Process and coating composition for coating a paper web
US6893536B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 2001 |
| Grant date | May 17, 2005 |
| Priority date | — |
| Expiry date | Jul 6, 2021 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H25/14
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a process for producing a coated paper web, According to the process, a paper web is formed from a fibrous raw material in a paper machine, the paper web is coated with a pigment-containing coating mix, and the coated paper web is calendered. According to the invention, the paper web is coated with a coating composition that contains as the mineral pigment mainly a mixture of gypsum and calcium carbonate, the amount of gypsum being at minimum 10% by weight of the total amount of gypsum and calcium carbonate. With mixtures of calcium carbonate and gypsum, such as mixtures of PCC and gypsum and mixtures of PCC, ground carbonate and gypsum, there are obtained simultaneously a sufficient gloss and smoothness as well as a brightness and opacity better than with PCC-kaolin pastes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.