Anti-dripping flame-retardant ETFE composite material as well as application and preparation method thereof

Abstract

The invention discloses an anti-dripping flame-retardant ETFE composite material as well as application and a preparation method thereof. The composite material comprises a resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite and an antioxidant, wherein the resin matrix is 100 parts by mass of ETFE; or 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, and the total of ETFE and ECTFE is 100 parts by mass. The composite material provided by the invention has excellent anti-dripping performance and good mechanical properties, and is suitable for being applied to preparation of building films; the preparation method of the composite material provided by the invention is simple, easy to operate and convenient for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of engineering plastics, and in particular to an anti-drip flame-retardant ETFE composite material and an application and a preparation method thereof. Background Art

[0002] ETFE (ethylene-tetrafluoroethylene copolymer) is the toughest fluoroplastic. It maintains the good heat resistance, chemical resistance and electrical insulation properties of PTFE (polytetrafluoroethylene), while greatly improving radiation resistance and mechanical properties. ETFE itself has excellent flame retardant properties. Compared with traditional blended additive flame retardant composite materials, it has better temperature resistance, aging resistance, barrier properties, etc.

[0003] However, the traditional ETFE film drips obviously in the combustion test. In actual use, for example, as a protective material, a large amount of organic molten droplets will be produced when a fire occurs, which is harmful to the environmental conditions and materials to be protected, and directly causes significant economic losses. Therefore, when used as a building material, it is often necessary to add an anti-dripping agent, such as montmorillonite, but its dispersibility is poor and its compatibility with ETFE is poor. The amount added cannot be too large. When the amount added exceeds 5%, it will seriously affect its film-forming shape. Even if a film is formed, its surface appearance is also 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, which can effectively improve its anti-drip flame retardancy while ensuring the excellent performance of the ETFE material, and is particularly suitable for use as a building membrane.

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

[0006] Wherein, the resin matrix is ​​100 parts by mass of ETFE; or

[0007] 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, and the total amount of ETFE and ECTFE is 100 parts by mass.

[0008] In the present invention, montmorillonite is modified to increase its dispersibility and compatibility with ETFE, and the addition amount is increased, thereby increasing the anti-dripping property of the composite material; at the same time, magnesium hydroxide is added to reduce the creep of ETFE melt during combustion, and at the same time, the parallelepiped structure has good spatial stability, is convenient for shell formation, and synergistically acts with the modified montmorillonite, which is more conducive to shell formation, wraps the gas decomposed during the combustion process, forms a mass shell, achieves the effect of smoke suppression and shell formation, and greatly improves the anti-dripping property. Even when the addition amount is equal to that of ordinary montmorillonite, the anti-dripping effect is far better than that of ordinary montmorillonite; at the same time, magnesium hydroxide also has a certain reinforcing effect, improves the molding crystallization behavior of the ETFE resin matrix, and improves the tensile strength; the addition of silicon dioxide improves the crystallization behavior of the ETFE resin and enhances the rigidity of the material.

[0009] In a specific embodiment, in parts by mass:

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

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

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

[0013] Antioxidant 0.1-0.6 parts by mass

[0014] Preferably, the modified montmorillonite is obtained by the following method: after dispersing the fluorine-containing silane 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 fluorine-containing silane coupling agent is heptadecafluorodecyltrimethoxysilane.

[0016] In this specific solution, the modified montmorillonite obtained by modifying montmorillonite with a fluorosilane coupling agent can be added to ETFE in a greatly increased amount and has good dispersibility, which is beneficial to improving the anti-drip property of the composite material.

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

[0018] In order to solve the above technical problems, the 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 architectural membranes. It can be understood that since the aforementioned anti-drip flame-retardant ETFE composite material has good anti-drip properties and excellent mechanical properties, it is suitable for use as an architectural membrane, especially as a protective material. When a fire occurs, it will not produce organic molten droplets, has good flame retardancy, and avoids greater harm and losses caused by fire.

[0019] In order to solve the above technical problems, the 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, blending and stirring the resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite and antioxidant, and then performing primary granulation through a twin-screw extruder to obtain primary granulated modified particles;

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

[0022] In the preparation method of the anti-drip flame-retardant ETFE composite material provided by the present invention, the resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite and antioxidant are first blended and stirred to improve the dispersibility of the components with lower content, so that they are evenly mixed, and then granulation is performed to make the components of the material evenly distributed; the two granulations are to further improve the dispersion uniformity of each component in the composite material, to avoid the occurrence of particles or agglomerates on the surface of the film in the later application of the film making process and affect the product quality, and after the two granulations, the performance of the material is more excellent and the anti-drip effect is better. The preparation method of the present invention is simple and easy to operate, and is convenient for industrial application.

[0023] In a specific embodiment, in step S1, the primary granulation further comprises drying the primary granulated modified particles at 70-90°C;

[0024] The molding temperature of the first granulation is 190-275℃;

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

[0026] 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, and the total amount of ETFE and ECTFE is 100 parts by mass.

[0027] In a specific embodiment, in parts by mass:

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

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

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

[0031] Antioxidant 0.1-0.6 parts by weight;

[0032] The modified montmorillonite is obtained by the following method: after dispersing the fluorine-containing silane coupling agent in water, adding montmorillonite, continuing to disperse to obtain a suspension, drying the suspension and grinding to obtain the modified montmorillonite.

[0033] In a specific embodiment, in step S2, the molding temperature of the re-granulation is 190-275°C; understandably, the re-granulation process of step S2 is the same as that of step S1.

[0034] The present invention modifies the ETFE material and adds an anti-dripping auxiliary agent, thereby ensuring the excellent performance of the ETFE material and effectively improving its anti-dripping and flame retardancy, and is particularly suitable for use as a building membrane. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

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

[0037] Ethylene tetrafluoroethylene copolymer (ETFE): density 1.75g / cm 3 , melt index 10-25g / 10min;

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

[0039] As well as montmorillonite, fluorine-containing silane coupling agent, silicon dioxide, magnesium hydroxide, antioxidant S80, and antioxidant 608.

[0040] The equipment in the embodiments of the present invention are all commercially available: a rotor mixer, a twin-screw granulator and a casting extruder (specially designed for high temperature resistance and corrosion resistance).

[0041] Preparation of modified montmorillonite: first disperse the fluorinated silane coupling agent in water, then add montmorillonite and continue to disperse to obtain a suspension, wherein the addition amount of the fluorinated silane coupling agent, montmorillonite and water is 1:(50-100):(80-200) parts by weight; then dry the suspension and grind to obtain modified montmorillonite, wherein the fluorinated silane coupling agent is heptadecafluorodecyltrimethoxysilane.

[0042] Example 1 Preparation of Anti-Drip Flame-Retardant ETFE Composite Material

[0043] S1. ETFE, ECTFE, silicon dioxide, magnesium hydroxide, modified montmorillonite, antioxidant S80 and antioxidant 608 are blended and stirred in a high-speed mixer. After being uniformly mixed, they are added into a twin-screw extruder, and the temperature is controlled at 190-275° C. to obtain a melt. The obtained melt is then pelletized by water cooling, and then dried at 80° C. to obtain primary granulated modified particles.

[0044] S2. The dried primary granulated modified particles are added into the twin-screw extruder again, the temperature is controlled at 190-275° C. to obtain a melt, and the obtained melt is pelletized by water cooling, and then dried at 80° C. to obtain anti-drip flame-retardant ETFE composite material particles.

[0045] In this embodiment, the addition amount of materials is shown in Table 1.

[0046] Example 2-Example 7 and Comparative Example

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

[0048] Table 1

[0049] Comparative Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 ETFE 100 100 95 90 85 88 88 88 ECTFE 0 0 5 10 15 12 12 12 Silicon dioxide 0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Magnesium hydroxide 0 15 15 15 15 10 5 8 Modified montmorillonite 0 5 5 5 5 10 15 12 Antioxidant S80 0 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Antioxidant 608 0 0.2 0.2 0.2 0.2 0.2 0.2 0.2

[0050] Embodiment 8 Performance Test

[0051] The testing method of the present invention is as follows:

[0052] The tensile strength and elongation at break are tested according to the test method of GB / T 1040.3-2006;

[0053] The flame retardancy and dripping test is to burn the sample for 30 seconds and observe whether there is dripping, whether the flame goes out after stopping the flame, and whether the material melts into a shell after burning.

[0054] Thermal shrinkage was tested at 130°C for 30 minutes;

[0055] Test sample preparation: The composite material particles obtained in Examples 1 to 7 and the comparative example were extruded into 50 μm films through a casting extruder, wherein the extrusion processing temperature was 220-285° C., and then cooled at 90-110° C. to obtain film samples.

[0056] The samples were tested and the test results are shown in Table 2:

[0057] Table 2

[0058]

[0059]

[0060] It can be seen from Table 2 that the anti-dripping performance of Examples 1 to 7 is better than that of the comparative example.

[0061] 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 in the scope of protection of the present invention.

Claims

1. An anti-drip flame-retardant ETFE composite material, characterized in that: It includes resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite and antioxidant; Wherein, the resin matrix is ​​100 parts by mass of ETFE; or 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, and the total amount of ETFE and ECTFE is 100 parts by mass.

2. The composite material according to claim 1, characterized in that In parts by mass: 0.3-1.0 parts by mass of silicon dioxide; 3-20 parts by mass of magnesium hydroxide; 3-20 parts by mass of modified montmorillonite; Antioxidant 0.1-0.6 parts by mass 3. The composite material according to claim 1, characterized in that The modified montmorillonite is obtained by the following method: after dispersing the fluorine-containing silane coupling agent in water, adding montmorillonite, continuing to disperse to obtain a suspension, drying the suspension and grinding to obtain the modified montmorillonite.

4. The composite material according to claim 3, characterized in that The fluorine-containing silane coupling agent is heptadecafluorodecyltrimethoxysilane.

5. The composite material according to claim 1, characterized in that The antioxidant includes antioxidant S80 and / or antioxidant 608.

6. Use of the anti-drip flame-retardant ETFE composite material according to any one of claims 1 to 5 in preparing architectural membranes.

7. A method for preparing the anti-drip flame-retardant ETFE composite material according to any one of claims 1 to 5, characterized in that: The steps include: S1, blending and stirring the resin matrix, silicon dioxide, magnesium hydroxide, modified montmorillonite and antioxidant, and then performing primary granulation through a twin-screw extruder to obtain primary granulated modified particles; S2. The modified particles obtained in step S1 are subjected to secondary granulation again through a twin-screw extruder to obtain anti-drip flame-retardant ETFE composite material particles.

8. The preparation method according to claim 7, characterized in that: In step S1, the primary granulation further comprises drying the primary granulated modified particles at 70-90°C; The molding temperature of the first granulation is 190-275℃; The resin matrix is ​​100 parts by mass of ETFE; or 85-98 parts by mass of ETFE and 2-15 parts by mass of ECTFE, and the total amount of ETFE and ECTFE is 100 parts by mass.

9. The preparation method according to claim 8, characterized in that: In parts by mass: 0.3-1.0 parts by mass of silicon dioxide; 3-20 parts by mass of magnesium hydroxide; 3-20 parts by mass of modified montmorillonite; Antioxidant 0.1-0.6 parts by weight; The modified montmorillonite is obtained by the following method: after dispersing the fluorine-containing silane coupling agent in water, adding montmorillonite, continuing to disperse to obtain a suspension, drying the suspension and grinding to obtain the modified montmorillonite, wherein the fluorine-containing silane coupling agent is heptadecafluorodecyltrimethoxysilane.

10. The preparation method according to claim 7, characterized in that: In step S2, the molding temperature of the second granulation is 190-275°C.

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