A kind of carbon dioxide based reactive polyurethane hot melt adhesive and preparation method thereof

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: 30-125 parts by weight of a modified carbon dioxide-based polycarbonate diol, 10-40 parts by weight of a polyol polymer, 5-35 parts by weight of a polyisocyanate, 5-10 parts by weight of a thermoplastic resin, and 0.1-2 parts by weight of a first catalyst. The present invention introduces a modified carbon dioxide-based polycarbonate diol having a six-membered ring and an amino side chain on the basis of a traditional reactive polyurethane hot melt adhesive, and this special structure can improve the bonding performance, heat and moisture resistance, and flexibility of the polyurethane hot melt adhesive, and the polyurethane hot melt adhesive has the advantages of being environmentally friendly, green, and low in cost, and is conducive to achieving carbon emission reduction, conforming to the concept of sustainable development, and conforming to economic and social benefits.

Description

Technical Field

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

[0002] With the development of electronic equipment integration, screwless and frameless, many traditional adhesives can no longer meet the design and use requirements of modern smart devices. Reactive polyurethane (PUR) hot melt adhesive is a high-performance environmentally friendly adhesive developed in response to the current development requirements of smart electronics. PUR hot melt adhesive has high bonding strength, does not contain organic solvents, and is green and environmentally friendly; at the same time, it can realize automated operation and improve production efficiency, and has broad prospects in the structural bonding of mobile electronic devices. However, the key raw material in PUR hot melt adhesive, polyol polymers, mostly come from limited fossil fuel resources, which greatly limits the green and environmentally friendly development of PUR hot melt adhesive. On the other hand, the bonding strength of PUR hot melt adhesive prepared using commonly used polyester polyols and polyether polyols needs to be further improved.

[0003] Polyols prepared from carbon dioxide as raw materials have been widely studied as environmentally friendly raw materials with broad development prospects. CN200780027326.1 discloses a method for preparing a polyether carbonate polyol, wherein the raw material carbon dioxide content is about 1% to 40% by weight, and the ratio of cyclic carbonate byproducts to the total amount of carbonate is less than about 0.3. The polyether carbonate polyol can be used to produce polyurethane foam materials with improved properties, which can improve the compatibility and fire resistance of carbon dioxide foaming agents, but its improvement effect has not been explored in the field of PUR hot melt adhesives. CN201810137490.8 discloses a carbon dioxide-based reactive polyurethane hot melt adhesive and a preparation method thereof, specifically disclosing the use of carbon dioxide-based diols and carbon dioxide-based tetraols to prepare reactive hot melt adhesives, the hot melt adhesive has high bonding strength, fast surface drying speed, good heat resistance and storage stability, and solves the problem of insufficient bonding strength on the surface of low-polarity materials to a certain extent, but the actual related bonding strength, heat and moisture resistance, and flexibility need to be further improved for current application requirements.

[0004] In summary, in order to meet the current application needs of electronic consumer products, how to prepare green and environmentally friendly polyurethane hot melt adhesives with excellent bonding strength, heat and moisture resistance, and flexibility has become a problem to be solved. Summary of the invention

[0005] The first object of the present invention is to provide a carbon dioxide-based reactive polyurethane hot melt adhesive having good bonding properties, heat and moisture resistance and flexibility.

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned carbon dioxide-based reactive polyurethane hot melt adhesive.

[0007] Specifically, the carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention comprises the following components: 30-125 parts by weight of modified carbon dioxide-based polycarbonate diol, 10-40 parts by weight of polyol polymer, 5-35 parts by weight of polyisocyanate, 5-10 parts by weight of thermoplastic resin and 0.1-2 parts by weight of first catalyst, wherein the modified carbon dioxide-based polycarbonate diol simultaneously contains 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):

[0008]

[0009] The above three structural units in the modified carbon dioxide-based polycarbonate diol are generally arranged in the form of random copolymerization. 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 (13-55): (13-55): 1. Taking the molar number of the structural unit represented by the general formula (III) as 1 mol, the molar number of the structural unit represented by the general formula (I) and the structural unit represented by the general formula (II) can be independently 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.

[0010] In one specific embodiment, the modified carbon dioxide-based polycarbonate diol is represented by the general formula (IV):

[0011]

[0012] In the general formula (IV), 0.92≤n≤0.98 (such as 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, etc.), m+n=1, and x represents a positive integer of 15-40 (such as 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, etc.).

[0013] The modified carbon dioxide-based polycarbonate diol can be obtained commercially or prepared according to various existing methods. In a preferred embodiment, the modified carbon dioxide-based polycarbonate diol is prepared according to the following method:

[0014] S1. placing the second catalyst in a high-pressure reactor, evacuating the high-pressure reactor at 50-80°C for at least 2 hours and filling it with CO2, adding propylene oxide and 1,2-epoxy-4-vinylcyclohexane into the high-pressure reactor under the protection of CO2, stirring, introducing CO2 into the reactor through a CO2 pressure regulator, placing the high-pressure reactor in a constant temperature bath at 28.5-32.0atm for copolymerization, the reaction time is 4-8 hours, and after the reaction is completed, cooling the high-pressure reactor to below 20°C to slowly release the remaining CO2 to obtain a carbon dioxide-based polycarbonate diol;

[0015] S2, adding carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, a free radical photoinitiator and an organic solvent into a reaction kettle and stirring until the solid is completely dissolved, and then reacting under ultraviolet light to obtain a thiol-ene reaction product;

[0016] S3, concentrating the obtained mercapto-ene reaction product, then slowly adding it into a non-solvent to precipitate a polymer, filtering and drying to obtain a modified carbon dioxide-based polycarbonate diol.

[0017] In a preferred embodiment, the second catalyst is selected from at least one of a carboxylate zinc catalytic system, a phenol oxide zinc catalytic system, a β-diimine 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.

[0018] In a preferred embodiment, the molar ratio of the amount of the second catalyst to the total amount of propylene oxide and 1,2-epoxy-4-vinylcyclohexane is 1:(2000-7000), such as 1:2000, 1:2500, 1:3000, 1:3500, 1:4000, 1:4500, 1:5000, 1:5500, 1:6000, 1:6500, 1:7000, etc., but is not limited to the listed values, and other unlisted combinations within this range are also applicable.

[0019] In a preferred embodiment, the molar ratio of 1,2-epoxy-4-vinylcyclohexane to propylene oxide is preferably 1:(13-55), such as 1:13, 1:15, 1:17, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, etc., but is not limited to the listed values, and other unlisted combinations within this range are also applicable.

[0020] The free radical photoinitiator can be any existing compound that can absorb ultraviolet light energy to generate free radicals, thereby initiating a thiol-ene click reaction between a thiol group and an olefin group. In a preferred embodiment, the free radical photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenyl propiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2- At least one of (dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-hexanophenone, bis-2,6-difluoro-3-pyrrolophenyl titanocene, methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl p-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthone, 2,4-diethylthioxanthone and 2-ethylanthraquinone.

[0021] The content of the modified carbon dioxide-based polycarbonate diol is 30-125 parts by weight, preferably 60-125 parts by weight, such as 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125 parts by weight, etc., but not limited to the numerical values ​​listed, other unlisted combinations in this range are equally applicable. When the content of the modified carbon dioxide-based polycarbonate diol is 60-125 parts by weight, the bonding performance, heat and moisture resistance and flexibility of the carbon dioxide-based reactive polyurethane hot melt adhesive are all better. In addition, the number average molecular weight of the modified carbon dioxide-based polycarbonate diol is preferably 2000-4000, such as 2000, 2200, 2500, 2800, 3000, 3200, 3500, 3800, 4000, etc., but not limited to the numerical values ​​listed, other unlisted combinations in this range are equally applicable.

[0022] The present invention has no particular limitation on the type of polyol polymer, which can be obtained by polycondensation reaction of polycarboxylic acid / polyanhydride and polyol, or by modification of prepolymer, including aliphatic polyol and aromatic polyol, which can be specifically selected from at least one of polyester polyol, polyether polyol, polycarbonate polyol and polybutadiene polyol. The aliphatic polyol type polyurethane has strong cohesive strength and adhesion due to the presence of more polar groups such as ester groups and amino groups in the molecule, and has high strength and wear resistance. The aromatic polyol type polyurethane has excellent hydrolysis resistance, heat resistance and adhesion. The polycarboxylic acid / polyanhydride can be selected from at least one of phthalic acid, adipic acid, halogenated phthalic acid, phthalic anhydride, etc. The polyol can be selected from at least one of ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol, 1,4-butanediol, etc. When the number average molecular weight of the polyol polymer is less than 2000, the flexibility of the hot melt adhesive will be reduced to a certain extent; when the weight average molecular weight of the polyol polymer is greater than 7000, the reactivity and compatibility of the hot melt adhesive system will be reduced, causing the bonding strength of the hot melt adhesive to decrease to a certain extent. Therefore, in order to better improve the flexibility and bonding strength of the carbon dioxide-based reactive polyurethane hot melt adhesive, the number average molecular weight of the polyol polymer is preferably 2000-7000.

[0023] The polyisocyanate is a compound with two or more isocyanate groups at the end of the molecular chain, and can be specifically an aromatic isocyanate and / or an aliphatic isocyanate. The aromatic isocyanate can be, for example, at least one of toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), tetramethylphenylene diisocyanate (TMXDI), etc. The aliphatic isocyanate can be, for example, selected from 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (H 12 At least one of MDI, trimethylhexane diisocyanate (TMDI), etc.

[0024] The thermoplastic resin can be any existing thermoplastic resin that can be used for polyurethane hot melt adhesive, and specific examples thereof include but are not limited to: at least one of polyurethane elastomer, acrylic resin, rosin resin, terpene resin, phenolic resin, C5 petroleum resin, C9 petroleum resin, EVA resin, coumarone resin, dicyclopentadiene resin and styrene resin.

[0025] The present invention has no particular limitation on the type of the first catalyst, as long as it can cause the modified carbon dioxide-based polycarbonate diol, polyol polymer and polyisocyanate to condense to form polyurethane. Specific examples include, but are not limited to: at least one of 2,2-dimorpholinyl diethyl ether, an organic bismuth catalyst, dibutyltin dilaurate and stannous octoate.

[0026] In a preferred embodiment, the carbon dioxide-based reactive polyurethane hot melt adhesive further includes an antioxidant, which can prevent the polyurethane hot melt adhesive from aging and extend its service life. Specific examples of the antioxidant include, but are not limited to, at least one of 2,6-tert-butyl-4-methylphenol, 4,4'-thiobis(6-tert-butyl-3-methylphenol), tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triphenyl phosphite, and trinonylphenyl phosphite. In addition, the content of the antioxidant is preferably 0.1-2 parts by weight, such as 0.1, 0.3, 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2 parts by weight, but is not limited to the listed values, and other unlisted combinations within this range are also applicable.

[0027] In a preferred embodiment, the carbon dioxide-based reactive polyurethane hot melt adhesive further includes an auxiliary agent, which can improve the storage stability, rheological properties, toughness, flame retardancy and other auxiliary properties required by the hot melt adhesive of the carbon dioxide-based reactive polyurethane hot melt adhesive. Specific examples of the auxiliary agent include, but are not limited to: at least one of a curing accelerator, a stabilizer, a coupling agent, a diluent, a toughening agent, a flame retardant, a pigment and a filler. In addition, the content of the auxiliary agent is preferably 0.5-10 parts by weight, such as 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts by weight, etc., but is not limited to the listed values, and other combinations not listed within this range are also applicable.

[0028] In a preferred embodiment, the carbon dioxide-based reactive polyurethane hot melt adhesive comprises the following components: 60-125 parts by weight of modified carbon dioxide-based polycarbonate diol, 10-40 parts by weight of polyol polymer, 5-35 parts by weight of polyisocyanate, 5-10 parts by weight of thermoplastic resin, 0.1-2 parts by weight of first catalyst, 0.1-2 parts by weight of antioxidant and 0.5-10 parts by weight of auxiliary agent. At this time, the components can be perfectly matched with each other, and the corresponding carbon dioxide-based reactive polyurethane hot melt adhesive has extremely excellent bonding performance, heat and moisture resistance, flexibility and aging resistance.

[0029] The present invention also provides a method for preparing the above-mentioned carbon dioxide-based reactive polyurethane hot melt adhesive, which comprises the following steps:

[0030] (1) adding a modified carbon dioxide-based polycarbonate diol, a polyol polymer and an optional antioxidant into a reaction kettle, heating the temperature to 80-110° C., and stirring to mix evenly; cooling the temperature to 75-80° C., adding the polyisocyanate into the reaction kettle while stirring, and stirring the reaction at a speed of 100-200 rpm under vacuum conditions for 1-3 hours;

[0031] (2) adding a thermoplastic resin, a first catalyst and an optional auxiliary agent into a reaction kettle, stirring at a speed of 100-200 rpm for 10-60 minutes under vacuum conditions, quickly discharging the material under nitrogen protection and sealing and storing, thereby obtaining the carbon dioxide-based reactive polyurethane hot melt adhesive.

[0032] The key to the present invention is to introduce a modified carbon dioxide-based polycarbonate diol having a structural unit derived from propylene oxide and a six-membered ring and a flexible sulfur-containing group and an amino group on the basis of a traditional reactive polyurethane hot melt adhesive. This special structure can improve the bonding performance, heat and moisture resistance and flexibility of the polyurethane hot melt adhesive. In addition, the modified carbon dioxide-based polycarbonate diol uses carbon dioxide as a raw material, and the corresponding polyurethane hot melt adhesive has the advantages of being environmentally friendly, green and environmentally friendly, and low cost, which helps to achieve carbon emission reduction, conforms to the concept of sustainable development, and meets economic and social benefits. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below through examples.

[0034] In the following preparation examples, propylene oxide is selected from P109309 of Shanghai Aladdin Biochemical Technology Co., Ltd.; 1,2-epoxy-4-vinylcyclohexane is selected from Celloxide 2000 of Daicel of Japan; and the photoinitiator DMPA is selected from 01049771 of Shanghai Titan Technology Co., Ltd.

[0035] In the following examples and comparative examples, the polyol polymer is a polyether polyol selected from Voranol 2000LM of Dow Chemical of the United States; the polyol polymer is a polyester polyol selected from Dynacoll 7250 of Evonik; the polyisocyanate is 4,4'-diphenylmethane diisocyanate selected from MDI-100 of Wanhua Chemical Company; the thermoplastic resin is an acrylate resin selected from BR106 of Mitsubishi Corporation of Japan; the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] selected from Irganox 1010 of BASF of Germany; the first catalyst is 2,2-dimorpholinyl diethyl ether selected from B802012 of Shanghai MacLean Biochemical Technology Co., Ltd.; the auxiliary agent is a silane coupling agent, which is γ-(2,3-epoxypropoxy)propyltrimethoxysilane selected from KBM-403 of Shin-Etsu Corporation of Japan.

[0036] Preparation Example 1

[0037] This preparation example is used to illustrate the preparation of modified carbon dioxide-based polycarbonate diol. The specific reaction steps are as follows:

[0038] Step 1: 0.68 g of SalenCo (III) NO3 catalyst is placed in a high-pressure reactor, the reactor is vacuumed and filled with CO2 at 60°C for 2 hours, 209 g of propylene oxide and 29.8 g of 1,2-epoxy-4-vinylcyclohexane are added to the reactor under the protection of CO2, and stirred, CO2 is introduced into the reactor through a CO2 pressure regulator, and the autoclave is placed in a constant temperature bath at 28.5-32.0 atm for copolymerization reaction, the reaction time is 6 hours, and after the reaction is completed, the reactor is cooled to below 20°C and the remaining CO2 is slowly released to obtain 397 g of carbon dioxide-based polycarbonate diol;

[0039] Step 2: Add 350 g of carbon dioxide-based polycarbonate diol, 16.50 g of cysteamine hydrochloride, 2.68 g of free radical photoinitiator DMPA and 500 mL of tetrahydrofuran into a reaction kettle, then stir the mixture until the solid is completely dissolved, and irradiate the reaction under ultraviolet light for 8 hours;

[0040] Step 3: Concentrate the reaction product solution, slowly add it into non-solvent methanol to dissolve and precipitate the polymer, and obtain a modified carbon dioxide-based polycarbonate diol with a number average molecular weight of 3500 after filtering and drying.

[0041] According to nuclear magnetic resonance detection, the modified carbon dioxide-based polycarbonate diol includes structural units represented by general formula (I), structural units represented by general formula (II) and structural units represented by general formula (III) in a molar ratio of 32:32:1.

[0042] Preparation Example 2

[0043] This preparation example is used to illustrate the preparation of modified carbon dioxide-based polycarbonate diol. The specific reaction steps are as follows:

[0044] Step 1: 0.11 g of SalenCo (III) NO3 catalyst is placed in a high-pressure reactor, the reactor is vacuumed and filled with CO2 at 60°C for 2 hours, 209 g of propylene oxide and 29.8 g of 1,2-epoxy-4-vinylcyclohexane are added to the reactor under the protection of CO2, and stirred, CO2 is introduced into the reactor through a CO2 pressure regulator, and the autoclave is placed in a constant temperature bath at 28.5-32.0 atm for copolymerization reaction, the reaction time is 6 hours, and after the reaction is completed, the reactor is cooled to below 20°C and the remaining CO2 is slowly released to obtain 244 g of carbon dioxide-based polycarbonate diol;

[0045] Step 2: Add 200 g of carbon dioxide-based polycarbonate diol, 19.19 g of cysteamine hydrochloride, 3.10 g of free radical photoinitiator DMPA and 300 mL of tetrahydrofuran into a reaction kettle, then stir the mixture until the solid is completely dissolved, and irradiate the reaction under ultraviolet light for 8 hours;

[0046] Step 3: Concentrate the reaction product solution, slowly add it into non-solvent methanol to dissolve and precipitate the polymer, and obtain a modified carbon dioxide-based polycarbonate diol with a number average molecular weight of 1800 after filtering and drying.

[0047] According to nuclear magnetic resonance detection, the modified carbon dioxide-based polycarbonate diol includes structural units represented by general formula (I), structural units represented by general formula (II) and structural units represented by general formula (III) in a molar ratio of 15:15:1.

[0048] Preparation Example 3

[0049] 10.0 mg of DMC catalyst and 25.0 g of sebacic acid chain transfer agent were placed in a high-pressure reactor. The reactor was evacuated and filled with CO2 at 60°C for 2 h. Under the protection of CO2, 100 g of propylene oxide was added into the reactor and stirred. CO2 was introduced into the reactor through a CO2 pressure regulator. The autoclave was placed in a constant temperature bath at 28.5-32.0 atm for copolymerization. The reaction time was 6 h. After the reaction, the reactor was cooled to below 20°C to slowly release the remaining CO2. 90 mg of tri(pentafluorophenyl)borane and 10 g of propylene oxide were added into the reactor. The temperature was raised to 100°C and the reaction was continued for 2 h. After the reaction is completed, the reactor used for the polymerization reaction is cooled to room temperature with a cold water bath at a temperature of 12 to 15°C, the unreacted propylene oxide is evaporated, and the residue is dried in a vacuum drying oven at 40°C to constant weight, thereby obtaining 126.9 g of poly(carbonate-ether) diol with a number average molecular weight of 1500.

[0050] Example 1

[0051] S1: Prepare the raw materials according to the following components and weight proportions:

[0052]

[0053] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0054] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0055] Example 2

[0056] S1: Prepare the raw materials according to the following components and weight proportions:

[0057]

[0058]

[0059] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0060] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0061] Example 3

[0062] S1: Prepare the raw materials according to the following components and weight proportions:

[0063]

[0064] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0065] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0066] Example 4

[0067] S1: Prepare the raw materials according to the following components and weight proportions:

[0068]

[0069] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0070] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0071] Example 5

[0072] S1: Prepare the raw materials according to the following components and weight proportions:

[0073]

[0074]

[0075] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0076] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0077] Example 6

[0078] S1: Prepare the raw materials according to the following components and weight proportions:

[0079]

[0080] S2: Add the modified carbon dioxide-based polycarbonate diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0081] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0082] Comparative Example 1

[0083] S1: Prepare the raw materials according to the following components and weight proportions:

[0084]

[0085] S2: Add the poly(carbonate-ether) diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0086] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0087] Comparative Example 2

[0088] S1: Prepare the raw materials according to the following components and weight proportions:

[0089]

[0090]

[0091] S2: Add the poly(carbonate-ether) diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0092] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0093] Comparative Example 3

[0094] S1: Prepare the raw materials according to the following components and weight proportions:

[0095]

[0096] S2: Add the poly(carbonate-ether) diol, polyether polyol Voranol 2000LM, polyester polyol Dynacoll 7250 and antioxidant Irganox 1010 prepared in S1 into a reactor, heat to 100°C, and stir to mix evenly; cool to 75°C, add the polyisocyanate MDI-100 prepared in S1 into the reactor while stirring, and react at a stirring speed of 150 rpm under vacuum conditions for 2 hours;

[0097] S3: Add the thermoplastic resin BR106 prepared in S1, the first catalyst 2,2-dimorpholinyl diethyl ether and the auxiliary silane coupling agent into the reaction kettle, stir at a speed of 150 rpm for 30 minutes under vacuum conditions, quickly discharge the material under nitrogen protection and seal it for storage, and a carbon dioxide-based reactive polyurethane hot melt adhesive can be obtained.

[0098] Test Case

[0099] The samples obtained from Examples 1-6 and Comparative Examples 1-3 were subjected to the following performance tests:

[0100] (1) Adhesive properties (tensile shear strength): Tested according to the standard GB / T 7124-2008 "Determination of tensile shear strength of adhesives (rigid material to rigid material)". Specifically, an aluminum plate with a size of 100 mm × 25 mm × 2 mm was selected, two aluminum plates were overlapped together, the bonding area was 12.5 mm × 25 mm, and the thickness of the adhesive layer was ensured to be 0.2 mm. The overlapped specimens were placed in a constant temperature and humidity chamber at a temperature of 25°C and a humidity of 50% RH for seven days for curing. The tensile shear strength was tested using a universal material tensile force testing machine at a tensile speed of 5 mm / min. The results are shown in Table 1.

[0101] (2) Melt viscosity: Place the sealed hot melt adhesive in a syringe heater at 100°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 100°C and keep it for 10 minutes to make the internal temperature of the hot melt adhesive uniform and degas. At 100°C, measure the constant temperature melt viscosity of the hot melt adhesive. The results are shown in Table 1.

[0102] (3) Tensile strength: Tested according to standard GB / T 1040.3-2006. First, the hot melt adhesive was injected into a 2 mm thick polytetrafluoroethylene mold, scraped flat, and placed in a constant temperature and humidity chamber at a temperature of 25°C and a humidity of 50% RH for 7 days of wet curing; a dumbbell-shaped cutter with a size of 6 mm × 115 mm was used to cut the cured hot melt adhesive film to prepare a specimen, and a WDW3020 electronic universal testing machine was used to test the tensile properties of the specimen at room temperature, with a tensile speed of 10 mm / min. The results are shown in Table 1.

[0103] Table 1 Performance test results of Examples 1-6 and Comparative Examples 1-3

[0104]

[0105] From the results in Table 1, it can be seen that the carbon dioxide-based reactive polyurethane hot melt adhesive provided by the present invention has good bonding performance, a very high bonding strength retention rate after heating and humidification, good heat and moisture resistance, a long elongation at break, and good flexibility. In addition, the modified carbon dioxide-based polycarbonate diol uses carbon dioxide as a raw material, and the corresponding polyurethane hot melt adhesive has the advantages of being environmentally friendly, green and environmentally friendly, and low cost, which helps to achieve carbon emission reduction, conforms to the concept of sustainable development, and meets economic and social benefits.

[0106] 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 carbon dioxide-based reactive polyurethane hot melt adhesive, characterized in that: The carbon dioxide-based reactive polyurethane hot melt adhesive comprises the following components: 30-125 parts by weight of modified carbon dioxide-based polycarbonate diol, 10-40 parts by weight of polyol polymer, 5-35 parts by weight of polyisocyanate, 5-10 parts by weight of thermoplastic resin and 0.1-2 parts by weight of a first catalyst, wherein the modified carbon dioxide-based polycarbonate diol simultaneously contains 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):

2. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: 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 (13-55):(13-55):

1.

3. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The modified carbon dioxide-based polycarbonate diol is prepared according to the following method: S1. placing the second catalyst in a high-pressure reactor, evacuating the high-pressure reactor at 50-80°C for at least 2 hours and filling it with CO2, adding propylene oxide and 1,2-epoxy-4-vinylcyclohexane into the high-pressure reactor under the protection of CO2, stirring, introducing CO2 into the reactor through a CO2 pressure regulator, placing the high-pressure reactor in a constant temperature bath at 28.5-32.0atm for copolymerization, the reaction time is 4-8 hours, and after the reaction is completed, cooling the high-pressure reactor to below 20°C to slowly release the remaining CO2 to obtain a carbon dioxide-based polycarbonate diol; S2, adding carbon dioxide-based polycarbonate diol, cysteamine hydrochloride, a free radical photoinitiator and an organic solvent into a reaction kettle and stirring until the solid is completely dissolved, and then reacting under ultraviolet light to obtain a thiol-ene reaction product; S3, concentrating the obtained mercapto-ene reaction product, then slowly adding it into a non-solvent to precipitate a polymer, filtering and drying to obtain a modified carbon dioxide-based polycarbonate diol.

4. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 3, characterized in that: The second catalyst is selected from at least one of a carboxylate zinc catalytic system, a phenol oxide zinc catalytic system, a β-diimine 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; the molar ratio of the amount of the second catalyst to the total amount of propylene oxide and 1,2-epoxy-4-vinylcyclohexane is 1:(2000-7000); the molar ratio of the 1,2-epoxy-4-vinylcyclohexane to propylene oxide is 1:(13-55).

5. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 3, characterized in that: The free radical photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenyl propiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2-(dimethylamino ... At least one of 1,1'-(methylenebis-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-hexanophenone, bis-2,6-difluoro-3-pyrrolophenyl titanocene, methyl benzoylformate, benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, methyl o-benzoylbenzoate, ethyl 4-dimethylaminobenzoate, isooctyl p-dimethylaminobenzoate, 4,4'-bis(diethylamino)benzophenone, isopropylthioxanthone, 2,4-diethylthioxanthone and 2-ethylanthraquinone.

6. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The amount of the modified carbon dioxide-based polycarbonate diol used is 60-125 parts by weight; the number average molecular weight of the modified carbon dioxide-based polycarbonate diol is 2000-4000.

7. The carbon dioxide-based 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 polybutadiene polyol; the number average molecular weight of the polyol polymer is 2000-7000.

8. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The polyisocyanate is a compound having two or more isocyanate groups at the molecular chain terminal.

9. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The thermoplastic resin is selected from at least one of polyurethane elastomer, acrylic resin, rosin resin, terpene resin, phenolic resin, C5 petroleum resin, C9 petroleum resin, EVA resin, coumarone resin, dicyclopentadiene resin and styrene resin.

10. The 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-dimorpholinyl diethyl ether, an organic bismuth catalyst, dibutyltin dilaurate and stannous octoate.

11. The carbon dioxide-based reactive polyurethane hot melt adhesive according to claim 1, characterized in that: The carbon dioxide-based reactive polyurethane hot melt adhesive also includes an antioxidant; the content of the antioxidant is 0.1-2 parts by weight; the antioxidant is selected from at least one of 2,6-tert-butyl-4-methylphenol, 4,4'-thiobis(6-tert-butyl-3-methylphenol), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triphenyl phosphite and trinonylphenyl phosphite.

12. The carbon dioxide-based reactive polyurethane hot melt adhesive according to any one of claims 1 to 11, characterized in that: The carbon dioxide-based reactive polyurethane hot melt adhesive also includes an auxiliary agent; the content of the auxiliary agent is 0.5-10 parts by weight; the auxiliary agent is selected from at least one of a curing accelerator, a stabilizer, a coupling agent, a diluent, a toughening agent, a flame retardant, a pigment and a filler.

13. The method for preparing the carbon dioxide-based reactive polyurethane hot melt adhesive according to any one of claims 1 to 12, characterized in that: The method comprises the following steps: (1) adding a modified carbon dioxide-based polycarbonate diol, a polyol polymer and an optional antioxidant into a reaction kettle, heating the temperature to 80-110° C., and stirring to mix evenly; cooling the temperature to 75-80° C., adding the polyisocyanate into the reaction kettle while stirring, and stirring the reaction at a speed of 100-200 rpm under vacuum conditions for 1-3 hours; (2) adding a thermoplastic resin, a first catalyst and an optional auxiliary agent into a reaction kettle, stirring at a speed of 100-200 rpm for 10-60 minutes under vacuum conditions, quickly discharging the material under nitrogen protection and sealing and storing, thereby obtaining the carbon dioxide-based reactive polyurethane hot melt adhesive.

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