Autodeposited coating of epoxy and OH groups-containing resin with NCO lower T crosslinker and higher T crosslinker

Abstract

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.

Dependencies are inferred from the claim text.