Anti-tarnishing rubber composition for colored tire and preparation method thereof

Abstract

The invention relates to the technical field of colored tire rubber, and particularly discloses an anti-tarnishing rubber composition for a colored tire and a preparation method of the anti-tarnishing rubber composition. According to the anti-discoloration rubber composition for the colored tire, the modified colored white carbon black is firstly prepared, then the solution polymerized styrene-butadiene rubber, the natural rubber and the ethylene propylene diene monomer are used as rubber matrixes, and the modified colored white carbon black is added for coloring and reinforcing; and adding auxiliary agents such as polydicyclopentadiene resin, titanium dioxide, a YDH-151 silane coupling agent, zinc oxide, stearic acid, sulfur, a TBBS accelerator, protective wax, an AFS / LG anti-aging agent, an antistatic agent and the like to prepare the anti-tarnishing rubber composition for the colored tire. The anti-discoloration rubber composition for the colored tire has the advantages of being stable in color, resistant to aging, good in stretchability, high in wear resistance and high in weather resistance.

Description

Technical Field

[0001] The present application relates to the technical field of colored tire rubber, and more specifically, to an anti-discoloration rubber composition for colored tires and a preparation method thereof. Background Art

[0002] Traditional tires are mostly black, which is difficult to meet the user's demand for diversified colors. Therefore, many tire manufacturers have launched colored tires and attracted a certain amount of attention in the market. Colored tires have changed the past situation of mainly black, making tires more fashionable and personalized.

[0003] At present, there are three main production processes for colored tires: (1) spray painting process, which uses laser to spray colored paint on the surface of the vulcanized tire, but the color of the tire produced by this process disappears quickly after wear; (2) glue process, which is to stick a colored film on the tire embryo and then vulcanize it, but this process is limited to the side of the tire; (3) full color process, that is, by adding colorants to the tire rubber, colorful tires are produced, but this process has the following problems: carbon black cannot be used, coloring fillers affect its durability, white carbon black is easy to agglomerate, processing is difficult, and the color changes due to aging resistance migration.

[0004] Therefore, there is still a need to further develop anti-discoloration rubber compositions for colored tires. Summary of the invention

[0005] In order to further improve the anti-discoloration performance of colored tires while ensuring that the basic performance of the tires is not affected, the present application provides an anti-discoloration rubber composition for colored tires and a preparation method thereof.

[0006] In the first aspect, the present application provides an anti-discoloration rubber composition for a colored tire, which adopts the following technical solution:

[0007] The invention discloses an anti-discoloration rubber composition for colored tires, which comprises the following compositions in parts by weight: 20-30 parts of solution-polymerized styrene-butadiene rubber, 50-60 parts of natural rubber, 10-30 parts of ethylene-propylene-diene rubber, 40-60 parts of modified colored white carbon black, 12-15 parts of titanium dioxide, 3-5 parts of polydicyclopentadiene resin, 8-10 parts of YDH-151 silane coupling agent, 3-5 parts of zinc oxide, 2-3 parts of stearic acid, 1-2 parts of sulfur and 1-2 parts of TBBS accelerator, 2.5-4.5 parts of protective wax, 3-5 parts of AFS / LG antioxidant and 1-2 parts of antistatic agent.

[0008] By adopting the above technical scheme, solution-polymerized styrene-butadiene rubber, natural rubber and EPDM rubber are used as rubber matrices, modified colored white carbon black is added for coloring and reinforcement, and auxiliary agents such as polydicyclopentadiene resin, titanium dioxide, YDH-151 silane coupling agent, zinc oxide, stearic acid, sulfur and TBBS accelerator, protective wax, AFS / LG antioxidant, antistatic agent and other auxiliary agents are added to prepare an anti-discoloration rubber composition for colored tires with excellent heat-oxidative aging resistance, ozone aging resistance, tensile properties, wear resistance, weather resistance and color stability.

[0009] Preferably, the modified colored silica is prepared by the following steps: S1, mixing sulfuric acid solution and (3-mercaptopropyl) triethoxysilane, stirring and activating for 10-15 minutes; S2, slowly adding water glass solution into S1 for reaction, when the pH value of the system is 3-4, adding colorant dispersion, then adding the remaining water glass solution, and continuing to stir until the reaction system is converted into gel; S3, filtering the formed gel, washing with water, drying and crushing to obtain colored silica; S4, dispersing the colored silica in n-hexane at 50-60°C by ultrasonic dispersion to obtain a colored silica dispersion; at the same time, stirring and dissolving a homopolymer of 2-methyl-1,3-butadiene in n-hexane at 50-60°C to obtain a homopolymer solution; then mixing the two, stirring for 4-6 hours, adding a photoinitiator BDK, continuing to stir for 1-1.5 hours and then stopping, then volatilizing the solvent, and irradiating with an ultraviolet lamp for 30-40 minutes to obtain a modified colored silica.

[0010] By adopting the above technical scheme, a colorant is added during the process of preparing white carbon black using sulfuric acid and water glass to improve the adsorption capacity of white carbon black for the colorant, and (3-mercaptopropyl)triethoxysilane is used to hydrophobically modify and disperse the generated white carbon black, and at the same time, the reaction between the homopolymer of 2-methyl-1,3-butadiene and the mercapto group is utilized to wrap the white carbon black, enhance the stability of the colorant, and prevent the color migration of the colorant caused by the antioxidant and the protective wax, resulting in discoloration; finally, the modified colored white carbon black is added to the rubber solution, and the white carbon black and the rubber are connected through the homopolymer of 2-methyl-1,3-butadiene, so as to replace the carbon black to achieve the reinforcement effect on the rubber and enhance its mechanical properties.

[0011] Preferably, the concentration of the sulfuric acid solution is 0.4-0.5 mol / L, the modulus of the water glass solution is 3-3.5, and the concentration is 0.4-0.5 mol / L; the concentration of the colorant dispersion is 0.3-0.5 g / L.

[0012] By adopting the above technical solution, the raw material at this concentration can form white carbon black powder with a smaller particle size and a larger specific surface area.

[0013] Preferably, the colorant in the colorant dispersion is an organic pigment, and the colorant dispersion further comprises a pigment synergist.

[0014] The colorant includes but is not limited to Phthalocyanine Blue, Color Red 144, and Pigment Yellow 183.

[0015] By adopting the above technical solution and using organic pigments as pigment colorants, the coloring power between the organic pigments and the formed white carbon black can be enhanced.

[0016] Preferably, the usage ratio of the sulfuric acid solution, (3-mercaptopropyl)triethoxysilane, water glass solution and colorant dispersion is (3-3.5)L:(0.2-0.4)g:(3-4)L:(1.5-2)L.

[0017] By adopting the above technical solution, the colored white carbon black prepared under this ratio has good dispersibility and stable coloring.

[0018] Preferably, the volume ratio of the colored silica dispersion to the homopolymer solution is (1-1.2):1.

[0019] Preferably, the concentration of the colored silica dispersion is 0.1-0.2 kg / L, and the concentration of the homopolymer solution is 0.05-0.08 g / L.

[0020] Preferably, the added amount of the photoinitiator BDK is 0.2-0.5% of the mass fraction of the colored white carbon black.

[0021] By adopting the above technical scheme, the homopolymer of 2-methyl-1,3-butadiene is reacted with thiol by an initiator to wrap the white carbon black and enhance the stability of the colorant.

[0022] In a second aspect, the present application provides a method for preparing the above-mentioned anti-discoloration rubber composition for colored tires.

[0023] A method for preparing an anti-discoloration rubber composition for a colored tire comprises the following steps: (1) mixing solution-polymerized styrene-butadiene rubber, natural rubber, ethylene-propylene-diene rubber and cyclohexane to prepare a rubber solution; (2) adding modified colored white carbon black to the rubber solution, mixing and dispersing the mixture evenly, stirring and flocculating, and drying the coagulated solid to obtain a masterbatch; (3) adding a mixture of the masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, zinc oxide, protective wax, AFS / LG antioxidant, antistatic agent and YDH-151 silane coupling agent to an internal mixer for mixing, and then placing the mixture on an open mixer for mixing with sulfur and TBBS accelerator to obtain a mixed rubber; and (4) leaving the mixed rubber for 7-8 hours and vulcanizing it on a flat vulcanizer to obtain the anti-discoloration rubber composition for a colored tire.

[0024] The vulcanization conditions are a temperature of 145-150°C, a pressure of 8-10MPa, and a vulcanization time of 25-30min.

[0025] By adopting the above technical solution, the modified colored silica is first mixed with the rubber solution, so that the dispersibility of the modified colored silica in the rubber can be enhanced.

[0026] In summary, this application has the following beneficial effects:

[0027] 1. The present application adopts solution-polymerized styrene-butadiene rubber, natural rubber and EPDM rubber as the rubber matrix, and coloring and reinforcing are performed by adding modified colored white carbon black. By adding auxiliary agents such as polydicyclopentadiene resin, titanium dioxide, YDH-151 silane coupling agent, zinc oxide, stearic acid, sulfur and TBBS accelerator, protective wax, AFS / LG antioxidant, antistatic agent and the like, an anti-discoloration rubber composition for colored tires with excellent heat-oxidative aging resistance, ozone aging resistance, tensile properties, wear resistance, weather resistance and color stability is prepared.

[0028] 2. In the present application, the colorant is preferably added during the preparation of silica using sulfuric acid and water glass to improve the adsorption capacity of silica for the colorant, and (3-mercaptopropyl) triethoxysilane is used to hydrophobically modify and disperse the generated silica, and at the same time, the reaction between the homopolymer of 2-methyl-1,3-butadiene and the mercapto group is utilized to wrap the silica, enhance the stability of the colorant, and prevent the color migration of the colorant caused by the antioxidant and the protective wax, resulting in discoloration; finally, the modified colored silica is added to the rubber solution, and the silica and rubber are connected through the homopolymer of 2-methyl-1,3-butadiene, thereby replacing carbon black to achieve the reinforcement effect on the rubber and enhance its mechanical properties.

[0029] 3. The anti-discoloration rubber composition prepared by the preparation method of the present application has stable color, aging resistance, good tensile properties, strong wear resistance, and excellent weather resistance, and can be used to prepare colored tires. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the embodiments.

[0031] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0032] Example

[0033] Example 1

[0034] The anti-discoloration rubber composition for colored tires comprises the following components in parts by weight: 25 parts of solution-polymerized styrene-butadiene rubber, 55 parts of natural rubber, 20 parts of EPDM rubber, 55 parts of modified colored white carbon black, 13 parts of titanium dioxide, 4 parts of polydicyclopentadiene resin, 9 parts of YDH-151 silane coupling agent, 4 parts of zinc oxide, 3 parts of stearic acid, 2 parts of sulfur and 2 parts of TBBS accelerator, 3 parts of protective wax, 4 parts of AFS / LG antioxidant, and 2 parts of HDC-305 antistatic agent.

[0035] The modified colored white carbon black is prepared by the following steps:

[0036] S1, mix 2L of 0.5mol / L sulfuric acid solution and 0.3g of (3-mercaptopropyl)triethoxysilane, and stir and activate for 15min;

[0037] S2, slowly add 3L of water glass solution with a modulus of 3.2 and a concentration of 0.5mol / L into S1 for reaction, when the pH value of the system is 4, add 2L of 0.3g / L colorant dispersion, and then add the remaining water glass solution, and continue stirring until the reaction system is converted into a gel; the colorant in the colorant dispersion is phthalocyanine blue, and the colorant dispersion also contains a pigment synergist (purchased from Lubrizol Corporation).

[0038] S3, filtering the formed gel, washing with water, drying and crushing to obtain colored white carbon black;

[0039] S4, dispersing colored silica in n-hexane by ultrasonic dispersion at 60°C to prepare a colored silica dispersion with a concentration of 0.1kg / L; at the same time, dissolving a homopolymer of 2-methyl-1,3-butadiene in n-hexane by stirring at 60°C to prepare a homopolymer solution with a concentration of 0.05g / L; then mixing the two in a volume ratio of 1:1, stirring for 5 hours, adding a photoinitiator BDK with a mass fraction of 0.3% of colored silica, continuing to stir for 1 and then stopping, then evaporating the solvent, and irradiating with a 365nm ultraviolet lamp for 30 minutes to obtain a modified colored silica.

[0040] The method for preparing the anti-discoloration rubber composition for colored tires comprises the following steps:

[0041] (1) mixing solution-polymerized styrene-butadiene rubber, natural rubber, EPDM rubber and cyclohexane in an amount 10 times the total mass of the rubber to prepare a rubber solution;

[0042] (2) adding the modified colored silica to the rubber solution, mixing and dispersing the mixture evenly, stirring and flocculating the mixture, and drying the flocculated solid to obtain a masterbatch;

[0043] (3) adding a mixture of masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, zinc oxide, protective wax, AFS / LG antioxidant, HDC-305 antistatic agent and YDH-151 silane coupling agent to an internal mixer for mixing, and then adding sulfur and TBBS accelerator to an open mixer for mixing to obtain a rubber mixture;

[0044] (4) The rubber mixture was allowed to stand for 8 hours and vulcanized on a flat vulcanizer at 148° C. and 9 MPa for 28 minutes to obtain an anti-discoloration rubber composition for colored tires.

[0045] Example 2

[0046] The anti-discoloration rubber composition for colored tires comprises the following components in parts by weight: 30 parts of solution-polymerized styrene-butadiene rubber, 60 parts of natural rubber, 10 parts of EPDM rubber, 40 parts of modified colored silica, 12 parts of titanium dioxide, 3 parts of polydicyclopentadiene resin, 8 parts of YDH-151 silane coupling agent, 3 parts of zinc oxide, 2 parts of stearic acid, 1 part of sulfur and 1 part of TBBS accelerator, 2.5 parts of protective wax, 3 parts of AFS / LG antioxidant and 1 part of HDC-305 antistatic agent.

[0047] The modified colored white carbon black is prepared by the following steps:

[0048] S1, mix 3L of 0.4mol / L sulfuric acid solution and 0.2g of (3-mercaptopropyl)triethoxysilane, and stir and activate for 10min;

[0049] S2, slowly add 3L of water glass solution with a modulus of 3 and a concentration of 0.4mol / L into S1 for reaction, when the pH value of the system is 3, add 1.5L of 0.3g / L colorant dispersion, and then add the remaining water glass solution, and continue stirring until the reaction system is converted into a gel; the colorant in the colorant dispersion is Color Red 144, and the colorant dispersion also contains a pigment synergist (purchased from Lubrizol Corporation).

[0050] S3, filtering the formed gel, washing with water, drying and crushing to obtain colored white carbon black;

[0051] S4, dispersing colored silica in n-hexane by ultrasonic dispersion at 50°C to prepare a colored silica dispersion with a concentration of 0.1kg / L; at the same time, dissolving a homopolymer of 2-methyl-1,3-butadiene in n-hexane by stirring at 50°C to prepare a homopolymer solution with a concentration of 0.05g / L; then mixing the two in a volume ratio of 1.2:1, stirring for 4h, adding a photoinitiator BDK with a mass fraction of 0.2% of colored silica, continuing to stir for 1h and then stopping, then evaporating the solvent, and irradiating with a 365nm ultraviolet lamp for 30min to obtain a modified colored silica.

[0052] The method for preparing the anti-discoloration rubber composition for colored tires comprises the following steps:

[0053] (2) mixing solution polymerized styrene butadiene rubber, natural rubber, EPDM rubber and cyclohexane in an amount 11 times the total mass of the rubber to prepare a rubber solution;

[0054] (2) adding the modified colored silica to the rubber solution, mixing and dispersing the mixture evenly, stirring and flocculating the mixture, and drying the flocculated solid to obtain a masterbatch;

[0055] (3) adding a mixture of masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, zinc oxide, protective wax, AFS / LG antioxidant, HDC-305 antistatic agent and YDH-151 silane coupling agent to an internal mixer for mixing, and then adding sulfur and TBBS accelerator to an open mixer for mixing to obtain a rubber mixture;

[0056] (4) The rubber mixture was allowed to stand for 7 hours and vulcanized on a flat vulcanizer at 145° C. and 8 MPa for 30 minutes to obtain an anti-discoloration rubber composition for colored tires.

[0057] Example 3

[0058] The anti-discoloration rubber composition for colored tires comprises the following components in parts by weight: 20 parts of solution-polymerized styrene-butadiene rubber, 50 parts of natural rubber, 30 parts of EPDM rubber, 60 parts of modified colored white carbon black, 15 parts of titanium dioxide, 5 parts of polydicyclopentadiene resin, 10 parts of YDH-151 silane coupling agent, 5 parts of zinc oxide, 3 parts of stearic acid, 2 parts of sulfur and 2 parts of TBBS accelerator, 4.5 parts of protective wax, 5 parts of AFS / LG antioxidant, and 2 parts of HDC-305 antistatic agent.

[0059] The modified colored white carbon black is prepared by the following steps:

[0060] S1, mix 3.5 L of 0.5 mol / L sulfuric acid solution and 0.4 g of (3-mercaptopropyl)triethoxysilane, and stir to activate for 15 min;

[0061] S2, slowly add 4L of water glass solution with a modulus of 3.5 and a concentration of 0.5mol / L into S1 for reaction, when the pH value of the system is 4, add 2L of 0.5g / L colorant dispersion, and then add the remaining water glass solution, and continue stirring until the reaction system is converted into a gel; the colorant in the colorant dispersion is Pigment Yellow 183, and the colorant dispersion also contains a pigment synergist (purchased from Lubrizol Corporation).

[0062] S3, filtering the formed gel, washing with water, drying and crushing to obtain colored white carbon black;

[0063] S4, dispersing colored silica in n-hexane by ultrasonic dispersion at 55°C to prepare a colored silica dispersion with a concentration of 0.15kg / L; at the same time, dissolving a homopolymer of 2-methyl-1,3-butadiene in n-hexane by stirring at 55°C to prepare a homopolymer solution with a concentration of 0.07g / L; then mixing the two in a volume ratio of 1.2:1, stirring for 6 hours, adding a photoinitiator BDK with a mass fraction of 0.5% of colored silica, continuing to stir for 1.5 hours and then stopping, then evaporating the solvent, and irradiating with a 365nm ultraviolet lamp for 40 minutes to obtain a modified colored silica.

[0064] The method for preparing the anti-discoloration rubber composition for colored tires comprises the following steps:

[0065] (3) mixing solution polymerized styrene butadiene rubber, natural rubber, EPDM rubber and cyclohexane in an amount 12 times the total mass of the rubber to prepare a rubber solution;

[0066] (2) adding the modified colored silica to the rubber solution, mixing and dispersing the mixture evenly, stirring and flocculating the mixture, and drying the flocculated solid to obtain a masterbatch;

[0067] (3) adding a mixture of masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, zinc oxide, protective wax, AFS / LG antioxidant, HDC-305 antistatic agent and YDH-151 silane coupling agent to an internal mixer for mixing, and then adding sulfur and TBBS accelerator to an open mixer for mixing to obtain a rubber mixture;

[0068] (4) The rubber mixture was allowed to stand for 8 hours and vulcanized on a flat vulcanizer at 150° C. and 10 MPa for 25 minutes to obtain an anti-discoloration rubber composition for colored tires.

[0069] Comparative Example

[0070] Comparative Example 1

[0071] The same as Example 1, except that: white carbon black (the preparation process of white carbon black is the same as that of Example 1, except that no colorant dispersion is added) is used instead of modified colored white carbon black, and is directly added to (2), that is: (2) white carbon black is added to the rubber solution, mixed and dispersed evenly, stirred and flocculated, and the coagulated solid is dried to obtain a masterbatch;

[0072] At the same time, phthalocyanine blue and (3-mercaptopropyl) triethoxysilane are directly added to (3), that is: (3) a mixture of masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, phthalocyanine blue, (3-mercaptopropyl) triethoxysilane, zinc oxide, protective wax, AFS / LG antioxidant, HDC-305 antistatic agent and YDH-151 silane coupling agent is added to an internal mixer for mixing, and then put on an open mixer and add sulfur and TBBS accelerator for mixing to obtain a mixed rubber.

[0073] Comparative Example 2

[0074] The same as Example 1, except that: no AFS / LG antioxidant and protective wax are added.

[0075] Comparative Example 3

[0076] The same as Example 1, except that the preparation process of the modified colored silica does not include S4, and the homopolymer of 2-methyl-1,3-butadiene is directly added to (3).

[0077] Performance testing

[0078] 1. The anti-discoloration rubber composition for colored tires prepared by using Example 1 to Example 3 and Comparative Example 1 to Comparative Example 3 was subjected to the following performance tests respectively: a. Tensile performance: tensile strength, elongation at break, 100% tensile stress and 300% tensile stress were tested according to the GB / T528-2009 test standard; b. Wear resistance: abrasion test was carried out according to the GB / T 42122-2022 test standard; c. Heat aging resistance: hot air aging (100°C×48h) tensile coefficient test was carried out according to the GB / T3512-2014 test standard; d. Ozone resistance: static ozone resistance (40°C×72h×50pphm×20%) crack test was carried out according to the GB / T7762-2014 test standard; e. Weather resistance: according to the GB / T3511-2001 test standard, the color change was observed after parking for 3 months. The test results are shown in Table 1.

[0079] Table 1. Performance test results

[0080]

[0081] It can be seen from Table 1 that the anti-discoloration rubber composition for colored tires prepared in Examples 1 to 3 has the best heat-oxidative aging resistance, ozone aging resistance, tensile properties, wear resistance, weather resistance and color stability. In combination with Comparative Examples 1 to 3, it can be seen that a colorant is added in advance during the preparation of silica, and (3-mercaptopropyl)triethoxysilane is used to disperse silica, and a homopolymer of 2-methyl-1,3-butadiene is used to wrap silica to enhance the stability of the colorant and prevent color migration and discoloration caused by antioxidants and protective wax to the colorant. At the same time, the homopolymer of 2-methyl-1,3-butadiene connects silica and rubber, which can replace carbon black to achieve the reinforcement effect on rubber and enhance its mechanical properties.

[0082] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, a person skilled in the art may make non-creative modifications to the present embodiment as needed, and such modifications shall be protected by the patent law as long as they are within the scope of protection claimed in the present application.

Claims

1. An anti-discoloration rubber composition for colored tires, characterized in that: The invention comprises the following compositions in parts by weight: 20-30 parts of solution-polymerized styrene-butadiene rubber, 50-60 parts of natural rubber, 10-30 parts of EPDM rubber, 40-60 parts of modified colored white carbon black, 12-15 parts of titanium dioxide, 3-5 parts of polydicyclopentadiene resin, 8-10 parts of YDH-151 silane coupling agent, 3-5 parts of zinc oxide, 2-3 parts of stearic acid, 1-2 parts of sulfur and 1-2 parts of TBBS accelerator, 2.5-4.5 parts of protective wax, 3-5 parts of AFS / LG antioxidant and 1-2 parts of antistatic agent.

2. The anti-discoloration rubber composition for colored tires according to claim 1, characterized in that: The modified colored white carbon black is prepared by the following steps: S1, mixing sulfuric acid solution and (3-mercaptopropyl) triethoxysilane, stirring and activating for 10-15 minutes; S2, slowly adding water glass solution into S1 for reaction, adding colorant dispersion when the pH value of the system is 3-4, then adding the remaining water glass solution, and continuing to stir until the reaction system is converted into gel; S3, filtering the formed gel, washing with water, drying and crushing to obtain colored white carbon black; S4, dispersing the colored white carbon black in normal hexane at 50-60° C. by ultrasonic dispersion to obtain a colored white carbon black dispersion; at the same time, stirring and dissolving a homopolymer of 2-methyl-1,3-butadiene in normal hexane at 50-60° C. to obtain a homopolymer solution; then mixing the two, stirring for 4-6 hours, adding a photoinitiator BDK, continuing to stir for 1-1.5 hours and then stopping, then volatilizing the solvent, and irradiating with an ultraviolet lamp for 30-40 minutes to obtain the modified colored white carbon black.

3. The anti-discoloration rubber composition for colored tires according to claim 2, characterized in that: The concentration of the sulfuric acid solution is 0.4-0.5 mol / L, the modulus of the water glass solution is 3-3.5, and the concentration is 0.4-0.5 mol / L; the concentration of the colorant dispersion is 0.3-0.5 g / L.

4. The anti-discoloration rubber composition for colored tires according to claim 3, characterized in that: The colorant in the colorant dispersion is an organic pigment, and the colorant dispersion also contains a pigment synergist.

5. The anti-discoloration rubber composition for colored tires according to claim 4, characterized in that: The dosage ratio of the sulfuric acid solution, (3-mercaptopropyl)triethoxysilane, water glass solution and colorant dispersion is (3-3.5) L: (0.2-0.4) g: (3-4) L: (1.5-2) L.

6. The anti-discoloration rubber composition for colored tires according to claim 5, characterized in that: The volume ratio of the colored silica dispersion to the homopolymer solution is (1-1.2):

1.

7. The anti-discoloration rubber composition for colored tires according to claim 6, characterized in that: The concentration of the colored white carbon black dispersion is 0.1-0.2 kg / L, and the concentration of the homopolymer solution is 0.05-0.08 g / L.

8. The anti-discoloration rubber composition for colored tires according to claim 7, characterized in that: The added amount of the photoinitiator BDK is 0.2-0.5% of the mass fraction of the colored white carbon black.

9. The method for preparing the anti-discoloration rubber composition for colored tires according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) mixing solution polymerized styrene-butadiene rubber, natural rubber, ethylene-propylene-diene rubber and cyclohexane to prepare a rubber solution; (2) adding modified colored white carbon black to the rubber solution, mixing and dispersing the mixture evenly, stirring and flocculating, and drying the coagulated solid to obtain a masterbatch; (3) adding a mixture of the masterbatch, stearic acid, polydicyclopentadiene resin, titanium dioxide, zinc oxide, protective wax, AFS / LG antioxidant, antistatic agent and YDH-151 silane coupling agent to an internal mixer for mixing, and then placing the mixture on an open mixer and adding sulfur and TBBS accelerator for mixing to obtain a rubber mixture; (4) allowing the rubber mixture to stand for 7-8 hours, and vulcanizing the mixture on a flat vulcanizer to obtain an anti-discoloration rubber composition for color tires.

10. The method for preparing the anti-discoloration rubber composition for colored tires according to claim 9, characterized in that: The vulcanization conditions are a temperature of 145-150°C, a pressure of 8-10MPa, and a vulcanization time of 25-30min.

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