Photo-thermal dual-curing resin composition as well as preparation method and application thereof

Abstract

The invention discloses a photo-thermal dual-curing resin composition as well as a preparation method and application thereof, and the photo-thermal dual-curing resin composition comprises the following components in parts by mass: 50-80 parts of bisphenol A epoxy resin, 5-8 parts of dicyclopentadiene epoxy resin, 50-110 parts of a photosensitive compound, 20-100 parts of a curing agent and 0.5-5 parts of a curing accelerator, 1-5 parts of a photoinitiator, 0.5-3.5 parts of a stabilizer, 0.1-1 part of a polymerization inhibitor, 0.5-7 parts of a silane coupling agent and 1-10 parts of a filler; the ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is (0.6-1.32): 1; the structure of the curing agent is as follows: # imgabs0 #, wherein R1 and R2 are respectively C2-C18 alkylene groups. The resin composition provided by the invention can realize low-temperature illumination pre-curing so as to achieve the purpose of rapid positioning, meanwhile, an adhesive layer can have high bonding strength through further thermosetting, so that the application requirements of rapid positioning and high bonding strength are met, and the formed adhesive layer has good humidity and heat resistance and high storage modulus, and is suitable for being used in the field of electronic devices. And the reliability of the product can be effectively improved.

Description

Technical Field

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

[0002] As the requirements for miniaturization, lightweight and high performance of electronic products become higher and higher, the performance requirements for adhesives used for bonding, sealing and coating of electronic components are also gradually increasing. In the electronics manufacturing industry, adhesives used for connecting electronic components need to have high bonding strength and moisture and heat resistance to ensure that electronic components do not shift during product transportation and use, thereby ensuring the reliability of electronic products. However, in the actual production process, in order to ensure that each electronic component is in the correct position, adhesives are usually required to be used for preliminary assembly and positioning of each electronic component. Traditional thermosetting resin systems require high temperatures and a long time to complete the curing process, so they cannot achieve rapid positioning during the assembly of electronic components, and the high curing temperature will damage high temperature sensitive materials; UV light curing resin systems can be rapidly cured by UV light, but the shaded parts are often not completely cured, so the effective bonding of electronic components cannot be guaranteed. Therefore, a light / heat dual-curing resin system that can achieve rapid photocuring positioning and heat-curing bonding has been proposed. This type of system usually includes a photocuring resin, a heat-curing resin, a curing agent, a photoinitiator, etc., and the curing agent is mostly a polythiol compound containing a thiol group that can react with epoxy groups and unsaturated groups.

[0003] However, the polythiol curing agents currently used generally have problems such as easy crystallization, high viscosity resulting in poor fluidity, or poor moisture and heat resistance, and poor chemical resistance. Among them, the crystallization of the curing agent during the storage of the adhesive will reduce the cross-linking density of the adhesive after curing, affecting the bonding strength of the adhesive layer; and the adhesive containing ester bond-type polythiol curing agents, the adhesive layer formed by it will have its bonding strength greatly reduced due to the hydrolysis of the ester bond in a high humidity environment, which cannot meet the bonding requirements and affects the reliability of the product.

[0004] Based on this, there is an urgent need for a new type of photo-thermal dual-curing resin composition, which can not only achieve fast and effective positioning, but also have a glue layer with high bonding strength, high storage modulus and good resistance to moisture and hot water hydrolysis after low-temperature thermal curing, so as to meet the application requirements in high-precision fields such as electronic circuits. Summary of the invention

[0005] To solve the above problems, the present invention provides a photo-thermal dual-curable resin composition, a preparation method and application thereof. The resin composition uses a homemade biphenyl-type polythiol compound as a curing agent, and cooperates with different types of epoxy resin monomers, acrylic resin monomers, etc., not only can the resin composition be quickly photo-fixed and low-temperature thermally cured, but the adhesive layer after complete curing has high bonding strength, high storage modulus and excellent moisture and heat resistance, which can meet the application requirements of high-precision fields such as electronic circuits.

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

[0007] The first aspect of the present invention provides a photo-thermal dual curable resin composition, wherein the photo-thermal dual curable resin composition comprises the following components in parts by mass:

[0008] The photothermal dual curable resin composition comprises the following components by mass: 50-80 parts of bisphenol A epoxy resin, 5-8 parts of dicyclopentadiene epoxy resin, 50-110 parts of photosensitive compound, 20-100 parts of curing agent, 0.5-5 parts of curing accelerator, 1-5 parts of photoinitiator, 0.5-3.5 parts of stabilizer, 0.1-1 parts of polymerization inhibitor, 0.5-7 parts of silane coupling agent, and 1-10 parts of filler;

[0009] The ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is (0.6-1.32): 1, and the total mass of the epoxy resin is the sum of the masses of the bisphenol A epoxy resin and the dicyclopentadiene epoxy resin;

[0010] The structure of the curing agent is as follows:

[0011]

[0012] Among them, R 1 , R 2 They are C2-C18 alkylene respectively.

[0013] In order to solve the problems that the polythiol curing agents currently used in light / heat dual-curing resin systems generally have, such as easy crystallization, high viscosity resulting in poor fluidity, poor moisture and heat resistance, poor chemical resistance, or the prepared light / heat dual-curing resin system has low bonding strength, poor moisture and heat resistance, and low storage modulus, the present invention optimizes the curing agent and the formula to obtain a light-heat dual-curing resin system with high bonding strength, high storage modulus and good moisture and heat resistance after curing. The details are as follows: (1) The present invention adopts a self-made biphenyl type polythiol compound as a thiol curing agent. The compound molecule contains a rigid biphenyl structure and four flexible alkylthiol groups, and the two alkylthiol groups distributed on the benzene ring are in the ortho position. 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 through high cross-linking density and significantly improve the toughness and storage modulus of the cured resin. The compound does not have an easily hydrolyzable group, so that the resin composition containing the curing agent can produce a high cross-linking density after curing and is not easy to hydrolyze, thereby significantly improving the bonding strength, heat resistance and moisture resistance of the cured resin. In addition, the biphenyl structure of the curing agent makes it have a lower viscosity and better fluidity. (2) The present invention optimizes the type and mass ratio of epoxy resin in the resin composition and controls the mass ratio of epoxy resin to photosensitive compound, so as to obtain a glue layer that can not only be quickly fixed by light, but also has high bonding strength, high storage modulus and excellent moisture and heat resistance after low-temperature thermosetting; the resin composition provided by the present invention uses bisphenol A type epoxy resin as the main epoxy resin monomer to ensure the bonding strength of the resin after curing, and at the same time introduces an appropriate amount of dicyclopentadiene epoxy resin. The resin monomer having dicyclopentadiene units can further improve the heat resistance of the glue layer after curing. and chemical resistance. On this basis, the ratio of the weight of epoxy resin monomer to the mass of photosensitive compound in the resin composition is controlled in a suitable range, such as 0.6-1.32. The appropriate amount of photosensitive compound can be rapidly polymerized under UV light initiation, so that the adhesive is initially solidified to play a role in rapid positioning. At the same time, in order to ensure that the resin composition has a high bonding strength after further low-temperature thermal curing, the content of epoxy resin monomer cannot be too low, so that after cross-linking and curing, it forms a mutually interlaced double network structure with the cross-linked network of the photosensitive compound to further improve the bonding strength and stability of the adhesive layer. Under the synergistic effect of the monomers, curing agents and other components in the above-mentioned resin composition formula, it can not only achieve rapid light fixation, but also the adhesive layer after low-temperature thermal curing has high bonding strength, high storage modulus and excellent moisture and heat resistance, meeting the application requirements of high-precision requirements in electronic circuits and other fields.

[0014] Furthermore, the ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is (0.9-1.1):1, such as 0.9:1, 1:1, 1.1:1, etc., including but not limited to the ratios listed above.

[0015] Furthermore, in the curing agent structure, R 1 , R 2 All are straight chain C3 alkylene.

[0016] Furthermore, the preparation method of the curing agent comprises the following steps: under a protective atmosphere,

[0017] (1) reacting 4,4'-biphenol and a compound represented by formula I 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 II;

[0018] (2) heating the first intermediate product to obtain a second intermediate product represented by formula III;

[0019] (3) reacting the second intermediate product with the compound represented by formula IV 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 V;

[0020] (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 VI;

[0021] (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;

[0022] The structures of the above formula I to formula VI are as follows:

[0023]

[0024] Wherein, X is Cl or Br;

[0025] h is 1, and l is any integer from 0 to 16.

[0026] 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.

[0027] In some preferred embodiments, in step (2), the heating reaction temperature is 150-250° C., and the heating reaction time is 10-18 h.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] Furthermore, the ratio of the molar amount of epoxy functional groups (derived from the epoxy resin) to the molar amount of thiol groups (derived from the curing agent) in the photothermal and dual curable resin composition is preferably 1:(0.5-2.0), more preferably 1:(0.9-1.2), such as 1:0.9, 1:1, 1:1.1, 1:1.2, etc., including but not limited to the molar ratios listed above. Among them, when the molar amount of epoxy functional groups to the molar amount of thiol groups in the photothermal and dual curable resin composition is 1, and the ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is 1:1, the comprehensive performance of the resin composition after curing is optimal.

[0032] Furthermore, the photosensitive compound is selected from one or more of epoxy (meth)acrylate resin, polyurethane (meth)acrylate resin, polyester (meth)acrylate resin, polyether (meth)acrylate resin, silane-modified (meth)acrylate resin, polyol (meth)acrylate resin, polyolefin (meth)acrylate resin, melamine (meth)acrylate resin, isocyanuric acid (meth)acrylate resin, and (meth)acrylated acrylic resin; in some preferred embodiments, the photosensitive compound is tricyclodecane dimethanol diacrylate.

[0033] Furthermore, the curing accelerator is selected from one or more of imidazole-based curing accelerators, tertiary amine-based curing accelerators and phosphorus compound-based curing accelerators, such as PN23.

[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, phenyl bis(2,4,6-trimethylbenzoyl)phosphine 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) ...2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone, )-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, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, and 2-ethylanthraquinone.

[0035] Furthermore, the stabilizer is selected from one or more of liquid borate compounds, aluminum chelating agents, and barbituric acid, such as triisopropyl borate.

[0036] Furthermore, the polymerization inhibitor is selected from one or more of phenol polymerization inhibitors, quinone polymerization inhibitors, inorganic compound polymerization inhibitors, and aromatic amine polymerization inhibitors, such as p-benzoquinone.

[0037] Furthermore, the silane coupling agent is selected from one or more of 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane.

[0038] Furthermore, the filler is selected from one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, talc, calcium carbonate, glass microspheres, graphite powder, metal powder, polytetrafluoroethylene, such as fumed silica.

[0039] Furthermore, the auxiliary agent is selected from one or more of a wetting agent, a dehydrating agent, a flame retardant, a diluent, a pigment, an antioxidant, an adhesion promoter, a defoaming agent, a leveling agent, a thixotropic agent, a leveling agent, and an ion capture agent; in some preferred embodiments, the wetting agent is BYK-333, and the dehydrating agent is Additive TI.

[0040] The second aspect of the present invention provides a method for preparing the photo-thermal dual curable resin composition described in the first aspect, wherein each component is weighed according to the formula and mixed evenly under light-proof conditions and a vacuum degree of -0.1MPa to -0.05MPa to obtain the photo-thermal dual curable resin composition.

[0041] The third aspect of the present invention provides a use of the light-curable and heat-curable dual-curable resin composition described in the first aspect in preparing an adhesive for sealing or bonding electronic components.

[0042] Furthermore, the photo-thermal dual-curable resin composition is coated or filled on the part to be treated, firstly subjected to UV light irradiation curing for 5 seconds for preliminary positioning, and then subjected to thermal curing post-treatment at 80°C.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides a photo-thermal dual-curable resin composition, which uses a homemade biphenyl-type polythiol compound as a curing agent, in conjunction with a specific type of epoxy resin monomer and a photosensitive compound, etc., not only can the resin composition be quickly photo-fixed and low-temperature thermally cured, but the adhesive layer after being fully cured has high bonding strength, high storage modulus and excellent moisture and heat resistance. The resin composition can be used as an adhesive or sealant in the bonding or packaging of electronic components, which can significantly improve the production efficiency of the product and is conducive to improving the reliability of the electronic product, meeting the application requirements of high-precision requirements in the field of electronic circuits, etc.

[0045] The curing agent used in the present invention is a self-made biphenyl type polythiol compound, which has a low preparation cost and is suitable for industrial mass production; more importantly, the polythiol compound is liquid at room temperature and has a low viscosity, can be directly used as a curing agent in the curing process of the photothermal dual curing resin composition, and is not easy to crystallize; the photothermal dual curing resin composition using the biphenyl type polythiol compound as a curing agent can not only achieve rapid curing and positioning under UV light at room temperature, but also has a highly active biphenyl type polythiol compound, which can achieve rapid curing of the resin composition at a lower temperature, thereby effectively avoiding thermal damage to the bonded material or the protected material under high temperature conditions, reducing energy consumption, and generating less internal stress and shrinkage during curing. Compared with other thiol curing agents, the glue layer after curing exhibits 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

[0046] Figure 1 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 1 H-NMR spectrum;

[0047] Figure 2 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl prepared in Example 1 13 C-NMR;

[0048] 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

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. 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, "50-80 parts of bisphenol A epoxy resin" means "50 to 80 parts of bisphenol A epoxy resin".

[0050] 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.

[0051] The sources of some of the raw materials used in the following examples and comparative examples are as follows:

[0052]

[0053]

[0055] The structure of commercial polythiol PEMP is shown below:

[0056]

[0057] 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:

[0058] 18.6 g of 4,4'-dihydroxybiphenyl, 36.3 g of allyl bromide, and 250 mL of acetone were added to the reactor, and 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added. 2 The reaction mixture was heated to 70 °C for 10 h under protection, and then the product was heated to 200 °C for 15 h. 36.3 g of allyl bromide, 250 mL of acetone, 55.3 g of anhydrous potassium carbonate and 2.6 g of 18-crown ether-6 were added. 2 The reaction was continued for 10 h under heating to 70 °C, and then the product was added to tetrahydrofuran dissolved with 45.7 g of thioacetic acid, and then 3.3 g of azobisisobutyronitrile was added, and then N 2 The mixture was heated to 70°C under protection for 16 h. The product was added to 150 mL of methanol and 150 mL of tetrahydrofuran, and 10 g of concentrated hydrochloric acid was added. The mixture was then heated to 70°C for 33 h. The tetrafunctional thiol compound was purified and the product was liquid at room temperature, light yellow in color, with a viscosity of 2.9 Pa·s and a yield of 91%.

[0059] The H NMR, C NMR and IR spectra of the products are shown in Figure 1-3 As shown, 4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl was prepared.

[0060] Example 1

[0061] The present embodiment provides a photothermal dual-curable resin composition, which includes the following components in parts by mass: 60 parts of bisphenol A epoxy resin, 6 parts of dicyclopentadiene epoxy resin, 66 parts of photosensitive compound (tricyclodecane dimethanol diacrylate), 48 parts of biphenyl type polythiol compound (4,4'-bis(3-mercaptopropoxy)-3,3'-bis(3-mercaptopropyl)biphenyl), 4 parts of curing accelerator (PN23), 3 parts of photoinitiator (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 1.5 parts of stabilizer (triisopropyl borate), 0.7 parts of inhibitor (p-benzoquinone), 3 parts of silane coupling agent (3-glycidyloxypropyltrimethoxysilane), 3.6 parts of wetting agent (BYK-333), 3.6 parts of gaseous silica, and 3.6 parts of dehydrating agent (Additive TI).

[0062] The above raw materials are mixed uniformly at room temperature and in the dark, and then degassing is performed. The discharged materials are packaged into black or brown sealed rubber tubes to obtain a resin composition.

[0063] Examples 2-14 and Comparative Examples 1-7

[0064] Examples 2-14 and Comparative Examples 1-7 respectively provide a light- and heat-curable dual-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.

[0065] The types of monomers and curing agents in the photothermal dual-curable resin compositions prepared in Examples 1-14 and Comparative Examples 1-7 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:

[0066] Table 1

[0067]

[0068]

[0069] In the table, a / b is the ratio of the molar amount of epoxy functional groups to the molar amount of mercapto groups in the resin composition.

[0070] Performance Testing

[0071] The performance tests of the light-heat dual curable resin compositions prepared in the above examples and comparative examples are as follows:

[0072] Curing conditions: The photo-thermal dual-curable resin composition prepared in the examples and comparative examples was squeezed out from a hose using a dispensing machine and firstly exposed to ultraviolet light (wavelength 365nm, light intensity 1000mW / cm 2 ) radiation curing for 5 seconds and then curing at 80°C for 60 minutes to obtain a cured sample.

[0073] 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 mm × 12.5 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. The tests were carried out at ambient temperatures of 25°C and 80°C, and the measured force values ​​were recorded as strength (MPa). The cured samples were subjected to heating and humidification conditions of 85°C / 85%RH / 500h, and the shear bonding strength (MPa) of the samples was tested again at an ambient temperature of 25°C and recorded.

[0074] 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 42mm×8mm×0.3mm sheet. The storage modulus was measured in a liquid nitrogen atmosphere and film stretching mode within a temperature range of 20 to 100°C, wherein the heating rate was 10°C / min and the test frequency was 10Hz, thereby determining the storage modulus (MPa) of the resin composition at 25°C and 80°C after curing.

[0075] The above test results are shown in Table 2 below:

[0076] Table 2

[0077]

[0078] As can be seen from Table 2, the adhesive layers of the photo-thermal dual-curable resin compositions prepared in Examples 1-14 after UV curing and further heat curing exhibit high bonding strength at room temperature and high temperature, and after being treated at 85°C / 85% RH for 500 hours, they still maintain a relatively high bonding strength, exhibit good moisture and heat resistance, and have a relatively high storage modulus at both room temperature and high temperature, thereby effectively improving the reliability of electronic products, especially those that are bonded or sealed.

[0079] It can be seen from Example 1 and Comparative Examples 1 and 2 that the structure of the curing agent has a great influence on the bonding strength, storage modulus, and moisture and heat resistance of the resin composition. Comparative Example 1 uses a thiol curing agent B (commercially available polythiol PETMP) as a curing agent to prepare a resin composition. The bonding strength at room temperature after complete curing is significantly lower than that of Example 1, and the bonding strength decreases significantly more than that of Example 1 under high temperature or humid and hot environments. The moisture and heat resistance is poor. This is because the molecular structure of the commercially available polythiol PETMP contains an ester group. Under a humid and hot environment, it is easy to hydrolyze, resulting in a significant decrease in the bonding strength of the adhesive layer. In addition, the storage modulus of the adhesive layer after curing the resin composition prepared by Comparative Example 1 is also low at room temperature and high temperature, affecting the reliability of the electronic products bonded or sealed therewith. The thiol curing agent C used in Comparative Example 2 has a biphenyl structure and does not contain an ester group. Relative to Comparative Example 1, the adhesive layer prepared by the resin composition has better moisture and heat resistance and storage modulus after curing, but the bonding strength is not significantly improved. The resin composition (Example 1) prepared by using the self-made thiol compound of the present invention as a curing agent, the bonding strength, storage modulus and moisture and heat resistance of the glue layer after curing are significantly better than those of Comparative Examples 1 and 2. This also shows that the position of the alkyl mercapto group on the benzene ring in the thiol compound will affect the crosslinking density of the glue layer after the resin composition is cured, and then affect the toughness, bonding strength, moisture and heat resistance and storage modulus of the glue layer. In addition, it can be seen from Example 1 and Comparative Example 3 that the type of monomer in the resin composition will affect the toughness, bonding strength and storage modulus of the glue layer after curing. When the dicyclopentadiene epoxy resin is missing in the resin composition, the bonding strength and storage modulus of the prepared glue layer (Comparative Example 3) are significantly reduced.

[0080] In addition, it can be seen from Examples 1-6 and Comparative Examples 4 and 5 that the mass ratio of the epoxy resin monomer to the photosensitive compound in the resin composition affects the bonding strength, moisture and heat resistance and storage modulus of the adhesive layer after curing. When other conditions are the same, when the ratio of (A1+A2) / A3 is in the range of 0.55-1.5, the comprehensive performance of the adhesive layer after the resin composition is cured first increases and then decreases with the increase of the ratio of the two. Among them, when (A1+A2) / A3 is less than 0.6, the bonding strength and storage modulus of the resin composition (Comparative Example 4) after curing are greatly reduced. When (A1+A2) / A3 is greater than 1.32, the bonding strength and storage modulus of the resin composition (Comparative Example 5) after curing do not change significantly, but the heat resistance and moisture and heat resistance are significantly reduced. When the ratio of (A1+A2) / A3 is 1, the adhesive layer of the prepared resin composition has relatively optimal comprehensive performance after curing.

[0081] It can be seen from Examples 1, 7-9 and Comparative Examples 6 and 7 that if the ratio a / b of the molar amount of epoxy functional groups in the epoxy resin in the resin composition to the molar amount of mercapto groups in the curing agent is too large or too small, the performance of the adhesive layer will be affected. When other conditions are the same, when the ratio of a / b is in the range of 1:(0.4-2.2), the comprehensive performance of the adhesive layer after the resin composition is cured first decreases and then increases with the increase of the ratio of the two. Among them, when the ratio of a / b is in the range of 1:(0.5-2), the adhesive layer after the corresponding resin composition is cured has high bonding strength, high storage modulus and good moisture and heat resistance. The resin composition with a / b controlled in the range of 1:(0.9-1) is more preferred.

[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 light-heat-dual curable resin composition, characterized in that: The photothermal dual curable resin composition comprises the following components by mass: 50-80 parts of bisphenol A epoxy resin, 5-8 parts of dicyclopentadiene epoxy resin, 50-110 parts of photosensitive compound, 20-100 parts of curing agent, 0.5-5 parts of curing accelerator, 1-5 parts of photoinitiator, 0.5-3.5 parts of stabilizer, 0.1-1 parts of polymerization inhibitor, 0.5-7 parts of silane coupling agent, and 1-10 parts of filler; The ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is (0.6-1.32): 1, and the total mass of the epoxy resin is the sum of the masses of the bisphenol A epoxy resin and the dicyclopentadiene epoxy resin; The structure of the curing agent is as follows: Among them, R 1 , R 2 They are C2-C18 alkylene respectively.

2. The light-curable and heat-curable resin composition according to claim 1, characterized in that: The ratio of the total mass of the epoxy resin to the mass of the photosensitive compound is (0.9-1.1):

1.

3. The light-curable and heat-curable resin composition according to claim 1, characterized in that: In the curing agent structure, R 1 , R 2 All are straight chain C3 alkylene.

4. The light-curable and heat-curable resin composition according to claim 1, characterized in that: The ratio of the molar amount of epoxy functional groups to the molar amount of mercapto groups in the light-heat dual curable resin composition is 1:(0.5-2.0).

5. The light-curable and heat-curable dual-curable resin composition according to claim 4, characterized in that: The ratio of the molar amount of epoxy functional groups to the molar amount of mercapto groups in the light-heat dual curable resin composition is 1:(0.9-1.2).

6. The light-curable and heat-curable dual-curable resin composition according to claim 1, characterized in that: The photosensitive compound is selected from one or more of epoxy (meth)acrylate resin, polyurethane (meth)acrylate resin, polyester (meth)acrylate resin, polyether (meth)acrylate resin, silane-modified (meth)acrylate resin, polyol (meth)acrylate resin, polyolefin (meth)acrylate resin, melamine (meth)acrylate resin, isocyanuric acid (meth)acrylate resin, and (meth)acrylated acrylic resin.

7. The light-curable and heat-curable dual-curable resin composition according to claim 1, characterized in that: The curing accelerator is selected from one or more of an imidazole curing accelerator, a tertiary amine curing accelerator and a phosphorus compound curing accelerator; 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, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, phenylbis(2,4,6-trimethylbenzoyl)phosphine 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)- One or more of 1-(4-morpholinophenyl)-1-butanone, 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone], 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-1-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, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, and 2-ethylanthraquinone; The stabilizer is selected from one or more of a liquid borate compound, an aluminum chelating agent, and barbituric acid; The polymerization inhibitor is selected from one or more of phenolic polymerization inhibitors, quinone polymerization inhibitors, inorganic compound polymerization inhibitors, and aromatic amine polymerization inhibitors; The silane coupling agent is selected from one or more of 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane; The filler is selected from one or more of silicon dioxide, aluminum oxide, magnesium oxide, zinc oxide, boron nitride, silicon carbide, talc, calcium carbonate, glass microspheres, graphite powder, metal powder, and polytetrafluoroethylene.

8. The light-curable and heat-curable dual-curable resin composition according to claim 1, characterized in that: The photo-thermal dual curable resin composition further comprises 0.1-15 parts of an auxiliary agent; The auxiliary agent is selected from one or more of a wetting agent, a dehydrating agent, a flame retardant, a diluent, a pigment, an antioxidant, an adhesion promoter, a defoaming agent, a leveling agent, a thixotropic agent, a leveling agent, and an ion capture agent.

9. A method for preparing the light-curable and heat-curable dual-curable resin composition according to any one of claims 1 to 8, characterized in that: The components are weighed according to the formula and mixed evenly under the conditions of being protected from light and having a vacuum degree of -0.1 MPa to -0.05 MPa to obtain the light- and heat-curable dual-curable resin composition.

10. Use of the photo-thermal dual curable resin composition according to any one of claims 1 to 8 in preparing an adhesive for sealing or bonding electronic components.

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