CPC Main Group
C04B 33/00 Clay-wares (monolithic refractories or refractory mortars C04B35/66; porous products C04B38/00)
Filing statistics
CPC C04B 33/00 belongs to the parent subclass C04B, which recorded 228,252 patent applications worldwide between 2013 and 2023. Annual filings grew from 10,861 in 2013 to 20,066 in 2023 (+85%), peaking at 27,356 applications in 2018. The most active applicants in class C04 are HALLIBURTON ENERGY SERVICES GROUP (2,158 applications), CHINESE ACADEMY OF SCIENCES (1,569 applications) and NGK INSULATORS (1,504 applications).
Source: EPO PATSTAT, worldwide filings
7 direct subcodes
Child Classifications
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- C04B 33/02 Preparing or treating the raw materials individually or as batches
- C04B 33/22 Grog products
- C04B 33/24 Manufacture of porcelain or white ware
- C04B 33/28 Slip casting (mechanical features B28B1/26)
- C04B 33/30 Drying methods
- C04B 33/32 Burning methods
- C04B 33/36 Reinforced clay-wares
Top Applicants
Top 10 applicants by patent filingsfor 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