U.S. patent application number 10/161546 was filed with the patent office on 2003-12-11 for elastomeric gloves having improved gripping characteristics.
This patent application is currently assigned to Kimberly-Clark Worldwide, Inc.. Invention is credited to Kister, Mary Elizabeth, Modha, Shanti.
Application Number | 20030226191 10/161546 |
Document ID | / |
Family ID | 29709764 |
Filed Date | 2003-12-11 |
United States Patent
Application |
20030226191 |
Kind Code |
A1 |
Modha, Shanti ; et
al. |
December 11, 2003 |
Elastomeric gloves having improved gripping characteristics
Abstract
An elastomeric glove having an outer layer that contains a
silicone emulsion is provided. For example, in one embodiment, the
glove contains a natural rubber latex substrate body, a donning
layer that is capable of being chlorinated, and an outer layer
formed from a silicone emulsion. It has been unexpectedly
discovered that the application of a silicone emulsion to the outer
layer can offset the slipperiness normally caused by chlorination
and thus enhance the gripping properties of the resulting
elastomeric glove. Specifically, it is believed that the silicone
emulsion can inhibit the ability of halogen atoms to bond with the
elastomeric material of the substrate, thereby limiting the level
of slipperiness usually imparted during chlorination.
Inventors: |
Modha, Shanti; (Alpharetta,
GA) ; Kister, Mary Elizabeth; (Cumming, GA) |
Correspondence
Address: |
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE
SC
29602-1449
US
|
Assignee: |
Kimberly-Clark Worldwide,
Inc.
|
Family ID: |
29709764 |
Appl. No.: |
10/161546 |
Filed: |
June 3, 2002 |
Current U.S.
Class: |
2/161.7 |
Current CPC
Class: |
C08J 2483/00 20130101;
A41D 2400/52 20130101; A61B 42/00 20160201; C08J 7/0427 20200101;
B29C 41/14 20130101; A41D 19/0058 20130101; B29D 99/0067 20130101;
B29L 2031/4864 20130101 |
Class at
Publication: |
2/161.7 |
International
Class: |
A41D 019/00 |
Claims
What is claimed is:
1. An elastomeric glove defining a wearer-contacting surface and a
grip surface, said glove comprising: a substrate body including a
layer made of an elastomeric material, said substrate body having
an inside surface and an outside surface; and an outer layer
overlying the outside surface of said substrate body and forming
the grip surface of the glove, said outer layer being formed from a
silicone emulsion, wherein said silicone emulsion has a solids
content of from about 0.1 weight % to about 10 weight %.
2. An elastomeric glove as defined in claim 1, wherein said
silicone emulsion contains a polysiloxane having at least one
functional group selected from the group consisting of amino,
carboxyl, hydroxyl, ether, polyether, aldehyde, ketone, amide,
ester, thiol groups, and combinations thereof.
3. An elastomeric glove as defined in claim 1, wherein said
silicone emulsion contains at least one emulsifying surfactant.
4. An elastomeric glove as defined in claim 1, wherein said
silicone emulsion has a solids content of from about 0.25 weight %
to about 5 weight %.
5. An elastomeric glove as defined in claim 1, wherein said
silicone emulsion has a solids content of from about 0.3 weight %
to about 1.0 weight %.
6. An elastomeric glove as defined in claim 1, wherein the
elastomeric material of said substrate body is selected from the
group consisting of styrene-ethylene-butylene-styrene block
copolymers, styrene-isoprene-styrene block copolymers,
styrene-butadiene-styrene block copolymers, styrene-isoprene block
copolymers, styrene-butadiene block copolymers, natural rubber
latex, nitrile rubbers, isoprene rubbers, chloroprene rubbers,
polyvinyl chlorides, silicone rubbers, and combinations
thereof.
7. An elastomeric glove as defined in claim 6, wherein the
elastomeric material of said substrate body is natural rubber
latex.
8. An elastomeric glove as defined in claim 1, further comprising a
donning layer that overlies the inside surface of said substrate
body.
9. An elastomeric glove as defined in claim 8, wherein said donning
layer contains a donning polymer that is halogenated.
10. An elastomeric glove as defined in claim 9, further comprising
a lubricant that coats the donning layer.
11. An elastomeric glove defining a wearer-contacting surface and a
grip surface, said glove comprising: a substrate body including a
layer made of an elastomeric material, said substrate body having
an inside surface and an outside surface; a donning layer overlying
the inside surface of said substrate body, said donning layer
comprising a donning polymer that is chlorinated; and an outer
layer overlying the outside surface of said substrate body and
forming the grip surface of the glove, said outer layer being
formed from a silicone emulsion.
12. An elastomeric glove as defined in claim 11, wherein said
silicone emulsion contains a polysiloxane having at least one
functional group selected from the group consisting of amino,
carboxyl, hydroxyl, ether, polyether, aldehyde, ketone, amide,
ester, thiol groups, and combinations thereof.
13. An elastomeric glove as defined in claim 11, wherein said
silicone emulsion has a solids content of from about 0.1 weight %
to about 10 weight %
14. An elastomeric glove as defined in claim 11, wherein said
silicone emulsion has a solids content of from about 0.25 weight %
to about 5 weight %.
15. An elastomeric glove as defined in claim 11, wherein said
silicone emulsion has a solids content of from about 0.3 weight %
to about 1.0 weight %.
16. An elastomeric glove as defined in claim 11, wherein the
elastomeric material of said substrate body is selected from the
group consisting of styrene-ethylene-butylene-styrene block
copolymers, styrene-isoprene-styrene block copolymers,
styrene-butadiene-styrene block copolymers, styrene-isoprene block
copolymers, styrene-butadiene block copolymers, natural rubber
latex, nitrile rubbers, isoprene rubbers, chloroprene rubbers,
polyvinyl chlorides, silicone rubbers, and combinations
thereof.
17. An elastomeric glove as defined in claim 16, wherein the
elastomeric material of said substrate body is natural rubber
latex.
18. An elastomeric glove as defined in claim 11, further comprising
a lubricant that coats said donning layer.
19. An elastomeric glove defining a wearer-contacting surface and a
grip surface, said glove comprising: a substrate body including a
layer made of an elastomeric material, said substrate body having
an outside surface; and an outer layer overlying the outside
surface of said substrate body and forming the grip surface of the
glove, said outer layer being formed primarily from a silicone
emulsion, wherein said silicone emulsion has a solids content of
from about 0.1 weight % to about 10 weight %.
20. A method for enhancing the gripping properties of an
elastomeric glove, said method comprising: providing an elastomeric
glove that contains a substrate body having a layer made of an
elastomeric material, said substrate body having an inside surface
and an outside surface, said elastomeric glove further containing a
donning layer that overlies the inside surface of said substrate
body; applying a silicone emulsion to the substrate body so that
said emulsion coats the outside surface of said substrate body; and
thereafter, exposing a halogen-containing compound to the
elastomeric glove.
21. A method as defined in claim 20, wherein said silicone emulsion
contains a polysiloxane having at least functional group selected
from the group consisting of amino, carboxyl, hydroxyl, ether,
polyether, aldehyde, ketone, amide, ester, thiol groups, and
combinations thereof.
22. A method as defined in claim 20, wherein said silicone emulsion
has a solids content of from about 0.1 weight % to about 10 weight
%.
23. A method as defined in claim 20, wherein said silicone emulsion
has a solids content of from about 0.25 weight % to about 5 weight
%.
24. A method as defined in claim 20, wherein said silicone emulsion
has a solids content of from about 0.3 weight % to about 1.0 weight
%.
25. A method as defined in claim 20, wherein the elastomeric
material of said substrate body is selected from the group
consisting of styrene-ethylene-butylene-styrene block copolymers,
styrene-isoprene-styrene block copolymers,
styrene-butadiene-styrene block copolymers, styrene-isoprene block
copolymers, styrene-butadiene block copolymers, natural rubber
latex, nitrile rubbers, isoprene rubbers, chloroprene rubbers,
polyvinyl chlorides, silicone rubbers, and combinations
thereof.
26. A method as defined in claim 25, wherein the elastomeric
material of said substrate body is natural rubber latex.
27. A method as defined in claim 20, wherein said donning layer
contains a donning polymer that is halogenated.
28. A method as defined in claim 20, wherein the halogen of said
halogen-containing compound is chlorine.
29. A method as defined in claim 20, further comprising applying a
lubricant to coat said donning layer.
Description
BACKGROUND OF THE INVENTION
[0001] Elastomeric gloves, such as surgical and examination gloves,
have traditionally been made of natural or synthetic elastomers to
provide a combination of good elasticity and strength. Due to their
tight fit over the hand, however, elastomeric gloves are often
difficult to don. To overcome this problem, powdered lubricants
were traditionally applied to the inside surface of the glove to
reduce friction between the skin and the elastomer. As an example,
epichlorohydrin-treated maize crosslinked starch was a common
powder applied to the inside of elastomeric gloves during
manufacture to permit them to be more readily slipped onto the hand
of the user.
[0002] Unfortunately, the use of powdered lubricants has drawbacks
in specific situations, such as the case of surgical gloves.
Specifically, if some of the powder escapes from the inside of the
glove into the surgical environment, as for example if the glove is
torn during the surgery, the powder may enter the surgical wound
and cause further complications for the patient. The powder may
also carry infectious agents and/or cause allergenic reactions in
the patient.
[0003] As a result, various other techniques were developed to aid
in the donnability of elastomeric gloves. For example, the surface
of natural rubber latex gloves has been chlorinated to reduce
friction between the wearer-contacting surface and a user's skin
when donned. Moreover, other techniques have also been developed to
enhance the lubricity of a glove's inner surface. One such
technique is described in U.S. Pat. No. 5,792,531 to Littleton, et
al. For instance, in one example, Littleton, et al. describes
forming a donning layer on an S-EB-S glove from an S-I-S mid-block
unsaturated block copolymer, chlorinating the resulting glove in a
washing machine, and then applying a lubricant to the
wearer-contacting surface of the glove that contains cetyl
pyridinium chloride and a silicone emulsion (DC 365 from Dow
Corning).
[0004] Although chlorination techniques, such as described above,
have resulted in a significant improvement in the donning
characteristics of many elastomeric gloves, other properties of the
glove are sometimes adversely affected. For instance, when
chlorinated, the outer, gripping surface of natural rubber latex
gloves are unintentionally provided with a slippery feel because
the inner and outer surfaces of the glove are simultaneously
chlorinated in a washing machine. As a result, a user wearing such
a glove often experiences difficulty in gripping and/or handling
objects. This may be a particularly significant problem for
surgical gloves, which are designed for use by doctors who are
commonly required to grip and handle surgical tools.
[0005] As such, a need currently exists for an elastomeric glove
that is able to achieve good gripping characteristics, even when
chlorinated.
SUMMARY OF THE INVENTION
[0006] In accordance with one embodiment of the present invention,
an elastomeric glove is disclosed that defines a wearer-contacting
surface and a grip surface. The glove comprises a substrate body
including a layer made of an elastomeric material that is capable
of being halogenated (e.g., chlorinated), the substrate body having
an inside surface and an outside surface. In some embodiments, the
elastomeric material of the substrate body is selected from the
group consisting of styrene-ethylene-butylene-styrene block
copolymers, styrene-isoprene-styrene block copolymers,
styrene-butadiene-styrene block copolymers, styrene-isoprene block
copolymers, styrene-butadiene block copolymers, natural rubber
latex, nitrile rubbers, isoprene rubbers, chloroprene rubbers,
polyvinyl chlorides, silicone rubbers, and combinations
thereof.
[0007] The glove further comprises an outer layer overlying the
outside surface of the substrate body and forming the grip surface
of the glove, the outer layer being formed from a silicone
emulsion. As is described in more detail below, the silicone
emulsion may allow the grip surface of the glove to maintain some
degree of tack, even after the glove is exposed to a
halogen-containing compound. In some embodiments, the silicone
emulsion contains a polysiloxane having at least one functional
group selected from the group consisting of amino, carboxyl,
hydroxyl, ether, polyether, aldehyde, ketone, amide, ester, thiol
groups, and combinations thereof. Moreover, the silicone emulsion
may have a solids content of from about 0.1 weight % to about 10
weight %. In another embodiment, the silicone emulsion may have a
solids content of from about 0.25 weight % to about 5 weight %.
Further, in still another embodiment, the silicone emulsion may
have a solids content of from about 0.3 weight % to about 1.0
weight %.
[0008] Besides the above-mentioned layers, the elastomeric glove
may also contain other additional layers. For example, in one
embodiment, the elastomeric glove further comprises a donning layer
that overlies the inside surface of the substrate body. The donning
layer may facilitate donning of the glove onto the hand of a user.
In some embodiments, the donning layer contains a donning polymer
that is halogenated (e.g., chlorinated). The glove may also contain
a lubricant that coats the donning layer. When utilized, the
lubricant may further facilitate damp donning of the glove.
[0009] In accordance with another embodiment of the present
invention, a method for enhancing the gripping properties of an
elastomeric glove is disclosed. The method comprises providing an
elastomeric glove that contains a substrate body having a layer
made of an elastomeric material, the substrate body having an
inside surface and an outside surface. The glove further contains a
donning layer that overlies the inside surface of the substrate
body. The method also comprises applying a silicone emulsion to the
substrate body so that the emulsion coats the outside surface of
the substrate body. Thereafter, the elastomeric glove is exposed to
a halogen-containing compound, such as a chlorine-containing
compound. The silicone emulsion inhibits halogenation of the outer
surface of the substrate body to improve the gripping
characteristics thereof.
[0010] Other features and aspects of the present invention are
discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended drawings, in which:
[0012] FIG. 1 is a perspective view of one embodiment of an
elastomeric glove made according to the invention;
[0013] FIG. 2 is a cross-sectional view of the glove illustrated in
FIG. 1 taken along a line 2-2; and
[0014] FIG. 3 is a block flow diagram illustrating one embodiment
of a method for forming an elastomeric glove of the present
invention.
[0015] Repeat use of reference characters in the present
specification and drawings is intended to represent the same or
analogous features or elements of the invention.
DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS
[0016] Reference now will be made in detail to various embodiments
of the invention, one or more examples of which are set forth
below. Each example is provided by way of explanation, not
limitation of the invention. In fact, it will be apparent to those
skilled in the art that various modifications and variations may be
made in the present invention without departing from the scope or
spirit of the invention. For instance, features illustrated or
described as part of one embodiment, may be used on another
embodiment to yield a still further embodiment. Thus, it is
intended that the present invention cover such modifications and
variations.
[0017] In general, the present invention is directed to an
elastomeric glove having an outer layer that contains a silicone
emulsion. For example, in one embodiment, the glove contains a
natural rubber latex substrate body, a donning layer that is
capable of being chlorinated, and an outer layer formed from a
silicone emulsion. It has been unexpectedly discovered that the
application of a silicone emulsion to the outer layer of the glove
may offset the slipperiness normally caused by chlorination and
thus enhance the gripping properties of the resulting elastomeric
glove. Specifically, it is believed that the silicone emulsion may
inhibit the ability of halogen atoms to bond with the elastomeric
material of the substrate, thereby limiting the level of
slipperiness usually imparted during chlorination.
[0018] Referring to FIGS. 1-2, for example, one embodiment of an
elastomeric glove 20 is illustrated that may be placed on the hand
of a user 22. The glove 20 includes a substrate body 24 having the
basic shape of the glove. The substrate body 24 may generally be
formed from any of a variety of natural and/or synthetic
elastomeric materials known in the art. For instance, some examples
of suitable elastomeric materials include, but are not limited to,
S-EB-S (styrene-ethylene-butylene-styren- e) block copolymers,
S-I-S (styrene-isoprene-styrene) block copolymers, S-B-S
(styrene-butadiene-styrene) block copolymers, S-I
(styrene-isoprene) block copolymers, S-B (styrene-butadiene) block
copolymers, natural rubber latex, nitrile rubbers, isoprene
rubbers, chloroprene rubbers, polyvinyl chlorides, silicone
rubbers, and combinations thereof. Other suitable elastomeric
materials that may be used to form the substrate body 24 may be
described in U.S. Pat. No. 5,112,900 to Buddenhagen, et al.; U.S.
Pat. No. 5,407,715 to Buddenhagen, et al.; U.S. Pat. No. 5,900,452
to Plamthottam; U.S. Pat. No. 6,288,159 to Plamthottam; and U.S.
Pat. No. 6,306,514 to Weikel, et al., which are incorporated herein
in their entirety by reference thereto for all purposes.
[0019] In one embodiment, the substrate body 24 is formed from
natural rubber latex. To form the substrate body 24 from natural
latex, a former is initially dipped into a coagulant bath that
facilitates later stripping of the glove from the former. The
coagulant bath may include compounds well known in the art, such as
calcium carbonate and calcium nitrate. Thereafter, the
coagulant-coated former is dried and subsequently dipped into one
or more latex baths. The resulting latex layer(s) are then
typically leached in water to extract a large percentage of the
water-soluble impurities in the latex and coagulant. The coated
former is then dried to cure (i.e., crosslink) the rubber. It
should be understood that the conditions, process, and materials
used in forming natural rubber gloves are well known in the art,
and are not critical to the practice of the present invention.
[0020] Regardless of the particular material used to form the
substrate body 24, the glove 20 also includes an outer layer 36
that covers the outer surface of the substrate body 24 during use
and forms a gripping surface 21 of the glove 20. The outer layer 36
contains a silicone emulsion that imparts enhanced tackiness to the
gripping surface 21. 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. The silicone emulsion generally contains
one or more silicone elastomers that are capable of interfering
with the bonding of halogen atoms with elastomeric material used to
form the substrate body 24 during halogenation. For instance,
natural rubber latex is a colloidal suspension of polyisoprene,
which generally has the following structure: 1
[0021] Typically, upon halogenation, the halogen atoms (e.g.,
chlorine, bromine, and the like) react with the polyisoprene to
reduce the tackiness of the latex. However, it has been discovered
in accordance with the present invention that the silicone emulsion
applied to the outer layer 36 may interfere with the reaction of
polyisoprene with the halogen atoms, thereby inhibiting the
slipperiness normally imparted to the outer layer 36. Specifically,
it is believed that, in some instances, the relatively hydrophobic
silicone repels the water-based halogenation solutions often
utilized, and in this manner, inhibits halogenation of the grip
surface 21. In other instances, it is believed that the silicone
contains functional groups that bond to the reactive sites that
would otherwise form bonds with halogen atoms during halogenation.
By reducing the level of halogen atom bonding, the gripping
properties of the resulting glove 20 are greatly improved.
[0022] Generally, any silicone capable of enhancing the grip
characteristics of the glove 20 may be used in the silicone
emulsion. In some embodiments, polydimethylsiloxane and/or modified
polysiloxanes may be used as the silicone component of the emulsion
in the present invention. For instance, some suitable modified
polysiloxanes that may 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.
[0023] Some suitable phenyl-modified polysiloxanes include, but are
not limited to, dimethyidiphenylpolysiloxane copolymers; dimethyl,
methylphenylpolysiloxane copolymers; polymethylphenylsiloxane; and
methylphenyl, dimethylsiloxane copolymers. Phenyl modified
polysiloxanes that have a relatively low phenyl content (less than
about 50 mole %) may be particularly effective in the present
invention. For example, the phenyl-modified polysiloxane may be a
diphenyl-modified silicone, such as a diphenylsiloxane-modified
dimethylpolysiloxane. In some embodiments, the phenyl-modified
polysiloxanes contain phenyl units in an amount from about 0.5 mole
% to about 50 mole %, in some embodiments in an amount less than
about 25 mole %, and in some embodiments, in an amount less than
about 15 mole %. In one particular embodiment, a
diphenylsiloxane-modified dimethylpolysiloxane may be used that
contains diphenylsiloxane units in an amount less than about 5 mole
%, and particularly in an amount less than about 2 mole %. The
diphenylsiloxane-modified dimethylpolysiloxane may be synthesized
by reacting diphenylsiloxane with dimethylsiloxane.
[0024] As indicated above, fluoro-modified polysiloxanes may also
be used in the present invention. For instance, one suitable
fluoro-modified polysiloxane that may be used is a trifluoropropyl
modified polysiloxane, such as a trifluoropropylsiloxane modified
dimethylpolysiloxane. A trifluoropropylsiloxane modified
dimethylpolysiloxane may be synthesized by reacting methyl, 3,3,3
trifluoropropylsiloxane with dimethylsiloxane. The fluoro-modified
silicones may contain from about 5 mole % to about 95 mole % of
fluoro groups, such as trifluoropropylsiloxane units. In another
embodiment, the fluoro-modified silicones may contain from about 40
mole % to about 60 mole % of fluoro groups. In one particular
embodiment, a trifluoropropylsiloxane-modified dimethylpolysiloxane
may be used that contains 50 mole % trifluoropropylsiloxane
units.
[0025] Besides the above-mentioned modified polysiloxanes, other
modified polysiloxanes may also be utilized in the present
invention. For instance, some suitable vinyl-modified polysiloxanes
include, but are not limited to, vinyldimethyl terminated
polydimethylsiloxanes; vinylmethyl, dimethylpolysiloxane
copolymers; vinyidimethyl terminated vinylmethyl,
dimethylpolysiloxane copolymers; divinylmethyl terminated
polydimethylsiloxanes; and vinylphenylmethyl terminated
polydimethylsiloxanes. Further, some methyl-modified polysiloxanes
that may be used include, but are not limited to, dimethylhydro
terminated polydimethylsiloxanes; methylhydro, dimethylpolysiloxane
copolymers; methylhydro terminated methyloctyl siloxane copolymers;
and methylhydro, phenylmethyl siloxane copolymers. In addition,
some examples of amino-modified polysiloxanes include, but are not
limited to, polymethyl(3-aminopropyl)-siloxane and
polymethyl[3-(2-aminoethyl)aminopr- opyl]-siloxane.
[0026] The particular polysiloxanes described above are meant to
include hetero- or co-polymers formed from polymerization or
copolymerization of dimethylsiloxane cyclics and diphenylsiloxane
cyclics or trifluoropropylsiloxane cyclics with appropriate
endcapping units. Thus, for example, the terms "diphenyl modified
dimethylpolysiloxanes" and "copoloymers of diphenylpolysiloxane and
dimethylpolysiloxane" may be used interchangeably. Moreover, other
examples of suitable polysiloxanes are believed to be described in
U.S. Pat. No. 5,742,943 to Chen and U.S. Pat. No. 6,306,514 to
Weikel, et al., which are incorporated herein in their entirety by
reference thereto for all purposes.
[0027] Besides containing a silicone, the silicone emulsion also
generally contains one or more emulsifying surfactants. Nonionic,
anionic, cationic, and amphoteric surfactants may all be suitable
for use in the present invention. For example, in some embodiments,
it may be desired to utilize one or more nonionic surfactants.
Nonionic surfactants typically have a hydrophobic base, such as a
long chain alkyl group or an alkylated aryl group, and a
hydrophilic chain comprising a certain number (e.g., 1 to about 30)
of ethoxy and/or propoxy moieties. Examples of some classes of
nonionic surfactants that may be used include, but are not limited
to, ethoxylated alkylphenols, ethoxylated and propoxylated fatty
alcohols, polyethylene glycol ethers of methyl glucose,
polyethylene glycol ethers of sorbitol, ethylene oxide-propylene
oxide block copolymers, ethoxylated esters of fatty
(C.sub.8-C.sub.18) acids, condensation products of ethylene oxide
with long chain amines or amides, condensation products of ethylene
oxide with alcohols, and mixtures thereof.
[0028] Various specific examples of suitable nonionic surfactants
include, but are not limited to, methyl gluceth-10, PEG-20 methyl
glucose distearate, PEG-20 methyl glucose sesquistearate,
C.sub.11-15 pareth-20, ceteth-8, ceteth-12, dodoxynol-12,
laureth-15, PEG-20 castor oil, polysorbate 20, steareth-20,
polyoxyethylene-10 cetyl ether, polyoxyethylene-10 stearyl ether,
polyoxyethylene-20 cetyl ether, polyoxyethylene-10 oleyl ether,
polyoxyethylene-20 oleyl ether, an ethoxylated nonylphenol,
ethoxylated octylphenol, ethoxylated dodecylphenol, or ethoxylated
fatty (C.sub.6-C.sub.22) alcohol, including 3 to 20 ethylene oxide
moieties, polyoxyethylene-20 isohexadecyl ether, polyoxyethylene-23
glycerol laurate, polyoxy-ethylene-20 glyceryl stearate, PPG-10
methyl glucose ether, PPG-20 methyl glucose ether,
polyoxyethylene-20 sorbitan monoesters, polyoxyethylene-80 castor
oil, polyoxyethylene-15 tridecyl ether, polyoxy-ethylene-6 tridecyl
ether, laureth-2, laureth-3, laureth-4, PEG-3 castor oil, PEG 600
dioleate, PEG 400 dioleate, 2,6,8-trimethyl-4-nonyloxypolyethylene
oxyethanol; 2,6,8-trimethyl-4-nonyloxypolyethylene oxyethanol;
alkyleneoxypolyethyleneoxyethanol;
alkyleneoxypolyethyleneoxyethanol;
alkyleneoxypolyethyleneoxyethanol; octylphenoxy polyethoxy ethanol;
and nonylphenoxy polyethoxy ethanol, and mixtures thereof.
[0029] Additional nonionic surfactants that may be used include
water soluble alcohol ethylene oxide condensates are the
condensation products of a secondary aliphatic alcohol containing
between about 8 to about 18 carbon atoms in a straight or branched
chain configuration condensed with between about 5 to about 30
moles of ethylene oxide. Such nonionic surfactants are commercially
available under the trade name Tergitol.RTM. from Union Carbide
Corp., Danbury, Conn. Specific examples of such commercially
available nonionic surfactants of the foregoing type are
C.sub.11-C.sub.15 secondary alkanols condensed with either 9 moles
of ethylene oxide (Tergitole 15-S-9) or 12 moles of ethylene oxide
(Tergitol.RTM. 15-S-12) marketed by Union Carbide Corp., (Danbury,
Conn.).
[0030] Other suitable nonionic surfactants include the polyethylene
oxide condensates of one mole of alkyl phenol containing from about
8 to 18 carbon atoms in a straight- or branched chain alkyl group
with about 5 to 30 moles of ethylene oxide. Specific examples of
alkyl phenol ethoxylates include nonyl condensed with about 9.5
moles of ethylene oxide per mole of nonyl phenol, dinonyl phenol
condensed with about 12 moles of ethylene oxide per mole of phenol,
dinonyl phenol condensed with about 15 moles of ethylene oxide per
mole of phenol and diisoctylphenol condensed with about 15 moles of
ethylene oxide per mole of phenol. Commercially available nonionic
surfactants of this type include Igepal.RTM. CO-630 (a nonyl phenol
ethoxylate) marketed by ISP Corp. (Wayne, N.J.). Suitable non-ionic
ethoxylated octyl and nonyl phenols include those having from about
7 to about 13 ethoxy units.
[0031] In addition to nonionic surfactants, the silicone emulsion
may also other types of surfactants. For instance, in some
embodiments, amphoteric surfactants may also be used. For instance,
one class of amphoteric surfactants that may be used in the present
invention are derivatives of secondary and tertiary amines having
aliphatic radicals that are straight chain or branched, wherein one
of the aliphatic substituents contains from about 8 to 18 carbon
atoms and at least one of the aliphatic substituents contains an
anionic water-solubilizing group, such as a carboxy, sulfonate, or
sulfate group. Some examples of amphoteric surfactants include, but
are not limited to, sodium 3-(dodecylamino)propionate, sodium
3-(dodecylamino)-propane-1-sulfonate, sodium 2-(dodecylamino)ethyl
sulfate, sodium 2-(dimethylamino)octadecanoa- te, disodium
3-(N-carboxymethyl-dodecylamino)propane-1-sulfonate, disodium
octadecyliminodiacetate, sodium 1-carboxymethyl-2-undecylimidazole,
and sodium N,
N-bis(2-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine.
[0032] Additional classes of suitable amphoteric surfactants
include phosphobetaines and the phosphitaines. For instance, some
examples of such amphoteric surfactants include, but are not
limited to, sodium coconut N-methyl taurate, sodium oleyl N-methyl
taurate, sodium tall oil acid N-methyl taurate, sodium palmitoyl
N-methyl taurate, cocodimethylcarboxymethylbetaine,
lauryldimethylcarboxymethylbetaine,
lauryidimethylcarboxyethylbetaine,
cetyidimethylcarboxymethylbetaine,
lauryl-bis-(2-hydroxyethyl)carboxymethylbetaine,
oleyldimethylgammacarbox- ypropylbetaine,
lauryl-bis-(2-hydroxypropyl)-carboxyethylbetaine,
cocoamidodimethylpropylsultaine,
stearylamidodimethylpropylsultaine,
laurylamido-bis-(2-hydroxyethyl)propylsultaine, di-sodium oleamide
PEG-2 sulfosuccinate, TEA oleamido PEG-2 sulfosuccinate, disodium
oleamide MEA sulfosuccinate, disodium oleamide MIPA sulfosuccinate,
disodium ricinoleamide MEA sulfosuccinate, disodium undecylenamide
MEA sulfosuccinate, disodium wheat germamido MEA sulfosuccinate,
disodium wheat germamido PEG-2 sulfosuccinate, disodium
isostearamideo MEA sulfosuccinate, cocoamphoglycinate,
cocoamphocarboxyglycinate, lauroamphoglycinate,
lauroamphocarboxyglycinate, capryloamphocarboxyglyci- nate,
cocoamphopropionate, cocoamphocarboxypropionate,
lauroamphocarboxypropionate, capryloamphocarboxypropionate,
dihydroxyethyl tallow glycinate, cocoamido disodium 3-hydroxypropyl
phosphobetaine, lauric myristic amido disodium 3-hydroxypropyl
phosphobetaine, lauric myristic amido glyceryl phosphobetaine,
lauric myristic amido carboxy disodium 3-hydroxypropyl
phosphobetaine, cocoamido propyl monosodium phosphitaine, lauric
myristic amido propyl monosodium phosphitaine, and mixtures
thereof.
[0033] In certain instances, it may also be desired to utilize one
or more anionic surfactants within the silicone emulsion. Suitable
anionic surfactants include, but are not limited to, alkyl
sulfates, alkyl ether sulfates, alkyl ether sulfonates, sulfate
esters of an alkylphenoxy polyoxyethylene ethanol, alpha-olefin
sulfonates, beta-alkoxy alkane sulfonates, alkylauryl sulfonates,
alkyl monoglyceride sulfates, alkyl monoglyceride sulfonates, alkyl
carbonates, alkyl ether carboxylates, fatty acids, sulfosuccinates,
sarcosinates, octoxynol or nonoxynol phosphates, taurates, fatty
taurides, fatty acid amide polyoxyethylene sulfates, isethionates,
or mixtures thereof.
[0034] Particular examples of some suitable anionic surfactants
include, but are not limited to, C.sub.8-C.sub.18 alkyl sulfates,
C.sub.8-C.sub.18 fatty acid salts, C.sub.8-C.sub.18 alkyl ether
sulfates having one or two moles of ethoxylation, C.sub.8-C.sub.18
alkamine oxides, C.sub.8-C.sub.18 alkoyl sarcosinates,
C.sub.8-C.sub.18 sulfoacetates, C.sub.8-C.sub.18 sulfosuccinates,
C.sub.8-C.sub.18 alkyl diphenyl oxide disulfonates,
C.sub.8-C.sub.18 alkyl carbonates, C.sub.8-C.sub.18 alpha-olefin
sulfonates, methyl ester sulfonates, and blends thereof. The
C.sub.8-C.sub.18 alkyl group may be straight chain (e.g., lauryl)
or branched (e.g., 2-ethylhexyl). The cation of the anionic
surfactant may be an alkali metal (e.g., sodium or potassium),
ammonium, C.sub.1-C.sub.4 alkylammonium (e.g., mono-, di-, tri), or
C.sub.1-C.sub.3 alkanolammonium (e.g., mono-, di-, tri).
[0035] Specific examples of such anionic surfactants include, but
are not limited to, lauryl sulfates, octyl sulfates, 2-ethylhexyl
sulfates, lauramine oxide, decyl sulfates, tridecyl sulfates,
cocoates, lauroyl sarcosinates, lauryl sulfosuccinates, linear
C.sub.10 diphenyl oxide disulfonates, lauryl sulfosuccinates,
lauryl ether sulfates (1 and 2 moles ethylene oxide), myristyl
sulfates, oleates, stearates, tallates, ricinoleates, cetyl
sulfates, and similar surfactants.
[0036] Cationic surfactants, such as cetylpyridinium chloride,
methylbenzethonium chloride, hexadecylpyridinium chloride,
benzalkonium chloride, hexadecyltrimethylammonium chloride,
dodecylpyridinium chloride, the corresponding bromides, a
hydroxyethylheptadecylimidazolium halide, coconut
alkyldimethylammonium betaine, and coco aminopropyl betaine, may
also be used in the silicone emulsion.
[0037] The amount of surfactant utilized in the silicone emulsion
may generally vary depending on the relative amounts of the other
components present within the emulsion. When utilized, the
surfactant may be present in the emulsion in an amount from about
0.001% to about 10% by weight of the silicone emulsion used to form
the outer layer 36. In another embodiment, the surfactant may be
present in an amount from about 0.001% to about 5% by weight of the
silicone emulsion. In still another embodiment, the surfactant may
be present in an amount from about 0.01% to about 1% by weight of
the silicone emulsion. For example, in one particular embodiment, a
nonionic surfactant may be present in the emulsion in an amount
between about 0.001% to about 5% by weight of the silicone
emulsion.
[0038] The silicone emulsion may also include one or more solvents.
Usually, the silicone emulsion contains at least one aqueous
solvent, such as water. The silicone emulsion may also contain
non-aqueous solvents that, although not required, sometimes aid in
dissolving certain components of the emulsion. Examples of some
suitable non-aqueous solvents include, but are not limited to,
glycols, such as propylene glycol, butylene glycol, triethylene
glycol, hexylene glycol, polyethylene glycols, ethoxydiglycol, and
dipropyleneglycol; alcohols, such as ethanol, n-propanol, and
isopropanol; triglycerides; ethyl acetate; acetone; triacetin; and
combinations thereof. The amount of solvent utilized in the
silicone emulsion may generally vary depending on the relative
amounts of the other components present within the formulation.
When utilized, the solvent is typically present in the formulation
in an amount from about 20% to about 99.99% by weight of the
silicone emulsion used to form the outer layer 36. In another
embodiment, the solvent may be present in an amount from about 70%
to about 98% by weight of the silicone emulsion.
[0039] The solids content of the outer layer 36 may generally be
varied to achieve the desired gripping properties. For example, the
silicone emulsion used to form the outer layer 36 may have a solids
content of from about 0.1 weight % to about 10 weight %. In another
embodiment, the silicone emulsion may have a solids content of from
about 0.25 weight % to about 5 weight %. In still another
embodiment, the silicone emulsion may have a solids content of from
about 0.3 weight % to about 1.0 weight %. To lower the solids
content of a commercially available silicone emulsion, for example,
additional amounts of solvent may be utilized. By varying the
solids content of the silicone emulsion, the presence of the
silicone in the glove may be controlled. For example, to form a
glove with a higher degree of gripping properties, the silicone
emulsion used in such layer may have a relatively high solids
content so that a greater percentage of the silicone is
incorporated into the layer during the forming process. The
thickness of the outer layer 36 may also vary. For example, the
thickness may range from about 0.001 millimeters to about 0.4
millimeters. In another embodiment, the thickness may range from
about 0.01 millimeters to about 0.30 millimeters. In still another
embodiment, the thickness may range from about 0.01 millimeters to
about 0.20 millimeters.
[0040] In one particular embodiment, the silicone emulsion is DC
365, which is a pre-emulsified silicone (35% solids content) that
is commercially available from Dow Corning Corporation (Midland,
Mich.) and believed to contain 40-70% water (aqueous solvent),
30-60% methyl-modified polydimethylsiloxane (silicone), 1-5%
propylene glycol (non-aqueous solvent), 1-5% polyethylene glycol
sorbitan monolaurate (nonionic surfactant), and 1-5% octylphenoxy
polyethoxy ethanol (nonionic surfactant). In another embodiment,
the silicone emulsion is SM 2140 (25% solids content), which is a
pre-emulsified silicone that is commercially available from GE
Silicones (Waterford, N.Y.) and believed to contain 30-60% water
(aqueous solvent), 30-60% amino-modified dimethylpolysiloxane
(silicone), 1-5% ethoxylated nonyl phenol (nonionic surfactant),
1-5% trimethyl-4-nonyloxypolyethyleneoxy ethanol (nonionic
surfactant), and minor percentages of acetaldehyde, formaldehyde,
and 1,4 dioxane. If desired, these pre-emulsified silicones may be
diluted with water or other solvents prior to use in the outer
layer 36.
[0041] Besides the outer layer 36 and the substrate body 24, the
glove 20 may also contain other layers. For example, as shown in
FIGS. 1-2, the glove 20 may contain a coating 26 that contacts the
body of the user 22 during use. In this embodiment, the coating 26
includes a donning layer 30 overlying and contacting the substrate
body 24 and a surfactant layer 32 overlying and contacting the
donning layer 30.
[0042] The donning layer 30 may contain any of a variety of
different elastomeric polymers that are capable of facilitating
donning of the glove. Some examples of suitable materials for the
donning layer 30 include, but are not limited to, polybutadienes
(e.g., syndiotactic 1,2 polybutadiene), polyurethanes, halogenated
copolymers, and the like. For instance, in one embodiment, an
unsaturated styrene-isoprene (SIS) having tri- or radial-blocks may
be utilized. In some embodiments, the SIS block copolymer has a
polystyrene end block content of from about 10% to about 20% by
weight of the total weight of the SIS block copolymer. In another
embodiment, the SIS block copolymer has a polystyrene end block
content of from about 15% to about 18% by weight, of the total
weight of the SIS block copolymer. Moreover, the molecular weight
of the polystyrene end blocks is typically at least about 5,000
grams per mole. Some examples of suitable mid-block unsaturated SIS
block copolymers include, but are not limited to, Kraton.RTM. D1107
available from Kraton Polymers and Vector.RTM. 511 and Vector.RTM.
4111 available from Dexco Polymers of Houston, Tex.
[0043] Another suitable donning material is 1,2 polybutadiene
(e.g., syndiotactic 1,2 polybutadiene). In one embodiment, for
example, the donning layer 30 is formed from a solution that
contains 5.0 weight % Presto Emulsion (15% solids), 2.0 weight %
magnesium carbonate, 3.0 weight % compounded natural rubber latex,
and 90.0 weight % deionized water. The "Presto Emulsion" is
manufactured by Ortec, Inc. of Easley, S.C. and is an emulsion of
1,2 syndiotactic polybutadiene in toluene and water. Other examples
of donning materials that may be utilized in the donning layer 30
may be described in U.S. Pat. No. 5,792,531 to Littleton, et al.,
which is incorporated herein in its entirety by reference thereto
for all purposes.
[0044] A lubricant 32 may also coat the donning layer 30 to aid in
donning the article when the user's body is either wet or dry. The
lubricant 32, for example, may include a cationic surfactant (e.g.,
cetyl pyridinium chloride), an anionic surfactant (e.g., sodium
lauryl sulfate), a nonionic surfactant, and the like. For instance,
in one embodiment, the lubricant 32 contains a quaternary ammonium
compound, such as that available Goldschmidt Chemical Corp. of
Dublin, Ohio under the trade name Verisoft BTMS, and a silicone
emulsion, such as that obtained from General Electric Silicone
under the trade name AF-60. Verisoft BTMS contains behnyl trimethyl
sulfate and cetyl alcohol, while AF-60 contains
polydimethylsiloxane, acetylaldehyde, and small percentages of
emulsifiers. In another embodiment, the lubricant 32 contains a
silicone emulsion that may be the same or different than the
silicone emulsion used to form the outer layer 36. For example, in
some embodiments, the lubricant layer 32 may contain DC 365 (Dow
Corning) or SM 2140 (GE Silicones).
[0045] An elastomeric article made in accordance with the present
invention may generally be formed using a variety of processes
known in the art. In fact, any process capable of making an
elastomeric article may be utilized in the present invention. For
example, elastomeric article formation techniques may utilize
dipping, spraying, halogenation, drying, curing, as well as any
other technique known in the art. In this regard, referring to FIG.
3, one embodiment of a method of dip-forming a glove will now be
described in more detail. Although a batch process is described and
shown herein, it should be understood that semi-batch and
continuous processes may also be utilized in the present
invention.
[0046] Initially, any well-known former, such as formers made from
metals, ceramics, or plastics, is provided. The formed is dried to
remove water residue by conveying it through a preheated oven (not
shown). The preheated former is then dipped into a bath containing
a coagulant, a powder source, a surfactant, and water (illustrated
as 62). The coagulant may contain calcium ions (e.g., calcium
nitrate) to break the protection system of the emulsion, thereby
allowing the latex to deposit on the former. The powder may be
calcium carbonate powder, which later acts as a release agent. The
surfactant provides good wetting to avoid forming a meniscus and
trapping air between the form and deposited latex, particularly in
the cuff area. As noted above, the former has been preheated in the
drying step and the residual heat dries off the water leaving, for
example, calcium nitrate, calcium carbonate powder, and surfactant
on the surface of the former. Other suitable coagulant solutions
are also described in U.S. Pat. No. 4,310,928 to Joung, which is
incorporated herein in its entirety by reference thereto for all
purposes.
[0047] The coated former is then dipped into a tank containing a
natural rubber latex bath (illustrated as 64). The bath contains,
for example, natural rubber latex, stabilizers, antioxidants,
curing activators, organic accelerators, vulcanizers, and the like.
The stabilizers are sometimes of the phosphate-type surfactants.
The antioxidants may be the phenol type, for example,
2,2'-methylenebis (4-methyl-6-t-butylphenol). The curing activator
may be zinc oxide. The organic accelerator may be dithiocarbamate.
The vulcanizer may be sulfur or a sulfur-containing compound. If
these materials are used, the stabilizer, antioxidant, activator,
accelerator and vulcanizer may be dispersed into water to avoid
crumb formation by using a ball mill. This dispersion is then mixed
into the latex. The former is dipped into one or more latex baths a
sufficient number of times to build up the desired thickness on the
former. By way of example, the substrate body 24 may have a
thickness of from about 0.004 to about 0.012 inches.
[0048] A bead roll station (not shown) may, in some embodiments, be
utilized to impart a cuff to the glove. For instance, the bead roll
station may contain one or more bead rolls such that the former is
indexed therethrough to be provided with cuffs. The latex-coated
former is then dipped into a leaching tank in which hot water is
circulated to remove the water-soluble components, such as residual
calcium nitrates and proteins contained in the natural latex (not
shown). This leaching process may continue for about twelve minutes
with the tank water being about 120.degree. F. Further, the
latex-coated former may then be dipped into a solution to form the
donning layer 30 of the glove (illustrated as numeral 66). In one
embodiment, for example, the glove is inverted once again and then
dipped into a composition of 1,2 syndiotactic polybutadiene.
[0049] Thereafter, the latex-coated former is sent to a curing
station where the natural rubber is vulcanized, typically in an
oven, thereby heat curing the rubber (not shown). The curing
station initially evaporates any remaining water in the latex
coating of the former and then proceeds to the higher temperature
vulcanization. The drying may occur from about 85.degree. C. to
about 95.degree. C., with a vulcanization step occurring at
temperatures from about 110.degree. C. to about 120.degree. C. For
example, in one embodiment, the gloves may be cured in a single
oven at a temperature of 115.degree. C. for about 20 minutes. If
desired, the oven may be divided into four different zones with a
former being conveyed through the zones of increasing temperature.
One example is an oven having four zones with the first two zones
being dedicated to drying and the second two zones being primarily
the vulcanization step. Each of the zones may have a slightly
higher temperature, for example, the first zone at about 80.degree.
C., the second zone at about 95.degree. C., a third zone at about
105.degree. C., and a final zone at about 115.degree. C. The
residence time of the former within a zone in this case may be
about ten minutes or so. The accelerator and vulcanizer contained
in the latex coating of the former are used to cross-link the
natural rubber therein. The vulcanizer forms sulfur bridges between
different rubber segments and the accelerator is used to speed up
sulfur bridge formation.
[0050] Upon being cured, the former may then be transferred to a
stripping station (not shown). 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 from the
former by turning the glove inside-out as it is stripped from the
former. Optionally, after being removed from the former, the glove
may be rinsed in water.
[0051] In accordance with the present invention, a silicone
emulsion may then be applied to enhance the gripping properties of
the glove. For example, in one embodiment, a silicone emulsion
(e.g., DC 365) is first thoroughly mixed with water using a high
shear mixer to achieve a homogeneous solution having the desired
solids content. Thereafter, the resulting emulsion may then be
applied to the grip surface of the glove in a variety of different
ways. For instance, in one embodiment, the glove is immersed in a
tumbler for a certain period of time (e.g., 1-10 minutes) during
which the grip surface of the glove is rinsed with the silicone
emulsion (illustrated as 68). Alternatively, the grip surface of
the glove may be sprayed with the silicone emulsion using a
conventional spray nozzle. Once applied with the silicone emulsion,
the silicone-coated glove is then dried (illustrated as numeral
70). For example, in some embodiments, the silicone-coated glove
may be dried at a temperature of from about 20.degree. C. to about
200.degree. C., and in some embodiments, from about 35.degree. C.
to about 115.degree. C.
[0052] After the drying process, the glove is then inverted and
halogenated (illustrated as numeral 72). The halogenation (e.g.,
chlorination) may be performed in any suitable manner known to
those skilled in the art. Such methods include (1) direct injection
of chlorine gas into a water mixture, (2) mixing high density
bleaching powder and aluminum chloride in water, (3) brine
electrolysis to produce chlorinated water, and (4) acidified
bleach. Examples of such methods are described in U.S. Pat. No.
3,411,982 to Kavalir; U.S. Pat. No. 3,740,262 to Agostinelli; U.S.
Pat. No. 3,992,221 to Homsy, et al.; U.S. Pat. No. 4,597,108 to
Momose; and U.S. Pat. No. 4,851,266 to Momose, U.S. Pat. No.
5,792,531 to Littleton, et al., which are incorporated herein in
their entirety by reference thereto for all purposes. In one
embodiment, for example, chlorine gas is injected into a water
stream and then fed into a chlorinator (a closed vessel) containing
the glove. The concentration of chlorine may be monitored and
controlled to control the degree of chlorination. The chlorine
concentration is typically at least about 100 ppm, in some
embodiments from about 200 ppm to about 3500 ppm, and in some
embodiments, from about 300 ppm to about 600 ppm, e.g., about 400
ppm. The time duration of the chlorination step may also be
controlled to control the degree of chlorination and may range, for
example, from about 1 to about 10 minutes, e.g., 4 minutes. Due to
the silicone emulsion applied to the grip surface, chlorination
will generally occur to a much greater extent on the
wearer-contacting surface, i.e., the donning side of the glove,
than on the grip surface of the glove.
[0053] Still within the chlorinator, the chlorinated glove may then
be rinsed with tap water at about room temperature (not shown).
This rinse cycle may be repeated as necessary. Once all water is
removed, the glove is tumbled to drain excess water.
[0054] A lubricant solution may then be added into the chlorinator
containing the glove that is then tumbled for about five minutes
(illustrated as numeral 74). This coats the donning side with the
lubricant solution to form the lubricant layer 32. In one
embodiment, for example, the lubricant layer 32 may contain a
silicone emulsion that may be the same as the silicone emulsion
used to form the outer layer 36, e.g., DC 365 (Dow Corning) or SM
2140 (GE Silicones), which are described in detail above. The
lubricant solution is drained from the chlorinator and may be
reused if desired.
[0055] The coated glove is then put into a drier and dried from
about 10 to 60 minutes (e.g., 40 minutes) at from about 20.degree.
C. to about 80.degree. C. (e.g., 40.degree. C.) to dry the donning
surface (not shown). The glove is then reinverted and the grip
surface is dried from about 20 to 100 minutes (e.g., 60 minutes) at
from about 20.degree. C. to about 80.degree. C. (e.g., 40.degree.
C.).
[0056] Although various constructions and techniques for forming
elastomeric articles have been described above, it should be
understood that the present invention is not limited to any
particular construction or technique for forming the article. For
example, the layers described above may not be utilized in all
instances. Additionally, other layers not specifically referred to
above may be utilized in the present invention.
[0057] Thus, as discussed above, a silicone emulsion may be used to
form an outer layer of a glove to enhance its gripping
characteristics. Specifically, it is believed that the silicone
emulsion may inhibit the ability of halogen atoms to bond with the
elastomeric material of the substrate, thereby limiting the level
of slipperiness usually imparted during chlorination. Surprisingly,
it has been discovered that the materials often used to enhance wet
lubricity of the wearer-contacting surface may have the opposite
effect when used to form the outer layer of the glove. This
discovery not only enables the gripping properties of the glove to
be enhanced, but also allows for the potential of using the same
material for the lubricant layer on the wearer-contacting surface
and for the outer layer on the grip surface, thereby reducing costs
and enhancing process efficiency.
[0058] The present invention may be better understood with
reference to the following examples.
EXAMPLE 1
[0059] The ability to form an elastomeric glove in accordance with
the present invention was demonstrated. Initially, a pre-heated,
glove-shaped former was dipped into a coagulant solution that
contained calcium nitrate, calcium carbonate, a surfactant, and
water. The coated former was then dipped into a dip tank containing
compounded, pre-vulcanized natural rubber latex. After dipping, the
former was removed from the natural rubber latex dip tank and
leached with water. The latex-coated former was then dipped into a
solution containing 5.0 weight % of a 1,2 syndiotactic
polybutadiene emulsion (15 weight % solids), 3.0 weight %
compounded natural rubber latex, 2.0 weight % magnesium carbonate,
and 90.0 weight % water to form the donning layer of the glove.
Thereafter, the latex-coated former was cured in an oven at a
temperature of 115.degree. C. for about 20 minutes. The glove was
manually removed from the former by turning the glove inside-out as
it was stripped from its corresponding former. After being removed
from the former, the glove was also rinsed in deionized water. The
thickness of the resulting glove was 0.25 millimeters.
[0060] To enhance the gripping properties of the outer surface, 1.5
grams of DC 365 (35% solids content) was added per 98.5 grams of
water to achieve a homogeneous solution having a solids content of
0.5%. The glove was then immersed in a tumbler for 5 minutes that
was injected with the diluted DC 365 emulsion. Once applied with
the silicone emulsion, the glove was then dried for 45 minutes at
about 80.degree. C.
[0061] After the drying process, the glove was turned inside out
and placed into a chlorinator. Chlorine gas mixed with a water
stream was injected into the chlorinator to chlorinate the donning
surface of the glove. The chlorine concentration was 400 ppm and
the pH was 1.74. The glove was immersed in the chlorine solution
for 2 minutes. In this particular example, cetyl pyridinium
chloride was also added to the chlorine solution at a concentration
of 0.25% by weight of the solution. After chlorination, the glove
was inverted and dried at a temperature of about 80.degree. C. for
45 minutes.
[0062] The glove sample described above was then tested to
determine the gripping characteristics of the glove. Specifically,
the glove was first donned on a wet hand. After donning the glove,
the wearer was asked to rate the tackiness of the gripping surface
of the glove on a scale from 1 to 5, with 4 representing optimum
tackiness.
[0063] Specifically, the rating scale is set forth in more detail
below:
1 Grip (Tackiness) Rating Scale Rating Description Example 5 Failed
Grip is too tacky, fingers stick together 4 Excellent Optimum grip
3 Acceptable Acceptable grip 2 Poor Grip is too slick to handle
instruments 1 Failed Very slippery
[0064] 15-30 samples were tested. It was determined that the
average grip rating for the samples was between 2 to 3.
EXAMPLE 2
[0065] A glove was formed as set forth above in Example 1, except
that the silicone emulsion applied to the outer surface was formed
by adding 2.65 grams of DC 365 (35 weight % solids content) per
97.35 grams of water to achieve a homogeneous solution having a
solids content of 0.9%.
[0066] The glove sample described above was then tested as set
forth in Example 1 to determine the gripping characteristics of the
glove. It was determined that the grip rating was 3.
EXAMPLE 3
[0067] A glove was formed as set forth above in Example 1, except
that chlorination was conducted at a chlorine concentration of 400
ppm for 4 minutes. After chlorination, the glove was rinsed (soft
water and deionized water). A DC 365 solution (1.5 weight % solids
content) was then applied to the donning surface of the glove as a
lubricant layer using a tumbling process. Specifically, 4.28 grams
of DC 365 (35% solids content) was added per 95.72 grams of water
to achieve a homogeneous solution having a solids content of 1.5%.
The glove was then immersed in a tumbler for 5 minutes that was
injected with the diluted DC 365 emulsion. The glove was then dried
at 40.degree. C. for 40 minutes, inverted, and dried again at
40.degree. C. for 60 minutes.
[0068] The glove sample described above was then tested as set
forth in Example 1 to determine the gripping characteristics of the
glove. It was determined that the grip rating was 3.
EXAMPLE 4
[0069] A glove was formed as set forth above in Example 1, except
that chlorination was conducted at a chlorine concentration of 400
ppm for 4 minutes. After chlorination, the glove was rinsed (soft
water and deionized water). A SM 2140 solution (1.0 weight % solids
content) was applied to the donning surface of the glove as a
lubricant layer using a tumbling process. Specifically, 4 grams of
SM 2140 (25% solids content) was added per 96 grams of water to
achieve a homogeneous solution having a solids content of 1.0%. The
glove was then immersed in a tumbler for 5 minutes that was
injected with the diluted SM 2140 emulsion. The glove was then
dried at 55.degree. C. for 40 minutes, inverted, and dried again at
55.degree. C. for 60 minutes.
[0070] The glove sample described above was then tested as set
forth in Example 1 to determine the gripping characteristics of the
glove. It was determined that the grip rating was 3.
EXAMPLE 5
[0071] The ability to form an elastomeric glove in accordance with
the present invention was demonstrated. Initially, a pre-heated,
glove-shaped former was dipped into a coagulant solution that
contained calcium nitrate, calcium carbonate, a surfactant, and
water. The coated former was then dipped into a dip tank containing
compounded, pre-vulcanized natural rubber latex. After dipping, the
former was removed from the natural rubber latex dip tank and
leached with water. The latex-coated former was then dipped into a
solution containing 5.0 weight % of a 1,2 syndiotactic
polybutadiene emulsion (15 weight % solids), 3.0 weight %
compounded natural rubber latex, 2.0 weight % magnesium carbonate,
and 90.0 weight % water to form the donning layer of the glove.
Thereafter, the latex-coated former was cured in an oven at a
temperature of 115.degree. C. for about 20 minutes. The glove was
manually removed from the former by turning the glove inside-out as
it was stripped from its corresponding former. After being removed
from the former, the glove was also rinsed in deionized water. The
thickness of the resulting glove was 0.25 millimeters.
[0072] To enhance the gripping properties of the outer surface,
0.86-1.14 grams of DC 365 (35% solids content) was added per
98.86-99.14 grams of water to achieve a homogeneous solution having
a solids content of 0.3-0.4%. The glove was then immersed in a
tumbler for 4 minutes that was injected with the diluted DC 365
emulsion. Once applied with the silicone emulsion, the glove was
then dried for 40 minutes at 40.degree. C.
[0073] After the drying process, the glove was turned inside out
and placed into a chlorinator. Chlorine gas mixed with a water
stream was injected into the chlorinator to chlorinate the donning
surface of the glove. The chlorine concentration was 400 ppm and
the pH was 1.74. The glove was immersed in the chlorine solution
for 6 minutes. After chlorination, the glove was rinsed (soft water
and deionized water). A SM 2140 (GE Silicones) was then applied to
the donning surface of the glove using a tumbling process.
Specifically, 1.2-1.6 grams of SM 2140 (25% solids content) was
added per 98.4-98.8 grams of water to achieve a homogeneous
solution having a solids content of 0.3-0.4%. The glove was then
immersed in a tumbler for 4 minutes that was injected with the
diluted SM 2140 emulsion. The glove was then dried at 55.degree. C.
for 40 minutes, inverted, and dried again at 55.degree. C. for 60
minutes.
[0074] The glove sample described above was then tested as set
forth in Example 1 to determine the gripping characteristics of the
glove. It was determined that the grip rating was 3.
[0075] While the invention has been described in detail with
respect to the specific embodiments thereof, it will be appreciated
that those skilled in the art, upon attaining an understanding of
the foregoing, may readily conceive of alterations to, variations
of, and equivalents to these embodiments. Accordingly, the scope of
the present invention should be assessed as that of the appended
claims and any equivalents thereto.
* * * * *