HiTone resins are used to improve the affinity of pigments in powder coatings

Powder coating manufacturers are constantly exploring ways to improve price/performance. The methods to reduce costs are: to improve the pigment filling, the construction of a thin coating. However, these methods can lead to a decrease in performance such as fluidity, gloss and cover. These problems can be overcome with high fill epoxy resins, flow aids and pigment aids. On the other hand, this also has a negative effect, which can lead to higher costs, yellowing and reduced powder stability.
the pigment content, the worse the appearance of the powder coating. Achieving the required covering force requires an increase in pigment content, especially if the construction coating is thin. The difference between the appearance of the standard pigment filling and the high pigment fill powder coating system is shown in figure
1
.
resin developed on the basis of the special theory
-HiTone
theory (high-tone theory) can overcome the problem of fluidity and appearance when filling high pigments. The aim of the study was to improve affinity between pigments and resins without affecting important properties such as fluidity, gloss and masking power. As already mentioned, the
theory
the use of HiTone can improve pigment affinity. The effect of the developed solution on the performance of colored powder coatings is discussed in this paper. In addition to appearance, the extrusion and abrasiveness of powder coatings that are estimated to have a high pigment fill can also be affected. The effect of high filling system on abrasiveness is also discussed in this paper.
experiments
synthesized standard
70/30

blend resins and
two
70/30
hybrid resins
(Uralac
®
P 770
and
Uralac P 772)
.
the Ualac P 772
is
fast-curing model
the Ualac P 770. The standard
60/40
blend resin and the
60/40
hybrid resin
(Uralac P 760)
, based on the
HiTone
theory, are
.

1
gives the performance of the
70/30
blend resin, while table
2
gives the performance of the
60/40
blend resin.
resins are tested with pigment contents of
33%

and
50
% of the pigment content, respectively. In these tests,

used
TiO2
(
Kronos
®
2310
). Table
3
a typical
70/30
and
60/40
blend resin formulations with pigment content of
33%
and
50%
quality ratio, respectively.
use
The Prism TSE 16 PC
two-bar extruder squeezes ingredients to prepare powder coatings, with a screw diameter of
16 mm
and a long diameter ratio of
14
. The extruse temperature is set at
120oC
, the extrusing speed is
200
-turn
/
per minute, and the torque is maintained at
75% to 90%
. After extrusion, the extruded material is ground with a
Retch ZM 100
centrifugal shredder and then screened through
Retch Vibro
with an aperture of
90
μ
m
. Finally, the powder coating is sprayed on the steel plate
(Q-panel S 46)
using the
GEMA PG1
spray gun, and then placed vertically in the
UT 6120
hot air oven of
Heraeus
. A coating
60
μ
m
thickness is used for further evaluation.
assessment
visually assessed mobility on painted plates and compared to
PCI
standards. Liquidity was also
by Veeco
's white-light interferometer. The device can perform
3D
quick scans of large surface areas (e.g. single scan
2x2 mm2
), with a height resolution of several nanometers and a lateral resolution of
600
nanometers. By using automatic
XY
forms and "pin-in" software, interferometers can even test larger samples
(
such as
10x2 mm2)
.
is based on the
The ASTM D 2794
the coating flexibility by recosting. From the back of the painted steel plate
160
160-inch pound impact. Also paint
alMg3
plate and cure it in a gradient oven from
150 to 250oC BYK-Gardner
for
10
minutes. These plates also carry
160
pounds of impact. Test
20
degrees and
60
degrees gloss and shadow with a
BYK-Gardner
reflector as standard
ASTM D 523
standard.
the cured plate is placed in the oven of
240oC

10
minutes,
220oC
oven for
1
hours to test heat resistance. Test the color difference between unprocessed and treated plates.
press
The ASTM D 2803
standard will be a cured plate with a width of
1mm
for salt spray testing. Place the plate in a salt
for
500 hours to measure average one-way rust starting at scratches. The
temperature
Tg
of powders and coatings is measured using a differential scan thermometer (
DSC
) at a heating rate of
5oC/min
.
results
fog shadow
the fog shadow value can reflect the appearance. Usually
,
the fog shadow value is low, the appearance is good, if the fog shadow value is high, the appearance is poor. The
of the final coating was
by the byk-Gardner-2000 image reflector. Figure
2
the results of fog shadow measurements of different pigment concentrations are given. Standard resins and newly developed
are compared

,
P 772
and
P 760
760.
standard resins have a very low fog shadow value when the pigment concentration is below
40% to 45 %
(mass ratio). When the pigment concentration is
45 %
(mass ratio), the fog shadow value increases. In contrast, with
Uralac P770
,
P 772
and
P 760
resins, the fog shadow value is much lower when pigment concentrations are as high as
55 %
(mass ratio).
the above test results, compared with the standard resin, the use of
HiTone
resin fills with more titanium dioxide without reducing fog performance.
gloss can
also reflect the appearance of good or bad. Usually, the gloss is high and the appearance is good. The gloss
was measured using the
by byK-Gardner's reflector. Figure
3
the gloss values of standard blended resins and
Hitone
resins
(P 770
,
P 772
and
P 760)
at different pigment concentrations. In figure
3
, a relationship
between
20 degrees gloss value and pigment concentration is made.
as can be seen, the gloss of the coating made of standard resin begins to decrease when the pigment concentration
40%
of the pigment. On the other hand,
system based
HiTone resin is much less time-reduced when pigment concentrations increase. Glossy and foggy results show that
pigment affinity
the HiTone resin is much better than that of standard resins.
liquidity
liquidity is related to many factors. In general, liquidity increases if the system is less reseditive. Similarly, other parameters such as viscosity and surface stress can affect fluidity. If the pigment affinity of the resin increases, the fluidity is expected to increase as the pigment concentration increases. Figure 4
the
results at different pigment concentrations are given. Compare the standard resin
the
HiTone resin. The flow is measured by comparing

PCI plate with a plate coated with
HiTone
resin or standard resin.
at low pigment concentrations, but differences were found at higher pigment concentrations. At higher pigment concentrations
the
is much better than standard resins. This result shows
increased
affinity with HiTone pigments improves fluidity, especially at high pigment concentrations.
in addition to
In addition
the flow of the PCI,000-plate comparison, the leveling of the powder-coated surface was measured with a white-light interferometer. A white-light interferometer was used to capture a paint concentration of
50%
(mass ratio) coating. A picture taken by a white light interferometer is shown
5
.
as can be seen from figure
5
, the fluidity of the
Uralac P 770
resin is superior to that of standard resins at pigment concentrations of
50%
(mass ratio). Based on the results of
tests,
HiTone polyester resin is more fluid than standard polyester resins at high pigment concentrations. This clearly shows that the
high-
system using HiTone theory improves the liquidity of the high-filling system.
abrasive
to determine the effect of high filling system on the power coefficient of consumption during grinding, the grinding test is carried out in the production stage. The power factor consumed is expressed by the electrical work required to grind each kilogram of product to the specified particle size. Grinding
all pigment concentration ranges
the
of the Ualac P 770. The Ualac P760
with
pigment concentration of
50%
(mass ratio). Due to the need for smaller particle sizes for thin coating construction, differences in the power coefficients consumed were measured in systems with an average particle size of
D50
of
30,
microns and
50
microns in the particle size distribution. Test
with
ACM10
air
abrasive grinder from the Hosokawa project. The polarity conditions during grinding are the maximum power consumption of the grinding rotor and the granulator rotor and the maximum pressure drop of the system. These conditions are found to have the most effect on the minimum particle size during grinding of high concentration pigment systems. To overcome this shortcoming, the grinding disc and the particler speed were adjusted. The results of the relevant tests are
table 4

5
.
as can be seen from tables
4
and
5
, the grinding plate and particler at
D50
with a pigment concentration of
50%
(mass ratio) are adjusted to
30
microns. This adjustment is made to prevent clogging.
the above results are graphically given
figure
6. The graph clearly shows that the pigment concentration increases and the power coefficient of consumption increases.
from Figure <b