Production of filled paper
US5827398A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 13, 1996 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Feb 13, 2016 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/10
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Filled paper is made by adding a cationising amount of cationic polymer to a slurry of precipitated calcium carbonate, mixing this slurry into a cellulosic suspension and forming a thin stock, adding anionic particulate material to the suspension before or after the slurry, mixing a polymeric retention aid into the thin stock which includes the precipitated calcium carbonate and the anionic particulate material, draining the thin stock on a screen to form a sheet and drying the sheet. A suitable slurry for this purpose is a slurry of 5 to 70% by weight precipitated calcium carbonate and cationic polymer selected from 0.1 to 1% cationic starch and 0.01 to 0.3% of a high charge density, relatively low molecular weight, cationic polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.