AEROSIL® R 972AEROSIL® R 974
SiCH3
CH3
AEROSIL® R 812 AEROSIL® R 812 S
SiCH3
CH3
CH3
AEROSIL® R 816
Si C16H33
AEROSIL® R 805
Si C8H17
AEROSIL® 200AEROSIL® 300AEROSIL® 380
Si OH
AEROSIL® for High Solid-Coatings Technical Information 1197
Cover: Diagram of hydrophilic AEROSIL® and surface groups of different hydrophobic grades of AEROSIL®
3
1
2
3
4
5
5.1
5.2
5.3
5.4
6
7
Introduction
AEROSIL® Grades for High Solids
Use of AEROSIL® in High Solids
Dispersion of AEROSIL®
Technical Application Testing of AEROSIL® in High Solids
AEROSIL® for Polyester-Systems
AEROSIL® for Acrylat-Systems
AEROSIL® for Alkyd-Systems
AEROSIL® for Epoxid-Systems
Practical Advice
Physico-Chemical Data of AEROSIL®
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5
6
7
9
9
12
17
17
20
21
Table of contents
Page
4
1 Introduction
This „Technical Information“ brochure is provided by Evonik Industries , as a supplier of raw materials to the coatings indus-try, as a further contribution to the development of environ-mentally-friendly coating systems. For decades, AEROSIL® has been an important additive for use in both conventional and environmentally-friendly paint systems. AEROSIL® is a highly dispersed amorphous silica which is produced by flame hydrolysis. By varying the manufacturing conditions, it is possible to produce a selection of grades which differ from one another as regards particle size and specific surface. The presence of silanol groups situated on the surface means that all nonaftertreated synthetic silicas are hydrophilic by nature. Hydrophobic products are obtained by replacing these silanol groups with organic groups during the manufac-turing process. Backed up by continuous research work and applied technology testing, Evonik is able to present a range of AEROSIL® grades in this Technical Information brochure which are ideally suited for use in high solids coatings.
Increased environmental awareness and the resulting legal pro-visions are forcing the coatings industry to reduce the emission of solvents (VOC / volatile organic compounds). This goes for the suppliers of raw materials as well as for paint manufactur-ers and processors. There are various concepts in the coatings industry for the development of environmentally-friendly coating systems:
• water-based coatings • high solids coatings • powder cotings • UV-curing sytems
These different environmentally-friendly systems may be com-bined to provide excellent results. An example of this is to be found in the range of automotive repair paints: water-thinnable base coats used together with high solids clear coats. The solvent content of high solids is reduced primarily by the use of binders with a low molecular weight. The VOC content can also be favourably influenced by the choice of suitable solvents, pigments and additives, and also by the method of application.
5
2 AEROSIL® Grades for High Solids
The technical application tests carried out in various coating systems and compiled in this TI show that the grades of AEROSIL® listed in the table are specially recommended for use in high solids coating systems.
According to current European chemical legislation, the following substances are not hazardous substances, nor are they classified as dangerous goods within international Transport regulations: AEROSIL® 200, AEROSIL® 300, AEROSIL® 380, AEROSIL® R 816, AEROSIL® R 972, AEROSIL® R 974, AEROSIL® R 805, AEROSIL® R 812, AEROSIL® R 812 S
AEROSIL® 200AEROSIL® 300AEROSIL® 380
AEROSIL® R 816 AEROSIL® R 972AEROSIL® R 974AEROSIL® R 805AEROSIL® R 812AEROSIL® R 812 S
hydrophilic AEROSIL® slightly hydrophilic AEROSIL® hydrophobic AEROSIL®
6
3 Use of AEROSIL® in High Solids
AEROSIL®, a multi-functional additive:
Positive effects of AEROSIL® in various stages of paint processing
production and storage
dispersibility(of the pigments)
stabilisation of pigments
reduced pigmentsettling
rheology (sag behaviour)
fixation ofspecial effectcoatings
optical properties(coloristics)
viscoelastic properties(adhesion, elasticity),scratch resistance
water- and corrosionresistance
application and drying
dry coating film
7
The incorporation of AEROSIL® in high solids coatings can be carried out with suitable dispersing equipment (e. g. pearl mill, ball mill). The ultimate effectiveness of AEROSIL® depends on a good dispersion. Furthermore, a high degree of dispersion leads to good optical properties (gloss, transparency).
4 Dispersion of AEROSIL®
The masterbatch method of dispersion is recommended for the incorporation of AEROSIL® in clear coats. When dispersion is carried out in a pearl mill, for example, an AEROSIL® concen-tration of 5 – 8 % (related to solid binder) has proven success-ful. This makes it possible to work economically and to achieve an optimum degree of dispersion. The desired final concentra-tion of AEROSIL® is then obtained by means of reduction. Table 1 shows the correlation between the dispersing energy and time and the coating properties. Excellent rheological and optical properties were obtained at grind values of < 10 µm. Further dispersion has no influence on constancy in the rheo-logical properties and in some cases even improves the optical properties.
The followig example describes the incorporation of AEROSIL® into a stoving enamel clear coat:
Millbase/masterbatch parts by weight Acrylic resin, 70 % solid 16.3 Solvesso 100 2.5 Xylene 2.5 AEROSIL® 200 0.6 Let down Acrylic resin, 70 % solid 42.1Melamine Resin, 70 % solid 24.1Butanol 1.5Butyl glycol acetate 4.5Xylene 2.5Silicone oil, 2 % solid 2.7UV-Absorber 1.3
Total: 100.6
Table 1 Influence of the dispersing time on the technical coating properties of AEROSIL® 200. Stoving enamel clear coat based on acrylate/melamine resin
Dispersing time 10 min 20 min 40 min 60 min
Grind value in µm 25 18 < 10 < 10
Viscosity in mPa • s (6 rpm) 842 822 857 847
Viscosity in mPa • s (60 rpm) 426 412 416 416
20°-Reflectometer value 84.4 86.9 88.7 89.0
Haze 62 33 16 9
8
An evaluation of the degree of dispersion is shown in Figure 1 us-ing electron micrographs of the dry clear coat film. The disper-sion experiments were conducted with a „Skandex disperser“ containing glass beads of 2 – 3 mm in diameter. Much shorter dispersing times would be adequate when a pearl mill is used for dispersion.
In pigmented coatings, the AEROSIL® is dispersed together with the pigments. The use of a dissolver for dispersion will only prove satisfactory in certain fields of application, e. g. for corrosion protection paints. The same degree of dispersion can be achieved as with standard pigments and fillers when AEROSIL® is included in the formulation.
The following example discribes the incorpora-tion of AEROSIL® into a pigmented coating:
Millbase parts by weigt Polyester resin, 100 % solid 19.3 Methyl isoamyl ketone 12.2 Wetting agent 0.4 Rutile titanium dioxide 38.4 AEROSIL® R 812 S 0.8
Reduction Polyester resin, 100 % solid 14.4 Melamin resin, 98 % solid 14.4 Catalyst 0.9 Total 100.8
40 min 10 min
20 min 60 min
Figure 1 Electron micrographs (120 x enlargement) used for evaluating the degree of dispersion of AEROSIL® 200 (see Table 1)
9
5 Technical Application Testing of AEROSIL® in High Solids
The test program includes a large number of binders of spe-cial significance for the high solids market. Added amounts of 0.4 – 1 % of AEROSIL® to the above coating systems were found to be suitable in the tests.
5.1 AEROSIL® for Polyester Systems The use of AEROSIL® as a rheological additive in high solids paints brings about a higher sag stability on vertical substrates and enables greater coating film thicknesses to be applied (see Figure2). The tests were conducted on a two-component PUR high solids coating based on polyester / polyisocyanate. Unlike the control paint which contained no AEROSIL®, sag formation was prevented, and after spray application a more than 40 % higher dry-film thickness was achieved.
The added amounts of AEROSIL® stated in this Technical Information brochure are all related to the total solids content of the respective paint formulation. These concen-trations should be regarded as guide values and may be adjusted as necessary.
High solid binder
saturated polyester
polyisocyanate
melamine resin
polyisocyanate
melamine resin
polyamide
polyaminemelamine resin
acrylate alkyd epoxy
Figure 2Increased sag stability during spray application (55 µm dry-film thickness) Left: Control, Right: Containing 0.4 % AEROSIL® R 812 S. White two-component top coat based on oil-free saturated polyester/ polyisocyanate
10
The use of rheological additives to increase the thixotropy or structural viscosity is generally accompanied by a certain thickening effect. Particularly in the case of high solids paint, this increase in viscosity should be kept to a minimum. As lower the viscosity, the less solvent is needed to regulate the desired efflux time for spray application (see Figure 3). Table 2 illustrates how the optimum AEROSIL® concentration can provide excellent rheological properties (sag stability) yet causes only an insignificant increase in the viscosity.
Rheological additives should only be used in top coats if they do not affect the optical properties. As Table 3 shows, AEROSIL® fulfils this demand if it has been well dispersed.
Adequate sag stability mostly cannot be achieved without the use of a rheological additive, especially in the case of binders for high solids stoving enamels with an extremely low molecu-lar weight. During the stoving process, the decrease in the viscosity of the binder caused by the temperature increase is greater than the increase in viscosity due to the evaporation of the solvent. Influence of the stoving process on the maximum wet-film thickness that may be applied (multi-notch applicator) Figure 4 demonstrates in the case of the stoving enamel with-out AEROSIL® how the maximum applicable wet-film thickness is reduced by 60 – 70 % due to the effects of the temperature during the stoving process.
This problem can be resolved by adding 1 % AEROSIL®. The results of the tests show how AEROSIL® R 812 S, in particular, prevents sagging during the stoving process (Thermal Sag control).
Figure 3 Adjustment of the spraying viscosity to allow an efflux time of 30 s DIN 4 mm. White 2-component top coat based on oil-free saturated polyester/polyisocyanate
Table 2 Influence of 0.4 % AEROSIL® R 812 S on the viscosity and sag stability White 2-component top coat based on oil-free saturated polyester/polyisocyanate
Table 3 Optical properties when using 0.4 % AEROSIL® R 812 S White 2-component top coat based on oil-free saturated polyester/polyisocyanate
Efflux time DIN 4 mm (original viscosity)
Solvent addition (spraying viscosity) (30 s DIN 4 mm)
Solids content (spraying viscosity)
Max. attainable dry-film thickness
Control 38 s 2.5 % 71.8 % 40 µm
AEROSIL® R 812 S 45 s 822 71.2 % 55 µm
20° -Reflectometer value 60° -Reflectometer value Haze
Control 88.4 96.0 34
AEROSIL® R 812 S 88.0 95.4 33
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0solvent [amount in %)]
efflu
x tim
e D
IN 4
mm
[s]
20
25
Control0,4 % AEROSIL® R 812 S
30
35
40
45
spraying viscosity
11
Good rheological effects are shown by both hydrophilic and hydrophobic grades of AEROSIL® in pigmented high solids stoving enamels. In such cases, other processing requirements regarding the paint properties play a role in the choice of the most appropriate grade of AEROSIL®. An important criterion for the choice of the optimum AEROSIL® grade may be the resistance to water, for example. Figure 5 illustrates how the use of hydrophobic AEROSIL® improves the water resistance. The use of anti-settling agents is often unavoidable in pig-mented coating systems. All of the AEROSIL® grades tested prevent the formation of solid sediment. The choice of the most appropriate grade of AEROSIL® is dependent on the chosen binder system, as shown in Figure 6. The rectangles depicted in this figure symbolically represent the glass paint jars which were used to evaluate the separation behaviour.
Figure 4 White stoving top coat based on oil-free polyester/melamine resin
Control / hydrophilic AEROSIL® hydrophobic AEROSIL®
Figure 6 Settling behaviour of rutile titanium dioxide following 4 weeks of storage at room temperature. 2-component PUR top coats based on polyester or acrylic resin
Acrylate 1:
Acrylate 2:
Control
Control
Control
200 R 972 R 805 R 812 S
200 R 972 R 805 R 812 S
200 R 972 R 805 R 812 S
solid sediment separation
Polyester
0
25
50
75
100
125
150
max
. app
licab
le w
et-f
ilmth
ickn
ess i
n μm
30 min 150 °C
solvent: methoxy propyl acetate solvent: methyl isoamyl ketone
Control ControlAEROSIL® R 812 S
AEROSIL® R 812 S
room temperature
Figure 5Water resistance after 360 h constant condensation climate conditions in accordance with DIN 50017 (2.5 x enlargement). White top coat stoving enamel based on polyester/melamine resin
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5.2 AEROSIL® for Acrylate-Systems In acrylic-based clear coats, the choice of AEROSIL® grade is dependent on the crosslinking components (polyisocyanate or melamine resin). Table 4 gives the viscosity values of a millbase containing 5 % AEROSIL® related to the solid acrylic resin. Figure 7 and 8 clearly show the influence of the cross-linking components on the rheological effectiveness of hydrophilic and hydrophobic AEROSIL®. For acrylate/melamine resin: hydrophilic AEROSIL® For acrylate/polyisocyanate: hydrophobic AEROSIL®
AEROSIL® concentrations of up to 2 %, related to the solids content, are possible in the two-component PUR clear coat, as a typical representative of the range of automotive repair paints.
Control AEROSIL® 200 AEROSIL® R 972 AEROSIL® R 805 AEROSIL® R 812 S
Viscosity in mPa•s (6 rpm) 117 187 237 1870 2070
Viscosity in mPa•s (60 rpm) 117 187 217 659 686
Shear thinning 6/60 rpm 1.0 1.0 1.1 2.8 3.0
Table 4 Millbase containing 5 % AEROSIL® related to the solid acrylic resin
Figure 7 Stoving enamel clear coat based on acrylate/melamine resin
Figure 8 2-component clear coat based on acrylate / polyisocyanate
visc
osity
in m
Pa•s
shear thinning1.0 2.6 1.2
1 %1 %
6 rpm 60 rpm
AEROSIL® R 812 S AEROSIL® 200Control
100
0
200
300
400
500
visc
osity
in m
Pa•s
shear thinning1.0 1.0 1.6 2.1 2,6
1 % 1,5 % 2 %1 %
6 rpm 60 rpm
AEROSIL® R 812 S
AEROSIL® R 812 S
AEROSIL® R 812 S
ControlAEROSIL®
200
400
0
200
600
800
1000
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Maximum attainable wet-film thickness of a white high solids paint without AEROSIL®. The wet-film thickness was determined with a multi-notch applicator (notch depth 75 – 300 µm)
The maximum wet-film thickness was increased by 25 µm (1 stripe) by an addition of AEROSIL® R 972.
The best sag control was achieved in this system with AEROSIL® R 812. The maximum wet-film thickness was increased by 75 µm or 50 % over the control paint not containing AEROSIL®.
In pigmented high solids coatings based on acrylic resin, the differences between hydrophilic and hydrophobic AEROSIL® as regards the rheological effects are much less noticeable than with clear coats. Good rheological effects are attained with both hydrophilic and hydrophobic AEROSIL®, independent of the cross-linking components. Hence, other technical coating characteristics determine the choice of the most suitable grades of AEROSIL®: Hydrophobic grades of AEROSIL® offer the following advan-tages over the hydrophilic grades: • improved corrosionprotection properties • improved mechanical properties • grater stability of viscosity during storage
Within the range of hydrophobic products, greater rheological control is achieved with R 805, R 812 and R 812 S than with R 972. Figure 9 – 11 below describe how the rheological behaviour of the various grades of AEROSIL® differs.
Figure 9Increased maximum attainable wet-film thickness by adding 1 % AEROSIL®White 2-component PUR top coat based on acrylate/polyisocyanate
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Comparison of the rheological behaviour of hydrophilic AEROSIL® 200 and hydrophobic AEROSIL® R 812: Figure 11 shows another test method which simulates the rhe-ological conditions during and after application, i. e. the param-eters largely responsible for sagging. Leaps in the shear stress were carried out by means of a Physica Rheometer MC 20.
The viscosity was initially measured at a stress of τ = 67 Pa and then again at an abruptly reduced stress of τ = 6 Pa. This leap function is used to measure the reformation of the viscosity.
Figure 10 Shear thinning when 1 % of AEROSIL® is added White 2-component top coat based on acrylate/polyisocyanate
Figure 11 Reformation of the viscosity (67/ 6Pa) when 1 % of AEROSIL® is added White 2-component PUR top coat based on acrylate/polyisocyanate
500 100 150 200 250shear velocity 1/s
AEROSIL® 200
visc
osity
in m
Pa•s
Control AEROSIL® R 812
300
500
700
900
1100
1300
1500
0 50 100 150 200 250 300 350 400 450time [s]
300
400
500
600
700
800high shear low shear
visc
osity
in m
Pa•s
AEROSIL® 200Control AEROSIL® R 812
15
250 h Salt spray test 500 h Salt spray test
Figure 12 shows the positive effect of AEROSIL® on the corrosion protection properties of coatings. The use of hydrophobic AEROSIL® is recommended to increase the anti-corrosion effect. The tests were conducted according to the following conditions: Test conditions 1 Salt spary test, as defined in DIN 50021 2 Regeneration of the coating film (48 h at room temperature) 3 Adhesion release by teasing of adhesive tape (e. g. Tesafilm)
Control Control
hydrophilic AEROSIL® hydrophilic AEROSIL®
hydrophobic AEROSIL® hydrophobic AEROSIL®
Figure 12Influence of 1 % AEROSIL® on the corrosion protection properties. White 2-component PUR top coat based on acrylate/polyisocyanate (photographs taken after completion of the test conditions 1 – 3)
16
In some cases where hydrophilic AEROSIL® is used, the rheo-logical properties may change during storage of the paint, whereas hydrophobic AEROSIL® stands out for its ability to maintain a constant viscosity.
Figure 13 Viscosity behaviour after storage. White 2-component PUR top coat based on acrylate/polyisocyanate
Figure 14 Shear thinning after storage. White 2-component PUR top coat based on acrylate/polyisocyanate
In Figure 13 and 14, the hydrophobic AEROSIL® R 812 is shown to demonstrate high stability of both viscosity and shear thinning following storage of the liquid coatings.
visc
osity
in m
Pa•s
[6 rp
m]
Control 1 % AEROSIL® 200 1 % AEROSIL® R 812
1 3 7 30storage of the coatings excluded hardener at room temperature [days]
0
300
600
900
1200
1500
1800
visc
osity
in m
Pa•s
[60
rpm
]
Control 1 % AEROSIL® 200 1 % AEROSIL® R 812
storage of the coatings excluded hardener at room temperature [days]
0.5
1.0
1.5
2.0
2.5
0.01 3 7 30
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5.3 AEROSIL® for Alkyd-Systems The alkyd resin sector offers an almost inexhaustible choice of binders. For this reason, preliminary tests should be carried out to decide which grade of AEROSIL® is most suitable.
5.4 AEROSIL® for Epoxid-Systems Epoxy resins are of great significance for the corrosion protec-tion sector. Hydrophobic AEROSIL® displays good rheological effectiveness when either polyamide resins or polyamines are used as the cross-linking agents.
Table 6 Influence of 1 % AEROSIL® on the rheological behaviour. White air-drying top coat based on long-oil alkyd resin
Table 5 Influence of 1 % AEROSIL® on the rheological behaviour. White stoving enamel top coat based on alkyd/melamine resin
Table 8 Influence of 1 % AEROSIL® on the Rheological properties. Corrosion protection primer based on epoxy/polyamine
Table 7 Influence of 1 % AEROSIL® on the rheological properties. Corrosion protection primer based on epoxy/polyamide
The AEROSIL® range includes a fitting product for almost every alkyd system. The rheological effect of AEROSIL® in the alkyd resin range is demonstrated in Table 5 and 6, using examples of a stoving enamel and a decorator‘s paint.
AEROSIL® R 805, in particular, is able to combine the characteristics of a high thixotropy or structural viscosity with the required low thickening effect. The good anti-corrosion properties are another reason for using hydrophobic AEROSIL®.
Control AEROSIL® 200 AEROSIL® R 972 AEROSIL® R 805 AEROSIL® R 812 S
Viskosity in mPa•s (6 rpm) 104 1170 371 559 265
Viskosity in mPa•s (60 rpm) 104 391 207 252 177
Shear thinning 6/60 rpm 1.0 3.0 1.8 2.2 1.5
Control AEROSIL® 200 AEROSIL® R 972 AEROSIL® R 805 AEROSIL® R 812 S
Viskosity in mPa•s (6 rpm) 331 561 752 882 1360
Viskosity in mPa•s (60 rpm) 331 561 611 645 701
Shear thinning 6/60 rpm 1.0 1.0 1.2 1.4 1.9
Control AEROSIL® 200 AEROSIL® R 972 AEROSIL® R 805 AEROSIL® R 812 S
Viskosity in mPa•s (6 rpm) 1040 2620 2740 3290 4120
Viskosity in mPa•s (60 rpm) 888 1820 1270 1280 1660
Shear thinning 6/60 rpm 1.2 1.4 2.2 2.6 2.5
Control AEROSIL® 200 AEROSIL® R 972 AEROSIL® R 805 AEROSIL® R 812 S
Viskosity in mPa•s (6 rpm) 1520 2220 4490 3910 7520
Viskosity in mPa•s (60 rpm) 1060 1750 1790 1430 2340
Shear thinning 6/60 rpm 1.4 1.3 2.5 2.7 3.2
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The hydrophobic grade AEROSIL® R 202, which has not been mentioned in this Technical Information brochure before now, can produce even better rheological effects than the other AEROSIL® grades listed here, when used in certain epoxy sys-tems. Due to its aftertreatment with polydimethyl siloxane, AEROSIL® R 202 is most suitable for use in single-layer coat-ings. The intercoat adhesion should be tested if it is to be used in multi-layer coatings.
Figure15 and 16 show viscosity profiles (original viscosity and brush-on viscosity) of a corrosion protection primer based on epoxy/polyamide. The use of the hydrophilic grade AEROSIL® 200 only brings about a thickening effect. Hydrophobic AEROSIL®, on the other hand (especially AEROSIL® R 805) leads to a clear increase in the thixotropy or structural viscosity.
Figure 15 Shear thinning at original viscosity. Corrosion protection primer based on epoxy/polyamide
Figure 16 Shear thinning at brush-on viscosity (80 s DIN 4 mm). Corrosion protection primer based on epoxy/polyamide
shear velocity in 1/s
visc
osity
in m
Pa•s
0 50 100 150 200 250 300800
1000
1200
1400
1600
1800
AEROSIL® 200Control AEROSIL® R 805
shear velocity in 1/s
visc
osity
in m
Pa•s
400
500
600
700
800
AEROSIL® 200Control AEROSIL® R 805
0 50 100 150 200 250 300
19
The description of the excellent rheological performance of AEROSIL® R 805 in 2-component epoxy systems is completed by the leap function shown in Figure 17. Measurements were conducted as described in the test pro-cedure on page 13. The viscosity profile in Figure18 confirms that hydrophobic AEROSIL® demonstrates good rheological effects, i. e. high structural viscosity while maintaining low thickening effects, even when polyamines are used as the cross-linking agents.
Figure 17 Reformation of viscosity (67/6 Pa). Corrosion protection primer based on epoxy/polyamide
Figure 18 Shear thinning. Corrosion protection primer based on epoxy/polyamine
time [s]
high shear low shear
visc
osity
in m
Pa•s
800
1000
1200
1400
1600
1800
AEROSIL® 200Control AEROSIL® R 805
0 50 100 150 200 250 300 350 400 450
shear velocity in 1/s
visc
osity
in m
Pa•s
1000
800
1200
1400
1600
1800
2000
2200
AEROSIL® 200Control AEROSIL® R 805
0 50 100 150 200 250 300
20
• 2-component clear coats: hydrophobic AEROSIL®
• pigmented 2-component coatings: hydrophobic AEROSIL®
• stoving enamel clear coats: hydrophilic AEROSIL®
• pigmented stoving enamels: hydrophobic and hydrophilic AEROSIL®
6 Practical Advice
The following guidelines are intended to make these tests as effective as possible:
• The rheological effectiveness of the hydrophobic grades of AEROSIL® R 812 / R 812 S and R 805 is greater than AEROSIL® R 972.
• Due to their higher specific surfaces, AEROSIL® 300 and AEROSIL® 380 display greater rheological effectiveness than AEROSIL® 200 in some cases, but require a more intensive dispersion.
• Due to its higher specific surface, AEROSIL® R 974 displays greater rheological effectiveness than AEROSIL® R 972 in some cases, but requires a more intensive dispersion.
• Thanks to its relatively low specific surface, AEROSIL® R 972 is the most easily dispersed product.
• With regards to its technical coating properties, the slightly hydrophobic AEROSIL® R 816 should be ranked between the hydrophilic AEROSIL® 200 and the hydrophobic grades of AEROSIL®.
• Hydrophobic AEROSIL® should be used to improve the water resistance and corrosion protection (e. g. primers).
• Depending on the coating system, AEROSIL® R 972 or AEROSIL® 200 can be recommended for use as antisettling agents.
All of the AEROSIL® grades mentioned in this Technical Infor-mation brochure are suitable for use as rheology control additives. The choice of which product should be used depends on the needs of the paint manufacturer. Preliminary tests are recommended due to the different coating formulations and the related influencing factors.
21
7 Physico-Chemical Data of AEROSIL®
1 In acc. with DIN ISO 92772 In acc. with DIN EN ISO 787/XI, JIS K 5101/20 (not sieved) 3 In acc. with DIN EN ISO 787/II, ASTM D 280, JIS K 5101/23 4 In acc. with DIN EN ISO 3262-20, ASTM D 1208, JIS K 5101/ 245 In acc. with DIN EN ISO 787/IX, ASTM D 1208, JIS K 5101/26 7 Based on the dried substance (2 hours at 105 °C) 8 Based on the ignited substance (2 hours at 1000 °C)10 HCI-content is part of ignition loss11 V- material is supplied in 20kg bags13 Water: Methanol = 1 : 1
AEROSIL®Test methods 200 300 380 COK 84 R 972 R 974 R 805 R 812 R 812 S R 816
Behaviour towards water hydrophilic hydrophobic slightly
hydrophobic
Appearance -fluffy white powder -
BET surface area BET 1 m2/g 200 ± 25 300 ± 30 380 ± 30 185 ± 30 110 ± 20 170 ± 20 150 ± 25 260 ± 30 220 ± 25 190 ± 20
Tamped density 2 approx. value g/L 50 50 50 50 50 50 60 60 60 60
Densified material (suffix „V“) g/L 120 120 120 – 90 90 – – – –
Densified material (suffix „VV“) g/L 50/75/120 50/75/120 – – – – 90 90 90 –
Loss on drying 3 (2 h at 105 °C) when leaving the plant wt. %
≤ 1.5
≤ 1.5
≤ 2.0
≤ 1.5
≤ 0.5
≤ 0.5
≤ 0.5
≤ 0.5
≤ 0.5
≤ 1.0
Loss on ignition 4,7 (2 h at 1000 °C) wt. % ≤ 1.0 ≤ 2.0 ≤ 2.5 ≤ 1.0 ≤ 2.0 ≤ 2.0 5.0 – 7.0 1.0 – 2.5 1.5 – 3.0 –
pH-value 5 3.7 – 4.7 3.7 – 4.7 3.7 – 4.7 3.6 – 4.3 3.6 – 4.4 13 3.7 – 4.7 13 3.5 – 5.5 13 5.5 – 7.5 13 5.5 – 7.5 13 4.0 – 5.5 13
C-content wt. % – – – – 0.6 – 1.2 0.7 – 1.3 4.5 – 6.5 2.0 – 3.0 3.0 – 4.0 0.9 – 1.8
SiO2 8 wt. % ≥ 99.8 ≥ 99.8 ≥ 99.8 82 – 86 ≥ 99.8 ≥ 99.8 ≥ 99.8 ≥ 99.8 ≥ 99.8 ≥ 99.8
Al2O3 8 wt. % ≤ 0.050 ≤ 0.050 ≤ 0.050 14 – 18 ≤ 0.050 ≤ 0.050 ≤ 0.050 ≤ 0.050 ≤ 0.050 ≤ 0.050
Fe2O3 8 wt. % ≤ 0.003 ≤ 0.003 ≤ 0.003 ≤ 0.100 ≤ 0.010 ≤ 0.010 ≤ 0.010 ≤ 0.010 ≤ 0.010 ≤ 0.010
TiO2 8 wt. % ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030
HCI 8, 10 wt. % ≤ 0.025 ≤ 0.025 ≤ 0.025 ≤ 0.100 ≤ 0.050 ≤ 0.010 ≤ 0.025 ≤ 0.025 ≤ 0.025 ≤ 0.025
Unit weight 11 (netto) kg 10 10 10 10 10 10 10 10 10 10
The data have no binding force.
This information and any recommendations, technical or otherwise, are presented in good faith and believed to be correct as of the date prepared. Recipients of this information and recommendations must make their own determination as to its suit-ability for their purposes. In no event shall Evonik assume liability for damages or losses of any kind or nature that result from the use of or reliance upon this information and recommendations. EVONIK EXPRESSLY DISCLAIMS ANY REPRESENTATIONS AND WARRANTIES OF ANY KIND, WHETHER EXPRESS OR IMPLIED, AS TO THE ACCURACY, COMPLETENESS, NON-INFRINGEMENT, MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE (EVEN IF EVONIK IS AWARE OF SUCH PURPOSE) WITH RESPECT TO ANY INFORMATION AND RECOMMENDATIONS PROVIDED. Reference to any trade names used by other companies is neither a recommendation nor an endorsement of the corresponding product, and does not imply that similar products could not be used. Evonik reserves the right to make any changes to the information and/or recommendations at any time, without prior or subsequent notice.
AEROSIL® is a registered trademark of Evonik Industries or its subsidiaries.
TI 1
197-
1 JU
L15
Europe / Middle-East /Africa / Latin AmericaEvonik Resource Efficiency GmbHBusiness Line SilicaRodenbacher Chaussee 4 63457 HanauGermany phone +49 6181 59-12532 fax +49 6181 59-712532 [email protected]
North America
Evonik CorporationBusiness Line Silica299 Jefferson RoadParsippany, NJ 07054-0677USA phone +1 800 233-8052 fax +1 973 [email protected]
Asia Pacific
Evonik (SEA) Pte. Ltd.Business Line Silica3 International Business Park#07-18, Nordic European CentreSingapore 609927 phone +65 6809-6877 fax +65 [email protected]
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