| 摘要 |
Amorphous silicas suitable for use as abrasives in transparent toothpastes can be prepared by a precipitation route. These silicas are distinguished by having a BET surface area of 100 to 450 m<2>/g, a weight mean particle size of 5 to 15 microns, a plastics abrasion value of 16 to 26, a mean pore diameter from 2 to 12 nm, a transmission of at least 70% in the refractive index range from 1.430 to 1.443 and an oil absorption in the range from about 70 to about 130 cm<3>/g. |
