Method of making paper
US6372089B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Feb 14, 2020 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H17/68
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Disclosed are stable, aqueous colloidal silicas having surface area of greater than 700 m2/g and S-values of from 20-50. These colloidal silicas do not require treatment with surface treatment agents such as aluminum to achieve stability. These colloidal silica aquasols can be produced and stored at concentrations of greater than 7 percent by weight SiO2 solids, and even as high as 15 percent by weight solids or higher, and remain stable at room temperature for at least 30 days compared to art-known silica aquasols. These colloidal silica sols demonstrate advantageously improved performance over art-known colloidal silica sols in applications such as in drainage and retention in papermaking processes.Also disclosed are processes for making aqueous colloidal silicas of the invention and the use of such colloidal silicas in papermaking processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.