- All sections
- D - Textilespaper
- D21C - Production of cellulose by removing non-cellulose substances from cellulose- containing materialsregeneration of pulping liquorsapparatus therefor
- D21C 3/22 - Other features of pulping processes
Patent holdings for IPC class D21C 3/22
Total number of patents in this class: 266
10-year publication summary
|
21
|
13
|
20
|
20
|
12
|
13
|
19
|
20
|
21
|
11
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Shell Internationale Research Maatschappij B.V. | 3551 |
9 |
| Shell Oil Company | 2141 |
9 |
| BASF SE | 20904 |
8 |
| Ecolab USA Inc. | 5471 |
8 |
| Valmet AB | 503 |
8 |
| GranBio Intellectual Property Holdings, LLC | 119 |
7 |
| Kemira Oyj | 1207 |
6 |
| SixRing Inc. | 162 |
6 |
| Kimberly-clark Worldwide, Inc. | 5504 |
5 |
| Nalco Company | 564 |
5 |
| Renmatix, Inc. | 131 |
5 |
| Pierson Capital Environmental (Beijing) Limited | 10 |
5 |
| Andritz Inc. | 333 |
4 |
| Eth Zurich | 1273 |
4 |
| Suzano S.A. | 200 |
4 |
| IFG Technologies, LLC | 8 |
4 |
| Circ, Inc. | 36 |
4 |
| The Procter & Gamble Company | 22037 |
3 |
| E. I. du Pont de Nemours and Company | 4095 |
3 |
| Andritz Oy | 282 |
3 |
| Other owners | 156 |