A flame-retardant waterproofing membrane and a method of making the same

Abstract

The present application relates to waterproofing membrane technical field, disclose a kind of flame-retardant waterproofing membrane and preparation method thereof, raw material each component is by weight fraction, including thermoplastic polyolefin elastomer 100 parts, modified flame retardant 20~40 parts, fiber filler 5~18 parts, lubricant 0~3 parts, antioxidant 0~3 parts, stabilizer 0~3 parts, pigment 0~15 parts;Modified flame retardant is with MOF@hexagonal boron nitride@phytic acid as core, on the surface of core crosslinking polysiloxane is polymerized.The flame-retardant waterproofing membrane provided by the present application, if MOF or modified MOF material is added to resin material alone, inevitably cause its and resin system compatibility problem.This application creatively uses microcapsule technology, and polysiloxane is polymerized on the surface of MOF material, not only can effectively solve the problem of MOF material dispersion, using polysiloxane has compatibility and combined with the flame-retardant characteristics of organic silicon, phosphorus promotes the formation of carbon at high temperature, silicon improves the thermal stability of carbon layer, so as to play the purpose of synergistic flame retardant.

Description

Technical Field

[0001] This invention relates to the field of waterproof membrane technology, and more specifically, to a flame-retardant waterproof membrane and its preparation method. Background Technology

[0002] Currently, with people placing increasing emphasis on building safety, the demand for flame-retardant and waterproof membranes is constantly growing, especially in commercial buildings and public facilities. Flame-retardant and waterproof membranes are building materials that combine waterproof and flame-retardant properties. They are mainly used in building roofs, basements, etc., to improve the fire safety of buildings while preventing water penetration.

[0003] Flame-retardant waterproof membranes mainly include polyvinyl chloride (PVC) waterproof membranes, ethylene propylene diene monomer (EPDM) waterproof membranes, and thermoplastic polyolefin (TPO) waterproof membranes. Among these membranes, PVC waterproof membranes contain plasticizers, which can easily release harmful substances due to plasticizer migration; EPDM waterproof membranes have high processing requirements. TPO waterproof membranes, on the other hand, do not contain plasticizers and are widely used due to their strong weather resistance, excellent mechanical properties, stain resistance, and ease of processing.

[0004] Improving the fire safety of buildings is imperative, as it relates to property and life safety. Therefore, the flame retardancy of TPO waterproof membranes needs further enhancement. In terms of improving flame retardancy, existing technologies include the addition of inorganic flame retardants, organic flame retardants, and organic-inorganic synergistic flame retardancy. Among these, the synergistic enhancement of flame retardancy through multiple flame retardants is currently the main improvement method, as illustrated by patents with publication numbers CN103242582A, CN117659882A, CN112694673A, and CN115746447A. These patents all involve blending multiple flame retardants into a system, but the improvement in flame retardancy is not significant. This is because when inorganic flame retardants are added to a polymer (or resin) system, they tend to agglomerate. In resin mixtures, they are difficult to disperse evenly due to differences in chemical properties, resulting in poor flame retardancy and deterioration of the material's mechanical properties. Meanwhile, organic flame retardants, such as some small-molecule flame retardants, are prone to migration, which can affect the flame retardant properties of materials. Summary of the Invention

[0005] The technical problem solved by this invention:

[0006] To address the shortcomings of existing technologies, a flame-retardant waterproof membrane and its preparation method are provided.

[0007] The technical solution adopted in this invention is as follows:

[0008] To address the aforementioned technical problems, the present invention aims to provide a flame-retardant waterproof membrane and its preparation method.

[0009] Based on this, the specific implementation plan is as follows:

[0010] A flame-retardant and waterproof membrane, comprising the following components by mass: 100 parts thermoplastic polyolefin elastomer, 20-40 parts modified flame retardant, 5-18 parts fiber filler, 0-3 parts lubricant, 0-3 parts antioxidant, 0-3 parts stabilizer, and 0-15 parts pigment; the modified flame retardant is a polysiloxane cross-linked polymerized on the surface of a core of MOF@hexagonal boron nitride@phytic acid.

[0011] In this invention, the preparation method of the modified flame retardant includes the following steps:

[0012] In the first step, zirconium tetrachloride and 2-aminoterephthalic acid are reacted hydrothermally, and then hexagonal boron nitride is added to continue the reaction to obtain intermediate I;

[0013] The second step is to disperse intermediate I, add phytic acid, and then process it to obtain intermediate II;

[0014] The third step involves processing intermediate II with HDTMS to obtain intermediate III;

[0015] In the fourth step, after intermediate III, octamethylcyclosiloxane, tetramethylammonium hydroxide, and tetrahydrofuran react, acetic acid and hexamethyldisiloxane are added to continue the reaction, and then the low-boiling-point substances are removed under vacuum to obtain the modified flame retardant.

[0016] Furthermore, zirconium tetrachloride and 2-aminoterephthalic acid were reacted in a molar ratio of 1:1, and the mass ratio of zirconium tetrachloride to hexagonal boron nitride was 1:1; the ratio of intermediate I to phytic acid was 1.5 g: 5 mL; the mass ratio of intermediate II to HDTMS was 1:1; and the mass ratio of intermediate III, methylcyclosiloxane, tetramethylammonium hydroxide, tetrahydrofuran, acetic acid, and hexamethyldisiloxane was 30:100:10:5:5:15.

[0017] In detail, the specific preparation method is as follows:

[0018] In the first step, zirconium tetrachloride was dissolved in DMF, then 2-aminoterephthalic acid was added and stirred. Glacial acetic acid was then added, and the mixture was placed in a hydrothermal reactor and reacted at 120°C for 2 hours. Next, hexagonal boron nitride nanosheets were added, stirred uniformly, and reacted again at 120°C for 20 hours. After the reaction was complete, the mixture was washed several times with ethanol and dried to obtain MOF@hexagonal boron nitride material. In the above steps, zirconium tetrachloride and 2-aminoterephthalic acid reacted in a molar ratio of 1:1, and the mass ratio of zirconium tetrachloride to hexagonal boron nitride was 1:1.

[0019] The second step involves dispersing the MOF@hexagonal boron nitride material in deionized water, adding a phytic acid solution (phytic acid to deionized water volume ratio of 1:4), and continuously stirring at 30°C for 6 hours. After multiple washings with deionized water and drying, the MOF@hexagonal boron nitride@phytic acid material is obtained. In the aforementioned steps, the ratio of MOF@hexagonal boron nitride to phytic acid is 1.5 g: 5 mL.

[0020] The third step is to disperse the obtained MOF@hexagonal boron nitride@phytic acid material in an aqueous ethanol solution (V 乙醇 V 水 The reaction solution was obtained by mixing a solution of ethanol and water in a ratio of 1:2, and the pH of the obtained reaction solution was adjusted to 10. The modified solution was then added dropwise to the reaction solution, and the mixture was stirred at room temperature for 12 hours. After washing with ethanol multiple times, the mixture was dried to obtain modified MOF@hexagonal boron nitride@phytic acid. The modified solution was an ethanol-water solution of HDTMS (V... 乙醇 V 水 =3:7), the mass ratio of MOF@hexagonal boron nitride@phytic acid to HDTMS is 1:1.

[0021] The fourth step involves uniformly mixing modified MOF@hexagonal boron nitride@phytic acid, octamethylcyclosiloxane, tetramethylammonium hydroxide, and tetrahydrofuran, then heating the mixture to 85°C and reacting for 5 hours. Acetic acid and hexamethyldisiloxane are then added, and the reaction continues for 1 hour. Finally, the mixture is heated to 150°C and vacuum-treated to remove low-boiling-point substances for 2 hours to obtain the modified flame retardant. The mass ratio of modified MOF@hexagonal boron nitride@phytic acid, octamethylcyclosiloxane, tetramethylammonium hydroxide, tetrahydrofuran, acetic acid, and hexamethyldisiloxane is 30:100:10:5:5:15.

[0022] In this invention, the thermoplastic polyolefin elastomer includes a polyolefin (at least one of PP and PE) and an elastomer (at least one of EPDM, NBR, IIR, and NR). The mass ratio of polyolefin to elastomer is 7:3.

[0023] In this invention, the fiber filler includes at least one of glass fiber and carbon fiber. When the fiber filler is added to the resin system, it needs to be treated with silane coupling agent KH550 first. The treatment method can be conventional, and the purpose is to improve its compatibility with the resin system.

[0024] In this invention, the antioxidant includes at least one of antioxidant 1010 and antioxidant 1076.

[0025] In this invention, the stabilizer is a light stabilizer, specifically UV531.

[0026] In this invention, the pigment includes at least one of titanium dioxide and carbon black.

[0027] In this invention, the lubricant is stearic acid or stearate.

[0028] The technical mechanism and beneficial effects of this invention are as follows:

[0029] (1) The flame-retardant waterproof membrane provided by the present invention utilizes MOF materials and modified flame retardants prepared by polysiloxanes, which can be applied to flame-retardant waterproof membranes, thus possessing the advantages of both mechanical properties and flame-retardant properties.

[0030] (2) The flame-retardant and waterproof membrane provided by the present invention integrates the modified flame retardant into the above two in the form of core and shell, which can give full play to the advantages of both and thus synergistically improve the flame retardant effect.

[0031] (3) The flame-retardant and waterproof membrane provided by this invention uses MOF material as a flame retardant. Its rigid skeleton, high specific surface area, and heat resistance significantly improve the flame-retardant effect. However, adding MOF material alone has limited improvement. Therefore, by introducing hexagonal carbon nitride and phytic acid into the MOF material—that is, introducing nitrogen and phosphorus elements—the flame-retardant effect is improved. Meanwhile, adding hexagonal boron nitride alone can easily cause accumulation and aggregation, resulting in poor flame-retardant performance.

[0032] (4) The flame-retardant and waterproof membrane provided by this invention, if MOF or modified MOF material is added to the resin material alone, will inevitably cause poor compatibility between it and the resin system. Based on this, we creatively utilize microencapsulation technology to polymerize polysiloxane on the surface of MOF material. This not only effectively solves the problem of MOF material dispersion, but also utilizes the compatibility of polysiloxane and the flame-retardant properties of combined organosilicon (to generate a silicon-carbon isolation layer to isolate oxygen), and utilizes phosphorus to promote char formation and silicon to enhance the thermal stability of the char layer at high temperatures, thereby achieving the purpose of synergistic flame retardancy.

[0033] (5) The flame-retardant and waterproof membrane provided by the present invention incorporates fiber fillers (carbon fiber, glass fiber) to improve the tensile strength, puncture resistance, stability and durability of the membrane. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0035] The preparation process of modified flame retardants includes the following operations:

[0036] In the first step, 0.45 g of zirconium tetrachloride was dissolved in 100 mL of DMF, then 0.35 g of 2-aminoterephthalic acid was added and stirred. Then 5 mL of glacial acetic acid was added, and the mixture was placed in a hydrothermal reactor and reacted at 120 °C for 2 h. After that, 0.45 g of hexagonal boron nitride was added, and the mixture was stirred evenly. The reaction was then carried out at 120 °C for another 20 h. After the reaction was completed, the mixture was washed several times with ethanol and dried to obtain MOF@hexagonal boron nitride material.

[0037] The second step involves dispersing 1.5g of MOF@hexagonal boron nitride material in 100mL of deionized water, adding 25mL of phytic acid solution (the volume ratio of phytic acid to deionized water is 1:4), stirring continuously at 30℃ for 6 hours, and then washing repeatedly with deionized water and drying to obtain MOF@hexagonal boron nitride@phytic acid material.

[0038] The third step involves dispersing the obtained 1g MOF@hexagonal boron nitride@phytic acid material in 150mL of ethanol aqueous solution (V 乙醇 V 水 The reaction solution was obtained by mixing the solution with an ethanol solution of 1 wt% HDTMS (e.g., 1:2), and the pH of the obtained reaction solution was adjusted to 10 (ammonia water can be used for adjustment). Then, the modified solution (1 wt% HDTMS in an ethanol aqueous solution, where V...) was added... 乙醇 :V 水 =3:7 (1g of HDTMS is sufficient) was added dropwise to the aforementioned reaction solution, and the mixture was stirred at room temperature for 12 hours. After washing with ethanol several times, the mixture was dried to obtain modified MOF@hexagonal boron nitride@phytic acid.

[0039] The fourth step involves uniformly mixing modified MOF@hexagonal boron nitride@phytic acid, octamethylcyclosiloxane, tetramethylammonium hydroxide, and tetrahydrofuran, then heating the mixture to 85°C and reacting for 5 hours. Acetic acid and hexamethyldisiloxane are then added, and the reaction continues for 1 hour. Finally, the mixture is heated to 150°C and vacuum-treated to remove low-boiling-point substances for 2 hours to obtain the modified flame retardant. The mass ratio of modified MOF@hexagonal boron nitride@phytic acid, octamethylcyclosiloxane, tetramethylammonium hydroxide, tetrahydrofuran, acetic acid, and hexamethyldisiloxane is 30:100:10:5:5:15.

[0040] Example 1

[0041] This embodiment provides a waterproof and flame-retardant roll material, the raw materials of which are 100 parts of thermoplastic polyolefin elastomer (7:3 PP and EPDM), 30 parts of the modified flame retardant prepared above, 10 parts of glass fiber treated with KH550, 1.5 parts of stearic acid, 1 part of antioxidant 1010, 1.5 parts of light stabilizer UV531, and 1 part of titanium dioxide.

[0042] Weigh each component raw material according to the aforementioned proportions, stir them evenly, then extrude and granulate them using a twin-screw extruder, and then extrude (200℃, 2.5m / min), calender, shape and rewind to obtain flame-retardant waterproof membrane.

[0043] Example 2

[0044] The difference between this embodiment and Embodiment 1 is that the raw material composition of the roll material is different.

[0045] Specifically, the composition is as follows: 100 parts thermoplastic polyolefin elastomer (7:3 PP and EPDM), 25 parts of the modified flame retardant prepared above, 15 parts of glass fiber treated with KH550, 1.5 parts of stearic acid, 1 part of antioxidant 1010, 1.5 parts of light stabilizer UV531, and 1 part of titanium dioxide.

[0046] Comparative Example 1

[0047] The difference between this comparative example and Example 1 is that in the modified flame retardant, MOF material, hexagonal boron nitride, and polysiloxane are blended to obtain the modified flame retardant. Here, polydimethylsiloxane is used as the polysiloxane.

[0048] Comparative Example 2

[0049] The difference between this comparative example and Example 1 is that the MOF material does not include hexagonal boron nitride and phytic acid.

[0050] Comparative Example 3

[0051] The difference between this comparative example and Example 1 is that the modified flame retardant does not include polysiloxane (i.e., it is not polysiloxane coated).

[0052] Experimental Example 1

[0053] The tests were conducted using Examples 1-2 and Comparative Examples 1-3 as samples. The measured parameters included: limiting oxygen index (GB / T2406.2-2009), vertical flammability rating (GB / T 2408-2008), tensile strength (GB / T 1040.2-2006), and impact strength (GB / T 12670-2008). The results are shown in Table 1.

[0054] Table 1. Measurement results for each sample

[0055]

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flame-retardant and waterproof membrane, characterized in that, The raw materials, by weight, include 100 parts of thermoplastic polyolefin elastomer, 20-40 parts of modified flame retardant, 5-18 parts of fiber filler, 0-3 parts of lubricant, 0-3 parts of antioxidant, 0-3 parts of stabilizer, and 0-15 parts of pigment; the modified flame retardant is a polysiloxane cross-linked polymer with MOF@hexagonal boron nitride@phytic acid as the core. The preparation method of the modified flame retardant is as follows: In the first step, zirconium tetrachloride and 2-aminoterephthalic acid are reacted hydrothermally, and then hexagonal boron nitride is added to continue the reaction to obtain intermediate I; zirconium tetrachloride and 2-aminoterephthalic acid are reacted in a molar ratio of 1:1, and the mass ratio of zirconium tetrachloride to hexagonal boron nitride is 1:

1. The second step involves dispersing intermediate I, adding phytic acid, and processing it to obtain intermediate II; the ratio of intermediate I to phytic acid is 1.5g:5mL. The third step involves processing intermediate II with HDTMS to obtain intermediate III; the mass ratio of intermediate II to HDTMS is 1:

1. In the fourth step, after intermediate III, octamethylcyclosiloxane, tetramethylammonium hydroxide, and tetrahydrofuran react, acetic acid and hexamethyldisiloxane are added to continue the reaction, and then the low-boiling-point substances are removed under vacuum to obtain the modified flame retardant; the mass ratio of intermediate III, octamethylcyclosiloxane, tetramethylammonium hydroxide, tetrahydrofuran, acetic acid, and hexamethyldisiloxane is 30:100:10:5:5:

15.

2. The flame-retardant and waterproof membrane according to claim 1, characterized in that, The fiber filler includes at least one of glass fiber and carbon fiber; it is treated with silane coupling agent KH550 before use.

3. The flame-retardant and waterproof membrane according to claim 1, characterized in that, Antioxidants include at least one of antioxidant 1010 and antioxidant 1076.

4. The flame-retardant and waterproof membrane according to claim 1, characterized in that, The stabilizer is UV531.

5. The flame-retardant and waterproof membrane according to claim 1, characterized in that, Pigments include at least one of titanium dioxide and carbon black.

6. The flame-retardant and waterproof membrane according to claim 1, characterized in that, The lubricant is stearic acid or stearate.

7. The flame-retardant and waterproof membrane according to claim 1, characterized in that, Thermoplastic polyolefin elastomers consist of polyolefins and elastomers in a mass ratio of 7:

3.

8. A method for preparing a flame-retardant and waterproof membrane as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Weigh each raw material according to the proportion, extrude and granulate them through a twin-screw extruder, and then extrude, calender, shape and rewind to obtain flame-retardant and waterproof membrane.

Images