At present, the prevailing high-speed and overloaded vehicle operating conditions put forward higher requirements on the inherent quality of heavy-duty bias tires, especially to avoid the heat generated by fatigue deformation during long-term driving. The phenomenon of shoulder void caused by the destruction of the joint surface of the material and the cord. The tensile stress of each component of the bias tire produced by our factory increases sequentially from the inner layer to the crown (in a "stepped shape"), but due to the low tensile stress of the original inner and outer layer rubber (the inner layer 4 ~ 5MPa, the outer layer rubber is about 6MPa), which is quite different from the tensile stress of the buffer layer rubber (about 10MPa), which makes the tire easily deformed due to insufficient rigidity during driving. Therefore, it is necessary to redesign the compound formula of the inner and outer layers of the tire to appropriately increase the tensile stress of the compound.

The cross-linking structure of vulcanizing agent DTDM is mainly polysulfide bond, and the polysulfide bond energy is small, unstable, and easy to change, so its heat aging resistance is poor, and vulcanization reversion is prone to occur during tire use. The original phenomenon, thus affecting the actual service life of the tire. To this end, we decided to use a semi-effective vulcanization system in the formulation of the tire inner and outer layers, and its cross-linking bonds are mainly monosulfide bonds and disulfide bonds, thereby reducing the heat generation of the rubber compound and improving the thermal stability of the compound. At the same time, the tensile stress of the rubber compound is improved, so the tensile stress of the inner and outer layers of the rubber compound can be improved without increasing the amount of carbon black to meet the design requirements. When choosing the semi-effective vulcanization system, the vulcanizing agent DTDM and the accelerator NOBS are used together. The vulcanizing agent DTDM has a sulfur mass fraction of about 0.27, which can decompose active sulfur at the vulcanization temperature, and is safe to operate. When used together with some common vulcanizing agents, the vulcanization speed can be increased.