Autodeposition compositions for polymeric coatings of reduced gloss are
prepared using resins having at least one hydroxy group and at least one
epoxy group per molecule, a low temperature crosslinker and a high
temperature crosslinker. The low temperature crosslinker forms a reactive
prepolymer that may be subsequently mixed or emulsified with a high
temperature crosslinker to form an autodeposition composition.
Alternatively, a hybrid crosslinking agent may be utilized which contains
both free isocyanate groups reactive at a relatively low temperature with
the resin and at least one functional group capable of reacting with the
resin only at a relatively elevated temperature. When deposited and cured,
the resulting coating has a matte finish that is resistant to surface
defects.