140 HIGH PERFORMANCE POLYMERS
The corrosion of a mold causes a great economical
loss because the mold is expensive. Moreover,it is then
difficult to precisely mold. In order to solve corrosive
problems involved in the PAS resins, it has been pro-
posed to blend various kinds of corrosion inhibitors.
However, certain corrosion inhibitors, such as
γ -alumina, calcium carbonate, zinc oxide, sodium
oxalate, etc., show insufficient corrosion inhibition.
For some corrosion inhibitors, the mechanical strength
of the PAS resin is deteriorated. More satisfactory cor-
rosion inhibitors are nickel compounds, such as nickel
carbonate, nickel hydroxide, and nickel citrate [80].
The anticorrosive effect is already satisfactory when
the corrosion inhibitor is added in