Version 3.3 / 15-04-05 / JD HDK
N20 Page 1 / 2
Characteristics
Synthetic, hydrophilic amorphous silica, produced via
flame hydrolysis
Special characteristics
White colloidal powder of high purity
Application
HDK
N20 is applied as a thickening and thixotropic
agent in many organic systems, e.g. in unsaturated
polyesters, coatings, printing inks, adhesives,
cosmetics and others. It is used as a reinforcing filler in
elastomers, mainly silicone-elastomers. HDK
N20
acts as a free flow additive in the production of
technical powders, in food and feed and in
pharmaceutical products.
Processing
A good dispersion of HDK
N20 is a must to assure
optimum performance.
More detailed information about the application and
processing of HDK
N20 is available in our HDK-
brochures and on the WACKER web site
(http://www.wacker.com/hdk
)
Storage
HDK
N20 has a shelf life of at least 24 months when
stored in unbroken original packaging in dry storage
areas. The ‘Best use before end’ date of each batch
appears on the product label.
Storage beyond the date specified on the label does
not necessarily mean that the product is no longer
usable. In this case however, the properties required
for the intended use must be checked for quality
assurance reasons.
HDK
N20
Pyrogenic Silica – Fumed Silica
Product data
Typical General Properties Test procedure Unit Value
SiO
2-content
1)
DIN EN ISO 3262-
19
% >99.8
loss on ignition
2)
at 1000 C / 2h
DIN EN ISO 3262-
19
% <2
density of SiO2
g/l 2200
refractive index
1.46
silanol group density
SiOH/nm
2
2
electric resistivity (density 40 g/l)
[ cm] >10
13
Physical-chemical properties Test procedure Unit Value
BET-surface area
DIN ISO 9277/ DIN
66132
m
2
/g 170 – 230
pH, in 4 % aqueous dispersion
DIN EN ISO 787-9 3.8 4.3
tamped density
DIN EN ISO 787-11 g/l ca. 40
loss on drying
3)
(2 h at 105 C)
DIN EN ISO 787-2 % < 1.5
sieve residue, acc. to Mocker > 40 m
DIN EN ISO 787-18 % < 0.04
1) based on the substance heated at 1000 C for 2 h
2) based on the substance dried at 105 C for 2 h
3) ex works
Version 3.3 / 15-04-05 / JD HDK
N20 Page 2 / 2
Packaging
HDK
N20 is offered in following packaging:
* paper bags on pallet:
10 kg or 20 lbs bags, (160 kg or 320 lbs per
pallet)
* Big bags:
200 lbs and 150 kg, (big bags on pallets)
* Silotruck:
depending on size of truck, approx. 3.5 to 5 tons
Details about packaging and handling:
(http://www.wacker.com/hdk
).
Safety information
Comprehensive instructions are given in the
corresponding Material Safety Data Sheets. They are
available on request from WACKER subsidiaries or
may be printed via the WACKER web site
(http://www.wacker.com/hdk
).
During transportation and processing HDK
N20 may
cause electrostatic charges.
Like other amorphous silicas HDK
N20 does not show
either carcinogenic (IARC classification, Volume 68,
1997) or mutagenic properties.
The management system has been
certified according
to DIN EN ISO 9001
and DIN EN ISO 14001
and HDK
are registered trademarks
of Wacker Chemie AG.
Version 3.3 from 15-04-05 replaces
Version 3.2 from 31-08-04
The data presented in this leaflet are in accordance with the present state of our
knowledge, but do not absolve the user from carefully checking all supplies
immediately on receipt. We reserve the right to alter product constants within the
scope of technical progress or new developments. The recommendations made in
this leaflet should be checked by preliminary trials because of conditions during
processing over which we have no control, especially where other companies raw
materials are also being used. The recommendations do not absolve the user from
the obligation of investigating the possibility of infringement of third parties rights
and, if necessary, clarifying the position. Recommendations for use do not constitute
a warranty, either express or implied, of the fitness or suitability of the products for a
particular purpose.
For technical, quality, or product
safety questions, please contact:
Wacker Chemie AG
WACKER SILICONES
Hanns-Seidel-Platz 4
81737 M nchen, Germany
e-mail: hdk@wacker.com
www.wacker.com