In this work we present the first of two papers devoted to the study of the X-ray spectral characteristics of Seyfert 1 galaxies in the Piccinotti sample .
In particular we analyse here the BeppoSAX broad band ( 0.1-100 keV ) data of 4 objects which , despite their X-ray brightness , have been historically poorly studied due to their late identification with an AGN ; these are H0111-149 ( MKN1152 ) , H0235-525 ( ESO198-G24 ) , H0557-385 ( IRAS F05563-3820 ) and H1846-786 ( IRAS F18389-7834 ) .
We have assumed for all the sources a baseline model which includes a power law with an exponential cut-off plus a reflection component and an iron K _ { \alpha } line ; we have also searched for the presence of intrinsic absorption and/or a soft excess component .
Our analysis indicates the presence of complex absorption in two objects ( H0557-385 and H0111-149 ) best described by a combination of two uniform absorbers , one cold and one warm .
Only in one source , H0557-385 , a soft excess component has been measured .
The primary continuum is best described by a canonical power law ( \Gamma =1.7-2 ) with a high energy cut-off in the range 40-130 keV .
A cold reflection component is likely present in all sources with values ranging from less than 0.6 to higher than 2 .
In 3 out of 4 objects we find a cold iron line having equivalent width typical of Seyfert 1s ( 100-200 eV ) .