HYDROPHOBIC SILICA-BASED POWDER, COMPOSITION FOR MOLDING RUBBER COMPRISING THE SAME, AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide hydrophobic silica-based powder that excels in dispersibility.SOLUTION: The hydrophobic silica-based powder comprises a confetti-like fine particle having a plurality of verrucose protrusions on the surface of a spherical particle. The coefficient of variation (CV value) of the particle size is within a range of 10-50%. The value of the surface roughness (SA1/SA2), which is a ratio of a specific surface area (SA1) measured by the BET method or Sears method to a specific surface area (SA2) converted from the average particle diameter (D2) measured by the image analysis method, is within a range of 1.1-5.0. The average particle diameter (D3) measured by the dynamic light scattering is within a range of 0.01-0.30 μm. The frequency of the particle size distribution within the same range is 60% or more.