scope:

This specification covers the qualifications and performance requirements for flexible, exterior, one component (1K), solventborne basecoat/one component solventborne clearcoat topcoats for use over plastic substrates, typically thermoplastic olefin, over a bake latitude of approximately 115 ºC to 135 ºC (240 ºF to 275 ºF). This topcoat system is not intended for use on large exterior surfaces such as fascia, spoilers, and rocker panels on vehicles produced for the North American market.

Material Description. Basecoat components of these systems are typically one component (solvent) acrylic/melamine. Clearcoat components of these systems are one component (solvent) technologies with varying cross-linking chemistries, but typically acrylic/melamine. Typical volume solids as sprayed are typically 35% to 50% for basecoats and 45% to 60% for clearcoats. Each combination of specific basecoat and clearcoat must be tested and approved as a basecoat/clearcoat system. The individual components are not interchangeable, and are approved for use only with combinations of basecoat/clearcoat of the total paint system which was used in the qualification testing. It must also be compatible with specific adhesion promoters and/or primers used with specific plastics.

Symbols. Not applicable.

Applicability. These topcoats are designed to be applied over an approved adhesion promoter or baked primer. All thermoplastic polyolefin substrates using 9984852 must be applied over an adhesion promoter (9984808 or 9984810) or flame treatment per GMW16133.