U.S. patent application number 12/114327 was filed with the patent office on 2008-11-06 for water soluble magnesium compounds as cleaning agents and methods of using them.
This patent application is currently assigned to ECOLAB INC.. Invention is credited to Michael E. Besse, Keith E. Olson, Lisa M. Sanders, Kim R. Smith, Brenda L. Tjelta.
Application Number | 20080274928 12/114327 |
Document ID | / |
Family ID | 39939966 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080274928 |
Kind Code |
A1 |
Smith; Kim R. ; et
al. |
November 6, 2008 |
WATER SOLUBLE MAGNESIUM COMPOUNDS AS CLEANING AGENTS AND METHODS OF
USING THEM
Abstract
The present invention relates to compositions and methods
employing a water soluble magnesium compound. In certain
embodiments, the composition includes water and water soluble
magnesium compound, but lacks other materials commonly used in
cleaning compositions. The methods and compositions can provide
magnesium ion at predefined ratios to calcium ion in water, such as
magnesium ion in a molar amount equal to or in excess over a molar
amount of calcium ion. A water soluble magnesium salt including an
anion of a water soluble calcium salt is more effective than a
magnesium salt with an anion of a water insoluble calcium salt.
These compositions can be used for reducing lime scale or
precipitate formation from hard water, removing soap scum, or the
like.
Inventors: |
Smith; Kim R.; (Woodbury,
MN) ; Besse; Michael E.; (Golden Valley, MN) ;
Tjelta; Brenda L.; (St. Paul, MN) ; Sanders; Lisa
M.; (Eagan, MN) ; Olson; Keith E.; (Apple
Valley, MN) |
Correspondence
Address: |
ECOLAB INC.
MAIL STOP ESC-F7, 655 LONE OAK DRIVE
EAGAN
MN
55121
US
|
Assignee: |
ECOLAB INC.
St. Paul
MN
|
Family ID: |
39939966 |
Appl. No.: |
12/114327 |
Filed: |
May 2, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60927575 |
May 4, 2007 |
|
|
|
Current U.S.
Class: |
510/161 |
Current CPC
Class: |
C23F 11/08 20130101;
C11D 7/10 20130101; C02F 5/02 20130101; C23F 11/18 20130101; C23G
1/22 20130101; C11D 3/10 20130101; C11D 3/044 20130101; C23F 11/124
20130101; C23G 1/20 20130101; C02F 2303/14 20130101; C11D 3/046
20130101; C11D 11/0023 20130101; C02F 5/06 20130101; C02F 2303/22
20130101 |
Class at
Publication: |
510/161 |
International
Class: |
C11D 3/20 20060101
C11D003/20 |
Claims
1. A method of cleaning ware comprising: contacting the ware in an
automatic warewashing machine with an aqueous composition
consisting essentially of water and a water soluble magnesium salt;
wherein the aqueous composition during contacting comprises
magnesium ion in a molar amount equal to or in excess over a molar
amount of calcium ion; recovering the ware with an acceptable
amount of hard water spotting.
2. The method of claim 1, wherein the aqueous composition is
substantially free of an additional functional component selected
from the group consisting essentially of a source of alkalinity,
organic surfactant or cleaning agent, pH modifier, builder,
processing aid, active oxygen compound, glass or metal corrosion
inhibitor, activator, rinse aid functional material, bleaching
agent, defoaming agent, anti-redeposition agent, stabilizing agent,
enzyme, chelating agent, detersive polymer, softener, source of
acidity, solubility modifier, bleaching agent, effervescent agent,
and activator for the source of alkalinity, and any combination
thereof.
3. The method of claim 1, wherein the aqueous composition is
substantially free of chelating agent, surfactant, and sheeting
agent.
4. The method of claim 1, wherein the water soluble magnesium salt
comprises an anion that forms a soluble calcium salt.
5. The method of claim 1, wherein an acceptable amount of hard
water spotting comprises up to about one quarter of the surface
spotted.
6. The method of claim 4, wherein the water soluble magnesium salt
is magnesium chloride.
7. The method of claim 1, wherein: the water soluble magnesium salt
comprises an anion that forms a sparingly soluble calcium salt; and
the aqueous composition during contacting comprises magnesium ion
in a molar amount equal to or greater than two-times the molar
amount of calcium ion.
8. The method of claim 1, wherein the water soluble magnesium salt
is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
9. The method of claim 1, wherein the aqueous composition consists
of water, water soluble magnesium salt, and a further ingredient
selected from the group consisting of antimicrobial agent,
viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, and mixture thereof.
10. The method of claim 1, wherein the aqueous composition consists
of water and water soluble magnesium salt.
11. The method of claim 1, wherein contacting comprises rinsing or
presoaking ware.
12. The method of claim 1, wherein contacting comprises rinsing or
presoaking a medical instrument.
13. The method of claim 1, further comprising reducing
precipitation of calcium salt or reducing scaling or reducing solid
deposits.
14. The method of claim 1, wherein the aqueous composition during
contacting comprises magnesium ion at a molar ratio of magnesium to
calcium greater than or equal to one.
15. A method of cleaning a hard surface comprising: contacting the
hard surface with an aqueous composition consisting essentially of
water and a water soluble magnesium salt; wherein the aqueous
composition during contacting comprises magnesium ion in a molar
amount equal to or in excess over a molar amount of calcium ion;
achieving hard surface with an acceptable amount of hard water
spotting.
16. The method of claim 15, wherein the aqueous composition is
substantially free of any additional functional component selected
from the group consisting essentially of source of alkalinity,
organic surfactant or cleaning agent, pH modifier, builder,
processing aid, active oxygen compound, glass or metal corrosion
inhibitor, activator, rinse aid functional material, bleaching
agent, defoaming agent, anti-redeposition agent, stabilizing agent,
enzyme, chelating agent, detersive polymer, softener, source of
acidity, solubility modifier, bleaching agent, effervescent agent,
activator for the source of alkalinity, and combinations
thereof.
17. The method of claim 15, wherein the aqueous composition is
substantially free of chelating agent, surfactant, and sheeting
agent.
18. The method of claim 15, wherein the water soluble magnesium
salt comprises an anion that forms a soluble calcium salt.
19. The method of claim 18, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodide, magnesium lactate, magnesium nitrate, magnesium
perchlorate, magnesium phosphinate, magnesium sulfate, magnesium
sulfite, magnesium molybdate, magnesium salicylate, magnesium
thiosulfate, a hydrate thereof, and a mixture thereof.
20. The method of claim 18, wherein the water soluble magnesium
salt is magnesium chloride.
21. The method of claim 15, wherein: the water soluble magnesium
salt comprises an anion that forms an sparingly soluble calcium
salt; and the aqueous composition during contacting comprises
magnesium ion in a molar amount equal to or greater than two-times
the molar amount of calcium ion.
22. The method of claim 15, wherein an acceptable amount of hard
water spotting comprises up to about one quarter of the surface
containing spots.
23. The method of claim 15, wherein the aqueous composition
consists of water, water soluble magnesium salt, and a further
ingredient selected from the group consisting of antimicrobial
agent, viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, and mixture thereof.
24. The method of claim 15, wherein the aqueous composition
consists of water and water soluble magnesium salt.
25. The method of claim 15, further comprising reducing
precipitation of calcium salt, scaling, or solid deposits.
26. The method of claim 15, wherein the aqueous composition during
contacting comprises magnesium ion at a molar ratio of magnesium to
calcium greater than or equal to one.
27. The method of claim 15, wherein contacting comprises rinsing
the hard surface.
28. The method of claim 27, wherein the hard surface is selected
from the group consisting essentially of ceramic tile, a window,
and a combination thereof.
29. The method of claim 15, wherein the hard surface includes soap
scum and contacting removes soap scum from the surface.
30. A method of cleaning ware comprising: contacting the ware in an
automatic warewashing machine with an aqueous composition
consisting of water, a water soluble magnesium salt and a further
ingredient selected from the group consisting of water,
antimicrobial agent, viscosity modifier, aesthetic enhancing agent,
lubricant, dispersant, preservative, thickener, or mixture thereof,
wherein the aqueous composition during contacting comprises
magnesium ion in a molar amount equal to or in excess over a molar
amount of calcium ion; recovering the ware with an acceptable
amount of hard water spotting.
31. The method of claim 30, wherein the water soluble magnesium
salt comprises an anion that forms a soluble calcium salt.
32. The method of claim 31, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
33. The method of claim 31, wherein the water soluble magnesium
salt is magnesium chloride.
34. The method of claim 30, wherein: the water soluble magnesium
salt comprises an anion that forms an insoluble calcium salt; and
the aqueous composition during contacting comprises magnesium ion
in a molar amount equal to or greater than two-times the molar
amount of calcium ion.
35. The method of claim 30, wherein an acceptable amount of hard
water spotting comprises up to about one quarter of the surface
spotted.
36. The method of claim 30, wherein the aqueous composition
consists of water and water soluble magnesium salt.
37. A method of cleaning a hard surface comprising: contacting the
hard surface with an aqueous composition consisting of water, a
water soluble magnesium salt and a further ingredient selected from
the group consisting of water, antimicrobial agent, viscosity
modifier, aesthetic enhancing agent, lubricant, dispersant,
preservative, thickener, or mixture thereof, wherein the aqueous
composition during contacting comprises magnesium ion in a molar
amount equal to or in excess over a molar amount of calcium ion;
achieving hard surface with an acceptable amount of hard water
spotting.
38. The method of claim 37, wherein the water soluble magnesium
salt comprises an anion that forms a soluble calcium salt.
39. The method of claim 38, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
40. The method of claim 38, wherein the water soluble magnesium
salt is magnesium chloride.
41. The method of claim 37, wherein: the water soluble magnesium
salt comprises an anion that forms an insoluble calcium salt; and
the aqueous composition during contacting comprises magnesium ion
in a molar amount equal to or greater than two-times the molar
amount of calcium ion.
42. The method of claim 37, wherein the aqueous composition
consists of water and water soluble magnesium salt.
43. The method of claim 37, wherein an acceptable amount of hard
water spotting comprises up to about one quarter of the surface
spotted.
44. A method of removing soap scum from an object, the method
comprising: contacting the soap scum on the object with an aqueous
composition consisting essentially of water and a water soluble
magnesium salt; removing soap scum from the object.
45. The method of claim 44, wherein removing the soap scum results
in a shiny surface.
46. The method of claim 44, wherein the soap scum comprises calcium
salt of fatty acid, triglyceride, and protein.
47. A method of removing soap scum from an object, the method
comprising: contacting the soap scum on the object with an aqueous
composition consisting of water, a water soluble magnesium salt and
a further ingredient selected from the group consisting of water,
antimicrobial agent, viscosity modifier, aesthetic enhancing agent,
lubricant, dispersant, preservative, thickener, or mixture thereof,
removing soap scum from the object.
48. An aqueous hard surface cleaner consisting essentially of water
and a water soluble magnesium salt; wherein upon dilution for use
as a hard surface cleaner the composition comprises the magnesium
ion in a molar amount equal to or in excess over a molar amount of
calcium ion; and the composition is substantially free of chelating
agent, surfactant, and sheeting agent.
49. The composition of claim 48, wherein the composition is
substantially free of any component selected from the group
consisting essentially of source of alkalinity, organic surfactant
or cleaning agent, pH modifier, builder, processing aid, active
oxygen compound, glass or metal corrosion inhibitor, activator,
rinse aid functional material, bleaching agent, defoaming agent,
anti-redeposition agent, stabilizing agent, enzyme, chelating
agent, detersive polymer, softener, source of acidity, solubility
modifier, bleaching agent, effervescent agent, and activator for
the source of alkalinity, and any combination thereof.
50. The composition of claim 48, wherein the water soluble
magnesium salt comprises an anion that forms a soluble calcium
salt.
51. The method of claim 48, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
52. The composition of claim 48, wherein the composition consists
of water and water soluble magnesium salt.
53. The composition of claim 48, wherein the composition consists
essentially of water, water soluble magnesium salt, and a further
ingredient selected from the group consisting of antimicrobial
agent, viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, or mixture thereof.
54. The composition of claim 48, wherein the water soluble
magnesium salt is magnesium chloride.
55. The composition of claim 48, wherein upon dilution for use the
composition comprises the magnesium ion at a wt-% greater than or
equal to one half times a wt-% of calcium ion.
56. The composition of claim 48, wherein: the water soluble
magnesium salt comprises an anion that forms a sparingly soluble
calcium salt; and the aqueous composition, upon dilution for use,
comprises magnesium ion in a molar amount equal to or greater than
two-times the molar amount of calcium ion.
57. A composition for cleaning ware consisting essentially of water
and a water soluble magnesium salt; wherein upon dilution for use
cleaning ware, the composition comprises the magnesium ion in a
molar amount equal to or in excess over a molar amount of calcium
ion; and the composition is substantially free of chelating agent,
surfactant, and sheeting agent.
58. The composition of claim 57, wherein the composition is
substantially free a component selected from the group consisting
essentially of source of alkalinity, organic surfactant or cleaning
agent, pH modifier, builder, processing aid, active oxygen
compound, glass or metal corrosion inhibitor, activator, rinse aid
functional material, bleaching agent, defoaming agent,
anti-redeposition agent, stabilizing agent, enzyme, chelating
agent, detersive polymer, softener, source of acidity, solubility
modifier, bleaching agent, effervescent agent, activator for the
source of alkalinity, and combinations thereof.
59. The composition of claim 57, wherein the water soluble
magnesium salt comprises an anion that forms a soluble calcium
salt.
60. The method of claim 57, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
61. The composition of claim 57, wherein the composition consists
of water and water soluble magnesium salt.
62. The composition of claim 57, wherein the water soluble
magnesium salt is magnesium chloride.
63. The composition of claim 57, wherein upon dilution for use the
composition comprises the magnesium ion at a molar ratio of
magnesium to calcium greater than or equal to one.
64. The composition of claim 57, wherein: the water soluble
magnesium salt comprises an anion that forms a sparingly soluble
calcium salt; and the aqueous composition, upon dilution for use,
comprises magnesium ion in a molar ratio of magnesium to calcium
equal to or greater than one.
65. An aqueous hard surface cleaner consisting of water, a water
soluble magnesium salt, and a further ingredient selected from the
group consisting of water, antimicrobial agent, viscosity modifier,
aesthetic enhancing agent, lubricant, dispersant, preservative,
thickener, or mixture thereof, wherein upon dilution for use as a
hard surface cleaner the composition comprises the magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion.
66. The composition of claim 65, wherein the water soluble
magnesium salt comprises an anion that forms a soluble calcium
salt.
67. The method of claim 65, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
68. The composition of claim 65, wherein the composition consists
of water and water soluble magnesium salt.
69. The composition of claim 65, wherein the water soluble
magnesium salt is magnesium chloride.
70. The composition of claim 65, wherein upon dilution for use the
composition comprises the magnesium ion at a molar ratio of
magnesium to calcium greater than or equal to one.
71. The composition of claim 65, wherein: the water soluble
magnesium salt comprises an anion that forms an insoluble calcium
salt; and the aqueous composition, upon dilution for use, comprises
magnesium ion in a molar amount equal to or greater than two-times
the molar amount of calcium ion.
72. A composition for cleaning ware consisting of water, a water
soluble magnesium salt, and a further ingredient selected from the
group consisting of water, antimicrobial agent, viscosity modifier,
aesthetic enhancing agent, lubricant, dispersant, preservative,
thickener, or mixture thereof, wherein upon dilution for use as a
hard surface cleaner the composition comprises the magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion.
73. The composition of claim 72, wherein the water soluble
magnesium salt comprises an anion that forms a soluble calcium
salt.
74. The method of claim 72, wherein the water soluble magnesium
salt is selected from the group consisting of magnesium acetate,
magnesium benzoate, magnesium bromide, magnesium bromate, magnesium
chlorate, magnesium chloride, magnesium chromate, magnesium
citrate, magnesium formate, magnesium hexafluorosilicate, magnesium
iodate, magnesium iodide, magnesium lactate, magnesium molybdate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, magnesium sulfate, magnesium sulfite,
magnesium thiosulfate, a hydrate thereof, and a mixture
thereof.
75. The composition of claim 72, wherein the composition consists
of water and water soluble magnesium salt.
76. The composition of claim 72, wherein the composition consists
essentially of water, water soluble magnesium salt, and a further
ingredient selected from the group consisting of antimicrobial
agent, viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, or mixture thereof.
77. The composition of claim 72, wherein the water soluble
magnesium salt is magnesium chloride.
78. The composition of claim 72, wherein upon dilution for use the
composition comprises the magnesium ion at a wt-% greater than or
equal to one half times a wt-% of calcium ion.
79. The composition of claim 72, wherein: the water soluble
magnesium salt comprises an anion that forms an insoluble calcium
salt; and the aqueous composition, upon dilution for use, comprises
magnesium ion in a molar amount equal to or greater than two-times
the molar amount of calcium ion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 60/927,575 filed on May 4, 2007 and entitled
"Compositions Containing Magnesium Salt and Methods of Using", the
disclosure of which is incorporated herein by reference.
[0002] This application is also related to: U.S. patent application
Ser. No. ______, entitled "Cleaning Compositions with Water
Insoluble Conversion Agents and Methods of Making and Using Them"
(Attorney Docket No. 2454USU1); U.S. patent application Ser. No.
______, entitled, "In Situ Generation of Nanoparticles Under
Alkaline Conditions" (Attorney Docket No. 2437USU1); U.S. patent
application Ser. No. ______, entitled "Water Treatment System and
Downstream Cleaning Methods" (Attorney Docket No. 2428USU1); U.S.
patent application Ser. No. ______, entitled "Cleaning Compositions
Containing Water Soluble Magnesium Compounds and Methods of Using
Them" (Attorney Docket No. 2488USU1); U.S. patent application Ser.
No. ______, entitled "MG++ Chemistry and Method for Fouling
Inhibition in Heat Processing of Liquid Foods and Industrial
Processes" (Attorney Docket No. 2400USU1); U.S. patent application
Ser. No. ______, entitled "Compositions Including Hardness Ion and
Gluconate and Methods Employing Them to Reduce Corrosion and Etch"
(Attorney Docket No. 163.2365USU1); U.S. patent application Ser.
No. ______, entitled "Compositions Including Hardness Ion and
Silicate and Methods Employing Them to Reduce Corrosion and Etch"
(Attorney Docket No. 163.2487USU1); U.S. patent application Ser.
No. ______, entitled "Compositions Including Hardness Ion and
Threshold Agent and Methods Employing Them to Reduce Corrosion and
Etch" (Attorney Docket No. 163.2406USU1); and U.S. patent
application Ser. No. ______, entitled "Warewashing Compositions for
Use in Automatic Dishwashing Machines and Method for Using"
(Attorney Docket No. 2378USU1), all commonly assigned to Ecolab,
Inc., are filed on the same date as this application being May 2,
2008 and are all incorporated herein by reference for all
purposes.
FIELD OF THE INVENTION
[0003] The present invention relates to compositions and methods
employing a water soluble magnesium compound. The present invention
is useful, among other things, in preparing a presoak or prewash
agent, a cleaning composition, or a rinse agent particularly for
hard surfaces. The invention also relates to methods of using such
compositions to reduce lime sale, remove soap scum, reduce hard
water spotting and the like. In certain embodiments, the
composition includes water and water soluble magnesium compound,
but lacks other materials commonly used in cleaning compositions.
The methods and compositions can provide magnesium ion at
predefined ratios to calcium ion in water, such as magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion. A water soluble magnesium salt including an anion of a water
soluble calcium salt is more effective than a magnesium salt with
an anion of a water insoluble calcium salt.
BACKGROUND OF THE INVENTION
[0004] The level of hardness in water can have undesirable effects
in many systems. For example, when hard water is used in
conjunction with cleaning compositions, hard water can cause
precipitation of hard water scale or components of a cleaning
agent. In general, hard water refers to water having a level of
calcium and magnesium ions in excess of about 100 ppm expressed in
units of ppm calcium carbonate.
[0005] Conventional methods add ingredients to hard water to
overcome the undesirable effects of hard water. Water softeners add
sodium ion to replace calcium and magnesium ions in hard water.
Conventional cleaning compositions include builders like chelating
agents, sequestrants, or threshold agents to tie up calcium and
magnesium ions in the hard water. A great deal of effort has gone
into developing new and better builders. Over the decades, a great
deal of effort has gone into making more and more complicated
detergent formulations in an attempt to provide desired performance
in hard water.
[0006] It is unexpected that going in the opposite direction from
the rest of the field to make a simpler composition could overcome
the undesirable effects of hard water. Even more so, it is entirely
unexpected that a simpler composition including added hardness ion
would have a beneficial effect on lime scale or precipitate
formation from hard water, removing soap scum, or the like.
SUMMARY OF THE INVENTION
[0007] The present invention departs from generally held beliefs
that complicated formulae are necessary to overcome the deleterious
and undesirable effects associated with hard water. When cleaning
or rinsing hard surfaces, the use of hard water often results in
hard water spotting, filming, staining, or soap scum left on the
surface. Hard water spotting, staining, filming, and scale are
particularly apparent when washing dishes in an automatic
warewashing machine, cleaning basins or countertops or other hard
surfaces in a kitchen or bathroom, or when washing vehicles. The
present invention includes simpler compositions that overcome the
stated undesirable effects of hard water. The present invention
comprises methods and compositions employing a water soluble
magnesium salt to counter the undesirable effects of calcium ion in
hard water. In fact, one embodiment of the present methods and
compositions employ nothing more than water soluble magnesium salt
and hard water to this end. The present compositions and methods
can reduce or prevent the formation of lime scale along with other
deleterious effects associated with the use of hard water for
cleaning hard surfaces. The present invention may be used to
prepare presoaks or prewashes, cleaning agents, or rinse agents.
The present invention relates to compositions and methods employing
a water soluble magnesium compound. In certain embodiments, the
composition includes water and water soluble magnesium compound,
but lacks other materials commonly used in cleaning compositions.
The methods and compositions can provide magnesium ion at
predefined ratios to calcium ion in water, such as magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion. The water soluble magnesium salt has an associated anion that
can exchange with the carbonate associated with the calcium ion. It
is preferred that the calcium anion product has the highest
possible solubility, but is not required. These compositions can be
used for reducing lime scale or precipitate formation from hard
water, removing soap scum, or the like.
[0008] In another embodiment, the present invention includes a
method of cleaning an object. This method can also reduce hard
water spotting, scaling, or deposits. The method can include
contacting the object with an aqueous composition including water
and a water soluble magnesium salt; and recovering the object with
an acceptable amount of hard water spotting, scaling, or deposits.
In this method, the aqueous composition during contacting can
include magnesium ion in a molar amount equal to or in excess over
a molar amount of calcium ion. In this method, it is preferred that
the water soluble magnesium salt can include an anion that forms a
water soluble salt with calcium.
[0009] In another embodiment, the present invention includes a
method of removing soap scum from an object. This method can
include contacting the soap scum on the object with an aqueous
composition of water and a water soluble magnesium salt; and
removing soap scum from the object. In this method, the aqueous
composition during contacting can include magnesium ion in a molar
amount equal to or in excess over a molar amount of calcium ion. In
this method, it is preferred that the water soluble magnesium salt
can include an anion that, together with calcium ion, forms a water
soluble calcium salt.
[0010] In yet another embodiment, the present invention includes a
method of preventing or reducing the deposit of soap scum on an
object. This method can include contacting the object with an
aqueous composition of water and a water soluble magnesium salt. In
this method, the aqueous composition during contacting can include
magnesium ion in a molar amount equal to or in excess over a molar
amount of calcium ion. In this method, it is preferred that the
water soluble magnesium salt can include an anion that, together
with calcium ion, forms a water soluble calcium salt.
[0011] In another embodiment, the present invention includes an
aqueous composition of water and a water soluble magnesium salt.
The present invention includes an aqueous composition consisting
essentially of water and a water soluble magnesium salt. Upon
dilution for use this composition can include magnesium ion in a
molar amount equal to or in excess over the molar amount of calcium
ion. A preferred composition can include water soluble magnesium
salt including an anion that, together with calcium ion, forms a
water soluble calcium salt.
[0012] The present invention includes in another embodiment a
composition including a water soluble magnesium salt and a further
ingredient selected from the group consisting of water
antimicrobial agent, viscosity modifier, aesthetic enhancing agent,
lubricant, dispersant, preservative, thickener, or mixture thereof.
In an embodiment, the present invention includes a composition
consisting essentially of a water soluble magnesium salt and the
further ingredient. Upon dilution for use this composition can
include magnesium ion in a molar amount equal to or in excess over
the molar amount of calcium ion. A preferred composition can
include water soluble magnesium salt can include an anion that,
together with calcium ion, forms a water soluble calcium salt.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIGS. 1-6 each have an x, y, and z axis. The x-axis is a
measure of the molar ratio of calcium to builder, e.g., STPP, or
water soluble magnesium compound. The y-axis is a measure of the
level of light transmittance thru the samples with 0% being no
light transmitted and 100% being the entire beam of light
transmitted. Full or partial loss of transmittance occurs as a
consequence of the presence of particulate formation in the
initially clear samples. An effective builder prevents or reduces
precipitation resulting in a clear sample. The z-axis is a measure
of the test temperature, ranging from 20-60.degree. C.
[0014] FIG. 1 is a comparative plot illustrating the performance of
STPP as a builder in the presence of various levels of calcium, at
various temperatures, and at a constant pH of 8.
[0015] FIG. 2 is a plot of the performance of magnesium chloride in
preventing precipitation in the presence of various levels of
calcium, at various temperatures, and at a constant pH of 8.
[0016] FIG. 3 is a comparative plot illustrating the performance of
STPP as a builder in the presence of various levels of calcium, at
various temperatures, and at a constant pH of 10.
[0017] FIG. 4 is a plot of the performance of magnesium chloride in
preventing precipitation in the presence of various levels of
calcium, at various temperatures, and at a constant pH of 10.
[0018] FIG. 5 is a comparative plot illustrating the performance of
STPP as a builder in the presence of various levels of calcium, at
various temperatures, and at a constant pH of 12.
[0019] FIG. 6 is a plot of the performance of magnesium chloride in
preventing precipitation in the presence of various levels of
calcium, at various temperatures, and at a constant pH of 12.
[0020] FIG. 7 is a photograph of the interior of a dishwashing
machine showing considerable lime scale deposition after it was run
for 100 cycles using 17 grain hard water only.
[0021] FIG. 8 is a photograph of the interior of a dishwashing
machines after it was run for 100 cycles using 17 grain hard water
and with water soluble magnesium compound, magnesium sulfate,
introduced as the sole rinse agent. The presence of magnesium
sulfate as the sole rinse agent prevented the build-up of lime
scale on metal. No builder or sheeting agent was needed to obtain
this benefit.
[0022] FIG. 9 is a photograph of six glasses. Glass "C" is a
control using hard water alone as the rinse agent. The other
glasses were rinsed using molar ratios of magnesium to calcium of
1:1, 1.5:1, 2:1, 2.5:1, or 3:1 and are labeled as such. These
ratios are based on the total amount of magnesium present including
that present in the incoming water. The results in FIG. 9 show that
water soluble magnesium compound, magnesium sulfate, as the sole
rinse agent reduced and prevented build-up of lime scale on
glasses. Surprisingly, in this example, the 1:1 molar ratio of
magnesium to calcium gave increased hard water scaling on glass,
while the higher ratios gave reduced scaling compared to the
control glass.
[0023] FIG. 10 is a photograph of two glasses, one subjected to 100
cycles in a dishwashing machine with magnesium chloride and the
other with magnesium sulfate. The molar ratio of magnesium to
calcium was 1:1. Unexpectedly, the 1:1 molar ratio of magnesium to
calcium showed better results than the control when magnesium
chloride was substituted for magnesium sulfate
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0024] As used herein, the term "water soluble" refers to a
compound that can be dissolved in water at a concentration of more
than 1 wt-%.
[0025] As used herein, the terms "sparingly soluble" or "sparingly
water soluble" refer to a compound that can be dissolved in water
only to a concentration of 0.1 to 1.0 wt-%.
[0026] As used herein, the term "water insoluble" refers to a
compound that can be dissolved in water only to a concentration of
less than 0.1 wt-%.
[0027] As used herein, the terms "chelating agent" and
"sequestrant" refer to a compound that forms a complex (soluble or
not) with water hardness ions (from the wash water, soil and
substrates being washed) in a specific molar ratio. Chelating
agents that can form a water soluble complex include sodium
tripolyphosphate, EDTA, DTPA, NTA, citrate, and the like.
[0028] Sequestrants that can form an insoluble complex include
sodium triphosphate, zeolite A, and the like. As used herein, the
terms "chelating agent" and "sequestrant" are synonymous.
[0029] As used herein, the term "free of chelating agent" refers to
a composition, mixture, or ingredients that do not contain a
chelating agent or sequestrant or to which a chelating agent or
sequestrant has not been added. Should a chelating agent or
sequestrant be present through contamination of a composition,
mixture, or ingredient that is free of chelating agent, the amount
of a chelating agent or sequestrant shall be less than 7 wt-%. In
another embodiment, such an amount of a chelating agent or
sequestrant is less then 2 wt-%. In other embodiments, such an
amount of a chelating agent or sequestrant is less then 0.5 wt-%
and in yet other embodiments, such an amount of a chelating agent
or sequestrant is less than 0.1 wt-%.
[0030] As used herein, the term "lacking an effective amount of
chelating agent" refers to a composition, mixture, or ingredients
that contains too little chelating agent or sequestrant to
measurably affect the hardness of water. Accordingly, an
ineffective amount of chelating agent or sequestrant will vary with
the hardness of the water and the dilution rate of a
concentrate.
[0031] As used herein, the term "threshold agent" refers to a
compound that inhibits crystallization of water hardness ions from
solution, but that need not form a specific complex with the water
hardness ion. This distinguishes a threshold agent from a chelating
agent or sequestrant. Threshold agents include a polyacrylate, a
polymethacrylate, an olefin/maleic copolymer, and the like.
[0032] As used herein, the term "antiredeposition agent" refers to
a compound that helps keep suspended in water instead of
redepositing onto the object being cleaned.
[0033] As used herein, the term "phosphate-free" refers to a
composition, mixture, or ingredient that does not contain a
phosphate or phosphate-containing compound or to which a phosphate
or phosphate-containing compound has not been added. Should a
phosphate or phosphate-containing compound be present through
contamination of a phosphate-free composition, mixture, or
ingredients, the amount of phosphate shall be less than 0.5 wt %.
More preferably, the amount of phosphate is less then 0.1 wt-%, and
most preferably, the amount of phosphate is less than 0.01 wt
%.
[0034] As used herein, the term "phosphorus-free" refers to a
composition, mixture, or ingredient that does not contain
phosphorus or a phosphorus-containing compound or to which
phosphorus or a phosphorus-containing compound has not been added.
Should phosphorus or a phosphorus-containing compound be present
through contamination of a phosphorus-free composition, mixture, or
ingredients, the amount of phosphorus shall be less than 0.5 wt %.
More preferably, the amount of phosphorus is less than 0.1 wt-%,
and most preferably the amount of phosphorus is less than 0.01 wt
%.
[0035] "Cleaning" means to perform or aid in soil removal,
bleaching, microbial population reduction, rinsing, or combination
thereof.
[0036] As used herein, the term "ware" includes items such as
eating and cooking utensils. As used herein, the term "warewashing"
refers to washing, cleaning, or rinsing ware.
[0037] As used herein, the term "hard surface" includes showers,
sinks, toilets, bathtubs, countertops, windows, mirrors,
transportation vehicles, floors, and the like. These surfaces can
be those typified as "hard surfaces" (such as walls, floors,
bed-pans, etc.,), or fabric surfaces, e.g., knit, woven, and
non-woven surfaces (such as surgical garments, draperies, bed
linens, bandages, etc.,), or patient-care equipment (such as
respirators, diagnostic equipment, shunts, body scopes, wheel
chairs, beds, etc.,), or surgical and diagnostic equipment.
[0038] As used herein, the phrase "health care surface" refers to a
surface of an instrument, a device, a cart, a cage, furniture, a
structure, a building, or the like that is employed as part of a
health care activity. Examples of health care surfaces include
surfaces of medical or dental instruments, of medical or dental
devices, of electronic apparatus employed for monitoring patient
health, and of floors, walls, or fixtures of structures in which
health care occurs. Health care surfaces are found in hospital,
surgical, infirmity, birthing, mortuary, and clinical diagnosis
rooms. Health care surfaces include articles and surfaces employed
in animal health care.
[0039] As used herein, the term "instrument" refers to the various
medical or dental instruments or devices that can benefit from
cleaning with a stabilized composition according to the present
invention.
[0040] As used herein, the phrases "medical instrument", "dental
instrument", "medical device", "dental device", "medical
equipment", or "dental equipment" refer to instruments, devices,
tools, appliances, apparatus, and equipment used in medicine or
dentistry. Such instruments, devices, and equipment can be cold
sterilized, soaked or washed and then heat sterilized, or otherwise
benefit from cleaning in a composition of the present invention.
These various instruments, devices and equipment include, but are
not limited to: diagnostic instruments, trays, pans, holders,
racks, forceps, scissors, shears, saws (e.g. bone saws and their
blades), hemostats, knives, chisels, rongeurs, files, nippers,
drills, drill bits, rasps, burrs, spreaders, breakers, elevators,
clamps, needle holders, carriers, clips, hooks, gouges, curettes,
retractors, straightener, punches, extractors, scoops, keratomes,
spatulas, expressors, trocars, dilators, cages, glassware, tubing,
catheters, cannulas, plugs, stents, scopes (e.g., endoscopes,
stethoscopes, and arthoscopes) and related equipment, and the like,
or combinations thereof.
[0041] As used herein, a solid cleaning composition refers to a
cleaning composition in the form of a solid such as a powder, a
particle, an agglomerate, a flake, a granule, a pellet, a tablet, a
lozenge, a puck, a briquette, a brick, a solid block, a unit dose,
or another solid form known to those of skill in the art. The term
"solid" refers to the state of the detergent composition under the
expected conditions of storage and use of the solid detergent
composition. In general, it is expected that the detergent
composition will remain in solid form when exposed to temperatures
of up to about 100.degree. F. and greater than about 120.degree.
F.
[0042] By the term "solid" as used to describe the processed
composition, it is meant that the hardened composition will not
flow perceptibly and will substantially retain its shape under
moderate stress or pressure or mere gravity, as for example, the
shape of a mold when removed from the mold, the shape of an article
as formed upon extrusion from an extruder, and the like. The degree
of hardness of the solid cast composition can range from that of a
fused solid block, which is relatively dense and hard, for example,
like concrete, to a consistency characterized as being malleable
and sponge-like, similar to caulking material.
[0043] As used herein, weight percent (wt-%), percent by weight, %
by weight, and the like are synonyms that refer to the
concentration of a substance as the weight of that substance
divided by the total weight of the composition and multiplied by
100.
[0044] As used herein, the term "about" modifying the quantity of
an ingredient in the compositions of the invention or employed in
the methods of the invention refers to variation in the numerical
quantity that can occur, for example, through typical measuring and
liquid handling procedures used for making concentrates or use
solutions in the real world; through inadvertent error in these
procedures; through differences in the manufacture, source, or
purity of the ingredients employed to make the compositions or
carry out the methods; and the like. The term about also
encompasses amounts that differ due to different equilibrium
conditions for a composition resulting from a particular initial
mixture. Whether or not modified by the term "about", the claims
include equivalents to the quantities.
[0045] It should 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 composition containing
"a compound" includes a mixture of two or more compounds. It should
also be noted that the term "or" is generally employed in its sense
including "and/or" unless the content clearly dictates
otherwise.
Methods and Compositions Employing Water Soluble Magnesium
Compound
[0046] The present invention is useful in preparing and in use as a
presoak or prewash, a cleaning agent, or a rinse agent for treating
a variety of surfaces. Compositions prepared according to the
invention are useful in automatic warewashing machines, in hand
dishwashing, in cleaning hard surfaces such as windows, mirrors,
ceramic tile and basins, granite, plastic, stainless steel, wood,
countertops, or vehicles to name a few. Compositions prepared
according to the invention are also useful in cleaning or treating
medical or dental equipment or instruments and in washing linens.
The present invention relates to compositions and methods employing
a water soluble magnesium compound. The present inventors have
discovered, unexpectedly, that a water soluble magnesium compound
can be employed to, for example, reduce lime scale or precipitate
formation from hard water, reduce formation of soap scum, remove
soap scum, or the like. In certain embodiments, the composition
includes and the method employs water and water soluble magnesium
compound but lacks other materials commonly used in cleaning
compositions. These compositions can be employed in any of a
variety of situations in which water spotting or scaling are a
problem, such as cleaning or rinsing a hard surface, such as tile,
glass ware, other ware, and the like.
[0047] The present inventors discovered that compositions of water
soluble magnesium salt that provide magnesium ion at predefined
ratios to calcium ion in water, such as magnesium ion in a molar
amount equal to or in excess over a molar amount of calcium ion,
advantageously reduce lime scale or precipitate formation from hard
water, remove soap scum, or the like. For example, magnesium ion
and calcium ion can be in a molar ratio of 1:1 or the composition
can include a greater amount of magnesium ion. In a more preferred
embodiment, magnesium ion and calcium ion can be in a molar ratio
of about 1.5:1 up to about 3:1. Further, the present inventors
discovered that a compositions of water soluble magnesium salt
including an anion of a water soluble calcium salt are more
effective than a magnesium salt with an anion of a water insoluble
calcium salt. These compositions can be used for reducing lime
scale or precipitate formation from hard water, removing soap scum,
or the like.
[0048] Surprisingly, water containing a water soluble magnesium
salt can have beneficial effects in reducing certain deleterious
effects of hard water. In fact, a composition of only water soluble
magnesium salt in hard water can have these beneficial effects. It
was unexpectedly discovered that a water soluble magnesium salt
worked as well as a conventional chelating agent or sequestrant
(sodium tripolyphosphate (STPP)) at preventing precipitation of
calcium salts. Also unexpectedly, a composition of only water
soluble magnesium salt in hard water reduced formation of lime
scale from hard water. Further, unexpectedly, rinse water
containing only a water soluble magnesium salt reduced formation of
lime scale from hard water on glasses after warewashing, and on the
portions of the dishwasher that contact water. Surprisingly, a
composition comprising only water soluble magnesium salt in hard
water removed soap scum from a tile. These benefits can be achieved
employing a composition including magnesium ion in a molar amount
equal to or in excess over a molar amount of calcium ion. These
benefits can be achieved at a lower concentration of water soluble
magnesium salt using a water soluble magnesium salt including an
anion of a water soluble calcium salt are more effective than a
magnesium salt with an anion of a water insoluble calcium salt.
[0049] As described above, these beneficial effects can be achieved
by a composition including water and water soluble magnesium
compound, but lacking other materials commonly used in cleaning
compositions. That is, in certain embodiments, a composition of
only water and water soluble magnesium compound can exhibit such
beneficial effects. The composition can include magnesium ion in a
molar amount equal to or in excess over a molar amount of calcium
ion. The composition can include water soluble magnesium salt using
a water soluble magnesium salt including an anion of a water
soluble calcium salt.
[0050] In certain embodiments, the present composition consists
essentially of water and water soluble magnesium compound. As used
herein, the phrases "consisting essentially of" or "consists
essentially of" refer to a composition including the listed
ingredients (e.g., water and water soluble magnesium compound) but
lacking an effective amount of any cleaning component commonly used
in cleaning compositions.
[0051] In an embodiment, the present composition is free of
cleaning components commonly used in cleaning compositions. As used
herein, the phrase "free of cleaning components commonly used in
cleaning compositions" refers to a composition, mixture, or
ingredient that does not contain a cleaning component commonly used
in cleaning compositions or to which a cleaning components commonly
used in cleaning compositions has not been added. Should a cleaning
component commonly used in cleaning compositions be present through
contamination of a composition free of cleaning components commonly
used in cleaning, the amount of cleaning component commonly used in
cleaning compositions shall be less than 0.5 wt %. More preferably,
the amount of cleaning component commonly used in cleaning
compositions is less then 0.1 wt-%, and most preferably, the amount
of cleaning component commonly used in cleaning compositions is
less than 0.01 wt %.
[0052] As used herein, "cleaning component commonly used in
cleaning compositions" refers to: source of alkalinity, organic
surfactant or cleaning agent (e.g., surfactant or surfactant
system, e.g., anionic, nonionic, cationic, and zwitterionic
surfactant), pH modifier (e.g., organic or inorganic source of
alkalinity or a pH buffering agent), builder (e.g., inorganic
builder such as silicate, carbonate, sulfate, salt or acid form
thereof), processing aid, active oxygen compound, glass or metal
corrosion inhibitor, activator, rinse aid functional material,
bleaching agent, defoaming agent, anti-redeposition agent,
stabilizing agent, enzyme, chelating agent or sequestrant (e.g.,
phosphonate, phosphate, aminocarboxylate, polycarboxylate, and the
like), detersive polymer, softener, source of acidity, solubility
modifier, bleaching agent or additional bleaching agent,
effervescent agent, or activator for the source of alkalinity.
[0053] As used herein, "cleaning component commonly used in
cleaning compositions" does not include antimicrobial agent,
secondary hardening agent, detergent filler, aesthetic enhancing
agent (i.e., dye, odorant, perfume), lubricant composition,
dispersant, or thickener.
[0054] In certain embodiments, the composition can also include
antimicrobial agent, viscosity modifier (cellulosic polymers, guar
derivatives and gums, etc.), aesthetic enhancing agent (i.e., dye,
odorant, perfume, fragrance), lubricant composition, dispersant,
preservative, or thickener.
[0055] As used herein with respect to ingredients of the present
compositions, water refers to potable water as obtained from a
municipal or private water system, e.g., a public water supply or a
well. The water can be hard water, city water, well water, water
supplied by a municipal water system, water supplied by a private
water system, treated water, or water directly from the system or
well. In an embodiment, the present method employs water that
wasn't treated with a polymeric water softener bed such as in use
today and which requires periodic regeneration with sodium chloride
to work. In general, hard water refers to water having a level of
calcium and magnesium ions in excess of about 100 ppm. Often, the
molar ratio of calcium to magnesium in hard water is about 2:1 or
about 3:1. Although most locations have hard water, water hardness
tends to vary from one location to another.
COMPOSITIONS OF THE INVENTION
[0056] In an embodiment, the present invention includes an aqueous
composition consisting essentially of water and a water soluble
magnesium salt. In an alternate embodiment, the aqueous composition
further consists essentially of thickener. In another embodiment,
the aqueous composition consists of water and a water soluble
magnesium salt. In yet another embodiment, the aqueous composition
consists essentially of water, water soluble magnesium salt, and a
further ingredient selected from the group consisting of
antimicrobial agent, viscosity modifier, aesthetic enhancing agent,
lubricant, dispersant, preservative, thickener, or mixture
thereof.
[0057] This composition can include, upon dilution for use,
magnesium ion in a molar amount equal to or in excess over a molar
amount of calcium ion. Upon dilution for use, the composition
includes magnesium ion at a wt-% greater than or equal to one half
times a wt-% of calcium ion. The water soluble magnesium salt
preferably includes an anion that forms an insoluble calcium salt;
and the aqueous composition, upon dilution for use, includes
magnesium ion in a molar amount equal to or greater than two-times
the molar amount of calcium ion. An aqueous composition of the
invention preferably includes less than 1 wt-% phosphorus and/or
less than 1 wt-% phosphate.
[0058] The present invention includes a composition including a
water soluble magnesium salt and a further ingredient selected from
the group consisting of antimicrobial agent, viscosity modifier,
aesthetic enhancing agent, lubricant, dispersant, preservative,
thickener, or mixture thereof. In an alternate embodiment, the
composition consists essentially of a water soluble magnesium salt
and a further ingredient selected from the group consisting of
antimicrobial agent, viscosity modifier, aesthetic enhancing agent,
lubricant, dispersant, preservative, thickener, or mixture
thereof.
[0059] In an embodiment, the composition is a solid block. The
solid block can include about 99 to 100 wt-% water soluble
magnesium salt. In such an embodiment, the composition preferably
comprises less than 1 wt-% phosphorus and/or less than 1 wt-%
phosphate.
[0060] The composition can include magnesium compound at a
predetermined ratio to the calcium in water. The magnesium compound
can be a water soluble magnesium salt including an anion that forms
a water soluble salt with calcium. Anions that form water soluble
salts with both magnesium ion and calcium ion include chloride and
acetate. Sulfate form a water soluble salt with magnesium, but its
calcium salt is water insoluble. The composition can lack an
effective amount or be substantially free of, for example,
chelating agent, sequestrant, builder, threshold agent, surfactant,
and sheeting agent.
METHODS OF THE INVENTION
[0061] It is contemplated that the cleaning compositions of the
invention can be used in a broad variety of industrial, household,
health care, vehicle care, and other such applications. Some
examples include surface antimicrobial, ware cleaning, vehicle
cleaning, floor cleaning, surface cleaning, pre-soaks, clean in
place, window cleaning, and a broad variety of other such
applications.
[0062] The present invention includes a method of cleaning an
object. This method of cleaning preferably results in reducing hard
water spotting, scaling, or deposits. This embodiment of the method
can include contacting the object with an aqueous composition
including water and a water soluble magnesium salt. The method can
also include recovering the object with an acceptable amount of
hard water spotting, scaling, or deposits.
[0063] The following rating system is used to grade spotting on
hard surfaces. In developing the rating system, clear glasses were
used. Surfaces having a rating of 1, 1.5 and 2 are considered to
have an acceptable amount of spotting. Surfaces having a rating of
3 have a marginally acceptable amount of spotting while surfaces
rated a 4 or a 5 have unacceptable amounts of spotting.
TABLE-US-00001 Rating Spots Film 1 Substantially No spotting No
film 1.5 1/8 surface spotted No film to barely perceptible 2 1/4
surface spotted Trace/barely perceptible 3 1/2 surface spotted
Slight film 4 3/4 surface spotted Moderate film 5 Entire surface
spotted Heavy film
As used herein, an acceptable amount of hard water spotting,
scaling, or deposits refers to surfaces rated a 1, 1.5 or 2 in the
provided grid. In other words, surfaces having as much as one
quarter of the surface spotted and/or only a barely perceptible
film present are deemed acceptable. In other embodiments, surfaces
having less than one quarter of the surface containing spots are
deemed acceptable. In yet other embodiments, surfaces have up to
about 1/8 of the surface containing spotting is deemed acceptable
and in other embodiments the surface is substantially free of
spotting.
[0064] During contacting, the aqueous composition can include
magnesium ion in a molar amount equal to or in excess over the
molar amount of calcium ion. In one embodiment, the aqueous
composition during contacting includes magnesium ion at a wt-%
greater than or equal to one half times the wt-% of calcium ion. In
another embodiment, the water soluble magnesium salt comprises an
anion that forms an insoluble or sparingly soluble calcium salt and
the aqueous composition during contacting includes magnesium ion in
a molar amount equal to or greater than two-times the molar amount
of calcium ion.
[0065] One skilled in the art will appreciate that the higher the
solubility of the calcium salt formed from the anion from the
soluble magnesium compound, the lower the ratio of magnesium to
calcium need be. In other words, if the calcium salt that forms is
highly soluble, the ratio of magnesium to calcium concentration
will approach 1:1 whereas, if the resultant calcium salt is low in
solubility, the ratio of magnesium to calcium will need to be
higher than 1:1.
[0066] In one embodiment of the present invention the aqueous
composition consists essentially of water and a water soluble
magnesium salt. In another embodiment, the aqueous composition
consists of water and a water soluble magnesium salt. In yet
another embodiment, the aqueous composition consists essentially of
water, water soluble magnesium salt, and a further ingredient
selected from the group consisting of antimicrobial agent,
viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, or mixture thereof.
[0067] The method can be applied to cleaning any of a variety of
objects. For example, contacting can include contacting any of a
variety of objects or surfaces. In one version of the method of the
invention, contacting includes rinsing a hard surface. The hard
surface is selected from the group consisting of ceramic tile, a
window, and a combination thereof. The hard surface may exist in a
bathroom or in a kitchen. In another embodiment, contacting
includes rinsing or presoaking ware. The invention may also be used
to rinse or wash a medical instrument or rinse or wash a vehicle in
a car wash.
[0068] The method can reduce any of a variety of detrimental
effects of hard water. In an embodiment, the method can reduce
scaling. The invention is remarkably effective in removing existing
soap scum from a hard surface. In such a method the soap scum on an
object is contacted with an aqueous composition including water and
a water soluble magnesium salt and the soap scum is removed from
the object. In another embodiment, the aqueous composition consists
essentially of water and a water soluble magnesium salt. The
aqueous composition may further consist essentially of thickener.
In an embodiment, the aqueous composition consists of water and a
water soluble magnesium salt. The aqueous composition may consist
essentially of water, water soluble magnesium salt, and a further
ingredient selected from the group consisting of antimicrobial
agent, viscosity modifier, aesthetic enhancing agent, lubricant,
dispersant, preservative, thickener, or mixture thereof.
[0069] The method can remove soap scum from any of a variety of
surfaces. In an embodiment, contacting includes contacting a
bathroom surface. Contacting may also include ceramic tile, an
interior surface of a warewashing machine and, removing the soap
scum resulting in a shiny surface. This method can be employed to
remove any of a variety of types of soap scum. For example, the
soap scum can include calcium salt of fatty acid, alone or in the
presence of other soils such as triglycerides and/or protein, which
can make the soap scum more adherent to surfaces.
[0070] This method can be employed to remove soap scum from any of
a variety of types of surfaces. The soap scum can be on a bathroom
surface. The bathroom surface can be a surface in or around a
shower, such as a shower stall, a plumbing fixture, a wall, a glass
shower door, or the like. The soap scum can be on a surface of a
warewashing machine. In an embodiment, the soap scum is on a hard
surface. The hard surface can be a vehicle, eating or cooking
utensil, architectural surface such as a window or floor, or a
countertop.
[0071] In this method, effectively removing the soap scum can refer
to removing a visually detectable amount of the soap scum from the
surface. In one aspect, effectively removing the soap scum results
in a shiny surface. Effectively removing the soap scum results in a
surface free of lime scale without having to use a water softening
polymer bed. In one embodiment of the invention, the aqueous
composition containing excess calcium ion contains at least about
50 ppm calcium ion, e.g. at least about 5 grain per gallon of
hardness due to calcium ion. In an embodiment of this method,
adding includes adding the water soluble magnesium compound to
achieve a total wt-% of magnesium ion of about half the wt-% of
calcium ion. For example, at least about 2 grains of total
magnesium ion for water containing 5 grains of calcium ion as water
hardness. In an embodiment of this method, adding includes adding
water soluble magnesium compound including an anion that forms a
soluble salt with calcium (e.g., MgCl.sub.2) to achieve a total
wt-% of magnesium ion of greater than about half the wt-% of
calcium ion (which is about a 1:1 molar ratio). In an embodiment of
this method, adding includes adding water soluble magnesium
compound including an anion that forms an insoluble salt with
calcium (e.g., MgSO.sub.4) to achieve a total wt-% of magnesium ion
of about the wt-% of calcium ion (which is about a 2:1 molar
ratio).
[0072] The present invention includes a composition or method
employing water soluble magnesium compound plus water for lime
scale control. In one embodiment, the present invention includes a
method of reducing calcium precipitate or lime scale from an
aqueous composition. This method can include: providing aqueous
composition containing excess calcium ion; adding a water soluble
magnesium compound to the aqueous composition containing excess
calcium ion; employing aqueous composition to which magnesium
compound was added for cleaning. The magnesium treated water can be
used for any of a variety of purposes in which it is desirable to
reduce calcium precipitate or lime scale from an aqueous
composition. For example, this method can include employing aqueous
composition to which magnesium compound was added for rinsing ware
in warewashing. The method can include providing magnesium ion at
predefined ratios to calcium ion in water, such as magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion. Such methods can advantageously reduce lime scale or
precipitate formation from hard water, remove soap scum, or the
like. The method can employ a water soluble magnesium salt
including an anion of a water soluble calcium salt are more
effective than a magnesium salt with an anion of a water insoluble
calcium salt.
[0073] The present invention also includes a method of reducing
precipitation of calcium salt from an aqueous composition. This
method can include: providing aqueous composition containing excess
calcium ion; adding a water soluble magnesium compound to the
aqueous composition containing excess calcium ion; and employing
the aqueous composition to which magnesium compound was added for
rinsing ware in warewashing, as a presoak for ware in warewashing,
as a detergent for ware in warewashing, for rinsing a vehicle in a
car wash, for rinsing a shower or other bathroom fixture, for
rinsing a window, or the like. The composition can be free of
builder, sequestrant, chelating agent, or threshold agent. The
method can include providing magnesium ion at predefined ratios to
calcium ion in water, such as magnesium ion in a molar amount equal
to or in excess over a molar amount of calcium ion. Such methods
can advantageously reduce lime scale or precipitate formation from
hard water, remove soap scum, or the like. The method can employ a
water soluble magnesium salt including an anion of a water soluble
calcium salt are more effective than a magnesium salt with an anion
of a water insoluble calcium salt.
[0074] The present invention includes a method of cleaning an
object. This method can include: providing a solid block of a water
soluble magnesium compound; contacting the solid block with an
aqueous composition to form an aqueous composition including water
soluble magnesium compound; and applying the aqueous composition
comprising water soluble magnesium compound to an object to clean
the object. The method can include providing magnesium ion at
predefined ratios to calcium ion in water, such as magnesium ion in
a molar amount equal to or in excess over a molar amount of calcium
ion. Such methods can advantageously reduce lime scale or
precipitate formation from hard water, reduce hard water spotting,
remove soap scum, or the like. The method can employ a water
soluble magnesium salt including an anion of a water soluble
calcium salt are more effective than a magnesium salt with an anion
of a water insoluble calcium salt.
[0075] In one embodiment, the present invention includes a solid
block cleaning composition. The solid block cleaning composition
can include about 99 to 100 wt-% water soluble magnesium
compound.
[0076] In another embodiment, the present methods can include
injecting the present aqueous composition or placing the present
solid composition into the water flow being used to rinse the
surface. In an embodiment, the present method employs water that
wasn't treated with a polymeric water softener bed such as in use
today requiring periodic regeneration with sodium chloride for
effectiveness.
[0077] Contacting can include any of numerous methods for applying
a composition, such as spraying the composition, immersing the
object in the composition, or a combination thereof. The
compositions can be applied in a variety of areas including
kitchens, bathrooms, factories, hospitals, dental offices and food
plants, and can be applied to a variety of hard surfaces having
smooth, irregular or porous topography. Suitable hard surfaces
include, for example, architectural surfaces (e.g., floors, walls,
windows, sinks, tables, counters and signs); eating utensils;
hard-surface medical or surgical instruments and devices; and
hard-surface packaging. Such hard surfaces can be made from a
variety of materials including, for example, ceramic, metal, glass,
wood or hard plastic.
[0078] A concentrate or use concentration of a composition of the
present invention can be applied to or brought into contact with an
object by any conventional method or apparatus for applying a
cleaning composition to an object. For example, the object can be
wiped with, sprayed with, and/or immersed in the composition, or a
use solution made from the composition. The composition can be
sprayed, or wiped onto a surface; the composition can be caused to
flow over the surface, or the surface can be dipped into the
composition. Contacting can be manual or by machine.
Water Soluble Magnesium Compounds
[0079] Suitable water soluble magnesium compounds include those
selected from the group consisting of magnesium acetate, magnesium
benzoate, magnesium bromide, magnesium bromate, magnesium chlorate,
magnesium chloride, magnesium chromate, magnesium citrate,
magnesium formate, magnesium hexafluorosilicate, magnesium iodate,
magnesium iodide, magnesium lactate, magnesium molybdate, magnesium
nitrate, magnesium perchlorate, magnesium phosphinate, magnesium
salicylate, magnesium sulfate, magnesium sulfite, magnesium
tartrate, magnesium thiosulfate, a hydrate thereof, and a mixture
thereof. These salts can be provided as hydrated salts or anhydrous
salts.
[0080] Suitable water soluble magnesium compounds include magnesium
salts with an anion that also forms a soluble salt with calcium.
Such salts include those selected from the group consisting of
magnesium acetate, magnesium benzoate, magnesium bromide, magnesium
bromate, magnesium chlorate, magnesium chloride, magnesium
chromate, magnesium formate, magnesium iodide, magnesium lactate,
magnesium nitrate, magnesium perchlorate, magnesium phosphinate,
magnesium salicylate, a hydrate thereof, and a mixture thereof.
These salts can be provided as hydrated salts or anhydrous
salts.
[0081] Water soluble magnesium compounds approved as GRAS for
direct food contact include magnesium chloride and magnesium
sulfate.
[0082] A cast or pressed solid block or puck of water soluble
magnesium compound can also contain water insoluble magnesium
compound. The water insoluble compound can slow the speed at which
the water soluble magnesium compound dissolves to provide a useful
solid cleaning composition. In certain embodiments, the ratio of
water soluble to water insoluble magnesium compound can be about
1:10 to about 10:1, about 1:5 to about 5:1, or about 1:3 to about
3:1.
Additional Ingredients
[0083] In certain embodiments, the composition can also include
antimicrobial agent, viscosity modifier (cellulosic polymers, guar
derivatives and gums, etc.), aesthetic enhancing agent (i.e., dye,
odorant, perfume, fragrance), lubricant composition, dispersant,
preservative, or thickener. Such ingredients are known and are
described in, for example, U.S. Patent Application Publication No.
2003/0139310 and/or No. 20060113506, which are incorporated herein
by reference for all purposes.
Ingredients to Exclude
[0084] The composition can lack an effective amount or be
substantially free of, for example, additional functional
components or ingredients such as chelating agent, sequestrant,
builder, threshold agent, surfactant, and sheeting agent.
[0085] The present composition can be substantially free of added
sequestrant or chelating agent or, even, free of added sequestrant
or chelating agent. In an embodiment, the present cleaning
composition is substantially free or free of added sequestrant or
chelating agent. Chelating agents or sequestrants include
phosphonates, phosphates, aminocarboxylates, polycarboxylates, and
the like.
[0086] In a preferred embodiment, the present composition does not
include and the present method does not employ a surfactant or
surfactant system. Excluded surfactants include anionic, nonionic,
cationic, and zwitterionic surfactants, which are commercially
available from a number of sources.
[0087] In another embodiment, the present composition does not
include and the present method does not employ a wetting or
sheeting agent. A wetting or sheeting agent is typically a water
soluble or dispersible low foaming organic material capable of
reducing the surface tension of the rinse water to promote sheeting
action and to prevent spotting or streaking caused by beaded water
after rinsing is completed.
Use Compositions
[0088] The present compositions include concentrate compositions
and use compositions. For example, a concentrate composition can be
diluted, for example with water, to form a use composition. In an
embodiment, a concentrate composition can be diluted to a use
solution before application to an object. For reasons of economics,
the concentrate can be marketed and an end user can dilute the
concentrate with water or an aqueous diluent to a use solution. The
level of active components in the concentrate composition is
dependent on the intended dilution factor and the desired
concentration of water soluble magnesium salt.
[0089] Generally, a dilution of about 1 fluid ounce to about 20
gallons of water to about 5 fluid ounces to about 1 gallon of water
is used for aqueous cleaning compositions. In the typical use
locus, the concentrate is diluted with a major proportion of water
using commonly available tap or service water mixing the materials
at a dilution ratio of about 3 to about 20 ounces of concentrate
per 100 gallons of water. A use solution may be prepared from the
concentrate by diluting the concentrate with water at a dilution
ratio that provides a use solution having desired properties. In an
exemplary embodiment, the concentrate may be diluted at a weight
ratio of diluent to concentrate of at least about 20:1 or about
20:1 to about 2000:1.
[0090] The concentrate may be diluted with water at the location of
use to provide the use solution. When the detergent composition is
used in an automatic warewashing or dishwashing machine, it is
expected that that the location of use will be inside the automatic
warewashing machine.
EMBODIMENTS OF SOLIDS
[0091] The present invention also relates to solid cleaning
compositions including a water soluble magnesium compound. For
example, the present invention includes a cast solid block of
magnesium chloride. By way of further example, the present
invention includes a pressed solid block or puck including water
soluble magnesium compound and magnesium carbonate.
[0092] According to the present invention, a solid cleaning
composition of a water soluble magnesium compound (e.g. magnesium
chloride) can be prepared by a method including: providing a powder
or crystalline form of a water soluble magnesium compound (e.g.
magnesium chloride); melting the powder or crystalline form of the
water soluble magnesium compound; transferring the molten water
soluble magnesium compound into a mold; and cooling the molten salt
to solidify it. For example, a solid block of magnesium chloride
was made by heating magnesium chloride hexahydrate to its melting
point of about 118.degree. C. The molten salt was then transferred
to a plastic container to afford a hard solid upon cooling to
ambient temperature. For forming a cast solid from magnesium
chloride, the presence of water of hydration (and additional water
if desired) affords a reduced melting point compared to the
anhydrous salt, allowing the temperature of the process to be
reduced to a practical level.
[0093] According to the present invention, a solid cleaning
composition of a water soluble magnesium compound (e.g. magnesium
carbonate) can be prepared by a method including: providing a
powder or crystalline form of a water soluble magnesium compound
(e.g. magnesium carbonate); gently pressing the water soluble
magnesium compound to form a solid (e.g., block or puck). A solid
block was made by compressing about 50 grams of magnesium carbonate
monohydrate for about 20 seconds at about 1000 psi.
[0094] A solid (e.g., block or puck, pressed or cast) form of a
water soluble magnesium compound can be used, for example, for
treating of potable water, for treating a facility or home's
overall water system, or for treating water fed into a mechanical
device such as a dishwasher, or car wash. The method can include,
for example, contacting the solid form of a water soluble magnesium
compound with water in need of treatment; and using the water for
cleaning. The magnesium ions can reduce undesirable precipitation
of calcium salts. The magnesium can thus continuously treat water
as the solid composition dissolves.
[0095] A solid cleaning or rinsing composition as used in the
present disclosure encompasses a variety of forms including, for
example, solids, pellets, blocks, and tablets, but not powders. It
should be understood that the term "solid" refers to the state of
the detergent composition under the expected conditions of storage
and use of the solid cleaning composition. In general, it is
expected that the detergent composition will remain a solid when
provided at a temperature of up to about 100.degree. F. or greater
than 120.degree. F.
[0096] In certain embodiments, the solid cleaning composition is
provided in the form of a unit dose. A unit dose refers to a solid
cleaning composition unit sized so that the entire unit is used
during a single washing cycle. When the solid cleaning composition
is provided as a unit dose, it can have a mass of about 1 g to
about 50 g. In other embodiments, the composition can be a solid, a
pellet, or a tablet having a size of about 50 g to 250 g, of about
100 g or greater, or about 40 g to about 11,000 g.
[0097] In other embodiments, the solid cleaning composition is
provided in the form of a multiple-use solid, such as, a block or a
plurality of pellets, and can be repeatedly used to generate
aqueous detergent compositions for multiple washing cycles. In
certain embodiments, the solid cleaning composition is provided as
a solid having a mass of about 5 g to 10 kg. In certain
embodiments, a multiple-use form of the solid cleaning composition
has a mass of about 1 to 10 kg. In further embodiments, a
multiple-use form of the solid cleaning composition has a mass of
about 5 kg to about 8 kg. In other embodiments, a multiple-use form
of the solid cleaning composition has a mass of about 5 g to about
1 kg, or about 5 g and to 500 g.
Packaging System
[0098] In some embodiments, the solid composition can be packaged.
The packaging receptacle or container may be rigid or flexible, and
composed of any material suitable for containing the compositions
produced according to the invention, as for example glass, metal,
plastic film or sheet, cardboard, cardboard composites, paper, and
the like.
[0099] Advantageously, since the composition is processed at or
near ambient temperatures, the temperature of the processed mixture
is low enough so that the mixture may be formed directly in the
container or other packaging system without structurally damaging
the material. As a result, a wider variety of materials may be used
to manufacture the container than those used for compositions that
processed and dispensed under molten conditions.
[0100] Suitable packaging used to contain the compositions is
manufactured from a flexible, easy opening film material.
Dispensing of the Processed Compositions
[0101] The solid cleaning composition according to the present
invention can be dispensed in any suitable method generally known.
The cleaning or rinsing composition can be dispensed from a
spray-type dispenser such as that disclosed in U.S. Pat. Nos.
4,826,661, 4,690,305, 4,687,121, 4,426,362 and in U.S. Pat. Nos. Re
32,763 and 32,818, the disclosures of which are incorporated by
reference herein for all purposes. Briefly, a spray-type dispenser
functions by impinging a water spray upon an exposed surface of the
solid composition to dissolve a portion of the composition, and
then immediately directing the concentrate solution including the
composition out of the dispenser to a storage reservoir or directly
to a point of use. When used, the product is removed from the
package (e.g.) film and is inserted into the dispenser. The spray
of water can be made by a nozzle in a shape that conforms to the
solid shape. The dispenser enclosure can also closely fit the
detergent shape in a dispensing system that prevents the
introduction and dispensing of an incorrect detergent. The aqueous
concentrate is generally directed to a use locus.
[0102] In an embodiment, the present composition can be dispensed
by immersing either intermittently or continuously in water. The
composition can then dissolve, for example, at a controlled or
predetermined rate. The rate can be effective to maintain a
concentration of dissolved cleaning agent that is effective for
cleaning.
[0103] In an embodiment, the present composition can be dispensed
by scraping solid from the solid composition and contacting the
scrapings with water. The scrapings can be added to water to
provide a concentration of dissolved cleaning agent that is
effective for cleaning.
[0104] The present invention can be better understood with
reference to the following examples. These examples are intended to
be representative of specific embodiments of the invention, and are
not intended as limiting the scope of the invention.
EXAMPLES
Example 1
Water Soluble Magnesium Compounds Reduce Precipitation of Calcium
Salts from Hard Water
[0105] This Example demonstrates that adding a hardness ion
(Mg.sup.2+) to water worked as well as a conventional chelating
agent or sequestrant (sodium tripolyphosphate (STPP)) at preventing
precipitation of calcium salts.
Materials and Methods
[0106] Formation of a precipitate in water reduces the transmission
of visible light through the water. A transmittance of 100%
indicates that no precipitate formed, while a transmittance of 0%
indicates that so much precipitate formed that light no longer
passed through the sample. Transmittance was measured for water
containing either MgCl.sub.2 (present invention) or STPP
(comparative example) at pH values of about 8, about 10, and about
12, and at temperatures of about 20.degree. C., about 45.degree.
C., and about 70.degree. C. Temperatures were chosen in an attempt
to reflect room temperature (20.degree. C.), general laundry
temperature (45.degree. C.) and general automatic warewashing
temperature (70.degree. C.). The results are reported in FIGS. 1-6
and the Tables below.
Results
[0107] The data obtained is shown in FIGS. 1-6 and the
corresponding Tables below.
[0108] The graphs in FIGS. 1-6, which each have an x, y, and z
axis. The x-axis is a measure of the molar ratio of calcium to
builder, e.g., STPP or water soluble magnesium compound. The y-axis
is a measure of the level of light transmittance thru the samples
with 0% being no light transmitted and 1100% being the entire beam
of light transmitted. Full or partial loss of transmittance occurs
as a consequence of the presence of particulate formation in the
initially clear samples. An effective builder prevents or reduces
precipitation resulting in a clear sample. The z-axis is a measure
of the test temperature, ranging from 20-60.degree. C.
[0109] FIG. 1 is illustrative of a comparative example. FIG. 1 is a
plot of the performance of STPP as a builder in the presence of
various levels of calcium, at various temperatures, and at a
constant pH of 8 and illustrating the impact of Ca/builder ratio
and temperature on the building performance of STPP. Data for FIG.
1 is provided in the table below. Generally, the plot of FIG. 1
shows that STPP is a good chelating agent and as expected as the
concentration of calcium ions increases and as the temperature
increases, STPP has decreasing effectiveness in chelating calcium
ions as reflected in the reduction in the transmittance of the
samples.
TABLE-US-00002 ppm % Ca/STPP Ca/STPP pH T (C.) CaCO3 Transmittance
(wt) (molar) 8 20 50 100 0.07 0.61 8 20 300 81.1 0.40 3.68 8 20 600
67.4 0.80 7.36 8 45 50 99.2 0.07 0.61 8 45 300 72.6 0.40 3.68 8 45
600 64.1 0.80 7.36 8 70 50 99.1 0.07 0.61 8 70 300 41.3 0.40 3.68 8
70 600 41.5 0.80 7.36
[0110] FIG. 2 is illustrative of the invention. FIG. 2 is a plot of
the performance of magnesium chloride in preventing precipitation
in the presence of various levels of calcium, at various
temperatures, and at a constant pH of 8. Data for FIG. 2 is
provided in the table below. This graph shows that a water soluble
salt of magnesium (e.g., magnesium chloride) was unexpectedly
capable of controlling the precipitation of water hardness even at
a neutral pH. Generally, the plot of FIG. 2 shows that magnesium
chloride is a good chelating agent and as the concentration of
calcium ions increases and as the temperature increases, magnesium
chloride has decreasing effectiveness in chelating calcium ions as
reflected in the reduction in the transmittance of the samples. The
results shown in FIG. 2 are surprisingly consistent with that shown
in the comparative FIG. 1.
TABLE-US-00003 ppm % Ca/MgCl.sub.2 Ca/MgCl.sub.2 pH T (C.) CaCO3
Transmittance (wt) (molar) 8 20 50 98.1 0.07 0.32 8 20 300 91.1
0.40 1.90 8 20 600 48 0.80 3.81 8 45 50 96.2 0.07 0.32 8 45 300
92.3 0.40 1.90 8 45 600 55.8 0.80 3.81 8 70 50 96.3 0.07 0.32 8 70
300 92.3 0.40 1.90 8 70 600 50.9 0.80 3.81
[0111] FIG. 3 is a plot illustrative of a comparative example. FIG.
3 shows the performance of STPP as a builder in the presence of
various levels of calcium, at various temperatures, and at a
constant pH of 10. Data for FIG. 3 is provided in the table below.
A comparison of this graph with the results obtained at pH 8 (FIG.
1) shows that the increased alkalinity gives reduced building
performance at elevated temperatures, particularly around
60.degree. C.
TABLE-US-00004 Temp. Ppm % Ca/STTP Ca/STPP pH (C.) CaCO.sub.3
Transmittance (wt) (molar) 10 20 50 99.7 0.07 0.61 10 20 300 70.6
0.40 3.68 10 20 600 51.2 0.80 7.36 10 45 50 98.5 0.07 0.61 10 45
300 49.9 0.40 3.68 10 45 600 36.8 0.80 7.36 10 70 50 98.2 0.07 0.61
10 70 300 22.4 0.40 3.68 10 70 600 26 0.80 7.36
[0112] FIG. 4 is a plot illustrative of the invention. FIG. 4 shows
the performance of magnesium chloride in preventing precipitation
in the presence of various levels of calcium, at various
temperatures, and at a constant pH of 10. Data for FIG. 4 is
provided in the table below. This graph shows that a water soluble
salt of magnesium (e.g., magnesium chloride) was unexpectedly
capable of controlling the precipitation of water hardness even at
a basic pH. The increased alkalinity did not significantly affect
the degree of calcium precipitation compared to pH 8 (FIG. 2). This
is unexpected.
TABLE-US-00005 ppm % Ca/MgCl.sub.2 Ca/MgCl.sub.2 pH T (C.) CaCO3
Transmittance (wt) (molar) 10 20 50 97.4 0.07 0.32 10 20 300 87.8
0.40 1.90 10 20 600 37.6 0.80 3.81 10 45 50 96.5 0.07 0.32 10 45
300 81.1 0.40 1.90 10 45 600 35.4 0.80 3.81 10 70 50 86.1 0.07 0.32
10 70 300 72.4 0.40 1.90 10 70 600 38.1 0.80 3.81 10 45 300 79.9
0.40 1.90 10 45 300 82 0.40 1.90 10 45 300 81.4 0.40 1.90
[0113] FIG. 5 is a plot illustrative of a comparative example. FIG.
5 shows the performance of STPP as a builder in the presence of
various levels of calcium, at various temperatures, and at a
constant pH of 12. Data for FIG. 5 is provided in the table below.
This graph shows that STPP has quit working to control calcium
precipitation at molar ratios of 4 Ca/STPP and higher with light
transmittance dropping down to about 20%. Once again elevated
temperatures make the STPP system more sensitive to water
hardness.
TABLE-US-00006 Temp. Ppm % Ca/STTP Ca/STPP pH (C.) CaCO.sub.3
Transmittance (wt) (molar) 12 20 50 98.8 0.07 0.61 12 20 300 35.4
0.40 3.68 12 20 600 25.5 0.80 7.36 12 45 50 99.2 0.07 0.61 12 45
300 26.4 0.40 3.68 12 45 600 19.7 0.80 7.36 12 70 50 100 0.07 0.61
12 70 300 20.3 0.40 3.68 12 70 600 13.4 0.80 7.36
[0114] FIG. 6 is illustrative of the invention. FIG. 6 shows a plot
of the performance of magnesium chloride in preventing
precipitation in the presence of various levels of calcium, at
various temperatures, and at a constant pH of 12. A comparison of
this graph with FIG. 5 shows that under very alkaline conditions a
water soluble magnesium compound such as magnesium chloride is
comparable to STPP in controlling water hardness
TABLE-US-00007 ppm % Ca/MgCl.sub.2 Ca/MgCl.sub.2 pH T (C.) CaCO3
Transmittance (wt) (molar) 12 20 50 78.9 0.07 0.32 12 20 300 65.9
0.40 1.90 12 20 600 30.9 0.80 3.81 12 45 50 69 0.07 0.32 12 45 300
57.6 0.40 1.90 12 45 600 27.6 0.80 3.81 12 70 50 62.9 0.07 0.32 12
70 300 51.1 0.40 1.90 12 70 600 24.7 0.80 3.81
Discussion
[0115] As can be seen in FIGS. 1-6, magnesium chloride matched or
exceeded the ability of STPP to soften water under most conditions.
By matched or exceeded the ability we mean that the magnesium
chloride reduced lime scale (as reflected by percent transmittance)
to a level comparable to or lower than that achieved with STPP,
e.g., for most molar ratios of calcium and builder. In particular,
the performance of magnesium chloride at pH values of 8 and 10
exceeded the performance of STPP at all temperature values.
[0116] At a pH value of 12, magnesium chloride started at about 80%
transmittance, but had a lower slope compared to STPP. The lower
slope indicates better control of water hardness precipitation as
the ratio of calcium/builder increased.
Example 2
Water Soluble Magnesium Compounds Reduce Formation of Scale from
Hard Water
[0117] This Example demonstrates that adding a hardness ion
(Mg.sup.2+) to water reduced formation of lime scale from hard
water.
Materials and Methods
[0118] Tap water with 17 grain hardness and a 2:1 Ca:Mg weight
ratio was spiked with various levels of magnesium chloride and then
incubated in glass bottles in a 140.degree. F. oven for about two
weeks. The bottles were then visually evaluated for lime scale
build-up.
Results
[0119] The results are presented in the table below.
TABLE-US-00008 Scale on Magnesium Chloride Added (wt-%) Bottle 0
present 0.007 present 0.067 present 0.48 none 2.4 none 7.2 none 14
none
[0120] The data clearly shows the benefit of adding water soluble
magnesium salt to the tap water. In particular, when 0.48 wt-% or
more of magnesium chloride was added, no lime scale build-up was
observed on the surface of the glass bottle. By contrast, when
either no magnesium was present, or when less magnesium chloride
was added, lime scale build-up was observed on the surface of the
glass bottle.
Example 3
Injecting Water Soluble Magnesium Compounds for Rinse Cycle Reduced
Formation of Scale from Hard Water in Warewashing Machine
[0121] This Example demonstrates that, injecting only a hardness
ion (Mg.sup.2+) into rinse water reduced formation of lime scale
from hard water on a dishwasher.
Materials and Methods
[0122] A dishwashing machine was run for 100 cycles using 17 grain
hard water for the wash and rinse cycles with no added rinse agent.
A dishwashing machine was run for 100 cycles using 17 grain hard
water and with water soluble magnesium compound, magnesium sulfate,
introduced as the sole rinse agent. The magnesium sulfate was
introduced at a molar ratio of magnesium ion to calcium ion of 1:1.
No detergent was used in any of the wash cycles.
Results
[0123] FIGS. 7 and 8 are photographs of interiors of dishwashing
machines after 100 cycles run using 17 grain hard water only or
using 17 grain hard water and with water soluble magnesium
compound, magnesium sulfate, introduced as the sole rinse
agent.
[0124] The presence of water soluble magnesium salt, magnesium
sulfate, as the sole rinse agent prevented the build-up of hard
water lime scale on metal as shown in FIG. 8. FIG. 8 shows the
interior of an automatic dishwashing machine with substantially no
lime scale. In fact, the interior of FIG. 8 is shiny and appears as
would the interior of a new automatic dishwashing machine. FIG. 7
shows appreciable hard water lime scale on the interior of the
machine. The lime scale is dull and the dishwasher appears as if a
white powder was dusted on the interior surfaces. No builder or
sheeting agent was needed to obtain this benefit.
Example 4
Magnesium Sulfate as a Source of Magnesium Ion in Excess Over
Calcium Ion Reduced Scale Formation on Glasses
[0125] This Example demonstrates that rinsing glasses with hard
water containing only added hardness ion (Mg.sup.2+) reduced
formation of lime scale from hard water on glasses when magnesium
ion was in excess over calcium ion.
Materials and Methods
[0126] A glass was run though a dishwashing machine for 100 cycles
using 17 grain hard water for the wash and rinse cycles with no
added rinse agent. Other glasses were run though a dishwashing
machine for 100 cycles using 17 grain hard water in a dishwashing
machine with water soluble magnesium compound, magnesium sulfate,
introduced as the sole rinse agent. In separate series of 100
cycles, the magnesium sulfate was introduced at varying
concentrations to provide molar ratios of magnesium ion to calcium
ion of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1. No detergent was used in
any of the wash cycles.
Results
[0127] The results in FIG. 9 show that water soluble magnesium
compound, magnesium sulfate, as the sole rinse agent reduced and
prevented build-up of hard water scale on glassware. In FIG. 9,
glass "C" is a control using hard water alone as the rinse agent.
The other glasses were rinsed using various molar ratios of
magnesium to calcium ranging from 1-3 moles magnesium ion to
calcium ion.
[0128] These ratios are based on the total amount of magnesium
present including that present in the incoming water. Glass "C" in
FIG. 9 is clouded in appearance. It looks as though it is frosted
or has been etched with an etchant. Glass 1:1 is even cloudier or
more frosted than the control glass. Glasses 1.5:1 up to glass 3:1
are increasingly clearer in appearance than the previous glass
(lower ratio) until the 3:1 glass has substantially no filming,
spotting, cloudiness, or etched appearance. Unlike the deposits on
the metal of the dishwasher, rinsing glasses with a 1:1 ratio of
magnesium to calcium increased precipitation of hard water scale
relative to the control. However, a 1.5:1 ratio and higher gave
significant improvement up to a glass free of lime scale at a ratio
of 3:1.
Example 5
Soluble Magnesium Salt Including Anion of Soluble Calcium Salt
Reduced Formation of Scale from Hard Water in Warewashing at Lower
Ratios
[0129] This Example shows a water soluble magnesium salt
(MgCl.sub.2) providing an anion that forms a water soluble calcium
salt reduced formation of lime scale from hard water at lower
ratios of Mg.sup.2+ to Ca.sup.2+ than a magnesium salt (MgSO.sub.4)
providing an anion of a water insoluble calcium salt.
Materials and Methods
[0130] A first glass and a second glass were run though a
dishwashing machine for 100 cycles using 17 grain hard water in a
dishwashing machine with water soluble magnesium compound,
magnesium chloride or magnesium sulfate, introduced as the sole
rinse agent. The water soluble magnesium compounds were introduced
at molar ratios of magnesium ion to calcium ion of 1:1. No
detergent was used in any of the wash cycles.
Results
[0131] The results in FIG. 10 compare glasses rinsed with two
sources of water soluble magnesium compound as the source of the
added magnesium ion. Magnesium chloride and calcium chloride are
both soluble. However, magnesium sulfate is soluble but calcium
sulfate is only slightly soluble.
TABLE-US-00009 Compound Water Solubility (20.degree. C.) magnesium
chloride 54.6 magnesium sulfate 33.7 calcium chloride 42.0 calcium
sulfate 0.2
Interestingly, magnesium chloride effectively reduced formation of
lime scale from hard water at a lower concentration than magnesium
sulfate.
[0132] A magnesium compound such as magnesium chloride where the
analogous calcium salt is water soluble was found to be more
effective in preventing hard water scale than one where the
analogous calcium salt is water insoluble. FIG. 10 illustrates this
at a 1:1 molar ratio of total magnesium ion to calcium ion for both
salts. The glass on the left, treated with a 1:1 molar ratio of
MgCl.sub.26H.sub.2O is substantially clear whereas the glass on the
right, treated with a 1:1 molar ratio of MgSO.sub.47H.sub.2O is
completely cloudy. The MgSO.sub.4 treated glass (right) appears as
if it has been dusted completely with an adherent powder.
Example 6
Water Containing Water Soluble Magnesium Compound Removed Soap
Scum
[0133] Surprisingly, rinsing a tile with hard water containing only
added hardness ion (Mg.sup.2+) removed soap scum from the tile.
Materials and Methods
[0134] A dilute mixture of coconut soap, hard water, and calcium
carbonate was placed on a black ceramic tile and allowed to air
dry. This was repeated five times, producing a heavily soiled tile.
A first section of the soiled tile was immersed in unheated 17
grain hard water for about 1 minute. A second section of the soiled
tile was immersed in unheated 17 grain hard water spiked with about
400 ppm of magnesium chloride. The middle section of the tile was
not soaked after soiling.
Results
[0135] The portion of the tile that was immersed in hard water
without magnesium ion showed considerable soap scum. The portion of
the tile immersed in hard water containing 400 ppm magnesium
chloride showed significantly less soap scum compared to the
portions of the tile that were immersed only in hard water or
untreated. The water containing water soluble magnesium compound
without a builder or surfactant effectively removed soap scum.
[0136] The magnesium chloride was added to obtain a weight ratio of
magnesium ion to calcium ion of 2:1 in the composition of water
soluble magnesium ion. Surprisingly, a composition of a water
soluble magnesium salt including magnesium ion in excess of calcium
ion, will not only reduce or prevent formation of lime scale from
hard water, but it will also remove soap scum.
Example 6
Water Soluble Magnesium Compound Reduced Streaking by Glass
Cleaner
[0137] This Example demonstrates that washing a window with
conventional glass cleaner formulation spiked with Mg.sup.2+
cleaned the window better than the conventional glass cleaner
without the additional hardness ion.
Materials and Methods
[0138] One side of a window was washed with a commercially
available glass cleaner. The other side was washed with the same
commercially available glass cleaner containing 200 ppm water
soluble magnesium salt, e.g., magnesium chloride.
Results
[0139] The left half of the window was cleaned with conventional
glass cleaner with 200 ppm magnesium chloride. The right half of
the window was cleaned with the same conventional glass cleaner
without the addition of magnesium chloride. Streaking on the glass
was greatly reduced with the addition of water soluble magnesium
salt to the formula. Surprisingly, the composition of glass cleaner
and water soluble magnesium salt cleaned the glass better than the
glass cleaner alone.
Example 7
Water Soluble Magnesium Compound Removed Rust
[0140] Surprisingly, soaking a rusty object in water containing
only added hardness ion (Mg.sup.2+) removed rust from the
object.
Materials and Methods
[0141] Pieces of rusty steel were placed in two beakers. One beaker
contained 400 ppm magnesium chloride in 17 grain water. The other
contained 17 grain water. After a couple of hours on the bench top,
the pieces of steel were removed.
Results
[0142] The water in the beaker containing rusty steel in 400 ppm
magnesium chloride in 17 grain water was rust colored. After
soaking, the hard water contained some small pieces of rust, but
was generally. The hard water did not dissolve rust. The water
spiked with water soluble magnesium salt dissolved rust.
Example 8
Water Soluble Magnesium Compounds Protect Surfaces
[0143] This Example illustrates that water soluble magnesium
compound (e.g., magnesium chloride) was found to protect a surface
from hard water.
Materials and Methods
[0144] The contact angle of deionized water on ceramic tiles was
studied. The tiles were first rinsed with a 1000 ppm solution of
either magnesium chloride or magnesium sulfate and then wiped dry.
The contact angle of deionized water on the tiles was measured and
the tiles then rinsed with 17 grain hard water, wiped dry, and the
contact angle of deionized water measured again.
Results
TABLE-US-00010 [0145] Water Contact Angle before hard after hard
water rinse water rinse ratio after/before untreated 37 48 1.3
MgCl.sub.2 21 28 1.3 MgSO.sub.4 11 24 2.2
Discussion
[0146] It was hypothesized that the benefits of water soluble
magnesium compounds might be a consequence of not only the water
solubility of the potential calcium salts which could form in
solution but also the interaction of the magnesium compound with
calcium containing substrates such as glass and ceramic. To test
this hypothesis, the contact angle of deionized water on ceramic
tiles was studied. Improved protection of a calcium-containing
substrate was indicated by reduced effect of a hard water rinse on
the contact angle of water on the substrate. In other words, a
lower ratio of the contact angle of water before and after hard
water rinsing of the substrate correlates to improved protection of
the substrate from hard water. The data demonstrates that magnesium
chloride provided superior protection to a calcium-containing
substrate such as a ceramic tile compared to magnesium sulfate.
Example 9
Solid Compositions of Water Soluble Magnesium Compound
[0147] Magnesium chloride was prepared as a cast solid block.
Magnesium carbonate was prepared as a pressed solid.
Methods and Results
[0148] Solids can be prepared from powders or crystalline materials
by melting and then transferring the molten material into a mold
for solidification upon cooling. A solid block of magnesium
chloride was made by heating magnesium chloride hexahydrate to its
melting point of about 118.degree. C. The molten salt was then
transferred to a plastic container to afford a hard solid upon
cooling to ambient temperature.
[0149] A solid block was made by compressing about 50 grams of
magnesium carbonate monohydrate for about 20 seconds at about 1000
psi.
[0150] Although magnesium carbonate is water insoluble, a pressed
block could also be made including both magnesium carbonate and a
water soluble magnesium salt, such as magnesium chloride.
Discussion
[0151] A pressed or cast solid of a water soluble magnesium
compound can be used, for example, for the treatment of potable
water, for the treatment of a facility or home's overall water
system, or for the treatment of water feed into a mechanical device
such as a dishwasher, clothes washer, or car wash. By adding
magnesium compound to the solid composition, when the composition
is diluted to a use solution, the magnesium ions can reduce
undesirable precipitation of calcium salts. The magnesium can thus
continually treat the equipment as the solid composition
dissolves.
[0152] Magnesium chloride and magnesium sulfate meet the FDA's GRAS
requirements and are approved as an unrestricted direct food
additive. Not wishing to be bound by theory, it is believed that,
in the pressed solid of magnesium carbonate, the water of hydration
can be a binding agent in the block. For forming a cast solid from
magnesium chloride, the presence of water of hydration (and
additional water if desired) affords a reduced melting point
compared to the anhydrous salt, allowing the temperature of the
process to be reduced to a practical level.
[0153] The invention has been described with reference to various
specific and preferred embodiments and techniques. However, it
should be understood that many variations and modifications may be
made while remaining within the spirit and scope of the
invention.
* * * * *