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CPC Subgroup Additional Only
C04B 2235/3217

Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina

Full Title

Aspects relating to ceramic starting mixtures or sintered ceramic products > Composition of constituents of the starting material or of secondary phases of the final product > Constituents and secondary phases not being of a fibrous nature > Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides > Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina

3 direct subcodes

Child Classifications

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  • C04B 2235/3218 Aluminium (oxy)hydroxides, e.g. boehmite, gibbsite, alumina sol
  • C04B 2235/322 Transition aluminas, e.g. delta or gamma aluminas
  • C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)

Top Applicants

Top 10 applicants by patent filingsfor 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