PROCESS FOR OBTAINING COMPOUND TROUGH PRECIPITATION OF SILICA INTO LATEX

摘要

Although the addition of precipitated silica confers peculiar mechanical properties to rubber compounds enabling its application in several areas, its incorporation process is extremely complex due to the difficult dispersion of silica in the elastomeric matrix, equipment wear and risk to the operators. The silica sequential precipitation process from any alkali silicate in an emulsion of latex of any origin not only enables the homogeneous distribution of silica in the elastomeric matrix, but also decreases the costs from the reduced wear of the rubber processing equipment and reduced production time, since the silica is already homogeneously incorporated into the matrix, reduction of risks due to the absence of fine particulates in the process/production environment of rubber compounds. Due to raw materials used: sulfuric acid at low concentrations and commercial purity, alkali silicate of any origin (mineral, ashes from rice husk, etc) and the production process is single, i.e., two manufacturing lines are not necessary: one for production of precipitated silica and another for production of rubber, the product cost becomes competitive, enabling thus the extensive employment and production in any conventional equipment of processing of rubber compounds, besides enabling the employment of high contents of silica incorporated above 50 phr, which currently is not possible due to dispersion problems and equipment wear.