Glycol Ether TPNB - Tripropylene Glycol Normal Butyl Ether - is a colorless liquid with mild odor, a slow evaporation rate, and a high boiling point. Glycol Ether TPNB is a non-HAP coalescent well suited for water-borne coatings. The hydrophobic nature of Glycol Ether TPNB leads to its low water solubility and high organic solubility.