Vulcanization connection adhesive for aramid fiber and steel wire rope core flame-retardant conveying belt and preparation method of vulcanization connection adhesive

Abstract

The invention discloses an aramid fiber and steel wire rope core flame-retardant conveyor belt vulcanization connection adhesive glue and a preparation method thereof, and the aramid fiber and steel wire rope core flame-retardant conveyor belt vulcanization connection adhesive glue comprises the following components by mass: 30-50 parts of natural rubber; 15 to 35 parts of chloroprene rubber; 25 to 45 parts of cis-butadiene rubber; 2-4 parts of a vulcanizing agent; 1-3 parts of an accelerant; 5-9 parts of an active agent; 4-8 parts of an adhesive; 3-7 parts of tackifying resin; 30 to 50 parts of high-wear-resistance carbon black; 10 to 20 parts of silicon dioxide; 1-3 parts of a coupling agent; 15 to 30 parts of aramid pulp; 2-4 parts of an anti-aging agent; and 50-80 parts of a flame retardant. The flame-retardant index of the adhesive disclosed by the invention meets the flame-retardant standard requirement of an underground coal mine; meanwhile, the bonding glue solves the technical problem that the aramid rope core flame-retardant conveying belt, the steel wire rope core flame-retardant conveying belt and the conveying belts made of two different materials are connected together and mixed for use, the bonding strength and dynamic bonding fatigue resistance of the aramid rope core flame-retardant conveying belt and the steel wire rope core flame-retardant conveying belt are improved, and the service life of the aramid rope core flame-retardant conveying belt and the steel wire rope core flame-retardant conveying belt is prolonged. And the service life of the connecting part of the two conveying belts is prolonged.

Description

Technical Field

[0001] This invention relates to the field of conveyor belt technology, and mainly to the vulcanization bonding adhesive for flame-retardant conveyor belts made of aramid and steel cord core, and its preparation method. Background Technology

[0002] Flame-retardant steel cord conveyor belts are a key component for material transport in underground mines. They enable high-capacity, long-distance, and high-speed material transport, and the conveyor line can be arranged in straight or curved lines, bypassing obstacles for flexible layout, greatly simplifying line design and improving conveying efficiency. Featuring high strength, impact resistance, low elongation, and long service life, flame-retardant steel cord conveyor belts are widely used in underground mines for transporting coal, ore, and slag, playing a vital role in coal and mineral mining and tunnel excavation for a long time.

[0003] Aramid rope core flame-retardant conveyor belts use aramid ropes as the tensile strength. Aramid fiber, also known as polyphenylene phthalate (PPD), is a new type of high-tech synthetic fiber with excellent properties such as ultra-high strength, high modulus, high temperature resistance, flame retardancy, acid and alkali resistance, and light weight. Its strength is 5-6 times that of steel wire, its modulus is 2-3 times that of steel wire or glass fiber, and its toughness is twice that of steel wire, while its weight is only about 1 / 5 that of steel wire. It does not decompose or melt at 560 degrees Celsius. Aramid rope core flame-retardant conveyor belts feature high strength, light weight, puncture resistance, and excellent flame retardant properties. They also have low energy consumption, are energy-saving and environmentally friendly during operation, and have a longer service life.

[0004] The replacement of steel cord flame-retardant conveyor belts with aramid cord flame-retardant conveyor belts has become a development trend in the flame-retardant conveyor belt industry. Current conveyor line maintenance typically involves replacing only a portion of the conveyor belts, rather than replacing the entire line. This necessitates bonding steel cord flame-retardant conveyor belts with aramid cord flame-retardant conveyor belts. However, due to the different materials of aramid cords and steel cords, the adhesive systems for vulcanization joints also differ. Using either steel cord flame-retardant conveyor belt vulcanization joint adhesive or aramid cord flame-retardant conveyor belt vulcanization joint adhesive results in lower bonding strength, leading to poor adhesion between the aramid cord flame-retardant conveyor belt and the steel cord flame-retardant conveyor belt vulcanization joint, affecting the safety and operational cycle of the conveyor belt.

[0005] In order to solve the above problems, this invention is hereby proposed. Summary of the Invention

[0006] One object of the present invention is to provide a vulcanizing adhesive for bonding aramid fibers and steel cord cores in flame-retardant conveyor belts.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] The vulcanized adhesive for flame-retardant conveyor belts with aramid fibers and steel cord cores is composed of the following components in parts by weight: natural rubber 30-50 parts; chloroprene rubber 15-35 parts; butadiene rubber 25-45 parts; vulcanizing agent 2-4 parts; accelerator 1-3 parts; activator 5-9 parts; adhesive 4-8 parts; tackifying resin 3-7 parts; high abrasion-resistant carbon black 30-50 parts; silica 10-20 parts; coupling agent 1-3 parts; aramid pulp 15-30 parts; antioxidant 2-4 parts; flame retardant 50-80 parts.

[0009] Preferably, the vulcanizing agent is sulfur.

[0010] Preferably, the accelerator is accelerator NS or accelerator DM.

[0011] Preferably, the activator is nano zinc oxide, light magnesium oxide and stearic acid.

[0012] Preferably, the adhesive is cobalt boroylide and adhesive EA.

[0013] Preferably, the tackifying resin is resorcinol-formaldehyde resin.

[0014] Preferably, the coupling agent is a silane coupling agent.

[0015] Preferably, the antioxidant is composed of antioxidant BLE, antioxidant 4010NA and microcrystalline wax.

[0016] Preferably, the flame retardant is composed of antimony trioxide, decabromodiphenyl ethane, and chlorinated paraffin.

[0017] Another object of the present invention is to provide a method for preparing a flame-retardant adhesive.

[0018] The objective of this invention can be achieved through the following technical solutions:

[0019] A method for preparing a flame-retardant adhesive includes a first-stage mixing and a second-stage mixing. The first-stage mixing includes the following steps: 30-50 parts of natural rubber, 15-35 parts of chloroprene rubber, and 25-45 parts of butadiene rubber are added to an internal mixer and mixed for 50-80 seconds; then 5-9 parts of activator, 3-7 parts of tackifying resin, 2-4 parts of antioxidant, 4-8 parts of adhesive, and 50-80 parts of flame retardant are added to the internal mixer, and mixing continues for 40-70 seconds; then 15-30 parts of aramid pulp, 10-20 parts of silica, 1-3 parts of coupling agent, and 30-50 parts of high abrasion-resistant carbon black are added, and mixing continues for 120-240 seconds. The top plug is raised and lowered, and when the mixture in the internal mixer reaches 120-140°C, the bottom plug is opened, and the mixed adhesive is discharged to a sheeting machine for further mixing for 180-240 seconds. Then, the mixture is sheeted, cooled, and the first-stage mixed adhesive is obtained.

[0020] The two-stage mixing process includes the following steps: the cooled first-stage compound rubber is fed into an internal mixer along with 2-4 parts of vulcanizing agent and 1-3 parts of accelerator, and mixed for 120-180 seconds. When the rubber temperature in the internal mixer reaches 80-100°C, the bottom jack is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 180-240 seconds, and then sheeted and cooled to obtain flame-retardant adhesive.

[0021] Beneficial technical effects:

[0022] The flame retardant index of the adhesive described in this invention meets the flame retardant standard requirements for underground coal mines. At the same time, the adhesive solves the technical problem of connecting and mixing two different materials, aramid cord flame retardant conveyor belts and steel wire cord flame retardant conveyor belts, improving the bonding strength and dynamic bonding fatigue resistance of the aramid cord flame retardant conveyor belts and steel wire cord flame retardant conveyor belts, and extending the service life of the connection parts of the two conveyor belts. 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] This invention provides a vulcanized bonding adhesive for flame-retardant conveyor belts with aramid rope cores and flame-retardant conveyor belts with steel wire rope cores. Its components are composed of the following parts by weight: 30-50 parts natural rubber; 15-35 parts chloroprene rubber; 25-45 parts butadiene rubber; 2-4 parts vulcanizing agent; 1-3 parts accelerator; 5-9 parts activator; 4-8 parts adhesive; 3-7 parts tackifying resin; 30-50 parts high abrasion-resistant carbon black; 10-20 parts silica; 1-3 parts coupling agent; 15-30 parts aramid pulp; 2-4 parts antioxidant; and 50-80 parts flame retardant.

[0025] This invention uses natural rubber, chloroprene rubber, and butadiene rubber as the main rubber compounds, high-abrasion-resistant carbon black and aramid pulp as reinforcing materials, cobalt boroyl chloride, resorcinol formaldehyde resin, and rubber adhesive EA as binders, antimony trioxide, decabromodiphenyl ethane, and chlorinated paraffin as flame retardants, and zinc oxide and stearic acid as activators. Combined with a vulcanization system (vulcanizing agent, accelerator), antioxidant, and tackifying resin, a flame-retardant adhesive with excellent physical and mechanical properties is prepared. The adhesive of this invention exhibits high bonding strength with both aramid cord core flame-retardant conveyor belts and steel cord core flame-retardant conveyor belts. Its flame-retardant performance meets the standards for underground coal mines and can improve the service life of the vulcanized connection between aramid fabric core flame-retardant belts and steel cord core flame-retardant conveyor belts.

[0026] Of the above components, the vulcanizing agent is preferably sulfur.

[0027] In the above components, the accelerator is preferably accelerator NS or accelerator DM.

[0028] In the above components, the active agent is preferably nano zinc oxide, light magnesium oxide and stearic acid.

[0029] Of the above components, the binder is preferably cobalt borylate and binder EA.

[0030] Of the above components, the tackifying resin is preferably resorcinol-formaldehyde resin.

[0031] Of the above components, the coupling agent is preferably a silane coupling agent.

[0032] In the above components, the reinforcing agent is preferably composed of carbon black N762, carbon black N330 and silicon dioxide.

[0033] In the above components, the antioxidant is preferably composed of antioxidant BLE, antioxidant 4010NA and microcrystalline wax.

[0034] In the above components, the flame retardant is preferably composed of antimony trioxide, decabromodiphenyl ethane, and chlorinated paraffin.

[0035] In a second aspect, the present invention provides a method for preparing a flame-retardant adhesive as described in the first aspect, comprising a first-stage mixing and a second-stage mixing.

[0036] First stage of mixing: Add 30-50 parts of natural rubber, 15-35 parts of chloroprene rubber, and 25-45 parts of butadiene rubber to a mixer and mix for 50-80 seconds; then add 5-9 parts of activator, 3-7 parts of tackifying resin, 2-4 parts of antioxidant, 4-8 parts of binder, and 50-80 parts of flame retardant to the mixer and continue mixing for 40-70 seconds; then add 15-30 parts of aramid pulp, 10-20 parts of silica, 1-3 parts of coupling agent, and 30-50 parts of high abrasion-resistant carbon black and continue mixing for 120-240 seconds. Raise and lower the top plug, and when the mixture in the mixer reaches 120-140°C, open the bottom plug. Discharge the mixed rubber to a sheeting machine and mix for another 180-240 seconds. Then sheet and cool to obtain the first stage of mixed rubber.

[0037] Two-stage mixing: The cooled first-stage compound is added to an internal mixer along with 2-4 parts of vulcanizing agent and 1-3 parts of accelerator. The mixture is mixed for 120-180 seconds. When the temperature of the rubber in the internal mixer reaches 80-100°C, the bottom jack is opened and the compound is discharged onto a sheeting machine. The mixture is then remixed for 180-240 seconds, then sheeted and cooled to obtain the second-stage rubber, which is the flame-retardant adhesive.

[0038] Example 1

[0039] (1) Formulation components by mass parts:

[0040] Natural rubber 35 parts; Chloroprene rubber 25 parts; Butadiene rubber 40 parts; Sulfur 2.5 parts; Accelerator NS 1.1 parts; Accelerator DM 0.6 parts; Nano zinc oxide 5 parts; Light magnesium oxide 2 parts; Stearic acid 2 parts; Resorcinol formaldehyde resin 3 parts; Adhesive EA 5 parts; Cobalt borate 2 parts; Carbon black N762 15 parts; Carbon black N330 30 parts; Precipitated silica 15 parts; Silane coupling agent 2 parts; Aramid pulp 20 parts; Antioxidant BLE 2; Antioxidant 4010NA 1 part; Antimony trioxide 10 parts; Chlorinated paraffin 30 parts; Decabromodiphenyl ethane 15 parts.

[0041] (2) Preparation method:

[0042] a. A section of mixing

[0043] Natural rubber, chloroprene rubber (plasticized), and butadiene rubber are added to a mixer and mixed for 60 seconds. Then, nano zinc oxide, light magnesium oxide, stearic acid, resorcinol formaldehyde resin, antioxidant BLE, antioxidant 4010NA, adhesive EA, cobalt borate, antimony trioxide, chlorinated paraffin, and decabromodiphenyl ethane are added to the mixer and mixed for another 65 seconds. Then, aramid pulp, silica, silane coupling agent, carbon black N762, and carbon black N330 are added and mixed for another 210 seconds. The top plug is raised and lowered, and when the mixture in the mixer reaches 135°C, the bottom plug is opened. The mixed rubber is discharged to a sheeting machine and mixed again for 200 seconds. Then, it is sheeted, cooled, and a section of mixed rubber is obtained.

[0044] b. Two-stage mixing

[0045] After cooling, the first-stage compound rubber is added to a mixer along with sulfur, accelerator NS, and accelerator DM. The mixture is mixed for 150 seconds. When the temperature of the rubber in the mixer reaches 95°C, the bottom jack is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 200 seconds, then sheeted and cooled to obtain the second-stage rubber, which is the flame-retardant adhesive.

[0046] Example 2

[0047] (1) Formulation components by mass parts:

[0048] Natural rubber 40 parts; Chloroprene rubber 25 parts; Butadiene rubber 35 parts; Sulfur 2.5 parts; Accelerator NS 1.1 parts; Accelerator DM 0.6 parts; Nano zinc oxide 5 parts; Light magnesium oxide 2 parts; Stearic acid 2 parts; Resorcinol formaldehyde resin 3 parts; Cobalt borate 2 parts; Adhesive EA 5 parts; Carbon black N762 20 parts; Carbon black N330 25 parts; Precipitated silica 15 parts; Silane coupling agent 2 parts; Aramid pulp 18 parts; Antioxidant BLE 2; Antioxidant 4010NA 1 part; Antimony trioxide 10 parts; Chlorinated paraffin 33 parts; Decabromodiphenyl ethane 15 parts.

[0049] (2) Preparation method:

[0050] a. A section of mixing

[0051] Natural rubber, chloroprene rubber (plasticized), and butadiene rubber are added to a mixer and mixed for 65 seconds. Then, nano zinc oxide, light magnesium oxide, stearic acid, resorcinol formaldehyde resin, antioxidant BLE, antioxidant 4010NA, cobalt borate, adhesive EA, antimony trioxide, chlorinated paraffin, and decabromodiphenyl ethane are added to the mixer, and mixing continues for 55 seconds. Then, aramid pulp, silica, silane coupling agent, carbon black N762, and carbon black N330 are added, and mixing continues for 195 seconds. The top plug is raised and lowered, and when the mixture in the mixer reaches 130°C, the bottom plug is opened, and the compound is discharged to a sheeting machine for further mixing for 220 seconds. Then, the sheet is discharged, cooled, and a section of compound is obtained.

[0052] b. Two-stage mixing

[0053] After cooling, the first-stage compound rubber is added to a mixer along with sulfur, accelerator NS, and accelerator DM. The mixture is mixed for 145 seconds. When the temperature of the rubber in the mixer reaches 90°C, the bottom bolt is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 210 seconds, then sheeted and cooled to obtain the second-stage rubber, which is the flame-retardant adhesive.

[0054] Example 3

[0055] (1) Formulation components by mass parts:

[0056] Natural rubber 40 parts; Chloroprene rubber 25 parts; Butadiene rubber 35 parts; Sulfur 2.5 parts; Accelerator NS 1.1 parts; Accelerator DM 0.6 parts; Nano zinc oxide 6 parts; Light magnesium oxide 2 parts; Stearic acid 2 parts; Resorcinol formaldehyde resin 3 parts; Cobalt borate 2 parts; Adhesive EA 5 parts; Carbon black N762 18 parts; Carbon black N330 27 parts; Precipitated silica 14 parts; Silane coupling agent 3 parts; Aramid pulp 20 parts; Antioxidant BLE 2; Antioxidant 4010NA 1 part; Antimony trioxide 11 parts; Chlorinated paraffin 28 parts; Decabromodiphenyl ethane 15 parts.

[0057] (2) Preparation method:

[0058] a. A section of mixing

[0059] Natural rubber, chloroprene rubber (plasticized), and butadiene rubber are added to a mixer and mixed for 70 seconds. Then, nano zinc oxide, light magnesium oxide, stearic acid, resorcinol formaldehyde resin, antioxidant BLE, antioxidant 4010NA, cobalt borate, adhesive EA, antimony trioxide, chlorinated paraffin, and decabromodiphenyl ethane are added to the mixer, and mixing continues for 60 seconds. Then, aramid pulp, silica, silane coupling agent, carbon black N762, and carbon black N330 are added, and mixing continues for 205 seconds. The top plug is raised and lowered, and when the mixture in the mixer reaches 135°C, the bottom plug is opened, and the compound is discharged to a sheeting machine for further mixing for 215 seconds. Then, the sheet is discharged, cooled, and a section of compound is obtained.

[0060] b. Two-stage mixing

[0061] After cooling, the first-stage compound rubber is added to a mixer along with sulfur, accelerator NS, and accelerator DM. The mixture is mixed for 155 seconds. When the temperature of the rubber in the mixer reaches 95°C, the bottom jack is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 230 seconds, then sheeted and cooled to obtain the second-stage rubber, which is the flame-retardant adhesive.

[0062] Example 4

[0063] (1) Formulation components by mass parts:

[0064] Natural rubber 45 parts; Chloroprene rubber 25 parts; Butadiene rubber 30 parts; Sulfur 2.7 parts; Accelerator NS 1.2 parts; Accelerator DM 0.6 parts; Nano zinc oxide 5 parts; Light magnesium oxide 2 parts; Stearic acid 2 parts; Resorcinol formaldehyde resin 4 parts; Cobalt borate 2 parts; Adhesive EA 4 parts; Carbon black N762 20 parts; Carbon black N330 25 parts; Precipitated silica 15 parts; Silane coupling agent 2 parts; Aramid pulp 23 parts; Antioxidant BLE 2; Antioxidant 4010NA 1 part; Antimony trioxide 10 parts; Chlorinated paraffin 28 parts; Decabromodiphenyl ethane 17 parts.

[0065] (2) Preparation method:

[0066] a. A section of mixing

[0067] Natural rubber, chloroprene rubber (plasticized), and butadiene rubber are added to a mixer and mixed for 65 seconds. Then, nano zinc oxide, light magnesium oxide, stearic acid, resorcinol formaldehyde resin, antioxidant BLE, antioxidant 4010NA, cobalt borate, adhesive EA, antimony trioxide, chlorinated paraffin, and decabromodiphenyl ethane are added to the mixer and mixed for another 70 seconds. Then, aramid pulp, silica, silane coupling agent, carbon black N762, and carbon black N330 are added and mixed for another 210 seconds. The top plug is raised and lowered, and when the mixture in the mixer reaches 135°C, the bottom plug is opened. The mixed rubber is discharged to a sheeting machine and then re-mixed for 225 seconds. After sheeting and cooling, a section of mixed rubber is obtained.

[0068] b. Two-stage mixing

[0069] After cooling, the first-stage compound rubber is added to a mixer along with sulfur, accelerator NS, and accelerator DM. The mixture is mixed for 160 seconds. When the temperature of the rubber in the mixer reaches 95°C, the bottom bolt is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 215 seconds, then sheeted and cooled to obtain the second-stage rubber, which is the flame-retardant adhesive.

[0070] The compound rubber obtained in Examples 1 to 4 was left to stand for 24 hours. The open-mix rubber was used to make rubber sheets of the required thickness. The rubber sheets were cut to the required size according to the size of the vulcanizing mold. The cut rubber sheets were placed in the mold and placed in a flat vulcanizing machine. The vulcanizing was carried out for 30 minutes under the vulcanizing conditions of 18 MPa pressure and 150°C to obtain vulcanized test pieces.

[0071] Table 1 Physical properties of vulcanizates in Examples 1-4

[0072]

[0073] As can be seen from the data in Table 1, the vulcanized rubbers of Examples 1 to 4 have excellent physical properties, and both flaming and flameless combustion meet the standard requirements for flame-retardant conveyor belts in underground coal mines.

[0074] The compound rubber obtained in Examples 1 to 4 was left to stand for 24 hours. The open-mix rubber was used to make a sheet of the required thickness. The sheet was cut into the same size as the vulcanizing mold. The cut sheet, steel wire rope or aramid rope was placed in a static bonding mold and placed in a flat vulcanizing machine. The vulcanizing was carried out for 45 minutes under vulcanizing conditions of 20 MPa pressure and 145°C to obtain a vulcanized sample.

[0075] Table 2 shows the bonding strength between the adhesives in Examples 1-4 and the steel wire rope and aramid rope.

[0076]

[0077] As can be seen from Table 2, the static bonding strength of the adhesives in Examples 1-4 with 6.0mm diameter steel wire rope and 6.0mm diameter aramid rope is much higher than the standard requirements for flame-retardant steel wire rope core conveyor belts.

[0078] The compound rubber obtained in Examples 1 to 4 was left to stand for 24 hours. The open-mix rubber was used to make a sheet of the required thickness. The sheet was cut into the same size as the vulcanizing mold. The cut sheet, steel wire rope or aramid rope was placed in a special mold for dynamic adhesive fatigue and placed in a flat vulcanizing machine. The vulcanizing was carried out for 40 minutes under the vulcanizing conditions of 20 MPa pressure and 145°C to obtain a vulcanized sample.

[0079] Table 3 shows the dynamic adhesion fatigue of adhesives to steel wire ropes and aramid ropes in Examples 1-4.

[0080]

[0081] Table 3 shows that the dynamic adhesion fatigue of the adhesives in Examples 1-4 with 6.0mm diameter steel wire rope and 6.0mm diameter aramid rope is far higher than the standard requirements for flame-retardant steel wire rope core conveyor belts.

[0082] The rubber compounds obtained in Examples 1-4 were left to stand for 24 hours. Then, a cold-feed extruder was used to calender the rubber sheets. The extruder head temperature was set to 60°C, the body temperature to 50°C, the screw temperature to 65°C, and the calendering roller temperature to 60°C. Adhesive sheets were calendered. Three-meter steel wire rope core flame-retardant conveyor belts and aramid rope core flame-retardant conveyor belts were taken respectively. The cover rubber and core rubber on the surface of both conveyor belts were removed, leaving the steel wire rope and aramid rope. Following the two-stage joint scheme in Appendix E of MT / T 668-2019, Flame-retardant Belt Joint Dimensions and Technical Requirements, the steel wire rope and aramid rope were cut and arranged as required. Adhesive sheets and cover rubber sheets were then laid on top. The joint was vulcanized using a joint vulcanizer at a vulcanization pressure of 2 MPa and a vulcanization temperature of 150°C for 35 minutes. The mixture was then allowed to cool naturally until the temperature dropped below 70°C. The vulcanizer was then opened to complete the preparation of the vulcanized joint sample.

[0083] The static tensile strength of the vulcanized joint specimens was tested in accordance with the requirements of MT / T 668-2019.

[0084] Table 4 shows the static joint breakage efficiency of the adhesives in Examples 1-4.

[0085] Example 1 Example 2 Example 3 Example 4 standard ≥90％ ≥90％ ≥90％ ≥90％ Connector efficiency 93％ 94％ 91％ 96％

[0086] Table 4 shows that the static joint breaking efficiency of the adhesive vulcanized bonded steel wire rope core flame-retardant conveyor belts and aramid rope core flame-retardant conveyor belts in Examples 1-4 is higher than the standard requirements for flame-retardant steel wire rope core conveyor belts.

[0087] In summary, the flame retardant index of the adhesive described in this invention meets the flame retardant standard requirements for underground coal mines. Furthermore, the adhesive solves the technical challenge of combining aramid core flame-retardant conveyor belts and steel wire rope core flame-retardant conveyor belts, improving the bonding strength and dynamic adhesion fatigue resistance of the two conveyor belts, and extending the service life of the connection points.

[0088] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt, characterized in that, Its components are composed of the following parts by weight: natural rubber 30-50 parts; chloroprene rubber 15-35 parts; cis-butadiene rubber 25-45 parts; vulcanizing agent 2-4 parts; accelerator 1-3 parts; activator 5-9 parts; adhesive 4-8 parts; tackifying resin 3-7 parts; high abrasion resistant carbon black 30-50 parts; silica 10-20 parts; coupling agent 1-3 parts; aramid pulp 15-30 parts; antioxidant 2-4 parts; flame retardant 50-80 parts.

2. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The vulcanizing agent is sulfur.

3. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The accelerators are accelerator NS and accelerator DM.

4. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The active agents are nano zinc oxide, light magnesium oxide and stearic acid.

5. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The adhesive is cobalt borate and adhesive EA.

6. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The tackifying resin is resorcinol-formaldehyde resin.

7. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The coupling agent is a silane coupling agent.

8. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The antioxidant is composed of antioxidant BLE, antioxidant 4010NA and microcrystalline wax.

9. The vulcanizing adhesive for bonding aramid fibers and steel wire rope cores to a flame-retardant conveyor belt according to claim 1, characterized in that, The flame retardant is composed of antimony trioxide, decabromodiphenyl ethane, and chlorinated paraffin.

10. A method for preparing a flame-retardant adhesive, characterized in that, The preparation method includes a first-stage mixing and a second-stage mixing. The first-stage mixing includes the following steps: 30-50 parts of natural rubber, 15-35 parts of chloroprene rubber, and 25-45 parts of butadiene rubber are added to an internal mixer and mixed for 50-80 seconds; then 5-9 parts of activator, 3-7 parts of tackifying resin, 2-4 parts of antioxidant, 4-8 parts of binder, and 50-80 parts of flame retardant are added to the internal mixer and mixed for another 40-70 seconds; then 15-30 parts of aramid pulp, 10-20 parts of silica, 1-3 parts of coupling agent, and 30-50 parts of high abrasion-resistant carbon black are added and mixed for another 120-240 seconds. The top plug is raised and lowered, and when the mixture in the internal mixer reaches 120-140°C, the bottom plug is opened, and the mixed rubber is discharged to a tablet press for further mixing for 180-240 seconds. Then, the tablets are extruded, cooled, and the first-stage mixed rubber is obtained. The two-stage mixing process includes the following steps: the cooled first-stage compound rubber is fed into an internal mixer along with 2-4 parts of vulcanizing agent and 1-3 parts of accelerator, and mixed for 120-180 seconds. When the rubber temperature in the internal mixer reaches 80-100°C, the bottom jack is opened, and the compound rubber is discharged onto a sheeting machine. It is then mixed again for 180-240 seconds, and then sheeted and cooled to obtain flame-retardant adhesive.

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