D21H 25/18
After-treatment of paper not provided for in groups d21h17/00 - d21h23/00: of
Official title: of old paper as in books, documents, e.g. restoring
D21H25/18 (After-treatment of paper not provided for in groups d21h17/00 - d21h23/00: of) appears on 86 US grants and 28 published applications in this corpus.
Search patents in D21H- Granted patents
- 86
- Published applications
- 28
- Assignees
- 43
- Inventors
- 158
- Latest grant
- 16 Jan 2024
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 1 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 3 | 0 |
| 1984 | 0 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 0 | 0 |
| 1988 | 1 | 0 |
| 1989 | 3 | 0 |
| 1990 | 1 | 0 |
| 1991 | 2 | 0 |
| 1992 | 5 | 0 |
| 1993 | 6 | 0 |
| 1994 | 4 | 0 |
| 1995 | 8 | 0 |
| 1996 | 3 | 0 |
| 1997 | 5 | 0 |
| 1998 | 3 | 0 |
| 1999 | 3 | 0 |
| 2000 | 2 | 0 |
| 2001 | 3 | 0 |
| 2002 | 4 | 1 |
| 2003 | 2 | 3 |
| 2004 | 4 | 5 |
| 2005 | 3 | 4 |
| 2006 | 2 | 1 |
| 2007 | 1 | 3 |
| 2008 | 1 | 1 |
| 2009 | 1 | 0 |
| 2010 | 0 | 0 |
| 2011 | 2 | 1 |
| 2012 | 0 | 0 |
| 2013 | 1 | 2 |
| 2014 | 0 | 1 |
| 2015 | 0 | 0 |
| 2016 | 1 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 1 |
| 2020 | 0 | 3 |
| 2021 | 0 | 1 |
| 2022 | 2 | 0 |
| 2023 | 2 | 0 |
| 2024 | 1 | 0 |
| 2025 | 0 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- Liquid-state temporary reinforcing material, preparation method therefor and application thereof16 Jan 2024US 11,873,605 B2Shanghai University
- Composition for use in the finishing, preservation, restoration of manufactures3 Oct 2023US 11,773,533 B2Universita' Degli Studi Di Roma “La Sapienza”
- Device for deacidifying, reinforcing and strengthening ancient books10 Jan 2023US 11,549,218 B2South China University of Technology
- Method for strengthening and reinforcing ancient books1 Nov 2022US 11,486,096 B2South China University of Technology
- Method and device for protecting paper sheet31 May 2022US 11,346,055 B2Hangzhou Zhongcai Technology Co., Ltd.
- Physical reutilization of siliconized papers30 Jan 2025US 2025/0034805 A1Evonik Operations GmbH
- Composition for use in the finishing, preservation, restoration of manufactures15 Apr 2021US 2021/0108362 A1Universita' Degli Studi Di Roma “La Sapienza”
- Liquid-state temporary reinforcing material, preparation method therefor and application thereof9 Jul 2020US 2020/0217009 A1Shanghai University
- Novel device for deacidifying, reinforcing and strengthening ancient books21 May 2020US 2020/0157742 A1South China University of Technology
- Novel method for strengthening and reinforcing ancient books21 May 2020US 2020/0157743 A1South China University of Technology
Most cited
By later US patents
- Sleeved tissue product81US 7,914,866 B2Kimberly-Clark Worldwide, Inc. · 2011
- Method of retarding paper degradation with time by treatment with melamine, and method of producing ageing-resistant paper coated with melamine33US 4,619,735 AMelamine Chemicals, Inc. · 1986
- Apparatus and method for drying and restoring wet books23US 5,038,494 ADocument Reprocessors · 1991
- Method of deacidifying paper21US 4,051,276 AThe United States Government as represented by the Librarian of Congress · 1977
- Method of deacidifying paper20US 3,969,549 AThe United States of America as represented by the Librarian of Congress · 1976