Humidity-heat-resistant photocuring adhesive based on carbon dioxide-based polyol and preparation method of humidity-heat-resistant photocuring adhesive

Abstract

The invention discloses a heat and humidity resistant photocuring adhesive based on carbon dioxide-based polyol and a preparation method of the heat and humidity resistant photocuring adhesive. The heat and humidity resistant photocuring adhesive comprises the following raw material components in parts by weight: 49-75 parts of modified polyurethane acrylate, 19-29 parts of a reactive diluent, 0.5-4 parts of a photoinitiator, 0.05-3.5 parts of a first polymerization inhibitor and 1-6 parts of an auxiliary agent. According to the invention, double bonds are introduced into modified polyurethane acrylate, rapid reaction can be realized under ultraviolet light to form a cross-linked network, relatively high initial adhesion is achieved, isocyanate groups are also introduced, reaction with moisture in air can be realized after initial positioning, and relatively high cohesive strength and adhesive force are achieved; carbon dioxide-based tetrahydric alcohol and diisocyanate are used for synthesizing modified polyurethane, carbonate bonds are high in polarity, can form hydrogen bonds with carbamic acid ester groups, and have high tensile strength, and the carbonate bonds are not easy to hydrolyze in water, so that the humidity and heat resistance of the ultraviolet light and moisture dual-curing adhesive is improved, and the ultraviolet light and moisture dual-curing adhesive can cope with more complex and harsh application environments.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to a moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol and a preparation method thereof. Background Art

[0002] Adhesion refers to the technology of connecting the surfaces of homogeneous or heterogeneous objects with adhesives. Compared with welding, riveting, bolting and other connection methods, it has the advantages of light weight, uniform stress distribution, strong caulking ability, and convenient construction. It is widely involved in various general fields, especially in electronics, automobiles, aerospace and other fields. Adhesives have four main functions in power batteries: providing protection for power batteries, providing safe and reliable lightweight design, thermal management, and helping power batteries cope with more complex use environments. Therefore, the application of adhesives is becoming more and more extensive, but at the same time, the performance requirements for adhesives are also getting higher and higher.

[0003] Traditional reactive polyurethane hot melt adhesive (PUR) is a polyurethane prepolymer prepared by the reaction of excess isocyanate and polyol. Due to the reasons such as the incomplete reaction between polyol and excess isocyanate caused by excess isocyanate and the reaction being blocked under high viscosity, unreacted free isocyanate is often present in the final product. Free isocyanate monomers will vaporize at 85-200°C to form irritating, allergic or toxic substances, which will endanger the health of practitioners. At the same time, the key raw material in traditional polyurethane adhesives - polyol polymers, mostly come from limited fossil fuel resources, which greatly limits the greenness of polyurethane adhesives; in addition, the bonding strength of polyurethane adhesives prepared from conventional polyester polyols and polyether polyols needs to be further improved.

[0004] In the field of electronic equipment assembly, the initial adhesion of polyurethane adhesives is essential to ensure the rapid positioning and fixation of components. During the electronic assembly process, adhesives need to adhere quickly to the surfaces of various materials, and initial adhesion adhesives can quickly form a seal and provide immediate protection, such as plastics, metals and flexible circuit boards. In the surface mounting process of electronic components such as resistors, capacitors and inductors, high initial adhesion adhesives can ensure that components are quickly positioned on printed circuit boards (PCBs) to prevent displacement before curing. In the manufacture of devices such as smartphones, tablets and computer monitors, initial adhesion adhesives are used to bond touch screens or displays to frames; in the bonding process between batteries and electronic devices, initial adhesion adhesives can quickly fix batteries to ensure the structural stability and safety of the device; the housings and components of electronic devices need to be sealed to prevent moisture and dust intrusion; in the bonding of flexible circuit boards to other electronic components, initial adhesion adhesives can ensure the rapid fixation of circuit boards on complex shapes or irregular surfaces; in the assembly of camera modules, initial adhesion adhesives are used to quickly fix lenses and sensors; connectors and cables in electronic devices need to be quickly fixed to avoid unstable connections or poor contact. It can be seen that initial adhesion adhesives play a key role in the assembly of electronic devices, not only improving production efficiency, but also ensuring the quality and reliability of the equipment. With the continuous development of the electronics industry, the requirements for adhesive performance are also constantly increasing to meet the needs of smaller and higher performance electronic devices.

[0005] Therefore, developing an environmentally friendly UV-moisture dual-curing adhesive with excellent initial adhesion to promote the replacement of traditional reactive polyurethane hot melt adhesive products remains an urgent problem to be solved. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol and a preparation method thereof. Carbon dioxide-based tetraol is prepared by using carbon dioxide and epoxy compounds, thereby avoiding the consumption of a large amount of fossil fuel resources and being more environmentally friendly. Modified polyurethane acrylate is synthesized by using carbon dioxide-based tetraol, diisocyanate and hydroxyl-containing acrylic derivatives, and is used to prepare ultraviolet light and moisture dual-curing adhesive. The obtained product has high initial adhesion and good moisture and heat resistance, thereby solving the problems of low initial adhesion and inability to quickly position traditional reactive polyurethane hot melt adhesive products.

[0007] In order to solve the above technical problems, the present invention provides a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol, comprising the following raw material components in parts by weight: 49 to 75 parts of modified polyurethane acrylate, 19 to 29 parts of reactive diluent, 0.5 to 4 parts of photoinitiator, 0.05 to 3.5 parts of first inhibitor and 1 to 6 parts of auxiliary agent; the general formula of the modified polyurethane acrylate is:

[0008]

[0009] Among them, the R 1 is a tetrabasic acid group, R 2 is H or alkyl, n is an integer from 5 to 20, R 3 is an alkyl group, R 4 It is an aliphatic, alicyclic, aromatic or aliphatic-aromatic group.

[0010] The present invention uses modified polyurethane acrylate, reactive diluent and free radical photoinitiator as raw materials to prepare a moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol. Among them, double bonds are introduced into the modified polyurethane acrylate, which has photosensitivity and can achieve rapid reaction under ultraviolet light to form a cross-linked network, achieving a higher initial adhesion. In practical applications, it has a faster positioning speed and a higher initial adhesion, effectively reducing equipment energy loss and accelerating production efficiency; at the same time, isocyanate groups are introduced into the modified polyurethane acrylate, which can react with moisture in the air after initial positioning, further improving the cross-linking density, so that the prepared ultraviolet light and moisture dual-curing adhesive has higher cohesive strength and adhesion.

[0011] Further, the active diluent is selected from one or more of isobornyl acrylate, isobornyl methacrylate, isooctyl acrylate, isooctyl methacrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, ethoxylated trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, n-butyl acrylate, isodecyl acrylate, lauric acid acrylate, cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, dicyclopentenyl acrylate, and pentaerythritol tetraacrylate.

[0012] Further, the photoinitiator is selected from one or more of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2,2-dimethoxy-2-phenylacetophenone, methyl benzoylformate, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexylphenyl ketone.

[0013] Furthermore, the auxiliary agent is selected from one or more of a curing accelerator, a stabilizer, a diluent, a toughening agent, a flame retardant, a pigment and a filler.

[0014] The second aspect of the present invention provides a method for preparing the moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to the first aspect, comprising the following steps:

[0015] S1, mixing carbon dioxide-based tetraol, diisocyanate and catalyst, reacting at 40-50° C. for 3-5 hours to obtain modified polyurethane;

[0016] S2, mixing the modified polyurethane, hydroxyl-containing acrylic acid derivative, antioxidant and second polymerization inhibitor at 70-80° C. until the NCO mass content is 4%-8%, to obtain the modified polyurethane acrylate;

[0017] S3. Mix the modified polyurethane acrylate, reactive diluent, photoinitiator, first inhibitor and auxiliary agent, and stir for 1 to 5 hours under vacuum degree -0.005 MPa to -0.2 MPa and temperature 20 to 40° C. to obtain a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol.

[0018] The present invention uses carbon dioxide-based tetraol and diisocyanate to synthesize modified polyurethane. The carbonate bond in the oligomer has high polarity and can form hydrogen bonds with carbamate groups. The cohesive energy between molecular chain segments is large, the polyurethane has high tensile strength, and the interface force on metal and plastic interfaces is large, and the bonding strength is large. In addition, the carbonate bond is not easy to hydrolyze in water and has a low water swelling rate, thereby improving the moisture and heat resistance of the ultraviolet light moisture dual-curing adhesive to cope with more complex and harsh application environments.

[0019] Furthermore, the molar ratio of the carbon dioxide-based tetraol, diisocyanate, and hydroxyl-containing acrylic acid derivative is 1:(4-4.2):(2-2.4).

[0020] Furthermore, the preparation method of the carbon dioxide-based tetraol is: mixing an epoxy compound, a tetrabasic acid, and a double metal cyanide complex catalyst, introducing CO 2 , reacting at 100-150° C. for 6-15 hours to obtain the carbon dioxide-based tetraol. The carbon dioxide-based tetraol is synthesized by carbon dioxide gas and epoxides, which opens up an artificial carbon cycle process, reduces the use of traditional petroleum-based raw materials, and can reduce dependence on petroleum resources.

[0021] Furthermore, the epoxy compound is selected from one or more of ethylene oxide, propylene oxide and butylene oxide.

[0022] Furthermore, the tetracarboxylic acid is selected from one or more of ethylenediaminetetraacetic acid, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2,3-propanetetracarboxylic acid, 1,1,4,4-butanetetracarboxylic acid, and 1,2,4,5-benzenetricarboxylic acid.

[0023] Furthermore, the double metal cyanide complex catalyst is K 3 Co(CN) 6 and / or Zn 3 Co(CN) 6 .

[0024] Furthermore, the hydroxyl-containing acrylic acid derivative is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate, hydroxyethyl acrylamide, hydroxypropyl methacrylate and hydroxypropyl acrylate.

[0025] Furthermore, the diisocyanate is selected from one or more of aliphatic, alicyclic, aromatic, and aliphatic-aromatic diisocyanates.

[0026] Further, the aliphatic and alicyclic diisocyanates are selected from ethylene diisocyanate, 1,1-ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, trimethylene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate (HMDI), 1,6 -hexamethylene diisocyanate (HDI), 1-isocyanato-2-diisocyanatomethylcyclopentane, 1-isocyanato-3-isocyanato-methyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or IPDI), bis-(4-isocyanatocyclohexyl)-methane, 2,4-dicyclohexylmethane diisocyanate, 1,3- or 1,4-bis-(isocyanatomethyl)-cyclohexane, bis-(4-isocyanato-3-methylcyclohexyl)-methane, 1-isocyanato-1-methyl-4(3)-isocyanatomethylcyclohexane, 2,4- or 2,6-hexahydrotoluene diisocyanate.

[0027] Furthermore, the first polymerization inhibitor and the second polymerization inhibitor are independently selected from one or more of p-hydroxyanisole, p-benzoquinone, hydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, phenothiazine and naphthoquinone.

[0028] Further, the antioxidant is selected from one or more of 2,6-di-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.

[0029] Furthermore, in S1, the catalyst is one or more of stannous octoate, dibutyltin dilaurate, and stannous octoate.

[0030] Beneficial effects of the present invention:

[0031] The present invention uses modified polyurethane acrylate, reactive diluent and free radical photoinitiator as raw materials to prepare a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol. The modified polyurethane acrylate introduces double bonds, has photosensitivity, can react quickly under ultraviolet light to form a cross-linked network, and achieves a higher initial adhesion. In practical applications, it has a faster positioning speed and a higher initial adhesion, effectively reducing equipment energy loss and accelerating production efficiency; at the same time, the modified polyurethane acrylate introduces isocyanate groups, which can react with moisture in the air after initial positioning, further improving the cross-linking density, so that the prepared ultraviolet light and moisture dual-curing adhesive has higher cohesive strength and adhesion.

[0032] The present invention uses carbon dioxide-based tetraol and diisocyanate to synthesize modified polyurethane, thereby avoiding the consumption of a large amount of fossil fuel resources by adhesive raw material components, reducing dependence on petroleum resources, and being more environmentally friendly; at the same time, the carbonate bond in the oligomer has a large polarity and can form a hydrogen bond with the carbamate group, the cohesive energy between the molecular chain segments is large, the tensile strength is high, the interface force on the metal and plastic interface is large, and the bonding strength is large; and the carbonate bond is not easy to hydrolyze in water and has a low water swelling rate, thereby improving the moisture and heat resistance of the UV light moisture dual-curing adhesive to cope with more complex and harsh application environments. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0034] Example 1

[0035] (1) Dry the autoclave in advance, then add 1g of K 3 Co(CN) 6, 10g of ethylenediaminetetraacetic acid and 780g of propylene oxide were added to the above reactor to replace CO 2 gas, and then 10MPa of CO 2 The gas was stirred at 100°C for 10 hours to obtain carbon dioxide-based tetraol.

[0036] (2) In a three-necked flask equipped with a thermometer, 134 g of isophorone diisocyanate and 50 mg of dibutyltin dilaurate were added, the temperature was raised to 50° C., 100 g of carbon dioxide-based tetraol was added in batches, and the mixture was stirred for reaction for 5 h to obtain a modified polyurethane.

[0037] (3) In a three-necked flask with a thermometer, the modified polyurethane obtained in step (2), 33 g of hydroxyethyl acrylate, 200 mg of 2,6-di-tert-butyl-4-methylphenol and 50 mg of hydroquinone are added under light-proof conditions, the temperature is maintained at 80° C., the NCO content is tested every 30 minutes, and heating is stopped when the NCO mass content is 6%. Modified polyurethane acrylate is obtained, wherein the molar ratio of carbon dioxide-based tetraol, diisocyanate and hydroxyl-containing acrylic acid derivative is 1:4.2:2.

[0038] (4) Add 64 parts of the modified polyurethane acrylate obtained in step (3), 10 parts of isobornyl acrylate, 10 parts of tetrahydrofuran acrylate, 5 parts of 2-phenoxyethyl acrylate, 0.5 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.1 parts of hydroquinone, and auxiliary agents (1 part of silane coupling agent, 2 parts of fumed silica) into a reaction kettle by weight, and stir for 3 hours under vacuum of -0.1 MPa and temperature of 25°C to obtain a moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol.

[0039] Example 2

[0040] The difference between this embodiment and embodiment 1 is that the contents of the following components are different:

[0041] 49 parts of modified polyurethane acrylate, 7.6 parts of isobornyl acrylate, 7.6 parts of tetrahydrofuran acrylate, 3.8 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0042] Example 3

[0043] The difference between this embodiment and embodiment 1 is that the contents of the following components are different:

[0044] 58 parts of modified polyurethane acrylate, 9.2 parts of isobornyl acrylate, 9.2 parts of tetrahydrofuran acrylate, 4.6 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0045] Example 4

[0046] The difference between this embodiment and embodiment 1 is that the contents of the following components are different:

[0047] 71 parts of modified polyurethane acrylate, 10.8 parts of isobornyl acrylate, 10.8 parts of tetrahydrofuran acrylate, 5.4 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0048] Example 5

[0049] The difference between this embodiment and embodiment 1 is that the contents of the following components are different:

[0050] 75 parts of modified polyurethane acrylate, 11.6 parts of isobornyl acrylate, 11.6 parts of tetrahydrofuran acrylate, 5.8 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0051] Example 6

[0052] (1) Dry the autoclave in advance, then add 1g of K 3 Co(CN) 6 , 10g of ethylenediaminetetraacetic acid and 660g of propylene oxide were added to the above reactor to replace CO 2 gas, and then 10MPa of CO 2 The gas was stirred at 150°C for 6 hours to obtain carbon dioxide-based tetraol.

[0053] (2) In a three-necked flask equipped with a thermometer, 157 g of 4,4′-dicyclohexylmethane diisocyanate and 50 mg of dibutyltin dilaurate were added, the temperature was raised to 50° C., 100 g of carbon dioxide-based tetraol was added in batches, and the mixture was stirred for reaction for 5 h to obtain a modified polyurethane.

[0054] (3) In a three-necked flask with a thermometer, the modified polyurethane obtained in step (2), 33 g of hydroxyethyl acrylate, 200 mg of 2,6-di-tert-butyl-4-methylphenol and 50 mg of hydroquinone are added under light-proof conditions, the temperature is maintained at 80° C., the NCO content is tested every 30 minutes, and heating is stopped when the NCO mass content is 6%. Modified polyurethane acrylate is obtained, wherein the molar ratio of carbon dioxide-based tetraol, diisocyanate and hydroxyl-containing acrylic acid derivative is 1:4.2:2.

[0055] (4) Add 64 parts of the modified polyurethane acrylate obtained in step (3), 10 parts of isobornyl acrylate, 10 parts of tetrahydrofuran acrylate, 5 parts of 2-phenoxyethyl acrylate, 0.5 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.1 parts of hydroquinone, and auxiliary agents (1 part of silane coupling agent, 2 parts of fumed silica) into a reaction kettle by weight, and stir for 3 hours under vacuum of -0.1 MPa and temperature of 25°C to obtain a moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol.

[0056] Example 7

[0057] The difference between this embodiment and embodiment 8 is that the contents of the following components are different:

[0058] 49 parts of modified polyurethane acrylate, 7.6 parts of isobornyl acrylate, 7.6 parts of tetrahydrofuran acrylate, 3.8 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0059] Example 8

[0060] The difference between this embodiment and embodiment 8 is that the contents of the following components are different:

[0061] 58 parts of modified polyurethane acrylate, 9.2 parts of isobornyl acrylate, 9.2 parts of tetrahydrofuran acrylate, 4.6 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0062] Example 9

[0063] The difference between this embodiment and embodiment 8 is that the contents of the following components are different:

[0064] 71 parts of modified polyurethane acrylate, 10.8 parts of isobornyl acrylate, 10.8 parts of tetrahydrofuran acrylate, 5.4 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0065] Example 10

[0066] The difference between this embodiment and embodiment 8 is that the contents of the following components are different:

[0067] 75 parts of modified polyurethane acrylate, 11.6 parts of isobornyl acrylate, 11.6 parts of tetrahydrofuran acrylate, 5.8 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 1 is that the contents of the following components are different:

[0070] 81 parts of modified polyurethane acrylate, 12.4 parts of isobornyl acrylate, 12.4 parts of tetrahydrofuran acrylate, 6.2 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that the contents of the following components are different:

[0073] 44 parts of modified polyurethane acrylate, 6.8 parts of isobornyl acrylate, 6.8 parts of tetrahydrofuran acrylate, 3.4 parts of 2-phenoxyethyl acrylate, and other steps remain unchanged.

[0074] Comparative Example 3

[0075] 64 parts of aliphatic polyurethane acrylate (ETERCURE6148J, Changxing, Taiwan, China), 10 parts of isobornyl acrylate, 10 parts of tetrahydrofuran acrylate, 5 parts of 2-phenoxyethyl acrylate, 0.5 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 0.1 parts of hydroquinone, and auxiliary agents (1 part of silane coupling agent, 2 parts of fumed silica) were added into a reactor by weight, and stirred for 3 hours under vacuum of -0.1 MPa and temperature of 25°C to obtain a moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol.

[0076] Comparative Example 4

[0077] 33 parts of polypropylene oxide diol and 33 parts of polyhexane adipate diol (PHA) were added to the reactor, and vacuum dehydrated at 120°C for 2 hours, with the vacuum degree maintained at -0.09MPa. Then cooled to 80°C, 12 parts of tetraisocyanate were added while stirring, and then the temperature was slowly raised to 80°C, while nitrogen was filled for protection, and the reaction was carried out for 2.5 hours. Then 21 parts of terpene resin, 0.5 parts of antioxidant Irganox1010, and 0.1 parts of catalyst dibutyltin dilaurate were added. Finally, vacuum was evacuated at a temperature of 100°C until no bubbles appeared to obtain polyurethane glue.

[0078] Test Case

[0079] The shear strength and tensile strength of the products prepared in the examples and comparative examples were tested for performance.

[0080] Tensile shear strength was used to test the initial and final bonding strengths: the surface of the polycarbonate substrate was wiped with ethanol, and after the ethanol evaporated completely, a 0.2 mm aluminum foil tape was pasted on one end of the substrate, and the products obtained in the above embodiments and comparative examples were applied to one end of the polycarbonate substrate to ensure that the resin composition was evenly applied to the bonding site. Subsequently, the two substrates were overlapped and clamped with a transparent plastic clip, and the sample was placed in an ultraviolet light source (365 nm, 100 mW / cm 2 ) Radiation curing for 10 seconds and then take out after full curing; The tensile shear strength test adopts GB / T 7124-2008 standard, and the tensile shear strength test is carried out on an electronic tensile testing machine. The test temperature is 25°C and the overlap area is 312.5mm 2 , the test rate is 5mm / min.

[0081] The tensile shear strength of double 85 is used to test the bonding strength of double 85: the tensile shear strength sample of polycarbonate-polycarbonate substrate after UV curing is placed in a high temperature and high humidity test chamber, and its tensile shear strength is tested after standing for 200 hours at 85℃ and 85% relative humidity according to GB / T 5170-2016 standard; the tensile shear strength test adopts GB / T 7124-2008 standard, and the tensile shear strength test is carried out on an electronic tensile testing machine, the test temperature is 25℃, and the overlap area is 312.5mm 2 , the test speed is 5mm / min.

[0082] Tensile strength: The tensile strength test was carried out according to GB / T 528 / 92 standard. The products obtained in the above embodiments and comparative examples were placed in a dumbbell-shaped polytetrafluoroethylene mold and placed in an ultraviolet light source (365nm, 100mW / cm 2 ) Radiation cure for 10 seconds and then remove after full curing. Test the width and thickness of the narrow parallel part of the dumbbell-shaped specimen. Place the dumbbell-shaped specimen evenly on the upper and lower clamps and stretch it at a test speed of 500 mm / min to measure the tensile strength of the specimen when it breaks.

[0083] The performance test results of the products obtained in the embodiments and comparative examples are shown in Table 1:

[0084] Table 1

[0085]

[0086]

[0087] Combined with the data in Table 1, it can be seen from the comparison between Example 1 and Comparative Examples 1-2 that when the ratio of modified polyurethane acrylate and active diluent exceeds the ratio range specified in the present invention, the synergistic effect between the components is weakened, and the initial bonding strength, final bonding strength, bonding strength after double 85 and tensile strength are all weakened to a certain extent. Among them, the initial bonding strength of Comparative Example 2 is reduced to 6.32MPa, and the final bonding strength is reduced to 7.46MPa, which makes it difficult to achieve the effect of rapid positioning.

[0088] From the comparison between Example 1 and Comparative Example 3, it can be seen that Comparative Example 3 uses commercially available UV glue, which has good initial adhesion, but its resistance to high temperature and high humidity is relatively poor, because it does not have carbonate bonds that are not easily hydrolyzed in water, the water swelling rate is high, and the resistance to humidity and heat is relatively poor; at the same time, because it does not have carbonate bonds with high polarity, it cannot form hydrogen bonds with carbamate groups, the cohesive energy between molecular chain segments is small, and the tensile strength is small. Finally, Comparative Example 4 is a conventional polyurethane glue, which has low initial adhesion and cannot be quickly positioned.

[0089] The UV light moisture dual-curing adhesives prepared in Examples 1-5 and Examples 6-10 of the present invention respectively regulate the ratio of modified polyurethane acrylate, reactive diluent, photoinitiator, inhibitor and additive, and have excellent initial bonding strength, final bonding strength, bonding strength after double 85% bonding and tensile strength. Among them, the initial and final viscosity effects of Example 1 and Example 6 are the best, and the initial bonding strengths of the two are as high as 6.61MPa and 6.62MPa, respectively, and the final bonding strengths are as high as 8.1MPa and 8.2MPa, and both have excellent bonding strength and tensile strength after double 85%.

[0090] From the comparison between Example 1 and Example 6, it can be seen that the present invention achieves similar effects by adjusting the type of diisocyanate in the preparation process of modified polyurethane acrylate. The reason why the curing adhesive prepared in the example has excellent effects is that the double bonds are introduced into the modified polyurethane acrylate, which can react quickly under ultraviolet light to form a cross-linked network and achieve a higher initial adhesion. At the same time, the isocyanate group is introduced into the modified polyurethane acrylate, which can react with moisture in the air after initial positioning, further improving the cross-linking density, so that the prepared UV-moisture dual-curing adhesive has higher cohesive strength and adhesion. The bonding strength after double 85 is high, and it also has excellent tensile strength, because the carbonate bond in the oligomer has a large polarity and can form hydrogen bonds with the carbamate group. The cohesive energy between the molecular segments is large, and it has high tensile strength, and the carbonate bond is not easy to hydrolyze in water, and has a low water swelling rate, thereby improving the moisture and heat resistance of the UV-moisture dual-curing adhesive.

[0091] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A moisture-heat-resistant photocurable adhesive based on carbon dioxide-based polyol, characterized in that: The invention comprises the following raw material components in parts by weight: 49 to 75 parts of modified polyurethane acrylate, 19 to 29 parts of active diluent, 0.5 to 4 parts of photoinitiator, 0.05 to 3.5 parts of first inhibitor and 1 to 6 parts of auxiliary agent; the general formula of the modified polyurethane acrylate is: Among them, the R 1 is a tetrabasic acid group, R 2 is H or alkyl, n is an integer from 5 to 20, R 3 is an alkyl group, R 4 It is an aliphatic, alicyclic, aromatic or aliphatic-aromatic group.

2. The heat-resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 1, characterized in that: The active diluent is selected from one or more of isobornyl acrylate, isobornyl methacrylate, isooctyl acrylate, isooctyl methacrylate, tetrahydrofuran acrylate, tetrahydrofuran methacrylate, trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, ethoxylated trimethylolpropane triacrylate, 1,6-hexanediol diol diacrylate, 1,4-butanediol diacrylate, n-butyl acrylate, isodecyl acrylate, lauric acid acrylate, cyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, dicyclopentenyl acrylate, and pentaerythritol tetraacrylate.

3. The heat-resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 1, characterized in that: The photoinitiator is selected from one or more of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2,2-dimethoxy-2-phenylacetophenone, methyl benzoylformate, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-hydroxycyclohexylphenyl ketone.

4. The heat-resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 1, characterized in that: The auxiliary agent is selected from one or more of a curing accelerator, a stabilizer, a diluent, a toughening agent, a flame retardant, a pigment and a filler.

5. A method for preparing a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to any one of claims 1 to 4, characterized in that: The steps include: S1, mixing carbon dioxide-based tetraol, diisocyanate and catalyst, reacting at 40-50° C. for 3-5 hours to obtain modified polyurethane; S2, mixing the modified polyurethane, hydroxyl-containing acrylic acid derivative, antioxidant and second polymerization inhibitor, and reacting at 70-80° C. until the NCO mass content is 4%-8%, to obtain the modified polyurethane acrylate; S3. Mix the modified polyurethane acrylate, reactive diluent, photoinitiator, first inhibitor and auxiliary agent, and stir for 1 to 5 hours under vacuum degree -0.005 MPa to -0.2 MPa and temperature 20 to 40° C. to obtain a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol.

6. The method for preparing the moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 5, characterized in that: The molar ratio of the carbon dioxide-based tetraol, diisocyanate and hydroxyl-containing acrylic acid derivative is 1:(4-4.2):(2-2.4).

7. The method for preparing a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 5, characterized in that: The preparation method of the carbon dioxide-based tetraol is as follows: an epoxy compound, a tetrabasic acid, and a double metal cyanide complex catalyst are mixed, CO2 is introduced, and the mixture is reacted at 100 to 150° C. for 6 to 15 hours to obtain the carbon dioxide-based tetraol; the tetrabasic acid is selected from one or more of ethylenediaminetetraacetic acid, 1,1,2,2-ethanetetracarboxylic acid, 1,1,2,3-propanetetracarboxylic acid, 1,1,4,4-butanetetracarboxylic acid, and 1,2,4,5-benzenetricarboxylic acid.

8. The method for preparing a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 5, characterized in that: The hydroxyl-containing acrylic acid derivative is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate, hydroxyethyl acrylamide, hydroxypropyl methacrylate and hydroxypropyl acrylate.

9. The method for preparing a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 5, characterized in that: The diisocyanate is selected from one or more of aliphatic, alicyclic, aromatic and aliphatic-aromatic diisocyanates.

10. The method for preparing a moisture-heat resistant photocurable adhesive based on carbon dioxide-based polyol according to claim 5, characterized in that: In S1, the catalyst is one or more of stannous octoate, dibutyltin dilaurate, and stannous octoate.

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