[0001] The present invention relates to compositions and methods for the rapid and facile
removal of tarnish from household articles having a surface comprising silver (e.g.,
sterling silver or silver plate) or a substantial amount of copper (e.g., copper,
brass, bronze or German silver).
[0002] Removing tarnish from household articles, such as silverware, silver candlesticks,
copper- bottomed cooking ware, brass candlesticks and the like, has long been a difficult,
unpleasant and time- consuming task. Silver, German silver or silver plated household
articles require considerable rubbing before the tarnish is removed, typically with
a polishing material that is itself difficult to remove from recesses (e.g., engraved
lines or crevices adjacent to rolled edges) in the surface of the article. Household
articles made of copper, brass or bronze generally require treatment with abrasive
cleansers and, once again, application of considerable "elbow grease". Also, typical
prior art polishing materials have unpleasant odors.
[0003] Various amines have been used previously for removing corrosion from industrial products.
However, the industrial applications of those amines have involved one or more of
long treatment times, excessively high temperatures, and the use
'of abrasive materials that are unacceptable for household articles. U.S. Patent 2,731,420
(Sylvester) refers to the use of certain ammonia derivatives in detergent compositions
that contain water soluble polyphosphates (which are now recognized as being harmful
to the environment) to inhibit the tendency of the polyphosphates to . tarnish German
silver, but there is no recognition by Sylvester that any of his ammonia derivatives
are useful to remove tarnish or would perform any useful function in a non-phosphorous
containing detergent composition.
[0004] The present invention, on the other hand, provides compositions and methods for the
convenient, rapid, and effective removal of tarnish from household articles. For example,
the compositions of the invention may be dishwashing liquids or dishwashing detergent
compositions for automatic dishwashers that include certain tarnish-removing additives.
[0005] We have found, surprisingly, that aqueous solutions of certain specific chelating
agents (also known as sequestering agents), either alone or with an accelerator selected
from certain amines or ammonium salts, may be used to remove rapidly and conveniently
tarnish from household articles. Indeed, a brief period of gentle rubbing with a sponge,
a nylon scrubber, or similar material is all that is required. It is particularly
surprising that certain of the aforementioned chelating agents (e.g., ethylenediamine)
are even effective by themselves to remove rapidly and conveniently tarnish from household
articles because other related amines (e.g., 1,4-diaminobutane, diethylenetriamine
and triethylenetetraamine) are not effective by themselves. More specifically, we
have found that when our chelating agent is an acyclic diamine in which the amino
groups are adjacent to one another or separated by only a single carbon atom, the
chelating agent is effective by itself to remove tarnish and an accelerator is not-required.
[0006] The aforementioned chelating agents and accelerators can be used to prepare aqueous
solutions that are useful in removing tarnish or they can conveniently be incorporated
in'conventional dishwashing formulations, both liquids and powders. The resulting
dishwashing formulations resemble quite closely general cleaning compositions but
will be more useful than such compositions because they will also remove tarnish.
Thus, the foregoing dishwashing formulations may be used to clean items that do not
require tarnish removal (e.g., articles of porcelain, stainless steel, aluminum or
glass) since the chelating agents and accelerators will not harm such materials, but
will also be useful in removing tarnish when the need arises.
[0007] More particularly, one embodiment of the present invention relates to a phosphorous-free
(e.g., containing no phosphates or polyphosphates) dishwashing detergent composition,
formulated in the form of a liquid, which is useful in washing dishes by hand and
is also useful in removing tarnish from household articles having a surface comprising
silver or a substantial amount of copper, said composition comprising water; a chelating
agent selected from the group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane,
1,2-diaminoisobutane, ethylenediamine tetraacetic acid, ethylenediamine tetraacetic
acid salts, diethylenetriamine pentaacetic acid, and diethylenetriamine pentaacetic
acid salts; at least one surfactant; and at least one antioxidant (e.g., butylated
hydroxytoluene (BHT) or butylated hydroxyanisole (BHA)); with the proviso that when
the chelating agent is other than ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane
or 1,2-diaminoisobutane, the composition also comprises an accelerator selected from
the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine,
1,4-diaminobutane, triethylenetetraamine, and ammonium salts. Preferably, the concentration
of the surfactant is at least about 25% by weight, based on the weight of the composition.
Other ingredients that are typically used in conventional liquid dishwashing detergent
compositions, such as dispensing aids (e.g., ethyl alcohol), stabilizing agents (in
addition to antioxidants which are discussed above), colorants and perfumes, may also
be included.
[0008] As used herein, a phosphorous-free composition means a solution that contains essentially
no phosphorous, i.e., no phosphorous or less than about 0.1% by weight of phosphorous.
[0009] In another embodiment, the present invention relates to a phosphorous-free dishwashing
detergent composition, formulated in the form of a powder, which is useful in washing
dishes in an automatic dishwasher and is also useful in removing tarnish from household
articles having a surface comprising silver or a substantial amount of copper, said
composition comprising a chelating agent selected from the group consisting of ethylenediamine,
1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane, ethylenediamine tetraacetic
acid, ethylenediamine tetraacetic acid salts, diethylenetriamine pentaacetic acid,
and diethylenetriamine pentaacetic acid salts; and at least one surfactant; with the
proviso that when the chelating agent is other than ethylenediamine, 1,2-diaminopropane,
1,3-diaminopropane or 1,2-diaminoisobutane, the composition also comprises an accelerator
selected from the group consisting of ethanolamine, diethanolamine, triethanolamine,
diethylenetriamine, 1,4-diaminobutane, triethylenetetraamine, and ammonium salts.
Preferably, the foregoing composition also comprises at least one suds control agent.
Other ingredients that are typically used in conventional powder dishwashing detergent
compositions, such as corrosion inhibitors (e.g., sodium silicates), colorants and
perfumes, may also be included.
[0010] In another embodiment; the present invention relates to a phosphorous-containing
(containing, for example, phosphates or polyphosphates) dishwashing detergent composition,
formulated in the form of a liquid, which is useful in washing dishes by hand and
is also useful in removing tarnish from household articles having a surface comprising
silver or a substantial amount of copper, said composition comprising water; a chelating
agent selected from the group consisting of 1,2-diaminopropane, 1,3-diaminopropane,
1,2-diaminoisobutane, ethylenediamine tetraacetic acid, ethylenediamine tetraacetic
acid salts, diethylenetriamine pentaacetic acid, and diethylenetriamine pentaacetic
acid salts; at least one phosphorous-containing builder; and at least one surfactant;
with the proviso that when the chelating agent is other than 1,2-diaminopropane, 1,3-diaminopropane,
or 1,2-diaminoisobutane, the composition also comprises an accelerator selected from
the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine,
1,4-diaminobutane, triethylenetetraamine, and ammonium salts. Preferably, the foregoing
composition also comprises at least one antioxidant (e.g., BET or BHA). It is also
preferred that the concentration of the surfactant be at least about 25% by weight,
based on the weight of the composition. Other ingredients that are typically used
in conventional liquid dishwashing detergent compositions may also be included.
[0011] In another embodiment, the present invention relates to a phosphorous-containing
dishwashing detergent composition, formulated in the form of a powder, which is useful
in washing dishes in an automatic dishwasher and is also useful in- removing tarnish
from household articles having a surface comprising silver or a substantial amount
of copper, said composition comprising a chelating agent selected from the group consisting
of 1,2-diaminopropane, 1,3- . diaminopropane, 1-2-diaminoisobutane, ethylenediamine
tetraacetic acid, ethylenediamine tetraacetic acid salts, diethylenetriamine pentaacetic
acid, and diethylenetriamine pentaacetic acid salts; at least one phosphorous-containing
builder; and at least one surfactant; with the proviso that when the chelating agent
is other than 1,2-diaminopropane, 1,3-diaminopropane or 1,2-diaminoisobutane, the
composition also comprises an accelerator selected from the group consisting of ethanolamine,
diethanolamine, triethanolamine, diethylenetriamine, 1,4-diaminobutane, triethylenetetraamine,
and ammonium salts. Preferably, the foregoing composition also comprises at least
one suds control agent. Other ingredients that are typically used in conventional
powder dishwashing detergent compositions may also be included.
[0012] The foregoing liquid compositions are particularly useful when one desires to remove
tarnish by hand. The foregoing powder compositions are particularly useful when one
desires to remove tarnish from household articles using an automatic dishwasher.
[0013] The liquid compositions of the present invention comprise at least about 0.1% by
weight (based on the weight of the composition) of chelating agent, and, if an accelerator
is present, at least about 0.1% by weight (based on the weight of the composition)
of accelerator. In addition, the weight ratio of chelating agent to accelerator, if
an accelerator is present, is in the range of about 1 to 5 to about 5 to 1. More preferably,
the chelating agent is present at a concentration 01 at least about 1% by weight and
the accelerator, if present, is present at a concentration of at least about 1% by
weight. In addition, the weight ratio of chelating agent to accelerator, if an accelerator
is present, is about 1 to 3 to about 3 to 1. The most preferred concentration is about
3% by weight for the chelating agent and, if an accelerator is present, about 2% by
weight for the accelerator. Higher concentrations are effective but are not advantageous
and are economically wasteful. The concentration of surfactant in the foregoing liquid
compositions is preferably at least about 25% by weight, based on the weight of the
composition.
[0014] The powder compositions of the invention preferably comprise at least about 1% by
weight (based on the weight of the composition), and more preferably at least about
3% by weight of chelating agent and, if an accelerator is present, at least about
1% by weight (based on the weight of the composition) and more preferably at least
about 3% by weight of accelerator. If an accelerator is present, the weight ratio
of chelating agent to the accelerator in such powder compositions should be in the
range of about 1 to 3 to about 3 to 1. More preferably, the ratio is about 2 to 1.
Most preferably, the concentration of the chelating agent will be about 6% by weight
and the concentration of the accelerator, if an accelerator is present, will be about
3.5% by weight. When using such a composition in a home dishwasher (e.g., the type
typically having a capacity for washing service for twelve and utilizing a wash water
temperature of about 140°F), the same amount of detergent composition as would normally
be used for washing a typical load of dishes will generally be effective in removing
tarnish.
[0015] The present invention also relates to a method of removing tarnish from household
articles having a surface comprising silver or a substantial amount of copper, said
method comprising rubbing the tarnished surface by hand with an aqueous solution comprising
a chelating agent selected from the group consisting of ethylenediamine, 1,2-diaminopropane,
1,3-diaminopropane, 1,3-diaminoisobutane, ethylenediamine tetraacetic acid, ethylenediamine
tetraacetic acid salts, diethyelenetriamine pentaacetic acid, and diethylenetriamine
pentaacetic acid salts, with the proviso that when the chelating agent is other than
ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane or 1,2-diaminoisobutane, said
aqueous solution also comprises an accelerator selected from the group consisting
of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine, 1,4-diaminobutane,
triethylenetetraamine, and ammonium salts. Preferably, the aqueous solution used in
this method is one of the liquid dishwashing detergent compositions described above.
[0016] In another embodiment, the present invention relates to a method of removing tarnish
from household articles having a surface comprising silver or a substantial amount
of copper, said method comprising contacting the tarnished surface in an automatic
dishwasher with an aqueous solution comprising a chelating agent selected from the
group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane,
ethylenediamine tetraacetic acid, ethylenediamine tetraacetic acid salts, diethyelenetriamine
pentaacetic acid, and diethylenetriamine pentaacetic acid salts, with the proviso
that when the chelating agent is other than ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane
or 1,2-diaminoisobutane, said aqueous solution also comprises an accelerator selected
from the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine,
1,4-diaminobutane, triethylenetetraamine, and ammonium salts. The foregoing aqueous
solution may be obtained by dissolving a dishwashing detergent composition, formulated
as a powder, in the wash water of the dishwasher during the dishwasher's wash cycle.
[0017] Although an accelerator is not required in the compositions and methods of the present
invention when the chelating agent is ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane,
or 1,2-diaminoisobutane, an accelerator may be used together with ethylenediamine,
1,2-diaminopropane, 1,3-diaminopropane, or 1,2-diaminoisobutane in such compositions
and methods. It is also within the scope of the present invention to use mixtures
of two or more chelating agents and to use mixtures of two or more accelerators.
[0018] As indicated above, each of the four chelating agents ethylenediamine, 1,2-diaminopropane,
1,3-diaminopropane and 1,2-diaminoisobutane are effective in removing tarnish even
in the absence of an accelerator. Other acyclic diamines in which the amino groups
are adjacent to one another or are separated by only a single carbon atom may be substituted
for the foregoing four chelating agents to form tarnish removing compositions. If
this is done, however, care should be taken that the chelating agent is one that is
soluble in aqueous solution to the extent necessary to prepare a solution having a
sufficiently high concentration of chelating agent to be effective in removing tarnish.
[0019] Preferred ammonium salts for use as an accelerator in the compositions and methods
of the present invention are those that are commercially available, relatively inexpensive
and non-toxic. Examples of such ammonium salts are ammonium chloride, ammonium nitrate
and ammonium sulfate. Ammonium salts of ethylenediamine tetraacetic acid and of diethylenetriamine
pentaacetic acid may be used without an additional accelerator since the ammonium
moiety of these salts functions as the accelerator.
[0020] Preferred salts of the foregoing polyamino- carboxylate chelatihg agents are ammonium
salts or the salts of alkaline metals such as sodium or potassium. Whether a particular
chelating agent is present, in solution, in acid or salt form will depend upon the
pH of the solution.
[0021] As used herein, surfactant shall include anionic, cationic and nonionic surfactants,
including soaps (i.e., alkaline salts of long-chain fatty acids). The preferred surfactants
for use in the liquid detergent compositions of the invention are anionic surfactants
such as linear sodium alkyl benzene sulfonates, linear alkyl sulfates and linear alkylethoxy
sulfates.
[0022] Commercial liquid dishwashing detergents generally contain at least one anionic surfactant
and many such detergents also contain a nonionic surfactant. Such detergents are generally
intended for use in washing dishes by hand.
[0023] For automatic dishwashing detergents, nonionic surfactants are preferred because
of their lower sudsing characteristics. Commercially used nonionic surfactants include
the alkyl ethoxylates, the ethoxylated alkyl phenols, the fatty acid ethanol amides,
and complex polymers of ethylene oxide, propylene oxide, and alcohols. Automatic dishwashing
detergents may also contain an anionic surfactant. Cationic surfactants may be used,
but are not often used, in automatic dishwashing detergents.
[0024] It may be advantageous to use an antioxidant (for example butylated hydroxyanisole
(BHA) or butylated hydroxytoluene (BHT)) in the compositions of the present invention
that comprise a surfactant. The antioxidant serves to prevent oxidation of the surfactant.
Examples of surfactants that are, otherwise, particularly susceptible to oxidation
are nonionic surfactants and certain anionic surfactants (e.g., lauryl alcohol derivatives).
[0025] A dishwashing detergent composition may, also contain one or more of the following
additives:
a) Builders. Builders function to sequester calcium and magnesium ions in water. Condensed
polyphosphates, such as pentasodium tripolyphosphate (STP) and tetrasodium pyrophosphate,
may be used in the dishwashing compositions of the invention, but such polyphosphates
are generally considered to be undesirable from an environmental standpoint. Nonphosphate
builders that may be used in the invention include, for example, trisodium nitrilotriacetate
(NTA) and tetrasodium ethylenediamine tetraacetate (EDTA). EDTA is also useful as
a chelating agent in the compositions of the present invention. Generally, when EDTA
is used as a builder, it is used in smaller quantities than would be preferred for
tarnish removal.
b) Corrosion Inhibitors. The tendency of alkaline detergents to corrode aluminum,
porcelain, and the overglaze on fine china may be prevented or minimized by adding
one or more corrosion inhibitors to the detergent. Suitable corrosion inhibitors include
the soluble sodium silicates.
c) sudsing Modifiers. sudsing modifiers may be used to increase sudsing when such
additional sudsing is desired to enhance the aesthetic appeal of the detergent. Anionic
surfactants, such as mono and diethanol amides of C10-16 fatty acids, can be used for this purpose. Sudsing modifiers can also be used to
depress sudsing in automatic dishwashers. This can be accomplished by the addition
of one or more of the C10-16 fatty acids to the detergent.
Sudsing modifiers that are used to depress sudsing are also referred to as suds control
agents.
[0026] In addition to the foregoing additives, other additives that are conventionally used
in dishwashing compositions may be utilized in the compositions of the present invention.
Such additives include colorants, perfumes and stabilizing agents.
[0027] The compositions described above may be used in several different ways to remove
tarnish from household articles. The following are illustrations of how the aforementioned
compositions may be used:
a) A small amount (e.g., about 5 ml) of a dishwashing liquid of the invention may
be applied full strength, at room temperature or slightly above room temperature (about
20 to 40°C), to a sponge or similar cleaning aid and then gently rubbed on a tarnished
article. Typically, only little effort is required when tarnish is removed in this
manner. Generally, the same amount of effort is required as would typically be used
to clean a Teflon@ coated surface, using, for example a sponge or a rubbing implement
such as a nylon scrubber.
b) A dishwashing liquid of the invention may be diluted with water, preferably with
warm water .having a temperature of from about 30 to about 50°C, in a dishpan and
subsequently applied to a tarnished article by hand, preferably using a rubbing implement
such as a sponge or a nylon scrubber.
c) A dishwashing powder of the invention may be used to remove tarnish from a tarnished
article (which may be present together with untarnished articles such as dishes, aluminum
pots and the like) in an automatic dishwasher. In such dishwashers, the dishwashing
powder is dissolved in hot water at high temperatures (i.e., 140°F or higher). The
scrubbing action that occurs during normal operation of the dishwasher is generally
sufficient to remove tarnish from household articles.
(d) A small amount of. a dishwashing powder of the invention may be placed on a rubbing
implement, e.g., a wet sponge or wet nylon scrubber, and gently rubbed on a tarnished
article. The person practicing this method may wish to cover his or her hands (e.g.,
with rubber gloves) in order to protect them from the dishwashing powder, which might
otherwise irritate the hands.
[0028] In another embodiment of the method of the invention, tarnish is removed from household
articles having a surface comprising silver or a substantial amount of copper by rubbing
by hand (preferably, using a rubbing implement such as a sponge or a nylon scrubber)
on such articles an aqueous solution consisting essentially of a chelating agent and,
if required, an accelerator (e.g., a solution that does not contain any surfactant
or phosphate builder). The concentrations of chelating agent and accelerator (if required)
in such an aqueous solution are preferably the same as the preferred concentrations
of those materials in the liquid dishwashing detergent as set forth above.
1. A liquid phosphorus-free dishwashing detergent and tarnish removing composition
comprising water; a chelating agent selected from the group consisting of ethylenediamine,
1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane, ethylenediamine tetraacetic
acid, ethylenediamine tetraacetic acid salts, diethylenetriamine pentaacetic acid,
and diethylenetriamine pentaacetic acid salts; at least one surfactant; and at least
one antioxidant; with the proviso that when the chelating agent is other than ethylenediamine,
1,2-diaminopropane, 1,3-diaminopropane or 1,2-diaminoisobutane, the composition also
comprises an accelerator selected from the group consisting of ethanolamine, diethalonamine,
triethanolamine, diethylenetriamine, 1,4-diaminobutane, triethylenetetraamine, and
ammonium salts, said composition containing essentially no phosphorous.
2. A phosphorous-free dishwashing detergent and tarnish removing composition, formulated
in the form of a powder, said composition comprising a chelating agent selected from
the group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane,
ethylenediamine tetraacetic acid, ethylenediamine tetraacetic acid salts, diethylenetriamine
pentaacetic acid, and diethylenetriamine pentaacetic acid salts; at least one surfactant;
with the proviso that when the chelating agent is other than ethylenediamine, 1,2-diaminopropane,
1,3-diaminopropane or 1,2-diaminoisobutane, the composition also comprises an accelerator
selected from the group consisting of ethanolamine, diethanolamine, triethanolamine,
diethylenetriamine, 1,4-diaminobutane, triethylenetetraamine, and ammonium salts,
said composition comprising essentially no phosphorous.
3. A liquid dishwashing detergent and tarnish removing composition, comprising water;
a chelating agent selected from the group consisting of 1,2-diaminopropane, 1,3-diaminopropane,
1,2-diaminoisobutane, ethylenediamine tetraacetic acid, ethylenediamine tetraacetic
acid salts, diethylenetriamine pentaacetic acid, and diethylenetriamine pentaacetic
acid salts; at least one surfactant; and at least one phosphorous-containing builder;
with the proviso that if the chelating agent is other than 1,2-diaminopropane, 1,3-diaminopropane
or 1,2-diaminoisobutane, the composition also comprises an accelerator selected from
the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine,
1,4-diaminobutane, triethylenetetraamine, and ammonium salts.
4. A dishwashing detergent and tarnish removing composition, formulated in the form
of a powder, said composition comprising a chelating agent selected from the group
consisting of 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane, ethylenediamine
tetraacetic acid, ethylenediamine tetraacetic acid salts, diethylenetriamine pentaacetic
acid and diethylenetriamine pentaacetic acid salts; at least one surfactant, and at
least one phosphorous containing builder; with the proviso that when the chelating
agent is other than 1,2-diaminopropane, 1,3-diaminopropane or 1,2-diaminoisobutane,
the composition also comprises an accelerator selected from the group consisting of
ethanolamine, diethanolamine, triethanolamine, diethylenetriamine, 1,4-diaminobutane,
triethylenetetraamine, and ammonium salts.
5. A composition according to claim 1 or claim 3 wherein the chelating agent is present
at a concentration of at least about 0.1% by weight of the detergent composition and,
if the accelerator is present, the accelerator is present at a concentration of at
least about 0.1% by weight of the detergent composition and the weight ratio of chelating
agent to accelerator is about 1 to 5 to about 5 to 1.
6. A composition according to any one of claims 2, 4 and 5 wherein the chelating agent
is present at a concentration of at least about 1% by weight of the detergent composition
and, if the accelerator is present, the accelerator is present at a concentration
of at least about 1% by weight of the detergent composition and the weight ratio of
chelating agent to accelerator is about 1 to 3 to about 3 to 1.
7. A composition according to claim 6 as appendant to claim 5, wherein the chelating
agent is present at a concentration of about 3% by weight and the accelerator, if
present, is present at a concentration of about 2% by weight.
8. A composition according to claim 6 as appendant to claim 2 or claim 4, wherein
the chelating agent is present at a concentration of at least 3% by weight and the
accelerator, if present, is present at a concentration of at least about 3% by weight.
9. A composition according to claim 8, wherein the concentration of the chelating
agent is about 6% by weight and the concentration of the accelerator if present, is
about 3.5% by weight.
10. A composition according to claim 2 or claim 4, said composition also comprising
at least one suds control agent.
11. A composition according to claim 10, said composition also comprising a corrosion
inhibitor.
12. A method of removing tarnish from household articles having a surface comprising
silver or a substantial amount of copper, said method comprising rubbing the tarnished
surface by hand with an aqueous solution comprising a chelating agent selected from
the group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diaminoisobutane,
ethylenediamine tetraacetic acid, ethylenediamine tetraacetic acid salts, diethylenetriamine
pentaacetic acid, and diethylenetriamine pentaacetic acid salts, with the proviso
thatwhen the chelating agent is other than ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane
or 1,2-diaminoisobutane, said aqueous solution also comprises an accelerator selected
from the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine,
1,4-diaminobutane, triethylenetetramine, and ammonium salts. 13. A method according
to claim 12, wherein said aqueous solution is a dishwashing liquid that also comprises
a surfactant.
14. A method according to claim 12, wherein the chelating agent is present at a concentration
of at least about 0.1% by weight of the detergent composition, and if the accelerator
is present, the accelerator is present at a concentration of at least about 0.1% by
weight of the detergent composition and the weight ratio of chelating agent to accelerator
is about 1 to 5 to about 5 to 1.
15. A method according to claim 14, wherein the chelating agent is present at a concentration
of at least about 1% by weight of the detergent composition and, if the accelerator
is present, the accelerator is present at a concentration of at least about 1% by
weight of the detergent composition and the weight ratio of chelating agent to accelerator
is about 1 to 3 to about 3 to 1.
16. A method according to claim 15, wherein the chelating agent is present at a concentration
of about 3% by weight and the accelerator, if present, is present at a concentration
of about 2% by weight.
17. A method of removing tarnish from household articles having a surface comprising
silver or a substantial amount of copper, said method comprising contacting the tarnished
surface in an automatic dishwasher when an aqueous solution comprising a chelating
agent selected from the group consisting of ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane,
1,2-diaminoisobutane, ethylenediamine tetraacetic acid, ethylenediamine tetraacetic
acid salts, diethylenetriamine pentaacetic acid, and diethylenetriamine pentaacetic
acid salts, and also comprising a surfactant, with the proviso that when the chelating
agent is other than ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane or 1,2-diaminoisobutane,
said aqueous solution also comprises an accelerator selected from the group consisting
of ethanolamine, diethanolamine, triethanolamine, diethylenetriamine, 1,4-diaminobutane,
triethylenetetramine, and ammonium salts.
18. A method according to claim 17, wherein said aqueous solution is obtained by dissolving
a dishwashing detergent composition, formulated as a powder, in the wash water of
the dishwasher during the wash cycle of the dishwasher.
19. A method according to claim 17, wherein the chelating agent is present at a concentration
of at least about 1% by weight of the detergent composition and, if the accelerator
is present, the accelerator is present at a concentration of at least about 1% by
weight of the detergent composition and the weight ratio of chelating agent to accelerator
is about 1 to 3 to about 3 to 1.
20. A method according to claim 19, wherein the chelating agent is present at a concentration
of at least about 3% by weight and the accelerator, is present, is present at a concentration
of at least about 3% by weight.
21. A method acording to claim 20, wherein the concentration of the chelating agent
is about 6% by weight and the concentration of the accelerator, if present, is about
3.5% by weight.