Abstract: The invention relates to a novel method of preparing silicas and to highly-structured silicas having the following characteristics: a specific surface area CTAB (SCTAB) of between 40 and 525 m2/g; a specific surface area BET (SBET) of between 45 and 550 m2/g; an object size distribution width Ld ((d84?d16)/d50), which is measured by XDC particle size analysis after deagglomeration with ultrasound, of at least 0.91; and a pore-size distribution such that ratio V(d5?d50)/V(d5?d100) is at least 0.66. The invention also relates to the use of said silicas as polymer reinforcing fillers.

Abstract: Diene rubber compositions are described containing a diene elastomer, a reinforcing inorganic filler, and a coupling agent wherein the inorganic filler includes a silica having the following characteristics: (a) a BET specific surface area between 45 and 400 m2/g; (b) a CTAB specific surface area between 40 and 380 m2/g; (c) an average particle size (by mass), dw, of 20 to 300 nm; and at least one of the following characteristics, preferably two and more preferably all three: (d) a particle size distribution such that dw?/CTAB)?30; (e) a porosity which meets the criterion L/FI??0.0025 CTAB+0.85; (f) an amount of silanols per unit of surface area, NSiOH/nm2; NSiOH/nm2??0.027 CTAB+10.5. These diene rubber compositions can be used for the manufacture of tires or of semi-finished products intended for tires.

Abstract: The invention concerns a method for preparing precipitated silica comprising reaction of a silicate with an acidifying agent whereby is obtained a precipitated silica suspension, then separating and drying said suspension. The invention is characterised in that said method comprises the following process: adding to the reaction medium at least a compound A of aluminium; then adding to the reaction medium an acidifying agent, said separation comprising filtration and disintegration of the cake derived from said filtration, said disintegration being preferably carried out in the presence of at least a compound B of aluminium. The thus prepared silica precipitates are particularly well adapted for use as reinforcing elastomer filler.

Abstract: A method of forming a zinc or indium oxide layer at the surface of phosphors deposited by serigraphy on a substrate, including the steps of adding the grains to a solution of a serigraphy binder in water, dissolving in the solution a zinc or indium nitrate, performing the serigraphy deposition, and annealing.