Infrared properties of Planetary Nebulae with [WR] and $wels$ central
  stars
  We report the IR properties of planetary nebulae with WR type and $wels$
central stars known to date and compare them with the IR properties of a sample
of PNe with H-rich central stars. We use near-, mid- and far-IR photometric
data from archives to derive the IR properties of PNe. We have constructed IR
colour-colour diagrams of PNe using measurements from $2MASS$, $IRAS$, $WISE$
and $Akari$ bands. [WR] PNe have a larger near-IR emission from the hot dust
component and also show a tendency for stronger 12$\mu$m emission as compared
to the other two groups. Cool AGB dust properties of all PNe are found to be
similar. We derived the dust colour temperatures, dust masses, dust-to-gas mass
ratios, IR luminosities and IR excess of PNe for these three groups. [WR] PNe
and $wels$-PNe tend to have larger mean values for dust mass when compared to
the third group. The average dust-to-gas mass ratio is found to be similar for
the three groups of PNe. While there is a strong correlation of dust
temperature and IR luminosity with the age for the three groups of PNe, the
dust mass, dust-to-gas mass ratios and IR excess are found to be non-varying as
the PNe evolve. [WR] PNe and $wels$-PNe show very similar distribution of
excitation classes and also show similar distribution with Galactic latitude.
