There is a difference between epoxy floor paint and wall epoxy paint.

Wall epoxy paint contain thixotropic additives while epoxy floor paint, marine epoxies, etc. do not.
Basically, thixotropic additives are gelling agents. They give the epoxy paint a gel-type status after it has been applied. The gel property does not show while applying the paint. The thixotropic agent gels the epoxy paint after the brushing or rolling of the epoxy paint has been completed. This 'gelling effect' will ensure that the thickness of the paint will be the same both at the top and the bottom of the vertical surface.

It is not recommended to use thixotropic paint to do epoxy floor paint . The more the epoxy paint flows after the application over the floor the more it will get self-levelled. Using a thixotropic epoxy paint on the floor might leave brush or roller marks and it might not level out smoothly or quickly.

Fumed silica is a thixotropic additive which when mixed with the epoxy resin system increases its viscosity and imparts the thixotropic characteristics before and during the potlife of the epoxy resin system.

The addition of thixotropic additives to the floor epoxy paint or marine epoxy resins will transform them to epoxy wall paint.Look for term " thixotropic " in the glossary

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You can find more about epoxy floor paint in the eBook"The Best Web Epoxy Links"