DIFF Main Group
C04B 11/00 Calcium sulfate cements
Introduced: September 1968
Of 8 combined children, 5 exist in both systems.
3 codes are CPC-only extensions.
4 shared codes have differing titles between IPC and CPC.
Child Classifications
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- C04B 11/05 obtaining anhydrite, (C04B11/028 takes precedence) since 1985 IPC+CPC Available in IPC and CPC
- C04B 11/26 ; starting from phosphogypsum or from waste, e.g. purification products of smoke (C04B11/02 takes precedence; chemical purification of smoke, fumes or exhaust gases B01D53/00 ) since 1985 +3 CPC IPC+CPC Available in IPC and CPC
- C04B 11/28 Mixtures thereof with other inorganic cementitious materials (C04B7/04, C04B7/153 take precedence) since 1985 IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class C04,2013–2023, worldwide · Source: EPO PATSTAT
- CHINESE ACADEMY OF SCIENCES 2,095
- WUHAN UNIVERSITY OF TECHNOLOGY 1,205
- NGK INSULATORS JP 1,133
- HALLIBURTON ENERGY SERVICES GROUP US 1,049
- SIKA TECHNOLOGY CH 1,041
- GUILIN UNIVERSITY OF TECHNOLOGY 807
- WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY 806
- SOUTHEAST UNIVERSITY 801
- CORNING US 777
- UNITED STATES GYPSUM COMPANY US 739
Top Applicants (CPC)
Class C04,2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 2,158
- CHINESE ACADEMY OF SCIENCES 1,569
- NGK INSULATORS JP 1,504
- SIKA TECHNOLOGY CH 1,181
- CORNING US 974
- WUHAN UNIVERSITY OF TECHNOLOGY 926
- UNITED STATES GYPSUM COMPANY US 882
- GE (GENERAL ELECTRIC COMPANY) US 828
- MITSUBISHI MATERIALS CORPORATION JP 792
- SAUDI ARABIAN OIL COMPANY SA 686