Ultraviolet resistance of epoxy vs. acrylic black paint

[Wicsteve]

We're trying to determine what is the realistic disadvantage of using epoxy E-coated component parts vs. acrylic E-coated parts in regards to ultraviolet protection. The paint color is black. What are the detrimental effects of ultraviolet? Wouldn't the black color in itself help resist ultraviolet deterioration?

 

[TVP]

Epoxy-based materials will have very poor resistance to UV radiation. Acrylic-based materials have much better performance. Polymers that are colored with carbon black tend to perform better, as carbon black has some beneficial interaction with the UV rays.

The mechanism for polymer degradation when exposed to UV radiation is pi bond (carbon to carbon double bond) scission. Epoxies generally contain many benzene rings, which are particularly susceptible to this damage.

 

[Wicsteve]

Thanks