Flame-retardant modified acrylic resin pressure-sensitive adhesive and production method thereof

Abstract

The invention relates to the field of adhesives, in particular to a flame-retardant modified acrylic resin pressure-sensitive adhesive and a production method thereof.The acrylate pressure-sensitive adhesive is formed by mixing an acrylate emulsion polymer serving as a main raw material and a curing agent, an antioxidant and a wetting agent serving as auxiliary materials, and the flame-retardant modified acrylic resin pressure-sensitive adhesive is prepared by means of miniemulsion polymerization. The acrylate emulsion polymer is prepared, the modified nano magnesium hydroxide and the modified polymeric monomer are added at the same time, the modified nano magnesium hydroxide is connected in the pressure-sensitive adhesive through chemical bonds, dispersion is more uniform, an isolation layer can be formed, and the flame retardant effect of the pressure-sensitive adhesive is improved; the modified polymeric monomer structure contains unsaturated alkenyl functional groups, a rigid heterocyclic structure and a large amount of N and P elements, so that the adhesive property, the high temperature resistance and the flame retardant effect of the acrylate pressure-sensitive adhesive can be improved.

Description

Technical Field

[0001] This invention relates to the field of adhesives, specifically to a flame-retardant modified acrylic resin pressure-sensitive adhesive and its production method. Background Technology

[0002] In modern life, pressure-sensitive adhesives have become an indispensable and important material for human use because they can bond quickly without solvents or heating. Among the many different types of pressure-sensitive adhesives, acrylic resin pressure-sensitive adhesives stand out due to their unique molecular structure and chemical properties. Their excellent antioxidant properties allow them to remain transparent and non-yellowing under ultraviolet light, ensuring stable bonding performance. In terms of physical properties, they combine flexibility and adhesion, enabling them to firmly bond to various materials such as metal, glass, and paper. They also adapt to temperature changes and have a wide range of applications. In particular, the rapid development of the electrical engineering field in recent years, with the significant trend of integration and miniaturization of electrical equipment, has further broadened the application of acrylic resin pressure-sensitive adhesives.

[0003] During the operation of electrical systems, the high-temperature environment generated by the continuous heating of various components accelerates the aging process of pressure-sensitive adhesives, leading to material performance degradation. To ensure the long-term stable operation of electrical equipment, pressure-sensitive adhesives must possess excellent high-temperature resistance, maintaining good adhesion and structural integrity under continuous high-temperature conditions. This prevents loosening of wiring or displacement of components caused by high-temperature softening and delamination. Simultaneously, to address the potential fire risk of electrical equipment, pressure-sensitive adhesives must also possess reliable flame-retardant properties. By slowing the flame propagation speed and inhibiting the combustion reaction, they effectively reduce the probability of fire accidents, creating a dual safety barrier for electrical systems. However, traditional acrylic resin pressure-sensitive adhesives have poor high-temperature resistance and flame retardancy, limiting their application range. Therefore, developing new acrylic resin pressure-sensitive adhesives that combine flame retardancy, high adhesion, and high-temperature resistance is crucial for improving the safety of electrical equipment, facilitating its application in smart grids, new energy vehicles, and other fields, and driving industry technological upgrades. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant modified acrylic resin pressure-sensitive adhesive and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions: A flame-retardant modified acrylic resin pressure-sensitive adhesive, comprising the following components by weight: 70-90 parts modified acrylic emulsion polymer, 5-10 parts diphenylmethane diisocyanate, 1-5 parts stannous octoate, 40-60 parts butyl acetate, 0.5-1 parts antioxidant, and 1-2 parts wetting agent.

[0006] Further, the modified acrylate emulsion polymer comprises the following raw materials in parts by weight: 30-50 parts methyl methacrylate, 5-15 parts butyl acrylate, 2-7 parts hydroxyethyl methacrylate, 0.2-0.7 parts modified polymer monomer, 0.4-1 part n-decane, 1-10 parts sodium dodecyl sulfate, 1-3 parts modified nano magnesium hydroxide, and 0.2-1 part azobisisobutyronitrile; Furthermore, the preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified polymer monomer, and n-decane are stirred evenly to obtain an oil phase; Step S2: Dissolve sodium dodecyl sulfate in deionized water, then add modified nano magnesium hydroxide, and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30-40 minutes between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5-10 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Purge nitrogen gas into the fine emulsion, control the temperature at 70-75℃, and react for 6-8 hours to obtain the modified acrylate emulsion polymer.

[0007] Furthermore, in step S4, the high-shear dispersing emulsifier rotates at a speed of 10,000-12,000 rpm.

[0008] Furthermore, in step S5, the nitrogen purging time is 30-60 minutes.

[0009] Furthermore, the preparation method of the modified nano-magnesium hydroxide includes the following steps: Step A: Add nano-magnesium hydroxide to tetrahydrofuran and disperse by ultrasonication to obtain a nano-magnesium hydroxide dispersion; Step B: Add allyl succinic anhydride to the nano magnesium hydroxide dispersion, stir at room temperature for 12-14 hours, after the reaction is complete, centrifuge, wash the product with ethanol 3-5 times, and dry in an oven to obtain modified nano magnesium hydroxide.

[0010] In the above technical solution, allyl succinic anhydride reacts with the hydroxyl groups on the surface of nano-magnesium hydroxide to generate an ester, thereby introducing alkenyl groups onto the surface of nano-magnesium hydroxide and providing reactive sites for subsequent polymerization reactions.

[0011] Furthermore, the method for preparing the modified polymeric monomer includes the following steps: Step SS1: Add polyaniline to the solvent and stir evenly. Add an ethanol solution prepared with sodium hydroxide and vinyl sulfonyl chloride and continue stirring for 24-26 hours. Filter and dry the filter cake in an oven to obtain modified polyaniline. Step SS2: Add a phosphorus-containing compound to toluene, purge with nitrogen, heat to 90-100℃, add modified polyaniline, after addition, heat to 100-115℃, react for 10-12 hours, cool to 80-90℃, add 25-30 ml of tetrahydrofuran, heat under reflux for 30-40 minutes, cool to room temperature, filter, and dry the solid in an oven to obtain the modified polymer monomer.

[0012] Further, in step SS1, the ethanol solution prepared from the vinylsulfonyl chloride has a mass-volume concentration of 8-9 g / L.

[0013] Further, in step SS1, the solvent is N-methylpyrrolidone.

[0014] Further, in step SS2, the phosphorus-containing compound is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

[0015] In the above technical solution, polyaniline undergoes an acylation reaction with the sulfonyl chloride group in vinyl sulfonyl chloride, which grafts alkenyl groups onto polyaniline, providing reactive sites and producing polyaniline containing alkenyl groups. The alkenyl groups in the alkenyl polyaniline react with the phosphorus-hydrogen bonds on DOPO, which grafts DOPO onto polyaniline to produce modified polyaniline.

[0016] A method for producing a flame-retardant modified acrylic resin pressure-sensitive adhesive includes the following steps: Step 1: Prepare all ingredients according to their weight percentages; Step 2: Add antioxidant, wetting agent, and butyl acetate to the reactor and stir for 5-10 minutes. Add modified acrylate emulsion polymer to the reactor, control the temperature at 70-75℃, stir for 50-60 minutes, cool to room temperature, then add diphenylmethane diisocyanate and stannous octoate to the reactor and stir for 15-30 minutes. Remove bubbles generated during the mixing process by vacuum degassing for 15-20 minutes to obtain pressure-sensitive adhesive.

[0017] Furthermore, in the second step, the antioxidant is di-tert-butyl-p-cresol; the wetting agent is GS-R877 type wetting agent.

[0018] The beneficial effects of this invention are: (1) The present invention prepares modified nano magnesium hydroxide by wet modification process, so that unsaturated alkenyl groups are grafted on its surface, providing reactive sites for subsequent polymerization reaction, so that it can better participate in the polymerization process of acrylate. Modified polyaniline introduces active groups by reacting with vinyl sulfonyl chloride, and then connects with DOPO by chemical bond, introducing substances containing flame retardant elements. The synergistic flame retardant effect of modified nano magnesium hydroxide and phosphorus-containing modified polymer monomers greatly improves the flame retardant performance of the prepared pressure-sensitive adhesive.

[0019] (2) The present invention uses fine emulsion polymerization technology to prepare acrylate emulsion polymers, which can provide a larger specific surface area and improve the polymerization rate. Furthermore, the modified nano magnesium hydroxide and modified polymer monomers participate in the reaction uniformly during the fine emulsion polymerization process, so that the flame retardant elements N and P, the high temperature resistant functional group benzene ring and rigid heterocycle can be evenly distributed in the polymer matrix, effectively improving the high temperature resistance and flame retardant properties of the pressure-sensitive adhesive. In addition, a large number of polymerizable unsaturated alkenyl functional groups can greatly increase the crosslinking density of the prepared acrylate polymer molecular chain, improve its cohesive force, and enable the pressure-sensitive adhesive to exhibit higher adhesion performance.

[0020] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 Infrared spectral analysis results of the modified polymer monomer. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 Preparation of acrylic resin pressure-sensitive adhesive: 0.5 parts of di-tert-butyl-p-cresol, 1 part of GS-R877 wetting agent, and 40 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 70 parts of modified acrylate emulsion polymer were added to the reaction vessel, the temperature was controlled at 70°C, and the mixture was stirred for 50 minutes. After cooling to room temperature, 5 parts of diphenylmethane diisocyanate and 1 part of stannous octoate were added to the reaction vessel and stirred for 15 minutes. The mixture was then degassed under vacuum for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0025] The preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Mix 40g methyl methacrylate, 10g butyl acrylate, 5g hydroxyethyl methacrylate, 0.5g modified polymer monomer, and 0.6g n-decane until homogeneous to obtain the oil phase; Step S2: Dissolve 5g of sodium dodecyl sulfate in deionized water, then add 1.5g of modified nano magnesium hydroxide, and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and 0.5g of azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30min between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Nitrogen gas is introduced into the fine emulsion, the temperature is controlled at 70℃, and the reaction is carried out for 6 hours to obtain the modified acrylate emulsion polymer.

[0026] The preparation method of modified nano-magnesium hydroxide includes the following steps: Step A: Add 3.5g of nano magnesium hydroxide to 100ml of tetrahydrofuran, disperse by ultrasonication, and stir in a 75℃ constant temperature water bath to obtain a nano magnesium hydroxide dispersion. Step B: Add 1g of allyl succinic anhydride to the nano magnesium hydroxide dispersion, stir at room temperature for 14h, after the reaction is complete, centrifuge, wash the product with ethanol 3-5 times, and dry in an oven to obtain modified nano magnesium hydroxide.

[0027] The ester content of modified nano magnesium hydroxide was tested by soap back titration. 0.3g was selected as the test sample, and the results showed that the ester content was 3.216mmol / g.

[0028] The preparation method of the modified polymer monomer includes the following steps: Step SS1: Add 1g of polyaniline to 300ml of N-methylpyrrolidone, stir well, add a solution prepared by 7g of sodium hydroxide, 2.5g of vinyl sulfonyl chloride and 200ml of ethanol, continue stirring for 24h, filter, and dry the filter cake in an oven to obtain modified polyaniline. Step SS2: Add 3.5g of DOPO to 100ml of toluene, purge with nitrogen, heat to 90℃, add 0.5g of modified polyaniline, after which heat to 115℃ and react for 10h, then cool to 90℃, add 25ml of tetrahydrofuran, heat under reflux for 30min, cool to room temperature, filter, and dry the solid in an oven to obtain the modified polymer monomer.

[0029] The modified monomers were prepared into potassium bromide tablets, and infrared analysis was performed. The results are as follows: Figure 1 As shown, 3431cm -1 The absorption peak appearing at 3285 cm⁻¹ is a characteristic absorption peak of nitrogen-hydrogen bonding. -1 The absorption peak appearing at 3064 cm⁻¹ is a characteristic absorption peak of hydroxyl groups. -1 The absorption peak appearing at 2900 cm⁻¹ is a characteristic absorption peak of the carbon-hydrogen bond of the benzene ring. -1 The absorption peak appearing at 1760 cm⁻¹ is a characteristic absorption peak of the carbon-hydrogen bonds in aliphatic chains. -1 The absorption peak appearing at 1515 cm⁻¹ is a characteristic absorption peak of the carbon-oxygen double bond in an ester group. -1 1445cm -1 The absorption peak appearing at 1350 cm⁻¹ is a characteristic absorption peak of phosphorus attached to a benzene ring. -1 The absorption peak appearing at 1205 cm⁻¹ is a characteristic absorption peak of the sulfur-oxygen double bond in sulfonyl chloride. -1 The absorption peak appearing at this point is a characteristic absorption peak of the phosphorus-oxygen double bond.

[0030] Example 2 Preparation of acrylic resin pressure-sensitive adhesive: 0.8 parts of di-tert-butyl-p-cresol, 1.2 parts of GS-R877 wetting agent, and 42 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 85 parts of modified acrylate emulsion polymer were added to the vessel, and the temperature was controlled at 70°C. Mechanical stirring was used for 50 minutes. The mixture was then cooled to room temperature. Next, 2 parts of stannous octoate and 6 parts of diphenylmethane diisocyanate were added to the reaction vessel and stirred for 15 minutes. Vacuum degassing was performed for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0031] The preparation methods for the modified nano-magnesium hydroxide and the modified polymer monomer are the same as in Example 1.

[0032] Example 3 Preparation of acrylic resin pressure-sensitive adhesive: One part of di-tert-butyl-p-cresol, two parts of GS-R877 wetting agent, and 50 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 90 parts of modified acrylate emulsion polymer were added to the vessel and the temperature was controlled at 70°C. The mixture was mechanically stirred for 50 minutes and then cooled to room temperature. Next, five parts of stannous octoate and ten parts of diphenylmethane diisocyanate were added to the reaction vessel and stirred for 15 minutes. The mixture was then degassed under vacuum for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0033] The preparation methods for the modified nano-magnesium hydroxide and the modified polymer monomer are the same as in Example 1.

[0034] Comparative Example 1 Preparation of acrylic resin pressure-sensitive adhesive: Take 42 parts of butyl acetate to prepare pressure-sensitive adhesive.

[0035] Comparative Example 2 Preparation of acrylic resin pressure-sensitive adhesive: 0.8 parts of di-tert-butyl-p-cresol, 1.2 parts of GS-R877 wetting agent, and 42 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 85 parts of modified acrylate emulsion polymer were added to the vessel, and the temperature was controlled at 70°C. Mechanical stirring was used for 50 minutes. The mixture was then cooled to room temperature. Next, 2 parts of stannous octoate and 6 parts of diphenylmethane diisocyanate were added to the reaction vessel and stirred for 15 minutes. Vacuum degassing was performed for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0036] The preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Mix 40g methyl methacrylate, 10g butyl acrylate, 5g hydroxyethyl methacrylate, and 0.6g n-decane until homogeneous to obtain the oil phase; Step S2: Dissolve 5g of sodium dodecyl sulfate in deionized water, then add 1.5g of modified nano magnesium hydroxide, and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and 0.5g of azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30min between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Nitrogen gas is introduced into the fine emulsion, the temperature is controlled at 70℃, and the reaction is carried out for 6 hours to obtain the modified acrylate emulsion polymer.

[0037] The preparation method of the modified nano-magnesium hydroxide is the same as that in Example 1.

[0038] Comparative Example 3 Preparation of acrylic resin pressure-sensitive adhesive: 0.8 parts of di-tert-butyl-p-cresol, 1.2 parts of GS-R877 wetting agent, and 42 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 85 parts of modified acrylate emulsion polymer were added to the vessel, and the temperature was controlled at 70°C. Mechanical stirring was used for 50 minutes. The mixture was then cooled to room temperature. Next, 2 parts of stannous octoate and 6 parts of diphenylmethane diisocyanate were added to the reaction vessel and stirred for 15 minutes. Vacuum degassing was performed for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0039] The preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Mix 40g methyl methacrylate, 10g butyl acrylate, 5g hydroxyethyl methacrylate, 0.5g modified polymer monomer, and 0.6g n-decane until homogeneous to obtain the oil phase; Step S2: Dissolve 5g of sodium dodecyl sulfate in deionized water and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and 0.5g of azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30min between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Nitrogen gas is introduced into the fine emulsion, the temperature is controlled at 70℃, and the reaction is carried out for 6 hours to obtain the modified acrylate emulsion polymer.

[0040] The preparation method of the modified polymer monomer is the same as that in Example 1.

[0041] Comparative Example 4 Preparation of acrylic resin pressure-sensitive adhesive: 0.8 parts of di-tert-butyl-p-cresol, 1.2 parts of GS-R877 wetting agent and 42 parts of butyl acetate were added to a reaction vessel and stirred for 5 minutes. Then, 85 parts of modified acrylate emulsion polymer were added to the vessel, and the temperature was controlled at 70°C. Mechanical stirring was used for 50 minutes. The mixture was then cooled to room temperature. Finally, 2 parts of stannous octoate were added to the reaction vessel and stirred for 15 minutes. Vacuum degassing was performed for 15 minutes to remove the bubbles generated during the mixing process, thus obtaining the pressure-sensitive adhesive.

[0042] The preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Mix 40g methyl methacrylate, 10g butyl acrylate, 5g hydroxyethyl methacrylate, and 0.6g n-decane until homogeneous to obtain the oil phase; Step S2: Dissolve 5g of sodium dodecyl sulfate in deionized water, then add 1.5g of modified nano magnesium hydroxide, and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and 0.5g of azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30-40 minutes between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Nitrogen gas is introduced into the fine emulsion, the temperature is controlled at 70℃, and the reaction is carried out for 6 hours to obtain the modified acrylate emulsion polymer.

[0043] The preparation methods for the modified nano-magnesium hydroxide and the modified polymer monomer are the same as those in Example 1.

[0044] Test case I. The acrylic pressure-sensitive adhesive from the examples and comparative examples was coated onto the surface of a PET film, cured at 80°C for 10 minutes, and then removed. A release film was then placed over the coated surface, and the film was cured at 50°C for 24 hours. The film was then removed and subjected to a 180° peel strength test. The test method was based on standard GB / T 2792-1998. After the test, the same batch of test samples were placed at 150°C for 48 hours and then subjected to a 180° peel strength test. II. The acrylic pressure-sensitive adhesive from the examples and comparative examples was coated on the surface of a PET film with dimensions of 127 mm in length, 13 mm in width, and 5 mm in thickness. After curing, the sample was placed in an environment with a temperature of 23°C and a humidity of 50% for 48 hours to equilibrate. The sample was then removed and subjected to a flame retardancy test, with the test method referring to standard UL94-2023. Analysis of the data shows that the acrylate emulsion polymers prepared in Examples 1-3, when used as the base material for pressure-sensitive adhesives, enable the acrylate pressure-sensitive adhesives to have good adhesion, temperature resistance, and flame retardant properties. When using acrylate emulsion polymers prepared without the addition of modified polymer monomers as the base material, the adhesion, temperature resistance, and flame retardant properties of the pressure-sensitive adhesives all decrease significantly. When using acrylate emulsion polymers prepared without the addition of diphenylmethane diisocyanate as the base material, the adhesion and temperature resistance of the pressure-sensitive adhesives are poor. Therefore, the addition of diphenylmethane diisocyanate can enhance the adhesion and temperature resistance of the pressure-sensitive adhesives.

[0045] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A flame-retardant modified acrylic resin pressure-sensitive adhesive, characterized in that, By weight, it includes the following components: 70-90 parts modified acrylate emulsion polymer, 5-10 parts diphenylmethane diisocyanate, 1-5 parts stannous octoate, 40-60 parts butyl acetate, 0.5-1 parts antioxidant, and 1-2 parts wetting agent.

2. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 1, characterized in that, The modified acrylate emulsion polymer comprises the following raw materials in parts by weight: 30-50 parts methyl methacrylate, 5-15 parts butyl acrylate, 2-7 parts hydroxyethyl methacrylate, 0.2-0.7 parts modified polymer monomer, 0.4-1 part n-decane, 1-10 parts sodium dodecyl sulfate, 1-3 parts modified nano magnesium hydroxide, and 0.2-1 part azobisisobutyronitrile; The preparation method of the modified acrylate emulsion polymer includes the following steps: Step S1: Mix methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, modified polymerizing monomer, and n-decane until homogeneous to obtain the oil phase; Step S2: Dissolve sodium dodecyl sulfate in deionized water, then add modified nano magnesium hydroxide, and stir until homogeneous to obtain an aqueous phase; Step S3: Divide the aqueous phase and azobisisobutyronitrile into three equal parts and add them to the oil phase simultaneously in three separate additions, with an interval of 30-40 minutes between each addition. After the addition is complete, a pre-emulsion is obtained. Step S4: Emulsify at high speed for 5-10 minutes using a high-shear dispersing emulsifier in an ice-water bath to obtain a stable monomer fine emulsion; Step S5: Purge nitrogen gas into the fine emulsion, control the temperature at 70-75℃, and react for 6-8 hours to obtain the modified acrylate emulsion polymer.

3. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 2, characterized in that, In step S4, the high shear dispersion emulsifier rotates at a speed of 10,000-12,000 rpm.

4. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 2, characterized in that, In step S5, nitrogen gas is passed through for 30-60 minutes.

5. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 2, characterized in that, The preparation method of the modified nano-magnesium hydroxide includes the following steps: Step A: Add nano-magnesium hydroxide to tetrahydrofuran and disperse by ultrasonication to obtain a nano-magnesium hydroxide dispersion; Step B: Add allyl succinic anhydride to the nano magnesium hydroxide dispersion, stir at room temperature for 12-14 hours, after the reaction is complete, centrifuge, wash the product with ethanol 3-5 times, and dry in an oven to obtain modified nano magnesium hydroxide.

6. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 2, characterized in that, The method for preparing the modified polymeric monomer includes the following steps: Step SS1: Add polyaniline to the solvent and stir until homogeneous. Add an ethanol solution prepared from sodium hydroxide and vinyl sulfonyl chloride and continue stirring for 24-26 hours. Filter the mixture and dry the filter cake in an oven to obtain modified polyaniline. Step SS2: Add a phosphorus-containing compound to toluene, heat to 90-100℃ under nitrogen protection, add modified polyaniline, and after the addition is complete, react for 10-12 hours, then cool to 80-90℃, add 25-30 ml of tetrahydrofuran, reflux for 30-40 min, cool to room temperature, filter, and dry the solid in an oven to obtain the modified polymer monomer.

7. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 6, characterized in that, In step SS1, the ethanol solution prepared from vinyl sulfonyl chloride has a mass-volume concentration of 8-9 g / L.

8. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 6, characterized in that, In step SS1, the solvent is N-methylpyrrolidone.

9. The flame-retardant modified acrylic resin pressure-sensitive adhesive according to claim 6, characterized in that, In step SS2, the phosphorus-containing compound is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO).

10. A method for producing a flame-retardant modified acrylic resin pressure-sensitive adhesive as described in claim 1, characterized in that, Includes the following steps: Step 1: Prepare all ingredients according to their weight percentages; Step 2: Add di-tert-butyl-p-cresol, GS-R877 wetting agent, and butyl acetate to the reactor and stir for 5-10 minutes. Then add the modified acrylate emulsion polymer to the reactor, control the temperature at 70-75℃, stir for 50-60 minutes, cool to room temperature, and then add diphenylmethane diisocyanate and stannous octoate to the reactor and stir for 15-30 minutes. Remove the bubbles generated during the mixing process by vacuum degassing for 15-20 minutes to obtain the pressure-sensitive adhesive.

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