Precipitated silica
US6169135A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1997 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Feb 28, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/17
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Silicas in the form of powder and substantially spherical beads or granules are characterized by a CTAB specific surface of 140 and 240 m.sup.2 /g a high ultrasonic disaggregation factor, an average diameter, which is small after ultrasonic disaggregation, and optionally, a porous distribution, the porous volume formed by the pores with a diameter of 175 to 275 .ANG. being less than 50% of the porous volume formed by the pores with diameters of 400 .ANG. or less. The silicas may be used as reinforcing fillers for elastomers. The invention also concerns a method for preparing precipitated silica of the type comprising the reaction of an alkaline metal silicate M with an acidifying agent, resulting in a suspension of precipitated silica, and the separation and drying of said suspension, wherein precipitation is performed as follows: (i) an initial seed is formed comprising a portion of the total quantity of alkaline metal silicate M in the reaction, the silicate concentration (expressed as SiO.sub.2) in said seed being less than 20 g/l; (ii) an acidifying agent is added to the initial seed until at least 5% of the quantity of M.sub.2 O in the initial seed is neutralized; (iii) the ac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.