Handbook of Solvents - George Wypych - ChemTech - Ventech!

1206 Margot Scheithauer
not refer to 1 liter of an actual varnish, but to a hypothetical product, which only expresses
the binding agent in liters.
This is demonstrated in Example 1, which will then also be calculated according to
other methods.
Example 1:
Water spray varnish: 30% solid matter content (binding agent and pigments)
10% solvent content
60% water content
varnish density: 1.0 g/cm 3
VOC (g/l) = (700 g - 600 g)/(1 l - 0.6 l) = 250 g/l
18.1.3.3 Determination of the VOC content according to ISO/DIS 11 890/1 5
and 2 6
18.1.3.3.1 VOC content > 15%
The calculation according to ISO/DIS 11 890/1 gives a more logical result. VOCs are given
here as a mass share in % of the ready-to-use varnish. At a VOC content > 15 % (of the mass
share), the determination is made by the differential approach:
VOC [% of the mass share] = 100 - nfA-m w
[18.1.2]
where:
nfA non-volatile parts determined by ISO 3251 22 (1 h/110°C)
mw mass as water in % of the mass parts, determined according to ISO 760 23 (after
Karl-Fischer)
Many more recently available techniques for water determination are not sufficiently
common and thus are not considered.
Example 2:
Water solvent stain: 5% solid matter content = non-volatile parts
25% solvent
70% water share
VOC (mass %) = 100 -5-70=25%
For density ≠ 1
VOC [g/l] = 10(100 - nfA-m w)ρ s
where:
ρs varnish density in g/ml at 23°C
In this case, the VOC content refers to 1lofactual varnish.
Example 3:
Solvent stain: 5% solid matter content
95% solvent share
VOC (g/l) = (100 -5-0)×0.9 = 855 g/l
Example 4:
Solvent/water stain: 5% solid matter content
70% solvent
25% water share
[18.1.3]