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DIFF Subgroup
C04B 11/028

Devices therefor

Introduced: January 1985

Full Title

Full titles differ between systems:

IPC:

Calcium sulfate cements > Dehydrating gypsum > Devices therefor

CPC:

Calcium sulfate cements > dehydrating gypsum > Devices therefor

CPC subdivides this area 4x more granularly than IPC with 6 additional codes.

6 codes are CPC-only extensions.

1 shared codes have differing titles between IPC and CPC.

IPC defines codes here since 1985.

Child Classifications

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  • C04B 11/0283 CPC only CPC only
  • C04B 11/0285 CPC only CPC only
  • C04B 11/0286 CPC only CPC only
  • C04B 11/0287 CPC only CPC only
  • C04B 11/0288 CPC only CPC only
  • C04B 11/032 for the wet process, e.g. dehydrating in solution or under saturated vapour conditions, since 1985 IPC+CPC Available in IPC and CPC
  • C04B 11/036 for the dry process, e.g. dehydrating in a fluidised bed or in a rotary kiln since 1985 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class C04,2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINESE ACADEMY OF SCIENCES 2,095
  2. WUHAN UNIVERSITY OF TECHNOLOGY 1,205
  3. NGK INSULATORS JP 1,133
  4. HALLIBURTON ENERGY SERVICES GROUP US 1,049
  5. SIKA TECHNOLOGY CH 1,041
  6. GUILIN UNIVERSITY OF TECHNOLOGY 807
  7. WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY 806
  8. SOUTHEAST UNIVERSITY 801
  9. CORNING US 777
  10. UNITED STATES GYPSUM COMPANY US 739

Top Applicants (CPC)

Class C04,2013–2023, worldwide · Source: EPO PATSTAT

  1. HALLIBURTON ENERGY SERVICES GROUP US 2,158
  2. CHINESE ACADEMY OF SCIENCES 1,569
  3. NGK INSULATORS JP 1,504
  4. SIKA TECHNOLOGY CH 1,181
  5. CORNING US 974
  6. WUHAN UNIVERSITY OF TECHNOLOGY 926
  7. UNITED STATES GYPSUM COMPANY US 882
  8. GE (GENERAL ELECTRIC COMPANY) US 828
  9. MITSUBISHI MATERIALS CORPORATION JP 792
  10. SAUDI ARABIAN OIL COMPANY SA 686