| 摘要 |
PROBLEM TO BE SOLVED: To provide a glass hard disk substrate polishing liquid composition that can attain both of a high polishing rate and low surface roughness, and can maintain the high polishing rate for a long time in a recycle polishing.SOLUTION: The glass hard disk substrate polishing liquid composition contains a silica grain that satisfies conditions 1 to 3 described below: 1) an average first-order grain diameter measured by a transmission type electron microscope is 10.0 nm or more and 20.0 nm or less; 2) an average degree of association of second-order aggregation measured by the transmission type electron microscope is 2.5 or more and 5.0 or less; 3) second-order aggregation in which a degree of constriction (envelope failure rate) expressed by a below-described expression (I) is 5.0% or more and 10.0% or less occupies 30% or more of grains as a whole, the degree of constriction=(envelope area-projection area)/envelope area×100 (I), where the projection area denotes an actual area of a transmission image of the grain captured by the transmission type electron microscope, and the envelope area denotes an area of a protrusion closure connecting a protrusion part so as to surround the grain photographed by the transmission type electron microscope. |
