D21H 21/02
Agents for preventing deposition on the paper mill equipment
Official title: Agents for preventing deposition on the paper mill equipment, e.g. pitch or slime control (removal of fats, resins, pitch, or waxes D21C9/08)
D21H21/02 (Agents for preventing deposition on the paper mill equipment) appears on 239 US grants and 184 published applications in this corpus.
Search patents in D21H- Granted patents
- 239
- Published applications
- 184
- Assignees
- 105
- Inventors
- 500
- Latest grant
- 28 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 2 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 3 | 0 |
| 1989 | 2 | 0 |
| 1990 | 8 | 0 |
| 1991 | 7 | 0 |
| 1992 | 5 | 0 |
| 1993 | 15 | 0 |
| 1994 | 7 | 0 |
| 1995 | 7 | 0 |
| 1996 | 14 | 0 |
| 1997 | 16 | 0 |
| 1998 | 7 | 0 |
| 1999 | 9 | 0 |
| 2000 | 8 | 0 |
| 2001 | 6 | 4 |
| 2002 | 8 | 6 |
| 2003 | 4 | 10 |
| 2004 | 1 | 7 |
| 2005 | 2 | 4 |
| 2006 | 4 | 11 |
| 2007 | 5 | 7 |
| 2008 | 4 | 14 |
| 2009 | 5 | 10 |
| 2010 | 4 | 7 |
| 2011 | 7 | 7 |
| 2012 | 5 | 7 |
| 2013 | 10 | 7 |
| 2014 | 8 | 6 |
| 2015 | 5 | 11 |
| 2016 | 7 | 6 |
| 2017 | 0 | 8 |
| 2018 | 5 | 10 |
| 2019 | 8 | 7 |
| 2020 | 11 | 6 |
| 2021 | 0 | 5 |
| 2022 | 4 | 5 |
| 2023 | 3 | 8 |
| 2024 | 5 | 2 |
| 2025 | 3 | 6 |
| 2026 | 0 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Pulp quality monitoring28 Oct 2025US 12,454,796 B2Kemira Oyj
- Method for suppressing sedimentation of suspended substance, method for suppressing pitch trouble, and method for detecting sedimentation of suspended substance11 Mar 2025US 12,247,354 B2Kurita Water Industries Ltd.
- Process for producing paper or board and a product thereof4 Feb 2025US 12,215,463 B2Kemira Oyj
- Paper coated with a functional polyolefin film24 Dec 2024US 12,173,452 B2Dow Global Technologies LLC
- Volatile fatty acid control20 Aug 2024US 12,065,367 B2Ecolab USA Inc.
- Water soluble amphoteric emulsion terpolymers, methods of making, and methods of use as retention and dewatering aids30 Jul 2026US 2026/0218455 A1
- Compositions and methods for the removal of scale build-up in pulp and paper process30 Apr 2026US 2026/0117460 A1Solenis Technologies, L.P.
- Composition and method for controlling volatile fatty acid content in pulp, paper, and/or board making processes29 Jan 2026US 2026/0028778 A1Solenis Technologies, L.P.
- Estimation device, estimation system, estimation program, and estimation method17 Jul 2025US 2025/0231168 A1Kurita Water Industries Ltd.
- Biocide control in paper making19 Jun 2025US 2025/0198086 A1Kemira Oyj
Most cited
By later US patents
- Antibiotic zeolite114US 4,938,958 AShinagawa Fuel Co., Ltd. · 1990
- Hydantoin-enhanced halogen efficacy in pulp and paper applications62US 5,565,109 ALonza Ltd. · 1996
- Method for using urea hydrochloride45US 5,672,279 APeach State Labs, Inc. · 1997
- C. antarctica lipase variants44US 6,074,863 ANovo Nordisk A/S · 2000
- Application of multiple enzyme blend to control industrial slime on equipment surfaces36US 5,071,765 ANalco Chemical Company · 1991