K-FLEX XM-337 is designed for VOC-compliant, 2-component polyurethanes and melamine baking systems with improved flexibility, hardness and toughness. 

The high Tg provides the hardness of an aromatic polyester but with light stability.  Despite its’ high viscosity (55,000 cP) it reduces efficiently to a spray viscosity at 85% solids with MIBK or n-butyl acetate. 

Excellent solubility is also found with most solvents, including exempt solvents like t-butyl acetate and Oxsol 100.

 Better performance was found with a 0.6mil K-Flex XM 337 modified acrylic film than a 0.6 and 2.1mil film of the acrylic control. 

Modification results of:
  • Pigmented acrylic 2-component polyurethane (14% XM-337 on TRS)
    • VOC reduced by 15.7%
    • Improved reverse impact resistance from <5 in-lbs to 150-160 in-lbs
    • Maintained the hardness of the acrylic
  • Acrylic/melamine (20 min/135 °C) clearcoat (15% XM-337 on TRS)
    • VOC reduced by 8.1%
    • Improved reverse impact resistance from <5 in-lbs to 130-140 in-lbs
    • Higher pendulum hardness of 145 cycles versus 134 for the acrylic control