In recent years, waterborne adhesion promoters applied to TPO substrates have
been widely studied for use as both interior and exterior automobile coatings
due to an increasing environmental awareness by industry. Furthermore, the
automotive coatings industry desires waterborne coatings for TPO substrates that
coalesce and adhere well at low baking temperatures, such as 80
Polyolefin Starting MaterialsPolyolefin with different propylene
content: Three different
propylene-based polyolefins with relatively low crystallinity and Tm
were used as the starting materials of WCFPOs. z-PO is a traditional polyolefin
polymerized with a Ziegler-Natta catalyst and contains a smaller amount of
propylene than the other polyolefins. m-PO is a metallocene polyolefin and has
as low a Tm as z-PO, although the propylene
content is much higher than that of the z-PO. m-PP is also polymerized with a
metallocene catalyst, but without any ethylene and other a-olefin monomers. The crystallinity and the
Tm of m-PP are low enough due to the low
tacticity. The starting materials were chosen for each resulting WCFPO to have
a similar molecular weight, Tm, and a minimum
film formation temperature (MFT).