- 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: 226
10-year publication summary
|
18
|
22
|
20
|
15
|
17
|
6
|
16
|
56
|
15
|
2
|
| 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| SixRing Inc. | 121 |
47 |
| GranBio Intellectual Property Holdings, LLC | 105 |
20 |
| API Intellectual Property Holdings, LLC | 80 |
10 |
| UPM-Kymmene Corporation | 868 |
6 |
| Valmet AB | 463 |
6 |
| Leaf Sciences Pty Ltd | 5 |
5 |
| Inbicon A/S | 66 |
5 |
| Uni-Charm Corporation | 611 |
4 |
| BASF SE | 19740 |
3 |
| Compagnie Industrielle de La Matiere Vegetale - Cimv | 27 |
3 |
| Kemira Oyj | 1167 |
3 |
| NORAM Engineering and Constructors Ltd. | 27 |
3 |
| Biopulping International Inc. | 3 |
3 |
| Virdia, LLC | 44 |
3 |
| Amppc Finland Oy | 5 |
3 |
| Wisconsin Alumni Research Foundation | 3774 |
2 |
| The Regents of the University of Michigan | 4409 |
2 |
| Andritz AG | 218 |
2 |
| Ch-bioforce Oy | 22 |
2 |
| Clean Chemistry, Inc. | 33 |
2 |
| Other owners | 92 |