Top IPC subclasses
1
|
C01B
|
1
|
non-metallic elementscompounds thereof
|
2
|
C01G
|
1
|
Compounds containing metals not covered by subclasses C01D or C01F
|
3
|
B01J
|
1
|
Chemical or physical processes, e.g. catalysis, colloid chemistry; their relevant apparatus
|
4
|
C07F
|
1
|
acyclic, carbocyclic, or heterocyclic compounds containing elements other than carbon, hydrogen, hal
|