Kao Corporation

Toshihiro Yano

Takuya Sawada

Masaki Komatsu

Motoi Konishi

Hiroji Hosokawa

Hayato Yoshikawa

Koichi Kawamoto

Jun Yoshida

Provided are an abrasion resistance improver for inorganic filler-containing rubber composition capable of giving high abrasion resistance to a rubber composition containing an inorganic filler, a rubber composition containing the abrasion resistance improver for rubber composition, a tire using the rubber composition, and a method for producing the abrasion resistance improver for rubber composition. The present invention are concerned with [1] an abrasion resistance improver for inorganic filler-containing rubber composition, including, as an active ingredient, lignin having an aldehyde yield rate by alkaline nitrobenzene oxidation of 12% by mass or more; [2] a rubber composition containing the abrasion resistance improver as set forth above in [1], a rubber, and an inorganic filler; [3] a tire using the rubber composition as set forth above in [2]; [4] a method for producing an abrasion resistance improver for inorganic filler-containing rubber composition, including, as an active ingredient, lignin having an aldehyde yield rate by alkaline nitrobenzene oxidation of 12% by mass or more, the method including steps (A-1) to (A-3); and [5] a method for producing an abrasion resistance improver for inorganic filler-containing rubber composition, including, as an active ingredient, lignin having an aldehyde yield rate by alkaline nitrobenzene oxidation of 12% by mass or more, the method including steps (B-1) and (B-2).

Additive for resins

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.

Low-permittivity resin composition

The present invention relates to (1) hollow silica particles including an outer shell portion having a mesoporous structure with an average pore size of from 1 to 10 nm, wherein the silica particles have an average particle diameter of from 0.05 to 10 &#x3bc;m, and 80% or more of the whole silica particles have a particle diameter falling within the range of &#xb1;30% of the average particle diameter; (2) composite silica particles including silica particles which include an outer shell portion having a mesoporous structure with an average pore size of from 1 to 10 nm, and have a BET specific surface area of 100 m/g or more, and a hydrophobic organic compound or a polymeric organic compound incorporated inside of the silica particles; and a process for producing the hollow silica particles.

Mesoporous silica particles

The present invention relates to (1) a mesoporous silica film having a mesoporous structure including meso pores having an average pore period of from 1.5 to 6 nm, wherein the meso pores are oriented in the direction of an angle of from 75 to 90&#xb0; relative to a surface of the film; (2) a structure including a substrate and the mesoporous silica film formed on the substrate; and (3) a process for producing a mesoporous silica film structure which includes the steps of preparing an aqueous solution containing a specific amount of a specific cationic surfactant; immersing a substrate in the aqueous solution and then adding a specific amount of a silica source capable of forming a silanol compound when hydrolyzed, to the aqueous solution, followed by stirring the resulting mixture at a temperature of from 10 to 100&#xb0; C., to form a mesoporous silica film on a surface of the substrate; and removing the cationic surfactant from the resulting mesoporous silica film structure.

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Wakayama, Japan

Toshihiro Yano