Pigment materials and their preparation and use
US6579410B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1997 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Oct 24, 2017 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H11/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A new composite material which is useful as a pigment in paper making or paper coating is produced by precipitating a white insoluble pigment compound, eg calcium carbonate, in an aqueous suspension containing a mixture of fine particulate material eg titanium dioxide particles and fibers, eg cellulosic fibers. These suspended solids in the mixture are derived from separate stocks and added together to produce the composite pigment material. The new material is a bonded matrix of the fibers and the white pigment compound having particles of the fine particulate material, eg TiO2, dispersed and bonded within the matrix. The new material may exist in the form of particles in dry or wet form which may be further treated in a known way prior to use in paper making or paper coating. Use of the new material allows expensive fine particulate material such as TiO2 particles to be better retained in a paper making composition whilst at the same time avoiding the known problem of agglomeration or ‘crowding’ of the fine particles which is known to affect adversely the optical properties of the composition produced using the fine particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.