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CN-121975192-A - High weather-resistant low-resistance rubber composition, preparation method and tire

CN121975192ACN 121975192 ACN121975192 ACN 121975192ACN-121975192-A

Abstract

The invention belongs to the technical field of tire rubber materials, and particularly discloses a high weather-resistant low-resistance rubber composition, a preparation method and application thereof, wherein the rubber composition is introduced with a novel modified metal material, and a compact dopamine-based chelating agent molecule protective film is formed on the surface of the metal material, so that the novel modified metal material has strong chelating, free radical capturing, interface tackifying and electron migration promoting effects, meanwhile, a uniform conductive network is formed by utilizing the cooperation of the modified metal and the conductive carbon black, so that the rubber composition can keep low resistivity, can obviously inhibit the rubber aging catalyzed by metal ions, and the tire prepared by the composition can obviously prolong the service life while meeting the severe electrostatic conductive requirement, and has low rolling resistance, excellent mechanical property and excellent weather resistance.

Inventors

  • LI XIAOXIAO
  • CHEN GUANTING

Assignees

  • 厦门正新橡胶工业有限公司

Dates

Publication Date
20260505
Application Date
20251229

Claims (10)

  1. 1. The high weather-proof low-resistance rubber composition is characterized by comprising, by mass, 100 parts of unsaturated nonpolar rubber, 5-10 parts of dopamine-based chelating agent modified metal materials, 5-10 parts of conductive carbon black, 10-20 parts of wear-resistant carbon black, 0.5-1 part of carbon black dispersing agent, 30-50 parts of white carbon black, 2.5-5 parts of silane coupling agent, 20-30 parts of processing oil, 3-5 parts of anti-aging agent, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 2.5-3 parts of sulfur and 0.5-1.0 part of accelerator.
  2. 2. The high weather resistance low resistance rubber composition according to claim 1, wherein the conductive carbon black is a combination of a first conductive carbon black and a second conductive carbon black in a mass ratio of 4-9:1, the first conductive carbon black has a nitrogen adsorption specific surface area of 200-300 m 2 /g, a DBP oil absorption value of 150-250 cm 3 /100 g, the second conductive carbon black has a nitrogen adsorption specific surface area of 800-1400m 2 /g, and a DBP oil absorption value of 300-550 cm 3 /100 g.
  3. 3. The high weather resistance low resistance rubber composition according to claim 1, wherein the accelerator is a first accelerator and a second accelerator are used together, the first accelerator is N-tert-butyl-2-benzothiazole sulfenamide and/or N, N-dicyclohexyl-2-benzothiazole sulfenamide, the amount is 0.3 to 0.8 parts by mass, and the second accelerator is diphenylguanidine and/or 1-o-tolylbiguanide, the amount is 0.2 to 0.7 parts by mass.
  4. 4. A dopamine-based chelant modified metal material for a high weather resistance and low electrical resistance rubber composition according to any one of claims 1 to 3, which comprises conductive metal powder, wherein a coating layer formed by a dopamine-based chelant is bonded to the surface of the metal powder.
  5. 5. A method of preparing a dopamine-based chelator modified metallic material as defined in claim 4, wherein the step of surface modifying the metallic material with a dopamine-based chelator comprises the steps of: (1) Firstly, washing metal powder with 0.1mol/L dilute hydrochloric acid or dilute sulfuric acid to remove a surface oxide layer, then washing with ethanol or acetone, and adding deionized water to prepare 1.0-2.0g/mL metal aqueous dispersion; (2) Adding deionized water and an ethanol mixed solvent to prepare a dopamine-based chelating agent treatment solution, wherein the concentration of the dopamine-based chelating agent in the dopamine-based chelating agent treatment solution is 0.02-0.05g/mL; (3) Mixing and stirring the aqueous metal dispersion liquid and the dopamine-based chelating agent treatment liquid in a volume ratio of 1:1 at a constant temperature of 50-60 ℃ for 10-20min; (4) And (5) carrying out suction filtration, washing and vacuum drying to obtain the dopamine-based chelating agent modified metal material.
  6. 6. The method for producing a dopamine-based chelator-modified metal material as defined in claim 5, wherein the metal powder in step (1) is one or a combination of two or more of copper powder, iron powder, aluminum powder, zinc powder, silver powder and manganese powder, and the particle size of the metal powder is 0.01-2. Mu.m.
  7. 7. The method for producing a dopamine-based chelator-modified metal material as defined in claim 5, wherein the method for producing a dopamine-based chelator in step (2) comprises the steps of: (2-1) dissolving the dopamine derivative, the conductive organic molecule and the basic inorganic salt in a molar ratio of 1:1.2-1.4:2.0-3.0 in 100-150ml of anhydrous N, N-dimethylformamide or acetonitrile solvent; (2-2) stirring and reacting for 4-8h at 60-80 ℃ under the protection of nitrogen; And (2-3) after the reaction is finished, cooling, filtering to remove inorganic salts, concentrating and purifying to obtain the dopamine-based chelating agent.
  8. 8. The method for producing a chelator-modified metal material according to claim 7, wherein in the step (2-1), the dopamine derivative is one or more of dopamine hydrochloride (3, 4-dihydroxyphenethylamine hydrochloride), dopamine hydrobromide (3, 4-dihydroxyphenethylamine hydrobromide), 6-hydroxydopamine hydrochloride (2, 4, 5-trihydroxybenzylamine hydrochloride) and 6-hydroxydopamine hydrobromide (2, 4, 5-trihydroxybenzylamine hydrobromide), the conductive organic molecule is a benzimidazole derivative and/or a pyridine derivative, the benzimidazole derivative is one or more of 2-chloromethylbenzimidazole, 2- (2-chloroethyl) benzimidazole, and the pyridine derivative is one or more of 2-chloromethylpyridine, 4-chloromethylpyridine, pyridine p-toluenesulfonate and N-octylpyridine bromide.
  9. 9. A method for preparing the high weather resistance and low resistance rubber composition according to any one of claims 1 to 3, wherein the dopamine-based chelant modified metal material according to claim 4 is added for mixing, comprising the steps of: (1) One-stage mixing, namely, using an internal mixer, wherein the initial temperature is 40-80 ℃, the rotating speed is 40-80 rpm, and the pressure is 0.3-0.5MPa. The first action, mixing 20-25s of the unsaturated nonpolar rubber composition, the second action, mixing 20-25s of the dopamine-based chelating agent modified metal material, the third action, mixing 20-25s of conductive carbon black, 2/3 carbon black and carbon black dispersing agent, the fourth action, cleaning and heating to 140-145 ℃ at a variable speed, mixing 40-60s, and discharging; (2) And two-stage mixing, namely, using an internal mixer, wherein the initial temperature is 40-80 ℃, the rotating speed is 40-80 rpm, and the pressure is 0.3-0.5MPa. Mixing the materials obtained by the first-stage mixing for 50-60s, mixing the materials obtained by the second-stage mixing for 40-50s by adding white carbon black, a silane coupling agent, residual carbon black, zinc oxide, stearic acid and an anti-aging agent, mixing the materials obtained by the third-stage mixing for 40-50s by adding processing oil, cleaning and heating to 150-155 ℃ at a variable speed, mixing for 100-120s, and discharging; (3) And final mixing, namely mixing by using an internal mixer at the initial temperature of 40-50 ℃ and the rotating speed of 30-50 r/min and the pressure of 0.3-0.5MPa. The preparation method comprises the steps of mixing 80% -90% of materials obtained by two-stage mixing for 20-25s, mixing the rest materials obtained by two-stage mixing, sulfur and an accelerator for 20-25s, cleaning and mixing for 30-40s, cleaning and mixing for 95-100 ℃ for discharging, discharging by an open mill, and cooling to obtain the target composition.
  10. 10. A tire, wherein the tread comprises the high weather resistance and low resistance rubber composition as claimed in any one of claims 1 to 3.

Description

High weather-resistant low-resistance rubber composition, preparation method and tire Technical Field The invention belongs to the technical field of tire rubber materials, and particularly relates to a high-weather-resistance low-resistance rubber composition, a preparation method and a tire. Background The tyre rubs with the road surface to generate static electricity in the running process, if the conductivity is insufficient, static electricity in the vehicle is accumulated to cause potential safety hazards such as fire and the like, so the conductivity of the tyre is a factor which cannot be ignored in running safety. The existing tire mainly uses insulating rubber as a matrix, relies on metal cords and carbon black to construct a conductive path, and can meet the general application. However, in the places where inflammable and explosive dangerous goods such as gunpowder, oil, chemical industry and the like are produced and used, higher requirements are put on the conductivity of the tire. Meanwhile, in order to meet the requirements of the label method on the rolling resistance and wet skid performance indexes of the tire, the use of white carbon black instead of carbon black is a trend, and the electric conductivity of the tire is further weakened by the insulativity of the white carbon black. In order to improve the conductivity of the tire, the industry tries to add metal conductive powder into the formula, but has the defects that ① metal powder has poor compatibility with rubber, large hysteresis and easy agglomeration to form foreign matters, and ② metal ions which damage the flexibility and fatigue resistance of the tire are easy to catalyze the oxidation of the rubber, seriously damage the aging resistance of the tire and aggravate early cracks, hardening and attenuation of the conductivity; The existing scheme for passivating metals by using metal chelating agents can improve ageing resistance, but still has the defects that ① chelating agents are poor in compatibility with rubber, ② chelating agents are easy to migrate and separate out, and the thicker fully-coated passivation layer has larger damage to metal conductivity and ③, and the existing commercial chelating agents have narrow applicability and are only effective on specific metals. Therefore, there is a need for a novel conductive rubber composition formulation that combines the properties of conductivity, compatibility, aging resistance, etc. required for tire rubber. Disclosure of Invention The invention aims to overcome the defects of the prior art, provides a high weather-resistant low-resistance rubber composition, a preparation method and a tire thereof, and solves the problems of compatibility, conductivity, aging resistance, application range, process complexity, cost and the like in the prior art. In order to achieve the aim, one of the technical schemes of the invention is that the high weather-resistant low-resistance rubber composition comprises, by mass, 100 parts of unsaturated nonpolar rubber, 5-10 parts of dopamine-based chelating agent modified metal materials, 5-10 parts of conductive carbon black, 10-20 parts of wear-resistant carbon black, 0.5-1 part of carbon black dispersing agent, 30-50 parts of white carbon black, 2.5-5 parts of silane coupling agent, 20-30 parts of processing oil, 3-5 parts of anti-aging agent, 2-5 parts of zinc oxide, 1-3 parts of stearic acid, 2.5-3 parts of sulfur and 0.5-1.0 part of accelerator. In a preferred embodiment of the present invention, the unsaturated nonpolar rubber is one or a combination of two or more of natural rubber, styrene and butadiene copolymer, polyisoprene rubber, and polybutadiene rubber. In a preferred embodiment of the present invention, the conductive carbon black is used in a mass ratio of 4 to 9:1 of a first conductive carbon black having a nitrogen adsorption specific surface area of 200 to 300 m 2/g and a DBP oil absorption value of 150 to 250 cm 3/100 g and a second conductive carbon black having a nitrogen adsorption specific surface area of 800 to 1400m 2/g and a DBP oil absorption value of 300 to 550 cm 3/100 g. In a preferred embodiment of the invention, the wear resistant carbon black has a nitrogen adsorption specific surface area of 70-130 m 2/g and a DBP oil absorption value of 90-140cm 3/100 g; In a preferred embodiment of the present invention, the accelerator is a first accelerator and a second accelerator are used in combination, the total amount of the first accelerator is 0.5 to 1.0 part, the first accelerator is N-tert-butyl-2-benzothiazole sulfenamide and/or N, N-dicyclohexyl-2-benzothiazole sulfenamide, the amount of the first accelerator is 0.3 to 0.8 part, and the second accelerator is diphenyl guanidine and/or 1-o-tolylbiguanide, the amount of the second accelerator is 0.2 to 0.7 part. The second technical scheme of the invention is that the dopamine-based chelating agent modified metal material for the high-weather-resistance low-res