D21C 9/1068
With o2
Official title: {with O2 (closed, see D21C9/147)}
D21C9/1068 (With o2) appears on 33 US grants and 9 published applications in this corpus.
Search patents in D21C- Granted patents
- 33
- Published applications
- 9
- Assignees
- 20
- Inventors
- 58
- Latest grant
- 7 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 2 | 0 |
| 1978 | 4 | 0 |
| 1979 | 3 | 0 |
| 1980 | 3 | 0 |
| 1981 | 8 | 0 |
| 1982 | 1 | 0 |
| 1983 | 3 | 0 |
| 1984 | 3 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 1 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 1 |
| 2020 | 1 | 1 |
| 2021 | 0 | 2 |
| 2022 | 0 | 1 |
| 2023 | 0 | 2 |
| 2024 | 1 | 0 |
| 2025 | 2 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- High yield chemical pulping and bleaching process7 Oct 2025US 12,435,469 B2GPCP IP Holdings LLC
- Oxygen treatment of high kappa fibers29 Apr 2025US 12,286,751 B2GPCP IP Holdings LLC
- Oxygen bleaching method of pulp1 Oct 2024US 12,104,321 B2Beijing Forestry University
- Bleaching and shive reduction process for non-wood fibers14 Jul 2020US 10,711,399 B2GPCP IP Holdings LLC
- Process for the delignifying bleaching of cellulose pulp by activating the pulp with NO.sub.2 and oxygen1 May 1984US 4,445,969 AMo och Domsjo Aktiebolag
- Use of cellulase to improve viscosity control of kraft dissolving pulp9 Oct 2025US 2025/0314012 A1Novozymes A/S
- Oxygen bleaching method of pulp31 Aug 2023US 2023/0272580 A1Beijing Forestry University
- High yield chemical pulping and bleaching process24 Aug 2023US 2023/0265609 A1GPCP IP Holdings LLC
- Oxygen Treatment of High Kappa Fibers7 Jul 2022US 2022/0213648 A1GPCP IP Holdings LLC
- Method For Preparing Dissolving Pulp By Totally Chlorine-Free Bleaching Of Poplar Kraft Pulp4 Mar 2021US 2021/0062419 A1Qilu University of Technology
Most cited
By later US patents
- Method and apparatus for treating pulp with oxygen in a multi-stage bleaching sequence49US 4,298,426 AWeyerhaeuser Company · 1981
- Treating pulp with oxygen41US 4,295,925 AWeyerhaeuser Company · 1981
- Oxygen delignification of wood pulp33US 4,198,266 AAirco, Inc. · 1980
- Method and apparatus for treating pulp with oxygen32US 4,295,926 AWeyerhaeuser Company · 1981
- Method for control of chemicals during gas treatment of suspensions32US 4,419,184 AKamyr, Inc. · 1983