U.S. patent application number 14/369316 was filed with the patent office on 2015-01-01 for low temperature vibration damping pressure sensitive adhesives and constructions.
The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Jason D. Clapper, David A. Gries, Kevin M. Lewandowski, Daniel J. Renninger, Thu-Van T. Tran, Arlin L. Weikel.
Application Number | 20150004405 14/369316 |
Document ID | / |
Family ID | 47521186 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150004405 |
Kind Code |
A1 |
Clapper; Jason D. ; et
al. |
January 1, 2015 |
LOW TEMPERATURE VIBRATION DAMPING PRESSURE SENSITIVE ADHESIVES AND
CONSTRUCTIONS
Abstract
This disclosure relates to viscoelastic damping materials and
constructions which may demonstrate low temperature performance and
adhesion and which may be used in making vibration damping
composites. Viscoelastic damping materials and constructions may
include polymers or copolymers of monomers according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I] wherein R.sup.1 is H,
CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group
containing 12 to 32 carbon atoms.
Inventors: |
Clapper; Jason D.; (Lino
Lakes, MN) ; Weikel; Arlin L.; (Roberts, WI) ;
Tran; Thu-Van T.; (Maplewood, MN) ; Lewandowski;
Kevin M.; (Inver Grove Heights, MN) ; Gries; David
A.; (Indianapolis, IN) ; Renninger; Daniel J.;
(Lebanon, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Family ID: |
47521186 |
Appl. No.: |
14/369316 |
Filed: |
December 26, 2012 |
PCT Filed: |
December 26, 2012 |
PCT NO: |
PCT/US2012/071650 |
371 Date: |
June 27, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61581374 |
Dec 29, 2011 |
|
|
|
61675536 |
Jul 25, 2012 |
|
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|
Current U.S.
Class: |
428/354 ;
428/355AC; 428/461; 428/523; 524/522; 524/560; 525/221;
526/279 |
Current CPC
Class: |
C09J 2423/00 20130101;
C09J 7/10 20180101; Y10T 428/2891 20150115; C09J 2433/00 20130101;
C08F 230/08 20130101; C09J 7/385 20180101; C09J 2433/006 20130101;
C08L 33/10 20130101; Y10T 428/31692 20150401; C09J 133/08 20130101;
Y10T 428/2848 20150115; C08L 33/08 20130101; C08K 3/36 20130101;
Y10T 428/31938 20150401; C08L 33/10 20130101; C08L 23/20
20130101 |
Class at
Publication: |
428/354 ;
428/355.AC; 428/523; 428/461; 524/560; 524/522; 525/221;
526/279 |
International
Class: |
C09J 7/02 20060101
C09J007/02; C08L 33/08 20060101 C08L033/08; C08F 230/08 20060101
C08F230/08; C08K 3/36 20060101 C08K003/36 |
Claims
1. A viscoelastic damping material comprising: a) a copolymer of:
i) at least one monomer according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I] wherein R.sup.1 is H,
CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group
containing 12 to 32 carbon atoms, and ii) at least one second
mononomer; and b) at least one adhesion-enhancing material.
2. The viscoelastic damping material according to claim 1 wherein
the adhesion-enhancing material is selected from the group
consisting of inorganic nanoparticles, core-shell rubber particles,
polybutene materials, and polyisobutene materials.
3. The viscoelastic damping material according to claim 1 wherein
the adhesion-enhancing material is silica nanoparticles.
4. The viscoelastic damping material according to claim 1 wherein
the adhesion-enhancing material is core-shell rubber particles.
5. The viscoelastic damping material according to claim 1 wherein
R.sup.2 is a branched alkyl group containing 15 to 22 carbon
atoms.
6. The viscoelastic damping material according to claim 1 wherein
R.sup.1 is H or CH.sub.3.
7. The viscoelastic damping material according to claim 1 wherein
said at least one second mononomer is selected from the group
consisting of acrylic acid, methacrylic acid, ethacrylic acid,
acrylic esters, methacrylic esters and ethacrylic esters.
8. A viscoelastic damping material comprising a copolymer of: i) at
least one monomer according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I] wherein R.sup.1 is H,
CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group
containing 12 to 32 carbon atoms, and ii) a monofunctional silicone
(meth)acrylate oligomer.
9. The viscoelastic damping material according to claim 8 wherein
R.sup.2 is a branched alkyl group containing 15 to 22 carbon
atoms.
10. The viscoelastic damping material according to claim 8 wherein
R.sup.1 is H or CH.sub.3.
11. The viscoelastic damping material according to claim 1
additionally comprising a plasticizer.
12. A viscoelastic construction comprising: a) at least one
viscoelestic layer comprising a polymer or copolymer of at least
one monomer according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I] wherein R.sup.1 is H,
CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group
containing 12 to 32 carbon atoms; bound to b) at least one PSA
layer comprising a pressure sensitive adhesive.
13. The viscoelastic construction according to claim 12, wherein
said viscoelestic layer is bound to at least two layers comprising
a pressure sensitive adhesive.
14. The viscoelastic construction according to claim 12 wherein
R.sup.2 is a branched alkyl group containing 15 to 22 carbon
atoms.
15. The viscoelastic construction according to claim 12 wherein
R.sup.2 is a branched alkyl group containing 16 to 20 carbon
atoms.
16. The viscoelastic construction according to claim 12 wherein
R.sup.1 is H or CH.sub.3.
17. The viscoelastic construction according to claim 12 wherein
said viscoelestic layer comprises copolymer which is a copolymer of
at least one second mononomer selected from the group consisting of
acrylic acid, methacrylic acid, ethacrylic acid, acrylic esters,
methacrylic esters, and ethacrylic esters.
18. The viscoelastic construction according to claim 12 wherein
said PSA layer comprises an acrylic pressure sensitive
adhesive.
19. The viscoelastic construction according to claim 18 wherein
said acrylic pressure sensitive adhesive is a copolymer of acrylic
acid.
20. A viscoelastic construction comprising a) discrete particles of
a polymer or copolymer of at least one monomer according to formula
I: CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I] wherein R.sup.1 is H,
CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a branched alkyl group
containing 12 to 32 carbon atoms; dispersed in b) a PSA layer
comprising a pressure sensitive adhesive.
21. The viscoelastic construction according to claim 20 wherein
said PSA layer comprises an acrylic pressure sensitive
adhesive.
22. The viscoelastic construction according to claim 21 wherein
said acrylic pressure sensitive adhesive is a copolymer of acrylic
acid.
23. A vibration damping composite comprising the viscoelastic
damping material of claim 1 adhered to at least one substrate.
24. The vibration damping composite according to claim 23 where the
viscoelastic damping material is adhered to at least two
substrates.
25. The vibration damping composite according to claim 23 where at
least one substrate is a metal substrate.
26. A vibration damping composite comprising the viscoelastic
construction of claim 12 adhered to at least one substrate.
27. The vibration damping composite according to claim 26 where the
multilayer viscoelastic construction is adhered to at least two
substrates.
28. The vibration damping composite according to claim 26 where at
least one substrate is a metal substrate.
29. A vibration damping composite comprising the viscoelastic
damping material of claim 8 adhered to at least one substrate.
30. The vibration damping composite according to claim 29 where the
viscoelastic damping material is adhered to at least two
substrates.
31. The vibration damping composite according to claim 29 where at
least one substrate is a metal substrate.
32. A vibration damping composite comprising the viscoelastic
construction of claim 20 adhered to at least one substrate.
33. The vibration damping composite according to claim 32 where the
multilayer viscoelastic construction is adhered to at least two
substrates.
34. The vibration damping composite according to claim 32 where at
least one substrate is a metal substrate.
Description
FIELD OF THE DISCLOSURE
[0001] This disclosure relates to viscoelastic damping materials
and constructions which may demonstrate low temperature performance
and adhesion and which may be used in making vibration damping
composites.
SUMMARY OF THE DISCLOSURE
[0002] Briefly, the present disclosure provides a viscoelastic
damping material comprising: a) a copolymer of: i) at least one
monomer according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I]
wherein R.sup.1 is H, CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a
branched alkyl group containing 12 to 32 carbon atoms, and ii) at
least one second mononomer; and b) at least one adhesion-enhancing
material. In some embodiments, the adhesion-enhancing material is
one of: inorganic nanoparticles, core-shell rubber particles,
polybutene materials, or polyisobutene materials. Typically R.sup.2
is a branched alkyl group containing 15 to 22 carbon atoms.
Typically R.sup.1 is H or CH.sub.3. Typically second mononomers are
acrylic acid, methacrylic acid, ethacrylic acid, acrylic esters,
methacrylic esters or ethacrylic esters esters. The viscoelastic
damping material may additionally comprise a plasticizer.
[0003] In another aspect, the present disclosure provides a
viscoelastic damping material comprising a copolymer of: i) at
least one monomer according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I]
wherein R.sup.1 is H, CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a
branched alkyl group containing 12 to 32 carbon atoms, and ii) a
monofunctional silicone (meth)acrylate oligomer. Typically R.sup.2
is a branched alkyl group containing 15 to 22 carbon atoms.
Typically R.sup.1 is H or CH.sub.3. The viscoelastic damping
material may additionally comprise a plasticizer.
[0004] In another aspect, the present disclosure provides a
viscoelastic construction comprising: a) at least one viscoelestic
layer comprising a polymer or copolymer of at least one monomer
according to formula I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I]
wherein R.sup.1 is H, CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a
branched alkyl group containing 12 to 32 carbon atoms; bound to b)
at least one PSA layer comprising a pressure sensitive adhesive. In
some embodiments, the viscoelestic layer is bound to at least two
layers comprising a pressure sensitive adhesive. Typically R.sup.2
is a branched alkyl group containing 15 to 22 carbon atoms.
Typically R.sup.1 is H or CH.sub.3. In some embodiments, the
viscoelestic layer comprises copolymer which is a copolymer of at
least one second mononomer selected from acrylic acid, methacrylic
acid, ethacrylic acid, acrylic esters, methacrylic esters, or
ethacrylic esters. In some embodiments, the PSA layer comprises an
acrylic pressure sensitive adhesive. In some embodiments, the PSA
layer comprises an acrylic pressure sensitive adhesive which is a
copolymer of acrylic acid.
[0005] In another aspect, the present disclosure provides a
viscoelastic construction comprising: a) discrete particles of a
polymer or copolymer of at least one monomer according to formula
I:
CH.sub.2.dbd.CHR.sup.1--COOR.sup.2 [I]
wherein R.sup.1 is H, CH.sub.3 or CH.sub.2CH.sub.3 and R.sup.2 is a
branched alkyl group containing 12 to 32 carbon atoms; dispersed in
b) a PSA layer comprising a pressure sensitive adhesive. In some
embodiments, the PSA layer comprises an acrylic pressure sensitive
adhesive. In some embodiments, the PSA layer comprises an acrylic
pressure sensitive adhesive which is a copolymer of acrylic
acid.
[0006] In another aspect, the present disclosure provides a
vibration damping composite comprising a viscoelastic damping
material or a vibration damping composite of the present disclosure
adhered to at least one substrate. In some embodiments, the
material or construction is adhered to at least two substrates. In
some embodiments, at least one substrate is a metal substrate.
DETAILED DESCRIPTION
[0007] The present disclosure provides material sets and
constructions that demonstrate a pressure sensitive adhesive (PSA)
that offers both vibration damping performance at very low
temperatures and high frequencies as well as substantial adhesive
performance and durability when used with a variety of substrates
over a wide range of temperatures. The combination of both low
temperature damping and adhesive performance attained using a
single material set or construction represents a significant
technical challenge in the field of visco-elastic damping
materials. In some embodiments of the present disclosure, this is
achieved through the use of specialty acrylic materials, specific
additives, multi-layer construction, or combinations of the
above.
[0008] The present disclosure provides material sets and
constructions that demonstrate a pressure sensitive adhesive that
offers both vibration damping performance at very low temperatures
and high frequencies as well as substantial adhesive performance
and durability when used with a variety of substrates over a wide
range of temperatures. In some embodiments, materials or
constructions according to the present disclosure exhibit high tan
delta, as measured by Dynamic Mechanical Analysis (DMA) at
-55.degree. C. and 10 Hz as described in the examples below. In
some embodiments, materials or constructions according to the
present disclosure exhibit tan delta (as measured by Dynamic
Mechanical Analysis (DMA) at -55.degree. C. and 10 Hz as described
in the examples below) of greater than 0.5, in some embodiments
greater than 0.8, in some embodiments greater than 1.0, in some
embodiments greater than 1.2, and in some embodiments greater than
1.4. In some embodiments, materials or constructions according to
the present disclosure exhibit high peel adhesion, as measured as
described in the examples below. In some embodiments, materials or
constructions according to the present disclosure exhibit peel
adhesion (as measured as described in the examples below) of
greater than 10 N/dm, in some embodiments greater than 20 N/dm, in
some embodiments greater than 30 N/dm, in some embodiments greater
than 40 N/dm, in some embodiments greater than 50 N/dm, and in some
embodiments greater than 60 N/dm. In some embodiments, materials or
constructions according to the present simultaneously achieve high
tan delta, at one or more of the levels described above, and high
peel strength, at one or more of the levels described above.
[0009] In some embodiments, viscoelastic damping materials
according to the present disclosure include long alkyl chain
acrylate copolymers which are copolymers of monomers including one
or more long alkyl chain acrylate monomers. The long alkyl chain
acrylate monomers are typically acrylic acid, methacrylic acid or
ethacrylic acid esters but typically acrylic acid esters. In some
embodiments, the side chain of the long alkyl chain contains 12 to
32 carbon atoms (C12-C32), in some embodiments at least 15 carbon
atoms, in some embodiments at least 16 carbon atoms, in some
embodiments 22 or fewer carbon atoms, in some embodiments 20 or
fewer carbon atoms, in some embodiments 18 or fewer carbon atoms,
and in some embodiments 16-18 carbon atoms. Typically, the long
alkyl chain has at least one branch point to limit crystallinity in
the formed polymer that may inhibit damping performance. Long chain
alkyl acrylates with no branch points may be used in concentrations
low enough to limit crystallinity of the formed polymer at
application temperatures. In some embodiments, additional
comonomers are selected from acrylic acid, methacrylic acid or
ethacrylic acid, but typically acrylic acid. In some embodiments,
additional comonomers are selected from acrylic, methacrylic or
ethacrylic esters, but typically acrylic esters.
[0010] In some embodiments, the long alkyl chain acrylate
copolymers comprise additional comonomers or additives that join in
the polymerization reaction, which imparting adhesive properties.
Such comonomers may include polyethylene glycol diacrylates.
[0011] In some embodiments, the long alkyl chain acrylate
copolymers comprise additional comonomers or additives that join in
the polymerization reaction, which can help to impart greater
adhesive properties through modulation of the rheological
properties of the viscoelastic damping copolymer, or through the
addition of functional groups. Such comonomers may include but are
not limited to (meth)acrylic acid, hydroxyethyl (meth)acrylate,
dimethylaminoethyl (meth)acrylate, monofunctional silicone
(meth)acrylates, and isobornyl (meth)acrylate.
[0012] In some embodiments, the viscoelastic damping copolymer may
be crosslinked to improve the durability and adhesion properties of
the material. Such crosslinking agents can include but are not
limited to photoactivated crosslinkers such as benzophenones, or
2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-triazine. Crosslinking
agents can also include copolymerizable multifunctional acrylates
such as polyethylene glycol diacrylate or hexanediol diacrylate as
examples.
[0013] In some embodiments the viscoelastic damping copolymer may
be polymerized through all known polymerization methods including
thermally activated or photoinitiated polymerization. Such
photopolymerization processes can include for example common
photoinitiators such as diphenyl (2,4,6-trimethylbenzoyl)-phosphine
oxide.
[0014] In some embodiments, viscoelastic damping materials
according to the present disclosure include long alkyl chain
acrylate copolymers and additional adhesion-enhancing materials
which impart adhesive properties. Such additional
adhesion-enhancing materials may include polybutenes, silicones, or
polyisobutenes. Such additional adhesion-enhancing materials may
also be particulate materials. Such particulate adhesion-enhancing
materials may include fumed silica, core-shell rubber particles, or
isostearyl acrylate microspheres.
[0015] In some embodiments, long alkyl chain acrylate copolymers
according to the present disclosure form a part of a multilayer
viscoelastic construction. In some embodiments, the long alkyl
chain acrylate copolymers according to the present disclosure form
a viscoelastic damping layer of a two-layer viscoelastic
construction, the second, attached layer being a layer of more
highly adhesive material over a broader temperature range. In some
embodiments, the long alkyl chain acrylate copolymers according to
the present disclosure form a viscoelastic damping core layer of a
multilayer viscoelastic construction, sandwiched between two layers
of more highly adhesive material. In some embodiments, the long
alkyl chain acrylate copolymers according to the present disclosure
form a layer of a multilayer viscoelastic construction which
additionally comprises at least one layer of more highly adhesive
material. In some embodiments, the long alkyl chain acrylate
copolymers according to the present disclosure form an interior
layer of a multilayer viscoelastic construction which additionally
comprises at least two layers of more highly adhesive material. In
some embodiments, the more highly adhesive material is an acrylic
PSA material.
[0016] In some embodiments, a two-layer viscoelastic construction
comprises a viscoelastic layer attached to a second layer which is
a layer of more highly adhesive material. In some embodiments, the
two-layer viscoelastic construction is made by lamination of a
viscoelastic layer to an adhesive layer. In some embodiments, the
two-layer viscoelastic construction is made by application of an
adhesive tape to a viscoelastic layer. In some embodiments, the
two-layer viscoelastic construction is made by application of an
adhesive in liquid or aerosolized form to a viscoelastic damping
layer to provide greater adhesion to the damping layer. In some
embodiments, the two-layer viscoelastic construction is made by
application of an adhesive in paste form to a viscoelastic layer.
In some embodiments, a two-layer viscoelastic construction is
provided in the form of a roll, sheet, or pre-cut article. In some
embodiments, a two-layer viscoelastic construction is made shortly
prior to use by application of an adhesive to a viscoelastic layer.
In some embodiments, a two-layer viscoelastic construction is made
in situ by application of an adhesive to a substrate followed by
application of a viscoelastic layer to the adhesive.
[0017] In some embodiments, the multilayer viscoelastic
construction comprises a viscoelastic layer sandwiched between two
layers of more highly adhesive material. In some embodiments, the
multilayer viscoelastic construction is made by lamination of a
viscoelastic layer to at least one adhesive layer. In some
embodiments, the multilayer viscoelastic construction is made by
application of an adhesive tape to at least one side of a
viscoelastic layer. In some embodiments, the multilayer
viscoelastic construction is made by application of an adhesive in
liquid form to at least one side of a viscoelastic layer. In some
embodiments, the multilayer viscoelastic construction is made by
application of an adhesive in paste form to at least one side of a
viscoelastic layer. In some embodiments, a multilayer viscoelastic
construction is provided in the form of a roll, sheet, or pre-cut
article. In some embodiments, a multilayer viscoelastic
construction is made shortly prior to use by application of an
adhesive to a viscoelastic layer. In some embodiments, a multilayer
viscoelastic construction is made in situ by application of an
adhesive to a substrate followed by application of a viscoelastic
layer to the adhesive, followed by application to the viscoelastic
layer of additional adhesive or an additional adhesive-bearing
substrate. In some embodiments, the multilayer construction is made
in-situ by application of the viscoelastic damping composition in
liquid form between two adhesive layers followed by a subsequent
cure of the damping layer to form the viscoelastic damping
copolymer.
[0018] The materials or constructions according to this disclosure
may be useful for aerospace applications in which maximum damping
performance of high frequency vibration energy is required at very
low temperatures, in combination with good adhesion properties.
[0019] Objects and advantages of this disclosure are further
illustrated by the following examples, but the particular materials
and amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this disclosure.
EXAMPLES
[0020] Unless otherwise noted, all reagents were obtained or are
available from Sigma-Aldrich Company, St. Louis, Mo., or may be
synthesized by known methods. Unless otherwise reported, all ratios
are by weight percent.
The following abbreviations are used to describe the examples:
[0021] .degree. F.: degrees Fahrenheit [0022] .degree. C.: degrees
Centigrade [0023] cm: centimeters [0024] g/cm.sup.3: grams per
cubic centimeter [0025] Kg: kilograms [0026] Kg/m.sup.3: kilograms
per cubic meter [0027] mil: 10.sup.-3 inches [0028] mJ/cm.sup.2:
milliJoules per square centimeter [0029] ml: milliliters
[0030] mm: millimeters [0031] .mu.m: micrometers [0032] N/dm:
Newtons per decimeter [0033] pcf: pounds per cubic foot [0034] pph:
parts per hundred
Test Methods
Peel Adhesion Test (PAT)
[0035] The force required to peel the test material from a
substrate at an angle of 180 degrees was measured according to ASTM
D 3330/D 3330M-04. Using a rubber roller, the adhesive sample was
manually laminated onto a primed 2 mil (50.8 .mu.m) polyester film,
obtained under the trade designation "HOSTAPHAN 3SAB" from
Mitsubishi Plastics, Inc., Greer, S.C., and allowed to dwell for 24
hours at 23.degree. C./50% relative humidity. A 0.5.times.6 inches
(1.27.times.12.7 cm) section was cut from the laminated film and
taped to either a 0.10 inch (2.54 mm) or 0.20 inch (5.08 mm) thick,
Shore A 70, 320 Kg/m.sup.3 polyether-polyurethane foam, or a grade
2024 aluminum test coupon, obtained from Aerotech Alloys, Inc.,
Temecula, Calif. The tape was then manually adhered onto the test
coupon using a 2 Kg rubber roller and conditioned for 24 hours at
23.degree. C./50% relative humidity. The peel adhesive force was
then determined using a tensile force tester, model "SP-2000",
obtained Imass Inc., Accord, Massachusetts, at a platen speed of 12
in./min (0.305 m/min.). Three tape samples were tested per example
or comparative, and the average value reported in N/dm. Also
reported are the failure modes, abbreviated as follows: [0036] A:
Adhesive tape cleanly delaminated from the substrate [0037] 2B:
Two-bond failure, wherein the adhesive tape delaminated from the
carrier backing [0038] C: Cohesive failure, wherein the adhesive
layer ruptured, leaving material on both the backing and the
substrate.
Dynamic Mechanical Analysis (DMA)
[0039] Dynamic Mechanical Analysis (DMA) was determined using a
parallel plate rheometer, model "AR2000" obtained from TA
Instruments, New Castle, Del. Approximately 0.5 grams of
visco-elastic sample was centered between the two 8 mm diameter,
aluminum parallel plates of the rheometer and compressed until the
edges of the sample were uniform with the edges of the plates. The
temperature of the parallel plates and rheometer shafts was then
raised to 40.degree. C. and held for 5 minutes. The parallel plates
were then oscillated at a frequency of 10 Hz and a constant strain
of 0.4% whilst the temperature was ramped down to -80.degree. C. at
a rate of 5.degree. C./min. Storage modulus (G'), and tan delta
were then determined.
Glass Transition Temperature (Tg)
[0040] Tan delta, the ratio of G''/G', was plotted against
temperature. Tg is taken as the temperature at maximum tan delta
curve.
Damping Loss Factor (DLF)
[0041] A composite material was prepared for Damping Loss Factor as
follows. A nominally 6 by 48 inch by 7 mil (15.24 by 121.92 cm by
0.178 mm) strip of aluminum was cleaned with a 50% aqueous solution
of isopropyl alcohol and wiped dry. A primer, type "LORD 7701",
obtained from Lord Corporation, Cary, N.C., was applied to a
nominally 6 by 48 by 0.1 inch (15.24 by 121.92 cm by 2.54 mm) strip
of 20 pcf (0.32 g/cm.sup.3) white foraminous micro cellular high
density polyurethane foam. The adhesive tape was applied to the
aluminum strip, nipped together to ensure wet out, then applied to
the primed surface of the high density urethane. A 5 mil (127
.mu.m) adhesive transfer tape, obtained under the trade designation
"VHB 9469PC" obtained from 3M Company, St. Paul, Minn., was then
applied on the opposite side of the urethane strip. The resulting
composite material cut into 2 by 24 inch (5.08 by 60.96 cm) samples
and applied to a 3.times.40 inch.times.0.062 mil (7.62.times.101.4
cm.times.1.58 mm) aluminum beam.
[0042] The beam was suspended by its first nodal points, and the
center of the beam mechanically coupled to an electromagnetic
shaker model "V203" from Bruel & Kjaer North America, Inc.,
Norcross, Ga., via an inline force transducer, model "208M63" from
PCB Piezotronics, Inc., Depew, New York, in a thermally controlled
chamber at temperatures of -10.degree. C., -20.degree. C. and
-30.degree. C. On the opposite side of the beam to the inline force
transducer was mounted an accelerometer, model "353B16 ICP", also
from Piezotronics, Inc. A broad band signal was sent to the
electromagnetic shaker and the force the shaker excerpted on the
beam was measured, as was the resulting acceleration of the beam.
The frequency response function (FRF) was calculated from the cross
spectrum of the measured acceleration and force, and from the
magnitude of the FRF, peak amplitudes were used to identify the
modal frequencies. The half power bandwidth around each modal
frequency was also identified as the span of frequencies between
the -3 dB amplitude points above and below the modal frequency. The
ratio of the half power bandwidth to modal frequency was calculated
and reported as the Damping Loss Factor.
Materials
[0043] Abbreviations for the reagents used in the examples are as
follows: [0044] A-75: A benzoyl peroxide, obtained under the trade
designation "LUPEROX A75" from Arkema, Inc. Philadelphia, Pa.
[0045] AA: Acrylic acid, obtained from Sigma-Aldrich Company, St.
Louis, Mo. [0046] BDDA: 1,4-butanediol diacrylate, obtained under
the trade designation "SR213" from Sartomer, USA, LLC, Exton, Pa.
[0047] DMAEMA: N,N-dimethylaminoethylmethacrylate, obtained from
Sigma-Aldrich Company. [0048] E-920: A
methacrylate-butadiene-styrene copolymer, obtained under the trade
designation "CLEARSTRENGTH E-920" from Arkema, Inc., King of
Prussia, Pa. [0049] F-85E: Ester of hydrogenated rosin, obtained
under the trade designation "FORAL 85-E" from Eastman Chemical
Company, Kingsport, Tenn. [0050] HDDA: 1,6-hexanediol diacrylate,
obtained under the trade designation "SR238B" from Sartomer, USA,
LLC. [0051] I-651: 2,2-Dimethoxy-1,2-diphenylethan-1-one, obtained
under the trade designation "IRGACURE 651" from BASF Schweiz AG,
Basel, Switzerland. [0052] IOA: Isooctyl acrylate, obtained under
the trade designation "SR440" from Sartomer, USA, LLC. [0053]
IOTMS: Isooctyltrimethoxysilane, obtained from Gelest, Inc.,
Morrisville, Pa. [0054] ISF-16: 2-hexyldecanol, obtained under the
trade designation "ISOFOL 16" from Sasol North America, Inc.,
Houston, Tex. [0055] ISF-18: 2-hexyldodecanol, obtained under the
trade designation "ISOFOL 18" from Sasol North America, Inc. [0056]
ISF-24: 2-decyltetradecanol, obtained under the trade designation
"ISOFOL 24" from Sasol North America, Inc. [0057] KB-1:
2,2-dimethoxy-1,2-di(phenyl)ethanone, obtained under the trade
designation "ESACURE KB1" from Lamberti USA, Inc., Conshohocken,
Pa. [0058] L-26M50: A 50% solution of tert-butyl
peroxy-2-ethylhexanoate in mineral spirits, obtained under the
trade designation "LUPEROX 26M50" from Arkema Inc. [0059] MTMS:
Methyltrimethoxysilane, obtained from Gelest, Inc. [0060] N2326: A
16.4% colloidal silica dispersion, obtained under the trade
designation "NALCO 2326" from Nalco Company, Naperville, Ill.
[0061] PB-100: Polyisobutene having a molecular weight of 250,000
obtained under the trade designation "OPPANOL B-100" from BASF
Corporation, Freeport, Tex. [0062] PB-910: Polybutene, having a
molecular weight of 910, obtained under the trade designation
"INDOPOL H-100" from Ineos Oligomers, League City, Tex. [0063]
PB-1000: Polyisobutene having a molecular weight of 1,000 obtained
under the trade designation "GLISSOPAL R-1000" from BASF
Corporation. [0064] PB-1900: Polybutene having a molecular weight
of 2,500 obtained under the trade designation "INDOPOL H-1900" from
BASF Corporation. [0065] PEGDA: Polyethylene glycol (600)
diacrylate, obtained under the trade designation "SR610" from
Sartomer, USA, LLC. [0066] R-100: A random butadiene-styrene
copolymer, obtained under the trade designation "RICON 100" from
Sartomer, USA, LLC. [0067] R-972: A hydrophobic fumed silica,
obtained under the trade designation "AEROSIL R-972" from Evonik
Degussa Corporation, Parsippany, New Jersey. [0068] RC-902: A
radiation curable silicone, obtained under the trade designation
"TEGO RC-902" from Evonik Degussa Corporation. [0069] S-1001:
Styrene Ethylene Propylene Block Copolymer, obtained under the
trade designation "SEPTON 1001" from Kuraray Co. Ltd., Tokyo,
Japan. [0070] SAMV: Ammonium lauryl sulfate, obtained under the
trade designation "STEPANOL AMV" from Stepan Company, Northfield,
Illinois. [0071] T-10: Clear silicone release liner, obtained under
the trade designation "CLEARSIL T-10" from Solutia, Inc. St. Louis,
Mo. [0072] T-50: Clear silicone release liner, obtained under the
trade designation "CLEARSIL T-50" from Solutia, Inc. [0073] T-145A:
Silicone resin, obtained under the trade designation "TOSPEARL
145A" from Momentive Performance Materials Holdings, LLC, Columbus
Ohio. [0074] TMT:
2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-triazine. [0075] TPO:
Diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide, obtained under
the trade designation "DAROCUR TPO" from BASF Schweiz AG. [0076]
467-MP: A 2 mil. (50.8 .mu.m) adhesive transfer tape having a paper
liner, obtained under the trade designation "ADHESIVE TRANSFER TAPE
467 MP" from 3M Company. [0077] 467-MPF: A 2 mil. (50.8 .mu.m)
adhesive transfer tape having a film liner, obtained under the
trade designation "ADHESIVE TRANSFER TAPE 467 MPF" from 3M Company
Non-commercial materials described in the examples were synthesized
as follows: [0078] HEDA: 2-hexa-1-decyl acrylate. 100 grams of
2-hexyl-1-decanol, 45.97 grams triethylamine and 350 grams of
methylene chloride were added to a 1 liter flask and cooled to
5.degree. C. using an ice bath. 41.1 grams acryloyl chloride was
slowly added, dropwise over one hour, while mechanically stirring
the mixture. After 10 hours the mixture was filtered and then
concentrated under vacuum at 25.degree. C. The remaining resultant
oil was diluted with ethyl acetate and washed with 1.0 Molar
hydrochloric acid, followed by 1.0 Molar sodium hydroxide solution,
then a saturated sodium chloride solution. The organic layer was
then concentrated under vacuum at 25.degree. C. The crude oil was
mixed with an equal amount of hexane and passed through a column of
neutral alumina to remove colored impurities, after which the
alumina was eluted with hexane. The collected filtrate was
concentrated under vacuum at 25.degree. C., resulting in a
colorless oil of 2-hexa-1-decyl acrylate. [0079] ISA: An isostearyl
acrylate. 197.17 grams ISF-18, 78.12 grams triethylamine and 700
grams of methylene chloride were added to a 2 liter flask and
cooled to 5.degree. C. using an ice bath. 69.86 grams acryloyl
chloride was slowly added, dropwise over one hour, while
mechanically stirring the mixture. After 10 hours the mixture was
filtered and then concentrated under vacuum at 25.degree. C. The
remaining resultant oil was diluted with ethyl acetate and washed
with 1.0 Molar hydrochloric acid, followed by 1.0 Molar sodium
hydroxide solution, then a saturated sodium chloride solution. The
organic layer was then concentrated under vacuum at 25.degree. C.
The crude oil was mixed with an equal amount of hexane and passed
through a column of neutral alumina to remove colored impurities,
after which the alumina was eluted with hexane. The collected
filtrate was concentrated under vacuum at 25.degree. C., resulting
in a colorless oil of 100% isostearyl acrylate. [0080] ISA-MS:
Isostearyl acrylate microspheres. Mixture A was prepared by adding
180 grams ISA, 0.58 grams A-75 and 1.8 grams BDDA to a 500 ml glass
jar and mixed in a roller mill until dissolved. Mixture B was
prepared by adding to a 1 liter glass beaker, 420 grams distilled
water, 7.2 grams SAMV and 1.8 grams BDDA, and dispersing until
homogeneous using a high shear mixer, model "OMNI-MIXER" from OCI
Instruments, Waterbury, Conn. Mixture A was then added to the glass
beaker and high shear mixing continued for approximately 2 minutes
until very small droplets of about 3 microns diameter were formed.
The product was then transferred to a 1 liter glass reactor
equipped with a mechanical stirrer. The reactor was filled with
nitrogen gas, heated to 65.degree. C., and held at this
temperature, with continuous stirring, for 24 hours, after which it
was cooled to 23.degree. C. The resulting suspension was filtered
through a cheese cloth to remove agglomerates and coagulated using
500 mls isopropanol. The coagulum was then dried in an oven at
45.degree. C. for approximately 16 hours.
Single-Layer Constructions
Sample 1
[0081] A 25 dram (92.4 mls) glass jar was charged with 19.6 grams
HEDA, 0.4 grams AA and 0.008 grams I-651. The monomer mixture was
stirred for 30 minutes at 21.degree. C., purged with nitrogen for 5
minutes, and then exposed to low intensity ultraviolet light, type
"BLACK RAY XX-15BLB" obtained from Fisher Scientific, Inc.,
Pittsburgh, Pa., until a coatable pre-adhesive polymeric syrup was
formed. An additional 0.032 grams I-651 and 0.03 grams PEGDA were
blended into the polymeric syrup using a high speed mixer, model
"DAC 150 FV" obtained from FlackTek, Inc., Landrum, S.C. The
polymeric syrup was then coated between silicone release liners
T-10 and T-50 at an approximate thickness of 8 mils (203.2 .mu.m)
and cured by means of UV-A light at 2,000 mJ/cm.sup.2.
Samples 2-6
[0082] The procedure generally described in Sample 1 was repeated,
according to the quantities of acrylate monomers listed in Table 1.
Physical characteristics of the resultant cured adhesive coatings
are listed in Table 2.
TABLE-US-00001 TABLE 1 Composition Additives (as pph of % Acrylate
Acrylate) Sample HEDA IOA ISA AA I-651 PEGDA 1 98.0 0 0 2.0 0.20
0.23 2 93.5 0 0 6.5 0.20 0.23 3 0 0 98.0 2.0 0.20 0.23 4 100.0 0 0
0 0.20 0.23 5 0 0 100.0 0 0.20 0.23 6 0 93.5 0 6.5 0.20 0.23
TABLE-US-00002 TABLE 2 Adhesion To Adhesion To Polyurethane
Aluminum Peel Peel Adhesive Fail- Adhesive Fail- Storage Tan Sam-
Force ure Force ure Modulus Delta ple (N/dm) Mode (N/dm) Mode @
-55.degree. C. @ -55.degree. C. 1 26 A 21 A 3.3 .times. 10.sup.6
0.96 2 21 A 48 A 2.0 .times. 10.sup.7 0.72 3 24 A 15 A 1.3 .times.
10.sup.7 1.09 4 3 C 3 C 1.1 .times. 10.sup.6 1.50 5 10 A 4 A 3.5
.times. 10.sup.6 1.36 6 25 A 64 A 3.1 .times. 10.sup.8 0.10
Sample 7
[0083] A 25 dram (92.4 mls) glass jar was charged with 19.6 grams
HEDA, 0.4 grams AA and 0.008 grams I-651. The monomer mixture was
stirred for 30 minutes at 21.degree. C., purged with nitrogen for 5
minutes, and exposed to the low intensity ultraviolet light until a
coatable pre-adhesive polymeric syrup was formed. An additional
0.032 grams I-651, 0.046 grams PEGDA and 2.0 grams R-972 were
subsequently blended into the polymeric syrup using the high speed
mixer. The polymeric syrup was then coated between silicone release
liners at an approximate thickness of 8 mils (203.2 .mu.m) and
cured by means of UV-A light at 2000 mJ/cm.sup.2.
Samples 8-33
[0084] The procedure generally described in Sample 7 was repeated,
wherein various amounts of fumed silica, plasticizer, polybutenes,
polyisobutenes, silicones, core-shell rubber particles and
isostearyl acrylate microspheres, were blended into the
pre-adhesive polymeric syrup according to the quantities listed in
Table 3. Physical characteristics of the resultant cured adhesive
coatings are listed in Table 4.
TABLE-US-00003 TABLE 3 Composition % Acrylate Additives (as pph of
Acrylate) Sample HEDA AA ISA R-972 PEGDA TMT ISF-24 PB-910 PB-1000
PB-1900 7 99.0 1.0 0 10.0 0.23 0 0 0 0 0 8 98.0 2.0 0 7.0 0.23 0 0
0 0 0 9 98.0 2.0 0 10.0 0.23 0 0 0 0 0 10 98.0 2.0 0 13.0 0.23 0 0
0 0 0 11 0 2.0 98.0 7.0 0.23 0 0 0 0 0 12 0 2.0 98.0 10.0 0.23 0 0
0 0 0 13 93.5 5.0 0 10.0 0.23 0 0 0 0 0 14 98.0 2.0 0 10.0 0.23 0
4.0 0 0 0 15 98.0 2.0 0 10.0 0.23 0 5.0 0 0 0 16 98.0 2.0 0 0 0.20
0 0 0 5.0 0 17 98.0 2.0 0 5.0 0.20 0 0 0 5.0 0 18 98.0 2.0 0 5.0
0.20 0 0 0 10.0 0 19 98.0 2.0 0 5.0 0.20 0 0 5.0 0 0 20 98.0 2.0 0
5.0 0.20 0 0 0 0 5.0 21 98.0 2.0 0 5.0 0 0.15 0 0 15.0 0 22 98.0
2.0 0 5.0 0.20 0 0 0 5.0 0 Composition % Acrylate Additives (as pph
of Acrylate) Sample HEDA AA IOA ISA-MS PEGDA TMT T-145A RC-902 HDDA
E-920 23 0 6.5 93.5 0 0 0 5.0 0 0 0 24 0 6.5 93.5 0 0 0 10.0 0 0 0
25 93.5 6.5 0 0 0 0 5.0 0 0 0 26 98.0 2.0 0 0 0 0 0 10.0 0.08 0 27
98.0 2.0 0 0 0.20 0 0 0 0 10.0 28 98.0 2.0 0 0 0 0.15 0 0 0 5.0 29
0 6.5 93.5 5.0 0.23 0 0 0 0 0 30 0 6.5 93.5 10.0 0.23 0 0 0 0 0 31
93.5 6.5 0 10.0 0.23 0 0 0 0 0 Composition % Acrylate Additives (as
pph of Acrylate) Sample HEDA AA IOA PEGDA HDDA PB-100 S-1001 D-TPO
32 100.0 0 0 0 0.1 6.0 0 0.3 33 100.0 0 0 0 0.1 0 10.0 0.3
TABLE-US-00004 TABLE 4 Adhesion To Adhesion To Polyurethane
Aluminum Peel Peel Adhesion Fail- Adhesion Fail- Storage Tan Sam-
Force ure Force ure Modulus Delta ple (N/dm) Mode (N/dm) Mode @
-55.degree. C. @ -55.degree. C. 7 2 A 1 A 1.4 .times. 10.sup.6 1.67
8 22 A 35 A 1.2 .times. 10.sup.7 0.96 9 26 A 27 A 4.0 .times.
10.sup.7 0.92 10 23 A 24 A 3.6 .times. 10.sup.7 0.89 11 153 C 120 C
1.8 .times. 10.sup.7 1.04 12 55 2B 77 2B 1.3 .times. 10.sup.7 1.01
13 24 A 47 2B 2.9 .times. 10.sup.7 0.64 14 96 C 92 C 2.6 .times.
10.sup.7 0.97 15 76 C 69 C 1.8 .times. 10.sup.6 0.95 16 26 A 22 A
1.5 .times. 10.sup.6 1.15 17 85 A 88 2B 7.7 .times. 10.sup.6 1.13
18 77 C 79 C 1.1 .times. 10.sup.7 1.22 19 57 A 39 A 8.1 .times.
10.sup.6 1.15 20 55 A 39 A 1.4 .times. 10.sup.7 1.08 21 54 A 48 A
8.4 .times. 10.sup.6 1.30 22 125 C 56 A 9.1 .times. 10.sup.6 1.04
23 16 A 37 A 3.5 .times. 10.sup.8 0.58 24 18 A 36 A 3.8 .times.
10.sup.8 1.26 25 20 A 22 A 3.0 .times. 10.sup.7 0.70 26 1 A 0 A 1.3
.times. 10.sup.6 1.16 27 16 A 12 A 7.2 .times. 10.sup.6 1.01 28 15
A 16 A 1.4 .times. 10.sup.7 1.06 29 31 A 77 A 2.7 .times. 10.sup.6
1.10 30 28 A 97 A 3.2 .times. 10.sup.6 1.10 31 26 A 68 A 5.2
.times. 10.sup.5 0.86 32 5 A 4 A 4.8 .times. 10.sup.6 1.35 33 2 A 3
A 7.7 .times. 10.sup.6 1.18
Visco-Elastic Core VEC-1
[0085] A 25 dram (92.4 mls) glass jar was charged with 19.8 grams
HEDA, 0.2 grams DMAEMA and 0.008 grams I-651. The monomer mixture
was stirred for 30 minutes at 21.degree. C., purged with nitrogen
for 5 minutes, and exposed to the low intensity ultraviolet light
until a coatable pre-adhesive polymeric syrup was formed. An
additional 0.032 grams I-651 and 0.03 grams TMT were subsequently
blended into the polymeric syrup using the high speed mixer. The
polymeric syrup was then coated between silicone release liners
T-10 and T-50 at an approximate thickness of 8 mils (203.2 .mu.m)
and cured by means of UV-A light at 2,000 mJ/cm.sup.2.
Visco-Elastic Cores VEC-2-VEC-10
[0086] The procedure generally described in VEC-1 was repeated,
according to the compositions listed in Table 5. With respect to
VEC-6, the nominal thickness was 16 mils (406.4 .mu.m). Physical
characteristics of the visco-elastic cores are listed in Table
6.
TABLE-US-00005 TABLE 5 Composition Additives Visco-Elastic %
Acrylate (as pph of Acrylate) Core HEDA ISA IOA DMAEMA TMT PEGDA
VEC-1 99.0 0 0 1.0 0.15 0 VEC-2 98.0 0 0 2.0 0.15 0 VEC-3 96.0 0 0
4.0 0.15 0 VEC-4 0 96.0 0 4.0 0 0.23 VEC-5 0 0 96.0 4.0 0 0.23
VEC-6 0 96.0 0 4.0 0.15 0 VEC-7 0 90.0 10.0 0 0.15 0 VEC-8 0 100.0
0 0 0.15 0 VEC-9 0 0 100.0 0 0.15 0 VEC-10 0 75.0 25.0 0 0.15 0
TABLE-US-00006 TABLE 6 Core Thickness Storage Modulus Tan Delta
Visco-Elastic Core mils (.mu.m) @ -55.degree. C. @ -55.degree. C.
VEC-1 8 (203.2) 2.4 .times. 10.sup.6 1.33 VEC-2 8 (203.2) 3.2
.times. 10.sup.6 1.32 VEC-3 8 (203.2) 5.1 .times. 10.sup.6 1.32
VEC-4 8 (203.2) 6.0 .times. 10.sup.6 1.36 VEC-5 8 (203.2) 2.6
.times. 10.sup.8 0.13 VEC-6 16 (406.4) 5.9 .times. 10.sup.6 1.37
VEC-7 8 (203.2) 1.0 .times. 10.sup.7 1.35 VEC-8 8 (203.2) 1.1
.times. 10.sup.7 1.34 VEC-9 8 (203.2) 2.6 .times. 10.sup.8 0.14
VEC-10 8 (203.2) 1.6 .times. 10.sup.7 1.26
Multi-Layer Constructions
Adhesive Skin SKN-1
[0087] A one quart (946 mls.) glass jar was charged with 372 grams
IOA, 28 grams AA and 0.16 grams I-651. The monomer mixture was
stirred for 30 minutes at 21.degree. C., purged with nitrogen for 5
minutes, and exposed to the low intensity (0.3 mW/cm.sup.2)
ultraviolet light until a coatable pre-adhesive polymeric syrup was
formed. An additional 0.64 grams I-651 and 0.6 grams TMT were
subsequently blended into the polymeric syrup using the high speed
mixer. The polymeric syrup was then coated between silicone release
liners T-10 and T-50 at an approximate thickness of 1 to 2 mils
(25.4-50.8 .mu.m) and cured by means of UV-A light at 1,500
mJ/cm.sup.2.
Adhesive Skins SKN-2-SKN-4
[0088] The procedure generally described in SKN-1 was repeated,
according to the monomer and tackifier compositions listed in Table
7.
TABLE-US-00007 TABLE 7 Composition Additives (as pph of Adhesive %
Acrylate Acrylate) Skin IOA AA TMT F-85E SKN-1 93.0 7.0 0.15 0
SKN-2 95.0 5.0 0.15 0 SKN-3 93.0 7.0 0.15 20.0 SKN-4 90.0 10.0 0.10
0
Sample 34
[0089] Adhesive skin SKN-1 was laid on a clean 12 by 48 by 0.5-inch
(30.5 by 121.9 by 1.27 cm) glass plate and the upper silicone
release liner removed. One of the silicone release liners was
removed from a sample of visco-elastic core VEC-3, and the exposed
surface of the core laid over the exposed adhesive skin of SKN-1.
The core and skin were then laminated together by manually applying
a hand roller over the release liner of the visco-elastic core. The
release liner covering the visco-elastic core removed, as was a
release liner of another sample of adhesive skin SKN-1. The skin
was then laminated onto the exposed core by means of the hand
roller, resulting in a SKN-1:VEC-3:SKN-1 laminate. The laminate was
then allowed to dwell for 24 hours at 50% RH and 70.degree. F.
(21.1.degree. C.) before testing.
Samples 35-42
[0090] The procedure generally described in Sample 34 was repeated,
according to the adhesive skin and visco-elastic core constructions
listed in Table 8. With respect to Sample 42, the adhesive skin is
represented by adhesive transfer tape 467-MP/467-MPF. Physical
characteristics of the resultant multi-layer constructions are also
presented in Table 8.
Sample 43
[0091] A one quart jar glass jar was charged with 405 grams ISA, 45
grams IOA and 0.18 grams I-651, corresponding to the composition
"VEC-7" of Table 5. The monomer mixture was stirred for 30 minutes
at 21.degree. C., purged with nitrogen for 5 minutes, and exposed
to the low intensity ultraviolet light until a coatable
pre-adhesive polymeric syrup was formed. An additional 0.72 grams
I-651 and 0.675 grams TMT were subsequently blended into the
polymeric syrup using the high speed mixer. The polymeric syrup was
then coated between layers of adhesive transfer tapes 467-MP and
467-MPF, at an approximate thickness of 8 mils (203.2 .mu.m), and
cured by means of UV-A light exposure through the 467-MPF side at
2,000 mJ/cm.sup.2.
Samples 44-46
[0092] The procedure generally described in Sample 43 was repeated,
according to the compositions for VEC-8, VEC-9 and VEC-10,
respectively, listed in Table 5. Physical characteristics of the
visco-elastic cores and of the resultant multi-layer constructions
are listed in Table 7 and Table 8, respectively.
TABLE-US-00008 TABLE 8 Adhesion To Adhesion To Polyurethane
Aluminum Visco- Adhesion Adhesion Adhesive Elastic Peel Force
Failure Peel Force Failure Sample Skin Core (N/dm) Mode (N/dm) Mode
34 SKN-1 VEC-3 92 A 77 A 35 SKN-2 VEC-3 39 A 59 A 36 SKN-1 VEC-2 46
A 59 A 37 SKN-1 VEC-1 44 A 59 A 38 SKN-3 VEC-3 55 A 83 A 39 SKN-4
VEC-3 81 A 83 A 40 SKN-4 VEC-4 88 2B 77 2B 41 SKN-4 VEC-6 68 A 63 A
42 467- VEC-5 70 A 112 A MP/MPF 43 467- VEC-7 45 2B 39 2B MP/MPF 44
467- VEC-8 37 C 39 C MP/MPF 45 467- VEC-9 47 A 49 A MP/MPF 46 467-
VEC-10 53 C 51 C MP/MPF
Damping Performance
[0093] DLF values were determined for selected adhesive samples
according to the test method described above. Results are listed in
Table 9.
TABLE-US-00009 TABLE 9 Number Sam- of Loss Factor @ -10.degree. C.
Loss Factor @ -20.degree. C. ple Layers 120 Hz 400 Hz 800 Hz 120 Hz
400 Hz 800 Hz 2 1 0.21 0.23 0.21 0.13 0.16 0.17 15 1 0.18 0.21 0.21
0.12 0.14 0.15 39 3 0.27 ND ND 0.23 0.27 ND 40 3 0.27 0.26 ND 0.24
ND ND 41 3 0.23 0.16 0.12 0.30 0.28 ND 42 3 0.17 0.20 0.21 0.07
0.07 0.08 43 3 0.26 0.20 0.17 0.27 0.16 0.18 ND = Not
detectable
[0094] Various modifications and alterations of this disclosure
will become apparent to those skilled in the art without departing
from the scope and principles of this disclosure, and it should be
understood that this disclosure is not to be unduly limited to the
illustrative embodiments set forth hereinabove.
* * * * *