Processes and compositions for brightness improvement in paper production
US9932709B2 · kind B2 · utility
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36References
9Claims
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Key dates
| Filing date | Mar 15, 2013 |
| Grant date | Apr 3, 2018 |
| Priority date | — |
| Expiry date | Jul 13, 2033 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/30
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Compositions and methods that preserve and enhance the brightness of pulp, and also improve the color of pulp or paper, when applied during different stages of a papermaking process, are disclosed. The compositions and methods maintain or enhance brightness, prevent yellowing, and enhance the performance of paper products. The compositions can include a mixture of reducing agents and can also include optical brighteners, chelants, polycarboxylates, or other additives. The mixture of reducing agents can include a borohydride, such as sodium borohydride, and any other reducing agent, such as a sulfite or bisulfite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.