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

Abstract

The invention relates to the technical field of flame-retardant adhesive manufacturing, in particular to water-based flame-retardant acrylic adhesive, aluminum foil flame-retardant woven cloth and a preparation method of the aluminum foil flame-retardant woven cloth. The invention provides a water-based flame-retardant acrylic adhesive which comprises a flame retardant and a water-based acrylic adhesive, and the flame retardant accounts for 10-15wt% of the water-based acrylic adhesive; wherein the flame retardant is prepared from the following components in parts by weight: 40 to 60 parts of DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) 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. According to the water-based flame-retardant acrylic adhesive, through a phosphorus-nitrogen synergistic flame-retardant mechanism, the overall flame-retardant grade of the water-based flame-retardant acrylic adhesive can reach V-0. In addition, the peel strength is not reduced while the flame retardance is improved, and the peel strength is greater than 3N / 15mm.

Description

Technical Field

[0001] The present invention relates to the technical field of flame-retardant glue manufacturing, and specifically relates to a water-based flame-retardant acrylic glue, an aluminum foil flame-retardant woven fabric, and their preparation methods. Background Art

[0002] As an important polymer adhesive, acrylic glue is widely used in fields such as packaging, electronics, construction, and automobiles. Especially in scenarios such as aluminum foil tapes and composite material bonding, its excellent initial adhesion, weather resistance, and adjustable mechanical properties have become core advantages. With the tightening of environmental protection regulations, traditional solvent-based acrylic glue is restricted by VOC emissions, and water-based acrylic glue has become the mainstream direction due to its characteristics of using water as the dispersion medium, low toxicity, environmental protection, and low cost. For example, through emulsion polymerization technology, a resin with a solid content of up to 80% can be prepared in a water-based system, and there is no need for organic solvents to assist in film formation, significantly reducing the environmental risks during production and use.

[0003] However, the inherent defects of water-based acrylic glue restrict its application in high-temperature scenarios. First, the hydrophilic groups (such as carboxyl groups) in its molecular chain result in insufficient water resistance, and it is prone to swelling and even debonding in high-temperature and high-humidity environments. Second, acrylic resin itself is flammable and difficult to meet the strict requirements for flame retardancy and heat resistance in automotive engine compartments, electronic component encapsulation, etc. Existing technologies can improve the flame retardancy by adding phosphorus / nitrogen-containing flame retardants (such as zirconium phosphate, nitrogen-containing phenolic resin) or organosilicon modification, but the coating is prone to softening at high temperatures, resulting in problems such as a decrease in adhesion, a decrease in peel strength, and an acceleration of thermal decomposition.

[0004] Therefore, developing a glue with both flame retardancy and high peel strength helps to solve the existing problems. Summary of the Invention

[0005] The present invention provides a water-based flame-retardant acrylic glue, an aluminum foil flame-retardant woven fabric, and their preparation methods. By compounding a specific flame retardant in the water-based acrylic glue, through the phosphorus-nitrogen synergistic flame retardant mechanism, the overall flame retardant grade of the water-based flame-retardant acrylic glue can reach V-0. In addition, while improving the flame retardancy, its peel strength does not decrease, and the peel strength is greater than 3N / 15mm.

[0006] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a water-based flame-retardant acrylic glue, which includes a flame retardant and a water-based acrylic glue. The flame retardant is 10-15 wt% of the water-based acrylic glue; wherein, by weight, the flame retardant includes: 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.

[0007] Preferably, the preparation method of the DOPO-modified cyclic phosphate is as follows: after 9,10-dioxo-9,10-dihydro-anhydro-10-phosphate reacts with epichlorohydrin to form an intermediate, cyclic phosphate is added and condensed with the intermediate under alkaline conditions, followed by recrystallization to obtain the DOPO-modified cyclic phosphate.

[0008] Preferably, the molar ratio of 9,10-dioxo-9,10-dihydro-anhydro-10-phosphate to epichlorohydrin is 1:1 to 1.5, and the molar ratio of cyclic phosphate to the intermediate is 1.2 to 1.8:1.

[0009] Preferably, the temperature of the reaction is 110 to 130 °C, and the reaction time is 1 to 3 h.

[0010] Preferably, the temperature of the condensation is 50 to 60 °C, and the time is 3 to 5 h.

[0011] Preferably, the alkaline condition is an environment with a pH of 8 to 10.

[0012] Preferably, the alkaline condition is adjusting the pH to 8 to 10 with an alkaline solution.

[0013] Preferably, the alkaline solution is at least one of ammonia water, sodium hydroxide solution, and sodium carbonate solution.

[0014] Preferably, the alkaline solution is 25% ammonia water.

[0015] Preferably, the solvent for recrystallization is alcohol.

[0016] Preferably, the solvent for recrystallization is ethanol and / or methanol.

[0017] Preferably, the water content of the ethanol is ≤ 0.1 wt%.

[0018] Preferably, the preparation method of the nitrogen-doped cyclic phosphate is as follows: after melamine and phosphoric anhydride are pre-reacted, cyclic phosphate is added and reacted under an inert atmosphere to obtain the nitrogen-doped cyclic phosphate.

[0019] Preferably, the molar ratio among melamine, phosphoric anhydride, and cyclic phosphate is 0.8 to 1:1 to 2:1.

[0020] Preferably, the temperature of the pre-reaction is 150 to 170 °C, and the time is 1 to 2 h.

[0021] Preferably, the temperature of the reaction is 180 to 220 °C, and the time is 3 to 5 h.

[0022] Preferably, the inert atmosphere includes nitrogen.

[0023] Preferably, the inert atmosphere is nitrogen and / or argon.

[0024] Preferably, in parts by weight, the aqueous acrylic adhesive contains: 50 - 60 parts of butyl acrylate, 20 - 25 parts of isooctyl acrylate, 2 - 3 parts of acrylic acid, 1 - 2 parts of 2 - hydroxyethyl methacrylate, 0.8 - 1.2 parts of sodium dodecyl sulfate, 0.5 - 0.8 parts of polyethylene glycol octyl phenyl 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.

[0025] A preparation method of an aqueous flame - retardant acrylic adhesive, comprising: S1. Mix DOPO - modified cyclic phosphate, nitrogen - doped cyclic phosphate, and melamine phosphate, then add trisodium citrate and sodium polyacrylate, and perform shear emulsification at 40 - 60 °C, and adjust the pH to 6.0 - 8.0 to obtain a flame retardant; S2. Prepare the aqueous acrylic adhesive according to the ratio, and stir according to the mass ratio of 0.1 - 0.15 of the flame retardant obtained in S1 to the aqueous acrylic adhesive to obtain the aqueous flame - retardant acrylic adhesive.

[0026] Preferably, the speed of the shear is 200 - 500 rpm.

[0027] Preferably, the emulsification time is 1 - 3 h.

[0028] Preferably, the solid content in the aqueous acrylic adhesive is 45 - 50 wt%.

[0029] Preferably, the viscosity of the aqueous acrylic adhesive is 800 - 1000 mPa·s.

[0030] An aluminum foil adhesive tape, comprising 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 the aqueous flame - retardant acrylic adhesive.

[0031] Preferably, the flame - retardant layer is a polyethylene flame - retardant woven fabric.

[0032] Preferably, the protective layer is a polyethylene film.

[0033] A preparation method of an aluminum foil flame - retardant woven fabric, comprising: S1. Gluing and unwinding: Adopt a dry - lamination process. After the flame - retardant woven fabric is glued, it is placed at the glued unwinding end, and the adhesive is the above - mentioned aqueous flame - retardant acrylic adhesive, and the aluminum foil is placed at the lamination unwinding end; Or, adopt a dry - lamination process. After the aluminum foil is glued, it is placed at the glued unwinding end, and the adhesive is the above - mentioned aqueous flame - retardant acrylic adhesive, and the flame - retardant woven fabric is placed at the lamination unwinding end; S2. Gradient compounding: After the arrangement in S1 is completed, under the movement of the production line, the four-section drying oven is heated step by step, and then roll compressing is carried out to form a composite product including an aluminum foil layer, an adhesive layer, and a flame-retardant woven fabric layer stacked in sequence. S3. Aging and shaping: After the composite product obtained in S2 is aged and shaped, an aluminum foil flame-retardant woven fabric is obtained.

[0034] Preferably, in S1, the flame-retardant woven fabric is a polyethylene flame-retardant woven fabric.

[0035] Preferably, in S2, the movement speed of the production line is 80 - 120 m / min.

[0036] Preferably, in S1, a protective film is compounded on one side of the flame-retardant woven fabric by a film laminating process, and then it is coated with adhesive on the other side and placed at the adhesive unwinding end. More preferably, the protective film is a polyethylene film lamination.

[0037] Preferably, in S1, after a protective film is compounded on one side of the flame-retardant woven fabric by a film laminating process, it is placed at the pressing unwinding end. More preferably, the protective film is a polyethylene film lamination.

[0038] Preferably, for the film laminating process: at 300 - 350 °C, with a linear speed of 100 - 150 m / min, film laminating is carried out.

[0039] The final structure of the aluminum foil flame-retardant woven fabric formed after adding the film laminating process is a composite product including an aluminum foil layer, an adhesive layer, a flame-retardant woven fabric layer, and a protective layer stacked in sequence.

[0040] Preferably, in S2, the way of step-by-step heating in the four-section drying oven is: passing through four drying ovens at 55 - 65 °C, 70 - 75 °C, 75 - 80 °C, and 80 - 85 °C in sequence.

[0041] Preferably, in S2, the temperature of roll compressing is 50 - 60 °C.

[0042] Preferably, in S3, the temperature of aging and shaping is 50 - 60 °C, and the time is 24 - 48 h.

[0043] Therefore, the present invention has the following beneficial effects: Through the phosphorus-nitrogen synergistic flame retardant and waterborne flame retardant acrylic adhesive mechanism of the present invention, the overall flame retardant grade can reach V-0. In addition, while improving the flame retardancy, its peel strength does not decrease, and the peel strength is greater than 3 N / 15 mm. Description of the Drawings

[0044] Figure 1 It is a schematic diagram of the clamping of the specimen during the peel test; Among them, 1 is the upper clamp, 2 is the lower clamp, 3 is the peeled part of the specimen, and 4 is the unpeeled specimen. Detailed Embodiments

[0045] The present invention will be further described below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0046] The sources of the raw materials in this part are as follows: Cyclic phosphate ester was purchased from GreenLink Chemical Technology Co., Ltd.; melamine phosphate, CAS No. 15541-60-3, was purchased from Aladdin; 9,10-dioxo-9,10-dihydro-anhydrous-10-phosphate ester, DOPO, CAS No. 35948-25-5, was purchased from Aladdin; trisodium citrate, CAS No. 68-04-2, was purchased from Aladdin; sodium polyacrylate, CAS No. 9003-04-7, was purchased from Aladdin; epichlorohydrin, CAS No. 106-89-8, was purchased from Aladdin; melamine, CAS No. 108-78-1, was purchased from Aladdin; phosphoric anhydride was purchased from Shandong Qiyun Chemical Co., Ltd.; butyl acrylate, BA, CAS No. 141-32-2, was purchased from Aladdin; isooctyl acrylate, 2-EHA, CAS No. 103-11-7, was purchased from Aladdin; acrylic acid, AA, CAS No. 79-10-7, was purchased from Aladdin; 2-hydroxyethyl methacrylate, HEMA, CAS No. 868-77-9, was purchased from Aladdin; sodium dodecyl sulfate, SDS, CAS No. 151-21-3, was purchased from Aladdin; polyethylene glycol octyl phenyl ether, OP-10, was purchased from Hai'an Petrochemical Company; ammonium persulfate, APS, CAS No. 7727-54-0, was purchased from Aladdin; terpene resin emulsion with a solid content of 50 wt% was purchased from Jinan Shenghe Chemical Co., Ltd.; 25% ammonia water, CAS No. 1336-21-6, was purchased from Aladdin; tributyl phosphate, TBP, CAS No. 126-73-8, was purchased from Aladdin; alkali-swellable ASE-60 was purchased from Qingdao Enze Chemical Co., Ltd.; benzoquinone, CAS No. 106-51-4, was purchased from Aladdin; maleic anhydride, CAS No. 108-31-6, was purchased from Nanjing Shengqinghe Chemical Co., Ltd.

[0047]

Example

[0048] ① Weigh deionized water, SDS, and OP-10 according to the above formulation and add them to the pre-emulsification kettle, stir and mix evenly; then add BA, 2-EHA, AA, and HEMA monomers in sequence, and stir at a high speed of 1000 rpm for pre-emulsification for 30 min to form a stable pre-emulsion.

[0049] ② Mix deionized water and 1 / 4 of the stable pre-emulsion, heat up to 80 °C, and then add 1 / 3 of the APS initiator to initiate seed polymerization. After the system shows a blue light, the remaining stable pre-emulsion and the remaining APS are added dropwise synchronously in three times, and the dropping rate is controlled to keep the reaction temperature between 85 and 88 °C. The polymerization reaction is completed after 4 h.

[0050] ③ After the polymerization is completed, cool down to 65 °C, add the terpene resin emulsion, and stir and mix at a low speed of 100 rpm for 30 min. Then add TBP to defoam, adjust the pH with 25% ammonia water, and filter and discharge.

[0051] ④ Add alkali-swellable ASE-60 to the system to thicken the system viscosity to 800 - 1000 mPa·s, and finally obtain an aqueous acrylic glue with a solid content of 46.8 wt%.

[0052] S2. Preparation of flame retardant: Formulation: 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.

[0053] ① Preparation of DOPO-modified cyclic phosphate: React 5 mol of DOPO and 7 mol of epichlorohydrin at 120 °C for 2 h to form an intermediate, then adjust the pH to 8.5 ± 0.05 with 25% ammonia water, add 15 mol of cyclic phosphate and 10 mol of intermediate, and condense at 60 °C for 4 h. Then recrystallize with absolute ethanol as a solvent to obtain a light yellow transparent liquid, namely DOPO-modified cyclic phosphate.

[0054] ② Preparation of nitrogen-doped cyclic phosphate: Pre-react 5 mol of melamine and 7 mol of phosphoric anhydride at 160 °C for 1 h, then add 5 mol of cyclic phosphate and react at 200 °C for 3 h under a nitrogen atmosphere to obtain a light brownish-yellow transparent viscous liquid, namely nitrogen-doped cyclic phosphate.

[0055] ③Weigh DOPO-modified cyclic phosphate, nitrogen-doped cyclic phosphate and melamine phosphate according to the above formula. Subsequently, add trisodium citrate and sodium polyacrylate, shear and emulsify at 500 rpm for 1 h at 50 °C, adjust the pH to 7.0 ± 0.05, and filter to obtain the flame retardant.

[0056] S3. Preparation of waterborne flame-retardant acrylic adhesive: Stir and dissolve according to the mass ratio of 0.1 of the flame retardant to the waterborne acrylic adhesive to obtain the waterborne flame-retardant acrylic adhesive.

[0057] S4. Preparation of aluminum foil flame-retardant woven fabric: Apply glue on the 105# sizing roller of the dry laminator. Place the PE flame-retardant woven fabric that has been laminated with 10 - 20 μm PE by the laminating machine on the glue-fed unwind end (the laminating temperature process is 330 °C and the linear speed is 120 m / min) to apply glue. The aluminum foil is at the lamination unwind end, the production line speed is 100 m / min, and the drying oven temperatures are 60 °C, 70 °C, 75 °C, and 80 °C respectively. Press and laminate through the pressure roller at room temperature to 50 °C. After lamination, the flame-retardant aluminum foil woven fabric can be obtained with the structure of aluminum foil / glue / PE flame-retardant woven fabric. Subsequently, place it in the curing chamber and cure at 60 °C for 24 h. After curing, a layer of polyethylene coating is formed on the surface of the flame-retardant aluminum foil woven fabric through the coating process to obtain the final product (the final flame-retardant aluminum foil woven fabric) with the structure of aluminum foil / glue / PE flame-retardant woven fabric / PE coating.

[0058] Comparative Example 1 Prepare the waterborne acrylic adhesive with the same formula in the same manner as in Example 1, and use the prepared waterborne acrylic adhesive as the glue for the aluminum foil flame-retardant woven fabric with the same structure.

[0059] Comparative Example 2 Prepare the flame retardant with the same formula in the same manner as in Example 1.

[0060] Comparative Example 3 Prepare the waterborne flame-retardant acrylic adhesive with the same formula in the same manner as in Example 1, except that: replace the cyclic phosphate with benzoquinone to prepare DOPO-modified benzoquinone, and the rest remains unchanged to obtain the waterborne flame-retardant acrylic adhesive. Use the prepared waterborne flame-retardant acrylic adhesive as the glue for the aluminum foil flame-retardant woven fabric with the same structure.

[0061] Comparative Example 4 Prepare the waterborne flame-retardant acrylic adhesive with the same formula in the same manner as in Example 1, except that: replace DOPO with maleic anhydride to prepare maleic anhydride-modified cyclic phosphate, and the rest remains unchanged to obtain the waterborne flame-retardant acrylic adhesive. Use the prepared waterborne flame-retardant acrylic adhesive as the glue for the aluminum foil flame-retardant woven fabric with the same structure.

[0062] Comparative Example 5 An aqueous flame-retardant acrylic adhesive with the same formulation was prepared in the same manner as in Example 1, except that in the preparation of the flame retardant, the amount of melamine phosphate was 8 parts by weight. The rest remained unchanged, and an aqueous flame-retardant acrylic adhesive was obtained. The obtained aqueous flame-retardant acrylic adhesive was used as the adhesive for an aluminum foil flame-retardant woven fabric with the same structure.

[0063] Comparative Example 6 An aqueous flame-retardant acrylic adhesive with the same formulation was prepared in the same manner as in Example 1, except that in the preparation of the flame retardant, the nitrogen-doped cyclic phosphate was replaced with an equal amount of cyclic phosphate. The rest remained unchanged, and an aqueous flame-retardant acrylic adhesive was obtained. The obtained aqueous flame-retardant acrylic adhesive was used as the adhesive for an aluminum foil flame-retardant woven fabric with the same structure.

[0064] Comparative Example 7 An aqueous flame-retardant acrylic adhesive with the same formulation was prepared in the same manner as in Example 1, except that in the preparation of the flame retardant, the amount of DOPO-modified cyclic phosphate was 65 parts by weight and the amount of nitrogen-doped cyclic phosphate was 12 parts by weight. The rest remained unchanged, and an aqueous flame-retardant acrylic adhesive was obtained. The obtained aqueous flame-retardant acrylic adhesive was used as the adhesive for an aluminum foil flame-retardant woven fabric with the same structure.

[0065] Comparative Example 8 An aqueous flame-retardant acrylic adhesive with the same formulation was prepared in the same manner as in Example 1, except that maleic anhydride was used to replace nitrogen doping to prepare maleic anhydride-modified cyclic phosphate, and the rest remained unchanged, and an aqueous flame-retardant acrylic adhesive was obtained. The obtained aqueous flame-retardant acrylic adhesive was used as the adhesive for an aluminum foil flame-retardant woven fabric with the same structure.

[0066]

Performance Test

[0067] V-1 grade: The single afterflame time ≤ 30 s, the total afterflame time ≤ 250 s, and other requirements are the same as those of V-0 grade.

[0068] V-2 grade: The afterflame time is the same as that of V-1 grade, but it is allowed that the molten drop briefly ignites absorbent cotton.

[0069] The specific operation steps are as follows: (1)Test conditions and procedures Specimen specifications Dimensions: length 125 mm ± 5 mm, width 13.0 mm ± 0.3 mm.

[0070] Pretreatment: Treat at normal temperature (23°C ± 2°C, 50% humidity) for 48 hours, or conduct high-temperature aging (70°C ± 2°C) for 168 hours.

[0071] Flame parameters Flame height: 20 mm ± 2 mm (blue flame), with methane or propane as the fuel.

[0072] Flame application time: 10 seconds ± 0.5 seconds each time, repeated twice.

[0073] Test environment Laboratory conditions: Temperature 15°C - 35°C, humidity 45% - 75%.

[0074] (2)Judgment standard details Afterglow / afterglow time: The continuous burning time after the flame is removed (e.g., ≤ 10 seconds for V-0 grade).

[0075] Burning range: The specimen shall not burn to the fixture fixed end.

[0076] Dripping behavior: Dripping is prohibited from igniting the cotton wool below for V-0 / V-1 grade, and short-term ignition is allowed for V-2 grade.

[0077] (3)Supplementary requirements Each group of 5 specimens needs to complete 10 tests, and the total burning time is statistically counted.

[0078] ② Aging test: Place the 15*15 cm sample aluminum foil with the back side into the aging chamber. One cycle is 12 hours, including 8 hours of UV irradiation at 60°C with 0.9 W / m 2 , and 4 hours of condensation at 50°C with 100% humidity for 7 days.

[0079] ③ Peel strength test: Peel at 90° with a tensile machine. The width of the peeled spline is 15.0 ± 0.1 mm and the length is 200 mm. The operation is shown as Figure 1 shown.

[0080] ④ Water vapor transmission rate: The sample size is 10.5 cm in diameter, and the test conditions for water vapor transmission rate are 38°C and 90% RH for 24 hours.

[0081] The obtained data results are shown in Table 1. It can be seen from Table 1 that benzoquinone (corresponding to Comparative Example 3) has limited solubility in water and is prone to precipitation and separation. In addition, benzoquinone may react with the double bonds in acrylate, affecting the bonding performance of the waterborne flame-retardant acrylic glue, resulting in a decline in peel strength. At the same time, the flame retardancy also drops from V-0 grade to V-1. In Comparative Example 4, maleic anhydride modification improves the compatibility of the flame retardant in the waterborne acrylic system, but the flame retardant performance is greatly reduced.

[0082] In addition, the amount of melamine phosphate in the flame retardant is changed. The ratio of phosphorus / nitrogen content changes accordingly, resulting in the disruption of the phosphorus-nitrogen synergistic mechanism, and the flame retardancy fails to reach the required effect or other negative effects occur. At the same time, when the cyclic phosphate lacks nitrogen doping, it will also cause the ratio of phosphorus / nitrogen content to change, resulting in the disruption of the phosphorus-nitrogen synergistic mechanism and the decline of flame retardancy. When the ratio between the DOPO-modified cyclic phosphate and the nitrogen-doped cyclic phosphate changes, it will also affect the phosphorus-nitrogen synergistic mechanism, resulting in the problem of declining flame retardancy.

[0083] In summary, only under the solution given in the present invention can the obtained waterborne flame-retardant acrylic adhesive ensure both high flame retardancy and good peel strength during application.

[0084] Table 1 Performance comparison table

Claims

1. An aqueous flame-retardant acrylic adhesive, characterized in that, It includes a flame retardant and a waterborne acrylic adhesive, and the flame retardant is 10-15 wt% of the waterborne acrylic adhesive; among them, by weight, the flame retardant includes: 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.

2. The water-based flame-retardant acrylic adhesive according to claim 1, wherein The preparation method of the DOPO-modified cyclic phosphate is as follows: after 9,10-dioxo-9,10-dihydro-anhydrous-10-phosphate reacts with epichlorohydrin to form an intermediate, cyclic phosphate is added and condensed with the intermediate under alkaline conditions, and then recrystallized to obtain the DOPO-modified cyclic phosphate.

3. The waterborne flame-retardant acrylic adhesive according to claim 2, wherein The molar ratio of 9,10-dioxo-9,10-dihydro-anhydrous-10-phosphate to epichlorohydrin is 1:1-1.5, and the molar ratio of cyclic phosphate to the intermediate is 1.2-1.8:

1.

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

5. The water-based flame-retardant acrylic adhesive according to claim 1, wherein The preparation method of the nitrogen-doped cyclic phosphate is as follows: after melamine and phosphoric anhydride are pre-reacted, cyclic phosphate is added and reacted in an inert atmosphere to obtain the nitrogen-doped cyclic phosphate.

6. The water-based flame-retardant acrylic adhesive according to claim 5, characterized in that The molar ratio among melamine, phosphoric anhydride and cyclic phosphate is 0.8-1:1-2:

1.

7. The water-based flame-retardant acrylic adhesive according to claim 1, wherein By weight, the waterborne acrylic adhesive contains: 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 dodecyl sulfate, 0.5-0.8 parts of polyethylene glycol octyl phenyl 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.

8. The preparation method of the waterborne flame-retardant acrylic adhesive according to any one of claims 1-7, includes: S1. Mix the DOPO-modified cyclic phosphate, nitrogen-doped cyclic phosphate, and melamine phosphate, then add trisodium citrate and sodium polyacrylate, shear and emulsify at 40-60 °C, and adjust the pH to 6.0-8.0 to obtain the flame retardant; S2. Prepare the waterborne acrylic adhesive according to the ratio, and stir according to the mass ratio of the flame retardant to the waterborne acrylic adhesive in S1 of 0.1-0.15 to obtain the waterborne flame-retardant acrylic adhesive.

9. A flame-retardant woven aluminum foil cloth, characterized in that, It includes 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 waterborne flame-retardant acrylic adhesive according to any one of claims 1-7.

10. The preparation method of the aluminum foil flame retardant woven fabric according to claim 9, characterized in that, Includes: S1. Gluing and unwind: Adopt the dry lamination process. After the flame-retardant woven fabric is glued, it is placed at the unwind end of the gluing, and the adhesive is the waterborne flame-retardant acrylic adhesive according to any one of claims 1-7, and the aluminum foil is placed at the unwind end of the lamination; Or, adopt the dry lamination process. After the aluminum foil is glued, it is placed at the unwind end of the gluing, and the adhesive is the waterborne flame-retardant acrylic adhesive according to any one of claims 1-7, and the flame-retardant woven fabric is placed at the unwind end of the lamination; S2. Gradient lamination: After the arrangement in S1 is completed, under the movement of the production line, the four-section drying oven is heated step by step, and then roll-pressed and laminated to form a composite product including an aluminum foil layer, an adhesive layer, and a flame-retardant woven fabric layer stacked in sequence; S3. Curing and shaping: The composite product obtained in S2 is cured and shaped to obtain an aluminum foil flame-retardant woven fabric.

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