| 摘要 |
The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m2/g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 ANGSTROM represents less than 50% of the pore volume consisting of the pores of diameters smaller than or equal to 400 ANGSTROM , a zinc content of between 1 and 5% by weight and by the fact that the number N of molecules of stearic acid consumed per nm2 of silica surface, when stearic acid is reacted with the said silica in xylene for 2 hours at 120 DEG C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers especially for improving their rheological properties. |
