New process for the preparation of precipitated silica, new precipitated silicas containing aluminum and their use for the reinforcement of elastomers

摘要

The invention relates to a new process for the preparation of precipitated silica which has an excellent 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 140 and 200 m²/g, a BET specific surface of between 140 and 200 m²/g, a DOP oil uptake lower than 300 ml/100 g, a median diameter, after disintegration with ultrasound, smaller than 3 m, an ultrasonic disintegration factor higher than 10 ml and an aluminum content of at least 0.35% by weight. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers.