Suspensions of silica particles in organic liquids are disclosed as well as a method for their preparation

Improved silica based matting agents are disclosed. The matting agents are useful in waterborne coatings composition to provide exceptional properties to a wood based substrate. Films resulting on the coated substrate unexpectedly provide improved chemical resistance, thermal stress resistance, weather resistance, and/or film clarity to the surface of a wood substrate. Methods of making and using the matting agents are also disclosed.

Spherically-shaped silica can include a precipitated silica powder having a d.sub.50 particle size selected within a range of greater than 20 m and up to 80 m, a di-octyl adipate oil absorption selected within a range of from 150 ml/100 g to 500 ml/100 g, an average circularity selected within a range of from 0.70 to 1.0, and an angle of repose, of less than 30. A process of preparing spherically-shaped silica powder is also included.

A microcrystalline talc particulate having a BET specific surface area no less than about 35 m.sup.2/g and one or both of: (a) a d.sub.50, by Sedigraph, no greater than about 2.0 5 ?m; and (b) a d.sub.50, by laser, no greater than about 5.0 ?m.

Improved silica based matting agents are disclosed. The matting agents are useful in waterborne coatings composition to provide exceptional properties to a wood based substrate. Films resulting on the coated substrate unexpectedly provide improved chemical resistance, thermal stress resistance, weather resistance, and/or film clarity to the surface of a wood substrate. Methods of making and using the matting agents are also disclosed.

The present invention relates to a method of preparing a high hydrophobic silica aerogel having a low tap density and a hydrophobic silica aerogel prepared thereby. The method of preparing a hydrophobic silica aerogel according to the present invention may have good productivity and economic efficiency, because preparation time is reduced by simultaneously performing surface modification and solvent substitution in a single step, and may control a degree of hydrophobicity of the prepared silica aerogel by controlling a surface modification reaction by including a step of adding ammonium hydroxide. Thus, a hydrophobic silica aerogel having excellent physical properties, such as tap density and specific surface area, as well as high hydrophobicity obtained by controlling the degree of hydrophobicity may be prepared.

The invention relates to material comprising a layered material having the composition Na.sub.x[Mg.sub.3-zLi.sub.y]Si.sub.4O.sub.10(T).sub.2, wherein x is in the range of 0.4 to 0.8, y is in the range of 0.0 to 0.8, 5z is in the range of 0.2 to 0.8, T independent of each occurrence represents F or OH, and x+(3?z)+y?4, wherein the powder X-ray diffraction pattern of the layered material has a 001 peak in the range of 8.00 to 5.88? 2Theta, and wherein the 001 peak has a full width at half of the peak maximum 10 of larger than 0.10?, and wherein the layered material has a Z-average particle size of 500 nm or higher, determined by dynamic laser light scattering on an aqueous dispersion of the material containing at most 1.5% by weight of the material.

A composite filler comprising thermally processed porous inorganic mixed particles of silica and at least one heteroparticle selected from the group consisting of zirconia, hafnia, or yttria and a polymer occupying the pores of the porous inorganic mixed particles, wherein the porous inorganic mixed particles are thermally processed at a temperature of from 650 to 900 C., as well as a dental restorative comprising a resin and a composite filler, and optionally other fillers, wherein said resin has a refractive index that increases upon curing, and wherein the opacities of the both uncured and cured restorative are less than 45.

A zinc oxide-containing composite particle (1) according to the present invention includes a porous silica particle (10), zinc oxide particles (20), and a coating layer (30). The zinc oxide particles (20) are enclosed within the porous silica particle (10). The coating layer (30) covers the porous silica particle (10) and contains a polysilsesquioxane. The zinc oxide-containing composite particle (1) can thus be provided as a particle having high acid resistance.

Spherically-shaped silica can include a precipitated silica powder having a d.sub.50 particle size selected within a range of greater than 20 ?m and up to 80 ?m, a di-octyl adipate oil absorption selected within a range of from 150 ml/100 g to 500 ml/100 g, an average circularity selected within a range of from 0.70 to 1.0, and an angle of repose, of less than 30?. A process of preparing spherically-shaped silica powder is also included.