Organic metal framework modified water-oxygen barrier epoxy glue and preparation method thereof

Abstract

The invention discloses organic metal framework modified water-oxygen barrier epoxy glue and a preparation method thereof. The glue is prepared from the following raw materials in parts by weight: 80 to 99 parts of epoxy resin, 0.5 to 4 parts of modified MOFs filler, 60 to 80 parts of curing agent, 0.5 to 3 parts of catalyst and 10 to 15 parts of flexibilizer. According to the invention, through multi-scale structural design and surface functional modification, the unique performance of the MOFs material is successfully integrated into an epoxy adhesive system; a hydrophobic interface is formed by combining pore size regulation and control with fluorosilane modification, so that a triple synergistic barrier mechanism based on size screening, chemical adsorption and hydrophobic shielding can be realized, and breakthrough improvement of the water-oxygen barrier property can be realized on the premise of not sacrificing various properties of the glue.

Description

Technical Field

[0001] This invention relates to the field of adhesive materials, and in particular to an organometallic framework modified water-oxygen barrier epoxy adhesive and its preparation method. Background Technology

[0002] In fields such as electronic packaging, aerospace, and new energy equipment, the infiltration of water molecules and oxygen is a key factor leading to the degradation of material performance. Water and oxygen intrusion can cause corrosion of metal substrates, hydrolytic aging of polymer materials, and short circuits in electronic components, severely impacting the long-term reliability and lifespan of products. For example, in OLED display packaging devices, water and oxygen barrier properties are critical. OLED devices are extremely sensitive to water vapor and oxygen, easily leading to problems such as bubbles, black spots, and low luminous efficiency, accelerating device aging. Epoxy adhesives are widely used as encapsulation adhesives due to their excellent adhesion, mechanical strength, and chemical stability. Metal-organic frameworks (MOFs), with their tunable pore structure (0.5-2 nm) and ultra-high specific surface area (up to 7000 m² / g), and the ability to precisely design the pore size and surface chemistry of MOFs through precise selection of metal nodes and organic ligands, along with their Lewis acid sites that selectively adsorb polar molecules, theoretically offer a water and oxygen barrier efficiency 2-3 orders of magnitude higher than traditional nanofillers, making them ideal functional materials for water and oxygen barrier properties.

[0003] Currently, traditional epoxy adhesive formulations still have significant shortcomings: on the one hand, the cured epoxy network has microscopic free volumes, providing diffusion channels for water and oxygen molecules; on the other hand, conventional fillers (such as silica, calcium carbonate, etc.) have limited interfacial compatibility with the resin matrix, making it difficult to form dense barrier paths. Moreover, due to the low aspect ratio, a high addition amount (10~20%) is required to form tortuous paths, which easily leads to stress concentration and sacrifices mechanical properties. Although graphene has superhydrophobicity, its poor dispersibility and conductivity may accelerate electrochemical corrosion.

[0004] Therefore, it is necessary to improve existing technologies to provide more reliable solutions. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a metal-organic framework-modified water-oxygen barrier epoxy adhesive and its preparation method. To solve the problems of low barrier efficiency due to the microscopic free volume after curing of epoxy adhesives, poor compatibility between conventional fillers and adhesive systems, and decreased mechanical properties in existing solutions, this invention proposes a MOF-modified epoxy adhesive solution. This solution, through multi-scale structural design and surface functionalization modification, successfully integrates the unique properties of MOF materials into the epoxy adhesive system as molecular sieve units. Combined with the hydrophobic interface formed by fluorosilane modification, a breakthrough improvement in water-oxygen barrier performance is achieved.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In the first aspect of the present invention, an organometallic framework modified water-oxygen barrier epoxy adhesive is provided, comprising the following raw materials in parts by weight: 80-99 parts of epoxy resin, 0.5-4 parts of modified MOFs filler, 60-80 parts of curing agent, 0.5-3 parts of catalyst, and 10-15 parts of toughening agent.

[0007] Preferably, the modified MOFs filler is prepared by the following method: The dried MOF material is added to a solvent to prepare a suspension with a concentration of 5-20 wt% MOF material. The suspension is ultrasonically treated for 15-60 minutes. Then, a surface treatment reagent of 1.5-6% of the mass of MOF material is added dropwise. After the addition is complete, the suspension is refluxed at 60-80℃ for 1-4 hours, cooled to room temperature, filtered, and the solid product is vacuum dried to obtain the modified MOF filler.

[0008] Preferably, the MOF material is one or more of ZIF-8, NH2-UiO-6 and MIL-101(Cr).

[0009] Preferably, the solvent is one or more selected from methanol, acetone, butanone, and ethyl acetate; The surface treatment reagent is one or two of the following: triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane, octadecyl orthophosphate, and γ-glycidoxypropyltrimethoxysilane.

[0010] Preferably, the modified MOFs filler is prepared by the following method: The dried MOF material was added to a solvent to prepare a suspension with a MOF material concentration of 10 wt%. The suspension was sonicated for 30 minutes. Then, a surface treatment reagent of 3% by mass of the MOF material was added dropwise. After the addition was completed, the suspension was refluxed at 70°C for 2 hours, cooled to room temperature, filtered, and the solid product was vacuum dried to obtain the modified MOF filler.

[0011] Preferably, the epoxy resin is one or more of bisphenol A type, bisphenol F type, or phenolic epoxy resin.

[0012] Preferably, the curing agent is one or more of methyl hexacyanic anhydride, methyltetrahydroanhydride, and green bridge anhydride; The catalyst is one or more of 2-methylimidazole, 2-ethyl-4-hydroxyimidazole, and dibutyltin dilaurate.

[0013] Preferably, the toughening agent is one or more of silicone-modified polyurethane, liquid hydroxyl polybutadiene, and carboxyl-terminated nitrile rubber.

[0014] A second aspect of the present invention provides a method for preparing the organometallic framework modified water-oxygen barrier epoxy adhesive as described above, comprising the following steps: By weight, 80-99 parts of epoxy resin, 0.5-5 parts of modified MOFs filler, 60-80 parts of curing agent, 0.5-3 parts of catalyst, and 10-15 parts of toughening agent are mixed, stirred evenly, and degassed under vacuum to obtain the organometallic framework modified water and oxygen barrier epoxy adhesive.

[0015] In a third aspect, the present invention provides a method for applying the organometallic framework modified water-oxygen barrier epoxy adhesive as described above. The method comprises: applying the organometallic framework modified water-oxygen barrier epoxy adhesive to the bonding surface, first curing it at 100-130°C for 0.5-2 hours, and then curing it at 140-160°C for 0.5-2 hours.

[0016] The beneficial effects of this invention are: This invention provides a metal-organic framework modified water and oxygen barrier epoxy adhesive and its preparation method. Through multi-scale structural design and surface functionalization modification, this invention successfully integrates the unique properties of MOF materials into the epoxy adhesive system. By controlling the pore size and forming a hydrophobic interface through fluorosilane modification, a triple synergistic barrier mechanism based on size sieving, chemical adsorption, and hydrophobic shielding can be achieved, resulting in a breakthrough improvement in water and oxygen barrier performance without sacrificing the various properties of the adhesive.

[0017] In this invention, MOFs with specific pore sizes and surface chemical properties are selected. Through the molecular sieve effect of the pore size and the in-situ hydrophobic surface, the adhesive is endowed with excellent water and oxygen barrier capabilities. Based on the properties of the selected MOFs, targeted modification treatment is carried out to improve their interfacial compatibility with epoxy resin. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0019] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0020] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0021] This invention provides an organometallic framework modified water and oxygen barrier epoxy adhesive, comprising the following raw materials in parts by weight: 80-99 parts epoxy resin, 0.5-4 parts modified MOFs filler, 60-80 parts curing agent, 0.5-3 parts catalyst, and 10-15 parts toughening agent.

[0022] In a preferred embodiment, the modified MOF filler was prepared by the following method: The dried MOF material is added to a solvent to prepare a suspension with a concentration of 5-20 wt% MOF material. The suspension is ultrasonically treated for 15-60 minutes. Then, a surface treatment reagent of 1.5-6% of the mass of MOF material is added dropwise. After the addition is complete, the suspension is refluxed at 60-80℃ for 1-4 hours, cooled to room temperature, filtered, and the solid product is vacuum dried to obtain the modified MOF filler.

[0023] In preferred embodiments, the MOF materials are one or more of ZIF-8, NH2-UiO-6, and MIL-101(Cr). ZIF-8 is formed by coordination of Zn²⁺ with 2-methylimidazole, and has a rhombic pore window (3.4 Å), smaller than the dynamic diameter of water molecules (3.8 Å), which can effectively perform molecular sieving. Its hydrophobic inner surface can significantly reduce water molecule adsorption, making it particularly suitable for high humidity environments. NH2-UiO-66: Zirconium-based MOFs have ultra-high stability (water boiling resistance >24 h), and after amino modification, they can react with epoxy groups through -NH2 to enhance interfacial bonding. Its 6.0 Å pore size can block oxygen molecules (3.46 Å) while allowing small molecules of curing agent to pass through; MIL-101(Cr) has a larger pore size (12-16 Å) and an ultra-large specific surface area (>4000 m²). 2 ( / g), with excellent adsorption performance.

[0024] In a preferred embodiment, the solvent is one or more of methanol, acetone, butanone, and ethyl acetate; The surface treatment reagent is one or two of the following: triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane, octadecyl phosphate, and γ-glycidoxypropyltrimethoxysilane.

[0025] In a preferred embodiment, the modified MOF filler was prepared by the following method: The dried MOF material was added to a solvent to prepare a suspension with a MOF material concentration of 10 wt%. The suspension was sonicated for 30 minutes. Then, a surface treatment reagent of 3% by mass of the MOF material was added dropwise. After the addition was completed, the suspension was refluxed at 70°C for 2 hours, cooled to room temperature, filtered, and the solid product was vacuum dried to obtain the modified MOF filler.

[0026] In a preferred embodiment, the epoxy resin is one or more of bisphenol A, bisphenol F, or phenolic epoxy resin. Bisphenol F epoxy resin (such as EPON 862) is beneficial for the uniform dispersion of MOFs due to its low viscosity and high crosslinking density, while bisphenol A has good toughness. Phenolic epoxy resin has high crosslinking density, good heat resistance, and a heat distortion temperature of over 200°C.

[0027] The curing agent is an acid anhydride curing agent. In a preferred embodiment, the curing agent is one or more of methyl hexacyanic anhydride, methyl tetrahydroanhydride, and green bridge anhydride. It can form a highly moisture-resistant network after curing, and its molecular size is larger than the pore size of MOFs (such as 3.4 Å of ZIF-8), so as to avoid the curing agent being trapped by the MOFs pores and affecting the reaction.

[0028] In a preferred embodiment, the catalyst is one or more of 2-methylimidazole, 2-ethyl-4-hydroxyimidazole, and dibutyltin dilaurate.

[0029] In a preferred embodiment, the toughening agent is one or more of silicone-modified polyurethane, liquid hydroxyl polybutadiene, and carboxyl-terminated nitrile rubber, which can improve the increased brittleness caused by MOFs filling and ensure the crack resistance of the adhesive layer under thermal cycling conditions.

[0030] This invention also provides a method for preparing the above-mentioned organometallic framework modified water-oxygen barrier epoxy adhesive, comprising the following steps: By weight, 80-99 parts of epoxy resin, 0.5-5 parts of modified MOFs filler, 60-80 parts of curing agent, 0.5-3 parts of catalyst, and 10-15 parts of toughening agent are mixed. The mixture is first stirred at low speed (200 rpm) for 5 minutes, then stirred at high speed (1500 rpm) to make it evenly mixed. The mixture is then degassed under vacuum to obtain an organometallic framework modified water-oxygen barrier epoxy adhesive.

[0031] The present invention also provides a method for applying the above-mentioned organometallic frame modified water-oxygen barrier epoxy adhesive. The method is as follows: after cleaning the bonding surface, apply the organometallic frame modified water-oxygen barrier epoxy adhesive to the bonding surface and control the thickness within a certain range. After leveling and defoaming, first cure it at 100-130℃ for 0.5-2 hours to achieve preliminary curing, and then cure it at 140-160℃ for 0.5-2 hours to achieve deep curing.

[0032] This invention provides a high-performance epoxy adhesive based on MOFs modification, which possesses excellent water and oxygen barrier capabilities without sacrificing the adhesive's various properties. This invention achieves water and oxygen barrier based on a triple synergistic barrier mechanism of "size sieving, chemical adsorption, and hydrophobic shielding": the microporous structure of MOFs selectively blocks water and oxygen molecules through the molecular sieve effect; the metal nodes adsorb permeating molecules through coordination; and the surface hydrophobic modification layer forms a low-energy barrier, significantly reducing the wettability of the material surface.

[0033] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0034] Example 1 An organometallic framework modified water-oxygen barrier epoxy adhesive, comprising the following raw materials in parts by weight: 1.5 parts modified MOF filler, 85 parts epoxy resin, 70 parts curing agent, 1 part catalyst, and 15 parts toughening agent.

[0035] The modified MOF filler was prepared by the following method: Dry ZIF-8 material (Shanghai Aladdin Biochemical Technology Co., Ltd., catalog number Z282555) was added to a solvent to prepare a 10wt% suspension, which was then sonicated for 30 minutes. A surface treatment reagent (3% of the mass of the added ZIF-8 material) was added dropwise, and the mixture was refluxed at 70℃ for 2 hours, then filtered and dried to obtain the modified MOF filler. The solvent was a mixed solution of methanol and acetone in a mass ratio of 3:7; the surface treatment reagent was POTS (triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane).

[0036] The epoxy resin is bisphenol A type epoxy resin (E-51), the curing agent is methyl hydrocyanic anhydride, the catalyst is 2-ethyl-4-hydroxyimidazole, and the toughening agent is carboxyl-terminated butadiene-acrylonitrile rubber (Dalian Liansheng New Material Group Co., Ltd., item number LSC-220).

[0037] The preparation method of the organometallic framework modified water-oxygen barrier epoxy adhesive includes the following steps: according to the formula ratio, the modified MOFs filler, epoxy resin, curing agent, catalyst and toughening agent are added to the mixer, first stirred at low speed (200 rpm) for 5 minutes and then stirred at high speed (1500 rpm) for 10 minutes to make it evenly mixed, and then vacuum degassing to obtain the organometallic framework modified water-oxygen barrier epoxy adhesive.

[0038] The application method of the organometallic framework modified water-oxygen barrier epoxy adhesive is as follows: After cleaning the bonding surface, add the above organometallic framework modified water-oxygen barrier epoxy adhesive within the target injection range, and control the thickness within a certain range (50-200μm); after leveling and defoaming, first cure at 120℃ for 1 hour to achieve preliminary curing, and then cure at 150℃ for 1 hour to complete deep curing.

[0039] Example 2 The difference between Example 2 and Example 1 is that the ZIF-8 material is replaced with NH2-UiO-6 (Shanghai Aladdin Biochemical Technology Co., Ltd., item number Z282601), and the surface treatment reagent used in the preparation process is OPA.

[0040] Example 3 The difference between Example 3 and Example 1 is that the MOF material is MIL-101(Cr) (Shanghai Aladdin Biochemical Technology Co., Ltd., item number T281776), and the surface treatment reagent used in the preparation process is OPA (octadecyl orthophosphate).

[0041] Example 4 The difference between Example 4 and Example 1 is that the epoxy resin is bisphenol F type epoxy resin (EPON 862).

[0042] Comparative Example 1 A water- and oxygen-barrier epoxy adhesive, comprising the following raw materials in parts by weight: 1.5 parts of nano-calcium carbonate filler (D50=40nm), 85 parts of epoxy resin, 70 parts of curing agent, 1 part of catalyst, and 15 parts of toughening agent. The preparation method of this organometallic framework modified water-oxygen barrier epoxy adhesive includes the following steps: According to the formula ratio, nano-calcium carbonate, epoxy resin, curing agent, catalyst, and toughening agent are added to a mixer. The mixture is first stirred at low speed (200 rpm) for 5 minutes, then stirred at high speed (1500 rpm) for 10 minutes to ensure uniform mixing. After vacuum degassing, the finished product is packaged. The specific selection of epoxy resin, curing agent, catalyst, and toughening agent is the same as in Example 1.

[0043] The application method of this water-oxygen barrier epoxy adhesive is the same as that in Example 1.

[0044] Comparative Example 2 The difference between this example and Example 1 is that the amount of modified MOFs filler added is changed to 5 parts by weight.

[0045] Comparative Example 3 The difference between this example and Example 1 is that unmodified ZIF-8 material is used instead of modified MOFs filler.

[0046] Test samples were prepared for Examples 1-4 and Control Example 1 above: Apply the adhesive to a clean surface, level it, and remove bubbles. First, cure it at 120°C for 1 hour to achieve initial curing, and then cure it at 150°C for 1 hour to achieve deep curing. The adhesive layer thickness is 100μm.

[0047] Perform performance testing according to their respective testing standards: Test the water vapor transmission rate; refer to ASTM E96 / E96M-24 "Standard Test Method for Water Vapor Transmission of Materials".

[0048] Oxygen permeability; tested according to ASTM D3985-05, "Standard Test Method for Measurement of Oxygen Permeability of Plastic Films and Sheets Using Coulomb Sensors".

[0049] Shear strength: Shear force test was conducted in accordance with the test standard GB / T 7124-2008 "Determination of tensile shear strength of adhesives".

[0050] The test results are shown in Table 1: Table 1 Based on the above test results, we can conclude that: Compared with Control Example 1, Examples 1-3 showed a significant reduction in water vapor permeability and oxygen permeability due to the introduction of specially treated MOFs packing materials, demonstrating their excellent water and oxygen barrier capabilities. In Example 2, the MOF material used was NH2-UiO-6. After the surface treatment agent used in the preparation process was OPA, the shear strength was lower than that in Example 1, indicating that its compatibility with the adhesive system was slightly worse, resulting in a decrease in mechanical properties after curing. In contrast, the surface treatment agent used in Example 1 was POTS, which contains fluoroalkyl chains that form covalent bonds with the OH groups on the surface of ZIF-8 through silane hydrolysis. This can improve the water and oxygen barrier properties of the adhesive and enhance the compatibility of the system. The specially treated MOF packing material used in Example 3 is MIL-101(Cr), which has a larger pore size and a poorer adsorption effect on water vapor and oxygen. Example 4 used bisphenol F epoxy resin, which has a higher viscosity and slightly poorer flowability, resulting in its performance being inferior to that of Example 1; In Comparative Example 2, when the amount of modified MOF filler added was increased to 5 parts, the shear strength also decreased sharply, indicating that excessive filler is not conducive to dispersion and will lead to a decrease in the mechanical properties of the adhesive. Comparative Example 3, which added unmodified ZIF-8, performed worse than Example 1 at the same addition amount, indicating poor compatibility.

[0051] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A metal-organic framework modified water-oxygen barrier epoxy adhesive, characterized in that, The raw materials include the following parts by weight: 80-99 parts epoxy resin, 0.5-4 parts modified MOFs filler, 60-80 parts curing agent, 0.5-3 parts catalyst, and 10-15 parts toughening agent.

2. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 1, characterized in that, The modified MOFs filler was prepared by the following method: The dried MOF material is added to a solvent to prepare a suspension with a concentration of 5-20 wt% MOF material. The suspension is ultrasonically treated for 15-60 minutes. Then, a surface treatment reagent of 1.5-6% of the mass of MOF material is added dropwise. After the addition is complete, the suspension is refluxed at 60-80℃ for 1-4 hours, cooled to room temperature, filtered, and the solid product is vacuum dried to obtain the modified MOF filler.

3. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 2, characterized in that, The MOF materials are one or more of ZIF-8, NH2-UiO-6 and MIL-101(Cr).

4. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 2, characterized in that, The solvent is one or more of methanol, acetone, butanone, and ethyl acetate; The surface treatment reagent is one or two of the following: triethoxy-1H,1H,2H,2H-tridecylfluoro-n-octylsilane, octadecyl orthophosphate, and γ-glycidoxypropyltrimethoxysilane.

5. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 2, characterized in that, The modified MOFs filler was prepared by the following method: The dried MOF material was added to a solvent to prepare a suspension with a MOF material concentration of 10 wt%. The suspension was sonicated for 30 minutes. Then, a surface treatment reagent of 3% by mass of the MOF material was added dropwise. After the addition was completed, the suspension was refluxed at 70°C for 2 hours, cooled to room temperature, filtered, and the solid product was vacuum dried to obtain the modified MOF filler.

6. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 1, characterized in that, The epoxy resin is one or more of bisphenol A type, bisphenol F type, or phenolic epoxy resin.

7. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 1, characterized in that, The curing agent is one or more of methyl hexacyanic anhydride, methyl tetrahydroanhydride, and green bridge anhydride; The catalyst is one or more of 2-methylimidazole, 2-ethyl-4-hydroxyimidazole, and dibutyltin dilaurate.

8. The organometallic framework modified water-oxygen barrier epoxy adhesive according to claim 1, characterized in that, The toughening agent is one or more of the following: silicone-modified polyurethane, liquid hydroxyl polybutadiene, and carboxyl-terminated nitrile rubber.

9. A method for preparing an organometallic framework modified water-oxygen barrier epoxy adhesive as described in any one of claims 1-8, characterized in that, Includes the following steps: By weight, 80-99 parts of epoxy resin, 0.5-5 parts of modified MOFs filler, 60-80 parts of curing agent, 0.5-3 parts of catalyst, and 10-15 parts of toughening agent are mixed, stirred evenly, and degassed under vacuum to obtain the organometallic framework modified water and oxygen barrier epoxy adhesive.

10. A method for applying the organometallic framework modified water-oxygen barrier epoxy adhesive as described in any one of claims 1-8, characterized in that, The method is as follows: apply organometallic frame modified water-oxygen barrier epoxy adhesive to the bonding surface, first cure at 100-130℃ for 0.5-2 hours, and then cure at 140-160℃ for 0.5-2 hours.

Images