U.S. patent application number 08/930020 was filed with the patent office on 2002-01-31 for tackified polydiorganosiloxane oligourea segmented copolymers and a process for making same.
Invention is credited to EVERAERTS, ALBERT I., MAZUREK, MIECZYSLAW H., MELANCON, KURT C., ROMANKO, WALTER R., SHERMAN, AUDREY A..
Application Number | 20020013442 08/930020 |
Document ID | / |
Family ID | 25458835 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020013442 |
Kind Code |
A1 |
SHERMAN, AUDREY A. ; et
al. |
January 31, 2002 |
TACKIFIED POLYDIORGANOSILOXANE OLIGOUREA SEGMENTED COPOLYMERS AND A
PROCESS FOR MAKING SAME
Abstract
Tackified compositions comprise a curable polydiorganosiloxane
oligourea segmented copolymer which has alternating soft
polydiorganosiloxane units and hard diisocyanate residues, the
diisocyanate residue being the diisocyanate minus the --NCO groups.
The units are connected together by urea linkages and the copolymer
has end groups that are reactive under free radical or moisture
cure conditions, and silicate resin. Also provided are
pressure-sensitive adhesives, hot melt adhesives, and vibration
damping composites, vibration damping constrained layer
constructions, a bi-directional vibration damping constrained layer
constructions, vibration damping shaped articles as well as a
method of vibrationally damping an article and processes for
producing curable vibration damping material.
Inventors: |
SHERMAN, AUDREY A.; (ST.
PAUL, MN) ; ROMANKO, WALTER R.; (AUSTIN, TX) ;
MAZUREK, MIECZYSLAW H.; (ROSEVILLE, MN) ; MELANCON,
KURT C.; (WHITE BEAR LAKE, MN) ; EVERAERTS, ALBERT
I.; (OAKDALE, MN) |
Correspondence
Address: |
MICHAEL SHERILL LAW OFFICES
4756 BANNING AVENUE SUITE 200
WHITE BEAR LAKE
MN
55110
|
Family ID: |
25458835 |
Appl. No.: |
08/930020 |
Filed: |
September 26, 1997 |
PCT Filed: |
April 25, 1996 |
PCT NO: |
PCT/US96/05829 |
Current U.S.
Class: |
528/28 |
Current CPC
Class: |
C08G 77/458 20130101;
C09J 183/10 20130101 |
Class at
Publication: |
528/28 |
International
Class: |
C08G 077/04 |
Claims
What is claimed is:
1. A curable tackified polydiorganosiloxane oligourea segmented
copolymer comprising (a) soft polydiorganosiloxane units, hard
polyisocyanate residue units, wherein the polyisocyanate residue is
the polyisocyanate minus the --NCO groups, optionally, soft and/or
hard organic polyamine units, wherein the residues of isocyanate
units and amine units are connected by urea linkages, and terminal
groups, wherein the terminal groups are functional endcapping
groups, and (b) silicate resins.
2. The curable tackified polydiorganosiloxane oligourea segmented
copolymer according to claim 1 represented by the repeating unit of
the following formula: 8wherein: each R is a monovalent moiety
which independently is an alkyl moiety preferably having about 1 to
12 carbon atoms, and which may be substituted with, for example,
trifluoroalkyl or vinyl groups, a vinyl radical or higher alkenyl
radical represented by the formula
--R.sup.2(CH.sub.2).sub.aCH.dbd.CH.sub.2 wherein R.sup.2 is
--(CH.sub.2).sub.b-- or --(CH.sub.2).sub.cCH.dbd.CH-- and a is 1, 2
or 3; b is 0, 3 or 6; and c is 3, 4 or 5, a cycloalkyl moiety
preferably having about 6 to 12 carbon atoms and which may be
substituted with alkyl, fluoroalkyl, and vinyl groups, or an aryl
moiety preferably having about 6 to 20 carbon atoms and which may
be substituted with, for example, alkyl, cycloalkyl, fluoroalkyl
and vinyl groups or R is a perfluoroalkyl group, a
fluorine-containing group, or a perfluoroether-containing group;
each Z is a polyvalent radical which is an arylene radical or an
aralkylene radical having from about 6 to 20 carbon atoms, an
alkylene or cycloalkylene radical having from about 6 to 20 carbon
atoms; each Y is a divalent moiety which independently is an
alkylene radical having 1 to 10 carbon atoms, an aralkylene radical
or an arylene radical having 6 to 20 carbon atoms; each A is
independently --B--, or --YSi(R).sub.2(OSi(R).sub- .2).sub.pY-- or
mixtures thereof; B is a polyvalent radical selected from the group
consisting of alkylene, aralkylene, cycloalkylene, phenylene,
polyalkylene oxide, and copolymers thereof, and mixtures thereof;
each D is a monovalent radical which independently is hydrogen, an
alkyl radical having 1 to 10 carbon atoms or an aryl or arylalkyl
radicals having about 6 to 20 carbon atoms; each X is a moiety
represented by the formula (a) a moiety represented by 9where each
of D, and Z are defined as above, or (b) a moiety represented by
10where each of Z and D are defined as above, K is independently
(i) a free radical polymerizable end group such as, for example
acrylate, methacrylate, acrylamido, methacrylamido and vinyl
groups; (ii) a moisture curable group such as, for example,
alkoxysilane and oximino silane groups, and (c) a moiety
represented by 11wherein D and K are defined as above. (d) a moiety
represented by 12m is about 0to 8; p is about 10 or larger; and t
is a about 1 to 12.
3. The polydiorganosiloxane oligourea segmented copolymer according
to claim 2 wherein at least 50% of the R moieties are methyl
radicals with the balance being monovalent alkyl or substituted
alkyl radicals, alkenylene radicals, phenyl radicals, or
substituted phenyl radicals.
4. The polydiorganosiloxane oligourea segmented copolymer of claim
2 wherein Z is 2,6-tolylene, 4,4'methylenediphenylene,
3,3'-dimethoxy-4,4'-biphenylene, tetramethyl-m-xylylene,
4,4'-methylenedicyclohexylene,
3,5,5-trimethyl-3-methylenecyclohexylene, 1,6-hexamethylene, or
1,4cyclohexylene.
5. The polydiorganosiloxane oligourea segmented copolymer of claim
4 wherein Z tetramethyl-m-xylylene.
6. The polydiorganosiloxane oligourea segmented copolymer according
to claim 1 wherein the silicate resin is an MQ silicate resin, an
MQD silicate resin or an MQT silicate resin.
7. A pressure sensitive adhesive article comprising (a) a
substrate, and (b) a pressure sensitive adhesive comprises a
curable tackified polydiorganosiloxane oligourea segmented
copolymer comprising (a) soft polydiorganosiloxane units, hard
polyisocyanate residue units, wherein the polyisocyanate residue is
the polyisocyanate minus the --NCO groups, optionally, soft and/or
hard organic polyamine units, wherein the residues of isocyanate
units and amine units are connected by urea linkages, and terminal
groups, wherein the terminal groups are functional endcapping
groups, and (b) silicate resins.
8. The pressure sensitive adhesive article according to claim 7,
wherein the substrate is paper, polyolefin, polyethylene
terephthalate, polycarbonate, polyvinyl chloride,
polytetrafluoroethylene, polyimide, cellulose acetate, and ethyl
cellulose, woven fabric formed of threads of synthetic or natural
materials such as cotton, nylon, or rayon, or glass or ceramic
material, or nonwoven fabric, metal, metallized polymeric film,
acrylic, silicone, urethane, polyethylene, polypropylene, neoprene
rubber, and the like, and filled and unfilled foamed materials, or
ceramic sheet material.
9. The pressure sensitive adhesive article according to claim 7,
wherein the pressure sensitive adhesive is cured.
10. A hot melt adhesive comprising (a) a curable tackified
polydiorganosiloxane oligourea segmented copolymer comprising (a)
soft polydiorganosiloxane units, hard polyisocyanate residue units,
wherein the polyisocyanate residue is the polyisocyanate minus the
--NCO groups, optionally, soft and/or hard organic polyamine units,
wherein the residues of isocyanate units and amine units are
connected by urea linkages, and terminal groups, wherein the
terminal groups are functional endcapping groups, and (b) silicate
resins.
11. The hot melt adhesive according to claim 7, wherein the
polydiorganosiloxane oligourea segmented copolymer is cured.
12. A bi-directional vibration damping constrained layer
construction comprising at least two rigid members, each rigid
member having a broad surface proximate a broad surface of another
rigid member and closely spaced therefrom, and a composition
comprising the curable tackified polydiorganosiloxane oligourea
segmented copolymer according to claim 2, wherein the composition
is contained between closely spaced, rigid members, adhered to the
members, and cured.
13. A process for producing a curable tackified
polydiorganosiloxane oligourea segmented copolymer comprising (a)
forming a polydiorganosiloxane oligourea segmented copolymer by
adding at least one polyisocyanate and at least one endcapping
agent that has end groups that are reactive under free radical or
moisture cure conditions to an organic solvent solution of at least
one polyamine, wherein the polyamine is at least one
polydiorganosiloxane diamine or a mixture of at least one
diorganosiloxane diamine and at least one organic polyamine, mixing
the solution and allowing the polyisocyanate, endcapping agents,
and polyamine to react to form a polydiorganosiloxane oligourea
segmented copolymer, (b) blending the polydiorganosiloxane
oligourea segmented copolymer solution with at least one silicate
resin, and (c) removing the organic solvent.
14. A process for producing curable tackified polydiorganosiloxane
oligourea segmented copolymer comprising the steps of (a)
continuously providing reactants, wherein the reactants comprise at
least one polyisocyanate, at least one polyamine, and at least one
endcapping agent to a reactor; (b) mixing the reactants in the
reactor; (c) allowing the reactants to react under substantially
solvent free conditions to form a polydiorganosiloxane oligourea
segmented copolymer; (d) conveying the copolymer from the reactor;
(e) providing the copolymer, at least one silicate tackifying
resin, and solvent to a second reactor; (f) mixing the copolymer,
the silicate tackifying resin, and the solvent in the second
reactor to form a tackified composition; and (g) conveying the
tackified composition from the second reactor.
15. An essentially solventless process for producing curable
tackified polydiorganosiloxane oligourea segmented copolymer
comprising the steps of (a) forming polydiorganosiloxane oligourea
segmented copolymer by continuously providing reactants, wherein
the reactants comprise at least one polyisocyanate, at least one
endcapping agent that has end groups that are reactive under free
radical or moisture cure conditions, and at least one polyamine to
a reactor, (b) mixing the reactants in the reactor, (c) allowing
the reactants to react to form a polydiorganosiloxane oligourea
copolymer, and (d) conveying polymer from the reactor and (e)
incorporating a silicate resin by blending the silicate resin with
reactants or the polydiorganosiloxane oligourea segmented
copolymer.
Description
TECHNICAL FIELD
[0001] This invention relates to tackified crosslinkable
polydiorganosiloxane oligourea segmented copolymer, in particular
to copolymers that are useful as pressure-sensitive adhesives, hot
melt adhesives, vibration damping compositions, as well as articles
made from such copolymers.
BACKGROUND OF THE INVENTION
[0002] Pressure-sensitive adhesive tapes have been used for more
than half a century for a variety of marking, holding, protecting,
sealing and masking purposes. Pressure-sensitive adhesive tapes
comprise a backing, or substrate, and a pressure-sensitive
adhesive. Pressure-sensitive adhesives are materials which adhere
with no more than applied finger pressure and are aggressively and
permanently tacky. Pressure-sensitive adhesives require no
activation, exert a strong holding force and tend to be removable
from a smooth surface without leaving a residue. In some
applications, interesting pressure-sensitive adhesives are silicone
based adhesives.
[0003] Traditionally, polydiorganosiloxane pressure-sensitive
adhesives have been made in solution. Conventional solvent based
polydiorganosiloxane pressure-sensitive adhesives are generally
blends of high molecular weight silanol functional
polydiorganosiloxanes, i.e., polydiorganosiloxane gums, and
copolymeric silanol functional silicate resin, i.e., MQ resins,
which comprise R.sub.3SiO.sub.1/2 units and SiO.sub.4/2 units. In
order to obtain the desired adhesive properties, it has been
necessary to react the copolymeric silicate resin with the
polydiorganosiloxane. Improvements in such pressure-sensitive
adhesive properties are achieved when the copolymeric
polydiorganosiloxane resin and polydiorganosiloxane are
intercondensed, providing intra- and inter-condensation within the
adhesive. This condensation step requires 1) the addition of a
catalyst, 2) reacting the copolymeric polydiorganosiloxane resin
and polydiorganosiloxane in solution, and 3) allowing the reaction
to take place over a period of time at elevated temperature.
[0004] Solutions of intercondensed polydiorganosiloxane
pressure-sensitive adhesives, are generally applied to a backing,
heated to remove solvent, and crosslinked, if necessary, to improve
physical properties. If crosslinking is needed, peroxide catalysts
are commonly used. Disadvantages of solution applied
polydiorganosiloxane pressure-sensitive adhesives include the need
for elaborate drying ovens to remove solvent, and if crosslinking
is required, ovens which operate at temperatures greater than
140.degree. C. are needed to initiate diaryl peroxide crosslinking
catalysts. Such high oven temperatures limit the substrates useful
in making pressure-sensitive adhesive tapes to those which can
withstand the elevated temperatures.
[0005] In the medical field, pressure sensitive adhesive tapes are
used for many different applications in the hospital and health
areas, but basically they perform one of two functions. They are
used to restrict movement, such as in various strapping
applications, or they are used to hold something in place, such as
a wound dressing. It is important in each function that the
pressure sensitive adhesive tape be compliant with and
non-irritating to the skin and adhere well to the skin without
causing skin damage on removal.
[0006] In recent years, pressure sensitive adhesives have been used
in transdermal patch applications as drug transport membranes or to
attach drug transport membranes to skin. Although there is
continued development of new drugs and the need for different
transport rates of existing drugs, pressure sensitive adhesives are
still needed that can transport such drugs at various rates.
Furthermore, there is a continuing need to adhere new drug
transport membrances to skin during a treatment period.
[0007] In the automotive industry, there are applications that
remain unaddressed by current tape products. One such application
relates to automative paints and finishes that are formulated for
environmental conservation, recyclability, enhanced appearance,
improved durability, as well as resistance to environmental sources
of contamination. Painted substrates using these new formulations
are difficult to adhere to with current tape products. Another
application involves mounting thermoplastic polyolefin automotive
body side moldings.
[0008] Similarly, early electrical tapes were black friction tapes,
and the adhesive was soft and often split when unwound. Current
electrical tapes have a layer of a pressure sensitive adhesive
applied to a plasticized polyvinyl chloride backing or a
polyethylene or rubber film backing. Electrical tape is used to
insulate, hold, reinforce and protect electrical wires. Other uses
include providing a matrix for varnish impregnation, identifying
wires in electrical circuitry, and protecting terminals during
manufacture of electrical circuit boards. Electrical tape, should
be stretchable, conformable and meet nonflammability
requirements.
[0009] Preformed pavement marking materials include pavement
marking sheet materials and raised pavement markers that are used
as highway and pedestrian crosswalk markings. They are often
reflective and strategically oriented to enhance reflective
efficiency when illuminated by vehicle headlamps at night. The
marking materials must adhere to a variety of surfaces such as
concrete or asphalt, that may be cold, hot, oily, damp, rough or
smooth. Present pavement marking adhesive generally have inadequate
initial bonding or inadequate permanent bonding to roadway surfaces
that are illustrated by five problem areas: (1) limited adhesive
tack at cold temperatures resulting in a narrow application window,
(2) reduced durability under shear or impact causing difficult
removal of temporary markings, (3) low molecular weight fractions
in the adhesives on removable markings that stain light colored
concrete surfaces, (4) limited ductility allowing raised markers to
sometimes shatter upon impact by vehicle tires and (5) insufficient
elasticity to fill in gaps between markers and rough road surfaces,
thus often leading to premature detachment of the marker from the
roadway surface.
[0010] Hot melt adhesives are compositions that can be used to bond
nonadhereing surfaces together into a composite. During application
to a substrate, hot melt adhesives should be sufficiently fluid to
wet the surface completely and leave no voids, even if the surface
is rough. Consequently, the adhesive must be low in viscosity at
the time of application. However, the bonding adhesive generally
sets into a solid to develop sufficient cohesive strength to remain
adhered to the substrate under stressful conditions.
[0011] For hot melt adhesives, the transition from fluid to solid
may be accomplished in several ways. First, the hot melt adhesive
may be thermoplastic that softens and melts when heated and becomes
hard again when cooled. Such heating results in sufficiently high
fluidity to achieve successful wetting. Alternatively, the hot melt
adhesive may be dissolved in a solvent or carrier that lowers the
viscosity of the adhesive sufficiently to permit satisfactory
wetting and raised the adhesive viscosity when the solvent or
carrier is removed. Such an adhesive can be heat activated, if
necessary.
[0012] Damping is the dissipation of mechanical energy as heat by a
material in contact with the source of that energy. The temperature
range and frequency range over which damping occurs can be quite
broad, depending upon the particular application. For instance, for
damping in tall buildings that experience wind sway or seismic
vibrations, the frequency range can go to as low as about 0.1 Hertz
(Hz) up to about 10 Hz. Higher frequency damping applications can
be those such as for computer disk drives (on the order of 1000 Hz)
or higher frequency applications (10,000 Hz). Furthermore, outdoor
damping applications can be exposed to a wide range of temperature
and humidity conditions.
[0013] While the performance of a surface layer damping treatment
depends largely on the dynamic properties of the viscoelastic
material, it is also dependent on other parameters. The geometry,
stiffness, mass, and mode shape of the combination of the damping
material and the structure to which it is applied will affect the
performance of the damping material.
[0014] Presently known viscoelastic materials consist of single
components or polymer blends. Since presently known single
component viscoelastic materials perform over fairly narrow
temperature ranges, conventional solutions to wide temperature
variations incorporate multiple layers of viscoelastic material,
with each layer being optimized for a different temperature
range.
SUMMARY OF THE INVENTION
[0015] Briefly, in one aspect of the present invention,
polydiorganicsiloxane oligourea segmented copolymers are provided
wherein such copolymers comprise (a) soft polydiorganosiloxane
diamine units, hard polyisocyanate residue units, wherein the
polyisocyanate residue is the polyisocyanate minus the --NCO
groups, optionally, soft and/or hard organic polyamine units,
wherein the residues of isocyanate units and amine units are
connected by urea linkages, and terminal groups, wherein the
terminal groups are functional endcapping groups, and (b) silicate
resins. The composition may also optionally contain free radical
initiators, silane crosslinking agents, moisture cure catalysts,
and nonreactive additives such as fillers, pigments, stabilizers,
antioxidants, flame retardants, plasticizers, compatibilizers and
the like.
[0016] The compositions of the present invention are particularly
useful as pressure sensitive adhesives and in one aspect of the
present invention, a curable pressure sensitive adhesive
composition is provided comprising (a) polydiorganosiloxane
oligourea segmented copolymer comprising alternating soft
polydiorganosiloxane units and hard polyisocyanate residue units,
wherein the residue units are polyisocyanate units minus the --NCO
groups, and optionally, soft and/or hard organic polyamine units,
wherein the residues of isocyanate units and amine units are
connected together by urea linkages and the copolymer has
functional terminal groups, and (b) silicate resins.
[0017] In another aspect of the present invention, the pressure
sensitive adhesives (PSAs) can be used to fabricate PSA articles,
wherein the PSA articles comprise a flexible substrate and a layer
of PSA prepared in accordance with the present invention.
Furthermore, the substrate may be any substrate that would be known
to those skilled in the art and may further be coated or treated to
provide a low energy release surface on one surface (typical, the
backside surface), such as coating with a low adhesion backsize, a
release coating and the like, such that the PSA article could be
rolled up on itself like a conventional roll of tape.
Alternatively, the substrate may be treated or coated with
additional layers to provide a tie layer, a primer layer, a barrier
layer and the like between the substrate and the adhesive
layer.
[0018] The present invention further provides vibration damping
compositions comprising (a) a curable polydiorganosiloxane
oligourea segmented copolymer comprising alternating soft
polydiorganosiloxane units, and optionally soft and/or hard organic
polyamine units and hard polyisocyanate residue units, wherein the
residue units are polyisocyanate units minus the --NCO groups, such
that the residues of isocyanate units and amine units are connected
together by urea linkages, and the copolymer has functional
terminal groups, and (b) silicate resin.
[0019] Additionally, the compositions of the present invention are
particularly useful as hot melt adhesives and in one aspect of the
present invention, a curable hot melt adhesive composition is
provided comprising (a) polydiorganosiloxane oligourea segmented
copolymer comprising alternating soft polydiorganosiloxane units
and hard polyisocyanate residue units, wherein the residue units
are polyisocyanate units minus the --NCO groups, such that the hard
units and the soft units are connected together by urea linkages
and the copolymer has functional terminal groups, and (b) silicate
resins.
[0020] In another aspect of the present invention, the hot melt
adhesives can be used to prepared rods, sheets, pellets and the
like that can be subsequently applied in a molten state to produce
an adhesive bond between different substrates. The substrate may be
any substrate that would be known to those skilled in the art and
would be especially useful in adhering low surface energy materials
and electronic components.
[0021] The present invention also provides a vibration damping
composite comprising at least one substrate and at least one layer
of the composition of the present invention The substrate may be
flexible, stiff, or rigid. Furthermore, the substrate may be any
substrate that would be known to those skilled in the art and may
further be coated or treated to provide a low energy release
surface, such as a coating with a low adhesion backsize, a release
coating and the like.
[0022] Such composites may be a constrained layer construction,
wherein the construction comprises at least one substrate having a
stiffness sufficient to cause resonation within the substrate in
response to an internal or external applied force and at least one
layer of the composition of the present invention. The constrained
layer construction preferably has a composite loss factor, tan
.delta. greater than or equal to 0.4 in the temperature range of
between about -80 and 150.degree. C. and in the frequency range of
0.01 to 100,000 Hz as evaluated by a Polymer Laboratories Dynamic
Mechanical Thermal Analyzer Mark II in the shear mode. The useful
temperature range depends on both the frequency and the
characteristics of the damping composition.
[0023] In another aspect, the composite article construction may be
such to provide a bi-directional vibration damping constrained
layer construction comprising at least two rigid members, and at
least one layer of the composition of the present invention.
Generally, each rigid member has a stiffness exceeding that of a
0.25 cm steel plate. Preferably, the vibration damping composition
has a tan .delta. greater than or equal to 0.4 in the temperature
range of -80.degree. C. and 150.degree. C. and in the frequency
range of 0.1 to 10 Hz, as evaluated by a Polymer Laboratories
Dynamic Mechanical Thermal Analyzer Mark II in the shear mode.
[0024] Advantageously, shaped articles can be produced, for
example, by techniques such as compression molding, injection
molding, casting, calendaring and extrusion. Curing can be provided
by techniques common for free radical or moisture cure crosslinking
reactions.
[0025] The compositions of the present invention have excellent
physical properties typically associated with polydiorganosiloxane
polymers such as moderate thermal and oxidative stabilities, UV
resistance, low index of refraction, low surface energy, and
hydrophobicity, resistance to degradation from exposure to heat,
and water, good dielectric properties, good adhesion to low surface
energy substrates, and flexibility at low temperatures. In
addition, the compositions exhibit a combination of unexpected
properties including, for example, excellent green strength, that
is, mechanical strength in the uncured state, allowing subsequent
operations to contact the surface before the compositions have
cured, controlled flow and crosslinked density characteristics
permitting thick coatings on irregular surfaces, good
conformability to irregular surfaces, excellent mechanical
properties typical of curable systems, excellent damping
performance over a broad temperature range, an ability to withstand
large strains, excellent adhesion to a variety of substrates when
formulated for adhesion, and handling characteristics that permit
easy attainment of desired thicknesses and shapes. Furthermore, the
compositions can be cured at room temperature, thus permitting use
of temperature sensitive substrates.
[0026] The compositions of the invention have good resistance to
environmental conditions and good performance over a broad range of
frequency and temperature. When used as vibration damping
materials, the compositions of the present invention have wide
utility for minimizing adverse vibration in constrained layer
damping treatments as well as minimizing adverse wind sway and
seismic influences in buildings subject to wide temperature and
humidity variations.
[0027] The present invention further provides a process for
producing curable compositions comprising (a) forming a
polydiorganosiloxane oligourea segmented copolymer by adding at
least one polyisocyanate and at least one endcapping agent that has
end groups that are reactive under free radical or moisture cure
conditions to an organic solvent solution of at least one
polyamine, wherein the polyamine is at least one
polydiorganosiloxane diamine or a mixture of at least one
diorganosiloxane diamine and at least one organic polyamine, mixing
the solution and allowing the polyisocyanate, endcapping agents,
and polyamine to react to form a polydiorganosiloxane oligourea
segmented copolymer, (b) blending the polydiorganosiloxane
oligourea segmented copolymer solution with at least one silicate
resin, and (c) removing the organic solvent.
[0028] The present invention still further provides a process for
preparing curable compositions comprising the steps of continuously
providing reactants, wherein the reactants comprise at least one
polyisocyanate, at least one polyamine, and at least one endcapping
agent to a reactor; mixing the reactants in the reactor; allowing
the reactants to react under substantially solvent free conditions
to form a polydiorganosiloxane oligourea segmented copolymer;
conveying the copolymer from the reactor; providing the copolymer,
at least one silicate tackifying resin, and solvent to a second
reactor; mixing the copolymer, the silicate tackifying resin, and
the solvent in the second reactor to form a tackified composition;
and conveying the tackified composition from the second
reactor.
[0029] The present invention still further provides an essentially
solventless process for producing curable compositions comprising
(a) forming polydiorganosiloxane oligourea segmented copolymer by
continuously providing reactants, wherein the reactants comprise at
least one polyisocyanate, at least one endcapping agent that has
end groups that are reactive under free radical or moisture cure
conditions, and at least one polyamine to a reactor, mixing the
reactants in the reactor, allowing the reactants to react to form a
polydiorganosiloxane oligourea copolymer, and conveying polymer
from the reactor and (b) incorporating a silicate resin by blending
the silicate resin with reactants or the polydiorganosiloxane
oligourea segmented copolymer.
[0030] This solventless process is environmentally advantageous as
there are no solvents to be evaporated from the final composition.
The continuous nature of this process has several other inherent
advantages over conventional solution polymerization processes. The
material can be extruded into a variety of shapes immediately
subsequent to polymerization which obviates the degradation, which
may be associated with additional heat from further reprocessing
steps. Another advantage of this substantially solventless,
continuous process is the ability to add or blend, in line, the
silicate resin, as well as various free radical initiators, silane
crosslinking agents, moisture cure catalysts, and nonreactive
fillers, plasticizers other polymers, and other property modifiers
into the polydiorganosiloxane oligourea segmented copolymer before,
during, or after formation of the copolymer.
[0031] Optionally, nonreactive additives such as fillers,
plasticizers, pigments, stabilizers, antioxidants, flame
retardants, compatibilizers and the like may be added at any point
in each of the above processes.
[0032] Each process of the present invention has unique advantages.
The solvent process permits the use of conventional solvent coating
equipment while resulting in curable tackified compositions whose
high green strength, i.e., strength prior to curing, permits
subsequent manufacturing operations before cure. The solventless
process permits thick coatings onto irregularly shaped surfaces,
use of conventional hot melt coating equipment with lower
processing temperatures than typically used with conventional hot
melt processable compositions, the advantage associated with high
green strength, as well as many advantages involving the
environment, economics, and safety that are associated with a
substantially solventless process. The combination of elements of
each process permits one to customize the silicate tackifying resin
concentration at a later date for specific applications while
retaining some of the advantages of each.
BRIEF DESCRIPTION OF THE DRAWING
[0033] FIG. 1 is a perspective view of a bi-directional vibration
damper of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0034] The polydiorganosiloxane oligourea segmented copolymers
useful in the curable tackified compositions of the present
invention can be represented by the formula 1
[0035] wherein:
[0036] each R is a monovalent moiety which independently is an
alkyl moiety preferably having about 1 to 12 carbon atoms, and
which may be substituted with, for example, trifluoroalkyl or vinyl
groups, a vinyl radical or higher alkenyl radical represented by
the formula --R.sup.2(CH.sub.2).sub.aCH.dbd.CH.sub.2 wherein
R.sup.2 is --(CH.sub.2).sub.b-- or --(CH.sub.2).sub.cCH.dbd.CH--
and a is 1, 2 or 3; b is 0, 3 or 6; and c is 3, 4 or 5, a
cycloalkyl moiety preferably having about 6 to 12 carbon atoms and
which may be substituted with alkyl, fluoroalkyl, and vinyl groups,
or an aryl moiety preferably having about 6 to 20 carbon atoms and
which may be substituted with, for example, alkyl, cycloalkyl,
fluoroalkyl and vinyl groups or R is a perfluoroalkyl group as
described in U.S. Pat. No. 5,028,679, wherein such description is
incorporated herein by reference, a fluorine-containing group, as
described in U.S. Pat. No. 5,236,997, wherein such description is
incorporated herein by reference, or a perfluoroether-containing
group, as described in U.S. Pat. Nos. 4,900,474 and 5,118,775,
wherein such descriptions are incorporated herein by reference;
preferably at least 50% of the R moieties are methyl radicals with
the balance being monovalent alkyl or substituted alkyl radicals
preferably having 1 to 12 carbon atoms, vinylene radicals, phenyl
radicals, or substituted phenyl radicals or R is a perfluoroalkyl
group as described in U.S. Pat. No. 5,028,679, wherein such
description is incorporated herein by reference, a
fluorine-containing group, as described in U.S. Pat. No. 5,236,997,
wherein such description is incorporated herein by reference, or a
polyperfluoroether-containing group, as described in U.S. Pat. Nos.
4,900,474 and 5,118,775, wherein such descriptions are incorporated
herein by reference;
[0037] each Z is a polyvalent radical which is an arylene radical
or an aralkylene radical preferably having from about 6 to 20
carbon atoms, an alkylene or cycloalkylene radical preferably
having from about 6 to 20 carbon atoms, preferably Z is
2,6-tolylene, 4,4'-methylenediphenylene,
3,3'-dimethoxy-4,4'-biphenylene, tetramethyl-m-xylylene,
4,4'-methylenedicyclohexylene,
3,5,5-trimethyl-3-methylenecyclohexylene, 1,6-hexamethylene,
1,4-cyclohexylene, and mixtures thereof;
[0038] each Y is a divalent moiety which independently is an
alkylene radical preferably having 1 to 10 carbon atoms, an
aralkylene radical or an arylene radical preferably having 6 to 20
carbon atoms;
[0039] each A is independently --B--, or
--YSi(R).sub.2(OSi(R).sub.2).sub.- pY-- or mixtures thereof;
[0040] B is a polyvalent radical selected from the group consisting
of alkylene, aralkylene, cycloalkylene, phenylene, polyalkylene
oxide, such as, polyethylene oxide, polypropylene oxide,
polytetramethylene oxide, and copolymers thereof, and mixtures
thereof;
[0041] each D is a monovalent radical which independently is
hydrogen, an alkyl radical preferably having 1 to 10 carbon atoms
or an aryl or arylalkyl radicals preferably having about 6 to 20
carbon atoms;
[0042] each X is a moiety represented by the formula
[0043] (a) a moiety represented by 2
[0044] where each of D, and Z are defined as above, or
[0045] (b) a moiety represented by 3
[0046] where each of Z and D are defined as above,
[0047] K is independently (i) a free radical polymerizable end
group such as, for example acrylate, methacrylate, acrylamido,
methacrylamido and vinyl groups; (ii) a moisture curable group such
as, for example, alkoxysilane and oximino silane groups, and
[0048] (c) a moiety represented by 4
[0049] wherein D and K are defined as above.
[0050] (d) a moiety represented by 5
[0051] m is about 0 to 8;
[0052] p is about 10 or larger, preferably about 15 to 2000, more
preferably about 30 to 1500; and
[0053] t is a about 1 to 12, preferably about 1 to 6, more
preferably about 1 to 4.
[0054] In the use of polyisocyanates (Z is a radical having a
functionality greater than 2) and polyamines (B is a radical having
functionality greater than 2), the structure of Formula I will be
modified to reflect branching at the polymer backbone.
[0055] The average degree of polymerization refers to the size of
the resultant oligomer molecule and is determined from the number
average of the residue of amine-containing reactant molecules in
the oligomer. There are two ways of obtaining the desired degree of
oligomerization: (1) control the isocyanate to amine ratio to
obtain either isocyanate or amine endcapped oligomer (X=a or d),
and (2) judiciously select the amount of monoamine or
monoisocyanate endcapper with stoichiometric amounts of isocyanate
and amine (X=b or c). The following table displays the mol ratios
of the various molecules necessary for building a molecule with the
desired encapper "X". For the use of polyamines and
polyisocyanates, the ratios may be adjusted accordingly.
1 X(a) X(b) X(c) X(d) Degree of t + m + 2 t + m + 4 t + m + 2 t + m
+ 2 oligomerization Diamines t + m + 2 t + m + 2 t + m + 2 t + m +
2 Diisocyanates t + m + 3 t + m + 3 t + m + 1 t + m + 1 Monoamines
-- 2 -- -- Monoisocyanates -- -- 2 --
[0056] Polydiorganosiloxane diamines useful in the process of the
present invention can be represented by the formula 6
[0057] wherein each of R, Y, D, and p are defined as above.
Generally, the number average molecular weight of the
polydiorganosiloxane diamines most useful in the present invention
range from about 700 to 150,000 or more.
[0058] Polydiorganosiloxane diamines (also referred to as silicone
diamines or diamines) useful in the present invention are any which
fall within Formula V above and include those having molecular
weights in the range of about 700 to 150,000. Polydiorganosiloxane
diamines are described, for example, in U.S. Pat. Nos. 5,026,890
and 5,276,122, wherein such descriptions are incorporated by
reference herein and JP 93087088. Preferred are substantially pure
polydiorganosiloxane diamines prepared as described in U.S. Pat.
No. 5,214,119, wherein such description is incorporated herein by
reference. The polydiorganosiloxane diamines having such high
purity are prepared from the reaction of cyclic organosiloxanes and
bis(aminoalkyl)disiloxanes utilizing an anhydrous aminoalkyl
functional silanolate catalyst such as tetramethylammonium
3-aminopropyldimethylsilanolate, preferably in an amount less than
0.15 weight percent based on the weight of the total amount of
cyclic organosiloxane with the reaction run in two stages.
[0059] Particularly preferred are polydiorganosiloxane diamines
prepared using cesium and rubidium catalysts. The preparation
includes combining under reaction conditions (1) an amine
functional endblocker represented by the formula 7
[0060] wherein each R, D, and Y are described as above and x is an
integer of about 0 to 150;
[0061] (2) sufficient cyclic siloxane to obtain a
polydiorganosiloxane diamine having a molecular weight greater than
the molecular weight of the endblocker and
[0062] (3) a catalytic amount of cesium hydroxide, rubidium
hydroxide, cesium silanolate, rubidium silanolate, cesium
polysiloxanolate, rubidium polysiloxanolate, and mixtures
thereof.
[0063] The reaction is continued until substantially all of the
amine functional endblocker is consumed. Then the reaction is
terminated by adding a volatile organic acid to form a mixture of a
polydiorganosiloxane diamine usually having greater than about 0.01
weight percent silanol impurities and one or more of the following:
a cesium salt of the organic acid, a rubidium salt of the organic
acid, or both such that there is a small molar excess of organic
acid in relation to catalyst. Then, the silanol groups of the
reaction product are condensed under reaction conditions to form
polydiorganosiloxane diamine having less than or equal to about
0.01 weight percent silanol impurities while the unreacted cyclic
siloxane is stripped, and, optionally, the salt is removed by
subsequent filtration.
[0064] Examples of polydiorganosiloxane diamines useful in the
present invention include polydimethylsiloxane diamine,
polydiphenylsiloxane diamine, polytrifluoropropylmethylsiloxane
diamine, polyphenylmethylsiloxane diamine,
poly(5-hexenyl)methylsiloxane diamine, polydiethylsiloxane diamine,
polydivinylsiloxane diamine, polyvinylmethylsiloxane diamine,
copolymers thereof and mixtures thereof.
[0065] Any polyisocyanate that can react with a monoamine or a
polyamine can be used in the present invention. Particularly useful
polyisocyanates are diisocyanates and are those that are
represented by the formula
OCN--Z--NCO (VIII)
[0066] where Z is defined as above.
[0067] Examples of such diisocyanates include, but are not limited
to, aromatic diisocyanates, such as 2,6-toluene diisocyanate,
2,5-toluene diisocyanate, 2,4-toluene diisocyanate, m-phenylene
diisocyanate, p-phenylene diisocyanate, methylene
bis(o-chlorophenyl diisocyanate),
methylenediphenylene-4,4'-diisocyanate, polycarbodiimide-modified
methylenediphenylene diisocyanate,
(4,4'-diisocyanato-3,3',5,5'-tetraethy- l) diphenylmethane,
4,4'-diisocyanato-3,3'-dimethoxybiphenyl (o-dianisidine
diisocyanate), 5-chloro-2,4-toluene diisocyanate,
1-chloromethyl-2,4-diisocyanato benzene, aromatic-aliphatic
diisocyanates such as m-xylylene diisocyanate,
tetramethyl-m-xylylene diisocyanate, aliphatic diisocyanates, such
as 1,4-diisocyanatobutane, 1,6-diisocyanatohexane,
1,12-diisocyanatododecane, 2-methyl-1,5-diisocyanatopentane, and
cycloaliphatic diisocyanates such as
methylenedicyclohexylene-4,4'-diisocyanate,
3-isocyanatomethyl-3,5,5tr- imethylcyclohexyl isocyanate
(isophorone diisocyanate) and cyclohexylene-1,4-diisocyanate.
[0068] Preferred diisocyanates include 2,6-toluene diisocyanate,
methylenediphenylene-4,4'-diisocyanate, polycarbodiimide-modified
methylenediphenyl diisocyanate, o-dianisidine diisocyanate,
tetramethyl-m-xylylene diisocyanate,
methylenedicyclohexylene-4,4'-diisoc- yanate,
3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone
diisocyanate), 1,6-diisocyanatohexane, and
cyclohexylene-1,4-diisocyanate.
[0069] Any triisocyanate that can react with the polyamine, and in
particular with the polydiorganosiloxane diamine of Formula VI, can
be used in the present invention. Examples of such triisocyanates
include, but are not limited to, polyfunctional isocyanates, such
as those produced from biurets, isocyanurates, adducts and the like
may be used. Some commercially available polyisocyanates include
portions of the DESMODUR.TM. and MONDUR.TM. series from Bayer and
the PAPI.TM. series from Dow Plastics. Preferred triisocyanates
include DESMODUR.TM. N-3300 and MONDUR.TM. 489.
[0070] The use of different polyisocyanates in the reaction will
modify the properties of the polydiorganosiloxane polyurea
segmented copolymer, thus affecting the rheological and mechanical
properties of the resulting compositions.
[0071] The endcapping agents contain free radically curable groups,
moisture curable groups, or a mixture thereof depending on the
properties desired in the resulting polydiorganosiloxane oligourea
segmented copolymer materials. Preferred endcapping agents are
governed by their costs and availability, and the specific
properties desired, and thus may vary with time.
[0072] Suitable endcapping agents for polydiorganosiloxane
oligourea segmented copolymers which would be terminated with amine
groups, were no endcapping agent present and which provide end
groups which are reactive under free radical curing conditions,
include but are not limited to isocyanatoethyl methacrylate,
alkenyl azlactones such as vinyl dimethyl azlactone and isopropenyl
dimethyl azlactone, m-isopropenyl-.alpha.,.alph- a.-dimethyl benzyl
isocyanate, and acryloyl ethyl carbonic anhydride. Some of these
endcapping agents, e.g., isocyanatoethyl methacrylate, are
commercially available, and others can be prepared using procedures
well-known to those skilled in the art. Alkenyl azlactones and
their preparations are described in U.S. Pat. No. 4,777,276,
wherein such description is incorporated herein by reference.
Acryloyl ethyl carbonic anhydride can be prepared from ethyl
chloroformate and acrylic acid by the method of R. Hatada and H.
Kondo given in Bull. Chem. Soc, Japan, 41 (10), 2521 (1968).
Preferred endcapping agents, for polydiorganosiloxane oligourea
segmented copolymers that would be amine terminated if no
endcapping agent were present includes, for example,
isocyanatoethyl methacrylate, vinyl dimethyl azlactone, and
acryloyl ethyl carbonic anhydride.
[0073] Suitable endcapping agents for polydiorganosiloxane
oligourea segmented copolymers which would be terminated with amine
groups were no end capping agent present, with end groups which are
reactive under moisture curing conditions include but are not
limited to isocyanatopropyl trimethoxysilane, isocyanatopropyl
triethoxysilane, isocyanatopropyl dimethoxy
(methylethylketoximino)silane, isocyanatopropyl diethoxy
(methylethylketoximino)silane, isocyanatopropyl monomethoxy
di(methylethylketoximino)silane, isocyanatopropyl monoethoxy
di(methylethylketoximino)silane, and isocyanatopropyl
tri(methylethylketoximino)silane. The diisocyanate which serves to
form the copolymer, may also serve as the moisture curable terminal
portion of the copolymer when the isocyanate groups provided by the
diisocyanate exceed the amine groups provided by the diamine.
[0074] Suitable endcapping agents for polydiorganosiloxane
oligourea segmented copolymers where the copolymer would be
isocyanate terminated if no endcapping agent were present, which
provide end groups which are reactive under moisture curing
conditions include but are not limited to aminopropyl
trimethoxysilane, aminopropyl triethoxysilane, aminopropyl
methyldimethoxysilane, aminopropyl methyldiethoxysilane,
aminopropyl dimethoxy (methylethylketoximino)silane, aminopropyl
diethoxy (methylethylketoximino)silane, aminopropyl monomethoxy
di(methylethylketoximino)silane, aminopropyl monoethoxy
di(methylethylketoximino)silane, and aminopropyl
tri(methylethylketoximin- o)silane. Preferred endcapping agents,
for polydiorganosiloxane oligourea segmented copolymers where the
copolymer would be isocyanate terminated if no endcapping agent
were present, include, for example, aminopropyl trimethoxysilane,
aminopropyl triethoxysilane and aminopropyl
methyldiethoxysilane.
[0075] Examples of organic polyamines useful in the present
invention include but are not limited to polyoxyalkylene diamine,
such as D-230, D-400, D-2000, D-4000, DU-700, ED-2001 and EDR-148,
all available from Huntsman, polyoxyalkylene triamine, such as
T-3000 and T-5000 available from Huntsman, polyalkylenes, such as
Dytek A and Dytek EP, available from DuPont.
[0076] The above polyamines, polyisocyanates, and endcapping agents
are used in the appropriate stoichiometric ratios to obtain curable
polydiorganosiloxane oligourea segmented copolymers with the
desired average degree of polymerization.
[0077] The silicate resin plays an important role in determining
the physical properties of the compositions of the present
invention. For example, as silicate resin content is increased from
low to high concentration, the glassy to rubbery transition occurs
at increasingly higher temperatures. Thus, varying silicate resin
concentration in vibration damping applications can shift the area
of maximum damping to the desired temperature range. Of course, the
M to Q ratio, D and T content and molecular weight of the resins
may significantly influence the relative "hardness" of the resin
and must be considered when selecting resin type and concentration.
Furthermore, one need not be limited to a single silicate resin as
it may be beneficial to employ a combination of resins in a single
damping composition to achieve desired damping performance.
[0078] Silicate resins useful in the present invention include
those composed of the following structural units, M, D, T, Q and
combinations thereof For example, MQ silicate resins, MQD silicate
resins, and MQT silicate resins that also may be referred to as
copolymeric silicate resins and that preferably have a number
average molecular weight of about 100 to about 50,000, more
preferably about 500 to about 10,000 and generally have methyl
substituents. Silicate resins include both nonfunctional and
functional resins, the functional resins having one or more
functionalities including, for example, silicon-bonded hydrogen,
silicon-bonded alkenyl, and silanol. MQ silicate resins are
copolymeric silicate resins having R'.sub.3SiO.sub.1/2 units and
SiO.sub.4/2 units. Such resins are described in, for example,
Encyclopedia of Polymer Science and Engineering, vol. 15, John
Wiley & Sons, New York, (1989), pp 265-270, and U.S. Pat. No.
2,676,182, U.S. Pat. No. 3,627,851, U.S. Pat. No. 3,772,247, and
U.S. Pat. No. 5,248,739, which are incorporated herein by
reference. MQ silicate resins having functional groups are
described in U.S. Pat. No. 4,774,310 that has silyl hydride groups,
U.S. Pat. No. 5,262,558 that has vinyl and trifluoropropyl groups,
and U.S. Pat. No. 4,707,531 that has silyl hydride and vinyl
groups, each of which is incorporated herein by reference. The
above-described resins are generally prepared in solvent. Dried, or
solventless, MQ silicate resins can be prepared as described in
U.S. Pat. No. 5,319,040, U.S. Pat. No. 5,302,685, and U.S. Pat. No.
4,935,484, each of which are incorporated herein by reference. MQD
silicate resins are terpolymers having R'.sub.3SiO.sub.1/2 units,
SiO.sub.4/2 units, and R'.sub.2SiO.sub.2/2 units such as are taught
in U.S. Pat. No. 2,736,721 which is incorporated herein by
reference. MQT silicate resins are terpolymers having
R'.sub.3SiO.sub.1/2 units, SiO.sub.4/2 units and R'SiO.sub.3/2
units such as are taught in U.S. Pat. No. 5,110,890 which is
incorporated herein by reference and Japanese Kokai HE 2-36234.
[0079] Commercially available silicate resins include SR-545, MQ
resin in toluene, available from General Electric Co., Silicone
Resins Division, Waterford, N.Y.; MQOH resins which are MQ silicate
resins in toluene, available from PCR, Inc., Gainesville, Fla.;
MQR-32-1, MQR-32-2, and MQR-32-3 resins which are MQD resin in
toluene, available from Shin-Etsu Chemical Co. Ltd., Torrance,
Calif., and PC-403, hydride functional MQ resin in toluene
available from Rhone-Poulenc, Latex and Specialty Polymers, Rock
Hill, S.C. Such resins are generally supplied in organic solvent
and may be employed in compositions of the present invention as
received. However, these organic solutions of silicate resin may
also be dried by any number of techniques known in the art, such as
spray drying, oven drying, steam drying, etc. to provide a silicate
resin at about 100% nonvolatile content for use in compositions of
the present invention. Also useful in compositions of the present
invention are blends of two or more silicate resins.
[0080] The compositions of the present invention preferably
contains about 20 to 80 parts by weight polydiorganosiloxane
oligourea segmented copolymer, more preferably about 25 to 75 parts
by weight, most preferably about 30 to 70 parts by weight. The
composition preferably contains about 20 to 80 parts by weight
silicate resin, more preferably about 25 to 75 parts by weight,
most preferably about 30 to 70 parts by weight. The total parts by
weight of the polydiorganosiloxane polyurea segmented copolymer and
the silicate resin equal 100.
[0081] Further, the compositions of the present invention may also
optionally contain various free radical initiators, silane
crosslinking agents, moisture cure catalysts, fillers, and other
property modifiers that are not reactive to the amine or isocyanate
groups and can also be blended into the compositions before,
during, or after formation of the oligourea has taken place. Free
radical initiators can be added in concentrations from 0.1 to 5.0
weight percent. Moisture cure crosslinking agents can be added in
concentrations up to about 40 weight percent and moisture cure
catalysts can be added in amounts up to about 10 weight percent to
moisture curable tackified polydiorganosiloxane oligourea segmented
copolymers to reduce the cure time.
[0082] Silane agents may be used to crosslink the moisture curable
polysiloxane oligourea segmented copolymers of the present
invention. Suitable silane crosslinking agents generally have the
formula R".sub.nSiW.sub.4-n where R" is a monovalent hydrocarbon
group, (for example, an alkyl, alkylenyl, aryl, or alkaryl group),
n is 0, 1 or 2, and W is a monovalent hydrolyzable group such as a
dialkylketoximino group, (for example, methylethylketoximino,
dimethylketoximino, or diethylketoximino), alkoxy group (for
example, methoxy, ethoxy, or butoxy), alkenoxy group (for example,
isopropenoxy), acyloxy group (for example, acetoxy), alkamido group
(for example, methylacetamido or ethylacetamido), acylamido group
(for example, phthalimidoamido). Silane crosslinking agents falling
within this category are commercially available, for example, from
Silar Laboratories, Scotia, N.Y. Particularly preferred silane
crosslinking agents are dialkylketoximinosilanes because they
exhibit good shelf-stability and do not form deleterious
by-products upon cure. Examples include
methyltri(methylethylketoximino)silane and
vinyltri(methylethylketoximino- )silane, both of which are
commercially available from Allied-Signal, Inc. Morristown, N.J.,
and alkoxysilanes available from OSi Chemicals, Lisle, Ill.
[0083] The free radically curable polydiorganosiloxane oligourea
segmented copolymer compositions of the invention can, depending
upon their viscosity, be coated, extruded, or poured, and rapidly,
completely, and reliably radiation cured to tackified materials
(even at high molecular weight) by exposure to electron beam,
visible or ultraviolet radiation. Curing is preferably carried out
in as oxygen-free an environment as possible, e.g., in an inert
atmosphere such as nitrogen gas or by utilizing a barrier of
radiation-transparent material having low oxygen permeability.
Curing can also be carried out under an inerting fluid such as
water. When visible or ultraviolet radiation is used for curing,
the silicone compositions may also contain photoinitiator. Suitable
photoinitiators include benzoin ethers, benzophenone and
derivatives thereof, acetophenone derivatives, camphorquinone, and
the like. Photoinitiator is generally used at a concentration of
from about 0.1% to about 5% by weight of the total polymerizable
composition, and, if curing is carried out under an inerting fluid,
the fluid is preferably saturated with the photoinitiator or
photoinitiators being utilized in order to avoid the leaching of
initiator from the silicone composition. The rapid cure observed
for these materials allows for the use of very low levels of
photoinitiator, thereby achieving a uniform cure of thick sections.
If desired, the silicone compositions of this invention can also be
cured thermally, requiring the use of thermal initiator such as
peroxides, azo compounds, or persulfates generally at a
concentration of from about 1% to about 5% by weight of the total
polymerizable composition. It is preferable that any thermal or
photo-initiator used be soluble in the silicone compositions
themselves, requiring no use of solvent.
[0084] Examples of suitable curing catalysts for moisture curable
polydiorganosiloxane oligourea segmented copolymers include alkyl
tin derivatives (e.g., dibutyltindilaurate, dibutyltindiacetate,
and dibutyltindioctoate commercially available as "T-series
Catalysts" from Air Products and Chemicals, Inc. of Allentown,
Pa.), and alkyl titanates (e.g., tetraisobutylorthotitanate,
titanium acetylacetonate, and acetoacetic ester titanate
commercially available from DuPont under the designation "TYZOR").
In general, however, it is preferred to select silane crosslinking
agents that do not require the use of curing catalysts to avoid
reducing shelf-life and adversely affecting the physical properties
of the vibration damping composition.
[0085] Other catalysts useful for moisture curable
polydiorganosiloxane oligourea segmented copolymers include acids,
anhydrides, and lower alkyl ammonium salts thereof which include
but are not limited to those selected from the group consisting of
trichloroacetic acid, cyanoacetic acid, malonic acid, nitroacetic
acid, dichloroacetic acid, difluoroacetic acid, trichloroacetic
anhydride, dichloroacetic anhydride, difluoroacetic anhydride,
triethylammonium trichloroacetate, trimethylammonium
trichloroacetate, and mixtures thereof.
[0086] Also useful for curing compositions of this invention are
the well known two component room temperature free radical
curatives consisting of a polymerization catalyst and an
accelerator. Common polymerization catalysts useful in this two
component curative include organic peroxides and hydroperoxides
such as dibenzoyl peroxide, t-butyl hydroperoxide, and cumene
hydroperoxide, that are not active at room temperature in the
absence of an accelerator. The accelerator component of the
curative consists of the condensation reaction product of a primary
or secondary amine and an aldehyde. Common accelerators of this
type are butyraldehyde-aniline and butyraldehyde-butylamine
condensation products sold by E.I. duPont de Nemours & Co. as
Accelerator 808.TM. and Accelerator 833.TM.. This catalyst system
may be employed to prepare a two-part free radically curable
organosiloxane oligourea segmented copolymer where the curable
copolymer is divided into two parts and to one part is added the
polymerization catalyst and to the other part is added the
accelerator. Upon mixing this two component system cures at room
temperature. Alternatively, the polymerization catalyst can be
incorporated in the free radically curable polyorganosiloxane
oligourea segmented copolymer and the accelerator can be applied to
a substrate such that when the free radically curable
organosiloxane oligourea segmented copolymer containing
polymerization catalyst contacts the "primed" substrate surface,
cure proceeds immediately at room temperature. Those of ordinary
skill in the art are familiar with such cure systems and could
readily adapt them to various product constructions.
[0087] Suitable fillers include those such as fumed silica, carbon
fibers, carbon black, glass beads, glass bubbles, glass fibers,
mineral fibers, clay particles, organic fibers, e.g., nylon,
polyimide, e.g., KEVLAR.TM., available from DuPont Co., and the
like, metal particles, and the like which can be added in amounts
of from about 5 to 50 parts per 100 parts of polydiorganosiloxane
oligourea segmented polymer and silicate resin. Other additives
such as dyes, pigments, thermal conductors such as alumina, boron
nitride, aluminum nitride, nickel particles, flame retardants,
stabilizers, antioxidants, compatibilizers, and the like can be
blended into these systems in amounts of from about 1 to 50 volume
percent of the composition.
[0088] The compositions of the invention can be made by a solution
process, a solventless process or a combination of the solventless
and the solution process. In each process, the compositions of the
present invention are prepared from the reaction of mixtures of
polyamines, polyisocyanates and endcapping agents in stoichiometric
amounts to obtain curable polydiorganosiloxane oligourea segmented
copolymers with desired degrees of polymerization, for example,
from about 2 to 12, and the mixture of these copolymers with
silicate resins to form curable polydiorganosiloxane oligourea
segmented copolymer materials useful as pressure sensitive
adhesives, vibration damping materials and/or hot melt adhesives.
Also in each process, initiators, cure catalysts and/or
crosslinking agents may be optionally added at any time during the
process to enhance the cure rate of chemically curable forms of the
invention. Generally these materials are not reactive until
exposure to some predetermined set of conditions, that is,
radiation, heat, and/or moisture. Depending on the situation, any
one of the three processes may be preferred.
[0089] In the solvent process, the substantially nonreactive
silicate resin can be introduced before, during, or after the
polyamines, polyisocyanates and endcapping agents have been
introduced. Preferably the silicate resin is added after the three
reactants have formed a curable polydiorganosiloxane oligourea
segmented copolymer. The reaction of the polyamines and
polyisocyanates is carried out in a dry solvent, or mixtures of
solvents, protected from atmospheric moisture. The solvents are
preferably unreactive with the polyamines, polyisocyanates and
endcapping agents. The starting materials and final products
preferably remain completely miscible in the solvents during and
after the completion of the polymerization. Suitable solvents
include polar liquids, such as alcohols, esters, aromatic
hydrocarbons, and chlorinated hydrocarbons, with tetrahydrofuran,
toluene and isopropylalcohol and methylene chloride being
especially useful. In synthesizing polydiorganosiloxane oligourea
segmented copolymers with isocyanate-functional end groups, it is
necessary to add the polyamine to a solution of polyisocyanates so
that the excess of the polyisocyanate with respect to the polyamine
is maintained.
[0090] These reactions can be conducted at room temperature or up
to the boiling point of the reaction solvent. The reaction is
preferably carried out at ambient temperature up to 50.degree.
C.
[0091] In the substantially solventless process of the present
invention, the polyamines, the polyisocyanates, the endcapping
agents, the optional free radical initiators or moisture cure
catalysts, and the silicate resin are mixed in a reactor and the
reactants are allowed to react to form the substantially linear
polydiorganosiloxane oligourea segmented copolymer which, with the
silicate resin, and, optionally, when cured, forms the tackified
composition of the invention.
[0092] The macromolecular size and architecture of the curable or
cured polydiorganosiloxane oligourea segmented copolymer can
influence properties such as shear strength, modulus, elongation
and tack. One skilled in the art can expect the optimum
polydiorganosiloxane oligourea segmented copolymer for the
composition of the invention for a particular application to be a
function of polyamine architecture, polyisocyanate, endcapping
agents, plasticizers, fillers and additives, cure type, mixing
rate, temperature, reactor throughput, reactor configuration and
size, residence time, residence time distribution, and extent of
cure. This process permits variations in the molecular weight and
architecture of the polydiorganosiloxane oligourea segmented
copolymer over a wide range, thus enabling one to tailor the
properties of the compositions of the present invention to suit a
variety of applications, such as for use as a vibration damping
material or a pressure sensitive adhesive or as hot melt
adhesives.
[0093] While the solvent process and the continuous solventless
process for making polydiorganosiloxane oligourea segmented
copolymer materials have advantages, some situations may occur
where a combination of the solvent and solventless processes is
preferred. In this third process, polydiorganosiloxane polyurea
segmented copolymer is made by the continuous solventless process
and subsequently mixed in solvent with the silicate resin solution,
and optional filler, plasticizer free radical initiator, moisture
cure catalyst, and silane crosslinking components.
[0094] In all three processes, the viscosity of the resulting
tackified compositions can be modified to obtain a viscosity
appropriate for the contemplated application and the coating method
to be used. For good coatability, the compositions utilized in the
invention typically has a viscosity of about 5 to about 10.sup.4
poise at processing temperatures. For the lower viscosities,
conventional coating methods such as knife coating, spray coating,
and roll coating can be used. At higher viscosities (that is, above
100 poise) the compositions can be extruded, die coated and knife
coated.
[0095] Any reactor that can provide intimate mixing of the
polyamine, polyisocyanate, endcapping agent and the reaction
product thereof is suitable for use in the invention. The process
is continuous using, for example a pin mixer, or a single or twin
screw extruder. Preferably, the reactor is a wiped surface
counter-rotating or co-rotating twin screw extruder.
[0096] The temperature in the reactor should be sufficient to
permit the chain extension reaction between the polyisocyanate, the
polyamine, and endcapping agent to occur. The temperature should
also be sufficient to permit conveying of the materials through the
reactor, and any subsequent processing equipment such as, for
example, feedblocks and dies. For conveying the reacted material,
the temperature preferably is in the range of about 20 to
250.degree. C., more preferably in the range of about 40 to
180.degree. C. Residence time in the reactor preferably varies from
about 5 seconds to 8 minutes, more preferably from about 15 seconds
to 3 minutes.
[0097] The residence time depends on several parameters, including,
for example the length to diameter ratio of the reactor, mixing
rates, overall flowrates, reactants, and the need to blend in
additional materials. For materials involving minimal or no
blending of a non-reactive component, the reaction can easily take
place in as little as 5:1 length to diameter units of a twin screw
extruder.
[0098] When a wiped surface reactor is used, it preferably has
relatively close clearances between the screw flight lands and the
barrel, with this value typically lying between 0.1 and 2 mm. The
screws utilized are preferably fully or partially intermeshing or
fully wiped in the zones where a substantial portion of the
reaction takes place.
[0099] Generally, chemical species that are substantially
unreactive with one another can be mixed together before
introduction into the reactor to simplify the process. Examples
include mixing a polyisocyanate with an endcapping monoisocyanate
and optionally a cure catalyst; a polyamine with a cure catalyst, a
polyamine with an endcapping monoamine, a polydiorganosiloxane
diamine with an organic polyamine, and optionally a cure catalyst
or suitable combinations thereof.
[0100] Because of the rapid reaction that occurs between amines and
isocyanates, the reactants are preferably fed into an extruder at
unvarying rates, particularly when using higher molecular weight
polydiorganosiloxane diamines, i.e., with molecular weight of about
50,000 and higher. Such feeding generally reduces undesirable
variability of the final product.
[0101] One method of insuring the continuous feeding of the very
low flow polyisocyanate, endcapping agent, and/or cure catalyst
streams in an extruder is to allow the feed line(s) to touch or
very nearly touch the passing threads of the screws. Another method
utilizes a continuous spray injection device which produces a
continuous stream of fine droplets of these materials into the
reactor.
[0102] The low flow materials such as polyisocyanate,
isocyanate-endcapping agent, and/or cure catalyst stream(s) can be
added into the reactor in a manner such as mentioned above before
the polyamine if the reactor is capable of conveying this stream in
a continuous and unvarying manner. The polyamine can then be added
downstream in the reactor. Alternatively, the polyisocyanate,
isocyanate endcapping agent, and/or cure catalyst stream(s) can
also be added after the polyamine has been introduced into the
reactor.
[0103] The silicate resin that is blended with the
polydiorganosiloxane oligourea segmented copolymer and the optional
fillers, free radical initiators, moisture cure catalysts and
silane crosslinking agents, or other materials that are essentially
non-reactive with the polydiorganosiloxane oligourea segmented
copolymer, can be added further downstream in the reactor after a
substantial portion of the reaction of the polyamine(s) and
polyisocyanate(s) has taken place. Another suitable order of
addition is addition of the polyamine first, the silicate resin and
the other non-reactive materials second, and the polyisocyanate(s)
third, with the polyisocyanate(s) fed in a continuous manner. If
the silicate resin can be conveyed in the reactor, it can be added
into the reactor first with the polyamine and polyisocyanate
following separately at later stages in the process in any order
that provides continuous and unvarying conveying of each
component.
[0104] In one embodiment, the compositions of the present invention
may be utilized as vibration damping materials alone, that is, free
layer treatment, or in conjunction with a stiff layer, i.e., as
part of a constrained-layer treatment. Vibration damping materials
are most efficiently used if they are sandwiched between the
structure/device to be damped and a relatively stiff layer, such as
thin sheet metal. This forces the viscoelastic material to be
deformed in shear as the panel vibrates, dissipating substantially
more energy than when the material deforms in extension and
compression as occurs in a free layer treatment. Preferably,
constrained-layer constructions consist of a laminate of one or
more stiff layers and one or more layers of the vibration damping
material.
[0105] For damping applications, it is further desirable that the
damping material, generally termed a viscoelastic material, have
the following properties: damping capabilities at high
temperatures, e.g., at 50.degree. C. and above; damping performance
that is substantially independent of temperature over the useful
temperature range; resistance to degradation from heat, and water
that may be encountered during use of the damping material; ability
to withstand large strains encountered in seismic and wind sway
damping situations; ease of bonding to rigid substrates; and
handling characteristics that permit easy attainment of desired
thicknesses and shapes.
[0106] Constrained-layer constructions can be prepared by several
processes. In the one process, a layer of the vibration damping
material is coated onto a release liner by conventional solution
coating or hot melt coating techniques known in the art. The layer
of resulting viscoelastic material is transferred to a stiff
backing and adhered thereto, thereby providing a constrained-layer
construction. If curing of the vibration damping material is
desirable, it can take place after it is first coated or after it
is transferred to the stiff backing. In another process, a layer of
vibration damping material is coated directly onto a stiff backing
by conventional solution coating or hot melt coating techniques
known in the art and optionally cured. In each case, the
constrained-layer construction is then affixed to the structure
requiring damping. The construction may be attached in any manner
provided that the constraining layer is only fixed to the vibrating
structure via the viscoelastic material interface, i.e. free of
mechanical attachment. When the structure subsequently vibrates
under the influence of an internally or externally applied force,
the vibration is damped.
[0107] Another application of the vibration damping materials of
the present invention is in a bi-directional damping unit such as
described in Nielsen, E. J. et al, "Viscoelastic Damper Overview
For Seismic and Wind Applications," Structural Engineering
Association of California, Tahoe Olympiad, October, 1994.
Bi-directional damping is the transference of subsonic oscillations
of a structure, such as a building, into the shear deformation of a
viscoelastic material for the purpose of damping the oscillations
of the structure. In this application, materials which have maximum
vibration damping capability preferably have shear storage moduli,
G', between about 6.9.times.10.sup.3 Pa to 3.45.times.10.sup.7 Pa,
more preferably 3.5.times.10.sup.4 Pa to 1.4.times.10.sup.7 Pa,
most preferably 3.5.times.10.sup.5 Pa to 6.9.times.10.sup.6 Pa at
the use temperature, and have a tan .delta. as high as possible
over the use temperature and frequency range. The materials also
preferably have an elongation in tension of at least 100 percent or
a shear strain capability of at least 100 percent within their use
range of temperature and frequency.
[0108] When the vibration damping material has pressure-sensitive
or hot melt adhesive properties, the material can usually be
adhered to a stiff layer without the use of an additional bonding
agent. However, it is sometimes necessary to use a thin layer, for
example, 20-50 .mu.m in thickness, of a high strength adhesive,
such as, for example, an acrylic adhesive, an epoxy adhesive, or a
silicone adhesive, all of which are well-known to those skilled in
the art, to bond the vibration damping composition of the invention
to a structure.
[0109] For most applications, the layer of viscoelastic material
has a thickness of at least 0.01 mm up to about 100 mm, more
preferably 0.05 to 100 mm. The viscoelastic material can be applied
by any of the techniques known in the art such as by spraying,
dipping, knife, or curtain coating, or molding, laminating,
casting, or extruding.
[0110] As mentioned above, a stiff layer is an essential part of
constrained-layer vibration-damping constructions of the present
invention. A suitable material for a stiff layer preferably has a
stiffness of at least about 100 times the stiffness, i.e., storage
modulus, of the vibration damping material, the stiffness of the
stiff layer being measured in extension. The desired stiffness of
the stiff layer is varied by adjusting the thickness of this layer,
for example from about 25 micrometers to 5 centimeters, depending
on the modulus of the stiff layer. Examples of suitable materials
include metals such as iron, steel, nickel, aluminum, chromium,
cobalt, and copper, and alloys thereof and stiff polymeric
materials such as polystyrene; polyester; polyvinyl chloride;
polyurethane; polycarbonate; polyimide; and polyepoxide;
fiber-reinforced plastics such as glass fiber-reinforced, ceramic
fiber-reinforced, and metal fiber-reinforced polyester; glasses;
and ceramics.
[0111] The vibration damping compositions of the present invention
are useful in a variety of applications which demand effective
damping over a broad range of temperature and frequency, with the
additional requirement that minimum and/or maximum modulus
requirements, over a specified range of temperatures, also be
satisfied. It is often desirable that the region of maximum
damping, that is, the point at which the loss factor is near a
maximum, occurs in the center of the desired damping temperature
and frequency range. Designing the optimum damping material for a
specific application requires understanding the effect the
polydiorganosiloxane oligourea segmented copolymer, the silicate
resin, optional free radical initiator, moisture cure catalyst,
silane crosslinking agent, and filler, and concentration of each
have on damping performance.
[0112] Curable pressure-sensitive adhesives of the invention,
dependent on specific formulation used, can be used to make
pressure-sensitive adhesive sheet materials that may take the form
of pressure-sensitive adhesive labels, pressure-sensitive adhesive
signs, pressure-sensitive adhesive marking indices,
pressure-sensitive adhesive tapes, including for example, foam-core
or foam-backed tapes, pressure-sensitive adhesive transfer tapes,
pressure-sensitive spray adhesives, pressure-sensitive adhesive
medical tapes and articles, including for example, transdermal drug
delivery devices, or pressure-sensitive adhesive coatings directly
onto desired articles.
[0113] Pressure-sensitive adhesive sheets are made by applying the
pressure-sensitive adhesive by well known hot melt coating, solvent
coating, or lamination processes. Suitable substrates for
pressure-sensitive adhesive sheets include paper and plastic films
such as polyolefins, such as polypropylene and polyethylene,
polyethylene terephthalate, polycarbonate, polyvinyl chloride,
polytetrafluoroethylene- , polyimide, such as DuPont's KAPTON.TM.,
cellulose acetate, and ethyl cellulose. Backings can also be of
woven fabric formed of threads of synthetic or natural materials
such as cotton, nylon, or rayon, such as those used in DUAL
LOCK.TM. Reclosable Fasteners and SCOTCHMATE.TM. Hook and Loop
Reclosable Fasteners, or glass or ceramic material, or they can be
nonwoven fabric such as air-laid webs of natural or synthetic
fibers or blends of these. In addition, suitable backings can be
formed of metal, metallized polymeric film, acrylic, silicone,
urethane, polyethylene, polypropylene, neoprene rubber, and the
like, and filled and unfilled foamed materials, or ceramic sheet
material. Primers and tie layers can be utilized but they are not
always necessary.
[0114] In the case of pressure-sensitive tapes, these materials are
typically applied by first making a tape construction which
comprises a layer of the curable pressure-sensitive adhesive
material coated evenly on a backing and which may be subsequently
cured as needed. The adhesive can then be covered with a liner,
rolled upon itself wherein the backside of the tape is release
coated, or applied directly to a desired surface.
[0115] A transfer tape can be made by coating the curable
composition between two liners both of which are coated with a
release coating and subsequently cured as needed. The release
liners often comprise a clear polymeric material such as a
polyolefin or a polyester that is transparent to ultraviolet
radiation. Preferably, each release liner is first coated with a
release material for the curable pressure-sensitive adhesive
utilized in the invention.
[0116] The curable adhesive compositions of the invention can also
be coated onto a differential release liner; that is, a release
liner having a first release coating on one side of the liner and a
second release coating coated on the opposite side, and
subsequently cured as needed. The two release coatings preferably
have different release values. For example, one release coating may
have a release value of 5 grams/cm (i.e., 5 grams of force is
needed to remove a strip of material 1 cm wide from the coating)
while the second release coating has a release value of 15
grams/cm. The curable pressure-sensitive adhesive material is
typically coated over the release liner coating having the higher
release value and subsequently cured as needed. The resulting tape
can be wound into a roll. As the tape is unwound, the curable or
cured pressure-sensitive adhesive adheres to the release coating
with the higher release value. After the tape is applied to a
substrate and subsequently cured as needed, the release liner can
be removed to expose a curable or cured adhesive surface for
further use and which may be subsequently cured as needed. The
curable pressure-sensitive adhesive coating may be cured at any
point in the process after it is coated.
[0117] Useful release liners include those that are suitable for
use with silicone adhesives and organic pressure-sensitive
adhesives. Useful release liner release coating compositions are
described in, for example, European Patent Publication 378,420,
U.S. Pat No. 4,889,753, and European Patent Publication No.
311,262. Commercially available release coating compositions
include SYL-OFF.TM. Q2-7785 fluorosilicone release coating,
available from Dow Corning Corp., Midland, Mich.; X-70-029HS
fluorosilicone release coating, available from Shin-Etsu Silicones
of America, Torrance, Calif., S TAKE-OFF.TM. 2402 fluorosilicone
release liner from Release International, Bedford Park, Ill., and
the like.
[0118] The hot melt adhesive compositions of the present invention
are useful in a variety of applications that require good adhesion
to different substrates, including low surface energy materials,
broad temperature range, minimized influence from humidity. They
are particularly useful in electronic industry to assemble
electrical components, wire tacking, wire terminal bonding,
insulations, potting, and sealing, for example, fixation of
deflection yoke.
[0119] The optional filler employed in compositions of the present
invention may be used for several purposes such as to affect a
change in dynamic mechanical performance, to increase thermal
conductivity, or to reduce the cost of the composition.
[0120] The present invention is further illustrated by the
following examples which are not intended to limit the scope of the
invention. In the examples all parts and percentages are by weight
unless otherwise indicated. All molecular weights reported are
number average molecular weights in g/mol.
Preparation of Polydimethylsiloxane Diamines
[0121] Multiple lots of some of the diamines were synthesized for
various examples. The actual number average molecular weight of the
different lots are determined by the following acid titration.
Sufficient polydimethylsiloxane diamine to yield about 1
milliequivalent of amine is dissolved in 50/50
tetrahydrofuran/isopropyl alcohol to form a 10% solution. This
solution is titrated with 1.0N hydrochloric acid with bromophenyl
blue as an indicator to determine number average molecular weight.
The molecular weights are dependent on the exact ratio of the
reactants used in the diamine synthesis and the extent of stripping
cyclic siloxanes. Remaining cyclics are diluents which increase the
titrated molecular weight of polydimethylsiloxane diamine.
[0122] Polydimethylsiloxane Diamine A
[0123] A mixture of 4.32 parts bis(3-aminopropyl)tetramethyl
disiloxane and 95.68 parts octamethylcyclotetrasiloxane was placed
in a batch reactor and purged with nitrogen for 20 minutes. The
mixture was then heated in the reactor to 150.degree. C. Catalyst,
100 ppm of 50% aqueous cesium hydroxide, was added and heating
continued for 6 hours until the bis(3-aminopropyl)tetramethyl
disiloxane had been consumed. The reaction mixture was cooled to
90.degree. C., neutralized with excess acetic acid in the presence
of some triethylamine, and heated under high vacuum to remove
cyclic siloxanes over a period of at least five hours. The material
was cooled to ambient temperature, filtered to remove any cesium
acetate which had formed, and titrated with 0.1N hydrochloric acid
to determine number average molecular weight. The molecular weights
were Lot 1: 5280 and Lot 2: 5,310.
[0124] Polydimethylsilaxane Diamine B
[0125] Polydimethylsiloxane diamine was prepared as described for
Polydimethylsiloxane Diamine A except 2.16 parts
bis(3-aminopropyl)tetram- ethyl disiloxane and 97.84 parts
octamethylcyclotetrasiloxane were used. The molecular weights of
Polydimethylsiloxane Diamine B was 10,700.
[0126] Polydimethylsiloxane Diamine C
[0127] A mixture of 21.75 parts Polydimethylsiloxane Diamine A and
78.25 parts octamethylcyclotetrasiloxane was placed in a batch
reactor, purged with nitrogen for 20 minutes and then heated in the
reactor to 150.degree. C. Catalyst, 100 ppm of 50% aqueous cesium
hydroxide, was added and heating continued for 3 hours until
equilibrium concentration of cyclic siloxanes was observed by gas
chromatography. The reaction mixture was cooled to 90.degree. C.,
neutralized with excess acetic acid in the presence of some
triethylamine, and heated under high vacuum to remove cyclic
siloxanes over a period of at least 5 hours. The material was
cooled to ambient temperature, filtered, and titrated with 0.1N
hydrochloric acid to determine number average molecular weight. The
molecular weight of Polydimethylsiloxane Diamine C was 22,300.
[0128] Polydimethylsiloxane Diamine D
[0129] Polydimethylsiloxane diamine was prepared as described for
Polydimethylsiloxane Diamine C except 12.43 parts
Polydimethylsiloxane Diamine A and 87.57 parts
octamethylcyclotetrasiloxane were used. Three lots of
Polydimethylsiloxane Diamine D were prepared. The molecular weights
were Lot 1: 35,700, Lot 2: 37,800, and Lot 3: 34,800.
[0130] Polydimethylsiloxane Diamine E
[0131] Polydimethylsiloxane diamine was prepared as described for
Polydimethylsiloxane Diamine C except that 8.7 parts
Polydimethylsiloxane Diamine A and 91.3 parts
octamethylcyclotetrasiloxane were used. The molecular weight of
Polydimethylsixone Diamine E was 58,700.
[0132] Polydiphenyldimethylsiloxane Diamine F
[0133] To a 3-necked round bottom flask fit with mechanical
stirrer, static nitrogen atmosphere, oil heating bath, thermometer,
and reflux condenser, were added 75.1 parts
octamethylcyclotetrasiloxane, 22.43 parts
octaphenylcyclotetrasiloxane, and 2.48 parts
bis(3-aminopropyl)tetramethyl disiloxane. Under static nitrogen
atmosphere, the reactants were heated to 150.degree. C. and
degassed under aspirator vacuum for 30 seconds before restoring
static nitrogen atmosphere. A charge of 0.2 g cesium hydroxide
solution (50% aqueous) was added to the flask and heating continued
for 16 hours at 150.degree. C. The flask was cooled to ambient
temperature and then 2 mL triethylamine and 0.38 mL acetic acid
were added. With good agitation flask was placed under a vacuum of
100 N/m.sup.2 (100 Pa), heated to 150.degree. C., and maintained at
150.degree. C. for 5 hours to remove volatile materials. After 5
hours heat was removed and contents cooled to ambient temperature.
The molecular weight of Polydiphenyldimethylsiloxane Diamine F was
9620.
[0134] Polydimethylsiloxane Oligourea Segmented Copolymer A
[0135] Polydimethylsiloxane Diamine D, Lot 1, molecular weight
35,700, was added to the first zone of an 18 mm co-rotating twin
screw extruder having a 40:1 length:diameter ratio (available from
Leistritz Corporation, Allendale, N.J.) at a rate of 7.93 g/min
(0.000444 equivalents amine/min). A mixture of 27.5 parts by weight
methylenedicyclohexylene-4,4'-diisocyanate, 16.3 parts by weight
isocyanatoethyl methacrylate and 56.2 parts by weight DAROCUR.TM.
1173, a photoinitiator available from Ciba-Geigy Corp., was fed
into the sixth zone at a rate of 0.181 g/min (0.000570 equivalents
isocyanate/min). The feed line of this stream was placed closely to
the screw threads. The extruder had double-start fully intermeshing
screws throughout the entire length of the barrel, rotating at 150
revolutions per minute. The temperature profile for each of the 90
mm long zones was: zones 1 and 2--30.degree. C.; zone 3--32.degree.
C.; zone 4--37.degree. C.; zone 5--50.degree. C.; zone
6--60.degree. C.; zone 7--80.degree. C.; zone 8--110.degree. C.;
and endcap--120.degree. C. The extrudate was cooled in air.
[0136] Polydimethyldiphenylsiloxane Oligourea Segmented Copolymer
B
[0137] To a 3-necked round bottom flask fit with static argon
atmosphere, pressure equalizing addition funnel, and mechanical
stirrer was added 100.3 parts Polydimethyldiphenylsiloxane Diamine
F and 94 parts toluene. To the addition funnel was added a solution
of 1.82 parts methylenedicyclohexylene-4,4'-diisocyanate, 1.08
parts isocyanatoethyl methacrylate, and 56.8 parts toluene, and
this solution was added dropwise to the stirred reaction flask over
a period of about 12 minutes. The flask contents stirred an
additional 4 hours to complete the reaction before draining from
the flask and packaging in a glass jar.
Test Methods
[0138] The following test methods were used to characterize the
polydimethylsiloxane oligourea segmented copolymers produced in the
Examples.
[0139] Characterization of Cured Samples
[0140] Samples were prepared using one of the following
methods:
[0141] 1) coating the pressure-sensitive adhesive, using a knife
coater with orifice set between about 125 to 150 .mu.m, between 38
.mu.m (1.5 mil) thick primed (aminated polybutadiene) polyester
film and 50 .mu.m (2 mil) thick polyester release liner.
[0142] 2) casting a solution of pressure-sensitive adhesive
directly onto a polyester film and allowing it to dry at 65.degree.
C. for 10 minutes to obtain a pressure-sensitive adhesive tape
having an adhesive thickness of 38 .mu.m (1.5 mil).
[0143] 3) hot melt coating the pressure-sensitive adhesive with a
1.91 cm diameter (3/4 inch) long single screw extruder (Haake)
rotating at 40 revolutions per minute (temperature profile of the
extruder was: zone 1--not controlled; zone 2--163.degree. C.; and
zone 3--188.degree. C., necktube and die (12.7 cm
wide)--210.degree. C.) between nip rolls with a 35.6 .mu.m (1.4
mil) thick polyethylene terephthalate film on one roll and a 50
.mu.m (2 mil) thick release liner on the other roll to achieve an
adhesive thickness of about 40-50 .mu.m (about 1.5-2 mil).
[0144] Free-radically curable materials were squeezed between two
polyester films to a thickness of approximately 1 mm and cured at
an intensity of 1.73 mW for a given length of time with low
intensity ultraviolet lights.
[0145] A Rheometrics RDA II Rheometer using dynamic temperature
ramp mode (-30.degree. C.-175.degree. C.) at a ramp rate of
5.degree. C., 25 mm parallel plates, a strain of 2.0% and a
frequency of 10.0 rad/s was used to measure the loss factor. Sample
thickness was 1-2 mm.
[0146] 180.degree. Peel Adhesion
[0147] Polydiorganosiloxane oligourea segmented copolymer based
pressure-sensitive adhesive coatings were covered with a release
liner and cut into 12.7 mm (0.5 inch) by 15 cm (6 inch) strips. The
release liner was removed and the strip adhered to a 10 cm (4 inch)
by 20 cm (8 inch) clean, solvent washed glass coupon using a 2 kg
(41/2 pound) roller passed twice over the strip. The bonded
assembly dwelled at room temperature for about twenty minutes and
was tested for 180.degree. peel adhesion using an I-Mass peel
tester at a separation rate of 30.5 cm/minute (12 inches/minute)
over a 10 second data collection time. Two samples were tested; the
reported adhesion value is an average of the two samples.
Preferably, the pressure-sensitive adhesive tapes have an
180.degree. peel adhesion of at least about 5.5 N/dm (5 oz./inch),
more preferably at least about 21.8 N/dm (20 oz./inch).
[0148] Shear Strength
[0149] Polydiorganosiloxane oligourea segmented copolymer based
pressure-sensitive adhesive coatings were covered with a release
liner and cut into 12.7 mm (0.5 inch) by 15 cm (6 inch) inch
strips. The release liner was removed and the strip adhered to a
stainless steel panel such that a 12.7 mm by 12.7 mm portion of
each strip was in firm contact with the panel with one end portion
of the tape being free. The panel with coated strip attached was
held in a rack such that the panel formed an angle of 178.degree.
with the extended tape free end which was tensioned by application
of a force of one kilogram applied as a hanging weight from the
free end of the coated strip. The 2.degree. less than 180.degree.
was used to negate any peel forces, thus insuring that only the
shear forces were measured, in an attempt to more accurately
determine the holding power of the tape being tested. The time
elapsed for each tape example to separate from the test panel was
recorded as the shear strength. Unless otherwise noted, all shear
failures reported herein were cohesive failures of the
adhesive.
[0150] 90.degree. Peel Adhesion
[0151] Test samples were prepared by removing the release liner
from the polydiorganosiloxane oligourea segmented copolymer based
pressure-sensitive adhesive of a coated loop substrate and adhering
the strip to a primed, anodized aluminum strip using a 41/2 pound
(2 kg) roller passed twice over the strip. The bonded assembly
dwelled at room temperature for 24 hours and was tested for
90.degree. peel adhesion using an INSTRON.TM. tensile tester at a
separation rate of 12 inches/minute (30.5 cm/minute). Three samples
were tested; the reported adhesion value is an average of the three
samples.
[0152] Vertical Burn Test
[0153] Reference: Federal Aviation Regulation (FAR) 25.853
paragraph (a) (1) (i)--60 Second Vertical Burn test
(unsupported)
[0154] Test samples were prepared by removing the release liner
from the polydiorganosiloxane oligourea segmented copolymer based
pressure-sensitive adhesive of a coated loop substrate and
suspending the sample in the test fixture described in above cited
FAR standard. The sample was subjected to flame from a Bunsen
burner for 60 seconds and then the flame was removed and the sample
was allowed to extinguish on its own. The Drip Extinguish Time was
the elapsed time between a flaming drip formation and the drip
flame extinction, the Extinguish Time was the elapsed time from
when the flame was removed to the time the sample ceased to flame,
and the Burn Length was determined by the distance the sample had
burned along its length.
[0155] Hot-Melt Adhesive Bonding Test
[0156] Tackified polydiorganosiloxane oligourea segmented
copolymers were tested as curable hot-melt adhesives by creating
overlap shear specimens, between two UV transparent substrates,
having an overlap area of about 1.61 cm.sup.2 and pulling the
overlap shear sample in an H-frame style Sintech testing machine at
a crosshead rate of 50.8 cm/min to assess adhesion. Samples were
prepared for testing as follows. A glass, or polymethylmethacrylate
(PMMA) slide measuring 0.32 cm.times.1.27 cm.times.5.08 cm was
cleaned with isopropanol. A small portion, about 0.2 g, of the
tackified UV curable hot-melt adhesive was placed on one glass
slide, covered with a second slide of glass and held in place with
a small spring steel notebook clip. Bond thickness was controlled
by placing two parallel strands of 12 mil (0.3 mm) diameter copper
wire, oriented in the cross direction with respect to the long
dimension of the glass about 0.2 cm from the end of the glass
coupons. The overlap shear sample was placed in a forced air oven
for 15-25 minutes at 140.degree. C. (glass), or 85.degree. C.
(PMMA), removed, allowed to cool to ambient conditions in air,
cured by exposure to low intensity UV light for 1 hour, trimmed to
size, and tested as described above. The maximum adhesion force at
break is reported in MN/m.sup.2.
[0157] Damping Properties (Storage modulus and Loss Factor)
[0158] Sample thickness was about 1 mm and was obtained using one
of the following methods for all but the bi-directional damper:
[0159] 1) pouring the solution onto a fluorosilicone coated 50
.mu.m thick polyethylene terephthalate release liner at the bottom
of an aluminum pan, allowing the solution to air dry overnight,
gathering the vibration damping material together in a thicker
mass, placing the mass between two release liners separated by a 1
mm spacer and in turn between two 5 mm glass plates, applying
sufficient pressure on the glass plate sandwich to allow the
uncured mass to flow out into a suitable 1 mm thick layer, and
unless otherwise noted, radiation curing the vibration damping
material by exposure, through the glass plates, to low intensity
ultraviolet radiation from General Electric F40BL lamps at an
intensity of 1.74 mW/cm.sup.2 for 20 minutes, or
[0160] 2) pouring a solution of the vibration damping material onto
a shallow TEFLON.TM. lined tray, drying the vibration damping
material by heating it in an oven at 65.degree. C. for 20 min, and
moisture curing by exposure to ambient temperature and humidity for
1 week, to obtain a 1 mm thick section.
[0161] The storage modulus, G', and the loss factor, tan .delta.,
were determined over a range of temperatures using a Polymer
Laboratories Dynamic Mechanical Thermal Analyzer (DMTA) Mark II and
a technique of multiplexing frequency during a thermal scan, i. e.,
properties were measured while both frequency and temperature were
changing. The temperature was varied from -100.degree. C. to
200.degree. C. at a rate of 2.degree. C./minute continuous.
Measurements were taken at a strain setting of 1, reported at a
frequency of 1.0 Hz, and were taken at about 3 to 5.degree. C.
intervals and interpolated to obtain measurements at 10.degree. C.
intervals for reporting purposes.
[0162] In these examples, the storage modulus, G', utility window
refers to the temperature range over which the storage modulus is
between 3.45.times.10.sup.5 Pa and 6.9.times.10.sup.6 Pa. The loss
factor, tan .delta., utility window refers to the temperature range
over which the loss factor is greater than or equal to 0.4. The
useful temperature range refers to the temperature range over which
storage modulus, G', is between 3.45.times.10.sup.5 Pa and
6.9.times.10.sup.6 Pa and the loss factor, tan .delta., is greater
than 0.4. When so indicated, melt flow means the sample exhibited
melt flow at high temperature. Melt flow is generally undesirable
for damping applications. Thus, materials that exhibit melt flow
must be utilized below the melt flow temperature.
[0163] In the following examples, all polyisocyanates and
endcapping agents were used as received and the isocyanate:amine
ratios for the polyisocyanates, polyamines, and endcapping agents
were calculated using the polyisocyanate molecular weight reported
by the polyisocyanate supplier, the polyamine molecular weight as
determined by acid titration, and the endcapping agent molecular
weight reported by the endcapping agent supplier.
EXAMPLES
Examples 1-5
[0164] In Example 1, a polydimethylsiloxane oligourea segmented
copolymer composition was made by reacting 52.76 parts (10.00
mmoles) Polydimethylsiloxane Diamine A, molecular weight 5280,
dissolved in 50 parts toluene, and a mixture of 1.75 parts (6.67
mmoles) of methylenedicyclohexylene-4,4'-diisocyanate and 1.03
parts (6.67 mmoles) of isocyanatoethyl methacrylate (available as
MOI from Showa Rhodia Chemicals, Tokyo, Japan) dissolved in 48
parts toluene and slowly added at room temperature to the solution
of diamine with vigorous stirring. Then, to the copolymer solution
was added SR-545 silicate resin solution to achieve 120 parts
(based on dry weight) per 100 parts polydimethylsiloxane oligourea
segmented copolymer (based on dry weight). To the copolymer/resin
solution was added 1 part DAROCUR.TM. 1173 (a photoinitiator
available from Ciba-Geigy, Hawthorne, N.Y.) per 100 parts of
copolymer/resin blend solids, and the solution was subsequently air
dried on a release liner film.
[0165] The resulting polydimethylsiloxane oligourea segmented
copolymer was coated using a knife coater at 130.degree. C. between
a 40 .mu.m (1.5 mil) primed polyester film and a 40 .mu.m (1.5 mil)
polyester release liner (S TAKE-OFF.TM., available from Release
International, Bedford Park, Ill.) to a coating thickness of about
50 .mu.m (2.0 mil), exposed to 1.73 mW for 20 minutes ultraviolet
radiation from a low intensity ultraviolet lamp Model General
Electric F40BL, to form a pressure-sensitive adhesive tape. The
results of testing are summarized in Table 1.
[0166] A second portion of the resulting polydimethysiloxane
oligourea segmented copolymer was pressed between two release
liners into a uniform sample of approximately 1 mm thickness, and
cured by exposure to low intensity UV lights to form a cured
vibration damping material.
[0167] In Example 2, a polydimethylsiloxane oligourea segmented
copolymer composition was prepared as in Example 1, except 500
parts (43.0 mmoles) Polydimethylsiloxane Diamine B, molecular
weight 10,700, dissolved in 300 parts toluene was substituted for
Diamine A, and a mixture of 7.51 parts (28.7 mmoles) of
methylenedicyclohexylene-4,4'-diisocyanate and 4.44 parts (28.7
mmoles) isocyanatoethyl methacrylate dissolved in 200 parts was
used in the synthesis of the polydimethylsiloxane oligourea
segmented copolymer.
[0168] A portion of the polydimethylsiloxane oligourea segmented
copolymer was coated and cured as in Example 1 to form a
pressure-sensitive adhesive tape.
[0169] In Example 3, a polydimethylsiloxane oligourea segmented
copolymer was prepared as in Example 1, except 600 parts (27.0
mmoles) Polydimethylsiloxane Diamine C, molecular weight 22,300,
dissolved in 404 parts toluene was substituted for Diamine A and a
mixture of 4.71 parts (18.0 mmoles) of
methylenedicyclohexylene-4,4'-diisocyanate and 2.79 parts (18.0
mmoles) of isocyanatoethyl methacrylate dissolved in 195 parts
toluene was used in the synthesis of the polydimethylsiloxane
oligourea segmented copolymer.
[0170] A portion of the resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1 to form a
pressure-sensitive adhesive tape.
[0171] Another portion of the solution was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0172] In Example 4, a polydimethylsiloxane oligourea segmented
copolymer was made by dissolving 10 parts Polydimethylsiloxane
Oligourea Segmented Copolymer A in a mixture of 17 parts toluene
and 2 parts 2-propanol containing 12 parts dried SR-545 silicate
resin (prepared by spray drying under nitrogen to achieve less than
1% toluene) and 0.1 part DAROCUR.TM. 1173 followed by air drying on
a release liner.
[0173] A portion of the resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1 to form a
pressure-sensitive adhesive tape.
[0174] Another portion of the solution was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0175] In Example 5, a polydimethylsiloxane oligourea segmented
copolymer was prepared as in Example 1, except 100 parts (2.01
mmoles) Polydimethylsiloxane Diamine E, molecular weight 58,700,
dissolved in 123 parts toluene were substituted for Diamine A, and
a mixture of 0.35 parts (1.34 mmoles) of
methylenedicyclohexylene-4,4'-diisocyanate and 0.21 parts (1.34
mmoles) of isocyanatoethyl methacrylate dissolved in 56 parts
toluene was used in the synthesis of the polydimethylsiloxane
oligourea segmented copolymer.
[0176] A portion of the resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1.
[0177] Another portion of the solution was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0178] Each of the pressure-sensitive adhesive tapes of Examples
1-5 which had a thickness of about 50 .mu.m, was tested for
180.degree. peel adhesion from glass and shear strength on
stainless steel. The results are reported in Table 1.
[0179] The storage modulus, G', and loss factor, tan .delta., were
determined at 1 Hz for the vibration damping materials of Examples
1 and 3-5 and are summarized in Table 2.
2TABLE 1 180.degree. Peel adhesion Shear Strength Example N/dm
(min) 1 31 >10,000 2 51 >10,000 3 33 >10,000 4 66 7,700
popoff 5 59 2300 popoff
[0180] The data in Table 1, demonstrates that generally, as the
molecular weight of the Polydimethylsiloxane Diamine used in
preparing the copolymer increased, the peel adhesion increased.
Those shear strength values which were reported as "popoff"
indicate adhesive failure mode, not necessarily indicative of shear
strength.
3TABLE 2 Temp Example 1 Example 3 Example 4 Example 5 (.degree. C.)
G' (Pa) Tan .delta. G' (Pa) Tan .delta. G' (Pa) Tan .delta. G' (Pa)
Tan .delta. -90 8.28 .times. 10.sup.7 0.03 8.57 .times. 10.sup.7
0.03 9.98 .times. 10.sup.7 0.04 7.55 .times. 10.sup.7 0.04 -80 7.61
.times. 10.sup.7 0.04 7.72 .times. 10.sup.7 0.04 8.92 .times.
10.sup.7 0.05 6.61 .times. 10.sup.7 0.06 -70 6.80 .times. 10.sup.7
0.05 6.63 .times. 10.sup.7 0.08 7.73 .times. 10.sup.7 0.07 5.48
.times. 10.sup.7 0.09 -60 6.05 .times. 10.sup.7 0.08 5.69 .times.
10.sup.7 0.11 6.22 .times. 10.sup.7 0.12 4.53 .times. 10.sup.7 0.14
-50 5.40 .times. 10.sup.7 0.09 4.82 .times. 10.sup.7 0.14 5.24
.times. 10.sup.7 0.15 3.65 .times. 10.sup.7 0.18 -40 4.82 .times.
10.sup.7 0.11 3.93 .times. 10.sup.7 0.18 4.31 .times. 10.sup.7 0.19
2.83 .times. 10.sup.7 0.24 -30 4.22 .times. 10.sup.7 0.12 3.03
.times. 10.sup.7 0.23 3.20 .times. 10.sup.7 0.26 1.97 .times.
10.sup.7 0.33 -20 3.51 .times. 10.sup.7 0.16 2.16 .times. 10.sup.7
0.31 2.15 .times. 10.sup.7 0.35 1.03 .times. 10.sup.7 0.52 -10 2.93
.times. 10.sup.7 0.19 1.49 .times. 10.sup.7 0.39 1.49 .times.
10.sup.7 0.44 5.37 .times. 10.sup.6 0.72 0 2.29 .times. 10.sup.7
0.23 8.36 .times. 10.sup.6 0.55 9.06 .times. 10.sup.6 0.57 2.82
.times. 10.sup.6 0.84 10 1.69 .times. 10.sup.7 0.29 4.44 .times.
10.sup.6 0.68 5.49 .times. 10.sup.6 0.68 1.52 .times. 10.sup.6 0.91
20 1.14 .times. 10.sup.7 0.36 2.35 .times. 10.sup.6 0.76 3.48
.times. 10.sup.6 0.75 8.06 .times. 10.sup.5 0.92 30 6.97 .times.
10.sup.6 0.45 1.27 .times. 10.sup.6 0.78 2.17 .times. 10.sup.6 0.77
4.33 .times. 10.sup.5 0.87 40 4.20 .times. 10.sup.6 0.52 6.58
.times. 10.sup.5 0.76 1.37 .times. 10.sup.6 0.79 2.50 .times.
10.sup.5 0.76 50 2.44 .times. 10.sup.6 0.57 3.76 .times. 10.sup.5
0.69 8.49 .times. 10.sup.5 0.79 1.58 .times. 10.sup.5 0.65 60 1.37
.times. 10.sup.6 0.62 2.32 .times. 10.sup.5 0.62 5.44 .times.
10.sup.5 0.76 1.09 .times. 10.sup.5 0.56 70 7.62 .times. 10.sup.5
0.66 1.51 .times. 10.sup.5 0.55 3.58 .times. 10.sup.5 0.72 8.24
.times. 10.sup.4 0.52 80 4.36 .times. 10.sup.5 0.68 1.08 .times.
10.sup.5 0.51 2.42 .times. 10.sup.5 0.67 6.37 .times. 10.sup.4 0.50
90 2.78 .times. 10.sup.5 0.67 8.45 .times. 10.sup.4 0.49 1.75
.times. 10.sup.5 0.64 5.11 .times. 10.sup.4 0.51 100 1.86 .times.
10.sup.5 0.66 6.50 .times. 10.sup.4 0.47 1.27 .times. 10.sup.5 0.61
4.12 .times. 10.sup.4 0.52 110 1.33 .times. 10.sup.5 0.63 5.02
.times. 10.sup.4 0.47 9.62 .times. 10.sup.4 0.60 3.31 .times.
10.sup.4 0.53 120 1.01 .times. 10.sup.5 0.58 3.88 .times. 10.sup.4
0.45 7.33 .times. 10.sup.4 0.60 2.51 .times. 10.sup.4 0.57 130 8.01
.times. 10.sup.4 0.52 3.37 .times. 10.sup.4 0.42 5.54 .times.
10.sup.4 0.60 2.15 .times. 10.sup.4 0.59 140 6.93 .times. 10.sup.4
0.43 3.01 .times. 10.sup.4 0.35 4.09 .times. 10.sup.4 0.60 1.73
.times. 10.sup.4 0.59 150 6.54 .times. 10.sup.4 0.32 2.85 .times.
10.sup.4 0.31 3.31 .times. 10.sup.4 0.59 1.63 .times. 10.sup.4 0.56
160 6.62 .times. 10.sup.4 0.23 2.99 .times. 10.sup.4 0.28 2.69
.times. 10.sup.4 0.57 1.43 .times. 10.sup.4 0.54 170 6.87 .times.
10.sup.4 0.17 2.83 .times. 10.sup.4 0.23 2.23 .times. 10.sup.4 0.55
1.21 .times. 10.sup.4 0.53 180 7.11 .times. 10.sup.4 0.14 2.22
.times. 10.sup.4 0.20 1.87 .times. 10.sup.4 0.52 7.49 .times.
10.sup.3 0.61 190 -- -- 1.11 .times. 10.sup.4 0.21 -- -- -- --
[0181] As can be seen from the data in Table 2, as the molecular
weight of the diamine used to produce the cured
polydimethylsiloxane oligourea segmented copolymer based vibration
damping material increased from 5,280 to 58,700, the utility window
for G' changed from 30 to 85.degree. C. for Example 1, 3 to
52.degree. C. for Example 3, 5 to 71.degree. C. for Example 4, and
-14 to 34.degree. C. for Example 5. Examples 1 and 3-5 had useful
tan .delta. utility windows of 25 to 143.degree. C., -9 to
132.degree. C., -13 to melt flow, and -25 to melt flow,
respectively. Thus, a useful temperature range was seen at 30 to
85.degree. C. for Example 1, and was the same as the G' utility
window for Examples 3-5 as these values were narrower than the
temperature ranges for tan .delta..
Examples 6-9
[0182] In Example 6, a mixture of 27.5 parts by weight
methylenedicyclohexylene-4,4'-diisocyanate, 16.3 parts
isocyanatoethyl methacrylate, and 56.3 parts DAROCUR.TM. 1173 was
fed into the first zone of an 18 mm co-rotating twin screw extruder
having a 40:1 length:diameter ratio (available from Leistritz
Corporation, Allendale, N.J.) at a rate of 0.105 g/min (0.000330
equivalents isocyanate/min). The feed line of the diisocyanate was
placed close to the screw threads. Polydimethylsiloxane Diamine D,
Lot 1, molecular weight 35,700, was injected into the second zone
at a rate of 6.2 g/min (0.000347 equivalents amine/min). Dry MQ
resin, obtained from General Electric Silicones as experimental
material #1170-002, and further dried overnight under vacuum at
55.degree. C. to less than 0.1% toluene was fed into zone four at a
rate of 8.0 g/min. The extruder had double-start fully intermeshing
screws throughout the entire length of the barrel, rotating at 300
revolutions per minute. The temperature profile for each of the 90
mm long zones was: zone 1--20.degree. C.; zone 2--25.degree. C.;
zone 3--46.degree. C.; zone 4--80.degree. C.; zone 5--90.degree.
C.; zone 6--115.degree. C.; zone 7--95.degree. C.; zone
8--110.degree. C.; and endcap--120.degree. C. Zone six was vacuum
vented to remove entrained air in the material. The resultant
polydimethylsiloxane oligourea segmented copolymer-based
pressure-sensitive adhesive was extruded, cooled in air, and
collected. The pressure-sensitive adhesive was coated and cured as
in Example 1 to form a pressure-sensitive adhesive tape having an
adhesive thickness of 50 .mu.m.
[0183] In Example 7, a polydimethylsiloxane oligourea segmented
copolymer pressure-sensitive adhesive composition was prepared as
in Example 1, except 100.0 parts (2.96 mmoles) Polydimethylsiloxane
Diamine D, (Lot 3) molecular weight 34,800, dissolved in a mixture
of 98 parts toluene was substituted for Diamine A, and a mixture of
0.58 parts (1.97 mmoles) of tetramethyl-m-xylylene diisocyanate and
0.31 parts (1.97 mmoles) of isocyanatoethyl methacrylate dissolved
in 29 parts toluene was used in the synthesis of the
polydimethylsiloxane oligourea segmented copolymer. The resulting
polydimethylsiloxane oligourea segmented copolymer
pressure-sensitive adhesive composition was coated and cured as in
Example 1 to form a pressure-sensitive adhesive tape having an
adhesive thickness of 62 .mu.m.
[0184] In Example 8, a polydimethylsiloxane oligourea segmented
copolymer pressure-sensitive adhesive composition was prepared as
in Example 1, except 100.0 parts (2.96 mmoles) Polydimethylsiloxane
Diamine D (Lot 3), molecular weight 34,800 in 93 parts toluene were
substituted for Diamine A, and a mixture of 0.50 parts (1.97
mmoles) of 1,12-diisocyanatododecane- , 0.31 parts (1.97 mmoles) of
isocyanatoethyl methacrylate in 32 parts toluene was used in the
synthesis of the polydimethylsiloxane oligourea segmented
copolymer. The resulting polydimethylsiloxane oligourea segmented
copolymer pressure-sensitive adhesive composition was coated and
cured as in Example 1 to form a pressure-sensitive adhesive tape
having an adhesive thickness of 62 .mu.m.
[0185] In Example 9, a polydimethylsiloxane oligourea segmented
copolymer pressure-sensitive adhesive composition was prepared as
in Example 1, except 100.0 parts (2.96 mmoles) Polydimethylsiloxane
Diamine D (Lot 3), molecular weight 34,800 in 95 parts toluene was
substituted for Diamine A and a mixture of 0.49 parts (1.97 mmoles)
of methylenediphenylene-4,4'-di- isocyanate, 0.31 parts (1.97
mmoles) of isocyanatoethyl methacrylate in 42 parts toluene and 3
parts 2-propanol was used in the synthesis of the
polydimethylsiloxane oligourea segmented copolymer. The resulting
polydimethylsiloxane oligourea segmented copolymer
pressure-sensitive adhesive composition was coated and cured as in
Example 1 to form a pressure-sensitive adhesive tape having an
adhesive thickness of 62 .mu.m.
[0186] The pressure-sensitive adhesive tapes of each of Examples
6-9 was tested for 180.degree. peel adhesion on glass and shear
strength on stainless steel. The results are set forth in Table
3.
4TABLE 3 180.degree. Peel adhesion Shear Example (N/dm) (min) 6 85
3,000 popoff 7 55 471 popoff 8 61 130 popoff 9 65 2410 popoff
[0187] The data in Table 3 demonstrates that the selection of
diisocyanate in preparing the copolymer portion of the
pressure-sensitive adhesive of the present invention was not
critical.
Examples 10-12
[0188] In Example 10, a vibration damping material was prepared and
tested as in Example 1, except 200 parts (37.9 mmoles)
Polydimethylsiloxane Diamine A, Lot 1, molecular weight 5280, in
200 parts toluene, a mixture of 6.17 parts (25.3 mmoles) of
tetramethyl-m-xylylene diisocyanate and 3.92 parts (25.3 mmoles) of
isocyanatoethyl methacrylate, were used in the synthesis of this
polydimethylsiloxane oligourea segmented copolymer. To this
solution was added SR-545 silicate resin solution to achieve 120
parts silicate resin (based on dry weight) per 100 parts copolymer
(based on dry weight). To this copolymer/resin solution was added
1.0 part DAROCUR.TM. 1173 per 100 parts of copolymer/resin blend
solids. The solution was subsequently poured onto a release liner,
dried, pressed between two release liners into a uniform sample of
approximately 1 mm thickness, and cured by exposure to low
intensity UV lights to form a cured vibration damping material.
[0189] Examples 11 and 12 were prepared in the same manner as
Example 10 except, in Example 11, 6.37 parts
1,12-diisocyanatododecane was substituted for the
tetramethyl-m-xylylene diisocyanate and, in Example 12, 6.33 parts
methylenediphenylene-4,4'-diisocyanate was substituted for the
tetramethyl-m-xylylene diisocyanate.
[0190] The storage modulus, G', and tan .delta. were determined for
the vibration damping materials of Examples 10-12. The results are
set forth in Table 4 with those of Example 1, a similar composition
employing dicyclohexylene-4,4'-diisocyanate as the
diisocyanate.
5TABLE 4 Temp Example 1 Example 10 Example 11 Example 12 (.degree.
C.) G' (Pa) Tan .delta. G' (Pa) Tan .delta. G' (Pa) Tan .delta. G'
(Pa) Tan .delta. -90 8.28 .times. 10.sup.7 0.03 8.74 .times.
10.sup.7 0.03 8.45 .times. 10.sup.7 0.03 1.05 .times. 10.sup.7 0.02
-80 7.61 .times. 10.sup.7 0.04 7.65 .times. 10.sup.7 0.06 7.85
.times. 10.sup.7 0.04 9.97 .times. 10.sup.7 0.02 -70 6.80 .times.
10.sup.7 0.05 6.73 .times. 10.sup.7 0.07 7.13 .times. 10.sup.7 0.05
9.41 .times. 10.sup.7 0.03 -60 6.05 .times. 10.sup.7 0.08 6.09
.times. 10.sup.7 0.08 6.34 .times. 10.sup.7 0.07 9.00 .times.
10.sup.7 0.04 -50 5.40 .times. 10.sup.7 0.09 5.45 .times. 10.sup.7
0.09 5.60 .times. 10.sup.7 0.09 8.47 .times. 10.sup.7 0.04 -40 4.82
.times. 10.sup.7 0.11 4.93 .times. 10.sup.7 0.10 4.94 .times.
10.sup.7 0.11 8.03 .times. 10.sup.7 0.05 -30 4.22 .times. 10.sup.7
0.12 4.33 .times. 10.sup.7 0.12 4.38 .times. 10.sup.7 0.12 7.64
.times. 10.sup.7 0.04 -20 3.51 .times. 10.sup.7 0.16 3.63 .times.
10.sup.7 0.15 3.59 .times. 10.sup.7 0.16 7.30 .times. 10.sup.7 0.05
-10 2.93 .times. 10.sup.7 0.19 3.19 .times. 10.sup.7 0.17 3.04
.times. 10.sup.7 0.19 7.05 .times. 10.sup.7 0.05 0 2.29 .times.
10.sup.7 0.23 2.67 .times. 10.sup.7 0.19 2.43 .times. 10.sup.7 0.23
6.72 .times. 10.sup.7 0.06 10 1.69 .times. 10.sup.7 0.29 2.17
.times. 10.sup.7 0.23 1.81 .times. 10.sup.7 0.30 6.32 .times.
10.sup.7 0.07 20 1.14 .times. 10.sup.7 0.36 1.68 .times. 10.sup.7
0.27 1.25 .times. 10.sup.7 0.38 5.85 .times. 10.sup.7 0.08 30 6.97
.times. 10.sup.6 0.45 1.24 .times. 10.sup.7 0.33 7.73 .times.
10.sup.6 0.48 5.26 .times. 10.sup.7 0.10 40 4.20 .times. 10.sup.6
0.52 8.74 .times. 10.sup.6 0.38 4.30 .times. 10.sup.6 0.56 4.56
.times. 10.sup.7 0.13 50 2.44 .times. 10.sup.6 0.57 6.02 .times.
10.sup.6 0.44 1.87 .times. 10.sup.6 0.66 3.78 .times. 10.sup.7 0.17
60 1.37 .times. 10.sup.6 0.62 4.04 .times. 10.sup.6 0.48 7.84
.times. 10.sup.5 0.71 2.89 .times. 10.sup.7 0.24 70 7.62 .times.
10.sup.5 0.66 2.71 .times. 10.sup.6 0.51 4.60 .times. 10.sup.5 0.70
2.03 .times. 10.sup.7 0.33 80 4.36 .times. 10.sup.5 0.68 1.79
.times. 10.sup.6 0.52 3.04 .times. 10.sup.5 0.66 1.30 .times.
10.sup.7 0.46 90 2.78 .times. 10.sup.5 0.67 1.19 .times. 10.sup.6
0.51 2.18 .times. 10.sup.5 0.62 7.51 .times. 10.sup.6 0.62 100 1.86
.times. 10.sup.5 0.66 8.26 .times. 10.sup.5 0.48 1.62 .times.
10.sup.5 0.57 4.34 .times. 10.sup.6 0.75 110 1.33 .times. 10.sup.5
0.63 5.94 .times. 10.sup.5 0.43 1.27 .times. 10.sup.5 0.51 2.41
.times. 10.sup.6 0.90 120 1.01 .times. 10.sup.5 0.58 4.37 .times.
10.sup.5 0.37 1.06 .times. 10.sup.5 0.43 1.35 .times. 10.sup.6 1.02
130 8.01 .times. 10.sup.4 0.52 3.23 .times. 10.sup.5 0.30 9.28
.times. 10.sup.4 0.35 7.49 .times. 10.sup.5 1.13 140 6.93 .times.
10.sup.4 0.43 2.27 .times. 10.sup.5 0.23 8.75 .times. 10.sup.4 0.26
4.05 .times. 10.sup.5 1.23 150 6.54 .times. 10.sup.4 0.32 1.31
.times. 10.sup.5 0.17 8.65 .times. 10.sup.4 0.18 2.03 .times.
10.sup.5 1.31 160 6.62 .times. 10.sup.4 0.23 5.65 .times. 10.sup.4
0.12 8.87 .times. 10.sup.4 0.12 9.92 .times. 10.sup.4 1.32 170 6.87
.times. 10.sup.4 0.17 4.01 .times. 10.sup.4 0.09 8.64 .times.
10.sup.4 0.11 4.86 .times. 10.sup.4 1.20 180 7.11 .times. 10.sup.4
0.14 3.64 .times. 10.sup.4 0.08 7.37 .times. 10.sup.4 0.09 2.42
.times. 10.sup.4 0.98 190 -- -- 3.02 .times. 10.sup.4 0.06 -- -- --
--
[0191] The data in Table 4 demonstrate that the vibration damping
materials of Examples 1 and 10-12, which were prepared using
curable polydimethylsiloxane oligourea segmented copolymers derived
from polydimethylsiloxane diamines of 5280 molecular weight and
various diisocyanates, had useful temperature ranges of 30 to
85.degree. C., 46 to 115.degree. C., 32 to 77.degree. C., and 91 to
142.degree. C., respectively.
Examples 13-15
[0192] In Example 13, a polydimethylsiloxane oligourea segmented
copolymer was made. 99.6 parts Polydimethylsiloxane Diamine D, Lot
2, molecular weight 37,800 and 0.4 parts ESACURE.TM. KB-1 free
radical initiator, available from Sartomer Co., Exton, Pa., were
fed at a rate of 3.58 g/min (0.000189 equivalents amine/min) into
the first zone of an 18 mm counter-rotating twin screw extruder
(available from Leistritz Corporation, Allendale, N.J.), MQ
silicate resin powder whose toluene content was less than 0.1
percent, as determined by loss in weight upon heating the silicate
resin under vacuum at 60.degree. C. for 16 hours, was fed at a rate
of 4.3 g/min into the second zone. A mixture of 62.8 parts
methylenedicyclohexylene-4,4'-diisocyanate and 37.2 parts
isocyanatoethyl methacrylate were fed at a rate of 0.026 g/min
(0.000186 equivalents isocyanate/min) into the fourth zone. The
extruder had a 40:1 length:diameter ratio and double-start fully
intermeshing screws throughout the entire length of the barrel,
rotating at 100 revolutions per minute. The temperature profile for
each of the 90 mm long zones was: zone 1 to 4--50.degree. C.; zone
5--95.degree. C.; zone 6--170.degree. C.; zone 7--180.degree. C.;
zone 8--125.degree. C.; and endcap--120.degree. C. Zone seven was
vacuum vented. The resultant polymer was extruded, cooled in air,
and collected.
[0193] A portion of the resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1 to provide
a pressure-sensitive adhesive tape.
[0194] Another portion of the copolymer was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0195] In Example 14, a polydimethylsiloxane oligourea segmented
copolymer was prepared as in Example 13, except a mixture of 83.5
parts by weight methylenedicyclohexylene-4,4'-diisocyanate and 16.5
parts by weight isocyanatoethyl methacrylate were fed at a rate
0.0249 g/min (0.000185 equivalents isocyanate/min) was fed into the
fourth zone, zone 6 was 180.degree. C., and zone 8 and the endcap
were 150.degree. C. The resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1 to form a
pressure-sensitive adhesive tape.
[0196] In Example 15, a polydimethylsiloxane oligourea segmented
copolymer was prepared as in Example 1, except 100 parts (2.96
mmoles) Polydimethylsiloxane Diamine D, Lot 3, molecular weight
34,800 was dissolved in 99 parts toluene was substituted for
Diamine A, and a mixture of 0.66 parts (2.35 mmoles) of
methylenedicyclohexylene-4,4'-diis- ocyanate and 0.13 parts (0.84
mmoles) isocyanatoethyl methacrylate in 65 parts toluene and 2
parts 2-propanol was used to prepare polydimethylsiloxane oligourea
segmented copolymer. Then, the copolymer solution was added SR-545
silicate resin solution to achieve 120 parts (based on dry weight)
per 100 parts polydimethylsiloxane oligourea segmented copolymer
(based on dry weight). To the copolymer/resin solution was added 1
part DAROCUR.TM. 1173 (a photoinitiator available from Ciba-Geigy,
Hawthorne, N.Y.) per 100 parts of copolymer/resin blend solids, and
the solution was subsequently air dried on a release liner
film.
[0197] A portion of the resulting polydimethylsiloxane oligourea
segmented copolymer was coated and cured as in Example 1 to form a
pressure-sensitive adhesive tape.
[0198] Another portion of the solution was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0199] The pressure-sensitive adhesive tapes of Examples 13-15 were
tested for 180.degree. peel adhesion to glass and for shear
strength to stainless steel. The results as well thickness and
average degree of polymerization are reported together in Table 5,
along with the data for Example 6 that was made using the same
reactants.
[0200] The storage modulus, G', and tan .delta. were determined for
the vibration damping materials of Examples 13 and 15, having an
average degree of polymerization of 2 and 7, respectively. The
results are set forth in Table 6 together with those for Example 4,
a similar composition having an average degree of polymerization
3.
6TABLE 5 180.degree. Peel Degree of Thickness adhesion Shear
strength Example Polymerization (.mu.m) (N/dm) (min) 13 2 62 48
1160 popoff 6 3 50 85 3000 popoff 14 5 150 131 5480 popoff 15 7 75
61 700 popoff
[0201] The data in Table 5 demonstrates pressure-sensitive adhesive
tapes can be prepared using adhesives with polydimethylsiloxane
oligourea segmented copolymers with varying degrees of
polymerization, from 2 to 7, have good adhesive properties.
7TABLE 6 Temp Example 4 Example 13 Example 15 (.degree. C.) G` (Pa)
Tan .delta. G` (Pa) Tan .delta. G` (Pa) Tan .delta. -90 9.98
.times. 10.sup.7 0.04 7.79 .times. 10.sup.7 0.05 7.56 .times.
10.sup.7 0.04 -80 8.92 .times. 10.sup.7 0.05 6.92 .times. 10.sup.7
0.06 6.59 .times. 10.sup.7 0.06 -70 7.73 .times. 10.sup.7 0.07 5.87
.times. 10.sup.7 0.09 5.40 .times. 10.sup.7 0.1 -60 6.22 .times.
10.sup.7 0.12 4.74 .times. 10.sup.7 0.14 4.34 .times. 10.sup.7 0.15
-50 5.24 .times. 10.sup.7 0.15 3.80 .times. 10.sup.7 0.19 3.37
.times. 10.sup.7 0.2 -40 4.31 .times. 10.sup.7 0.19 2.94 .times.
10.sup.7 0.25 2.46 .times. 10.sup.7 0.26 -30 3.20 .times. 10.sup.7
0.26 2.01 .times. 10.sup.7 0.35 1.60 .times. 10.sup.7 0.37 -20 2.15
.times. 10.sup.7 0.35 1.03 .times. 10.sup.7 0.55 8.65 .times.
10.sup.6 0.54 -10 1.49 .times. 10.sup.7 0.44 5.33 .times. 10.sup.6
0.71 4.87 .times. 10.sup.6 0.7 0 9.06 .times. 10.sup.6 0.57 3.46
.times. 10.sup.6 0.74 2.59 .times. 10.sup.6 0.81 10 5.49 .times.
10.sup.6 0.68 2.31 .times. 10.sup.6 0.74 1.27 .times. 10.sup.6 0.9
20 3.48 .times. 10.sup.6 0.75 1.48 .times. 10.sup.6 0.73 6.72
.times. 10.sup.5 0.91 30 2.17 .times. 10.sup.6 0.77 9.59 .times.
10.sup.5 0.71 3.50 .times. 10.sup.5 0.84 40 1.37 .times. 10.sup.6
0.79 6.53 .times. 10.sup.5 0.68 2.03 .times. 10.sup.5 0.72 50 8.49
.times. 10.sup.5 0.79 4.41 .times. 10.sup.5 0.65 1.32 .times.
10.sup.5 0.61 60 5.44 .times. 10.sup.5 0.76 3.06 .times. 10.sup.5
0.61 9.23 .times. 10.sup.4 0.55 70 3.58 .times. 10.sup.5 0.72 2.21
.times. 10.sup.5 0.58 6.79 .times. 10.sup.4 0.53 80 2.42 .times.
10.sup.5 0.67 1.62 .times. 10.sup.5 0.56 5.08 .times. 10.sup.4 0.53
90 1.75 .times. 10.sup.5 0.64 1.20 .times. 10.sup.5 0.55 3.96
.times. 10.sup.4 0.57 100 1.27 .times. 10.sup.5 0.61 9.21 .times.
10.sup.4 0.56 2.85 .times. 10.sup.4 0.64 110 9.62 .times. 10.sup.4
0.60 7.01 .times. 10.sup.4 0.56 2.03 .times. 10.sup.4 0.76 120 7.33
.times. 10.sup.4 0.60 5.47 .times. 10.sup.4 0.56 1.38 .times.
10.sup.4 0.83 130 5.54 .times. 10.sup.4 0.60 4.29 .times. 10.sup.4
0.58 8.15 .times. 10.sup.3 0.99 140 4.09 .times. 10.sup.4 0.60 3.42
.times. 10.sup.4 0.55 5.67 .times. 10.sup.3 1.09 150 3.31 .times.
10.sup.4 0.59 3.03 .times. 10.sup.4 0.52 5.94 .times. 10.sup.3 0.94
160 2.69 .times. 10.sup.4 0.57 2.88 .times. 10.sup.4 0.5 6.34
.times. 10.sup.3 0.81 170 2.23 .times. 10.sup.4 0.55 2.54 .times.
10.sup.4 0.47 4.86 .times. 10.sup.3 0.78 180 1.87 .times. 10.sup.4
0.52 2.17 .times. 10.sup.4 0.47 -- -- 190 -- -- 1.26 .times.
10.sup.4 0.54 -- --
[0202] The data in Table 6 demonstrates that the vibration damping
materials of Examples 3, 13 and 15, which were prepared using
curable polydimethylsiloxane oligourea segmented copolymers of
polydimethylsiloxane diamines of about 37,000 molecular weight and
the same diisocyanates but with degrees of polymerization of 3, 2,
and 7 respectively, had useful temperature ranges of 5 to
71.degree. C., -14 to 57.degree. C., and -16 to 30.degree. C.,
respectively.
Examples 16-18
[0203] In Example 16, a polydimethylsiloxane oligourea segmented
copolymer prepared as in Example 6 was hot melt coated with a 1.91
cm diameter (3/4 inch) single screw Haake extruder (commercially
available from Haake, Inc., Saddlebrook, N.J. 07662) rotating at 40
revolutions per minute with a temperature profile of: zone 1--not
controlled, zone 2--163.degree. C., zone 3--188.degree. C., and
necktube and die (12.7 cm wide) -210.degree. C., cast between nip
rolls with a 35.6 .mu.m (1.4 mil) polyethylene terephthalate film
on one roll and S TAKE-OFF.TM. release liner on the other to a
coating thickness of about 25 .mu.m (1.0 mil), and, subsequently,
exposed to 1.73 mW for 20 minutes ultraviolet radiation provided by
a low intensity ultraviolet lamp Model F40BL, available from
General Electric Co. to effect curing.
[0204] In Example 17, Polydimethylsiloxane Diamine D, Lot 3,
molecular weight 34,800, was added the first zone of an 18 mm
co-rotating twin screw extruder having a 40:1 length:diameter ratio
(available from Leistritz Corporation, Allendale, N.J.) at a rate
of 6.23 g/min (0.000358 equivalents amine/min). MQ resin dried to
about 1% toluene, obtained from GE Silicones as experimental
#1170-002, was fed into zone 2 at a rate of 8.27 g/min. A mixture
of 27.5 parts by weight methylenedicyclohexylene-4,-
4'-diisocyanate, 16.3 parts by weight isocyanatoethyl methacrylate,
and 56.3 parts DAROCUR.TM. 1173 was fed into the fifth zone at a
rate of 0.105 g/min (0.000330 equivalents isocyanate/min). The feed
line of this stream was placed close to the screw threads. The
extruder had double-start fully intermeshing screws throughout the
entire length of the barrel, rotating at 300 revolutions per
minute. The temperature profile for each of the 90 mm long zones
was: zones 1 and 2--30.degree. C.; zone 3--35.degree. C.; zone
4--50.degree. C.; zone 5--60.degree. C.; zone 6--75.degree. C.;
zone 7--90.degree. C.; zone 8--110.degree. C.; and
endcap--120.degree. C. The extrudate was cooled in air. The
resulting polydimethylsiloxane oligourea segmented copolymer was
coated and cured as in Example 16 to produce a pressure-sensitive
adhesive tape.
[0205] In Example 18, Polydimethylsiloxane Diamine D, Lot 3,
molecular weight 34,800, was added the first zone of an 18 mm
co-rotating twin screw extruder having a 40:1 length:diameter ratio
(available from Leistritz Corporation, Allendale, N.J.) at a rate
of 6.23 g/min (0.000358 equivalents amine/min). MQ resin dried to
about 1% toluene, obtained from GE Silicones as experimental
#1170-002, was fed into zone 2 at a rate of 8.6 g/min. A mixture of
27.5 parts by weight methylenedicyclohexylene-4,4- '-diisocyanate,
16.3 parts by weight isocyanatoethyl methacrylate, and 56.3 parts
DAROCUR.TM. 1173 was fed into the fifth zone at a rate of 0.106
g/min (0.000333 equivalents isocyanate/min). The feed line of this
stream was placed close to the screw threads. The extruder had
double-start fully intermeshing screws throughout the entire length
of the barrel, rotating at 300 revolutions per minute. The
temperature profile for each of the 90 mm long zones was: zones 1
and 2--34.degree. C.; zone 3--40.degree. C.; zone 4--50.degree. C.;
zone 5--60.degree. C.; zone 6--75.degree. C.; zone 7--90.degree.
C.; zone 8--110.degree. C.; and endcap--120.degree. C. The
extrudate was cooled in air. The resulting polydimethylsiloxane
oligourea segmented copolymer was coated and cured as in Example 16
to produce a pressure-sensitive adhesive tape.
[0206] The pressure-sensitive adhesive tapes of Examples 16-18 on
which the adhesive thickness was 25 .mu.m (1 mil) were tested for
180.degree. peel adhesion to glass and shear strength on stainless
steel. The results are set forth in Table 7.
8 TABLE 7 180.degree. Peel Copolymer/resin Adhesion Shear Strength
Example Ratio (N/dm) (min) 16 1/1.2 55 1900 popoff 17 1/1.3 65 5900
popoff 18 1/1.4 63 5700 popoff
[0207] The data in Table 7 demonstrates that polydimethylsiloxane
oligourea segmented copolymer pressure-sensitive adhesive
compositions of the invention which were made by a solventless
process, hot-melt processed using conventional equipment, and
ultraviolet radiation cured had good adhesive properties.
Examples 19-26
[0208] In Examples 19-26, polydimethylsiloxane oligourea segmented
copolymers were prepared as follows. Polydimethylsiloxane Oligourea
Segmented Copolymer A was dissolved in toluene and mixed with
varying amounts of SR-545 MQ silicate resin solution containing
DAROCUR.TM. 1173 under slow agitation as in Example 5. For each 10
parts of Copolymer A, the following amounts of silicate resin were
used: Example 19--5 parts; Example 20--8 parts; Example 21--10
parts; Example 22--13 parts; Example 23--14 parts; Example 24--15
parts; Example 25--17 parts; and Example 26--23 parts. The
resulting compositions were coated and cured as in Example 1 to
provide pressure-sensitive adhesive tapes.
[0209] Other portions of Examples 20 and 26 were each poured onto a
release liner, dried, pressed between two release liners into a
uniform sample of approximately 1 mm thickness, and cured by
exposure to low intensity UV lights to form a cured vibration
damping material.
[0210] The 180.degree. peel adhesion to glass and the shear
strength to stainless steel determined for each pressure-sensitive
adhesive tape of Examples 19-26, the thickness of the tape of
Example 19 being 62 .mu.m while the thickness of the others was 50
.mu.m. The maximum tan .delta. at 10 Hz was determined for Examples
20-26. The results are set forth in Table 8.
9 TABLE 8 180.degree. Peel Shear adhesion strength Max tan .delta.
Example (N/dm) (min) (.degree. C.) 19 2 7 popoff -- 20 24 720
popoff -10 21 46 5500 popoff 15 22 73 1900 popoff 35 23 73
>10000 60 24 79 >10000 65 25 -- >5000 60 26 -- >5000
>120
[0211] The data in Table 8 demonstrates that at low silicate resin
content the polydimethylsiloxane oligourea segmented copolymer
pressure-sensitive adhesive compositions show marginal adhesive
performance, while at high silicate resin content, partial two-bond
failure occurred (Example 24) or total two-bond failure occurred
(Examples 25-26), that is, the adhesive adhered to the glass better
than to the tape backing. Adhesion to the backing is problematic,
although high peel adhesion to glass and good shear properties are
observed.
[0212] The shear creep viscosity of the uncured compositions of
Examples 20-21, 6, and 22-24 was measured as a function of
temperature using Rheometrics DSR in a Step Stress Mode (creep).
The results as well as the ratio of copolymer/resin are set forth
in Table 9.
10TABLE 9 Shear Creep Viscosity (Pa .multidot. s) Temp Ex. 20 Ex.
21 Ex. 6 Ex. 22 Ex. 23 Ex. 24 (.degree. C.) 1/0.8 1/1 1/1.2 1/1.3
1/1.4 1/1.5 25 1.78 .times. 10.sup.5 4.71 .times. 10.sup.5 1.46
.times. 10.sup.6 1.94 .times. 10.sup.6 4.84 .times. 10.sup.7 1.29
.times. 10.sup.7 35 -- 1.54 .times. 10.sup.5 6.18 .times. 10.sup.5
9.53 .times. 10.sup.5 3.19 .times. 10.sup.6 4.21 .times. 10.sup.6
45 4.21 .times. 10.sup.4 5.92 .times. 10.sup.4 2.28 .times.
10.sup.5 3.43 .times. 10.sup.5 9.80 .times. 10.sup.5 1.81 .times.
10.sup.6 50 -- -- 1.23 .times. 10.sup.5 1.78 .times. 10.sup.5 5.21
.times. 10.sup.5 1.06 .times. 10.sup.6 60 8.21 .times. 10.sup.3
1.37 .times. 10.sup.4 4.11 .times. 10.sup.4 5.20 .times. 10.sup.4
1.37 .times. 10.sup.5 2.88 .times. 10.sup.5 70 -- 5.14 .times.
10.sup.3 1.42 .times. 10.sup.4 1.71 .times. 10.sup.4 3.56 .times.
10.sup.4 8.26 .times. 10.sup.4 80 1.03 .times. 10.sup.3 2.24
.times. 10.sup.3 5.65 .times. 10.sup.3 6.29 .times. 10.sup.3 1.20
.times. 10.sup.4 2.87 .times. 10.sup.4 90 -- 9.50 .times. 10.sup.2
2.46 .times. 10.sup.3 2.52 .times. 10.sup.3 4.40 .times. 10.sup.3
9.03 .times. 10.sup.3 100 -- 5.08 .times. 10.sup.2 9.25 .times.
10.sup.2 1.07 .times. 10.sup.3 1.57 .times. 10.sup.3 3.38 .times.
10.sup.3
[0213] The data in Table 9 demonstrates the effect of temperature
on shear creep viscosity of the polydimethylsiloxane oligourea
segmented copolymer pressure-sensitive adhesive compositions of
Examples 5 and 20-24. The low shear creep viscosities at moderate
temperatures are indicative of compositions which are excellent for
hot-melt coating.
[0214] The storage modulus and tan .delta. were determined for the
vibration damping materials of Examples 20 and 26. The results are
set forth in Table 10, together with those for Example 4, a similar
composition containing 54.5 percent MQ silicate resin.
11TABLE 10 Temp Example 4 Example 20 Example 26 (.degree. C.) G`
(Pa) Tan .delta. G` (Pa) Tan .delta. G` (Pa) Tan .delta. -90 9.98
.times. 10.sup.7 0.04 5.48 .times. 10.sup.7 0.10 7.68 .times.
10.sup.7 0.02 -80 8.92 .times. 10.sup.7 0.05 4.13 .times. 10.sup.7
0.12 7.30 .times. 10.sup.7 0.02 -70 7.73 .times. 10.sup.7 0.07 2.91
.times. 10.sup.7 0.17 6.81 .times. 10.sup.7 0.03 -60 6.22 .times.
10.sup.7 0.12 1.84 .times. 10.sup.7 0.27 6.44 .times. 10.sup.7 0.04
-50 5.24 .times. 10.sup.7 0.15 8.99 .times. 10.sup.6 0.45 6.04
.times. 10.sup.7 0.05 -40 4.31 .times. 10.sup.7 0.19 4.22 .times.
10.sup.6 0.61 5.65 .times. 10.sup.7 0.05 -30 3.20 .times. 10.sup.7
0.26 2.18 .times. 10.sup.6 0.66 5.26 .times. 10.sup.7 0.06 -20 2.15
.times. 10.sup.7 0.35 1.26 .times. 10.sup.6 0.64 4.80 .times.
10.sup.7 0.08 -10 1.49 .times. 10.sup.7 0.44 8.59 .times. 10.sup.5
0.60 4.44 .times. 10.sup.7 0.09 0 9.06 .times. 10.sup.6 0.57 5.74
.times. 10.sup.5 0.56 3.96 .times. 10.sup.7 0.11 10 5.49 .times.
10.sup.6 0.68 3.98 .times. 10.sup.5 0.51 3.42 .times. 10.sup.7 0.14
20 3.48 .times. 10.sup.6 0.75 2.96 .times. 10.sup.5 0.48 2.84
.times. 10.sup.7 0.18 30 2.17 .times. 10.sup.6 0.77 2.21 .times.
10.sup.5 0.45 2.23 .times. 10.sup.7 0.23 40 1.37 .times. 10.sup.6
0.79 1.68 .times. 10.sup.5 0.44 1.59 .times. 10.sup.7 0.31 50 8.49
.times. 10.sup.5 0.79 1.31 .times. 10.sup.5 0.43 9.67 .times.
10.sup.6 0.46 60 5.44 .times. 10.sup.5 0.76 1.04 .times. 10.sup.5
0.44 4.66 .times. 10.sup.6 0.71 70 3.58 .times. 10.sup.5 0.72 8.01
.times. 10.sup.4 0.46 2.16 .times. 10.sup.6 1.01 80 2.42 .times.
10.sup.5 0.67 6.33 .times. 10.sup.4 0.48 6.25 .times. 10.sup.5 1.45
90 1.75 .times. 10.sup.5 0.64 4.74 .times. 10.sup.4 0.51 1.75
.times. 10.sup.5 2.01 100 1.27 .times. 10.sup.5 0.61 3.71 .times.
10.sup.4 0.55 5.41 .times. 10.sup.4 2.35 110 9.62 .times. 10.sup.4
0.60 2.78 .times. 10.sup.4 0.58 2.17 .times. 10.sup.4 2.40 120 7.33
.times. 10.sup.4 0.60 2.03 .times. 10.sup.4 0.59 9.14 .times.
10.sup.3 2.63 130 5.54 .times. 10.sup.4 0.60 1.59 .times. 10.sup.4
0.62 -- -- 140 4.09 .times. 10.sup.4 0.60 1.26 .times. 10.sup.4
0.59 -- -- 150 3.31 .times. 10.sup.4 0.59 1.28 .times. 10.sup.4
0.56 -- -- 160 2.69 .times. 10.sup.4 0.57 1.31 .times. 10.sup.4
0.49 -- -- 170 2.23 .times. 10.sup.4 0.55 1.41 .times. 10.sup.4
0.42 -- -- 180 1.87 .times. 10.sup.4 0.52 1.19 .times. 10.sup.4
0.40 -- --
[0215] As can be seen from the data in Table 10, Examples 20, 4,
and 26, having increasingly higher MQ silicate resin concentrations
of 44.4, 54.5, and 70 weight percent, respectively, caused the
useful temperature range to increase from -47 to 15.degree. C. in
Example 20, 5 to 71.degree. C. in Example 4, 55 to 85.degree. C. in
Example 26.
Example 27
[0216] In Example 27, a pressure-sensitive adhesive was prepared as
in Example 6. After the adhesive was extruded, cooled and
collected, 49.7 parts of adhesive and 50.3 parts toluene were
blended and coated on to a primed polyester backing using a knife
coater, dried in an air circulating oven at 60.degree. C. for 10
minutes, laminated with a release liner and cured at 1.73 mW for 20
minutes under low intensity ultraviolet lights to provide a dry
adhesive thickness of 100 .mu.m (4 mils). The 180.degree. peel
adhesion from glass was 70 N/dm and the shear strength on stainless
steel was >5000 min.
Example 28
[0217] In Example 28, a composition was prepared as in Example 1,
except 100.3 parts (10.4 mmoles) Polydiphenyldimethylsiloxane
Diamine F, molecular weight 9620 was dissolved in 94 parts toluene
and substituted for the Diamine A, and a mixture of 1.82 parts
(6.95 mmoles) of methylenedicyclohexylene-4,4'-diisocyanate and
1.08 parts (6.95 mmoles) of isocyanatoethyl methacrylate dissolved
in 57 parts toluene was used to prepare
polydimethyldiphenylsiloxane oligourea segmented copolymer. To the
solution was added 25 parts SR-545 silicate resin solution per 100
parts polydimetliyldiphenylsiloxane oligourea segmented copolymer,
and 1 part DAROCUR.TM. 1173 per 100 parts of copolymer/resin blend
solids.
[0218] A portion of the solution was subsequently air dried,
coated, and cured as in Example 1. The 180.degree. peel adhesion to
glass and the shear strength on stainless steel were determined and
were, respectively, 58 N/dm and >3000 min.
[0219] Another portion of the solution was pressed between two
release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0220] The storage modulus, G', and tan .delta. were determined for
the vibration damping material of Example 28 and the results are
reported in Table 11.
12TABLE 11 Temp Example 28 (.degree. C.) G` (Pa) Tan .delta. -90
8.61 .times. 10.sup.7 0.08 -80 1.96 .times. 10.sup.7 0.56 -70 2.30
.times. 10.sup.6 0.65 -60 8.16 .times. 10.sup.5 0.35 -50 5.66
.times. 10.sup.5 0.18 -40 4.89 .times. 10.sup.5 0.11 -30 4.60
.times. 10.sup.5 0.07 -20 4.47 .times. 10.sup.5 0.06 -10 4.43
.times. 10.sup.5 0.06 0 4.38 .times. 10.sup.5 0.06 10 4.27 .times.
10.sup.5 0.06 20 4.16 .times. 10.sup.5 0.08 30 3.96 .times.
10.sup.5 0.11 40 3.63 .times. 10.sup.5 0.15 50 3.21 .times.
10.sup.5 0.19 60 2.75 .times. 10.sup.5 0.21 70 2.34 .times.
10.sup.5 0.22 80 2.02 .times. 10.sup.5 0.20 90 1.79 .times.
10.sup.5 0.18 100 1.63 .times. 10.sup.5 0.14 110 1.53 .times.
10.sup.5 0.11 120 1.43 .times. 10.sup.5 0.09 130 1.36 .times.
10.sup.5 0.07 140 1.33 .times. 10.sup.5 0.05 150 1.31 .times.
10.sup.5 0.04 160 1.30 .times. 10.sup.5 0.03 170 1.29 .times.
10.sup.5 0.03 180 1.24 .times. 10.sup.5 0.04 190 1.11 .times.
10.sup.5 0.04
[0221] As can be seen from the data in Table 11, the vibration
damping material of Example 28, containing 20 percent MQ silicate
resin, and based on a curable polydimethyldiphenylsiloxane
oligourea segmented copolymer derived from
polydimethyldiphenylsiloxane diamine of molecular weight 9620, had
a storage modulus utility window, G', of -75 to 45.degree. C., a
loss factor, tan .delta., utility window of -82 to -62.degree. C.,
and a useful temperature range of -75 to -62.degree. C.
Example 29
[0222] In Example 29, a vibration damping material was formulated
by dissolving 10 parts Polydimethylsiloxane Oligourea Segmented
Copolymer A in toluene and adding MQD silicate resin solution
MQR-32-3 (70 weight percent in toluene, available from Shin-Etsu
Silicones of America, Inc., Torrance, Calif.) to provide 400 parts
silicate resin (based on dry weight) per 100 parts copolymer (based
on dry weight). To this copolymer/resin solution was added 1.0 part
DAROCUR.TM. 1173 per 100 parts of copolymer/resin blend solids. The
sample was dried, then well mixed in a 50 gram mixing head at 75
rpm and a temperature of 150.degree. C. for 10 minutes on a mixer
(available from C. W. Brabender Instruments, Inc., South
Hackensack, N.J.). The mixed sample was pressed, cured, and tested
as in Example 1 to provide a vibration damping material. The
storage modulus and tan .delta. were determined for Example 29. The
results are set forth in Table 12.
13TABLE 12 Temp Example 29 (.degree. C.) G` (Pa) Tan .delta. -90
7.90 .times. 10.sup.7 0.02 -80 7.54 .times. 10.sup.7 0.02 -70 7.11
.times. 10.sup.7 0.03 -60 6.69 .times. 10.sup.7 0.05 -50 6.07
.times. 10.sup.7 0.06 -40 5.49 .times. 10.sup.7 0.08 -30 4.81
.times. 10.sup.7 0.10 -20 4.14 .times. 10.sup.7 0.13 -10 3.61
.times. 10.sup.7 0.15 0 2.94 .times. 10.sup.7 0.19 10 2.21 .times.
10.sup.7 0.27 20 1.38 .times. 10.sup.7 0.42 30 6.52 .times.
10.sup.6 0.67 40 3.33 .times. 10.sup.6 0.85 50 1.68 .times.
10.sup.6 0.98 60 9.61 .times. 10.sup.5 1.06 70 4.99 .times.
10.sup.5 1.15 80 2.66 .times. 10.sup.5 1.27 90 1.27 .times.
10.sup.5 1.44 100 5.60 .times. 10.sup.4 1.69 110 2.01 .times.
10.sup.4 1.99 120 7.06 .times. 10.sup.3 1.94 130 3.61 .times.
10.sup.3 1.38 140 2.04 .times. 10.sup.3 0.90 150 1.11 .times.
10.sup.3 1.10
[0223] The data in Table 12 demonstrate that Example 29, a cured
vibration damping composition of the present invention, formulated
at a silicate resin concentration of 80 percent provides a useful
temperature range of 29 to 77.degree. C.
Example 30
[0224] In Example 30, Polydimethylsiloxane Diamine B, molecular
weight 10,700, was fed into the third zone of an 18 mm co-rotating
twin screw extruder having a 40:1 length:diameter ratio (available
from Leistritz Corporation, Allendale, N.J.) at a rate of 6.63
g/min (0.000620 equivalents amine/min). A mixture of 32.9 parts by
weight tetramethyl-m-xylylene diisocyanate, 32.2 parts by weight
isocyanatopropyltriethoxy silane, 33.8 parts by weight octyl
triethoxy silane, and 1.0 parts by weight dibutyl tin dilaurate was
fed into the third zone at a rate of 0.298 g/min (0.00120
equivalents isocyanate/min). The feed line of this stream was
placed close the screw threads. MQ resin dried from solvent to
about 1.3% toluene (obtained from General Electric Silicones as
experimental material #1170-002) was fed to zone 5 at a rate of 10
g/min. The extruder had double-start fully intermeshing screws
throughout the entire length of the barrel, rotating at 300
revolutions per minute. The temperature profile for each of the 90
mm zones was: zones 1 through 3--30.degree. C.; zone 4--35.degree.
C.; zone 5--45.degree. C.; zone 6--80.degree. C.; zone
7--90.degree. C.; zone 8 and endcap--120.degree. C. Zone seven was
vacuum vented to remove entrained air. The MQ silicate resin had
not incorporated uniformly into the polydiorganosiloxane oligourea
segmented copolymer.
[0225] Thirty parts by weight of this copolymer blend was dissolved
in 70 parts tetrahydrofuran, then coated onto a primed 38 .mu.m
(1.5 mil) thick polyester film and dried at 65.degree. C. for 10
minutes to produce a 38 .mu.m (1.5 mil) thick adhesive and allowed
to cure for 1 week at 21.degree. C. and 50% relative humidity.
[0226] The 180.degree. peel adhesion to glass was tested and
resulted in two-bond failure; the shear strength on stainless steel
was >3000 minutes.
[0227] The storage modulus and tan 8 were determined for Example 30
and the results are set forth in Table 13.
Example 31
[0228] In Example 31, 50 parts (0.287 mmol) Polydimethylsiloxane
Diamine C, Lot 2, molecular weight 34,800, was dissolved in 50
parts toluene. To this solution with vigorous stirring was added
0.2 parts (0.181 mmol) aminopropyltriethoxysilane. 0.5 parts (0.382
mmol) methylenedicyclohexylene-4,4'-diisocyanate, 0.25 parts (0.439
mmol) trifluoroacetic acid catalyst, and 83.4 parts SR-545 MQ
silicate resin. The solution was subsequently poured onto a release
liner and dried at 65.degree. C. for 20 minutes. The resultant
polydimethylsiloxane oligourea segmented copolymer-based partially
cured vibration damping material was allowed to cure at 21.degree.
C. and 50 percent relative humidity for 7 days to obtain a 0.2 mm
thick sample of fully cured vibration damping material from which
sections were laminated together, under nip pressure, to a total
thickness of 1 mm.
[0229] The storage modulus and tan .delta. were determined for
Example 31 and the results are set forth in Table 13.
14TABLE 13 Temp Example 30 Example 31 (.degree. C.) G` (Pa) Tan
.delta. G` (Pa) Tan .delta. -90 8.68 .times. 10.sup.7 0.03 7.82
.times. 10.sup.7 0.06 -80 7.95 .times. 10.sup.7 0.03 6.49 .times.
10.sup.7 0.08 -70 7.24 .times. 10.sup.7 0.05 5.33 .times. 10.sup.7
0.12 -60 6.62 .times. 10.sup.7 0.07 4.42 .times. 10.sup.7 0.15 -50
6.10 .times. 10.sup.7 0.07 3.51 .times. 10.sup.7 0.20 -40 5.65
.times. 10.sup.7 0.08 2.62 .times. 10.sup.7 0.26 -30 5.19 .times.
10.sup.7 0.10 1.72 .times. 10.sup.7 0.36 -20 4.63 .times. 10.sup.7
0.12 8.54 .times. 10.sup.6 0.58 -10 4.25 .times. 10.sup.7 0.13 4.78
.times. 10.sup.6 0.74 0 3.67 .times. 10.sup.7 0.16 2.49 .times.
10.sup.6 0.89 10 3.09 .times. 10.sup.7 0.20 1.16 .times. 10.sup.6
1.07 20 2.54 .times. 10.sup.7 0.24 4.98 .times. 10.sup.5 1.27 30
1.92 .times. 10.sup.7 0.31 1.79 .times. 10.sup.5 1.49 40 1.32
.times. 10.sup.7 0.41 6.96 .times. 10.sup.4 1.68 50 7.74 .times.
10.sup.6 0.58 2.64 .times. 10.sup.4 1.80 60 4.08 .times. 10.sup.6
0.77 1.19 .times. 10.sup.4 1.81 70 2.01 .times. 10.sup.6 0.95 7.5
.times. 10.sup.3 1.36 80 8.68 .times. 10.sup.5 1.14 3.88 .times.
10.sup.3 1.22 90 3.65 .times. 10.sup.5 1.27 4.27 .times. 10.sup.3
0.52 100 1.69 .times. 10.sup.5 1.25 -- -- 110 9.55 .times. 10.sup.4
1.13 -- -- 120 5.74 .times. 10.sup.4 1.02 -- -- 130 2.89 .times.
10.sup.4 1.00 -- -- 140 1.53 .times. 10.sup.4 1.03 -- --
[0230] The data in Table 13 demonstrate that moisture cure
vibration damping compositions Example 30 and 31 have useful
temperature ranges of 52 to 91.degree. C., and -16 to 24.degree. C.
respectively.
Example 32
[0231] The polydimethylsiloxane oligourea segmented copolymer of
Example 32 was prepared as in Example 23, except the
pressure-sensitive adhesive was coated from a 70.degree. C. melt
using a single screw Haake Rheocord extruder (commercially
available from Haake, Inc., Saddlebrook, N.J. 07662), with a
temperature profile set at zone 1--off, zone 2--66.degree. C., zone
3--94.degree. C., and die--94.degree. C., at a thickness of 0.27 mm
(10.5 mils) between a hook and loop fastener (SCOTCHMATE.TM.
SJ-3418, commercially available from 3M Co., St. Paul, Minn.) and a
clear, release liner film (S TAKE-OFF). The composition was cured
by subjecting the composition to 1.73 mW for 20 minutes low
intensity Ultraviolet (UV) radiation.
[0232] Samples were prepared and tested for 90.degree. Peel
Adhesion. After one day aging at room temperature, the peel
adhesion was 1.44 kN/m and after the 1 day at room temperature plus
7 days at 70.degree. C. (158.degree. F.) aging, the peel adhesion
was 1.68 kN/m, an increase of 17 percent. The data shows that the
composition of the invention has good initial adhesion and no
adhesion loss after exposure of the composition to elevated
temperature. Also, -20.degree. F. (-29.degree. C.) shock resistance
was determined by conditioning samples prepared as for the
90.degree. Peel Adhesion in a -20.degree. F. (-29.degree. C.)
freezer for 24 hours, and upon removal, immediately test for
adhesion by hand. The samples did not fail and the adhesive
appeared to still be rubbery (flexible and tough).
[0233] Additionally, samples were prepared and tested for Vertical
Burn according to the test method described herein. The sample
passed the Extinguish Time (15 seconds maximum) and the Burn Length
(6 inches/15.2 cm maximum). The sample failed to meet the 3 second
maximum Drip Extinguish Time. However, it is believed that the
sample would pass with the addition of a small amount of
non-halogen flame retardant.
Example 33
[0234] In Example 33, a vibration damping material was prepared as
in Example 1, except a mixture of 67 parts (3.0 mmoles)
Polydimethylsiloxane Diamine C, molecular weight 22,300, and 15.84
parts (3.0 mmoles) Polydimethylsiloxane Diamine A, molecular weight
5280, in 69 parts toluene, and a mixture of 0.98 parts (4.0 mmoles)
of tetramethyl-m-xylylene diisocyanate and 0.62 parts (4.0 mmoles)
of isocyanatoethyl methacrylate was used in the synthesis of this
polydimethylsiloxane oligourea segmented copolymer. To this
solution was added SR-545 silicate resin solution to achieve 120
parts silicate resin (based on dry weight) per 100 parts copolymer
(based on dry weight). To this copolymer/resin solution was added
1.0 DAROCUR.TM. per 100 parts of copolymer/resin blend solids. The
solution was subsequently poured onto a release liner, dried,
pressed between two release liners into a uniform sample of
approximately 1 mm thickness, and cured by exposure to low
intensity UV lights to form a cured vibration damping material.
[0235] The storage modulus and tan .delta. for Example 33 were
determined and the results are set forth in Table 14.
15TABLE 14 Temp Example 33 (.degree. C.) G` (Pa) Tan .delta. -90
7.71 .times. 10.sup.7 0.04 -80 6.72 .times. 10.sup.7 0.06 -70 5.67
.times. 10.sup.7 0.08 -60 4.91 .times. 10.sup.7 0.10 -50 4.14
.times. 10.sup.7 0.13 -40 3.32 .times. 10.sup.7 0.17 -30 2.53
.times. 10.sup.7 0.23 -20 1.76 .times. 10.sup.7 0.30 -10 1.25
.times. 10.sup.7 0.38 0 7.59 .times. 10.sup.6 0.50 10 4.67 .times.
10.sup.6 0.57 20 2.76 .times. 10.sup.6 0.62 30 1.58 .times.
10.sup.6 0.67 40 9.22 .times. 10.sup.5 0.67 50 5.27 .times.
10.sup.5 0.68 60 3.03 .times. 10.sup.5 0.69 70 1.75 .times.
10.sup.5 0.68 80 1.12 .times. 10.sup.5 0.66 90 7.38 .times.
10.sup.4 0.62 100 5.14 .times. 10.sup.4 0.58 110 3.72 .times.
10.sup.4 0.51 120 2.80 .times. 10.sup.4 0.39 130 2.35 .times.
10.sup.4 0.29 140 1.68 .times. 10.sup.4 0.26 150 1.02 .times.
10.sup.4 0.18 160 8.02 .times. 10.sup.3 0.06 170 5.99 .times.
10.sup.3 0.12 180 3.51 .times. 10.sup.3 0.04
[0236] The data in Table 14 demonstrate that a vibration damping
composition of the present invention, formulated using a curable
polydimethylsiloxane polyurea segmented copolymer prepared using a
blend of two polydimethylsiloxane diamines having molecular weights
of 5,280 and 22,300 provides a useful temperature range of 2 to
57.degree. C.
Example 34
[0237] In Example 34, a vibration damping material was synthesized
using the solventless process. A first free-radically curable
vibration damping composition using Polydimethylsiloxane Diamine A
and a second free-radically curable vibration damping composition
using Polydimethylsiloxane Diamine C were prepared, and then
combined in equal portions by weight in toluene solution.
[0238] To prepare the first composition, Polydimethylsiloxane
Diamine A, molecular weight 5,280, was fed into the first zone of
an 18 mm co-rotating twin screw extruder having a 40:1
length:diameter ratio (available from Leistritz Corporation,
Allendale, N.J.) at a rate of 6.22 g/min (0.00236 equivalents
amine/min). MQ silicate resin, containing 1% toluene, obtained from
General Electric Silicone Products Division, Waterford, N.Y. as
experimental material #1170-002 was fed into zone 2 at a rate of
7.6 g/min. A mixture of 50.8 parts by weight tetramethyl-m-xylylene
dilsocyanate, 32.3 parts by weight isocyanatoethyl methacrylate,
and 33.9 parts by weight DAROCUR.TM. 1173 was fed into the sixth
zone at a rate of 0.378 g/min (0.00236 equivalents isocyanatelmin).
The feed line of this stream was placed close to the screw threads.
The extruder had double-start fully intermeshing screws throughout
the entire length of the barrel, rotating at 200 revolutions per
minute. The temperature profile for each of the 90 mm long zones
was: zones 1 through 4--20 to 30.degree. C.; zone 5--40.degree. C.;
zone 6--60.degree. C.; zone 7--90.degree. C.; zone 8--100.degree.
C.; and endcap--120.degree. C. The extrudate was cooled in air, and
collected.
[0239] To prepare the second composition, Polydimethylsiloxane
Diamine C, molecular weight 22,300, was fed into the first zone of
an 18 mm co-rotating twin screw extruder having a 40:1
length:diameter ratio (available from Leistritz Corporation,
Allendale, N.J.) at a rate of 6.22 g/min (0.000558 equivalents
amine/min). MQ silicate resin #1170-002, was fed into zone 2 at a
rate of 7.56 g/min. A mixture of 33.3 parts by weight
tetramethyl-m-xylylene diisocyanate, 21.1 parts by weight
isocyanatoethyl methacrylate, and 45.6 parts by weight DAROCUR.TM.
1173 was fed into the sixth zone at a rate of 0.134 g/min (0.000549
equivalents isocyanatelmin). The feed line of this stream was
placed close to the screw threads. The extruder had double-start
fully intermeshing screws throughout the entire length of the
barrel, rotating at 50 revolutions per minute. The temperature
profile for each of the 90 mm long zones was: zones 1 through
4--30.degree. C.; zone 5--40.degree. C.; zone 6--60.degree. C.;
zone 7--90.degree. C.; zone 8 and endcap--120.degree. C. The
resultant polymer was extruded, cooled in air, and collected.
[0240] Equal weights of the two curable vibration damping
compositions were dissolved in toluene. The solution was
subsequently poured onto a release liner, dried, pressed between
two release liners into a uniform sample of approximately 1 mm
thickness, and cured by exposure to low intensity UV lights to form
a cured vibration damping material.
[0241] The storage modulus and tan .delta. for Example 34 were
determined and are set forth in Table 15.
16TABLE 15 Temp Example 34 (.degree. C.) G` (Pa) Tan .delta. -90
7.60 .times. 10.sup.7 0.04 -80 6.77 .times. 10.sup.7 0.05 -70 5.76
.times. 10.sup.7 0.07 -60 4.98 .times. 10.sup.7 0.09 -50 4.34
.times. 10.sup.7 0.11 -40 3.79 .times. 10.sup.7 0.13 -30 3.26
.times. 10.sup.7 0.15 -20 2.72 .times. 10.sup.7 0.18 -10 2.37
.times. 10.sup.7 0.19 0 1.95 .times. 10.sup.7 0.23 10 1.55 .times.
10.sup.7 0.27 20 1.18 .times. 10.sup.7 0.32 30 8.35 .times.
10.sup.6 0.39 40 5.84 .times. 10.sup.6 0.45 50 4.09 .times.
10.sup.6 0.50 60 2.65 .times. 10.sup.6 0.56 70 1.71 .times.
10.sup.6 0.60 80 1.06 .times. 10.sup.6 0.62 90 6.65 .times.
10.sup.5 0.62 100 4.33 .times. 10.sup.5 0.60 110 2.91 .times.
10.sup.5 0.55 120 1.96 .times. 10.sup.5 0.50 130 1.37 .times.
10.sup.5 0.46 140 9.44 .times. 10.sup.4 0.41 150 6.05 .times.
10.sup.4 0.36 160 3.69 .times. 10.sup.4 0.32 170 2.25 .times.
10.sup.4 0.26 180 1.77 .times. 10.sup.4 0.24
[0242] The data in Table 15 demonstrate that a vibration damping
composition of the present invention, prepared using a blend of two
curable vibration damping compositions, each derived from different
polydimethylsiloxane diamines having molecular weights of 5,280 and
22,300 respectively, provides a useful temperature range of 36 to
106.degree. C.
Example 35
[0243] In Example 35, Polydimethylsiloxane Diamine D, Lot 3,
molecular weight 34,800, was fed into the first zone of an 18 mm
co-rotating twin screw extruder having a 40:1 length:diameter ratio
(available from Leistritz Corporation, Allendale, N.J.) at a rate
of 6.23 g/min (0.000358 equivalents amine/min). MQ silicate resin
#1170-002 was fed into zone 2 at a rate of 7.67 g/min. A mixture of
27.46 parts by weight methylenedicyclohexylene-4,4'-diisocyanate,
16.25 parts by weight isocyanato ethyl methacrylate, and 56.29
parts DAROCUR.TM. 1173 was fed into the fifth zone at a rate of
0.105 g/min (0.000330 equivalents isocyanate/min). The feed line of
this stream was placed close to the screw threads. The extruder had
double-start fully intermeshing screws throughout the entire length
of the barrel, rotating at 300 revolutions per minute. The
temperature profile for each of the 90 mm long zones was: zones 1
and 2--30.degree. C.; zone 3--35.degree. C.; zone 4--50.degree. C.;
zone 5--60.degree. C.; zone 6--75.degree. C.; zone 7--90.degree.
C.; zone 8--110.degree. C.; and endcap--120.degree. C. The
extrudate was cooled in air and collected.
[0244] To a Brabender mixer fit with a 50 gram mixing head at a
temperature of 150.degree. C. and agitators rotating at a speed of
50 rpm, was added 40 grams of the curable vibration damping
composition prepared above. After mixing for 1 minute, 40 grams
alumina, type WA, size 180 (supplied by Micro Abrasives
Corporation, Westfield, Mass.) was added, and mixed for 10 minutes.
The sample was collected, cooled to room temperature, and pressed
between glass plates as in Example 1. The sample was radiation
cured through the glass plates by placing the sample between two
banks of Sylvania F15/T8/BLB low intensity ultraviolet lamps, at an
intensity of 1.0 mW/cm.sup.2 for 3 hours, to provide a cured
vibration damping composition. The storage modulus and loss factor
were determined for this material and are set forth in Table
16.
17TABLE 16 Temp Example 35 (.degree. C.) G` (Pa) Tan .delta. -90
9.33 .times. 10.sup.7 0.02 -80 8.63 .times. 10.sup.7 0.02 -70 7.74
.times. 10.sup.7 0.03 -60 6.87 .times. 10.sup.7 0.05 -50 5.91
.times. 10.sup.7 0.06 -40 4.97 .times. 10.sup.7 0.08 -30 3.96
.times. 10.sup.7 0.10 -20 2.84 .times. 10.sup.7 0.13 -10 1.99
.times. 10.sup.7 0.15 0 1.12 .times. 10.sup.7 0.19 10 5.43 .times.
10.sup.6 0.27 20 3.45 .times. 10.sup.6 0.42 30 2.31 .times.
10.sup.6 0.67 40 1.69 .times. 10.sup.6 0.85 50 1.04 .times.
10.sup.6 0.98 60 6.83 .times. 10.sup.5 1.06 70 4.33 .times.
10.sup.5 1.15 80 2.80 .times. 10.sup.5 1.27 90 2.06 .times.
10.sup.5 1.44 100 1.46 .times. 10.sup.5 1.69 110 1.07 .times.
10.sup.5 1.99 120 8.45 .times. 10.sup.4 1.94 130 6.34 .times.
10.sup.4 1.38 140 4.35 .times. 10.sup.4 0.90 150 3.19 .times.
10.sup.4 1.10
[0245] The data in Table 16 demonstrate that a cured vibration
damping composition containing 50 percent alumina filler provides a
useful temperature range of from 17 to 76.degree. C.
Example 36
[0246] In Example 36, a vibration damping material was prepared by
mixing 59.4 g Polydimethyldiphenylsiloxane Oligourea Segmented
Copolymer B, 131.1 g SR-545 MQ resin solution at 68 percent solids,
and 1.9 g DAROCUR.TM. 1173 photoinitiator under slow agitation
until homogeneous. The solution was poured into an aluminum tray
lined with fluorosilicone coated 50 .mu.m thick polyester release
liner. The material was dried by exposure to ambient conditions for
72 hours. Then, the tray was placed in a vacuum oven at ambient
temperature and a pressure of 100 Pa for 16 hours. The tray was
removed from the oven and the sample was inverted and placed again
in the vacuum oven under the same conditions for 8 hours. The
material was pressed between 5 mm thick glass plates lined with the
above-described release liner to obtain a section having a
thickness of about 6.4 mm. The section was radiation cured, through
the glass plates, by placing the composite between two banks of
Sylvania F15/T8/BLB low intensity ultraviolet lamps, at an
intensity of 1.0 mW/cm.sup.2 for 3.5 hours.
[0247] To construct a bi-directional vibration damper from this
cured composition, the release liners were removed and the slab was
abraded with a SCOTCHBRITE.TM. #7447 Hand Pad, available from 3M
Company, Maplewood, Minn., to roughen the surface of the slab. A
bi-directional vibration damping device, similar in appearance to
FIG. 1, was constructed by cutting two square sections measuring 38
mm per side and having a thickness of 6.4 mm from the slab, bonding
the broad faces of the square sections of vibration damping
material 1, using a structural epoxy adhesive, to 4.7 mm thick cold
rolled steel plate 2 and members 3a and 3b of FIG. 1, that had been
cleaned prior to assembly by sand blasting and solvent degreasing.
The epoxy bonded bi-directional vibration damping assembly was
fixtured for 24 hours at room temperature to maintain parallelism
between the steel members and the viscoelastic pieces during epoxy
cure.
[0248] The damper assembly was rigidly mounted in an MTS model
number 312.21 hydraulically actuated closed loop feedback control
testing machine (Minneapolis, Minn.) fit with a temperature
controlled chamber. Three cycles of dynamic mechanical testing were
then performed at temperatures of 0.degree. C., 15.degree. C.,
21.degree. C., and 36.degree. C. at strains of 50% and 100% at each
temperature. The storage modulus, G', and loss factor, tan .delta.,
measured at 1 Hz were determined and are reported in Table 17.
18 TABLE 17 Example 19 Temp (.degree. C.) Strain (%) G` Tan .delta.
0 50 1.03 .times. 10.sup.6 1.88 15 50 6.55 .times. 10.sup.5 1.88 21
50 5.53 .times. 10.sup.5 1.82 36 50 3.32 .times. 10.sup.5 1.67 0
100 5.04 .times. 10.sup.5 2.05 15 100 3.80 .times. 10.sup.5 1.94 21
100 3.37 .times. 10.sup.5 1.85 36 100 2.22 .times. 10.sup.5
1.67
[0249] The results in Table 17 demonstrate that the storage
modulus, G', and the loss factor, tan .delta., of this curable
vibration damping composition are high and relatively insensitive
to changes in temperature. These are particularly desirable
features of viscoelastic materials employed in bi-directional
damping constructions.
Example 37
[0250] In Example 37, 0.30 grams 1,12-diaminedodecane (Available
from Aldrich), and 100.0 grams Polydimethylsiloxane Diamine D, Lot
2, molecular weight 37,800, was dissolved in 100 grams of a 50/50
toluene/isopropanol mixture. To the solution was added dropwise a
mixture of 0.46 grams isocyanatoethylmethacrylate and 0.72 grams
tetramethyl-m-xylylene diisocyanate in 20 grams of a 50/50
toluene/isopropanol mixture. To the solution was added 1.0 gram
Darocur.TM. 1173, and the resulting mixture was dried in air to
form a white, viscous fluid.
[0251] Twenty grams of the polymer was dissolved in 25 grams of a
50/50 toluene/isopropanol mixture. To the solution was added 30
grams dried MQ resin, and the solution was agitated slowly until
homogeneous. The somewhat hazy solution was dried in air on a
release liner to form a tacky, compliant material. One part of the
dried polymer was coated at 130.degree. C. between 38 .mu.m primed
polyester and a release liner to a thickness of 38 .mu.m, exposed
to UV light to cure, and tested for PSA properties and the peel
force from glass was 85.4 N/dm
[0252] Another part of the dried polymer containing MQ resin was
subsequently pressed between two release liners to a thickness of
approximately 1 mm and cured by exposure to low intensity UV lights
for 20 minutes. Dynamic mechanical properties of the material were
tested as in Example 5 and are reported in Table 18.
Example 38
[0253] In Example 38, 1.9 grams 1,12-diaminedodecane, and 100.0
grams Polydimethylsiloxane Diamine A, molecular weight 5,280, were
dissolved in 100 grams of a 50/50 toluene/isopropanol mixture. To
the solution was added dropwise a mixture of 2.94 grams
isocyanatoethylmethacrylate and 4.62 grams tetramethyl-m-xylylene
diisocyanate in 20 grams of a 50/50 toluene/isopropanol mixture. To
the solution was added 1.0 gram Darocur.TM. 1173, and the resulting
mixture was dried in air to form a hazy, semisolid.
[0254] Twenty grams of the dried polymer was dissolved in 25 grams
of a 50/50 toluene/isopropanol mixture. To the solution was added
30 grams dried MQ resin, and the solution was agitated slowly until
homogeneous. The solution was dried in air on a release liner to
form a stiff, somewhat tacky, material.
[0255] One part of the dried polymer containing MQ resin was used
to prepare a hot melt adhesive bond according to the procedure
described previously and tested for adhesive bond strength.
19 Glass PMMA Stress at break MN/m.sup.2 >1.2 (glass shattered)
1.26 Strain at break % n/a 458
[0256] Another part of the dried polymer containing MQ resin was
subsequently pressed between two release liners to a thickness of
approximately 1 mm and cured by exposure to low intensity UV lights
for 20 minutes. Dynamic mechanical properties of the material were
tested as in Example 5 and are reported in Table 18.
Example 39
[0257] In Example 39, 0.96 grams Polamine.TM. 1H1000 (available
from Air Products and Chemicals, Inc. Allentown, Pa.), and 100.0
grams Polydimethylsiloxane Diamine D, Lot 2, molecular weight
37,800, was dissolved in 100 grams of a 50/50 toluene/isopropanol
mixture. To the solution was added dropwise a mixture of 0.46 grams
isocyanatoethylmethacrylate and 0.72 grams tetramethyl-m-xylylene
diisocyanate in 20 grams of a 50/50 toluene/isopropanol mixture. To
the solution was added 1.0 gram Darocur.TM. 1173, and the resulting
mixture was dried in air to form white, very viscous fluid. Twenty
grams of the dried polymer was dissolved in 25 grams of a 50/50
toluene/isopropanol mixture. To the solution was added 30 grams
dried MQ resin, and the solution was agitated slowly until
homogeneous.
[0258] One part of the somewhat hazy solution was dried in air on a
release liner to form a tacky, compliant material that was coated
at 130.degree. C. between 38 .mu.m primed polyester and a release
liner to provide a PSA layer having a thickness of 25 .mu.m, cured
by exposure to UV, and tested for PSA properties and the peel force
from glass was 37.2 N/dm
[0259] Another part of the dried polymer containing MQ resin was
subsequently pressed between two release liners to a thickness of
approximately 1 mm and cured by exposure to low intensity UV lights
for 20 minutes. Dynamic mechanical properties of the material were
tested as in Example 5 and are reported in Table 18.
Example 40
[0260] In Example 40, 5.24 grams tetramethyl-m-xylylene
diisocyanate was charged to a 500 mL flask in 10 milliliters of
dichloromethane. To this was added 31.7 grams of Jeffamine D-2000
(available form Huntsman Corp.), and the sample was well mixed.
Next was added a solution of 61.4 grams of Polydimethylsiloxane
Diamine A, molecular weight 5,280, in 40 mL dichloromethane. Next,
1.66 grams isocyanatoethylmethacrylate was added and the solution
was mixed for 15 minutes, followed by the addition of 1.1 grams
Darocur.TM. 1173. The mixture was allowed to dry on a release liner
in the dark to form a bluish, somewhat inhomogeneous semisolid.
[0261] Twenty grams of the dried polymer was dissolved in 25 grams
of a 50/50 toluene/isopropanol mixture. To the solution was added
30 grams dried MQ resin, and the solution was agitated slowly until
homogeneous. The solution was dried in air on a release liner to
form a stiff, somewhat tacky, material.
[0262] One part of the dried polymer containing MQ resin was used
to prepare a hot melt adhesive bond according to the procedure
described previously and tested for adhesive bond strength.
20 Glass PMMA Stress at break MN/m.sup.2 >2.0 0.4 Strain at
break % 2330 331
[0263] Another part of the dried polymer was subsequently pressed
between two release liners to a thickness of approximately 1 mm and
cured by exposure to low intensity UV lights for 20 minutes.
Dynamic mechanical properties of the material were tested as in
Example 5 and are reported in Table 18.
21TABLE 18 Temp Example 37 Example 38 Example 39 Example 40
(.degree. C.) G' (Pa) Tan .delta. G' (Pa) Tan .delta. G' (Pa) Tan
.delta. G' (Pa) Tan .delta. -90 7.27 .times. 10.sup.7 0.03 5.80
.times. 10.sup.7 0.03 7.55 .times. 10.sup.7 0.03 6.65 .times.
10.sup.7 0.02 -80 6.71 .times. 10.sup.7 0.03 5.36 .times. 10.sup.7
0.03 7.14 .times. 10.sup.7 0.03 6.33 .times. 10.sup.7 0.02 -70 5.93
.times. 10.sup.7 0.06 4.80 .times. 10.sup.7 0.05 6.48 .times.
10.sup.7 0.04 5.97 .times. 10.sup.7 0.02 -60 5.31 .times. 10.sup.7
0.09 4.55 .times. 10.sup.7 0.06 5.91 .times. 10.sup.7 0.05 5.69
.times. 10.sup.7 0.04 -50 4.72 .times. 10.sup.7 0.11 4.58 .times.
10.sup.7 0.07 5.24 .times. 10.sup.7 0.07 5.03 .times. 10.sup.7 0.06
-40 4.05 .times. 10.sup.7 0.13 4.36 .times. 10.sup.7 0.08 4.75
.times. 10.sup.7 0.08 3.94 .times. 10.sup.7 0.10 -30 3.40 .times.
10.sup.7 0.17 4.02 .times. 10.sup.7 0.09 4.20 .times. 10.sup.7 0.11
3.09 .times. 10.sup.7 0.12 -20 2.75 .times. 10.sup.7 0.22 3.66
.times. 10.sup.7 0.10 3.31 .times. 10.sup.7 0.16 2.39 .times.
10.sup.7 0.16 -10 2.28 .times. 10.sup.7 0.27 3.27 .times. 10.sup.7
0.11 2.38 .times. 10.sup.7 0.25 1.85 .times. 10.sup.7 0.19 0 1.63
.times. 10.sup.7 0.36 2.92 .times. 10.sup.7 0.13 1.61 .times.
10.sup.7 0.35 1.35 .times. 10.sup.7 0.23 10 1.07 .times. 10.sup.7
0.49 2.57 .times. 10.sup.7 0.15 9.11 .times. 10.sup.6 0.53 9.72
.times. 10.sup.6 0.26 20 5.35 .times. 10.sup.6 0.77 2.16 .times.
10.sup.7 0.18 4.35 .times. 10.sup.6 0.75 7.50 .times. 10.sup.6 0.26
30 2.79 .times. 10.sup.6 0.92 1.72 .times. 10.sup.7 0.22 2.46
.times. 10.sup.6 0.89 6.16 .times. 10.sup.6 0.25 40 1.68 .times.
10.sup.6 1.08 1.27 .times. 10.sup.7 0.27 1.36 .times. 10.sup.6 1.01
4.98 .times. 10.sup.6 0.25 50 9.14 .times. 10.sup.5 1.22 8.79
.times. 10.sup.6 0.33 5.09 .times. 10.sup.5 1.12 3.56 .times.
10.sup.6 0.25 60 4.52 .times. 10.sup.5 1.32 5.60 .times. 10.sup.6
0.41 1.67 .times. 10.sup.5 1.12 2.72 .times. 10.sup.6 0.28 70 1.56
.times. 10.sup.5 1.38 2.99 .times. 10.sup.6 0.49 9.03 .times.
10.sup.4 1.02 1.96 .times. 10.sup.6 0.37 80 1.01 .times. 10.sup.5
1.31 1.73 .times. 10.sup.6 0.55 4.68 .times. 10.sup.4 0.91 1.20
.times. 10.sup.6 0.53 90 6.03 .times. 10.sup.4 1.21 1.13 .times.
10.sup.6 0.58 3.31 .times. 10.sup.4 0.83 6.73 .times. 10.sup.5 0.68
100 3.65 .times. 10.sup.4 1.11 7.53 .times. 10.sup.5 0.60 2.33
.times. 10.sup.4 0.76 3.63 .times. 10.sup.5 0.75 110 2.69 .times.
10.sup.4 1.04 5.21 .times. 10.sup.5 0.58 1.77 .times. 10.sup.4 0.66
1.34 .times. 10.sup.5 0.68 120 2.01 .times. 10.sup.4 0.97 3.54
.times. 10.sup.5 0.54 1.46 .times. 10.sup.4 0.56 5.80 .times.
10.sup.4 0.62 130 1.60 .times. 10.sup.4 0.85 2.38 .times. 10.sup.5
0.45 1.13 .times. 10.sup.4 0.43 5.26 .times. 10.sup.4 0.57 140 1.41
.times. 10.sup.4 0.75 1.78 .times. 10.sup.5 0.40 8.37 .times.
10.sup.3 0.39 4.59 .times. 10.sup.4 0.54 150 1.21 .times. 10.sup.4
0.65 1.18 .times. 10.sup.5 0.31 5.61 .times. 10.sup.3 0.27 4.00
.times. 10.sup.4 0.50 160 1.07 .times. 10.sup.4 0.60 5.60 .times.
10.sup.4 0.24 5.73 .times. 10.sup.3 0.27 3.38 .times. 10.sup.4 0.48
170 9.15 .times. 10.sup.3 0.54 4.30 .times. 10.sup.4 0.19 5.33
.times. 10.sup.3 0.28 2.71 .times. 10.sup.4 0.44 180 8.07 .times.
10.sup.3 0.50 3.03 .times. 10.sup.4 0.16 4.38 .times. 10.sup.3 0.25
2.18 .times. 10.sup.4 0.41 190 5.77 .times. 10.sup.3 0.51 -- --
1.54 .times. 10.sup.3 0.4 1.25 .times. 10.sup.4 0.36
[0264] The data in Table 18 for Examples 37 and 38 show that
polydimethylsiloxane oligourea segmented copolymeric vibration
damping compositions derived from a polydimethylsiloxane diamine of
about 38,000 or 5,000 molecular weight and a hydrocarbon polyamine,
1,12-diamine dodecane, provide damping materials having useful
temperature ranges of 17 to 61.degree. C. and 58 to 116.degree. C.
respectively.
[0265] The data in Table 18 for Examples 39 and 40 show that the
damping composition of Example 39, containing a mixture of a
polydimethylsiloxane diamine of about 38,000 molecular weight and
Polamine.TM. 1H1000, a polytetramethyleneoxide diamine of about
1,000 MW, provided a useful temperature range of 14 to 51.degree.
C., and that the damping composition of Example 40, containing a
mixture of a polydimethylsiloxane diamine of about 5,000 molecular
weight and Jeffamine D-2000, a polypropyleneoxide diamine of about
2,000 MW, provided a useful temperature range of 75 to 96.degree.
C.
Example 41
[0266] In Example 41 Polydimethylsiloxane Diamine A, Lot 1,
molecular weight 5,280 was fed into the first zone of an 18 mm
co-rotating twin screw extruder having a 40:1 length:diameter ratio
(available from Leistritz Corporation, Allendale, N.J.) at a rate
of 6.22 g/min (0.00236 equivalents amine/min). MQ silicate resin,
containing 1% toluene, obtained from General Electric Silicone
Products Division, Waterford, N.Y. as experimental material
#1170-002 was fed into zone 2 at a rate of 7.6 g/min. A mixture of
50.8 parts by weight tetramethyl-m-xylylene diisocyanate, 32.3
parts by weight isocyanatoethyl methacrylate, and 33.9 parts by
weight DAROCUR.TM. 1173 was fed into the sixth zone at a rate of
0.378 g/min (0.00236 equivalents isocyanate/min). The feed line of
this stream was placed close to the screw threads. The extruder had
double-start fully intermeshing screws throughout. The entire
length of the barrel, rotating at 200 revolutions per minute. The
temperature profile for each of the 90 mm long zones was: zones 1
through 4--20 to 30.degree. C.; zone 5--40.degree. C.; zone
6--60.degree. C.; zone 7--90.degree. C.; zone 8--100.degree. C.;
and endcap--120.degree. C. The extrudate was cooled in air, and
collected.
[0267] A portion of the composition was heated to 200.degree. C. in
a metal can and applied to various components of a printed circuit
board for the purpose of rigidizing and potting components on the
board. The printed circuit board assembly was put into a freezer at
-20 to -15.degree. C. for 12 hours with no adhesive failure
(debonding) or solder cracking noted. Another portion of this
composition was tested as a curable hot-melt adhesive according to
the procedure described previously. Test results are given
below
22 Glass PMMA Stress at break MN/m.sup.2 >2.4 (glass shattered)
0.7 Strain at break % n/a 378
Example 42
[0268] In Example 42, 38.0 parts Polydimethylsiloxane Diamine A,
Lot 1, molecular weight 5,280, and 30.0 parts toluene were added to
a round bottom flask fit with mechanical stirrer. To this stirred
solution was added dropwise a mixture of 1.26 parts
methylenecyclohexylene-4,4'-diisoc- yanate, 0.74 parts
isocyanatoethylmethacrylate, and 10 parts toluene. The copolymer
thus formed was employed to prepare a thermally curable
polydimethylsiloxane oligourea segmented copolymeric adhesive by
blending 30 parts of the copolymer solution with 36.4 parts MQ
resin solution SR545 at 62.2% solids and 0.38 parts benzoyl
peroxide, and agitating until homogeneous. The solution was poured
out onto a release liner and allowed to air dry at ambient
temperature. After drying, the sample was pressed between release
liners to obtain a 30 mil thick layer that was employed to
construct an overlap shear sample to assess adhesive bond strength.
The overlap shear sample was prepared as previously described with
the exception that steel adherents were employed and that after
assembly at room temperature the sample was placed in a forced air
oven at 85.degree. C. for 5 minutes to allow the sample to flow
out, followed by 10 minutes at 170.degree. C. to cure the sample.
The cured adhesive bond was tested as in Example 41 and found to
provide a maximum stress at break of 1.03 MN/m.sup.2 at a strain of
560%.
[0269] The various modifications and alterations of this invention
will be apparent to those skilled in the art without departing from
the scope and spirit of this invention and this invention should
not be restricted to that set forth herein for illustrative
purposes.
* * * * *