Innovative Binder Technology for High-Solids Industrial Coatings
Test Formulation
The properties of the aforementioned
resins were compared using formulated
2-pack paints. Two variants of the new
silicone hybrid resins were compared
with a commercial high-solids polyester:
• A Silicone hybrid resin with more
flexible segments;
• B Silicone hybrid resin with rigid
segments; and
• C High-solids polyester.
A typical test formulation for the silicone hybrid resin is shown in Table 1.
Non-volatile data and VOC content of
the paints is shown in Table 2.
Chemical Resistance
After paint application and curing, resistance to liquids was tested according to
ÖNORM EN 12720 “Furniture – assessment of resistance of surfaces to cold liquids.” The resistance was tested according
to ÖNORM A 1605-12 within Class
1-B1; test results are shown in Figure 2.
The assessment criteria for determining
chemical resistance is noted in Table 3.
Silicone hybrid B shows immediately
– and particularly after a recovery of 24
hours – optimum resistance to the liquids
mentioned above. This is attributable to
the higher rigid segment content in the
silicone hybrid.
Silicone hybrid resin B exhibits outstanding resistance to various liquids in
tests carried out according to DIN EN
ISO 2812-4 (Table 4).
Salt Spray Test
The use of the new type of silicone hybrid results in paint films with a very
high crosslinking density. This, together
with skillful formulation of pigments
and fillers in the paint, is an important
influence in withstanding the salt spray
test. A 2-pack epoxy primer was applied to a sand-blasted steel substrate.
The primer was then overcoated with a
white topcoat based either on the new
type of silicone hybrid resins or on conventional polyester C. The test was carried out in accordance with DIN EN
ISO 12944 Category C5 I and M. The
images (Figure 3) show results after
1440 hours.
Stone Impact Test
Resistance to stone impact was tested ac-
cording to DIN EN ISO 20567 1. Metal
panels were prepared by painting them
with 2-pack epoxy primer and topcoats
based on silicone hybrid resins (A, B)
and polyester (C). After a period of re-
covery, testing was carried out on the
coated panels.
The results (Table 5 and Figure 4)
Table 2: VOC and NVC content of NCO cured paints.
Figure 2: Chemical resistance testing.
Table 3: Assessment criteria.
