Tire sidewall rubber composition, tire sidewall rubber and application thereof

Abstract

The invention provides a tire sidewall rubber composition, tire sidewall rubber and application thereof, and particularly relates to the technical field of tire manufacturing. The tire sidewall rubber composition comprises the following components in parts by weight: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 35-65 parts of a flame retardant, 7-13 parts of an activating agent, 1-3 parts of an activating auxiliary agent, 3-6 parts of an anti-aging agent, 1.5-3 parts of a vulcanizing agent and 1-3 parts of an accelerant, the flame retardant comprises antimony trioxide. According to the tire sidewall rubber composition provided by the invention, through the synergistic effect of the raw materials, the maintenance of physical properties is ensured while the flame retardant property is improved, and dual optimization of the flame retardant property and the physical properties is realized. Meanwhile, the invention provides a mixing method of the tire sidewall rubber, and the problem that high-part white carbon black is not easy to disperse is solved.

Description

Technical Field

[0001] The invention relates to the technical field of tire manufacturing, and in particular to a tire sidewall rubber composition, a tire sidewall rubber and applications thereof. Background Art

[0002] In the rubber industry, rubber is widely used in tires, tracks, conveyor belts, hoses, soles, cables and other products due to its excellent physical properties (such as resilience, insulation, plasticity, wear resistance, oil resistance and acid and alkali resistance). However, as a high-molecular flammable material, rubber is prone to thermal cracking reactions in high temperature or near fire environments, releasing flammable rubber hydrocarbon gas, which may spontaneously combust when in contact with oxygen and reaching a certain concentration. Especially in the sidewall part of the tire, since it does not directly contact the ground and does not bear large stress, it mainly works in a flexed state. Therefore, in addition to having good physical properties, it also needs to have good flame retardant properties to ensure driving safety.

[0003] However, the natural rubber, carbon black, microcrystalline wax and other materials used in traditional tire sidewall formulas release toxic gases when burned, posing a threat to the environment and human health. Although the use of silica instead of carbon black can improve the flame retardant performance to a certain extent, silica as a filler is difficult to disperse, resulting in cohesion and dispersion difficulties in the mixing process, affecting the uniformity and smoothness of the rubber compound. In addition, the use of flame retardants may affect other properties of the tire, such as flexural properties and aging resistance. Therefore, how to improve the flame retardant performance of the tire while avoiding the impact on other properties, reducing production costs and reducing environmental pollution is the main problem facing current technology.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] One of the objects of the present invention is to provide a tire sidewall rubber composition to alleviate at least one of the above-mentioned technical problems in the prior art.

[0006] A second object of the present invention is to provide a tire sidewall rubber.

[0007] A third object of the present invention is to provide an application of tire sidewall rubber.

[0008] In order to solve the above-mentioned technical problems, the present invention particularly adopts the following technical solutions: The first aspect of the present invention provides a tire sidewall rubber composition, which comprises, by weight: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 35-65 parts of flame retardant, 7-13 parts of activator, 1-3 parts of activation aid, 3-6 parts of antioxidant, 1.5-3 parts of vulcanizing agent and 1-3 parts of accelerator.

[0009] The flame retardant includes antimony trioxide.

[0010] Furthermore, the flame retardant further comprises chlorinated paraffin and / or tricresyl phosphate.

[0011] Furthermore, the activator includes magnesium oxide and / or zinc oxide.

[0012] The activating aid includes stearic acid.

[0013] Furthermore, the brand of the antioxidant includes at least one of antioxidant 4020, antioxidant RD and antioxidant 4010NA.

[0014] The vulcanizing agent includes sulfur.

[0015] The brand of the accelerator includes at least one of NA-22, DM and CZ.

[0016] Furthermore, the grade of the carbon black includes at least one of N220, N234, N330, N326, N375 and N660.

[0017] The white carbon black is vapor deposition white carbon black or precipitation white carbon black.

[0018] The white carbon black has a silicon dioxide content of ≥99.8%, an average particle size of 8-19 nm, a specific surface area of ​​130-400 m² / g, a DBP oil absorption value of 1.5-2 cm³ / g, a relative density of 2.00-2.30 g / cm³, a pH value of 3.9-4.0, and a moisture content of 1.0-1.5%.

[0019] Furthermore, the tire sidewall rubber composition comprises, by weight: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 30-40 parts of antimony trioxide, 0-10 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 2-5 parts of magnesium oxide, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 2-4 parts of antioxidant 4020, 1-2 parts of antioxidant RD, 1.5-3 parts of sulfur and 1-3 parts of accelerator.

[0020] The second aspect of the present invention provides a tire sidewall rubber, which is mainly obtained by mixing the tire sidewall rubber composition.

[0021] Further, the mixing comprises the following steps: A. mixing white carbon black and antimony trioxide and dispersing them uniformly to obtain a suspension; then mixing the suspension with natural rubber to obtain a first masterbatch; B. mixing butadiene rubber, chloroprene rubber, carbon black, microcrystalline wax, remaining flame retardant, activator, activation aid and antioxidant and performing two-stage mixing to obtain a second masterbatch; C. adding the first masterbatch to the second masterbatch and mixing them in three stages and four stages to obtain a third masterbatch; D. Adding a vulcanizing agent and an accelerator to the third masterbatch and mixing them in five stages to obtain the tire sidewall rubber.

[0022] The one-stage mixing process is: mixing the suspension and part of the natural rubber for 20-60 seconds, adding the plug to the remaining natural rubber plug and mixing for 20-50 seconds, and mixing until the temperature reaches 150-165° C. to discharge the rubber.

[0023] Furthermore, the two-stage mixing includes mixing for 20-60 seconds, mixing with the plug lifted and pressed for 20-35 seconds, and then mixing with the plug lifted and pressed to 150-165° C. for debonding in this order.

[0024] The three-stage mixing includes mixing for 15-50s, mixing for 15-30s with the bolt lifted and the bolt pressed, and then mixing to 140-150°C for debonding with the bolt lifted and the bolt pressed.

[0025] The four-stage mixing includes mixing for 15-60 seconds, mixing with the plug lifted and the plug pressed for 20-40 seconds, and then mixing with the plug lifted and the plug pressed until the temperature reaches 135-145° C. for debonding.

[0026] The five-stage mixing includes mixing for 10-50 seconds, mixing with the plug lifted and the plug pressed for 15-30 seconds, and then mixing with the plug lifted and the plug pressed until the temperature reaches 95-115° C. for debonding.

[0027] The third aspect of the present invention provides the use of the tire sidewall rubber in the preparation of fire truck tires, hazardous chemicals transport vehicle tires or coal mine underground transport vehicle tires.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects: The tire sidewall rubber composition provided by the present invention improves the flame retardancy by partially replacing natural rubber with chloroprene rubber. Chloroprene rubber exhibits excellent flame retardant properties due to the chlorine atoms in its molecular structure, which can effectively curb the combustion process. In addition, antimony trioxide, as a flame retardant, reacts with the chlorine element in chloroprene rubber to generate antimony chloride, which forms a covering layer on the surface of the rubber material, effectively isolating oxygen, and further enhancing the flame retardant effect of the material. In terms of mechanical properties, the addition of white carbon black significantly improves the strength and toughness of the composition. At the same time, antimony trioxide not only plays a role as a flame retardant, but also improves the dispersibility of white carbon black in the rubber material, allowing the addition amount of white carbon black to be increased, thereby further improving the mechanical properties of the composition. Through this synergistic effect, the tire sidewall rubber composition of the present invention not only improves the flame retardancy, but also ensures the maintenance of physical properties, achieving dual optimization of flame retardancy and physical properties.

[0029] The tire sidewall rubber provided by the present invention, in view of the advantages of the above-mentioned tire sidewall rubber composition, enables the prepared tire sidewall rubber to have better flame retardancy, wear resistance, aging resistance and tear resistance, is suitable for various harsh working environments, expands the application fields of tire sidewall rubber, and promotes the development of related industries.

[0030] The application of the tire sidewall rubber provided by the present invention provides better raw materials for preparing fire truck tires, hazardous chemical transport vehicle tires or coal mine underground transport vehicle tires. It releases less toxic gas during combustion, making it an ideal choice in modern society with increasing environmental awareness, and meets the modern tire industry's needs for high performance, high safety and environmental protection. DETAILED DESCRIPTION

[0031] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, but not all of the embodiments. The components of the embodiment of the present invention can be arranged and designed in various different configurations.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0033] The first aspect of the present invention provides a tire sidewall rubber composition, which comprises, by weight: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 35-65 parts of flame retardant, 7-13 parts of activator, 1-3 parts of activation aid, 3-6 parts of antioxidant, 1.5-3 parts of vulcanizing agent and 1-3 parts of accelerator.

[0034] The flame retardant includes antimony trioxide.

[0035] The tire sidewall rubber composition provided by the present invention improves the flame retardancy by partially replacing natural rubber with chloroprene rubber. Chloroprene rubber exhibits excellent flame retardant properties due to the chlorine atoms in its molecular structure, which can effectively curb the combustion process. In addition, antimony trioxide, as a flame retardant, reacts with the chlorine element in chloroprene rubber to generate antimony chloride, which forms a covering layer on the surface of the rubber material, effectively isolating oxygen, and further enhancing the flame retardant effect of the material. In terms of mechanical properties, the addition of white carbon black significantly improves the strength and toughness of the composition. At the same time, antimony trioxide not only plays a role as a flame retardant, but also improves the dispersibility of white carbon black in the rubber material, allowing the addition amount of white carbon black to be increased, thereby further improving the mechanical properties of the composition. Through this synergistic effect, the tire sidewall rubber composition of the present invention not only improves the flame retardancy, but also ensures the maintenance of physical properties, achieving dual optimization of flame retardancy and physical properties.

[0036] Specifically, in the traditional tire sidewall rubber formula, natural rubber is partially replaced by chloroprene rubber. Chloroprene rubber is a synthetic rubber with excellent flame retardancy. Its molecular structure contains chlorine atoms, which can effectively prevent the spread of combustion. By adjusting the proportion of chloroprene rubber, the purpose of improving flame retardancy and avoiding negative impact on other properties can be achieved. Chloroprene rubber contains chlorine, which has the property of isolating the fire source and extinguishing itself. Antimony trioxide is used as a flame retardant in the formula. It can combine with chlorine in chloroprene rubber to generate antimony chloride, which covers the surface of the rubber compound, blocks the intrusion of oxygen, and has excellent flame retardancy.

[0037] Typically but not limiting, the number of natural rubber in the composition can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, or any value in the range of 5 to 20 parts; the number of butadiene rubber can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts or 40 parts, or any value in the range of 20 to 40 parts; the number of chloroprene rubber can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts 7 parts, 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 100 parts, 101 parts, 102 parts, 103 parts, 104 parts, 105 parts, 106 parts, 107 parts, 108 parts, 109 parts, 110 parts, 111 parts, 112 parts, 113 parts, 114 parts, 115 parts, 116 parts, 117 parts, 118 parts, 119 parts, 120 parts, 121 parts, 122 parts, 123 parts, 124 parts, 125 parts, 126 parts, 127 parts, 128 parts, 129 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, The amount of white carbon black can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, or any value within the range of 10 to 20 parts; the amount of microcrystalline wax can be 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts or 2.9 parts, 3 parts, or any value within the range of 2 to 3 parts; the amount of flame retardant can be 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts , 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts or 65 parts, or any value in the range of 35-65 parts; the number of activators can be 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, or any value in the range of 7-13 parts; the number of activating aids can be 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts, or any value in the range of 1-3 parts; the number of antioxidants can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts or 6 parts, or any value in the range of 3-6 parts; the number of vulcanizing agents can be 1.5 parts, 2 parts, 2.5 parts or 3 parts, or any value within the range of 1.5 to 3 parts; the number of promoters can be 1 part, 1.5 parts, 2 parts or 2.5 parts, 3 parts, or any value within the range of 1 to 3 parts.

[0038] Furthermore, the flame retardant further comprises chlorinated paraffin and / or tricresyl phosphate. Chlorinated paraffin is a chlorinated derivative of paraffin, which has both anti-aging and flame retardant properties, and effectively protects the aging properties of the composition while being flame retardant.

[0039] Add appropriate amounts of antimony trioxide and chlorinated paraffin to the rubber formula. Antimony trioxide is a highly effective flame retardant that can promote the carbonization of rubber and form a carbon layer that isolates the air, thereby preventing combustion. Chlorinated paraffin and tricresyl phosphate can both cool and isolate oxygen, thereby reducing the possibility of combustion. By precisely controlling the amount of these two flame retardants added, the purpose of improving flame retardancy and reducing environmental pollution can be achieved.

[0040] In the present invention, the flame retardant may be a combination of antimony trioxide and chlorinated paraffin, a combination of antimony trioxide and tricresyl phosphate, or a combination of antimony trioxide, chlorinated paraffin and tricresyl phosphate.

[0041] Furthermore, the activator includes magnesium oxide and / or zinc oxide. Magnesium oxide can be used as a vulcanizing agent, an activating agent, and a filler, and can increase the tensile stress of the vulcanized rubber, and improve the physical properties lost by using chloroprene rubber instead of natural rubber. Because the use of chloroprene rubber slows down the vulcanization speed, the use of magnesium oxide is also conducive to the increase of the vulcanization speed, and because of the presence of magnesium ions, the thermal conductivity of the rubber is increased, and it is not easy to cause heat accumulation, thereby achieving the purpose of flame retardancy.

[0042] The activating aid includes stearic acid.

[0043] Furthermore, the brand of the antioxidant includes at least one of antioxidant 4020, antioxidant RD and antioxidant 4010NA.

[0044] The vulcanizing agent includes sulfur.

[0045] The accelerator includes NA-22, and the preferred addition amount is 0.5 to 1 part. Accelerator NA-22 effectively solves the problem that chloroprene rubber is not easy to vulcanize. By selecting an appropriate compounding system, rapid vulcanization and safe operation can be performed. The vulcanized product has high tensile strength and small permanent compression deformation.

[0046] The brand of the accelerator also includes at least one of DM and CZ.

[0047] Typically but not limiting, the preferred addition amount of the accelerator may be 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1.0 part, or any value within the range of 0.5 to 1 part.

[0048] Furthermore, the grade of the carbon black includes at least one of N220, N234, N330, N326, N375 and N660, preferably N330.

[0049] The white carbon black is vapor deposition white carbon black or precipitation white carbon black.

[0050] The white carbon black has a silicon dioxide content of ≥99.8%, an average particle size of 8-19 nm, a specific surface area of ​​130-400 m² / g, a DBP oil absorption value of 1.5-2 cm³ / g, a relative density of 2.00-2.30 g / cm³, a pH value of 3.9-4.0, and a moisture content of 1.0-1.5%.

[0051] The white carbon black with the above characteristics has good filler dispersion performance due to its high purity, high specific surface area and controllable structure. It can better enhance the mechanical strength and wear resistance of rubber, enhance physical and mechanical properties, and improve the temperature resistance of rubber. In addition, although the price of vapor deposition white carbon black is relatively high, its excellent reinforcement effect can reduce the use of other expensive raw materials in rubber products to a certain extent, thereby reducing the overall cost, making this white carbon black have significant advantages in the manufacture of high-performance rubber products. Furthermore, the tire sidewall rubber composition, measured by weight, comprises: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 30-40 parts of antimony trioxide, 0-10 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 2-5 parts of magnesium oxide, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 2-4 parts of antioxidant 4020, 1-2 parts of antioxidant RD, 1.5-3 parts of sulfur and 1-3 parts of accelerator.

[0052] Typically but not limiting, the natural rubber in the composition may be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts, or any value within the range of 5 to 20 parts; the butadiene rubber may be 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38 or 40 parts, or any value within the range of 20 to 40 parts; the chloroprene rubber may be 50, 51, 52, 53, 54, 55, 56, 57 , 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts or 80 parts, can also be any value in the range of 50 to 80 parts; the number of carbon black parts can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43 The number of parts of white carbon black can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, or any value in the range of 10 to 20 parts; the number of parts of microcrystalline wax can be 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts or 2.9 parts, 3 parts, or any value in the range of 2 to 3 parts; the number of parts of antimony trioxide can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts or 40 parts, or any value in the range of The number of chlorinated paraffin can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts, or any value in the range of 0 to 10 parts; the number of tricresyl phosphate can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 parts, or any value in the range of 5 to 15 parts; the number of magnesium oxide can be 2, 2.5, 3, 3.5, 4 or 5 parts, or any value in the range of 2 to 5 parts; the number of zinc oxide can be 5, 5.5, 6, 6.5, 7 or 8 parts, or any value in the range of 5 to 8 parts; the number of stearic acid can be 1, 1.5 parts, 2 parts or 3 parts, or any value within the range of 1 to 3 parts; the number of antioxidant 4020 can be 2 parts, 2.5 parts, 3 parts or 3.5 parts, 4 parts, or any value within the range of 2 to 4 parts; the number of antioxidant RD can be 1 part, 1.5 parts or 2 parts, or any value within the range of 1 to 2 parts; the number of sulfur can be 1.5 parts, 2 parts, 2.5 parts or 3 parts, or any value within the range of 1.5 to 3 parts; the number of accelerators can be 1 part, 1.5 parts, 2 parts or 2.5 parts, 3 parts, or any value within the range of 1 to 3 parts. .

[0053] The second aspect of the present invention provides a tire sidewall rubber, which is mainly obtained by mixing the tire sidewall rubber composition.

[0054] The tire sidewall rubber provided by the present invention, in view of the advantages of the above-mentioned tire sidewall rubber composition, enables the prepared tire sidewall rubber to have better flame retardancy, wear resistance, aging resistance and tear resistance, is suitable for various harsh working environments, expands the application fields of tire sidewall rubber, and promotes the development of related industries.

[0055] Further, the mixing comprises the following steps: A. Mix white carbon black and antimony trioxide and disperse them uniformly to obtain a suspension; then mix the suspension with natural rubber to obtain a first masterbatch.

[0056] White carbon black is a filler with high reinforcing performance but difficult to disperse. There are great process difficulties, such as easy to aggregate during mixing, difficult to disperse and making the rubber material not smooth. The present invention adopts the method of pre-treating white carbon black and preparing it with antimony trioxide to prepare antimony trioxide white carbon black pre-dispersed suspension, and then mixing it with natural rubber to prepare antimony trioxide white carbon black masterbatch, which effectively solves the problem of poor dispersion. Through the use of the above materials and the preparation method, a tire sidewall rubber composition that is both flame retardant and can ensure the physical properties of the rubber material is obtained.

[0057] B. mixing butadiene rubber, chloroprene rubber, carbon black, microcrystalline wax, remaining flame retardant, activator, activation aid and antioxidant and performing two-stage mixing to obtain a second masterbatch; C. adding the first masterbatch to the second masterbatch and mixing them in three stages and four stages to obtain a third masterbatch; D. Adding a vulcanizing agent and an accelerator to the third masterbatch and mixing them in five stages to obtain the tire sidewall rubber.

[0058] The above mixing process optimizes the traditional tire production process to reduce production costs and improve economic benefits. For example, the new vulcanization process can shorten the vulcanization time and improve production efficiency; the new mixing process can more evenly distribute the flame retardant and reinforcing filler to improve the flame retardant performance.

[0059] The one-stage mixing process is: mixing the suspension and part of the natural rubber for 20-60 seconds, adding the plug to the remaining natural rubber plug and mixing for 20-50 seconds, and mixing until the temperature reaches 150-165° C. to discharge the rubber.

[0060] Furthermore, the two-stage mixing includes mixing for 20-60 seconds, mixing with the plug lifted and pressed for 20-35 seconds, and then mixing with the plug lifted and pressed to 150-165° C. for debonding in this order.

[0061] The three-stage mixing includes mixing for 15-50s, mixing for 15-30s with the bolt lifted and the bolt pressed, and then mixing to 140-150°C for debonding with the bolt lifted and the bolt pressed.

[0062] The four-stage mixing includes mixing for 15-60 seconds, mixing with the plug lifted and the plug pressed for 20-40 seconds, and then mixing with the plug lifted and the plug pressed until the temperature reaches 135-145° C. for debonding.

[0063] The five-stage mixing includes mixing for 10-50 seconds, mixing with the plug lifted and the plug pressed for 15-30 seconds, and then mixing with the plug lifted and the plug pressed until the temperature reaches 95-115° C. for debonding.

[0064] Typically but not restrictively, the two-stage mixing includes mixing in a sequential order, wherein the mixing time may be 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s or 60s; the mixing time for lifting the bolt and pressing the bolt may be 20s, 22s, 24s, 26s, 28s, 30s, 32s, 34s ​​or 35s; then the mixing for lifting the bolt and pressing the bolt may be performed until the temperature reaches 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C, 163°C, 164°C or 165°C before debinding.

[0065] Typically but not restrictively, the three-stage mixing includes mixing in a sequential order, wherein the mixing time may be 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s; the mixing time for lifting the bolt and pressing the bolt may be 15s, 18s, 21s, 24s, 27s, 30s; then the mixing is performed by lifting the bolt and pressing the bolt until the temperature reaches 140°C, 142°C, 144°C, 146°C, 148°C, 150°C before degumming.

[0066] Typically but not restrictively, the four-stage mixing includes mixing in a sequential order, wherein the mixing time may be 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s or 60s; the mixing time for lifting the bolt and pressing the bolt may be 20s, 25s, 30s, 35s, 40s; then the mixing is carried out by lifting the bolt and pressing the bolt until the temperature reaches 135°C, 137°C, 139°C, 141°C, 143°C, 145°C before degumming.

[0067] Typically but not restrictive, the five-stage mixing includes mixing in a sequential order, wherein the mixing time may be 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s; the mixing time for lifting the bolt and pressing the bolt may be 15s, 20s, 25s, 30s; then the mixing is carried out by lifting the bolt and pressing the bolt until the temperature reaches 95°C, 100°C, 105°C, 110°C, 115°C before degumming.

[0068] The third aspect of the present invention provides the use of the tire sidewall rubber in the preparation of fire truck tires, hazardous chemicals transport vehicle tires or coal mine underground transport vehicle tires.

[0069] The application of the tire sidewall rubber provided by the present invention provides better raw materials for preparing fire truck tires, hazardous chemical transport vehicle tires or coal mine underground transport vehicle tires. It releases less toxic gas during combustion, making it an ideal choice in modern society with increasing environmental awareness, and meets the modern tire industry's needs for high performance, high safety and environmental protection.

[0070] In conjunction with the examples, some embodiments of the present invention are described in detail below. In the absence of conflict, the following examples and features in the examples can be combined with each other. The raw materials used in the examples and comparative examples of the present invention, if no specific conditions are specified, are carried out under normal conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0071] The silica used in the following examples and comparative examples is the deposited silica supplied by Quecheng Silicon Chemical Co., Ltd.; the accelerator DM is provided by LANXESS Chemical, and the accelerator CZ is provided by LANXESS Chemical.

[0072] Example 1 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0073] Example 2 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 10 parts of natural rubber, 40 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 15 parts of carbon black N330, 15 parts of white carbon black, 15 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.6 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0074] Example 3 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 10 parts of natural rubber, 20 parts of butadiene rubber, 70 parts of chloroprene rubber, 40 parts of antimony trioxide, 20 parts of carbon black N330, 10 parts of white carbon black, 10 parts of chlorinated paraffin, 5 parts of tricresyl phosphate, 2 parts of high aromatic oil, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.6 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0075] Example 4 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 10 parts of natural rubber, 15 parts of butadiene rubber, 75 parts of chloroprene rubber, 25 parts of carbon black N660, 10 parts of white carbon black, 35 parts of antimony trioxide, 5 parts of chlorinated paraffin, 5 parts of tricresyl phosphate, 3 parts of high aromatic oil, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.8 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0076] Example 5 This embodiment provides a tire sidewall rubber. The difference from Embodiment 1 is that carbon black N330 is used to replace carbon black N375. The remaining raw materials and methods are the same as those in Embodiment 1 and will not be described again.

[0077] Example 6 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 35 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0078] Example 7 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 10 parts of chlorinated paraffin, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0079] Example 8 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0080] Example 9 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 9 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0081] Example 10 This embodiment provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 9 parts of magnesium oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0082] Embodiment 11 This embodiment provides a tire sidewall rubber obtained by mixing a composition. The formula of the composition is exactly the same as that of Embodiment 1, but the mixing method is different.

[0083] Comparative Example 1 This comparative example provides a tire sidewall rubber obtained by mixing the following composition: 40 parts of natural rubber, 60 parts of butadiene rubber, 50 parts of carbon black N330, 2 parts of 203 resin, 5 parts of high aromatic oil, 2 parts of stearic acid, 3 parts of antioxidant 4020, 1 part of antioxidant RD, 1.5 parts of microcrystalline wax, 3 parts of zinc oxide, 1.5 parts of sulfur, and 0.8 parts of accelerator CZ (without NA-22).

[0084] Comparative Example 2 This comparative example provides a tire sidewall rubber, which is different from Example 1 in that antimony trioxide is not added, the amount of chlorinated paraffin is 20 parts, and the amount of tricresyl phosphate is 25 parts. The other raw materials are the same as those in Example 1 and will not be repeated here.

[0085] Comparative Example 3 This comparative example provides a tire sidewall rubber obtained by mixing the following composition: 40 parts of natural rubber, 60 parts of butadiene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0086] Comparative Example 4 This comparative example provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 24 parts of carbon black N375, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 4 parts of magnesium oxide, 5 parts of zinc oxide, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0087] Comparative Example 5 This comparative example provides a tire sidewall rubber obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 30 parts of antimony trioxide, 10 parts of carbon black N375, 20 parts of white carbon black, 5 parts of chlorinated paraffin, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 0.5 parts of antioxidant RD, 1.5 parts of microcrystalline wax, 1.8 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0088] Preparation Example 1 The preparation methods of Examples 1-10 and Comparative Examples 2, 3 and Comparative Example 5 are as follows: 1. First, place white carbon black and antimony trioxide in a stirring kettle and stir them evenly to prepare antimony trioxide white carbon black pre-dispersed suspension, and then mix the suspension with natural rubber to prepare the first masterbatch, which is reserved for later use.

[0089] The specific process of the first stage mixing is: add antimony trioxide and white carbon black pre-dispersed suspension and half of the mass of natural rubber into the internal mixer, control the speed at 40-55rpm, mix for 20-60s, lift the plug to add the remaining natural rubber, press the plug to mix for 20-50s, and mix until the temperature is 150-165℃ to discharge the rubber.

[0090] 2. The remaining raw materials, except the vulcanizer and the accelerator, are mixed in two stages to prepare the second masterbatch.

[0091] The specific process of the two-stage mixing is: the rotation speed is controlled at 40~55rpm, mixing is carried out in sequence for 20~60s, the plug is lifted and pressed for mixing for 20~35s, and then the plug is lifted and pressed for mixing to 150~165℃ and the glue discharge is carried out at 40~55 rpm.

[0092] 3. The first masterbatch prepared in step 1 is added to the second masterbatch, and the mixture is mixed in three stages and four stages to obtain the third masterbatch.

[0093] The specific process of the three-stage mixing is: the rotation speed is controlled at 40~55rpm, mixing is carried out in sequence for 15~50s, the plug is lifted and pressed to mix for 15~30s, and then the plug is lifted and pressed to mix until the temperature reaches 140~150℃ for degumming.

[0094] The specific process of the four-stage mixing is: the rotation speed is controlled at 40~55rpm, mixing is carried out in sequence for 15~60s, mixing with the plug lifted and the plug pressed for 20~40s, and then mixing with the plug lifted and the plug pressed until the temperature reaches 135~145℃ for degumming.

[0095] 4. Add a vulcanizing agent and an accelerator to the third masterbatch and mix them in five stages to obtain the tire sidewall rubber.

[0096] The specific process of the five-stage mixing is: the rotation speed is controlled at 20-35 rpm, mixing is carried out in sequence for 10-50 s, the plug lifting and pressing mixing is carried out for 15-30 s, and then the plug lifting and pressing mixing is carried out to 95-115°C for degumming.

[0097] Preparation Example 2 The preparation methods of Example 11, Comparative Example 1 and Comparative Example 4 are as follows: 1. One-stage mixing: The raw materials other than the vulcanizing agent and the accelerator are mixed in one stage. The specific process of the one-stage mixing is that the rotation speed is controlled at 40-55 rpm, and the mixing is carried out in sequence for 30-70 seconds, the plug is lifted and pressed, and the mixing is carried out for 20-35 seconds, and then the plug is lifted and pressed, and the mixing is carried out to 150-165°C and the rubber discharge is 40-55 rpm to obtain a mixed rubber.

[0098] 2. Second stage mixing: the rotation speed is controlled at 40-55 rpm, the first stage mixed rubber is mixed in sequence for 15-50 s, the plug is lifted and pressed for mixing for 15-30 s, and then the plug is lifted and pressed for mixing until the temperature is 140-150 ℃ for rubber discharge to obtain the second stage mixed rubber.

[0099] 3. Vulcanization stage: Add vulcanizing agent and accelerator to the above two-stage mixed rubber, control the speed at 20-35rpm, mix for 10-50s, remove the plug and mix for 15-30s, then remove the plug and mix until the temperature is 95-115℃ to discharge the rubber, and obtain the final mixed rubber.

[0100] Test Example 1 The tire sidewall rubbers obtained in the examples and comparative examples were subjected to performance tests.

[0101] Including: 300% elongation stress M300 is carried out in accordance with the provisions of GB / T528-1998; tensile strength TB is carried out in accordance with the provisions of GB / T528-1998; elongation at break EB% is carried out in accordance with the provisions of GB / T528-1998; hardness is carried out in accordance with the provisions of GB / T531.1-2008; flexure test is carried out in accordance with the provisions of GB / T 1233-2008.

[0102] The flame retardant performance was tested by Qingdao Sinochem New Materials Laboratory, a third-party testing agency, and the testing method was carried out in accordance with the provisions of MT / T113-1995.

[0103] The obtained data are shown in Tables 1 and 2 below.

[0104] Table 1

[0105] Table 2

[0106] It can be seen from the embodiment and the comparative example that the physical properties and flame retardant properties of the embodiment have a good balance, ensuring both flame retardant properties and physical properties, while the physical properties of the comparative example are similar to those of the embodiment, but its flame retardant properties are poor. Compared with the prior art, the present invention has obvious and positive progress. The tire prepared by the present invention has the characteristics of high performance and high flame retardancy, which greatly improves the service life of the tire.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tire sidewall rubber composition, characterized in that: In parts by weight, the composition comprises: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 35-65 parts of flame retardant, 7-13 parts of activator, 1-3 parts of activation aid, 3-6 parts of antioxidant, 1.5-3 parts of vulcanizing agent and 1-3 parts of accelerator; The flame retardant includes antimony trioxide.

2. The tire sidewall rubber composition according to claim 1, characterized in that: The flame retardant further comprises chlorinated paraffin and / or tricresyl phosphate.

3. The tire sidewall rubber composition according to claim 1, characterized in that: The activator comprises magnesium oxide and / or zinc oxide; The activating aid includes stearic acid.

4. The tire sidewall rubber composition according to claim 1, characterized in that: The brand of the antioxidant includes at least one of antioxidant 4020, antioxidant RD and antioxidant 4010NA; The vulcanizing agent includes sulfur; The brand of the accelerator includes at least one of NA-22, DM and CZ.

5. The tire sidewall rubber composition according to any one of claims 1 to 4, characterized in that: The grade of the carbon black includes at least one of N220, N234, N330, N326, N375 and N660; The white carbon black is vapor deposition white carbon black or precipitation white carbon black.

6. The tire sidewall rubber composition according to any one of claims 1 to 4, characterized in that: In parts by weight, the composition comprises: 5-20 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 10-50 parts of carbon black, 10-20 parts of white carbon black, 2-3 parts of microcrystalline wax, 30-40 parts of antimony trioxide, 0-10 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 2-5 parts of magnesium oxide, 5-8 parts of zinc oxide, 1-3 parts of stearic acid, 2-4 parts of antioxidant 4020, 1-2 parts of antioxidant RD, 1.5-3 parts of sulfur and 1-3 parts of accelerator.

7. A tire sidewall rubber, characterized in that: The tire sidewall rubber composition is mainly obtained by kneading the tire sidewall rubber composition according to any one of claims 1 to 6.

8. The tire sidewall rubber according to claim 7, characterized in that: The mixing comprises the following steps: A. mixing white carbon black and antimony trioxide and dispersing them uniformly to obtain a suspension; then mixing the suspension with natural rubber to obtain a first masterbatch; B. mixing butadiene rubber, chloroprene rubber, carbon black, microcrystalline wax, remaining flame retardant, activator, activation aid and antioxidant and performing two-stage mixing to obtain a second masterbatch; C. adding the first masterbatch to the second masterbatch and mixing them in three stages and four stages to obtain a third masterbatch; D. Adding a vulcanizing agent and an accelerator to the third masterbatch and mixing them in five stages to obtain the tire sidewall rubber.

9. The tire sidewall rubber according to claim 8, characterized in that: The mixing process of the first stage is: mixing the suspended matter and part of the natural rubber for 20-60 seconds, adding the plug to the remaining natural rubber plug and mixing for 20-50 seconds, and mixing until the temperature reaches 150-165° C. to discharge the rubber; The two-stage mixing includes mixing for 20-60 seconds, mixing for 20-35 seconds with the bolt lifted and the bolt pressed, and then mixing to 150-165° C. for debonding with the bolt lifted and the bolt pressed; The three-stage mixing includes mixing for 15-50 seconds, mixing for 15-30 seconds with the bolt lifted and the bolt pressed, and then mixing to 140-150° C. for debonding with the bolt lifted and the bolt pressed; The four-stage mixing includes mixing for 15-60 seconds, mixing for 20-40 seconds with the bolt lifted and the bolt pressed, and then mixing until the temperature reaches 135-145° C. for debonding. The five-stage mixing includes mixing for 10-50 seconds, mixing with the plug lifted and the plug pressed for 15-30 seconds, and then mixing with the plug lifted and the plug pressed until the temperature reaches 95-115° C. for debonding.

10. Use of the tire sidewall rubber according to any one of claims 7 to 9 in preparing tires for fire fighting vehicles, tires for hazardous chemicals transport vehicles or tires for coal mine underground transport vehicles.

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