C09K 23/18
Quaternary ammonium compounds
C09K23/18 (Quaternary ammonium compounds) appears on 145 US grants and 110 published applications in this corpus.
Search patents in C09K- Granted patents
- 145
- Published applications
- 110
- Assignees
- 102
- Inventors
- 378
- Latest grant
- 21 Jul 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 2 | 0 |
| 1981 | 2 | 0 |
| 1982 | 1 | 0 |
| 1983 | 6 | 0 |
| 1984 | 3 | 0 |
| 1985 | 3 | 0 |
| 1986 | 2 | 0 |
| 1987 | 3 | 0 |
| 1988 | 4 | 0 |
| 1989 | 2 | 0 |
| 1990 | 1 | 0 |
| 1991 | 3 | 0 |
| 1992 | 1 | 0 |
| 1993 | 3 | 0 |
| 1994 | 3 | 0 |
| 1995 | 1 | 0 |
| 1996 | 4 | 0 |
| 1997 | 6 | 0 |
| 1998 | 2 | 0 |
| 1999 | 4 | 0 |
| 2000 | 4 | 0 |
| 2001 | 4 | 0 |
| 2002 | 3 | 3 |
| 2003 | 4 | 6 |
| 2004 | 5 | 9 |
| 2005 | 0 | 6 |
| 2006 | 3 | 3 |
| 2007 | 4 | 5 |
| 2008 | 3 | 3 |
| 2009 | 0 | 0 |
| 2010 | 4 | 2 |
| 2011 | 2 | 5 |
| 2012 | 1 | 0 |
| 2013 | 2 | 7 |
| 2014 | 0 | 2 |
| 2015 | 4 | 1 |
| 2016 | 3 | 8 |
| 2017 | 5 | 5 |
| 2018 | 3 | 3 |
| 2019 | 2 | 2 |
| 2020 | 3 | 5 |
| 2021 | 3 | 1 |
| 2022 | 2 | 13 |
| 2023 | 2 | 5 |
| 2024 | 7 | 9 |
| 2025 | 8 | 3 |
| 2026 | 5 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Methods and formulations for treating oil-containing porous media for oil recovery21 Jul 2026US 12,686,809 B2University of Wyoming
- Stable cationic polyacrylamide dispersions and use thereof in papermaking2 Jun 2026US 12,644,230 B2Kemira Oyj
- Coating process3 Mar 2026US 12,564,860 B2Bluescope Steel Limited
- Solubilizing agent and solubilizing solution24 Feb 2026US 12,559,681 B2Nof Corporation
- Amphoteric compounds6 Jan 2026US 12,516,019 B2Eastman Chemical Company
- Coating process6 Aug 2026US 2026/0225129 A1Bluescope Steel Limited
- Surfactant compositions derived from waste streams, and methods30 Jul 2026US 2026/0218053 A1Kemira Oyj
- Self-destructive barite filter cake in water-based and oil-based drilling fluids1 Jan 2026US 2026/0002066 A1King Fahd University of Petroleum and Minerals
- Self-destructive barite filter cake in water-based and oil-based drilling fluids1 Jan 2026US 2026/0002067 A1King Fahd University of Petroleum and Minerals
- Nanoparticle-surfactant stabilized foams25 Dec 2025US 2025/0388802 A1Cnergreen Corp.
Most cited
By later US patents
- Viscoelastic surfactant fluids and related methods of use217US 6,258,859 B1Rhodia Inc. · 2001
- Viscoelastic surfactant fluids and related methods of use173US 6,703,352 B2Schlumberger Technology Corporation · 2004
- Viscoelastic surfactant fluids and related methods of use119US 6,482,866 B1Schlumberger Technology Corporation · 2002
- Foaming and silt suspending agent111US 4,113,631 AThe Dow Chemical Company · 1978
- Foaming and silt suspending agent103US 4,108,782 AThe Dow Chemical Company · 1978