There is disclosed a method of producing etched non-porous particles. The method includes, in some examples, coating a non-porous particle with a hydrophilic polymer and treating the coated particle with acid or base. Also provided is etched non-porous particles capable of separating a variety of analytes, including biomolecules.

A reactive silicone composition including component (S) and component (T) below, the component (S): a reactive silicone compound including a condensation product of a diaryl silicate compound represented by Formula [1] and a silicon compound represented by Formula [2],

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(wherein Ar.sup.1 and Ar.sup.2 each independently represent a phenyl group optionally substituted by a C.sub.1-6 alkyl group and X represents a hydrolyzable reactive group), the component (T): modified titanium oxide-containing oxide colloidal particles produced by bonding an organosilicon compound to surfaces of titanium oxide-containing oxide colloidal particles (C) having an average particle diameter of from 2 to 100 nm and including, as a core, titanium oxide-containing metal oxide colloidal particles (A), surfaces of which are coated with a coating including silicon dioxide- and tin oxide-containing composite oxide colloidal particles (B).

The invention relates to a novel process for preparing a precipitated silica, in which: a silicate is reacted with an acidifying agent, so as to obtain a suspension of precipitated silica, said suspension of precipitated silica is filtered, so as to obtain a filter cake, said filter cake is subjected to a liquefaction operation comprising the addition of an aluminum compound, after the liquefaction operation, a drying step is performed, characterized in that at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation. The invention also relates to novel precipitated silicas and to uses thereof.

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.

Provided are a composition including at least one selected from silica particles in a shape in which a plurality of spherical silicas are connected in a bead shape or silica particles in a shape in which a plurality of spherical silicas are connected in a plane, and a solvent, in which at least a part of hydroxy groups on a surface of the silica particles is treated with a hydrophobizing treatment agent which reacts with the hydroxy group; a film formed of the composition; a structural body; a color filter; a solid-state imaging element; and an image display device.

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 preparing a precipitated silica, to precipitated silicas, and to uses thereof. The process of the invention generally includes reacting a silicate with an acidifying agent, so as to obtain a suspension of precipitated silica; filtering the precipitated silica to obtain a filter cake; subjecting the filter cake to a liquefaction operation to form a second filter cake; and drying the second filter cake. In the process of the invention, at least one polycarboxylic acid is added to the filter cake, during or after the liquefaction operation.

The present invention provides a surface-treated silica filler for suppressing an increase in viscosity when added to a resin composition used for applications such as a semiconductor sealing material, and the resin composition containing the surface-treated silica filler. The surface-treated silica filler of the present invention is surface-treated with a basic substance having an acid dissociation constant (pKa) of its conjugate acid of 9.4 or more.

A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90≤F.sub.BEFORE/F.sub.AFTER≤1.10, and 5≤F.sub.SINTERING/F.sub.BEFORE≤20, in which F.sub.BEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method, F.sub.AFTER represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles after washing, which is obtained from the pore distribution curve in the nitrogen gas adsorption method, and F.sub.SINTERING represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from the pore distribution curve in the nitrogen gas adsorption method.

Aqueous dispersion containing a hydrophilic metal oxide powder comprising a metal oxide and a surface modification of the metal oxide, wherein a) the metal oxide is selected from the group consisting of TiO.sub.2, ZrO.sub.2, SiO.sub.2, Al.sub.2O.sub.3, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4, Sb.sub.2O.sub.3, WO.sub.3, CeO.sub.2 and mixed oxides thereof and b) the surface modification b1) comprises silicon atoms and aluminum atoms and b2) the silicon atoms are at least partly bonded to a hydrocarbon radical via a C atom and b3) the Al/Si molar ratio of the surface modification is 1:2-1:20.