Dual-curing composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of organic adhesives, in particular to a dual-curing composition and a preparation method and application thereof. The dual-curing composition comprises an acrylic monomer, an acrylate oligomer, a photoinitiator, dual-curing resin, first epoxy resin and a modified curing agent, wherein the molecules of the dual-curing resin contain acrylate groups and epoxy groups at the same time; the modified curing agent comprises an amine curing agent and a prepolymer of second epoxy resin. According to the dual-curing composition disclosed by the invention, through compounding and synergistic interaction of the components, reactions such as carbon-carbon double bond polymerization, epoxy ring opening and amido addition are carried out under ultraviolet irradiation and normal temperature, so that dual curing is realized through cross-linking polymerization, and devices such as a perovskite battery and the like can be efficiently packaged. Wherein the dual-curing resin further increases the chain length of the polymer, so that a compact three-dimensional network structure is formed after the composition is cured, the moisture and gas blocking performance of the cured composition is improved, and the stability of a packaged device is improved.

Description

Technical Field

[0001] The present application relates to the technical field of organic adhesives, and in particular to a dual-cure composition and a preparation method and application thereof. Background Art

[0002] The stability of existing perovskite batteries is poor. This is due to the inherent ionic properties of perovskite materials. Under high temperature and high humidity environments, halides undergo irreversible hydration reactions when in contact with water. Over time, the perovskite light-absorbing layer material undergoes phase change, decomposition, and dissolution, resulting in a decrease in photoelectric conversion efficiency.

[0003] In order to effectively prevent the external environment such as water vapor and oxygen from damaging the internal structure of perovskite solar cells, effective packaging is required to improve the service life of perovskite cells and the stability of photoelectric conversion efficiency. Common packaging technologies include glass-polymer-glass packaging, which is a packaging method that uses a laminator to heat, laminate, and cure to bond perovskite cells, glass, and other multilayer films through thermoplastic polymer materials. Common hot-pressed polymer materials include polyolefin thermoplastic elastomers, ethylene-vinyl acetate copolymers, and polyurethane hot-melt films. However, this type of material requires high-temperature hot pressing at 130 to 150°C. High-temperature hot pressing will destroy perovskite films, functional materials, and additives, causing chemical reactions, which will affect the photoelectric conversion efficiency and stability of perovskite solar cells. Moreover, the complex roll-to-roll processing method affects the production efficiency of industrialization.

[0004] In addition, there are also technologies for encapsulation through inorganic materials and organic composite materials. However, the overall encapsulation performance of these materials is poor, and it is often difficult to take into account multiple requirements such as moisture barrier, gas barrier, adhesion to the substrate, encapsulation efficiency, and cost. Summary of the invention

[0005] The purpose of the present application is to provide a dual-cure composition and a preparation method and application thereof, aiming to solve the technical problem of poor packaging effect of perovskite cells in the prior art.

[0006] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In a first aspect, the present application provides a dual-cure composition, comprising an acrylic monomer, an acrylate oligomer, a photoinitiator, a dual-cure resin, a first epoxy resin, and a modified curing agent;

[0008] Among them, dual-cure resins contain both acrylate groups and epoxy groups in their molecules;

[0009] The modified curing agent includes a prepolymer of an amine curing agent and a second epoxy resin.

[0010] The dual-cure composition of the present application can undergo carbon-carbon double bond polymerization, epoxy ring opening, and amine addition reactions under ultraviolet light and room temperature through the synergistic effect of the above-mentioned components, thereby achieving dual curing through cross-linking polymerization. Specifically, the dual-cure composition includes, on the one hand, acrylic monomers, acrylic ester oligomers, and photoinitiators, which can be cross-linked and cured under ultraviolet light; on the other hand, it includes a first epoxy resin and a modified curing agent, the modified curing agent includes an amine curing agent and a prepolymer of a second epoxy resin to modify the amine curing agent, and the amine group in the modified curing agent can undergo a ring-opening addition reaction with the first epoxy resin, and can be cured at room temperature; on the other hand, the dual-cure resin contains acrylate groups and epoxy groups, which can serve as a bridge to connect the light-curing component and the epoxy-curing component, increase the polymer chain length, so that the composition forms a dense three-dimensional network structure after curing, and improves the moisture and gas barrier properties of the composition after curing.

[0011] In a second aspect, the present application provides a method for preparing the dual-cure composition of the above application, comprising the following steps:

[0012] The components comprising the dual cure composition are mixed.

[0013] The preparation method of the present application mixes the components of the dual-cure composition, and the obtained dual-cure composition can be cross-linked and polymerized under ultraviolet light irradiation and room temperature to achieve dual curing, and has the properties of barrier moisture and barrier gas. Compared with the existing high-temperature packaging technology, the dual-cure composition prepared by the preparation method does not require high-temperature curing, reduces damage to functional materials, and is beneficial to improving the stability of perovskite batteries. In addition, the preparation method has controllable process, high production efficiency, and high curing and packaging efficiency.

[0014] In a third aspect, the present application provides an application of the dual-cure composition of the present application in any one of OLED encapsulation and solar cell encapsulation.

[0015] Since the dual-curing composition of the above application can be dual-cured under ultraviolet light and room temperature, and has good moisture barrier, gas barrier, impact resistance, weather resistance and other properties after film formation, it can be used for the encapsulation of optoelectronic devices such as OLED encapsulation and solar cell encapsulation, with fewer encapsulation curing processes and high encapsulation efficiency. Compared with the existing high-temperature encapsulation technology, since high-temperature curing is not required during the curing and encapsulation process, the damage to functional materials can be reduced, which is beneficial to improving the stability of optoelectronic devices such as perovskite solar cells and OLED devices. DETAILED DESCRIPTION

[0016] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0018] In this application, "at least one" means one or more, "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0019] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0020] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass in the embodiment description of the present application can be μg, mg, g, kg and other mass units known in the chemical industry.

[0021] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0022] The first aspect of the embodiment of the present application provides a dual-cure composition, which includes an acrylic monomer, an acrylic ester oligomer, a photoinitiator, a dual-cure resin, a first epoxy resin, and a modified curing agent;

[0023] Among them, dual-cure resins contain both acrylate groups and epoxy groups in their molecules;

[0024] The modified curing agent includes a prepolymer of an amine curing agent and a second epoxy resin.

[0025] The dual-cure composition of the embodiment of the present application can undergo carbon-carbon double bond polymerization, epoxy ring opening, and amine addition reactions under ultraviolet light and room temperature through the synergistic effect of the above-mentioned components, thereby achieving dual curing through cross-linking polymerization. Specifically, the dual-cure composition includes, on the one hand, acrylic monomers, acrylic acid ester oligomers, and photoinitiators, which can be cross-linked and cured under ultraviolet light; on the other hand, it includes a first epoxy resin and a modified curing agent, the modified curing agent includes an amine curing agent and a prepolymer of a second epoxy resin to modify the amine curing agent, and the amine group in the modified curing agent can undergo a ring-opening addition reaction with the first epoxy resin, and can be cured at room temperature; on the other hand, the dual-cure resin contains acrylate groups and epoxy groups, which can serve as a bridge to connect the light-curing component and the epoxy-curing component, increase the polymer chain length, so that the composition forms a dense three-dimensional network structure after curing, and improves the moisture and gas barrier properties of the composition after curing. Therefore, the dual-cure composition of the embodiment of the present application can efficiently encapsulate devices such as perovskite cells. The formed cured film is firmly bonded to the device and can block moisture and gas. Compared with the existing high-temperature packaging technology, the dual-cure composition of the embodiment of the present application does not require high-temperature curing, which reduces damage to functional materials and is beneficial to improving the stability of perovskite cells.

[0026] About UV curing components (acrylic monomer, acrylate oligomer, photoinitiator):

[0027] Acrylic monomer: Acrylic monomer contains unsaturated double bonds, which can be initiated by a photoinitiator and initiate free radical polymerization under the action of ultraviolet light to achieve ultraviolet light curing and film formation. In some embodiments, the acrylic monomer may include at least one of isobornyl acrylate, isobornyl methacrylate, lauric acid acrylate, tricyclodecane dimethanol dimethacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, and ethoxylated bisphenol A diacrylate. These acrylic monomers contain monofunctional, difunctional, and multifunctional unsaturated double bonds. Combinations of acrylic monomers with different functionalities are optional. These acrylic monomers can give the dual-curing composition ultraviolet light curing properties.

[0028] Acrylate oligomer: It is an important film-forming component in UV-curing components. Acrylate oligomer contains unsaturated double bonds, which can be initiated by photoinitiators and undergo free radical polymerization under the action of ultraviolet light, further accelerating the curing speed. At the same time, it also makes the cured film layer have certain hardness, moisture barrier, gas barrier, corrosion resistance, weather resistance and other properties, thereby improving the film-forming performance and facilitating the encapsulation of devices such as perovskite batteries.

[0029] In some embodiments, the acrylate oligomer may include at least one of epoxy-modified acrylate and polybutadiene-based polyurethane acrylate. Among them, epoxy-modified acrylate can be prepared by ring-opening esterification of epoxy resin and acrylic acid, or by epoxy resin modified grafted acrylic acid group. The functional group is an unsaturated double bond and does not contain epoxy groups. Epoxy-modified acrylate as an acrylate oligomer is beneficial to accelerate the curing speed of the dual-cure composition, and its molar mass can be 230 to 5000 g / mol. In the exemplary example, at least one of the models of Sartomer CN151NS and Sartomer CN159NS can be included. Polybutadiene-based polyurethane acrylate is beneficial to improve the water resistance of the film-forming dual-cure composition, and its molar mass can be 1000 to 3500 g / mol. In the exemplary example, the polybutadiene-based polyurethane acrylate can be the following molecular structure:

[0030]

[0031] Wherein, n can be 10 to 38, and R1 can be the following structure:

[0032]

[0033] The main chain of the polybutadiene polyurethane acrylate of the structural formula is composed of an alkyl group, and the end contains an ester group, a benzene ring and other groups, which further enables the dual-cure composition to have excellent water resistance, chemical resistance and heat resistance after film formation, and is more conducive to encapsulating devices such as perovskite batteries. In the exemplary embodiment, the polybutadiene polyurethane acrylate can include at least one of the models such as TE-2000 of Japan Soda Co., Ltd. and DR-U252 of Changxing Chemical.

[0034] Photoinitiator: can absorb ultraviolet light and generate free radicals, thereby initiating the polymerization of acrylic monomers and acrylic ester oligomers and cross-linking and curing to form a film. In some embodiments, the above-mentioned photoinitiator may include at least one of 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-methylphenyl propane-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphosphonic acid ethyl ester, and phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide. These photoinitiators can be used together with the above-mentioned acrylic acid and acrylic ester oligomers as photocuring components to give the dual-curing composition the properties of ultraviolet light curing.

[0035] About epoxy curing components (first epoxy resin, modified curing agent):

[0036] First epoxy resin: The first epoxy resin contains epoxy groups, which can undergo a ring-opening addition reaction with the amine group in the modified curing agent, so that the dual-curing composition can also be cross-linked and cured at room temperature, and cooperate with the ultraviolet light curing component to achieve a dual-curing effect, forming a cured film layer with water and air insulation, and improving the packaging effect of devices such as perovskite batteries. In some embodiments, the first epoxy resin can include at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, aliphatic epoxy resin, dicyclopentadiene phenol epoxy resin, naphthalene epoxy resin and biphenyl epoxy resin.

[0037] The modified curing agent includes a prepolymer of an amine curing agent and a second epoxy resin, and may also include other types of thermal curing agents. Since the amine curing agent contains an amine group and the second epoxy resin contains an epoxy group, the two can undergo a ring-opening addition reaction, so that the molecular chain of the amine curing agent is extended, and the compatibility of the modified curing agent with other components is improved, and the amine group retained in the prepolymer can be ring-opening and added with the first epoxy resin in the composition. Therefore, the modified curing agent is conducive to accelerating the curing rate of the modified curing agent and the first epoxy resin, and is also conducive to improving the degree of three-dimensional network cross-linking during the curing process, and enhancing the properties of the film-forming film such as water barrier, gas barrier, and film layer strength.

[0038] In some embodiments, the prepolymer can be obtained by polycondensation reaction of an amine curing agent and a second epoxy resin under the action of a catalyst. Among them, the amine curing agent can include at least one of polyetheramine and alicyclic amine, and the molar mass of the amine curing agent can be 230-5000 g / mol. In the exemplary embodiment, the amine curing agent can be a polyetheramine, which contains a primary amine group and can react with the second epoxy resin by ring-opening addition. The molar mass of the polyetheramine can be 230-5000 g / mol, so that the low molar mass polyetheramine has a higher amine value, which is conducive to the formation of the prepolymer, and is conducive to the modified curing agent and the first epoxy resin to form a film by ring-opening addition. Moreover, the low molar mass polyetheramine has low viscosity and good fluidity, which is more conducive to dispersion and uniform prepolymerization. In the exemplary embodiment, the second epoxy resin can include at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated epoxy resin, and alicyclic epoxy resin. Among them, the bisphenol A epoxy resin contains a rigid structure of benzene rings, and the polyetheramine is mainly a soft segment. The prepolymer obtained by condensation prepolymerization modification has low surface tension and moderate viscosity, which is conducive to the curing effect, so that the dual-curing composition has high water resistance, weather resistance, and impact resistance after curing. In the exemplary example, the catalyst can be an organic substance containing active hydrogen, such as alcohols, phenols, organic weak acids, etc. In the exemplary example, the catalyst can include at least one of oxalic acid, acetic acid, and nonylphenol, which can accelerate the polycondensation reaction.

[0039] Furthermore, the mass ratio of the catalyst, the amine curing agent, and the second epoxy resin can be (40-50): (20-40): (10-20). In the exemplary embodiment, it can include but is not limited to any ratio of (40 or 43 or 46 or 50): (20 or 25 or 30 or 35 or 40): (10 or 13 or 16 or 20) or a range between any two ratios. The raw materials of these mass ratios are subjected to condensation prepolymerization reaction to extend the chain of the amine curing agent, and the obtained prepolymer still retains excess amino groups and the catalyst, which is beneficial to the cross-linking and curing of the modified curing agent and the first epoxy resin, and is beneficial to the formation of a water-proof and air-proof packaging film.

[0040] In the demonstration example, the modified curing agent can be prepared by condensation prepolymerization according to the following steps: in a protective atmosphere, the catalyst and the amine curing agent are stirred evenly at room temperature, the temperature is raised to 50-65°C and stirred for 10-15 minutes, and then the temperature is raised to 80-90°C, and the second epoxy resin is added dropwise while stirring, with a dropping frequency of 10 drops / minute. After the dropping is completed, the temperature is raised to 100-120°C, stirred for prepolymerization for 1-2 hours, and then the temperature is raised to 130-150°C for condensation prepolymerization for 1-2 hours, and finally cooled to room temperature to obtain the modified curing agent.

[0041] In practical applications, since the composition will gradually solidify at room temperature after the modified curing agent is added, the dual-cure composition of the embodiment of the present application can be directly used as a composition containing the above-mentioned components when used, or the modified curing agent can be stored separately from other components and the modified curing agent can be added when used.

[0042] About dual-cure resins:

[0043] The molecules of dual-cure resin contain both acrylate groups and epoxy groups. The acrylate groups can cooperate with the above-mentioned UV-curing components to cross-link and cure, and initiate free radical polymerization with acrylic acid and acrylate oligomers under the action of photoinitiator and ultraviolet light. The epoxy groups can also cure with epoxy curing components and react with the amine groups in the modified curing agent by ring-opening addition. Therefore, the dual-cure resin can serve as a bridge between the photocuring component and the epoxy curing component, increase the polymer chain length, form a complex three-dimensional structure and cross-link and cure, improve the moisture barrier, gas barrier, impact resistance and other properties after film formation, and is more conducive to the encapsulation of devices such as perovskite batteries.

[0044] The dual-curing resin molecules may contain monofunctional, difunctional, or multifunctional acrylate groups and epoxy groups. In the exemplary embodiment, the dual-curing resin may include at least one of the models EA-1010N of Shin Nakamura Chemical and DR-U084 / 6278 of Changxing Chemical. These dual-curing resins have a relatively high molar mass and high steric hindrance, and a low degree of self-polymerization under the action of modified curing agents and ultraviolet light. Therefore, during curing, the dual-curing resin has a low self-crosslinking polymerization ratio, and the main reaction is to react with the photocuring component and the epoxy curing component respectively, as a bridge between the two types of components, increase the polymer chain length, and are more conducive to forming a complex three-dimensional structure and crosslinking and curing, thereby improving the moisture barrier, gas barrier, impact resistance and other properties after film formation.

[0045] The dual-cure composition of the embodiment of the present application includes a UV curing component, an epoxy curing component and a dual-cure resin for synergistic effect, and specifically may include the following components in parts by weight:

[0046] Acrylic acid monomer 20-40 parts

[0047] Acrylate oligomer 10-30 parts

[0048] Photoinitiator 0.5-5 parts

[0049] Dual-curing resin 5-10 parts

[0050] 10-30 parts of the first epoxy resin

[0051] 10 to 30 parts of modified curing agent.

[0052] The dual-curing composition obtained by these components in mass parts can take into account the performance and advantages of UV curing and room temperature curing, which is beneficial to improve the barrier properties of moisture, gas, impact resistance, etc. after film formation. In the exemplary embodiment, the mass parts of acrylate monomers can include any value of 20 parts, 25 parts, 30 parts, 40 parts or a range between any two values; the mass parts of acrylic oligomers can include any value of 10 parts, 15 parts, 20 parts, 30 parts or a range between any two values; the mass parts of photoinitiators can include any value of 0.5 parts, 1 parts, 3 parts, 5 parts or a range between any two values; the mass parts of dual-curing resins can include any value of 5 parts, 7 parts, 8 parts, 10 parts or a range between any two values; the mass parts of the first epoxy resin can include any value of 10 parts, 15 parts, 20 parts, 25 parts, 30 parts or a range between any two values; the mass parts of modified curing agents can include any value of 10 parts, 15 parts, 20 parts, 25 parts, 30 parts or a range between any two values.

[0053] About other components:

[0054] In some embodiments, the dual-cure composition further includes at least one of bismaleimide, epoxy toughening agent, epoxy diluent, filler, and coupling agent, which can respectively improve various properties of the dual-cure composition. Optionally, the dual-cure composition can contain all of these components.

[0055] Among them, bismaleimide belongs to polyimide resin, contains two active terminal functional groups, and can generate maleimide monoradicals under the action of photoinitiator and ultraviolet light, and then cross-link and cure. Therefore, bismaleimide also belongs to the above-mentioned ultraviolet curing component, which is beneficial to improve the aging resistance, weather resistance, moisture and heat resistance and other properties of the dual-curing composition. In some embodiments, the molar mass of bismaleimide can be 600-2000g / mol. Since bismaleimide with high molar mass is often solid, and bismaleimide with these molar masses is generally liquid and has a generally low viscosity, it is beneficial to disperse evenly and reduce the viscosity and consistency of the entire dual-curing composition, and it is more beneficial to fill the dual-curing composition into the side seam of the device through capillary action in applications such as packaging, thereby improving the packaging effect. In the exemplary embodiment, the bismaleimide includes a low-viscosity liquid bismaleimide based on a non-hydrogenated dimer diamine main chain, and may include at least one of the models BMI-689, BMI-1400, BMI-1700, and BMI-1500 of DesignerMolecules Inc., which is further beneficial to the application effect and film-forming performance. Among them, the molecular structure formula of BMI-689 is as follows:

[0056]

[0057] The molecular structure of BMI-1400 is as follows:

[0058]

[0059] Among them, n is 1 to 10.

[0060] The epoxy toughening agent is beneficial to improve the toughness of the dual-curing composition, and is further beneficial to form a relatively flexible film, so as to avoid the above-mentioned ultraviolet light curing component and epoxy curing component from having too high a density after cross-linking, resulting in a film with too high hardness and lack of toughness. In some embodiments, the epoxy toughening agent can include at least one of a carboxyl-terminated nitrile rubber modified epoxy resin, a core-shell rubber particle modified epoxy resin, an acrylate rubber modified epoxy resin, a silicone rubber copolymerized epoxy resin, and a nano-SiO2 copolymerized epoxy resin.

[0061] The epoxy diluent is beneficial for uniform dispersion of the components and reduces the viscosity and consistency of the dual-cure composition, which is beneficial for the dual-cure composition to fill the edge seams of the device through capillary action in applications such as packaging, thereby improving the packaging effect. In some embodiments, the epoxy diluent may include at least one of glycidyl ether, glycidyl ester, and glycidyl amine.

[0062] The filler mainly improves the strength, wear resistance, heat resistance and other properties of the dual-cure composition after film formation, and can also adjust the volume shrinkage of the dual-cure composition during film formation, so as to be more suitable for the device to be packaged and reduce film cracking. In some embodiments, the filler can include at least one of silicon micropowder, nano calcium carbonate, talc, fumed silica, and organic modified bentonite.

[0063] The coupling agent can improve the compatibility and adhesion between the dual-curing composition and the device to be packaged, and can modify the surface of materials such as glass in the device, thereby facilitating the adhesion and bonding of the adhesive film and the packaged device. In some embodiments, the coupling agent includes a silane coupling agent, which can include at least one of γ-glycidyloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and vinyltri(2-methoxyethoxy)silane.

[0064] In some embodiments, the following components are included in parts by weight:

[0065]

[0066] The components of these parts by mass can obtain a dual-curing composition that can take into account the performance and advantages of UV curing and room temperature curing, and further help to improve the barrier properties of moisture, gas, impact resistance, weather resistance, heat resistance, toughness, adhesion, etc. after film formation. In the exemplary embodiment, the mass parts of acrylate monomer, acrylate oligomer, photoinitiator, dual-curing resin, first epoxy resin, and modified curing agent can refer to the ranges above. Further, bismaleimide can include 3 parts, 5 parts, 7 parts, 10 parts of any value or a range between any two values; the mass part of epoxy toughener can include 1 part, 4 parts, 7 parts, 10 parts of any value or a range between any two values; the mass part of epoxy diluent can include 5 parts, 8 parts, 10 parts of any value or a range between any two values; the mass part of filler can include 10 parts, 13 parts, 15 parts, 18 parts of any value or a range between any two values; the mass part of coupling agent can include 1 part, 1.5 parts, 2 parts, 3 parts of any value or a range between any two values. The properties of the dual-cure composition and the film-forming product can be adjusted by varying the mass fractions of these components.

[0067] The dual-cure composition of the embodiment of the present application can be cured by UV irradiation first and then cured at room temperature for a secondary time, and has excellent film-forming properties. After testing, the shear strength after UV curing is greater than 2MPa, the volume shrinkage after complete curing is less than 1.35%, and the glass transition temperature (Tg) is greater than 110°C. The shear strength of the glass substrate-dual-cure composition-glass substrate sample used on the glass substrate after curing is greater than 7MPa, and the shear strength retention rate after dual 85 aging for 1000h is more than 85%, indicating good moisture and heat resistance, and the water vapor transmission rate (1mm 60°C 100%RH) is only 1.0-1.8g / m 2 d, oxygen permeability is only 0.08~0.12cm 3 / m 2 0.1MPa, indicating excellent water and gas barrier properties.

[0068] The second aspect of the present application embodiment provides a method for preparing the dual-cure composition of the above-mentioned embodiment of the present application, comprising the following steps:

[0069] S10: Mixing components including the dual-cure composition.

[0070] The preparation method of the embodiment of the present application mixes the components of the dual-cure composition to obtain a dual-cure composition including an ultraviolet light-curing component, an epoxy-curing component, and a dual-cure resin. The dual-cure composition can be cross-linked and polymerized under ultraviolet light irradiation and room temperature to achieve dual curing, and has the properties of barrier against moisture and gas. Compared with the existing high-temperature packaging technology, the dual-cure composition prepared by the preparation method does not require high-temperature curing, reduces damage to functional materials, and is beneficial to improving the stability of the perovskite battery. In addition, the preparation method has controllable process, high production efficiency, and high curing and packaging efficiency.

[0071] In an exemplary embodiment, the above step S10 may include the following steps:

[0072] S11: performing a first mixing process on the ultraviolet curing component and the dual-curing resin at a certain temperature to obtain a first mixture;

[0073] S12: adding the first epoxy resin to the first mixture at a certain temperature to perform a second mixing process to obtain a second mixture;

[0074] S13: adding a modified curing agent to the second mixture to perform a third mixing process;

[0075] The preparation method is conducive to the uniform dispersion of each component to obtain a dual-cure composition. Among them, the raw materials in step S11 may include acrylic monomers, acrylic oligomers, photoinitiators, dual-cure resins, and may further include bismaleimide. Acrylic monomers, acrylic oligomers, dual-cure resins, and bismaleimide can be added to a hybrid engine, and the stirring temperature is controlled at 50 to 60°C, the stirring speed is 300 to 400 rpm, and stirring is performed for 30 to 35 minutes until the mixture is uniform. Since the above-mentioned photoinitiators are mostly solid or have high viscosity at room temperature, the photoinitiator can be added last, the temperature is raised to 80 to 85°C, and stirring is performed for 2 to 3 hours until the photoinitiator is completely dissolved.

[0076] In step S12, in addition to the first epoxy resin, at least one of epoxy toughening agent, epoxy diluent, filler, and coupling agent may be further added to perform a second mixing treatment. In addition, the second epoxy resin may be mixed evenly with these components and then mixed with the first mixture obtained by the first mixing treatment for a second mixing treatment. In the exemplary embodiment, the first mixture may be cooled to 50-60°C and kept warm, and then the first epoxy resin, epoxy toughening agent, filler, and coupling agent may be added, and the stirring speed may be controlled to 800-1000rpm, and stirred for 1-2h until the filler is fully infiltrated and no obvious particles are present, and finally the epoxy diluent may be added and stirred for 20-30min to make the mixture evenly mixed;

[0077] Step S13 needs to be performed last, because the dual-cure composition will gradually solidify after adding the modified curing agent, so it is generally added to the above components before preparing for application. In the exemplary embodiment, the second mixture can be cooled to a temperature below 25°C, the modified curing agent is added to the hybrid engine, the stirring speed is controlled to 200-300 rpm, and the mixture is stirred for 30-40 minutes to be evenly mixed, and finally the dual-cure composition is obtained by filtering the material.

[0078] A third aspect of the embodiments of the present application provides an application of the dual-cure composition of the above embodiments of the present application in any field of OLED encapsulation and solar cell encapsulation.

[0079] Since the dual-curing composition of the above-mentioned application embodiment can be dual-cured under ultraviolet light and room temperature, and has good moisture barrier, gas barrier, impact resistance, weather resistance and other properties after film formation, it can be used for the encapsulation of optoelectronic devices such as OLED encapsulation and solar cell encapsulation, with fewer encapsulation curing processes and high encapsulation efficiency. Compared with the existing high-temperature encapsulation technology, since high-temperature curing is not required during the curing and encapsulation process, the damage to functional materials can be reduced, which is beneficial to improving the stability of optoelectronic devices such as perovskite solar cells and OLED devices.

[0080] In the demonstration example, the encapsulation can be performed by spin coating, dipping, injection, dispensing, etc., depending on the type and size of the encapsulated device. In addition, the dual-cure composition can flow into the tiny edge seams of the optoelectronic device through capillary action to improve the coverage of the encapsulation. The dual-cure composition has a low volume shrinkage rate during the curing process, which is conducive to reducing the phenomenon of encapsulation film cracks, etc.

[0081] The following describes the invention in conjunction with specific embodiments.

[0082] Example 1

[0083] This embodiment provides a dual-cure composition and a preparation method thereof. The component types and weight parts are shown in Table 1. The preparation method includes the following steps S1 to S4:

[0084] S1: Preparation of modified curing agent

[0085] 43g oxalic acid (catalyst) and 35g polyetheramine (BASF EC301, molar mass 230g / mol) were stirred evenly at room temperature, heated to 50-65°C and stirred for 10-15min, then heated to 80-90°C, and bisphenol A epoxy resin (Hansen EPIKOTE 828EL, i.e., the second epoxy resin) was added dropwise while stirring, with a dropping frequency of 10 drops / minute. After the addition was completed, the temperature was raised to 100-120°C, stirred for prepolymerization for 1-2h, and then heated to 130-150°C for condensation prepolymerization for 1-2h, so that the primary amine group in the polyetheramine and the epoxy resin underwent a ring-opening addition reaction. The above operations were all carried out under nitrogen protection, and the modified curing agent was obtained after cooling to room temperature, which contained a prepolymer of polyetheramine and bisphenol A epoxy resin and oxalic acid.

[0086] S2: First Mixing Process

[0087] Adding acrylic acid monomer, acrylic acid ester oligomer and bismaleimide into a hybrid engine, controlling the stirring temperature at 50-60° C. and the stirring speed at 300-400 rpm, stirring for 30-35 minutes until the mixture is uniformly mixed, adding a photoinitiator, raising the temperature to 80-85° C., stirring for 2-3 hours until the photoinitiator is completely dissolved, and obtaining a first mixture;

[0088] S3: Second Mixing Process

[0089] The first mixture is cooled to 50-60° C., the first epoxy resin, epoxy toughening agent, filler, and coupling agent are added, the stirring speed is controlled to 800-1000 rpm, and the mixture is stirred for 1-2 hours until the filler is fully soaked and no obvious particles are present, the epoxy diluent is added, and the mixture is stirred for 20-30 minutes to mix evenly to obtain a second mixture;

[0090] S4: Third Mixing Process

[0091] The second mixture is cooled to a material temperature below 25° C., a modified curing agent is added to a hybrid power machine, the stirring speed is controlled to 200 to 300 rpm, and the mixture is stirred for 30 to 40 minutes to be evenly mixed, and the material is filtered to obtain a dual-curing composition.

[0092] Example 2

[0093] This embodiment provides a dual-cure composition and a preparation method thereof. The types and weights of the components are shown in Table 1. The only difference from Example 1 is that bismaleimide is not included and the content of acrylate oligomer is increased. The total weight of the dual-cure composition is the same as that of Example 1.

[0094] Example 3

[0095] This embodiment provides a dual-cure composition and a preparation method thereof. The types and weights of the components are shown in Table 1. The only difference from Example 1 is that the types and amounts of acrylic monomer, acrylic ester oligomer, dual-cure resin, and bismaleimide are adjusted, and the rest are the same as Example 1.

[0096] Example 4

[0097] This embodiment provides a dual-cure composition and a preparation method thereof. The types and weight parts of the components are shown in Table 1. The only difference from Example 1 is that the types and amounts of acrylic monomer, acrylic ester oligomer, dual-cure resin, first epoxy resin, epoxy toughening agent, epoxy diluent, and epoxy curing agent are adjusted, and the rest are the same as Example 1.

[0098] Comparative Example 1

[0099] This comparative example provides a dual-cure composition and a preparation method thereof. The types of components and weight parts are shown in Table 1. The only difference from Example 1 is that step S1 is not included, the components do not contain a modified curing agent, and BASF's D230 curing agent (polyetheramine) is directly used, with a weight part of 12.5 parts. The rest is the same as Example 1.

[0100] Comparative Example 2

[0101] This comparative example provides a dual-cure composition and a preparation method thereof. The types and weights of the components are shown in Table 1. The only difference from Example 1 is that step S1 is not included and the components do not contain a dual-cure resin. The rest is the same as Example 1.

[0102] The differences between Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Table 1.

[0103] Table 1

[0104]

[0105] In Table 1, IBOA in the acrylic monomer is isobornyl acrylate, DPHA is dipentaerythritol hexaacrylate, and LA is lauric acid acrylate; DR-U252 in the acrylate oligomer comes from Changxing Chemical, and TE-2000 comes from Japan Soda; EA-1010N in the dual-cure resin comes from Shin-Nakamura Chemical; BMI-689 and BMI-1400 in the bismaleimide are both from Designer Molecules Inc.; 828EL in the first epoxy resin comes from EPIKOTE and is a bisphenol A epoxy resin; MX-154 in the epoxy toughener comes from Japan Kaneki; AFG-90 in the epoxy diluent comes from Shanghai Huayi; D230 in the epoxy curing agent comes from BASF, and SE203G-SEJ in the filler comes from Japan Yaduma, which is a silica filler.

[0106] The units of the amounts of the components in Table 1 are all parts by mass. The “ / ” in Table 1 represents that no component was added, and the part by mass is 0.

[0107] Performance Test:

[0108] 1. Viscosity test

[0109] An advanced rheometer was used, using a C20 / 1° cone plate, setting the temperature to 25°C, the speed to 1 rpm, keeping warm for 30 seconds, and testing for 1 minute to obtain the average value as the test result, and the results are recorded in Table 2;

[0110] 2. Shear strength test

[0111] With reference to ASTM D1002 and GB / T7124-2008 "Determination of tensile shear strength of adhesives", two glass substrates with a thickness of 2 mm were provided, and the dual-cure composition was dripped on one surface of the glass substrate to a thickness of about 0.2 mm, and then another glass substrate was attached to the surface to obtain a glass-dual-cure composition-glass sample.

[0112] First, cure with UV light. The UV light uses a 365nm LED lamp with a radiation energy of 2000-2500mJ / cm 2 After UV irradiation, leave it at room temperature for 24 hours until it is completely cured.

[0113] The shear strength after UV irradiation curing and the shear strength after complete curing were tested respectively. The test method was to use a universal tensile machine to refer to the "ASTM D638" standard, and the average value of three groups was tested as the test result, and the results were recorded in Table 2. At the same time, the POE polyolefin elastomer film in the prior art was used as a blank control group.

[0114] 3. Curing volume shrinkage test

[0115] A certain mass of the dual-cure composition was weighed and its density was tested using a densitometer to calculate the compact volume. Then, an equal mass of the glue was weighed and UV-cured on a cube flat-bottom nozzle and cured at room temperature. After complete curing and cooling, the density of the solidified glue block was tested using a densitometer to calculate the solid volume. The solid volume of the liquid was divided by the liquid volume to obtain the curing shrinkage rate, and the results were recorded in Table 2.

[0116] 4. Glass transition temperature test

[0117] The glass transition temperature was tested by dynamic mechanical analysis (DMA) on the cured samples which were cured by UV irradiation and then left at room temperature for 48 h. The results are recorded in Table 2.

[0118] 5. Water vapor transmission rate test

[0119] The water vapor transmission rate test uses the infrared method and refers to the "GB 26253-2010" standard test. The cured film sample is prepared with a thickness of 1 mm and placed in a constant temperature and humidity environment (60°C, 100% RH) for testing. The results are recorded in Table 2.

[0120] 6. Oxygen permeability test

[0121] The oxygen transmission rate was tested according to the ASTM D3985 standard, and the cured film samples were prepared with a thickness of 1 mm. The results are recorded in Table 2.

[0122] 7. Moisture and heat resistance test

[0123] According to the dual 85 1000h test requirements, the sample was placed in a constant temperature and humidity environment of 85°C, 85% RH for a total of 1000h. According to the above shear strength test, a glass-dual-cured composition-glass was prepared. After UV curing and room temperature static curing, a sample was obtained. The shear strength of the sample before and after treatment in the environment was tested to obtain the shear strength retention rate. The results are recorded in Table 2.

[0124] 8.Performance stability test

[0125] The same type of perovskite battery was encapsulated using the same automated dispensing process. It was first UV-cured and then placed at room temperature for 48 hours until fully cured. According to the double 85 1000h test requirements, the encapsulated perovskite battery samples were placed in a constant temperature and humidity environment of 85°C, 85% RH for a total of 1000 hours. The photoelectric conversion efficiency of the samples before and after treatment in the environment was tested, and the photoelectric conversion efficiency retention rate was obtained. The results are recorded in Table 2.

[0126] Table 2

[0127]

[0128] The POE film in Table 2 is in solid state, with no viscosity test data and no need for UV curing, so there is no shear strength after UV curing. The two test results are represented by “ / ”.

[0129] Combined with Table 1, it can be seen from Table 2 that the main difference between Example 1 and Comparative Example 1 is whether the curing agent is modified. After the polyetheramine is modified in Example 1, the initial shear strength, final bonding strength, glass transition temperature, water-proof and oxygen-proof properties, and anti-aging properties of the dual-cure composition after curing into a film are all better, while the curing agent in Comparative Example 1 is not pre-polymerized and modified, and its performance is not as good as that of Example 1.

[0130] Comparison of Example 2 with other examples shows that the introduction of bismaleimide can significantly improve the moisture and heat resistance and aging resistance of the cured film. Liquid polybutadiene polyurethane acrylate is introduced into the acrylate oligomer in each example, which further improves the temperature resistance and water resistance of the cured film.

[0131] Compared with Comparative Example 2 which does not contain dual-cure resin, Examples 1 to 4 all contain dual-cure resin. The dual-cure resin molecules contain both acrylate groups and epoxy groups, which can serve as a bridge between the UV-curing component and the epoxy-curing component during the curing process, increase the polymer chain length, and facilitate the further formation of a complex three-dimensional structure and cross-linking and curing, thereby improving the moisture barrier, gas barrier, shear strength and other properties of the film after formation.

[0132] Compared with the embodiments, Comparative Example 2 does not contain dual-curing resin, so the UV-curing component and the epoxy-curing component cannot be effectively connected, and the chain length cannot be further increased and three-dimensional cross-linked and cured. Therefore, the performance after film formation is not as good as that of the embodiments.

[0133] Compared with Comparative Example 1, Comparative Example 2 and the control sample, Examples 1 to 4 are liquid reactive adhesives with higher crosslinking density, no need for solvents, higher photoelectric conversion efficiency retention after aging test, better device stability, and photoelectric conversion efficiency retention rates of more than 93%. At the same time, automated dispensing equipment can be used for continuous operation, which is more convenient to operate than POE film, providing a strong guarantee for cost reduction and efficiency improvement in industrialization.

[0134] In summary, the dual-cure composition of the present application can be used for encapsulation of optoelectronic devices such as perovskite cells to effectively protect the devices and reduce the impact of moisture, gas, etc. in the external environment on the devices. At the same time, the curing efficiency is high, and the curing process does not require high-temperature heating, which has little impact on the functional materials of the optoelectronic devices and is conducive to improving the stability of the devices.

[0135] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A dual-cure composition, characterized in that: It includes acrylic monomer, acrylic ester oligomer, photoinitiator, dual-curing resin, first epoxy resin, and modified curing agent; Wherein, the dual-curing resin contains both acrylate groups and epoxy groups in its molecules; The modified curing agent includes a prepolymer of an amine curing agent and a second epoxy resin.

2. The dual-cure composition according to claim 1, characterized in that: The prepolymer is obtained by polycondensation reaction of the amine curing agent and the second epoxy resin under the action of a catalyst; wherein, The mass ratio of the catalyst, the amine curing agent and the second epoxy resin is (40-50): (20-40): (10-20); And / or, the amine curing agent includes at least one of polyetheramine and alicyclic amine; and / or, the molar mass of the amine curing agent is 230 to 5000 g / mol; and / or, the second epoxy resin comprises at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated epoxy resin, and alicyclic epoxy resin; And / or, the catalyst includes at least one of oxalic acid, acetic acid, and nonylphenol.

3. The dual-cure composition according to claim 1 or 2, characterized in that The composition comprises the following components in parts by weight:

4. The dual-cure composition according to claim 1 or 2, characterized in that: The acrylic monomer includes at least one of isobornyl acrylate, isobornyl methacrylate, lauric acid acrylate, tricyclodecane dimethanol dimethacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, and ethoxylated bisphenol A diacrylate; And / or, the acrylate oligomer includes at least one of epoxy-modified acrylate and polybutadiene-based polyurethane acrylate; And / or, the photoinitiator includes at least one of 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-methylphenyl propane-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphosphonate, and phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide; And / or, the first epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, aliphatic epoxy resin, dicyclopentadiene phenol epoxy resin, naphthalene epoxy resin and biphenyl epoxy resin.

5. The dual-cure composition according to claim 1 or 2, characterized in that: The dual-cure composition further comprises at least one of bismaleimide, epoxy toughening agent, epoxy diluent, filler and coupling agent.

6. The dual-cure composition according to claim 5, characterized in that: The molar mass of the bismaleimide is 600-2000 g / mol.

7. The dual-cure composition according to claim 5, characterized in that: The epoxy toughening agent includes at least one of a carboxyl-terminated nitrile rubber modified epoxy resin, a core-shell rubber particle modified epoxy resin, an acrylate rubber modified epoxy resin, a silicone rubber copolymerized epoxy resin, and a nano-SiO2 copolymerized epoxy resin; And / or, the epoxy diluent includes at least one of glycidyl ether, glycidyl ester, and glycidyl amine; And / or, the filler includes at least one of silicon micropowder, nano calcium carbonate, talcum powder, fumed silica, and organic modified bentonite; And / or, the coupling agent includes at least one of γ-glycidyloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and vinyltri(2-methoxyethoxy)silane.

8. The dual-cure composition according to claim 5, characterized in that The composition comprises the following components in parts by weight: 20 to 40 parts of the acrylic acid monomer 10 to 30 parts of the acrylic acid ester oligomer 9. A method for preparing a dual-cure composition according to any one of claims 1 to 8, characterized in that: The steps include: The components comprising the dual-cure composition are subjected to a mixing process.

10. Use of the dual-cure composition according to any one of claims 1 to 8 in any one of OLED encapsulation and solar cell encapsulation.

Images