A flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines and a preparation method thereof

Abstract

The present invention relates to a super wear-resistant covering rubber for a flame-retardant conveyor belt for underground coal mines and a preparation method thereof, wherein the covering rubber comprises chloroprene rubber, butadiene rubber, carbon black, ultra-high molecular weight polyethylene powder, antioxidant, flame retardant, stearic acid, active magnesium oxide, zinc oxide, sulfur and accelerator; and the preparation method thereof comprises the steps of primary banburying, secondary banburying and side-by-side rubber, tertiary banburying and side-by-side rubber, refining and sheeting and cooling. The covering rubber of the present invention has excellent wear resistance and excellent flame retardant performance, and the preparation method of the covering rubber has few steps and is easy to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of conveyor belt production, and specifically discloses a super wear-resistant covering rubber for a flame-retardant conveyor belt used underground in a coal mine and a preparation method thereof. Background Art

[0002] Although coal has a low Mohs hardness and is a soft mineral that causes less wear on the conveyor belt surface, the newly mined coal has not been screened by the coal washing plant and contains some gangue. The hardness of the gangue is relatively high, causing serious wear and damage to the belt surface. The conveyor belt on the same line can be used for more than 3 years when the coal seam contains less gangue, but can only be used for 10-12 months when the coal seam contains more gangue, which is a huge difference. In order to solve this problem, conveyor belt manufacturers often reduce the amount of flame retardants to improve wear resistance. The reduction of flame retardants will bring the risk of unqualified flame retardant performance; or use a large amount of butadiene rubber, which causes the physical and mechanical properties of the covering rubber to deteriorate. Regardless of which method is used, the wear cannot reach 100mm. 3 the following. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a super wear-resistant covering rubber for a flame-retardant conveyor belt for underground coal mines with excellent wear resistance and excellent flame retardancy and a preparation method thereof.

[0004] According to the technical solution provided by the present invention, the super wear-resistant covering rubber for the flame-retardant conveyor belt used in underground coal mines comprises the following components:

[0005] 50-80 parts by weight of chloroprene rubber, 20-50 parts by weight of butadiene rubber, 35-50 parts by weight of carbon black, 1-5 parts by weight of ultra-high molecular weight polyethylene powder, 4.5-5 parts by weight of antioxidant, 40-55 parts by weight of flame retardant, 1-1.5 parts by weight of stearic acid, 2-4 parts by weight of active magnesium oxide, 1-5 parts by weight of zinc oxide, 0.5-2 parts by weight of sulfur, and 1.7-2.5 parts by weight of accelerator;

[0006] After adding chloroprene rubber, butadiene rubber and ultra-high molecular weight polyethylene powder into an internal mixer, internal mixing is carried out, and then stearic acid, active magnesium oxide, antioxidant, flame retardant and carbon black are added for mixing to obtain a section of rubber material, which is placed in an internal mixer after being parked, and sulfur, accelerator and zinc oxide are added for mixing. After mixing, the rubber is discharged, and the rubber is re-refined after the discharge. After re-refining, the sheet is taken out and cooled to obtain the flame-retardant conveyor belt wear-resistant covering rubber for underground coal mines.

[0007] Preferably, the chloroprene rubber is one or two of chloroprene rubber CR322, chloroprene rubber CR232, chloroprene rubber M40, and chloroprene rubber PS40.

[0008] Preferably, the DBP absorption value of the carbon black is between 120 and 180.

[0009] Preferably, the molecular weight of the ultra-high molecular weight polyethylene powder is between 4 million and 6 million.

[0010] Preferably, the antioxidant is three or four of the antioxidant microcrystalline wax, antioxidant 4010NA, antioxidant RD, and antioxidant OD.

[0011] Preferably, the flame retardant is two or more of the flame retardant chlorinated paraffin, flame retardant antimony trioxide, flame retardant aluminum hydroxide, and flame retardant zinc borate.

[0012] Preferably, the accelerator is one or more of accelerator DTDM, accelerator TMTD, accelerator NS, accelerator DM, and accelerator NA-22.

[0013] The preparation method of the above-mentioned flame-retardant conveyor belt wear-resistant covering rubber for underground coal mines comprises the following steps:

[0014] a. Add 50-80 parts by weight of chloroprene rubber, 20-50 parts by weight of butadiene rubber, and 1-5 parts by weight of ultra-high molecular weight polyethylene powder into an internal mixer and mix for 1-2 minutes;

[0015] b. Lift the top bolt and add 5-8 parts by weight of antioxidant, 35-55 parts by weight of flame retardant, 0.5-1.5 parts by weight of stearic acid, 1-5 parts by weight of active magnesium oxide and 35-50 parts by weight of carbon black into the internal mixer for internal mixing. After internal mixing for 2-3 minutes, discharge the rubber to obtain a rubber compound, which is left for at least 8 hours.

[0016] c. Put the rubber obtained in step b, 1-5 parts by weight of zinc oxide, 1-2 parts by weight of sulfur, and 2-3 parts by weight of accelerator into an internal mixer, mix for 1-2 minutes, and then discharge the rubber;

[0017] d. After the rubber is discharged, it is refined for 1-2.5 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to 0-40℃ to obtain the super wear-resistant covering rubber for flame-retardant conveyor belts in underground coal mines.

[0018] The covering rubber of the invention has excellent wear resistance and excellent flame retardancy, and the preparation method of the covering rubber has few steps and is easy to operate. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with specific embodiments below. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] A method for preparing a flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines, the preparation method comprising the following steps:

[0022] a. Put 50 parts by weight of chloroprene rubber CR322, 50 parts by weight of butadiene rubber and 1 part by weight of ultra-high molecular weight polyethylene powder into an internal mixer and mix for 2 minutes. The molecular weight of the ultra-high molecular weight polyethylene powder is between 4 million and 6 million.

[0023] b. Lift the top bolt and add 2 parts by weight of antioxidant microcrystalline wax, 1.5 parts by weight of antioxidant 4010NA, 1.5 parts by weight of antioxidant RD, 30 parts by weight of flame retardant chlorinated paraffin, 5 parts by weight of flame retardant antimony trioxide, 10 parts by weight of flame retardant zinc borate, 10 parts by weight of flame retardant aluminum hydroxide, 1.5 parts by weight of stearic acid, 2 parts by weight of active magnesium oxide and 50 parts by weight of carbon black into an internal mixer. After mixing for 3 minutes, discharge the rubber to obtain a rubber compound, which is left for 8 hours. The DBP absorption value of the carbon black is 120-180.

[0024] c. Put the rubber obtained in step b, 1 part by weight of zinc oxide, 2 parts by weight of sulfur, 1.2 parts by weight of accelerator CZ and 0.5 parts by weight of accelerator DM into an internal mixer, mix for 2 minutes and then discharge the rubber;

[0025] d. After the rubber is discharged, it is refined for 2.5 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to 0-40℃ to obtain the super wear-resistant covering rubber for flame-retardant conveyor belts in underground coal mines.

[0026] The super wear-resistant covering rubber for flame-retardant conveyor belts for underground coal mines obtained in Example 1 was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 10 MPa, and a vulcanization time of 40 minutes. The physical and mechanical properties of the super wear-resistant covering rubber for flame-retardant conveyor belts for underground coal mines after vulcanization are shown in Table 1, and the flame retardant properties are shown in Table 2.

[0027] Example 2

[0028] A method for preparing a flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines, the preparation method comprising the following steps:

[0029] a. Put 30 parts by weight of chloroprene rubber CR322, 50 parts by weight of chloroprene rubber M40, 20 parts by weight of butadiene rubber and 5 parts by weight of ultra-high molecular weight polyethylene powder into an internal mixer and mix for 1.5 minutes. The molecular weight of the ultra-high molecular weight polyethylene powder is between 4 million and 6 million.

[0030] b. Lift the top bolt, add 2 parts by weight of antioxidant microcrystalline wax, 1 part by weight of antioxidant 4010NA, 1.5 parts by weight of antioxidant OD, 25 parts by weight of flame retardant chlorinated paraffin, 5 parts by weight of flame retardant antimony trioxide, 5 parts by weight of flame retardant zinc borate, 5 parts by weight of flame retardant aluminum hydroxide, 1 part by weight of stearic acid, 4 parts by weight of active magnesium oxide and 35 parts by weight of carbon black into an internal mixer, mix for 2 minutes and then discharge the rubber to obtain a rubber compound, which is left for 10 hours. The DBP absorption value of the carbon black is between 120 and 180.

[0031] c. Put the rubber obtained in step b, 5 parts by weight of zinc oxide, 0.5 parts by weight of sulfur, 1.5 parts by weight of accelerator DTDM and 1 part by weight of accelerator DM into an internal mixer, mix for 2 minutes and then discharge the rubber;

[0032] d. After the rubber is discharged, it is refined for 2.5 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to 0-40℃ to obtain the super wear-resistant covering rubber for flame-retardant conveyor belts in underground coal mines.

[0033] The flame retardant conveyor belt super wear-resistant covering rubber for underground coal mines obtained in Example 2 was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 10 MPa, and a vulcanization time of 40 minutes. The physical and mechanical properties of the flame retardant conveyor belt super wear-resistant covering rubber for underground coal mines after vulcanization are shown in Table 1, and the flame retardant properties are shown in Table 2.

[0034] Example 3

[0035] A method for preparing a flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines, the preparation method comprising the following steps:

[0036] a. Put 40 parts by weight of chloroprene rubber CR322, 40 parts by weight of chloroprene rubber CR232, 20 parts by weight of butadiene rubber and 5 parts by weight of ultra-high molecular weight polyethylene powder into an internal mixer and mix for 1.5 minutes. The molecular weight of the ultra-high molecular weight polyethylene powder is between 4 million and 6 million.

[0037] b. Lift the top bolt, add 2 parts by weight of antioxidant microcrystalline wax, 1 part by weight of antioxidant 4010NA, 1.5 parts by weight of antioxidant OD, 25 parts by weight of flame retardant chlorinated paraffin, 5 parts by weight of flame retardant antimony trioxide, 5 parts by weight of flame retardant zinc borate, 5 parts by weight of flame retardant aluminum hydroxide, 1 part by weight of stearic acid, 4 parts by weight of active magnesium oxide and 35 parts by weight of carbon black into an internal mixer, mix for 2 minutes and then discharge the rubber to obtain a rubber compound, which is left for 12 hours. The DBP absorption value of the carbon black is between 120 and 180.

[0038] c. Put the rubber obtained in step b, 5 parts by weight of zinc oxide, 0.5 parts by weight of sulfur, 1 part by weight of accelerator DTDM and 1 part by weight of accelerator DM into an internal mixer, mix for 2 minutes and then discharge the rubber;

[0039] d. After the rubber is discharged, it is refined for 2.5 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to 0-40℃ to obtain the super wear-resistant covering rubber for flame-retardant conveyor belts in underground coal mines.

[0040] The super wear-resistant covering rubber for flame-retardant conveyor belts for underground coal mines obtained in Example 3 was vulcanized on a flat vulcanizer at a vulcanization temperature of 150° C., a vulcanization pressure of 10 MPa, and a vulcanization time of 40 min. The physical and mechanical properties of the super wear-resistant covering rubber for flame-retardant conveyor belts for underground coal mines after vulcanization are shown in Table 1, and the flame retardant properties are shown in Table 2.

[0041] Comparative Example 1

[0042] A method for preparing a flame-retardant wear-resistant covering rubber for a conveyor belt used in underground coal mines, the method comprising the following steps:

[0043] a. Take 50 parts by weight of natural rubber and plasticize it on an open mill, set the roller distance at 2-4 mm, set the roller temperature at 35-50° C., and plasticize for 10 minutes to obtain a plasticized rubber;

[0044] b. 50 parts by weight of butadiene rubber and 50 parts by weight of the plasticated natural rubber obtained in a are put into an internal mixer and kneaded for 1 minute;

[0045] c. Lift the top bolt and add 2 parts by weight of RD, 2 parts by weight of 4010NA, 3 parts by weight of microcrystalline wax, 40 parts by weight of chlorinated paraffin, 8 parts by weight of antimony trioxide, 30 parts by weight of zinc borate, 20 parts by weight of aluminum hydroxide, 50 parts by weight of carbon black, 1.5 parts by weight of stearic acid and 5 parts by weight of zinc oxide into an internal mixer. Mix for 3.5 minutes and then discharge the rubber to obtain a rubber compound, which is then left for 8 hours.

[0046] d. Add the rubber obtained in step c, 0.8 parts by weight of sulfur, 1.5 parts by weight of DTDM and 1.2 parts by weight of accelerator CZ into an internal mixer, mix for 3 minutes and then perform debonding;

[0047] e. After the rubber is discharged, it is refining for 3 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to room temperature to obtain the flame-retardant conveyor belt covering rubber for underground coal mines.

[0048] The flame retardant conveyor belt covering rubber for underground coal mines obtained in Comparative Example 1 was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 10 MPa, and a vulcanization time of 40 minutes. The physical and mechanical properties of the flame retardant conveyor belt covering rubber for underground coal mines after vulcanization are shown in Table 1, and the flame retardant properties are shown in Table 2.

[0049] Comparative Example 2

[0050] A method for preparing a flame-retardant wear-resistant covering rubber for a conveyor belt used in underground coal mines, the method comprising the following steps:

[0051] a. Take 40 parts by weight of natural rubber and plasticize it on an open mill, set the roller distance at 2-4 mm, set the roller temperature at 35-50° C., and plasticize for 10 minutes to obtain a plasticized rubber;

[0052] b. 40 parts by weight of cis-1,4-butadiene rubber, 20 parts by weight of chloroprene rubber CR121 and 40 parts by weight of the plasticated natural rubber obtained in a are put into an internal mixer and kneaded for 1 minute;

[0053] c. Lift the top bolt and add 2 parts by weight of RD, 2 parts by weight of 4010NA, 3 parts by weight of microcrystalline wax, 30 parts by weight of chlorinated paraffin, 8 parts by weight of antimony trioxide, 20 parts by weight of zinc borate, 10 parts by weight of aluminum hydroxide, 50 parts by weight of carbon black, 1.5 parts by weight of stearic acid and 4 parts by weight of activated magnesium oxide into an internal mixer. After mixing for 3 minutes, discharge the rubber to obtain a rubber compound, which is left for 8 hours.

[0054] d. Put the rubber obtained in step c, 5 parts by weight of zinc oxide, 0.5 parts by weight of sulfur, 1.5 parts by weight of DTDM, 0.8 parts by weight of accelerator NS and 0.5 parts by weight of accelerator DM into an internal mixer, mix for 3 minutes and then discharge the rubber;

[0055] e. After the rubber is discharged, it is refining for 3 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to room temperature to obtain the flame-retardant conveyor belt covering rubber for underground coal mines.

[0056] The flame retardant conveyor belt covering rubber for underground coal mines obtained in Comparative Example 2 was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 10 MPa, and a vulcanization time of 40 minutes. The physical and mechanical properties of the flame retardant conveyor belt covering rubber for underground coal mines after vulcanization are shown in Table 1, and the flame retardant properties are shown in Table 2.

[0057] Table 1

[0058] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength / MPa 17.5 20.8 19.2 15.4 17.1 Elongation / % 542 502 485 568 554 hardness 67 69 69 66 65 <![CDATA[Wear / mm 3 > 78 80 85 148 135

[0059] Table 2

[0060]

[0061] Note: Table 2 is tested according to MT668-2019 standard.

[0062] As can be seen from Table 1, the average wear of Examples 1-3 is 81 mm 3 The average wear of comparative example 1-2 is 141.5 mm 3 It can be seen that the super wear-resistant covering rubber for the flame-retardant conveyor belt for underground coal mines obtained by Examples 1-3 has excellent wear resistance.

[0063] It can be seen from Table 2 that the average remaining propane length of the tunnel of Examples 1-3 is 840 mm, and the average remaining propane length of the tunnel of Comparative Example 1-2 is 701 mm. It can be seen that the super wear-resistant covering rubber for the flame-retardant conveyor belt for underground coal mines obtained by Examples 1-3 has excellent flame retardant properties.

[0064] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines, characterized by: The covering glue contains the following components: 50-80 parts by weight of chloroprene rubber, 20-50 parts by weight of butadiene rubber, 35-50 parts by weight of carbon black, 1-5 parts by weight of ultra-high molecular weight polyethylene powder, 4.5-5 parts by weight of antioxidant, 40-55 parts by weight of flame retardant, 1-1.5 parts by weight of stearic acid, 2-4 parts by weight of active magnesium oxide, 1-5 parts by weight of zinc oxide, 0.5-2 parts by weight of sulfur, and 1.7-2.5 parts by weight of accelerator; After adding chloroprene rubber, butadiene rubber and ultra-high molecular weight polyethylene powder into an internal mixer, internal mixing is carried out, and then stearic acid, active magnesium oxide, antioxidant, flame retardant and carbon black are added for internal mixing to obtain a section of rubber material, which is placed in an internal mixer after being parked, and sulfur, accelerator and zinc oxide are added for internal mixing. After internal mixing, the rubber is discharged, and after the discharge of the rubber, it is refining, and after refining, the sheet is taken out and cooled to obtain the flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines.

2. The flame-retardant super-wear-resistant covering rubber for underground coal mine conveyor belts according to claim 1 is characterized in that: The chloroprene rubber is one or two of chloroprene rubber CR322, chloroprene rubber CR232, chloroprene rubber M40 and chloroprene rubber PS40.

3. The flame-retardant super wear-resistant covering rubber for underground coal mine conveyor belts according to claim 1 is characterized in that: The DBP absorption value of the carbon black is 120-180.

4. The flame-retardant super-wear-resistant covering rubber for underground coal mine conveyor belts according to claim 1 is characterized in that: The molecular weight of the ultra-high molecular weight polyethylene powder is between 4 million and 6 million.

5. The flame-retardant conveyor belt super wear-resistant covering rubber for underground coal mines according to claim 1 is characterized by: The antioxidant is three or four of the antioxidant microcrystalline wax, antioxidant 4010NA, antioxidant RD, and antioxidant OD.

6. The flame-retardant super wear-resistant covering rubber for underground coal mine conveyor belts according to claim 1, characterized in that: The flame retardant is two or more of the flame retardant chlorinated paraffin, flame retardant antimony trioxide, flame retardant aluminum hydroxide, and flame retardant zinc borate.

7. The flame-retardant super-wear-resistant covering rubber for underground coal mine conveyor belts according to claim 1 is characterized by: The accelerator is one or more of accelerator DTDM, accelerator TMTD, accelerator NS, accelerator DM, and accelerator NA-22.

8. The method for preparing the super wear-resistant covering rubber for flame-retardant conveyor belts for underground coal mines according to any one of claims 1 to 7, characterized in that The preparation method comprises the following steps: a. Add 50-80 parts by weight of chloroprene rubber, 20-50 parts by weight of butadiene rubber, and 1-5 parts by weight of ultra-high molecular weight polyethylene powder into an internal mixer and mix for 1-2 minutes; b. Lift the top bolt and add 5-8 parts by weight of antioxidant, 35-55 parts by weight of flame retardant, 0.5-1.5 parts by weight of stearic acid, 1-5 parts by weight of active magnesium oxide and 35-50 parts by weight of carbon black into the internal mixer for internal mixing. After internal mixing for 2-3 minutes, discharge the rubber to obtain a rubber compound, which is left for at least 8 hours. c. Put the rubber obtained in step b, 1-5 parts by weight of zinc oxide, 1-2 parts by weight of sulfur, and 2-3 parts by weight of accelerator into an internal mixer, mix for 1-2 minutes, and then discharge the rubber; d. After the rubber is discharged, it is refined for 1-2.5 minutes. After refining, it is cut into sheets with a thickness of 8-12mm and cooled to 0-40℃ to obtain the super wear-resistant covering rubber for flame-retardant conveyor belts in underground coal mines.

Images