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DIFF Subgroup
C01B 33/18

Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)

Introduced: September 1968

Title

Titles differ between systems:

IPC: Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof

CPC: Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)

Full Title

Full titles differ between systems:

IPC:

Silicon; Compounds thereof > Silicon oxides; Hydrates thereof > Silica; Hydrates thereof, e.g. lepidoic silicic acid > Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof

CPC:

Silicon; Compounds thereof ( C01B21/00, C01B23/00 take precedence; persilicates C01B15/14; carbides C01B32/956) > Silicon oxides; Hydrates thereof > Silica; Hydrates thereof, e.g. lepidoic silicic acid > Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)

CPC subdivides this area 3x more granularly than IPC with 2 additional codes.

2 codes are CPC-only extensions.

IPC defines codes here since 1980.

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Top Applicants

Top Applicants (IPC)

Class C01,2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINESE ACADEMY OF SCIENCES 5,794
  2. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 3,286
  3. LG CHEM KR 2,689
  4. BASF (BADISCHE ANILIN & SODA FABRIK) DE 1,669
  5. CENTRAL SOUTH UNIVERSITY 1,531
  6. KMUST (KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY) 1,252
  7. SUMITOMO METAL MINING COMPANY JP 1,073
  8. ZHEJIANG UNIVERSITY 1,061
  9. PANASONIC INTELLECTUAL PROPERTY JP 1,058
  10. PANASONIC INTELLECTUAL PROPERTY 1,038

Top Applicants (CPC)

Class C01,2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINESE ACADEMY OF SCIENCES 4,293
  2. LG CHEM KR 3,317
  3. BASF (BADISCHE ANILIN & SODA FABRIK) DE 2,219
  4. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 2,154
  5. OMYA INTERNATIONAL CH 1,524
  6. PANASONIC INTELLECTUAL PROPERTY JP 1,362
  7. SAUDI ARABIAN OIL COMPANY SA 1,298
  8. SUMITOMO METAL MINING COMPANY JP 1,286
  9. CENTRAL SOUTH UNIVERSITY 1,243
  10. L'AIR LIQUIDE SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE FR 1,238