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.

An aqueous dispersion comprising a surface-modified hydrophilic mixed oxide powder comprising silicon and aluminum and water, characterized in that

a) the surface of the particles has Si and Al atoms and
b) the surface modification has an Si atom bonded to a hydrocarbon radical via a C atom, and
c) the carbon content of the surface-modified mixed oxide powder is 3-25% by weight.

According to one embodiment, a pattern formation method can include performing a first processing of causing a surface of a first member of a processing body to be hydrophobic. The processing body includes the first member and a second member. The second member is provided at a portion of the first member. The method can include performing a second processing of causing the processing body to contact an atmosphere including a metal compound. The second processing is after the first processing. The method can include performing a third processing of processing the processing body in an atmosphere including at least one selected from the group consisting of water, oxygen, and ozone. The third processing is after the second processing. In addition, the method can include removing, after the third processing, at least a portion of another portion of the first member by using the second member as a mask.

Compositions for forming a silicone elastomer and the silicone elastomers thereby which have improved characteristics and which can be used for medical devices are disclosed. The composition for forming a silicone elastomer can include (A) an organopolysiloxane having silicon-bonded alkenyl groups; (B) an organohydrogensiloxane having an average of two or more silicon-bonded hydrogen atoms in the molecule; (C) an inorganic filler; and (D) a filler treatment agent which includes an alkenyl-containing group, e.g., an alkenyl-containing organosilane or organosilazane.

Provided are a protective negative electrode for a lithium metal battery, which includes a lithium metal negative electrode, and a protective film disposed on the lithium metal negative electrode and including a filler bound with a siloxane functional group and a polymer; and a lithium metal battery including the same.

Provided is an external additive for toner, which is suitable for producing a toner having excellent storage stability and chargeability. A silica fine powder suitable for being added to the external additive for toner is also provided. The silica fine powder has a specific surface area of 15 m.sup.2/g or more and 90 m.sup.2/g or less, a loose bulk density of 0.09 g/cm.sup.3 or more and 0.18 g/cm.sup.3 or less, a carbon content of 0.25 wt % or more and 0.90 wt % or less, and a hydrophobicity of 60% or more and 75% or less. It is preferable that a ratio (A)/(B) of the loose bulk density of the silica fine powder after surface treatment (A) to a loose bulk density of the silica fine powder before the surface treatment (B) be 1.05 or more and 1.60 or less.

The present invention relates to spherical, dense micrometre-sized particles comprising colourants. The invention also relates to a material comprising these particles intended for use in papermaking, paint, agri-food, cosmetics or pharmaceuticals. It also relates to the process for preparing these particles and their incorporation in a matrix.

Metal oxide-polymer composite particles have a median particle size D50 of 40-75 nm or 100-150 nm and an average RTA of at least 0.06. Alternatively or in addition, metal oxide-polymer composites comprise two or more populations of metal oxide particles differing in size, particle size distribution, or shape. Alternatively or in addition, the use of a multicomponent hydrophobizing system including an alkylsilane to fabricate metal oxide-polymer composite particles increases the tribocharge of the composite particles.

The method for producing a surface-modified base material according to the present invention includes a step of bringing a base material having a polar group present on a surface thereof into contact with a hydrosilane compound having a molecular structure A and having a SiH group composed of a silicon atom of the molecular structure A and a hydrogen atom bonded to the silicon atom in the presence of a borane catalyst so as to allow a dehydrocondensation reaction to take place between the base material and the compound, thereby forming the base material surface-modified with the molecular structure A. This production method is capable of surface-modifying a base material at a lower temperature in a shorter time than conventional methods and allows a wide variety of options for the form, type, and application of the base material, the mode of the modification reaction, and the type of the molecular structure with which the base material is surface-modified.

The invention relates to a hydrophobic silica powder which is unprecedentedly insensitive to environmental humidity with which electrophotographic toner can possess stable electro static charge that leads to stable quality of printed image. The hydrophobic silica powder has the following physicochemical properties; average primary particle size (D) is 30-2000 nm, B*D<430 nm, while B stands for weight % of adsorbed water vapor on silica (100 weight %) when the partial pressure of water to the equilibrium vapor pressure of water at 25 C. is 80% and D stands for average primary particle size (nm) of the silica powder, B/C<2.7, while C stands for weight % of adsorbed water vapor on silica (100 weight %) when the partial pressure of water to the equilibrium vapor pressure of water at 25 C. is 20%, and carbon content>0.30 wt.-%.