A method for producing new nanomaterials, 80 to 100 mol % of which are composed of TiO.sub.2 and 0 to 20 mol % are composed of another metal or semi-metal oxide that has a specific surface of 100 to 300 m.sup.2.g.sup.1and 1 to 3 hydroxyl groups per nm.sup.2.

Silica particles having a d50 median particle size from 8 to 20 m, a sphericity factor (S.sub.80) of at least 0.9, a BET surface area from 0.1 to 8 m.sup.2/g, a total mercury intrusion pore volume from 0.35 to 0.8 cc/g, and a loss on ignition from 3 to 7 wt. %, are disclosed, as well as methods for making these silica particles, and dentifrice compositions containing the silica particles.

Silica particles having a d50 median particle size from 8 to 20 m, a sphericity factor (S.sub.80) of at least 0.9, a BET surface area from 0.1 to 8 m.sup.2/g, a total mercury intrusion pore volume from 0.35 to 0.8 cc/g, and a loss on ignition from 3 to 7 wt. %, are disclosed, as well as methods for making these silica particles, and dentifrice compositions containing the silica particles.

The present invention discloses glycoxy silanes as a source of silica and silica precipitated by advantageous chemical reactions preferably beginning with biogenic silica. Alkoxy COS.sub.1 are hydrolyzed in a controlled fashion to nucleate formation of nanoparticles of silica. The growth rate of the particles is controlled by various parameters such that particles of known sizes, size distributions, specific surface areas and pore sizes and size distributions are recovered.

The invention relates to matted UV varnishes comprising silicon dioxide, the surface thereof having been modified by means of treatment with a multiple bond organopolysiloxane so as to be particularly well-suited for use as a matting material for UV varnishes, and to a method for producing same.

The invention relates to matted UV varnishes comprising silicon dioxide, the surface thereof having been modified by means of treatment with a multiple bond organopolysiloxane so as to be particularly well-suited for use as a matting material for UV varnishes, and to a method for producing same.

Disclosed herein is a continuous process for preparing a silica product, comprising: (a) continuously feeding an acidulating agent and an alkali metal silicate into a loop reaction zone comprising a stream of liquid medium; wherein at least a portion of the acidulating agent and the alkali metal silicate react to form a silica product in the liquid medium of the loop reaction zone; (b) continuously recirculating the liquid medium through the loop reaction zone; and (c) continuously discharging from the loop reaction zone a portion of the liquid medium comprising the silica product. Silica products and dentifrice compositions comprising the silica products are also disclosed. A continuous loop reactor is also disclosed.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, in the absence of an aluminium compound; wherein a mixture of polycarboxylic acids is added to the filter cake, during or after the liquefaction operation. It also relates to novel precipitated silicas and to their uses.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, in the absence of an aluminium compound; wherein a mixture of polycarboxylic acids is added to the filter cake, during or after the liquefaction operation. It also relates to novel precipitated silicas and to their uses.

The invention relates to a process for the preparation of a novel precipitated silica, wherein: a silicate is reacted with an acidifying agent, so as to obtain a silica suspension; said silica suspension is filtered, so as to obtain a filter cake; said filter cake is subjected to a liquefaction operation, optionally in the presence of an aluminium compound; wherein at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation. It also relates to a novel precipitated silica and to its uses.