Silica is one of the inorganic fillers. Since the affinity of the inorganic filler to the rubber-based organic polymer is lower than that of the carbon black, the white carbon black is difficult to be individually dispersed in the primary structure in the rubber, and mainly It is a form in which many monomers or aggregates are agglomerated together. In essence, it is incapable of being dispersed in rubber in a single primary structure by mixing conditions. In addition, inorganic filler particles are not easily The rubber macromolecules are wetted, and the affinity between the particles is often greater than the affinity between the rubber and the particles, so the filler particles tend to agglomerate, and the particles dispersed in the rubber tend to agglomerate. Silica has a porous structure and a high structural structure, and has a large interaction force during kneading, and most of the rubber can be dispersed in the form of aggregates during kneading, so that it is less likely to cause self-agglomeration and has good dispersibility. It has a favorable side compared with other inorganic fillers. Generally, the silica used in the shoe material can be surface-treated without using a polyol or a silane coupling agent in advance. However, due to the stronger surface activity, a large number of hydrophilic groups exist, and when the moisture is too low, hydrogen bonding is liable to occur, which makes it difficult to mix into the rubber. When the moisture rises too high, the interface with the rubber is often poorly combined, so that there is a gap between the white carbon black and the rubber than the other fillers. If the surface treatment is not performed, the reinforcing performance also decreases.
Generally, a polyol or a silane coupling agent may be added during the kneading, and the addition of the white carbon black to the accelerator may not only reduce the adsorption of the accelerator, but also improve the affinity of the rubber and the rubber compound. However, the surface energy of the silica after the addition of the active agent and the coupling agent is necessarily decreased, and its adsorption property is lowered, which is disadvantageous to the formation of a binding gel during the mixing of the silica, which is disadvantageous to the reinforcement, but at the same time The effect between the particles is also lowered, so that the wettability between the silica and the polymer such as rubber is increased, which is advantageous for reinforcing, and the effect is often the above unfavorable and advantageous comprehensive result. Therefore, whether using a silane coupling agent or a combination of polyols, the amount must be appropriate.