A chemically modified precipitated silica characterised by the presence of alkyl moieties chemically bound to the silica and a process for its manufacture.

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.

In order to provide a filler composition for fabricating a high-performance filler achieving good productivity while preventing worsening of a working environment and production of a VOC and to provide a filler and a method for producing the filler, a filler composition of the present invention contains wet silica, a polyoxyethylene unsaturated fatty acid ester, and a sulfur-containing silane coupling agent.

A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90F.sub.BEFORE/F.sub.AFTER1.10, and 5F.sub.SINTERING/F.sub.BEFORE20, 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.

A method of forming nanoparticles having superhydrophobicity includes preparing a PDMS film including a structure having a predetermined shape on a surface thereof, and generating the nanoparticles having superhydrophobicity on the surface of the PDMS film by combusting the surface of the PDMS film using a diffusion flame. Transparent nanoparticles having superhydrophobicity and oleophobicity may be generated simply and easily on the surface of the PDMS film.

A hydrophobic silica powder is disclosed that exhibits reduced desorption of a charge control agent, on the charge-controllable surface, and that is capable of imparting charge properties within a suitable range to toner resin particles to which the hydrophobic silica particles are externally added. A hydrophobic silica powder is characterized in that (1) the hydrophobic silica powder has a hydrophobicity of 50% or more; (2) an amount X is 0.1 mass % or more, the amount X being an amount of at least one compound selected from the group consisting of a quaternary ammonium ion, a mono-azo complex, and a mineral acid ion extracted with a mixture solvent of methanol and a ethanesulfonic acid aqueous solution: and (3) the amount X and an amount Y satisfy the following formula (I):

Y/X<0.15(I),

the amount Y being an amount of the at least one compound extracted with water.

The present invention provides organofunctional siloxane coupling agents, dipodal siloxanes, siloxane block copolymers and a specific method for preparing these organofunctional siloxanes through an addition reaction of hydrido alkoxysilane and organofunctional disiloxanes to an organocyclosiloxane with a catalyst. The addition reaction of the current invention does not result in polymerization and therefore the novel siloxane couplings agents are free of cyclosiloxanes and polymeric siloxanes. This makes them apt for adhesives, coatings and sealant applications. The present invention also relates to the use of these organofunctional siloxane compounds for the treatment of fillers and surfaces.

A plasticizer composition to be used in a transparent resin for optics, wherein the plasticizer composition includes: a composite aggregated particulate material; and a liquid plasticizer having dispersed therein the composite aggregated particulate material. The composite aggregated particulate material includes an inorganic aggregate material being a granular material formed of aggregates of an inorganic particulate material formed of silica having a specific surface area particle diameter of not less than 0.8 nm and not greater than 80 nm, and an organic coating material formed of an organic matter coating a surface of the inorganic aggregate material. A mass of the organic coating material is not less than 0.8% and not greater than 80% with respect to a sum of a mass of the inorganic aggregate material and a mass of the organic coating material. Both mechanical properties and optical properties are realized by mixing the plasticizer composition.

A method for manufacturing granulated silica. The method includes granulating silica powders each having a primary particle size of 5 to 50 nm by use of water, and hydrophobizing each surface of the silica powders with a silicon atom-containing hydrophobizing agent before or simultaneously with the granulation step.

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.