What is a two-component water based polyurethane finish?

Wednesday, 22 November 2017

That’s a question you may have asked but the explanation is not always as simple as it sounds. 

 In this article, we’ll try to demystify two-component finishes by considering its components, strengths and weaknesses.

First lets address exactly what a two-component finish consists of. Yes you guessed right there are 2 necessary elements. Part A is a water based polyurethane, and Part B consists of a catalyst or crosslinking agent. 

Catalysts are used in a variety of different applications, but in the waterbased finish industry the 2 most popular are isocyanate and aziridine. What are the differences?

 Isocyanate are a family of highly reactive, very toxic chemicals which when combined with polyurethane act as a hardener. Once added to the finish there is a  3-4 hour open time to apply the coating. After that the isocyanate starts to congeal the finish making it impossible to work with. The remaining catalyzed finish is no longer of any value.   

The Aziridine is an organic chemical compound which is designed to provide superior durability and chemical resistance. While still toxic and requires proper care when working with it, this product is less toxic than its predecessor. Once added to the finish, the catalyst is active for 12 hours, after which the effectiveness of the catalyst is no longer remains, yet the product remains liquid and with care could even be re-catalyzed. There is no loss of product when Aziridine is used as the catalyst.   

 Finitec offers in the Finitec Expert program a two-component water based polyurathane called Ex-Duo which uses aziridine as its catalyst. But unlike other water based finish manufactures the full line of Finitec Expert finishes can be catalysed to enhance their performance.

But why choose a two-component over a single-component finish?

When incorporating the catalyst in the finish we accelerate the cure, and improve the finishes ability to resist water, abrasion and chemical products.

Hope this article helped answer your question.   

 If you have any questions or concerns regarding two-component finishes, please feel free to contact Jeff Cowx Finitec s coating specialist at jcowx@finitec-inc.com