Application Testing of Propionate Solvents (1)

1. Butyl Propionate (NBP) Test (Comparison with Xylene and Propylene Glycol Methyl Ether Acetate)

Experimental Formula:

The solvents were propyl propionate (NPP), xylene (XYL), and butyl acetate (BAC), resulting in three formulations.

Paints were prepared according to the above formulas and viscosity tests were conducted. The experimental results are as follows:

From the above data, it can be concluded that compared to XYL and PMA, NBP has better solvency, resulting in a lower viscosity after thinning. Furthermore, during the continuous 4-hour viscosity monitoring, NBP showed the smallest change in viscosity, indicating that this system has a longer pot life and higher application tolerance.

Drawdown panels were made, baked at 80°C for 1 hour, and the panel appearance was examined with related tests conducted.

Test Item	XYL	PMA	NBP
Film Thickness, μm	20.3, 32.9, 45.8	20.2, 35.7, 46.9	17.8, 28.2, 35.4
Hardness	HB	HB	HB
Adhesion, Grade	0	0	0
Impact Resistance, Direct 50cm	Cracked	Cracked	Cracked
Gloss, 20/60/85°	80.9, 92.9, 97.6	85.9, 93.5, 97.8	85.4, 93.6, 98.3
Panel Appearance

The NBP system had the thinnest film, followed by XYL and PMA , which corresponds to the initial drawdown viscosity: lower viscosity results in better flow and a thinner film. The gloss of the NBP system was slightly higher, but not significantly. All three panels showed good appearance with no obvious differences.