Import mesh with submeshes from OBJ?

I'm trying to export an OBJ file from 3ds max with 3 submeshes. I have:

• assigned them all different material ID's

• given a multi-sub material to the object

• named all the submaterials

• checked the "export materials" checkbox in the export dialog

However, when I attach a script that shows me how many submeshes are in the object, it still says 1

code:

 void Start () {
 Debug.Log(mesh.subMeshCount);
 }

result:

 1

What am I doing wrong here?