Silres® MK Powder - Brenntag Specialties, Inc.

SILRES® MK
METHYL SILICONE RESIN
Product description
SILRES® MK is a solvent-free, solid methyl silicone
resin whose high reactivity and heat resistance make it
ideal as a binder for all kinds of laminates and
moldings. SILRES® MK has the highest SiO ² content
of all WACKER silicone resins (after complete
oxidation: approx. 82 % SiO ² , expressed in terms of
solid resin [DSC]) and is soluble in aromatics, esters,
ketones and selected paraffins and chlorinated
hydrocarbons.
Special features
- highest SiO ² content of all WACKER silicone resins
- very high binding strength
- little smoke evolution on pyrolysis
- excellent thermal stability
- ideal for producing non-stick prepregs with
excellent storage stabilitys
Application
The primary application for SILRES® MK is the
production of laminates and moldings based on
inorganic raw materials, such as mica, alumina,
magnesium oxide, glassfibers and silica. A particular
advantage of SILRES® MK is that it can be
incorporated from aqueous suspension.
In molding compounds, SILRES® MK is permanently
stable up to 300 °C, and can withstand brief exposure
to 350 °C. Above 350 °C and as the temperature rises,
the methyl silicone resin undergoes oxidative
degradation to silica, carbon dioxide and water. Very
little smoke is evolved during this thermal degradation
and soot-like decomposition products are not formed.
The SiO ² backbone left behind after decomposition
joins the fillers into molded shapes of high mechanical
strength. The heat resistance of products ceramified in
this way is limited by the fillers and support materials
employed.
Processing
The quality of the end product is determined mainly by
the concentration of curing agent, the drying and
compression temperatures and the pressure
employed. The best processing conditions must be
determined by preliminary trials.
SILRES® MK may be processed in powder form, as an
aqueous suspension and in solution. When it is applied
from solution, be aware that the higher the solids
content, the lower is the storage stability of the
solution. For this reason, we recommend adding at
least 5 wt. % of an alcohol, such as ethanol or butanol,
to concentrated SILRES® MK solutions.
The recommended catalyst is 2 – 5 wt.% WACKER ®
Catalyst F 100 %, expressed in terms of the resin
employed. Information about alternative catalysts are
given in the table below.
After any solvent has been removed, the assembly is
cured under heat and, if necessary, pressure (typical
curing conditions: 200 °C, 30 - 60 minutes).
Please follow the general information provided in our
leaflet “Manufacture of Silicone-Bound Rigid Mica
Products with Wacker Silicones.”
Storage
The 'Best use before end' date of each batch is shown
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.
Technical data sheet for SILRES® MK / Version: 1.2 / Date of last alteration: 06.02.2012 1 / 2

Safety notes
Comprehensive instructions are given in the
corresponding Material Safety Data Sheets. They are
Product data
available on request from WACKER subsidiaries or
may be printed via WACKER web site
http://www.wacker.com.
Typical general characteristics Inspection Method Value
Supply form white powder
Melting point / Melting range 35 - 55 °C
Bulk density 500 kg/m³
Thermal decomposition min. 350 °C
These figures are only intended as a guide and should not be used in preparing specifications.
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.
The management system has been
certified according to DIN EN ISO
9001 and DIN EN ISO 14001
WACKER is a trademark of Wacker
Chemie AG.
SILRES® is a trademark of Wacker
Chemie AG.
For technical, quality, or product
safety questions, please contact:
Wacker Chemie AG
Hanns-Seidel-Platz 4
81737 München, Germany
info.silicones@wacker.com
www.wacker.com
Technical data sheet for SILRES® MK / Version: 1.2 / Date of last alteration: 06.02.2012 2 / 2