Spinous silica-based sol and method of producing the same
The present invention provides a sol of spinous silica-based particles in which silica-based particles having peculiar forms, spinous forms are dispersed in a solvent. The spinous silica-based particles have verrucous projections formed on surfaces of spherical silica-based particles. In the spinous particles, a value of the surface roughness (SA 1 /SA 2, SA 1 indicating a specific surface area measured by the BET method or the Sears method and SA 2 indicating a specific surface area converted from an average particle diameter (D 2 ) measured by the image analysis method) is in the range from 1.7 to 10. Furthermore the average diameter (D 2 ) measured by the image analysis method is in the range from 7 to 150 nm.
1. A sol of spinous silica-based particles comprising:
a solvent, and
spinous silica-based particles dispersed in the solvent, each spinous silica-based particle having a spherical particle and a plurality of verrucous projections on a surface of the spherical particle with a surface roughness value ((SA 1 )/(SA 2 )) in a range from 1.7 to 10 wherein SA 1 indicates a specific surface area measured by the BET method or the Sears method and SA 2 indicates a specific surface area converted from an average particle diameter (D 2 ) measured by the image analysis method and also with the average particle diameter (D 2 ) measured by the image analysis method in a range from 7 to 150 nm.
2. The sol of spinous silica-based particles according to claim 1 , wherein the spinous silica-based particles comprise silica or alumina-silica composite.
3. The sol of spinous silica-based particles according to claim 1 , wherein sphericity of the spinous silica-based particles is in the range from 0.8 to 1.
4. The sol of spinous silica particles according to claim 1 , wherein a coefficient of variation (CV value) of diameters of the spinous silica-based particles is in a range from 10 to 50%.
5. The sol of spinous silica-based particles according to claim 1 , wherein the verrucous projections are verrucous concave-convex-shaped projections, and the spinous silica-based particles comprise silica cores which are coated with alumina and silica.
6. A polishing agent comprising the sol of spinous silica-based particles according to claim 1 .
7. A composition for polishing containing the sol of spinous silica-based particles according to claim 1 .
8. A sol of spinous silica particles comprising:
a solvent, and
spinous silica particles dispersed in the solvent, each spinous silica particle having a spherical particle and a plurality of verrucous projections on a surface of the spherical particle with the surface roughness value ((SA 1 )/(SA 2 )) in a range from 1.7 to 10 wherein SAl indicates a specific surface area measured by the BET method or the Sears method and SA 2 indicates a specific surface area converted from an average particle diameter (D 2 ) measured by the image analysis method and also with the average particle diameter (D 2 ) measured by the image analysis method in a range from 7 to 150 nm.
9. The sol of spinous silica particles according to claim 8 , wherein a coefficient of variation (CV value) of diameters of the spinous silica particles is in a range from 10 to 50%.
10. A polishing agent comprising the sol of spinous silica-based particles according to claim 8 .
11. A composition for polishing containing the sol of spinous silica-based particles according to claim 8 .
12. A sol of spinous alumina-silica composite particles comprising:
a solvent, and
spinous alumina-silica composite particles distributed in the solvent, each spinous alumina-silica composite particle having a spherical silica particle and a plurality of verrucous projections comprising silica and alumina on a surface of the spherical silica particle with the surface roughness value ((SA 1 )/(SA 2 )) in a range from 1.7 to 10 wherein SAl indicates a specific surface area measured by the BET method or the Sears method and SA 2 indicates a specific surface area converted from an average particle diameter (D 2 ) measured by the image analysis method and also with the average particle diameter (D 2 ) measured by the image analysis method in the range from 7 to 150 nm.
13. The sol of spinous alumina-silica composite particles according to claim 12 , wherein a coefficient of variation (CV value) of diameters of the spinous alumina-silica particles is in a range from 10 to 50%.
14. A polishing agent comprising the sol of spinous silica-based particles according to claim 12 .
15. A composition for polishing containing the sol of spinous silica-based particles according to claim 12 .