3. Mooney viscosity of rubber compound
The ability of silica to form a gel is comparable to that of carbon black. Therefore, when the white carbon black is mixed, the Mooney viscosity of the rubber is increased, so that the processing property is deteriorated, so in the formulation containing silica. The choice and amount of softener is important. Paraffin hydrocarbons, naphthenes and aromatic hydrocarbons are often added to the IIR. The amount varies depending on the amount of silica and the Mooney viscosity, and is generally 15-30%. In NR, the softening effect of plant softeners such as rosin oil and tall oil is the best, the effect of synthetic softener is not great, and the softening effect of mineral oil is the lowest.

4. Vulcanization rate of rubber compound
The surface of the white carbon black particles has a large number of micropores, and has a strong adsorption effect on the vulcanization accelerator, so that the vulcanization is obviously delayed. In order to avoid this phenomenon, on the one hand, the amount of the promoter can be appropriately increased; on the other hand, the active agent can be used to preferentially adsorb the active agent on the surface of the silica, thus reducing its adsorption to the promoter.

The active agent is generally a nitrogen- or oxygen-containing amine, an alcohol, or an alcohol amine low molecular compound. Amines are more suitable for NR, such as diethanolamine, triethanolamine, butanediamine, hexamethylenetetramine, and the like. For SBR, alcohols are more suitable, such as hexanetriol, diethylene glycol, glycerol, polyethylene glycol, and the like. The amount of active agent should be determined according to the amount of white carbon black, the pH value and the rubber type. The general dosage is 1 to 3% of white carbon black.