U.S. patent application number 16/193392 was filed with the patent office on 2019-03-21 for calcium hypochlorite compositions with transient color indicators and method of using the same.
The applicant listed for this patent is Arch Chemicals, Inc.. Invention is credited to Janet Akande, Janet Jones, Amber Khanzada, Michael Unhoch.
Application Number | 20190082699 16/193392 |
Document ID | / |
Family ID | 56406776 |
Filed Date | 2019-03-21 |
United States Patent
Application |
20190082699 |
Kind Code |
A1 |
Jones; Janet ; et
al. |
March 21, 2019 |
CALCIUM HYPOCHLORITE COMPOSITIONS WITH TRANSIENT COLOR INDICATORS
AND METHOD OF USING THE SAME
Abstract
A water treatment composition for treating a body of water is
provided that provides visual feedback to the end-user of the
effectiveness of the composition. The composition contains a
majority of calcium hypochlorite particles; and an effective amount
of colored particles containing an oxidizable pigment oxidizable
dye and a water soluble material. The colored particles release the
oxidizable dye to the body of the water to provide a transient
color to the recreational water during dissolution of the
composition in the body of water, the transient color providing a
visual cue to the end-user signaling of the biocidal activity of
the composition. Also provided is a method of applying the water
treatment composition to recreational water.
Inventors: |
Jones; Janet; (Columbia,
MO) ; Khanzada; Amber; (Alpharetta, GA) ;
Akande; Janet; (Fayetteville, GA) ; Unhoch;
Michael; (Tyrone, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Arch Chemicals, Inc. |
Allendale |
NJ |
US |
|
|
Family ID: |
56406776 |
Appl. No.: |
16/193392 |
Filed: |
November 16, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15003248 |
Jan 21, 2016 |
|
|
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16193392 |
|
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|
62106010 |
Jan 21, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01N 59/00 20130101;
A01N 59/00 20130101; C02F 1/688 20130101; A01N 59/06 20130101; C02F
2103/42 20130101; C02F 2303/04 20130101; C02F 1/76 20130101; A01N
59/06 20130101 |
International
Class: |
A01N 59/06 20060101
A01N059/06; C02F 1/76 20060101 C02F001/76; C02F 1/68 20060101
C02F001/68; A01N 59/00 20060101 A01N059/00 |
Claims
1. A water treatment composition for treating a body of
recreational water, the composition comprising: a majority of
calcium hypochlorite particles; and an effective amount of colored
particles comprising, an oxidizable pigment, an oxidizable dye, a
composition of an oxidizable pigment and a water soluble material,
a composition of oxidizable dye and a water soluble material, or a
mixture thereof; wherein the colored particles release the
oxidizable pigment and/or the oxidizable dye to the body of the
recreational water to provide a transient color emanating from the
composition to the recreational water during dissolution of the
composition in the body of recreational water, the transient color
providing a visual cue signaling biocidal activity of the
composition to an end-user; and wherein the composition is
substantially free of surfactants to avoid foaming of the
water.
2. The water treatment composition according to claim 1, wherein
the water treatment composition is granular, having particles of
calcium hypochlorite and the colored particles.
3. The water treatment composition according to claim 1, wherein
the composition is a compacted tablet.
4. The water treatment composition according to claim 1, wherein
the colored particles comprise the oxidizable dye and a water
soluble material.
5. The water treatment composition according to claim 4, wherein
the oxidizable dye is placed on the surface of the water soluble
material.
6. The composition according to claim 5, wherein the water soluble
material comprises an inorganic salt, a gum or a resin.
7. The composition according to claim 6 wherein the water soluble
material comprises an inorganic salt.
8. The composition according to claim 7, wherein the inorganic salt
comprises sodium chloride.
9. The composition according to claim 1, wherein the water soluble
material comprises a first water soluble material and a second
water soluble material, and the oxidizable pigment and/or
oxidizable dye is mixed with the second water soluble material to
form a mixture, and the mixture is coated onto the first water
soluble material.
10. The composition according to claim 9, wherein the first and
second water soluble material each comprise a salt.
11. The composition according to claim 9, wherein the first and
second water soluble material are each sodium chloride.
12. The composition according to claim 1, wherein the colored
particles comprise between about 0.1% by weight to about 10% by
weight of the total weight of the composition.
13. The composition according to claim 12, wherein the colored
particles comprise between about 1% by weight to about 6% by weight
of the total weight of the composition.
14. The composition according to claim 12, wherein the oxidizable
dye comprises between 0.01 and 2.0% by weight of the
composition.
15. The composition according to claim 1, wherein the calcium
hypochlorite particles comprises between 60 and 99.9% by weight of
the composition.
16. The composition according to claim 15, further comprising up to
30% by weight, based on the total weight of the composition, of
additional active components selected from the group consisting of
water clarifiers, scale inhibitors, stabilizers, water softeners,
corrosion inhibitors, algaecides, fungicides, binders, or a mixture
thereof.
17. The composition according to claim 15, further comprising: i)
0.1-20% by weight of magnesium sulfate heptahydrate; ii) 0.01-10%
by weight of aluminum sulfate; and iii) 0.01-10% by weight of
sodium hexametaphosphate.
18. The composition according claim 17, wherein the composition
comprises between 0.1% and 10% by weight of the colored
particles.
19. The composition according to claim 18, comprising: i) 75-85% by
weight of the calcium hypochlorite; ii) 2.0%-6.0% by weight of the
colored particles; iii) 10-20% by weight of magnesium sulfate
heptahydrate; iv) 0.1-2.0% by weight of aluminum sulfate; and v)
0.1-2.0% by weight of sodium hexametaphosphate
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/003,248, filed Jan. 21, 2016, which claims priority
under 35 U.S.C. .sctn. 119(e) from Provisional Application No.
62/106,010, filed Jan. 21, 2015, the contents of each of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to calcium hypochlorite
compositions useful for treating recreational water systems and,
more particularly, to calcium hypochlorite compositions that
exhibit a transient color indicator (i.e., a flash of color) in
recreational water systems.
BACKGROUND OF THE INVENTION
[0003] Calcium hypochlorite is known for use as a treatment for
recreational water systems, such as pools, spas, hot tubs, and the
like and other similar water systems. Calcium hypochlorite serves
as a source of available chlorine in the form of an pH dependent
equilibrium of hypochlorous acid (HOCl) and hypochlorite anions
(ClO.sup.-), which acts as a biocide to keep the water systems free
of water-borne pathogens and other organisms such as algae. The
water-borne pathogens and other organisms, if not controlled, can
result in unwanted film formation, unwanted clouding of the water
and/or can make the water system unusable for its intended purpose.
Examples of calcium hypochlorite compositions are shown in various
patents such as U.S. Pat. Nos. 3,793,216; 4,201,756; 4,876,003;
4,928,813; 4,145,306; 4,192,763; 4,692,335; 4,865,760; 4,961,872;
5,009,806; 5,164,109; and 5,753,602.
[0004] Calcium hypochlorite is available in various forms,
including solid granules and solid tablets. Each of these forms has
their advantages and disadvantages. Granular forms offer lower
shipping weight, less storage space, minimal spill hazards and
safer handling. Granular calcium hypochlorite is particularly
convenient for shock treatment since the granules can be broadcast
over the surface of the water, added to the pool skimmer with the
circulation system running, or pre-diluted in water and added to
the pool. Calcium hypochlorite in tablet form offers all the
advantages of the granular form but is capable of more effectively
delivering a continuous level of chlorination.
[0005] However, calcium hypochlorite is colorless when dissolved in
water. As a result, the end-user is not provided with any type of
visual feedback confirming the delivery of the calcium hypochlorite
to the water.
[0006] While transient color indicators have not been used with
recreational water systems, transient color indicators have been
used with bleach formulations for cleaning and disinfectant
applications. One of the earliest attempts to provide a "flash of
color" to cleaning formulations is found in British Publication No.
GB 1,049,051. In GB 1,049,051, the applicants incorporated an
"indicator dye" into a powder cleaning preparation to provide the
end-user with an indicator of the activity of the preparation
during use. The cleaning preparation also included
chlorine-containing oxidizing agent or a dry oxygen bleaching agent
in addition to surfactants. The "indicator dye" is a water-soluble
dye that provides an initial color to the water which subsequently
disappears after a period of time due to bleaching caused by the
bleaching agent. Prior to use, the "indicator dye" is protected
from initial bleaching with a water-soluble gum or resin coating.
The gum or resin coating may be applied by spray drying the dye
particles.
[0007] An attempt to provide transient color indicators to
disinfectants is found in U.S. Pat. No. 4,248,827. U.S. Pat. No.
4,248,827 describes a method for sanitizing toilets with a two-part
liquid disinfectant system. One chamber of the described dispensing
system contains a hypochlorite sanitizing solution. The other
chamber contains a dye solution bleachable via oxidation from a
colored state to a colorless state. The release of both solutions
during the flush cycle is intended to provide transitory visual
signal that can last from 5 seconds up to 10 minutes. The liquid
formulations can also contain a variety of surfactants, in addition
to other agents, to increase sanitizing efficacy.
[0008] Another attempt to provide transient color indicators to
cleaning formulations is found in International Publication No.
WO99/07817. WO99/07817 describes decolorizing compositions as an
indicator system for detergent formulations. The decolorizing
composition is intended to provide a visual indicator to wash
liquor/solvent that decolorizes over a predetermined amount of
time. The decolorizing composition is a mixture of dye particles
and bleach particles where the bleach particles are provided with
at least one binder coating. The binder coating or coatings prevent
the dye from being bleached and decolorized thereby controlling the
amount of time the visual indicator is presented to the
end-user.
[0009] In addition, there are halogen-releasing compositions which
contain colored salt particles that are added calcium hypochlorite
for the purposes of identifying the concentration of the chlorine
in the composition. For example, see U.S. Pat. No. 5,049,385.
However, the amount of the dye in the salt is such that there is no
color change in the water in which the composition is added.
[0010] In view of the above, there is a need to provide
recreational water systems with a transient color indicator when
treated with calcium hypochlorite allowing the end-user to
ascertain whether the calcium hypochlorite is dispersed in the
recreational water.
SUMMARY OF THE INVENTION
[0011] The present invention provides water treatment composition
containing calcium hypochlorite that includes a transient color
indicator as well as a method of treating a body of water using
this water treatment composition. The body of water is a body of
water that may need sanitization/disinfecting and includes, for
example, recreational bodies of water. In one embodiment, the water
treatment composition includes a majority of calcium hypochlorite
particles, and an effective amount of particles of an oxidizable
pigment, an oxidizable dye or a mixture thereof. The oxidizable
pigment and/or oxidizable dye particles provide a transient color
to the recreational water during dissolution of the water treatment
composition in the water. The transient color provides a visual cue
to an end-user of the biocidal activity provided to the body of
recreational water by the water treatment composition. The
oxidizable pigment and/or oxidizable dye particles may be provided
with a water soluble coating or may be adhered or adsorbed onto the
surface of a water soluble material. The water-soluble material may
serve to inhibit premature bleaching of the oxidizable dye by the
calcium hypochlorite particles contained in the water treatment
composition prior to administering the water treatment composition
to the recreational water. The water treatment composition is also
substantially free of surfactants to avoid foaming of the
recreational water. In a different embodiment, a body of
recreational water is treated by administering to the recreational
water a biocidal amount of the water treatment composition
described herein.
[0012] The water treatment composition may be in the form of
granules or in the form of a tablet. As a granular composition, the
calcium hypochlorite and colored particles are in a granular form.
Alternatively, the granular formula may be tableted as a compacted
tablet.
[0013] In one embodiment, the water treatment composition contains
colored particles which are an oxidizable dye and a water soluble
material. The water soluble material may be an inorganic salt, a
gum or a resin. In a particular embodiment, the water soluble
material is an inorganic salt, in particular sodium chloride.
[0014] In another embodiment, the water soluble material may
include a first water soluble material and a second water soluble
material. The oxidizable pigment and/or oxidizable dye is mixed
with the second water soluble material to form a mixture, and the
mixture is then coated onto the first water soluble material. The
first and second water soluble materials may each be an inorganic
salt, in particular sodium chloride.
[0015] In a further embodiment, the colored particles make up from
about 0.1% by weight to about 10% by weight of the total weight of
the water treatment composition. In a particular embodiment, the
colored particles make up about 1% to about 6% by weight of the
water treatment composition. In these embodiments, the oxidizable
dye may be between 0.01 and 2.0% by weight of the composition.
[0016] In yet another embodiment, the calcium hypochlorite makes up
between about 60% and 99.9% by weight of the total water treatment
composition. In a particular embodiment, the calcium hypochlorite
makes up between about 75% and 85% by weight of the total weight of
the water treatment composition.
[0017] In an additional embodiment, the water treatment composition
may contain up to 30% by weight, based on the total weight of the
composition, of additional active components selected from the
group consisting of water clarifiers, scale inhibitors,
stabilizers, water softeners, corrosion inhibitors, algaecides,
fungicides, binders, or a mixture thereof.
[0018] In another embodiment, the present invention provides a
method of treating a body of water with a biocidal composition
which provides a visual cue to an end-user treating the
recreational body of water signifying the effectiveness of the
biocidal composition. The method includes administering to the body
of water a biocidal amount of the composition of the invention, and
allowing the composition to dissolve or disperse in the water to
release the pigment or dye into the body of water, providing a
transient color to the body of water during dissolution of the
composition in the body of water. As previously described, the
biocidal composition includes (i) a majority of calcium
hypochlorite particles, and (ii) an effective amount of colored
particles. The composition is also substantially free of
surfactants to avoid foaming of the water. The colored particles
may be an oxidizable pigment, an oxidizable dye, a composition of
an oxidizable pigment and a water soluble material, a composition
of oxidizable dye and a water soluble material, or a mixture
thereof. The colored particles release the oxidizable pigment
and/or the oxidizable dye to the body of the recreational water to
provide a transient color to the recreational water during
dissolution of the composition in the body of recreational water.
Once again, the transient color provides a visual cue signaling
biocidal activity of the composition to the end-user.
[0019] The present invention provides several advantages due to the
incorporation of the bleachable pigment or dye as a transient color
indicator. For example, the end-user will be provided with a visual
signal of the biocidal activity provided by the water treatment
composition. Depending on the dosage form and method of
administration, the length of transient color signal is variable
but will last until the water treatment composition is effectively
dispersed into the water being treated. These and other advantages
will become more apparent from the detailed description discussed
below.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In accordance with the present invention, a water treatment
composition, containing a calcium hypochlorite composition, is
provided for treating bodies of water. The body of water may be
recreational water such as pools, hot tubs, spas or any other
artificial body of water used for recreational purposes.
Alternatively, the body of water may be other bodies of water that
are non-recreational in nature, but need sanitization, such as
ornamental ponds, water fountains and toilet bowls. Generally, the
purpose of the composition is for treating recreational bodies of
water. The water treatment composition contains a calcium
hypochlorite composition that includes a majority of calcium
hypochlorite particles, and an effective amount of particles
containing an oxidizable pigment, an oxidizable dye or a mixture of
the oxidizable pigment and oxidizable dye. The oxidizable pigment
and/or oxidizable dye provides a transient color to the
recreational water during dissolution of the water treatment
composition. The purpose of the transient color is to provide
visual feedback or visual cue to the end-user of the biocidal
activity the composition delivers to the recreational water and
that the composition has been dispersed into the recreational water
effectively.
[0021] The oxidizable pigment and/or oxidizable dye particles may
each include a readily-dissolvable, water-soluble material around
the pigment or dye, which may inhibit premature bleaching of the
oxidixable pigment and/or oxidizable dye in the composition. The
readily-dissolvable, water-soluble material may be a coating on the
pigment or dye, or a carrier for the pigment or dye. As a coating,
the coating inhibits bleaching of the pigment or dye prior to the
composition being administered to the body of recreational water.
Alternatively, as a carrier, the pigment or dye is attached to or
adsorbed onto a surface of a water-soluble material. In another
embodiment, the pigment or dye may be placed on the surface of or
absorbed into a readily-dissolvable, water soluble carrier and the
carrier with the pigment or dye is then coated with additional
readily-dissolvable, water-soluble material, which may be the same
or different from the readily-dissolvable, water-soluble material
used as the carrier. In addition, the composition is also
substantially free of surfactants to avoid possible foaming of the
recreational water.
[0022] The composition of the invention may contain a majority of
calcium hypochlorite particles. A "majority" means at least 50
percent by weight ("wt. %") of the composition is calcium
hypochlorite based on the total weight of the composition. The
composition may be a granular form or a tablet form. In either
form, the calcium hypochlorite can range from 50.0 to 99.9 wt. %
based on the total weight of the composition and, more
particularly, can range from 60.0% to 99.0% by weight of the
composition. Other embodiments, the calcium hypochlorite can be in
the range of about 65.0% to about 90% by weight of the composition.
In a particular embodiment, the calcium hypochlorite is present in
an amount of 75% to 85% by weight of the composition.
[0023] The calcium hypochlorite to be used in the composition of
the invention can be either anhydrous or hydrated. Anhydrous
calcium hypochlorite, which is commercially available, should
contain at least about 60% by weight of Ca(OCl).sub.2. Hydrated
calcium hypochlorite should contain at least about 50% by weight of
Ca(OCl).sub.2 and have a water content ranging from about 4 to
about 15 wt. %. Hydrated calcium hypochlorite can be prepared by
the methods described, in U.S. Pat. Nos. 3,544,267 and 3,669,984,
both of which incorporated by reference in their entireties.
[0024] The composition also includes an effective amount of colored
particles to provide the body of recreational water with a
transient color, signaling to the end-user the biocidal activity
that the composition is providing to the water and that the
composition has been effectively dispersed into the water being
treated. The colored particles may be a pigment or a dye. As used
herein, a "pigment" is a water insoluble material, which a "dye" is
a water soluble material. If a pigment is used, the pigment may be
used alone or with a water soluble material, provided that the
pigment is stable in the calcium hypochlorite. Dyes are generally
in liquid form, such as an aqueous solution. In the case of dyes,
generally the dye needs a water soluble material or a water
dispersible material, as a substrate for the dye, which is
described in more detail below. In this context, an effective
amount refers to an amount of the colored particles that provides a
visible but transient color emanating from the composition while
the water treatment composition dissolves in the water. The color
is transient due to the pigment or dye being bleached as the dye is
oxidized by the dissolved calcium hypochlorite. As a result of the
transient nature of the color signal is provided but, preferably,
does not alter the overall hue or color of the recreational
water.
[0025] In an embodiment, the colored particles will contain between
6% to 40% by weight of the dye and 60% to 94% by weight of the
water soluble material, based on the total weight of the colored
particles. In a particular embodiment, the colored particles will
contain between 10% to 25% by weight of the dye and 75% to 90% by
weight of the water soluble material based on the total weight of
the colored particles. In addition, the colored particle will be
present in the composition containing the calcium hypochlorite and
the colored particles in an amount between 0.1% and 10% by weight,
based on the total weight of the composition. In one embodiment,
the composition will contain between 1% and 6% by weight of the
composition of the colored particles.
[0026] In another embodiment, the colored particles containing the
oxidizable pigment or oxidizable dye and water soluble material, if
present, may also be distinctly visible from the calcium
hypochlorite in the composition. In a different embodiment, the
coated, colored particles containing the oxidizable dye and water
soluble material are not distinctly visible from the calcium
hypochlorite in the composition.
[0027] The duration of the transient color is variable and is
effected by the selection of the oxidizable pigment or oxidizable
dye and the size of the pigment or dye particles. The duration of
the transient color should be at least one second and can extend up
to 2 or 3 minutes or longer. In another embodiment, the duration of
the transient color range from 2 seconds to 1 minute. Typically,
the color will last between 3 seconds and 30 seconds. In accordance
with the invention, any oxidizable pigment may be used, provided
that the pigment is stable with the calcium hypochlorite, meaning
that the pigment should not react with the calcium hypochlorite
during storage. Several are commercially available. A
representative pigment which is stable in the calcium hypochlorite
is Ultramarine Blue. In the case of oxidizable dyes, the dye is
desirably non-reactive with the calcium hypochlorite, or is made to
be non-reactive with the calcium hypochlorite with the use of a
water soluble or water dispersible material. Representative
examples of oxidizable dyes that are commercially available
include, but not limited to, Acid Green 5, Acid Green 9, Acid Green
74, Acid Violet 49, Acid Blue 9 and Acid Blue 7. Of these
oxidizable dyes, Acid Blue 9 is of particular interest. As will be
apparent to one skilled in the art, the average size of the pigment
or dye particles will be directly proportional to the duration of
the transient color signal. Stated otherwise, an increase in the
average size of the pigment or dye particles will increase the
duration of the transient color signal provided to the recreational
water.
[0028] In the present invention, the water soluble material may be
an inorganic salt, water soluble resin or gum. Ideally, the water
soluble material is readily water soluble, meaning that it will
dissolve within 60 seconds of contacting the water. Ideally, the
water soluble material should dissolve in less than about 15
seconds, generally within about 1 to about 10 seconds. If a water
soluble resin or gum is used, it should be compatible with the
calcium hypochlorite, meaning that it should not react with the
calcium hypochlorite during storage. Exemplary inorganic salts
include sodium chloride, potassium chloride, calcium chloride, and
the like. Of these salts, sodium chloride is of particular
interest.
[0029] In one embodiment, each of the colored dye particles
contains an oxidizable dye and with a readily-dissolvable,
water-soluble material. The water-soluble material may be a coating
place on the dye or are placed on the surface of a water-soluble
material. The coating may protect the dye particle from premature
bleaching by the calcium hypochlorite prior to the composition
being administered to the recreational water. Reference to
readily-dissolvable means that the water soluble material, whether
a coating or a substrate, dissolves quickly once the particles are
exposed to the water. This allows the readily oxidizable dye
thereby allowing the transient color (i.e., a flash of color) to
emanate from the composition. In one embodiment, the coating should
dissolve within a few seconds of the composition contacting the
water. In another embodiment, the coating should dissolve within
0-10 seconds of contacting the water in which the composition is
placed.
[0030] As will be appreciated by those skilled in the art, the
actual time frame in which the coatings dissolve is affected by
variables such as the coating material and the coating thickness.
In one embodiment, the water-soluble coating is a gum or resin,
provided that the gum or resin will not adversely react with the
calcium hypochlorite.
[0031] The water-soluble coatings should have a thickness ranging
from about 1 to about 100 microns. Alternatively, the dye may be
coated onto the inorganic material, where the inorganic material is
in the form of a particle. The coating can be applied by any known
method. One suitable method is spray drying the coating onto the
dye particles or dye solutions may be spray dried onto inorganic
salt particles. Spray drying is known in the art and can be
completed by forming a solution of one material, and the solution
is sprayed onto the particle.
[0032] Generally, the colored particles will have a majority of
particles with a particle size which in the range of about 150
microns and 850 microns (10 mesh to 20 mesh). The actual size of
the particles is not critical to the invention, however, smaller
particles may be too small and dissolve too quickly. Typically, a
majority (greater than 50%) will have a particle size greater than
400 microns.
[0033] Additional active ingredients for pool, spa and water
treatment may be mixed into the composition. For example,
additional active ingredients, such as water clarifiers, scale
inhibitors, stabilizers, water softeners, corrosion inhibitors,
algaecides, fungicides, binders, or mixtures thereof, may be mixed
into the composition. Such ingredients, as well as others, are
known to those of skill in the art. Particularly, the additional
active ingredient in the present invention includes active
ingredient components having known functional properties such as
copper sulfate, zinc sulfate, aluminum sulfate, sodium citrate,
sodium borate, sodium tripolyphosphate (STPP), sodium
hexametaphosphate (SHMP). One particular ingredient is a
stabilizer. A suitable stabilizer is magnesium sulfate which is
hydrated. A particular magnesium sulfate is magnesium sulfate
heptahydrate. In a particular embodiment, the composition will
contain 0.1-20% by weight of magnesium sulfate heptahydrate;
0.01-10% by weight of aluminum sulfate; and 0.01 - 10% by weight of
sodium hexametaphosphate. More particularly, a composition may
contain 10-20% by weight of magnesium sulfate heptahydrate;
0.1-2.0% by weight of aluminum sulfate; and) 0.1-2.0% by weight of
sodium hexametaphosphate, in addition to the calcium hypochlorite
and the colored particles.
[0034] The compositions of the present invention are also
substantially free of surfactants or any other component that could
render the recreational water unsuitable for recreational use. For
example, the omission of surfactants helps to avoid possible
foaming of the water which would render the water unsuitable for
recreational use. Reference to "substantially free" means the
composition at most contains trace amounts.
[0035] As noted above, the compositions of the invention can be in
either granular form or in tableted form. In granular form, the
composition is a mixture of the calcium hypochlorite particles and
the colored particles. In tableted form, the composition may be
tableted with different structures. For example, the composition
can be tableted so that the colored particles are dispersed
homogenously throughout the composition where the calcium
hypochlorite is the major or carrier phase. In another embodiment,
the composition is tableted with separate distinct layers for the
calcium hypochlorite and for the colored particles.
[0036] In the granular form, the calcium hypochlorite and the
colored particles are manufactured separately and blended together
using known techniques. In addition, the additional ingredients
could also be added using these blending techniques.
[0037] In accordance with the invention, the composition is
administered to the body of recreational water in a biocidal
effective amount to inhibit microbial growth that can cause
unwanted film formation or unwanted clouding of the water.
Typically, a biocidal amount is an amount of the composition that
provides the body of recreational water with a residual free
chlorine level of at least 1 ppm. The free chlorine levels can also
be significantly higher on an intermittent basis to provide a shock
treatment to the recreational water system. Generally, the residual
free chlorine levels for recreational water systems should be less
than about 20 ppm and are generally in the range of about 1 to 10
ppm.
[0038] As will be apparent to one skilled in the art, the actual
method of administering the composition of the invention can be
varied. For example, the granules and tablets can be directly added
to the recreational water. In the case of granules, an initial
flash of color will emanate from the granules that dissipate after
a predetermined amount of time once the hypochlorite anions in the
water oxidize and bleach the dye to a colorless state. In the case
of compacted tablets, an initial flash of color will and continue
to emanate from the tablet until the tablet is exhausted or fully
dissolved or utilized. As a result of the continued presence of the
initial flash of color from the tablet, an end-user noticing the
absence of the transient color can then re-add the tableted
composition to the water to replenish free chlorine levels, as
needed. In another embodiment, the granules or tablets can be added
via a dispenser that controls the dissolution rate of the
composition thereby providing a sustained initial flash of color to
the water. The absence of the transient color will provide a visual
signal to the end-user that the composition in the dispenser has
been extinguished and needs to be replenished, if necessary.
[0039] The following non-limiting examples have been provided to
further illustrate the unique advantages of the present
invention.
EXAMPLES
Preparation of the Colored Particles.
[0040] A solution containing Hiacid Azure Blue 50 percent liquid
(Acid blue 9) was provided, which contained about 50% by volume of
the Acid blue 9 dye. Sodium Chloride salt particles were provided
as well. The solution of the dye was sprayed onto the sodium
chloride particles and allowed to dry. Analysis of the particles
showed that the salt particles contained about 15% by weight of the
dye on the surface of the salt particles.
Preparation of the Calcium Hypochlorite/Colored Particle Blend
[0041] The salt particles were then blended with a granular calcium
hypochlorite available from HTH containing about 16% magnesium
sulfate heptahydrate, forming a composition containing about 5% by
weight of the colored particle and 15% by weight of the magnesium
sulfate heptahydrate and 80% calcium hypochlorite in a granular
form.
Application of the Composition to Recreational Water
[0042] A cup (8 oz) of the granular composition was broadcast
spread onto the surface of a swimming pool. As the granular
composition contacted the water, the water turned from a nearly
colorless clear to a bright blue. The bright blue color appeared on
the surface of the pool and below the surface of the pool as the
granular composition sunk to the bottom of the pool and the dye was
released from the composition. The bright blue color lasted
approximately 20 seconds and quickly diminished as the calcium
hypochlorite oxidized the dye, to a colorless color.
* * * * *