Accelerator is a kind of compound that can improve the vulcanization speed and cross-linking degree of sulfur yellow and other vulcanizing agents. Its main role is to speed up the vulcanization speed, shorten the vulcanization time, improve the physical and mechanical properties of the rubber, reduce the amount of sulfur yellow and avoid sulfur yellow frosting. There are many kinds of accelerators, such as dithiocarbamates, thiazoles, sulfonamides, guanidines, thioureas, xanthates, aldehydes and amines.
The most commonly used accelerators are generally the TMTD, TMTM, TETD, which have a high tendency to scorch, high tensile stress and tensile strength. DM M of thiazole class is a widely used and inexpensive accelerator which has the advantages of good vulcanization flatness, aging resistance, not easy to crack, good wear resistance, etc. Adding a small amount of quat promoter can rapidly improve the vulcanization speed.
Although TMTD accelerator has fast sulfur speed and high vulcanization degree, it has poor processing safety and is easy to scorch and over sulfur; thiazole and sub-sulfonamide vulcanization rubber has high tensile strength and good wear resistance, heat resistance and aging resistance, and the flatness of vulcanization is also good. also good. In order to further improve the speed of vulcanization, to achieve a higher value, the design of the vulcanization system in the rubber formulation often uses 2-3 accelerators and to receive the effect of complementing each other or activation, so as to adapt to the processing process and improve product quality needs.