U.S. patent application number 16/053588 was filed with the patent office on 2018-12-13 for targeted performance of hypohalite methods thereof.
The applicant listed for this patent is THE CLOROX COMPANY. Invention is credited to Dewain Garner, Jared Heymann, William L. Smith.
Application Number | 20180355289 16/053588 |
Document ID | / |
Family ID | 48982364 |
Filed Date | 2018-12-13 |
United States Patent
Application |
20180355289 |
Kind Code |
A1 |
Garner; Dewain ; et
al. |
December 13, 2018 |
TARGETED PERFORMANCE OF HYPOHALITE METHODS THEREOF
Abstract
This invention relates to extend the benefits of using
hypochlorite compounds such as sodium hypochlorite to clean and
disinfect articles while reducing or eliminating the side effects
of treating an article with a strong oxidant material. The
invention relates to a single step process involving mixing of
precursor compositions of a suitable hypohalite or hypohalous acid
with a solution of a reducing agent. Optionally a buffer may be
present in either or both precursor compositions, such that at time
of use such active hypohalous acid concentration in the resulting
aqueous mixture remains at a sufficient activity level to effect
one or more desired benefits against a target substrate for a
desired period of time. The oxidant is substantially consumed by
reaction with the reducing agent after the time needed for
achieving the desired benefit has passed.
Inventors: |
Garner; Dewain; (Copley,
OH) ; Smith; William L.; (Pleasanton, CA) ;
Heymann; Jared; (Pleasanton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE CLOROX COMPANY |
OAKLAND |
CA |
US |
|
|
Family ID: |
48982364 |
Appl. No.: |
16/053588 |
Filed: |
August 2, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15285314 |
Oct 4, 2016 |
10066193 |
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16053588 |
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14671144 |
Mar 27, 2015 |
9499774 |
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15285314 |
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13672911 |
Nov 9, 2012 |
9029311 |
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14671144 |
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61600348 |
Feb 17, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C11D 3/3956 20130101;
C11D 3/22 20130101; C11D 3/3951 20130101; A01N 59/00 20130101; C11D
3/0042 20130101; B65D 85/70 20130101; C11D 3/26 20130101; C11D 7/10
20130101; C11D 3/3958 20130101; C11D 17/041 20130101; B05C 9/06
20130101; C11D 3/048 20130101; B65D 25/08 20130101; C11D 7/105
20130101; C11D 3/10 20130101; B65D 25/04 20130101; A01N 47/44
20130101; C11D 3/3953 20130101; C11D 3/0047 20130101; C11D 3/3955
20130101; A01N 59/00 20130101; A01N 25/32 20130101 |
International
Class: |
C11D 3/395 20060101
C11D003/395; C11D 17/04 20060101 C11D017/04; A01N 47/44 20060101
A01N047/44; C11D 7/10 20060101 C11D007/10; C11D 3/26 20060101
C11D003/26; C11D 3/10 20060101 C11D003/10; C11D 3/04 20060101
C11D003/04; C11D 3/00 20060101 C11D003/00; B65D 85/00 20060101
B65D085/00; B65D 25/08 20060101 B65D025/08; B65D 25/04 20060101
B65D025/04; B05C 9/06 20060101 B05C009/06; A01N 59/00 20060101
A01N059/00 |
Claims
1. A method for treating a surface, the method comprising:
providing a two-part composition comprising: an oxidant first part
comprising a hypohalous acid or a hypohalite; and a reductant
second part comprising a glucose, wherein the first and second
parts are initially separate; and mixing the oxidant first part
with the reductant second part to form a mixed composition; and
contacting the mixed composition with a surface to provide
oxidizing benefits to the surface whereby the oxidant is reduced by
the reductant to prevent damage caused by prolonged exposure to the
hypohalous acid or the hypohalite.
2. The method of claim 1, wherein the hypohalous acid or the
hypohalite comprises from about 0.001% to about 10% by weight of
the two-part composition.
3. The method of claim 1, wherein the hypohalous acid or the
hypohalite comprises from about 0.005% to about 5% by weight of the
two-part composition.
4. The method of claim 1, wherein the hypohalous acid or the
hypohalite comprises from about 0.005% to about 0.2% by weight of
the two-part composition.
5. The method of claim 1, further comprising a pH buffer comprising
at least one member of an organic acid, a phosphate, a bicarbonate
or a carbonate.
6. The method of claim 5, wherein the buffer is said carbonate.
7. The method of claim 5, wherein the buffer is said phosphate.
8. The method of claim 5, wherein the buffer is said
bicarbonate.
9. The method of claim 5, wherein the buffer is said organic
acid.
10. The method of claim 5, wherein the second part comprises the
buffer.
11. The method of claim 1, wherein the oxidant is hypohalite.
12. The method of claim 1, wherein the hypohalite is a
hypochlorite.
13. The method of claim 1, wherein the oxidant is hypohalous
acid.
14. The method of claim 1, wherein the surface is a hard
surface.
15. The method of claim 1, wherein the surface is a soft surface.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending U.S. patent
application Ser. No. 15/285,314, filed on Oct. 4, 2016, which is a
continuation of U.S. patent application Ser. No. 14/671,144, filed
on Mar. 27, 2015, and now U.S. Pat. No. 9,499,774, which is
continuation of U.S. patent application Ser. No. 13/672,911, filed
Nov. 9, 2012, and now U.S. Pat. No. 9,029,311, which claims the
benefit of U.S. Provisional Patent Application No. 61/600,348,
filed Feb. 17, 2012 entitled TARGETED PERFORMANCE OF HYPOHALITE
COMPOSITIONS, METHODS AND SYSTEMS THEREOF, the disclosures of which
are incorporated herein in their entirety.
BACKGROUND OF THE INVENTION
1. The Field of the Invention
[0002] The present invention relates to hypohalite-based cleaners
for use on hard, soft, animal and human surfaces.
2. Description of Related Art
[0003] Currently, hypohalite based cleaners achieve great efficacy
for cleaning, bleaching, and disinfection. However, these cleaners
have some negative side effects. Hypohalite based cleaners
typically contain strong bleaching species and have certain
undesirable side effects associated with their use such as strong
odors, tendency to overbleach, surface corrosion, and a tendency to
leave behind chlorinated species, such as chloramines, which leave
an unpleasant odor after treatment. Thus, there is a continuing
need for a cleaner that could leverage the benefits of hypochlorite
bleach usage while minimizing or preventing any negative side
effects. Surprisingly, the present invention addresses these
issues.
BRIEF SUMMARY OF THE INVENTION
[0004] One aspect of the invention is directed to a method for
preparing a mixed composition and treating a surface; the method
comprising: providing a two-part composition comprising: an oxidant
first part comprising a hypohalous acid or a hypohalite; and a
reductant second part comprising a nitrite, wherein the first and
second parts are initially separate from one another; mixing the
oxidant first part with the reductant second part to form a mixed
composition that provides oxidizing benefits for a limited
duration, the oxidant reacting with a reductant to reduce the
oxidant concentration so as to prevent or minimize negative side
effects to the surface otherwise associated with prolonged oxidant
exposure longer than the limited duration; and contacting the mixed
composition with a surface to provide oxidizing benefits to the
surface for a limited duration while preventing or minimizing
negative side effects to the surface associated with prolonged
oxidant exposure.
[0005] In another aspect of the invention, there is a method for
preparing a mixed composition and treating a surface, the method
comprising: providing a two-part composition comprising: an oxidant
first part comprising a hypochlorite, the hypochlorite comprising
up to about 15% by weight of the two-part composition; and a
reductant second part comprising a nitrite, the nitrite comprising
from about 0.01% to about 15% by weight of the two-part
composition, wherein the first and second parts are initially
separate from one another; mixing the oxidant first part with the
reductant second part to form a mixed composition that provides
oxidizing benefits for a limited duration, the oxidant reacting
with a reductant to reduce the oxidant concentration so as to
prevent or minimize negative side effects to the surface otherwise
associated with prolonged oxidant exposure longer than the limited
duration; and contacting the mixed composition with a surface to
provide oxidizing benefits to the surface for a limited duration
while preventing or minimizing negative side effects to the surface
associated with prolonged oxidant exposure.
[0006] In yet another embodiment of the method, there is a method
for preparing a mixed composition and treating a surface, the
method comprising: providing a two-part composition comprising: an
oxidant first part comprising a hypohalite, the hypohalite
consisting of sodium hypohalite; and a reductant second part
comprising a nitrite, the nitrite consisting of sodium nitrite,
wherein the first and second parts are initially separate from one
another; mixing the oxidant first part with the reductant second
part to form a mixed composition that provides oxidizing benefits
for a limited duration, the oxidant reacting with a reductant to
reduce the oxidant concentration so as to prevent or minimize
negative side effects to the surface otherwise associated with
prolonged oxidant exposure longer than the limited duration; and
contacting the mixed composition with a surface to provide
oxidizing benefits to the surface for a limited duration while
preventing or minimizing negative side effects to the surface
associated with prolonged oxidant exposure.
[0007] Further features and advantages of the present invention
will become apparent to those of ordinary skill in the art in view
of the detailed description of preferred embodiments below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] To further clarify the above and other advantages and
features of the present invention, a more particular description of
the invention will be rendered by reference to specific embodiments
thereof which are illustrated in the drawings located in the
specification. It is appreciated that these drawings depict only
typical embodiments of the invention and are therefore not to be
considered limiting of its scope. The invention will be described
and explained with additional specificity and detail through the
use of the accompanying drawings in which:
[0009] FIG. 1 is a plot showing conceptual zones related to the
present invention including a beneficial zone, a quenching zone and
a detrimental zone.
[0010] FIG. 2 is a plot of percentage initial hypochlorite
remaining as a function of time using a sodium nitrite reductant
with no buffer system at various reductant/oxidant ratios.
[0011] FIG. 3 is a plot of percentage initial hypochlorite
remaining as a function of time using a sodium nitrite reductant
with no buffer system at various mixture pHs.
[0012] FIG. 4 is a plot of percentage initial hypochlorite
remaining as a function of time using a sodium nitrite reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several embodiments of the invention.
[0013] FIG. 5 is a plot of percentage initial hypochlorite
remaining as a function of time using a sodium nitrite reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several additional embodiments of the invention.
[0014] FIG. 6 is a plot of percentage initial hypochlorite
remaining as a function of time using a fructose reductant with a
carbonate buffer system according to several embodiments of the
invention.
[0015] FIG. 7 is a plot of percentage initial hypochlorite
remaining as a function of time using a fructose reductant with a
carbonate buffer system according to several embodiments of the
invention.
[0016] FIG. 8 is a plot of percentage initial hypochlorite
remaining as a function of time using a fructose reductant with a
mixed acetate, phosphate, and carbonate buffer system according to
several additional embodiments of the invention.
[0017] FIG. 9 is a plot of percentage initial hypochlorite
remaining as a function of time using a fructose reductant with a
carbonate buffer system according to an embodiment of the invention
that is configured to effectively quench the oxidant within about
10 minutes.
[0018] FIG. 10 is a plot of percentage initial hypochlorite
remaining as a function of time using CaEDTA as a reductant with a
mixed acetate, phosphate, and carbonate buffer system according to
several embodiments of the invention.
[0019] FIG. 11 is a plot of percentage initial hypochlorite
remaining as a function of time using potassium sorbate reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several embodiments of the invention.
[0020] FIG. 12 is a plot of percentage initial hypochlorite
remaining as a function of time using potassium sorbate reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several additional embodiments of the invention.
[0021] FIG. 13 is a plot of percentage initial hypochlorite
remaining as a function of time using guanidine hydrochloride
reductant with a carbonate buffer system according to several
embodiments of the invention.
[0022] FIG. 14 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium lactate as a reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several embodiments of the invention.
[0023] FIG. 15 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium lactate as a reductant
with acetate buffer system according to several embodiments of the
invention at different reductant/oxidant ratios.
[0024] FIG. 16 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium citrate as a reductant
with a mixed acetate, phosphate, and carbonate buffer system
according to several embodiments of the invention.
[0025] FIG. 17 is a plot of percentage of initial hypochlorite
remaining as a function of time using sodium citrate as a reductant
with no buffer system according to several embodiments of the
invention, illustrating the effect of mix pH on reactivity.
[0026] FIG. 18 is a plot of measured solution pH over time of
inventive solutions using sodium citrate as a reductant with no
buffer system demonstrating that control of hypochlorite lifetime
is adversely affected by changing pH in these unbuffered solutions,
and that hypochlorite lifetime may be "tuned" to a desired duration
without adjusting the reductant/oxidant ratio in a citric acid
system.
[0027] FIG. 19 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium tetrathionate as a
reductant with a mixed succinate, phosphate, and carbonate buffer
system according to several embodiments of the invention at various
reductant/oxidant ratios.
[0028] FIG. 20 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium tetrathionate as a
reductant with a mixed succinate phosphate, and carbonate buffer
system according to several additional embodiments of the invention
at various reductant/oxidant ratios.
[0029] FIG. 21 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium thiosulfate reductant
with a mixed acetate, phosphate, and carbonate buffer system.
[0030] FIG. 22 is a plot of percentage initial hypochlorite
remaining as a function of time using sodium thiosulfate reductant
with a carbonate buffer system.
[0031] FIG. 23 is a plot of percentage initial hypochlorite
remaining as a function of time using a mixture of fructose and
nitrite reductants with a carbonate buffer system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Definitions
[0032] Before describing the present invention in detail, it is to
be understood that this invention is not limited to particularly
exemplified systems or process parameters that may, of course,
vary. It is also to be understood that the terminology used herein
is for the purpose of describing particular embodiments of the
invention only, and is not intended to limit the scope of the
invention in any manner.
[0033] All publications, patents and patent applications cited
herein, whether supra or infra, are hereby incorporated by
reference in their entirety to the same extent as if each
individual publication, patent or patent application was
specifically and individually indicated to be incorporated by
reference.
[0034] The term "comprising" which is synonymous with "including,"
"containing," or "characterized by," is inclusive or open-ended and
does not exclude additional, unrecited elements or method
steps.
[0035] The term "consisting essentially of" limits the scope of a
claim to the specified materials or steps "and those that do not
materially affect the basic and novel characteristic(s)" of the
claimed invention.
[0036] The term "consisting of" as used herein, excludes any
element, step, or ingredient not specified in the claim.
[0037] It must be noted that, as used in this specification and the
appended claims, the singular forms "a," "an" and "the" include
plural referents unless the content clearly dictates otherwise.
Thus, for example, reference to a "surfactant" includes one, two or
more such surfactants.
[0038] As used herein, the term "disinfect" shall mean the
elimination of many or all pathogenic microorganisms on surfaces
with the exception of bacterial endospores.
[0039] As used herein, the term "sanitize" shall mean the reduction
of contaminants in the inanimate environment to levels considered
safe according to public health ordinance, or that reduces the
bacterial population by significant numbers where public health
requirements have not been established. An at least 99% reduction
in bacterial population within a 24 hour time period is deemed
"significant."
[0040] As used herein, the term "sterilize" shall mean the complete
elimination or destruction of all forms of microbial life and which
is authorized under the applicable regulatory laws to make legal
claims as a "sterilant" or to have sterilizing properties or
qualities.
[0041] The "reductant/oxidant Ratio" or "RIO" ratio is defined as a
molar ratio, being the molar equivalents of reductant present
divided by the molar equivalents of oxidant present in the combined
compositions of the invention, thus being a ratio of the total
reductant molar concentration to the total oxidant molar
concentration present, and not a weight nor volume ratio of the
materials. The RIO ratio may be denoted as a simple number or in
ratio format with respect to 1, for example "5" or "5:1".
[0042] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which the invention pertains. Although
a number of methods and materials similar or equivalent to those
described herein can be used in the practice of the present
invention, the preferred materials and methods are described
herein.
[0043] In the application, effective amounts are generally those
amounts listed as the ranges or levels of ingredients in the
descriptions, which follow hereto. Unless otherwise stated, amounts
listed in percentage ("wt %'s") are in wt % (based on 100 weight %
active) of the particular material present in the referenced
composition, any remaining percentage being water or an aqueous
carrier sufficient to account for 100% of the composition, unless
otherwise noted. For very low weight percentages, the term "ppm"
corresponding to parts per million on a weight/weight basis may be
used, noting that 1.0 wt % corresponds to 10,000 ppm.
II. Introduction
[0044] This invention relates to compositions, methods and systems
of providing the benefits of using hypochlorite compounds such as
sodium hypochlorite to clean and disinfect articles while reducing
or eliminating the side effects associated with treating an article
with a strong oxidant material. The invention further relates to a
single step process involving mixing a hypochlorite (e.g., sodium
hypochlorite) with a reducing agent and optionally, a buffer at the
time of use such that the hypochlorite ion or hypochlorous acid
concentration in the resulting aqueous mixture remains at a
sufficient activity level to effect one or more desired benefits
against a target substrate for a desired period of time, while
providing that the oxidant is then substantially consumed by
reaction with the reducing agent after the time needed for
achieving the desired benefit has passed. Desired benefits enabled
by the present invention include, but are not limited, to the
ability to effectively sterilize, disinfect and/or bleach the
surface of an article, or an article itself, while extinguishing
remaining oxidant to minimize and/or prevent further oxidation,
surface corrosion, dye damage and the like.
[0045] This invention has the further benefits of preventing side
effects or damage caused by prolonged exposure to hypochlorite,
such as surface damage, dye discoloration or malodor generation,
while providing benefits of hypochlorite use, including but not
limited to disinfection, sterilization, stain removal,
deodorization, mold removal, toxin and/or allergen remediation,
and/or laundry textile bleaching and whitening. In one embodiment
of the invention, the precursor compositions, mixed precursor
compositions and associated methods of use herein provide a single
step, convenient to use application of a "time of use" composition
which does not require post mixing manipulation by the user.
Another embodiment provides a shelf stable product including two
precursor compositions that can be stored and mixed before or at
time of use to provide an end use composition in which stability of
a strong oxidant has been maximized for commercial and retail
usage.
[0046] A need exists for compositions, systems and methods that can
provide a one step aqueous composition formed by mixing a
hypochlorite species with a reducing agent at the time of use that
is capable of limiting in a predictable and controllable way the
time that an article is exposed to the hypochlorite. To that end,
it has surprisingly been discovered that control over hypochlorite
lifetime is highly dependent on solution conditions such as the
ratio of reductant to hypochlorite oxidant species and pH. It has
also been discovered that many different reductants may be used and
that these can be selected based on the operational conditions
desired. This discovery led to the further discovery that
hypochlorite lifetime may be adjusted as desired by the careful
selection of operational conditions such as pH and R/0 ratio and
reductant identity.
[0047] It has been further discovered that a combination of one or
more reducing agents may be used to control the lifetime of the
hypochlorite component after mixing of the precursor compositions
to form the usage composition. A further discovery is that addition
of a buffer to such a time of use mixed system provides optimal
performance in terms of the ability to "tune" the exposure time of
the active bleaching system. Additionally, the present invention
has the further advantage in that it may be used to deliver
benefits derived from use of additional compounds and materials,
such as surfactants, dyes and fragrances, which may be only
marginally stable in the presence of hypochlorite over a typical
product shelf life. Such optional components may be delivered
simultaneously along with the primary bleaching and disinfectant
benefit of the strong hypochlorite species where previously not
achievable, e.g., because the two precursor compositions may be
stored or maintained separately prior to the time of mixing.
[0048] One aspect of the invention relates to a single step process
involving mixing an oxidant (e.g., sodium hypochlorite) with a
reducing agent at the time of use such that the hypochlorite ion or
hypochlorous acid concentration in the resulting aqueous mixture
remains sufficient to effect the desired benefit for a desired
period of time, while also providing that the oxidant is
substantially consumed by reaction with the reducing agent after
the time needed for achieving the desired benefit has passed. The
composition may optionally include a buffer.
[0049] For example, one aspect of the invention is a single step
process for activating and then timely deactivating a hypochlorite
based oxidant, so as to achieve the desired benefits of performance
on a treated article, while at the same time preventing side
effects or damage caused by prolonged exposure to hypochlorite.
Thus, the inventive embodiments provide one or more benefits of
hypochlorite use, such as disinfection, sterilization, stain
removal, deodorization, mold removal, toxin and/or allergen
remediation, or laundry textile bleaching and whitening, while
preventing negative side effects such as surface damage, dye
discoloration and malodor generation.
[0050] One aspect of the invention relates to controlling the
duration of zone 1 and zone 2. The duration of each zone depends on
the desired benefit and the undesired effect to be avoided.
Depending on the embodiment zone 1 may last for 30 seconds, 1
minute, 2 minutes, 5 minutes, 10 minutes, 30 minutes, 60 minutes,
or any length of time encompassed within a range in which the end
points of the range are defined by any of the above durations
(e.g., 30 seconds to 60 minutes, 2 minute to 30 minutes, etc.).
Depending on the embodiment zone 2 may last for 30 seconds, 1
minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 20 minutes, 30
minutes, 60 minutes, or any length of time encompassed within a
range in which the end points of the range are defined by any of
the above durations.
[0051] FIG. 1 shows the zone of optimum utility (benefit) where
achieving a maximal hypohalite bleach benefit with minimal adverse
effects by neutralization of the hypohalite bleach after the
desired benefit substantially occurs and before adverse effects
substantially begin to affect the treated article. When thus
viewed, treatment of a surface or article with an ideal improved
hypohalite bleaching composition may be viewed as having three time
zones of exposure. The first zone is the "benefit zone" and lasts
long enough to substantially deliver the desired benefit to the
treated surface or article. This benefit zone is generally shorter
than the other two because of the rapid reactivity of hypohalite
bleach species. In an ideal system, greater than about 50% of the
initial hypohalite bleach concentration remains by the end of the
benefit zone. Alternatively greater than about 60%, or greater than
about 80% of the initial hypohalite bleach may remain.
[0052] The second zone is the "quenching zone" and is the time
between substantial delivery of the benefit and detectable
occurrence of the any detrimental aspects of treatment. Significant
reduction of hypohalite bleach concentration ideally occurs during
the duration of this quenching zone. Generally, the hypohalite
concentration is reduced by at least 75% in this zone.
Consequently, less than about 20% of the initial hypohalite bleach
remains, alternatively less than about 10% of the initial
hypohalite bleach, or alternatively less than about 5% of the
initial hypohalite bleach remains by the end of this quenching
zone. In some embodiments less than 1% of the initial hypohalite
bleach remains at the end of this quenching zone.
[0053] The third zone is the "detrimental effect zone" and is
denoted by the observance of some undesired effect of hypohalite
bleach such as odor, dye damage or surface damage. This zone is
usually longer than either of the previous zones. Its duration
generally corresponds to a length of time it takes for any
remaining hypohalite bleach to be consumed by reactions with soil,
substrate or itself. In one embodiment, the hypohalite bleach
concentration in zone 2 is sufficiently reduced to essentially
prevent significant undesired effects that might otherwise occur in
zone 3. In preferred embodiments of the invention, the quenching in
zone 2 sufficiently reduces the concentration of hypohalite bleach
such that zone 3 is essentially avoided. The quenching in zone 2
may sufficiently reduce the concentration of hypohalite bleach so
that any undesired effects are acceptable, alternatively, any
undesired effects in zone 3 are not objectionable. Still
alternatively, the quenching is sufficient so that there are no
detectable undesired effects.
III. Oxidant--Hypohalous Acid and Salts
[0054] In one embodiment of the invention, the compositions
comprise hypohalite, defined as hypohalous acid and/or salts
thereof. Suitable hypohalous acids and salts may be provided by a
variety of sources, including compositions that lead to the
formation of halide ions and/or hypohalite ions.
[0055] In another embodiment of the invention wherein the
compositions herein are liquid, the hypohalite component may be an
alkali metal and/or alkaline earth metal hypochlorite, or mixtures
thereof. Compositions may include an alkali metal and/or alkaline
earth metal hypochlorite selected from the group consisting of
sodium hypochlorite, potassium hypochlorite, magnesium
hypochlorite, lithium hypochlorite calcium hypochlorite, and
mixtures thereof.
[0056] The hypohalous acid and/or salt composition may be an
equilibrium mixture of hypochlorous acid and salts of hypochlorite.
The active hypohalite specie(s) may be present in an amount from
above zero to about 15 wt % of the composition, or from about 0.001
wt % (10 ppm) to about 10 wt % of the composition, or from about
0.005 (50 ppm) to about 5 wt % of the composition, or from about
0.005 wt % (50 ppm) to about 0.2 wt % (2000 ppm) of the
composition.
[0057] In another embodiment a bromide salt may be added to convert
all or part of the hypochlorite and/or hypochlorous acid to
hypobromite and/or hypobromous acid. Examples of suitable bromide
salts include, but are not limited to alkali metal salts of
bromine, such as sodium bromide, potassium bromide, and
combinations thereof. The bromide salt may be added in combination
with the reductant. The inclusion of the bromide salt may
advantageously alter the reaction rate with the reductant or
enhance the benefit achieved from the hypohalous acids and salts.
The bromide salt may be used in an amount sufficient to form
hypobromite and/or hypobromous acid by conversion of about 0.001%
to about 20%, or from about 0.01% to about 10%, or from about 0.1%
to about 100%, or from about 1% to about 80%, or from about 25% to
about 75%, or from about 80% to about 100% of the hypochlorite or
hypochlorous acid.
[0058] The amount of available halogen oxidant in the composition
may be determined by placing samples of the composition into about
50 milliliters of distilled water, followed by addition of about 10
milliliters of a 10 wt % solution of potassium iodide and addition
of about 10 milliliters of a 10 volume % solution of sulfuric acid,
the resulting mixture being well stirred. The resulting yellow to
brown solution, whose color is the result of oxidation of free
iodine ion (I.sup.-) to molecular iodine (I.sub.2), is then
volumetrically titrated to an essentially colorless endpoint by
addition of standardized 0.1 Molar sodium thiosulfate
(Na.sub.2S.sub.2O.sub.3) titrant. Calculation then expresses the
result as percent of available molecular chlorine (Cl.sub.2), that
is to say assigning two equivalents per mole of titrated hypohalite
oxidant. Stability results are then expressed by repeated assays
over time using identically prepared samples resulting from the
same composition, normalized to 100 percent representative of the
starting available chlorine measured initially.
[0059] Alternatively, at lower concentrations of hypochlorite,
generally below about 2,000 ppm or 0.2 wt %, spectroscopic
measurement of the absorption of aqueous solutions may be used to
monitor the concentration, and resulting changes, of the
hypochlorous acid species in solution. The solution absorbs bluish
light, accounting for the yellowish color of solutions including
this oxidant. By use of controls, the relative level of
hypochlorite can then be monitored and calculated by measuring
absorbance of solutions by means of a suitable instrument, such as
a spectrophotometer.
IV. Preferred Reductants
[0060] Generally, any compound capable of being solubilized into an
aqueous solution that is capable of reacting with an oxidant such
as hypochlorite ion or hypochlorous acid may be employed as a
reductant in the present invention. Several exceptions are known
and noted below as materials not suitable for use as reductants in
the present invention.
[0061] A large number of materials are suitable as reductants, and
may be selected for their particular properties and ability to
control the beneficial exposure time of hypochlorous systems.
[0062] Reductants may be selected from several different groups,
and selection of a reductant and/or group may be dependent on the
desired operating conditions for the formula and its intended use.
For example, physical characteristics of the potential reducing
agent such as reduction potential, solubility, pKa, polarizability
or dipole moment may be considered by one skilled in the art to
assist in the selection of an appropriate reductant.
[0063] Reductants suitable for use in the present invention may in
general be categorized in the following groups of materials sharing
one or more similar chemical, physical, or reactive properties.
[0064] In one embodiment, reductants may be selected from Group 1
materials, which include, but are not limited to inorganic reducing
agents such as the alkali or alkaline earth metal salts of nitrite,
tetrathionate, and/or thiosulfate, similar materials, and
combinations thereof. In one embodiment, the group 1 reductant
comprises a nitrite.
[0065] In another embodiment, reductants may be selected from Group
2 materials, which include, but are not limited to, organo-nitrogen
reducing agents such as guanidine hydrogen chloride, urea, amines,
alkanolamines, alkylamides, alkanolamides, similar materials, and
combinations thereof. Included in this group are polymers of
organo-nitrogen reducing agents such as polyvinyl pyrrolidone and
similar materials.
[0066] In another embodiment, reductants may be selected from Group
3 materials, which include, but are not limited to sugars,
otherwise known in the art as monosaccharides, disaccharides and
oligosaccharides. Included in this group are normal sugars, such as
for example, the class of edible crystalline carbohydrates which
include lactose and fructose. Also included in this group are
reducing sugars, which are sugars having an open-chain form with an
aldehyde group or a free hemiacetal group, including
monosaccharides which contain an aldehyde group known as aldoses,
and those with a ketone group known as ketoses. Also included in
this group are polymeric sugars such as starches, carbohydrates,
cellulose, gums, derivatives thereof, or like polymers which have
at least one repeating monomer that is susceptible to oxidation as
defined herein. Examples of suitable reducing sugars include, but
are not limited to monosaccharides (e.g., glucose, glyceraldehyde
and galactose); disaccharides, (e.g., lactose and maltose), similar
materials, and combinations thereof.
[0067] In another embodiment, reductants may be selected from Group
4 materials, which include, but are not limited to chelating
agents, sequestrants and similar materials capable of ionic binding
with an alkaline earth metal counter cation (e.g., calcium or
magnesium ions) such as disodium calcium EDTA (ethylene diamine
tetra-acetic acid), BAPTA
(1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid), DTPA
(Pentetic acid or diethylene triamine pentaacetic acid), EGTA
(ethylene glycol tetraacetic acid), the like, and combinations
thereof.
[0068] In another embodiment, reductants may be selected from Group
5 materials, which include, but are not limited to oxidizable
organic acids and/or salts of organic acids which include the known
organic carboxylic acids whose acidity is associated with having a
carboxyl group (--COOH) such as sorbic acid or salts thereof,
citric acid or salts thereof, lactic acid or salts thereof,
ascorbic acid or salts thereof, maleic acid or salts thereof,
fumaric acid or salts thereof, oxalic acid or salts thereof, acetic
acid and salts thereof, glycolic acid and salts thereof, tartaric
acid and salts thereof, and combinations thereof. Many other
aliphatic and cycloaliphatic carboxylic acids and salts thereof
with amino, hydroxyl, keto, sulfhydro or other oxidizable
substituents, or that contain double or triple carbon-carbon bonds
are also suitable. Also included in this group are polymers and
copolymers of oxidizable organic acids which have at least one
repeating monomer that is susceptible to oxidation as defined
herein, such as polyacrylic acids and salts thereof, and
combinations thereof.
[0069] In another embodiment, reductants may be selected from Group
6 materials, which include, but are not limited to alcohols such as
methanol, ethanol, propanol, butanol, phenol, ethylene glycol and
other similar materials and their isomers bearing at least one
hydroxyl (--OH) group covalently bonded to an alkyl, aryl or phenyl
group. Included in this group are polymeric alcohols which have at
least one repeating monomer that is susceptible to oxidation as
defined herein, such as polyvinyl alcohol and the like. Additional
materials in this group include polyhydric alcohols, being those
materials with more than one hydroxyl group, including but not
limited to propylene glycol, glycerin, erythritol, xylitol,
mannitol, sorbitol and similar materials, and combinations
thereof.
[0070] In another embodiment, reductants may be selected from Group
7 materials, which include, but are not limited to oxidizable
surfactants, which include those surfactants having a nitrogen or
quaternary nitrogen functionality, such as lauryl amine oxide,
benzalkonium chloride, lauryl dimethyl ammonium chloride, similar
materials, and combinations thereof.
[0071] In another embodiment, more than one reductant may be
selected. When employing multiple reductants, more than one
reductant may be selected from a group or reductants from different
groups may be combined.
[0072] Reductants may suitably be employed in the present invention
at levels between about 0.01 wt % to about 15 wt %, or
alternatively from about 0.05 wt % to about 10 wt %, or yet
alternatively from about 0.1 wt % to about 1 wt %. Reductant molar
ratios with respect to the oxidant (e.g., sodium hypochlorite) may
be selected from a range from between about 0.01:1 to about 100:1,
or alternatively from about 0.05:1 to about 50:1, or yet
alternatively from about 0.1:1 to about 10:1.
[0073] Additionally, in further embodiments of the invention, low
levels of halide salts such as sodium bromide and/or salts of
bromine, iodine and/or salts of iodine, may be added to any of the
above reductants (quenchers) to modify the reaction time with the
hypochlorite or other hypohalide. Suitable levels of these halides
and/or halide salts range from 0.0001 wt % to about 1 wt %, or
alternatively from about 0.001 wt % to about 0.5 wt %, or yet
alternatively from about 0.01 wt % to about 0.1 wt %. Reductant
molar ratios with respect to the oxidant (e.g. sodium hypochlorite)
may be selected from a range from between about 0.01:1 to about
100:1, or alternatively from about 0.05:1 to about 50:1, or yet
alternatively from about 0.1:1 to about 10:1.
V. Examples of Unsuitable Reductants
[0074] Some materials that have been found to not work effectively
as reductants in the present invention, either by reacting too
quickly or too slowly to be of practical utility, include
non-reducing sugars such as sucrose, hydrogen peroxide, sodium
sulfite, non-oxidizable buffers such as the acids and salts of
phosphates, borates, carbonates and the like; non-oxidizable salts
such as sodium chloride, sodium sulfate, and the like; and
saturated unbranched carboxylic acids without a double bond or an
oxidizable substituent.
VI. Buffer
[0075] Suitable buffers include those materials capable of
controlling ultimate solution pH and which themselves resist
reaction with the oxidant and remain in sufficient concentration to
control the pH throughout the entire duration of Zone 1 or the
benefit period. Suitable buffers further include those buffers that
are non-consumable with respect to action by the oxidant. In
addition, other suitable buffers are selected from the group of
those materials having an acid dissociation constant (Ka) at
20.degree. C. in the range between 1.times.10.sup.-2 and
1.times.10.sup.-12, between 1.times.10.sup.-3 and
1.times.10.sup.-11, between 1.times.10.sup.-3 and
1.times.10.sup.-8, or between 1.times.10.sup.-8 and
1.times.10.sup.-12.
[0076] Buffers that can be used in the present inventive systems
may be selected dependent on the desired pH of the final one step
composition to be targeted. In some embodiments of the invention it
may be desired to employ a combination of buffers of differing acid
dissociation values to achieve optimal mixed solution conditions.
In some embodiments of the invention, it is desirable to have the
buffer concentration on a molar basis be less than the initial
concentration of hypochlorite in order to adequately control the
ultimate solution pH during the quenching reaction at a minimal
cost. In additional embodiments of the invention, it is desirable
to have a buffer concentration that is at least equally
concentrated on a molar basis as the initial concentration of
hypochlorite in order to adequately control the ultimate solution
pH during the extent of the quenching reaction. In yet other
embodiments of the invention, it is desirable to have a buffer
concentration that is at least about twice as concentrated on a
molar basis as the initial concentration of hypochlorite in order
to adequately control the ultimate solution pH during the extent of
the quenching reaction. In yet other embodiments of the invention,
the buffer concentration may be greater than twice the initial
molar concentration of hypochlorite for maximum control of the
ultimate solution pH during the extent of the quenching
reaction.
[0077] The following are non-limiting examples of buffers that may
be used singly, or in combination to control the pH in embodiments
of the inventive compositions. Suitable buffers include salts
and/or corresponding conjugate acids and bases of the following
classes of materials, and their derivatives: carbonates,
bicarbonates, boric acid and borates, silicates, di- and mono-basic
phosphates or phosphoric acid, monocarboxylic or polycarboxylic
acids such as acetic acid, succinic acid, octanoic acid, the like,
and combinations thereof.
[0078] In addition, suitable buffers may include a combination of
one or more buffering molecules and contain an additional inorganic
acid (e.g., hydrochloric, phosphoric, sulfuric and/or nitric acid)
or an organic acid (e.g., acetic acid) to adjust the
buffer/quencher composition to the desired or appropriate solution
pH to provide the ultimate desired pH when mixed with the
hypohalous containing precursor composition to form the single step
use compositions. Suitable buffers may include a combination of one
or more buffering molecules and contain an additional inorganic
base (e.g., sodium hydroxide and/or sodium silicate) in order to
adjust the buffer/hypohalous precursor composition to the desired
or appropriate solution pH to provide the ultimate desired pH when
mixed with the buffered quencher precursor composition to form the
single step use composition.
[0079] Appropriate ranges for the buffer in the present invention
may be between about 0.01 wt % to about 15 wt %, or alternatively
from about 0.05 wt % to about 10 wt %, or yet alternatively from
about 0.1 wt % to about 1 wt %. The buffer molar ratio with respect
to the hypohalite material present (i.e., buffer/oxidant molar
ratios) may range from between about 0.01:1 to about 100:1, or
alternatively from about 0.05:1 to about 50:1, or yet alternatively
from about 0.1:1 to about 10:1.
[0080] One example embodiment of a buffer appropriate for a nitrite
quencher at pH 8.5 as explored in the nitrite example section
herein employs a 0.022 wt % sodium hypochlorite solution (oxidant
composition), to be combined with 0.045 wt % sodium nitrite, 0.09
wt % sodium phosphate dibasic, and 0.06 wt % sodium carbonate with
an additional 0.02 wt % hydrochloric acid on the quencher side
(quencher composition) at the time of formulation to achieve a pH
of about 8.26 in the quencher precursor composition. Upon mixing
with the hypochlorite oxidant precursor composition at the time of
use, the resulting pH of the ultimate inventive one step use
composition is about 8.5, and the ultimate solution maintains this
approximate pH throughout the reduction process during treatment of
a target substrate.
[0081] Combinations of buffers may also occur upon mixing. For
example, in one embodiment of the invention hypochlorite is
buffered with carbonate before mixing and the reductant side is
buffered with succinic acid before mixing. In another embodiment, a
buffering system may include a mixed carbonate and succinic acid
system.
[0082] Thus, additional embodiments are included in which
compatible buffer materials may be added to the oxidant precursor
composition and/or the reductant precursor compositions of the
invention for convenience or other means.
VII. Other Optional Ingredients
[0083] Optional ingredients include, but are not limited to,
surfactants, wetting agents, dispersing agents, hydrotropes,
solvents, polymers, rheology control agents, chelating agents,
abrasives, fragrances, colorants, anticorrosion agents and other
functional additives.
[0084] The combined solution may contain an effective amount of a
wetting agent to reduce the contact angle of the solution on the
surface to about 30.degree. or less. Alternatively, the contact
angle may be about 20.degree. or less, or about 10.degree. or less.
Ideally the contact angle will be as close as possible to 0.degree.
and the combined solution will readily flow into the cracks and
crevasses of the surface to allow effective hypochlorite exposure.
The wetting agent can be any substance commonly described in the
art that does not react rapidly with hypochlorite anion or
hypochlorous acid. These include surfactants, pairs of oppositely
charged surfactants, polymeric wetting agents, and polyelectrolyte
complexes of a charged polymer with an oppositely charged micelle
of a single surfactant or a mixture of surfactants, and mixtures
thereof.
[0085] Dispersing agents that enhance the removal of microorganisms
from skin into suspension are also effective at increasing
antimicrobial activity and sanitization. These may also be present
in the combined solution. Total amounts of wetting agents and
dispersing agents in the combined solution may typically be between
about 5 mg/L to about 200 g/L, alternatively from about 10 mg/L to
about 100 g/L, or from about 50 mg/L to about 50 g/L, or from about
100 mg/L to about 20 g/L. It is desirable to use the least amount
of wetting and dispersing agents to provide effective wetting to
minimize the amount of residue that may remain when the product is
used without rinsing.
[0086] Exemplary wetting or dispersing agents include various
surfactants (e.g., cationic surfactants, anionic surfactants,
nonionic surfactants, amphoteric and/or zwitterionic surfactants),
hydrotropes, polymers and copolymers. Cationic surfactants may also
act as a phase transfer agent for the hypochlorous acid
disinfecting agent. Mixtures of surfactants often produce better
results than a single surfactant. Particularly effective are
mixtures of cationic or pseudo-cationic surfactants with anionic
surfactants that associate to synergistically decrease interfacial
tensions and increase wetting and dispersion. Such mixtures are
also more efficient so the required concentration is reduced while
improving performance.
[0087] Particular exemplary cationic surfactants include
alkyltrimethylammonium, alkylpryidinium, and alkylethylmorpholinium
salts, in which the alkyl group contains 4 to 18 carbon atoms,
alternatively 12 to 16 carbon atoms. The alkyl chains may be linear
or branched or contain an aryl group. The counterion may be, but is
not limited to, chloride, sulfate, methylsulfate, ethylsulfate, or
toluene sulfonate. Other suitable cationic surfactants include
dialkyldimethyl ammonium salts, in which the alkyl groups each
contain 4 to 12 carbon atoms such as dioctyldimethyl ammonium
chloride. Other suitable cationic surfactants may have two
quaternary ammonium groups connected by a short alkyl chain such as
N-alkylpentamethyl propane diammonium chloride. In the above
cationic surfactants the methyl substituents can be completely or
partially replaced by other alkyl or aryl substituents such as
ethyl, propyl, butyl, benzyl, and ethylbenzyl groups, for example
octyldimethylbenzyl ammonium chloride and tetrabutylammonium
chloride.
[0088] Nitrogen containing surfactants may also act as phase
transfer catalysts as well as wetting and dispersing agents. They
may be amphoteric or zwitterionic. These include amine oxides,
sarcosinates, taurates and betaines. Examples include
C.sub.8-C.sub.18 alkyldimethyl amine oxides (e.g.,
octyldimethylamine oxide, lauryldimethylamine oxide, and
cetyldimethylamine oxide), C.sub.4-C.sub.16 dialkylmethylamine
oxides (e.g. didecylmethylamine oxide), C.sub.8-C.sub.18 alkyl
morpholine oxide (e.g. laurylmorpholine oxide), tetra-alkyl diamine
dioxides (e.g. tetramethyl hexanane diamine dioxide, lauryl
trimethyl propane diamine dioxide), C.sub.8-C.sub.18 alkyl betaines
(e.g. decylbetaine and cetylbetaine), C.sub.8-C.sub.18 acyl
sarcosinates (e.g. sodium lauroylsarcosinate), C.sub.8-C.sub.18
acyl C.sub.1-C.sub.6 alkyl taurates (e.g. sodium
cocoylmethyltaurate), C.sub.8-C.sub.18 alkyliminodipropionates
(e.g. sodium lauryliminodipropionate), and combinations
thereof.
[0089] Many other surfactants may also be suitable for use as
dispersing agents within the hypochlorite disinfecting compositions
of the present invention. Examples of anionic surfactants include,
but are not limited to, C.sub.6-C.sub.16 fatty acid soaps (e.g.
sodium laurate), C.sub.8-C.sub.18 linear or branched alkyl sulfates
(e.g. sodium laurylsulfate, and sodium tetradecylsulfate),
C.sub.6-C.sub.18 linear or branched alkyl sulfonates (e.g. sodium
octane sulfonate and sodium secondary alkane sulfonate), alpha
olefin sulfonates, C.sub.6-C.sub.16 acyl isethionates (e.g. sodium
cocoyl isethionate), C.sub.6-C.sub.18 alkyl, aryl, or alkylaryl
ether sulfates, C.sub.6-C.sub.18 alkyl, aryl, or alkylaryl ether
methylsulfonates, C.sub.6-C.sub.18 alkyl, aryl, or alkylaryl ether
carboxylates, sulfonated alkyldiphenyloxides (e.g. sodium
dodecyldiphenyloxide disulfonate), and combinations thereof.
[0090] Examples of nonionic surfactants include, but are not
limited to, mono or poly alkoxylated (e.g. ethoxylated or
propoxylated) C.sub.6-C.sub.12 linear or branched alkyl phenols,
C.sub.6-C.sub.22 linear or branched aliphatic primary or secondary
alcohols, and C.sub.2-C.sub.8 linear or branched aliphatic glycols.
Block or random copolymers of C.sub.2-C.sub.6 linear or branched
alkylene oxides are also suitable nonionic surfactants. Capped
nonionic surfactants in which the terminal hydroxyl group is
replaced by halide; C.sub.1-C.sub.8 linear, branched or cyclic
aliphatic ether; C.sub.1-C.sub.8 linear, branched or cyclic
aliphatic ester; phenyl, benzyl or C.sub.1-C.sub.4 alkyl aryl
ether; or phenyl, benzyl or C.sub.1-C.sub.4 alkyl aryl ester may
also be used in this invention. Other suitable nonionic surfactants
include mono or polyalkoxylated amides of the formula
R.sup.1CONR.sup.2R.sup.3 and amines of the formula
R.sup.1NR.sup.2R.sup.3 wherein R.sup.1 is a C.sub.5-C.sub.31 linear
or branched alkyl group and R.sup.2 and R.sup.3 are C.sub.1-C.sub.4
alkyl, C.sub.1-C.sub.4 hydroxyalkyl, or alkoxylated with 1-3 moles
of linear or branched alkylene oxides.
[0091] Suitable alkylpolysaccharides for use herein are disclosed
in U.S. Pat. No. 4,565,647 to Llenado, having a linear or branched
alkyl, alkylphenyl, hydroxyalkyl, or hydroxyalkylphenyl group
containing from 6 to 30 carbon atoms and a polysaccharide, e.g., a
polyglycoside, hydrophilic group containing from 1.3 to 10
saccharide units. Suitable saccharides include, but are not limited
to, glucosides, galactosides, lactosides, and fructosides.
Alkylpolyglycosides may have the formula:
R.sup.2O(CnH.sub.2nO).sub.t(glycosyl).sub.x wherein R.sup.2 is
selected from the group consisting of alkyl, alkylphenyl,
hydroxyalkyl, hydroxyalkylphenyl, and mixtures thereof in which the
alkyl groups contain from 10 to 18 carbon atoms; n is 2 or 3; t is
from 0 to 10, and x is from 1.3 to 10.
[0092] Fatty acid saccharide esters and alkoxylated fatty acid
saccharide esters are also suitable for use in the present
invention. Examples include, but are not limited to, sucrose
esters, such as sucrose cocoate, and sorbitan esters, such as
polyoxyethylene(20) sorbitan monooleate and polyoxyethylene(20)
sorbitan monolaurate.
[0093] A wide variety of phosphate ester surfactants are also
suitable. These include mono, di, and tri esters of phosphoric acid
with C.sub.4-C.sub.18 alkyl, aryl, alkylaryl, alkyl ether, aryl
ether and alkylaryl ether alcohols (e.g. disodium octyl phosphate).
Wetting and dispersing is also achieved using sulfonated short
chain alkyl benzenes and naphthalenes (e.g. sodium xylene sulfonate
and sodium methylnaphthalene sulfonate).
[0094] Wetting and dispersion may also be improved by including a
hydrotrope. Examples of hydrotropes include, but are not limited
to, water soluble salts of low molecular weight organic acids such
as the alkali metal (sodium and/or potassium) salts of aromatic
sulfonic acids, aliphatic sulfates, aliphatic sulfonates, and
aliphatic carboxylates. Specific exemplary materials include, but
are not limited to, toluene sulfonate, cumene sulfonate, xylene
sulfonate, naphthalene sulfonate, methyl naphthalene sulfonate,
octyl sulfate, octyl sulfonate, octanoic acid, decanoic acid, and
combinations thereof.
[0095] The compositions can be further improved using relatively
low molecular weight water soluble polymers. Such polymers aid
dispersion, but usually do not decrease interfacial tensions as
well as surfactants. These polymers may be anionic or cationic, or
contain a mixture of cationic and anionic groups. Common
polycarboxylate polymers are made from acrylic acid and maleic
acid. These may also be copolymers with various olefins,
methacrylate, styrene, methylvinylether, vinylpyrrolidone, etc.
Polyvinylpyrrolidone is an example of a nonionic dispersant.
Sulfonate groups can be included using sulfonated styrene or other
sulfonated alkenes. Polysulfonated polymeric dispersants can also
be made by sulfonating various alkyl or aryl polymers. Naphthalene
sulfonate formaldehyde copolymers are also useful dispersants.
Cationic groups can be included using alkenes with quaternary
ammonium groups such as vinyl alkyl trimethylammonium, vinyl
N-alkyl pyridinium, and vinyl N-alkylmorpholinium. An example of a
cationic polymer is DADMAC, poly diallyl dimethyl ammonium
chloride. Typically the water soluble polymer will have 10 to 1,000
monomer units, or 20 to 200 monomer units. Mixtures of polymers
with oppositely charged surfactants may provide a synergistic
decrease of interfacial tension, improved wetting, and improved
dispersion.
[0096] The combined solution may contain an optional fragrance or
perfume to impart a pleasant odor that masks the odor of
hypochlorous acid and its reaction products with soils and
proteins. Such fragrances may generally be mixtures of volatile and
semi-volatile organic compounds that are readily available from
commercial sources. Selected fragrances should comprise compounds
that are slow to react with hypochlorous acid and be listed as
inert materials by regulatory agencies such as the US FDA. Many
suitable such compounds will be known to those of skill in the art
in light of the present disclosure. The combined solution may have
from about 1 mg/L to about 10 g/L of fragrance. The fragrance
concentration may be from about 10 mg/L to about 5 g/L,
alternatively from about 0.1 g/L to about 3 g/L, and yet,
alternatively from about 0.1 g/L to about 2 g/L.
[0097] The combined solution may contain rheology control agents,
thickeners, gelling agents and viscosity adjusters to provide the
desired product feel and form. For example the combined solution
could be a thickened liquid, a gel, or a foam. Suitable thickening
agents include, for example, natural and synthetic gums or gum like
materials such as gum tragacanth, carboxy-methylcellulose,
polyvinyl pyrrolidone, and/or starch. Linear or branched
polycarboxylate polymers are also suitable, especially various high
molecular weight polycarboxylates with multiple chains that are
linked together as substituents on a multi-functional molecule to
create a star-like molecule. Inorganic thickeners including
alumina, various clays, organo-modified clays, aluminates and
silicates are also suitable thickening agents. Thickening can also
be achieved using combinations of oppositely charged or
pseudo-charged surfactants or combinations of surfactants and
polymers. Examples include combinations of anionic surfactants such
as fatty acids, alkyl sulfates, or alkyl sulfonates with cationic
polymers such as DADMAC, polyallyldimethylammonium chloride,
combinations of cationic or pseudo cationic surfactants such as
alkyl pyridinium salts, alkyltrimethyl ammonium salts
alkyldimethylamine oxides, alkyl betaines, or acylsarcosinates with
anionic polymers, anionic surfactants, arylsulfonates, or
substituted aryl sulfonates, and surfactants such as alkyl ether
sulfates that thicken by balancing the alkyl chain length with the
number of ether linkages. Various alkaline earth or alkali metal
salts of phosphates, halides, carbonates, nitrates, borates, and
sulfates can be used to adjust viscosity. The concentration of
thickening agents in the combined solution may be from about 0.01
g/L to about 300 g/L, alternatively from about 1 g/L to about 100
g/L, and yet alternatively from about 5 g/L to about 50 g/L.
[0098] The combined solution may also contain surfactants as
described above that create foam when the solution is dispensed.
Certain combinations of surfactants will synergistically increase
the amount and longevity of the foam. In addition other ingredients
such as water soluble polymers and viscosity modifiers can increase
the amount or longevity of the foam. The formulation can also
include a foam booster to increase the amount or longevity of foam.
Examples of foam boosters include, but are not limited to, fatty
acid amides, alkoxylated fatty acid amides, fatty acid amides of
alkanolamines, fatty acid amides of alkoxylated alkanolamines, and
fatty acid amides of alkanolamide esters. Particles with diameters
less than 1 micron can also be included to stabilize and enhance
foams. Examples of such particles include, but are not limited to,
precipitated soaps, precipitated or fumed silica, aluminosilicates,
clays, zeolites, metal silicates, metal carbonates, metal oxides,
metal hydroxides, and various nanoparticles of carbon or other
elements.
[0099] The combined solution may contain a number of other
adjuvants that provide functional benefits. These include, but are
not limited to solvents, abrasives and surfactants for soil removal
and cleaning; emulsifiers; rinse aids; drying agents; lubricants;
and irritation reducers. Some functional adjuvants include
inorganic salts, silicones, fats, fatty acids, fatty acid esters
and ethers, squalene, lanolin and its derivatives, lecithin and its
derivatives, polycarboxylic acid polymers and copolymers,
hydrogenated poly aliphatic compounds, alkanes, parabens, alkyl
parabens, gelatin, mica, talc, clay, titanium dioxide, pumice, UV
absorbers, and similar compounds.
VIII. Uses
[0100] In one aspect of the invention, the products have target
uses such as for the treatment of hard surfaces, soft surfaces, and
air. In one embodiment, the inventive compositions have target uses
that include treatment of human and animal surfaces.
[0101] Examples of hard surfaces to which the invention can be
applied include surfaces composed of refractory materials such as:
glazed and unglazed tile, porcelain, ceramics as well as stone
including marble, granite, and other stones surfaces; glass;
metals; plastics such as, but not limited to polycarbonate,
styrene, polyester, vinyl; Fiberglass, FORMICA, CORIAN and other
hard surfaces known in the industry. Other hard surfaces include
lavatory fixtures such as shower stalls, bathtubs and bathing
appliances (racks, shower doors, shower bars) toilets, bidets, wall
and flooring surfaces.
[0102] Further hard surfaces include painted surfaces and those
associated with kitchen environments and other environments
associated with food preparation, including cabinets and countertop
surfaces as well as walls and floor surfaces especially those which
include refractory materials, plastics, FORMICA, CORIAN, and stone.
Also included are joining materials commonly used in association
with such surfaces, including but not limited to grout, caulking,
rubber and vinyl sealant materials, gaskets, rubber and vinyl
forms, stucco, mastic, plaster, concrete, mortar, silica, cement,
polyurethane, and the like.
[0103] Examples of soft surfaces include clothing, fabrics,
textiles, carpets, rugs, upholstery, and other textile covered
furniture, curtains, draperies and the like made from natural and
man-made fibers.
[0104] Further examples of soft surfaces include paper and pulp,
and materials made from paper or cellulosic materials, including
but not limited to wallpaper and fiberboard.
[0105] Examples of suitable human and animal surfaces that may be
treated according to the present invention include skin, wounds,
hair, teeth, fur and the mucous membranes.
[0106] In one embodiment, inventive compositions can be supplied
directly to surfaces to effect treatment. In another embodiment,
the inventive compositions can be diluted into water to treat
submerged articles, such as for example, in laundry applications or
bucket dilutions to clean shoes, toys and other small objects.
[0107] In another embodiment, the inventive compositions can be
used as a disinfectant, sanitizer, and/or sterilizer to treat
microbially challenged surfaces, articles and/or objects.
[0108] In yet another embodiment, the inventive compositions can be
used to remove, denature or inactivate allergens or allergen
generating species. Dust mites, house dust, animal dander, animal
hair, and the like, represent a mix of substances that contain
allergens. Not all substances found in dust mite, house dust,
animal dander, animal hair, etc. are capable of inducing an immune
response, much less an allergic response. Some of these substances
are antigens and will induce a specific immune response. Some of
these antigens are also allergens and will induce a
hypersensitivity response in susceptible individuals. Common
allergens present indoors include, but are not limited to,
Dermarophagoides pteronyssinus and Dermatophagoides farinae (both
from dust mites), Felis domesticus (from cats), Canis familiaris
(from dogs), Blatella germanica (from German cockroach),
Penicillium, Aspergillus and Cladosporium (from fungi), as well as
allergens from outdoors that enter the indoor environment, e.g.,
pollen allergens.
[0109] In a further embodiment, the inventive compositions can be
used on food preparation surfaces and can contain only food-safe
ingredients. Compositions for use herein may contain only materials
that are food grade or GRAS ("generally regarded as safe"),
including, of course, direct food additives affirmed as GRAS, to
protect against possible misuse by the consumer. Failure to rinse
thoroughly after cleaning is less of a concern if all of the
ingredients are GRAS and/or food grade. In the United States, the
use and selection of cleaning ingredients for the purpose of
washing fruits and vegetables is described by the United States
Code of Federal Regulations, Title 21, Section 173. 315:
"Ingredients for use in washing or to assist in the peeling of
fruits and vegetables". These regulations restrict the ingredients
that can be used for direct contact with food to those described as
GRAS, and a few other selected ingredients. These sections also
provide certain limitations on the amount of material that can be
used in a given context.
[0110] In one embodiment, the present invention encompasses the
method of spraying an effective amount of the composition for
reducing malodor onto household surfaces. The household surfaces
can be selected from the group consisting of countertops, cabinets,
walls, floors, bathroom surfaces and kitchen surfaces. Other
suitable household surfaces include pet areas, pet litter, litter
boxes, pet bowls, and pets. The present invention encompasses the
method of spraying a mist of an effective amount of the composition
for reducing malodor onto fabric and/or fabric articles. The
present invention relates to the method of spraying a mist of an
effective amount of the composition into the air for reducing
malodor impression to a consumer. The present invention relates to
a method of spraying a mist of an effective amount of the
composition onto cat litter, pet bedding and pet houses for
reducing malodor impression or to consume malodor. The present
invention also relates to methods of spraying a mist of an
effective amount of the composition onto household pets for
reducing malodor impression. In yet another embodiment, the
inventive compositions may be used to treat mold, fungus, mildew,
mildew spores, algae and surfaces and materials contaminated
therewith, providing the benefit of bleaching, decolorization and
removal of the contaminants, and further providing reduced odor
from bleaching byproducts such as chloramines that would otherwise
remain after treatment with hypohalite bleach alone.
[0111] In another embodiment, the invention encompasses
compositions and methods for using them as wash additives for
treating clothing and textiles for the purpose of disinfection,
bleaching, whitening, and odor and stain removal. In other
embodiments, the inventive compositions may be used to remove ink,
wine, juice, food, clay and make-up stains from clothing and
textiles, providing enhanced stain removal with reduced dye and
fabric damage.
IX. Product Containers and Product Form
[0112] Any container adapted to separately hold and then deliver
the two precursor compositions of the invention may suitably be
employed. In the most basic embodiment the first precursor
composition contains the oxidant and the second precursor
composition contains a reductant and optionally a buffer.
Alternatively, the first precursor composition contains the oxidant
and an optional buffer and the second precursor composition
contains a reductant. In alternative embodiments, either or both
precursor compositions may contain additional surfactants, buffers,
pigments, dyes, fragrances or other additives desired for product
stability, appearance, performance or consumer acceptance.
[0113] In one embodiment, the hypochlorite composition is stored in
one side of a dual container, while the reductant composition is
stored on the other side of the container, and the two compositions
are mixed by the action of opening both sides and pouring the two
compositions into a third receptacle where they mix to form the
inventive compositions described herein. The packaging may be sized
so that a portion of each solution is dispensed for each use or
premeasured into a unit dose so the entire contents are used for a
single use. The components may be packaged in pouches, ampoules,
bottles, water soluble films, or various other options. The
components may be combined in various ratios depending on the
composition of each component.
[0114] In other embodiments, dual pouches, segmented containers,
sprayers which combine two liquid compositions during dispensing,
one or more rollers which apply, individually or mixed, the liquid
compositions to a surface, and/or two separate bottles or
containers holding the two precursor compositions of the invention,
may be employed. In a preferred embodiment, the two compartments
will be combined into a single package that controls the mixing of
the two components as the combined solution is dispensed.
[0115] In one aspect of the embodiment, the two chambers or
compartments can be side by side and adjacent to each other in a
substantially parallel arrangement. In an alternative aspect of the
embodiment, one chamber is completely or partially contained within
the other chamber. These two chambers may or may not be concentric.
The chambers may have the same or different volumes depending on
the concentrations of ingredients used in each component and the
required mixing ratios. In one aspect of the embodiment, each
chamber may have a connection to the delivery device. Examples of
delivery devices include, but are not limited to, trigger sprayers,
aerosol valves, flip-top dispensers, push-pull valves, pumps, and
spray transducers. The delivery devices may also incorporate a
propellant or air to promote the formation of foam. The device may
also include a means of controlling particle size and spray
pattern. The combined solution may be dispensed as an aerosol, a
spray, a liquid, a gel, or a foam. In one aspect, the composition
may be applied directly to a surface. In another aspect, it may be
applied to an applicator such as a sponge or a wipe.
[0116] Other embodiments may employ either oxidant or reductant as
a dry powder or solution on a nonwoven, woven, synthetic or natural
substrate, sponge or cloth and the other component, oxidant or
reductant, as a water or other liquid solution that is applied to
dissolve or mix with the first component. The solution could be
dispensed from a separate container, from a pouch embedded in the
substrate or a pouch separated from the substrate by a valve or an
irreversibly burstable wall. The liquid contained in the pouch or
capsule that is embedded in the substrate may be released when the
pouch or capsule is compressed or squeezed. The pouch or capsule
may have one exit or more than one exit points for more complete
distribution of the liquid onto the substrate. Alternatively, the
substrate may contain two or more pouches or capsules wherein at
least one pouch or capsule contains the oxidant solution and at
least one other pouch or capsule contains the reductant solution.
During use the pouches or capsules rupture whereby the two
solutions are released and mix within the substrate. In an
alternate embodiment each solution could be applied to a different
substrate (e.g., nonwoven) and these substrates brought into
contact as they are removed from or dispensed from the package.
[0117] Other embodiments include substrates that are separated by
barriers. For example, a substrate may have two sides separated by
an impervious layer, where Part A is contained in liquid form on
the first side and part B is contained in liquid form on the second
side. The surface to be treated is first wiped with side 1 to
release the active and then wiped with side 2 to neutralize the
active applied with side 1. Alternatively, a substrate may have two
zones that are separated by an impervious layer, where the first
zone contains part A in liquid form and the second zone contains
part B in liquid form. The first zone comprises the total surface
of the substrate. The second zone, separated from the first zone by
the impervious barrier, is smaller than the first zone and is
located on one side of the substrate. Prior to use, part A cannot
mix with part B because the impervious layer prevents the movement
of liquids between the two zones. However, when used both zones
come into contact with the surface being treated causing part A to
mix with part B on said surface.
[0118] In another embodiment, the substrate has two zones that are
separated by a capillary barrier, where the first zone contains
part A in liquid form and the second zone contains part B in liquid
form. Prior to use, part A cannot mix with part B because the
capillary barrier prevents the movement of liquids between the two
zones. However, when used both zones come into contact with the
surface being treated causing part A to mix with part B on said
surface. The shape of the two zones may vary. In one embodiment the
substrate may be divided in half with the capillary barrier down
the middle of the substrate. In another embodiment the first zone
may be centrally located on the substrate with the second zone
surrounding the first zone.
[0119] The delivery device may include a means of controlling the
mixing ratio of the components. Such devices may rely on the
orifice diameter to meter the flow or they may operate by having
different pump chamber volumes or rates of pumping. The chambers
may connect directly to the delivery device or they may have a dip
tube or siphon tube to connect each chamber to the delivery device.
In any case, the chambers may be connected to a mixing chamber that
is connected to the delivery device, may be connected separately to
the delivery device, or may by dispensed through separate devices.
For example, a dual chamber system may have a separate siphon tube
connecting each chamber to a mixing chamber of a trigger spray head
with a single nozzle, or connecting each chamber to separate,
adjacent nozzles. In another embodiment, a dual chamber system with
a siphon tube connects each chamber to a mixing chamber of a pump
dispenser that dispenses the combined solution through a single
tube that is easily directed to the point of use.
[0120] In one embodiment, the two precursor compositions are in the
form of aqueous compositions. In other embodiments, either of, or
both of the precursor compositions may be in solid form initially,
and then dissolved and/or diluted into water to form an aqueous
precursor composition, which can then be combined with the second
precursor composition at time of use to produce the inventive
composition. In other embodiments, either of, or both of the
precursor compositions may be in a thickened liquid or gel form
initially, and then dissolved and/or diluted into water to form an
aqueous precursor composition, which can then be combined with the
second precursor composition at time of use to produce the
inventive composition. In other embodiments, either of, or both of
the precursor compositions may be in a thickened liquid or gel form
initially and then mixed with the other composition in the form of
a gel or solid to produce the inventive composition.
X. Examples
[0121] Without being bound by theory, it is believed that further
functionality and both lower and higher concentration ranges of
oxidant, reductant and buffer materials can be employed in a range
of embodiments according to the present invention than those ranges
presented in the following examples. For the purposes of
illustration of effect, example embodiments of the invention were
in many cases selected in which intermediate hypochlorite
compositions were employed solely to enable spectroscopic
measurement of the active bleaching species, the levels selected
for means of illustration being suitable for direct absorption
measurements and thus being limited only with respect to
spectroscopic limitations of path length, molar absorbance and
saturation (optical quenching in concentrated systems) enabling the
level of oxidant to be easily monitored and measured to show
trends. These trends illustrating examples are not intended to
establish limits of utility on hypochlorite, buffer, or reductant
concentration, or ratios.
Example 1--Nitrite
[0122] In one embodiment of the invention, nitrite has been found
to be a suitable reductant operational across the ranges of
concentration illustrated below. Accordingly, in one embodiment of
the invention, nitrite has been explored as a reductant as shown in
FIG. 2, where the materials and composition parameter ranges
explored are as follows: sodium hypochlorite (0.02 wt % to 0.3 wt
%), sodium nitrite (0.03 wt % to 0.8 wt %), solution pHs from 6 to
11, wherein the molar ratio of reductant to oxidant (i.e., RIO)
varied from 3:1 to 1:2.
[0123] In these embodiments, the effect of increasing R/O ratio is
clearly evident with higher ratios eliminating hypochlorite more
quickly FIG. 2. Further, the importance of controlling pH is
evident in FIG. 3, where at higher pHs the reaction proceeds slower
in embodiments of the invention where the initial pH is raised.
[0124] A broad range of conditions may be used to control the rate
of hypochlorite consumption (this data may be plotted as
hypochlorite ppm if desired). The reaction conditions for FIGS. 4
and 5 are captured in Table 1, in which embodiments of the
invention employ use of a buffer of 0.08 wt % sodium acetate, 0.14
wt % sodium phosphate dibasic, 0.08 wt % sodium bicarbonate and
0.11 wt % sodium carbonate, adjusted prior to mixing with
sufficient hydrochloric acid so that the indicated pH results upon
mixing the oxidant and reductant.
TABLE-US-00001 TABLE 1 Formula Reductant (Traces in FIG. 4
Oxidant.sup.[1] Nitrite Buffered Ratio and FIG. 5) (wt %) (wt %) pH
R/O.sup.[2] 1 0.048 0.045 6.0 1.0 2 0.033 0.030 10.0 1.0 3 0.048
0.045 11.0 1.0 4 0.022 0.045 8.5 2.2 5 0.033 0.059 7.0 1.9 6 0.033
0.059 10.0 1.9 7 0.048 0.069 8.5 1.5 8 0.064 0.059 7.0 1.0 9 0.048
0.045 8.5 1.0 10 0.064 0.059 10.0 1.0 .sup.[1]Sodium hypochlorite
.sup.[2]Molar reductant/Oxidant Ratio (R/O)
Example 2--Fructose
[0125] Fructose and other reducing sugars have been found to be
suitable for use in the present invention as reductants. Results
show an improved utility in higher pH solutions. Without being
bound by theory this is believed to be due to reduced reactivity of
the sugar toward hypochlorite when the sugar exists in its closed
cyclic ester conformation. Elevated pH promotes hydrolysis of the
sugar ring to the open configuration which is more reactive with
hypochlorite.
[0126] Ranges of explored parameters and solution conditions tested
were as follows: sodium hypochlorite from 0.02 wt % to 1.0 wt %;
fructose from 0.05 wt % to 2.77 wt %, solution pHs from pH 7 to pH
13.4; covering a range of RIO ratios from about 0.7:1 to about
21.7:1.
[0127] In this series of embodiments, at elevated pH a broad range
of conditions may be used to control the rate of hypochlorite
consumption. A sub-sample of reaction conditions and results are
found in Table 2 and FIGS. 6-7.
TABLE-US-00002 TABLE 2 Formula Reductant (Traces in FIG. 6 Oxidant
Fructose Buffered Ratio and FIG. 7) (wt %) (wt %) pH R/O 1 0.033
0.796 12.7 10.0 2 0.048 1.171 9.7 10.0 3 0.048 1.171 13.4 10.0 4
0.064 0.796 13.1 5.1 5 0.074 1.171 12.7 6.5 6 0.033 1.546 13.1 19.4
7 0.048 1.802 12.7 15.4 8 0.064 1.546 13.3 10.0 9 0.048 1.171 13.3
10.0
[0128] Additional utility was found in additional embodiments of
the invention employing a lower solution pH as shown in Table 3
below and corresponding FIGS. 8 and 9. These embodiments used a
buffer of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant.
TABLE-US-00003 TABLE 3 Reductant Formula Oxidant Fructose Buffered
Ratio (Traces in FIG. 8) (wt %) (wt %) pH R/O 1 0.048 0.448 11.0
10.0 2 0.074 0.448 8.5 6.5 3 0.033 0.592 7.0 19.4 4 0.033 0.592
10.0 19.4 5 0.048 0.690 8.5 15.4
[0129] In yet another embodiment, fructose also can work well at
higher hypochlorite concentrations as shown in FIG. 9. The single
trace corresponds to a formula containing 1 wt % hypochlorite and
7.24 wt % fructose at an initial starting pH of pH 13.0, which is
seen to effectively self-extinguish with respect to the level of
remaining oxidant (hypochlorite) within about a 10 minute time
period following initial mixing.
Example 3--Chelants
[0130] Other embodiments of the invention may employ selected
chelants (sequestrants), such as disodium calcium EDTA (CaEDTA),
which can be used to limit hypochlorite lifetime in a controlled
fashion at lower pH where EDTA alone acts too rapidly in quench the
initial hypochlorite concentration. EDTA reacts almost instantly at
any pH below 12, but CaEDTA has utility in the near neutral region.
Without being bound by theory, it is believed that the calcium salt
likely works because the chelation of an aqueous calcium ion by
EDTA makes the molecule much less reactive toward hypochlorite. The
utility of using pH neutral compounds such as chelants as effective
reductants or quenching agents enables ultimate solutions near
neutral pH to be employed in the present invention. Again, without
being bound by theory, it is believed that chelants act as does the
class of other acidic reductants, because at lower pHs the mother
ligand (here the partially chelated EDTA species) begins to release
calcium ions and revert to a more hypochlorite-reactive acidic EDTA
form.
[0131] Conditions tested in several illustrative embodiments used a
typical calcium ion sequestrant. The ranges of material tested are:
sodium hypochlorite from 0.02 wt % to 0.07 wt %; CaEDTA from 0.26
wt % to 3.8 wt %; solution pHs from between pH 6.0 to about pH 9.0;
covering a range of reductant (CaEDTA) to oxidant (hypochlorite)
ratios of between 1:1 and about 22:1.
[0132] In these inventive embodiments, various conditions can be
used to tune the CaEDTA reaction with hypochlorite. Conditions for
the plot shown in FIG. 10 used a buffer of 0.08 wt % sodium
acetate, 0.14 wt % sodium phosphate dibasic, 0.08 wt % sodium
bicarbonate and 0.11 wt % sodium carbonate, adjusted prior to
mixing with sufficient hydrochloric acid so that the indicated pH
results upon mixing the oxidant and reductant, corresponding to
Formulas shown in Table 4.
TABLE-US-00004 TABLE 4 Reductant Formula Oxidant CaEDTA Buffered
Ratio (Traces for FIG. 10) (wt %) (wt %) pH R/O 1 0.033 1.654 7.0
10.0 2 0.064 1.654 7.0 5.1 3 0.033 3.212 7.0 19.4 4 0.048 3.743 8.5
15.4 5 0.064 3.212 7.0 10.0
Example 4--Sorbates
[0133] Potassium sorbate represents another chemical class of
reductants with tunable reactivity with hypochlorite useful in
formulating embodiments of the invention. The control of a soluble
sorbate reaction with hypochlorite is very effective at slightly
acidic to slightly basic solution pHs, within a wide range of
concentrations and ratios of the respective reactants.
[0134] Here, example embodiments of the invention were tested
covering a range of compositions as follows: sodium hypochlorite
between 0.02 wt % to 0.08 wt %, potassium sorbate between 0.06 wt %
to 1.5 wt %, at solution pHs of between pH 6 and pH 8.5, covering a
range of R/O ratios between about 0.5:1 to about 22:1, as
illustrated in Table 5 and Table 6.
TABLE-US-00005 TABLE 5 Reductant Formula Oxidant K Sorbate Buffered
Ratio (Traces for FIG. 11) (wt %) (wt %) pH R/O 1 0.033 0.066 7.0
1.0 2 0.048 0.098 6.0 1.0 3 0.064 0.066 7.0 0.5 4 0.074 0.098 8.5
0.7 5 0.033 0.129 7.0 1.9 6 0.064 0.129 7.0 1.0
[0135] FIG. 11 shows the plot of some experimental conditions with
buffers of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant, corresponding to Formulas in Table 5 illustrating
selected embodiments of the invention.
TABLE-US-00006 TABLE 6 Reductant Formula Oxidant K Sorbate Buffered
Ratio (Traces for FIG. 12) (wt %) (wt %) pH R/O 1 0.033 0.664 7.0
10.0 2 0.064 0.664 7.0 5.1 3 0.022 0.976 8.5 21.7 4 0.074 0.976 8.5
6.5 5 0.048 0.451 8.5 4.6 6 0.048 1.502 8.5 15.4
[0136] FIG. 12 shows the plot of some experimental conditions with
buffers of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant, corresponding to Formulas in Table 6.
Example 5--Guanidine Hydrochloride
[0137] In other embodiments of the invention, organic bases such as
guanidine hydrochloride may also be used to control hypochlorite
levels. Here, levels of components were explored within the limits
stated for illustrative purposes: sodium hypochlorite between 0.03
wt % to 0.07 wt %, guanidine hydrochloride between 0.03 wt % to
0.07 wt %, at solution pHs between pH 8.5 and pH 11, covering RIO
ratios of between 0.5:1 to about 1:1, as shown in Table 7 and FIG.
13.
TABLE-US-00007 TABLE 7 Reductant Formula Oxidant Guanidine HCl
Buffered Ratio (Traces for FIG. 13) (wt %) (wt %) pH R/O 1 0.033
0.042 10.0 1.0 2 0.048 0.062 11.0 1.0 3 0.064 0.042 10.0 0.5 4
0.048 0.029 8.5 0.5
Example 6--Organic Acids
[0138] Single equivalent organic acids and alpha-carboxylic acids
such as lactic acid can be successfully utilized in additional
embodiments of the invention in order to limit hypochlorite
lifetimes, as illustrated in Table 8. Solution conditions over a
select range were tested as follows: sodium hypochlorite between
about 0.03 wt % to 0.2 wt %, sodium lactate between 0.06 wt % and
2.42 wt %, at starting solution pHs of between pH 3.5 and pH 9,
covering a ratio of lactate/hypochlorite (R/O) of between 1:1 to
about 40:1.
TABLE-US-00008 TABLE 8 Reductant Formula Oxidant Sodium Lactate
Buffered Ratio (Traces in FIG. 14) (wt %) (wt %) pH R/O 1 0.033
0.495 7.0 10.0 2 0.048 0.728 6.0 10.0 3 0.033 0.962 7.0 19.4 4
0.064 0.962 7.0 10.0 5 0.048 0.728 8.5 10.0
[0139] FIG. 14 shows a plot of experimental conditions with a
buffer of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant.
[0140] Lactic acid will also work at higher hypochlorite
concentrations. The formulas tested and shown in FIG. 15 explore
use of 2.42 wt % lactic acid with RIO ratios of about 10:1 and
about 40:1 with an acetic acid buffer. These embodiments of the
invention contain 0.55 wt % of DowFax C10L, a short chain
hydrotrope obtained from the Dow Chemical Company.
Example 7--Citric Acid
[0141] Citric acid may be used to control the exposure of
hypochlorite by time of use mixing in yet further embodiments of
the invention as illustrated in Table 9. Solution conditions over a
select range where tested as follows: sodium hypochlorite between
about 0.03 wt % to 0.2 wt %, Trisodium citrate between 0.06 wt %
and 2.42 wt %, at starting solution pHs of between pH 4.0 and pH 9,
covering a ratio of citrate/hypochlorite (R/O) of between 1:1 to
about 40:1.
TABLE-US-00009 TABLE 9 Reductant Formula Oxidant Trisodium Citrate
Buffered Ratio (Traces in FIG. 16) (wt %) (wt %) pH R/O 1 0.033
0.495 7.0 10.0 2 0.048 0.728 6.0 10.0 3 0.064 0.495 7.0 5.1 4 0.033
0.962 7.0 19.4 5 0.064 0.962 7.0 10.0
[0142] FIG. 16 shows a plot of experimental conditions with a
buffer of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant.
[0143] FIGS. 17 and 18 present embodiments of the invention wherein
the inventive principle is illustrated that both the initial pH of
the citrate solution and the final mixture pH are important in
controlling exposure time to the hypohalite bleach. Additionally,
these demonstrate the need for a buffer system not only to
determine the initial mixed solution pH but to prevent pH drift as
a result of the reaction between the reductant and hypochlorite.
The pH of the 3.46 wt % sodium citrate solution was adjusted to the
indicated value with hydrochloric acid. The solution was then mixed
with an equal volume of 0.4 wt % sodium hypochlorite. It can be
seen that by reducing the pH of the initial mixed solution, the
rate of hypochlorite consumption may be increased. Further it is
illustrated that the pH must not be allowed to rise to ensure
complete consumption of all of the hypochlorite. Unbuffered systems
with alkaline trending experience a rise in pH over time that
correlates to a less favorable slowing in reactivity. In these
embodiments of the invention, countering an uncontrolled change or
rise in pH may be particularly important to driving the reaction to
completion with low ratios of citrate/hypochlorite, which may not
be obtainable absent the use of an effective pH controlling
buffering system as employed in the described systems.
[0144] Embodiments of the invention using citrate quenched
bleaching systems were explored over a range of compositional
parameters as follows: sodium hypochlorite from 0.01 wt % to about
3 wt %; sodium citrate from about 0.18 wt % to 5.16 wt %; at
solution pHs of about pH 4 to pH 10, covering a ratio of
reductant/oxidant of from about 1:1 to about 20:1.
[0145] Traces in FIGS. 17 and 18 show the tunability of these
embodiments and the importance of the additional buffer system to
prevent excessively large changes in solution pH with respect to
the initial starting pH throughout the time period corresponding to
the extinction of the hypochlorite active. The initial pH of the
buffer side is indicated in the legend. In this particular
embodiment of the invention, FIG. 18 illustrates the need for the
inventive approach to keep the pH below pH 8, where only small
changes in net hydronium ion (H.sub.3O.sup.+) and hydroxide ion
(OH) can otherwise effect large (>pH 3 to 5 unit) swings in
solution pH.
Example 8--Tetrathionate
[0146] In another embodiment of the invention, tetrathionate
provides good control over hypochlorite exposure in the neutral to
alkaline solution pH range. Tetrathionate allows good control over
the pH of the mixed solution by avoiding the instant reactions and
pH jumps observed with other sulfur containing reducing agents like
thiosulfate or sulfite.
[0147] FIGS. 19 and 20 show the impact of mixing ratio on
hypochlorite exposure over a range of illustrative embodiments. The
initial bleach solution was buffered at pH 10.2 with 1.27 wt %
sodium carbonate and the tetrathionate was buffered at pH 6.7 with
a 0.32 wt % succinate, 0.48 wt % phosphate buffer prior to mixing.
In these embodiments, a 1:1 vol:vol mixing ratio produced the
hypochlorite exposure curves shown in FIGS. 19-20.
[0148] Compositional ranges explored experimentally were as
follows: sodium hypochlorite from 0.01 wt % to about 0.74 wt %;
sodium tetrathionate from about 0.41 wt % to about 1.22 wt %, with
solution pHs of pH 8 to pH 11, covering a range of RIO ratios of
between 0.1:1 to about 5.3:1.
[0149] The effect of initial pH of the mixed solution is
demonstrated in FIG. 19. In these embodiments of the invention, the
sodium tetrathionate was buffered at pH 7.87 or pH 9.51 with 0.26
wt % sodium carbonate. The initial pH of the solutions when mixed
at a ratio of 1:1 vol:vol was 9.5 and 10.1, respectively. It is to
be noted that the initial pH of the mixture may be used to control
the length of hypochlorite exposure in the present inventive
systems, providing a means of adjusting the benefit period of
hypochlorite activity as desired for its intended application.
Example 9--Thiosulfate
[0150] In yet another embodiment of the invention, thiosulfate may
be utilized to provide control over hypochlorite exposure. Without
being bound by theory, it is believed that thiosulfate behaves
similarly to tetrathionate with the exception of a rapid initial pH
increase that occurs directly upon mixing concurrent with the
instantaneous loss of a molar equivalent of hypochlorite. The
remaining hypochlorite reacts slowly in a conditionally dependent
fashion until a rapid decrease in pH is observed. This rapid
decline in pH correlates with the consumption of all of the
remaining hypochlorite. In these illustrative embodiments of the
invention, by addition of a buffer system to the thiosulfate the pH
may be controlled solely by the mixing of the two materials and
precludes the necessity of a subsequent pH adjustment step.
[0151] Compositional ranges and conditions that were explored
experimentally in these embodiments of the invention are as
follows: sodium hypochlorite from about 0.01 wt % to about 0.74 wt
%; sodium thiosulfate from about 0.1 wt % to about 11.16 wt %;
solution pH of about pH 8 to about pH 11, covering a range of
ratios of reductant/oxidant of about 1:1 to about 4:1.
[0152] In Table 10 and FIG. 21 experimental conditions include a
buffer of 0.08 wt % sodium acetate, 0.14 wt % sodium phosphate
dibasic, 0.08 wt % sodium bicarbonate and 0.11 wt % sodium
carbonate, adjusted prior to mixing with sufficient hydrochloric
acid so that the indicated pH results upon mixing the oxidant and
reductant.
TABLE-US-00010 TABLE 10 Reductant Sodium Formula Oxidant
thiosulfate Buffered Ratio (Traces in FIG. 21) (wt %) (wt %) pH R/O
1 0.033 0.066 10.0 1.0 2 0.048 0.073 11.0 1.0 3 0.064 0.050 7.0 0.5
4 0.064 0.050 10.0 0.5 5 0.074 0.073 8.5 0.7 6 0.048 0.034 8.5
0.5
[0153] The composition of the buffer can be used to control the
hypochlorite exposure without an additional pH adjusting step. In
FIG. 22, the advantages of the present inventive buffering system
are shown in several embodiments of the invention with respect to
controlling the transient hypochlorite lifetime for a solution of
hypochlorite and thiosulfate with an R/O ratio of about 0.55:1. The
0.60 wt % hypochlorite solution used a carbonate buffer and the
1.09 wt % sodium thiosulfate solution used a combination of 2.59 wt
% sodium succinate, 0.28 wt % sodium phosphate dibasic and a 0.24
wt % sodium phosphate monobasic buffer. The thiosulfate solution
has a pH of 6.7. The pH of the bleach solution is determined by the
carbonate buffer. Hypochlorite solutions with 0.12 wt % bicarbonate
with 0.06 wt % carbonate have a pH of 9.7 (solid line in FIG. 22).
Hypochlorite solutions with 0.08 wt % bicarbonate and 0.11 wt %
carbonate have a pH of 10.1 (dashed line in FIG. 22). The
composition of buffer present in the solutions prior to mixing
controls the exposure time of hypochlorite.
Example 10--Mixture of Reducing Agents
[0154] Another embodiment of the invention may employ a combination
of reducing agents to control the hypochlorite exposure time at a
desired pH. An example of such as system employs both Nitrite and
Fructose as reductants. Without being bound by theory it is
believed that such a combination would be advantageous to maintain
a constant and rapid rate of hypochlorite consumption.
[0155] Levels of components were explored within the limits stated
for illustrative purposes: sodium hypochlorite between 0.4 wt % to
0.8 wt %, Fructose at 5.8%, Nitrite between 0.07 wt % to 1.5 wt %,
at solution pH of pH 11.5, covering R/O ratios of between 3:1 to
about 6:1 for fructose, and 1:1 to about 4:1 for Nitrite as shown
in Table 11 and FIG. 23.
TABLE-US-00011 TABLE 11 Reductant Fructose - Oxidant Nitrite (wt %)
Buffered Ratio R/O Formula (wt %) Fructose Nitrite pH Fructose
Nitrite 1 0.800 5.808 0.000 11.5 3.0 0.0 2 0.800 5.808 0.741 11.5
3.0 1.0 3 0.800 5.808 1.483 11.5 3.0 2.0 4 0.400 5.808 0.000 11.5
6.0 0.0 5 0.400 5.808 0.741 11.5 6.0 2.0 6 0.400 5.808 1.483 11.5
6.0 4.0
[0156] FIG. 23 shows hypochlorite lifetimes resulting from the
conditions detailed in Table 11. The buffer system for all
solutions in table 11 was 1.0% sodium carbonate with 0.25% sodium
hydroxide.
Product Examples
[0157] The above examples explored a variety of embodiments of the
present invention that can be exploited to achieve a desired
beneficial effect, showing details of tuning the various parameters
of initial controlled solution pH and reductant/oxidant ratio. In
addition, some practical product examples are presented here as
non-limiting embodiments of inventive compositions useful for
commercial cleaning products and solutions by way of
illustration.
Example 11--Mold and Mildew Remover
[0158] Tables 12 and 13 show non-limiting embodiments of mold and
mildew removers using compositions of the present invention.
TABLE-US-00012 TABLE 12 Product Composition (wt %).sup.[1] Product
No. 1 2 3 4 5 Reductant/Oxidant 0.33 0.67 0.25 0.25 0.25 Ratio
(R/O) Sodium Hypochlorite 2.23 2.23 2.23 2.23 2.23 Sodium
Bicarbonate 0.00 0.00 0.55 2.10 1.68 Sodium Carbonate 1.59 -- 0.90
3.71 4.24 Sodium Tetrathionate 2.70 5.40 2.03 2.03 2.03 Succinic
Acid 0.30 -- -- -- 0.24 Sodium Succinate 0.41 0.81 -- -- 0.49
DowFax C10L 0.55 0.55 0.55 0.55 0.55 pH mixture.sup.[2] 10.6 10.5
10.5 10.5 10.5 .sup.[1]Weight % based on 100% active, unless
otherwise noted .sup.[2]pH of mixture of R and O precursor
compositions
TABLE-US-00013 TABLE 13 Product Composition (wt %) Product No. 6 7
8 9 10 Reductant/Oxidant Ratio (R/O) 2.5 2.5 5 1.2 10 Sodium
Hypochlorite 0.37 0.37 0.19 0.37 0.37 Sodium Bicarbonate -- -- --
-- -- Sodium Carbonate 1.06 -- -- 1.06 1.06 Trisodium Citrate 3.23
3.23 3.23 1.55 12.90 Succinic Acid 2.13 1.18 0.59 3.54 1.54 Sodium
Succinate -- 1.62 2.43 0.81 2.92 DowFax C10L 0.55 0.55 0.55 0.55
0.50 pH mixture 6 6 6.5 5.25 7.04
Example 12--Acid Bathroom Cleaner with Hypochlorite
[0159] Table 14 shows non-limiting embodiments of an acidic
bathroom cleaner using compositions according to the present
invention.
TABLE-US-00014 TABLE 14 Product Composition (wt %) Product No. 11
12 13 14 15 Reductant/Oxidant Ratio (R/O) 2.5 5 25 10 100 Sodium
Hypochlorite 0.37 0.19 0.04 0.37 0.04 Sodium Carbonate 0.53 0.26
0.53 1.06 1.59 Lactic acid 1.13 1.13 1.13 4.50 4.50 Succinic Acid
2.36 0.59 0.30 -- -- Sodium Succinate -- 0.81 0.81 2.11 3.08 DowFax
C10L 0.55 0.55 0.55 0.55 0.55 pH mixture 4 5 5.1 4.5 5.1
Example 13--Stain or Spot Remover for Carpets or Laundry
[0160] Tables 15 and 16 show non-limiting embodiments of a spot
and/or stain remover composition suitable for use on carpets or as
a laundry stain pretreatment according to the present
invention.
TABLE-US-00015 TABLE 15 Product Composition (wt %) Product No. 16
17 18 19 Reductant/Oxidant Ratio (R/O) 3.2 12 24 120 Sodium
Hypochlorite 0.19 0.19 0.19 0.04 Sodium Hydroxide 1.00 1.00 1.00
0.20 Sodium Carbonate 0.53 1.06 5.30 10.60 Fructose 1.44 5.40 10.81
10.81 DowFax C10L 5.0 5.0 5.0 5.0 pH mixture 13.4 13.4 13.4
12.7
TABLE-US-00016 TABLE 16 Product Composition (wt %) Product No. 20
21 22 23 Reductant/Oxidant Ratio (R/O) 1 0.2 2 0.5 Sodium
Hypochlorite 0.04 0.19 0.37 0.74 Sodium Bicarbonate 0.08 -- 0.08 --
Sodium Carbonate 0.11 0.53 10.60 3.18 Guanidine HCL 0.05 0.05 0.96
0.48 Sodium Phosphate monobasic 20.00 30.00 10.00 10.00 Sodium
Phosphate dibasic -- 0.14 0.14 0.14 DowFax C10L 5.0 5.0 5.0 5.0 pH
mixture 7.5 8.1 11.9 11.7
Example 14--Hand Sanitizer
[0161] Table 17 shows non-limiting embodiments of a hand sanitizer
composition according to the present invention suitable for use on
hands, skin, nails and epidermis for convenient disinfection and/or
presurgical preparation.
TABLE-US-00017 TABLE 17 Product Composition (wt %) Product No. 24
25 26 27 28 Reductant/Oxidant Ratio (R/O) 100 5 1 2 0.25 Sodium
Hypochlorite 0.01 0.07 0.15 0.30 0.30 Sodium Bicarbonate -- 0.04
0.04 0.04 0.04 Sodium Carbonate 0.11 0.11 0.21 0.42 0.42 Sodium
Ascorbate 1.98 0.99 0.40 1.58 0.20 Sodium Phosphate monobasic 0.24
0.24 0.24 0.30 0.60 Sodium Phosphate dibasic 0.14 -- 0.14 0.14 0.14
Propylene glycol 1.0 1.0 1.0 1.0 1.0 pH mixture 7.6 7.7 9.1 10
8.3
Example 15--Dilutable Hard Surface Cleaner
[0162] Table 18 shows non-limiting embodiments of dilutable hard
surface cleaning compositions according to the present invention
suitable for use on treating surfaces such as countertops, floors,
walls, stove surfaces, tile, grout and bathroom surfaces and the
like.
TABLE-US-00018 TABLE 18 Product Composition (wt %) Product No. 29
30 Reductant/Oxidant Ratio (R/O) 2 2 Sodium Hypochlorite 4.47 0.45
Sodium Bicarbonate -- -- Sodium Carbonate 6.36 0.64 Trisodium
Citrate 30.97 3.10 Succinic Acid 2.36 0.24 Sodium Succinate 3.24
0.32 Sodium Lauryl Sulfate 10.0 1.0 pH mixture .sup.[1] 10 10
Dilution ratio .sup.[2] 1:100 1:10 .sup.[1] pH of mixture of R and
O precursor compositions .sup.[2] Subsequent dilution of mixed
compositions into water at indicated volume:volume ratio
Example 16--Through the Wash Dilutable Laundry Additive
[0163] Table 19 shows non-limiting embodiments of a "through the
wash" dilutable laundry additive for bleaching, whitening, stain
removal and potential laundry disinfection, according to the
present invention.
TABLE-US-00019 TABLE 19 Product Composition (wt %) Product No. 31
32 Reductant/Oxidant Ratio (R/O) 1.4 1.1 Sodium Hypochlorite 5.40
5.40 Sodium Carbonate 3.18 0.21 Sodium Nitrite 6.90 5.52 Sodium
Lauryl Sulfate 1.00 1.00 pH mixture .sup.[1] 11.9 11.3 Dilution
ratio .sup.[2] 1:300 1:300 pH after dilution .sup.[3] 10.58 9.9
.sup.[1] pH of mixture of R and O precursor compositions .sup.[2]
Subsequent dilution of mixed compositions into water at indicated
volume:volume ratio .sup.[3] pH of diluted composition after mixing
of R and O precursor compositions and dilution with water at
prescribed dilution ratio
Example 17--Surface Disinfectant
[0164] Table 20 shows non-limiting embodiments of direct use
surface disinfectant compositions according to the present
invention.
TABLE-US-00020 TABLE 20 Product Composition (wt %) Product No. 33
34 35 36 37 38 Reductant/Oxidant Ratio 1.27 1.27 0.67 0.67 3.33 24
(R/O) Sodium Hypochlorite 0.22 0.22 0.22 0.22 0.11 0.04 Sodium
Carbonate 0.08 0.08 0.08 0.08 0.08 0.08 Trisodium Citrate 0.98 0.98
0.52 0.52 1.29 3.10 Succinic Acid 0.35 0.35 0.47 0.47 0.24 0.18
Sodium Succinate -- -- 0.08 0.08 0.49 0.57 Potassium Bromide --
0.08 -- 0.04 -- -- Sodium Lauryl Sulfate 10.0 10.0 1.0 1.0 1.0 1.0
pH mixture 5.7 5.7 5.3 5.3 6.2 6.3
[0165] Without departing from the spirit and scope of this
invention, one of ordinary skill can make various changes and
modifications to the invention to adapt it to various usages and
conditions. As such, these changes and modifications are properly,
equitably, and intended to be, within the full range of equivalence
of the following claims.
* * * * *