Anti-drip flame-retardant ETFE composite material, use, and preparation method

Abstract

Disclosed are an anti-drip flame-retardant ETFE composite material, a use, and a preparation method. The composite material comprises a resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite, and an antioxidant, wherein the resin matrix consists of 100 parts by mass of ETFE, or the resin matrix consists of 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, the sum of ETFE and ECTFE being 100 parts by mass. The composite material provided by the present invention exhibits excellent anti-drip properties and good mechanical properties, and is applicable to the preparation of architectural membranes. The composite material preparation method provided by the present invention is simple, easy to operate, and convenient for industrial production.

Description

An anti-dripping flame-retardant ETFE composite material, its application, and preparation method. Technical Field

[0001] This invention relates to the field of engineering plastics technology, and in particular to an anti-dripping flame-retardant ETFE composite material, its application, and preparation method. Background Technology

[0002] ETFE (ethylene-tetrafluoroethylene copolymer) is the toughest fluoroplastic. While maintaining the good heat resistance, chemical resistance, and electrical insulation properties of PTFE (polytetrafluoroethylene), it has significantly improved radiation resistance and mechanical properties. ETFE itself has excellent flame retardant properties, and compared with traditional blended flame retardant composite materials, it is superior in terms of temperature resistance, aging resistance, and barrier properties.

[0003] However, traditional ETFE films exhibit significant dripping during combustion tests. In practical applications, such as as protective materials, they produce large amounts of molten organic droplets during fires, harming the protected environment and materials, and directly causing significant economic losses. Therefore, when used as building materials, anti-dripping agents, such as montmorillonite, are often added. However, montmorillonite has poor dispersibility and compatibility with ETFE, and its addition amount cannot be too large. When the addition amount exceeds 5%, it will seriously affect its film formation, and even if a film is formed, its surface appearance will be very poor. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an anti-drip flame-retardant ETFE composite material and its application and preparation method. While ensuring the excellent performance of ETFE material, it can also effectively improve its anti-drip flame retardancy, making it particularly suitable for use as a building membrane.

[0005] To solve the above-mentioned technical problems, the first aspect of the present invention is to provide an anti-drip flame-retardant ETFE composite material, comprising a resin matrix, silica, magnesium hydroxide, modified montmorillonite, and an antioxidant.

[0006] The resin matrix is ​​100 parts by weight of ETFE; or

[0007] 85-98 parts by weight of ETFE and 2-15 parts by weight of ECTFE, with a total of 100 parts by weight of ETFE and ECTFE.

[0008] In this invention, montmorillonite is modified to increase its dispersibility and compatibility with ETFE, thereby increasing the amount added and thus enhancing the anti-dripping properties of the composite material. Simultaneously, magnesium hydroxide is added to reduce the creep of the ETFE melt during combustion. Its parallelepiped structure provides good spatial stability, facilitating shell formation. Working synergistically with the modified montmorillonite, it further promotes shell formation, encapsulating the gases decomposed during combustion to form a clustered shell, achieving a smoke-suppressing effect and significantly improving anti-dripping properties. Even at the same addition amount as ordinary montmorillonite, its anti-dripping effect is far superior. Furthermore, magnesium hydroxide also has a reinforcing effect, improving the molding and crystallization behavior of the ETFE resin matrix and increasing tensile strength. The addition of silica improves the crystallization behavior of the ETFE resin, enhancing the rigidity of the material.

[0009] In one specific scheme, measured in parts by mass:

[0010] 0.3-1.0 parts by weight of silicon dioxide;

[0011] 3-20 parts by weight of magnesium hydroxide;

[0012] 3-20 parts by weight of modified montmorillonite;

[0013] Antioxidant 0.1-0.6 parts by weight.

[0014] Preferably, the modified montmorillonite is obtained by the following method: dispersing a fluorosilane coupling agent in water, adding montmorillonite, continuing to disperse to obtain a suspension, drying the suspension and grinding to obtain the modified montmorillonite.

[0015] More preferably, the fluorinated silane coupling agent is heptadecafluorodecyltrimethoxysilane.

[0016] In this specific scheme, the modified montmorillonite obtained by modifying montmorillonite with fluorosilane coupling agent can be added to ETFE in a significantly larger amount and has good dispersibility, which is beneficial to improving the anti-dripping properties of the composite material.

[0017] In one specific embodiment, the antioxidant includes antioxidant S80 and / or antioxidant 608. Preferably, the antioxidant includes antioxidant S80 and antioxidant 608 in a mass ratio of 1:0.5-2.0.

[0018] To address the aforementioned technical problems, a second aspect of the present invention is to provide an application of the aforementioned anti-drip flame-retardant ETFE composite material in the preparation of building membranes. Understandably, because the aforementioned anti-drip flame-retardant ETFE composite material has good anti-drip properties and excellent mechanical properties, it is suitable for use as a building membrane, especially as a protective material. In the event of a fire, it will not produce molten organic drips, exhibits good flame retardancy, and avoids greater harm and loss caused by fire.

[0019] To address the aforementioned technical problems, a third aspect of the present invention is to provide a method for preparing the aforementioned anti-drip flame-retardant ETFE composite material, comprising the following steps:

[0020] S1. After mixing and stirring the resin matrix, silica, magnesium hydroxide, modified montmorillonite and antioxidant, the mixture is first granulated through a twin-screw extruder to obtain the first granulated modified particles.

[0021] S2. The primary granulated modified particles obtained in step S1 are granulated again through a twin-screw extruder to obtain anti-dripping flame-retardant ETFE composite material particles.

[0022] The preparation method of the anti-dripping flame-retardant ETFE composite material provided by this invention involves first mixing and stirring the resin matrix, silica, magnesium hydroxide, modified montmorillonite, and antioxidant to improve the dispersibility of components with lower content, ensuring uniform mixing. Granulation is then performed to ensure uniform component distribution. This double granulation further enhances the dispersion uniformity of the components in the composite material, preventing the appearance of particles or agglomerates on the film surface during later film-making processes, which could affect product quality. After double granulation, the material exhibits superior performance and better anti-dripping effect. The preparation method of this invention is simple and easy to operate, facilitating industrial application.

[0023] In one specific scheme, step S1, the primary granulation also includes drying the primary granulated modified particles at 70-90°C.

[0024] The initial granulation temperature is 190-275℃;

[0025] The resin matrix is ​​100 parts by weight of ETFE; or

[0026] 85-98 parts by weight of ETFE and 2-15 parts by weight of ECTFE, with a total of 100 parts by weight of ETFE and ECTFE.

[0027] In one specific scheme, measured in parts by mass:

[0028] 0.3-1.0 parts by weight of silicon dioxide;

[0029] 3-20 parts by weight of magnesium hydroxide;

[0030] 3-20 parts by weight of modified montmorillonite;

[0031] Antioxidant 0.1-0.6 parts by weight;

[0032] Modified montmorillonite is obtained by the following method: after dispersing a fluorosilane coupling agent in water, montmorillonite is added, and dispersion is continued to obtain a suspension. The suspension is dried and ground to obtain modified montmorillonite.

[0033] In one specific embodiment, in step S2, the molding temperature for re-granulation is 190-275℃; understandably, the re-granulation process in step S2 is the same as that in step S1.

[0034] This invention modifies ETFE material by adding anti-drip additives, which not only ensures the excellent performance of ETFE material, but also effectively improves its anti-drip and flame retardant properties, making it particularly suitable for use as a building membrane. Detailed Implementation

[0035] The technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] The raw materials used in the embodiments of this invention are all commercially available, including:

[0037] Ethylene tetrafluoroethylene copolymer (ETFE): density 1.75 g / cm³, melt index 10-25 g / 10 min;

[0038] Ethylene trifluorochloroethylene copolymer (ECTFE): melt index range 5-10 g / 10 min;

[0039] In addition, montmorillonite, fluorinated silane coupling agents, silica, magnesium hydroxide, antioxidant S80, and antioxidant 608.

[0040] The equipment used in the embodiments of this invention is all commercially available: a rotor mixer, a twin-screw granulator, and a cast extruder (for high temperature and corrosion resistance).

[0041] Preparation of modified montmorillonite: First, disperse the fluorosilane coupling agent in water, then add montmorillonite and continue to disperse to obtain a suspension. The ratio of fluorosilane coupling agent, montmorillonite and water is 1:(50-100):(80-200) parts by mass. Then, dry and grind the suspension to obtain modified montmorillonite. The fluorosilane coupling agent is heptadecafluorodecyltrimethoxysilane.

[0042] Example 1: Preparation of Anti-dripping Flame-retardant ETFE Composite Material

[0043] S1. ETFE, ECTFE, silica, magnesium hydroxide, modified montmorillonite, antioxidant S80, and antioxidant 608 are mixed and stirred in a high-speed mixer. After being mixed evenly, the mixture is added to a twin-screw extruder and the temperature is controlled at 190-275℃ to obtain a melt. The obtained melt is then water-cooled and pelletized, and then dried at 80℃ to obtain primary granulated modified particles.

[0044] S2. The dried, initially granulated modified particles are added back into the twin-screw extruder, and the temperature is controlled at 190-275℃ to obtain a melt. The obtained melt is then water-cooled and pelletized, and then dried at 80℃ to obtain anti-dripping flame-retardant ETFE composite material particles.

[0045] In this embodiment, the amount of material added is detailed in Table 1.

[0046] Examples 2-7 and Comparative Examples

[0047] The preparation methods of Examples 2 to 7 and the comparative examples are the same as those of Example 1, except that the components of each material are different, as detailed in Table 1:

[0048] Table 1

[0049] Example 8 Performance Test

[0050] The testing method of this invention is as follows:

[0051] Tensile strength and elongation at break were tested according to the test method of GB / T 1040.3-2006;

[0052] The flame retardancy and dripping tests involve burning the sample continuously for 30 seconds, observing whether it drips, how it extinguishes after the flame is stopped, and the shell-like state of the molten material after burning.

[0053] Heat shrinkage was tested at 130℃ for 30 minutes;

[0054] Test sample preparation: The composite material particles obtained in Examples 1 to 7 and the comparative examples were extruded into 50 μm films using a casting extruder. The extrusion temperature was 220-285℃, and the films were then cooled at 90-110℃ to obtain film samples.

[0055] The samples were tested, and the test results are shown in Table 2:

[0056] Table 2

[0057] As can be seen from Table 2, the anti-drip performance of Examples 1 to 7 is superior to that of the comparative examples.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 drip-resistant, flame-retardant ETFE composite material, characterized in that, It includes a resin matrix, silica, magnesium hydroxide, modified montmorillonite, and antioxidants; The resin matrix is ​​100 parts by weight of ETFE; or 85-98 parts by weight of ETFE and 2-15 parts by weight of ECTFE, with a total of 100 parts by weight of ETFE and ECTFE.

2. The composite material as described in claim 1, characterized in that, By weight: 0.3-1.0 parts by weight of silicon dioxide; 3-20 parts by weight of magnesium hydroxide; 3-20 parts by weight of modified montmorillonite; Antioxidant 0.1-0.6 parts by weight.

3. The composite material as described in claim 1, characterized in that, Modified montmorillonite is obtained by the following method: after dispersing a fluorosilane coupling agent in water, montmorillonite is added, and dispersion is continued to obtain a suspension. The suspension is dried and ground to obtain modified montmorillonite.

4. The composite material as described in claim 3, characterized in that, The fluorinated silane coupling agent is heptadecafluorodecyltrimethoxysilane.

5. The composite material as described in claim 1, characterized in that, Antioxidants include antioxidant S80 and / or antioxidant 608.

6. The application of the anti-drip flame-retardant ETFE composite material as described in any one of claims 1-5 in the preparation of building membranes.

7. A method for preparing an anti-drip flame-retardant ETFE composite material as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. After mixing and stirring the resin matrix, silica, magnesium hydroxide, modified montmorillonite and antioxidant, the mixture is first granulated through a twin-screw extruder to obtain the first granulated modified particles. S2. The primary granulated modified particles obtained in step S1 are granulated again through a twin-screw extruder to obtain anti-dripping flame-retardant ETFE composite material particles.

8. The preparation method according to claim 7, characterized in that, In step S1, the primary granulation also includes drying the primary granulated modified particles at 70-90℃. The initial granulation temperature is 190-275℃; The resin matrix is ​​100 parts by weight of ETFE; or 85-98 parts by weight of ETFE and 2-15 parts by weight of ECTFE, with a total of 100 parts by weight of ETFE and ECTFE.

9. The preparation method according to claim 8, characterized in that, By weight: 0.3-1.0 parts by weight of silicon dioxide; 3-20 parts by weight of magnesium hydroxide; 3-20 parts by weight of modified montmorillonite; Antioxidant 0.1-0.6 parts by weight; Modified montmorillonite is obtained by the following method: a fluorinated silane coupling agent is dispersed in water, montmorillonite is added, and dispersion is continued to obtain a suspension. The suspension is dried and ground to obtain modified montmorillonite. The fluorinated silane coupling agent is heptadecafluorodecyltrimethoxysilane.

10. The preparation method according to claim 7, characterized in that, In step S2, the molding temperature for re-granulation is 190-275℃.