The invention relates to a precipitated silica production process that includes a precipitation reaction between a silicate and an acid, in which the acid used in at least one of the steps of the process is a concentrated acid.

Precipitated silica production process

Provided is a hydrophilic precipitated silica which is well suited to use in silicone rubber formulations (RTV-1, RTV-2, HTV and LSR), particularly well suited to use in HTV silicone rubber formulations. It has a BET surface area of 185˜260 m2/g, a CTAB surface area of 100˜160 m2/g, a BET/CTAB ratio of 1.2˜2.6, and a conductivity of <250 μS/cm. Also provided are a process for producing the precipitated silica and the use of the precipitated silica for thickening and reinforcing silicone rubber formulations.

Hydrophilic silica as filler for silicone rubber formulations

The present invention is directed to a process for producing treated filler including (a) treating a slurry of untreated filler which has not been previously dried, with a treating composition including an organosilane material of specified structure (I); and (b) drying the treated filler slurry. The present invention also is directed to treated filler prepared by the process, as well as rubber compounding compositions and tires including the treated filler.

Treated fillers, compositions containing same, and articles prepared therefrom

The invention concerns a novel method for preparing a precipitated silica, wherein: a silicate is reacted with at least one acidifying agent so as to obtain a precipitated silica suspension; the precipitated silica suspension is filtered in order to obtain a filter cake; the filter cake is subjected to a disintegration operation involving the addition of an aluminium compound; following the disintegration operation, a drying step is carried out. The invention is characterized in that, during or after the disintegration operation, methylglutaric acid is added to the filter cake. The invention also concerns novel precipitated silicas and their uses.

Novel method for preparing precipitated silicas, novel precipitated silicas and their uses, in particular for strengthening polymers

The invention relates to a method for the production of precipitated silica, in which a silicate is reacted with an acidifying agent in order to obtain a suspension of precipitated silica (S1), followed by: a separation step in order to obtain a cake, a cake-disintegration step in order to obtain a suspension of precipitated silica (S2), and a suspension drying step. According to the invention, a membrane concentration step is performed between the disintegration step and the drying step.

Method for the production of precipitated silica, comprising a membrane concentration step

The invention relates to a novel silica production method comprising the reaction of a silicate with at least one acid, in which the acid used in at least one of the steps is a concentrated acid, preferably selected from the group containing sulphuric acid having a concentration of at least 80 wt.-%, in particular at least 90 wt.-%, acetic acid or formic acid having a concentration of at least 90 wt.-%, nitric acid having a concentration of at least 60-wt.%, phosphoric acid having a concentration of at least 75 wt.-%, hydrochloric acid having a concentration of at least 30 wt.-%.

Precipitated-silica production method

Carboxylic acids are employed during the preparation of precipitated silica or a suspension of precipitated silica to provide precipitated silicas with low water uptake, which are useful, for example, as reinforcing fillers for silicon matrices.

Preparation of precipitated silicas useful as fillers in silicon matrices

L'invention concerne l'utilisation d'acide carboxylique lors de la preparation de silice precipitee ou de suspension de silice precipitee, les silices precipitees obtenues, en particulier a faible reprise en eau, utilisables notamment comme charge renforcante dans les matrices silicones.

Procede de preparation de silice precipitee, silice precipitee obtenue et utilisations, notamment comme charge dans les matrices silicones

A precipitated silica production process that includes a precipitation reaction between a silicate and an acid is described, in which the acid used in at least one of the steps of the process is a concentrated acid.

Joël Racinoux

Papers

Precipitated silica production process

Precipitated-silica production method

Preparation of precipitated silicas useful as fillers in silicon matrices

Procede de preparation de silice precipitee, silice precipitee obtenue et utilisations, notamment comme charge dans les matrices silicones

Novel precipitated silica production process