U.S. patent application number 10/649549 was filed with the patent office on 2005-03-03 for polyvinyl chloride glove having improved chemical resistance.
This patent application is currently assigned to Kimberly-Clark Worldwide. Invention is credited to Englebert, Scott Stephen, Vistins, Maris.
Application Number | 20050044609 10/649549 |
Document ID | / |
Family ID | 34216980 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050044609 |
Kind Code |
A1 |
Vistins, Maris ; et
al. |
March 3, 2005 |
Polyvinyl chloride glove having improved chemical resistance
Abstract
A glove having improved chemical permeation resistance includes
a substrate body formed from polyvinyl chloride and a barrier layer
overlying at least a portion of the substrate body, where the
barrier layer is formed from an acrylic polymer having a glass
transition temperature of from about -30.degree. C. to about
30.degree. C.
Inventors: |
Vistins, Maris; (Alphareta,
GA) ; Englebert, Scott Stephen; (Fairburn,
GA) |
Correspondence
Address: |
KIMBERLY-CLARK WORLDWIDE, INC.
401 NORTH LAKE STREET
NEENAH
WI
54956
|
Assignee: |
Kimberly-Clark Worldwide
|
Family ID: |
34216980 |
Appl. No.: |
10/649549 |
Filed: |
August 27, 2003 |
Current U.S.
Class: |
2/159 |
Current CPC
Class: |
A41D 19/0058 20130101;
B32B 27/30 20130101 |
Class at
Publication: |
002/159 |
International
Class: |
A41D 019/00 |
Claims
1. A glove having improved chemical permeation resistance
comprising: a substrate body comprising polyvinyl chloride; and a
barrier layer overlying at least a portion of the substrate body,
the barrier layer comprising an acrylic polymer having a glass
transition temperature of from about -30.degree. C. to about
30.degree. C.
2. The glove of claim 1, wherein the barrier layer is present in an
amount of from about 3 mass % to about 8 mass % of the glove.
3. The glove of claim 1, wherein the barrier layer is present in an
amount of from about 4 mass % to about 6 mass % of the glove.
4. The glove of claim 1, wherein the barrier layer is a
skin-contacting layer.
5. The glove of claim 1, wherein the barrier layer is visually
distinct from the substrate body.
6. The glove of claim 1, further comprising a donning layer
overlying at least a portion of the barrier layer, wherein the
donning layer is a skin-contacting layer.
7. The glove of claim 6, wherein the donning layer comprises a
polyurethane.
8. The glove of claim 6, wherein the donning layer is present in an
amount of from about 0.1 mass % to about 2 mass % of the glove.
9. The glove of claim 6, wherein the donning layer is present in an
amount of from about 0.3 mass % to about 1 mass % of the glove.
10. A glove having improved chemical permeation resistance
comprising: a substrate body comprising polyvinyl chloride; a
barrier layer overlying at least a portion of the substrate body,
the barrier layer comprising an acrylic polymer; and a donning
layer overlying at least a portion of the barrier layer, the
donning layer comprising a polyurethane.
11. The glove of claim 10, wherein the acrylic polymer has a glass
transition temperature of from about -30.degree. C. to about
30.degree. C.
12. The glove of claim 10, wherein the acrylic polymer has a glass
transition temperature of from about -20.degree. C. to about
20.degree. C.
13. The glove of claim 10, wherein the acrylic polymer has a glass
transition temperature of from about -10.degree. C. to about
10.degree. C.
14. The glove of claim 10, wherein the glove is resistant to 70%
isopropyl alcohol for at least 90 minutes using ASTM F739-99a.
15. The glove of claim 10, wherein the glove is resistant to 70%
isopropyl alcohol for at least 100 minutes using ASTM F739-99a.
16. The glove of claim 10, wherein the glove is resistant to 70%
isopropyl alcohol for at least 110 minutes using ASTM F739-99a.
17. The glove of claim 10, wherein the glove is resistant to 70%
isopropyl alcohol for at least 120 minutes using ASTM F739-99a.
18. A method of forming a glove having improved chemical permeation
resistance comprising: preparing a substrate body from a polyvinyl
chloride plastisol; and forming a barrier layer over at least a
portion of the substrate body, the barrier layer being formed from
a barrier layer composition comprising an acrylic emulsion.
19. The method of claim 18, further comprising forming a donning
layer over at least a portion of the barrier layer.
20. The method of claim 18, further comprising rendering the
barrier layer visually distinct from the substrate body.
21. The method of claim 19, wherein the step of rendering the
barrier layer visually distinct from the substrate body comprises
adding a colorant to the barrier layer composition.
Description
BACKGROUND
[0001] In recent years, there has been an increasing emphasis in
the medical community on developing gloves that offer various
degrees and types of protection. Medical practitioners are
frequently exposed to solvents such as isopropyl alcohol and other
chemicals that may puncture the glove and compromise the barrier
afforded by the glove. Gloves formed from thermoplastic resins,
such as polyvinyl chloride (PVC), have a history of poor permeation
resistance to some chemicals relative to gloves formed from a
coagulated rubber latex, such as natural rubber or nitrile rubber.
As such, there is a recognized need for a PVC glove with improved
resistance to chemical permeation.
SUMMARY OF THE INVENTION
[0002] The present invention generally relates to a glove having
improved chemical permeation resistance. The glove includes a
substrate body formed from polyvinyl chloride, and a barrier layer
overlying at least a portion of the substrate body, where the
barrier layer is formed from an acrylic polymer having a glass
transition temperature of from about -30.degree. C. to about
30.degree. C. The barrier layer may be present in any suitable
amount, and in some instances, may be present in an amount of from
about 3 mass % to about 8 mass % of the glove. In other instances,
the barrier layer may be present in an amount of from about 4 mass
% to about 6 mass % of the glove. The barrier layer may be a
skin-contacting layer. In some instances, the barrier layer may be
visually distinct from the substrate body. The glove may also
include a donning layer overlying at least a portion of the barrier
layer, where the donning layer is a skin-contacting layer.
[0003] The present invention further relates to a glove having
improved chemical permeation resistance including a substrate body
formed polyvinyl chloride, a barrier layer overlying at least a
portion of the substrate body, where the barrier layer is formed
from an acrylic polymer, and a donning layer overlying at least a
portion of the barrier layer, where the donning layer is formed
from a polyurethane. In some instances, the acrylic polymer may
have a glass transition temperature of from about -30.degree. C. to
about 30.degree. C. In other instances, the acrylic polymer may
have a glass transition temperature of from about -20.degree. C. to
about 20.degree. C. In yet other instances, the acrylic polymer may
have a glass transition temperature of from about -10.degree. C. to
about 10.degree. C. The glove is generally resistant to 70%
isopropyl alcohol for at least 90 minutes using ASTM F739-99a. In
some instances, the glove may be resistant to 70% isopropyl alcohol
for at least 100 minutes using ASTM F739-99a. In other instances,
the glove may be resistant to 70% isopropyl alcohol for at least
110 minutes using ASTM F739-99a. In yet other instances, the glove
may be resistant to 70% isopropyl alcohol for at least 120 minutes
using ASTM F739-99a.
[0004] The present invention also relates to a method of forming a
glove having improved chemical permeation resistance. The method
includes preparing a substrate body from a polyvinyl chloride
plastisol, and forming a barrier layer over at least a portion of
the substrate body, where the barrier layer is formed from a
barrier layer composition comprising an acrylic emulsion. The
method may include forming a donning layer over at least a portion
of the barrier layer. The method may further include rendering the
barrier layer visually distinct from the substrate body by, for
example, adding a colorant to the barrier layer composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of a glove that may be formed
according to the present invention;
[0006] FIG. 2A is an exemplary cross-sectional illustration of the
article of FIG. 1 taken along a line 2-2, the article including a
substrate body and a barrier layer; and
[0007] FIG. 2B is an exemplary cross-sectional illustration of the
article of FIG. 1 taken along a line 2-2, the article including a
substrate body, a barrier layer, and a donning layer.
DESCRIPTION
[0008] The present invention generally relates to an article having
improved resistance to chemical permeation, and a method of forming
such an article. The article of the present invention features
improved resistance to chemical permeation through use of a barrier
layer formed from an acrylic emulsion. In particular, the article
of the present invention features improved permeation resistance to
isopropyl alcohol as measured by ASTM F739-99a entitled "Standard
Test Method for Resistance of Protective Clothing Materials to
Permeation by Liquids or Gases Under Conditions of Continuous
Contact". The glove is generally resistant to 70% isopropyl alcohol
for at least 80 minutes using ASTM F739-99a. In some instances, the
glove may be resistant to 70% isopropyl alcohol for at least 85
minutes using ASTM F739-99a. In other instances, the glove may be
resistant to 70% isopropyl alcohol for at least 90 minutes using
ASTM F739-99a. In other instances, the glove may be resistant to
70% isopropyl alcohol for at least 100 minutes using ASTM F739-99a.
In yet other instances, the glove may be resistant to 70% isopropyl
alcohol for at least 110 minutes using ASTM F739-99a. In yet other
instances, the glove may be resistant to 70% isopropyl alcohol for
at least 120 minutes using ASTM F739-99a.
[0009] An article made according to the present invention, for
example, a glove 20, generally includes an inside surface 22 and an
outside surface 24 (FIG. 1). As used herein, the "inside surface"
refers to the surface of the article that contacts the body of the
wearer. As used herein, the "outside surface" refers to the surface
of the article that is distal from the body of the wearer. The
glove includes a substrate body 26 having a first surface 28 and a
second surface 30 (FIGS. 2A-2B). As used herein, "first surface"
refers to the surface of the substrate body proximal to the body of
the wearer. As used herein, "second surface" refers to the surface
of the substrate body distal to the body of the wearer.
[0010] The article of the present invention may include a single
layer or multiple layers as desired. In a single layer glove
including only the substrate body, the first surface may form the
inside surface of the glove. However, in a multi-layer glove having
additional layers proximal to the body of the wearer, the
additional layer or layers may each form a portion of the inside
surface, or the entire inside surface, as desired. Likewise, in a
single layer glove including only the substrate body, the second
surface may form the outside surface of the glove. However, in a
multi-layer glove having additional layers distal from the body of
the wearer, the additional layer or layers may each form a portion
of the outside surface, or the entire outside surface, as
desired.
[0011] For example, as depicted in FIG. 2A, the article may include
a barrier layer 32 overlying at least a portion of the first
surface 28 of the substrate body 26. In such an article, the
barrier layer 32 forms at least a portion of the inside surface 22
of the glove 20. As depicted in FIG. 2B, the article may also
include other layers, such as a donning layer 34 that overlies at
least a portion of the barrier layer 32. In such an article, the
donning layer 34 forms at least a portion of the inside surface 22
of the glove 20.
[0012] The substrate body 26 (FIGS. 2A-2B) is generally formed from
a polymeric material, and in some instances, may be formed from a
thermoplastic polymer resin. In one such embodiment, the substrate
body may be formed from a polyvinyl chloride (PVC) resin. While
articles formed from a PVC resin are described in detail herein, it
should be understood that any other suitable polymeric material or
combination of polymeric materials may be used with the present
invention.
[0013] The barrier layer 32 (FIGS. 2A-2B) may be formed from any
suitable polymer that provides increased chemical resistance, and
in some embodiments, may be formed from an acrylic polymer. While
any suitable acrylic polymer may be used as desired, it has been
discovered that use of an acrylic polymer that has a glass
transition temperature of from about -30.degree. C. to about
30.degree. C. provides a barrier layer that is durable even after
donning or manipulation of the article. In some embodiments, an
acrylic polymer having a glass transition temperature of from about
-20.degree. C. to about 20.degree. C. may be used to form the
barrier layer of the present invention. In other embodiments, an
acrylic polymer having a glass transition temperature of from about
-10.degree. C. to about 10.degree. C. may be used to form the
barrier layer of the present invention. In one such embodiment, an
acrylic polymer having a glass transition temperature of about
-3.degree. C. may be used to form the barrier layer of the present
invention.
[0014] The acrylic polymer may be provided in any suitable manner,
and in some instances, may be provided as an acrylic emulsion. In
some instances, it may be desirable to select an acrylic emulsion
that readily forms a film without use of crosslinking agents,
curatives, or the like. In some such instances, the acrylic
emulsion may form a film at room temperature. This provides a
significant process advantage over other polymer coatings that
require curing to form a durable coating.
[0015] One such acrylic emulsion that may be suitable for use with
the present invention is commercially available from Noveon, Inc.
(Cleveland, Ohio) under the trade name HYCAR.RTM. 2679 Emulsion
("HYCAR.RTM. 2679"). HYCAR.RTM. 2679 has a glass transition
temperature of about -3.degree. C. and is believed to contain about
50 mass % TSC, less than 50 mass % water, and a small amount of
formaldehyde. Another acrylic emulsion that may be suitable for use
with the present invention is commercially available from Noveon,
Inc. (Cleveland, Ohio) under the trade name HYCAR.RTM. 2671
Emulsion ("HYCAR.RTM. 2671"). HYCAR.RTM. 2671 is believed to
contain about 53 mass % TSC, less than 47 mass % water, and a small
amount of formaldehyde. Yet another acrylic emulsion that may be
suitable for use with the present invention is commercially
available from Noveon, Inc. (Cleveland, Ohio) under the trade name
HYCAR.RTM. 26349 Emulsion ("HYCAR.RTM. 26349"). HYCAR.RTM. 26349
has a glass transition temperature of about 15.degree. C. and is
believed to contain about 49 mass % TSC, less than about 51 mass %
water, and a small amount of formaldehyde.
[0016] In some embodiments, the barrier layer may be visually
distinct from the substrate body. For instance, the barrier layer
may include a colorant that enables the wearer to recognize the
existence of multiple layers in the glove. Alternatively, the
substrate body may include a colorant to create visually distinct
layers. In one embodiment, the substrate body and the barrier layer
may each include a colorant, so that the inside of the glove is
predominantly one color, while the outside of the glove is another
color.
[0017] Any suitable colorant may be used to create a visual
distinction between layers as desired. One such colorant that may
be suitable for use with the present invention is commercially
available from Sun Chemical Corporation (Amelia, Ohio) under the
trade name FLEXIVERSE.RTM. Phthalo Blue Dispersion
("FLEXIVERSE.RTM."). FLEXIVERSE.RTM. is a resin based aqueous
dispersion that is believed to contain an acrylic resin,
phthalocyanine blue, and water.
[0018] Additionally, the glove of the present invention may include
a donning layer 34 (FIG. 2B). The donning layer may be formed from
any polymeric material that facilitates donning of the article, and
in some instances, may include a polyurethane. One such
polyurethane that may be suitable for use with the present
invention is available from Soluol Chemical Co., Inc. (West
Warwick, R.I.) under the trade name SOLUCOTE.RTM. 117-179.
SOLUCOTE.RTM. 117-179 is provided as a waterborne polyurethane
dispersion having from about 10-20 mass % total solids content
(TSC).
[0019] In other embodiments, the donning layer may be formed from a
blend of an acrylic polymer and a polyurethane. One such blend that
may be suitable for use with the present invention is available
from Jatrac, Inc. (Kyoto, Japan) under the trade name SMOOTHER
Anti-Stick Agent ("SMOOTHER"). SMOOTHER is believed to contain
about 5 mass % polyurethane latex, 3 mass % polyacrylic latex, 2
mass % polyvinyl chloride latex, 3 mass % mica, and water.
[0020] While exemplary donning layer materials are set forth
herein, it should be understood that any suitable donning layer
material may be used as desired. Furthermore, various lubricating
materials may be added to the donning layer composition as desired
or needed to enhance donning. Some such materials may include a
flattening agent, a lubricant, for example, a wax or a silicone, or
particulate matter, for example, silica.
[0021] The glove of the present invention may be formed using a
variety of processes, for example, dipping, spraying, tumbling,
drying, and curing. An exemplary dipping process for forming a
glove is described herein, though other processes may be employed
to form various gloves having different characteristics.
Furthermore, it should be understood that a batch, semi-batch, or a
continuous process may be used with the present invention.
[0022] A glove is formed on a hand-shaped mold, termed a "former".
The former may be made from any suitable material, such as glass,
metal, porcelain, or the like. The surface of the former defines at
least a portion of the surface of the glove to be manufactured.
[0023] In general, the glove is formed by dipping the former into a
series of compositions as needed to attain the desired glove
characteristics. The glove may be allowed to solidify between
layers. Any combination of layers may be used, and although
specific layers are described herein, it should be understood that
other layers and combinations of layers may be used as desired.
Thus, in one embodiment, the glove may include a substrate body 26
and a barrier layer 32 (FIG. 2A). In another embodiment, the glove
may include a substrate body 26, a barrier layer 32, and a donning
layer 34 (FIG. 2B).
[0024] In one embodiment, the substrate body may be formed from a
plastisol using a dipping process. As used herein, a "plastisol"
refers to a dispersion of fine resin particles in a plasticizer.
The plastisol is formed by mixing the resin particles into the
plasticizer with sufficient shear to form a stable system. Any
suitable resin may be used as desired, and in some instances, the
resin includes polyvinyl chloride (PVC). While articles formed from
PVC are described in detail herein, it should be understood that
any other suitable thermoplastic material or combination of
thermoplastic materials may be used with the present invention.
Thus, for example, the resin may include a
styrene-ethylene-butylene-styrene block copolymer, a nitrile
butadiene polymer, or any other polymer capable of forming a film
without use of a coagulant. Furthermore, while exemplary process
conditions are described herein, it should be understood that such
conditions depend on the desired thickness of the article, the
viscosity of the composition, the time required to gel the article,
and so forth.
[0025] The former may first be heated to a temperature of about
100.degree. F. (38.degree. C.) to about 200.degree. F. (93.degree.
C.), for example, 150.degree. F. (66.degree. C.). The former is
then dipped into a plastisol containing a suitable thermoplastic
resin, for instance, PVC, and a plasticizer. The composition may be
maintained at any suitable temperature, and in some instances, is
maintained at a temperature of from about 75.degree. F. (24.degree.
C.) to about 175.degree. F. (79.degree. C.), for example,
105.degree. F. (40.degree. C.).
[0026] The formers are then removed from the composition to drain.
The time permitted to drain ("drain time") determines the mass of
the glove, its thickness, and so forth, based on the temperature of
the former and the viscosity of the plastisol. The formers are then
advanced to a fusion oven where the substrate body fuses on the
former. In one instance, the fusion oven may be maintained at about
300.degree. F. (149.degree. C.) to about 500.degree. F.
(260.degree. C.), for example, 450.degree. F. (232.degree. C.), and
the former may be in the oven for about 3 to about 8 minutes, for
example, 6 minutes.
[0027] The fused PVC substrate body on the former is then cooled to
a temperature of about 100.degree. F. (38.degree. C.) to about
200.degree. F. (93.degree. C.), for example, 150.degree. F.
(66.degree. C.), by exposing the formers to one or more cooling
fans, as appropriate.
[0028] The former is then dipped into a composition to form the
barrier layer. As stated herein, the barrier layer may be formed
from any suitable material, and in some instances, may be formed
from an acrylic emulsion. One such acrylic emulsion that may be
suitable is HYCAR.RTM. 2679, described in detail above. Where
desired, the composition may include other additives. In one
embodiment, the composition may include a colorant to render the
barrier layer visually distinct from the substrate body. Where
other layers are present, the barrier layer may also be visually
distinct from such other layers as desired.
[0029] The barrier layer is then dried in an oven maintained at a
temperature of about 350.degree. F. to about 450.degree. F., for
example, 392.degree. F. (200.degree. C.) for about 60 seconds to
about 120 seconds, for example, 90 seconds, and cooled to a
temperature of about 100.degree. F. (38.degree. C.) to about
200.degree. F. (93.degree. C.), for example, 150.degree. F.
(66.degree. C.), by exposing the formers to one or more cooling
fans, as appropriate.
[0030] The barrier layer may be present in the finished article any
suitable amount, and in some embodiments, the barrier layer may be
present in an amount of from about 3 mass % to about 8 mass % of
the article. In other embodiments, the barrier layer may be present
in an amount of from about 4 mass % to about 6 mass % of the
article. In yet another embodiment, the barrier layer may be
present in an amount of about 5.7 mass % of the article.
[0031] Where no separate donning layer is desired, various
lubricating materials may be added to the barrier layer composition
as desired or needed to enhance donning. Some such materials may
include a flattening agent, a lubricant, for example, a wax or a
silicone, or particulate matter, for example, silica. As used
herein, the term "silicone" generally refers to a broad family of
synthetic polymers that have a repeating silicon-oxygen backbone,
including, but not limited to, polydimethylsiloxane and
polysiloxanes having hydrogen-bonding functional groups selected
from the group consisting of amino, carboxyl, hydroxyl, ether,
polyether, aldehyde, ketone, amide, ester, and thiol groups. In
some embodiments, polydimethylsiloxane and/or modified
polysiloxanes may be used as the silicone component in accordance
with the present invention. For instance, some suitable modified
polysiloxanes that can be used in the present invention include,
but are not limited to, phenyl-modified polysiloxanes,
vinyl-modified polysiloxanes, methyl-modified polysiloxanes,
fluoro-modified polysiloxanes, alkyl-modified polysiloxanes,
alkoxy-modified polysiloxanes, amino-modified polysiloxanes, and
combinations thereof.
[0032] In some embodiments, the barrier layer may include a
silicone emulsion. One such silicone emulsion that may be used is
DC 365, a pre-emulsified silicone (35% TSC) that is commercially
available from Dow Corning Corporation (Midland, Mich.). DC 365 is
believed to contain 40-70 mass % water, 30-60 mass %
methyl-modified polydimethylsiloxane, 1-5 mass % propylene glycol,
1-5 mass % polyethylene glycol sorbitan monolaurate, and 1-5 mass %
octylphenoxy polyethoxy ethanol. Another silicone emulsion that may
be used with the present invention is SM 2140, commercially
available from GE Silicones (Waterford, N.Y.). SM 2140 is a
pre-emulsified silicone (50% TSC) that is believed to contain 30-60
mass % water, 30-60 mass % amino-modified polydimethylsiloxane,
1-5% ethoxylated nonyl phenol, 1-5 mass %
trimethyl-4-nonyloxypolyethyleneoxy ethanol, and minor percentages
of acetaldehyde, formaldehyde, and 1,4 dioxane. Another silicone
emulsion that may be suitable for use with the present invention is
SM 2169 available from GE Silicones (Waterford, N.Y.). SM 2169 is a
pre-emulsified silicone that is believed to contain 30-60 mass %
water, 60 to 80 mass % polydimethylsiloxane, 1-5 mass %
polyoxyethylene lauryl ether, and a small amount of formaldehyde.
Yet another silicone that may be useful with the present invention
is commercially available from GE Silicones (Waterford, N.Y.) under
the trade name AF-60. AF-60 is believed to contain
polydimethylsiloxane, acetylaldehyde, and small percentages of
emulsifiers. If desired, these pre-emulsified silicones may be
diluted with water or other solvents prior to use.
[0033] In another embodiment, the barrier layer composition may
contain a quaternary ammonium compound, such as that commercially
available from Goldschmidt Chemical Corporation of Dublin, Ohio
under the trade name VERISOFT.RTM. BTMS. VERISOFT.RTM. BTMS is
believed to contain behnyl trimethyl sulfate and cetyl alcohol.
Thus for example, in one embodiment, the lubricant layer may
include a quaternary ammonium compound such as VERISOFT.RTM. BTMS
and a silicone emulsion such as SM 2169. In other embodiments, such
a barrier layer composition may include, for example, a cationic
surfactant (e.g., cetyl pyridinium chloride), an anionic surfactant
(e.g., sodium lauryl sulfate), a nonionic surfactant, or the
like.
[0034] Where desired, the former may be dipped into a composition
to form a donning layer to facilitate donning of the glove. One
such donning layer composition that may be suitable for use with
the present invention may include SMOOTHER Anti-Stick Agent,
described in detail above. The donning layer composition may be
maintained at about 100.degree. F. (38.degree. C.) to about
200.degree. F. (93.degree. C.), for example, 150.degree. F.
(66.degree. C.). The donning layer on the former may then be dried
in an oven, for example, for about 2-3 minutes at a temperature of
about 200.degree. F. (93.degree. C.) to about 400.degree. F.
(204.degree. C.), for example, 300.degree. F. (149.degree. C.).
[0035] The donning layer may be present in the finished article any
suitable amount, and in some embodiments, the donning layer may be
present in an amount of from about 0.1 mass % to about 2 mass % of
the article. In other embodiments, the donning layer may be present
in an amount of from about 0.3 mass % to about 1 mass % of the
article. In yet another embodiment, the donning layer may be
present in an amount of about 0.6 mass % of the article.
[0036] Alternatively, the barrier layer may be dusted with a powder
to facilitate donning. One such dusting powder that may be suitable
for use with the present invention is USP grade starch.
[0037] The former is then sent to a bead rolling station, where the
cuff is rolled slightly and permitted to solidify. The former may
then be transferred to a stripping station where the glove is
removed from the former. The stripping station may involve
automatic or manual removal of the glove from the former. For
example, in one embodiment, the glove is manually removed and
turned inside out as it is stripped from the former. By inverting
the glove in this manner, the donning layer formed on the exposed
surface of the substrate body on the former becomes the interior of
the glove.
[0038] The resulting glove features improved barrier
characteristics when exposed to isopropyl alcohol. These
discoveries are evidenced by the following example, which is not
intended to be limiting in any manner.
EXAMPLE
[0039] Improved chemical permeation of the glove of the present
invention was demonstrated. Various competitive polyvinyl chloride
gloves (Samples A-D) were compared with a glove formed according to
the present invention (Sample E).
[0040] The experimental gloves (Sample E) were prepared by first
heating the glove formers to about 65.degree. C. The formers were
then dipped into a polyvinyl chloride plastisol maintained at about
45.degree. C. The plastisol was then fused in an oven at
200.degree. C. for about 5 minutes. The formers were then cooled to
a temperature of about 100.degree. C. and dipped into a barrier
layer composition including about 10 mass % HYCAR.RTM. 2679. The
barrier layer was then dried at about 200.degree. C. The formers
were again cooled to a temperature of about 100.degree. C. and
dipped into a donning layer composition including about 1 mass %
SMOOTHER. The donning layer was then dried at about 200.degree. C.
The gloves were then cooled and removed from the formers.
[0041] The gloves were tested for chemical permeation resistance
according to ASTM F739-99a entitled "Standard Test Method for
Resistance of Protective Clothing Materials to Permeation by
Liquids or Gases Under Conditions of Continuous Contact" using 70%
isopropyl alcohol as the challenge chemical. Three repetitions were
performed. The results of the analysis are presented below.
1 Mass/unit area Sample thickness Breakthrough Sample
(g/m{circumflex over ( )}2) (mm) detection time (min) A 154.0 0.130
67 B 131.8 0.118 47 C 143.4 0.128 77 D 150.8 0.129 77 E 127.4 0.113
130
[0042] The results indicate that the glove formed according to the
present invention (Sample E) offers a significant improvement in
chemical permeation resistance when compared with several
competitive products (Samples A-D). Thus, although the glove of the
present invention (Sample E) has a lower mass/unit area and a lower
thickness, it provides a greater barrier to isopropyl alcohol.
[0043] The invention may be embodied in other specific forms
without departing from the scope and spirit of the inventive
characteristics thereof. The present embodiments therefore are to
be considered in all respects as illustrative and not restrictive,
the scope of the invention being indicated by the appended claims
rather than by the foregoing description, and all changes which
come within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *