Water-based flame-retardant acrylic adhesive, aluminum foil flame-retardant woven fabric and preparation method thereof

Abstract

The present invention relates to the technical field of flame-retardant adhesive manufacturing, and specifically to a water-based flame-retardant acrylic adhesive, an aluminum foil flame-retardant woven fabric, and a preparation method thereof. The present invention provides a water-based flame-retardant acrylic adhesive, comprising a flame retardant and a water-based acrylic adhesive, wherein the flame retardant accounts for 10 to 15 wt% of the water-based acrylic adhesive; wherein, in parts by weight, the flame retardant comprises: 40 to 60 parts of DOPO-modified cyclic phosphate, 15 to 35 parts of nitrogen-doped cyclic phosphate, 10 to 20 parts of melamine phosphate, 2 to 5 parts of trisodium citrate, and 2 to 5 parts of sodium polyacrylate. The water-based flame-retardant acrylic adhesive achieves an overall flame retardancy rating of V-0 through a phosphorus-nitrogen synergistic flame retardant mechanism. In addition, while improving flame retardancy, its peel strength does not decrease, and the peel strength is greater than 3N / 15mm.

Description

Technical Field

[0001] The invention relates to the technical field of flame-retardant adhesive manufacturing, and in particular to water-based flame-retardant acrylic adhesive, aluminum foil flame-retardant woven fabric and preparation methods thereof. Background Art

[0002] Acrylic glue, as an important polymer adhesive, is widely used in packaging, electronics, construction, and automotive fields. Especially in scenarios such as aluminum foil tape and composite material bonding, its excellent initial adhesion, weather resistance, and adjustable mechanical properties have become its core advantages. As environmental regulations become stricter, traditional solvent-based acrylic glues are restricted due to VOC emissions. Water-based acrylic glues, with their water-based dispersion medium, low toxicity, environmental protection, and low cost, have become the mainstream direction. For example, water-based systems can prepare resins with a solid content of up to 80% through emulsion polymerization technology, and do not require organic solvents to assist in film formation, significantly reducing environmental risks during production and use.

[0003] However, the inherent flaws of water-based acrylic adhesives restrict their application in high-temperature environments. First, the hydrophilic groups (such as carboxyl groups) in their molecular chains lead to insufficient water resistance, making them prone to swelling and even debonding in high-temperature and high-humidity environments. Second, acrylic resins are inherently flammable, making it difficult to meet the stringent flame retardancy and temperature resistance requirements of automotive engine compartments, electronic component packaging, and other applications. Existing technologies improve flame retardancy by adding phosphorus / nitrogen flame retardants (such as zirconium phosphate and nitrogen-containing phenolic resins) or silicone modifications. However, the coatings tend to soften at high temperatures, resulting in reduced adhesion, decreased peel strength, and accelerated thermal decomposition.

[0004] Therefore, developing a glue that is both flame retardant and has high peel strength will help solve the current problems. Summary of the Invention

[0005] The present invention provides a water-based flame-retardant acrylic adhesive, an aluminum foil flame-retardant woven fabric, and methods for preparing the same. By compounding a specific flame retardant with the water-based acrylic adhesive, the adhesive achieves a V-0 flame retardancy rating through a phosphorus-nitrogen synergistic flame retardancy mechanism. Furthermore, while achieving improved flame retardancy, the adhesive's peel strength remains unchanged, exceeding 3N / 15mm.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a water-based flame-retardant acrylic adhesive, comprising a flame retardant and the water-based acrylic adhesive, wherein the flame retardant accounts for 10 to 15 wt% of the water-based acrylic adhesive; wherein, in parts by weight, the flame retardant comprises: 40 to 60 parts of DOPO-modified cyclic phosphate, 15 to 35 parts of nitrogen-doped cyclic phosphate, 10 to 20 parts of melamine phosphate, 2 to 5 parts of trisodium citrate, and 2 to 5 parts of sodium polyacrylate.

[0008] Preferably, the preparation method of the DOPO-modified cyclic phosphate is as follows: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and epichlorohydrin react to generate an intermediate, and then cyclic phosphate is added to the intermediate for condensation under alkaline conditions and recrystallization to obtain the DOPO-modified cyclic phosphate.

[0009] Preferably, the molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to epichlorohydrin is 1:1-1.5, and the molar ratio of cyclic phosphate to intermediate is 1.2-1.8:1.

[0010] Preferably, the reaction temperature is 110-130° C., and the reaction time is 1-3 h.

[0011] Preferably, the condensation temperature is 50-60° C., and the condensation time is 3-5 h.

[0012] Preferably, the alkaline condition is an environment with a pH of 8 to 10.

[0013] Preferably, the alkaline condition is to adjust the pH to 8-10 with alkali solution.

[0014] Preferably, the alkali solution is at least one of ammonia water, sodium hydroxide solution and sodium carbonate solution.

[0015] Preferably, the alkali solution is 25% ammonia water.

[0016] Preferably, the recrystallization solvent is alcohol.

[0017] Preferably, the recrystallization solvent is ethanol and / or methanol.

[0018] Preferably, the water content of the ethanol is ≤0.1 wt%.

[0019] Preferably, the preparation method of the nitrogen-doped cyclic phosphate is as follows: after pre-reacting melamine and phosphoric anhydride, the cyclic phosphate is added and reacted in an inert atmosphere to obtain the nitrogen-doped cyclic phosphate.

[0020] Preferably, the molar ratio of melamine, phosphoric anhydride and cyclic phosphate is 0.8-1:1-2:1.

[0021] Preferably, the pre-reaction temperature is 150-170° C., and the time is 1-2 h.

[0022] Preferably, the reaction temperature is 180-220° C., and the reaction time is 3-5 h.

[0023] Preferably, the inert atmosphere comprises nitrogen.

[0024] Preferably, the inert atmosphere is nitrogen and / or argon.

[0025] Preferably, the water-based acrylic adhesive contains, in parts by weight: 50-60 parts of butyl acrylate, 20-25 parts of isooctyl acrylate, 2-3 parts of acrylic acid, 1-2 parts of hydroxyethyl methacrylate, 0.8-1.2 parts of sodium lauryl sulfate, 0.5-0.8 parts of polyethylene glycol octylphenyl ether, 0.2-0.3 parts of ammonium persulfate, 10-15 parts of terpene resin emulsion with a solid content of 50 wt%, 0.1-0.2 parts of tributyl phosphate, 0.2-1.5 parts of 25% ammonia water, and 0.5-6 parts of deionized water.

[0026] A method for preparing a water-based flame-retardant acrylic adhesive, comprising:

[0027] S1. DOPO-modified cyclic phosphate, nitrogen-doped cyclic phosphate, and melamine phosphate are mixed, followed by the addition of trisodium citrate and sodium polyacrylate, followed by shear emulsification at 40-60°C, and adjusting the pH to 6.0-8.0 to obtain a flame retardant.

[0028] S2. Prepare water-based acrylic adhesive according to the ratio of flame retardant in S1 to water-based acrylic adhesive, and stir to obtain water-based flame-retardant acrylic adhesive.

[0029] Preferably, the shearing speed is 200-500 rpm.

[0030] Preferably, the emulsification time is 1 to 3 hours.

[0031] Preferably, the solid content of the water-based acrylic adhesive is 45-50 wt%.

[0032] Preferably, the viscosity of the water-based acrylic adhesive is 800-1000 mPa·s.

[0033] An aluminum foil adhesive tape comprises an aluminum foil layer, an adhesive layer, a flame retardant layer, and a protective layer stacked in sequence; the adhesive used in the adhesive layer is water-based flame retardant acrylic adhesive.

[0034] Preferably, the flame retardant layer is polyethylene flame retardant woven fabric.

[0035] Preferably, the protective layer is a polyethylene coating.

[0036] A method for preparing an aluminum foil flame-retardant woven fabric, comprising:

[0037] S1. Gluing and unwinding: Using a dry lamination process, the flame-retardant woven fabric is glued and placed at the glue unwinding end. The glue is the above-mentioned water-based flame-retardant acrylic glue, and the aluminum foil is placed at the pressing unwinding end;

[0038] Alternatively, a dry lamination process is used, wherein the aluminum foil is glued and placed at the glue unwinding end, wherein the glue is the above-mentioned water-based flame-retardant acrylic glue, and the flame-retardant braid is arranged at the pressing unwinding end;

[0039] S2. Gradient Lamination: After S1 is completed, the four-stage drying tunnel heats the product step by step while the production line is in motion. The product is then rolled and laminated to form a composite product consisting of a stacked aluminum foil layer, an adhesive layer, and a flame-retardant woven fabric layer.

[0040] S3. Curing and shaping: The composite product obtained in S2 is cured and shaped to obtain an aluminum foil flame-retardant woven fabric.

[0041] Preferably, in S1, the flame retardant woven fabric is polyethylene flame retardant woven fabric.

[0042] Preferably, in S2, the movement speed of the production line is 80-120 m / min.

[0043] Preferably, in S1, a protective film is laminated on one side of the flame-retardant woven fabric using a laminating process, and then adhesive is applied to the other side and placed at the adhesive unwinding end. More preferably, the protective film is a polyethylene laminating film.

[0044] Preferably, in S1, a protective film is laminated on one side of the flame-retardant woven fabric and then placed at the press-fit unwinding end. More preferably, the protective film is a polyethylene laminate.

[0045] Preferably, the laminating process is carried out at 300-350° C. and a line speed of 100-150 m / min.

[0046] The final structure of the aluminum foil flame retardant woven fabric formed after adding the laminating process is a composite product in which an aluminum foil layer, an adhesive layer, a flame retardant woven fabric layer and a protective layer are stacked in sequence.

[0047] Preferably, in said S2, the four-stage drying tunnel is heated step by step by sequentially passing through four drying tunnels of 55-65°C, 70-75°C, 75-80°C, and 80-85°C.

[0048] Preferably, in S2, the temperature of the pressing rollers during lamination is 50-60°C.

[0049] Preferably, in S3, the aging and setting temperature is 50-60° C., and the time is 24-48 h.

[0050] Therefore, the present invention has the following beneficial effects: Through the phosphorus-nitrogen synergistic flame retardant water-based flame-retardant acrylic adhesive mechanism, the present invention can achieve an overall flame retardancy rating of V-0. Furthermore, while improving flame retardancy, its peel strength does not decrease, and the peel strength is greater than 3N / 15mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1Schematic diagram of sample clamping during peeling test;

[0052] Among them, 1 is the upper clamp, 2 is the lower clamp, 3 is the peeled part of the sample, and 4 is the unpeeled sample. DETAILED DESCRIPTION

[0053] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0054] The raw materials in this section come from the following sources:

[0055] Cyclic phosphate, purchased from Green Union Chemical Technology Co., Ltd.; melamine phosphate, CAS No. 15541-60-3, purchased from Aladdin; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, DOPO, CAS No. 35948-25-5, purchased from Aladdin; trisodium citrate, CAS No. 68-04-2, purchased from Aladdin; sodium polyacrylate, CAS No. 9003-04-7, purchased from Aladdin; epichlorohydrin, CAS No. 106-89-8, purchased from Aladdin; melamine, CAS No. 108-78-1, purchased from Aladdin; phosphoric anhydride, purchased from Shandong Qiyun Chemical Co., Ltd.; butyl acrylate, BA, CAS No. 141-32-2, purchased from Aladdin; 2-ethylhexyl acrylate, CAS No. 103-11-7, purchased from Aladdin; acrylic acid, AA, CAS No. No. 79-10-7, purchased from Aladdin Company; hydroxyethyl methacrylate, HEMA, CAS No. 868-77-9, purchased from Aladdin Company; sodium dodecyl sulfate, SDS, CAS No. 151-21-3, purchased from Aladdin Company; polyethylene glycol octylphenyl ether, OP-10, purchased from Hai'an Petrochemical Company; ammonium persulfate, APS, CAS No. 7727-54-0, purchased from Aladdin Company; terpene resin emulsion, solid content 50wt%, purchased from Jinan Shenghe Chemical Company; 25% ammonia water, CAS No. 1336-21-6, purchased from Aladdin Company; tributyl phosphate, TBP, CAS No. 126-73-8, purchased from Aladdin Company; alkali swelling type ASE-60, purchased from Qingdao Enze Chemical Company; benzoquinone, CAS No. 106-51-4, purchased from Aladdin Company; maleic anhydride, CAS No. 108-31-6, purchased from Nanjing Shengqinghe Chemical Company.

[0056] [Example]

[0057] Example 1

[0058] S1. Preparation of water-based acrylic adhesive:

[0059] Formula: by weight, 60 parts of butyl acrylate, 20 parts of isooctyl acrylate, 2 parts of acrylic acid, 1 part of hydroxyethyl methacrylate, 0.8 parts of sodium lauryl sulfate, 0.5 parts of polyethylene glycol octylphenyl ether, 0.2 parts of ammonium persulfate, 10 parts of terpene resin emulsion with a solid content of 50 wt%, 0.1 parts of tributyl phosphate, 0.2 parts of 25% ammonia water, and 5.2 parts of deionized water.

[0060] ① According to the above formula, deionized water, SDS, and OP-10 were weighed and added to the pre-emulsification kettle, and stirred to mix evenly; then BA, 2-EHA, AA, and HEMA monomers were added in sequence, and pre-emulsified at 1000 rpm for 30 minutes to form a stable pre-emulsion.

[0061] ② Mix deionized water and one-quarter of the stabilized pre-emulsion, raise the temperature to 80°C, and then add one-third of the APS initiator to initiate seed polymerization. Once the system glows blue, add the remaining stabilized pre-emulsion and the remaining APS simultaneously in three separate drops. Control the addition rate to maintain the reaction temperature between 85°C and 88°C. The polymerization reaction is complete after 4 hours.

[0062] ③ After polymerization, cool to 65°C and add the terpene resin emulsion. Mix at 100 rpm for 30 minutes. Then add TBP to defoam, adjust the pH with 25% ammonia water, and filter the mixture.

[0063] ④ Add alkali-swellable ASE-60 to the system to thicken it to a viscosity of 800~1000 mPa·s, and finally obtain a water-based acrylic adhesive with a solid content of 46.8 wt%.

[0064] S2. Preparation of flame retardant:

[0065] Formula: By weight, 50 parts of DOPO-modified cyclic phosphate, 25 parts of nitrogen-doped cyclic phosphate, 15 parts of melamine phosphate, 5 parts of trisodium citrate, and 5 parts of sodium polyacrylate.

[0066] ① Preparation of DOPO-modified cyclic phosphate: 5 mol DOPO and 7 mol epichlorohydrin were reacted at 120°C for 2 h to generate an intermediate. The pH was then adjusted to 8.5±0.05 with 25% aqueous ammonia. 15 mol cyclic phosphate was added to 10 mol of the intermediate and condensed at 60°C for 4 h. Subsequently, recrystallization using anhydrous ethanol was performed to obtain a light yellow transparent liquid, namely, DOPO-modified cyclic phosphate.

[0067] ② Preparation of nitrogen-doped cyclic phosphate: 5 mol of melamine and 7 mol of phosphoric anhydride were pre-reacted at 160°C for 1 h, and then 5 mol of cyclic phosphate was added and reacted at 200°C for 3 h under a nitrogen atmosphere to obtain a light brown transparent viscous liquid, namely nitrogen-doped cyclic phosphate.

[0068] ③ DOPO-modified cyclic phosphate, nitrogen-doped cyclic phosphate, and melamine phosphate were weighed according to the above formula. Trisodium citrate and sodium polyacrylate were then added and emulsified at 500 rpm at 50°C for 1 h. The pH was adjusted to 7.0 ± 0.05, and the flame retardant was obtained by filtration.

[0069] S3. Preparation of water-based flame-retardant acrylic adhesive: stirring and dissolving the flame retardant to obtain water-based flame-retardant acrylic adhesive in a mass ratio of 0.1.

[0070] S4. Preparation of aluminum foil flame-retardant woven fabric: A 105# adhesive roller was used on a dry laminating machine to apply glue. PE flame-retardant woven fabric, which had been coated with 10-20 μm of PE by a laminating machine, was placed at the adhesive unwinding end (laminating temperature was 330°C and line speed was 120 m / min). Aluminum foil was placed at the laminating unwinding end. The line speed was 100 m / min, and the drying oven temperatures were 60°C, 70°C, 75°C, and 80°C. The fabric was laminated using a press roller at a temperature between room temperature and 50°C. This laminated fabric had a structure of aluminum foil / adhesive / PE flame-retardant woven fabric. The fabric was then placed in an aging chamber at 60°C for 24 hours. After aging, a polyethylene coating was formed on the surface of the flame-retardant aluminum foil woven fabric using a laminating process, resulting in a final product structure of aluminum foil / adhesive / PE flame-retardant woven fabric / PE coating (final flame-retardant aluminum foil woven fabric).

[0071] Comparative Example 1

[0072] Aqueous acrylic glue with the same formula was prepared in the same manner as in Example 1, and an aluminum foil flame-retardant woven fabric with the same structure was made using the prepared aqueous acrylic glue as glue.

[0073] Comparative Example 2

[0074] A flame retardant with the same formulation was prepared in the same manner as in Example 1.

[0075] Comparative Example 3

[0076] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, except that benzoquinone was used instead of cyclic phosphate to prepare the DOPO-modified benzoquinone. All other modifications remained unchanged. A water-based flame-retardant acrylic adhesive was then used as an adhesive for an aluminum foil flame-retardant woven fabric of the same structure.

[0077] Comparative Example 4

[0078] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, except that maleic anhydride was substituted for DOPO to prepare the maleic anhydride-modified cyclic phosphate. All other components remained unchanged to produce a water-based flame-retardant acrylic adhesive. This water-based flame-retardant acrylic adhesive was then used as a glue for an aluminum foil flame-retardant woven fabric of the same structure.

[0079] Comparative Example 5

[0080] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, except that in the preparation of the flame retardant (S2), melamine phosphate was used in an amount of 8 parts. All other factors remained unchanged to produce a water-based flame-retardant acrylic adhesive. A flame-retardant aluminum foil woven fabric of the same structure was also prepared using the prepared water-based flame-retardant acrylic adhesive as a glue.

[0081] Comparative Example 6

[0082] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, with the following difference: In the flame retardant preparation (S2), the nitrogen-doped cyclic phosphate was replaced with an equal amount of cyclic phosphate. All other conditions remained unchanged to produce a water-based flame-retardant acrylic adhesive. A flame-retardant aluminum foil woven fabric of the same structure was also prepared using the prepared water-based flame-retardant acrylic adhesive as an adhesive.

[0083] Comparative Example 7

[0084] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, except that in the preparation of the flame retardant (S2), the DOPO-modified cyclic phosphate was used in an amount of 65 parts and the nitrogen-doped cyclic phosphate was used in an amount of 12 parts. All other conditions remained unchanged to produce a water-based flame-retardant acrylic adhesive. A flame-retardant woven aluminum foil fabric of the same structure was also prepared using the prepared water-based flame-retardant acrylic adhesive as an adhesive.

[0085] Comparative Example 8

[0086] A water-based flame-retardant acrylic adhesive with the same formulation as in Example 1 was prepared, except that maleic anhydride was used instead of nitrogen doping to prepare the maleic anhydride-modified cyclic phosphate. All other aspects remained unchanged to produce a water-based flame-retardant acrylic adhesive. A flame-retardant aluminum foil woven fabric of the same structure was also produced using the prepared water-based flame-retardant acrylic adhesive as a glue.

[0087]

Performance test

[0088] The determination methods of aluminum foil flame retardant woven fabric are:

[0089] ①Vertical burning test adopts UL94 standard

[0090] ‌Level Classification‌:

[0091] V-0: Single afterflame time ≤ 10 seconds, total afterflame time ≤ 50 seconds, no molten droplets ignite the absorbent cotton.

[0092] Level V-1: Single afterflame time ≤ 30 seconds, total afterflame time ≤ 250 seconds, other requirements are the same as Level V-0.

[0093] ‌V-2‌: The afterflame time is the same as V-1, but molten droplets are allowed to briefly ignite the absorbent cotton.‌

[0094] The specific steps are as follows:

[0095] (1) Test conditions and procedures

[0096] ‌Specimen specifications‌

[0097] Size: Length 125mm±5mm, width 13.0mm±0.3mm‌.

[0098] Pretreatment: 48 hours at room temperature (23°C ± 2°C, 50% humidity), or 168 hours at high temperature (70°C ± 2°C).

[0099] ‌Flame Parameters‌

[0100] Flame height: 20mm±2mm (blue flame), gas is methane or propane.

[0101] Flame application time: 10 seconds ± 0.5 seconds each time, repeated twice.

[0102] ‌Test Environment‌

[0103] Laboratory conditions: temperature 15℃~35℃, humidity 45%~75%.

[0104] (2) Details of the judgment criteria

[0105] Afterflame / Afterglow time: The time the flame continues to burn after it is removed (e.g. V-0 level ≤ 10 seconds).

[0106] Burning range: The specimen must not burn to the fixed end of the fixture.

[0107] ‌Droplet behavior‌: V-0 / V-1 levels prohibit droplets from igniting the absorbent cotton below, while V-2 levels allow for brief ignition‌.

[0108] (3) Supplementary requirements

[0109] Each group of 5 samples needs to complete 10 tests and calculate the total burning time.

[0110] ②Aging test: Place the 15*15cm sample aluminum foil with the back side in the aging box for 12 hours, of which 8 hours are 60℃ UV irradiation 0.9 W / m 2 , 4h 50℃ condensation, humidity 100%, for 7 days.

[0111] ③ Peel strength test: 90° peeling on a tensile machine, the peeling strip width is 15.0±0.1mm, and the length is 200mm. The operation is as follows Figure 1 shown.

[0112] ④ Water vapor transmission rate: The sample size is 10.5 cm in diameter, and the water vapor transmission rate test conditions are 38°C, 90 RH%, and 24 hours.

[0113] ‌

[0114] The data obtained are shown in Table 1. As can be seen from Table 1, benzoquinone (corresponding to Comparative Example 3) has limited solubility in water and is prone to precipitation and separation. Furthermore, benzoquinone may react with double bonds in acrylates, affecting the adhesive properties of the water-based flame-retardant acrylic adhesive, resulting in a decrease in peel strength and a reduction in flame retardancy from V-0 to V-1. In Comparative Example 4, maleic anhydride modification improves the flame retardant's compatibility in the water-based acrylic system, but significantly reduces flame retardancy.

[0115] In addition, changing the amount of melamine phosphate in the flame retardant will change the phosphorus / nitrogen ratio, resulting in the destruction of the phosphorus-nitrogen synergistic mechanism, resulting in flame retardancy that does not meet the required effect or other negative effects. At the same time, the lack of nitrogen doping in the cyclic phosphate will also cause the phosphorus / nitrogen ratio to change, resulting in the destruction of the phosphorus-nitrogen synergistic mechanism and a decrease in flame retardancy. When the ratio between DOPO-modified cyclic phosphate and nitrogen-doped cyclic phosphate changes, it will also affect the phosphorus-nitrogen synergistic mechanism, resulting in a decrease in flame retardancy.

[0116] In summary, only under the solution provided by the present invention can the obtained water-based flame-retardant acrylic adhesive simultaneously ensure high flame retardancy and good peel strength when used.

[0117] Table 1 Performance comparison table

[0118]

Claims

1. A water-based flame-retardant acrylic adhesive, characterized in that: The invention comprises a flame retardant and a water-based acrylic adhesive, wherein the flame retardant accounts for 10-15 wt% of the water-based acrylic adhesive; wherein, in parts by weight, the flame retardant comprises: 40-60 parts of DOPO-modified cyclic phosphate, 15-35 parts of nitrogen-doped cyclic phosphate, 10-20 parts of melamine phosphate, 2-5 parts of trisodium citrate, and 2-5 parts of sodium polyacrylate; The preparation method of the DOPO modified cyclic phosphate comprises: reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and epichlorohydrin to generate an intermediate, adding a cyclic phosphate and the intermediate to condense under alkaline conditions, and recrystallizing to obtain the DOPO modified cyclic phosphate; The preparation method of the nitrogen-doped cyclic phosphate comprises the following steps: pre-reacting melamine and phosphoric anhydride, adding cyclic phosphate, and reacting in an inert atmosphere to obtain the nitrogen-doped cyclic phosphate.

2. The water-based flame-retardant acrylic adhesive according to claim 1, characterized in that: The molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to epichlorohydrin is 1:1-1.5, and the molar ratio of cyclic phosphate to the intermediate is 1.2-1.8:

1.

3. The water-based flame-retardant acrylic adhesive according to claim 1 or 2, characterized in that: The reaction temperature is 110-130° C., and the reaction time is 1-3 h.

4. The water-based flame-retardant acrylic adhesive according to claim 1, characterized in that: The molar ratio of melamine, phosphoric anhydride and cyclic phosphate is 0.8~1:1~2:

1.

5. The water-based flame-retardant acrylic adhesive according to claim 1, characterized in that: The water-based acrylic adhesive contains, in parts by weight, 50 to 60 parts of butyl acrylate, 20 to 25 parts of isooctyl acrylate, 2 to 3 parts of acrylic acid, 1 to 2 parts of hydroxyethyl methacrylate, 0.8 to 1.2 parts of sodium lauryl sulfate, 0.5 to 0.8 parts of polyethylene glycol octylphenyl ether, 0.2 to 0.3 parts of ammonium persulfate, 10 to 15 parts of a terpene resin emulsion with a solid content of 50 wt%, 0.1 to 0.2 parts of tributyl phosphate, 0.2 to 1.5 parts of 25% ammonia water, and 0.5 to 6 parts of deionized water.

6. The method for preparing the water-based flame-retardant acrylic adhesive according to any one of claims 1 to 5, comprising: S1. DOPO-modified cyclic phosphate, nitrogen-doped cyclic phosphate, and melamine phosphate are mixed, followed by the addition of trisodium citrate and sodium polyacrylate, followed by shear emulsification at 40-60°C, and adjusting the pH to 6.0-8.0 to obtain a flame retardant. S2. Prepare water-based acrylic adhesive according to the ratio of flame retardant in S1 to water-based acrylic adhesive, and stir to obtain water-based flame-retardant acrylic adhesive.

7. A flame-retardant aluminum foil woven fabric, characterized in that: The invention comprises an aluminum foil layer, an adhesive layer, and a flame-retardant woven fabric layer stacked in sequence; the adhesive used in the adhesive layer is the water-based flame-retardant acrylic adhesive as claimed in any one of claims 1 to 5.

8. The method for preparing the flame-retardant aluminum foil woven fabric according to claim 7, wherein: include: S1. Glue and unwinding: using a dry lamination process, the flame-retardant woven fabric with glue is placed at the glue unwinding end, the glue is a water-based flame-retardant acrylic glue as described in one of claims 1 to 5, and the aluminum foil is placed at the pressing unwinding end; Alternatively, a dry lamination process is used, wherein the aluminum foil adhesive is placed at the adhesive unwinding end, wherein the adhesive is the water-based flame-retardant acrylic adhesive as claimed in any one of claims 1 to 5, and the flame-retardant braid is arranged at the pressing unwinding end; S2. Gradient Lamination: After S1 is completed, the four-stage drying tunnel heats the product step by step while the production line is in motion. The product is then rolled and laminated to form a composite product consisting of a stacked aluminum foil layer, an adhesive layer, and a flame-retardant woven fabric layer. S3. Curing and shaping: The composite product obtained in S2 is cured and shaped to obtain an aluminum foil flame-retardant woven fabric.

Images