Note: Descriptions are shown in the official language in which they were submitted.
COOLING MATERIAL
[0001]
Technical Field
[0002] Embodiments of the present disclosure relate generally to
fabrics used
for apparel having enhanced cooling properties, and in particular to fabrics
that
utilize absorbent polymer elements coupled to a wicking base fabric to enhance
cooling.
Background
[0003] Performance fabric materials such as wicking materials and
cooling
materials typically take the form of uniform layers that are woven into or
otherwise
incorporated into the interior of a garment. Cooling fabrics that incorporate
a layer of
cooling materials such as highly absorbent polymers have shortcomings,
particularly
when incorporated into the fabric as a continuous layer. For example, a
uniform layer
of polymer material may impede the transfer of moisture vapor or restrict air
passage
through the fabric. Furthermore, such cooling materials may impede a desired
characteristic of the base fabric, such as drape, texture, stretch, and the
like. Thus,
the use of a layer of cooling material may impede the breathability (or
another
function) of the underlying base fabric.
Brief Description of the Drawings
[0004] Embodiments of the present disclosure will be readily
understood by
the following detailed description in conjunction with the accompanying
drawings.
Embodiments are illustrated by way of example and not by way of limitation in
the
figures of the accompanying drawings.
[0005] Figures 1A-1D show several perspective views of one example of
a
cooling material having a base fabric with a high moisture wicking rate and a
discontinuous pattern of highly absorbent polymer elements disposed thereon,
CA 2944485 2018-03-13
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
including a view of moisture contacting one portion of the base fabric (Figure
1A), a
view of the base fabric dispersing the moisture over a large surface area via
a
wicking action (Figure 18), a view of the highly absorbent polymer elements
absorbing moisture from the base fabric (Figure 1C), and a view of the
moisture
evaporating from the absorbent polymer elements (Figure 1D), in accordance
with
various embodiments;
[0006] Figures 2A-2H illustrate a variety of specific, non-limiting
examples of
patterns of individual highly absorbent polymer elements in accordance with
various
embodiments;
[0007] Figures 3A-3F illustrate a variety of specific, non-limiting
examples of
patterns of interconnected highly absorbent polymer elements, in accordance
with
various embodiments; and
[0008] Figures 4A and Figure 48 show a comparison of the efficacy of a
control cooling polymer fabric (Figure 4A) versus a new cooling material
(Figure 48)
having a base fabric with a high moisture wicking rate, and a highly absorbent
polymer element disposed thereon, in accordance with various embodiments.
Detailed Description of Embodiments
[0009] In the following detailed description, reference is made to the
accompanying drawings which form a part hereof, and in which are shown by way
of
illustration embodiments in which the disclosure may be practiced. It is to be
understood that other embodiments may be utilized and structural or logical
changes
may be made without departing from the scope of the present disclosure.
Therefore,
the following detailed description is not to be taken in a limiting sense, and
the
scopes of embodiments, in accordance with the present disclosure, are defined
by
the appended claims and their equivalents.
[0010] Various operations may be described as multiple discrete operations
in
turn, in a manner that may be helpful in understanding embodiments of the
present
invention; however, the order of description should not be construed to imply
that
these operations are order dependent.
[0011] The description may use perspective-based descriptions such as
up/down, back/front, and top/bottom. Such descriptions are merely used to
facilitate
the discussion and are not intended to restrict the application of embodiments
of the
present invention.
2
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
[00121 The terms "coupled" and "connected," along with their derivatives,
may
be used. It should be understood that these terms are not intended as synonyms
for
each other. Rather, in particular embodiments, "connected" may be used to
indicate
that two or more elements are in direct physical contact with each other.
"Coupled"
may mean that two or more elements are in direct physical contact. However,
"coupled" may also mean that two or more elements are not in direct contact
with
each other, but yet still cooperate or interact with each other.
[0013] For the purposes of the description, a phrase in the form "A/B" or
in the
form "A and/or B" means (A), (B), or (A and B). For the purposes of the
description, a
phrase in the form -at least one of A, B, and C" means (A), (B), (C), (A and
B), (A
and C), (B and C), or (A, B and C). For the purposes of the description, a
phrase in
the form "(A)B" means (B) or (AB) that is. A is an optional element.
[0014] The description may use the phrases "in an embodiment," or "in
embodiments," which may each refer to one or more of the same or different
embodiments. Furthermore, the terms "comprising," "including," "having," and
the
like, as used with respect to embodiments of the present disclosure, are
synonymous.
[0015] In various embodiments, cooling materials for clothing and other
body
gear are disclosed that may use a discontinuous pattern (whether
interconnected or
having independent elements) of highly absorbent polymer elements coupled to a
body-facing surface of a base fabric that has a low resistance to moisture
spread
(e.g., a high wicking rate). In various embodiments, the highly absorbent
polymers
may leave portions of the base fabric exposed, for example, areas of the base
fabric
may be left uncovered between or among the highly absorbent polymer elements.
Additionally, the highly absorbent polymer elements may be significantly more
absorbent than the base fabric, such as two, three, four, five, or even ten or
more
times more absorbent. In various embodiments, the cooling materials may be
used
to manage moisture (e.g., sweat) and body heat.
[0016] In various embodiments, when the cooling material is exposed to
moisture, the base fabric may quickly wick the moisture away from the skin.
The
moisture may then be dispersed through/along the base fabric over a wide
surface
area via a wicking action, and the highly absorbent polymer elements may begin
absorbing moisture, both from the base fabric and directly from the skin. In
various
embodiments, this process may cause a redistribution of moisture, first from a
3
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
localized area of the base fabric to a larger area of the base fabric, and
then from the
base fabric into the highly absorbent polymer elements.
[0017] Thus, in various embodiments, by spreading the moisture over a large
surface area of the base fabric, and by drawing the moisture from the base
fabric
into the highly absorbent polymer elements, evaporation from the base fabric
may be
facilitated, which may accelerate the evaporative cooling experienced by the
wearer.
Additionally, in various embodiments, once the highly absorbent polymer
elements
have absorbed moisture from the base fabric, they may retain the moisture
close to
the skin surface and produce a prolonged evaporative cooling sensation for the
user,
for example when compared to that produced by the base fabric alone. In
various
embodiments, the highly absorbent polymer elements, and the uncovered portions
of
base fabric therebetween, may permit the base fabric to retain certain desired
characteristics, such as stretch, drape, breathability, moisture vapor
transfer, air
permeability, and/or wicking.
[0018] For the purposes of the present description, the term "discontinuous
pattern of highly absorbent polymer elements" includes an ordered or
disordered
pattern of independent elements, a matrix of interconnected elements, or a
hybrid of
both, with portions of the base fabric left exposed and uncovered by the
elements
between or amongst the discontinuous pattern. As used herein, the term
"absorbance" refers to the ability of a fiber or a polymer to absorb moisture,
for
example by diffusion. Absorbance typically is expressed as a percentage of
weight of
the starting material. By contrast, as used herein, the term "wicking" or
'wickability"
refers to the movement of bulk fluid along or between fibers, for example in a
fabric
or other textile. As such, a fabric or other textile may have both a high
wicking rate
and low absorbance.
[0019] As used herein, the term "endothermic" as applied to a process
refers
to a process in which the system absorbs energy from its surroundings in the
form of
heat. As applied to a fabric or composition, the term "endothermic" as used
herein
refers to a fabric or composition that absorbs heat from its surroundings, for
instance
upon a change of state or upon absorbing water or other fluids. For an
endothermic
reaction, All (the change in enthalpy) is greater than zero.
[0020] Figures 1A-10 show several perspective views of one example of a
cooling material having a base fabric with a high moisture wicking rate and a
discontinuous pattern of highly absorbent polymer elements disposed thereon,
4
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
including a view of moisture contacting one portion of the body-facing side of
the
base fabric (Figure 1A), a view of the base fabric dispersing the moisture
over a
large surface area via a wicking action (Figure 1B), a view of the highly
absorbent
polymer elements absorbing moisture from the base fabric (Figure IC), and a
view
of the moisture evaporating from the absorbent polymer elements through the
base
fabric and away from the body (Figure 1D), in accordance with various
embodiments. In various embodiments, a cooling material 100 may include a
plurality of highly absorbent polymer elements 104 disposed on a base fabric.
[0021] Thus, in various embodiments, the base fabric 102 may have a high
moisture wicking rate and a low absorbance compared to the absorbance of the
highly absorbent polymer elements 104. Wicking rate may be measured using any
of
a variety of tests known to those of skill in the art. For instance, one
measure
involves determining the distance a fixed volume of moisture spreads from an
emanation point when dropped onto the surface of a fabric. Generally, the
greater
the distance the moisture travels from the emanation point, the stronger the
"wickability" of the fabric. Other suitable tests of wicking rate include the
Vertical
Wick Test (e.g., AATCC 197) and the moisture management test (MMT). As defined
herein, a fabric having a "high wicking rate" wicks at least three inches in
ten minutes
as measured using the Vertical Wick Test (AATCC 197).
[0022] Absorbance is also easily determined in a laboratory setting. In
various
embodiments, for example, when measured with a moisture sorption balance at
30 C and 80% relative humidity, the base fabric 102 may absorb about 0 - 2.0%
of
its weight in moisture, such as about 0.25 - 1.5%, about 0.5- 1.0%, or about
0.8%. In
various embodiments, by contrast, when measured with a moisture sorption
balance
at 30 C and 80% relative humidity, the highly absorbent polymer elements 104
may
absorb about 3.0 - 20% of their weight in moisture, such as about 3.3%, about
5.0%,
or about 10%. In some embodiments, the highly absorbent polymer elements 104
may absorb even more moisture, such as about 50% or even 100% of their weight
in
water.
[0023] In various embodiments, the highly absorbent polymer elements 104
may be several fold more absorbent than the base fabric 102, such as about 2X,
3X
4X 5X, 10X, 20X, 50X, 100X, 200X, or even 300X (or more) as absorbent than the
base fabric 102. For example, in one specific, non-limiting example, the
highly
absorbent polymer elements 104 may absorb about 3.3% moisture by weight as
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
measured under the conditions listed above, whereas the base fabric 102 may
absorb only about 0.8% moisture by weight, making for about a four-fold
difference
in absorbance between the base fabric 102 and the highly absorbent polymer
elements 104. Without being bound by theory, it is believed that this
absorbance
differential between the base fabric 102 and the highly absorbent polymer
elements
104 pulls moisture from the base fabric 102 into the highly absorbent polymer
elements 104, thus enhancing evaporative cooling and creating a sensation of
dryness in the base fabric 102.
[0024] In various embodiments, the highly absorbent polymer elements 104
may be disposed in a generally discontinuous array or pattern, whereby some of
the
base fabric 102 may be exposed within or between adjacent highly absorbent
polymer elements 104. In various embodiments, the highly absorbent polymer
elements 104 may be arranged in an array of separate elements, whereas in
other
embodiments, discussed at greater length below, the highly absorbent polymer
elements 104 may be arranged in an interconnected pattern. In some
embodiments,
a highly absorbent polymer element may take the form of a solid shape or
closed
loop member, such as a circle, square, hexagon, or other shape. In other
embodiments, the discontinuous pattern of highly absorbent polymer elements
104
may take the form of a lattice, grid, or other interconnected pattern.
[0025] As illustrated in Figures 1A and 1B, the highly absorbent polymer
elements 104 are positioned on the surface of the base fabric 102 facing the
wearer's skin, and as moisture 106 contacts the base fabric 102 (Figure 1A)
(for
instance, in the form of sweat from the skin of the wearer), it begins to
spread and
disperse laterally through the base fabric 102 (Figure 1B) due to the base
fabric's
high moisture wicking rate and low resistance to moisture spread. In some
embodiments, the base fabric 102 may be treated with a hydrophilic compound in
order to increase its moisture wicking rate or a hydrophobic compound to
assist in
movement of moisture in a desired direction. The base fabric's lower
absorbance
(compared to that of the highly absorbent polymer elements 104) also permits
the
moisture to travel freely within the cooling material 100.
[0026] As illustrated in Figure 1C, moisture may then contact the highly
absorbent polymer elements 104 and may begin to be absorbed, enhancing
evaporative cooling through the base fabric 102 and creating a sensation of
dryness
for the user. For example, in some embodiments, the highly absorbent polymer
6
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
elements 104 pull moisture from the surrounding base fabric 102, causing
accelerated evaporation and allowing the base fabric 102 to dry quickly, for
example
more quickly than base fabric 102 dries without highly absorbent polymer
elements
104. During this process, the highly absorbent polymer elements 104 absorb
moisture from the base fabric 102, and this redistribution of the moisture is
facilitated
both by the absorbance properties of the highly absorbent polymer elements 104
and the base fabric's low resistance to moisture spread and lower absorbance
when
compared to the highly absorbent polymer elements 104. This redistribution of
the
moisture from the base fabric 102 to the highly absorbent polymer elements 104
accelerates evaporative cooling from the base fabric 102 (and thereby the skin
of the
user), and also prepares the cooling material 100 for more prolonged cooling.
[0027] In various embodiments, moisture may have a higher equilibrium
concentration in the highly absorbent polymer elements 104 than it has in the
base
fabric 102. Without being bound by theory, it is believed that this difference
in
absorbance levels may create a concentration gradient within the cooling
material
100 as the highly absorbent polymer elements 104 absorb moisture from the base
fabric 102. In various embodiments, the moisture concentration gradient drives
moisture out of the base fabric 102 and into the highly absorbent polymer
elements
104. As the highly absorbent polymer elements 104 absorb moisture from the
base
fabric 102, the base fabric 102 is then capable of absorbing more moisture,
such as
perspiration from the body.
[0028] As illustrated in Figure *ID, moisture retained in the highly
absorbent
polymer elements 104 causes prolonged evaporation, pulling moisture in a
direction
away from the skin of the wearer (see arrows) until the cooling material 100
returns
to a dry state, in accordance with various embodiments. During this phase of
cooling,
the base fabric 102 may be largely dry, and most of the cooling function of
the
cooling material 100 may be provided by evaporation from the highly absorbent
polymer elements 104 during the prolonged cooling phase. In various
embodiments,
positioning the highly absorbent polymer elements 104 against (or next to) the
skin
of the wearer may help the wearer to experience a sensation of prolonged
evaporative cooling. For example, evaporation from the highly absorbent
polymer
elements 104 causes a reduction in the temperature of the cooling elements 104
in
much the same way that evaporation from the skin surface cools the skin. Thus,
in
various embodiments, positioning the cooler highly absorbent polymer elements
104
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
on the body-facing surface of the base fabric 102 allows the wearer to
perceive this
cooling sensation, whereas the cooling sensation may be less noticeable if the
highly
absorbent polymer elements 104 were positioned on the outward-facing surface
of
the base fabric 102. In some embodiments, the cooling fabrics disclosed herein
may
provide a cooling phase, defined as the period of cooling resulting from
evaporation
of a particular quantity of liquid/sweat, that lasts 110%, 120%, 150%, 200%
(or even
more) as long as the cooling phase provided by the base fabric alone.
[0029] Prior to the present disclosure, it was widely believed that
positioning
the cooling elements on the outward-facing surface of the base fabric 102
would
produce a superior cooling effect, as this arrangement allows for evaporation
from
the highly absorbent polymer elements 104 to proceed unencumbered by the base
fabric 102. However, as disclosed herein, it has now been found that
positioning the
highly absorbent polymer elements 104 on the body-facing surface of the base
fabric
102 enhances the coolness sensation perceived by the wearer, while still
allowing
moisture to evaporate and a steady rate through the base fabric 102.
[0030] As described below in greater detail, the highly absorbent polymer
elements 104 may include one or more hygroscopic polymers, such as a polymer
that may absorb and retain a liquid, and in some examples, may absorb
extremely
large amounts of a liquid relative to its mass. Hygroscopic polymers that
absorb
large amounts of liquids are referred to as superabsorbent polymers.Such water
absorbing polymers, which are classified as hydrogels when cross-linked,
absorb
aqueous solutions through hydrogen bonding with water molecules. A
superabsorbent polymer's ability to absorb water generally is a factor of the
ionic
concentration of the aqueous solution. For instance, in deionized and
distilled water,
a superabsorbent polymer may absorb 500 times its weight (for example, from 30-
60 times its own volume) and can become up to 99.9% liquid, but when put into
a
0.9% saline solution, the absorbency drops to approximately 50 times its
weight.
[0031] In various embodiments, the total absorbance and swelling capacity
may be controlled by the type and degree of cross-linkers used to make the
gel. Low
density cross-linked superabsorbent polymers generally have a higher absorbent
capacity and swell to a larger degree. These types of superabsorbent polymers
also
have a softer and more sticky gel formation. High cross-link density polymers
exhibit
lower absorbent capacity and swell, but the gel strength is firmer and can
maintain
particle shape even under modest pressure.
8
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
[0032] Superabsorbent polymers are commonly made from the polymerization
of acrylic acid blended with sodium hydroxide in the presence of an initiator
to form a
poly-acrylic acid sodium salt (e.g., sodium polyacrylate). Other materials
also may be
used to make a superabsorbent polymer, such as polyacrylamide copolymer,
ethlyene maleic anhydride copolymer, cross-linked carboxymethylcellulose,
polyvinyl
alcohol copolymers, cross-linked polyethylene oxide, and starch grafted
copolymer
of polyacrylonitrile (PAN). In other embodiments, the polymers may be a
homopolymer, and may include polysaccharides, polyurethanes, polyamides,
polyacrylates, and the like.
[0033] In specific embodiments, a highly absorbent polymer element may
include, for example, any suitable natural or synthetic polymeric material
that, in a
dry form, is capable of absorbing and storing many times its weight in water.
Specific, non-limiting examples of natural gums that may be used in highly
absorbent
polymer elements include xanthan, agar, pectin, locust bean gum, hydroxypropyl
guar gum, polyglucomannan gum, cationic guar gum, anionic guar gum, alginate,
irish moss, and gum arabic. Specific, non-limiting examples of cellulosics
that may
be used in highly absorbent polymer elements include methyl cellulose, ethyl
cellulose, carboxymethyl cellulose, carboxy ethyl cellulose, hydroxyethyl
cellulose,
hydroxymethyl cellulose, and hydroxypropylcellulose.
[0034] Specific, non-limiting examples of synthetic hydrogel polymers that
may be used in highly absorbent polymer elements include suitable crosslinked,
water-swellable acrylic copolymers. In particular embodiments, the synthetic
hydrogel polymers may include, without limitation, copolymers that include
repeat
units from one or more monomers selected from (meth)acrylic acid, maleic acid,
2-
(meth)acrylamido-2-methyl propane sulfonic acid, styrene sulfonate, vinyl
sulfonic
acid, and their corresponding ammonia, amine and alkali metal salts,
(meth)acrylarnide, vinyl alcohol, vinyl acetate, maleic anhydride, alkyl vinyl
ethers,
vinylmorpholinone, vinylpyrridine, vinyl pyrrolidone, and acrylonitrile; and
one or
more crosslinking agents selected from N,NE-methylenebis(meth)acrylamide,
(poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol
di(meth)acrylate,
trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, glycerol
acrylate
methacrylate, ethylene-oxide-modified trimethylolpropane tri(meth)acrylate.
pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate,
Malty'
cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine,
9
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
poly(meth)allyloxyalkanes, (poly)ethylene glycol diglycidyl ether, glycerol
diglycidyl
ether, ethylene glycol, polyethylene glycol, propylene glycol, glycerol,
pentaerythritol,
ethylenediamine, ethylene carbonate, propylene carbonate, polyethylenimine,
glycidyl (meth)acrylate, diallyl sucrose, triallyi sucrose Maltyl amine, and
Manyl
methyl ammonium chloride. Other specific examples of cooling polymers may
include paraffin (CnH2r32+), fatty acids (CI-13(CH2)2nCOOH), salt hydrates
(MnH20),
hygroscopic materials, trirnethylolethane, and lauric acid. In particular
embodiments,
the highly absorbent polymer elements may include polyamlate and/or sodium
polyacrylate mixed or cross-linked with a non-soluble compound, such as
polyurethane.
[0035] Other specific, non-limiting examples include styrenic block
copolymers, which are thermoplastic elastomers that may include at least three
blocks, for instance two hard polystyrene end blocks and one soft, elastomeric
(e.g.,
polybutadiene, polyisoprene, or their hydrogenated equivalents) midblock. In
various
embodiments, the hard and soft blocks may be immiscible, so that, on a
microscopic
scale, the polystyrene blocks form separate domains in the rubber matrix,
thereby
providing physical cross links to the rubber.
[0036] Additional highly absorbent polymers and methods to manufacture
such polymers are described, without limitation, in U.S. Patent Nos.
6,469,080,
6,399,668. 6,127,454, 6,087,002, 5,244,735, 4,925,603, and 4,734,478.
Additional
non-limiting examples of highly absorbent polymers that may be used in
accordance
with various embodiments include those available under the trade names
ALCOSORe from Ciba Specialty Chemicals, Chatanooga, Tenn.; DRYTECFr from
the Dow Chemical Company, Midland, Mich.; NORSOCRYt, and AQUAKEEF: ) from
Atofina, Paris, France; HYDROSORBTm from HYDROSOR8 Inc., Orange, Calif.;
AQUALIC CA t from Nippon, Shokubai Co., Ltd., Osaka, Japan; and PERMAXml
from The Lubrizol Corporation, Wickliffe, Ohio.
[0037] In various embodiments, the highly absorbent polymer elements 104
may cover a sufficient surface area of the base fabric 102 to achieve the
desired
degree of cooling, for example, having a surface coverage area of the highly
absorbent polymer elements 104 of about 5- 50%, about 10- 40%, about 15- 30%,
or about 20% in various embodiments. This coverage range leaves about 50¨ 95%,
about 60 - 90%, about 70 - 85%, or about 80% of the base fabric 102 uncovered
in
various embodiments. Generally, a sufficient area of base fabric 102 should be
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
exposed to provide the desired base fabric function (e.g., stretch, drape,
texture,
breathability, moisture vapor transfer, air permeability, and/or wicking). For
example,
if there is too little exposed base fabric, properties such as moisture vapor
transfer
and/or permeability may suffer greatly, and even disproportionately to the
percentage of coverage. As used herein, the term "surface coverage area"
refers to
a measurement taken from seam to seam on a given garment, and does not
necessarily correspond to the percentage of the entire garment covered by the
highly
absorbent polymer elements.
[0038] In accordance with various embodiments, the base fabric 102 may be a
part of any form of clothing or bodywear, which term is used herein to include
anything worn on or used close to the body, including, but not limited to,
athletic
wear such as compression garments, t-shirts, shorts, tights, sleeves,
headbands and
the like, outerwear such as jackets, pants, scarves, shirts, hats, gloves,
mittens, and
the like, footwear such as shoes, boots, slippers, and the like, sleepwear,
such as
pajamas, nightgowns, and robes, undergarments such as underwear, thermal
underwear, undershirts, brassieres, socks, hosiery, and the like, and other
items
used close to the body, such as bedding, towels, backpacks, and the like.
[0039] In various embodiments, the highly absorbent polymer elements 104
may be disposed on a base fabric 102 having one or more desired properties or
characteristics. For example, the underlying base fabric 102 may have
properties
such as air permeability, moisture vapor transfer, and/or wickability, which
are
common needs for bodywear used in both indoor and outdoor applications. In
some
embodiments, the underlying base fabric 102 may have other desirable
attributes,
such as abrasion resistance, anti-static properties, anti-microbial activity,
water
repellence, flame repellence, hydrophilicity, hydrophobicity, wind resistance,
UV
protection, resiliency, stain resistance, wrinkle resistance, and the like. In
some
embodiments, the areas of uncovered base fabric 102 between and/or inside
highly
absorbent polymer elements 104 may help allow the base fabric 102 to have a
desired drape, look, stretch, and/or texture. Specific examples of suitable
base
fabrics 102 may include nylon, polyester, rayon, cotton, spandex, wool, silk,
or a
blend thereof, or any other material having a desired look, feel, weight,
thickness,
weave, texture, or other desired property. One example for a suitable base
fabric
102 is a fabric made from polyester fiber, although any fabric having suitable
properties, such as high wickability and very low absorbance may be used. As
used
11
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
herein, the term "low absorbance" when used with reference to a fabric, refers
to a
fabric having fibers that absorb less than 1.0% moisture by weight when
measured
at 80% relative humidity and 30 C.
[0040] in various embodiments, configuring the cooling material to allow a
designated percentage of the base fabric 102 to remain uncovered by the highly
absorbent polymer elements 104 may allow that portion of the base fabric 102
to
perform the desired functions, while still leaving enough surface area of
highly
absorbent polymer elements 104 to cool the body to a desired degree. In
various
embodiments, single-layer bodywear may be used, and may be comprised of a
single layer of the base fabric 102, whereas other embodiments may use
multiple
layers of fabric, including, for example, one or more additional layers of the
base
fabric or another fabric. For instance, the base fabric 102 may be used as a
fabric
lining for bodywear.
[0041] In various embodiments, the highly absorbent polymer elements 104
may be disposed on a lower or inside surface of the base fabric 102 (e.g., an
inside
surface of the body gear, facing the skin), placing the highly absorbent
polymer
elements 104 in a good position for absorbing sweat directly from the skin of
a user.
However, in some embodiments, the highly absorbent polymer elements 104 may be
at least partially integrated into or may at least partially permeate base
fabric 102, so
long as they still face the body of a user.
[0042] In various embodiments, the highly absorbent polymer elements 104
may have little or no endothermicity. Endothermicity is measured using
Differential
scanning calorimetry (DSC), which is a technique that monitors heat effects
associated with phase transitions and chemical reactions as a function of
temperature. In a DSC, the difference in heat flow to the sample and a
reference at
the same temperature is recorded as a function of temperature. The reference
is an
inert material such as alumina, or just an empty aluminum pan. The temperature
of
both the sample and reference are increased at a constant rate. Since the DSC
is at
constant pressure, heat flow is equivalent to enthalpy changes, and can be
either
positive or negative. In an endothermic process, such as most phase
transitions,
heat is absorbed and, therefore, heat flow to the sample is higher than that
to the
reference. Hence AdH/dt is positive.
[0043] in various embodiments, the absorbance of water by certain
materials,
including certain superabsorbent polymers, is an endothermic process. Prior to
the
12
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
present disclosure, it was believed that the endothermic properties of certain
materials, such as cooling polymers and phase change materials, caused the
bulk of
the cooling sensation perceived by a user of a cooling fabric incorporating
these
materials. Thus, prior to the present disclosure, polymers deemed suitable for
use in
cooling fabrics typically had at least some endothermic properties.
[0044] Surprisingly, as disclosed herein, it has now been found that
endothermic properties are not necessary or desirable properties for a cooling
polymer, as evaporative cooling provides the bulk of the cooling effect that
is
perceived by a user when the highly absorbent elements are positioned on the
body-
facing surface of the base fabric. Additionally, endothermic materials can be
costly
and may have other undesirable characteristics relating to durability and
texture. As
such, in various embodiments, a highly absorbent polymer for use in the
disclosed
cooling fabrics may have no endothermic properties. As defined herein, a "non-
endothermic" polymer is defined herein to include any polymer having an
enthalpy of
less than 10 Jg-1 as measured by DSC.
[0045] In various embodiments. the highly absorbent polymer elements 104
may be permanently coupled to the base fabric 102 in a variety of ways,
including,
but not limited to gluing, heat pressing, printing, or stitching. In some
embodiments,
the cooling elements may be coupled to the base fabric by frequency welding,
such
as by radio or ultrasonic welding. In some embodiments, the highly absorbent
polymer elements 104 may be coupled to the base fabric using gravure coating.
In
some specific, non-limiting examples, the gravure coating process may use an
engraved roller running in a coating bath, which fills the engraved dots or
lines of the
roller with the coating material (e.g., the gel making up the cooling
elements). The
excess coating on the roller may be wiped off using a blade, and the coating
may
then be deposited onto the substrate (e.g., the base fabric) as it passes
between the
engraved roller and a pressure roller. In various embodiments, the gravure
coating
process may include direct gravure, reverse gravure, or differential offset
gravure,
and in various embodiments, the coat weight may be controlled by the percent
of
solids, the gravure volume, the pattern depth, and/or the speed of the gravure
cylinder.
[0046] In various embodiments. the highly absorbent polymer elements may
be applied in a pattern or a continuous or discontinuous array. For example,
as
illustrated in Figures 2A -2H, the highly absorbent polymer elements may take
the
13
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
form of an array of discrete solid or closed loop members, adhered or
otherwise
secured to the base fabric in a desired pattern. Such a configuration has been
found
to provide cooling to the user while still allowing the base fabric to perform
desired
properties (e.g., breathe and stretch). In various embodiments, such
discontinuous,
discrete, separate cooling elements may take the form of circles, triangles,
squares,
pentagons, hexagons, octagons, stars. crosses, crescents, ovals, or any other
solid
shape or a substantially closed loop member that includes a center portion
inside the
closed loop member wherein the base fabric remains exposed.
[0047] Although the embodiments illustrated in Figures 2A ¨ 2H show the
highly absorbent polymer elements as separate, discrete elements, in some
alternate embodiments, some or all of cooling elements may be arranged such
that
they are in connection with one another, such as stripes or a matrix/lattice
pattern or
any other pattern that permits partial coverage of the base fabric. For
example, as
illustrated in Figures 3A ¨ 3F, the configuration of cooling elements disposed
on a
base fabric may be in the form of a variety of partially or completely, and
the pattern
may combine both discontinuous elements (such as those illustrated in Figures
2A ¨
2H) and interconnected geometrical patterns (such as those illustrated in
Figures 3A
¨ 3F). In various embodiments, the pattern of highly absorbent polymer
elements
may be symmetrical, ordered, random, and/or asymmetrical. Further, as
discussed
below, the pattern of highly absorbent polymer elements may be disposed on the
base fabric at strategic locations to improve the performance of the bodywear.
In
various embodiments, the size and/or spacing of the highly absorbent polymer
elements may also be varied in different areas of the bodywear to balance the
need
for enhanced cooling properties and preserve the functionality of the base
fabric.
[0048] In various embodiments, the placement, pattern, and/or coverage
ratio
of the cooling elements may vary. For example the cooling elements may be
concentrated in certain areas where cooling may be more critical (e.g., the
body
core) and non existent or extremely limited in other areas where the function
of the
base fabric property is more critical. In various embodiments, different areas
of the
bodywear may have different coverage ratios, e.g. 30% at the chest and 5% at
the
limbs, in order to help optimize, for example, the need for cooling and
breathability.
[0049] In various embodiments. the size of the highly absorbent polymer
elements may be largest (or the spacing between them may be the smallest) in
the
core regions of the body for enhanced cooling in those areas, and the size of
the
14
SUBSTITUTE SHEET (RULE 26)
CA 02944495 2016-09-29
WO 2015/153926
PC1/US2015/024176
highly absorbent polymer elements may be the smallest (or the spacing between
them may be the largest) in peripheral areas of the body. In some embodiments,
the
degree of coverage by the highly absorbent polymer elements may vary in a
gradual
fashion over the entire garment as needed for regional cooling.
[0050] Examples
[0051] Example 1
[0052] This example illustrates a comparison of the heat-managing
properties
of an existing cooling polymer fabric (Omni Freeze ZeroTM) with a new cooling
material that has a discontinuous pattern of highly absorbent polymers coupled
to a
base fabric that has a low resistance to moisture spread. The temperature of
both
fabrics was measured after having moisture added using a steamer. Figure 4A
illustrates the Delta T of the control cooling polymer fabric, and Figure 4B
illustrates
the Delta T of the new cooling material. The new cooling material performed
better,
reaching a larger Delta T while keeping an extended cooling beyond the control
cooling polymer fabric.
[0053] Although certain embodiments have been illustrated and described
herein, it will be appreciated by those of ordinary skill in the art that a
wide variety of
alternate and/or equivalent embodiments or implementations calculated to
achieve
the same purposes may be substituted for the embodiments shown and described
without departing from the scope of the present disclosure. Those with skill
in the art
will readily appreciate that embodiments in accordance with the present
disclosure
may be implemented in a very wide variety of ways. This application is
intended to
cover any adaptations or variations of the embodiments discussed herein.
Therefore,
it is manifestly intended that embodiments in accordance with the present
disclosure
be limited only by the claims and the equivalents thereof.
SUBSTITUTE SHEET (RULE 26)
