Flame-retardant acrylic acid adhesive, flame-retardant acrylic acid foam tape and preparation method of flame-retardant acrylic acid adhesive

Abstract

The invention discloses a flame-retardant acrylic adhesive, a flame-retardant acrylic foam tape and a preparation method, the flame-retardant acrylic adhesive comprises the following raw materials by mass: 70-90 parts of a soft monomer, 10-30 parts of a functional monomer, 10-30 parts of an acrylate monomer, 0.1-1.5 parts of a photoinitiator A, 0.1-1.5 parts of a photoinitiator B, 4-9 parts of hollow glass microspheres, and 0.05-0.2 part of a cross-linking agent. The flame-retardant coating is prepared from the following components in parts by weight: 1 to 3 parts of fumed silica, 0.01 to 0.2 part of chain transfer agent, 0.01 to 0.2 part of silane coupling agent, 0.05 to 0.5 part of color paste, 30 to 65 parts of flame-retardant powder and 5 to 15 parts of flame-retardant monomer. The flame-retardant acrylic foam tape prepared from the flame-retardant acrylic adhesive disclosed by the invention has excellent flame-retardant effect and high viscosity, and the preparation process is environment-friendly and efficient.

Description

Technical Field

[0001] This invention belongs to the field of flame retardant adhesive technology, specifically relating to a flame retardant acrylic adhesive, a flame retardant acrylic foam tape, and a preparation method thereof. Background Technology

[0002] High-viscosity acrylic flame-retardant foam, as a functional polymer material, integrates three major technical characteristics: pressure-sensitive adhesion, fire safety, and stress buffering. Its core technology focuses on molecular structure design, achieving flame retardancy with an oxygen index >28% through chemical bonding between an acrylate copolymer matrix and an environmentally friendly flame retardant, while maintaining a peel strength >3000 gf / in. This material uses a closed-cell foaming process to form a micron-level honeycomb structure, replacing traditional welding processes in applications such as sealing new energy vehicle battery packs and fire-resistant bonding of electronic devices.

[0003] Flame-retardant foam tape is widely used in electronic appliances, automotive parts, and mechanical components due to its sealing, shock absorption, and fireproof properties. It is especially used in lithium battery packs where stringent requirements such as flame retardancy, heat insulation, and resistance to compression deformation must be met.

[0004] With the increasing requirements for thermal runaway protection of power batteries, traditional flame-retardant foam tapes are prone to becoming a medium for fire spread in extreme scenarios such as battery thermal runaway due to insufficient flame-retardant performance. Traditional flame-retardant foam tapes will melt and drip at temperatures above 300°C, which cannot meet the fire protection and isolation requirements of new energy battery packs. In addition, in automotive interior applications, exterior trim parts need to withstand temperature difference cycles of -40°C to 90°C, while traditional flame-retardant foam tapes will curl up and fail.

[0005] Therefore, there is an urgent need to develop new materials that combine high flame retardancy with durable adhesion. Summary of the Invention

[0006] The purpose of this invention is to provide a flame-retardant acrylic adhesive, a flame-retardant acrylic foam tape, and a preparation method thereof. The flame-retardant acrylic foam tape has both excellent flame-retardant effect and high adhesion.

[0007] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0008] A flame-retardant acrylic adhesive, comprising the following raw materials in parts by weight: 70-90 parts soft monomer, 10-30 parts functional monomer, 10-30 parts acrylate monomer, 0.1-1.5 parts photoinitiator A, 0.1-1.5 parts photoinitiator B, 4-9 parts hollow glass microspheres, 0.05-0.2 parts crosslinking agent, 1-3 parts fumed silica, 0.01-0.2 parts chain transfer agent, 0.01-0.2 parts silane coupling agent, 0.05-0.5 parts nano pigment, 30-65 parts flame-retardant powder, and 5-15 parts flame-retardant monomer.

[0009] In one or more embodiments of the present invention, the D50 of the hollow glass microspheres is 50μm-100μm.

[0010] In one or more embodiments of the present invention, the average particle size of the fumed silica is less than or equal to 30 nm.

[0011] In one or more embodiments of the present invention, the soft monomer is at least one selected from n-butyl acrylate and isooctyl acrylate; and / or,

[0012] The functional monomer is at least one selected from acrylic acid, N-vinylpyrrolidone, hydroxyethyl acrylate, β-carboxyethyl acrylate, N-vinylcaprolactam, and N,N-dimethylamide; and / or,

[0013] The acrylate monomer is at least one of methyl methacrylate, isobornyl acrylate, and isobornyl methacrylate.

[0014] In one or more embodiments of the present invention, the flame-retardant monomer is at least one selected from phosphate monoacrylate and diphosphate methacrylate; and / or,

[0015] The flame retardant powder is at least one of Daer Chemical 7228 and Daer Chemical 8314.

[0016] In one or more embodiments of the present invention, the photoinitiator A is at least one selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 4,6-trimethylbenzoyl)phosphine oxide, α-dimethoxy-α-phenylacetophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or,

[0017] The photoinitiator B is at least one selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 4,6-trimethylbenzoyl)phosphine oxide, α-dimethoxy-α-phenylacetophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or

[0018] The crosslinking agent is at least one selected from hexanediol diacrylate, trimethylolpropane triacrylate, and acrylamide; and / or...

[0019] The chain transfer agent is dodecyl mercaptan; and / or,

[0020] The silane coupling agent is KBM-403.

[0021] Another specific embodiment of the present invention provides the following technical solution:

[0022] A method for preparing a flame-retardant acrylic adhesive, the method comprising the following steps:

[0023] The soft monomer, functional monomer, appropriate amount of photoinitiator A and appropriate amount of chain transfer agent are mixed and reacted under ultraviolet irradiation to obtain the prepolymer;

[0024] A flame-retardant acrylic adhesive is obtained by mixing prepolymer, acrylate monomers, residual photoinitiator A, photoinitiator B, crosslinking agent, residual chain transfer agent, silane coupling agent, nano-color paste, flame retardant powder, flame retardant monomer, hollow glass microspheres, and fumed silica.

[0025] In one or more embodiments of the present invention, the prepolymer and acrylate monomers are first mixed, then the remaining photoinitiator A, photoinitiator B, crosslinking agent, remaining chain transfer agent, silane coupling agent, color paste, flame retardant powder and flame retardant monomer are added and mixed, and finally hollow glass microspheres and fumed silica are added and mixed to obtain a flame retardant acrylic adhesive.

[0026] In one or more embodiments of the present invention, the raw materials are mixed and then subjected to vacuum negative pressure degassing treatment to obtain flame-retardant acrylic adhesive.

[0027] Another specific embodiment of the present invention provides the following technical solution:

[0028] A flame-retardant acrylic foam tape includes an acrylic foam adhesive layer and a release layer stacked together, wherein the acrylic foam adhesive layer is formed by a flame-retardant acrylic adhesive.

[0029] Compared with existing technologies, this invention uses a compound of flame-retardant powder and flame-retardant monomers, while optimizing the proportions of other raw materials, to produce flame-retardant acrylic foam tape with excellent flame-retardant properties, high viscosity, and strong adhesion. Furthermore, this invention employs a UV curing system, making it more environmentally friendly and efficient. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of flame-retardant acrylic foam tape in one embodiment of the present invention.

[0032] Explanation of key figure labels:

[0033] 1. Acrylic foam adhesive layer; 2. Release layer. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0035] A specific embodiment of the present invention provides a flame-retardant acrylic adhesive, comprising the following raw materials in parts by weight: 70-90 parts of soft monomer, 10-30 parts of functional monomer, 10-30 parts of acrylate monomer, 0.1-1.5 parts of photoinitiator A, 0.1-1.5 parts of photoinitiator B, 4-9 parts of hollow glass microspheres, 0.05-0.2 parts of crosslinking agent, 1-3 parts of fumed silica, 0.01-0.2 parts of chain transfer agent, 0.01-0.2 parts of silane coupling agent, 0.05-0.5 parts of nano-color paste, 30-65 parts of flame-retardant powder, and 5-15 parts of flame-retardant monomer.

[0036] Specifically, this invention uses soft monomers, functional monomers, and acrylic monomers as main raw materials, and through polymerization, imparts excellent tack and adhesion to the adhesive. Simultaneously, by leveraging the synergistic effect of flame-retardant powder and flame-retardant monomers, the flame retardancy of the adhesive is significantly improved, achieving a UL94 V0 level. Furthermore, the use of a photoinitiator enables the adhesive to be light-cured, making the process more environmentally friendly and efficient.

[0037] By combining the above raw materials, the adhesive in this invention possesses both high viscosity and high flame retardant properties.

[0038] Furthermore, the soft monomer is at least one of n-butyl acrylate and isooctyl acrylate; the functional monomer is at least one of acrylic acid, N-vinylpyrrolidone, hydroxyethyl acrylate, β-carboxyethyl acrylate, N-vinylcaprolactam, and N,N dimethylamide; the acrylate monomer is at least one of methyl methacrylate, isobornyl acrylate, and isobornyl methacrylate; the flame retardant monomer is at least one of phosphate monoacrylate and phosphate dimethacrylate; and the flame retardant powder is at least one of Daer Chemical 7228 and Daer Chemical 8314.

[0039] Furthermore, photoinitiator A is at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 1-hydroxycyclohexylphenyl ketone (184), 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (907), 4,6-trimethylbenzoyl)phosphine oxide (TPO), α-dimethoxy-α-phenylacetophenone (651), and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819), and photoinitiator B ...hydroxycyclohexylphenyl ketone (184), 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (907), 2-hydroxycyclohexylphenyl ketone (184), 2-hydroxycyclohexylphenyl ketone (184), 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (907), 2-hydroxycyclohexylphenyl ketone (184), 2-hydroxycyclohexylphenyl ketone (907), 2-hydroxycyclohexylphenyl ketone (184), The product contains at least one of hexylphenyl ketone (184), 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone (907), 4,6-trimethylbenzoyl)phosphine oxide (TPO), α-dimethoxy-α-phenylacetophenone (651), and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819), with at least one of hexanediol diacrylate (HDDA), trimethylolpropane triacrylate (TMPTA), and acrylamide (AM) as the crosslinking agent, dodecyl mercaptan as the chain transfer agent, and KBM-403 as the silane coupling agent.

[0040] Furthermore, the D50 of the hollow glass microspheres is 50μm-100μm.

[0041] Specifically, hollow glass microspheres help enhance the mechanical properties and thermal insulation of adhesives. By controlling their particle size, they can be uniformly dispersed in the adhesive, thereby effectively improving the performance of the adhesive. Hollow glass microspheres can be selected from Zhongke Huaxing C20, Shenglete HS20 (D50: 65μm, D90: 110μm), and Shenglete HL15 (D50 particle size: 80μm, D90 particle size: 120μm).

[0042] Furthermore, the average particle size of fumed silica is less than or equal to 30 nm.

[0043] Specifically, fumed silica helps enhance the strength of adhesives while improving their thixotropic and rheological properties. By controlling the particle size and optimizing the filling of fumed silica in the system, the performance of the adhesive can be improved.

[0044] Another specific embodiment of the present invention provides a method for preparing a flame-retardant acrylic adhesive, comprising the following steps:

[0045] Step 1: The soft monomer, functional monomer, appropriate amount of photoinitiator A and appropriate amount of chain transfer agent are reacted under ultraviolet irradiation to obtain the prepolymer.

[0046] Specifically, in this step, the amount of photoinitiator A used is approximately 20% of the total amount of photoinitiator A, and the amount of chain transfer agent used is approximately 20% of the total amount of chain transfer agent.

[0047] Step 2: Mix the prepolymer, acrylate monomers, residual photoinitiator A, photoinitiator B, crosslinking agent, residual chain transfer agent, silane coupling agent, color paste, flame retardant powder, flame retardant monomer, hollow glass microspheres, and fumed silica to obtain a flame retardant acrylic adhesive.

[0048] Specifically, the prepolymer and acrylate monomers are first mixed, then the remaining photoinitiator A, photoinitiator B, crosslinking agent, remaining chain transfer agent, silane coupling agent, colorant, flame retardant powder, and flame retardant monomer are added and mixed. Finally, hollow glass microspheres and fumed silica are added and mixed. After mixing, vacuum degassing is performed. By mixing the raw materials in steps, each raw material can be uniformly dispersed in the system, thereby ensuring that the obtained adhesive has excellent tack and adhesion.

[0049] In addition, by first preparing the prepolymer in step 1 and then preparing the finished product in step 2, the adhesive properties can be optimized, resulting in an adhesive that has both excellent flame retardancy and adhesion.

[0050] Another specific embodiment of the present invention provides a flame-retardant acrylic foam tape, such as... Figure 1 As shown, it includes an acrylic foam adhesive layer and a release layer stacked together, wherein the acrylic foam adhesive layer is formed by the aforementioned flame-retardant acrylic adhesive.

[0051] Specifically, the release layer can be a commonly used release film, such as PE release film.

[0052] The present invention will be further described in detail below with reference to specific embodiments.

[0053] The raw materials used in this invention are sourced from the following sources: hollow glass microspheres, Saint-Lite HL15; fumed silica, Evonik R972; nano pigments, Cody oil-based pigments; and other raw materials, unless otherwise specified, are obtained commercially available.

[0054] Example 1

[0055] The flame-retardant acrylic adhesive and flame-retardant acrylic foam tape were prepared as follows in this embodiment:

[0056] (1) Preparation of prepolymer

[0057] 85 parts by mass of the soft monomer n-butyl acrylate and 20 parts by mass of the functional monomer hydroxyethyl acrylate were mixed to form a mixed monomer solution. The mixed monomer solution was added to a reactor, and 0.1 parts by mass of photoinitiator A (2-hydroxy-2-methyl-1-phenyl-1-propanone) and 0.05 parts by mass of chain transfer agent (dodecyl mercaptan) were added to the reactor. The mixture was stirred for 20 minutes under nitrogen protection. After thorough stirring, the polymerization reaction was initiated under ultraviolet light (LED light source with a wavelength of 365 nm). When the viscosity of the reaction system reached a certain value (4000-7000 CPS is sufficient for easy coating), the ultraviolet light was turned off to obtain the prepolymer.

[0058] (2) Preparation of flame-retardant acrylic foam tape by photocuring

[0059] S1. Weigh 100 parts by weight of prepolymer and 15 parts by weight of methyl methacrylate, mix and stir for 2 hours to ensure that the prepolymer and acrylate monomer are completely and evenly mixed.

[0060] S2. Based on step S1, add 0.1 parts by weight of photoinitiator A (2-hydroxy-2-methyl-1-phenyl-1-propanone), 0.15 parts by weight of photoinitiator B (2-hydroxy-2-methyl-1-phenyl-1-propanone), 0.12 parts by weight of crosslinking agent (hexanediol diacrylate), 0.02 parts by weight of chain transfer agent (dodecyl mercaptan), 0.03 parts by weight of silane coupling agent (KBM-403), 0.1 parts by weight of nano-color paste, 50 parts by weight of flame retardant powder (Daor Chemical 7228), and 8 parts by weight of flame retardant monomer (acrylate monophosphate). Stir for 1 hour to ensure that all additives are fully mixed and homogeneous.

[0061] S3. Based on step S2, add 4 parts by mass of hollow glass microspheres and 3 parts by mass of fumed silica, stir for 2 hours to ensure the filler is fully and evenly mixed, and obtain flame-retardant acrylic adhesive.

[0062] S4. The flame-retardant acrylic adhesive obtained in step S3 is degassed under vacuum negative pressure and coated with a double roller coating head. After curing by ultraviolet light, flame-retardant acrylic foam tape (700μm thickness product) is obtained.

[0063] Examples 2-4, Comparative Examples 1-3

[0064] The preparation of flame-retardant acrylic adhesive and flame-retardant acrylic foam tape in Examples 2-4 and Comparative Examples 1-3 is basically the same as that in Example 1. The difference is that the amount of each raw material used in step (2) of light curing to prepare flame-retardant acrylic foam tape is different, as shown in Table 1.

[0065] Table 1. Raw material usage in each embodiment and comparative example

[0066]

[0067] The following tests were performed on the tapes used in each embodiment and comparative example:

[0068] (1) 90° peel test, according to GB / T 2792-2014 "Test method for peel strength of adhesive tape", as follows:

[0069] 1) Preparation of experimental conditions

[0070] a. The test environment was a constant temperature and humidity environment with a temperature of (23±1)℃ and a relative humidity of 50%±5%.

[0071] b. Testing Machine: A constant-speed tensile testing machine is used. The automatic recorder records the value once every 1 mm of adhesive tape is peeled off. The testing machine must be equipped with two grippers, upper and lower. The grippers should clamp the entire specimen, and the lower gripper, which applies the tensile force, descends at a uniform speed of (5 ± 0.2) mm / s. The automatic recorder plots the peel curve. This instrument must be calibrated, with a maximum error of 2%.

[0072] c. Cleaning agents and cleaning materials: Cleaning agents are general chemical grade acetone, isopropanol, methanol, methyl ethyl ketone, n-heptane, etc.; cleaning materials are lint-free, easily absorbent medical degreased gauze, cotton thread, or cotton paper.

[0073] d. Stainless steel test plate. The stainless steel plate should be very flat, at least 125 mm long, 50 mm wide, and 1.1 mm thick. It should be annealed and polished, with a bright surface and a roughness (GB / T 2523—2008) of (50±25) nm.

[0074] e. The pressure roller is a stainless steel cylinder with a smooth surface, measuring (85±2.5) mm in diameter and (45±1.5) mm in width. Its surface is covered with approximately 6 mm thick rubber with a Shore A hardness of 80±5. The total mass is (2±0.1) kg. The pressure roller can be rolled mechanically or manually, with the rolling speed controllable at (10±0.5) mm / s.

[0075] 2) Preparation of tape samples

[0076] a. The entire roll of adhesive tape sample, test steel plate, rolling mill, etc. should be placed in the test environment and left for more than 24 hours.

[0077] b. Cut at least three tape samples, each 25 mm wide (with a limited deviation of ±0.5 mm allowed) and approximately 300 mm long.

[0078] 3) Test Procedure

[0079] a. Test plate pretreatment: Wipe the steel plate with the above-mentioned cleaning agent and dry it with the above-mentioned cleaning material. Repeat the cleaning process three times. For the final wipe, use methyl ethyl ketone or acetone. Allow the steel plate to air dry for at least 10 minutes. If it will not be used within 10 hours, it must be cleaned again. Within 5 minutes of unwinding, attach the sample to the test plate and let it stand under constant temperature and humidity conditions for 20 minutes.

[0080] b. After peeling 25mm, fix the sample in the upper and lower clamps, and start the testing machine to automatically record data.

[0081] (2) Rolling ball initial tack test, according to GB / T 4852-2002 "Test method for initial tack of pressure sensitive adhesive tape (rolling ball method)", the specific details are as follows:

[0082] Samples: The dimensions are at least 25mm wide and 250mm long; the quantity should be no less than 4.

[0083] a. Use a level to fix the test apparatus horizontally on the test platform, with the inclined plane at a standard 30° angle;

[0084] b. Secure the test strip of the tape to the surface of the inclined plate with the adhesive side facing up using positioning tape, and attach the polyester film to the specified position of the upper rolling section of the test strip, ensuring that the length of both the rolling section and the measuring section is 100 mm. The rolling section should be flat and free of defects such as bubbles and wrinkles.

[0085] c. Use tweezers to place the clean steel ball into the ball release device. Adjust the front-to-back position of the ball release device so that the center of the steel ball is located on the starting line of the rolling section. Before the formal test, a single sample is allowed to be tested multiple times, but the left-to-right position of the ball release device should be adjusted so that the rolling trajectory of the steel ball does not overlap each time. When the sample width is greater than 25mm, the 25mm wide area in the center of the sample is the effective test area. Pre-select the largest steel ball: Gently open the ball release device and observe whether the rolling steel ball is stuck in the test section (stop moving for more than 5 seconds). From largest to smallest, take steel balls of different sizes and perform an appropriate number of tests until the largest steel ball that can be stuck in the test section is found.

[0086] d. For the formal test, take 3 samples and perform a rolling ball test once for each sample using the largest ball size steel ball. If a sample cannot stick to the steel ball, it can be replaced with a steel ball of a smaller size for another test. If it still cannot stick, the test must be repeated.

[0087] Test results are expressed as the number of the largest steel ball that can be stuck.

[0088] If all three steel balls attached to the three samples are the largest ball size, or if two are the largest ball size and the size of the third ball is only smaller than the largest ball size, the test result is expressed as the largest ball size. If one is the largest ball size and the sizes of the other two balls are only smaller than the largest ball size, the test result is expressed as the ball size of the ball that is only smaller than the largest ball size.

[0089] (3) Flame retardancy test, according to GB / T 2408-2021 "Determination of flammability of plastics - Horizontal and Vertical Methods", including tape substrate and adhesive, as follows:

[0090] Sample size: 125mm×13mm, thickness ≤13mm. Two groups were tested (5 pieces per group). One group was pretreated at room temperature (23℃ / 50% humidity environment conditioning for 48 hours), and the other group was aged at 70℃ for 7 days. The flame height was 20mm. Two 10-second ignitions were performed, and the afterflame time (t1 / t2) and whether the dripping material ignited the cotton were recorded at intervals.

[0091] Result determination: V-0: The flame extinguishes within 10 seconds after a single ignition, and the total burning time of the 5 samples is ≤50 seconds. No molten droplets ignite the absorbent cotton below.

[0092] V-1: The flame extinguishes within 30 seconds after a single ignition, and the total burning time of 5 samples is ≤250 seconds. Molten droplets are permitted but will not ignite the absorbent cotton.

[0093] V-2: Same as V-1, but allows molten droplets to ignite the absorbent cotton.

[0094] Table 2 Performance Test Results

[0095] As can be seen from the above, by adding an appropriate proportion of flame retardant powder and flame retardant monomer, the tape produced by this invention can achieve a UL94V0 flame retardant effect and has high adhesion, which is suitable for most application scenarios.

[0096] Combining Comparative Examples 1 and 2, adding flame retardant powder alone can achieve a flame retardant effect of V0, but the amount added is relatively large, which significantly affects the performance; it is difficult to achieve a good flame retardant effect by using flame retardant monomers alone; the synergistic effect of the two can achieve a better flame retardant effect with less impact on performance.

[0097] It can also be seen from Examples 1 and 4 that adding more hollow glass microspheres will affect the flame retardant effect and reduce the performance. Therefore, it is possible to add an appropriate amount of hollow glass microspheres to optimize the flame retardant effect and performance of the tape.

[0098] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of this disclosure. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this disclosure.

[0099] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A flame-retardant acrylic adhesive, characterized in that, The flame-retardant acrylic adhesive comprises the following raw materials in parts by weight: 70-90 parts soft monomer, 10-30 parts functional monomer, 10-30 parts acrylate monomer, 0.1-1.5 parts photoinitiator A, 0.1-1.5 parts photoinitiator B, 4-9 parts hollow glass microspheres, 0.05-0.2 parts crosslinking agent, 1-3 parts fumed silica, 0.01-0.2 parts chain transfer agent, 0.01-0.2 parts silane coupling agent, 0.05-0.5 parts nano pigment, 30-65 parts flame-retardant powder, and 5-15 parts flame-retardant monomer.

2. The flame-retardant acrylic adhesive according to claim 1, characterized in that, The hollow glass microspheres have a D50 of 50μm-100μm.

3. The flame-retardant acrylic adhesive according to claim 1, characterized in that, The average particle size of the fumed silica is less than or equal to 30 nm.

4. The flame-retardant acrylic adhesive according to claim 1, characterized in that, The soft monomer is at least one of n-butyl acrylate and isooctyl acrylate; and / or The functional monomer is at least one selected from acrylic acid, N-vinylpyrrolidone, hydroxyethyl acrylate, β-carboxyethyl acrylate, N-vinylcaprolactam, and N,N-dimethylamide; and / or, The acrylate monomer is at least one of methyl methacrylate, isobornyl acrylate, and isobornyl methacrylate.

5. The flame-retardant acrylic adhesive according to claim 1, characterized in that, The flame-retardant monomer is at least one of phosphate monoacrylate and diphosphate methacrylate; and / or The flame retardant powder is at least one of Daer Chemical 7228 and Daer Chemical 8314.

6. The flame-retardant acrylic adhesive according to claim 1, characterized in that, The photoinitiator A is at least one selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 4,6-trimethylbenzoyl)phosphine oxide, α-dimethoxy-α-phenylacetophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or The photoinitiator B is at least one selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 4,6-trimethylbenzoyl)phosphine oxide, α-dimethoxy-α-phenylacetophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or The crosslinking agent is at least one selected from hexanediol diacrylate, trimethylolpropane triacrylate, and acrylamide; and / or... The chain transfer agent is dodecyl mercaptan; and / or, The silane coupling agent is KBM-403.

7. A method for preparing the flame-retardant acrylic adhesive according to any one of claims 1-6, characterized in that, The preparation method of the flame-retardant acrylic adhesive includes the following steps: The soft monomer, functional monomer, appropriate amount of photoinitiator A and appropriate amount of chain transfer agent are mixed and reacted under ultraviolet irradiation to obtain the prepolymer; A flame-retardant acrylic adhesive is obtained by mixing prepolymer, acrylate monomers, residual photoinitiator A, photoinitiator B, crosslinking agent, residual chain transfer agent, silane coupling agent, nano-color paste, flame retardant powder, flame retardant monomer, hollow glass microspheres, and fumed silica.

8. The method for preparing the flame-retardant acrylic adhesive according to claim 7, characterized in that, First, the prepolymer and acrylate monomers are mixed evenly. Then, the remaining photoinitiator A, photoinitiator B, crosslinking agent, remaining chain transfer agent, silane coupling agent, color paste, flame retardant powder and flame retardant monomer are added and mixed evenly. Finally, hollow glass microspheres and fumed silica are added and mixed evenly to obtain flame retardant acrylic adhesive.

9. The method for preparing the flame-retardant acrylic adhesive according to claim 8, characterized in that, After the raw materials are mixed evenly, they are subjected to vacuum negative pressure degassing treatment to obtain flame-retardant acrylic adhesive.

10. A flame-retardant acrylic foam tape, characterized in that, It includes an acrylic foam adhesive layer and a release layer stacked together, wherein the acrylic foam adhesive layer is formed by the flame-retardant acrylic adhesive according to any one of claims 1-6.

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