CPC Subgroup
D21H 17/67 Water-insoluble compounds, e.g. fillers, pigments
Full Title
Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution > Inorganic compounds > Water-insoluble compounds, e.g. fillers, pigments
3 direct subcodes
Child Classifications
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- D21H 17/68 siliceous, e.g. clays
- D21H 17/69 modified, e.g. by association with other compositions prior to incorporation in the pulp or paper
Top Applicants
Top 10 applicants by patent filingsfor 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