U.S. patent application number 13/833581 was filed with the patent office on 2014-07-17 for antimicrobial polymer systems using multifunctional organometallic additives for thermoset hosts.
This patent application is currently assigned to DMR INTERNATIONAL, INC.. The applicant listed for this patent is MARC CHASON, Daniel Roman Gamota, Rick Latella. Invention is credited to MARC CHASON, Daniel Roman Gamota, Rick Latella.
Application Number | 20140199358 13/833581 |
Document ID | / |
Family ID | 51165312 |
Filed Date | 2014-07-17 |
United States Patent
Application |
20140199358 |
Kind Code |
A1 |
CHASON; MARC ; et
al. |
July 17, 2014 |
ANTIMICROBIAL POLYMER SYSTEMS USING MULTIFUNCTIONAL ORGANOMETALLIC
ADDITIVES FOR THERMOSET HOSTS
Abstract
Described are antimicrobial polymer products made from mixtures
of antimicrobial organometallic additives dispersed throughout a
polymer host matrix.
Inventors: |
CHASON; MARC; (Schaumburg,
IL) ; Gamota; Daniel Roman; (Palatine, IL) ;
Latella; Rick; (Woodstock, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHASON; MARC
Gamota; Daniel Roman
Latella; Rick |
Schaumburg
Palatine
Woodstock |
IL
IL
IL |
US
US
US |
|
|
Assignee: |
DMR INTERNATIONAL, INC.
WOODSTOCK
IL
|
Family ID: |
51165312 |
Appl. No.: |
13/833581 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61751940 |
Jan 14, 2013 |
|
|
|
Current U.S.
Class: |
424/409 ;
514/494; 514/495; 514/499 |
Current CPC
Class: |
A01N 55/02 20130101;
A01N 59/16 20130101; A01N 59/20 20130101; A01N 37/02 20130101; A01N
37/02 20130101; A01N 25/10 20130101; A01N 25/10 20130101; A01N
37/02 20130101; A01N 25/10 20130101; A01N 59/20 20130101; A01N
37/02 20130101; A01N 59/16 20130101 |
Class at
Publication: |
424/409 ;
514/495; 514/499; 514/494 |
International
Class: |
A01N 55/02 20060101
A01N055/02 |
Claims
1. A product comprising: a substrate, and a thermoset powder
coating on the substrate, wherein the thermoset powder coating
comprises a polymer host matrix and one or more antimicrobial
organometallic additives dispersed throughout the polymer host
matrix, wherein each of the one or more antimicrobial
organometallic additives is water insoluble or sparingly soluble in
water and comprises a long-chain fatty acid group, and wherein a
majority of metallic species dispersed throughout the polymer host
matrix are in the one or more antimicrobial organometallic
additives.
2. The product of claim 1, wherein the one or more antimicrobial
organometallic additives comprise silver stearate.
3. The product of claim 1, wherein the one or more antimicrobial
organometallic additives comprise cupric stearate.
4. The product of claim 1, wherein the one or more antimicrobial
organometallic additives comprise zinc stearate.
5. The product of claim 1, wherein the one or more antimicrobial
organometallic additives comprise a mixture of two or more members
of the group consisting of the following antimicrobial
organometallic additives: silver stearate, cupric stearate and zinc
stearate.
6. The product of claim 1, wherein the product has a degree of
antimicrobial activity of 99% or greater.
7. The product of claim 6, wherein the one or more antimicrobial
organometallic additives together comprise no more than about 3% by
volume of the total volume of the polymer host matrix and the one
or more antimicrobial organometallic additives together.
8. The product of claim 1, wherein the product comprises a coating
and a substrate, and wherein the polymer host matrix is at least
part of the coating.
9. A method comprising the following step: (a) heating a mixture on
a substrate to melt the mixture to form a thermoset powder coating
on the substrate, wherein the mixture comprises one or more
antimicrobial organometallic powders mixed with a thermosetting
powder, wherein the thermoset powder coating comprises a polymer
host matrix and one or more antimicrobial organometallic additives
dispersed throughout the polymer host matrix, wherein each of the
one or more antimicrobial organometallic additives is water
insoluble or sparingly soluble in water and comprises a long-chain
fatty acid group, and wherein a majority of metallic species
dispersed throughout the polymer host matrix are in the one or more
antimicrobial organometallic additives.
10. The method of claim 9, wherein the one or more antimicrobial
organometallic additives comprise silver stearate.
11. The method of claim 9, wherein the one or more antimicrobial
organometallic additives comprise cupric stearate.
12. The method of claim 9, wherein the one or more antimicrobial
organometallic additives comprise zinc stearate.
13. The method of claim 9, wherein the one or more antimicrobial
organometallic additives comprise a mixture of two or more members
of the group consisting of the following antimicrobial
organometallic additives: silver stearate, cupric stearate and zinc
stearate.
14. The method of claim 9, wherein the thermoset powder coating a
degree of antimicrobial activity of 99% or greater.
15. The method of claim 14, wherein the one or more antimicrobial
organometallic additives together comprise no more than about 3% by
volume of the total volume of the polymer host matrix and the one
or more antimicrobial organometallic additives together.
16. A product comprising: a substrate, and a thermoset powder
coating on the substrate, wherein the thermoset powder coating
comprises a polymer host matrix and one or more antimicrobial
organometallic additives dispersed throughout the polymer host
matrix, and wherein the one or more antimicrobial organometallic
additives comprise a mixture of two or more members of the group
consisting of the following antimicrobial organometallic additives:
silver stearate, cupric stearate and zinc stearate.
17. The product of claim 16, wherein the product has a degree of
antimicrobial activity of 99% or greater, and wherein the one or
more antimicrobial organometallic additives together comprise no
more than about 3% by volume of the total volume of the polymer
host matrix and the one or more antimicrobial organometallic
additives together.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority to U.S.
Provisional Patent Application No. 61/751,940 to Chason et al.,
entitled "ANTI-MICROBIAL POLYMER SYSTEMS USING MULTIFUNCTIONAL
ORGANOMETALLIC ADDITIVES," filed Jan. 14, 2013 which is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to antimicrobial polymer
systems.
[0004] 2. Related Art
[0005] Material surfaces of polymer products may become
contaminated with disease-causing agents. For example, used in
aqueous environments or environments where moisture is present,
microbes may be transferred to the surface of the polymer
products.
SUMMARY
[0006] According to a first broad aspect, the present invention
provides a product comprising: a polymer host matrix comprising
polyurethane, and one or more antimicrobial organometallic
additives dispersed throughout the polymer host matrix, wherein
each of the one or more antimicrobial organometallic additives is
water insoluble or sparingly soluble in water and comprises a
long-chain fatty acid group, and wherein a majority of metallic
species dispersed throughout the polymer host matrix are in the one
or more antimicrobial organometallic additives.
[0007] According to a second broad aspect, the present invention
provides a method comprising the following step: (a) mixing one or
more antimicrobial organometallic additives with a liquid
polyurethane at room temperature to form a polymer product
comprising the one or more antimicrobial organometallic additives
dispersed throughout the polymer host matrix, wherein each of the
one or more antimicrobial organometallic additives is water
insoluble or sparingly soluble in water and comprises a long-chain
fatty acid group, wherein a majority of metallic species dispersed
throughout the polymer host matrix are in the one or more
antimicrobial organometallic additives.
[0008] According to a third broad aspect, the present invention
provides a product comprising: a polymer host matrix comprising
polyurethane, and one or more antimicrobial organometallic
additives dispersed throughout the polymer host matrix, wherein the
one or more antimicrobial organometallic additives comprise a
mixture of two or more members of the group consisting of the
following antimicrobial organometallic additives: silver stearate,
cupric stearate and zinc stearate.
[0009] According to a fourth broad aspect, the present invention
provides a product comprising: a substrate, and a thermoset powder
coating on the substrate, wherein the thermoset powder coating
comprises a polymer host matrix and one or more antimicrobial
organometallic additives dispersed throughout the polymer host
matrix, wherein each of the one or more antimicrobial
organometallic additives is water insoluble or sparingly soluble in
water and comprises a long-chain fatty acid group, and wherein a
majority of the metallic species dispersed throughout the polymer
host matrix are in the one or more antimicrobial organometallic
additives.
[0010] According to a fifth broad aspect, the present invention
provides a method comprising the following step: (a) heating a
mixture on a substrate to melt the mixture to form a thermoset
powder coating on the substrate, wherein the mixture comprises one
or more antimicrobial organometallic powders mixed with a
thermosetting powder, wherein the thermoset powder coating
comprises a polymer host matrix and one or more antimicrobial
organometallic additives dispersed throughout the polymer host
matrix, wherein each of the one or more antimicrobial
organometallic additives is water insoluble or sparingly soluble in
water and comprises a long-chain fatty acid group, and wherein a
majority of the metallic species dispersed throughout the polymer
host matrix are in the one or more antimicrobial organometallic
additives.
[0011] According to a sixth broad aspect, the present invention
provides a product comprising: a substrate, and a thermoset powder
coating on the substrate, wherein the thermoset powder coating
comprises a polymer host matrix and one or more antimicrobial
organometallic additives dispersed throughout the polymer host
matrix, and wherein the one or more antimicrobial organometallic
additives comprise a mixture of two or more members of the group
consisting of the following antimicrobial organometallic additives:
silver stearate, cupric stearate and zinc stearate.
[0012] According to a seventh broad aspect, the present invention
provides a product comprising: a polymer host matrix comprising
paraffin wax, and one or more antimicrobial organometallic
additives dispersed throughout the polymer host matrix, wherein
each of the one or more antimicrobial organometallic additives is
water insoluble or sparingly soluble in water and comprises a
long-chain fatty acid group, and wherein a majority of metallic
species dispersed throughout the polymer host matrix are in the one
or more antimicrobial organometallic additives.
[0013] According to an eighth broad aspect, the present invention
provides a method comprising the following step: (a) mixing one or
more antimicrobial organometallic additives with liquid paraffin
wax to form a polymer product comprising the one or more
antimicrobial organometallic additives dispersed throughout the
polymer host matrix, wherein each of the one or more antimicrobial
organometallic additives is water insoluble or sparingly soluble in
water and comprises a long-chain fatty acid group, wherein a
majority of metallic species dispersed throughout the polymer host
matrix are in the one or more antimicrobial organometallic
additives.
[0014] According to a ninth broad aspect, the present invention
provides a product comprising: a polymer host matrix comprising
paraffin wax, and one or more antimicrobial organometallic
additives dispersed throughout the polymer host matrix, wherein
each of the one or more antimicrobial organometallic additives is
water insoluble or sparingly soluble in water and comprises a
long-chain fatty acid group, and wherein the one or more
antimicrobial organometallic additives comprise a mixture of two or
more members of the group consisting of the following antimicrobial
organometallic additives: silver stearate, cupric stearate and zinc
stearate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated herein and
constitute part of this specification, illustrate exemplary
embodiments of the invention, and, together with the general
description given above and the detailed description given below,
serve to explain the features of the invention. The sizes and the
relative heights, widths, diameters, thicknesses, etc. of features
in the drawings are not necessarily to scale unless specifically
indicated otherwise. For example, in the drawings the thickness of
a coating in the drawings may be shown thicker relative to the
substrate on which the coating is coated to allow for details of
the components of the coating to be better illustrated. Also in the
drawings, organometallic additives are shown as being much larger
than these components would be in the polymer host matrix in which
these components are dispersed for ease of illustration. In the
drawings, the organometallic additives are depicted as circles.
This is only a schematic representation as the additive form factor
of the present invention may be circular, spherical, linear,
branched or other form factor.
[0016] FIG. 1 is a schematic drawing of a polymer product having
dispersed therein an organometallic additive according to one
embodiment of the present invention.
[0017] FIG. 2 is a schematic drawing of a polymer product having
dispersed therein three organometallic additives according to one
embodiment of the present invention.
[0018] FIG. 3 is a schematic drawing of a polymer coating having
dispersed therein three organometallic additives on a substrate
according to one embodiment of the present invention.
[0019] FIG. 4 is a schematic drawing of a composite product
including a polymer layer having dispersed therein three
organometallic additives and a polymer edge coating having
dispersed therein three organometallic additives according to one
embodiment of the present invention.
[0020] FIG. 5 is a schematic drawing of a composite product
including two polymer layers having dispersed therein three
organometallic additives and a polymer edge coating having
dispersed therein three organometallic additives according to one
embodiment of the present invention.
[0021] FIG. 6 is a schematic drawing of a composite product
including two polymer layers having dispersed therein three
organometallic additives and a polymer edge coating having
dispersed therein three organometallic additives according to one
embodiment of the present invention.
[0022] FIG. 7 is a schematic drawing of a elongated polymer product
having dispersed therein three organometallic additives according
to one embodiment of the present invention.
[0023] FIG. 8 is a cross-sectional view of the product of FIG.
7.
[0024] FIG. 9 is a schematic drawing of a reinforced polymer
product having dispersed therein three organometallic additives
according to one embodiment of the present invention.
[0025] FIG. 10 is a cross-sectional view of the product of FIG.
9.
[0026] FIG. 11 is a schematic drawing of a spherical
core-containing polymer product having dispersed therein three
organometallic additives according to one embodiment of the present
invention.
[0027] FIG. 12 is a cross-sectional view of the product of FIG.
11.
[0028] FIG. 13 is a schematic drawing of a rectangular box-shaped
core-containing polymer product having dispersed therein three
organometallic additives according to one embodiment of the present
invention.
[0029] FIG. 14 is a cross-sectional view of the product of FIG.
13.
[0030] FIG. 15 is a graph of various host polymers containing
stearate based organometallic additives showing antimicrobial
efficacy performance for various embodiments of the present
invention.
[0031] FIG. 16 is a graph showing a curve fit to the data set of
FIG. 15.
[0032] FIG. 17 is a graph of the stearate chemistry data set of
FIG. 16 with the inclusion of data where the antimicrobial
organometallic additive is an acetate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definitions
[0033] Where the definition of terms departs from the commonly used
meaning of the term, applicant intends to utilize the definitions
provided below, unless specifically indicated.
[0034] For purposes of the present invention, it should be noted
that the singular forms, "a," "an," and "the" include reference to
the plural unless the context as herein presented clearly indicates
otherwise.
[0035] For purposes of the present invention, directional terms
such as "top," "bottom," "upper," "lower," "above," "below,"
"left," "right," "horizontal," "vertical," "up," "down," etc. are
merely used for convenience in describing the various embodiments
of the present invention. The embodiments of the present invention
may be oriented in various ways. For example, the diagrams,
apparatuses, etc. shown in the drawing figures may be flipped over,
rotated by 90.degree. in any direction, reversed, etc.
[0036] For purposes of the present invention, a value or property
is "based" on a particular value, property, the satisfaction of a
condition or other factor, if that value is derived by performing a
mathematical calculation or logical decision using that value,
property, the satisfaction of a condition or other factor.
[0037] For purposes of the present invention, the term
"antimicrobial" refers to a material that kills or inhibits the
growth of microorganisms such as bacteria, viruses, fungi, molds or
protozoans.
[0038] For purposes of the present invention, the term
"antimicrobial organometallic additive" refers to an organometallic
additive that imparts antimicrobial properties to a product of
which the antimicrobial organometallic additive is a part or
increases the antimicrobial properties of a product of which the
antimicrobial organometallic additive is a part.
[0039] For purposes of the present invention, the term "degree of
antimicrobial activity" refers to the percentage reduction in
Colony Forming Units (CFU) observed when a polymer product is
subjected to JIS Z 2801 test protocol described below in the
Examples section. For example, if a 99.99831% reduction in Colony
Forming Units (CFU) is observed for a polymer product, the product
has a 99.99831% degree of antimicrobial activity.
[0040] For purposes of the present invention, the term "dispersed
throughout" refers to one or more antimicrobial organometallic
additives being distributed relatively evenly throughout a polymer
host matrix.
[0041] For purposes of the present invention, the term "long-chain
fatty acid" refers to a fatty acid having an aliphatic tail of 13
or more carbon atoms.
[0042] For purposes of the present invention, the term "long-chain
fatty acid group" refers to the ester group derived from a
long-chain fatty acid. An example of a long-chain fatty acid group
is a stearate group.
[0043] For purposes of the present invention, the term "majority"
refers to a majority by molar amount. For example, if there were a
mixture of antimicrobial organometallic additives comprising 1.0
mole of cupric stearate and 1.0 mole of silver stearate present in
a polymer product, 0.1 total moles of metals in a UV absorber
dispersed throughout the polymer product and 0.2 moles of metal
ions in a color in the polymer product, the antimicrobial
organometallic additives would constitute a majority of the
metallic species in the polymer product: 2.0 total moles of
antimicrobial organometallic additives to 0.3 total moles of
metallic species from other sources dispersed throughout the
polymer.
[0044] For purposes of the present invention, the term "metallic
species" refers to the metals, metal ions and metal-containing
compounds present in a polymer product, depending on the polymer
product. In addition to the metals in the antimicrobial
organometallic additive of the present invention, polymer products
of the present invention may also include metallic species that are
metals, metal ions and metal-containing compounds such as metal
salts, metal oxides, organometallic oxides, etc.
[0045] For purposes of the present invention, the term
"organometallic additive" refers to a compound including a metal
bound to an organic radical, where the metal species has a valence
state of +1, +2, +3, etc.
[0046] For purposes of the present invention, the term "polymer
host matrix" refers to a polymer or mixtures of polymers in which
one or more antimicrobial organometallic additives are dispersed. A
polymer may be a copolymer. A polymer host matrix includes
components in addition to the polymer that do not react with the
organometallic additives dispersed in the polymer host matrix. For
example, the polymer host matrix may be fiberglass which comprises
a polymer having dispersed therein glass fibers. Other fibers, such
as carbon or graphene, metals and ceramics may also be used, as
well as polymer fibers such as Kevlar.RTM. (DuPont's registered
trademark for a para-aramid synthetic fiber).
[0047] For purposes of the present invention, the term "room
temperature" refers to a temperature of from about 20.degree. C. to
about 25.degree. C.
[0048] For purposes of the present invention, the term "a solid
solution in a polymer host matrix" refers to an organometallic
additive mechanically dispersed throughout and suspended within the
polymer host matrix.
[0049] For purposes of the present invention, the term "sparingly
soluble in water" refers to a substance having a solubility of 0.1
g per 100 ml of water to 1 g per 100 ml of water. Unless specified
otherwise, the term "sparingly soluble" and "sparingly soluble in
water" are used interchangeably in the description of the invention
below to refer to substances that are sparingly soluble in
water.
[0050] For purposes of the present invention, the term
"thermosetting powder" refers to a powder that when applied and
subjected to heat will melt, flow and chemically crosslink to form
a film coating on a substrate. Thermosetting powders are primarily
composed of relatively high molecular weight solid resins and a
crosslinker. The primary resins used in the formulation of a
thermosetting powder are: epoxy, polyester and acrylic. These
primary resins may be used with different crosslinkers to produce a
variety of powder coatings.
[0051] For purposes of the present invention, the term "thermoset
powder coating" refers to a film coating formed by melting, flowing
and chemically crosslinking a thermosetting powder. Chemical
reactions during the curing cycle of a thermoset powder coating
create a polymer network which may provide resistance to coating
breakdown. Once cured and crosslinked, this polymer network will
not melt and flow again if heat is applied.
[0052] For purposes of the present invention, the term "water
insoluble" refers to a substance that has a solubility of less than
0.1 g per 100 ml of water.
DESCRIPTION
[0053] Because material surfaces may become contaminated with
disease-causing agents, there is a need for materials with
anti-bacterial, anti-virus, anti-fungal, anti-mold, etc.
functionality; these are generally referred to as antimicrobials.
Polymeric materials made from organic materials, inorganic
materials or organic-inorganic material blends are ubiquitous in
the environment, and if made to reduce antimicrobial
disease-causing agents would play a valuable role in producing a
healthier environment.
[0054] Three general classes of art for producing antimicrobial
bulk polymers and polymer surfaces using additive systems currently
exist: (1) nanoscale metal particles, (2) metal aluminosilicates,
and (3) organic compounds. Although this art has demonstrated some
utility it suffers from several limitations of which the following
are the most often cited: [0055] (1) wears out due to repeated
handling, washing or scrubbing of surface applied materials, [0056]
(2) renders the bulk material not recyclable, [0057] (3) does not
confer significant antimicrobial resistance, [0058] (4) narrow
range of effectiveness against antimicrobial agents, [0059] (5) is
toxic to viruses and molds with potential toxicity to humans at the
levels employed, [0060] (6) modification required of existing
plastic product manufacturing, equipment or processes, [0061] (7)
post-production steps required for surface coating, [0062] (8)
incomplete coverage/coating due to "hidden" surfaces, [0063] (9) is
incompatible with critical geometries, such as products having
micro-scale tolerances or dimensions.
[0064] In addition to the above-mentioned limitations of the
existing art, the current products employing metal and
aluminosilicate antimicrobial additives: (a) are costly, (b) have
final product process-related issues such as reduced
time-to-fabrication tooling wear out, therefore requiring more
frequent tool replacement, and (c) require novel chemical moieties
as surface ligands to help disperse and keep the particles from
settling or agglomerating. Furthermore, current products employ
organic antimicrobial additives that cannot be readily incorporated
with many organic materials since these antimicrobial additives
are: (a) chemically aggressive and inhibit the reaction processes
of many thermosets and (b) degrade the mechanical, thermal and
optical properties of many thermoplastics and thermosets.
[0065] An example of existing art appears in United States Patent
Application No. 2011/0002872 to Ohashi et al., but this patent
application does not describe the final form of the product that
integrates the antimicrobial invention, but instead describes a
conversion process (e.g., thermal decomposition) of a fatty acid
metal salt for forming ultrafine metal particles that can be
dispersed in a resin for further processing.
[0066] In one embodiment, the present invention provides a polymer
product comprising a polymer host matrix having dispersed therein
at least one antimicrobial organometallic additive or a blend of
antimicrobial organometallic additives that impart antimicrobial
properties to the bulk and surface of the polymer host matrix.
[0067] In one embodiment, the present invention provides uniformly
dispersed antimicrobial functionality in a variety of host matrix
polymer materials and a broad range of form factors. For example,
the dispersed antimicrobial organometallic additives may be used to
impart antimicrobial properties to the bulk and surface of a
polymer host matrix in the form of bulk polymer products, film
polymer products, sheet polymer products, polymer coating products,
coated polymer products, composite polymer products, fibrous
polymer products, a rod polymer products, core-containing polymer
products and other types of polymer products.
[0068] In one embodiment, the present invention provides a polymer
product comprising a polymer host matrix having dispersed therein
at least one distributed metal type of antimicrobial organometallic
additive or a blend of antimicrobial organometallic additives of
more than one type of metal, said antimicrobial organometallic
additives imparting antimicrobial properties to the bulk polymer
products, film polymer products, sheet polymer products, polymer
coating products, coated polymer products, composite polymer
products, fibrous polymer products, a rod polymer products,
core-containing polymer products and other types of polymer
products.
[0069] In one embodiment of the present invention, the
antimicrobial organometallic additive is about 0.008% to about 3%
by volume of the total volume of the mixture of the antimicrobial
organometallic additive in the polymer host matrix. In one
embodiment of the present invention, the antimicrobial
organometallic additive is about 0.008% to about 2.5% by volume of
the total volume of the mixture of the antimicrobial organometallic
additive in the polymer host matrix. In one embodiment of the
present invention, the antimicrobial organometallic additive is
about 0.008% to about 2% by volume of the total volume of the
mixture of the antimicrobial organometallic additive in the polymer
host matrix.
[0070] In one embodiment of the present invention, the blend of the
antimicrobial organometallic additive is about 0.008% to about 3%
by volume of the total volume of the mixture of the antimicrobial
organometallic additive in the polymer host matrix. In one
embodiment of the present invention, the blend of the antimicrobial
organometallic additive is about 0.008% to about 2.5% by volume of
the total volume of the mixture of the antimicrobial organometallic
additive in the polymer host matrix. In one embodiment of the
present invention, the blend of the antimicrobial organometallic
additive is about 0.008% to about 2% by volume of the total volume
of the mixture of the antimicrobial organometallic additive in the
polymer host matrix.
[0071] In one embodiment, the present invention provides the
ability to integrate one or more antimicrobial organometallic
additives comprised of metals that are compatible with a variety of
host matrix polymer materials that can be processed using
conventional manufacturing equipment to fabricate various types of
polymer products. In one embodiment of the present invention, the
antimicrobial organometallic additives form a solid solution with
the polymer host matrix and are distributed homogeneously
throughout the polymer. Furthermore, the polymer host matrix may be
an organic material, an inorganic material (e.g., silicone, etc.)
or an organic-inorganic material blend. Also, the polymer host
matrix may demonstrate the physical properties of a solid material,
a liquid material, or a material having both solid-like and
liquid-like physical properties.
[0072] In one embodiment of the present invention, an antimicrobial
organometallic additive is an organic chemical moiety chemically
bonded to a metal, either covalently or ionically. The chemical
structure provides for enhanced miscibility throughout the polymer
host matrix to produce various types of polymer products. Organic
chemical moieties that may be bound to a metal in an antimicrobial
organometallic additive of the present invention include but are
not limited to the following chemical moieties: hydrocarbons,
acetates, stearates, laureates, palmitates, oleates, abietates,
fatty acids, etc.
[0073] Metals that may be used in the antimicrobial organometallic
additives of the present invention include, but are not limited to,
copper (Cu), silver (Ag), gold (Au), iridium (Ir), palladium (Pd),
platinum (Pt), iron (Fe), nickel (Ni), cobalt (Co), zinc (Zn),
niobium (Nb), ruthenium (Ru), rhodium (Rh), tellurium (Te),
antimony (Sb), bismuth (Bi), tin (Sn), gallium (Ga), indium (In),
titanium (Ti), vanadium (V), chromium, (Cr), manganese (Mn),
molybdenum (Mo), tungsten (W), tantalum (Ta), hafnium (Hf),
zirconium (Zr), scandium (Sc), and yttrium (Y), aluminum (Al),
cadmium (Cd), mercury (Hg), thalium (Tl), lead (Pb), selenium
(Se).
[0074] Metals that may be used in the antimicrobial organometallic
additives of the present invention include alkali metals and alkali
earth metals including, but are not limited to lithium (Li), sodium
(Na), potassium (K), rubidium (Rb) cesium (Cs), beryllium (Be),
magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba).
[0075] Metals for the antimicrobial organometallic additives may be
selected based on required functionality (e.g., anti-bacterial,
anti-virus, anti-fungal, anti-mold, etc.) and may be chosen from
the categories of transition metals, post-transition metals,
metalloids, lanthanides, actinides, rare earth metals, alkaline
earth metals, and alkali metals.
[0076] Suitable polymers that may be used in the polymer host
matrix of the polymer products of the present invention include
thermoplastics and thermosets and mixtures thereof.
[0077] In one embodiment of the present invention, the polymer host
matrix may comprise a thermoplastic such as polyethylene (PE),
polypropylene (PP), polycarbonate (PC), polystyrene (PS), polyamide
(PA), polybutylene terephthalate (PBT), polyethylene terephthalate
(PET), wax (e.g., paraffin, etc.), etc. In one embodiment, the
polymer host matrix polymer may be a blend comprising more than one
thermoplastic.
[0078] In one embodiment of the present invention, the polymer host
matrix may comprise a thermoset plastic such as an epoxy, a
phenolic, a cyanate ester, a bismaleimide, a polyimide, an acrylic,
a silicone, a urethane, a latex, etc. In one embodiment, the
polymer host matrix polymer may be a blend comprising more than one
thermoset.
[0079] In one embodiment of the present invention, the polymer host
matrix may comprise a polyurethane. The polymer host matrix may be
a one-part polyurethane liquid polymer or a two-part polyurethane
liquid polymer. The polyurethane polymer host matrix may be air
cured, thermally cured, or UV-radiation cured.
[0080] In one embodiment of the present invention, the polymer host
matrix may comprise a stable dispersion (emulsion) of polymer
microparticles in an aqueous medium such as, but not limited to
natural and synthetic latexes. The polymer host matrix may be a
single polymer, a polymer blend, a co-polymer, or a co-polymer
blend.
[0081] In one embodiment of the present invention, the polymer host
matrix may comprise a mixture of a polymer and other materials such
as glass. For example, the host matrix may be fiberglass which is a
plastic matrix reinforced with fine glass fibers.
[0082] In various embodiments of the present invention, the polymer
host matrix of the present invention may be formulated to achieve
specific materials properties e.g., optical (clarity, refractive
index, color, transparency), mechanical (elongation, glass
transition temperature, coefficient of thermal expansion, elastic
and shear modulus, toughness, adhesion, surface roughness),
rheological (viscosity, melt flow index, surface energy, etc.),
electrical (dielectric strength) and antimicrobial efficacy as
required for optimal end product performance.
[0083] During thermal processing of the polymer host matrix and the
antimicrobial organometallic additive, the antimicrobial
organometallic additive may be converted to an
organometallic-oxide.
[0084] In one embodiment, the present invention may be used as a
bulk polymer product. In one embodiment, the present invention may
be used as a polymer film. In one embodiment, the present invention
may be used as a polymer sheet.
[0085] Bulk polymer products such as but not limited to master
blends, toys, electronic housings, automotive interior panels,
airplane passenger compartment structures, dental appliances such
as mouth protectors, mouth guards, dentures and retainers,
corrective vision devices (contact lenses, contact lens storage
containers, eye glass frames), windows, aquarium walls, soap
dispensers, paper towel dispensers, toilet paper dispensers,
portable toilets, and portable washing stations. In these products,
the host matrix bulk polymer provides substantial structural
integrity for the device or application.
[0086] Film polymer products include but are not limited to
flexible wrapping agents, film coats, and laminates. These products
may have surface treatments to provide static or chemical adhesion
as commonly used for promotional advertising, and marketing posters
and labels. Film materials may be used in combination with touch
screens and displays. Another example of a film polymer product is
currency (banknotes). Furthermore, the film may be transparent,
contain graphic art, text, or a combination of these. In these
products, the film polymer provides little structural integrity to
the device, but acts as a barrier or as a carrier of graphic
information. In one embodiment, the film material is less than 0.1
mm thick.
[0087] FIGS. 1 and 2 illustrate in schematic form polymer products
that each may be a bulk polymer product, a film polymer product or
a sheet polymer product, depending on factors such as the
dimensions of the polymer product, the polymer host matrix used,
the physical properties of the polymer product, etc.
[0088] FIG. 1 depicts a polymer product 102 having dispersed
therein an antimicrobial organometallic additive 112 distributed
uniformly throughout a polymer host matrix 118. Some antimicrobial
organometallic additive 112 resides at an upper surface 122 and a
lower surface 124, as indicated by arrows 132 and 134,
respectively. Some antimicrobial organometallic additive 112
resides at a left surface 142 and a right surface 144, as indicated
by arrows 152 and 154, respectively.
[0089] FIG. 2 depicts a polymer product 202 having dispersed
therein antimicrobial organometallic additives 212, 214, 216
distributed uniformly throughout a polymer host matrix 218.
Antimicrobial organometallic additives 212, 214, 216 are different
from each other. Some antimicrobial organometallic additives 212,
214 and 216 reside at an upper surface 220 as indicated by arrows
222, 224 and 226, respectively. Some antimicrobial organometallic
additives 212, 214 and 216 reside at a lower surface 230 as
indicated by arrows 232, 234 and 236, respectively. Some
antimicrobial organometallic additives 212, 214 and 216 reside at a
left surface 240 as indicated by arrows 242, 244 and 246,
respectively. Some antimicrobial organometallic additives 212, 214
and 216 reside at a right surface 250 as indicated by arrows 252,
254 and 256, respectively.
[0090] Although one antimicrobial organometallic additive is shown
in FIG. 1 and three different antimicrobial organometallic
additives are shows in FIG. 2, a polymer product of the present
invention may include any number of different antimicrobial
organometallic additives. The metal part of each of the
antimicrobial organometallic additives may be the same or different
and/or the organic part of each of the antimicrobial organometallic
additives may be the same or different.
[0091] The polymer product of FIG. 1 and/or FIG. 2 may have
virtually any size or shape. For example, polymer products of FIG.
1 and/or FIG. 2 may be a block of material, a film, a sheet,
etc.
[0092] A polymer product of the present invention that is a block
of material may be made in various shapes such as spherical,
rectangular box-shaped, cube-shaped, ellipsoid-shaped, cone-shaped,
pyramidal, rod-shaped, ring-shaped, disks, rectangular
plate-shaped, irregularly shaped, etc. A spherical or nearly
spherical polymer product may be used in balls for purifying
liquids such as but not limited to water and water-based fruit
juices and forming master batches for draw-down during manufacture
of the final polymer product. A spherical or nearly spherical
polymer product may be fabricated with different densities so that
polymer product may float at different levels in a liquid
environment.
[0093] In one embodiment, the polymer product of FIG. 1 and/or FIG.
2 may be a bulk polymer product that is at least 0.01 mm thick.
[0094] In one embodiment, the polymer product of FIG. 1 and/or FIG.
2 may be a film polymer product having a thickness of less than or
equal to 1.0 mm.
[0095] In one embodiment, the polymer product of FIG. 1 and/or FIG.
2 may be a bulk product or a sheet. For example, the polymer
product may be a bulk or sheet product used separately or in
combination with items such as but not limited to mass transit
windows, building windows, and aquarium walls. These sheet products
may have surface treatments to provide static or chemical adhesion
to an underlying transparent material such as but not limited to
glass, polycarbonate, acrylics and poly(methyl methacrylate). In
these products, the sheet polymer provides limited structural
integrity to the device and acts as a barrier. Examples of a film
polymer product used separately are bags (e.g., food, waste
management), privacy curtains (hospital rooms, examining rooms,
etc.) and gloves (e.g., hygiene, contamination protection).
Furthermore, the sheet may be transparent, contain graphic art,
text, or a combination of both. In one embodiment of the present
invention, the sheet polymer product is greater than 0.01 mm and
less than or equal to 10 mm thick.
[0096] In one embodiment the present invention provides polymer
coatings comprising one or more antimicrobial organometallic
additives uniformly dispersed in a polymer material. Such coatings
may have a variety of uses such as for powder coats, paints, shrink
wraps, films, etc. In polymer coatings, the polymer coating may act
as a surface protector and barrier. The polymer coatings of the
present invention may be used on a variety of substrates such as
carts, hospital gurneys, desks, chairs, metal gratings, shelving
(e.g., refrigerator, produce, dairy, candy, and health care
products), filters, and corrugated metal such as used for
architectural wall finishing, etc. Polymer coatings of the present
invention may also be coated on substrates such as gratings, animal
cages, livestock fencing, animal feeding containers (bowls,
troughs, plates, dispensers), filters, architectural wall
finishing, privacy walls in bathrooms, hand dryers, hand rails and
escalator guard rails). A polymer coating of the present invention
may be transparent, translucent or opaque and may be colored with
dyes (e.g., organic polymers, inorganic suspensions). A polymer
coating host matrix that is transparent has a refractive index of
at least 1.1 at 633 nm with optical transmission of >90% from
375 to 600 nm. In one embodiment of the present invention, a
coating may be less than 1 mm thick.
[0097] A polymer coating of the present invention may be formed by
mixing one or more antimicrobial organometallic additive in powder
form with a polymer host matrix material in powder form, such as a
thermosetting powder, to form a mixture in which the one or more
antimicrobial organometallic additives are dispersed throughout the
mixture. The mixture may then be heated to melt the mixture and
form a polymer coating product in which the one or more
antimicrobial organometallic additives are suspended in the polymer
host. The coating product may be heated in place on the substrate
to form a coating or the coating product may be heated and then
applied to the substrate as a coating.
[0098] A polymer coating of the present invention may be formed by
mixing one or more antimicrobial organometallic additive in powder
form with a polymer host matrix material in liquid form to form a
mixture in which the one or more antimicrobial organometallic
additives are dispersed throughout the liquid. The liquid mixture
may then be applied to a substrate to form a polymer coating
product in which the one or more antimicrobial organometallic
additives are suspended in the polymer host. The coating product
may be heated in place on the substrate to form a coating,
polymerized on the substrate using ultraviolet radiation (UV) to
form a coating, dried via evaporation of solvent to form a coating,
polymerized on the substrate via chemical reactions (i.e., curing)
to form a coating. Examples of polymer host materials are latex
paints, oil-based paints, 1-part polyurethane, 2-part polyurethane,
1-part epoxy, 2-part epoxy, etc.
[0099] FIG. 3 shows a polymer coated substrate 302 according to one
embodiment of the present invention. Polymer coated substrate 302
comprises a polymer coating 312 coated on a substrate 314. Polymer
coating 312 contains a blend of three different antimicrobial
organometallic additives, i.e., antimicrobial organometallic
additives 322, 324 and 326, dispersed uniformly throughout a
polymer host matrix 328 of polymer coating 312. Antimicrobial
organometallic additives 322, 324 and 326 are present at a surface
330 of polymer coating 312, as shown by arrows 332, 334 and 336,
respectively, and at an interface 340 between polymer coating 312
and substrate 314, as shown by arrows 342, 344 and 346,
respectively. Polymer coating 312 is chemically and/or mechanically
bonded to the substrate 314 at interface 340.
[0100] Although three antimicrobial organometallic additives are
shown in the polymer coating of FIG. 3, there may be one, two,
three, four or more antimicrobial organometallic additives in a
polymer coating of the present invention. The antimicrobial
organometallic additives may be of the same chemistry or they may
be of different chemistries.
[0101] The substrate on which a polymer coating of the present
invention is coated may be a metal such as aluminum, titanium,
copper, brass, bronze, nickel, pewter, silver, gold, stainless
steel, carbon steel, steel, molybdenum, Inconel, alloys of these
metals, etc., a ceramic such as aluminum oxide (sapphire), ceramic
tile, glass (borosilicate, soda-lime-silicate, quartz), granite,
marble, etc., a plastic such as a vinyl polymer, polycarbonate,
polyethylene, polypropylene, PEN, PET, wax (paraffin) etc, or any
other type of suitable substrate material.
[0102] In one embodiment, the present invention provides a
composite product including one or more antimicrobial
organometallic additives in a polymer host matrix. Such composite
products include fabrics, bandages, tents, mats (e.g., wrestling,
gymnastics, bathroom), tarps, clothing used by first responders,
clothing used by campers, clothing used for recreational purposes,
work clothing, sports clothing, uniforms, space suits, military
operations personnel, healthcare professionals, and hospital staff
(e.g., surgical garments), etc. In a composite product of the
present invention, a discrete layer or film comprising the one or
more antimicrobial organometallic additives in a polymer host
matrix is integrated into the composite product. A polymer layer
comprising one or more antimicrobial organometallic additives in a
polymer host matrix acts as a surface protector and barrier. The
barrier functionality of such a polymer layer may include
transmission of liquid such as water, and gases such as water vapor
and air. In one embodiment, such a polymer layer is less than 1 mm
thick.
[0103] FIG. 4 shows a composite product 402 according to one
embodiment of the present invention. Composite product 402 includes
a polymer layer 412, an inner layer 414 and an outer layer 416.
Coated on edges 422, 424 and 426, respectively, of polymer layer
412, inner layer 414 and outer layer 416 is an edge coating 428.
Polymer layer 412 comprises a blend of three different
antimicrobial organometallic additives, i.e., antimicrobial
organometallic additives 432, 434 and 436, dispersed uniformly
throughout a polymer host matrix 438. Edge coating 428 comprises a
blend of three different antimicrobial organometallic additives,
i.e., antimicrobial organometallic additives 442, 444 and 446,
dispersed uniformly throughout a polymer host matrix 448.
Antimicrobial organometallic additives 432, 434 and 436 are also
present at exterior surfaces 450 of polymer host matrix 438 as
shown by arrows 452, 454 and 456, respectively. Antimicrobial
organometallic additives 442, 444 and 446 are present at exterior
surface 460 of polymer host matrix 448 as shown by arrows 462, 464
and 466. An interface 472 provides mechanical and/or chemical
bonding between polymer layer 412 and inner layer 414. An interface
474 provides mechanical and/or chemical bonding between inner layer
414 and outer layer 416.
[0104] Although the edge coating in FIG. 4 is shown as covering the
edges of the polymer layer, the inner layer and the outer layer, in
some embodiments of the present invention, the edges of only one or
two of these layers may be coated with the edge coating.
[0105] Although in FIG. 4, an edge coating is only shown on the
left-hand side of the composite product, in some embodiments of the
present invention, there may be an edge-coating on both the
left-hand and right-hand side of the composite product. The edge
coatings on each side may be the same or different.
[0106] Although three antimicrobial organometallic additives are
shown in the polymer layer and the edge coating of FIG. 4, there
may be one, two, three, four or more antimicrobial organometallic
additives in an edge coating or polymer layer of a composite
product of the present invention. The antimicrobial organometallic
additive may be the same chemistry or different chemistry.
[0107] The polymer host matrix and the antimicrobial organometallic
additives of the polymer layer and the edge coating may be the same
or different.
[0108] In one embodiment of the present invention, the polymer
layer of a composite product may have a thickness of 10 mm or
less.
[0109] In one embodiment of the present invention the outer layer
and inner layer of the composite product may be porous to allow
transmission of liquids such as water, and gases such as water
vapor and air to the polymer layer.
[0110] The inner and outer layers may be made from a variety of
materials including woven or non-woven textiles such as silk,
cotton, polymer textiles or blends thereof, high strength plastics
such as but not limited to poly-paraphenylene terephthalamide
(e.g., Kevlar.RTM.), and metals such as but not limited to
aluminum, titanium, copper, brass, bronze, nickel, pewter, silver,
gold, stainless steel, carbon steel, steel, molybdenum, Inconel,
alloys of these metals, etc., a ceramic such as aluminum oxide
(sapphire), ceramic tile, glass (borosilicate, soda-lime-silicate,
quartz), granite, marble, etc., a plastic such as a vinyl polymer,
polycarbonate, polyethylene, polypropylene, PEN, PET, wax
(paraffin) etc., or any other type of suitable substrate
material.
[0111] FIG. 5 shows a composite product 502 according to one
embodiment of the present invention. Composite product 502 includes
a lower polymer layer 512, an inner layer 514 and an upper polymer
layer 516. Coated on edges 522, 524 and 526, respectively, of lower
polymer layer 512, inner layer 514 and upper polymer layer 516 is
an edge coating 528. Lower polymer layer 512 comprises a blend of
three different antimicrobial organometallic additives, i.e.,
antimicrobial organometallic additives 532, 534 and 536, dispersed
uniformly throughout a polymer host matrix 538. Upper polymer layer
516 comprises a blend of three different antimicrobial
organometallic additives, i.e., antimicrobial organometallic
additives 542, 544 and 546, dispersed uniformly throughout a
polymer host matrix 548. Edge coating 528 comprises a blend of
three different antimicrobial organometallic additives, i.e.,
antimicrobial organometallic additives 552, 554 and 556, dispersed
uniformly throughout a polymer host matrix 558. Antimicrobial
organometallic additives 532, 534 and 536 are present at exterior
surfaces 560 of polymer host matrix 538 as shown by arrows 562, 564
and 566, respectively. Antimicrobial organometallic additives 542,
544 and 546 are present at exterior surfaces 570 of polymer host
matrix 548 as shown by arrows 572, 574 and 576, respectively.
Antimicrobial organometallic additives 552, 554 and 556 are present
at exterior surface 580 of polymer host matrix 548 as shown by
arrows 582, 584 and 586. An interface 592 provides mechanical
and/or chemical bonding between lower polymer layer 512 and inner
layer 514. An interface 594 provides mechanical and/or chemical
bonding between inner layer 514 and upper polymer layer 516.
[0112] Although the edge coating in FIG. 5 is shown as covering the
edges of the lower polymer layer, the inner layer and the upper
polymer layer, in some embodiments of the present invention, the
edges of only one or two of these layers may be coated with the
edge coating.
[0113] Although in FIG. 5, an edge coating is only shown on the
left-hand side of the composite product, in some embodiments of the
present invention, there may be an edge-coating on both the
left-hand and right-hand side of the composite product. The edge
coatings on each side may be the same or different.
[0114] Although three antimicrobial organometallic additives are
shown in the lower polymer layer, upper polymer layer and the edge
coating of FIG. 5, there may be one, two, three, four or more
antimicrobial organometallic additives in an edge coating or
polymer layer of a composite product of the present invention. The
antimicrobial organometallic additive may be the same chemistry or
different chemistry.
[0115] The polymer host matrix and the antimicrobial organometallic
additives of the lower polymer layer, upper polymer layer and the
edge coating may be the same or different for each of the lower
polymer layer upper polymer layer and the edge coating.
[0116] In one embodiment of the present invention, the lower
polymer layer and/or upper polymer layer of a composite product may
have a thickness of 1 mm or less.
[0117] In one embodiment of the present invention the inner layer
of the composite product may be porous to allow transmission of
liquids such as water, and gases such as water vapor and air to the
polymer layer.
[0118] The inner layer may be made from a variety of materials
including woven or non-woven textiles such as silk, cotton or
blends thereof, high strength plastics such as but not limited to
poly-paraphenylene terephthalamide (e.g., Kevlar.RTM.), and metals
such as but not limited to aluminum, titanium, copper, brass,
bronze, nickel, pewter, silver, gold, stainless steel, carbon
steel, steel, molybdenum, Inconel, alloys of these metals, etc., a
ceramic such as aluminum oxide (sapphire), ceramic tile, glass
(borosilicate, soda-lime-silicate, quartz), granite, marble, etc.,
a plastic such as a vinyl polymer, polycarbonate, polyethylene,
polypropylene, PEN, PET, wax (paraffin) etc., or any other type of
suitable substrate material.
[0119] FIG. 6 shows a composite product 602 according to one
embodiment of the present invention. Composite product 602 includes
a lower polymer layer 608, a lower inner layer 610, a middle inner
layer 612, an upper inner layer 614 and an upper polymer layer 616.
Coated on edges 618, 620, 622, 624 and 626, respectively, of lower
polymer layer 608, lower inner layer 610, middle inner layer 612,
upper inner layer 614 and upper polymer layer 616 is an edge
coating 628. Lower polymer layer 608 comprises a blend of three
different antimicrobial organometallic additives, i.e.,
antimicrobial organometallic additives 632, 634 and 636, dispersed
uniformly throughout a polymer host matrix 638. Upper polymer layer
616 comprises a blend of three different antimicrobial
organometallic additives, i.e., antimicrobial organometallic
additives 642, 644 and 646, dispersed uniformly throughout a
polymer host matrix 648. Edge coating 628 comprises a blend of
three different antimicrobial organometallic additives, i.e.,
antimicrobial organometallic additives 652, 654 and 656, dispersed
uniformly throughout a polymer host matrix 658. Antimicrobial
organometallic additives 632, 634 and 636 are present at exterior
surfaces 660 of polymer host matrix 638 as shown by arrows 662, 664
and 666, respectively. Antimicrobial organometallic additives 642,
644 and 646 are present at exterior surfaces 670 of polymer host
matrix 648 as shown by arrows 672, 674 and 676, respectively.
Antimicrobial organometallic additives 652, 654 and 656 are present
at exterior surface 680 of polymer host matrix 648 as shown by
arrows 682, 684 and 686. An interface 690 provides mechanical
and/or chemical bonding between lower polymer layer 608 and lower
inner layer 610. An interface 692 provides mechanical and/or
chemical bonding between lower inner layer 610 and middle inner
layer 612. An interface 694 provides mechanical and/or chemical
bonding between middle inner layer 612 and upper inner layer 614.
An interface 696 provides mechanical and/or chemical bonding
between upper inner layer 614 and upper polymer layer 616.
[0120] Although the edge coating in FIG. 6 is shown as covering the
edges of the lower polymer layer, the lower inner layer, the middle
inner layer, the upper inner layer and the upper polymer layer, in
some embodiments of the present invention, the edges of only one,
two, three or four of these layers may be coated with the edge
coating.
[0121] Although in FIG. 6, an edge coating is only shown on the
left-hand side of the composite product, in some embodiments of the
present invention, there may be an edge-coating on both the
left-hand and right-hand side of the composite product. The edge
coatings on each side may be the same or different.
[0122] Although three antimicrobial organometallic additives are
shown in the lower polymer layer, upper polymer and the edge
coating of FIG. 6, there may be one, two, three, four or more
antimicrobial organometallic additives in an edge coating or
polymer layer of a composite product of the present invention. The
antimicrobial organometallic additive may be the same chemistry or
different chemistry.
[0123] The polymer host matrix and the antimicrobial organometallic
additives of the lower polymer layer upper polymer layer and the
edge coating may be the same or different for each of the lower
polymer layer upper polymer layer and the edge coating.
[0124] In one embodiment of the present invention, the lower
polymer layer and/or upper polymer layer of a composite product may
have a thickness of 1 mm or less.
[0125] In one embodiment of the present invention, the lower inner
layer, middle inner layer and/or upper middle layer of the
composite product may be porous to allow transmission of liquids
such as water, and gases such as water vapor and air to the polymer
layer.
[0126] The lower inner layer, middle inner layer and/or upper
middle layer may each be made from a variety of materials including
woven or non-woven textiles such as silk, cotton, polymer textiles
or blends thereof, high strength plastics such as but not limited
to poly-paraphenylene terephthalamide (e.g., Kevlar.RTM.), and
metals such as but not limited to aluminum, titanium, copper,
brass, bronze, nickel, pewter, silver, gold, stainless steel,
carbon steel, steel, molybdenum, Inconel, alloys of these metals,
etc., a ceramic such as aluminum oxide (sapphire), ceramic tile,
glass (borosilicate, soda-lime-silicate, quartz), granite, marble,
etc., a plastic such as a vinyl polymer, polycarbonate,
polyethylene, polypropylene, PEN, PET, wax (paraffin) etc., or any
other type of suitable substrate material.
[0127] In one embodiment, the present invention may be a fiber
polymer product. Fiber polymer products of the present invention
may be used in various types of products such as floor coverings
(e.g., carpets, rugs), artificial turf (e.g., residential,
athletic, landscaping), window shades and draperies, privacy
curtains, wall coverings (e.g., wall paper), seating upholstery,
air filters, water filters, thread, fabric, cloth, clothing,
textiles, etc.
[0128] In one embodiment of the present invention, a fiber polymer
product may have a diameter of 10 mm or less.
[0129] In one embodiment, the present invention may be a rod
polymer product. Rod polymer products of the present invention may
be used in such products as a guard rails, hand rails (e.g., for a
banister, escalator), door handles, grab bars, shower rods,
shopping cart handles, extruded products, facemasks for helmets,
electrical wiring, etc. The rod form may be modified to form belts,
or have multiple surfaces, detents, notches, flats, indents,
etc.
[0130] In one embodiment of the present invention, a rod polymer
product may have a diameter of 10 mm or greater.
[0131] FIGS. 7 and 8 illustrate in schematic form an elongated
polymer product having dispersed therein three antimicrobial
organometallic additives according to one embodiment of the present
invention. The elongated polymer product of FIGS. 7 and 8 may be a
fiber polymer product or a rod-shaped polymer product, depending on
factors such as the dimensions of the polymer product, the polymer
host matrix used, the physical properties of the polymer product,
etc.
[0132] FIGS. 7 and 8 depict an elongated polymer product 702 having
dispersed therein antimicrobial organometallic additives 712, 714
and 716 distributed uniformly throughout a polymer host matrix 718.
Antimicrobial organometallic additives 712, 714 and 716 are
different from each other. Some antimicrobial organometallic
additives 712, 714 and 716 reside at an outer surface 720 as
indicated by arrows 722, 724 and 726, respectively.
[0133] Although three antimicrobial organometallic additives are
shown in the polymer product of FIGS. 7 and 8, there may be one,
two, three, four or more antimicrobial organometallic additives in
a fiber polymer product or a rod polymer product of the present
invention. The organometallic additive may be of the same chemistry
or different chemistry
[0134] Although the cross-sectional shape of the polymer product
shown in FIGS. 7 and 8 is circular, a fiber polymer product or
rod-shaped polymer product of the present invention may have any
cross-sectional shape such as oval, triangular, square,
rectangular, hexagonal, polygonal, I-shaped, U-shaped, star-shaped,
asterix-shaped, multi-polygonal, multi-dimensional. etc.
[0135] In one embodiment, the present invention may be a reinforced
fiber polymer product. Reinforced fiber polymer products of the
present invention may be used in various types of products such as
floor coverings (e.g., carpets, rugs), artificial turf (e.g.,
residential, athletic, landscaping), window shades and draperies,
privacy curtains, wall coverings (e.g., wall paper), seating
upholstery, air filters, water filters, electrical wiring, thread,
fabric, cloth, clothing, textiles, etc.
[0136] In one embodiment of the present invention, a reinforced
fiber polymer product may have a diameter of 10 mm or less.
[0137] In one embodiment, the present invention may be a rod
polymer product. Rod polymer products of the present invention may
be used in such product as a guard rails, hand rails (e.g., for a
banister, escalator), door handles, grab bars, shower rods,
shopping cart handles, extruded products, facemasks for helmets,
electrical wiring, etc. The rod form may be modified to form belts,
or have multiple surfaces, detents, notches, flats, indents,
etc.
[0138] In one embodiment, a reinforced rod polymer product may have
a diameter of 10 mm or greater.
[0139] FIGS. 9 and 10 illustrate in schematic form a reinforced
polymer product having dispersed therein three antimicrobial
organometallic additives according to one embodiment of the present
invention. The reinforced polymer product of FIGS. 9 and 10 may be
a reinforced fiber polymer product or a reinforced rod-shaped
polymer product depending on factors such as the dimensions of the
polymer product, the polymer host matrix used, the physical
properties of the polymer product, etc.
[0140] FIGS. 9 and 10 depict a reinforced polymer product 902
having dispersed therein antimicrobial organometallic additives
912, 914 and 916 distributed uniformly throughout a polymer host
matrix 918. Antimicrobial organometallic additives 912, 914 and 916
are different from each other. Some antimicrobial organometallic
additives 912, 914 and 916 reside at an outer surface 920 as
indicated by arrows 922, 924 and 926, respectively. A support
structure 932 runs through polymer product 902. An interface 942
provides mechanical and chemical bonding between the polymer host
fiber matrix 918 and support structure 932.
[0141] Although three antimicrobial organometallic additives are
shown in the reinforced polymer product of FIGS. 9 and 10, there
may be one, two, three, four or more antimicrobial organometallic
additives in a reinforced polymer product of the present invention.
The antimicrobial organometallic additives may be the same
chemistry or different chemistry.
[0142] Although the cross-sectional shape of the reinforced polymer
product and support structure shown in FIGS. 9 and 10 is circular,
a reinforced polymer product and/or support structure of the
present invention may have any cross-sectional shape such as oval,
triangular, square, rectangular, hexagonal, polygonal, I-shaped,
U-shaped, star-shaped, asterix-shaped, multi-polygonal,
multi-dimensional, etc. The reinforced polymer product and support
structure may have the same or different cross-sectional shapes.
The support structure may also be non-existent so that the
resulting structure forms a hollow tube, pipe, or other structure
with an opening substantially throughout its body.
[0143] The length of a support structure relative to a reinforced
polymer product may be the same as the reinforced polymer product,
shorter than the reinforced polymer product or longer than the
reinforced polymer product. A reinforced polymer product may also
include more than one support structure that may be arranged along
the same axis in the reinforced polymer product and/or along
different axes in the reinforced polymer product and/or scattered
throughout the reinforced polymer product.
[0144] The support structure of a reinforced polymer product may
form the bulk of a reinforced polymer product. The support
structure of a reinforced polymer product may be made of various
materials such as a metal, ceramic, a plastic material, etc. or
combinations thereof, depending on the desired property of the
reinforced polymer product.
[0145] FIGS. 11, 12, 13 and 14 illustrate in schematic form two
examples of core-containing polymer products of the present
invention. FIGS. 11 and 12 illustrate a spherical-shaped
core-containing polymer product having dispersed therein three
antimicrobial organometallic additives according to one embodiment
of the present invention. FIGS. 13 and 14 illustrate a rectangular
box-shaped core-containing polymer product having dispersed therein
three antimicrobial organometallic additives according to one
embodiment of the present invention.
[0146] Spherical or nearly spherical products may be used in
purifying liquids such as water, water-based fruit juices, etc.
Pelletized polymer products used as the feedstock in the
manufacture of final polymer products by thermal injection molding,
extrusion, etc., can also have spherical or near spherical form.
The spherical or nearly spherical products may be fabricated with
different densities so that they may float at different levels in a
liquid environment. Non-spherical shapes, such as but not limited
to rods, rings, disks, rectangular plates, pyramidal and other
geometries may also be used.
[0147] A polymer product of the present invention that is a
core-containing polymer product may be made in various shapes such
as spherical, rectangular box-shaped, cube-shaped,
ellipsoid-shaped, cone-shaped, pyramidal, rod-shaped, ring-shaped,
disks, rectangular plate-shaped, irregularly shaped, etc. A
spherical or nearly spherical polymer product may be used in balls
for purifying liquids such as but not limited to water, water-based
liquids, water-based fruit juices, milk, etc. Pelletized polymer
products used as the feedstock in the manufacture of final polymer
products, for example, thermal injection molding, extrusion, etc.,
can also have spherical or near spherical form. A spherical or
nearly spherical polymer product may be fabricated with different
densities so that the polymer product may float at different levels
in a liquid environment.
[0148] FIGS. 11 and 12 depict a spherical core-containing polymer
product 1102 having dispersed therein antimicrobial organometallic
additives 1112, 1114 and 1116 distributed uniformly throughout a
polymer host matrix 1118. Antimicrobial organometallic additives
1112, 1114 and 1116 are different from each other. Some
antimicrobial organometallic additives 1112, 1114 and 1116 reside
at an outer surface 1120 as indicated by arrows 1122, 1124 and
1126, respectively. A core 1132 is located inside polymer product
1102 and may also contain antimicrobial organometallic additives or
not. An interface 1142 provides mechanical and chemical bonding
between the polymer host matrix 1118 and core 1132.
[0149] FIGS. 13 and 14 depict a rectangular box-shaped
core-containing polymer product 1302 having dispersed therein
antimicrobial organometallic additives 1312, 1314 and 1316
distributed uniformly throughout a polymer host matrix 1318.
Antimicrobial organometallic additives 1312, 1314 and 1316 are
different from each other. Some antimicrobial organometallic
additives 1312, 1314 and 1316 reside at an outer surface 1320 as
indicated by arrows 1322, 1324 and 1326, respectively. A core 1332
is located inside polymer product 1302 and may also contain
antimicrobial organometallic additives or not. An interface 1342
provides mechanical and chemical bonding between the polymer host
matrix 1318 and core 1332.
[0150] A core-containing polymer product of the present invention
may have various shapes such as spherical (as shown in FIGS. 11 and
12), rectangular box-shaped (as shown in FIGS. 13 and 14),
cube-shaped, ellipsoid-shaped, cone-shaped, pyramidal, rod-shaped,
ring-shaped, disks, rectangular plate-shaped, irregularly shaped,
multi-polygonal, multi-dimensional, etc. A spherical or nearly
spherical core-containing polymer product may be Although three
antimicrobial organometallic additives are shown in the
core-containing polymer products of FIGS. 11, 12, 13 and 14 and
there may be one, two, three, four or more antimicrobial
organometallic additives in a reinforced polymer product of the
present invention. The antimicrobial organometallic additive may be
the same chemistry or different chemistry.
[0151] A core-containing polymer product of the present invention
may have various shapes such as spherical (as shown in FIGS. 11 and
12), rectangular box-shaped (as shown in FIGS. 13 and 14),
cube-shaped, ellipsoid-shaped, cone-shaped, pyramidal, rod-shaped,
ring-shaped, disks, rectangular plate-shaped, irregularly shaped,
multi-polygonal, multi-dimensional, etc. A spherical or nearly
spherical core-containing polymer product may be used in balls for
purifying liquids such as but not limited to water, water-based
liquids, water-based fruit juices, milk, etc. Pelletized polymer
products used as the feedstock in the manufacture of final polymer
products, for example, thermal injection molding, extrusion, etc.,
can also have spherical or near spherical form. A spherical or
nearly spherical polymer may be fabricated with different densities
so that they may float at different levels in a liquid
environment.
[0152] The antimicrobial organometallic additive in any of the
polymer products and/or any portion and/or layer of a polymer
product of the present invention may be at various ratios with
respect to each other. For example, when a blend of three
antimicrobial organometallic additives are dispersed in a polymer
host matrix of the present invention, the ratio of the
antimicrobial organometallic additives may be 1:1:1, 1:2:1, 2:3:4,
or any other suitable ratio.
[0153] In one embodiment, the antimicrobial organometallic
additives are a majority of the metallic species present in a
polymer host matrix of a polymer product of the present invention.
In some embodiments of the present invention there may be low
levels of metals or metal ions present from other additives
dispersed throughout the polymer host matrix (e.g., UV protectors,
colorants, etc.). In some embodiments of the present invention, the
antimicrobial organometallic additives may be the only metallic
species present in a polymer host matrix of a polymer product of
the present invention.
[0154] In one embodiment, the antimicrobial polymer products of the
present invention include antimicrobial organometallic additives
that are water insoluble or sparingly soluble in water. A single
water insoluble or sparingly insoluble antimicrobial organometallic
additive may be employed or mixtures of water insoluble and/or
sparingly soluble antimicrobial organometallic additives may be
employed. In one embodiment of the present invention, the water
insoluble antimicrobial organometallic additives may comprise a
long-chain fatty acid group as their organic component. Such
compounds include, metal stearates and mixtures thereof. Suitable
metal stearates that provide antimicrobial activity to a polymer
product include, silver stearate, cupric stearate, zinc stearate,
etc., and mixtures thereof. One advantage of using water insoluble
antimicrobial organometallic additives having a long-chain fatty
acid group as their organic component is that that they should
provide long-lasting antimicrobial activity to polymer products,
even when the polymer products are exposed to moisture or immersed
in water. The water insolubility of such additives and the presence
of the long-chain fatty acid group should cause such additives to
stay bound and/or complexed in the polymer of the polymer product
and not leach into the moisture or water. This is different than
that for water soluble antimicrobial organometallic additives, for
example, acetate based systems.
[0155] In one embodiment, the present invention provides a
polyurethane product having antimicrobial activity that may be made
by mixing one or more antimicrobial organometallic additives of the
present invention with a liquid polyurethane at room
temperature.
[0156] In one embodiment, the present invention provides a powder
coat product, such as a thermoset powder coating. A thermoset
powder coating may be formed by mixing one or more antimicrobial
organometallic additives in powder form with a thermosetting powder
to form a powder mixture. The powder mixture is then applied to a
substrate and heated to melt, flow and chemically crosslink the
components of the thermosetting powder in the powder mixture to
form a thermoset film coating on the substrate. The thermoset
coating has the one or more antimicrobial organometallic additives
dispersed therein. The temperature that is used to form the
thermoset film coating depends on the particular components of the
thermosetting powder. In one embodiment, the temperature used to
form the thermoset film coating is from 170.degree. C. to
215.degree. C.
[0157] In one embodiment of the present invention, the polymer host
matrix may be paraffin wax. A paraffin wax product of the present
may be formed by mixing one or more antimicrobial organometallic
additives with liquid paraffin wax at temperature of 37.degree. C.
to 100.degree. C. to form a paraffin wax product having the one or
more antimicrobial organometallic additives dispersed throughout
the polymer host matrix.
[0158] The present invention will now be described by way of
example.
EXAMPLES
[0159] The testing of antimicrobial activity for the polymer
samples in Examples 1, 2, 3, 4, 5, 6, 7, 8 and 9 below is performed
using the Antimicrobial Test Laboratories' JIS Z 2801 Test for
Antimicrobial Activity of Plastics. A summary of the JIS Z 2801
Test procedure is provided below: [0160] (1) The test microorganism
is prepared, usually by growth in a liquid culture medium. [0161]
(2) The suspension of test microorganism is standardized by
dilution in a nutritive broth (this affords microorganisms the
potential to grow during the test). [0162] (3) Control and test
surfaces are inoculated with microorganisms, in triplicate, and
then the microbial inoculum is covered with a thin, sterile film.
Covering the inoculum spreads it, prevents it from evaporating, and
ensures close contact with the antimicrobial surface. [0163] (4)
Microbial concentrations are determined at "time zero" by elution
followed by dilution and plating. [0164] (5) A control is run to
verify that the neutralization/elution method effectively
neutralizes the antimicrobial agent in the antimicrobial surface
being tested. [0165] (6) Inoculated, covered control and
antimicrobial test surfaces are allowed to incubate undisturbed in
a humid environment for 24 hours. [0166] (7) After incubation,
microbial concentrations are determined Reduction of microorganisms
relative to initial concentrations and the control surface is
calculated.
Example 1
[0167] Composition 1. Silver stearate powder is added to a clear
coat powder coat material supplied by The Finishing Company,
Addison, Ill. Thermosetting powders are composed of relatively high
molecular weight resins, typically blends of epoxy, polyester and
acrylic, with crosslinking agents and color additives as required.
Suppliers include DuPont, BASF, etc. The silver stearate powder and
clear coat powder are then mixed vigorously to disperse the silver
stearate powder in the clear coat powder and to form a powder
blend. The powder blend is 2.5% silver stearate and 97.5% clear
coat powder by volume. An approximately 5 ml sample of this powder
blend is placed in an aluminum foil dish. The sample is heated at
380.degree. F. for 10 minutes and then removed from the oven to
cool. The sample is tested for antimicrobial activity using the JIS
Z 2801 test procedure. A 99.99996% reduction in Colony Forming
Units (CFU) is observed for this sample. The silver stearate powder
used in this example has a particle size of less than 25 .mu.m. The
clear coat powder used in this example has a particle size of less
than 25 .mu.m.
Example 2
[0168] Composition 2. Cupric stearate powder is added to a clear
coat powder coat material supplied by The Finishing Company,
Addison, Ill. The cupric stearate powder and clear coat powder are
then mixed vigorously to disperse the cupric stearate powder in the
clear coat powder and to form a powder blend. The powder blend is
2.5% cupric stearate and 97.5% clear coat powder by volume. An
approximately 5 ml sample of this powder blend is placed in an
aluminum foil dish. The sample is heated at 380.degree. F. for 10
minutes and then removed from the oven to cool. The sample is
tested for antimicrobial activity using the JIS Z 2801 test
protocol. A 99.99996% reduction in CFU is observed for this sample.
The cupric stearate powder used in this example has a particle size
of less than 25 .mu.m. The clear coat powder used in this example
has a particle size of less than 25 .mu.m.
Example 3
[0169] Composition 3. Cupric stearate powder and silver stearate
powder are added to a clear coat powder coat material of supplied
by The Finishing Company, Addison, Ill. The cupric stearate powder
and clear coat powder are then mixed vigorously to disperse the
cupric stearate powder and silver stearate powder in the clear coat
powder and to form a powder blend. The powder blend is 1% cupric
stearate, 1% silver stearate and 98% clear coat powder by volume.
The powder blend is deposited via an electrostatic powder coat
process onto stainless steel test coupons to form a sample. The
sample is tested for antimicrobial activity using the JIS Z 2801
test protocol. A 99.99994% reduction in CFU is observed for this
sample. The cupric stearate powder used in this example has a
particle size of less than 25 .mu.m. The silver stearate powder
used in this example has a particle size of less than 25 .mu.m. The
clear coat powder used in this example has a particle size of less
than 25 .mu.m.
Example 4
[0170] Composition 4. Cupric acetate powder supplied by
Sigma-Aldrich, St. Louis. Mo. is added to a clear coat powder coat
material supplied by The Finishing Company, Addison, Ill. The
cupric acetate powder and clear coat powder are then mixed
vigorously to disperse the cupric acetate powder in the clear coat
powder and to form a powder blend. The powder blend is 2.8% cupric
acetate and 97.2% clear coat powder by volume. An approximately 5
ml sample of this powder blend is placed in an aluminum foil dish.
The sample is heated at 380.degree. F. for 10 minutes and then
removed from the oven to cool. The sample is tested for
antimicrobial activity using the JIS Z 2801 test protocol. A
99.99831% reduction in CFU is observed for this sample. The cupric
acetate powder used in this example has a particle size of less
than 25 .mu.m. The clear coat powder used in this example has a
particle size of less than 25 .mu.m.
Example 5
[0171] Composition 5. Silver acetate powder supplied by
Sigma-Aldrich, St Louis, Mo. is added to a clear coat powder coat
material supplied by The Finishing Company, Addison, Ill. The
silver acetate powder and clear coat powder are then mixed
vigorously to disperse the silver acetate powder in the clear coat
powder and to form a powder blend. The powder blend is 2.8% silver
acetate and 97.2% clear coat powder by volume. An approximately 5
ml sample of this powder blend is placed in an aluminum foil dish.
The sample is heated at 380.degree. F. for 10 minutes and then
removed from the oven to cool. The sample is tested for
antimicrobial activity using the JIS Z 2801 test protocol. A
99.99831% reduction in Colony Forming Units (CFU) is observed for
this sample. The silver acetate powder used in this example has a
particle size of less than 25 .mu.m. The clear coat powder used in
this example has a particle size of less than 25 .mu.m.
[0172] The thermoset powder coatings of Examples 1, 2, 3, 4 and 5,
i.e., Compositions 1, 2, 3, 4 and 5, demonstrate that cupric
stearate, silver stearate and mixtures of cupric stearate and
silver stearate are compatible with thermoset powder coatings and
provide antimicrobial properties to the thermoset powder
coating.
Example 6
[0173] Composition 6. Silver stearate powder and cupric stearate
powder were added to commercial polypropylene pellets (supplied by
a commercial manufacturer). A 2% by volume powder blend was
produced (1% silver stearate and 1% cupric stearate) with about 1
pound of polypropylene pellets. The samples were thermal injection
molded into disks by a commercial manufacturer following standard
industry processes for polypropylene. The sample is tested for
antimicrobial activity using the JIS Z 2801 test protocol and
99.99989% reduction in Colony Forming Units (CFU) is observed for
this sample. The silver stearate powder used in this example had a
particle size of less than about 25 .mu.m. The cupric stearate
powder used in this example had a particle size of less than about
25 .mu.m. The polypropylene pellet size was about 4 mm.
Example 7
[0174] Composition 7. Silver stearate powder and cupric stearate
powder were added to commercial polypropylene pellets (supplied a
commercial manufacturer). A 0.2% by volume powder blend was
produced (0.1% silver stearate and 0.1% cupric stearate) with about
1 pound of polypropylene pellets. The samples were thermal
injection molded into disks by a commercial manufacturer following
standard industry processes for polypropylene. The sample is tested
for antimicrobial activity using the JIS Z 2801 test protocol and
99.76966% reduction in Colony Forming Units (CFU) is observed for
this sample. The silver stearate powder used in this example had a
particle size of less than about 25 .mu.m. The cupric stearate
powder used in this example had a particle size of less than about
25 .mu.m. The polypropylene pellet size was about 4 mm. This
demonstrates that the volume fraction of additive can produce
different efficacy levels in the final product. This enables
optimization for a variety of product attributes e.g. cost,
efficacy, processing, and performance via permutations of the metal
and organic components.
[0175] The injection molded products of Examples 6 and 7, i.e.,
Compositions 6 and 7, demonstrate that cupric stearate and silver
stearate mixtures are compatible with injection molded polymer
products and provide antimicrobial properties to the injection
molded polymer product.
Example 8
[0176] Composition 8. Cupric stearate powder and silver stearate
powder was added to 2-part commercial polyurethane (Envirotex Lite
Pour-on High Gloss Finish Polyurethane, Environmental Technology,
Inc, Fields Landing Calif. 95537) at room temperature. A 1.1% by
volume powder blend was produced (1% cupric stearate and 0.1%
silver stearate) with the liquid polyurethane. The polyurethane was
cast over a test coupon per the manufacturer's directions. The
sample is tested for antimicrobial activity using the JIS Z 2801
test protocol and 99.99997% reduction in Colony Forming Units (CFU)
is observed for this sample.
Example 9
[0177] Composition 9. Cupric stearate powder and silver stearate
powder was added to 1-part commercial water-based polyurethane
(Hanson Group, Atlanta Ga.). A 1.1% by volume powder blend was
produced (1% cupric stearate and 0.1% silver stearate) with the
liquid water-based polyurethane at room temperature. The
polyurethane was spray deposited over a test coupon per the
manufacturer's standard operating procedures. The sample is tested
for antimicrobial activity using the JIS Z 2801 test protocol and
99.99982% reduction in Colony Forming Units (CFU) is observed for
this sample.
[0178] The polyurethane coatings of Examples 8 and 9, i.e.,
Compositions 8 and 9, demonstrate that cupric stearate and silver
stearate mixtures are compatible with polyurethane and provide
antimicrobial properties to a polyurethane coating. Composition 9
also demonstrates that a polyurethane including the antimicrobial
organometallic additives cupric stearate and silver stearate may be
deposited as a coating on a substrate via spray deposition
techniques, the spray deposition techniques used in Example 9 being
different that the electrostatic-based powder coat process
technique described above in Example 3.
[0179] This enables optimization of the antimicrobial
organometallic additives used for a variety of product attributes
e.g. cost, efficacy, processing, and performance via permutations
of the metal and organic components. The results for various
embodiments of the present invention employing organometallic
stearate additives in host polymers are summarized in FIG. 15 which
shows various host polymers containing stearate based
organometallic additives showing antimicrobial efficacy
performance. As seen in FIG. 15, there is a "plateau region" where
efficacy is not strongly affected by changes in the volume fraction
of organometallic stearate additive(s) added to the host polymer.
In addition to concentration measured by volume fraction,
concentration can also be measured by atom fraction or molecular
fraction. At lower volume fraction concentrations, the efficacy
increases smoothly with the concentration. This curve, and
resulting curve fit parameters, enable optimization in the amount
of organometallic stearate additive used in compositions of the
present invention. Note in FIG. 15 that the Compositions 1 and 2
overlap each other.
[0180] FIG. 16 shows the data depicted in FIG. 15 that has been fit
with a curve defined by Equation 1 below:
Y=b+(a-b))/(1+10.sup.(X-c)) (Equation 1)
where Y is the Log Reduction result derived from the JIS Z 2081
test protocol, X is the concentration of the antimicrobial
organometallic additive and parameters a=-2.306.times.10.sup.6,
b=6.769 and c=-5.530. Equation 1 is a type of dose reduction model,
and the fitted data has a chi-square value of 1.163 and an R-square
value of 0.975, indicating a reasonable fit to the data. Other
equations or systems of equations can also be used, for example the
sum of a linear function to approximate the slowly varying
concentration "plateau region" plus a polynomial function to
approximate the smoothly increasing section of the data set prior
to the "plateau region."
[0181] FIG. 16 shows the efficacy performance data grouped by
various host polymers, i.e., powder coat material, polypropylene,
and polyurethane, with one or more antimicrobial organometallic
stearate additives. There is a plateau where efficacy is not
affected by changes in the volume fraction of antimicrobial
organometallic additive(s) added to the host polymer. At lower
volume fraction concentrations, the efficacy varies smoothly with
the concentration. This curve, and resulting curve fit parameters,
enables optimization of cost and efficacy, via permutations in the
concentrations of the antimicrobial organometallic additives.
[0182] FIG. 17 is a graph of the stearate chemistry data set of
FIG. 16 with the inclusion of data where the antimicrobial
organometallic additive is an acetate (Compositions 4 and 5).
[0183] Similar to FIG. 16, FIG. 17 has a "plateau region" where
efficacy is not strongly affected by changes in the volume fraction
of antimicrobial organometallic additive(s) added to the host
polymer. At lower volume fraction concentrations, the efficacy
increases smoothly with the concentration. This curve, and
resulting curve fit parameters, enables optimization of cost and
efficacy, via permutations in the concentrations of the
antimicrobial organometallic additive(s).
[0184] The data in FIG. 17 has been fit with the curve defined by
Equation 1 above, where Y is the Log Reduction result derived from
the JIS Z 2081 test protocol, X is the concentration of the
antimicrobial organometallic additive(s) and parameters a=-5.759E6,
b=6.433 and c=-5.957. In this case, the fitted data has a
CHI-Square value of 3.614 and an R-square value of 0.922,
indicating a still reasonable fit to the data. Other equations or
systems of equations can also be used, for example the sum of a
linear function to approximate the slowly varying concentration
"plateau region" plus a polynomial function to approximate the
smoothly increasing section of the data set prior to the "plateau
region".
Example 10
[0185] Composition 10. Cupric stearate powder and silver stearate
powder was added to commercial food grade paraffin wax (Gulf Wax
Household Paraffin Wax, distributed by Royal Oak Enterprises, LLC,
Roswell, Ga. 30076). A 1.1% by volume powder blend was produced (1%
cupric stearate and 0.1% silver stearate) by adding the powders to
molten wax at a temperature of about 90.degree. C. The molten wax
mixture was deposited over a paper substrate (butcher paper). The
sample coated the substrate in a uniform manner Immersion in water
for 48 hours did not cause the paper substrate of wax-coated paper
to wet. It is expected that this sample will have antimicrobial
activity similar to the antimicrobial activity of the samples
described above in Examples 1, 2, 3, 4, 5, 6, 7, 8 and 9.
[0186] All documents, patents, journal articles and other materials
cited in the present application are incorporated herein by
reference.
[0187] Having described a particular embodiment of the present
invention, it will be apparent that modifications and variations
are possible without departing from the scope of the invention as
defined in the appended claims. Furthermore, it should be
appreciated that all examples provided in the present disclosure,
while illustrating a particular embodiment of the invention, are
provided as non-limiting examples and are, therefore, not to be
taken as limiting the various aspects so illustrated.
[0188] While the present invention has been disclosed with
references to certain embodiments, numerous modifications,
alterations and changes to the described embodiments are possible
without departing from the sphere and scope of the present
invention, as defined in the appended claims. Accordingly, it is
intended that the present invention not be limited to the described
embodiments, but that it has the full scope defined by the language
of the following claims and equivalents thereof.
* * * * *