Type UR (urethane resin) conformal coatings are a popular choice for conformal coating projects because of their resistance to chemical solvents, hardness, and moisture protection.  There are many different varieties of type UR conformal coatings such as:

• HumiSeal 1A33
• HumiSeal 1A20
• Humiseal 1A27
• Humiseal 2A64
• HumiSeal 1A34
• Hysol PC18M
• CONATHANE CE-1155-35
• CONAP CE-1170
• CONATHANE CE-1164
• Techspray Fine-L-Kote
• MG Chemicals 4223
• Electrolube PUC

You should consider using type ur conformal coating whenever your application has any issues with chemical resistivity as type ur coatings are very resistant to chemical solvents.  Type ur conformal coating is also smart to include in any tin whisker mitigation strategy, as NASA studies have shown that urethane conformal coatings are one of the few ways to successfully mitigate tin whisker growth.  Finally, applications that can see any direct mechanical wear against the coating should consider urethane conformal coatings as well.

Download Our Guide on Urethane Resins