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CPC Subgroup
D21H 21/44

Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods

Full Title

Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties > characterised by function or properties in or on the paper (D21H19/66, D21H27/02 take precedence) > Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper (watermarking B41M3/10, D21F1/44; security printing B41M3/14; securities or banknotes characterised by colour effects B42D25/29, B42D25/30; testing paper currency or valuable papers for genuineness G07D7/00) > Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods

2 direct subcodes

Child Classifications

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  • D21H 21/46 Elements suited for chemical verification or impeding chemical tampering, e.g. by use of eradicators
  • D21H 21/48 Elements suited for physical verification, e.g. by irradiation

Top Applicants

Top 10 applicants by patent filingsfor class D21, 2013–2023, worldwide · Source: EPO PATSTAT

  1. VOITH PATENT DE 1,857
  2. STORA ENSO FI 1,552
  3. KEMIRA FI 1,173
  4. KIMBERLY-CLARK CORPORATION US 1,107
  5. VALMET TECHNOLOGIES FI 965
  6. VALMET SE 943
  7. P&G (PROCTER & GAMBLE COMPANY) US 941
  8. OMYA INTERNATIONAL CH 821
  9. UPM-KYMMENE CORPORATION FI 512
  10. SEIKO EPSON CORPORATION JP 501