coupling agent, a water absorbent, 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 low-viscosity polyol compound has a glass transition temperature of 0℃ or lower and a melting point of 40℃ or lower; and the ionic liquid has a melting point of 25℃ or lower.

2. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The total content of the polyisocyanate compound and the low-viscosity polyol compound is 75-92%, the content of the ionic liquid is 2-15%, the content of the rheological 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%, based on the total weight of the preparation raw materials of the electrically detachable single-component reactive polyurethane hot melt adhesive.

3. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The polyisocyanate compound is at least one selected from 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 xylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-pentane diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate, tetramethyl xylene diisocyanate, norbornane dimethylene isocyanate, lysine diisocyanate, triphenylmethane triisocyanate, thiophosphoric acid triphenyl isocyanate, and 1,6,11-undecane triisocyanate.

4. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The low-viscosity polyol compound has a number average molecular weight of 400-6000 g / mol, and is at least one selected from liquid polyester polyol, liquid polyether polyol, liquid polycarbonate polyol, liquid polycaprolactone polyol, fatty acid dimer diol, and hydroxyl-terminated polybutadiene polyol.

5. The electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 1, wherein The ionic liquid is composed of a cation and an anion, the cation is at least one selected from imidazole cation, pyrrole cation, quaternary ammonium salt cation, quaternary phosphonium salt cation, pyrrolidine cation, and piperidine cation, and the anion is at least one selected from trifluoromethane sulfonate anion, tetrafluoroborate anion, hexafluorophosphate anion, bisfluoromethane sulfonimide anion, hydrogen sulfate anion, ethyl sulfate anion, and p-toluene sulfonate anion.

6. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 1, characterized in that, The ionic liquid is selected from at least one of 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium triflate, 1-ethyl-2,3-dimethylimidazolium triflate, 1-octyl-3-methylimidazolium triflate, 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-dimethylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,3-diethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-2,3-dimethylimidazolium bisfluorosulfonylimide, N-butylpyridinium tetrafluoroborate, hexyltriethylammonium bis(trifluoromethanesulfonyl)imide, methyltrioctylphosphonium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidinium bisfluorosulfonylimide, N-butyl-N-methylpyrrolidinium trifluoromethanesulfonate, and N-propyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide.

7. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 1, characterized in that, The rheology modifier is fumed silica.

8. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 1, characterized in that, The silane coupling agent is selected from at least one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-isocyanatopropyltrimethoxysilane.

9. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 1, characterized in that, The water absorbing agent is selected from at least one of molecular sieve desiccant, oxazolidine water scavenger, p-toluenesulfonylisocyanate, and triethyl orthoformate.

10. The electrically detachable one-component reactive polyurethane hot melt glue according to claim 1, characterized in that, The catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, zinc isooctoate, bismuth isooctoate, triethylamine, diethylenetriamine, triethylenediamine, N-ethylmorpholine, and 2,2-dimorpholinodiethyl ether.

11. The process for preparing the electrically detachable one-component reactive polyurethane hot-melt adhesive according to any one of claims 1 to 10, characterized in that, The method comprises uniformly mixing a polyisocyanate compound, a low-viscosity polyol compound, an ionic liquid, and optionally a rheology modifier, a silane coupling agent, a water absorbent, and a catalyst to obtain an electrically detachable one-component reactive polyurethane hot melt adhesive.

12. The method for preparing the electrically detachable one-component reactive polyurethane hot melt adhesive according to claim 11, characterized in that, The mixing step comprises: S1, dehydrating the low-viscosity polyol compound, the ionic liquid, the rheology modifier, the silane coupling agent, and the water absorbent to obtain a pretreated product; S2, stirring and reacting the pretreated product, the polyisocyanate compound, and the catalyst at 70-90°C for 1-5h to obtain the one-component reactive polyurethane hot melt adhesive.

13. Use of the electrically detachable one-component reactive polyurethane hot melt adhesive according to any one of claims 1-10 in bonding electronic products.

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