SCIENTIFIC RESEARCH AND DEVELOPMENT
QUARTZ CERAMIC BULK-IMPREGNATED WITH AN ORGANOSILICON
BINDER HAVING A SPIRAL-CYCLIC STRUCTURE
E. I. Suzdal’tsev
and E. V. Gorelova
Translated from Novye Ogenupory, No. 7, pp. 27 – 29, July, 2013.
Original article submitted April 23, 2013.
A method is presented for making a nonporous quartz ceramic that is resistant to high temperatures. The
method entails bulk impregnation with product MFSS-8 (an acetone solution of methyl phenyl spirosiloxane),
which is an organosilicon binder with a spiral-cyclic structure. The main properties of the ceramic material are
described along with the results of its certification for use in products employed in electronics.
Keywords: bulk-impregnated quartz ceramic, organosilicon binder, polymerization, electronic-grade products.
Quartz ceramics are widely used in electronic devices
because they are among the materials that are the most trans-
parent to radio waves. However, the operating characteristics
of products made of quartz ceramics are strongly affected by
quartz’ open porosity (8 – 11%), since the absorption of
moisture by the material sharply alters its dielectric charac-
teristics and makes it necessary to seal the product .
Quartz ceramics are also relatively low in strength, which
significantly limits their range of application.
One method of making porous materials stronger while
also protecting them from moisture is their partial or com
plete impregnation with solutions of organosilicon polymers
and subsequent polymerization. To make quartz-ceramic
products that are used at high temperatures stronger while
keeping their dielectric properties stable, it is best to use
heat-resistant organosilicon polymers whose dielectric prop
erties remain stable over a sufficiently broad temperature
range. The following methods of impregnation are used, the
method chosen depending on the function of the product and
the requirements that it must satisfy: complete impregnation;
one-sided impregnation to a shallow depth (to 1 mm) or to a
depth that varies over the height of the product.
The idea of using organosilicon resins to protect quartz
ceramics from external climatic factors is not new . How
ever, the practice that has been followed for many years in
the production of electronic devices is to subject products to
so-called surface impregnation to a shallow depth
(1 – 2 mm). This has been done out of the fear that intensive
heating of quartz ceramics in service might result in degrada-
tion of the polymer and damaging of the material by the
gases formed in the process. Surface impregnation of quartz
ceramics has serious shortcomings, one of the most signifi-
cant being that the ceramic is being protected from moisture
by a relatively thin surface film whose integrity could be dis-
turbed even by light mechanical loading. This would allow
moisture to enter the ceramic, which in turn would adversely
affect its electronic properties.
One proposal that emanated from research studies and
was later substantiated experimentally is that quartz ceramics
be completely protected from water absorption by subjecting
them to bulk impregnation with an organosilicon resin — the
product MFSS-8 (a solution of methyl phenyl spirosiloxane
in acetone). This polymer was chosen because of its good ad
hesive properties, high thermal stability (it can withstand
temperatures up to 450°C for long periods of time), and the
absence of carbon in the polymer’s degradation products.
Bulk impregnation of quartz ceramics with MFSS-8 and sub
sequent polymerization completely prevents the absorption
of water not only because of the formation of an outer film of
organosilicon resin but also because the pore channels inside
the ceramic itself are closed. This was confirmed in an exper
iment in which bulk-impregnated quartz-ceramic specimens
were subjected to gradual grinding in the thickness direction;
water absorption by the specimens was monitored through
out this process. No changes were seen in this parameter. We
thus set the goals of thoroughly investigating one bulk-im
pregnated quartz ceramic, deciding on the specifications for
Refractories and Industrial Ceramics Vol. 54, No. 4, November, 2013
1083-4877/13/05404-0285 © 2013 Springer Science+Business Media New York
OAO ONPP “Tekhnologiya”, Obninsk, Kaluga Oblast, Russia.