U.S. patent application number 10/681831 was filed with the patent office on 2004-09-30 for reinforced polymer shock absorbing pad.
Invention is credited to Kriesel, Matt.
Application Number | 20040191446 10/681831 |
Document ID | / |
Family ID | 32995741 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040191446 |
Kind Code |
A1 |
Kriesel, Matt |
September 30, 2004 |
Reinforced polymer shock absorbing pad
Abstract
Disclosed is a reinforced polymeric pad comprising a polymeric
gel and a substrate encapsulated within an envelope. The substrate
can have a density less than that of the gel. The gel typically
comprises an epoxidized vegetable oil, a thermoplastic polymer and
a prepolymer and the substrate may be formed from a foamed plastic.
The reinforced polymeric pad exhibits low rebound velocity and
hysteresis, and possesses good energy-attenuating properties and is
capable of absorbing repeat shocks without structural damage.
Inventors: |
Kriesel, Matt; (Melrose,
WI) |
Correspondence
Address: |
Matt Kriesel
Impact Gel Corporation
204 North Washington Street
Melrose
WI
54642
US
|
Family ID: |
32995741 |
Appl. No.: |
10/681831 |
Filed: |
October 8, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10681831 |
Oct 8, 2003 |
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10672706 |
Sep 26, 2003 |
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10672706 |
Sep 26, 2003 |
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10613740 |
Jul 3, 2003 |
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10613740 |
Jul 3, 2003 |
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10094030 |
Mar 7, 2002 |
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6588511 |
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Current U.S.
Class: |
428/35.7 |
Current CPC
Class: |
A01L 7/02 20130101; Y10T
428/1352 20150115 |
Class at
Publication: |
428/035.7 |
International
Class: |
B65D 001/00 |
Claims
What is claimed is:
1. A reinforced polymeric pad comprising: a shock absorbing
envelope comprising a polymer gel substantially surrounding a
substrate.
2. The reinforced polymeric pad of claim 1, wherein the pad
comprises a top layer and a bottom layer.
3. The reinforced polymeric pad of claim 2, wherein the layers are
formed from a resilient polymeric material.
4. The reinforced polymeric pad of claim 2, wherein the layers are
formed from a woven material.
5. The reinforced polymeric pad of claim 1, wherein the substrate
has a density less than the polymeric gel.
6. The reinforced polymeric pad of claim 1, wherein the substrate
is formed from a foamed polymeric material.
7. The reinforced polymeric pad of claim 6, wherein the substrate
is formed from a foamed PVC.
8. The reinforced polymeric paid of claim 1, wherein the polymeric
material comprises at least greater than 50% by weight of an
epoxidized vegetable oil, a thermoplastic polymer; and a
prepolymer.
9. The reinforced polymeric pad of claim 8, further including an
activator.
10. The reinforced polymeric pad of claim 9, wherein the activator
is an alkyl tin compound.
11. The reinforced polymeric pad of claim 8, wherein the epoxidized
vegetable oil is selected from the group consisting of soybean oil,
linseed oil, and combinations thereof.
12. The reinforced polymeric pad of claim 8, wherein the prepolymer
comprises an isocyanate selected from the group of aliphatic,
cycloaliphatic, araliphatic, aromatic, heterocyclic
polyisocyaniates and combinations thereof.
13. The reinforced polymeric pad of claim 8, wherein in the
thermoplastic polymer is substantially free of a polyurethane.
14. The reinforced polymeric pad of claim 8, wherein the
thermoplastic polymer comprises a polydiene.
15. The reinforced polymeric pad of claim 8, wherein the
thermoplastic polymer is a polybutadiene.
16. A reinforced polymeric pad comprising: a shock absorbing
envelope comprising a top and bottom layer forming the envelope
containing a polymeric gel and a substrate having a density less
than the density of the polymeric gel.
17. The reinforced polymeric pad of claim 16, wherein the substrate
is formed from a foamed polymeric material.
18. The reinforced polymeric pad of claim 16, wherein the top and
bottom layers are formed from a resilient non-woven material.
19. The reinforced polymeric pad of claim 16 comprising an
epoxidized vegetable oil, a thermoplastic polymer substantially
free of a polyurethane and a prepolymer.
20. The reinforced polymeric pad of claim 16, further including an
activator.
21. The reinforced polymeric pad of claim 20, wherein the activator
is an alkyl tin compound.
22. The reinforced polymeric pad of claim 16, wherein the
prepolymer comprises an isocyanate selected from the group of
aliphatic, cycloaliphatic, araliphatic, aromatic, heterocyclic
polyisocyaniates and combinations thereof.
23. The reinforced polymeric pad of claim 16, wherein the polymeric
gel comprises on a percent weight basis of the gel at least greater
than about 50% of a vegetable based plasticizer, between about 20%
and about 40% of a thermoplastic polymer, and between about 5% and
about 20% of a prepolymer.
24. A method of forming a reinforced polymeric pad comprising:
forming a shock absorbing envelope by sealing within a top and
bottom layer a polymeric gel and a substrate having a density less
than the density of the polymeric gel.
25. The method of forming a reinforced polymeric of claim 24
wherein the polymeric gel if formed by combining an epoxidized
vegetable oil, a polydiene and a cyano group.
26. The method of forming a reinforced polymeric pad of claim 24,
wherein the polydiene is selected from polybutadiene, polyisoprene,
polychloroprene, polynobornene, copolymers, terpolymers and
combinations thereof.
27. The method of forming a reinforced polymeric pad of claim 24,
wherein the top and bottom layer are sealed by fusing the two
layers along the periphery of the pad.
28. The reinforced polymeric pad of claim 24, wherein the gel
comprises about 20% to about 40% of the polydiene.
29. The reinforced polymeric pad of claim 24, wherein the cyano
group is an isocyanate group.
30. The reinforced polymeric pad of claim 24, further comprising an
alkyl tin compound.
31. The reinforced polymeric pad of claim 30, wherein the gel
comprises up to about 5% by weight of the alkyl tin compound.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. ______, filed Sep. 26, 2003, which is a
continuation-in-part U.S. patent application Ser. No. 10/613,740,
filed Jul. 3, 2003, which is a continuation-in-part of U.S. patent
application Ser. No. 10/094,030, filed Mar. 7, 2002, the contents
of which are hereby incorporated in their entirety.
FIELD OF THE INVENTION
[0002] This invention generally relates to polymeric pads and in
greater detail the invention relates to a viscoelastic,
shock-attenuating elastomeric pad comprising a reinforcing
material.
BACKGROUND OF THE INVENTION
[0003] Enhanced participation in contact sports, such as football,
soccer, and rugby, along with enhanced participation in other high
impact energy activities, such as inline skating and white water
kayaking, has fueled the demand and need for improved impact
absorbing materials. These types of contact sports and high-impact
activities often cause application of high energy impacts against
discrete portions of the human body that often cause bruises and
even more serious injuries, such as broken or fractured bones.
[0004] Besides the noted contact sports and high energy impact
activities, there are a number of other activities that, in the
event of an accident or spill, may cause injury to the body. Until
the past few years, participation in these activities, such as
bicycle riding, was not considered to be an activity requiring much
protective equipment. Now, however, bicycle riders of all ages are
routinely advised to wear a protective bicycle helmet. Also, over
the past few years, there has been a tremendous growth in off-road
activities, such as mountain biking, motocross on both bicycles and
motorcycles, and all terrain vehicle (ATV) usage on off-road
trails.
[0005] There has been a tremendous rate of growth in other
applications for impact absorbing materials. Even in more mundane
activities, such as walking, there has been an increased emphasis
upon energy-absorbing surfaces and products for human beings.
Manufacturers are increasingly marketing energy absorbing soles for
shoe purchasers. Indeed, there is a large market demand for after
market impact absorbing shoe inserts. Marketing of such shoe
inserts is often targeted to participants in sports such as
basketball, football, soccer, and running, where repetitive impact
during each successive step may cause injuries to the foot and
lower leg, such as sprains, shin splints, and even broken
bones.
[0006] Due to the enhanced market for impact absorbing materials,
great strides have been made toward reducing injuries generated by
impacts that are applied against the human body. However, many of
these new impact absorbing materials merely amount to laminates of
multiple layers. Typically, such layers suffer from a couple of
different problems. For example, a layer will often inhibit the
ability of adjacent layers to fully exhibit the properties, such as
elasticity, of the adjacent layers. For example, where a pair of
layers are laminated together, and both layers have a certain
degree of elasticity, the layer with the lower degree of elasticity
will inhibit the layer with the higher degree of elasticity from
fully exhibiting that higher degree of elasticity. Also, where one
layer is fairly rigid and an adjacent continuous layer is fairly
flexible, the fairly rigid layer will inhibit the ability of the
flexible continuous layer to exhibit the flexibility.
[0007] The existing impact absorbing materials that are formed of
layers necessarily must sacrifice some degree of impact absorbing
capability. First, layer thickness is typically minimized to
prevent the impact absorbing material from becoming too heavy and
bulky for consumer tastes. Also, to the degree that impact
absorbance depends upon elevated rigidity in one of the layers,
existing impact absorbing materials consequently sacrifice
flexibility and the ability to conform to complex three-dimensional
shapes in favor of enhanced impact absorbance capability, or,
alternatively, sacrifice impact absorbing capability in favor of
enhanced flexibility and ability to conform to complex
three-dimensional surfaces.
[0008] As another example, impact absorbing products have been
developed that incorporate a fluid within a polymeric envelope.
When an impact is applied against one portion of the envelope, the
fluid is displaced to a portion of the envelope located away from
the impact point on the envelope. The envelope is typically made of
a somewhat flexible polymeric material. The energy of the impact
against the envelope is typically dissipated by generation of
pressure in the fluid, with the consequential expansion of the
envelope. While such an impact absorbing material does,
theoretically, have many benefits, practical considerations limit
the actyual capabilities of such a material. For example, the
volume of fluid within the envelope must typically be limited due
to the density of the fluid contained within the envelope and the
consequent overall weight of the fluid-filled envelope. Such
limitations of the envelope volume necessarily limit the thickness
of the fluid layer within the envelope, which thereby detracts from
the impact absorbing capabilities of the fluid-filled envelope.
[0009] Thus, a need exists for an impact absorbing material that
exhibits both enhanced flexibility and conformability along with
enhanced impact absorbing capabilities. Furthermore, what is needed
is an impact resistant material this is both light weight and
flexible.
SUMMARY OF THE INVENTION
[0010] The present invention generally relates to a reinforced
polymeric pad for absorbing energy comprising a polymeric gel and a
substrate contained within an envelope. The pad exhibits low
rebound velocity and high hysteresis, among other desirable
characteristics which are conducive to the function of a good
energy-attenuating material. The polymeric pad is capable of
repeatedly absorbing shock without structural damage and without
appreciable sag due to prolonged exposure to continuous dynamic
loading.
[0011] Generally the reinforced polymeric pad comprises a polymeric
gel and substrate enveloped by a top and bottom layer. The
substrate has a density less than that of the polymeric gel. The
substrate may be formed from a foamed plastic and may be a
continuous sheet or have perforations placed throughout. The
polymeric gel can be formed from an epoxidized vegetable oil, a
thermoplastic polymer and a prepolymer. The epoxidized vegetable
oil generally encompasses either an epoxidized soybean or linseed
oil, or combinations of the two. The top and bottom layer can be
formed from a non-woven resilient material.
[0012] In an additional embodiment, the reinforced polymeric pad
comprises a gel formed from an epoxidized vegetable oil and a
thermoplastic polymer which is substantially free of a
polyurethane, and a substrate formed from a foamed plastic. The
foamed plastic has a density less than that of the polymeric gel.
The pad comprises an envelope formed from two opposed layers joined
at the periphery. The gel and substrate are contained within the
envelope, and in one embodiment, the gel surrounds the
substrate.
[0013] A further embodiment includes a method of forming a
reinforced polymeric pad by joining two opposed layers to form an
envelope containing within a polymeric gel and a substrate. The
opposed layers may be fused together at the periphery using heat or
may be mechanically joined. The layers are typically formed from a
resilient non-woven material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a side view of the present reinforced polymeric
pad depicting the shock absorbing envelope comprising both the
polymeric gel and the substrate; and
[0015] FIG. 2 depicts a further embodiment of the reinforced
polymeric pad depicting the substrate having various perforations
enveloped in an envelope comprising the polymeric gel.
DETAILED DESCRIPTION
[0016] In greater detail, the present invention comprises a
reinforced polymeric pad including a shock absorbing envelope
comprising a polymer gel and a substrate. The shock absorbing
envelope is formed by the joining of two opposed layers 4, 6 joined
at the periphery to comprise a compartment formed between the two
layers 4, 6 wherein a substrate and polymeric gel are
contained.
[0017] The layers 4, 6 defining the envelope are typically formed
from a non-woven material such as a resilient polymeric polymer
sheet and are capable of withstanding repeated impact. The two
opposed layers 4, 6 defining the envelope in which the polymeric
material and substrate 10 are contained, may be formed of most any
material capable of providing impact resistance.
[0018] The substrate 10 typically has a density less than that of
the polymeric gel 8 and decreases the overall weight of the pad 2
while adding some rigidity to it. The substrate 10 may be formed of
most any material so long as it does not impede the impact
resistance of the reinforced pad 2. For example, the substrate 10
may be formed from a foamed plastic such as a polyvinyl chloride,
or the substrate 10 may be formed from a felt material.
[0019] The polymeric gel 8 component of the reinforced pad 2 may be
comprised of most any elastomeric material. While the gel 8
component is described as a polymeric gel 8, the term "gel" is not
meant to be restrictive and is only used to describe the component
as having gel-like qualities. The use of the term "gel" is not
intended to be restrictive as to describing only a colloidal
system, but is used to describe any semi-solid substance that is
both resilient and elastic. Typically, the polymeric gel 8 is
formed from an epoxidized vegetable oil combined with a prepolymer
and a thermoplastic polymer. The gel 8 compound is capable of
absorbing impact and energy and has a density greater than that of
the substrate 10.
[0020] Opposed Layers
[0021] The opposed layers 4, 6 defining an envelope therebetween,
can be fused together using heat if the layers 4, 6 are formed from
a material conducive to such fusing. An example of a fusible
material would be a vinyl sheet or other polymeric material that
melts and fuses upon solidification. Additionally the layers 4, 6
may be joined using mechanical means such as stitching, stapling or
other fasteners. Adhesives may also be used to join the layers 4, 6
together, or a combination of any of the methods mentioned above or
those known in the art may be used for joining the layers 4, 6.
[0022] The reinforced polymeric shock absorbing pad 2 may be
comprised of one or more envelopes residing in a single pad 2. The
two opposed layers 4, 6 may be joined at multiple points creating a
plurality of envelopes encompassing the substrate 10 and gel
compound.
[0023] The opposed layers 4, 6 may be formed from a sheet of a
resilient polymeric material. Additionally, the opposed layers 4, 6
may be formed from a woven or a non-woven material capable of
containing the gel 8 and substrate 10 and able to withstand
rupturing upon impact. Furthermore, it is contemplated that the
envelope may be comprised of more that two layers 4, 6 and that the
envelope may be encased in a further envelope to add protection and
durability to the pad 2.
[0024] Substrate
[0025] The substrate 10 functions essentially as a filler for
providing both weight reduction in the pad 2 and rigidity. The
substrate 10 may be formed from a foam polymer such as a PVC, or a
nonwoven material such as a felt pad. Additionally, other materials
are also known in the art, which have a density less than the gel 8
and can provide the same functions. The substrate 10 may formed
from a continuous sheet of material or may have perforations as
illustrated in FIG. 2. Additionally, the substrate 10 may
substantially span the entire envelope or just reside in a portion
of the envelope. In one embodiment it is contemplated that the
substrate 10 spans at least 50% or more of the area of the pad 2.
In a further embodiment, the substrate 10 spans at least 75% of the
pad 2.
[0026] The thickness of the substrate 10 is limited only be the
desired ultimate thickness of the pad 2 and the desired overall
weight in the pad 2. Furthermore, the substrate 10 may be a
continuous sheet or be comprised of multiple sheets within the pad
2. It is further contemplated that the substrate 10 may be
comprised of particles such as foamed beads of PVC, which are less
dense that the polymeric gel 8.
[0027] Polymeric Gel
[0028] The energy absorbing polymeric compound may be comprised of
most any polymeric gel. Typically, and in an embodiment, the gel 8
has a density greater than the substrate 10. The gel 8 incorporated
into the envelope is both viscoelastic and shock-attenuating.
[0029] An example gel 8 compound is one that comprises an
epoxidized vegetable oil combined with a prepolymer and a
thermoplastic polymer. Additionally, a catalyst or an accelerant
may be added to the energy absorbing compound to aid in the
formation of the compound. Typically the activator or accelerant is
a metal activator such as an alkyl tin compound.
[0030] The elastomeric compound includes an epoxidized vegetable
oil which can function as a plasticizer. By way of example, the
epoxidized vegetable oils can include epoxidized soybean oil,
epoxidized linseed oil and epoxidized tall oil. Additional examples
of epoxidized vegetable oils include epoxidized corn oil,
epoxidized cottonseed oil, epoxidized perilla oil and epoxidized
safflower oil. Epoxidized vegetable oils are typically obtained by
the epoxidation of triglycerides of unsaturated fatty acid and are
made by epoxidizing the reactive olefin groups of the naturally
occurring triglyceride oils. Typically, the olefin groups are
epoxidized using a peracid. One example of an acceptable epoxidized
vegetable oil is an epoxidized soybean oil, Paraplex G-62,
available from C.P. Hall Company of Chicago, Ill. Paraplex G-62 can
function as both a plasticizer and a processing aid and is a high
molecular weight epoxidized soybean oil on a carrier having an
auxiliary stabilizer for a vinyl group.
[0031] The elastomeric composition includes a prepolymer. Various
prepolymers may be utilized in the present composition so long as
they do not substantially hinder the desired viscoelastic,
shock-attenuating attributes of the elastomeric compound.
Typically, the prepolymer is an isocyanate.
[0032] The thermoplastic component can include most any
thermoplastic compound having elastomeric properties. In one
embodiment of the gel 8, thermoplastic compounds comprising
polyurethane are excluded. Acceptable thermoplastic component
includes polydienes. An example polydiene includes polybutadiene.
Typically, the activator or catalyst is an alkyl tin compound is
also added to the gel 8 compound. A specific example of an alkyl
tin compound is a dioctyltin carboxylate.
[0033] It is within the scope of the present invention to
incorporate other additives such as fillers, pigments, surfactants,
plasticizers, organic blowing agents, as stabilizers, and the like,
in the manufacture of the reinforced polymeric shock absorbing pad
2.
[0034] It will be understood by those skilled in the art that while
the present invention has been discussed above with respect to
various preferred embodiments and/or features thereof, numerous
changes, modification, additions and deletions can be made thereto
without departing from the spirit and scope of the invention as set
forth in the following claims.
* * * * *