High-barrier synthetic polymer sealant pressure-sensitive adhesive and preparation method thereof

Abstract

The application relates to the technical field of pressure-sensitive adhesive, and particularly discloses a high-barrier synthetic polymer sealing pressure-sensitive adhesive and a preparation method thereof.The sealing pressure-sensitive adhesive provided by the application fills barium sulfate in the pores and interlayer structures of montmorillonite and covalently grafts hydrophobic polybutadiene on the surface, so that the water-proof and moisture-proof performance of the pressure-sensitive adhesive is remarkably improved.Meanwhile, the double bonds in the polybutadiene are in-situ copolymerized with acrylate monomers, the rigid nano filler is anchored in the polymer network as a covalent node, the coordination crosslinking of aluminum acetylacetonate and the rheological tackifying effect of rosin resin are combined, the problems that the water vapor barrier, the high initial adhesion and the high holding adhesion are mutually restricted in the high-barrier packaging material are effectively solved, and the pressure-sensitive adhesive is endowed with excellent sealing reliability and long-term use stability.

Description

Technical Field

[0001] This invention relates to the field of pressure-sensitive adhesive technology, specifically to a high-barrier synthetic polymer sealing pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Pressure-sensitive adhesives (PSA) are a type of adhesive that is highly sensitive to pressure, requiring only slight finger pressure to achieve a strong bond with the substrate. Due to their unique advantages, such as no need for heating or solvent curing, ease of use, rapid bonding, and excellent initial tack, PSA is now widely used in many fields, including electronics, photovoltaics, automotive manufacturing, aerospace, precision instruments, medical dressings, and building sealing. Especially in high-end electronic devices such as flexible displays (e.g., OLEDs), semiconductor packaging, smartphones, automotive precision screens, and lithium batteries, PSA not only performs structural bonding, shock absorption, and mechanical positioning functions between components, but also serves as a crucial interface sealing and protective layer, playing a vital role in isolating external corrosive media and protecting internal sensitive components from environmental damage. It is an indispensable interface bonding material in precision manufacturing.

[0003] However, traditional pressure-sensitive adhesives often exhibit severely insufficient water-blocking and moisture-proofing properties when facing harsh operating environments such as high temperature and high humidity. This can easily lead to premature failure of the precision components they protect due to moisture oxidation and electrochemical corrosion. This is mainly because: on the one hand, commonly used acrylic pressure-sensitive adhesives contain a large number of highly polar groups such as ester and carboxyl groups in their polymer chains. These groups have strong water absorption properties, and the three-dimensional molecular network structure inside the adhesive is relatively loose with a large free volume, making it easy for water vapor molecules to dissolve and rapidly diffuse and penetrate the adhesive layer. On the other hand, although existing technologies often introduce inorganic fillers through physical blending to extend the water vapor permeation path, the inorganic filler surface is highly hydrophilic and has extremely poor compatibility with the hydrophobic polymer matrix, making it very easy for it to agglomerate severely in the colloid. When subjected to long-term heating, temperature changes, or mechanical deformation such as bending and stretching, the incompatible "filler-polymer" contact interface is very prone to micro-cracks or stress cracks. These interface cracks will instantly transform into "capillary channels" for rapid water permeation, causing the water vapor permeability to increase rather than decrease, and even causing debonding and sagging due to phase separation.

[0004] Therefore, how to design a sealing pressure-sensitive adhesive with excellent barrier properties and adhesive cohesive strength is a key technical problem that urgently needs to be solved in the field of barrier encapsulation materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-barrier synthetic polymer sealing pressure-sensitive adhesive and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add the composite modified montmorillonite to methyl methacrylate and disperse it evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 2-ethylhexyl acrylate and methacrylic acid to an organic solvent and disperse it evenly by ultrasonication. Subsequently, add the initiator azobisisobutyronitrile and heat the reaction under nitrogen protection to obtain a prepolymer solution. S2. Add rosin resin to the prepolymer solution and stir until homogeneous. Then add aluminum acetylacetone solution and continue stirring until homogeneous to obtain a high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0007] In the technical solution disclosed in this invention, the preparation method of the composite modified montmorillonite is as follows: (1) Disperse sodium montmorillonite in deionized water, then add soluble barium salt to it, heat and stir, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) Barium montmorillonite was ultrasonically dispersed in deionized water, and then sodium sulfate solution was added dropwise. After the addition was complete, the mixture was stirred and reacted. After centrifugation, washing, drying and grinding, the composite filler was obtained. (3) Disperse the composite filler in an ethanol aqueous solution, adjust the pH of the solution to 4-5, then add silane coupling agent KH560, stir and treat, filter, wash and dry to obtain epoxy-grafted composite filler; (4) Disperse the epoxy-grafted composite filler in a mixed solvent of xylene and cyclohexanone, then add carboxyl-terminated polybutadiene and triphenylphosphine to it, heat the reaction, and after the reaction is completed, filter, wash, dry and grind to obtain the composite modified montmorillonite.

[0008] Specifically, in step (1), the mass ratio of sodium montmorillonite to soluble barium salt is 10:2-4. For example, 10:2, 10:2.5, 10:3, 10:3.5, and 10:4 can be selected, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0009] Specifically, the soluble barium salt is selected from barium chloride, barium nitrate, or barium acetate.

[0010] Specifically, in step (1), the temperature of the heating and stirring treatment is 50-60℃, and the heating and stirring treatment time is 2-4h.

[0011] Specifically, in step (2), the mass ratio of barium montmorillonite to sodium sulfate solution is 4-8:10-15.

[0012] More specifically, the sodium sulfate solution has a mass fraction of 5-10%.

[0013] Specifically, in step (3), the mass ratio of the composite filler and the silane coupling agent KH560 is 10:0.8-1.5. For example, 10:0.8, 10:1.0, 10:1.2, and 10:1.5 can be selected, but are not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] Specifically, in step (4), the mass ratio of epoxy-grafted composite filler, carboxyl-terminated polybutadiene, and triphenylphosphine is 10:2-5:0.05-0.1.

[0015] Specifically, in step (4), the temperature of the heating reaction is 105-115℃ and the heating reaction time is 6-8h.

[0016] In the technical solution disclosed in this invention, by filling barium sulfate into the interlayer and micropores of montmorillonite, the packing density of the filler is improved, the permeation path of water vapor molecules is extended, and thus the barrier performance of the pressure-sensitive adhesive against water vapor molecules is improved. Then, carboxyl-terminated polybutadiene is grafted onto the surface of the composite filler. The carboxyl-terminated polybutadiene contains double bonds, which are covalently incorporated into the macromolecular chain of the pressure-sensitive adhesive through double bond addition, eliminating the hidden danger of micro-cracks easily generated at the inorganic / organic interface, and further improving the barrier performance. At the same time, the rigid inorganic filler is "anchored" to the molecular chain, serving as the core bearing unit, locking the relative slippage of the polymer chain, so that the pressure-sensitive adhesive has excellent adhesion properties.

[0017] In the technical solution disclosed in this invention, by weight, the amount of composite modified montmorillonite is 3-5 parts, the amount of methyl methacrylate is 15-25 parts, the amount of 2-ethylhexyl acrylate is 40-60 parts, the amount of methacrylic acid is 2-5 parts, the amount of azobisisobutyronitrile is 0.3-0.6 parts, the amount of rosin resin is 5-10 parts, and the amount of aluminum acetylacetonate solution is 1-2 parts.

[0018] Specifically, the mass fraction of the aluminum acetylacetone solution is 5-10%.

[0019] In the technical solution disclosed in this invention, in step S1, the temperature of the heating reaction is 75-80℃, and the heating reaction time is 4-8h.

[0020] In the technical solution disclosed in this invention, rosin resin, as a high-molecular tackifying resin, can be uniformly dissolved in an acrylate matrix, giving the pressure-sensitive adhesive excellent instantaneous flowability and wettability. When a slight finger pressure is applied, the adhesive can spread instantly and fully wet the surface of the substrate to be bonded, thereby obtaining excellent initial tack.

[0021] In the technical solution disclosed in this invention, aluminum acetylacetonate is used as a metal chelating crosslinking agent. Its active aluminum ions undergo multi-point coordination chelation with the carboxyl groups on the copolymer backbone to construct a crosslinking network structure, which further restricts the relative slippage between macromolecular chains, giving the pressure-sensitive adhesive extremely high cohesive strength and making the adhesive layer have high holding power.

[0022] The present invention also provides a high-barrier synthetic polymer sealing pressure-sensitive adhesive prepared by the above preparation method.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The sealing pressure-sensitive adhesive provided by the present invention significantly improves the water-blocking and moisture-proof performance of the pressure-sensitive adhesive by filling the pores and interlayer structure of montmorillonite with barium sulfate and covalently grafting hydrophobic polybutadiene onto the surface. At the same time, by utilizing the double bonds in polybutadiene to copolymerize with acrylate monomers in situ, the rigid nanofiller is anchored in the polymer network as a covalent node. Combined with the coordination crosslinking of aluminum acetylacetonate and the rheological tackifying effect of rosin resin, the problem of water vapor barrier, high initial tack and high holding power mutually restricting each other in high barrier packaging materials is effectively solved, giving the pressure-sensitive adhesive excellent sealing reliability and long-term use stability.

[0024] (2) This invention improves the packing density of the filler by filling barium sulfate into the interlayer and micropores of montmorillonite, which prolongs the permeation path of water vapor molecules and thus improves the barrier performance of the pressure-sensitive adhesive against water vapor molecules. Then, carboxyl-terminated polybutadiene is grafted onto the surface of the composite filler. The carboxyl-terminated polybutadiene contains double bonds, which are covalently incorporated into the macromolecular chain of the pressure-sensitive adhesive through double bond addition, eliminating the hidden danger of micro-cracks easily generated at the inorganic / organic interface and further improving the barrier performance. At the same time, the rigid inorganic filler is "anchored" to the molecular chain and acts as the core bearing unit, locking the relative slippage of the polymer chain, so that the pressure-sensitive adhesive has excellent adhesion performance.

[0025] (3) The aluminum acetylacetonate provided by the present invention is a metal chelating crosslinking agent. Its active aluminum ions undergo multi-point coordination chelation with the carboxyl groups on the copolymer backbone to construct a crosslinking network structure, which further restricts the relative slippage between macromolecular chains, giving the pressure-sensitive adhesive extremely high cohesive strength and making the adhesive layer have high holding power. Detailed Implementation

[0026] The present invention will be further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0027] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0028] The sodium-based montmorillonite used in this embodiment of the invention has a mesh size of 400; the average relative molecular weight of the carboxyl-terminated polybutadiene is 3000; and the CAS number of the rosin resin is 85026-55-7.

[0029] Example 1

[0030] A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 5 parts of composite modified montmorillonite to 25 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 60 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.4 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 10 parts of rosin resin and stir until homogeneous. Then add 2 parts of aluminum acetylacetonate solution (toluene) with a mass fraction of 10% and continue stirring until homogeneous to obtain the high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0031] The preparation method of the composite modified montmorillonite is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of deionized water, then add 2g of barium chloride, stir at 60℃ for 2h, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) 4g of barium montmorillonite was ultrasonically dispersed in 100mL of deionized water, and then 10g of sodium sulfate solution was added dropwise at a rate of 1d / s. The mass fraction of sodium sulfate solution was 10%. After the addition was completed, the mixture was stirred at 60℃ for 3h. After centrifugation, washing, drying, and grinding through a 400-mesh sieve, the composite filler was obtained. (3) Disperse 10g of composite filler in 100mL of ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), adjust the pH of the solution to 4, then add 0.8g of silane coupling agent KH560, stir at room temperature for 3h, filter, wash and dry to obtain epoxy-grafted composite filler. (4) Disperse 10g of epoxy-grafted composite filler in a mixed solvent of 100mL xylene and 20mL cyclohexanone, then add 2g of carboxyl-terminated polybutadiene and 0.05g of triphenylphosphine, heat at 105℃ for 8h, and after the reaction is completed, filter, wash, dry, grind through a 400-mesh sieve to obtain composite modified montmorillonite.

[0032] Example 2

[0033] A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 3 parts of composite modified montmorillonite to 15 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 40 parts of 2-ethylhexyl acrylate and 2 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.3 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 5 parts of rosin resin and stir until homogeneous. Then add 1 part of aluminum acetylacetonate solution (toluene) with a mass fraction of 10% and continue stirring until homogeneous to obtain the high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0034] The preparation method of the composite modified montmorillonite is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of deionized water, then add 4g of barium chloride, stir at 60℃ for 2h, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) Disperse 8g of barium montmorillonite in 100mL of deionized water by ultrasonication, and then add 15g of sodium sulfate solution at a rate of 1d / s. The mass fraction of sodium sulfate solution is 10%. After the addition is complete, stir and react at 60℃ for 3h. After centrifugation, washing, drying and grinding through a 400-mesh sieve, the composite filler is obtained. (3) Disperse 10g of composite filler in 100mL of ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), adjust the pH of the solution to 4, then add 1g of silane coupling agent KH560, stir at room temperature for 3h, filter, wash and dry to obtain epoxy-grafted composite filler. (4) Disperse 10g of epoxy-grafted composite filler in a mixed solvent of 100mL xylene and 20mL cyclohexanone, then add 5g of carboxyl-terminated polybutadiene and 0.1g of triphenylphosphine, heat at 105℃ for 8h, and after the reaction is completed, filter, wash, dry, grind through a 400-mesh sieve to obtain composite modified montmorillonite.

[0035] Example 3

[0036] A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 4 parts of composite modified montmorillonite to 20 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 50 parts of 2-ethylhexyl acrylate and 4 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.5 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 8 parts of rosin resin and stir until homogeneous. Then add 1.5 parts of aluminum acetylacetonate solution (toluene) with a mass fraction of 10% and continue stirring until homogeneous to obtain the high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0037] The preparation method of the composite modified montmorillonite is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of deionized water, then add 3g of barium chloride, stir at 60℃ for 2h, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) Disperse 6g of barium montmorillonite in 100mL of deionized water by ultrasonication, and then add 15g of sodium sulfate solution at a rate of 1d / s. The mass fraction of sodium sulfate solution is 10%. After the addition is complete, stir and react at 60℃ for 3h. After centrifugation, washing, drying and grinding through a 400-mesh sieve, the composite filler is obtained. (3) Disperse 10g of composite filler in 100mL of ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), adjust the pH of the solution to 4, then add 1.5g of silane coupling agent KH560, stir at room temperature for 3h, filter, wash and dry to obtain epoxy-grafted composite filler. (4) Disperse 10g of epoxy-grafted composite filler in a mixed solvent of 100mL xylene and 20mL cyclohexanone, then add 4g of carboxyl-terminated polybutadiene and 0.08g of triphenylphosphine, heat at 105℃ for 8h, and after the reaction is completed, filter, wash, dry, grind through a 400-mesh sieve to obtain composite modified montmorillonite.

[0038] Comparative Example 1 A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 5 parts of composite modified montmorillonite to 25 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 60 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.4 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 10 parts of rosin resin and stir until homogeneous. Then add 2 parts of aluminum acetylacetonate solution (toluene) with a mass fraction of 10% and continue stirring until homogeneous to obtain the high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0039] The preparation method of the composite modified montmorillonite is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of ethanol aqueous solution (volume ratio of ethanol to water is 4:1), adjust the pH of the solution to 4, then add 0.8g of silane coupling agent KH560, stir at room temperature for 3h, filter, wash and dry to obtain epoxy-grafted montmorillonite. (2) Disperse 10g of epoxy-grafted montmorillonite in a mixed solvent of 100mL xylene and 20mL cyclohexanone, then add 2g of carboxyl-terminated polybutadiene and 0.05g of triphenylphosphine, and heat at 105℃ for 8h. After the reaction is completed, filter, wash, dry, grind and pass through a 400-mesh sieve to obtain composite modified montmorillonite.

[0040] Compared to Comparative Example 1 and Example 1, no barium sulfate was loaded onto montmorillonite.

[0041] Comparative Example 2 A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 5 parts of composite filler to 25 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 60 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.4 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 10 parts of rosin resin and stir until homogeneous. Then add 2 parts of aluminum acetylacetonate solution (toluene) with a mass fraction of 10% and continue stirring until homogeneous to obtain the high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0042] The preparation method of the composite filler is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of deionized water, then add 2g of barium chloride, stir at 60℃ for 2h, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) 4g of barium montmorillonite was ultrasonically dispersed in 100mL of deionized water, and then 10g of sodium sulfate solution was added dropwise at a rate of 1d / s. The mass fraction of sodium sulfate solution was 10%. After the addition was completed, the mixture was stirred at 60℃ for 3h. After centrifugation, washing, drying, and grinding through a 400-mesh sieve, the composite filler was obtained.

[0043] Compared to Example 1, the composite filler in Comparative Example 2 did not have carboxyl-terminated polybutadiene grafted onto it.

[0044] Comparative Example 3 A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive includes the following steps: S1. First, add 5 parts of composite modified montmorillonite to 25 parts of methyl methacrylate and disperse evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 60 parts of 2-ethylhexyl acrylate and 5 parts of methacrylic acid to a mixed solvent of 75 parts of toluene and 25 parts of ethyl acetate and disperse evenly by ultrasonication. Then, add 0.4 parts of azobisisobutyronitrile and react at 78°C for 6 hours under nitrogen protection to obtain a prepolymer solution. S2. Cool the prepolymer solution to 40°C, then add 10 parts of rosin resin and stir until homogeneous to obtain a high-barrier synthetic polymer sealing pressure-sensitive adhesive.

[0045] The preparation method of the composite modified montmorillonite is as follows: (1) Disperse 10g of sodium montmorillonite in 100mL of deionized water, then add 2g of barium chloride, stir at 60℃ for 2h, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) 4g of barium montmorillonite was ultrasonically dispersed in 100mL of deionized water, and then 10g of sodium sulfate solution was added dropwise at a rate of 1d / s. The mass fraction of sodium sulfate solution was 10%. After the addition was completed, the mixture was stirred at 60℃ for 3h. After centrifugation, washing, drying, and grinding through a 400-mesh sieve, the composite filler was obtained. (3) Disperse 10g of composite filler in 100mL of ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), adjust the pH of the solution to 4, then add 0.8g of silane coupling agent KH560, stir at room temperature for 3h, filter, wash and dry to obtain epoxy-grafted composite filler. (4) Disperse 10g of epoxy-grafted composite filler in a mixed solvent of 100mL xylene and 20mL cyclohexanone, then add 2g of carboxyl-terminated polybutadiene and 0.05g of triphenylphosphine, heat at 105℃ for 8h, and after the reaction is completed, filter, wash, dry, grind through a 400-mesh sieve to obtain composite modified montmorillonite.

[0046] Compared to Example 1, Comparative Example 3 did not include aluminum acetylacetone solution.

[0047] The pressure-sensitive adhesives prepared in Examples 1-3 and Comparative Examples 1-3 of this invention were subjected to performance tests, as detailed below: Initial tack test; measured according to GB / T 4852-2002, the test result is expressed as the ball number of the largest steel ball that the pressure-sensitive tape can stick to; Holding power test; determined according to GB / T 4851-2014; Peel strength test: Determined according to GB / T 2792-2014 (Test method for 180° peel strength of adhesive tape); Water vapor transmission rate test: The test was conducted in accordance with the test method for water vapor transmission rate of pressure-sensitive adhesive tape in GB / T 15331-2020. The test conditions were: temperature 38℃±0.5℃, relative humidity 90%±2%RH. The test results are shown in Table 1.

[0048] Table 1 Performance test results for different groups As can be seen from the table, compared with comparative examples 1-3, the pressure-sensitive adhesive prepared in the embodiments of the present invention has excellent water vapor barrier properties and adhesive properties.

[0049] Finally, it should be noted that the above embodiments do not limit the present invention in any way. Those skilled in the art can make modifications and improvements based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a high-barrier synthetic polymer sealing pressure-sensitive adhesive, characterized in that, Includes the following steps: S1. First, add the composite modified montmorillonite to methyl methacrylate and disperse it evenly to obtain composite methyl methacrylate. Then, add the composite methyl methacrylate, 2-ethylhexyl acrylate and methacrylic acid to an organic solvent and disperse it evenly by ultrasonication. Subsequently, add the initiator azobisisobutyronitrile and heat the reaction under nitrogen protection to obtain a prepolymer solution. S2. Add rosin resin to the prepolymer solution and stir until homogeneous. Then add aluminum acetylacetone solution and continue stirring until homogeneous to obtain a high-barrier synthetic polymer sealing pressure-sensitive adhesive.

2. The preparation method according to claim 1, characterized in that, In step S1, the preparation method of the composite modified montmorillonite is as follows: (1) Disperse sodium montmorillonite in deionized water, then add soluble barium salt to it, heat and stir, and then centrifuge, wash and dry to obtain barium montmorillonite; (2) Barium montmorillonite was ultrasonically dispersed in deionized water, and then sodium sulfate solution was added dropwise. After the addition was complete, the mixture was stirred and reacted. After centrifugation, washing, drying and grinding, the composite filler was obtained. (3) Disperse the composite filler in an ethanol aqueous solution, adjust the pH of the solution to 4-5, then add silane coupling agent KH560, stir and treat, filter, wash and dry to obtain epoxy-grafted composite filler; (4) Disperse the epoxy-grafted composite filler in a mixed solvent of xylene and cyclohexanone, then add carboxyl-terminated polybutadiene and triphenylphosphine to it, heat the reaction, and after the reaction is completed, filter, wash, dry and grind to obtain the composite modified montmorillonite.

3. The preparation method according to claim 2, characterized in that, In step (1), the mass ratio of sodium montmorillonite to soluble barium salt is 10:2-4.

4. The preparation method according to claim 2, characterized in that, In step (2), the mass ratio of barium montmorillonite to sodium sulfate solution is 4-8:10-15, and the mass fraction of sodium sulfate solution is 5-10%.

5. The preparation method according to claim 2, characterized in that, In step (3), the mass ratio of the composite filler and the silane coupling agent KH560 is 10:0.8-1.

5.

6. The preparation method according to claim 2, characterized in that, In step (4), the mass ratio of epoxy-grafted composite filler, carboxyl-terminated polybutadiene and triphenylphosphine is 10:2-5:0.05-0.

1.

7. The preparation method according to claim 2, characterized in that, In step (4), the temperature of the heating reaction is 105-115℃ and the heating reaction time is 6-8h.

8. The preparation method according to claim 1, characterized in that, By weight, the components are: 3-5 parts of composite modified montmorillonite, 15-25 parts of methyl methacrylate, 40-60 parts of 2-ethylhexyl acrylate, 2-5 parts of methacrylic acid, 0.3-0.6 parts of azobisisobutyronitrile, 5-10 parts of rosin resin, and 1-2 parts of aluminum acetylacetonate solution, wherein the mass fraction of aluminum acetylacetonate solution is 5-10%.

9. The preparation method according to claim 1, characterized in that, In step S1, the temperature of the heating reaction is 75-80℃, and the heating reaction time is 4-8h.

10. The high-barrier synthetic polymer sealing pressure-sensitive adhesive prepared by the preparation method according to any one of claims 1-9.

Images