A dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive and its preparation method

Abstract

The present invention belongs to the field of polyurethane hot melt adhesives, and relates to a carbon dioxide-based reactive polyurethane hot melt adhesive and a preparation method thereof. The carbon dioxide-based reactive polyurethane hot melt adhesive comprises the following components in parts by weight: 10-50 parts of unsaturated carbon dioxide-based polycarbonate polyol, 5-25 parts of polyester polyol, 6-35 parts of polyether polyol, 4-30 parts of polyisocyanate, 5-25 parts of tackifying resin, 0.5-2.5 parts of a first free radical photoinitiator, and 0.1-2 parts of a first catalyst. The carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention contains a carbon dioxide-based polycarbonate polyol having a six-membered ring, an amino group, and an unsaturated carbon-carbon double bond. This special structure can not only achieve ultraviolet curing and meet the requirements for rapid positioning in the electronic field, but also improve the adhesion performance and heat and moisture resistance of the polyurethane hot melt adhesive. In addition, the unsaturated carbon dioxide-based polycarbonate polyol uses carbon dioxide as a raw material, which is more environmentally friendly and meets the goal of green development.

Description

Technical Field

[0001] The present invention belongs to the field of polyurethane hot melt adhesives, and particularly relates to a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive and a preparation method thereof. Background Art

[0002] Reactive polyurethane hot melt adhesive is a non-solvent-based multi-functional adhesive. The system does not contain volatile organic compounds (VOCs), can undergo a polymerization reaction with moisture, and form a firm bond between different types of substrates. Due to its high bonding strength, good solvent resistance, high cohesive strength, good impact resistance, weather resistance, etc., it has been widely used in furniture manufacturing, electronic packaging, wood bonding and other fields.

[0003] The bonding of reactive polyurethane hot melt adhesive is divided into two stages: First, after applying the adhesive at high temperature, the hot melt adhesive quickly cools and solidifies, generating an initial bonding strength for the adherend material. Then, the isocyanate groups react with moisture in the air through a wet curing reaction to achieve the final structural strength. Since the penetration of moisture in the air is slow after applying the adhesive, the initial bonding strength is usually very low, and complete curing often takes several days. Modifying reactive polyurethane hot melt adhesive with UV-curable acrylate compounds can achieve the performance of UV / moisture dual curing, thereby improving the initial bonding strength by rapid curing under UV light. However, current UV / moisture dual-curable polyurethane hot melt adhesives mostly use small molecule modifiers. For example, CN109705794A discloses a low-viscosity UV / moisture dual-curable polyurethane hot melt adhesive, which adds a small molecule hydroxyacrylate to the polyurethane hot melt adhesive system. CN103305174A and CN105255435A disclose a method of introducing UV-curable acrylate groups by reacting HDI trimer with hydroxyacrylate monomers. However, introducing such small molecule modifiers into high-viscosity hot melt adhesives will affect the bonding strength and heat and moisture resistance of PUR hot melt adhesives.

[0004] Therefore, how to develop a carbon dioxide-based reactive polyurethane hot melt adhesive with rapid positioning function, good bonding strength and heat and moisture resistance has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive with rapid positioning, high bonding strength, good heat and moisture resistance and environmental friendliness, and a preparation method thereof.

[0006] Specifically, the present invention provides a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive, wherein the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive comprises the following components in parts by weight:

[0007]

[0008] The total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyester polyol is not less than 40% of the weight of the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive; the total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyether polyol is not less than 42% of the weight of the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive;

[0009] The molecular chain of the unsaturated carbon dioxide-based polycarbonate polyol simultaneously includes a structural unit represented by the general formula (I), a structural unit represented by the general formula (II), and a structural unit represented by the general formula (III):

[0010]

[0011] In a preferred embodiment, the molar ratio of the structural unit represented by the general formula (I), the structural unit represented by the general formula (II), and the structural unit represented by the general formula (III) is (10 - 55):(10 - 55):1.

[0012] In a preferred embodiment, the unsaturated carbon dioxide-based polycarbonate polyol is prepared by the following method:

[0013] S11. At 60 - 80 °C, evacuate the reaction kettle and replace it with CO2, then cool it to room temperature. Under the protection of CO2, add a second catalyst, a chain transfer agent, propylene oxide, and 3,4-epoxy-1-cyclohexene into the reaction kettle, stir evenly, and then increase the pressure in the reaction kettle by introducing CO2 through a gas pressure regulator. Control the temperature of the reaction kettle at 60 - 80 °C for copolymerization reaction to obtain a carbon dioxide-based polycarbonate diol;

[0014] S12. Add the carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, a second free radical photoinitiator, and an organic solvent into the reaction kettle and stir until the solid is completely dissolved. Then carry out a thiol-ene click reaction under ultraviolet light irradiation, and then concentrate the obtained reaction solution to obtain a thiol-ene reaction product;

[0015] S13. Add the thiol-ene reaction product, glycidyl methacrylate, and an organic solvent into the reaction kettle and stir until the solid is completely dissolved. Then raise the temperature to 40 - 50 °C for a ring-opening reaction. Then slowly add the obtained ring-opening reaction product into a non-solvent to dissolve and precipitate the polymer, and filter and dry it to obtain the unsaturated carbon dioxide-based polycarbonate polyol.

[0016] In a preferred embodiment, the ratio of the sum of the weights of propylene oxide and 3,4-epoxy-1-cyclohexene to the weight of the second catalyst is (1000 - 50000):1.

[0017] In a preferred embodiment, the molar ratio of the 3,4-epoxy-1-cyclohexene to propylene oxide is 1:(10 - 55).

[0018] In a preferred embodiment, the second catalyst is selected from at least one of zinc carboxylate catalyst systems, zinc phenoxide catalyst systems, β-diketiminate zinc catalyst systems, pyridine-zinc catalyst systems, porphyrin catalyst systems, SalenMX catalyst systems, rare earth catalyst systems, double metal cyanide catalyst systems, and supported catalyst systems.

[0019] In a preferred embodiment, the chain transfer agent is selected from at least one of aliphatic carboxylic acids, cycloaliphatic carboxylic acids, aromatic carboxylic acids, and low molecular weight hydroxy-containing compounds.

[0020] In a preferred embodiment, the pressure of the copolymerization reaction is 28.5 - 32.0 atm, and the time is 4 - 8 h.

[0021] In a preferred embodiment, the time of the thiol-ene click reaction is 6 - 10 hours; the time of the ring-opening reaction is 1 - 2 hours.

[0022] In a preferred embodiment, the non-solvent is selected from at least one of methanol, water, n-hexane, and ether.

[0023] In a preferred embodiment, the number average molecular weight of the unsaturated carbon dioxide-based polycarbonate polyol is 1500 - 5000 Da.

[0024] In a preferred embodiment, the weight average molecular weight of the polyester polyol is 1000 - 5000 Da.

[0025] In a preferred embodiment, the weight average molecular weight of the polyether polyol is 1000 - 5000 Da.

[0026] In a preferred embodiment, the tackifying resin is selected from at least one of polyurethane elastomers, acrylic resins, EVA resins, rosin resins, terpene resins, phenolic resins, dicyclopentadiene resins, and styrene resins.

[0027] In a preferred embodiment, the first free radical photoinitiator and the second free radical photoinitiator are selected from at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinobenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolidinophenyl)titanocene, methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl 4-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropyl thioxanthone, 2,4-diethylthioxanthone, and 2-ethylanthraquinone.

[0028] In a preferred embodiment, the first catalyst is selected from at least one of 2,2-dimorpholinodiethyl ether, an organic bismuth catalyst, dibutyltin dilaurate, and stannous octoate.

[0029] In a preferred embodiment, the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive further comprises an additive.

[0030] In a preferred embodiment, the amount of the additive is 0.1-10 parts by weight.

[0031] In a preferred embodiment, the additive is selected from at least one of a polymerization inhibitor, an antioxidant, a silane coupling agent, a water scavenger, a flame retardant, an antifoaming agent, a leveling agent, and a homogenizing agent.

[0032] In a preferred embodiment, the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive further comprises a filler.

[0033] In a preferred embodiment, the amount of the filler is 0.1-10 parts by weight.

[0034] In a preferred embodiment, the filler is selected from at least one of silica, alumina, talc, calcium carbonate, glass microspheres, metal powder, and polytetrafluoroethylene filler.

[0035] The present invention also provides a method for preparing the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive, which includes uniformly mixing an unsaturated carbon dioxide-based polycarbonate polyol, a polyester polyol, a polyether polyol, a polyisocyanate, a tackifying resin, a first free radical photoinitiator, a first catalyst, and optionally additives and fillers under light-shielded and moisture-insulated conditions.

[0036] In a preferred embodiment, the method of uniformly mixing is carried out by a method including the following steps:

[0037] S21: Add the unsaturated carbon dioxide-based polycarbonate polyol, the polyester polyol, the polyether polyol, the tackifying resin, and optionally additives and fillers into a reaction kettle, heat up to 150 - 170 °C, and dehydrate for 2 - 4 hours under stirring conditions with a vacuum degree lower than -0.08 MPa and a rotation speed of 100 - 200 rpm, and then cool down to 70 - 80 °C;

[0038] S22: Add the polyisocyanate into the reaction kettle in step S1, heat up to 120 - 160 °C, stir at a speed of 100 - 200 rpm under vacuum conditions for 1 - 2 hours, and then cool down to 90 - 100 °C;

[0039] S23: Under light-shielded conditions, add the first free radical photoinitiator and the first catalyst into the reaction kettle in step S2, stir at a speed of 100 - 200 rpm under vacuum conditions for 20 - 60 minutes, and quickly discharge and seal for storage under light-shielded and nitrogen protection conditions to obtain the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive.

[0040] The key of the present invention lies in introducing, on the basis of the traditional reactive polyurethane hot melt adhesive, a carbon dioxide-based polycarbonate polyol having a structural unit derived from propylene oxide and having a six-membered ring, a flexible sulfur-containing group, an amino group, and an unsaturated carbon-carbon double bond. This special structure can not only achieve ultraviolet curing and meet the requirements for rapid positioning in the electronic field, but also improve the adhesive performance and heat and moisture resistance of the polyurethane hot melt adhesive. In addition, the unsaturated carbon dioxide-based polycarbonate polyol used in the present invention uses carbon dioxide as a raw material, making the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive more environmentally friendly. Detailed Embodiments

[0041] The dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention comprises an unsaturated carbon dioxide-based polycarbonate polyol, a polyester polyol, a polyether polyol, a polyisocyanate, a tackifying resin, a first free radical photoinitiator, a first catalyst, and optionally, an auxiliary agent and a filler. Among them, the content of the unsaturated carbon dioxide-based polycarbonate polyol is 10-50 parts by weight, such as 10, 15, 20, 25, 30, 35, 40, 45, 50 parts by weight, etc. The content of the polyester polyol is 5-25 parts by weight, such as 5, 8, 10, 12, 15, 18, 20, 22, 25 parts by weight, etc. The content of the polyether polyol is 6-35 parts, such as 6, 10, 15, 20, 25, 30, 35 parts by weight, etc. The content of the polyisocyanate is 4-30 parts by weight, such as 4, 8, 10, 15, 20, 25, 30 parts by weight, etc. The content of the tackifying resin is 5-25 parts by weight, such as 5, 8, 10, 12, 15, 18, 20, 22, 25 parts by weight, etc. The content of the first free radical photoinitiator is 0.5-2.5 parts by weight, such as 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5 parts by weight, etc. The content of the first catalyst is 0.1-2 parts by weight, such as 0.1, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0 parts by weight, etc. The dosages of the auxiliary agent and the filler are each independently 0.1-10 parts by weight, such as 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts by weight, etc. In addition, the total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyester polyol is not less than 40% of the weight of the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive, for example, it can be 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, etc. The total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyether polyol is not less than 42% of the weight of the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive, for example, it can be 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, etc.

[0042] The molecular chain of the unsaturated carbon dioxide-based polycarbonate polyol simultaneously comprises a structural unit represented by the general formula (I), a structural unit represented by the general formula (II), and a structural unit represented by the general formula (III):

[0043]

[0044] The above three structural units in the unsaturated carbon dioxide-based polycarbonate polyol are generally arranged in a random copolymerization form. Among them, the molar ratio of the structural unit represented by the general formula (I), the structural unit represented by the general formula (II), and the structural unit represented by the general formula (III) is preferably (10-55):(10-55):1. Based on 1 mol of the molar number of the structural unit represented by the general formula (III), the molar numbers of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) can be independently 10 mol, 13 mol, 15 mol, 18 mol, 20 mol, 22 mol, 25 mol, 28 mol, 30 mol, 32 mol, 35 mol, 38 mol, 40 mol, 42 mol, 45 mol, 48 mol, 50 mol, 52 mol, 55 mol, etc.

[0045] In a specific embodiment, the unsaturated carbon dioxide-based polycarbonate polyol is represented by the general formula (IV):

[0046]

[0047] In the general formula (I), 0.90≤n≤0.98 (such as 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, etc.), n+m = 1, and x represents a positive integer from 10 to 45 (such as 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, etc.). In addition, the number-average molecular weight of the unsaturated carbon dioxide-based polycarbonate polyol is preferably 1500-5000 Da, such as 1500 Da, 2000 Da, 2500 Da, 3000 Da, 3500 Da, 4000 Da, 4500 Da, 5000 Da, etc.

[0048] In a preferred embodiment, the unsaturated carbon dioxide-based polycarbonate polyol is prepared according to the following steps:

[0049] S11. At 60-80 °C, evacuate the reaction kettle and replace it with CO2, then cool it to room temperature. Under the protection of CO2, add a second catalyst, a chain transfer agent, propylene oxide, and 3,4-epoxy-1-cyclohexene into the reaction kettle, stir evenly, and then increase the pressure by introducing CO2 into the reaction kettle through a gas pressure regulator. Control the reaction kettle temperature at 60-80 °C for copolymerization reaction to obtain a carbon dioxide-based polycarbonate diol;

[0050] S12. Add the carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, the second free radical photoinitiator, and the organic solvent into a reaction kettle, and stir until the solids are completely dissolved. Then, carry out the thiol-ene click reaction under ultraviolet light irradiation. After that, concentrate the obtained reaction solution to obtain the thiol-ene reaction product.

[0051] S13. Add the thiol-ene reaction product, glycidyl methacrylate, and the organic solvent into a reaction kettle, and stir until the solids are completely dissolved. Then, raise the temperature to 40 - 50 °C to carry out the ring-opening reaction. After that, slowly add the obtained ring-opening reaction product into a non-solvent to dissolve and precipitate the polymer. After filtration and drying, an unsaturated carbon dioxide-based polycarbonate polyol is obtained.

[0052] In the preparation process of the above-mentioned unsaturated carbon dioxide-based polycarbonate polyol, in step S11, the ratio of the sum of the weights of propylene oxide and 3,4-epoxy-1-cyclohexene to the weight of the second catalyst is preferably (1000 - 50000):1, such as 1000:1, 2000:1, 3000:1, 4000:1, 5000:1, 6000:1, 7000:1, 8000:1, 9000:1, 10000:1, 12000:1, 14000:1, 16000:1, 18000:1, 20000:1, 25000:1, 30000:1, 35000:1, 40000:1, 45000:1, 50000:1, etc. The molar ratio of 3,4-epoxy-1-cyclohexene to propylene oxide is preferably 1:(10 - 55), such as 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, etc. The chain transfer agent can be selected from at least one of aliphatic carboxylic acids, cycloaliphatic carboxylic acids, aromatic carboxylic acids, and low-molecular-weight hydroxyl-containing compounds. In addition, the temperature of the copolymerization reaction is preferably 60 - 80 °C, the pressure is preferably 28.5 - 32.0 atm, and the time is preferably 4 - 8 h.

[0053] In the preparation process of the above-mentioned unsaturated carbon dioxide-based polycarbonate polyol, in step S12, the time of the thiol-ene click reaction is preferably 6 - 10 hours. In addition, the carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, the second free radical photoinitiator, and the organic solvent can be added into the reaction kettle in any order, and there is no special limitation on this.

[0054] In the preparation process of the above-mentioned unsaturated carbon dioxide-based polycarbonate polyol, in step S13, the temperature of the ring-opening reaction is 40-50 °C, and the time is preferably 1-2 hours. The non-solvent can be various existing inert liquid solvents that do not dissolve the target product, unsaturated carbon dioxide-based polycarbonate polyol, but dissolve impurities such as unreacted raw materials. Specific examples thereof include, but are not limited to, at least one of methanol, water, n-hexane, and ether. Adding the ring-opening reaction product to the non-solvent can separate the unsaturated carbon dioxide-based polycarbonate polyol from the impurities, thereby improving the purity of the unsaturated carbon dioxide-based polycarbonate polyol.

[0055] In the present invention, for the convenience of distinction and description, the catalyst contained in the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive is referred to as the "first catalyst", and the catalyst used in the first step in the process of preparing the unsaturated carbon dioxide-based polycarbonate polyol is referred to as the "second catalyst"; the free radical photoinitiator contained in the dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive is referred to as the "first free radical photoinitiator", and the free radical photoinitiator used in the second step in the process of preparing the unsaturated carbon dioxide-based polycarbonate polyol is referred to as the "second free radical photoinitiator". Among them, the first catalyst is preferably selected from at least one of 2,2-dimorpholinodiethyl ether, organobismuth catalyst, dibutyltin dilaurate, and stannous octoate. The second catalyst is preferably selected from at least one of a zinc carboxylate catalyst system, a zinc phenoxide catalyst system, a β-diketimine zinc catalyst system, a pyridine-zinc catalyst system, a porphyrin-based catalyst system, a SalenMX-based catalyst system, a rare earth catalyst system, a double metal cyanide catalyst system, and a supported catalyst system. Both the first free radical photoinitiator and the second free radical photoinitiator can be various existing compounds that can absorb ultraviolet light energy to generate free radicals, thereby initiating the thiol-ene click reaction between thiol and alkene or initiating the free radical polymerization reaction of unsaturated double bonds. Specific examples thereof include, but are not limited to: 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphonate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinobenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolylphenyl)titanocene, methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl 4-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthone, 2,4-diethylthioxanthone, and at least one of 2-ethylanthraquinone.

[0056] The polyester polyol can be obtained by the esterification reaction of a polycarboxylic acid and a polyol. Among them, specific examples of the polycarboxylic acid include, but are not limited to, at least one of terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic 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-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and cyclohexanediol. In addition, the polyester polyol can also be a poly-ε-caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone. The polyether polyol can be a ring-opening polymer of a tetrahydrofuran-based compound and / or a bisphenol A polyalkylene oxide modified body. Among them, the tetrahydrofuran-based compound can be, for example, tetrahydrofuran, 3-methyltetrahydrofuran, etc. The bisphenol-type polyalkylene oxide modified body refers to a polyether polyol obtained by adding an alkylene oxide (such as ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, etc.) to the active hydrogen part of the bisphenol-type molecular skeleton, and can be a random copolymer or a block copolymer. In addition, when the weight average molecular weight of the polyester polyol and the polyether polyol is less than 1000, the flexibility of the polyurethane hot melt adhesive will be reduced to a certain extent; when the weight average molecular weight of the polyester polyol and the polyether polyol is greater than 5000, the reactivity and compatibility of the polyurethane hot melt adhesive system will be reduced, resulting in a certain degree of decrease in the bonding strength of the polyurethane hot melt adhesive. Therefore, in order to more favorably improve the flexibility and bonding strength of the carbon dioxide-based reactive polyurethane hot melt adhesive, the weight average molecular weight of the polyester polyol and the polyether polyol is preferably independently 1000-5000 Da.

[0057] The polyisocyanate is a compound with two or more isocyanate groups at the molecular chain terminals, and can specifically be an aromatic isocyanate and / or an aliphatic isocyanate. Among them, specific examples of the aromatic isocyanate include, but are not limited to, at least one of toluene diisocyanate (TDI), diphenylmethane-4,4'-diisocyanate (MDI), tetramethylxylylene diisocyanate (TMXDI), etc. Specific examples of the aliphatic isocyanate can be selected from at least one of 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (H 12 MDI), trimethylhexane diisocyanate (TMDI), etc.

[0058] The tackifying resin can be various existing thermoplastic resins that can be used in polyurethane hot melt adhesives, and specific examples thereof include, but are not limited to, at least one of polyurethane elastomers, acrylic resins, EVA resins, rosin resins, terpene resins, phenolic resins, dicyclopentadiene resins, and styrene resins.

[0059] The double-curable carbon dioxide-based reactive polyurethane hot melt adhesive may further include additives. The types of the additives can be selected according to actual situations. For example, it can be selected from at least one of polymerization inhibitors, antioxidants, silane coupling agents, water removers, flame retardants, defoamers, leveling agents, and homogenizing agents. The specific types of these additives can all be conventional selections in the art, and those skilled in the art can all know this, so no further elaboration will be made here.

[0060] The carbon dioxide-based reactive polyurethane hot melt adhesive may further include inorganic fillers, which can improve the mechanical properties of the carbon dioxide-based reactive polyurethane hot melt adhesive at this time. Specific examples of the inorganic fillers include but are not limited to at least one of silica, alumina, talc, calcium carbonate, glass microspheres, metal powders, and polytetrafluoroethylene fillers.

[0061] The preparation method of the double-curable carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention includes uniformly mixing an unsaturated carbon dioxide-based polycarbonate polyol, a polyester polyol, a polyether polyol, a polyisocyanate, a tackifying resin, a first radical photoinitiator, a first catalyst, and optionally additives and fillers under light-shielded and moisture-insulated conditions.

[0062] The present invention has no particular limitation on the method of uniformly mixing each component under light-shielded and moisture-insulated conditions, as long as the uniform mixing of each component can be achieved and the entire mixing process is ensured to be unaffected by light and moisture. In a preferred embodiment, the method of uniformly mixing is carried out by a method including the following steps: S21. Add the unsaturated carbon dioxide-based polycarbonate polyol, the polyester polyol, the polyether polyol, the tackifying resin, and optionally additives and fillers into a reaction kettle, heat up to 150-170 °C, and dehydrate for 2-4 hours under stirring conditions with a vacuum degree lower than -0.08 MPa and a rotation speed of 100-200 rpm, and then cool down to 70-80 °C; S22. Add the polyisocyanate into the reaction kettle in step S1, heat up to 120-160 °C, stir at a speed of 100-200 rpm under vacuum conditions for 1-2 hours, and then cool down to 90-100 °C; S23. Under light-shielded conditions, add the first radical photoinitiator and the first catalyst into the reaction kettle in step S2, stir at a speed of 100-200 rpm under vacuum conditions for 20-60 minutes, and quickly discharge and seal for storage under light-shielded and nitrogen protection to obtain the double-curable carbon dioxide-based reactive polyurethane hot melt adhesive. Among them, the types and dosages of each component have been described above, so no further elaboration will be made here.

[0063] The technical solutions of the present invention will be further described and illustrated according to the following examples. Unless otherwise specified, the parts in the following examples and comparative examples are all parts by weight.

[0064] In the following examples, unless otherwise specified, the raw materials or processing technologies used are all conventional commercially available raw material products or conventional processing technologies in the art.

[0065] The sources of the raw materials used in the following preparation examples are as follows:

[0066] The double metal cyanide (DMC) catalyst was purchased from Changzhou Hongyu Chemical Co., Ltd., named double metal cyanide complex catalyst; the chain transfer agent was citric acid, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with the product number C108869; propylene oxide was purchased from Shanghai Macklin Biochemical Co., Ltd., with the product number P816084; 3,4-epoxy-1-cyclohexene was purchased from Sigma-Aldrich, with the product number 669911; cysteamine hydrochloride was purchased from TCI (Shanghai) Chemical Industry Development Co., Ltd., with the product number A0296; phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide was purchased from Shanghai Macklin Biochemical Co., Ltd., with the product number P831909; glycidyl methacrylate was purchased from Wuxi Mingri Chemical Technology Co., Ltd., with the product number GMA; pyrogallol was purchased from Shanghai Macklin Biochemical Co., Ltd., with the product number P815678; diethylzinc was purchased from Shanghai Titan Technology Co., Ltd., with the product number 01375817; allyl glycidyl ether was purchased from Shanghai Aladdin Chemistry Co., Ltd., with the product number R003047.

[0067] The sources of the raw materials used in the following examples and comparative examples are as follows:

[0068] The polyester polyol is Dynacoll 7360 from Evonik Industries; the polyether polyol is polypropylene oxide PPG2000, selected from Voranol 2000LM of The Dow Chemical Company in the United States; the diphenylmethane-4,4'-diisocyanate is MDI-100 from Wanhua Chemical Group Co., Ltd.; the tackifying resin is an acrylic resin, selected from BR113 of Mitsubishi Chemical Corporation in Japan; the free radical photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone and ethyl 2,4,6-trimethylbenzoyl phenylphosphinate, selected from Omnirad 1173 of IGM and TPO-L of Liangzhi Chemical (China) Co., Ltd. in Germany respectively; the catalyst is 2,2-dimorpholinodiethylether, selected from B802012 of Macklin; the additives include a silane coupling agent and an antioxidant. The silane coupling agent is γ-(2,3-epoxypropoxy)propyltrimethoxysilane, selected from KH-560 of Jiangsu Runfeng Synthetic Technology Co., Ltd.; the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], selected from Irganox 1010 of BASF in Germany; the filler is fumed silica, selected from REOLOSIL QS-10 of Tokuyama Corporation in Japan.

[0069] Preparation Example 1

[0070] This preparation example is used to illustrate the preparation of unsaturated carbon dioxide-based polycarbonate polyols. The specific reaction process and steps are as follows:

[0071] Step 1: At 70 °C, evacuate the reaction kettle and replace it with CO2, cool it to room temperature, and add a double metal cyanide (DMC) catalyst, a chain transfer agent, propylene oxide, and 3,4-epoxy-1-cyclohexene into the reaction kettle under the protection of CO2 (the weight ratio of the double metal cyanide catalyst to the sum of the weights of propylene oxide and 3,4-epoxy-1-cyclohexene is 1:5000), and stir evenly; then, increase the pressure of the reaction kettle to 28.5 - 32.0 atm by introducing CO2 through a gas pressure regulator, and place the reaction kettle in a 70 °C constant temperature oil bath for copolymerization reaction for 4 h to obtain carbon dioxide-based polycarbonate diol;

[0072] Step 2: Add tetrahydrofuran to the reaction kettle, then add 0.1 mol of carbon dioxide-based polycarbonate diol, 0.15 mol of cysteamine hydrochloride, and 0.003 mol of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, stir until the solid is completely dissolved, stir and react under ultraviolet light irradiation for 8 hours, and then concentrate the obtained reaction product solution to obtain a thiol-ene reaction product with a yield of 90.8%;

[0073] Step 3: Add tetrahydrofuran into the reaction kettle, then add 0.1 mol of the thiol-ene reaction product and 0.12 mol of glycidyl methacrylate, stir until completely dissolved, heat up to 45 °C and stir for reaction for 1.5 hours. Slowly add the obtained reaction product solution into a large amount of non-solvent for precipitation, filter, and obtain unsaturated carbon dioxide-based polycarbonate polyol after vacuum drying, with a yield of 92.3%. Detected by a nuclear magnetic resonance instrument, the unsaturated carbon dioxide-based polycarbonate polyol contains structural units shown in general formula (I), structural units shown in general formula (II), and structural units shown in general formula (III) with a molar ratio of 31:31:1.

[0074] Preparation Example 2

[0075] This preparation example is used to illustrate the preparation of unsaturated carbon dioxide-based polycarbonate polyol, and the specific reaction steps are as follows:

[0076] Step 1: At 70 °C, evacuate the reaction kettle and replace it with CO2, cool to room temperature, add a double metal cyanide (DMC) catalyst, a chain transfer agent, propylene oxide, and 3,4-epoxy-1-cyclohexene into the reaction kettle under the protection of CO2 (the weight ratio of the double metal cyanide catalyst to the sum of the weights of propylene oxide and 3,4-epoxy-1-cyclohexene is 1:50000), and stir evenly; then increase the pressure of CO2 in the reaction kettle to 28.5 - 32.0 atm through a gas pressure regulator, and place the reaction kettle in a 70 °C constant temperature oil bath for copolymerization reaction for 4 h to obtain carbon dioxide-based polycarbonate diol;

[0077] Step 2: Add tetrahydrofuran into the reaction kettle, then add 0.1 mol of carbon dioxide-based polycarbonate diol, 0.15 mol of cysteamine hydrochloride, and 0.003 mol of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, stir until the solid is completely dissolved, stir for reaction for 8 hours under ultraviolet light irradiation, and then concentrate the obtained reaction product solution to obtain the thiol-ene reaction product, with a yield of 89.5%;

[0078] Step 3: Add tetrahydrofuran into the reaction kettle, then add 0.1 mol of the thiol-ene reaction product and 0.12 mol of glycidyl methacrylate, stir until completely dissolved, heat up to 45 °C and stir for reaction for 1.5 hours. Slowly add the obtained reaction product solution into a large amount of non-solvent for precipitation, filter, and obtain unsaturated carbon dioxide-based polycarbonate polyol after vacuum drying, with a yield of 91.6%. Detected by a nuclear magnetic resonance instrument, the unsaturated carbon dioxide-based polycarbonate polyol contains structural units shown in general formula (I), structural units shown in general formula (II), and structural units shown in general formula (III) with a molar ratio of 17:17:1.

[0079] Preparation Example 3

[0080] This preparation example refers to Macromol. Rapid Commun. 21, 754-757 (2000) and is used to illustrate the preparation of polycarbonate polyols containing allyl glycidyl ether groups in the structure. The specific reaction process and steps are as follows:

[0081] Under argon protection, a 25 ml dioxane solution containing 7.5 mmol of pyrogallol was slowly added to a dioxane solution containing 15 mmol of diethylzinc (ZnEt2) at room temperature, and continuous stirring was carried out until no more ethane was released, obtaining an ethylzinc / pyrogallol catalyst.

[0082] Under argon protection, 100 mmol of allyl glycidyl ether and 4 mmol of ethylzinc / pyrogallol catalyst were added to the reaction kettle at room temperature. Then, CO2 was introduced into the reaction kettle through a gas pressure regulator to increase the pressure to 28.5 - 32.0 atm, and the reaction was carried out at 35 °C for 44 hours, and then the reaction was stopped by reducing the pressure. The obtained product was diluted with dichloromethane, washed with 10% aqueous HCl solution, then washed with water, and finally dichloromethane was removed by vacuum distillation to obtain a polycarbonate polyol containing allyl ether in the structure.

[0083]

[0084] Examples 1 - 6

[0085] Examples 1 - 6 are used to illustrate the preparation method of a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive. The difference is that the types of carbon dioxide-based polycarbonate polyols used and the weight parts of raw materials are different. The specific raw materials (weight parts) are shown in Table 1. The specific steps are as follows:

[0086] S1. Add unsaturated carbon dioxide-based polycarbonate polyol, polyester polyol, polyether polyol, tackifying resin, additives, and fillers to the reaction kettle, heat up to 160 °C, dehydrate for 3 hours under stirring conditions with a vacuum degree lower than -0.08 MPa and a rotation speed of 150 rpm, and then cool down to 70 °C;

[0087] S2. Add diphenylmethane-4,4'-diisocyanate to the reaction kettle in step S1, heat up to 150 °C, stir at a speed of 150 rpm under vacuum conditions for 1.5 hours, and then cool down to 90 °C;

[0088] S3. Under light-shielded conditions, add the first radical photoinitiator and the first catalyst to the reaction kettle in step S2, stir at a speed of 150 rpm under vacuum conditions for 30 minutes, and quickly discharge and seal for storage under light-shielded and nitrogen protection conditions to obtain a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive.

[0089] Comparative Examples 1 - 6

[0090] Prepare the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to the method of Example 1, except that the total weight of the carbon dioxide-based polycarbonate polyol and polyester polyol and the total weight of the carbon dioxide-based polycarbonate polyol and polyether polyol exceed the given range. The specific raw materials (parts by weight) are shown in Table 1. The specific steps are as follows:

[0091] S1. Add the unsaturated carbon dioxide-based polycarbonate polyol, polyester polyol, polyether polyol, tackifying resin, additives and fillers into a reaction kettle, heat up to 160 °C, dehydrate for 3 hours under stirring conditions with a vacuum degree lower than -0.08 MPa and a rotation speed of 150 rpm, and then cool down to 70 °C;

[0092] S2. Add diphenylmethane-4,4'-diisocyanate into the reaction kettle in step S1, heat up to 150 °C, stir at a speed of 150 rpm under vacuum conditions for 1.5 hours, and then cool down to 90 °C;

[0093] S3. Under light-shielding conditions, add the first free radical photoinitiator and the first catalyst into the reaction kettle in step S2, stir at a speed of 150 rpm under vacuum conditions for 30 minutes, and quickly discharge and seal for storage under light-shielding and nitrogen protection to obtain the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive.

[0094]

[0095] Test Example

[0096] (1) Coat the polyurethane hot melt adhesives of the examples and comparative examples on a PET film with a thickness of about 0.2 mm. After curing by ultraviolet light irradiation, place it at room temperature for 5 min to test the initial 180° peel strength. Then place the sample in a constant temperature and humidity environment at room temperature with a humidity of 65%, and take samples every 24 hours to test the 180° peel strength to investigate the curing degree. After the sample is completely cured, test the final 180° peel strength and shear strength. Take three parallel tests for each specimen and take the average value. The results are shown in Table 2.

[0097] (2) Subject the completely cured sample to high temperature and high humidity testing under the conditions of 85 °C and 95% humidity for 72 hours. Then place the sample at room temperature for 24 hours and test the peel strength, which is the 180° peel strength after high temperature and high humidity testing. The results are shown in Table 2.

[0098] (3) The retention rate of the 180° peel strength after high temperature and high humidity testing = Q1 / Q0×100%, where Q1 is the 180° peel strength after high temperature and high humidity testing, and Q0 is the final 180° peel strength. The results are shown in Table 2.

[0099] (4) The complete curing time is judged by reaching more than 95% of the final 180° peel strength. The results are shown in Table 2.

[0100] Table 2

[0101]

[0102] Analyzing the data in Table 1 and Table 2, the following conclusions can be found:

[0103] (1) The dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention has a high initial bonding strength after ultraviolet light irradiation, a fast moisture curing speed, a high final bonding strength. In addition, it has a high shear strength after complete curing and good results in the damp heat resistance test.

[0104] (2) In Examples 1-6 and Comparative Examples 1-3, three different unsaturated carbon dioxide-based polycarbonate polyols (PPC) were used to prepare reactive polyurethane hot melt adhesives. The initial bonding strength in Examples 1-3 was significantly higher than that in Comparative Examples 1-3, indicating that acrylate modification of carbon dioxide-based polycarbonate polyols can effectively improve the initial bonding strength of the hot melt adhesive under UV light. However, the reactive hot melt adhesive prepared from PPC in Preparation Example 3 does not have the characteristics and advantages of a dual-curable reactive polyurethane hot melt adhesive. At the same time, the final bonding strength in Examples 1-3 was also significantly higher than that in Comparative Examples 1-3, indicating that through the reasonable combination and reaction of the reactive polyurethane hot melt adhesive system in the present invention, while improving the initial bonding strength of the hot melt adhesive, a relatively high final bonding strength can still be maintained, so as to meet multiple requirements in product bonding.

[0105] (3) The initial bonding strength, final bonding strength and shear strength in Examples 1-3 were significantly higher than those in Examples 4-6, which shows that the addition amount of the double metal cyanide catalyst plays an important role in the preparation of carbon dioxide-based polycarbonate polyols. Beyond the reasonable range in the present invention, it will have an adverse effect on the performance of the polyurethane hot melt adhesive.

[0106] (4) Comparing and analyzing Examples 1-3 with Comparative Examples 1-6, it can be found that when the total weight of the carbon dioxide-based polycarbonate polyol and the polyester polyol and the total weight of the carbon dioxide-based polycarbonate polyol and the polyether polyol exceed the reasonable range in the present invention, the performance of the polyurethane hot melt adhesive deteriorates.

[0107] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive, characterized in that, The double-curable carbon dioxide-based reactive polyurethane hot melt adhesive comprises the following components in parts by weight: Unsaturated carbon dioxide-based polycarbonate polyol: 10 - 50 parts; Polyester polyol: 5 - 25 parts; Polyether polyol: 6 - 35 parts; Polyisocyanate: 4 - 30 parts; Tackifying resin: 5 - 25 parts; First radical photoinitiator: 0.5 - 2.5 parts; First catalyst: 0.1 - 2 parts; The total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyester polyol is not less than 40% of the weight of the double-curable carbon dioxide-based reactive polyurethane hot melt adhesive; the total weight of the unsaturated carbon dioxide-based polycarbonate polyol and the polyether polyol is not less than 42% of the weight of the double-curable carbon dioxide-based reactive polyurethane hot melt adhesive; The molecular chain of the unsaturated carbon dioxide-based polycarbonate polyol simultaneously includes a structural unit represented by the general formula (I), a structural unit represented by the general formula (II), and a structural unit represented by the general formula (III): （Ⅰ） （Ⅱ） （Ⅲ）； The molar ratio of the structural unit represented by the general formula (I), the structural unit represented by the general formula (II), and the structural unit represented by the general formula (III) is (10 - 55):(10 - 55):1; The unsaturated carbon dioxide-based polycarbonate polyol is prepared by the following method: S11. At 60 - 80 °C, evacuate the reaction kettle and replace it with CO2, then cool it to room temperature. Under the protection of CO2, add a second catalyst, a chain transfer agent, propylene oxide, and 3,4-epoxy-1-cyclohexene into the reaction kettle. The ratio of the sum of the weights of propylene oxide and 3,4-epoxy-1-cyclohexene to the weight of the second catalyst is (1000 - 50000):

1. Stir evenly, and then increase the pressure of the reaction kettle by introducing CO2 through a gas pressure regulator. Control the temperature of the reaction kettle at 60 - 80 °C for copolymerization reaction to obtain a carbon dioxide-based polycarbonate diol; S12. Add the carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, a second radical photoinitiator, and an organic solvent into the reaction kettle and stir until the solid is completely dissolved. Then carry out a thiol-ene click reaction under ultraviolet light irradiation. After that, concentrate the obtained reaction solution to obtain a thiol-ene reaction product; S13. Add the thiol-ene reaction product, glycidyl methacrylate, and an organic solvent into the reaction kettle and stir until the solid is completely dissolved. Then raise the temperature to 40 - 50 °C for ring-opening reaction. After that, slowly add the obtained ring-opening reaction product into a non-solvent to dissolve and precipitate the polymer. Filter and dry to obtain the unsaturated carbon dioxide-based polycarbonate polyol.

2. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The molar ratio of 3,4-epoxy-1-cyclohexene to propylene oxide is 1:(10 - 55).

3. The dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, wherein The second catalyst is selected from at least one of a zinc carboxylate catalytic system, a zinc phenoxide catalytic system, a β-diketiminate zinc catalytic system, a pyridine-zinc catalytic system, a porphyrin catalytic system, a SalenMX catalytic system, a rare earth catalytic system, a double metal cyanide catalytic system, and a supported catalytic system.

4. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The chain transfer agent is selected from at least one of aliphatic carboxylic acids, aromatic carboxylic acids, and low-molecular-weight hydroxyl-containing compounds.

5. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The pressure of the copolymerization reaction is 28.5 - 32.0 atm, and the time is 4 - 8 h; the time of the thiol-ene click reaction is 6 - 10 h; the time of the ring-opening reaction is 1 - 2 h.

6. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The non-solvent is selected from at least one of methanol, water, n-hexane, and diethyl ether.

7. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The number-average molecular weight of the unsaturated carbon dioxide-based polycarbonate polyol is 1500 - 5000 Da.

8. The double-curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The weight-average molecular weight of the polyester polyol is 1000 - 5000 Da.

9. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, wherein The weight-average molecular weight of the polyether polyol is 1000 - 5000 Da.

10. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, wherein The tackifying resin is selected from at least one of polyurethane elastomer, acrylic resin, EVA resin, rosin resin, terpene resin, phenolic resin, dicyclopentadiene resin, and styrene resin.

11. The double-curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The first free radical photoinitiator and the second free radical photoinitiator are selected from at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylacetophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoyl phenylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinobenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-phenylhexanone, bis(2,6-difluoro-3-pyrrolphenyl)titanocene dichloride, methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl 4-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthone, 2,4-diethylthioxanthone, and 2-ethylanthraquinone.

12. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that, The first catalyst is selected from at least one of 2,2-dimorpholinodiethylether, organobismuth catalyst, dibutyltin dilaurate, and stannous octoate.

13. The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, wherein, The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive further comprises an auxiliary agent; the dosage of the auxiliary agent is 0.1 - 10 parts by weight; the auxiliary agent is selected from at least one of polymerization inhibitor, antioxidant, silane coupling agent, water scavenger, flame retardant, defoaming agent, leveling agent, and homogenizing agent.

14. The double-curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, wherein The doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive further comprises a filler; the dosage of the filler is 0.1 - 10 parts by weight; the filler is selected from at least one of silica, alumina, talc, calcium carbonate, glass microspheres, metal powder, and polytetrafluoroethylene filler.

15. The preparation method of the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to any one of claims 1-14, characterized in that, The method includes uniformly mixing an unsaturated carbon dioxide-based polycarbonate polyol, a polyester polyol, a polyether polyol, a polyisocyanate, a tackifying resin, a first free radical photoinitiator, a first catalyst, and optionally, auxiliaries and fillers under light-shielded and water-vapor-isolated conditions.

16. The preparation method of the doubly curable carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 15, characterized in that, The method of uniformly mixing is carried out by a method including the following steps: S21. Add the unsaturated carbon dioxide-based polycarbonate polyol, the polyester polyol, the polyether polyol, the tackifying resin, and optionally, auxiliaries and fillers into a reaction kettle, heat up to 150-170 °C, dehydrate for 2-4 hours under a stirring condition with a vacuum degree lower than -0.08 MPa and a rotation speed of 100-200 rpm, and then cool down to 70-80 °C; S22. Add the polyisocyanate into the reaction kettle in step S1, heat up to 120-160 °C, stir at a speed of 100-200 rpm under a vacuum condition for 1-2 hours, and then cool down to 90-100 °C; S23. Under light-shielded conditions, add the first free radical photoinitiator and the first catalyst into the reaction kettle in step S2, stir at a speed of 100-200 rpm under a vacuum condition for 20-60 minutes, quickly discharge the material and seal it for storage under light-shielded and nitrogen protection conditions to obtain a dual-curable carbon dioxide-based reactive polyurethane hot melt adhesive.

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