  Only ~10 blazars have been detected in soft gamma-rays by OSSE and the PDS,
often in flaring state. We investigate the impact of the imaging and spectral
capabilities of the IBIS instrument on board INTEGRAL on the study of blazars.
The objectives are: 1) to remove ambiguities in the identification of some
blazars as soft gamma-ray emitters; 2) to determine the spectral shape of
"extreme synchrotron" blazars, namely sources with high F_X/F_radio ratios, for
which the synchrotron component peaks at far UV-soft X-ray frequencies. We
expect that in these sources the synchrotron peak shifts to higher energies
during outbursts, making them strong soft gamma-ray emitters, and therefore
possible targets for INTEGRAL wide band X- and gamma-ray spectroscopy.
