Analysis of chemical abundances in planetary nebulae with [WC] central
  stars. II. Chemical abundances and the abundance discrepancy factor
  (Abridged) We present the abundance analysis of 12 PNe ionized by [WC]-type
stars and wels obtained from high-resolution spectrophotometric data. Our main
aims are to determine the chemical composition of the PNe and to study the
behaviour of the abundance discrepancy problem (ADF) in this type of planetary
nebulae. The detection of a large number of optical recombination lines (ORLs)
and collisionally excited lines (CELs) from different ions were presented
previously. Most of the ORLs were reported for the first time in these PNe.
Ionic abundances were derived from the available CELs and ORLs, using
previously determined physical conditions. Based on these two sets of ionic
abundances, we derived the total chemical abundances in the nebulae using
suitable ICFs (when available). In spite of the [WC] nature of the central
stars, moderate ADF(O^++), in the range from 1.2 to 4, were found for all the
objects. We found that when the quality of the spectra is high enough the ORLs
O^++/H^+ abundance ratios obtained from different multiplets excited mainly by
recombination are very similar. Possible dependence of ADFs with some nebular
characteristics were analysed, finding no correlation. Abundances derived from
CELs were corrected by determining the t^2 parameter. O abundances for PNe,
derived from ORLs, are in general larger than the solar abundance. We derived
the C/O ratio from ORLs and N/O and alpha-element/O ratios from CELs and found
that these PNe are, in average, N-and C-richer than the average of large PN
samples. About half of our sample is C-rich (C/O>1). The alpha-elements grow in
lockstep with O abundance. Comparing the N/O and C /O ratios with those derived
from stellar evolution models, we estimate that about half of our PNe have
progenitors with initial masses > 4 M_sun. No correlation was found between the
stellar [WC]-type and the nebular abundances.
