Kao Corporation

Masaki Komatsu

Toshihiro Yano

Hiroji Hosokawa

Jun Yoshida

The present invention relates to a method for producing mesoporous silica particles including a silica-containing outer shell portion with a mesoporous structure. The method includes the steps of: (I) pressurizing a mixed solution containing a hydrophobic organic compound, a surfactant, and an aqueous solvent by a high-pressure emulsification method so as to form an emulsion that includes emulsion droplets containing the hydrophobic organic compound; (II) adding a silica source to the emulsion so as to form a silica-containing outer shell portion with a mesoporous structure on a surface of the emulsion droplets, and precipitating composite silica particles including the outer shell portion and the emulsion droplets on an inner side relative to the outer shell portion; and (III) removing the emulsion droplets from the composite silica particles. According to the production method of the present invention, it is possible to produce easily mesoporous silica particles that have a small average particle size and include fewer coarse particles. Thus, the mesoporous silica particles produced by this method are useful in fields that handle a paint composition for an antireflection film and a coating film.

Method for producing mesoporous silica particles

The present invention relates to a low-dielectric resin composition having sufficiently low dielectric constant and dissipation factor, a low-dielectric film formed of the low-dielectric resin composition, processes for producing the low-dielectric resin composition and the low-dielectric film, and a coating agent for low-dielectric films. According to the present invention, there are provided (1) a low-dielectric resin composition including hollow silica particles having an average particle size of from 0.05 to 3 &#x3bc;m and a BET specific surface area of less than 30 m/g, and a matrix resin in which the hollow silica particles are dispersed; (2) a low-dielectric film including the low-dielectric resin composition; (3) a process for producing the low-dielectric resin composition which includes the steps of preparing hollow silica particles (A) containing air inside thereof or core/shell type silica particles (B) in which a material capable of being dissipated by calcination to form hollow portions therein is encapsulated; calcination the hollow silica particles (A) or the core/shell type silica particles (B) at a temperature higher than 950&#xb0; C. to prepare hollow silica particles (C); and dispersing the hollow silica particles (C) in a matrix resin-forming material to prepare a dispersion of the particles; and (4) a coating agent for low-dielectric films including the hollow silica particles, and a matrix resin-forming material in which the hollow silica particles are dispersed.

Growing community of inventors

Wakayama, Japan

Masaki Komatsu