A UV moisture curing reactive polyurethane hot melt adhesive and preparation method thereof

Abstract

The present invention belongs to the field of adhesives, and relates to a UV moisture curing reactive polyurethane hot melt adhesive with high initial strength and low free isocyanate content and a preparation method thereof. The UV moisture curing reactive polyurethane hot melt adhesive comprises an acrylate modified polyurethane body, a tackifying resin and a photoinitiator, and the acrylate modified polyurethane body is prepared according to the following method: an excess of low free polyurethane prepolymer is subjected to a first nucleophilic addition reaction with a polyol polymer, and the obtained isocyanate di-terminated polyurethane prepolymer is subjected to a second nucleophilic addition reaction with a hydroxy acrylate compound. The UV moisture curing reactive polyurethane hot melt adhesive provided by the present invention has high initial bonding strength, good impact resistance and low free isocyanate content (<0.1wt%), and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the field of adhesives, and in particular relates to a UV moisture-curing reactive polyurethane hot melt adhesive with high initial strength, good impact resistance and low free isocyanate content, and a preparation method thereof. Background Art

[0002] Traditional reactive polyurethane hot melt adhesive (PUR) is a polyurethane prepolymer prepared by the reaction of excess isocyanate and polyol. Due to the excess isocyanate, the incomplete reaction of polyol and excess isocyanate, and the reaction is blocked under high viscosity, etc., unreacted free isocyanate is often present in the final product. Free isocyanate monomers will vaporize at 85-200°C to form irritating, allergic or toxic substances, which will endanger the health of practitioners. The draft of the restriction of free isocyanates drafted by the European Chemicals Agency (ECHA) shows that when the free isocyanate content in the reactive polyurethane hot melt adhesive is >1wt%, there is a risk of carcinogenesis; if the free isocyanate content is between 0.1-1wt%, there is a risk of inhalation or skin contact; products with a free isocyanate content of more than 0.1wt% will be restricted for use in industry and certain professional fields unless the safety of users can be protected; and products with a free isocyanate content of <0.1wt% can be exempted from this regulatory restriction. Therefore, there is an urgent need to develop reactive polyurethane hot melt adhesives with excellent bonding properties and low free isocyanate content to meet the application needs of low free reactive polyurethane hot melt adhesives in the fields of automobiles, new energy, consumer electronics, woodworking, textiles, etc.

[0003] Among the existing solutions for low-free reactive polyurethane hot melt adhesives, there is a physical method such as vacuum distillation to remove free isocyanate monomers, but this method is only applicable to a small number of low-boiling point isocyanate monomers and requires expensive equipment and cumbersome processes. In addition, there is also a technology that uses low-free isocyanate oligomers with a free isocyanate content of less than 0.1% to replace isocyanate monomers and react with polyols to prepare low-free isocyanate reactive polyurethane hot melt adhesives, but the low-free reactive polyurethane hot melt adhesives prepared by the prior art are simply analogous to the design ideas of traditional reactive polyurethane hot melt adhesives, and the molar ratio of isocyanate groups in low-free isocyanate oligomers to hydroxyl groups in polyol polymers is controlled between (1.5-2.5):1. The traditional reactive polyurethane hot melt adhesive is designed in this way because the isocyanate component added to the traditional reactive polyurethane hot melt adhesive is a small molecular monomer. If the molar amount is too much (more than 2.5), there will be too many isocyanate monomers remaining in the final product. Too many isocyanate monomers have not reacted with the macromolecular polyol to form flexible macromolecules, which will make the hard segment ratio of the final product too high after curing and lack flexibility. However, low-free polyurethane oligomers are different from isocyanate monomers. Simply analogizing the design concept of traditional reactive polyurethane hot melt adhesives, low-free isocyanate reactive polyurethane hot melt adhesives prepared using low-free isocyanate oligomers with a free isocyanate content of less than 0.1% have the defects of high melt viscosity and low bonding strength. These defects limit the practical application of low-free reactive polyurethane hot melt adhesives in the fields of automobiles, new energy batteries, consumer electronics, woodworking, textiles, etc. For example, in US20170002239A, Bayer's low-free MDI oligomer VPLS2397 was used to replace MDI monomer and react with polyol to prepare a reactive polyurethane hot melt adhesive. The free MDI monomer of the final product was <0.1wt%, but the bulk strength decreased by about 50%. In addition, there is also a technology that uses part of the isocyanate monomer and part of the low-free polyurethane oligomer (free isocyanate content is less than 0.1wt%) to react with polyol. The bulk strength of the reactive polyurethane hot melt adhesive obtained by this method is improved, but a small amount of the added isocyanate monomer still remains, so that the final free isocyanate content is still higher than 0.1%, and generally increases to 0.4-1%. Furthermore, the low-free reactive polyurethane hot melt adhesive obtained by the existing method generally has poor impact resistance, and there is a risk of debonding after the bonded parts fall, and the reliability is poor.

[0004] In addition, the moisture curing reaction of reactive polyurethane hot melt adhesive mainly relies on the chemical reaction between isocyanate groups and moisture to gradually form a cross-linked chemical structure, thereby achieving a higher bonding strength. Due to the slow reaction rate of isocyanate groups and moisture, it often takes a relatively long curing time to form a higher bonding strength. In practical applications, it is usually necessary to customize a specific pressure holding mold, and a longer pressure holding time is required, which increases production costs and reduces production efficiency. Reactive polyurethane hot melt adhesives with low free isocyanate content will also face the problems of slow curing speed and low initial bonding strength. In order to improve the initial bonding strength of reactive polyurethane hot melt adhesives, the traditional method is to use an acrylate chemical grafting modification method to prepare UV moisture-curing reactive polyurethane hot melt adhesives, and use UV light to initiate rapid curing to improve the initial bonding strength. However, the UV moisture-curing reactive polyurethane hot melt adhesives prepared by the prior art still have a high free isocyanate monomer content, which poses a greater safety hazard and a risk of endangering the health of users. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the existing polyurethane hot melt adhesive, such as low initial bonding strength, poor impact resistance and high free isocyanate content, and to provide a UV moisture-curable reactive polyurethane hot melt adhesive with high initial bonding strength, good impact resistance and low free isocyanate content (<0.1wt%) and a preparation method thereof.

[0006] Specifically, the present invention provides a UV moisture-curable reactive polyurethane hot melt adhesive, comprising an acrylate-modified polyurethane body, a tackifying resin and a photoinitiator, wherein the acrylate-modified polyurethane body is prepared according to the following method:

[0007] S11, subjecting an excess of low-free polyurethane prepolymer to a first nucleophilic addition reaction with a polyol polymer to obtain an isocyanate di-terminated polyurethane prepolymer;

[0008] S12, subjecting the isocyanate di-terminated polyurethane prepolymer to a second nucleophilic addition reaction with a hydroxy acrylate compound to obtain an acrylate-modified polyurethane body;

[0009] The molar equivalent ratio of the hydroxyl group in the polyol polymer, the isocyanate group in the low-free polyurethane prepolymer and the hydroxyl group in the hydroxy acrylate compound is 1:(3-4):(0.4-1.2), and at the same time, (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of the hydroxy acrylate compound=2.5-5.

[0010] In the present invention, the molar equivalent of the polyol polymer based on hydroxyl groups is 1 mol, the molar equivalent of the low free polyurethane prepolymer based on isocyanate groups is 3-4 mol, such as 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4 mol and any value therebetween; the molar equivalent of the hydroxy acrylate compound based on hydroxyl groups is 0.4-1.2 mol, such as 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2 mol and any value therebetween.

[0011] In the present invention, (the molar amount of isocyanate groups in the low free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of the hydroxyl acrylate compound = 2.5-5, such as 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0 mol and any value therebetween.

[0012] In a preferred embodiment, based on the total weight of the reactive polyurethane hot melt adhesive, the content of the acrylate modified polyurethane body is 75-90%, such as 75%, 78%, 80%, 82%, 85%, 88%, 90% and any value therebetween; the content of the tackifying resin is 5-20%, such as 5%, 8%, 10%, 12%, 15%, 18%, 20% and any value therebetween; the content of the photoinitiator is 0.5-5%, such as 0.5%, 1%, 2%, 3%, 4%, 5% and any value therebetween.

[0013] In a preferred embodiment, the low-free polyurethane prepolymer is a low-free polyether polyol-based polyurethane prepolymer and / or a low-free polyester polyol-based polyurethane prepolymer, and the content of free isocyanate contained in the low-free polyurethane prepolymer is less than 0.1wt%. In the present invention, both ends of the low-free polyether polyol-based polyurethane prepolymer and the low-free polyester polyol-based polyurethane prepolymer are terminated by isocyanate groups.

[0014] In a preferred embodiment, the low-free polyether polyol-based polyurethane prepolymer is obtained by reacting a polyether polyol with a polyisocyanate monomer. Specific examples of the polyether polyol include, but are not limited to, at least one of a ring-opening polymer, a random copolymer, and a block copolymer of ethylene glycol, propylene glycol, tetrahydrofuran, and 3-methyltetrahydrofuran. Specific examples of the polyisocyanate monomer include, but are not limited to, at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated MDI, polymerized MDI, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate, tetramethylxylene diisocyanate, and norbornane diisocyanate. The low free polyether polyol-based polyurethane prepolymer is commercially available, and examples thereof include Adiprene LF TE 915, Adiprene LF TE 1050, Adiprene LF TE 980, Adiprene LF TE 330, Adiprene LF TE 365, Adiprene LF TE 440, Adiprene LFM G730, Adiprene LFM G750, Adiprene LFM G600, Adiprene LFMI G600, and Adiprene LFMI G1000 from LANXESS.

[0015] In a preferred embodiment, the low-free polyester polyol-based polyurethane prepolymer is obtained by reacting a polyester polyol with a polyisocyanate monomer. Specific examples of the polyester polyol include, but are not limited to, at least one of polyethylene adipate diol, polypropylene adipate diol, polybutylene adipate diol, polybutylene adipate diol, poly(1,4-butylene adipate diol), poly(neopentyl adipate diol) and poly(1,6-hexane adipate diol). Specific examples of the polyisocyanate monomer include, but are not limited to, at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethylxylene diisocyanate, and norbornane diisocyanate. The low-free polyester polyol-based polyurethane prepolymer can be obtained commercially, such as Adiprene LFM S200, Adiprene LFM S300, Adiprene LFM S500 of LANXESS.

[0016] In a preferred embodiment, the polyol polymer is at least one selected from polyester polyol, polyether polyol, polycarbonate polyol and polyalkylene polyol.

[0017] In a preferred embodiment, the polyester polyol is at least one of a polyester polyol obtained by esterification of a polycarboxylic acid and a polyol and a poly-ε-caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone. Specific examples of the polycarboxylic acid include, but are not limited to, at least one of terephthalic acid, isophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid, and dodecamethylene dicarboxylic acid. Specific examples of the polyol include, but are not limited to, at least one of ethylene glycol, propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and cyclohexanediol.

[0018] In a preferred embodiment, the polyether polyol is selected from at least one of the ring-opening polymers, random copolymers and block copolymers of ethylene glycol, propylene glycol, tetrahydrofuran, 3-methyltetrahydrofuran and bisphenol-type polyoxyalkylene modified bodies. The bisphenol-type polyoxyalkylene modified body is a polyether polyol obtained by adding an alkylene oxide to the active hydrogen part of the bisphenol-type molecular skeleton, and can be a random copolymer or a block copolymer. Specific examples of the alkylene oxide include, but are not limited to, at least one of ethylene oxide, propylene oxide, butylene oxide and isobutylene oxide.

[0019] In a preferred embodiment, the polycarbonate polyol is selected from at least one of polycarbonate 1,6-hexanediol ester polyol, polycarbonate-1,4-butanediol-1,6-hexanediol ester diol, polycarbonate-1,5-pentanediol-1,6-hexanediol ester diol, polycaprolactone hexanediol, polycarbonate-1,4-cyclohexanedimethanol-1,6-hexanediol ester diol, polyethylene carbonate diol, polypropylene carbonate diol, polybutylene carbonate diol and polyhexane carbonate diol.

[0020] In a preferred embodiment, the polyalkylene polyol is selected from at least one of polybutadiene polyol, hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol.

[0021] In a preferred embodiment, the hydroxyacrylate compound is selected from at least one of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, caprolactone-modified hydroxyethyl acrylate and caprolactone-modified hydroxypropyl acrylate.

[0022] In a preferred embodiment, the tackifying resin is selected from at least one of thermoplastic acrylic resin, polyurethane resin, amorphous poly-alpha-olefin resin, rosin resin, rosin pentaerythritol ester, petroleum resin, terpene resin and EVA resin.

[0023] In a preferred embodiment, the photoinitiator is selected from at least one of benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds and thioxanthone.

[0024] In a preferred embodiment, the conditions of the first nucleophilic addition reaction include a temperature of 70-90°C, such as 70°C, 72°C, 75°C, 78°C, 80°C, 82°C, 85°C, 88°C, 90°C and any value therebetween; a rotation speed of 100-200r / min, such as 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200r / min and any value therebetween; and a time of 1-5h, such as 1h, 2h, 3h, 4h, 5h and any value therebetween.

[0025] In a preferred embodiment, the conditions of the second nucleophilic addition reaction include a temperature of 70-90°C, such as 70°C, 72°C, 75°C, 78°C, 80°C, 82°C, 85°C, 88°C, 90°C and any value therebetween; a rotation speed of 100-200r / min, such as 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200r / min and any value therebetween; and a time of 1-5h, such as 1h, 2h, 3h, 4h, 5h and any value therebetween.

[0026] In the present invention, the nucleophilic addition reaction between the excess low-free polyurethane prepolymer and the polyol polymer is referred to as the "first nucleophilic addition reaction", and the nucleophilic addition reaction between the isocyanate di-terminated polyurethane prepolymer and the hydroxy acrylate compound is referred to as the "second nucleophilic addition reaction". The terms "first" and "second" are only for the convenience of distinction and description and have no other special meanings.

[0027] In a preferred embodiment, the first nucleophilic addition reaction and / or the second nucleophilic addition reaction are carried out in the presence of a catalyst. Specific examples of the catalyst include, but are not limited to, at least one of dibutyltin dilaurate, stannous octoate, triethylamine, diethylenetriamine, triethylenediamine, N-ethylmorpholine and 2,2-dimorpholinyl diethyl ether. In addition, based on the total weight of the reactive polyurethane hot melt adhesive, the amount of the catalyst can be 0.1-1%, such as 0.1%, 0.3%, 0.5%, 0.8%, 1.0% and any value therebetween.

[0028] The present invention also provides a method for preparing the UV moisture curing reactive polyurethane hot melt adhesive, which comprises the following steps:

[0029] S21, dehydrating the polyol polymer and the tackifying resin under vacuum stirring at 100-120° C. and a speed of 100-200 r / min for 1-5 h, and then cooling to 70-90° C. to obtain a pretreated product;

[0030] S22, reacting the pretreated product, the low-free polyurethane prepolymer and the catalyst at 70-90° C. and a speed of 100-200 r / min under vacuum stirring for 1-5 h to obtain an isocyanate di-terminated polyurethane prepolymer;

[0031] S23, reacting the isocyanate di-terminated polyurethane prepolymer, hydroxy acrylate compound and photoinitiator at 70-90° C. and at a speed of 100-200 r / min under vacuum stirring for 1-5 hours to obtain a UV moisture-curing reactive polyurethane hot melt adhesive.

[0032] The specific types and amounts of the reagents used in the preparation method of the UV moisture-curing reactive polyurethane hot melt adhesive have been described above and will not be repeated here.

[0033] The existing low-free reactive polyurethane hot melt adhesive is mainly prepared by reacting low-free polyurethane prepolymer (free isocyanate content is less than 0.1wt%) to partially or completely replace isocyanate monomer and polyol. When low-free polyurethane prepolymer is used to replace part of isocyanate monomer, due to the addition of a small amount of isocyanate monomer, the final free isocyanate monomer content will still be higher than 0.1%. When low-free polyurethane prepolymer is used to completely replace isocyanate monomer in equimolar terms, although the free isocyanate content in the final product can be reduced to less than 0.1wt%, there are defects such as high melt viscosity and low initial bonding strength. It is speculated that the reason may be that: low-free polyurethane prepolymer has more flexible chain segment components than isocyanate monomer, the molecular weight of polyurethane prepolymer is larger, and the molar number of isocyanate groups in polyurethane prepolymer is lower than that of isocyanate monomer in the same mass fraction. When an equal molar amount of polyurethane prepolymer is used to replace isocyanate monomer and polyol to form a polyurethane hot melt adhesive, the hard segment component will be less and the soft segment component will be higher. The isocyanate content of the final product will be lower and the molecular weight will be higher, resulting in the final product having the defects of high melt viscosity and low initial bonding strength.

[0034] The use of UV moisture-curing reactive polyurethane hot melt adhesive modified by acrylate can use UV light to initiate free radical polymerization of acrylate compounds, and improve the initial bonding strength by rapid curing after light exposure. However, the existing technology uses excessive isocyanate monomers in UV moisture-curing reactive polyurethane hot melt adhesives modified by acrylates, and the isocyanate monomers do not react fully, resulting in a high free isocyanate content in the final product. There is still a problem of high free isocyanate content, which endangers the health of practitioners.

[0035] The present invention fully considers the difference between low-free polyurethane prepolymer (free isocyanate content is less than 0.1wt%) and isocyanate monomer, and low-free polyurethane prepolymer cannot be used as isocyanate monomer. The traditional idea of ​​using low-free polyurethane oligomer to simply replace isocyanate monomer and react with polyol to prepare low-free reactive polyurethane hot melt adhesive is abandoned, and the limitation that the molar ratio of isocyanate group to hydroxyl group in polyol is generally controlled at (1.5-2.5):1 in traditional reactive polyurethane hot melt adhesive is broken. Combined with the actual difference between low-free polyurethane prepolymer and isocyanate monomer, the low-free polyurethane prepolymer is creatively and significantly improved. The amount of polyurethane prepolymer used is to set the molar ratio of isocyanate groups in low-free polyurethane prepolymer to hydroxyl groups in polyol polymer at (3-4):1, and at the same time introduce a small amount of acrylate compounds into the low-free reactive polyurethane hot melt adhesive, and at the same time control the molar amount of (molar amount of isocyanate groups in low-free polyurethane prepolymer-molar amount of hydroxyl groups in polyol polymer) / molar amount of hydroxy acrylate compounds to 2.5-5, so that not only the isocyanate content in the reactive polyurethane hot melt adhesive finally obtained can be reduced to less than 0.1wt%, but also the melt viscosity can be reduced, and the initial bonding strength and impact resistance can be improved. It is speculated that the reason may be that: the added polyurethane prepolymer does not fully participate in the chain extension reaction with the polyol polymer, and some excess polyurethane prepolymer remains. The molecular weight of this excess polyurethane prepolymer is relatively small, which can reduce the melt viscosity of the entire system; in addition, the introduced hydroxy acrylate compounds can be quickly cured after UV light exposure, thereby improving the initial bonding strength of the adhesive; furthermore, if the amount of hydroxy acrylate compounds added is too small, the initial bonding strength improvement effect is not obvious, and if the hydroxy acrylate content is added too much, the flexibility of the adhesive after curing becomes poor, and the impact resistance is poor. Controlling the (molar amount of isocyanate groups in low-free polyurethane prepolymer-molar amount of hydroxyl groups in polyol polymer) / molar amount of hydroxy acrylate compounds to 2.5-5 can achieve a higher initial strength while maintaining good impact resistance. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below by way of examples. The examples of the embodiments are intended to explain the present invention and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0037] Example 1

[0038] By weight, 11.5 g (3.820 mmol) of polybutylene adipate diol with a number average molecular weight of 3000, 15.3 g (7.641 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 10.0 g of polyacrylic resin BR106 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 45.0 g (30.56 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LFG963A, 16.0 g (3.820 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S200 and 0.1 g of stannous octoate are stirred at a speed of 150 r / min for 2 h under vacuum conditions, and then 1.1 g (9.169 mmol) of 2-hydroxyethyl acrylate and 1.0 g of photoinitiator TPO are added (the molar equivalent ratio of hydroxyl groups in the polyol polymer, isocyanate groups in the low-free polyurethane prepolymer and hydroxyl groups in the hydroxy acrylate compound is 1:3:0.4; at the same time, (molar amount of isocyanate groups in the low-free polyurethane prepolymer-molar amount of hydroxyl groups in the polyol polymer) / molar amount of hydroxy acrylate compounds = 5), and stirred at a speed of 150 r / min for 2 h under vacuum conditions. The material is discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which is sealed in a vacuum and stored away from light.

[0039] Example 2

[0040] By weight, 6.6 g (3.324 mmol) of poly (neopentyl adipate glycol) with a number average molecular weight of 2000, 13.3 g (6.649 mmol) of poly (caprolactone glycol) with a number average molecular weight of 2000, and 15.0 g of polyacrylic resin BR113 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 44.4 g (23.27 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LF TE440, 18.6 g (6.649 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S300, and 0.1 g 2,2-dimorpholinyl diethyl ether was stirred at a speed of 150 r / min for 2 h under vacuum conditions, and then 1.4 g (11.97 mmol) of 2-hydroxyethyl acrylate and 0.5 g of photoinitiator 819 (the molar equivalent ratio of hydroxyl groups in the polyol polymer, isocyanate groups in the low-free polyurethane prepolymer and hydroxyl groups in the hydroxy acrylate compound was 1:3:0.6; at the same time, (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of hydroxy acrylate compounds = 3.3) were added, and stirred at a speed of 150 r / min for 2 h under vacuum conditions. The material was discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum and stored away from light.

[0041] Example 3

[0042] By weight, 9.5 g (2.703 mmol) of polyhexanediol adipate diol with a number average molecular weight of 3500, 16.2 g (8.110 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 20.0 g of polyacrylic resin BM751 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 29.8 g (32.44 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LF TE915 and 18.2 g (10.81 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S500 and 1.0 g of dibutyltin dilaurate were stirred at a speed of 150 r / min for 2 h under vacuum conditions, and then 3.4 g (25.95 mmol) of 2-hydroxypropyl acrylate and 2.0 g of photoinitiator 184 were added (the molar equivalent ratio of hydroxyl groups in the polyol polymer, isocyanate groups in the low-free polyurethane prepolymer and hydroxyl groups in the hydroxy acrylate compound was 1:4:1.2; at the same time, (molar amount of isocyanate groups in the low-free polyurethane prepolymer-molar amount of hydroxyl groups in the polyol polymer) / molar amount of hydroxy acrylate compounds = 2.5), and the mixture was stirred at a speed of 150 r / min for 2 h under vacuum conditions. The material was discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum and stored away from light.

[0043] Example 4

[0044] By weight, 11.9 g (3.405 mmol) of polybutylene adipate diol with a number average molecular weight of 3500, 10.2 g (10.21 mmol) of polycarbonate-1,5-pentanediol-1,6-hexanediol ester diol with a number average molecular weight of 1000, and 14.0 g of polyalphaolefin resin VESTOPLAST 520 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 35.4 g (44.26 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LFTE1050, 19.1 g (6.809 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S300 and 0.5 g of stannous octoate were stirred at a speed of 150 r / min for 2 h under vacuum conditions, and then 3.9 g (29.96 mmol) of 2-hydroxypropyl acrylate and 5.0 g of photoinitiator ITX (the molar equivalent ratio of hydroxyl groups in the polyol polymer, isocyanate groups in the low-free polyurethane prepolymer and hydroxyl groups in the hydroxy acrylate compound was 1:3.75:1.1; at the same time, (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of hydroxy acrylate compounds = 2.5), and the mixture was stirred at a speed of 150 r / min for 2 h under vacuum conditions. The material was discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum and stored away from light.

[0045] Example 5

[0046] By weight, 17.4 g (8.720 mmol) of polycaprolactone diol with a number average molecular weight of 2000, 5.8 g (2.907 mmol) of polycarbonate-1,4-butanediol-1,6-hexanediol ester diol with a number average molecular weight of 2000, and 12.0 g of polyurethane resin Pearlbond539 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 29.9 g (34.88 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LF TE980, 24.4 g (5.814 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S200, and 0.4 g (34.88 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S200 were added. 2,2-dimorpholinyl diethyl ether was stirred at a speed of 150 r / min for 2 h under vacuum conditions, and then 6.0 g (17.44 mmol) of caprolactone-modified acrylate PLACCEL FA2D and 4.0 g of photoinitiator TPO (the molar equivalent ratio of hydroxyl groups in the polyol polymer, isocyanate groups in the low-free polyurethane prepolymer and hydroxyl groups in the hydroxy acrylate compound was 1:3.5:0.75; at the same time, (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of hydroxy acrylate compounds = 3.3) was added, and stirred at a speed of 150 r / min for 2 h under vacuum conditions. The material was discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum seal away from light.

[0047] Example 6

[0048] By weight, 16.5 g (8.258 mmol) of polytetramethylene glycol with a number average molecular weight of 2000, 8.3 g (4.129 mmol) of polyisophthalic acid hexanediol with a number average molecular weight of 2000, and 11.0 g of polyurethane resin Pearlbond523 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h at 150 r / min stirring conditions, then 40.4 g (35.10 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LF G730, 13.9 g (8.258 mmol) of low-free polyester polyol-based polyurethane prepolymer Adiprene LFM S500, and 0.6 g of dibutyltin dilaurate were added, stirred at a speed of 150 r / min under vacuum conditions for 2 h, and then 6.4 g (18.58 mmol) of caprolactone-modified acrylate PLACCEL was added. FA2D, 3.0g photoinitiator 819 (the molar equivalent ratio of hydroxyl group in polyol polymer, isocyanate group in low free polyurethane prepolymer and hydroxyl group in hydroxy acrylate compound is 1:3.5:0.75; at the same time, (molar amount of isocyanate group in low free polyurethane prepolymer - molar amount of hydroxyl group in polyol polymer) / molar amount of hydroxy acrylate compound = 3.3), stir at a speed of 150r / min for 2h under vacuum conditions, discharge the material to obtain UV moisture-curing reactive polyurethane hot melt adhesive, and store it in a light-proof vacuum seal.

[0049] Comparative Example 1

[0050] By weight, 31.7 g (10.58 mmol) of polybutylene adipate diol with a number average molecular weight of 3000, 42.3 g (21.15 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 10.0 g of acrylic resin BR106 were added to a reaction bottle, heated to 110°C, and vacuum dehydrated for 2 hours under stirring conditions of 150 r / min, then cooled to 80°C, 15.9 g (63.46 mmol) of 4,4'-diphenylmethane diisocyanate (MDI) and 0.1 g of stannous octoate were added, and the material was discharged after stirring at a speed of 150 r / min under vacuum conditions for 2 hours to obtain a traditional reactive polyurethane hot melt adhesive, which was vacuum sealed for storage.

[0051] Comparative Example 2

[0052] By weight, 17.0 g (5.674 mmol) of polybutylene adipate diol with a number average molecular weight of 3000, 22.7 g (11.35 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 10.0 g of acrylic resin BR106 were added to a reaction bottle, heated to 110° C., vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80° C., 50.2 g (34.04 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LFG963A and 0.1 g of stannous octoate were added, and the mixture was stirred at a speed of 150 r / min under vacuum conditions for 2 h and then discharged to obtain a low-free reactive polyurethane hot melt adhesive prepared by reacting a low-free polyether polyol-based polyurethane prepolymer with equimolar substitution of 4,4'-diphenylmethane diisocyanate (MDI) monomer and polyol, which was vacuum sealed for storage.

[0053] Comparative Example 3

[0054] By weight, 22.2 g (7.386 mmol) of polybutylene adipate diol with a number average molecular weight of 3000, 29.5 g (14.77 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 10.0 g of acrylic resin BR106 were added to a reaction bottle, heated to 110°C, vacuum dehydrated for 2 h under stirring conditions of 150 r / min, and then cooled to 80°C, 5.5 g (22.16 mmol) of 4,4'-diphenylmethane diisocyanate (MDI), 32.7 g (22.16 mmol) of low-free polyether polyol-based polyurethane prepolymer Adiprene LFG963A and 0.1g of stannous octoate are stirred at a speed of 150r / min under vacuum conditions for 2h and then discharged to obtain a low-free reactive polyurethane hot melt adhesive prepared by partially replacing 4,4-diphenylmethane diisocyanate (MDI) monomer with polyol by a low-free polyurethane prepolymer, which is vacuum sealed and stored.

[0055] Comparative Example 4

[0056] By weight, 30.4 g (10.13 mmol) of polybutylene adipate diol with a number average molecular weight of 3000, 40.5 g (2.025 mmol) of polyoxypropylene ether diol with a number average molecular weight of 2000, and 10.0 g of polyacrylic resin BR106 were added to a reaction bottle, heated to 110°C, vacuum dehydrated for 2 hours under stirring conditions of 150 r / min, and then cooled to 80°C, 15.2 g (60.76 mmol) of 4,4-diphenylmethane diisocyanate (MDI) and 0.1 g of stannous octoate were added, and stirred at a speed of 150 r / min for 2 hours under vacuum conditions, and then 2.8 g (24.31 mmol) of 2-hydroxyethyl acrylate and 1.0 g of photoinitiator TPO were added, and stirred at a speed of 150 r / min for 2 hours under vacuum conditions. The material was discharged to obtain a UV moisture-curing reactive polyurethane hot melt adhesive prepared from isocyanate monomers, which was sealed in a vacuum and stored away from light.

[0057] Comparative Example 5

[0058] A UV moisture-curing reactive polyurethane hot melt adhesive was prepared according to the method of Example 5, except that the amount of the low-free polyether polyol-based polyurethane prepolymer Adiprene LF TE980 was adjusted to 19.95 g (23.25 mmol) to control the molar equivalent ratio of the hydroxyl group in the polyol polymer to the isocyanate group in the low-free polyurethane prepolymer to be 1:2.5. The other conditions were the same as in Example 5 to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum container away from light.

[0059] Comparative Example 6

[0060] A UV moisture-curing reactive polyurethane hot melt adhesive was prepared according to the method of Example 5, except that the amount of the caprolactone-modified acrylate PLACCEL FA2D was adjusted to 24.0 g (69.762 mmol) to control the molar equivalent ratio of the hydroxyl group in the polyol polymer to the hydroxyl group in the hydroxy acrylate compound to be 1:3. The other conditions were the same as in Example 5 to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum container away from light.

[0061] Comparative Example 7

[0062] A UV moisture-curing reactive polyurethane hot melt adhesive was prepared according to the method of Example 5, except that the amount of caprolactone-modified acrylate PLACCEL FA2D was adjusted to 10.0 g (29.07 mmol) so that (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of the hydroxyl acrylate compound was 2. The other conditions were the same as in Example 5 to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum container away from light.

[0063] Comparative Example 8

[0064] A UV moisture-curing reactive polyurethane hot melt adhesive was prepared according to the method of Example 5, except that the amount of caprolactone-modified acrylate PLACCEL FA2D was adjusted to 3.33 g (9.689 mmol) so that (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of the hydroxyl acrylate compound was 6. The other conditions were the same as in Example 5 to obtain a UV moisture-curing reactive polyurethane hot melt adhesive, which was sealed in a vacuum container away from light.

[0065] Test Case

[0066] The samples of the embodiment and the comparative example were subjected to comparative tests in the following manner:

[0067] (1) Melt viscosity: Place the sealed polyurethane hot melt adhesive in a syringe heater at 110°C for 10 minutes. At this time, the hot melt adhesive has become a molten fluid. Quickly pour it into the sleeve of the Brookfield-DV2T viscometer, set the heater temperature at 110°C and keep it for 10 minutes to make the internal temperature of the hot melt adhesive uniform and degas. At a temperature of 110°C, measure the constant temperature melt viscosity of the hot melt adhesive. The results are shown in Table 1.

[0068] (2) Adhesive strength: The hot melt adhesive obtained in the embodiment and the comparative example was dispensed at 110°C using a dispensing machine to apply a 25 mm*25 mm rectangular adhesive frame with a width of about 1 mm on the polycarbonate substrate. Then, another polycarbonate substrate was attached to the polycarbonate substrate. After the dispensing and lamination, the polycarbonate substrate was irradiated with 365 nm UV light at 2000 MJ / cm 2 The sample was cured in an environment of 25°C and 50% RH for 1 min, 30 min and 24 h, and then the produced bonding sample was run along the pulling direction at a speed of 10 mm / min using a universal material testing machine until the bonding of the sample failed. The maximum force value displayed by the instrument was recorded, and the bonding strength of the hot melt adhesive to the polycarbonate substrate was calculated in combination with the bonding area. The results are shown in Table 1.

[0069] (3) Drop ball impact test: Use a glue dispenser to dispense the hot melt adhesive obtained in the embodiment and the comparative example at 110°C, and apply a 25mm*25mm rectangular glue frame on the polycarbonate substrate with a width of about 1mm, and then attach another polycarbonate substrate to the polycarbonate substrate. After the glue dispensing and lamination is completed, the sample is cured in an environment of 25°C and 50% RH for 24 hours, and then the bonded sample is placed flat, and a drop ball tester is used with a weight of 200g to repeatedly free-fall and impact one of the polycarbonate substrates of the bonded sample from a height of 200mm until the bonded substrates are separated by the impact, and the number of impacts displayed by the instrument is recorded. The results are shown in Table 1.

[0070] (4) Free isocyanate content: The content of free isocyanate monomer in the reactive polyurethane hot melt adhesive was quantitatively calculated using the external standard method. The chromatograms of the sample to be tested and the standard were recorded respectively. The content of free isocyanate in the sample to be tested was calculated based on the integrated area of ​​the specific peak on the chromatogram. The results are shown in Table 1.

[0071] Table 1

[0072]

[0073]

[0074] It can be seen from the comparison of Examples 1-6 with Comparative Example 1 that the 1min bonding strength of the UV moisture-curing reactive polyurethane hot melt adhesive provided by the present invention is much higher than that of the traditional reactive polyurethane hot melt adhesive, indicating that it has the characteristics of fast curing speed, high initial bonding strength and good impact resistance. In addition, the free isocyanate content of the UV moisture-curing reactive polyurethane hot melt adhesive provided by the present invention is all below 0.1wt%, which is significantly lower than the free isocyanate content in the traditional reactive polyurethane hot melt adhesive, greatly increasing the safety of use and avoiding harm to the health of practitioners. It can be seen from the comparison of Examples 1-6 with Comparative Examples 2-8 that the UV moisture-curing reactive polyurethane hot melt adhesive provided by the present invention has the characteristics of low melt viscosity, high initial and final bonding strength, good impact resistance and low free isocyanate content, taking into account the safety of use and the reliability of bonding, and has excellent comprehensive performance. Compared with the low free reactive polyurethane hot melt adhesive prepared by the prior art, the comprehensive performance is greatly improved, which can meet the performance requirements of more application scenarios, can meet a variety of practical application requirements, and has broad application prospects.

[0075] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A UV moisture curing reactive polyurethane hot melt adhesive, characterized in that: The UV moisture curing reactive polyurethane hot melt adhesive comprises an acrylate modified polyurethane body, a tackifying resin and a photoinitiator, and the acrylate modified polyurethane body is prepared according to the following method: S11, subjecting an excess of low-free polyurethane prepolymer to a first nucleophilic addition reaction with a polyol polymer to obtain an isocyanate di-terminated polyurethane prepolymer; S12, subjecting the isocyanate di-terminated polyurethane prepolymer to a second nucleophilic addition reaction with a hydroxy acrylate compound to obtain an acrylate-modified polyurethane body; The molar equivalent ratio of the hydroxyl group in the polyol polymer, the isocyanate group in the low-free polyurethane prepolymer and the hydroxyl group in the hydroxy acrylate compound is 1:(3-4):(0.4-1.2), and at the same time, (the molar amount of isocyanate groups in the low-free polyurethane prepolymer-the molar amount of hydroxyl groups in the polyol polymer) / the molar amount of the hydroxy acrylate compound=2.5-5; The low-free polyurethane prepolymer is a low-free polyether polyol-based polyurethane prepolymer and / or a low-free polyester polyol-based polyurethane prepolymer, and the content of free isocyanate contained in the low-free polyurethane prepolymer is less than 0.1wt%.

2. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: Based on the total weight of the reactive polyurethane hot melt adhesive, the content of the acrylate-modified polyurethane body is 75-90%, the content of the tackifying resin is 5-20%, and the content of the photoinitiator is 0.5-5%.

3. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 2, characterized in that: The low-free polyether polyol-based polyurethane prepolymer is obtained by reacting a polyether polyol with a polyisocyanate monomer; the polyether polyol is selected from at least one of ring-opening polymers, random copolymers and block copolymers of ethylene glycol, propylene glycol, tetrahydrofuran and 3-methyltetrahydrofuran; the polyisocyanate monomer is selected from at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated MDI, polymerized MDI, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate, tetramethylxylene diisocyanate and norbornane diisocyanate.

4. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 2, characterized in that: The low-free polyester polyol-based polyurethane prepolymer is obtained by reacting a polyester polyol with a polyisocyanate monomer; the polyester polyol is selected from at least one of polyethylene adipate diol, polypropylene adipate diol, polybutylene adipate diol, poly1,4-butylene adipate diol, polyneopentyl adipate diol and poly1,6-hexane adipate diol; and the polyisocyanate monomer is selected from at least one of isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, hydrogenated MDI, polymerized MDI, 1,5-naphthalene diisocyanate, 1,4-phenylene diisocyanate, xylene diisocyanate, tetramethylxylene diisocyanate and norbornane diisocyanate.

5. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The polyol polymer is selected from at least one of polyester polyol, polyether polyol, polycarbonate polyol and polyalkylene polyol.

6. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 5, characterized in that: The polyester polyol is at least one of a polyester polyol obtained by esterification reaction of a polycarboxylic acid and a polyol and a poly-ε-caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone; the polycarboxylic acid is selected from at least one of terephthalic acid, isophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylene dicarboxylic acid and dodecamethylene dicarboxylic acid; the polyol is selected from at least one of ethylene glycol, propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol and cyclohexanediol.

7. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 5, characterized in that: The polyether polyol is selected from at least one of ring-opening polymers, random copolymers and block copolymers of ethylene glycol, propylene glycol, tetrahydrofuran, 3-methyltetrahydrofuran and bisphenol-type polyoxyalkylene modified bodies; the bisphenol-type polyoxyalkylene modified body is a polyether polyol obtained by adding an alkylene oxide to the active hydrogen part of the bisphenol-type molecular skeleton, and the alkylene oxide is selected from at least one of ethylene oxide, propylene oxide, butylene oxide and isobutylene oxide.

8. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 5, characterized in that: The polycarbonate polyol is selected from at least one of polycarbonate 1,6-hexanediol ester polyol, polycarbonate-1,4-butanediol-1,6-hexanediol ester diol, polycarbonate-1,5-pentanediol-1,6-hexanediol ester diol, polycaprolactone hexanediol, polycarbonate-1,4-cyclohexanedimethanol-1,6-hexanediol ester diol, polyethylene carbonate diol, polypropylene carbonate diol, polybutylene carbonate diol and polyhexylene carbonate diol.

9. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 5, characterized in that: The polyalkylene polyol is selected from at least one of polybutadiene polyol, hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol.

10. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The hydroxyacrylate compound is selected from at least one of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, caprolactone-modified hydroxyethyl acrylate and caprolactone-modified hydroxypropyl acrylate.

11. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The tackifying resin is selected from at least one of thermoplastic acrylic resin, polyurethane resin, amorphous poly-alpha-olefin resin, rosin resin, petroleum resin, terpene resin and EVA resin.

12. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The photoinitiator is selected from at least one of benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds and thioxanthone.

13. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The conditions of the first nucleophilic addition reaction include a temperature of 70-90° C., a rotation speed of 100-200 r / min, and a time of 1-5 h.

14. The UV moisture curing reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The conditions of the second nucleophilic addition reaction include a temperature of 70-90° C., a rotation speed of 100-200 r / min, and a time of 1-5 h.

15. The method for preparing the UV moisture curing reactive polyurethane hot melt adhesive according to any one of claims 1 to 14, characterized in that: The method comprises the following steps: S21, dehydrating the polyol polymer and the tackifying resin under vacuum stirring at 100-120° C. and a speed of 100-200 r / min for 1-5 h, and then cooling to 70-90° C. to obtain a pretreated product; S22, reacting the pretreated product, the low-free polyurethane prepolymer and the catalyst at 70-90° C. and a speed of 100-200 r / min under vacuum stirring for 1-5 h to obtain an isocyanate di-terminated polyurethane prepolymer; S23, reacting the isocyanate di-terminated polyurethane prepolymer, hydroxy acrylate compound and photoinitiator at 70-90° C. and at a speed of 100-200 r / min under vacuum stirring for 1-5 hours to obtain a UV moisture-curing reactive polyurethane hot melt adhesive.

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