DIFF Main Group
D21H 25/00 After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
Introduced: January 1990
Title
Titles differ between systems:
IPC: After-treatment of paper not provided for in groups
CPC: After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
Full Title
Full titles differ between systems:
IPC:
After-treatment of paper not provided for in groups
CPC:
After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
Of 5 combined children, 4 exist in both systems.
1 codes are CPC-only extensions.
4 shared codes have differing titles between IPC and CPC.
IPC defines codes here since 1990.
Child Classifications
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- D21H 25/02 Chemical or biochemical treatment (D21H25/18 takes precedence) since 1990 IPC+CPC Available in IPC and CPC
- D21H 25/04 Physical treatment, e.g. heating, irradiating (D21H25/18 takes precedence; dryer section of machines for making continuous webs of paper D21F5/00) since 1990 IPC+CPC Available in IPC and CPC
- D21H 25/08 Rearranging applied substances, e.g. metering, smoothing; Removing excess material since 1990 IPC+CPC Available in IPC and CPC
- D21H 25/18 of old paper as in books, documents, e.g. restoring since 1990 IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class D21,2013–2023, worldwide · Source: EPO PATSTAT
- VOITH PATENT DE 1,809
- STORA ENSO FI 1,467
- KEMIRA FI 1,086
- KIMBERLY-CLARK CORPORATION US 935
- VALMET TECHNOLOGIES FI 924
- VALMET SE 904
- P&G (PROCTER & GAMBLE COMPANY) US 862
- OJI HOLDINGS CORPORATION 696
- OMYA INTERNATIONAL CH 584
- SOUTH CHINA UNIVERSITY OF TECHNOLOGY 571
Top Applicants (CPC)
Class D21,2013–2023, worldwide · Source: EPO PATSTAT
- VOITH PATENT DE 1,857
- STORA ENSO FI 1,552
- KEMIRA FI 1,173
- KIMBERLY-CLARK CORPORATION US 1,107
- VALMET TECHNOLOGIES FI 965
- VALMET SE 943
- P&G (PROCTER & GAMBLE COMPANY) US 941
- OMYA INTERNATIONAL CH 821
- UPM-KYMMENE CORPORATION FI 512
- SEIKO EPSON CORPORATION JP 501