Flame-retardant antistatic EVA composite material and preparation method thereof

Abstract

The invention belongs to the technical field of polymer composite foam materials, and particularly relates to a flame-retardant antistatic EVA composite material and a preparation method thereof. The flame-retardant antistatic EVA composite material is prepared from the following raw materials in parts by weight: 80 to 100 parts of ethylene-vinyl acetate copolymer, 15 to 25 parts of flame-retardant antistatic agent, 3 to 8 parts of flame-retardant aid, 2.5 to 5 parts of foaming agent, 0.5 to 1.5 parts of zinc oxide, 0.5 to 1.2 parts of cross-linking agent, 0.3 to 0.8 part of zinc stearate and 0.3 to 0.8 part of stearic acid. The self-made flame-retardant antistatic agent is introduced into the EVA matrix, so that the flame-retardant, antistatic and mechanical properties of the EVA composite material are remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polymer composite foam materials, and particularly relates to a flame-retardant and antistatic EVA composite material and a preparation method thereof. BACKGROUND

[0002] EVA is prepared by copolymerization of ethylene and vinyl acetate. Due to excellent flexibility, high transparency, processing performance and good chemical stability, EVA is widely used in shoe materials, packaging, toys and other fields. In particular, EVA foam material has become the preferred material for products such as sports shoe insole, packaging liner and yoga mat due to its light weight, softness, shock absorption and heat insulation.

[0003] However, EVA material itself is highly flammable, with a low limiting oxygen index (LOI) of about 17%~19%, and is prone to melt dripping during combustion, posing a huge fire hazard. On the other hand, the volume resistivity of EVA is extremely high, usually above 10 14 Ω·cm, and is prone to accumulate static electricity, which seriously limits its application in fields sensitive to static electricity such as electronic device packaging and mine protection facilities.

[0004] For EVA foam material, it is more challenging to simultaneously achieve flame retardation and antistatic function than ordinary EVA composite material. On the one hand, the porous structure of foam increases the contact area with oxygen while providing cushioning performance, which in turn accelerates the combustion speed and makes the flame more likely to spread. Traditional flame retardants or conductive fillers usually need a high addition amount to be effective. These large amounts of inorganic fillers can severely damage the foaming process, resulting in uneven cell structure, increased density, deteriorated resilience, and hardening of the material, losing the core value of foam material. On the other hand, small molecule antistatic agents are prone to migrate, volatilize or fail during high-temperature processing of foaming, and are prone to precipitate during use, resulting in unstable and non-durable antistatic performance.

[0005] Currently, the methods for improving the performance of EVA foam mostly use physical blending of multiple additives, such as CN108752722A uses three-dimensional graphene hollow spheres as antistatic agents, and CN108976588A uses graphene-coated zinc hexahydroxy stannate and nitrogen-doped graphene hollow spheres as functional fillers. These methods are effective to some extent, but still cannot escape the contradiction between high addition amount and performance interference, and the coexistence of multiple fillers may bring new problems such as poor compatibility and difficult dispersion.

[0006] Therefore, developing a multifunctional integrated additive with high efficiency, low additive amount, good compatibility with foaming process, and excellent and durable flame-retardant and antistatic properties of EVA foam has become a technical problem to be solved by those skilled in the art, and has great market application value. SUMMARY

[0007] In order to overcome the deficiencies of the prior art, the primary purpose of the present application is to provide a flame-retardant and antistatic EVA composite material with excellent flame-retardant, antistatic and mechanical properties.

[0008] Another purpose of the present application is to provide a preparation method of the above-mentioned flame-retardant and antistatic EVA composite material.

[0009] The purpose of the present application is achieved by the following technical solutions: A flame-retardant and antistatic EVA composite material comprises the following raw materials in parts by weight: ethylene-vinyl acetate copolymer 80-100 parts, flame-retardant and antistatic agent 15-25 parts, flame-retardant additive 3-8 parts, foaming agent 2.5-5 parts, zinc oxide 0.5-1.5 parts, crosslinking agent 0.5-1.2 parts, zinc stearate 0.3-0.8 parts and stearic acid 0.3-0.8 parts. The structural formula of the flame-retardant and antistatic agent is as follows: .

[0010] Further, the flame-retardant and antistatic agent is prepared by the following preparation process: (1) o-vanillin is added to an ethanol solution, then sodium p-aminobenzenesulfonate is added, and the reaction is carried out under stirring; after the reaction is completed, the precipitate is collected and washed with water, and then dried to obtain intermediate 1; The structural formula of the intermediate 1 is as follows: ; (2) dimeric glycerol and phosphoric acid are added to xylene for reflux reaction, and after the reaction is completed, the reaction liquid is separated and purified by column chromatography to obtain intermediate 2; The structural formula of the intermediate 2 is as follows: ; (3) the intermediate 1 and the intermediate 2 are added to xylene for reflux reaction, and after the reaction is completed, the reaction liquid is dialyzed and freeze-dried to obtain the flame-retardant and antistatic agent.

[0011] Further, the molar ratio of o-vanillin to sodium p-aminobenzenesulfonate in step (1) is 1:(1-1.2); and the reaction time is 10-12 h.

[0012] Further, the molar ratio of the dimeric glycerol and phosphoric acid in step (2) is 1:(4-4.2); the reflux reaction time is 3-5 h.

[0013] Further, the molar ratio of the intermediate 1 and intermediate 2 in step (3) is (1-1.2):1; the reflux reaction time is 5-8 h; the molecular weight cut-off of the dialysis is 500 Da.

[0014] Further, the flame retardant aid is nano montmorillonite; the foaming agent is azodicarbonamide; the crosslinking agent is dicumyl peroxide or azobisisobutyronitrile.

[0015] Further, the content of vinyl acetate in the ethylene-vinyl acetate copolymer is 15-20 wt%.

[0016] A preparation method of the above-mentioned flame-retardant antistatic EVA composite material, comprising the following steps: (a) according to the weight fraction, ethylene-vinyl acetate copolymer, flame-retardant antistatic agent, flame retardant aid, foaming agent, zinc oxide, crosslinking agent and stearic acid and zinc stearate are mixed and then added to a preheated internal mixer, and the internal mixing is carried out at 80-100℃ for 3-5 min to obtain a premix; (b) the premix is transferred to a double roller mill, and after opening and rolling for 5-6 min, it is passed through a thin pass, and a mixed sheet is obtained; (c) the mixed sheet is placed in a preheated flat vulcanizing machine for mold foaming, and after exhaust, secondary mold pressing is carried out; finally, pressure holding and water cooling are carried out for 5-8 min, and the flame-retardant antistatic EVA composite material is obtained after demolding.

[0017] Further, in step (b), the number of thin passes is 5-8, and the temperature is 90-110℃; the thickness of the mixed sheet is 3-5 mm.

[0018] Further, in step (c), the temperature of the mold foaming and secondary mold pressing is 150-170℃, and the pressure is 10-12 MPa; the mold foaming time is 5-8 min, and the secondary mold pressing time is 3-5 min.

[0019] The present application has the following effects relative to the prior art: 1.The present application realizes the synergistic effect of flame retardation and antistatic function by synthesizing a new type of flame-retardant antistatic agent and introducing it into the EVA matrix, while improving the mechanical properties of the material. The flame-retardant antistatic agent contains phosphorus, nitrogen, sulfonic acid groups and other flame-retardant and conductive groups in its molecular structure, which can promote the carbonization reaction and effectively inhibit the generation of molten droplets during combustion, significantly improving the flame retardation performance of the material. At the same time, through the ion conduction mechanism, the volume resistivity of the material is significantly reduced, from the insulating level to the antistatic level, giving the material excellent antistatic properties.

[0020] 2.The flame-retardant antistatic EVA composite material of the present application has excellent flame-retardant and antistatic properties while its mechanical properties are also improved to a certain extent. The flame-retardant antistatic agent introduced in the present application can form hydrogen bonds and van der Waals forces with the EVA molecular chain through the functional groups such as phosphorus, nitrogen and sulfonic acid groups in its structure, thereby enhancing the intermolecular bonding force and improving the tensile strength and elongation at break of the material. In addition, the flame-retardant antistatic agent has good compatibility with the EVA matrix and is not easy to migrate or precipitate during foaming, ensuring the uniformity and fineness of the cell structure, reducing the problems of coarse cells and uneven density caused by filler addition, and thus improving the overall mechanical properties of the material. DETAILED DESCRIPTION

[0021] The technical solutions of the present application are further described below in conjunction with specific embodiments. However, those skilled in the art should understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, such as those not specifically mentioned, are conventional products obtained through market channels.

[0022] Example 1 A flame-retardant antistatic EVA composite material, comprising the following raw materials in parts by weight: ethylene-vinyl acetate copolymer 90 parts, flame-retardant antistatic agent 20 parts, nano-montmorillonite 5 parts, foaming agent azodicarbonamide 4 parts, zinc oxide 1 part, crosslinking agent dicumyl peroxide 0.8 parts, zinc stearate 0.5 parts and stearic acid 0.5 parts.

[0023] The flame-retardant antistatic agent is prepared by the following preparation process: (1) Add o-vanillin (CAS: 148-53-8, 0.1 mol) to a 90 mL volume fraction of 75% ethanol solution, then add sodium p-aminobenzenesulfonate (CAS: 515-74-2, 0.11 mol), and stir for 11 h; after the reaction is completed, collect the precipitate and wash it with water, and dry to obtain intermediate 1; 1 H NMR(C 14 H 12NNaO5S, 400 MHz, d6-DMSO) δ 13.78(s, 1H, OH), 8.89(s, 1H, CH=N), 7.82(d, 2H, Ar-H), 7.50(d, 2H, Ar-H), 7.35(d,1H, Ar-H), 7.05 (d, 1H, Ar-H), 6.88 (t, 1H, Ar-H), 3.83(s, 3H, CH3) ; HRMS(ESI + ): [M] calculated 329.03, found 329.04.

[0024] The reaction process is as follows: (2) Dipolyglycerol (CAS: 59113-36-9, 0.15 mol), phosphoric acid (CAS: 7664-38-2, 0.62 mol) were added into 110 mL of xylene, and refluxed for 4 h; after the reaction was completed, the reaction liquid was separated and purified by column chromatography to obtain intermediate 2; 1 HNMR(C6H 18 O 17 P, 400 MHz, d6-DMSO) δ 4.46 (d, 4H, CH2), 4.36-4.31(m, 2H, CH), 4.2(s, 8H, OH), 3.85(d, 4H, CH2) ; HRMS (ESI + ): [M] calculated 485.95, found 485.96.

[0025] The reaction process is as follows: (3) Intermediate 1 (0.11 mol) and intermediate 2 (0.1 mol) were added into xylene (90 mL), and refluxed for 7 h; after the reaction was completed, dialysis was performed using a 500 Da dialysis bag, and freeze-drying was performed to obtain the flame-retardant antistatic agent; 1 H NMR(C 62 H 58 N4Na4O 33P4S4, 400 MHz, d6-DMSO) δ 8.91(s, 4H, CH=N), 7.82(d, 8H, Ar-H),7.52-7.48(m, 12H, Ar-H), 7.25 (d, 4H, Ar-H), 7.14 (t, 4H, Ar-H), 4.46 (d, 4H,CH2), 4.36-4.31(m, 2H, CH), 4.2 (s, 4H, OH), 3.85(d, 4H, CH2), 3.83(s, 12H,CH3); HRMS (ESI + ): [M] calculated 1730.04, found 1730.06.

[0026] The reaction process is as follows: The embodiment also provides a preparation method of the above-mentioned flame-retardant antistatic EVA composite material, comprising the following steps: (a) The raw materials are weighed according to the above-mentioned weight proportions, and the ethylene-vinyl acetate copolymer, the flame-retardant antistatic agent, the nano-montmorillonite, the azodicarbonamide, the zinc oxide, the dicumyl peroxide, the stearic acid and the zinc stearate are mixed and then added into a preheated internal mixer, and the internal mixing is carried out at 80°C and 30 rpm for 4 min to obtain a premix; (b) The premix obtained in step (a) is quickly transferred into a two-roll open mill, and the open mixing is carried out at 100°C for 5 min and the thin passing is carried out for 6 times, and finally the roll gap is adjusted to 4 mm to obtain a mixed sheet; (c) The mixed sheet obtained in step (b) is placed into a preheated flat vulcanizing machine, and the mold pressing and foaming are carried out at 10 MPa and 160°C for 6 min; then the mold is opened, and after the gas is discharged, the secondary mold pressing is carried out at 10 MPa and 160°C for 4 min; finally, the water cooling is carried out for 6 min under the pressure holding state, and then the mold is opened to obtain the flame-retardant antistatic EVA composite material.

[0027] Example 2 A flame-retardant antistatic EVA composite material comprises the following raw materials in weight proportions: ethylene-vinyl acetate copolymer 80 parts, flame-retardant antistatic agent 15 parts, nano-montmorillonite 3 parts, foaming agent azodicarbonamide 2.5 parts, zinc oxide 0.5-1.5 parts, crosslinking agent azobisisobutyronitrile 0.5 parts, zinc stearate 0.3 parts and stearic acid 0.3 parts.

[0028] The flame-retardant antistatic agent is prepared by the following preparation process: (1) o-vanillin (0.1 mol) was added to 80 mL of an ethanol solution with a volume fraction of 75%, and then sodium p-aminobenzenesulfonate (0.1 mol) was added, and the reaction was stirred for 10 h; after the reaction was completed, the precipitate was collected and washed with water, and after drying, intermediate 1 was obtained; the intermediate 1 was characterized by 1 The results of H NMR and HRMS were consistent with those of Example 1.

[0029] (2) Dimeric glycerol (0.15 mol) and phosphoric acid (0.6 mol) were added to 100 mL of xylene, and the reaction was refluxed for 3 h; after the reaction was completed, the reaction solution was separated and purified by column chromatography to obtain intermediate 2; the intermediate 2 was characterized by 1 The results of H NMR and HRMS were consistent with those of Example 1.

[0030] (3) Intermediate 1 (0.1 mol) and intermediate 2 (0.1 mol) were added to 80 mL of xylene, and the reaction was refluxed for 5 h; after the reaction was completed, dialysis was performed using a 500 Da dialysis bag to obtain the flame-retardant antistatic agent; the flame-retardant antistatic agent was characterized by 1 The results of H NMR and HRMS were consistent with those of Example 1.

[0031] The present embodiment also provides a preparation method of the above-mentioned flame-retardant antistatic EVA composite material, which comprises the following steps: (a) The raw materials were weighed according to the above-mentioned weight fractions, and the ethylene-vinyl acetate copolymer, the flame-retardant antistatic agent, the nanometer montmorillonite, the azodicarbonamide, the zinc oxide, the azobisisobutyronitrile, the stearic acid, and the zinc stearate were mixed and then added to a preheated internal mixer, and the mixture was mixed at 90°C and 20 rpm for 3 min to obtain a premix; (b) The premix obtained in step (a) was quickly transferred to a two-roll open mill, and the mixture was milled at 90°C for 6 min and passed through 5 times of thin pass, and finally the roll gap was adjusted to 3 mm for sheeting to obtain a mixed sheet; (c) The mixed sheet obtained in step (b) was placed in a preheated flat vulcanizing machine, and the mixture was molded and foamed at 11 MPa and 150°C for 5 min; then the mold was opened, and after the gas was discharged, the mixture was subjected to secondary molding at 11 MPa and 150°C for 3 min; finally, the mixture was water-cooled for 8 min under pressure, and then the mold was opened to obtain the flame-retardant antistatic EVA composite material.

[0032] Example 3 A flame-retardant antistatic EVA composite material comprises the following raw materials in weight fractions: ethylene-vinyl acetate copolymer 100 parts, flame-retardant antistatic agent 25 parts, nanometer montmorillonite 8 parts, foaming agent azodicarbonamide 5 parts, zinc oxide 1.5 parts, crosslinking agent dicumyl peroxide 1.2 parts, zinc stearate 0.8 parts, and stearic acid 0.8 parts.

[0033] The flame-retardant antistatic agent is prepared by the following preparation process: (1) o-vanillin (0.1 mol) is added to a 100 mL ethanol solution with a volume fraction of 75%, and then sodium p-aminobenzenesulfonate (0.12 mol) is added, and the reaction is stirred for 12 h; after the reaction is completed, the precipitate is collected and washed with water, and after drying, intermediate 1 is obtained; the structure of intermediate 1 is 1 The results of H NMR and HRMS are consistent with those of Example 1.

[0034] (2) Dimeric glycerol (0.15 mol) and phosphoric acid (0.63 mol) are added to 120 mL of xylene, and the reaction is refluxed for 5 h; after the reaction is completed, the reaction solution is separated and purified by column chromatography to obtain intermediate 2; the structure of intermediate 2 is 1 The results of H NMR and HRMS are consistent with those of Example 1.

[0035] (3) Intermediate 1 (0.12 mol) and intermediate 2 (0.1 mol) are added to 100 mL of xylene, and the reaction is refluxed for 8 h; after the reaction is completed, dialysis is performed using a 500 Da dialysis bag to obtain the flame-retardant antistatic agent; the structure of the flame-retardant antistatic agent is 1 The results of H NMR and HRMS are consistent with those of Example 1.

[0036] The present embodiment also provides a preparation method of the flame-retardant antistatic EVA composite material described above, comprising the following steps: (a) The raw materials are weighed according to the above weight fractions, and the ethylene-vinyl acetate copolymer, the flame-retardant antistatic agent, the nano-montmorillonite, the azobisformamide, the zinc oxide, the dicumyl peroxide, the stearic acid, and the zinc stearate are mixed and then added to a preheated internal mixer, and the mixture is mixed at 100°C and 40 rpm for 5 min to obtain a premix; (b) The premix obtained in step (a) is quickly transferred to a two-roll open mill, and the mixture is milled at 110°C for 6 min and passes through 8 times of thin passage, and finally the roll gap is adjusted to 5 mm to obtain a milled sheet; (c) The milled sheet obtained in step (b) is placed in a preheated flat vulcanizing machine after being placed at room temperature for 24 h, and is molded and foamed at 12 MPa and 170°C for 8 min; then the mold is opened, and after the gas is discharged, the mold is closed again at 12 MPa and 170°C for 5 min; finally, the mold is opened after water cooling for 5 min under pressure, and the flame-retardant antistatic EVA composite material is obtained.

[0037] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that the flame-retardant antistatic agent of Example 1 is omitted.

[0038] Test Example The EVA composite materials prepared in Examples 1-3 and Comparative Example 1 were subjected to the following performance tests.

[0039] Tensile properties: The tensile strength and elongation at break of the EVA composite materials of Examples 1-3 and Comparative Example 1 were tested according to GB / T 1040.1-2018 "Determination of tensile properties of plastics - Part 1: General principles", with a tensile speed of 50 mm / min, and the average value of 5 samples in each group was taken, and the results are shown in Table 1.

[0040] Volume resistivity: The volume resistivity of the EVA composite materials of Examples 1-3 and Comparative Example 1 was tested according to GB / T 31838.2-2019 "Solid insulating materials - Determination of the dielectric and resistive properties - Part 2: Resistive properties (DC method) Volume resistance and volume resistivity", and the results are shown in Table 1.

[0041] Flame retardant properties: UL-94 vertical burning test was carried out according to GB / T 2408-2021 "Determination of the flammability of plastics - Horizontal and vertical methods", and limiting oxygen index test was carried out according to GB / T 2406.2-2009 "Determination of the flammability of plastics - Part 2: Test methods - Method 2: Test in room temperature", and the average value of 5 samples in each group was taken, and the results are shown in Table 1.

[0042] Table 1 As can be seen from Table 1, the EVA composite materials prepared in Examples 1-3 all exhibit excellent mechanical properties, flame retardant properties and antistatic properties. In terms of mechanical properties, the tensile strength and elongation at break are both maintained at a high level, indicating that the introduction of the flame-retardant antistatic agent does not significantly negatively affect the mechanical properties of the EVA matrix.

[0043] Compared with Example 1, the volume resistivity of Comparative Example 1 without the addition of the flame-retardant antistatic agent is as high as 10 14Ω·cm, the limiting oxygen index is only 19.5%, and the UL-94 grade is HB, indicating that it does not have antistatic and flame-retardant functions. The above results show that the application realizes the dual functions of flame retardation and antistatic by introducing the self-made flame-retardant antistatic agent at a lower addition amount, and the mechanical properties are also improved to a certain extent. The analysis shows that, on the one hand, the self-made flame-retardant antistatic agent of the application contains flame-retardant and conductive groups such as phosphorus, nitrogen and sulfonic acid groups in the molecular structure, which can promote the char forming reaction and effectively inhibit the generation of melt drops during combustion, significantly improving the flame-retardant performance of the material; at the same time, the volume resistivity of the material is significantly reduced through the ion conduction mechanism, reducing it from the insulating level to the antistatic level, and giving the material excellent antistatic performance. On the other hand, the flame-retardant antistatic EVA composite material of the application maintains excellent flame-retardant and antistatic properties while the mechanical properties are also improved to a certain extent. The flame-retardant antistatic agent introduced by the application can form hydrogen bonds and van der Waals forces with the EVA molecular chain through the functional groups such as phosphorus, nitrogen and sulfonic acid groups in its structure, thereby enhancing the intermolecular bonding force and improving the tensile strength and elongation at break of the material. In addition, the flame-retardant antistatic agent has good compatibility with the EVA matrix and is not easy to migrate or precipitate during foaming, ensuring the uniformity and fineness of the cell structure, reducing the problems of coarse cells and uneven density caused by the addition of fillers, and further improving the overall mechanical properties of the material.

[0044] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the application, but not to limit it. The basic principles and main features of the application have been described above with specific embodiments, and some modifications or replacements can be made on the basis of the application, but these modifications or replacements do not make the corresponding technical solutions deviate from the scope of the application.

Claims

1. A flame retardant antistatic EVA composite material, characterized in that, The raw materials include the following weight parts: ethylene-vinyl acetate copolymer 80-100 parts, flame-retardant antistatic agent 15-25 parts, flame-retardant auxiliary agent 3-8 parts, foaming agent 2.5-5 parts, zinc oxide 0.5-1.5 parts, crosslinking agent 0.5-1.2 parts, zinc stearate 0.3-0.8 parts, and stearic acid 0.3-0.8 parts; The structural formula of the flame-retardant antistatic agent is as follows: 。 2. The flame retardant antistatic EVA composite material according to claim 1, characterized in that, The flame-retardant antistatic agent is prepared by the following preparation process: (1) o-vanillin is added to an ethanol solution, then sodium p-aminobenzenesulfonate is added, and the reaction is carried out under stirring; after the reaction is completed, the precipitate is collected and washed with water, and then dried to obtain intermediate 1; The structural formula of the intermediate 1 is as follows: ； (2) dimeric glycerol and phosphoric acid are added to xylene for reflux reaction, and after the reaction is completed, the reaction solution is separated and purified by column chromatography to obtain intermediate 2; The structural formula of the intermediate 2 is as follows: ； (3) the intermediate 1 and the intermediate 2 are added to xylene for reflux reaction, and after the reaction is completed, the reaction solution is dialyzed and freeze-dried to obtain the flame-retardant antistatic agent.

3. The flame retardant antistatic EVA composite material according to claim 2, characterized in that, In step (1), the molar ratio of o-vanillin to sodium p-aminobenzenesulfonate is 1:(1-1.2); the reaction time is 10-12 h.

4. The flame retardant antistatic EVA composite material according to claim 2, characterized in that, In step (2), the molar ratio of dimeric glycerol to phosphoric acid is 1:(4-4.2); the reflux reaction time is 3-5 h.

5. The flame retardant antistatic EVA composite material according to claim 2, characterized in that, In step (3), the molar ratio of the intermediate 1 to the intermediate 2 is (1-1.2):1; the reflux reaction time is 5-8 h; the molecular weight cut-off of the dialysis is 500 Da.

6. The flame retardant antistatic EVA composite material according to claim 1, characterized in that, The flame-retardant auxiliary agent is nano-montmorillonite; the foaming agent is azodicarbonamide; and the crosslinking agent is dicumyl peroxide or azobisisobutyronitrile.

7. The flame retardant antistatic EVA composite material according to claim 1, characterized in that, The content of vinyl acetate in the ethylene-vinyl acetate copolymer is 15-20 wt%.

8. A process for the preparation of flame retardant antistatic EVA composite material as claimed in any one of claims 1 to 7, characterized in that, The method comprises the following steps: (a) ethylene-vinyl acetate copolymer, flame-retardant antistatic agent, flame-retardant auxiliary agent, foaming agent, zinc oxide, crosslinking agent, stearic acid, and zinc stearate are mixed according to the weight parts, and then added to a preheated internal mixer, and then mixed for 3-5 min at 80-100℃ to obtain a premix; (b) the premix is transferred to a two-roll open mill, and then opened for 5-6 min, and then passed through a thin pass, and then sheeted to obtain a mixed sheet; (c) the mixed sheet is placed in a preheated flat curing press for mold foaming, and then exhausts, and then subjected to secondary mold pressing; finally, pressure is maintained for 5-8 min for water cooling, and then the mold is opened to obtain the flame-retardant antistatic EVA composite material.

9. A process for the preparation of flame retardant antistatic EVA composite material as claimed in claim 8, wherein, In step (b), the thin pass is performed 5-8 times at a temperature of 90-110℃; and the thickness of the mixed sheet is 3-5 mm.

10. A process for the preparation of flame retardant antistatic EVA composite as claimed in claim 8, wherein, In step (c), the temperature of the mold foaming and the secondary mold pressing is both 150-170℃, and the pressure is both 10-12 MPa; the mold foaming time is 5-8 min, and the secondary mold pressing time is 3-5 min.

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