U.S. patent application number 11/149729 was filed with the patent office on 2006-03-23 for reinforcement for composite materials and method for making the reforcement.
Invention is credited to James W. Freitag, Donald W. Taylor.
Application Number | 20060062998 11/149729 |
Document ID | / |
Family ID | 35219669 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060062998 |
Kind Code |
A1 |
Taylor; Donald W. ; et
al. |
March 23, 2006 |
Reinforcement for composite materials and method for making the
reforcement
Abstract
A reinforced composite structure is disclosed comprising at
least a reactive resin, thermosetting system or other suitable
resin composition sandwiched between two metal, thermoplastic or
ceramic substrate materials. The structure can also be modified
through the addition of one or more fabrics, metallic meshes,
fibers, polymer spacers or other suitable materials positioned
within the resin composition and sandwiched between the substrate
materials. The resulting structure comprises a composite with
reduced thickness and weight as compared to solid metal panels of
corresponding flexural strength. The composition of the structure
also allows for the tailoring of the properties to affect sound
abatement, insulation, strength, and toughness among other
characteristics. The structure can be formed and cut to shape to
fit any of a number of suitable applications such as ceiling tiles
and bulkhead panels in marine vessels.
Inventors: |
Taylor; Donald W.; (Liberty,
MO) ; Freitag; James W.; (Kearney, MO) |
Correspondence
Address: |
ORSCHELN MANAGEMENT CO
P O BOX 280
2000 US HIGHWAY 63 SOUTH
MOBERLY
MO
65270
US
|
Family ID: |
35219669 |
Appl. No.: |
11/149729 |
Filed: |
June 10, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60579051 |
Jun 10, 2004 |
|
|
|
60625051 |
Nov 3, 2004 |
|
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Current U.S.
Class: |
428/364 |
Current CPC
Class: |
B32B 5/022 20130101;
B32B 15/08 20130101; C08G 59/4207 20130101; B32B 2307/304 20130101;
B32B 2311/24 20130101; B32B 2307/102 20130101; B32B 2262/101
20130101; B32B 2605/12 20130101; B32B 27/40 20130101; B32B 25/14
20130101; B32B 2307/558 20130101; Y10T 428/2913 20150115; B32B
2250/03 20130101; B32B 2262/02 20130101; B32B 2607/02 20130101;
D01F 6/66 20130101; B32B 2250/40 20130101; C08J 2363/00 20130101;
B32B 15/06 20130101; C08J 5/24 20130101; B32B 2419/04 20130101;
B32B 15/20 20130101; B32B 2305/08 20130101; B32B 15/14
20130101 |
Class at
Publication: |
428/364 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Claims
1) A composite comprising at least one heat cured epoxy composition
that is reinforced with at least one fibrous composition and
located between two substrates.
2) The composite of claim 1 wherein the substrates comprise
aluminum.
3) The composite of claim 1 wherein the heat cured epoxy
composition further comprises a curing agent comprising at least
one metal acrylate.
4) The composite of claim 3 wherein the metal acrylate comprises
zinc diacrylate.
5) A fiber comprising a heat curable epoxy functional compound and
at least one metal acrylate curing agent.
6) The fiber of claim 5 wherein the fiber is substantially free of
at least one member selected from the group consisting of
polyamides, dicyandiamides, imidizoles, imidizole compounds,
amines, ureas, substituted ureas, boron trifluoride and complexes,
polysulfides, anhydrides, melamines, amidoamines, and
phenol/formaldehyde.
7) The fiber of claim 5 wherein the metal acrylate curing agent
comprises zinc diacrylate.
8) The composite of claim 1 wherein the fibrous composition
comprises the fiber of claim 7.
9) The fiber of claim 5 further comprising at least one phenoxy
resin.
10) The composite of claim 1 wherein the fibrous composition
comprises fiberglass.
Description
CROSS REFERENCE TO RELATED PATENT AND PATENT APLICATIONS
[0001] The subject matter of the instant invention is related to
U.S. patent application Ser. No. 10/729,339, filed on Dec. 4, 2003;
application Ser. No. 10/978,081, filed on Oct. 27, 2004; and
application Ser. No. 11/003,758, filed on ______; all hereby
incorporated by reference.
[0002] This application claims the benefit of Provisional
Application No. 60/579,051, filed on Jun. 10, 2004 and Provisional
Application No. 60/625,051, filed on Nov. 3, 2004. The disclosure
of these Provisional Applications is hereby incorporated by
reference.
FIELD OF THE INVENTION
[0003] The subject matter of this invention relates to composite
structures, and reinforcement compositions and methods for making
the reinforcement compositions. The subject matter of this
invention also relates to fibrous materials that can be used as
reinforcement materials, among other uses.
BACKGROUND OF THE INVENTION
[0004] Solid aluminum ceiling tiles have traditionally been used in
marine vessels. Replacing these aluminum ceiling tiles and possibly
other similar products or materials within a ship with composite
materials may reduce the overall weight of the ship. Other
composite reinforcement applications comprise bulkheads (marine
& aircraft), tractor trailers, industrial sheet metal, air
conditioning duct, repair patch aircraft or industrial, automotive,
appliances, pipes and pipe-lines, storage tanks, recreational
vehicles, among applications. Composite materials may also bring
other added benefits such as, inter alia, sound abatement, added
toughness, increased insulation, among other properties.
SUMMARY OF THE INVENTION
[0005] In one aspect, the instant invention enhances properties
(e.g., mechanical properties) of panels traditionally composed of
sheets or plates (with or without a cosmetic or paint coating), by
replacing them with a reinforced composite structure. The
reinforced composite structure comprises at least one reinforcing
material comprising at least one member selected from the group
consisting of an epoxy (or epoxy functional compounds), a polyester
or other suitable resin composition (which optionally can embed or
contact in at least one of fabrics, metallic meshes, polymer
spacers, among other suitable materials), that is positioned (e.g.,
"sandwiched") between sheets or plates. The sheets or plates can
comprise any suitable material such as metals ceramics, among other
materials. The sheets or plates can be subsequently processed into
a wide range of configurations (e.g., the structure may allow for
increased formability and/or easier cutting and shaping, allowing
the composite structure to be cut or shaped into a virtually
unlimited array of configurations).
[0006] The resultant composite comprises a layered structure which
can have a reduced thickness compared to the traditional solid
metal sheet (e.g., the reinforcing material between the metal
sheets permits using relatively thin metal). The composite
structure's properties can be tailored to meet the requirements for
a wide range of end uses. Properties that may be modified comprise
at least one of weight, sound abatement, insulation, tear strength,
toughness, stiffness, formability, flame retardence, among other
properties.
[0007] Another aspect of the invention relates to a fibrous
material. The inventive fibrous material can be reactive and
incorporate a curing resin system (e.g., the fiber is comprised of
a reactive resin and a curing agent), embedded within the
aforementioned reinforcing material, among other uses.
DETAILED DESCRIPTION
[0008] The invention comprises a reinforced composite structure
comprising at least one substrate, at least one reactive resin
system, at least one reinforcing material, among other components
that can aid in tailoring the properties of the resultant
structure. The reinforcing material is position between at least
two substrates or "sandwiched" by substrates. If desired, the
reinforcing material can comprise a fibrous structure that is
embedded by a thermosetting composition (e.g., a blend comprising
an epoxy functional compound). The fibrous structure can optionally
be embedded within the reinforcing material or reactive resin
system.
[0009] The substrate may comprise ferrous or nonferrous metals or
alloys comprising at least one member selected from the group
consisting of aluminum beryllium, brass, bronze, copper, lead,
magnesium, molybdenum, nickel, steel, stainless steel, tin,
titanium or thermoplastic materials such as ABS polymers, AES
polymers, ASA polymers, cyclo olefin polymers, acetal, acrylic,
cellulose, fluoro polymers, ethylene vinyl acetate, ethylene butyl
acrylate, ethylene methyl acrylate, polyamide-imide, polyarylamide,
polyaryl sulfone, polycarbonate, polyesters, polystyrene,
polyurethane, polyolefins, and blends thereof, or ceramic materials
such as aluminum nitride, boride, carbide, halide, nitride,
oxide-aluminum, oxide-magnesium, oxide-silicon, oxide-titanium,
oxide-zirconium, among others. The substrate material may be foil
(e.g., about 0.08 mm thick), or relatively thick (e.g., up to about
10 mm thick), but typically should be of adequate thickness to
provide sufficient strength to prevent tearing in processing or
application (e.g., typically about 0.4 mm to about 1.5 mm
thick).
[0010] A reinforcing material comprising at least one resin
composition can be formulated to enhance toughness, strength,
stiffness, insulation, sound dampening, conductivity, impact
resistance, corrosion protection or other properties required by
the intended application. The resin can also be formulated to
enable the composite structure to be more formable. The reactive
resin system can have a relatively high expansion, a low to high
modulus of elasticity, low to high energy absorbent, have flame
retardence, among other selected properties. The resin composition
can be employed as a single or multiple layers. The reactive resin
or thermosetting system can be 1-part, 2-part, room temperature or
force dried, heat, ultraviolet, EB, sonic wave or microwave
activated and may be composed of single or multiple parts that may
be extruded, powder coat, pumpable, gel, spray-on, wipe-on, paste,
filament or any other formation and application methods. Resin
compositions such as the resin described in U.S. Pat. Nos.
6,638,590; 6,110,999; 6,461,691 and U.S. patent application Ser.
Nos. 10/375,555; 10/729,339; 10/268,309; the disclosure of by which
is hereby incorporated by reference, acrylics including monomers
and their methacrylate counterparts (with or without functional
groups), acrylic acrylates, acrylic functional materials, alkyds,
diallyl phthalates, epoxies, epoxy esters, epoxy functional
materials, fluoropolymers, furans, melamines, oligomers such as
amine modified polyether acrylates, epoxy acrylates and
methacrylates, functional acrylics, polyester acrylates, urethane
acrylates, methacrylates, among other oligomers, phenolics,
phenoxy, polybutadiene (with and without functional groups),
polyesters, polyimides, polyurethanes, silicones (with or without
functional groups), silicone acrylates, SMC, vinyl esters and
blends thereof may be used depending on the desired properties of
the resulting composite.
[0011] In one aspect of the invention, the substrate comprises
aluminum or aluminum alloy panels or sheets and the reinforcing
resin comprises an epoxy cured with at least one metallic acrylate
(e.g., zinc diacrylate). The instant invention permits making a
composite with aluminum substrates with minimal or no preparation
of the aluminum surface. If desired, the epoxy can be modified with
at least one polymer to provide a more flexible composite.
[0012] The amount and thickness of the resin will vary with the
desired properties. While any suitable thickness can be employed,
when the composite comprises a structural component the thickness
normally ranges from about 0.05 mm to about 0.5 mm. Sound dampening
applications may employ a resin thickness of about 0.5 mm to about
10 mm. The use of internal fabric or mesh layers or other spacers
(as described below) can reduce the amount of resin composition
needed, produce an even bond line, reduce cost associated with the
resin composition, among other advantages.
[0013] In one aspect of the invention, at least one woven or fabric
layer is located between the substrates. Fabric layers can comprise
an open mesh or any suitable mesh pattern that would meet the
requirements of the intended application. The fabric should be of
proper thickness and composition to provide the desired toughness,
tear strength, stiffness, insulation, sound dampening, or other
specific properties for a particular application. Fabrics ranging
from about 0.08 mm to about 10 mm thick but usually about 0.1 mm to
about 1.5 mm may be used. Fabrics or meshes such as those
comprising knitted, woven or non-woven yarns, fibers, filaments or
mats, films, thick gauge films, Kevlar, fiberglass, carbon fiber,
thermoplastics (such as ABS polymers, AES polymers, ASA polymers,
cyclo olefin polymers, SMA polymers, acetal, acrylic, cellulose,
fluoro polymers, ethylene vinyl acetate, ethylene butyl acrylate,
ethylene methyl acrylate, polyamide-imide, polyarylamide, polyaryl
sulfone, polycarbonate, polyesters, polystyrene, polyurethane,
polyolefins and blends thereof), perforated thermoplastic film
(thin and thick gauges), wire mesh or perforated ferrous or
non-ferrous metals or alloys may be incorporated depending on the
desired properties of the resulting composite structure. Normally
the fabric is embedded within a reactive resin. The fabric layers
can also comprise the inventive fibrous material and be used alone
or with the resin.
[0014] The composite structure can also be constructed using
unwoven fibers, particles, cubes, spheres, beads, bubbles, or other
spacers composed of materials such as glass, Kevlar, graphite,
ceramic, vectran, thermoplastics (such as polyesters (nylon), ABS
polymers, AES polymers, ASA polymers, cyclo olefin polymers, SMA
polymers, acetal, acrylic, cellulose, fluoro polymers, ethylene
vinyl acetate, ethylene butyl acrylate, ethylene methyl acrylate,
polyimide, polyamide-imide, polyarylamide, polyaryl sulfone,
polycarbonate, polystyrene, polyurethane, polyolefins and blends
thereof instead of or in addition to fabric, metallic mesh or other
suitable fabrics. The fibers, particles, cubes or other spacers
could also be fabricated from the same or different reactive resin
or thermosetting system that is to be used to form the reinforced
composite structure. The fibers, particles, cubes or spacers chosen
for use may be applied by mixing with the reactive resin or
thermosetting system or by being sprayed, laminated, extruded,
pumped, sprinkled, or otherwise dispersed on to a component of the
composite structure. Quantities of the fibers, particles, cubes or
other spacer chosen may range from about 0.1 wt % to about 70 wt %
but typically range from about 1 wt % to about 30 wt % of the
reactive resin or thermosetting system weight. Polymer or metallic
spacers (e.g., nylon, metallic or non metallic cubes mixed into a
resin composition) can provide a means of spacing between the
substrate materials (e.g., in order to minimize squeeze out or
movement of the resin composition between the substrates and add
conductivity path when metallic spacers used). The polymer spacers
permit forming a uniform layer of reinforcing material within of
the composite. The weight percent of the spacers can be adjusted
for a given end use, but in general range from about 2% to about
10% weight is appropriate.
[0015] Another aspect of the invention relates to a method for
producing the composite without using fabrics, fiber shreds or
spacers by employing an epoxy resin or other suitable thermosetting
compositions formulated such that the compositions are drawn into a
monofilament or string or formed into a non-woven fabric (e.g.,
refer to Examples 4 and 5). The monofilament could be used to
assemble a resin layer by crisscrossing, weaving or arranging the
monofilament in any suitable layout. This monofilament could then
be sandwiched between the substrates and cured to form the
composite. The arrangement of the monofilament and its diameter
could be used as parameters to determine the contact area, amount
of air trapped between the substrates and the thickness of the
resulting composite structure (the particular arrangement can also
be modified to reduce costs). If desired, spray bound cloth can
also be processed from the thermosetting composition, to provide a
non woven reactive fabric.
[0016] In one aspect of the invention, the reinforced composite
structure may be produced by interlaying structural resin saturated
fabric (described above and for example, an epoxy based system the
embeds a fiberglass mesh), between the substrates. The fabric may
be saturated with resin by dipping, roll coating or by using a
pump-on, spray-on or other suitable process. If no fabric is used,
the reactive resin or thermosetting system may be pumped, sprayed,
extruded or applied by any other suitable method directly onto the
substrate material. Next, the remaining substrate layer can be
applied mechanically, by hand or by another suitable method. Once
assembled, the structure can be cured by convection, induction,
radiant, radio frequency or other suitable method of heating. The
time of heating and the cure temperatures of the reactive resin or
thermosetting system are determining factors in selecting the cure
properties of the composition.
[0017] In one aspect of the invention, the substrates sandwich at
least one epoxy functional composition that is heat cured with at
least one metal acrylate (e.g., zinc diacrylate). If desired, the
epoxy functional composition can be reinforced with at least one
reinforcing material.
[0018] Another aspect of the invention relates to a fiber
composition and to methods for making the composition. The fiber
can comprise at least one epoxy functional compound that is heat
cured with at least one metal acrylate cured composition such as
that described in the Cross-Referenced Patents and Patent
Applications. The inventive fiber composition can be employed alone
or as a component of the previously described reinforcing material
(e.g., a fibrous mass comprising the inventive fiber composition
can be applied between substrates and heated to form a composite).
The fiber is normally substantially free of conventional curing
agents. By "substantially free of conventional curing agents", it
is meant that an epoxy functional compound fiber is cured while in
the presence of less than about 0.1 to about 1.0 wt. % (e.g., about
0% of conventional epoxy curing agents) of the following compounds
polyamides, dicyandiamides, imidizoles, imidizole compounds,
amines, ureas, substituted ureas, boron trifluoride and complexes,
polysulfides, anhydrides, melamines, amidoamines,
phenol/formaldehyde, among other conventional curing agents. While
the inventive fiber can be cured in combination with such
conventional curing agents, the instant invention obviates the
necessity of such compounds, among other benefits.
[0019] The following Examples are provided to illustrate certain
aspects of the invention and shall not limit the scope of the
invention as recited in any claims appended hereto.
EXAMPLES
Example 1
Composition and Method for Producing Reinforced Composite Structure
for 3-Point Flexural Strength Testing
[0020] The composites constructed by this Example comprised a heat
reactive material that was "sandwiched" between 2 substrates. The
substrates used in these tests were alloy 3003 aluminum panels
(McMaster-Carr Supply Co) with a thickness of 0.016'' (0.41 mm).
The reactive resin compositions were prepared by mixing in a tin
cup by hand (Methods A and B), or by mixing with a double arm
Baker-Perkins lab mixer (Method C).
[0021] The composite structures were prepared by one of the
following methods: [0022] Method A. Saturated the fabric with the
material and applied between 2 aluminum panels. Hand pressure was
applied to achieve good "wet out." "Bull dog" clips were applied at
the ends of the panels to hold the "sandwich" together. The
composite was then cured for 5 minutes at 400.degree. F. [0023]
Method B. The material was applied with spacer cubes mixed in to an
aluminum panel. The other aluminum panel was then applied to form a
"sandwich." Hand pressure was applied to achieve good "wet out." A
weight of approximately 1 lb was placed on top of the composite
while it was cured for 5 minutes at 400.degree. F. [0024] Method C.
The reactive resin material was pressed at 160-180.degree. F. A
fabric or spacer cubes were then placed on the material and
repressed so that the fabric or cubes became embedded into the
reactive resin material. The reactive resin and fabric or spacer
cube material was then placed between 2 aluminum panels. Hand
pressure was applied to achieve good "wet out." Spring clips ("Bull
dog" clips) were applied at the ends to hold the "sandwich"
together. The composite structure was then cured for 5 minutes at
400 F.
[0025] Test samples were constructed that were 1'' wide by 6''
long. The materials used to construct the test samples are listed
below in Tables 1 and 2. After constructing the test samples
measurements were taken to determine their thickness, weight per
area, flexural strength and displacement. Flexural strength was
found by completing 3-point flexural strength tests over a span of
4'', at a crosshead speed of 1''/minute and support and load bars
equaling 0.5''d. The control samples used for the tests were
aluminum ceiling panels with a cosmetic coating. Measurements of
the control samples showed the control samples to have a weight per
area of 2.33 g/in.sup.2 and a thickness of 0.0570''. The control
samples were also shown to have flexural strength of 16 lbs. at
0.6'' displacement (the values were the same for normal or inverted
testing). The compositions of the test samples and the results of
the measurements and flexural tests are shown in Tables 3, 4 and 5.
TABLE-US-00001 TABLE 1 Fabrics From BGF Industries (* =
Fiberglass): Breaking Strength Weave Yarn Description Count Weight
Warp Fill Thickness Style Finish Pattern Warp Fill (Ends .times.
Picks) (oz/yd.sup.2) (lbs/in) (lbs/in) (in) *1659 Greige Leno ECG
150 1/0 ECG 75 1/0 20 .times. 10 1.6 80 70 0.0042 *3714 558 Plain
ECG 37 1/0 ECK 18 1/0 18 .times. 28 11.7 78 280 0.0140 *7628 558
Plain ECG 75 1/0 ECG 75 1/0 44 .times. 31 6 N/A N/A 0.0068 *7628
White Plain ECG 75 1/0 ECG 75 1/0 44 .times. 31 .apprxeq.6 N/A N/A
.apprxeq.0.0068 *7628 Black Plain ECG 75 1/0 ECG 75 1/0 44 .times.
31 .apprxeq.6 N/A N/A .apprxeq.0.0068 5285 618 4 HS 1140 T965 1140
T965 17 .times. 17 5 650 650 0.0100 Kevlar .RTM. 49 Kevlar .RTM.
49
[0026] TABLE-US-00002 TABLE 2 Maxi-Blast Inc Cubes: Company Product
Name Description Maxi-Blast Inc. PA-20 Nylon 0.02'' cube .times.
0.035'' diagonal (Polyamide) Cubes (0.50 mm cube .times. 0.88 mm
diagonal)
[0027] TABLE-US-00003 TABLE 3 Example Epalloy 8240 90% 90% 90% (CVC
Specialty - Epoxy) Epon 828 90% (Resolution - Epoxy) PC-300 10% 10%
10% 10% (Sartomer - Metallic Diacrylate Maxi-Blast PA-20
(Maxi-Blast Inc. - Nylon Cubes) Fabric 1659/Greige 1659/Greige
7628/Black 7628/White Cure Schedule 5 mins at 400 F. 5 mins at 400
F. 5 mins at 400 F. 5 mins at 400 F. Composite Prepared by Method A
Prepared by Method A Prepared by Method A Prepared by Method A
Thickness 0.0410'' (1.04 mm) 0.0415'' (1.05 mm) 0.0485'' (1.23 mm)
0.0425'' (1.08 mm) Weight per Area 1.50 g/in.sup.2 1.54 g/in.sup.2
1.68 g/in.sup.2 1.64 g/in.sup.2 Flex Strength 10.8 lbs 11 lbs 13.5
lbs 11.1 lbs Displacement 0.51'' 0.55'' 0.49'' 0.59'' Comments This
approaches the This approaches the This approaches the This
approaches the strength of the Control strength of the Control
strength of the Control strength of the Control and has a weight
per and has a weight per and has a weight per and has a weight per
area reduction of 36% area reduction of 34% area reduction of 36%
area reduction of 30%
[0028] TABLE-US-00004 TABLE 4 Example Epalloy 8240 90% 90% 90% (CVC
Specialty - Epoxy) Epon 828 85% (Resolution - Epoxy) PC-300 10% 10%
10% 10% (Sartomer - Metallic Diacrylate Maxi-Blast PA-20 5%
(Maxi-Blast Inc. - Nylon Cubes) Fabric 7628/558 3714/558 Kevlar
5285/618 Cure Schedule 5 mins at 400 F. 5 mins at 400 F. 5 mins at
400 F. 5 mins at 400 F. Composite Prepared by Method A Prepared by
Method A Prepared by Method A Prepared by Method B Thickness
0.0515'' (1.31 mm) 0.0475'' (1.21 mm) 0.0515 (1.31 mm) 0.0630''
(1.60 mm) Weight per Area 1.72 g/in.sup.2 1.77 g/in.sup.2 1.64
g/in.sup.2 1.76 g/in.sup.2 Flex Strength 16.2 lbs 13.0 lbs 13.3 lbs
17.6 lbs Displacement 0.25'' 0.44'' 0.58'' 0.39'' Comments This is
similar to the This approaches the This approaches the This is
similar to the strength of the Control strength of the Control
strength of the Control strength of the Control and has a weight
per and has a weight per and has a weight per and has a weight per
area reduction of 26% area reduction of 24% area reduction of 30%
area reduction of 24%
[0029] TABLE-US-00005 TABLE 5 Example Vamac DP 150 g (DuPont -
Elastomer) LER HH 225 g (InChem - Epoxy/Phenoxy) Epon 1001F 150 g
(Resolution - Epoxy) HM 443 400 g (Hoosier Magnetics - Metal
Powder) Zinc Oxide 0.5 g (Midwest Zinc - Zinc Oxide) Perkadox
BC-40K-pd 10 g (AkroChem - Peroxide) SR 9016 20 g (Sartomer -
Metallic Diacrylate) Lica 38J 2 g (Kenrich Petrochemicals -
Titanate) Fabric 1659/Greige Cure Schedule 5 mins at 400 F.
Composite Prepared by Method C Thickness 0.0665'' (1.69 mm) Weight
per Area 1.79 g/in.sup.2 Flex Strength 4.9 lbs Displacement 0.50''
Comments This doesn't approach the strength of the Control but has
a weight per area reduction of 23%
Example 2
Testing Weight Reduction Over Solid Materials
[0030] The reinforced composite structure for this Example
comprised a one-part epoxy formulation and glass beads which were
"sandwiched" between two (2) aluminum substrates. The epoxy
formulation comprised 50 grams of InChemRez LER-HH (distributed by
Mozel) and 5 grams of Erisys DDA10 powder cure (supplied by CVC
Specialty Chemicals, Inc.). The two ingredients of the epoxy were
mixed in a tin cup by hand or with a high speed disperser until a
homogenous mixture were obtained. If needed the materials (with or
without the curing agent) may be preheated prior to mixing. Glass
beads 0.00984'' (0.25 mm) in diameter (supplied by MO-SCI
Corporation) were used. The aluminum substrates were alloy 3003
(supplied by McMaster-Carr Supply Co.) and were 0.016'' (0.41 mm)
in thickness. To construct the samples for these tests an adequate
amount of the epoxy formulation was applied to one side of an
aluminum panel. Enough epoxy was added to cover the entire surface
with a thin layer. About 0.2 to about 0.6 grams (or as commonly
described by one skilled in the art, about 1 or 2 pinches) of glass
beads were then sprinkled by hand onto the epoxy layer to provide
an even dispersion of beads across the surface. The second aluminum
panel was then applied over the glass beads and pressed by hand
onto the glass beads and epoxy to form the composite. Next,
"bulldog" clips were attached to the composite to press the layers
together while the composite was thermally cured at 400.degree. F.
for 30 minutes. An optional cosmetic coating or paint may be
applied to the outer aluminum surfaces if desired.
[0031] To test the feasibility of the aluminum composite panels,
two samples were constructed by the method above. Weight
calculations were made on a standard electronic balance and
compared to both a standard aluminum ceiling tile used as the
control sample (the control sample contained a cosmetic coating on
its surface) and a single aluminum substrate. Rigidity tests were
also performed by attempting to flex the samples by hand and
comparing to the control (standard aluminum ceiling tile). The test
results are shown in Table 6 below. The tests demonstrated that the
aluminum composite samples reduce the weight of the panels by
greater than 33% while also reducing the thickness and maintaining
nearly the same rigidity. TABLE-US-00006 TABLE 6 Aluminum Aluminum
Control Ceiling Composite Composite Sample Panel Aluminum Only
(Sample #1) (Sample #2) Dimensions 10'' .times. 4'' .times.
0.0570'' 12'' .times. 6'' .times. 0.016'' 10'' .times. 4'' .times.
0.0472'' 9'' .times. 2'' .times. 0.04803'' (1.45 mm) (0.41 mm)
(1.20 mm) (1.22 mm) Area 40 in.sup.2 72 in.sup.2 40 in.sup.2 18
in.sup.2 Weight 0.2056 lbs 0.1111 lbs 0.1367 lbs 0.0605 lbs 93.33 g
50.42 g 62.06 g 27.47 g Weight/Area 0.00514 lbs/in.sup.2 0.00154
lbs/in.sup.2 0.00342 lbs/in.sup.2 0.00336 lbs/in.sup.2 2.333
g/in.sup.2 0.7003 g/in.sup.2 1.552 g/in.sup.2 1.526 g/in.sup.2
Rigidity Observed to Observed to approach the approach the rigidity
of the rigidity of the control ceiling control ceiling panel.
panel. Comments 33.5% weight 34.6% weight reduction vs. the
reduction vs. the Control Ceiling Control Ceiling Panel.* Panel.*
*The cosmetic coating or paint is not included in this
calculation.
Example 3
Production of Epoxy Resin Monofilament
[0032] The compositions of Example #5 were placed in a stainless
steel crucible and mixed with a stirring rod or other suitable
mixing method. (Some compositions may require more intensive mixing
and thus may require the use of a double arm mixer or other
suitable mixing method) After mixing, the composition was heated to
activate the composition. At this temperature (about 130.degree. F.
for the Vamac.RTM. composition of Example #5) the components became
sticky or nearly molten and appeared somewhat flakey. Care was
taken so as not to exceed the curing temperature of the
composition. Next, a stirring rod (or other suitable tool) was
dipped by hand into the surface of the mixture and raised above and
away from the surface until the mixture that stuck to the stirring
rod began to neck and form a small diameter filament (about 1 mm in
diameter.) The filament was rotated so as to wind the filament onto
the stirring rod. Careful attention was paid to the rate at which
the filament was wound in order to insure a generally consistent
diameter in the filament and to allow enough distance and time for
the filament to cool before being wound onto the stirring rod to
avoid sticking. Spools of the filament could then be used to
produce the desired mesh or other pattern of the filament.
Example 4
Composition of Epoxy Resin Monofilament or Non-Woven Epoxy Resin
Fabric
[0033] Epoxy resin compositions compatible with the procedure
depicted in Example #4 were produced. The compositions used capable
of being heat activated by industrial methods including convection,
induction, radiant heating or other method common to one skilled in
the art. The epoxy resin compositions had physical properties to
allow formation of a non-woven fabric or a filament which would be
suitable for producing a woven web, crisscross pattern, or other
acceptable layout of the filament. The composition comprised a
blend of elastomer such as ethylene methyl acrylate copolymer
(Vamac.RTM. from DuPont), solid epoxy resin such as Epon.TM. Resin
1001 (from Resolution Performance Products), phenoxy resin and
phenoxy resin blends from (Inchem) and a curing agent. Pre-blended
formulations such as HyPox RK 84 (a 40% nitrile rubber blend from
CVC Specialty Chemicals, Inc.) were also tested. The epoxy
composition normally had a viscosity and thermal properties to
allow filament formation below the heat activation temperature, but
also to allow rapid skinning for winding of the filament.
Compositions ranging from about 20% to about 40% by weight of
elastomer were tested. The compositions showed that generally
greater than about 30% by weight of the elastomer component was
required to obtain adequate flexibility in the product. These
compositions can be formed into a filament, spray bond cloth, used
in the aforementioned reinforcing material, among other uses.
TABLE-US-00007 Product Name Compound Supplier Amount Composition 1
SR 9016 ZDA Sartomer 10% Epon 1009 solid epoxy Resolution 40% Epon
828 Liquid epoxy Resolution 40% TC 140 ethylene methacrylate Exxon
10% Composition 2 SR 9016 ZDA Sartomer 10% Epon 1007 solid epoxy
resin Resolution 45% Paphen 200 phenoxy resin Inchem 10% Epon 834
liquid epoxy Resolution 35% Composition 3 SR 9016 ZDA Sartomer 10%
Epon 1007 epoxy resin Resolution 40% Paphen 200 phenoxy resin
Inchem 10% Epon 834 liquid epoxy Resolution 30% TC 140 ethylene
methacrylate Exxon 10%
[0034] While desirable results are obtained by using ZDA as an
epoxy curing agent, if desired Compositions 1-3 above can be cured
by using Dicyandiamide alone or in combination with ZDA.
Dicyandiamide is available commercially as ErysisDDA10 (CVC
specialty chemical).
[0035] While the apparatus, compositions and methods of this
invention have been described in terms of preferred or illustrative
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the process described herein without
departing from the concept and scope of the invention. All such
similar substitutes and modifications apparent to those skilled in
the art are deemed to be within the scope and concept of the
invention and the appended claims.
* * * * *