- All sections
- D - Textiles; paper
- D21C - Production of cellulose by removing non-cellulose substances from cellulose- containing materials; regeneration of pulping liquors; apparatus therefor
- D21C 3/20 - Pulping cellulose-containing materials with organic solvents
Patent holdings for IPC class D21C 3/20
Total number of patents in this class: 233
10-year publication summary
|
25
|
10
|
13
|
17
|
11
|
23
|
29
|
6
|
11
|
0
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| GranBio Intellectual Property Holdings, LLC | 111 |
22 |
| API Intellectual Property Holdings, LLC | 78 |
9 |
| E. I. du Pont de Nemours and Company | 4252 |
8 |
| The Regents of the University of California | 19493 |
7 |
| Canfor Pulp Ltd. | 16 |
5 |
| Licella Pty Limited | 29 |
5 |
| National Technology & Engineering Solutions of Sandia, LLC | 1876 |
5 |
| Virdia, LLC | 37 |
5 |
| Shell Internationale Research Maatschappij B.V. | 3721 |
4 |
| Shell Oil Company | 2155 |
4 |
| Buckman Laboratories International, Inc. | 239 |
4 |
| IFP Energies Nouvelles | 2818 |
4 |
| Politecnico di Milano | 826 |
4 |
| Stora Enso Oyj | 1603 |
4 |
| Annikki GmbH | 68 |
3 |
| Celanese International Corporation | 911 |
3 |
| Chemstone, Inc. | 23 |
3 |
| Evrnu, SPC | 16 |
3 |
| Nalco Company | 597 |
3 |
| Texas Tech University System | 542 |
3 |
| Other owners | 125 |