U.S. patent application number 13/300050 was filed with the patent office on 2012-03-15 for cushioning device.
This patent application is currently assigned to MSD Consumer Care, Inc.. Invention is credited to Charles E. Lundy, JR., Philip C. Yang.
Application Number | 20120060304 13/300050 |
Document ID | / |
Family ID | 40940231 |
Filed Date | 2012-03-15 |
United States Patent
Application |
20120060304 |
Kind Code |
A1 |
Yang; Philip C. ; et
al. |
March 15, 2012 |
CUSHIONING DEVICE
Abstract
A cushioning device comprising a sticky surface, the device
comprising a gel material bound to a thermoplastic film material
having a polarity compatible with the gel material, wherein the
thermoplastic film material further comprises a pressure sensitive
adhesive located on a surface of the film material opposite to the
surface that is bonded to the gel material.
Inventors: |
Yang; Philip C.; (Memphis,
TN) ; Lundy, JR.; Charles E.; (Germantown,
TN) |
Assignee: |
MSD Consumer Care, Inc.
Memphis
TN
|
Family ID: |
40940231 |
Appl. No.: |
13/300050 |
Filed: |
November 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12163280 |
Jun 27, 2008 |
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13300050 |
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Current U.S.
Class: |
12/142R |
Current CPC
Class: |
B29K 2075/00 20130101;
B32B 2479/00 20130101; B32B 7/12 20130101; A43B 13/189 20130101;
C09J 7/29 20180101; A61F 13/061 20130101; C09J 2475/006 20130101;
B32B 27/08 20130101; B32B 2255/26 20130101; A61F 13/064 20130101;
B29C 39/003 20130101; C08L 2666/02 20130101; B32B 2437/02 20130101;
B32B 27/40 20130101; B29C 39/10 20130101; C09J 2301/162 20200801;
B29L 2031/507 20130101; B32B 2255/10 20130101 |
Class at
Publication: |
12/142.R |
International
Class: |
A43D 39/00 20060101
A43D039/00 |
Claims
1.-58. (canceled)
59. A method for providing enhanced adhesion performance of a heel
cushioning device in a shoe, which method comprises attaching to
the inside of a shoe opposite the heel of a user a polyurethane gel
cushioning device comprising an adhesive surface, the device
comprising a layer of polyurethane gel material having an upper and
lower surface and two layers of thermoplastic polyurethane film
material, each layer of said thermoplastic polyurethane film
material comprising upper and lower surfaces, wherein the upper
surface of the polyurethane gel material is bonded with the lower
surface of one of said layers of thermoplastic polyurethane film
material and the lower surface of the polyurethane gel material is
bonded with the upper surface of the other of said layer of
thermoplastic polyurethane film material, wherein at least one of
the layers of thermoplastic polyurethane film material comprises a
pressure sensitive adhesive on a surface opposite the surface
bonded to the polyurethane gel material thereby providing the
adhesive surface of the heel cushioning device, wherein the
adhesive surface of the heel cushioning device is positioned to
attach the heel cushioning device to the inside of the shoe.
60. The method of claim 59, wherein the pressure sensitive adhesive
comprises acrylic adhesives, methacrylate adhesives, rubber-based
adhesives,
61. The method of claim 59, wherein the pressure sensitive adhesive
is an adhesive based on styrene copolymers or silicones and
combinations thereof.
62. The method of claim 61, wherein the styrene copolymers comprise
styrene-isoprene-styrene (SIS), styrene-ethylene-butylene-styrene
(SEBS), styrene-butadiene-styrene (SBS) copolymers with at least
one tackifier, or combinations thereof.
63. The method of claim 59, wherein the acrylic adhesive comprises
ethylene ethyl acrylate (EEA), ethylene methyl acrylate (EMA)
copolymers, or combinations thereof.
64. The method of claim 59, wherein the pressure sensitive adhesive
has a thickness of between about 0.0125 mm and about 0.25 mm.
65. The method of claim 59, wherein the polyurethane gel material
has a Shore 00 hardness of between about 10 and about 80
66. The method of claim 59, wherein the polyurethane gel material
has a Shore 00 hardness of between about 30 and about 60.
67. The method of claim 59, wherein the polyurethane gel material
has a Shore 00 hardness of Shore 00 hardness of about 50.
68. The method of claim 59, wherein the polyurethane gel material
has a thickness of between 0.3 and 3 mm.
69. The method of claim 59, wherein the thermoplastic polyurethane
film material has a Shore A hardness of between about 40 to about
95.
70. The method of claim 59, wherein the thermoplastic polyurethane
film material has a thickness of between 0.025 mm and 0.25 mm.
71. The method of claim 59, wherein said thermoplastic polyurethane
film material has a thickness of at least 0.025 mm.
72. A method for providing enhanced adhesion performance of a
cushioning device in a shoe, comprising providing a cushioning
device comprising a gel material comprising top and bottom surfaces
and at least one layer of thermoplastic film material comprising a
top and bottom surface bonded to one or both of said top and bottom
surfaces of said gel material, wherein at least one of said at
least one layer of thermoplastic film material comprises a pressure
sensitive adhesive opposite to the surface contacting said gel
material thereby providing an adhesive surface of the cushioning
device, wherein the adhesive surface of the device is positioned so
as to attach the device to the inside of the shoe.
73. The method of claim 72, wherein the gel material is a
polyurethane gel material.
74. The method of claim 72, wherein the thermoplastic film material
is a polyurethane material.
75. The method of claim 72, wherein the gel material is SEBS gel
material.
76. The method of claim 72, wherein the thermoplastic film material
is SEBS material.
77. The method of claim 72, wherein the pressure sensitive adhesive
comprises acrylic adhesives, methacrylate adhesives, rubber-based
adhesives,
73. The method of claim 72, wherein the pressure sensitive adhesive
is an adhesive based on styrene copolymers or silicones and
combinations thereof.
74. The method of claim 73, wherein the styrene copolymers comprise
styrene-isoprene-styrene (SIS), styrene-ethylene-butylene-styrene
(SEBS), styrene-butadiene-styrene (SBS) copolymers with at least
one tackifier, or combinations thereof.
75. The method of claim 72, wherein the acrylic adhesive comprises
ethylene ethyl acrylate (EEA), ethylene methyl acrylate (EMA)
copolymers, or combinations thereof.
76. The method of claim 72, wherein the pressure sensitive adhesive
has a thickness of between about 0.0125 mm and about 0.25 mm.
77. The method of claim 72, wherein the polyurethane gel material
has a Shore 00 hardness of between about 10 and about 80
78. The method of claim 72, wherein the polyurethane gel material
has a Shore 00 hardness of between about 30 and about 60.
79. The method of claim 72, wherein the polyurethane gel material
has a Shore 00 hardness of Shore 00 hardness of about 50.
80. The method of claim 72, wherein the polyurethane gel material
has a thickness of between 0.3 and 3 mm.
81. The method of claim 72, wherein the thermoplastic polyurethane
film material has a Shore A hardness of between about 40 to about
95.
82. The method of claim 72, wherein the thermoplastic polyurethane
film material has a thickness of between 0.025 mm and 0.25 mm.
83. The method of claim 72, wherein said thermoplastic polyurethane
film material has a thickness of at least 0.025 mm.
Description
BACKGROUND OF THE INVENTION
[0001] The subject invention is directed to cushioning devices
comprising a pressure sensitive adhesive. In particular, the
invention concerns the use of pressure sensitive adhesive materials
to improve the hold of soft gel cushioning devices. One of the key
attributes of the footwear cushions is to prevent the footwear from
rubbing sensitive areas of skin, in particular in the heel area.
However, in order to achieve all the desired attributes of the
cushion, the cushion needs to stay in place firmly during movement
associated with normal use of footwear. Cushioning devices made of
soft gels are known in the art and are desirable for their comfort,
flexibility, durability and look. The assignee of this invention,
Schering-Plough Healthcare Products, Inc., markets a cushioning
device under the trade name Dr. Scholl's.RTM. Gel Heel Liner, which
comprises a thermoplastic polyurethane (TPU) film bonded to a
polyurethane (PU) gel, where the PU gel is produced in a way to
have a sticky surface. However, no additional adhesive is used in
this product. The Heel Liner is packaged with a release film to
preserve the tackiness of the PU gel sticky surface, which is then
applied to the shoe to hold the liner in place. The TPU film
provides a nonstick surface opposite the sticky surface, which
nonstick contacts the wearers foot, sock, or hosiery.
[0002] It has now been determined, however, that the sticky PU gel
does not hold the liner in place for extended periods of use as may
be desired for a cushioning element. Pressure sensitive adhesive
materials have been used in the art. However, direct modification
of a sticky PU gel with a pressure sensitive adhesive did not
produce a cushioning element with a stronger hold. Thus, a
cushioning device that provides the benefit of a gel and provides
for long term hold in the shoe where placed would be desirable.
Further, a method of manufacturing a gel cushioning device with a
pressure sensitive adhesive would also be desirable. These and
other advantages follow from the invention described and claimed
here.
SUMMARY OF THE INVENTION
[0003] The subject invention provides a cushioning device
comprising a layer of polyurethane gel material comprising top and
bottom surfaces, at least one layer of thermoplastic polyurethane
film material bonded to the one or both of said top and bottom
surfaces thereof, and a layer of pressure sensitive adhesive bonded
to one of said at least one thermoplastic polyurethane film
material, wherein the pressure sensitive adhesive is located on a
surface of the thermoplastic polyurethane film opposite to the
surface contacting said bottom surface of said polyurethane gel
material.
[0004] The subject invention also provides a gel cushioning device
comprising a sticky surface, the device comprising a gel material
bound to a thermoplastic film material having good compatibility
with the gel material, wherein the thermoplastic film material
further comprises a pressure sensitive adhesive located on a
surface of the film material opposite to the surface that is bonded
to the gel material.
[0005] The subject invention further provides gel cushioning device
comprising a sticky surface, the device comprising a layer of gel
material having an upper and lower surface and two layers of
thermoplastic film material, each film material comprising upper
and lower surfaces, wherein the upper surface of the gel material
is bonded with the lower surface of one of said layers of film
material and the lower surface of the gel material is bonded with
the upper surface of the other of said layers of film material,
wherein at least one of the layers of film material comprises a
pressure sensitive adhesive on a surface opposite the surface
bonded to the gel material thereby providing the sticky surface of
the device.
[0006] The subject invention also provides a method of constructing
a gel cushioning device comprising a sticky surface, which
comprises loading gel material into a mold cavity comprising at
least one layer of thermoplastic film material, said at least one
layer of thermoplastic film material comprising upper and lower
surfaces, and curing the gel material to form a solid gel, such
that the cured gel material is bonded with the film material and
wherein said at least one of the layer of thermoplastic film
material comprises a pressure sensitive adhesive on a surface
opposite the surface bonded to the gel material thereby providing
the sticky surface of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A depicts a cross section of a prior art cushioning
element.
[0008] FIG. 1B depicts a cross section of an example embodiment of
the cushioning element of the invention.
[0009] FIG. 2 depicts a cross section of a second example
embodiment of the cushioning element of the invention.
DETAILED DESCRIPTION
[0010] As depicted in FIG. 1, the products of the invention
comprise an advance over prior art TPU/PU molded cushioning
elements in that they provide for a means to attach a pressure
sensitive adhesive to a gel material to provide extra holding
capabilities. FIG. 1A shows a cross section of a prior art material
comprising gel material (104) bonded to a film material (102). The
film material provides an exterior surface that resists friction to
allow for smooth contact with skin or articles of clothing. FIG. 1B
shows a cross section of an example embodiment of the subject
invention wherein a layer of gel material having top and bottom
surfaces comprises two layers of film material (102, 103) bonded to
each surface of the gel material. In the practice of the invention,
the gel material may comprise, for example polyurethane gel,
styrenic based gels, or silicone gels. The gel materials useful in
the invention may typically have a Shore 00 hardness of between
about 10 and about 80, preferably between about 30 and about 60. In
certain embodiments of the invention, the polyurethane gel
materials are used and may have a Shore 00 hardness of about 50.
The gel material may typically have a thickness of between 0.3 and
3 mm. The film material may comprise thermoplastic polymeric film
material that is compatible with the gel material used in the
cushion. For example, where a polyurethane gel material is used in
the cushion, the film material will likely comprise a thermoplastic
polyurethane film material. Likewise, when an SEBS gel material is
used in the cushion, the film material will likely comprise SEBS
thermoplastic film. The film materials may typically have a Shore A
hardness of between about 40 to about 95 and may typically have a
thickness of between 0.025 mm and 0.25 mm. In certain embodiments
according to this invention where more than one layer of film is
used, the individual layers of film will have the same thickness.
In certain additional embodiments according to this invention,
individual layers of film will have different thicknesses. In
practice, varying the thickness of the film will affect the
softness and flexibility of the film and will likewise affect the
softness and flexibility of the final gel cushion product. In
certain embodiments, a thermoplastic polyurethane film is used and
may be at least 0.025 mm thick.
[0011] As used herein polyurethane material will be understood to
encompass polymers that contain a plurality of urethane linkages
and comprised of either aliphatic or aromatic isocyanate
prepolymers, and combinations thereof, both with either di or
trifunctional polyol polymers or prepolymers. The polyurethane
material may optionally also contain other kinds of chemical
linkages formed from the reactions of polyisocyanates, including
but not limited to urea linkages, isocyanurate linkages,
oxazolidone linkages, biuret linkages, allophanate linkages,
combinations of these, and the like. Polyurethane gel materials are
typically formed by reacting polyisocyanates with polyols. Examples
of poly isocyanates include those formed from aliphatic or aromatic
isocyanate prepolymers or combinations thereof. Examples of polyols
include di or trifunctional polyol polymers or prepolymers Examples
of polyols used include polyether polyols such as polyethylene
oxide) and polypropylene oxide), modified polyether polyols,
polytetramethylene glycol, condensation polyester polyols produced
by reacting dicarboxylic acids with dials, lactone-type polyester
polyols produced by ring opening polymerization of
epsilon-caprolactone or the like, and polycarbonate polyols, vinyl
polymers into which hydroxyl groups are introduced such as polyols
having polyisobutylene as the main chain.
[0012] The gel layer can also be made from a non-foam elastomer
such as the class of materials known as viscoelastic polymers or
silicone gels, which show high levels of damping when tested by
dynamic mechanical analysis performed in the range of -50 degree
Celsius to 100 degrees Celsius. Gels material can include, but not
limited to, the Kraton family of styrene-olefin-rubber block
copolymers, thermoplastic polyurethanes, thermoset polyurethanes,
thermoplastic poly olefins, polyamides, polyureas, polyesters and
other polymer materials that reversibly soften as a function of
temperature. The preferred elastomers are a Kraton block copolymer
of styrene/ethylene-co-butylene/styrene (SEBS) or
Styrene/butadiene/styrene (SBS) with mineral oil incorporated into
the matrix as a plasticizer.
[0013] As used herein, pressure sensitive adhesives (also known as
contact adhesives) are those that form viscoelastic bonds that are
aggressively and permanently tacky, adhere without the need of more
than slight pressure, and require no activation by water, solvent
or heat. Pressure sensitive adhesives are typically available in
solvent and latex or water based forms and are often based on
non-crosslinked rubber adhesives, acrylics or polyurethanes.
[0014] In certain embodiments of the invention, the pressure
sensitive adhesives may comprise acrylic and methacrylate
adhesives, rubber-based pressure sensitive adhesives, styrene
copolymers such as styrene-isoprene-styrene (SIS) and
styrene-butadiene-styrene (SBS) copolymers with at least one
tackifier, and silicones. Acrylic adhesives often use an acrylate
system such as ethylene ethyl acrylate (EEA) or ethylene methyl
acrylate (EMA) copolymers, which are used to form hot melt PSA
adhesives. Natural rubber, synthetic rubber or elastomer adhesives
may typically comprise a variety of materials such as silicone,
polyurethane, chloroprene, butyl, polybutadiene, isoprene or
neoprene. Rubber and elastomers are characterized by their high
degree of flexibility and elasticity.
[0015] In certain embodiments, the pressure sensitive adhesive
material may comprise acrylate-based adhesive materials. The
thickness of the layer of the pressure sensitive adhesive material
may be varied by those of ordinary skill in the art according to
the adhesive material used and the desired tack. In the practice of
certain example embodiments of the invention, the pressure
sensitive adhesive may have a thickness of between about 0.0125 mm
and about 025 mm.
[0016] An additional aspect of the invention comprises a method of
manufacturing a cushioning element comprising a polyurethane gel
material, which method comprises the step of bonding a polyurethane
gel and a thermoplastic film material, wherein the thermoplastic
film material comprises a pressure sensitive adhesive. In
preparation of one embodiment of the invention it was discovered
that the pressure sensitive adhesive layer cannot bond directly to
the soft polyurethane gel during the molding process. To overcome
this limitation, a layer of thermoplastic film material comprising
the pressure sensitive adhesive layer was added to the mold and
bonded to the polyurethane gel.
[0017] In certain embodiments of the invention, the cushioning
element is prepared by a direct molding process where the gel
material is applied directly to the mold, for example by injecting
the gel prepolymer into the mold cavity. During a direct molding
process, before the gel material is injected, the film material
layer comprising the pressure sensitive adhesive is applied to the
mold cavity with the adhesive on the side of the film material
closest to the mold and then the PU gel material is injected into
the mold over the film material. The mold can be treated to resist
bonding of the pressure sensitive adhesive or a release liner
material can be applied in the mold first before the film material
is applied to the mold. In certain embodiments of the invention,
the mold may be preheated to the desired curing temperature prior
to injecting the gel material or heated after all materials are
loaded into the mold. For example, when using polyurethane gel
materials according to the invention the mold temperature is
typically between 85-95 C and the cycle time is approximately 8
min. The pressure is typically low and not critical for this type
of operation provided that the pressure is high enough to fill the
cavity-mold with polyurethane prepolymer.
[0018] As depicted in FIG. 2, a release liner 106 is shown
contacting the exposed surface of the PSA layer depicted in FIG.
1B. In this example embodiment of the invention, the gel cushion
can be manufactured by direct molding process. In this manner, the
thin release liner laminate comprises the bottom layer assembly of
the gel cushioning element and also aids in the ease of removing
the formed gel cushioning element from a mold. The top
thermoplastic film comprises the cover layer of the liner during
the molding process. The release liner can be kept on the product
when packaged for sale and discarded before applying the gel
cushioning element to a surface, such as a shoe or other article of
footwear. In certain embodiments the cushioning device may further
comprise a synthetic rubber foam, a woven cotton fabric, a
synthetic fiber, a knit fabric, a polyvinyl chloride film, and/or a
synthetic non-woven fabric.
[0019] The products of the invention can be formed into any shape
suitable for use as a cushioning device, for example for insertion
into footwear to prevent rubbing between sensitive skin and hard or
exposed surfaces of the footwear. The cushioning elements can also
be applied to other garments e.g., hats, helmets, protective
sporting gear such as elbow and knee pads and other garments
requiring extra padding for comfort, sizing and/or safety.
Cushioning elements according to the invention may also be applied
to surfaces which come in contact with body parts to provide
protection from injury such as, e.g., chairs, desks, cabinets,
tables, doors and door frames, among others. Depending on the size
and shape of the object to which the cushioning element is applied,
certain shapes will better protect different areas of the body from
contact with the object. In certain example embodiments the
products are molded in the shape of, e.g., circles, parabolas,
stars, squares, rectangles, rounded rectangles, half-moon, among
others. The appropriate shape of the cushioning element can be
determined based on the size and surface of the object to which the
cushioning element will be applied. In alternative example
embodiments, the cushioning element can be provided as a sheet of
material that the user can cut to a desired shape. The sheet of
material can also be provided with preformed shapes that can be
removed as desired for the appropriate protection from contact with
the object.
EXPERIMENTAL
[0020] A human wear test was conducted to compare the unmodified
polyurethane gel cushion containing a sticky gel surface with a
modified polyurethane gel cushion of the present invention
containing a pressure sensitive adhesive. The test was run to
determine if a cushioning device according to the invention would
provide appropriate adhesion performance when compared to the
unmodified polyurethane gel heel liner. Prior to the wear test, a
probe tack test was conducted on both devices according to ASTM D
2979-01 to measure the force required to separate an adhesive and
adherend shortly after they have been contacted under a defined
load of known duration and at a specified temperature. The devices
were also tested for shear hold according to PSTC-107 A, which
measures the adhesive material's ability to remain adhered under a
constant load applied parallel to the surface of the material and
substrate, in particular measuring the shear adhesion when applied
to a vertical standard steel panel. The two devices were determined
to have the following adhesion tack and shear hold:
TABLE-US-00001 PU gel without PSA PU gel with PSA Probe Tack (g)
449 +/- 9 422 +/- 39 Shear Hold (min) 445 +/- 220 325 +/- 173
[0021] Based on the results of the probe tack test and the shear
hold test, those of ordinary skill in the art would recognize that
the two heel liner devices have essentially the same adhesion tack
and shear hold, and would be expected to have the same adhesion
performance in use, i.e., the ability to stay in place in a shoe
under normal wear.
[0022] The adhesion performance of heel liner cushions formed
according to the invention was then evaluated in a wear test by
volunteers who inserted the devices into their shoes and wore them
for three days of normal use. The test subjects were divided such
that 23 subjects evaluated the unmodified heel liners while 22
subjects evaluated the heel liner modified with PSA. Both the
unmodified heel liners and the modified heel liners were similar in
appearance so the test subjects did not know which device they were
wearing. After three days, the test subjects were asked to rate
their agreement or disagreement with whether the cushion stayed in
place during normal use, rating according to a seven point
scale:
TABLE-US-00002 Answer Rating agree extremely 1 agree moderately 2
agree slightly 3 neither agree or disagree 4 disagree slightly 5
disagree moderately 6 disagree extremely 7
The sum of the top three rating answers indicated a positive
feedback of the performance of the heel liner cushion adhesion and
the sum of the bottom three rating answers indicated the negative
feedback to the performance of the heel liner cushion. The results
were as follows:
TABLE-US-00003 Unmodified Modified Top 3 box 13 21 Bottom 3 box 10
1
[0023] As shown, the modified heel liners produced according to the
subject invention containing the PSA produced an overwhelmingly
positive feed back from users. Conversely, the unmodified heel
liners showed equivocal results of positive and negative feed back.
The statistical analysis (p of 0.0041) of the wear test results
indicated that the liners modified with PSA according to the
invention provide a better adhesion performance during wear than
the unmodified version, which result was unexpected based on the
probe tack and shear hold tests on the cushions.
[0024] Several embodiments of the present invention are
specifically described herein. However, it will be appreciated that
modifications and variations of the present invention are covered
by the above teachings and within the purview of the appended
claims without departing from the spirit and intended scope of the
invention.
* * * * *