Properties of Fluoro-Silicone Modifed Films
April 2014 www.coatingsworld.com Coatings World | 35
In SyStem IV, an in house, all silicone epoxy resin based cationic UV epoxy cured system uses a cycloaliphatic epoxy silicone (Silmer ePC e9 from Siltech) with the relevant percentage
of FAS (0.2%, 0.5%, 1%, 3%, 5%) added, along with 0.5%
UV9380C by momentive (a cationic catalyst for UV curing.)
Formulations were as follows:
TABLE E: FORMULATIONS OF SYSTEM IV – CATIONIC UV
EPOXY SILICONE WITH VARIOUS FAS ADDITIVES
the above formulations are mixed, and then drawn down
on Leneta paper in a 1 mil thickness coating using a wire-wound
rod #10. each paper is then placed in a 10 m W/cm2 UV box for
1 hour to cure, and then kept at room temperature for at least
one day before testing.
In SyStem V, commercial Behr 1050 flat white paint was obtained from a retail store and the fluoroalkylsilicone samples
were post-added. After thorough mixing, each paint sample
was drawn down on Leneta paper in a 1 mil thickness coating
using a wirewound rod 10. each paper is allowed to dry at
ambient conditions for approximately seven days before testing.
Stain Resistance ASTM D3450
For Systems I, II and III: one drop of test fluid stain was carefully applied to the test surface. Creation of an indentation was
avoided when using a marker or pen because this would reduce
the rub tester’s effectiveness. the solution was allowed to remain for one hour before being wiped with paper towel. Any
staining is observed and recorded from 1-10 (1 being the worst,
and 10 being completely clean.) next a Sutherland 2000 rub
tester is used to wipe the stain with a Kimwipe saturated with
water for 25 cycles ( 50 wipes) at 84 rpm. the remaining stain is
evaluated qualitatively again from 1-10.
System IV & V differed in that only 42 rubs were used on the
rub tester and a 64:1 diluted solution of commercial cleaner was
used instead of water.
test fluids used: Blue pen ink, black marker ink, silicone pigments (by Dispersion technologies Inc. and Smooth-On Inc.,)
black sharpie ink, red sharpie ink, graphite pencil, printer ink,
crayon, and pencil crayon.
Finger Print Resistance
Finger print resistance was determined by visual inspection of
finger imprints remaining on the panel surface after gentle pressing and rubbing with fingers. A score of 10 is the best, which
represents absence of finger prints, and 0 is the worst.
Gloss
Gloss is measured with a ByK-Gardner 60° micro-glossmeter.
Gloss value is directly recorded from the micro-glossmeter display. 0 is the lowest possible score.
Mar Resistance
First, the initial 60° gloss is measured using a ByK-Gardner
60° micro-glossmeter. the gloss value is read directly from the
micro-glossmeter display. Afterwards, the sample is rubbed for
500 rubs at 84 rpm using a 4 lb test block attached to a nylon
scrubbing pad. A final 60° gloss value is recorded again. mar
resistance is quantified by percent remaining gloss after rubbing. Qualitative scores are also recorded from 1-10. ( 10 is the
best). For low gloss paint sample, only the qualitative scores
are collected.
Coefficient of Friction
Slip was measured with ChemInstruments Coefficient of Friction
-500. (test speed: 15 cm/min; travel length: 15 cm; Sled weight:
200 grams. the Sled surface is covered with AStm-specified
rubber). Static coefficient of friction was directly obtained from
the equipment, representing the ratio of the horizontal component of the force (required to overcome the initial friction) to
the vertical component of the object weight. Dynamic (Kinetic)
coefficient of friction was also directly obtained from the equipment, representing the ratio of the horizontal component of the
force (required to cause the object to slide at a constant velocity)
to the vertical component of the object weight. the greater the
value, the higher the friction is for the substrate.
