U.S. patent application number 10/943122 was filed with the patent office on 2007-08-16 for hardenable reaction resin system.
Invention is credited to Wolfgang Endres, Marco Holst, Irene Jenrich, Kristian Leo, Markus Muzic.
Application Number | 20070191513 10/943122 |
Document ID | / |
Family ID | 34195776 |
Filed Date | 2007-08-16 |
United States Patent
Application |
20070191513 |
Kind Code |
A1 |
Jenrich; Irene ; et
al. |
August 16, 2007 |
Hardenable reaction resin system
Abstract
A hardenable reaction resin system, in particular a casting
compound, laminating resin, or impregnating resin, which is to be
processed as a two-component compound and contains a resin
component, a mineral filler, and polymer particles dispersed in the
resin component. The filler includes nanoparticles.
Inventors: |
Jenrich; Irene; (Winnenden,
DE) ; Leo; Kristian; (Burgstetten, DE) ;
Muzic; Markus; (Murr, DE) ; Endres; Wolfgang;
(Remshalden, DE) ; Holst; Marco; (Stuttgart,
DE) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
34195776 |
Appl. No.: |
10/943122 |
Filed: |
September 16, 2004 |
Current U.S.
Class: |
523/443 ;
524/492 |
Current CPC
Class: |
H05K 2201/0209 20130101;
C08K 2201/011 20130101; H05K 3/285 20130101; C08K 3/013 20180101;
B82Y 30/00 20130101; H05K 2201/0212 20130101; H05K 2201/0257
20130101 |
Class at
Publication: |
523/443 ;
524/492 |
International
Class: |
C08L 63/00 20060101
C08L063/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2003 |
DE |
10345139.0 |
Sep 30, 2003 |
DE |
10345312.1 |
Claims
1. A hardenable reaction resin system which is to be processed as a
two-component compound, comprising: a resin component; a mineral
filler including nanoparticles; and polymer particles dispersed in
the resin component.
2. The reaction resin system according to claim 1, wherein the
system is one of a casting compound, a laminating resin, and an
impregnating resin.
3. The reaction resin system according to claim 1, wherein the
filler contains silica powder.
4. The reaction resin system according to claim 1, wherein the
filler contains fused silica powder.
5. The reaction resin system according to claim 3, wherein the
filler contains surface-modified nanoparticles.
6. The reaction resin system according to claim 3, wherein the
filler has particles of two different grain size distributions, one
grain size distribution being in the nanometer range.
7. The reaction resin system according to claim 1, wherein the
resin component contains an epoxy resin.
8. The reaction resin system according to claim 7, wherein the
epoxy resin is a resin based on one of a bifunctional and a
multifunctional epoxide.
9. The reaction resin system according to claim 1, wherein the
resin component contains a resin based on at least one of bisphenol
A, bisphenol B and bisphenol F.
10. The reaction resin system according to claim 1, wherein the
polymer particles dispersed in the resin component are silicone
elastomer particles.
11. The reaction resin system according to claim 10, wherein the
silicone elastomer particles have a particle diameter of 10 nm to
100 .mu.m.
12. A method for manufacturing a hardenable reaction resin system,
comprising the steps of: in a first step, dispersing nanoparticles
in a resin component; and in a second step, mixing the
nanoparticles dispersed in the resin component with polymer
particles dispersed in the resin component producing the reaction
resin system.
13. The method according to claim 12, wherein the reaction resin
system is for impregnating electrical windings.
14. The method according to claim 12, wherein the reaction resin
system is for casting diodes and ignition coils.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a hardenable reaction resin
system, a method for manufacturing same, as well as its use.
BACKGROUND INFORMATION
[0002] Systems based on a resin which hardens via a chemical
reaction play a significant role in the manufacture of industrial
components. When such reaction resin systems are used for
insulation purposes, they usually have a high filler content. High
filler contents result in a high thermal and mechanical resistance
of the hardened reaction resin systems.
[0003] German Patent Application No. DE 100 51 051 describes such
epoxy resin-based reaction resin systems. They contain up to 75 wt.
% filler. Higher filler contents are impossible to implement in the
systems described therein, because they would have a negative
effect on the viscosity, i.e., processability of the casting
compound.
[0004] An object of the present invention is to provide a
hardenable reaction resin system which has a high thermal and
mechanical resistance, yet is easy to process.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is achieved by providing
a reaction resin system which is usable as a two-component system
and contains nanoparticles as a filler. By using nanoparticles as a
filler, reaction resin systems having up to 90 wt. % filler
content, yet being castable, are achievable.
[0006] When hardened, the reaction resin system has low linear
shrinkage and is characterized by a higher elongation at rupture
and a low thermal expansion coefficient.
[0007] Furthermore, the reaction resin system preferably has fused
silica or silica flour particles as a filler, which results in a
particularly pronounced thermal stability, a low expansion
coefficient, and a low dielectric constant.
[0008] In a particularly advantageous embodiment, the reaction
resin system has bisphenol A, bisphenol B, and/or bisphenol F,
optionally mixed with an epoxy, as the resin component. This resin
system has a high degree of cross-linking and therefore high
mechanical stability when hardened.
DETAILED DESCRIPTION
[0009] A reaction resin system according to the present invention
has three basic components: a resin component A, a filler B, and
polymer particles C, which are dispersed in resin component A. In
addition, at least one hardener D and commonly used additives are
provided such as one or more antifoaming agents, sedimentation
inhibitors, or adhesion promoters.
[0010] In general, it should be kept in mind that the reaction
resin system must form a stable system before and during processing
to prevent the components from separating. Thus, filler particles B
and polymer particles C should form stable dispersions with resin
component A, and, if there are more resin components A, resin
components A should form stable solutions or emulsions among
themselves. This stability must be ensured during both processing
and hardening of the reaction resin system.
[0011] Basically a plurality of monomers, cross-linkable compounds,
or mixtures of such compounds may be used as resin component A.
Particularly advantageous is the use of compounds having at least
one epoxy function, optionally mixed with other compounds with or
without an epoxy function. Thus, for example, diepoxides,
triepoxides, or tetraepoxides are suitable; the commercially
available compounds mentioned in the following are provided as
examples. Cycloaliphatic, preferably ring-epoxidized diepoxides,
such as (I) and (VI) have been found particularly suitable.
##STR1## ##STR2##
[0012] Resin component A may include one or more of compounds (I)
to (VII) or other resin components. Alternatively, resin components
based on bisphenol A, bisphenol B, and/or bisphenol F, PUR, or
cyanate esters alone or in mixtures with one another or with
suitable epoxy resin components may be used.
[0013] Furthermore, a novolak epoxy resin may be used as resin
component A, in particular a cresol-novolak epoxy resin of the
following composition: ##STR3##
[0014] Resin component A is contained in the reaction resin system
in a proportion of 5% to 95 wt. %, preferably 10% to 60 wt. %, in
particular 12% to 28 wt. %.
[0015] The reaction resin system also contains a filler B, which,
if appropriately selected, reduces the shrinkage of the hardened
reaction resin system and increases the thermal stability and tear
resistance of the hardened reaction resin system. Filler B contains
nanoparticles, nanoparticles being understood as a particle
fraction whose mean grain size distribution d.sub.50is in the
nanometer range. Aluminum oxide, chalk, silicon carbide, boron
nitride, carbon black, and talcum, for example, are suitable as
fillers. Filler B preferably has particles of silica flour (powder)
or fused silica or mixtures of same. In a particularly preferred
embodiment, filler B has particles of two different grain size
distributions d.sub.50. A first part of the filler particles is
characterized by a grain size distribution in the nanometer range,
and a second part of filler particles is preferably characterized
by a grain size distribution d.sub.50 preferably in the micrometer
range.
[0016] By using nanoparticles, the overall proportion of filler B
in the reaction resin system may be increased to 90 wt. %, the
reaction resin system still remaining sufficiently fluid during
processing and hardening. The total filler content in the reaction
resin system may thus equal 2% to 90 wt. %, preferably 50% to 70
wt. %, in particular 2% to 25 wt. %.
[0017] The use of silanized filler particles has been found to be
particularly suitable, because the modification of the filler
particle surfaces ensures improved bonding of filler B to resin
matrix A of the reaction resin system. To be able to set the degree
of silanization of filler B, either the filler is previously
treated with a silanizing agent and the presilanized filler is
mixed into the reaction resin system, or the silanizing agent is
added to the reaction resin system and the actual silanization
reaction takes place in the reaction resin system. Alternatively,
filler B may also have a chemically modified surface in the form of
a polymer layer, of PMMA, for example (known as core shell
particles).
[0018] The reaction resin system also contains polymer particles
dispersed in resin component A as third component C. These are
polysiloxane-containing polymers in particular, component C
preferably representing a dispersion of one or more silicones in
resin component A. Preferably silicone particles in the form of
silicone resin particles or silicone elastomer particles having a
particle diameter of 10 nm to 100 .mu.m are used. Basically, the
silicone particles may have a chemically modified surface in the
form of a polymer layer, for example, of PMMA (known as core shell
particles); however, it has been found that untreated or
surface-functionalized silicone particles are better suited for
achieving the object of the present invention. Alternatively,
elastomer particles of acrylonitryl-butadiene-styrene
copolymerizate (ABS) are also suitable.
[0019] The reaction resin system contains up to 25 wt. %,
preferably up to 10 wt. % of polymer particles C.
[0020] To ensure that the reaction resin system as a two-component
system is processable, a hardener is also provided.
Hexahydrophthalic acid anhydride or methyl nadic acid anhydride
(MNSA), for example, are suitable for this purpose.
[0021] The present reaction resin system may be used either as an
impregnating resin or as a casting compound. For processing as an
impregnating resin, for impregnating electrical windings, for
example, the winding to be impregnated is rotated, and either
immersed into the liquid impregnating resin or the liquid
impregnating resin is dripped onto the rotating winding. The
impregnated winding is hardened thermally, for example, or via
UV-supported cross-linking.
[0022] If the reaction resin system is used as a casting compound,
casting to form a molded part is performed at a higher temperature.
When the reaction resin system is heated to the appropriate
temperature, it has such a low viscosity and such a high capillary
effect that it may be cast even into unfavorable geometries, such
as casting gaps having a diameter of <300 .mu.m. This makes very
short cycle times possible at the same time. The cast reaction
resin system is exposed to a temperature of 60.degree. to
110.degree. C. for 30 to 300 minutes or a temperature of
120.degree. C. for 10 to 100 minutes to achieve gelling of the
reaction resin system. Subsequently it is exposed to a temperature
of 140.degree. to 220.degree. C. for 10 to 90 minutes to harden the
molded part.
[0023] The following exemplary embodiments of reaction resin
systems present their compositions (in wt. %) and the resulting
properties after hardening. Exemplary embodiments 1, 2, 6, and 7
are reference samples containing no polymer particles C or
nanoparticles as filler B.
1. Resin component A corresponds to a cycloaliphatic epoxide.
[0024] Compositions TABLE-US-00001 Exemplary Embodiment 1 2 3 4 5
Resin component A 16.96 45.9 13.52 12.53 18.3 Cycloaliphatic
epoxide Filler B 62.52 -- 62.87 57.9 49.97 Fused silica Filler B --
-- 3.65 3.38 5.0 Fused silica nanoparticles Polymer particles C --
-- 3.65 3.39 5.0 Silicone elastomer Additives 0.59 -- 0.34 0.318
0.08 Hardeners 19.93 54.1 15.97 14.78 21.65
[0025] The above compositions resulted in the following property
profile: TABLE-US-00002 Exemplary Embodiment 1 2 3 4 5 Viscosity at
2800 34 5160 13000 1500 60.degree. C. [mPa*s] Linear -0.3 -0.2 0.15
0.15 0.1 shrinkage [%] Glass 230 -- 239 226 180 transition
temperature [.degree. C.] Thermal 32-35 67 23 21 35 expansion
coefficient [10.sup.-6*1/.degree. C.] E-module 8990/ 2890/ 9750/
10360/ 6730/ bending/ 10200 2900 10390 11060 6410 tensile test
[N/mm.sup.2] Tension at 104/61 124/40 108/72 98/64 107/68
rupture/tear [N/mm.sup.2] Elongation at 1.0/ 5.4/ 1.24/ 1.05/ 1.76/
rupture/tear 0.62 1.46 0.91 0.73 1.26 [%]
II. Resin component A corresponds to a bisphenol A resin.
[0026] Compositions TABLE-US-00003 Exemplary Embodiment 6 7 8 Resin
component A 51.5 25.73 20.6 Bisphenol A Filler B Fused silica -- --
49.9 Filler B Fused silica -- 49.92 4.99 nanoparticles Polymer
particles C -- -- 4.99 Silicone elastomer Additives -- 0.16 0.18
Hardeners 48.5 24.19 19.34
[0027] The above compositions resulted in the following property
profile: TABLE-US-00004 Exemplary Embodiment 6 7 8 Viscosity at
60.degree. C. [mPa*s] 51 -- 1630 Linear shrinkage [%] 0.7 -- 0.36
Glass transition temperature 149 -- 133 [.degree. C.] Thermal
expansion 66 -- 33 coefficient [10.sup.-6*1/.degree. C.] E-module
bending/tensile test 2920 6930/7050 9000/75400 [N/mm.sup.2] Tension
at rupture/tear 130/55 144/89 149/73 [N/mm.sup.2] Elongation at
rupture/tear [%] 9.39/2.45 2.47/1.79 2.06/1.65
[0028] Due to its thermal stability when hardened, the reaction
resin system is suitable primarily for components exposed to
temperatures up to 240.degree. C., at least from time to time.
[0029] The reaction resin system according to the present invention
thus may be used, for example, for casting diodes, ignition coils,
or electronic components. Furthermore, electric windings may be
impregnated using the reaction resin system.
* * * * *