- 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 3/04 - Pulping cellulose-containing materials with acids, acid salts, or acid anhydrides
Patent holdings for IPC class D21C 3/04
Total number of patents in this class: 243
10-year publication summary
|
22
|
20
|
15
|
17
|
6
|
17
|
59
|
16
|
17
|
1
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| SixRing Inc. | 141 |
58 |
| GranBio Intellectual Property Holdings, LLC | 111 |
21 |
| API Intellectual Property Holdings, LLC | 78 |
10 |
| UPM-Kymmene Corporation | 912 |
6 |
| Valmet AB | 494 |
6 |
| Leaf Sciences Pty Ltd | 5 |
5 |
| Uni-Charm Corporation | 605 |
4 |
| BASF SE | 20387 |
3 |
| Compagnie Industrielle de La Matiere Vegetale - Cimv | 27 |
3 |
| Kemira Oyj | 1205 |
3 |
| NORAM Engineering and Constructors Ltd. | 28 |
3 |
| Biopulping International Inc. | 3 |
3 |
| IFG Technologies, LLC | 7 |
3 |
| Virdia, LLC | 37 |
3 |
| Amppc Finland Oy | 5 |
3 |
| New Energy Blue LLC | 14 |
3 |
| Wisconsin Alumni Research Foundation | 3819 |
2 |
| The Regents of the University of Michigan | 4570 |
2 |
| Andritz AG | 227 |
2 |
| Ch-bioforce Oy | 23 |
2 |
| Other owners | 98 |