Production process of flame-retardant laminated belt for coal mine

Abstract

The present application relates to a kind of coal mine with flame-retardant laminated belt production process, belong to transportation auxiliary material technical field;The flame-retardant laminated belt is composed of laminated core belt, vulcanization adhesive layer and flame-retardant covering layer, wherein, the component of flame-retardant covering layer is: cis-butadiene rubber 8-12wt%, magnesium hydroxide flame retardant 32-38wt%, reinforcing agent 4-5.2wt%, modified synergist 4.5-7.5wt%, vulcanizing agent 1.2-1.5wt%, accelerator 0.25-0.3wt% and antioxidant 0.1-0.12wt%, the balance is neoprene;Modified synergist is formed by N-phenyl p-phenylenediamine self-polymerization short-chain polyaniline, then by methyl mercaptoacetate and its end amino amine ester exchange is made, with chelation-crosslinking bifunctional modified synergist, realize the multidimensional optimization of magnesium hydroxide flame-retardant system.

Description

Technical Field

[0001] This invention belongs to the field of transportation auxiliary materials technology, specifically, it relates to a production process for flame-retardant laminated belts for coal mines. Background Technology

[0002] Flame-retardant laminated strips are key components of underground conveying systems in coal mines, and their flame-retardant and mechanical properties directly affect mine safety. Traditional technologies often use inorganic hydroxides (such as magnesium hydroxide and aluminum hydroxide) as flame retardants, utilizing their properties of releasing water of crystallization upon heating and forming a metal oxide coating to achieve flame retardancy. However, these flame retardants have the following insurmountable drawbacks:

[0003] Inorganic particles have poor interfacial compatibility with the rubber matrix. Excessive filling leads to a significant decrease in the material's toughness and wear resistance, while insufficient filling results in insignificant flame retardant effects, making it difficult to meet the flame retardant requirements for mining applications. This makes it difficult to synergistically optimize mechanical and flame retardant properties. In existing technologies, some attempts have been made to introduce highly efficient organic flame retardants such as phosphorus-based and nitrogen-based flame retardants to reduce the amount of inorganic flame retardants used. Although these flame retardants have high flame retardant efficiency, their thermal stability is insufficient, and they are prone to thermal migration during high-temperature vulcanization. The amount of highly efficient organic flame retardants used does not match the performance improvement, which greatly limits their development in industrial production. In addition, in compound flame retardant systems, especially those with high organic content, the lack of a continuous carbon layer during combustion makes them prone to dripping, posing a significant risk to coal mining. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a production process for flame-retardant laminated belts for coal mines.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A flame-retardant laminated belt for coal mines comprises a laminated core belt, a vulcanized bonding layer, and a flame-retardant covering layer. The flame-retardant covering layer consists of: 8-12 wt% butadiene rubber, 32-38 wt% magnesium hydroxide flame retardant, 4-5.2 wt% reinforcing agent, 4.5-7.5 wt% modifier and synergist, 1.2-1.5 wt% vulcanizing agent, 0.25-0.3 wt% accelerator, and 0.1-0.12 wt% antioxidant, with the balance being chloroprene rubber.

[0007] The modified synergist is prepared by the following method:

[0008] Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran are premixed under a nitrogen atmosphere, and hydrochloric acid is added to acidify the premixed solution to a pH of 3-4. The temperature is controlled at 40-55℃ in a water bath, and ammonium persulfate solution is slowly added and stirred for 5.5-7 hours. Water is added to wash and precipitate the precipitate. The mixture is washed until neutral to obtain the intermediate.

[0009] In step A1 above, the ratio of N-phenyl-p-phenylenediamine, ammonium persulfate, and tetrahydrofuran is 0.1 mol: 2.2-2.8 g: 150-200 mL. Under acidic oxidation conditions, N-phenyl-p-phenylenediamine self-polymerizes to form short-chain polyaniline. The specific reaction route is as follows:

[0010]

[0011] Step A2: Mix the intermediate, methyl mercaptoacetate and dimethyl sulfoxide in a dry atmosphere, add trimethylaluminum and mix, heat to 90-110℃, stir and react for 2.5-3.2h, remove dimethyl sulfoxide under reduced pressure, wash the substrate with ethanol solution and dry to obtain the modified synergist;

[0012] In step A2 above, the ratio of intermediate, methyl thioglycolate, trimethylaluminum, and dimethyl sulfoxide is 10 g : 8-12 mmol : 25-40 mg : 65-85 mL. Under the catalysis of trimethylaluminum, the intermediate undergoes amino-ester exchange with methyl thioglycolate. The specific reaction route is as follows:

[0013]

[0014] Preferably, the reinforcing agent is carbon black, which has a small particle size, good reinforcing effect, and can provide a certain degree of conductivity, thus synergistically improving the antistatic ability of the flame-retardant coating layer with the modifier.

[0015] Preferably, the vulcanizing agent is sulfur, which has good vulcanizing ability on both the rubber matrix and the modifier / synergist.

[0016] A production process for flame-retardant laminated belts for coal mines includes the following steps:

[0017] Process S1: Mix and plasticize chloroprene rubber and butadiene rubber, add accelerator and antioxidant for premixing, then add magnesium hydroxide flame retardant, reinforcing agent and modifier for final mixing, and finally add vulcanizing agent to sheet the raw rubber sheet.

[0018] Process S2: Apply vulcanizing adhesive to the surface of the laminated core strip, cold press and bond raw rubber sheets, steam pressurize and vulcanize, and discharge to obtain flame-retardant laminated strip.

[0019] In process S1, the plasticizing temperature is 55℃ and the mixing temperature is 90-100℃.

[0020] In process S2, the temperature of steam pressurization vulcanization is 145-160℃, the steam pressure is 0.5-0.6MPa, and the vulcanization time is 60-80min.

[0021] The beneficial effects of this invention are:

[0022] This invention, based on existing inorganic flame retardant systems, uses magnesium hydroxide as a flame retardant and introduces a modified synergist with chelation-crosslinking dual functions to achieve multi-dimensional optimization of the magnesium hydroxide flame retardant system. This modified synergist is formed by the self-polymerization of N-phenyl-p-phenylenediamine into short-chain polyaniline, followed by amine ester exchange between methyl mercaptoacetate and its terminal amino groups. The thioamide structure in the modified synergist molecule forms a chelating effect with magnesium hydroxide, while the terminal thiol groups crosslink with the rubber molecular chains, constructing a strong interfacial layer between the inorganic and organic phases. This significantly improves the reinforcing efficiency of magnesium hydroxide, resulting in a significant improvement in the mechanical strength and wear resistance of the flame-retardant coating layer. Under the chelating and composite effect, the short-chain polyaniline is anchored to the magnesium hydroxide... On the magnesium surface, magnesium hydroxide-polyaniline composite units are formed. The multi-benzene ring conjugated structure of the polyaniline acts as an electron transport bridge, synergistically constructing a three-dimensional conductive pathway with reinforcing agents such as carbon black, resulting in a significant decrease in resistivity and effectively suppressing static electricity accumulation. During combustion, the multi-benzene ring structure of polyaniline rapidly carbonizes to form a dense network skeleton, which combines with magnesium oxide particles generated from the decomposition of magnesium hydroxide to form a carbon-ceramic composite barrier layer, with significant oxygen barrier and smoke suppression effects. At the same time, the carbon layer effectively supports the material morphology and avoids the generation of molten droplets, with no molten droplet phenomenon observed in vertical combustion tests. In addition, the modifier can be added directly during the mixing process without complex pretreatment, is highly compatible with existing rubber processing technology, and is suitable for industrial production. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Preparation of flame-retardant laminated tape, as detailed below:

[0025] I. Preparation of Modified Synergists

[0026] Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran were premixed under a nitrogen atmosphere, and hydrochloric acid was added to acidify the premixed solution to pH 3. The water bath temperature was controlled at 40℃, and a 1% (w / w) ammonium persulfate aqueous solution was slowly added and stirred for 7 hours. The ratio of N-phenyl-p-phenylenediamine, ammonium persulfate and tetrahydrofuran was 0.1 mol: 2.2 g: 150 mL. Finally, water was added to wash and precipitate the precipitate. The mixture was washed until neutral to obtain the intermediate.

[0027] Step A2: The intermediate, methyl mercaptoacetate, and dimethyl sulfoxide were mixed in a dry atmosphere, and trimethylaluminum was added and mixed. The mixture was heated to 90°C and stirred for 3.2 h. The ratio of the intermediate, methyl mercaptoacetate, trimethylaluminum, and dimethyl sulfoxide was 10 g: 8 mmol: 40 mg: 65 mL. Finally, the dimethyl sulfoxide was removed by vacuum distillation. The substrate was washed with ethanol solution and dried to obtain the modified synergist.

[0028] II. Preparation of Flame-Retardant Laminated Strips

[0029] In this embodiment, the flame-retardant coating layer consists of: 10 wt% butadiene rubber, BR9000 type rubber raw material; 32 wt% magnesium hydroxide flame retardant, XS-MHS-25 type commercially available flame retardant; 5.2 wt% reinforcing agent, N550 type carbon black; 4.5 wt% modifier and synergist, self-made in this embodiment; 1.5 wt% vulcanizing agent, vulcanizing agent grade sulfur powder raw material; 0.3 wt% accelerator, TMTD accelerator; 0.12 wt% antioxidant, RD antioxidant; the balance is chloroprene rubber, CR3222 type rubber raw material;

[0030] Process S1: Mix chloroprene rubber and butadiene rubber and plasticize at 55°C for 15 minutes. Then add accelerator and antioxidant, and premix at 90°C for 5 minutes. After that, add magnesium hydroxide flame retardant, reinforcing agent and modifier and finally mix for 8 minutes. Pass the mixed rubber through a thin tube 3 times and add vulcanizing agent. Sheet the rubber to obtain raw rubber sheet.

[0031] Process S2: Based on the required conveying intensity of the coal mine, steel wire laminated core belt is selected, and YFL 9288 type vulcanizing rubber is coated on the surface. Raw rubber sheets are then bonded to the surface of the vulcanizing rubber and cold-pressed at 1.5MPa. The belt is then fed into a vulcanizing kettle for steam pressurization vulcanization. The process parameters are controlled as follows: temperature 160℃, steam pressure 0.6MPa, and vulcanization time 60min. The raw rubber sheets vulcanize to form a flame-retardant covering layer, and the interlayer vulcanizing rubber vulcanizes to form a vulcanized bonding layer, thus obtaining a flame-retardant laminated belt.

[0032] Example 2: Preparation of flame-retardant laminated tape, as detailed below:

[0033] I. Preparation of Modified Synergists

[0034] Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran were premixed under a nitrogen atmosphere, and the premixed solution was acidified with hydrochloric acid to a pH of 4. The water bath temperature was controlled at 55°C, and a 1% (w / w) ammonium persulfate aqueous solution was slowly added and stirred for 5.5 h. The ratio of N-phenyl-p-phenylenediamine, ammonium persulfate and tetrahydrofuran was 0.1 mol: 2.8 g: 200 mL. Finally, water was added to wash and precipitate the precipitate. The mixture was washed until neutral to obtain the intermediate.

[0035] Step A2: The intermediate, methyl mercaptoacetate, and dimethyl sulfoxide were mixed in a dry atmosphere, and trimethylaluminum was added and mixed. The mixture was heated to 110°C and stirred for 2.5 h. The ratio of the intermediate, methyl mercaptoacetate, trimethylaluminum, and dimethyl sulfoxide was 10 g: 12 mmol: 25 mg: 85 mL. Finally, the dimethyl sulfoxide was removed by vacuum distillation. The substrate was washed with ethanol solution and dried to obtain the modified synergist.

[0036] II. Preparation of Flame-Retardant Laminated Strips

[0037] In this embodiment, the flame-retardant coating layer consists of: 8 wt% butadiene rubber, BR9000 type rubber raw material; 38 wt% magnesium hydroxide flame retardant, XS-MHS-25 type commercially available flame retardant; 4 wt% reinforcing agent, N550 type carbon black; 7.5 wt% modifier and synergist, self-made in this embodiment; 1.2 wt% vulcanizing agent, vulcanizing agent grade sulfur powder raw material; 0.25 wt% accelerator, TMTD accelerator; 0.1 wt% antioxidant, RD antioxidant; the balance is chloroprene rubber, CR3222 type rubber raw material;

[0038] Process S1: Mix chloroprene rubber and butadiene rubber and plasticize at 55°C for 15 minutes. Then add accelerator and antioxidant, and premix at 100°C for 3 minutes. After that, add magnesium hydroxide flame retardant, reinforcing agent and modifier and finally mix for 11 minutes. Pass the mixed rubber through a thin tube 4 times and add vulcanizing agent. Sheet the rubber to obtain raw rubber sheet.

[0039] Process S2: Based on the required conveying intensity of the coal mine, steel wire laminated core belt is selected, and YFL 9288 type vulcanizing rubber is coated on the surface. Raw rubber sheets are then bonded to the surface of the vulcanizing rubber and cold-pressed at 1.5MPa. The belt is then fed into a vulcanizing kettle for steam pressurization and vulcanization. The process parameters are controlled as follows: temperature 145℃, steam pressure 0.5MPa, and vulcanization time 80min. The raw rubber sheets vulcanize to form a flame-retardant covering layer, and the interlayer vulcanizing rubber vulcanizes to form a vulcanized bonding layer, thus obtaining a flame-retardant laminated belt.

[0040] Example 3: Preparation of flame-retardant laminated tape, as detailed below:

[0041] I. Preparation of Modified Synergists

[0042] Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran were premixed under a nitrogen atmosphere, and the premixed solution was acidified with hydrochloric acid to a pH of 4. The water bath temperature was controlled at 50°C, and a 1% (w / w) ammonium persulfate aqueous solution was slowly added and stirred for 6.5 h. The ratio of N-phenyl-p-phenylenediamine, ammonium persulfate and tetrahydrofuran was 0.1 mol: 2.4 g: 180 mL. Finally, water was added to wash and precipitate the precipitate. The mixture was washed until neutral to obtain the intermediate.

[0043] Step A2: The intermediate, methyl mercaptoacetate, and dimethyl sulfoxide were mixed in a dry atmosphere, and trimethylaluminum was added and mixed. The mixture was heated to 100°C and stirred for 2.8 h. The ratio of the intermediate, methyl mercaptoacetate, trimethylaluminum, and dimethyl sulfoxide was 10 g: 10 mmol: 30 mg: 70 mL. Finally, the dimethyl sulfoxide was removed by vacuum distillation. The substrate was washed with ethanol solution and dried to obtain the modified synergist.

[0044] II. Preparation of Flame-Retardant Laminated Strips

[0045] In this embodiment, the flame-retardant coating layer consists of: 12 wt% butadiene rubber, BR9000 type rubber raw material; 35 wt% magnesium hydroxide flame retardant, XS-MHS-25 type commercially available flame retardant; 4.5 wt% reinforcing agent, N550 type carbon black; 7 wt% modifier and synergist, self-made in this embodiment; 1.3 wt% vulcanizing agent, vulcanizing agent grade sulfur powder raw material; 0.28 wt% accelerator, TMTD accelerator; 0.1 wt% antioxidant, RD antioxidant; the balance is chloroprene rubber, CR3222 type rubber raw material;

[0046] Process S1: Mix chloroprene rubber and butadiene rubber and plasticize at 55°C for 15 minutes. Then add accelerator and antioxidant, and premix at 100°C for 4 minutes. After that, add magnesium hydroxide flame retardant, reinforcing agent and modifier and finally mix for 10 minutes. Pass the mixed rubber through a thin tube 4 times and add vulcanizing agent. Sheet the rubber to obtain raw rubber sheet.

[0047] Process S2: Based on the required conveying intensity of the coal mine, steel wire laminated core belt is selected, and YFL 9288 type vulcanizing rubber is coated on the surface. Raw rubber sheets are then bonded to the surface of the vulcanizing rubber and cold-pressed at 1.5MPa. The belt is then fed into a vulcanizing kettle for steam pressurization vulcanization. The process parameters are controlled as follows: temperature 150℃, steam pressure 0.5MPa, and vulcanization time 75min. The raw rubber sheets vulcanize to form a flame-retardant covering layer, and the interlayer vulcanizing rubber vulcanizes to form a vulcanized bonding layer, thus obtaining a flame-retardant laminated belt.

[0048] Example 4: Preparation of flame-retardant laminated tape, as detailed below:

[0049] I. Preparation of Modified Synergists

[0050] Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran were premixed under a nitrogen atmosphere, and hydrochloric acid was added to acidify the premixed solution to pH 3. The water bath temperature was controlled at 45℃, and 1% (w / w) ammonium persulfate aqueous solution was slowly added and stirred for 6 hours. The ratio of N-phenyl-p-phenylenediamine, ammonium persulfate and tetrahydrofuran was 0.1 mol: 2.6 g: 160 mL. Finally, water was added to wash and precipitate the precipitate. The mixture was washed until neutral to obtain the intermediate.

[0051] Step A2: The intermediate, methyl mercaptoacetate, and dimethyl sulfoxide were mixed in a dry atmosphere, and trimethylaluminum was added and mixed. The mixture was heated to 110°C and stirred for 2.7 h. The ratio of the intermediate, methyl mercaptoacetate, trimethylaluminum, and dimethyl sulfoxide was 10 g: 9 mmol: 35 mg: 80 mL. Finally, the dimethyl sulfoxide was removed by vacuum distillation. The substrate was washed with ethanol solution and dried to obtain the modified synergist.

[0052] II. Preparation of Flame-Retardant Laminated Strips

[0053] In this embodiment, the flame-retardant coating layer consists of: 11 wt% butadiene rubber, BR9000 type rubber raw material; 35 wt% magnesium hydroxide flame retardant, XS-MHS-25 type commercially available flame retardant; 4.8 wt% reinforcing agent, N550 type carbon black; 6.2 wt% modifier and synergist, self-made in this embodiment; 1.3 wt% vulcanizing agent, vulcanizing agent grade sulfur powder raw material; 0.25 wt% accelerator, TMTD accelerator; 0.11 wt% antioxidant, RD antioxidant; the balance is chloroprene rubber, CR3222 type rubber raw material;

[0054] Process S1: Mix chloroprene rubber and butadiene rubber and plasticize at 55°C for 15 minutes. Then add accelerator and antioxidant, and premix at 100°C for 5 minutes. After that, add magnesium hydroxide flame retardant, reinforcing agent and modifier and finally mix for 10 minutes. Pass the mixed rubber through a thin tube 4 times and add vulcanizing agent. Sheet the rubber to obtain raw rubber sheet.

[0055] Process S2: Based on the required conveying intensity of the coal mine, steel wire laminated core belt is selected, and YFL 9288 type vulcanizing rubber is coated on the surface. Raw rubber sheets are then bonded to the surface of the vulcanizing rubber and cold-pressed at 1.5MPa. The belt is then fed into a vulcanizing kettle for steam pressurization vulcanization. The process parameters are controlled as follows: temperature 155℃, steam pressure 0.6MPa, and vulcanization time 70min. The raw rubber sheets vulcanize to form a flame-retardant covering layer, and the interlayer vulcanizing rubber vulcanizes to form a vulcanized bonding layer, thus obtaining a flame-retardant laminated belt.

[0056] Comparative Example 1: This comparative example is based on Example 4, but without the addition of a modifier or synergist. The remaining amount is supplemented by chloroprene rubber to 100 wt%, and the rest of the implementation process is exactly the same.

[0057] Comparative Example 2 is the same as Example 4, except that the modifier was replaced with 1.8 wt% of silane coupling agent KH-580 and 4.4 wt% of polyaniline, and the rest of the implementation process was exactly the same.

[0058] The flame-retardant coating layer underwent relevant performance testing, including: basic performance testing, with hardness testing performed according to GB / T 531.1-2008 and tensile performance testing performed according to GB / T 528-2009, as shown in Table 1; and service performance testing, with flame-retardant performance testing performed according to AS1334.10-1994, and the flame-retardant rating tested according to UL94 standard, with roller friction testing performed according to AS1334.11-1988 and antistatic testing performed according to AS1334.9-1982, as shown in Table 2.

[0059] Table 1

[0060]

[0061] As can be seen from the data in Table 1, the flame-retardant coating layer prepared above has moderate hardness, and the flame-retardant coating layer of the embodiment has superior overall strength and toughness performance.

[0062] Table 2

[0063]

[0064] As shown in Table 2, the flame-retardant coatings prepared above all exhibit flame-retardant times of less than 10 seconds, demonstrating a certain degree of flame retardancy. In contrast, the comparative example showed clearly visible molten droplets during the vertical burning test, achieving a flame-retardant rating of only V-2. The example showed low roller abrasion and a surface resistivity of 10 Ω·cm. 7 It has a large quantity and good antistatic effect, which is beneficial to the safe transportation of coal in coal mines.

[0065] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A flame-retardant laminated belt for coal mines, comprising a laminated core belt, a vulcanized bonding layer, and a flame-retardant covering layer, characterized in that, The flame-retardant coating layer consists of: 8-12 wt% butadiene rubber, 32-38 wt% magnesium hydroxide flame retardant, 4-5.2 wt% reinforcing agent, 4.5-7.5 wt% modifier and synergist, 1.2-1.5 wt% vulcanizing agent, 0.25-0.3 wt% accelerator, and 0.1-0.12 wt% antioxidant, with the balance being chloroprene rubber; The modified synergist is prepared by the following method: Step A1: N-phenyl-p-phenylenediamine and tetrahydrofuran are premixed under a nitrogen atmosphere, and hydrochloric acid is added to acidify the premixed solution to a pH of 3-4. The temperature is controlled at 40-55℃ in a water bath, and ammonium persulfate solution is slowly added and stirred for 5.5-7 hours. Water is added to wash and precipitate the precipitate. The mixture is washed until neutral to obtain the intermediate. Step A2: Mix the intermediate, methyl mercaptoacetate and dimethyl sulfoxide in a dry atmosphere, add trimethylaluminum and mix, heat to 90-110℃, stir and react for 2.5-3.2 h, remove dimethyl sulfoxide under reduced pressure, wash the substrate with ethanol solution and dry to obtain the modified synergist.

2. The flame-retardant laminated strip for coal mines according to claim 1, characterized in that, The ratio of N-phenyl-p-phenylenediamine, ammonium persulfate, and tetrahydrofuran is 0.1 mol: 2.2-2.8 g: 150-200 mL.

3. The flame-retardant laminated strip for coal mines according to claim 2, characterized in that, The ratio of intermediate, methyl mercaptoacetate, trimethylaluminum and dimethyl sulfoxide is 10g: 8-12mmol: 25-40mg: 65-85mL.

4. The flame-retardant laminated strip for coal mines according to claim 1, characterized in that, The reinforcing agent is carbon black.

5. The flame-retardant laminated strip for coal mines according to claim 1, characterized in that, The sulfiding agent is sulfur.

6. A production process for a flame-retardant laminated strip for coal mines according to any one of claims 1-5, characterized in that, The process includes the following steps: Process S1: Mix and plasticize chloroprene rubber and butadiene rubber, add accelerator and antioxidant for premixing, then add magnesium hydroxide flame retardant, reinforcing agent and modifier for final mixing, and finally add vulcanizing agent to sheet the raw rubber sheet. Process S2: Apply vulcanizing adhesive to the surface of the laminated core strip, cold press and bond raw rubber sheets, steam pressurize and vulcanize, and discharge to obtain flame-retardant laminated strip.

7. The production process of a flame-retardant laminated belt for coal mines according to claim 6, characterized in that, The plasticizing temperature is 55℃, and the mixing temperature is 90-100℃.

8. The production process of a flame-retardant laminated strip for coal mines according to claim 6, characterized in that, The steam pressurization temperature is 145-160℃, the steam pressure is 0.5-0.6MPa, and the vulcanization time is 60-80min.

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