Tire outer protection rubber composition, tire outer protection rubber and application thereof

Abstract

The invention provides a tire outer protection rubber composition, tire outer protection rubber and application thereof, and particularly relates to the technical field of tire manufacturing. The tire outer protection rubber composition comprises the following components in parts by weight: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 30-75 parts of a flame retardant, 3-6 parts of an activating agent, 0.5-1.5 parts of an activating auxiliary agent, 3-6 parts of an anti-aging agent, 1-4 parts of a vulcanizing agent and 3-5.5 parts of an accelerant, the flame retardant comprises antimony trioxide. According to the tire outer protection 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 outer protection 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, in particular to a tire outer rubber composition, a tire outer rubber and applications thereof. Background Art

[0002] During the use of the tire, the outer rubber is in direct contact with the rim and is subjected to stress, which makes it very easy to accumulate heat and pose a risk of flammability. Therefore, the outer rubber should not only have good physical properties, but also good flame retardant properties. It is well known that carbon black as a filler in rubber will increase the risk of combustion, so people often use white carbon black instead of carbon black. However, white carbon black is a filler that is difficult to disperse. It is easy to agglomerate during mixing and is difficult to disperse, resulting in an uneven rubber compound, which brings challenges to the process.

[0003] Rubber itself is a kind of high molecular flammable material. When it is in a high temperature environment or near a fire source for a long time, it is easy to produce thermal cracking reaction and release flammable rubber hydrocarbon gas. When these gases come into contact with oxygen and reach a certain concentration, they may spontaneously ignite with open flames. Therefore, in these application environments, the flame retardancy and flame retardancy of rubber become particularly important. With the development of the tire industry, the requirements for tire performance are getting higher and higher. Among them, flame retardancy is an important indicator, which directly affects the driving safety of rubber products. Traditional tire outer formulas are mainly made of natural rubber, carbon black, microcrystalline wax and other materials. These materials will release a large amount of toxic gases when burned, posing a serious threat to the environment and human health. Therefore, improving the flame retardancy of tire outers has become an important task at present.

[0004] Although existing solutions can improve the flame retardant properties of tires to a certain extent, there are still some problems. First, the use of these flame retardants may affect other properties of the tire, such as wear resistance, aging resistance, etc. Secondly, conventional flame retardant formulas often use white carbon black instead of carbon black. This high white carbon black system has the problem of being difficult to disperse, which in turn affects the mixing process. Therefore, how to improve the flame retardant properties of tires while avoiding the impact on other properties, reducing production costs, and reducing environmental pollution is the main problem facing current technology. This requires us to innovate in the formulation and production process of tire outer protective rubber to achieve safer and more environmentally friendly tire production.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a tire outer rubber composition to alleviate at least one of the above-mentioned technical problems in the prior art.

[0007] A second object of the present invention is to provide a tire outer rubber.

[0008] A third object of the present invention is to provide an application of a tire outer rubber.

[0009] 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 outer rubber composition, which comprises, by weight: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 30-75 parts of flame retardant, 3-6 parts of activator, 0.5-1.5 parts of activation aid, 3-6 parts of antioxidant, 1-4 parts of vulcanizing agent and 3-5.5 parts of accelerator; 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 and N375.

[0017] The white carbon black includes 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 outer rubber composition comprises, by weight: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 25-45 parts of antimony trioxide, 0-15 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 3-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 3-6 parts of antioxidant, 1-4 parts of sulfur, 0.5-1.5 parts of accelerator NA-22, and 2.5-4.5 parts of the first accelerator; The brand of the first accelerator includes at least one of DM and CZ.

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

[0021] 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.

[0022] B. Mix the other raw materials except the vulcanizer and the accelerator, and perform two-stage mixing to obtain the second masterbatch.

[0023] C. Adding the first masterbatch to the second masterbatch and performing three-stage mixing and four-stage mixing to obtain a third masterbatch.

[0024] D. Adding a vulcanizing agent and an accelerator into the third masterbatch and kneading the mixture in five stages to obtain the tire outer rubber.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The third aspect of the present invention provides the use of the tire outer rubber in the preparation of fire truck tires, hazardous chemicals transport vehicle tires or coal mine underground transport vehicle tires.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects: The tire outer 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 chlorides, which form 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 outer 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.

[0032] The tire outer rubber provided by the present invention, in view of the advantages of the above-mentioned tire outer rubber composition, makes the prepared tire outer rubber have better flame retardancy, wear resistance, aging resistance and tear resistance, is suitable for various harsh working environments, expands the application fields of tire outer rubber, and promotes the development of related industries.

[0033] The application of the tire outer 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

[0034] 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.

[0035] 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.

[0036] The first aspect of the present invention provides a tire outer rubber composition, which comprises, by weight: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 30-75 parts of flame retardant, 3-6 parts of activator, 0.5-1.5 parts of activation aid, 3-6 parts of antioxidant, 1-4 parts of vulcanizing agent and 3-5.5 parts of accelerator; The flame retardant includes antimony trioxide.

[0037] The tire outer rubber composition provided by the present invention improves the flame retardant performance 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 isolates oxygen, and further enhances 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 outer rubber composition of the present invention not only improves the flame retardant performance, but also ensures the maintenance of physical properties, achieving dual optimization of flame retardant and physical properties. The synergistic effect between the raw materials, while improving the flame retardant performance of the tire, avoids the influence on its hardness, elongation and other properties.

[0038] Typically but not limiting, the various components of the composition can specifically include the following proportions: natural rubber can be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts or 30 parts, or any value within the range of 5 to 30 parts; butadiene rubber can be 20 parts, 25 parts, 30 parts, 35 parts or 40 parts, or any value within the range of 20 to 40 parts; chloroprene rubber can be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts, or any value within the range of 50 to 80 parts; carbon black can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts or 45 parts, or any value within the range of 20 to 45 parts; white carbon black can be 10 parts, 15 parts, 20 parts, 25 parts or 30 parts, or any value within the range of 10 to 30 parts. any value within the range of 30-75 parts; the flame retardant may be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 60 parts, 65 parts or 75 parts, or any value within the range of 30-75 parts; the activator may be 3 parts, 4 parts, 5 parts or 6 parts, or any value within the range of 3-6 parts; the activation aid may be 0.5 parts, 0.75 parts, 1 parts or 1.25 parts, or any value within the range of 0.5-1.5 parts; the antioxidant may be 3 parts, 4 parts, 5 parts or 6 parts, or any value within the range of 3-6 parts; the vulcanizer may be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts or 4 parts, or any value within the range of 1-4 parts; the accelerator may be 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5.5 parts, or any value within the range of 3-5.5 parts.

[0039] Chloroprene rubber is a synthetic rubber with good aging resistance and flame retardant properties, and can replace natural rubber. It should be noted that the total amount of natural rubber, butadiene rubber and chloroprene rubber as elastic matrix is ​​100 parts.

[0040] Furthermore, the flame retardant further comprises chlorinated paraffin and / or tricresyl phosphate.

[0041] Chloroprene is a synthetic rubber with good aging resistance and flame retardant properties, and can replace natural rubber. Chloroprene contains chlorine, which is non-spontaneous and can extinguish itself by isolating the fire source. Antimony trioxide is used as a flame retardant in the formula. It can combine with the chlorine in chloroprene to form antimony chloride, which covers the surface of the rubber and blocks the invasion of oxygen, and has excellent flame retardant effect. Antimony trioxide is an inorganic filler with good flame retardant effect and can be used as a flame retardant. Chloroprene is a chlorinated derivative of paraffin, which has both anti-aging and flame retardant properties. It can effectively protect the aging properties of the composition while being flame retardant; tricresyl phosphate can replace organic aromatic softeners to achieve flame retardant effect.

[0042] 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.

[0043] 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.

[0044] The activating aid includes stearic acid.

[0045] Furthermore, the brand of the antioxidant includes at least one of antioxidant 4020, antioxidant RD and antioxidant 4010NA.

[0046] The vulcanizing agent includes sulfur.

[0047] 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.

[0048] Typically but not limiting, the preferred addition amount of the accelerator NA-22 can 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.

[0049] Furthermore, the grade of the carbon black includes at least one of N220, N234, N330, N326 and N375, preferably N220, N375 and N330.

[0050] The white carbon black is vapor deposition white carbon black or precipitation white carbon black.

[0051] 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%.

[0052] 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. Further, the tire outer rubber composition, measured by weight, comprises: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of flame retardant, 25-45 parts of antimony trioxide, 0-15 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 3-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 3-6 parts of antioxidant, 1-4 parts of sulfur, 0.5-1.5 parts of accelerator NA-22, and 2.5-4.5 parts of first accelerator; The brand of the first accelerator includes at least one of DM and CZ.

[0053] Typically but not limiting, the various components of the composition may specifically include the following proportions: natural rubber may be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts or 30 parts, or any value within the range of 5 to 30 parts; butadiene rubber may be 20 parts, 25 parts, 30 parts, 35 parts or 40 parts, or any value within the range of 20 to 40 parts; chloroprene rubber may be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts , or any value within the range of 50 to 80 parts; carbon black can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts or 45 parts, or any value within the range of 20 to 45 parts; white carbon black can be 10 parts, 15 parts, 20 parts, 25 parts or 30 parts, or any value within the range of 10 to 30 parts; antimony trioxide can be 25 parts, 30 parts, 35 parts, 40 parts or 45 parts, or any value within the range of 25 to 45 parts; chlorine The amount of paraffin wax can be 0, 5, 10 or 15 parts, or any value within the range of 0 to 15 parts; the amount of tricresyl phosphate can be 5, 10 or 15 parts, or any value within the range of 5 to 15 parts; the amount of zinc oxide can be 3, 4, 5 or 6 parts, or any value within the range of 3 to 6 parts; the amount of stearic acid can be 0.5, 0.75, 1 or 1.25 parts, or any value within the range of 0.5 to 1.5 parts; the amount of antioxidant It can be 3 parts, 4 parts, 5 parts or 6 parts, or any value within the range of 3-6 parts; sulfur can be 1 part, 2 parts, 3 parts or 4 parts, or any value within the range of 1-4 parts; accelerator NA-22 can be 0.5 parts, 1 part or 1.5 parts, or any value within the range of 0.5-1.5 parts; the first accelerator can be 2.5 parts, 3 parts, 3.5 parts, 4 parts or 4.5 parts, or any value within the range of 2.5-4.5 parts.

[0054] The second aspect of the present invention provides a tire outer rubber, which is mainly obtained by mixing the tire outer rubber composition.

[0055] The tire outer rubber provided by the present invention, in view of the advantages of the above-mentioned tire outer rubber composition, makes the prepared tire outer rubber have better flame retardancy, wear resistance, aging resistance and tear resistance, is suitable for various harsh working environments, expands the application fields of tire outer rubber, and promotes the development of related industries.

[0056] 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.

[0057] B. Mix the other raw materials except the vulcanizer and the accelerator, and perform two-stage mixing to obtain the second masterbatch.

[0058] C. Adding the first masterbatch to the second masterbatch and performing three-stage mixing and four-stage mixing to obtain a third masterbatch.

[0059] D. Adding a vulcanizing agent and an accelerator into the third masterbatch and kneading the mixture in five stages to obtain the tire outer rubber.

[0060] The above mixing process is to optimize the traditional tire production process to reduce production costs and improve economic benefits. 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.

[0061] The method is to pre-treat the white carbon black and prepare the white carbon black pre-dispersed suspension with antimony trioxide, and then mix it with natural rubber to prepare the white carbon black masterbatch of antimony trioxide, which effectively solves the problem of poor dispersion. Through the combination of the above materials and the preparation method, a tire outer rubber composition that is both flame retardant and can ensure the physical properties of the rubber material is obtained.

[0062] 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.

[0063] 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.

[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] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] The third aspect of the present invention provides the use of the tire outer rubber in the preparation of fire truck tires, hazardous chemicals transport vehicle tires or coal mine underground transport vehicle tires.

[0072] The application of the tire outer 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.

[0073] 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.

[0074] 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.

[0075] Example 1 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0076] Example 2 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 10 parts of natural rubber, 30 parts of butadiene rubber, 60 parts of chloroprene rubber, 40 parts of antimony trioxide, 40 parts of carbon black N330, 15 parts of white carbon black, 10 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.6 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0077] Example 3 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 70 parts of chloroprene rubber, 10 parts of natural rubber, 20 parts of butadiene rubber, 30 parts of antimony trioxide, 35 parts of carbon black N375, 20 parts of white carbon black, 10 parts of chlorinated paraffin, 5 parts of tricresyl phosphate, 1 part of stearic acid, 1 part of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.8 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0078] Example 4 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 65 parts of chloroprene rubber, 15 parts of natural rubber, 20 parts of butadiene rubber, 40 parts of carbon black N220, 10 parts of white carbon black, 35 parts of antimony trioxide, 15 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 1 part of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0079] Example 5 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 45 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0080] Example 6 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 11 parts of chlorinated paraffin, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0081] Example 7 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 3 parts of zinc oxide, 2 parts of magnesium oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0082] Example 8 This embodiment provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of magnesium oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0083] Example 9 This embodiment provides a tire outer 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.

[0084] Comparative Example 1 This comparative example provides a tire outer rubber, which is obtained by mixing the following composition: 60 parts of natural rubber, 40 parts of butadiene rubber, 76 parts of carbon black N330, 3 parts of 203 resin, 1.5 parts of high aromatic oil, 1 part of stearic acid, 1 part of antioxidant 4020, 5 parts of zinc oxide, 1.7 parts of sulfur, and 1.8 parts of accelerator CZ.

[0085] Comparative Example 2 This comparative example provides a tire outer rubber, which is different from Example 1 in that antimony trioxide is not added, the amount of chlorinated paraffin is 15 parts, and the amount of tricresyl phosphate is 42 parts. The other raw materials are the same as those in Example 1 and will not be repeated here.

[0086] Comparative Example 3 This comparative example provides a tire outer rubber, which is obtained by mixing the following composition: 40 parts of natural rubber, 60 parts of butadiene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 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 4 This comparative example provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 45 parts of carbon black N375, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 5 parts of zinc oxide, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0088] Comparative Example 5 This comparative example provides a tire outer rubber, which is obtained by mixing the following composition: 20 parts of natural rubber, 30 parts of butadiene rubber, 50 parts of chloroprene rubber, 40 parts of antimony trioxide, 25 parts of carbon black N375, 30 parts of white carbon black, 5 parts of chlorinated paraffin, 12 parts of tricresyl phosphate, 1 part of stearic acid, 2 parts of antioxidant 4020, 1 part of antioxidant RD, 1 part of microcrystalline wax, 1.6 parts of sulfur, 0.5 parts of accelerator NA-22, 1 part of accelerator DM, and 1.5 parts of accelerator CZ.

[0089] Preparation Example 1 The preparation methods of Examples 1-8 and Comparative Examples 3-5 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.

[0090] The specific process of the first stage mixing is: add antimony trioxide and white carbon black pre-dispersed suspension and half of the natural rubber into the internal mixer, control the speed at 40-55rpm, mix for 20-60s, lift the plug and add the remaining natural rubber, press the plug and mix for 20-50s, mix to 150-165℃, and discharge the rubber.

[0091] 2. The remaining raw materials, except the vulcanizer and the accelerator, are mixed in two stages to prepare the second masterbatch.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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 raised and the plug pressed for 20~40s, and then mixing with the plug raised and the plug pressed until the temperature reaches 135~145℃ for degumming.

[0096] 4. Add a vulcanizing agent and an accelerator to the third masterbatch and mix them in five stages to obtain the tire outer rubber.

[0097] 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.

[0098] Preparation Example 2 The preparation methods of Example 9 and Comparative Examples 1-2 are as follows: 1. One-stage mixing: except for the vulcanizing agent and accelerator, other raw materials are mixed in one stage. The specific process of one-stage mixing is that the speed is controlled at 40-55 rpm, mixing is carried out in sequence for 30-70 seconds, the bolt is lifted and pressed for mixing for 20-35 seconds, and then the bolt is lifted and pressed for mixing to 150-165℃ and the rubber is discharged at 40-55 rpm. There is no process of making the first masterbatch.

[0099] 2. Second stage mixing: the speed is controlled at 40-55 rpm, mixing is performed in the order of 15-50 seconds, lifting the plug and pressing the plug for 15-30 seconds, and then lifting the plug and pressing the plug to mix until the temperature reaches 140-150℃ for rubber discharge. The second stage mixed rubber is obtained.

[0100] 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.

[0101] Test Example 1 The tire outer rubber obtained in the examples and comparative examples was subjected to performance tests.

[0102] 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; permanent deformation test is carried out in accordance with the provisions of GB / T 7759.1-2015.

[0103] 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.

[0104] The obtained data are shown in Tables 1 and 2 below.

[0105] Table 1

[0106] Table 2

[0107] 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.

[0108] 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 outer rubber composition, characterized in that: In parts by weight, the composition comprises: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 30-75 parts of flame retardant, 3-6 parts of activator, 0.5-1.5 parts of activation aid, 3-6 parts of antioxidant, 1-4 parts of vulcanizing agent and 3-5.5 parts of accelerator; The flame retardant includes antimony trioxide.

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

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

4. The tire outer 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 outer 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 and N375; The white carbon black includes vapor deposition white carbon black or precipitation white carbon black.

6. The tire outer rubber composition according to any one of claims 1 to 4, characterized in that: In parts by weight, the composition comprises: 5-30 parts of natural rubber, 20-40 parts of butadiene rubber, 50-80 parts of chloroprene rubber, 20-45 parts of carbon black, 10-30 parts of white carbon black, 1-3 parts of microcrystalline wax, 25-45 parts of antimony trioxide, 0-15 parts of chlorinated paraffin, 5-15 parts of tricresyl phosphate, 3-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 3-6 parts of antioxidant, 1-4 parts of sulfur, 0.5-1.5 parts of accelerator NA-22, and 2.5-4.5 parts of the first accelerator; The brand of the first accelerator includes at least one of DM and CZ.

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

8. The tire outer 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 other raw materials except the vulcanizing agent and the accelerator, 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 into the third masterbatch and kneading the mixture in five stages to obtain the tire outer rubber.

9. The tire outer 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 outer 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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