Method of bleaching recycled papers with hydrogen peroxide stabilized with a methylolhydantoin
US6432262B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2001 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jun 8, 2021 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/1036
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of stabilizing hydrogen peroxide in an aqueous solution, such as a circulating water slurry, comprising a peroxide, such as hydrogen peroxide. The aqueous solution may include organic matter. The method comprises adding an aldehyde donor, such as a methylolhydantoin, to the solution (or slurry). The inventors have discovered that aldehyde donors significantly reduce the decomposition of hydrogen peroxide by catalase and other peroxide decomposing enzymes, which are often present in recycled paper. As a result, less hydrogen peroxide needs to be added to a solution to effectively bleach organic matter in the solution. Furthermore, aldehyde donors are safe to handle and cost effective. Another embodiment is a method of bleaching recycled papers in a circulating water slurry comprising organic matter. The method comprises adding hydrogen peroxide and an aldehyde donor to the slurry. Yet another embodiment is a method of inhibiting catalase and/or other peroxide decomposing enzymes in an aqueous solution, such as a circulating water slurry, comprising adding an aldehyde donor to the aqueous solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.