A retroreflective powder coating composition including a film-forming resin and a plurality of retroreflective particles. The film-forming resin including a base particle, a metallic coating, a pigment coating composition, and a substantially transparent siloxane coating.

Disclosed in certain embodiments are polymer compositions comprising closed-cell metal oxide particles and methods of preparing the same. In at least one embodiment, a closed-cell metal oxide particle comprises a metal oxide matrix defining an array of closed-cells. Each closed-cell encapsulates a media-inaccessible void volume. The outer surface of the closed-cell metal oxide particle is defined by the array of closed-cells.

The present invention relates to the use of copolymers obtained by polymerization of maleic anhydride and of styrene, for preparing particles of mineral matter having a weight-loss start temperature greater than or equal to 220 C., as measured by thermogravimetric analysis (TGA) between 150 C. and 600 C.

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.

Disclosed are a silica sol composition including silica, an anionic dispersant, a cationic dispersant, an epoxy silane coupling agent, and an organic solvent, and a method for preparing the same. In the silica sol composition, a uniform surface modification of silica particles may be achieved by using an anionic dispersant and a cationic dispersant, and it is possible to effectively enhance the compatibility between a silica filler whose surface is modified with an epoxy group and a resin which is an underfill composition.

A porous plate-shaped filler is a plate shape having an aspect ratio of 3 or more, and has a minimum length of 0.1 to 50 m and a porosity of 20 to 90%. Furthermore, the porous plate-shaped filler 1 includes plate-shaped pores 2 having an aspect ratio of 1.5 or more. Consequently, in the porous plate-shaped filler, a thermal conductivity is low. The heat insulation film includes the porous plate-shaped filler, whereby a heat insulation effect of the heat insulation film can improve.

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, 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 flake-like substrate has an average particle size of 0.1 to 11 m and an average thickness of 0.1 to 1.0 m and has a particle size distribution in which D9935 m, D10045 m, 3<D90/D10, and (D90D99D100)/D503200 are satisfied, where D10 is a particle size at which a cumulative volume fraction from a smaller-particle side reaches 10%, D50 is a particle size at which the cumulative volume fraction from the smaller-particle side reaches 50%, D90 is a particle size at which the cumulative volume fraction from the smaller-particle side reaches 90%, D99 is a particle size at which the cumulative volume fraction from the smaller-particle side reaches 99%, and D100 is a particle size at which the cumulative volume fraction from the smaller-particle side reaches 100%.

A method for coating a surface of fused silica material is provided. A surface of a piece of material is pre-conditioned with a hydrolyzing reagent creating an SiOH or ROH bond on the surface. The surface is covered with thionyl chloride for a predetermined amount of time converting the SiOH bond on the surface to an SiCl. The thionyl chloride is removed and the surface is covered with a compound or mixture having an amine group converting the SiCl bond to an SiNR bond. The compound or mixture is removed.

This invention relates to a defoamer active. The defoamer active may include hydrophobized silica particles obtained by treating silica particles with a hydrophobilizing agent. The silica particles may have a BET surface of less than about 150 m.sup.2/g, a surface pH of at least about 10, and a median particle size ranging from about 2 m to about 50 m. The carbon content of the hydrophobized silica particles may not be more than 3%.