The invention relates to a process for preparing a silane, to a process for modifying a silica with the silane, and to a modified silica.

The process for preparing a silane of the formula I) comprises at least the following steps: a) providing a substance (R.sup.1).sub.oSi—R.sup.2—HNC(═O)NH-A-NH.sub.2; b) providing a substance HOC(═O)-A-S.sub.2-A-C(═O)OH; c) activating the substance from step b) through reaction with oxalyl chloride to form ClC(═O)-A-S.sub.2-A-C(═O)Cl; d) reacting at least two equivalents of the substance from step a) with one equivalent of the substance from step a), thereby obtaining a silane of the formula I); e) optionally purifying the silane of the formula I) obtained in step d)

(R.sup.1).sub.oSi—R.sup.2—HNC(═O)NH-A-HNC(═O)-A-S.sub.k-A-C(═O)NH-A-NHC(═O)—R.sup.2—Si(R.sup.1),  I)

wherein the groups A within a molecule may be identical or different and are aromatic groups.

An inorganic oxide particles which have a minute particle diameter at which no interference fringes occur in a coating film and high transparency can be secured even when applied to a high refractive index substrate, and in which excitation by ultraviolet radiation is almost completely suppressed, a coating composition containing such particles, and an optical member having a cured film formed from the coating composition. Inorganic oxide particles obtained by bonding an organosilicon compound having a nitrogen-containing heterocyclic group to the surface of modified metal oxide colloid particles (C) having an average particle diameter of 2 to 100 nm, which include metal oxide colloid particles (A) having an average primary particle diameter of 2 to 60 nm as nuclei and with the nuclei surface coated with a coating composed of inorganic oxide colloid particles (B) having an average primary particle diameter of 1 to 4 nm.

An organic substance-attached porous inorganic oxide particle including porous inorganic oxide particle and an organic substance attached to the surface of the porous inorganic oxide particle. The organic substance-attached porous inorganic oxide particle satisfies a formula below

(Cf−Ce)/2>1

where Cf represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after the particle is washed, and Ce represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after two-minute surface etching of the particle.

The present invention is a multilayered composite comprising porous metal oxide particles that are covalently bonded by way of inorganic ether groups to one or more sites of a first polyhydroxyl-functionalized polymer. This first polymer is in turn covalently bonded by way of inorganic ether groups to one or more sites of a second polyhydroxyl-functionalized polymer. The multilayered composites can be prepared by contacting porous inorganic-oxide particles with a sufficient amount of OH-reactive crosslinking agent to form metal oxide particles imbibed with the crosslinking agent, and then contacting the inorganic-oxide particles with a solution of polyhydroxyl-functionalized polymer under reactive conditions.

A silicone oil-treated fumed silica and a method of producing the silicone oil-treated fumed silica are provided. The silicone oil-treated fumed silica, which has the following physical properties: A) the silicone oil-treated fumed silica has a degree of hydrophobicity of 68 vol % or more; B) the silicone oil-treated fumed silica has a silicone oil fixation rate of from 60 mass % to 95 mass %; and C) a composition obtained by adding 6 parts by mass of the silicone oil-treated fumed silica to 100 parts by mass of an amine composition containing trimethylolpropane polyoxypropylene triamine and 1,3-bis(aminomethyl)cyclohexane at a mass ratio of 95:5 has a viscosity of 4,000 mPa.Math.s or more after the composition is left to stand at 25° C. for 1 hour.

A system and method for producing an aerogel composite material includes a reaction vessel having a movable carrier basket for receiving a plurality of fiber mats, and a plurality of plates to space the fiber mats apart from one another. Once the plates have been removed, there are gaps between the aerogel insulating boards, through which hot drying air can be blown during a drying process. The method has the advantage that the quantities of solvents and reagents to be disposed of are minimal, and in addition thereto, no complex work-up processes are necessary.

Modified precipitated silica is produced in a one pot synthesis by forming precipitated silica and modifying with an organosiliconate. The modified precipitated silica is washed following preparation, affording a modified precipitated silica with low levels of ionic substances.

A production method for an electronic material filler includes: a preparation step of preparing a silica particle material produced by a dry method; and a first surface treatment step of performing surface treatment on the silica particle material with a silane compound having a vinyl group, a phenyl group, a phenylamino group, an alkyl group having four or more carbon atoms, a methacryl group, or an epoxy group, to obtain a first surface treatment-processed particle material. After the silica particle material is produced by the dry method, the silica particle material is not brought into contact with liquid water, and has a particle diameter of 100 nm to 600 nm or a specific surface area of 5 m.sup.2/g to 35 m.sup.2/g.

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.

Stable suspensions of silica particles in water-immiscible polar organic liquids are provided.