A UV light-curing resin composition and its preparation method and application

Abstract

The present invention discloses a UV-curable resin composition, a preparation method and an application thereof. The UV-curable resin composition comprises the following components in parts by mass: 40-60 parts of an unsaturated monomer, 60-90 parts of a polythiol compound, 1-6 parts of a photoinitiator, and 0.1-1 part of a polymerization inhibitor; the unsaturated monomer contains at least one of a substituted or unsubstituted aromatic ring, heteroaromatic ring, and carbocyclic ring; the structure of the polythiol compound is as follows: wherein, R is one of H, F, Cl, methyl, and trifluoromethyl, and R<supgt;1< / supgt; and R<supgt;2< / supgt> are each an alkylene group having 2 to 18 carbon atoms. After the resin composition containing the specific unsaturated monomer and polythiol compound is cured by UV light irradiation, it exhibits high adhesive strength, high toughness, and good heat and humidity resistance, and has a high storage modulus at both room temperature and high temperature, which can effectively improve the stability and reliability of the adhesive layer at room temperature / high temperature, and has good application prospects in aspects such as electronic component sealing or bonding.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to a UV light-curing resin composition and a preparation method and application thereof. Background Art

[0002] In the manufacturing process of image sensor modules for mobile phones and other electronic products, adhesives or sealants with excellent mechanical properties, electrical properties, heat resistance, chemical resistance, and bonding strength are often required. In addition, in the assembly and assembly of electronic components, for the purpose of maintaining reliability, adhesives and sealants with high bonding strength, good moisture and heat resistance, and high reliability are required regardless of the material of the bonded material.

[0003] UV light-curing adhesives do not require heating during curing and can be cured quickly by UV light initiation, which can effectively avoid damage to electronic devices caused by high temperatures. Therefore, they are currently one of the main types of adhesives used for bonding or sealing electronic components. However, the traditional acrylate free radical UV light-curing system is easily affected by oxygen inhibition during the UV light curing process due to the reaction mechanism of free radical chain self-polymerization. Therefore, the oxygen inhibition effect will bring many inconveniences to the light-curing process and reduce the performance of the light-curing product. The mercapto-ene system is a new type of UV light-curing system. The gradually increasing reaction mechanism makes the inhibition effect of oxygen on its light-curing process very small. Therefore, no inert gas protection is required during curing, the light initiation efficiency is greatly improved, and the amount of photoinitiator can be reduced. Then, the existing mercapto-ene UV light curing system (for example, a sealant for display elements disclosed in CN105706264A) mainly has the following problems: (1) the thiol compound used contains an ester bond structure that is easily hydrolyzed, which inevitably causes the product to have poor hydrolysis resistance; (2) the polythiol curing agent used in the mercapto-ene UV light curing system has insufficient mercapto functional groups, low crosslinking density after curing, low bonding strength, low storage modulus at room temperature and high temperature conditions, and poor connection reliability.

[0004] Based on this, there is an urgent need for a UV-curable resin composition that has high bonding strength, good toughness, high storage modulus and good resistance to moisture and heat hydrolysis after curing, so as to meet the high performance requirements of the adhesive such as bonding strength and reliability in the bonding and packaging of electronic components. Summary of the invention

[0005] To solve the above problems, the present invention provides a UV light-curable resin composition and a preparation method and application thereof. Under the synergistic effect of an unsaturated monomer with a specific structure and a homemade polythiol compound, the prepared UV light-curable resin composition can be quickly cured under UV light to form a glue layer with a high cross-linking density. The glue layer has high bonding strength, good toughness, and good resistance to moisture and heat hydrolysis, and can maintain a relatively high storage modulus at room temperature and high temperature environments, thereby effectively improving the stability and reliability of the glue layer at room temperature / high temperature, and has good application prospects in sealing or bonding electronic parts.

[0006] Specifically, the following technical solutions are provided:

[0007] The first aspect of the present invention provides a UV light-curable resin composition, which comprises the following components in parts by mass: 40-60 parts of an unsaturated monomer, 60-90 parts of a polythiol compound, 1-6 parts of a photoinitiator, and 0.1-1 parts of an inhibitor;

[0008] The unsaturated monomer comprises a first monomer containing three carbon-carbon double bonds, a second monomer containing two carbon-carbon double bonds, and a third monomer containing a single carbon-carbon double bond, and the first monomer, the second monomer, and the third monomer all contain at least one of an aromatic ring, an aromatic heterocycle, and a carbon ring;

[0009] The mass ratio of the first monomer to the second monomer and the third monomer is 1:(0.05-0.2):(0.05-0.25);

[0010] The structure of the polythiol compound is as follows:

[0011]

[0012] Wherein, R is one of H, F, Cl, methyl, and trifluoromethyl, and R 1 , R 2 They are C2-C18 alkylene respectively.

[0013] Furthermore, the aromatic ring includes but is not limited to a benzene ring, the aromatic heterocyclic ring includes but is not limited to a s-triazine ring, and the carbon ring includes but is not limited to adamantane.

[0014] Further, the first monomer is preferably triallyl isocyanurate, the second monomer is preferably bisphenol A diallyl ether, and the third monomer is preferably 2-adamantyl acrylate, including but not limited to the monomer types listed above. More preferably, the mass ratio of the first monomer to the second monomer and the third monomer is preferably 1: (0.07-0.15): (0.07-0.22).

[0015] Based on the current mercapto-ene UV light-curing system, there are problems such as low bonding strength, poor hydrolysis resistance, and low storage modulus. When used in electronic component bonding or packaging, it will lead to poor product reliability. To solve the above problems, the present invention provides a novel UV light-curing resin composition, which uses a first monomer (such as triallyl isocyanurate) with a rigid ring structure and three carbon-carbon double bonds as the main monomer, so that the cross-linking density of the resin composition after light curing is large, providing basic mechanical properties; at the same time, an appropriate amount of a second monomer (such as bisphenol A diallyl ether, which has a bisphenol-type structure to improve the bonding force) and a third monomer (such as 2-adamantyl acrylate, which has an alicyclic chain and provides toughness) are introduced to adjust the toughness of the light-cured adhesive layer. By mixing the above three monomers in an appropriate ratio, the resin composition, after UV curing, has good flexibility and a high storage modulus under the premise that the bonding strength meets the use range, so that the adhesive layer will not lose strength because it is too soft, nor will it crack because it is too hard, thereby having excellent moisture and heat resistance. On this basis, the present invention adopts a homemade biphenyl type polythiol compound as a thiol curing agent, wherein the compound molecule contains a rigid biphenyl structure and four flexible alkylthiol groups, and the two alkylthiol groups distributed on the benzene ring are ortho positions, and the compound is used as a curing agent to cure the resin, wherein the biphenyl structure of the curing agent can give the cured resin good heat resistance, and the four thiol groups with a specific position structure can further improve the heat resistance of the cured resin and significantly improve the toughness of the cured resin through high crosslinking density, and the compound does not have an easily hydrolyzed group, and the resin composition containing the curing agent can produce a high crosslinking density after curing and is not easy to hydrolyze, thereby significantly improving the bonding strength, heat and moisture resistance, toughness, etc. of the cured resin. Under the synergistic effect of the above-mentioned monomers and the specific thiol curing agent (self-made polythiol compound), the resin composition exhibits high bonding strength and high toughness after UV curing, and still maintains a relatively high bonding strength after high temperature and high humidity aging, and has a relatively high storage modulus at room temperature and high temperature environment, and can be used as an adhesive or sealant for bonding or packaging of electronic components, which is beneficial to improving the reliability of electronic products.

[0016] Furthermore, in the structure of the polythiol compound, R is H, and R 1 , R 2 All are straight chain C3 alkylene.

[0017] Furthermore, the preparation method of the mercaptan curing agent comprises the following steps:

[0018] (1) reacting a compound represented by Formula I and a compound represented by Formula II in the presence of a first base reagent, a first phase transfer catalyst and a first solvent to obtain a first intermediate product represented by Formula III;

[0019] (2) heating the first intermediate product to obtain a second intermediate product represented by formula IV;

[0020] (3) reacting the second intermediate product with the compound represented by formula V in the presence of a second base reagent, a second phase transfer catalyst and a second solvent to obtain a third intermediate product represented by formula VI;

[0021] (4) reacting the third intermediate product with thioacetic acid in the presence of a free radical initiator and a third solvent to obtain a fourth intermediate product represented by formula VII;

[0022] (5) reacting the fourth intermediate product with an acid reagent or a base reagent in the presence of a fourth solvent to obtain the thiol curing agent;

[0023] The structures of the above formula I to formula VII are as follows:

[0024]

[0025] Wherein, R is one of H, F, Cl, methyl, and trifluoromethyl;

[0026] X is Cl or Br;

[0027] h is 1, and l is any integer from 0 to 16.

[0028] In some preferred embodiments, in step (1), the first alkaline reagent can be selected from one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, and p-dimethylaminopyridine; the first phase transfer catalyst is selected from one or more of crown ethers, onium salts, ammonium salts, sulfonium salts, arsenic salts, polyethers, non-cyclic polyethers, and tertiary amine catalysts; the first solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 60-90°C, and the reaction time is 6-15h.

[0029] In some preferred embodiments, in step (2), the heating reaction temperature is 150-250° C., and the heating reaction time is 10-18 h.

[0030] In some preferred embodiments, in step (3), the second alkaline reagent can be selected from one or more of potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, and p-dimethylaminopyridine; the second phase transfer catalyst can be selected from one or more of crown ethers, onium salts, ammonium salts, sulfonium salts, arsenic salts, polyethers, non-cyclic polyethers, and tertiary amine catalysts; the second solvent can be selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 60-90°C, and the reaction time is 6-15h.

[0031] In some preferred embodiments, in step (4), the free radical initiator is selected from one or more of azo, organic peroxide and redox initiators, such as azobisisobutyronitrile or benzoyl peroxide; the third solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol and methanol; the reaction temperature is 60-90°C, and the reaction time is 15-25h.

[0032] In some preferred embodiments, in step (5), the acid reagent is hydrochloric acid and / or sulfuric acid, and the base reagent includes but is not limited to sodium hydroxide; the fourth solvent is selected from one or more of acetone, ethyl acetate, tetrahydrofuran, N,N'-dimethylformamide, dichloromethane, dioxane, ethanol, and methanol; the reaction temperature is 55-95°C, and the reaction time is 25-40h.

[0033] Furthermore, the ratio of the total molar amount of carbon-carbon double bonds (derived from the unsaturated monomer) to the total molar amount of thiol groups (derived from the polythiol compound) in the UV light-curable resin composition is preferably 1:(0.9-1.2), for example, 1:0.9, 1:1, 1:1.1, 1:1.2, etc., including but not limited to the ratios listed above, and more preferably 1:1.1.

[0034] Further, the 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-dimethylamino-1-(4-morpholinylbenzylphenyl)butanone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinylphenyl)-1-butanone. Ketone, 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 one or more of 2-ethylanthraquinone; in some preferred embodiments, the photoinitiator is 2,2-dimethoxy-2-phenylacetophenone.

[0035] Furthermore, the polymerization inhibitor is selected from one or more of hydroquinone, p-hydroxyanisole, p-benzoquinone, methylhydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 4-hydroxypiperidinol oxygen free radical, phenothiazine, and anthraquinone; in some preferred embodiments, the polymerization inhibitor is p-hydroxyanisole.

[0036] Furthermore, the UV light-curable resin composition further comprises 0.1-5 parts of a coupling agent and 0.1-20 parts of an auxiliary agent.

[0037] Furthermore, the coupling agent is selected from one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 8-epoxypropoxyoctyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane.

[0038] Furthermore, the auxiliary agent is selected from one or more of fillers, antioxidants, stabilizers, flame retardants, diluents, pigments, defoamers, leveling agents, leveling agents, ion capture agents, such as fumed silica.

[0039] The second aspect of the present invention provides a method for preparing the UV light-curing resin composition described in the first aspect, wherein each component is weighed according to a formula and mixed evenly under light-proof conditions to obtain the UV light-curing resin composition.

[0040] The third aspect of the present invention provides a use of the UV light-curable resin composition described in the first aspect in preparing an adhesive for sealing or bonding electronic components.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The invention provides a UV light-curable resin composition, comprising three unsaturated monomers containing different carbon-carbon double bond functionalities and ring structures and a polythiol compound with a specific structure. Under the synergistic effect of the above monomers and the specific polythiol compound, the resin composition exhibits high bonding strength and good toughness after UV curing, still maintains relatively high bonding strength after high-temperature and high-humidity aging, and has a relatively high storage modulus at room temperature and high-temperature environments. The resin composition can be used as an adhesive or sealant in the bonding or packaging of electronic components, which is beneficial to improving the reliability of electronic products.

[0043] The thiol curing agent used in the present invention has low preparation cost and is suitable for industrial mass production; more importantly, the thiol curing agent is in liquid state at room temperature and has low viscosity, and can be directly used as a curing agent in the curing process of a UV light-curable resin composition, so that the resin composition can be quickly cured by UV light at room temperature, and the internal stress and shrinkage degree generated during curing are small. Compared with other thiol curing agents, the resin composition cured by the thiol curing agent exhibits low water absorption, better bonding strength and moisture and heat resistance, etc., and is more suitable for bonding and sealing of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 1 H-NMR spectrum;

[0045] Figure 2 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 13 C-NMR;

[0046] Figure 3 This is the IR spectrum of 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1. DETAILED DESCRIPTION

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. The symbol "-" between two numbers herein means "to", for example, "40-60 parts of unsaturated monomers" means "40 to 60 parts of unsaturated monomers".

[0048] The present invention is further described below in conjunction with the accompanying drawings and 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.

[0049] The sources of some of the raw materials used in the following examples and comparative examples are as follows:

[0050]

[0051] The structure of commercial polythiol PEMP is shown below:

[0052]

[0053] The preparation of the biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl used in the following examples and comparative examples is as follows:

[0054] (1) 18.6 g of 4,4'-dihydroxybiphenyl and 36.3 g of allyl bromide were dissolved in 250 mL of acetone, and then 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added, and the mixture was stirred at 70° C. for 12 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation, and the filtrate was washed with water and dried to obtain a first intermediate product with a yield of 94%;

[0055] (2) 26.6 g of the first intermediate product was heated to 200° C. under N2 protection for 13 h, and purified to obtain the second intermediate product with a yield of 84%;

[0056] (3) 26.6 g of the second intermediate product and 36.3 g of allyl bromide were dissolved in 250 mL of acetone, 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added, and the mixture was stirred at 70° C. for 10 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation, and the filtrate was washed with water and dried to obtain a third intermediate product with a yield of 89%;

[0057] (4) 34.7 g of the third intermediate product and 45.7 g of thioacetic acid were dissolved in 300 mL of tetrahydrofuran, and 3.3 g of azobisisobutyronitrile was added. The mixture was stirred at 65° C. for 16 h under N2 protection. After filtering, the solvent and excess raw materials in the filtrate were removed by reduced pressure distillation. The filtrate was washed with water and dried to obtain a fourth intermediate product with a yield of 80%;

[0058] (5) 65.1 g of the fourth intermediate product and 10 g of concentrated hydrochloric acid were dissolved in 150 mL of tetrahydrofuran and 150 mL of methanol, and the mixture was stirred at 65° C. for 33 h under N2 protection. The solvent and excess raw materials in the filtrate were removed by vacuum distillation after filtration, and the mixture was washed with water and dried to obtain a liquid product 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl. Its H NMR spectrum, C NMR spectrum and IR spectrum were as follows: Figure 1-3 As shown, 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl was prepared.

[0059] Example 1

[0060] The present embodiment provides a UV light-curable resin composition, which includes the following components in parts by mass: 40 parts of triallyl isocyanurate, 4 parts of bisphenol A diallyl ether, 5 parts of 2-adamantyl acrylate, 71 parts of biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl, 1 part of photoinitiator 2,2-dimethoxy-2-phenylacetophenone, 1 part of fumed silica, 1 part of silane coupling agent and 0.3 parts of inhibitor p-hydroxyanisole.

[0061] The above raw materials are mixed uniformly at room temperature and protected from light, and then degassing is performed. The discharged materials are packaged into black or brown sealed rubber tubes to obtain a resin composition.

[0062] Examples 2-9 and Comparative Examples 1-8

[0063] Examples 2-9 and Comparative Examples 1-8 respectively provide a UV light-curable resin composition, which differs from Example 1 only in that the type or content of the monomer and / or curing agent in the resin composition formula is different, and the rest are the same.

[0064] The types of monomers and curing agents in the UV light-curable resin compositions prepared in Examples 1-9 and Comparative Examples 1-8 are shown in Table 1 below, wherein the thiol curing agent A is a homemade biphenyl type polythiol compound 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl, the thiol curing agent B is a commercial polythiol PEMP, and the thiol curing agent C is 5,5'-bis(3-mercaptopropyl)-2,2'-bis(3-mercaptopropoxy)biphenyl:

[0065] Table 1

[0066]

[0067] In the table, a / b is the ratio of the molar amount of carbon-carbon double bonds to the molar amount of mercapto groups in the resin composition.

[0068] Performance Testing

[0069] The performance tests of the resin compositions prepared in the above examples and comparative examples are as follows:

[0070] Curing conditions: squeeze out the glue from the hose using a dispensing machine, then use a UV light source (wavelength 365nm, light intensity 1000mW / cm 2 ) Radiation curing for 15 seconds to obtain a cured sample.

[0071] Glass transition temperature (°C): The test was carried out using the Q-800 dynamic mechanical analysis tester (DMA) of TA Instruments of the United States. The resin compositions prepared in the above embodiments and comparative examples were completely cured and made into 42 mm × 8 mm × 0.3 mm sheets. The change of the loss factor (tan δ) with temperature was measured in a liquid nitrogen atmosphere and film stretching mode within the temperature range of -40 to 250°C. The heating rate was 10°C / min and the test frequency was 10 Hz, so as to determine the glass transition temperature Tg (°C) of the resin composition after curing. The smaller the Tg value, the better the toughness of the resin after curing.

[0072] Bonding strength (MPa): The resin compositions prepared in the above embodiments and comparative examples were respectively coated on sheets to prepare test samples with a bonding area of ​​25.4 mm × 5 mm and a thickness of the adhesive layer of 0.1 mm. The test samples were cured respectively, and then the two sheets of the completely cured samples were pulled apart in opposite directions using a universal testing machine and tested at an ambient temperature of 25°C. The measured force values ​​were recorded as strength (MPa). The cured samples were subjected to heating and humidification conditions of 85°C / 85%RH / 750h, and the shear bonding strength (MPa) of the samples was tested again at an ambient temperature of 25°C and recorded.

[0073] Storage modulus (MPa): Storage modulus refers to the amount of energy stored in a material due to elastic (reversible) deformation when it is deformed, reflecting the elasticity of the material. The dynamic mechanical properties of the sample were tested using the Q800 dynamic thermomechanical analyzer from TA in the United States. The resin composition prepared in the above embodiments and comparative examples was completely cured to form a 30mm×10mm×1mm sheet. The test was conducted in a single cantilever mode with a temperature range of 30 to 200°C, a heating rate of 3K / min, a vibration frequency of 1Hz, and an amplitude of 10μm. The storage modulus (MPa) of the cured resin composition at 25°C and 80°C was determined respectively.

[0074] The above test results are shown in Table 2 below:

[0075] Table 2

[0076]

[0077] As can be seen from Table 2, the UV light-curable resin composition prepared in Examples 1-8 exhibits a relatively high bonding strength after UV curing at room temperature, which is better than the bonding strength of the UV light-curable resin composition (Comparative Example 1) prepared using commercial polythiol PEMP as a curing agent; and it can still maintain high bonding strength after heating and humidification treatment, showing excellent moisture and heat resistance, while the bonding strength of the UV light-curable resin composition prepared in Comparative Example 1 after curing is significantly reduced after heating and humidification treatment. This is because the polythiol PEMP used contains an easily hydrolyzed ester bond structure, resulting in poor hydrolysis resistance of the formed adhesive layer. In addition, the UV light-curable resin composition prepared in the above embodiments has good toughness and a relatively high storage modulus at room temperature and high temperature, and the products bonded or sealed therewith have better reliability.

[0078] It can be seen from Example 1 and Comparative Example 2 that the position of the alkylthiol group on the benzene ring in the polythiol compound will affect the crosslinking density of the adhesive layer after the resin composition is cured, and further affect the toughness, bonding strength, moisture and heat resistance, and storage modulus of the adhesive layer. Among them, the two alkylthiol groups on the benzene ring in the thiol curing agent used in Example 1 are ortho-positioned, and the adhesive layer prepared by curing the epoxy resin with the compound has better toughness, bonding strength, moisture and heat resistance, and storage modulus.

[0079] It can be seen from Examples 1, 6, 7 and Comparative Examples 3 and 4 that the content of the monomer, the content of the curing agent and the ratio a / b of the two will affect the performance of the resin composition after curing, especially the effect on the bonding strength and storage modulus. Among them, if the relative content of the monomer is too little (Comparative Example 3) or the relative content of the curing agent is too much (Comparative Example 4), and the ratio a / b does not fall within the preferred range of 0.9-1.2, the bonding strength of the prepared resin composition is significantly reduced, and the storage modulus is reduced.

[0080] It can be seen from Example 1 and Comparative Examples 5 and 6 that the second monomer and the third monomer are both indispensable in the resin composition. The lack of the second monomer or the third monomer will cause the bonding strength of the prepared resin composition (such as Comparative Examples 5 and 6) to drop significantly, and the storage modulus will be significantly reduced, and the reliability of the product bonded or sealed therewith is poor. In addition, it can be seen from Example 1 and Comparative Examples 7 and 8 that the content of the second monomer and the third monomer in the UV light-curable resin composition protected by the present invention should not be too much. Too much content of the second monomer will cause the toughness of the UV light-curable resin composition to deteriorate and the strength to be reduced. Although too much content of the third monomer will improve the toughness of the adhesive layer after the resin composition is cured, the adhesive layer is too soft and will cause the adhesive strength of the adhesive layer to decrease. Therefore, the content of the three monomers in the resin composition needs to be controlled in a suitable range, for example, 1: (0.05-0.2): (0.05-0.25), more preferably 1: (0.07-0.15): (0.07-0.22), so as to obtain an adhesive layer with both high bonding strength and good toughness.

[0081] In summary, the present invention introduces three monomers with specific structures into the UV light-curable resin composition, and by controlling the content ratio of the three monomers and coordinating with a specific thiol curing agent (self-made polythiol compound), the UV light-curable resin composition can exhibit high bonding strength and high toughness after UV curing, and still maintains a relatively high bonding strength after high-temperature and high-humidity aging, and has a relatively high storage modulus at room temperature and high-temperature environments. It can be used as an adhesive or sealant for bonding or packaging of electronic components, effectively improving the reliability of electronic products.

[0082] 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 UV light-curable resin composition, characterized in that: The UV light-curable resin composition comprises the following components by mass: 40-60 parts of unsaturated monomers, 60-90 parts of polythiol compounds, 1-6 parts of photoinitiators, and 0.1-1 parts of inhibitors; The unsaturated monomer comprises a first monomer containing three carbon-carbon double bonds, a second monomer containing two carbon-carbon double bonds, and a third monomer containing a single carbon-carbon double bond, and the first monomer, the second monomer, and the third monomer all contain at least one of an aromatic ring, an aromatic heterocycle, and a carbon ring; The mass ratio of the first monomer to the second monomer and the third monomer is 1:(0.05-0.2):(0.05-0.25); The structure of the polythiol compound is as follows: ， Wherein, R is one of H, F, Cl, methyl, and trifluoromethyl, and R 1 , R 2 are C2-C18 alkylene respectively; The ratio of the total molar amount of carbon-carbon double bonds to the total molar amount of mercapto groups in the UV light-curable resin composition is 1:(0.9-1.2).

2. The UV light-curable resin composition according to claim 1, characterized in that: The first monomer is triallyl isocyanurate; The second monomer is bisphenol A diallyl ether; The third monomer is 2-adamantyl acrylate.

3. The UV light-curable resin composition according to claim 2, characterized in that: The mass ratio of the first monomer to the second monomer and the third monomer is 1:(0.07-0.15):(0.07-0.22).

4. The UV light-curable resin composition according to claim 1, characterized in that: In the structure of the polythiol compound, R is H, and R 1 , R 2 All are straight chain C3 alkylene.

5. The UV light-curable resin composition according to claim 1, characterized in that: The photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylphenyl propiotone, 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)-1-(4-morpholinylphenyl)-1-butanone, 1,1'-(methylenedi-4-thiophenyl ... ,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 one or more of 2-ethylanthraquinone; The polymerization inhibitor is selected from one or more of hydroquinone, p-hydroxyanisole, p-benzoquinone, methylhydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 4-hydroxypiperidinol oxygen free radical, phenothiazine, and anthraquinone.

6. The UV light-curable resin composition according to claim 1, characterized in that: The UV light-curable resin composition further comprises 0.1-5 parts of a coupling agent and 0.1-20 parts of an auxiliary agent.

7. The UV light-curable resin composition according to claim 6, characterized in that: The coupling agent is selected from one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 8-epoxypropoxyoctyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane; The auxiliary agent is selected from one or more of fillers, antioxidants, stabilizers, flame retardants, diluents, pigments, defoamers, leveling agents, leveling agents, and ion capture agents.

8. A method for preparing the UV light-curable resin composition according to any one of claims 1 to 7, characterized in that: The components are weighed according to the formula and mixed evenly under light-proof conditions to obtain the UV light-curable resin composition.

9. Use of the UV light-curable resin composition according to any one of claims 1 to 7 in preparing an adhesive for sealing or bonding electronic components.

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