The present invention is to provide a toner for developing electrostatic images, which has an excellent balance between low-temperature fixability and heat-resistant shelf stability, which has good toner conveyance amount stability and printing durability, and which has less occurrence of fog in a high temperature and high humidity environment. Disclosed is a toner for developing electrostatic images, comprising colored resin particles containing a binder resin and a colorant, and an external additive, wherein the toner comprises, as the external additive, fine silica particles in an amount of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the colored resin particles, the fine silica particles having a hydrophobicity of 15 to 49% that is determined after a high-temperature and high-humidity incubation.

An object of the present invention is to provide a silica particle having excellent polishing characteristics and storage stability. The present invention relates to a silica particle in which a proportion of silanol groups present on a surface represented by (x/y)×100% is 15% or less, where a content of silanol groups on the surface is x mass % and a content of bulk silanol groups is y mass %.

An object of the present invention is to provide a silica particle having excellent polishing characteristics and storage stability, a method for producing the silica particle, a silica sol containing the silica particles, and a polishing composition containing the silica sol.

Another object of the present invention is to provide a polishing method, a method for producing a semiconductor wafer, and a method for producing a semiconductor device, which are excellent in productivity of an object to be polished. The silica particle in the present invention satisfies formula (1): y≥4.2 where a d value measured by wide-angle X-ray scattering is y ∪.

The disclosure relates to the field of electronic materials, and in particular to a composite film of fluorinated polybenzoxazole (6FPBO) and triple-shelled mesoporous silica hollow spheres, and to its preparation and use. The composite film comprises fluorinated polybenzoxazole as a matrix and amino-functionalized triple-shelled mesoporous silica hollow spheres which are dispersed in the fluorinated polybenzoxazole matrix. A mass ratio of (amino-functionalized triple-shelled mesoporous silica hollow spheres)/(fluorinated polybenzoxazole) is 1/100 to 5/100. The composite film has excellent thermal stability and a lower dielectric constant.

The disclosure relates to the field of electronic materials, and in particular to a composite film of fluorinated polybenzoxazole (6FPBO) and triple-shelled mesoporous silica hollow spheres, and to its preparation and use. The composite film comprises fluorinated polybenzoxazole as a matrix and amino-functionalized triple-shelled mesoporous silica hollow spheres which are dispersed in the fluorinated polybenzoxazole matrix. A mass ratio of (amino-functionalized triple-shelled mesoporous silica hollow spheres)/(fluorinated polybenzoxazole) is 1/100 to 5/100. The composite film has excellent thermal stability and a lower dielectric constant.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica. Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

To provide modified colloidal silica capable of improving the stability of the polishing speed with time when used as abrasive grains in a polishing composition for polishing a polishing object that contains a material to which charged modified colloidal silica easily adheres, such as a SiN wafer, and to provide a method for producing the modified colloidal silica. Modified colloidal silica, being obtained by modifying raw colloidal silica, wherein the raw colloidal silica has a number distribution ratio of 10% or less of microparticles having a particle size of 40% or less relative to a volume average particle size based on Heywood diameter (equivalent circle diameter) as determined by image analysis using a scanning electron microscope.

The present invention discloses the an aerogel material featuring of low thermal conductivity, low dielectric constant (low-D.sub.K) and low dielectric-loss (low-D.sub.F) and a preparation method therefor. The method comprises steps of: (1) mix and hydrolysis, (2) dispersion and condensation, (3) molding, and (4) drying. The prepared pure aerogel or fiber/aerogel composite is further processed by steps of: (5) polymer solution impregnating, (6) solvent drying and (7) crosslinking-solidifying to obtain a polymer/aerogel composite or a polymer/fiber/aerogel composite featuring of high strength, low thermal conductivity, low-D.sub.K and low-D.sub.F. The method provided by the present invention does not involve highly conductive solvents or additives, and a highly porous structure is formed so that the dielectric constant and dielectric loss of the aerogel material are significantly reduced, suitable for 5G communications, microwave circuits, protection and insulation for electric vehicle lithium battery modules.

The present invention discloses the an aerogel material featuring of low thermal conductivity, low dielectric constant (low-D.sub.K) and low dielectric-loss (low-D.sub.F) and a preparation method therefor. The method comprises steps of: (1) mix and hydrolysis, (2) dispersion and condensation, (3) molding, and (4) drying. The prepared pure aerogel or fiber/aerogel composite is further processed by steps of: (5) polymer solution impregnating, (6) solvent drying and (7) crosslinking-solidifying to obtain a polymer/aerogel composite or a polymer/fiber/aerogel composite featuring of high strength, low thermal conductivity, low-D.sub.K and low-D.sub.F. The method provided by the present invention does not involve highly conductive solvents or additives, and a highly porous structure is formed so that the dielectric constant and dielectric loss of the aerogel material are significantly reduced, suitable for 5G communications, microwave circuits, protection and insulation for electric vehicle lithium battery modules.

A silica membrane filter 10 includes an ultrafiltration membrane 15, which is disposed on a support body 14 and which contains an element 14 as a primary component, and a silica membrane 18 which is disposed on the ultrafiltration membrane 15 and which has an aryl group. The ultrafiltration membrane 15 has a structure infiltrated by Si of the silica membrane 18, the atomic ratio A (=Si/M) of Si to the element M in a membrane-side region 16, which is a region corresponding to 25% of the ultrafiltration membrane 15 from the silica membrane 18, satisfies 0.01≤A≤0.5, and the ratio A/B of the atomic ratio A to the atomic ratio B (=Si/M) in a base-material-side region 17, which is a region corresponding to 25% from the support body 14, is within the range of 1.1 or more.