Note: Descriptions are shown in the official language in which they were submitted.
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MOLTEN PLASTIC POLYMER FIBERS AND PRODUCTS MADE THEREFROM
This is a divisional application of Canadian
Patent Application No. 2,137,513, filed December 7, 1994.
Field of the Invention
This invention relates to absorbent products and
absorbent materials useful in the manufacture of absorbent
products, such as sanitary napkins, pantyliners,
incontinence devices, diapers, and to such related absorbent
products.
The subject matter of this divisional application
is directed towards substrates, and articles containing
substrates, coated on at least one side with plastic
microfibers.
The subject matter of the parent was restricted
towards substrates, and articles containing substrates,
coated on at least one side with adhesive microfibers.
However, it should be understood that the expression "the
invention" and the like, used herein, encompass the subject
matter of both the parent and this divisional application.
Background of the Invention
Absorbent products such as sanitary napkins and
diapers typically comprise an absorbent core, a liquid
impermeable backing material, and a liquid permeable facing
material. The impermeable backing material prevents the
bodily fluid from seeping out from the absorbent core and
staining the wearer's clothing. The absorbent core is also
covered with a facing material that, inter alia, also serves
to contain the absorbent core.
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Normally, absorbent articles, such as pantyliners,
sanitary napkins, baby and adult diapers, as well as other
adult incontinence devices, are formed by securing a liquid
impermeable film to an absorbent core and then attaching a
facing material to the impermeable film thereby securing the
absorbent core between these two layers. See, e.g., Datta,
et al., U.S. Patent No. 4,892,534. This process is both
time consuming and expensive. Moreover, if the facing is
not in intimate contact with the core, the
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liquid on the surface of the facing will puddle up and not
penetrate through the facing but rather run off the surface.
This is highly undesirable behavior.
It is also undesirable to have the absorbent
products move during use. The attachment systems presently
available often fail fn this regard. During storage, the
attachment systems adhesive is covered with a release liner.
Polyethylene or silicone coated polyethylene paper is
frequently used on the liners. Current adhesive attachment
systems consist of continuous coating of pressure-sensitive
adhesives and a continuous silicone coating on a release
liner. Adhesives are normally thermoplastic rubber based and
hot melt coated, and are typically plasticized with oil. For
various reasons, the oil is an undesirablc component of the
adhesive. It imparts poor holding properties to the adhesive
and tends to move in the system by migrating frog the
adhesive to the film, which is quite undesirable. The
release liner on the attachment adhesive is not~naily silicone
or polyethylene coated paper. The resulting surface finish
of silicone coated papers is super smooth and the adhesive
contact is 100 with the release surface, which can be
problematic. Depending on the type of silicone coating, the
silicone release system may cause the adhesive to be too
easily released or too difficult to release, which is
undesirable. Thus, it is important that the release paler
have optimum release properties and at the same tine make
effective contact with the adhesive.
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Many absorbent products optionally contain liquid
absorbers, or odor absorbing materials to mask the potential
odor z~ssociated with the excreted bodily fluids. It has been
very difficult to immobilize such absorbents in disposable
producers. Frequently the powder moves, which is very
undesirable. In the past powders have been immobilized on
foams" or on continually coated pressure-sensitive adhesive
surfaces to adhere absorbent powder, and then inserted into
the absorbent product. However, these approaches are
expensive because a great quantity of adhesive is required
for ionmobilizing such materials.
Despite the advances that have been made in the
field of absorbent products such as sanitary napkins,
pantyliners, diapers, and incontinence products, there are
still needs to be addressed. For example, there is a need
for absorbent products that have better liquid transport
properties and better odor and liquid absorbing properties.
There is a further need for absorbent products with more
effective attachment systems to give the user more security
that the product will remain in place during routine use.
There is also a need for absorbent products that are
manufactured using less expensive and more efficient
techniques. The present invention addresses these, as well
as other needs in the art.
8umma~r~t of the Invention
The present invention utilizes microfiber
technology to provide absorbent products that have good
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liquid transport properties, good liquid and odor absorbing
properties, good attachment systems, and at the same time are
produced efficiently and cost effectively. The microfibers
of the invention comprise pressure-sensitive adhesives and/or
plastic polymers, depending on the purpose the microfiber
coating is to serve.
In general, the invention relates to a variety of
substrates coated with microfibers, either pressure-sensitive
adhesive microfibers or plastic polymer microfibers, at a
weight in the range of about 0.05 to 2 ounces/square yard;
the weight typically depends on the particular substrate, the
particular microfibers, and the particular use of the
substrate.
The pressure-sensitive adhesive microfibe~-s may be
coated onto substrates, such as a facing, backing, or
absorbent product to improve the absorbent products' liquid
transport properties, impart good liquid and odor absorbing
properties, and good attachment systems. Pressure-sensitive
adhesives generally comprise an elastomeric component, which
comprises a linear or radial A-B-A block copolymer and a
simple A-H block copolymer or combinations thereof, wherein
said A blocks are derived from styrene and said B blocks are
derived from alkenes or dienes; a resin component that
comprises a solid or liquid tackifier; and optionally a
plasticizer.
The plastic polymer microfibe~cs are used, inter
alia, for forming absorbent articles in situ or for forming
release liners with enhanced release properties. These
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plastic polymers are selected from the group consisting of
polyethylene, polypropylene, ethylene vinylacetate,
copolyesters, and plastic or thenooplastic rubber alloys.
In various embodiments, the microfibers typically
have an average diameter of less than about 100 microns;
however, this parameter also depends on the substrate, the
microfibers, and the particular use the microfiber coating is
to serve. The substrate may be an apertured, liquid
permeable film; a liquid impermeable backing; an absorbent
panel or core; or an absorbent product. Many of the
pressure-sensitive adhesive microfiber coated substrates and
plastic polymer microfiber coated substrates of the invention
may be used as components in a wide variety of absorbent
products such as sanitary napkins, pantyliners, incontinence
devices, and diapers, without limitation. For example, the
attachment systems, components with enhanced liquid transport
properties, and the odor and liquid absorbing components
disclosed herein have general application to absorbent
articles. ~ach of these embodiments, as well as others, are
discussed below.
In one embodiment of the invention, absorbent
components having enhanced liguid transport properties are
presented. These components may be incorporated into a wide
variety of absorbent products. These components typically
comprise a liquid permeable facing material coated with
pressure-sensitive adhesive microfibers. The coated facing
material is then placed adjacent to an absorbent core, with
the coated side adjacent to the core. The coating of
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pressure-sensitive microfibers enhances liquid transport
properties by placing the facing and absorbent core in
intimate contact with each other. Products incorporating
these components may further comprise a liquid impermeable
backing.
In another embodiment of the invention, pressure-
sensitive adhesive microfibers may be used to prepare liquid
or odor absorbing components that may be incorporated into a
variety of absorbent ;products. Components such as a facing
or backing material or an absorbent core are coated with
pressure-sensitive adhesive microfibers. The pressure-
sensitive adhesive microfibers are further coated with a
liquid or odor absorbent.
In another embodiment of the invention, systems for
attaching absorbent products to a wearer's garment are
disclosed. The attachment systems of the invention comprise
a substrate that is coated with pressure-sensitive adhesive
microfibers on the side of the substrate that faces the
garment, and a release paper that protects the pressure-
sensitive adhesive coating up until the time the product is
used. These attachment systems may be used in a variety of
absorbent products.
Another aspect of the invention relates to forming
absorbent products ire situ. These absorbent products have
~5 plastic polymer micrafiber coatings in place of standard
liquid permeable covers and/or liquid impermeable backings --
that is, the facing and backing can be formed in situ. For
example, an absorbent core may be coated with plastic polymer
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microfibers on the body-facing side of the absorbent core
thereby forming a liquid permeable~facing over the core. In
another example, an absorbent core may be sprayed on both
sides with plastic polymer microfibers, forming a liquid
permeable facing surface on one side of the absorbent-core
and a liquid impermeable backing surface on the opposite side
of the absorbent core.
The invention further embodies absorbent products
for adhesive attachment to a wearer's garment incorporating
the aforementioned components. Such absorbent products
comprise a liquid impermeable backing, which may optionally
be coated with pressure-sensitive adhesive microfibers, and
optionally have a liquid or odor absorbent immobilized on it;
a liquid permeable facing, which may optionally be coated
with pressure-sensitive adhesive microfibers, and optionally
have a liquid or odor absorbent immobilized on ft; an
absorbent core fixed between the facing and backing, which
may optionally be coated with pressure-sensitive a~esive
microfibers, and optionally have a liquid or odor absorbent
immobilized on it; pressure-sensitive microfiber adhesive
coating on the body-facing surface of the backing that is
contacted with the wearer's garment; and a release paper
covering over the pressure-sensitive adhesive.
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According to one aspect of the invention of the
parent application, there is provided a substrate coated on
at least one surface with pressure-sensitive adhesive
microfibers at a weight of about 0.05 to about 2
ounces/square yard, wherein said pressure-sensitive adhesive
microfibers comprise about 100 parts of an elastomeric
component; about 20 to 300 parts of a resin component; and
about 0 to about 70 parts of a plasticizer, with parts
expressed in parts per one hundred parts by weight of the
elastomeric component; and said microfibers have an average
diameter of less than about 100 microns.
According to another aspect of the invention of
the parent application, there is provided the substrate
defined herein wherein said substrate is an apertured,
liquid permeable film.
According to still another aspect of the invention
of the parent application, there is provided an absorbent
article comprising: a) the liquid permeable film defined
herein; and b) an absorbent core, wherein said core is
contacted with said microfiber adhesive coated surface of
said liquid permeable film.
According to yet another aspect of the invention
of the parent application, there is provided the substrate
defined herein wherein said substrate is a liquid
impermeable backing.
According to a further aspect of the invention of
the parent application, there is provided the substrate
defined herein wherein said substrate is an absorbent
product intended for adhesive attachment to a wearer's
garment, wherein said pressure-sensitive adhesive microfiber
coating is on the garment facing surface of said absorbent
product.
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According to yet a further aspect of the invention
of the parent application, there is provided the absorbent
product defined herein wherein said pressure-sensitive
adhesive microfiber coating has a coating weight of about
0.2 to about 1 ounces/square yard, wherein said elastomeric
component comprises about 10-100 parts of a linear or radial
A-B-A block copolymer and about 0-90 parts of a simple A-B
block copolymer, wherein said A blocks are derived from
styrene or styrene homologues, and comprise between about 5
to about 50~ by weight of the A-B copolymer; said B blocks
are derived from alkenes or dienes; and the total styrene
content is less than about 50~; and said resin component
comprises a tackifier and said microfibers have an average
diameter of less than about 50 microns.
According to still a further aspect of the
invention of the parent application, there is provided the
absorbent product defined herein wherein said pressure-
sensitive adhesive microfiber coating has a coating weight
of between about 0.2 to about 0.5 ounces/square yard or less
and said microfibers have an average diameter of between
about 1 to about 25 microns.
According to another aspect of the invention of
the parent application, there is provided an absorbent
product for adhesive attachment to a wearer's garment
comprising: a) a liquid impermeable backing; b) a liquid
permeable facing; c) an absorbent core fixed between said
facing and backing; d) a pressure-sensitive adhesive
microfiber coating on the surface of said backing that is
contacted with said wearer's garment; e) a release paper
covering, wherein said release paper is a paper coated with
microfibers of a plastic polymer wherein the plastic polymer
is selected from the group consisting of polyethylene,
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polypropylene, ethylene vinylacetate, copolyesters and
plastic and thermoplastic rubber alloys.
According to yet another aspect of the invention
of the parent application, there is provided an absorbent
product for adhesive attachment to a wearer's garment
comprising: a) an absorbent core coated on one side with
plastic polymer microfibers, wherein said plastic polymer is
selected from the group consisting of polyethylene,
polypropylene, ethylene vinylacetate, copolyesters, and
plastic and thermoplastic rubber alloys, and said plastic
polymer microfibers have a coating weight between about 0.2
to about 0.8 ounces/square yard; and said plastic polymer
microfibers have a diameter between about 0.5 to about 25
microns; b) a liquid impermeable backing secured to said
core on the side opposite the side coated with plastic
polymer microfibers; c) a pressure-sensitive adhesive
microfiber coating on the surface of said backing that is
contacted with said wearer's garment, wherein said pressure-
sensitive adhesive microfibers have a coating weight of
about 0.2 to about 0.4 ounces/square yard, and said
pressure-sensitive adhesive microfibers have an average
diameter of less than about 50 microns; d) a release paper
covering, wherein said release paper is a paper coated with
microfibers of a plastic polymer wherein the plastic polymer
is selected from the group consisting of polyethylene,
polypropylene, ethylene vinylacetate, copolyesters and
plastic and thermoplastic rubber alloys.
According to a further aspect of the invention of
the parent application, there is provided an absorbent
product for adhesive attachment to a wearer's garment
comprising: a) an absorbent core coated on both sides with
plastic polymer microfibers, wherein said plastic polymer is
selected from the group consisting of polyethylene,
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polypropylene, ethylene vinylacetate, copolyesters, and
plastic and thermoplastic rubber alloys; and said plastic
polymer microfibers have a coating weight between about 0.2
to about 0.8 ounces/square yard; and said plastic polymer
microfibers have a diameter between about 1 to about 25
microns; b) a pressure-sensitive adhesive microfiber coating
on the surface of said backing that is contacted with said
wearer s garment, wherein said pressure-sensitive adhesive
microfibers have a coating weight of about 0.2 to about 0.4
ounces/square yard; and said pressure-sensitive adhesive
microfibers have an average diameter of less than about 50
microns; c) a release paper covering, wherein said release
paper is a paper coated with microfibers of a plastic
polymer wherein the plastic polymer is selected from the
group consisting of polyethylene, polypropylene, ethylene
vinylacetate, copolyesters and plastic and thermoplastic
rubber alloys.
According to one aspect of the present divisional
application, there is provided an~article of manufacture
comprising a substrate coated with microfibers of a plastic
polymer, wherein said plastic polymer is selected from the
group consisting of polyethylene, polypropylene, ethylene
vinylacetate, copolyesters, and plastic and thermoplastic
rubber alloys.
According to another aspect of the present
divisional application, there is provided an absorbent
product comprising: a) an absorbent core, wherein said
absorbent core is coated with plastic polymer microfibers on
one side, wherein said plastic polymer is selected from the
group consisting of ~>olyethylene, polypropylene, ethylene
vinylacetate, copolyesters, and plastic and thermoplastic
rubber alloys; and b) a liquid impermeable backing, wherein
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said backing is adjacent to the absorbent core on the side
opposite of the plastic polymer microfiber coating.
According to still another aspect of the present
divisional application, there is provided an absorbent
product comprising an absorbent core, wherein said absorbent
core is coated on both sides with plastic polymer microfibers
thereby forming a permeable liquid facing surface on one side
of the absorbent core and an impermeable liquid backing
surface on the opposite side of the absorbent core, wherein
said plastic polymer is selected from the group consisting of
polyethylene, polypropylene, ethylene vinylacetate,
copolyesters, and plastic and thermoplastic rubber alloys.
According to one aspect of the present divisional
application, there is provided an absorbent product
comprising an absorbent core having an upper surface directly
coated with plastic polymer microfibers and a liquid
impermeable backing adhered to a lower surface, the absorbent
product being formed by the following steps: forming an
absorbent core having an upper surface and a lower surface,
the upper surface being on a side opposite the lower surface,
directly coating the upper surface of the absorbent core by
spraying the upper surface with plastic polymer microfibers
to form a liquid permeable facing surface, wherein said
plastic polymer is selected from the group consisting of
polyethylene, polypropylene, ethylene vinylacetate,
copolyesters, and plastic rubber alloys; and adhering a
liquid impermeable backing to the lower surface of the
absorbent core wherein the entire liquid permeable facing
surface is in intimate contact and directly secured to the
absorbent core.
According to another aspect of the present
divisional application, there is provided an absorbent
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product comprising an absorbent core having an upper surface
and a lower surface directly coated with plastic polymer
microfibers, the absorbent product being formed by the
following steps: forming an absorbent core having an upper
surface and a lower surface, the upper surface being on a
side opposite the lower surface, directly coating said
absorbent core on both the upper surface and the lower
surface by spraying the upper surface and the lower surface
with plastic polymer microfibers thereby forming a liquid
permeable facing surface on one side of the absorbent core
and a liquid impermeable backing surface on the opposite side
of the absorbent core, wherein said plastic polymer is
selected from the group consisting of polyethylene,
polypropylene, ethylene vinylacetate, copolyesters, and
plastic rubber alloys; and wherein the entire facing surface
and the entire backing surface are in intimate contact and
directly secured to the absorbent core.
Brief Description of the Drawings
Figure 1 depicts a top and bottom view of an
absorbent product that is formed in situ. The absorbent
core 3 is being coated with microfibers 2 on the top
surface, the
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surface that faces the user's body 4, using a spray nozzle l
to form the liquid permeable facing. Fibers are also being
sprayed on the bottom S, the surface facing the wearer's
garment, to form the liquid impermeable backing 5. The
fibers are being sprayed onto the core's top and bottom
surfaces using a nozzle 1. The spray nozzle method is only
one method of spraying microfibers onto substrates. The
fibers sprayed using this method are typically spiral.
Another method for spraying microfibers is the melt-blown die
ifl technique, which sprays the mizrofibers straight; this
technique is preferable.
Figure 2-depicts an absorbent core 17 with a liquid
impermeable backing 6 secured to the core's 17 bottom side.
The top of the core 17 is being coated 9 with microfibers 8
thereby forming a liquid permeable facing 7 on the side of
the core opposite the backing 6.
Figure 3 depicts an absorbent product, sanitary napkin, with
a portion cut away to show the core 12; the facing 10 and
backing ii are also depicted. The core 1Z may be coated with
microfibers as depicted in Figure 1 before it is contacted
with the facing 10. Alternatively, the facing 10 or backing
11 may be coated with microfibers before being contacted with
the core 12. The microfibers sprayed on these various
substrates may have a liquid or odor absorbent immobilized on
it before the sanitary napkin is assembled.
Figure ~ illustrates a sanitary napkin and its various
components. The absorbent core 15 is fixed between the
facing 18 and the backing 16. The backing i6 is coated with
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adhesive microfibers 13 and then covered with a release paper
i4.
etailed Description of the Preferred Embodiments
The present invention presents absorbent
components, absorbent products, and materials utilizing
micro.fibers of pressure-sensitive adhesives and/or plastic
polymers. These pressure-sensitive adhesive and plastic
polymer microfibers are formed using molten spray technology.
The resulting microfibers can be incorporated, inter 8lia,
into absorbent articles to enhance liquid transport
properties, enhance liquid and odor absorbing properties, and
provide good attachment systems. The use of these pressure-
sensitive adhesives and plastic polymer microfibers produce
absorbent products more efficiently and economically than
available methods.
In the context of this invention, the term
"substrate" refers to any material that pan receive the
pressure-sensitive adhesive or plastic polymer microfibers in
accordance with the invention; for example, a facing
material, backing material, absorbent core, or absorbent
product, without limitation. As used herein, the
terminology "facing material" means that liquid-permeable
component of the absorbent product that is in contact with
the user's skin when in use and covers at least one side of
the absorbent core. The terminology "backing material"
means, as used herein, that portion of the absorbent product
that biomes in contact with the wearer's clothing and covers
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~ l0
at least one side of the absorbent core. In the context of
the invention, the terms "absorbent core" or "absorbent
panel" are used interchangeably, and mean that component of
the absorbent product fixed between the facing and backing
materials to absorb bodily fluid. The terminology "liquid
absorbent," "odor absorbent," and "super absorbent" refers to
any material that is capable of absorbing liquid or odor. In
the context of this invention, a "plasticizer" means any
material that gives an otherwise rigid material, such as
plastic, flexibility. Typically, plasticizers are used in
pressure-sensitive adhesives to give such adhesives wetness
or tackiness. As used herein "elastomeric" refers to
thermoplastic materials that can be linear, radial, or
branched molecular structures that will repeatedly soften
when heated and solidify when cooled, such as acrylics,
polyethylenes, polypropylenes, nylons, and thermoplastic
rubbers as styrene or isoprene and are a component of the
pressure-sensitive adhesives of the invention. In the
context of this invention, "resin" refers to any solid or
liquid organic material of natural or synthetic origin that
has a:n undefined melting point, and is generally a polymer.
As used herein, the term "plastic polymers" refers to
thermoplastic polymer materials such as polyethylene,
polypropylene, ethylene vinylacetate, copolyesters, and
rubber or plastic alloys, and are used in forming, inter
slis, absorbent products in situ and release liners. The
term "microfibers," as used herein, refers collectively to
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microfibers of pressure-sensitive adhesives and/or
thermoplastics, unless otherwise specified.
Fiberized pressure-sensitive adhesives and plastic
polymers can be applied in hot melt form using a spray
fiberization method to form absorbent components and products
with good attachment properties, good liquid transport
properties, and good odor and liquid absorbing properties.
Equipment is known in the art for forming microfibers -- the
microfiber nozzle spray (see Figures 1 and 2) or the melt
l0 blown die fiber formation process. Both of these systems
produce small diameter fibers having an average diameter not
greater than about 100 microns, the melt blown die process is
preferred. In both systems the molten microfibers are
extruded through a microspray nozzle or through a plurality
of circular capillaries as filaments which are then processed
through a low or high velocity gas (i.e., air) stream that
attenuates the filaments of molten microfibers to reduce
their diameter to a desired range for use in components of
absorbent products and absorbent products. These microfibers
when still in a substantially molten state or after some
cooling, depending on the microfibers and desired use, are
deposited on a desired substrate and allowed to cool further.
The microfibers of the invention are employed in
various manners in formulating absorbent articles and
materials used as component parts of absorbent articles, but
the microfibers generally preferably have certain properties.
The materials preferably have a high melt index, at least
above 100, and more preferably above 1000; thus requiring a
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low volume of air in the fiber making process. Such
materials will be readily apparent to those skilled in the
art once armed with the present disclosure and may be used
without departing from the spirit of the invention. The
microfibers are typically microsized, have an average
diameter of less than about 100 microns so they do not
interfere with liquid transport. where it is desired that
the microfibers not be affected by liquid, the microfibers
will preferably be hydrophobic, (i.e., when used to form a
liquids impermeable backing material). The microfiber
compositions preferably have a high plasticity so that they
do not: flow out excessively once deposited on a substrate.
The mi.crofibers preferably have a reasonable strength and the
pressure-sensitive adhesive microfibers, in particular,
should have good adhesive properties.
Typically the plastic polymers are selected from
the group consisting essentially of polyethylene,
polypropylene, ethylene vinylacetate, copolyesters, and
plastic or thermoplastic rubber alloys.
Typically the pressure-sensitive adhesives of the
invention comprise an elastomeric component, a resin
component, and optionally a plasticizer to enhance wetness
and tackiness. Generally, the pressure-sensitive adhesives
comprise linear or radial block copolymers jA-B-A), simple
block copolymers (A-B), or combinations thereof. The A-
block,s (end blocks) are derived, (i.e., polymerised), from
styrene or styrene homologues, and the B-blocks (center
blocks) are derived from conjugated dienes, such as isoprene
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or butadiene, or from lower alkenes, such as ethylene and
butylene, and polymers and copolymers thereof. Preferably,
these pressure-sensitive adhesives typically comprise
styrene-isoprene-styrene (SIS) thermoplastic block copolymers
having a low coupling efficiency (about 15-65t) and less than
about 30~ styrene.
In certain preferred embodiments, the pressure-
sensitive adhesive microfibers will have styrene-isoprene
(SI) i.n the elastomer, and are tackified with a solid or
l0 liquid resin, and may optionally be plasticized with a liquid
resin or liquid rubber. Following is a discussion of
preferred embodiments with all parts expressed in parts per
one hundred parts by weight of the elastomeric component.
The discussion of the pressure-sensitive adhesive microfibers
presents two general compositions, which may have varying
ratiofc of polymers. These two general compositions are for
illustrative purposes and are not intended to limit the
invention.
In certain compositions, the elastomeric component
preferably comprises from about 10 to about 100 parts of a
linear or radial A-H-A block copolymer and about 0 to about
90 parts of a simple A-B block copolymer, more preferably
from about 15 to about 75 parts of a linear or radial A-H-A
block copolymer and about 25 to about 85 parts of a simple A-
B block copolymer, more preferably from about 35 to about 75
parts of a linear or radial A-H-A block copolymer and about
25 to about 65 parts of a simple A-H block copolymer, more
preferably from about 50 to about 9O parts of a linear or
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radial A-8-A block copolymer and about 10 to about 50 parts
of a simple A-8 block copolymer, more preferably, the
elastomeric component will comprises from about 60 to about
80 parts of a linear or radial A-8-A block copolymer and
about 20 to about 40 parts of a simple A-B block copolymer,
the A blocks in the A-B block copolymer comprise from about 5
to about 50% by weight of the A-8 copolymer, more preferably
between about 10 to about 40%, and more prEferably between
about 10 to about 35%; and the total A-B and A-B-A copolymers
comprise less than about.50% styrene, more preferably less
than about 40%, and more preferably less than about 30%; and
the resin component comprises from about 20 to about 300
parts of a tackifier such as a solid or liquid resin or
combinations for said elastomeric component, more preferably
from about 100 to about 140 parts of a tackifier such as a
solid or liquid resin or combinations thereof for said
elastomeric component, more preferably 50 to 120 parts of a
solid or liquid resin or combinations thereof.
In other preferred embodiments, the elastomeric
component will comprise from about 15 to about 45 parts of a
linear or radial A-e-A block copolymer and about 55 to about
85 parts of a simple A-8 block copolymer, more preferably
from about 60 to about 7'S parts of the A-H block copolymer
and about 25 to about 40 parts of the A-8-A block copolymer,
the A blocks in the A-H block copolymer ~prefe~cably constitute
from about 5 to about 50% by weight of the A-B copolymer,
more preferably from about 10 to about 30%, from about 5 to
about 20%, more preferably from about 10 to about 18%, and
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more preferably from about 12 to about 16%.; and the total A-
B and A-H-A copolymers comprise less than about 30% styrene,
more preferably less than about 25%, and more preferably less
than about 20%; and the resin component preferably will
comprise from about 20 to about 300 parts of a tackifier such
as a solid or liquid resin or combinations thereof, more
preferably between about 40 to about 20a, and more preferably
50 to 120 parts of a resin.
These and other pressure-sensitive adhesives
suitable for practicing the claimed invention are set forth
in U.S. Patents Nos: 4,136,071, 4,080,348, and 4,759,?54
issued to Rorpman on January 23, 1979, March 21, 1978, and
July 26, 1988, respectively . Certain
components of the pressure-sensitive adhesives that may be
used in practicing certain specific aspects of the claimed
invention are commercially available. For example, Kraton RD
6043 is an SiS (styrene-isoprene-styrene) thermoplastic
rubber having a 42% coupling efficiency and 220,000 M.W., and
17% styrene and is available from the Shell Company. Kraton
111? is a commercially available thermoplastic rubber having
a 65% coupling efficiency and 1?% styrene. Kraton 111? i-s a
polystyrene-polyisoprene-polystyrene thermoplastic elastomer
sold by the Shell Company and is believed to comprise about
35 parts A-B and about 65 parts A-B-A. Other such pressure-
sensitive adhesive materials will be readily apparent to
those skilled in the art once armed with the present
CA 02499804 1994-12-07
74484-74D
~ 16
disclosure and may be used without departing from the spirit
of the invention.
The resin component consists essentially of
tackifier resins for the elastomeric component. In general
any compatible conventional tackifier resin or mixture of
such resins may be used. Suitable resins are any compatible
conventional tackifier resins or mixtures thereof. These
resins include, but are not limited to, hydrocarbon resins,
rosin and rosin derivatives, and polyterpenes. WingtackT~"
Plus, for example, is a commercially available resin.
Wingtack~"Plus is a solid tackifier resin sold by Goodyear
Tire and Rubber Company consisting predominantly of
polymerized structures derived from piperylene and isoprene
with a softening point of about 95°C. Other resins suitable
for use as tackifiers will be readily apparEnt to those
skilled in the art once armed with the present disclosure and
may be used without departing from the spirit of the
invention.
Plasticizers for pressure-sensitive adhesives
include, but are not limited to, LIR 310, which is a liquid
SI (styrene-isoprene) polymer available commercially from
Arakawa Chemical Company. WingtackT~"l0 is a liguid
hydrocarbon tackifier of resin believed to comprise synthetic
polyt erpene, and is used as a plasticizes for pressure-
sensitive adhesives. It has a softening point of 10°C, a
viscosity of 20-40,000 cps at room temperature and a
molecular weight of about 450. It is available from Goodyear
Chemical Company. Other plasticizers will be readily
CA 02499804 1994-12-07
74484-74D
apparent to those skilled in the art and may be used without
departing from the spirit of the invention.
Generally, the pressure-sensitivs adhesive and the
plastic polymer microfibers preferably have an average
diameter of less than about 100 microns, more preferably less
than about 50 microns, and in certain embodiments more
preferably between about 0.5 to about 25 microns. The
microfibers~ coating weight is preferably less than about 2
ounce;s/square yard, in certain other embodiments more
preferably about 0.75 ourrces/square yard, in certain other
embodiments more preferably betweEn about 0.3 to about 0.6
ounces/sguare yard, in yet other embodiments more preferably
between about 0.2 to about 0.3 ounces/square yard, and in
certain other embodiments more preferably the coating has a
weight of between about 0.05 to about 0.15 ounces/squara
yard. The particular variables are di$cussed below in
connection with various embodiments. The choice of the
microfibers, coating weight of the microfibers, and tit
diameter of the microfibers is typically dictated by the
particular use of the microfiber compositions.
The microfiber compositions used in the various
embodiments of the invention may also contain other
materials, such as antioxidants, heat stabilizers, and
ultraviolet absorbers. Antioxidants that may be incorporated
into the compositions, in particular the pressure-sensitive
adhesive compositions, include, but are not limited to,
Sanot~ovar A, which is a trademark for 2,5 diteriaryl amyl
hydroquinone, ditertiary butyl cresol, and Butyl 8imate,
CA 02499804 1994-12-07
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ig -
which is a trademark for zinc di-n-butyl-dithiocarbamate.
Any others known to those skilled in the art may be used
without departing from the spirit of the invention.
Fillers, such as zinc oxide, aluminum hydrate,
clay, calcium carbonate, titanium dioxide, carbon black, and
others may also be incorporated into the microfiber
compositions, in particular the pressure-sensitive adhesive
microfiber compositions, without departing from the spirit of
the invention. The various embodiments using pressure-
sensitive adhesive microfibers and/or plastic polymer
microfibers are presented below.
In general, one aspect of the invention presents a
substrate coated on at least one surface with pressure-
sensitive adhesive microfibers at a weight in the range of
aboul: 0.05 to about 2 ounces/square yard wherein said
pressure-sensitive adhesive microfibers comprise an
elastomeric component, a resin component, and optionally a
plasticizer; and said microfibers have an average diameter of
less than about 100 microns. Preferably, the elastomeric
component comprises a linear or radial A-H-A block copolymer
and a~ simple A-B block copolymer, wherein said.A blocks are
derived from styrene or styrene homologues and said ~ blocks
are derived from alkenes or dienes. The polymers of the
elastomeric component and their ratios have been discussed
above; the resin component and its ratio in the pressut~e-
sens;itive adhesive has also been discussed above.
In one more specific embodiment, the substrate is a
liquid permeable facing material 10. The facing material 10
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~ 1!
is coated with pressure-sensitive adhesive microfibers on the
side to be contacted with the core 12. These microfiber~
have a~ weight from about 0.05 to about 0.4 ounces/square
yard; preferably the coating weight is about 0.25
ounces>/square yard, mole preferably about. 0.18 ounces/-square
yard, and more preferably about 0.10 ounces/square ya=d. The
average diameter of the pressure-sensitive adhesive
microfibers is less than about 50 microns, more preferably
betweE=n about 1 to about 25 microns.
A facing material to coated with a layer of
pressure-sensitive adhesive microfibers can be used to
produce an absorbent product with enhanced liquid transport
properties. The pressure-sensitive adhesive microfiber
coated surface (underside of 10) of the facing material 10 is
placed adjacent to an absorbent coze iZ or panel, and the
adhesive fibers serve to maintain the facing in intimate
contact with the core while not obstructing passage of fluid
through the facing to the core i2. This structure ali~ows the
instantaneous transportation of liquids from the surface of
the facing material into the absorbent panel, leaving a
substantially dry surface on the body-facing surface of the
facing material. This is highly desirable because the user
is then protected from the liquid caused by bodily exudate.
The coated liquid permeable facing material is
incorporated into an absorbent product using techniques known
in the art. For example, the pressure-sensitive adhesive
coated side of the liquid permeable facing material is placed
adjacent to the absorbent core so that the two are in
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74484 -~ 74D
~ 20 ~
intimate contact, and then the outer rim of the facing
material is secured to the core. Any methods known to those
skilled in the art for accomplishing this contact may be used
without departing from the spirit of the invention.
Absorbent cores suitable for use with this
invention may be formed from both absorbent pulp fibers and
resilient, synthetic fibers. The pulp fibers are generally
formed from fiberizing wood pulp sheets and generally
comprise a combination of long and short fibers. Suitable
resilient, synthetic fibers include, but are not limited to,
polyester and polyethylene fibers. The relative amounts of
pulp fibers and synthetic fibers are not critical and can be
determined by one skilled in designing such products, in an
effort to balance and achieve the desired properties of
absorbency and resiliency. The wood pulp fibers and synthetic
fiber's may be blended homogeneously throughout the absorbent
core, or the relative proportions of each may vary throughout
the absorbent core.
Absorbent cores may also be formed by other known
techniques in which the fibers, pulp and/or synthetic, are
airlaid. To form the most stable core, the fibers in the
core are preferably bonded to one another. This may be done
by heating the core to a temperature above the melting
temperature of the synthetic fibers so those fibers fuse and
bond to one another. Alternatively, bonding agents such as
different thermo-bonding fibers, hot melt spray adhesives,
and bonding powders may be utilized. Sge~cific means that can
be used to bond the fibers together include convection ovens,
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- Zl
di-electric ovens (radio frequency and microwave), infrared
ovens, heated calendar rolls, forced hot-air ovens, forced
hot air during the panel forming process, and spray hot melt
adhesive during the panel forming process.
The liquid permeable facing provided on the
absorbent structure of the present invention should
preferably be a film or fabric having a high degree of
moisture permeability. For example, the fabric may be
polyester, polyethylene, polypropylene, bicomponent fiber,
nylon, rayon, or the like. The most suitable fabrics have
unusually high elongation, loft, softness and drape
characteristics. Films that are perforated or noncontinuous
are also satisfactory. Though the cover is moisture
permeable, it is preferably of the type which after
permeation of the moisture, prevents strike-back of the body
fluid when the absorbent structure is approaching saturation.
The liquid impermeable backing may be a liquid-
impermeable polyolefin film, e.g., ~oiyethylene or
polyethylene terephthalate.
In another specific embodiment, pressure-sensitive
adhesive microfibers may also be used to immobilize liquid or
odor absorbents on components of absorbent products, such as
a facing 10 or backing ii material, or absorbent core iZ.
These coated components may then be irncorporated into
absorbent products as depicted in Figures 3 and 4.
Heretofore, it has been difficult to immobilize
particular liquid or odor absorbents on a substrate (i.e., a
facing or backing material or an absorbent core) and then
CA 02499804 1994-12-07
74484--74D
Z~ -
incorporate the substrate into absorbent products. Often
these liquid or odor absorbers are powders that tend to move.
The pressure-sensitive adhesives can prevent this movement.
when used in this manner, the substrate receiving the
pressure-sensitive adhesive microfibers may be an absorbent
panel i2, facing material 1o, or backing material ii. It is
preferred that the coating weight be less than about 0.75
ounces/square yard, more preferably between about 0.35
ounces/square yard to about 0.6 ounces/square yard, and more
preferably about 0.4 ounces/square yard. It is preferred
that i:he average diameter of the pressure-sensitive adhesive
microfibers be less than about 50 microns, more preferably
between about 1 to about 25 microns. Absorbent products
containing liquid or odor absorbents, as described above, may
be made according to methods known to those skilled in the
art without departing from the spirit of the invention.
Generally, an absorbent powder is immobilized on a
pressure-sensitive adhesive coated facing material 10 before
the side of the facing material coated with the pressure-
sensitive adhesive (underside of 10) is contacted with an
absorbent core i2.
The absorbent powders or liquids that may be
incorporated into the absorbent products of the invention
will ',be readily apparent to those skilled in the art. For
example, superabsorbents are well known in the art. One type
of superabsorbent material provides particles or fibers that
may be described chemically as having a backbone of natural
or synthetic polymers with hydrophilic groups or polymers
CA 02499804 1994-12-07
74484-74D
~ 2~ ~
containing hydrophilic groups being chemically bonded to the
backbone or an intimate mixture therewith. Included in this
class of materials are such modified natural and regenerated
polymE:rs as polysaccharides including, for example, cellulose
and starch and regenerated cellulose which are modified by
being carboxylalkylated, phosphonoalkylated, sulfoalkylated,
or phosphorylated to render them highly hydrophilic. Such
modified polymers may also be cross-linked to improve their
water-insolubility. Odor control agents suitable for
practicing this invention include, but are not limited ~to,
baking soda and activated charcoal. Any other liquid or odor
absorlbent materials known to those skilled in the art may be
used without departing from the spirit of the invention.
In another specific embodiment of the invention,
the pressure-sensitive adhesive microfiber coating is used as
part ~of an attachment system 13 and 1~ for attaching
absorbent products to the user's garment. The substrate to
receive the coating 13 (see e.g., Figures 3 and 4) in this
embodiment is an absorbent product (see Figure 4); the side
facing the user's garment will receive the coating. The
coating 13 comprises pressure-sensitive adhesive microfibers
having a coating weight of between about 0.2 to about l
ouncea/square yard, more preferably between about 0.2 to
about: 0.75 ounces/square yard, and more preferably about 0.25
ounce~s/square yard or less. The pressure-sensitive adhesive
microfibers preferably have an average diameter of less than
about: 50 microns, more preferably less than 30 microns, and
more preferably have an average diameter of between about 1
CA 02499804 1994-12-07
74484-74D
. Zi
to about 25 microns. In preferred embodiments, the substrate
is an absorbent product, preferably the pressure-sensitive
adhesive microfiber coating 13 is on the garment facing
surface of the absorbent product (see Figure 4).
In another aspect of the invention, absorbent
products formed in situ using molten fiber spray technology
are disclosed, rather. than assembling the absorbent product
from the individual components -- facing, backing, and core
(see Figures 1 and 2). In this aspect of the invention, the
s0 microfibers are plastic polymers. The plastic polymer
microfibers may be sprayed 1 directly on an absorbent core 3,
and may perform as a facing 1, backing 5, or both.
In one embodiment, only the facing fabric is
eliminated (see Figure 2). Generally, this approach requires
that the absorbent care i7 be formed first and then contacted
with a liquid impermeable barrier 6. The barrier ', which
may optionally be coated with pressure-sensitive adhesive
microfibers before being contacted with the core 17, and
optionally have a liquid or odor absorbent immobilised on it,
2o is preferably laminated to one surface of the absorbent core
19 before a plastic polymer microfiber coating is placed on
the opposite surface of the core ~. Methods for securing the
backing to the core are known in the art and may be used
without departing form the spirit of the invention. The
facing material 9 is then sprayed 9 directly on the absorbent
core i7 by spraying melt blown plastic polymer microfibers 1
on the surface of the absorbent core 19 opposite the side
that is in contact with the liquid impermeable barrier. In
CA 02499804 1994-12-07
74484-74D
- 25
forming the facing side 9, plastic polymer hydrophilic
microfibers or a very thin layer of hydrophobic microfibers g
are sprayed onto the absorbent core i9, which will permit
liquid strike-through and deliver a nearly dry cover. Here
the plastic polymer microfibers should be cooled before
coating the absorbent core.
In another embodiment of the invention, both the
facing and the backing material are eliminated (see Figure
1). generally, the backing 5 is replaced with plastic
polymer hydrophobic micr.ofibers 2 sprayed 1 on the absorbent
panel. The facing is formed as described above.
The plastic polymers used in forming absorbent
products in situ are preferably selected from the group
consi:ating of polyethylene, polypropylene, ethylene
vinylacetate, copolyesters, and plastic or thermoplastic
rubber alloys, with polyethylene preferred. The plastic
polymer microfibers may be hydrophilic, hydrophobic, or
combinations thereof depending on the intended purpose. In
forming the facing, the molten microfibers should be cooled
before being coated onto the substrate. The coating weight
is preferably between about 0.2 to 1 ounces/square yard, more
preferably between about 0.5 to 0.9 ounc.es/square yard, and
more preferably about. 0.6 to 0.8 ounces/square yard. If the
fibers are hydrophobic, the coating weight should be between
about 0.2 to about 0.75 ounces/square yard, more preferably
between about 0.3 to about 0.6 ounces/square yard, and more
preferably between about 0.2 to about 0.4 ounces/square yard.
If hydrophilic fibers are used, the coating weight should be
CA 02499804 1994-12-07
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~ 26 ~
between about 0.2 to about 1 ounces/square yard, more
preferably between about 0.2 to about 0.8 ounces/square yard,
and more preferably between about 0.2 to about 0.6
ounces/sguare yard. xf the fibers are a combination of
hydrophobic and hydrophilic fibers the same parameters as
discussed in connection with the hydrophobic fibers applies.
The plastic polymer microfibers preferably have an
average diameter of about 100 microns or less, more
preferably between about 1 to about 50 microns, and more
preferably have an average diameter of between about 0.5
microns to about 25 microns.
The plastic polymer microfibers described above may
also be used to coat release liners 1~ or papers l1 used to
cover adhesive attachment strips 18 on absorbent products
(see Figure 4). Such release liners take advantage of the
same spray technology and provides a release liner with
optimum~release properties. The melt blown plastic polymer
microfibers 13 are sprayed on a paper substrate in a mohten
state, which delivers a somewhat course surface with good
release properties without the use of silicone reagents that
are currently used in the art. The plastic polymer is as
described above, with polyethylene preferred. In certain
preferred embodiments, the plastic polymer microfiber coating
has a weight of about 1 ounces/sguare yard and the
microfibers have an average diameter of about 100 microns or
less. More preferably, the plastic polymer is polyethylene
and has a coating weight between about 0.2 to about 1
ounces/square yard; more preferably the coating weight is
CA 02499804 1994-12-07
74484--74D
~ 29
between about 0.4 to 0.9 ounces/square yard, and more
preferably between about 0.65 to 0.80 ounces/square yard, and
the microfibers have an average diameter between about 0.5 to
about 25 microns. The polymer may also be compounded with
the release agents to further improve the release properties
of the paper, such as AcrawaX C which is a synthetic wax
having a melting point between 83°-143°C. AcrawaX C is used
as an anti-tack agent and is available from Lenza Inc.
In another aspect of this invention, absorbent
products incorporating the components of the invention are
disclosed. In one embodiment of the invention, an absorbent
product for adhesive attachment to a wearer s garment is
presented (see Figure 4). This product comprises a liquid
impermeable backing is; a liquid permeable facing is; and an
absorbent core 15 fixed between the backing 16 and facing 1~.
The backing and/or facing may optionally be coated with
pressure-sensitive adhesive microfibers before contacting
with the absorbent core i5. The facing, backing, o=
absorbent core may further have a liquid or odor absorbent
immobilized on it.
In another embodiment of the invention, an
absorbent product comprising an absorbent core; a liquid
impermeable backing; a facing material formed in situ from
plastic polymer microfibers; pressure-sensitive adhesive
microfiber coating on the side of the backing that is
contacted with the wearer s garment, and a release paper, as
previously described is disclosed. Figures 1 and 4 are
illustrative.
CA 02499804 1994-12-07
74484-74D
. Z1 ..
In another embodiment, an absorbent product
comprising an absorbent core; a facing and backing formed ~n
situ from plastic polymer microfibers; pressure-sensitive
adhesive microfiber coating on the side of the backing that
is contacted with the wearer s garment; and a release paper,
as previously described is disclosed. Figures 2 and 4 are
i l lust.rative .
The parameters for these absorbent products, such
as the particular microfibers used, the coating weight, and
size of the microfibers,.is as discussed above in connection
with the various components of the invention.
The invention is further illustrated in the
following examples. These examples are for illustrative
purposes only and should not be construed as limiting the
appended claims.
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'74484-74D
- 29
EEAMPLEB
Exampl~s l
Forming Hydrophobic Fibers
Hydrophobic fibers may be formed from Petrothene~"
low density polyethylene resin NA 601 which has a melt index
of 2000. This product is commercially available from USI
Corporation. The fibers are formed by spraying the molten
material through a spray nozzle at 350°F, at low air
consumption.
Example Z
Forming 8ydrophilic Fibers
There are two ways to form hydrophilic fibers. The
first approach is to spray surface active dispersion on
formed thermoplastic fibers. The other is to incorporate
surface active agent concentrate into the plastic pellets,
DOW XU°U1518.15, prior to fiber spray. The surface active
pellets are melted and mixed together with the fiber forming
plastic. A typical formulation would be:
PetrotheneMNA601 100
1N1
Dow XU 61518.15 25
The PetrotheneMis the fiber forming polyethylene
which is mixed with Low surface Active Concentrate.
As in the case of hydrophobic fibers in Example 1,
the hydrophilic fibers were formed with a spray nozzle set-up
at 3a0°F and at a low air consumption.
CA 02499804 1994-12-07
74484-74D
- 30 -
Example 3
Forming Microtibera and components Comprisiag Pressur~-
Bensitiv. Adhesives
The sprayed or melt blown pressure-sensitive
adhesive microfibers consist of small diameter adhesive
fibers having an average diameter not greater than about 100
microns, preferably atrout 50 microns, and more preferably
having a diameter of from about 1-25 microns. These
microfibers are made by extruding a molten, pressure-
sensitive adhesive through a micro-spray nozzle or through a
plura7.ity of fine, usually circular capillaries as filaments
into a low velocity gas (e. g., air) stream that attenuates
the filaments of the ioolten pressure-sensitive adhesive
mater~~al to reduce their diameter to the range stated above.
The pressure-sensitivce adhesive microfibers are carried by
the low velocity gas atream and are deposited on either a
facing or backing, which is then brought into contract with
an ab:~orbent panel.
The commonly used equipment for fiberization is the
well-:known melt blown die or the spray nozzle set-up.
Some typical f fiber forming hot melt pressure-
sensitive adhesives are as follows (the units are parts):
Formula Formula formula
1 2 3
TM
Kraton 1117 100
KratonMRP 6V03 100 100
TM
Wingtack Plus 130 130 120
WingtackM 10 50
hIRM310 50
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- 31 -
Butyl 2imateM 2 2 2
TM
Santovar A 1 1 1
The Kratori RD 6403 is a Shell SIS (Styrene-
isoprene-styrene) thermoplastic rubber having 42% coupling
efficiency and 220,000 M.W. It has i7% styrene.
The KratotiM1117 is a commercially available
thermoplastic rubber having 65% coupling efficiency and 17%
styrene.
TM
Wingtack Plus is a solid hydrocarbon resin supplied
by Goodyear Chemical Company and used as a tackifier for
thermoplastic rubber. It has a softening point of 95°C.
TIA
Wingtack 10 is a liquid hydrocarbon resin and is
used as a plasticizes. It has a softening point of 10°C.
LIR~"310 is a liguid SI polymer available
commercially from Kur,aray Chemical Company, and it is used in
the formulation as a plasticizes.
The plastic polymer microfibers may be prepared
using the same equipment. Examples 1 and 2 are illustrative
of plastic polymer microfiber formulations.
Example 4
Components Coated Witb Pressure-Sensitive Adhesives for
Adhering Liquid or Odor Absorbents
A typical pressure-sensitive adhesive formulation
which can be formed into a microfiber and which will have
high adherence to the odor or liquid absorbent powder:
CA 02499804 1994-12-07
74484--74D
- 32 -
TM
Kraton 1117 100
Wingtack"~ Plus 130
Butyl 2i~mateM 2
SantovarMA 1
The KratoriMis a thermoplastic rubber which gives
the internal strength to the pressure-sensitive adhesive.
The Wingtacl~MPlus is a hydrocarbon tackifier to
give t:he adhesive tack properties.
Both Butyl ZimateMand SantovarMA are antioxidants
for improved aging stability.
Example S
Polyethylene Release Surface
A low density polyethylene resin available from
USI, Petrothene NA 601, has been successfully formed into
molten fibers and deposited onto paper surface using the
molten fiber spray technology discussed in Example 1.
Esamp7.e 6
Modified Polyethylene Release surface
The polyethylene from Example 5 can be modified
with a high melting wax before fiberization like AcrawaXMC.
An addition of 2-5% of the wax before fiberization will
further enhance the release properties.
CA 02499804 1994-12-07
74484--74D
- 33 -
Example 7
Pressure-sensitive Aahe:sive Microfibers Formed ltitDout
Plasti~cisar
Kratori~" 1:11'7 100
Wingtack~Plus 130
Butyl 2i~mate 2
Santovai'"A 1
The KratoriMRu'bber is tackified with Wingtack Plus
and stabilized with two antioxidants; Butyl 2imate and
,°
Santovar A.
Example 8
Plasticized Pressure-S~ebsitive Adhesive Microfiber
compositions
Kraton 1117 100
,w
Wingtack Plus 130
Wingtack 10 50
Santovaz~" A 2
Butyl zimate 1
Kratori 1112 100
Arizona 7115 L 120
,°
Exxon ECR 143 H 40
Butyl Zi.mate'" 2
Santovar~ A 1
The plasticized formulations are plasticized with
liquid. Wingtack 10 resin and Exxon ~CR 143H resin. Exxon ECR
143 H is a light color hydrogenated aliphatic resin. it has
a softening point of 12°C and a viscosity of 4212 cps at 50°C
CA 02499804 1994-12-07
74484-74D
- 3~ -
and an average molecular weight of 462. It is available from
Exxon Chemical Co. they could also be plasticized with
liquidl elastomers. Arizona 7115 L is a terpene based
tackifier with a softening point of about 115°C. it is
available from ArizonaMChemical Co. KratonM1112 is a
styrene-isoprene (SI) polymer believed to be about 14%
styrene, 86% isoprene, and 40% di-block (SI). It has a melt
index of about 23°C and is available from Shell Chemical Co.
