DIFF Subgroup
C01B 33/157 After-treatment of gels
Introduced: January 1980
Full Title
Full titles differ between systems:
IPC:
Silicon; Compounds thereof > Silicon oxides; Hydrates thereof > Silica; Hydrates thereof, e.g. lepidoic silicic acid > Colloidal silica, e.g. dispersions, gels, sols > After-treatment of gels
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 > Colloidal silica, e.g. dispersions, gels, sols > After-treatment of gels
IPC and CPC are identically structured here. All 2 subcodes exist in both systems.
IPC defines codes here since 1980.
Child Classifications
Navigate with arrow keys, Enter to open