FIELD OF THE INVENTION
[0001] This invention relates to detergent compositions, especially enzyme/bleach-containing
detergent compositions, and to methods for machine dishwashing in a domestic dishwasher.
BACKGROUND OF THE INVENTION
[0002] Automatic Dishwashing is a demanding field in which specialized detergent formulations
are required to deliver efficient and effective sanitization and cleansing of dishware,
including stain removal and tough food cleaning. Automatic Dishwashing has some unique
constraints as compared to fabric laundering, for example, spotlessness and lack of
film is desired on glasses and silverware. In many laundering operations, in contrast,
there is a tolerance for substances which may be greasy, oily, soapy or lubricious,
often fabric softeners or fatty acid salts, being deposited on fabrics.
[0003] In modern automatic dishwashing formulations, tough food cleaning performance is
essential, and this is commonly accomplished by detersive enzymes. Alkalis are also
used, but may be highly corrosive, especially at high levels. Stain removal is best
accomplished by a variety of bleaches.
[0004] Owing to the enzyme-deactivating nature of some of the most effective bleaches, especially
hypochlorite bleaches, compromise detergent formulations have often been provided.
This includes formulations in which a relatively mild and enzyme-compatible bleach,
such as perborate, is combined with the enzymes; optionally with activators. Such
formulations are commercially available in some geographies.
[0005] Various efforts have been made to increase the compatibility of detersive enzymes
with deactivating materials. Such efforts include the engineering of improved enzymes
and the provision of stabilized enzyme particles for fabric laundering. The latter
can contain one or more stabilizing agents, anti-oxidants, or bleach scavengers. The
types and amounts of such agents are selected to enhance product stability on storage
or to improve enzyme stability when a domestic water supply contains, as it commonly
does for health reasons, a certain limited amount of free chlorine.
[0006] Thus U.S. Patents 3,755,085, Tivin, issued Sept. 30, 1970 and 3,893,954, Tivin, issued
July 8, 1975, describe detergent compositions for fabric laundering containing enzyme
and chlorine scavenger such as tris(hydroxymethyl)aminomethane and a variety of additional
amino alcohols. U.S. Patent 4,810,413, Pancheri et al, issued Mar. 7, 1989, describes
granular detergent compositions, exemplified by fabric laundering detergents, comprising
an enzyme component that is inactivated by free chlorine, a chlorine scavenger which
is a salt containing an ammonium cation, a detergent surfactant, and a detergent builder.
Chlorine scavengers described include not only ammonium salts but anions such as sulfite,
bisulfite, thiosulfite, thiosulfate, carbamate and ascorbate, and combinations thereof.
[0007] Machine Dishwashing by use of tablets for the sequential release of different materials,
which can include bleach and enzymes, is described in EP 481, 547 A1, published April
22, 1994, by Unilever NV. It is taught that delaying the release of bleach provides
superior results. This system is a macro-particle having, on one hand convenience,
but on the other hand, the known disadvantages of tablets as compared to granular
detergents.
[0008] U.S. Patent 5,324,649, Arnold et al, issued Jun. 28, 1994, describes enzyme-containing
granules coated with hydrolyzed polyvinyl alcohol or copolymer thereof, optionally
further comprising a chlorine scavenger and/or other materials such as a lubricant.
These particles very rapidly release their enzyme activity, as shown, for example,
by Fig. 3 of this patent in which enzyme activity released from the granule reaches
a maximum after only about one minute. Usefully for purposes of background herein,
Arnold et al describe common enzyme-processing and coating operations, pigments or
process additives such as Titanium Dioxide useful for producing acceptably colored
enzyme particles, substances which can be present in commercial enzyme broths, enzyme
cores and core materials, and enzyme protecting agents or scavengers such as ammonium
sulfate, ammonium citrate, urea, guanidine hydrochloride, guanidine carbonate, guanidine
sulfonate, thiourea dioxide, monoethanolamine, diethanolamine, triethanolamine, amino
acids such as glycine, sodium glutamate and the like, and proteins such as bovine
serum albumin, casein and the like.
[0009] U.S. Patent 4,973,417, Falholt, issued Nov. 27, 1990, describes enteric coated detergent
enzymes, optionally comprising anti-oxidants. It is explained therein that this improves
stability of the enzyme granules in humid environments in presence of strongly oxidizing
bleaches. Other aspects of the disclosure useful for background purposes herein include
description of "cores" exhibiting particle sizes between 2 and 2000 micron, fluid
bed processing such as Wurster bed processing or rotor bed (Glatt) processing, and
specific copolymers such as copolymers of methacrylic acid and an acrylic acid ester,
preferably a methyl or ethyl ester, which are used to produce the coating. Such polymers
have low solubility at pH = 6 but have solubility which rises rapidly for pH values
above 6. Fillers, plasticizers and the like may be used to produce the enteric coated
enzyme particles and antioxidant such as sodium bisulfite or ascorbate may be used.
[0010] U.S. Patent 5,254,283, Arnold and Becker, issued Oct. 19, 1993, describes isophthalic
polymer-coated particles which comprise enzymes and oxidant scavengers or enzyme protecting
agents. Fig. 1 of this patent shows a rapid release of ammonium sulfate starting at
time = 0 and reaching a maximum at 0.5 minutes, and a gradually increasing release
of enzyme starting also at time = 0 and reaching a maximum at about 2 minutes.
[0011] Other approaches to compatibilize enzymes with bleaches for increased storage stability
or treatment of chlorine in the water supply include coating the bleach component,
using clay coatings on enzyme and/or on bleach, and the like.
[0012] Regardless of the efforts made especially in storage stabilization and avoidance
of enzyme "shock" from chlorinated water, and even in the area of sequencing the delivery
of ingredients in tablets, no completely satisfactory solutions have been found leading
to the successful commercial introduction of automatic dishwashing granules comprising
effective amounts of enzyme-deactivating bleach and detersive enzymes such as proteases
and amylases in a compatible fashion. Moreover, enzyme particles now typically available
for use in automatic dishwashing have one or more shortcomings in the areas of bleach
compatibility, spotting/filming, storage stability and the like.
[0013] Since hypochlorite and similar enzyme-deactivating bleaches are highly reactive,
it would have been expected that the best way to sequentially deliver such bleaches
with enzymes in automatic dishwashing would be to release the enzyme first, permit
it to work for an extended period to best effect, and then "finish" the cleaning operation
with a short burst of the quickly-acting enzyme-deactivating bleach. In terms of detergent
design this suggests (a) coating the bleach and (b) maximizing the rapid release of
enzymes alter adventitious chlorine in the wash water has been scavenged. Such logic
would lead the formulator of automatic dishwashing granules to select, from the range
of release profiles of commercial enzymes, those enzymes which are fast-released,
after an initial delivery of some scavenger to treat the water. Bleach coatings are
known. See U.S. Patent 4,867,895, Choy, issued Sept. 19, 1989, and the hereinbefore
referenced EP 481,574 A.
[0014] Despite the above putative sequence, it has now unexpectedly been discovered that
for automatic dishwashing purposes, excellent bleaching and enzymatic action are obtained
in a staged release operation in which first, a rapidly-acting bleach is delivered
and allowed to act for a limited period, for example a few minutes; then this bleach,
along with any chlorine which may originally have been in the water, are destroyed
or converted to an enzyme-compatible form (in either case "compatibilized" with detersive
enzyme) using an effective, preferably "more-than-chlorine-scavenging" amount of a
bleach scavenger (the phrase "more than scavenging" referring to the fact that significantly
more scavenger is needed than the amount which would be needed merely to deal with
the chlorination of the water supply); and then, for a third, and now more substantial
time period, the enzyme component of the granular automatic dishwashing detergent
formulation is provided and allowed to act.
[0015] This discovery leads to a specific selection in an automatic dishwashing detergent
of those enzyme particles which delay release of enzyme to a greater extent than is
considered ideal for laundry or chlorinated water control purposes, yet to a lesser
extent than would be observed from the use of say, a typical agricultural fertilizer
coating and its associated release profile.
[0016] Without intending to be limited by theory, it is believed that the early release
of the enzyme-deactivating bleach co-incides with a time period in the overall wash
operation in which food soils have been dispersed to the minimum extent. This minimizes
wasteful reaction of the bleach with dispersed food soil and permits it to react to
good effect with colored stains or deposits on the dishware. Later in the wash, food
soils, often "dried-on" food, are dispersed, and as is known, actually assist in stabilizing
the later-released enzymes as they perform their more leisurely, but nonetheless vital
action.
[0017] It is therefore an object herein to provide an improved granular detergent comprising
detersive enzymes, bleach scavengers, enzyme-deactivating bleaches and certain coating
polymers, in a format engineered to deliver staged release of the desired ingredients,
especially in the washing process of commercial domestic automatic dishwashing appliances,
so that the sum of stain-removing, cleaning and spotting/filming benefits of the bleach
and enzymes is maximized. Other objects include the provision of improved methods
for providing compatibilized staged release of bleaches followed by enzymes in a cleaning
operation.
BACKGROUND ART
[0018] Controlled Release Technology (Agrigultural, Pharmaceutical), Coating Processes (Powder
Technology, Spray Technology), Bleaching Agents, Enzymes, and Ammonium Salts are reviewed
in Kirk Othmer, Encyclopedia of Chemical Technology, Fourth Edition, John Wiley and
Sons, New York, incorporated by reference. See also the hereinbefore referenced U.S.
3,755,085, 3,893,954, 4,810,413, 5,324,649, 4,973,417 and 5,254,283; as well as EP
481,547 A.
SUMMARY OF THE INVENTION
[0019] The present invention relates to a detergent composition for the release of bleach
followed by enzyme, said composition comprising: (a) at least one enzyme-deactivating
bleach, such as a hypochlorite, for example in the form of sodium dichloroisocyanurate;
(b) at least one bleach scavenger, for example ammonium sulfate or sodium bisulfite;
and (c) at least one detersive enzyme, for example a mixture of protease and amylase;
and wherein further, upon mixing with water, said detergent composition begins releasing:
(i) a stain-removal effective amount of said enzyme-deactivating bleach, followed
by (ii) a compatibilizing amount of said bleach scavenger, followed thereafter by
(iii) a cleaning-effective amount of said detersive enzyme.
[0020] Critical herein is the notion of "compatibilizing" the enzyme with the bleach. The
term "compatibilizing" for the present purposes encompasses (1) irreversibly reacting
the bleach to destroy it, for example using sodium bisulfite or a hydrogen peroxide
source as bleach scavenger; or (2) chemically reacting the bleach to convert it to
an enzyme-compatible form, for example by forming an N-halo compound which releases
hypochlorite with difficulty or (3) suppressing the dissociation of an N-halo compound
which readily releases hypohalite, by means of a hydrolysis-suppressing amount of
bleach scavenger. Accordingly, in general, a "compatibilizing amount" of bleach scavenger
may vary quite widely depending upon the precise bleach scavenger selected. Nonetheless,
it will be clear that a "compatibilizing amount" of bleach scavenger is generally
substantially in excess of the amount required either to measurably improve storage
stability of enzymes, or to deal with the typical low levels of chlorine in chlorinated
water supplies.
[0021] The terms "stain removal effective amount" and "cleaning-effective amount" encompass
typical levels of the ingredients referred to as used in automatic dishwashing, and,
along with "compatibilizing" amounts, are further illustrated in detail hereinafter.
[0022] In preferred embodiments of the instant detergent compositions, there is moreover
a requirement that a specific dissolution profile of the detergent be respected. A
"dissolution profile" herein refers to the release with time into a washing solution
of the detergent ingredients, especially the aforementioned enzyme-deactivating bleach,
bleach scavenger and enzyme. "Dissolution" need not proceed to the molecular level,
provided that ingredients become available for cleaning action, chemical reaction
with each other, or other practical measures. Accordingly, in a preferred embodiment,
the invention encompasses a detergent composition for use in a washing appliance,
said detergent composition having granular form and further, having a dissolution
profile releasing substantially all of said stain-removal effective amount of said
enzyme-deactivating bleach in no more than about the first 75%, more preferably in
no more than about 50%, more preferably still, no more than a period less than 50%
of a wash cycle of said appliance. The term "substantially all" is intended to refer
to the maximum amount practically deliverable, which is typically somewhat less than
100%, resulting from minor amounts of clumping or loss on the walls of the appliance.
With reference to a dissolution profile which is graphically represented as amount
of ingredient released vs time, said percentages are simply percentages of the total
time a wash cycle of the appliance requires. Appliances can vary in "wash cycle" or
"cycle time", typically depending on the geography in which they are prevalent.
[0023] The present invention further provides improved granular automatic dishwashing detergents
and improved cleaning methods, which may either rely on said granular detergent or
may be independent of any particular product form. More preferably, detergent compositions
herein have the form of granular automatic dishwashing detergents for use in domestic
automatic dishwashing appliances wherein further, the detergent composition has a
dissolution profile releasing more than 50% of said cleaning-effective amount of said
detersive enzyme no sooner than about 2 minutes into a wash cycle of said appliance.
More preferably still, said dissolution profile is one releasing more than 50% of
said compatibilizing amount of said bleach scavenger no sooner than about 1 minute
into a wash cycle of said appliance. Accordingly, it will be understood and appreciated
that the preferred detergent compositions herein differ particularly in the total
amounts of ingredients delivered, and in their dissolution with time, as compared
to conventional detergents.
[0024] The present invention also encompasses a detergent composition comprising: (a) a
plurality of particles of a first kind, each comprising: (i) one or more detersive
enzymes, (ii) one or more bleach scavengers, surrounding or admixed with said detersive
enzymes, and (iii) one or more coating layers comprising a coating polymer and at
least partially separating said detersive enzymes from at least a portion of said
bleach scavengers; and (b) a plurality of particles of a second kind, each comprising
at least one enzyme-deactivating bleach; whereby, when said detergent composition
is dispensed into water in an automatic dishwashing appliance, the concentration of
said enzyme-deactivating bleach is reduced to less than about about 1 ppm prior to
the release of no more than about 50% of said detersive enzyme, on a weight basis.
Thus, coating polymers, as are more fully described and illustrated hereinafter, are
used as one manner of practically delivering the desired dissolution profiles.
[0025] The present invention also provides a method for compatible (or compatibilized -
these terms having the same connotations as introduced in connection with "compatibilizing",
supra) staged release of an enzyme-deactivating bleach followed by one or more detersive
enzymes in an aqueous washing process in a domestic washing appliance [preferably
a domestic automatic dishwashing appliance having the customary high-shear water spraying
action (which differs from the action of conventional fabric laundering appliances)]
having at least one wash cycle of finite total duration (such duration can differ
quite widely, for example some wash cycles are only about 5 minutes in duration whereas
others can extend for an hour or longer). Said method comprises (a) a step of releasing,
in a first period starting at about 30 sec. into said cycle and finishing at a time
which is not more than about 49% of said total duration, a stain removal effective
amount of said enzyme-deactivating bleach; followed by (b) a step of releasing, in
a second period starting at about 1 minute into said cycle and continuing for from
about 30 sec. to the end of said cycle, at least one bleach scavenger capable of destroying
said enzyme-deactivating bleach or of reacting therewith to form an enzyme-compatible
bleach; and followed thereafter by (c) a step of releasing, in a third period starting
at about 1 minute into said cycle and continuing for from about 30 sec. to the end
of said cycle, said detersive enzyme, and wherein further said release of detersive
enzyme is delayed relative to the release of the bleach scavenger by a time sufficient
to produce a cleaning-effective amount of said detersive enzyme.
[0026] All percentages and proportions herein are by weight, and all references cited are
hereby incorporated by reference, unless otherwise specifically indicated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is illustrative of a dissolution profile for a granular detergent composition
for automatic dishwashing which is in conformity with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] As noted, dissolution profiles of detergent compositions herein are of great importance.
In a highly preferred embodiment, the invention encompasses a detergent composition
for use in a domestic automatic washing appliance, said detergent composition having
granular form and further, having a dissolution profile wherein: (1) substantially
all of said enzyme-deactivating bleach is released in a first period, starting at
about 30 sec. or greater into, and ending at no more than about 49% of, the total
duration of a single wash cycle of said appliance; (2) substantially all of said bleach
scavenger is released in a second period, starting at about 1 min. or greater into
said wash cycle, and (3) substantially all of said detersive enzyme is released in
a third period, starting at about 1 min. or greater into said wash cycle, but delayed
relative to the release of the bleach scavenger by a time sufficient to provide a
cleaning-effective amount of detersive enzyme.
[0029] Dissolution profiles in preferred terms can also be described with reference to disposal
of enzyme-deactivating bleach before ingress of too much of the sensitive enzyme component.
Thus in a preferred detergent, said dissolution profile is such that the concentration
in water of enzyme-deactivating bleach not reacted with said bleach scavenger when
the concentration of said detersive enzyme in water first reaches about 10% of said
cleaning-effective amount, is less than about 0.2 ppm, preferably leass than about
0.1 ppm, more preferably still less than about 0.05 ppm, most desirably, less than
about 0.01 ppm.
Detergent Compositions
[0030] Detergent composition of the present invention comprise detersive enzymes, enzyme-deactivating
bleaches, bleach scavengers and, in preferred embodiments, coating polymers.
[0031] "Detersive enzyme", as used herein, means any enzyme having a cleaning, stain removing
or otherwise beneficial effect in a detergent composition. Preferred detersive enzymes
are hydrolases such as proteases, amylases and lipases. Highly preferred for automatic
dishwashing are amylases and/or proteases, including both current commercially available
types and improved types which, though more bleach compatible, have a remaining degree
of bleach deactivation susceptibility.
[0032] "Enzyme-deactivating bleach", as used herein, refers specifically to any oxidizing
bleach for which there is a measurable activity-reducing effect on detersive enzymes
during normal use conditions, typically at pH's in the range from about 9 to about
12. Assay of detersive enzyme by conventional methods in presence of a bleach can
be used to determine whether the bleach is "enzyme deactivating". Particularly strongly
enzyme-deactivating bleaches include sodium hypochlorite, which can be liberated from
any convenient source, such as sodium dichloroisocyanurate, as well as hypobromites
and persulfates, especially monopersulfate.
[0033] The hereinbefore referenced Tivin patents identify perborate as an enzyme-incompatible
bleach. Moreover the hereinbefore referenced EP 481,547 A suggests combining chlorine
bleaches with perborate so as to improve bleaching. According to the present invention,
perborate and other convenient sources of hydrogen peroxide (when used in a pH range
of about 9 to about 12 in the instant detergent compositions) are not "enzyme-deactivating".
In fact, for purposes of the present invention, they react chemically with, and destroy,
hypochlorite and other enzyme-deactivating bleaches herein. Thus, in general, hydrogen
peroxide and other peroxides such as perborate or percarbonate are capable of acting
as reducing agents, and in this model (desirably for the present invention) are examples
of the essential bleach scavenger component further defined hereinafter. In another
mode, they are capable of functioning as an optional, enzyme-compatible bleach herein,
in which case they can be delivered to the wash after all enzyme-deactivating bleach
has been destroyed. In a third aspect, a single aliquot of perborate or an equivalent
hydrogen peroxide source may be used in part as "bleach scavenger" and serve later,
in-part, as an enzyme-compatible bleach.
[0034] "Bleach scavenger", as used herein, refers to any bleach-reactive compound which
either destroys enzyme-deactivating bleach or converts it to a milder, enzyme-compatible
form. Bleach scavengers may include compounds known in the art as chlorine scavengers
or antioxidants. Certain preferred bleach scavengers for the present purposes may
react irreversibly to destroy enzyme-deactivating bleach. Such is the case, for example,
with sodium bisulfite as well as the sodium perborates and sodium percarbonate. Other
preferred bleach scavengers are selected from those which react reversibly according
to the reaction:

where the double-headed arrow indicates an equilibrium or reversible reaction. Highly
preferred of such compounds are those which have small hydrolysis constants, i.e.,
compounds which, at a pH in the range from about 9 to about 12, bind hypochlorite
strongly and thereby effectively limit the concentration of the sum of chlorine, hypochlorous
acid and hypochlorite in the wash water. In this instance, a pronounced enzyme-compatibilizing
effect can be obtained at more economical levels of the bleach scavenger. In contrast,
when such compounds have large hydrolysis constants, i.e., bind hypochlorite weakly,
large excesses of the compound are required to effectively scavenge hypochlorite.
[0035] The present detergent compositions moreover comprise, in particles more fully defined
hereinafter, one or more coating polymers, such as acrylate polymers or isophthalate
polymers. Coating polymers herein are film-forming polymers useful to delay release
of detersive enzyme for a time sufficiently delayed relative to the bleach scavenger,
as described herein.
[0036] In general, the instant detergent compositions may also comprise one or more additional
materials, such as low foaming nonionic surfactants (especially useful in automatic
dishwashing to control spotting/filming); builders which control calcium and/or magnesium
and may have a buffering action, optionally with the further addition of water-soluble
dispersants which modify and inhibit crystal growth of calcium and/or magnesium salts;
alkalis to adjust pH; chelating agents which control transition metals; and additional
bleach-modifying materials such as promoters in the form of bromide salts, bleach
catalysts or bleach activators, provided that any such bleach-modifying materials
are delivered in such a manner as to be compatible with the purposes of the present
invention. The present detergent compositions may, moreover, comprise one or more
conventional enzyme particle-making materials, including enzyme cores or "nonpareils",
pigments, and the like, though in general, materials used for the production of particles
herein are preferably checked for compatibility with spotting/filming on glassware.
Test methods for spotting/filming are generally described in the automatic dishwashing
detergent literature, including DIN test methods. Certain plasticizers, such as oily
phthalates, especially at longer chain lengths, and insoluble materials such as clays,
as well as long-chain fatty acids or soaps which form soap scum are preferably limited
or excluded from the instant compositions when they are to be incorporated in automatic
dishwashing compositions.
[0037] Although, as noted, amounts of the essential ingredients can vary within wide ranges,
preferred detergent compositions herein (which have a 1% aqueous solution pH of from
about 9 to about 12) are those wherein (a) said stain-removal effective amount of
said enzyme-deactivating bleach is sufficient to provide a maximum bleach concentration
in water of from about 10 ppm to about 500 ppm, although concentrations in the order
of about 100 ppm are typical; (b) said compatibilizing amount of said bleach scavenger
is sufficient to at least equal about 70%, preferably about 80% or more, of the stoichiometric
amount of said enzyme-deactivating bleach; and (c) said cleaning-effective amount
of said detersive enzyme is sufficient to provide a detersive enzyme concentration
in water of from about 0.0001 to about 500 ppm (more typical enzyme levels are low,
as indicated hereinafter). The term "stoichiometric amount" refers to the amount required
for a reaction between enzyme-deactivating bleach and bleach scavenger on a molar
basis, as may be calculated from a writing of the chemical equation for the reaction.
Enzyme-Deactivating Bleach
[0038] In general, any enzyme-deactivating bleach susceptible to the action of bleach scavengers
may be used herein. Such bleaches are, in general, oxidizing bleaches rather than
reducing bleaches, and do not include, as noted, the "amphoteric" bleach hydrogen
peroxide. Preferred enzyme-deactivating bleaches for automatic dishwashing purposes
are those which produce rapid and effective removal of tea and coffee stains from
dishware. Preferred enzyme-deactivating bleaches include those selected from the group
consisting of chlorine bleaches, bromine bleaches, persulfate bleaches and mixtures
thereof. Persulfate bleaches, especially monopersulfate in any convenient form, such
as OXONE as supplied by Dupont, are useful herein. More typically, chlorine bleaches
or mixtures thereof with bromine bleaches will be used. Suitable chlorine bleaches
are further illustrated and described in the hereinbefore referenced Kirk-Othmer review
entitled "Bleaching Agents (Survey)", in Vol. 4, at pages 271-299, published in 1993
by John Wiley and Sons, New York, incorporated by reference. Preferred chlorine bleaches
herein differ from chlorine itself both on account of generally alkaline environment
and because of practical considerations.
[0039] Thus preferred chlorine bleaches are illustrated by chlorinated trisodium phosphate
and the chlorinated isocyanurates, especially sodium dichloroisocyanurate. To be noted,
since rapid release of the enzyme-deactivating bleach is desired, it is preferred
not to use the least soluble chlorine bleaches; for example the halogenated hydantoins
tend to dissolve too slowly. Particles of enzyme-deactivating bleach may be used in
smaller size fractions than those normally used in conventional formulations in order
to improve the velocity of release. However, reduced particle size may affect storage
stability. In order to offset this difficulty, coatings may be applied to the enzyme-deactivating
bleach component. Coatings of bleaches have, as noted, been described in the art.
[0040] The invention is not limited to the use of chlorinated bleaches. Thus, in preferred
embodiments, stain removal benefits may be enhanced by the addition of an N-Bromo
compound or a bromide salt to the compositions.
Bleach Scavengers
[0041] Bleach scavengers suitable for use herein generally comprise at least one bleach-scavenging
moiety. Such a moiety can be selected from the group consisting of reducing sulfur
moieties, N-halo forming nitrogen moieties, reducing sugar moieties, peroxy moieties
capable of acting as reducing agents, hydroxycarboxylate moieties, aminoalcohol moieties,
and mixtures thereof. In alternate terms, bleach scavenging moieties herein can suitably
be selected from the group consisting of ammonium, N-H - containing substituted ammonium,
-NH2, =NH, sulfamate, imidodisulfonate, glutamate, carbamate, cyanurate, isocyanurate,
aminoacid, bisulfite, bisulfate, sulfite, thiosulfate, perborate, percarbonate, reducing
sugar, ascorbate, malate, and mixtures thereof.
[0042] Highly preferred detergent compositions herein are those wherein said bleach scavenger
is selected from the group consisting of ammonium sulfate, ammonium citrate and sodium
bisulfite. Ammonium sulfate, ammonium thiosulfate, ammonium bisulfite, and sodium
bisulfite are praticularly preferred.
[0043] Preferably the bleach scavenger herein is a hydrophilic, rapid-dissolving, low molecular
weight, nonhygroscopic, nondeliquescent solid compound. Such compounds can be non-charged,
for example a reducing sugar; or may be ionic, in which case the active moiety can
be the cation, as in ammonium sulfate or ammonium benzoate; the anion, as in sodium
glutamate; or both, as in ammonium glutamate. Out of the many available bleach scavengers,
liquid forms, such as certain liquid aminoalcohols, are not preferred. Also, in order
that the bleach scavenger will dissolve and diffuse rapidly thoughout the wash solution,
the scavenger preferably has a molecular weight below about 2,000, preferably, below
about 500, and is preferably not surface-active to a high degree. Typically, if surface-active,
the bleach scavenger will have a critical micelle concentration in excess of about
10
-2 molar, preferably, in excess of about 10
-1 molar. Preferably, the bleach scavenger is therefore not a protein, although such
substances have elsewhere been used as bleach scavengers and are inherently present
in food soils. Suitably the bleach scavenger is selected from reducing inorganic scavengers,
especially those which are sulfur-containing; reducing organic scavengers, such as
reducing sugars; N-H functional compounds, especially ammonium salts, sulfamates,
carbamates, cyanurates, isocyanurates, amino-acids; aromatic N-H functional amines;
ascorbate; hydroxycarboxylic acids, especially malate; and enzyme-compatible redox
bleaches which can act as reducing agents, such as sodium perborate (any convenient
soluble solid-form source of hydrogen peroxide such as sodium percarbonate will suffice).
[0044] More preferably the bleach scavenger is selected from reducing sugars; ammonium citrate,
ammonium sulfate, sulfamates; ascorbates; glutamates; aromatic N-H functional amines;
sodium perborate monohydrate; and sodium percarbonate.
[0045] If desired, the bleach scavenger can have its mechanical properties modified, for
example for binding purposes in a particle, by the inclusion of any inert substance
which does not measurably spoil spotting/filming performance of the detergent.
[0046] In highly preferred detergents herein, said bleach scavenger is ammonium sulfate;
optionally, said ammonium sulfate may have its binding properties modified, for example
by a cellulose derivative.
[0047] In a granular detergent, bleach scavengers herein can be incorporated entirely within
detersive enzyme-containing particles; or they may be divided into a portion which
is incorporated with the enzyme into particles of a first kind and a portion which
is incorporated into particles of a third kind (the enzyme-deactivating bleach being
included in particles of a second kind). In general, particles of the third kind,
when present, need to contain only bleach scavenger, preferably with coating materials
such as the coating polymers used in particles of the first kind. Nonetheless, there
may be added to any such particles one or more materials improving the mechanical
handling characteristics, aesthetics etc.
Detersive Enzymes
[0048] In general, as noted, detergent compositions herein comprise one or more detersive
enzymes. If only one enzyme is used, it is preferably an amyolytic enzyme when the
composition is for automatic dishwashing use. Highly preferred for automatic dishwashing
is a mixture of proteolytic enzymes and amyloytic enzymes.
[0049] In general, the enzymes to be incorporated include proteases, amylases, lipases,
cellulases, and peroxidases, as well as mixtures thereof. Other types of enzymes may
also be included. They may be of any suitable origin, such as vegetable, animal, bacterial,
fungal and yeast origin. However, their choice is governed by several factors such
as pH-activity and/or stability optima, thermostability, stability versus active detergents,
builders, etc. In this respect bacterial or fungal enzymes are preferred, such as
bacterial amylases and proteases, and fungal cellulases.
[0050] Enzymes are normally incorporated in the instant detergent compositions at levels
sufficient to provide a "cleaning-effective amount". The term "cleaning-effective
amount" refers to any amount capable of producing a cleaning, stain removal or soil
removal effect on substrates such as fabrics, dishware and the like. Since enzymes
are catalytic materials, such amounts may be very small. In practical terms for current
commercial preparations, typical amounts are up to about 5 mg by weight, more typically
about 0.01 mg to about 3 mg, of active enzyme per gram of the composition. Stated
otherwise, the compositions herein will typically comprise from about 0.001% to about
6%, preferably 0.01%-1% by weight of a commercial enzyme preparation. Protease enzymes
are usually present in such commercial preparations at levels sufficient to provide
from 0.005 to 0.1 Anson units (AU) of activity per gram of composition. For automatic
dishwashing purposes, it may be desirable to increase the active enzyme content of
the commercial preparations, in order to minimize the total amount of non-catalytically
active materials delivered and thereby improve spotting/filming results.
[0051] Suitable examples of proteases are the subtilisins which are obtained from particular
strains of
B.
subtilis and
B.
licheniformis. Another suitable protease is obtained from a strain of
Bacillus, having maximum activity throughout the pH range of 8-12, developed and sold by Novo
Industries A/S as ESPERASE®. The preparation of this enzyme and analogous enzymes
is described in British Patent Specification No. 1,243,784 of Novo. Proteolytic enzymes
suitable for removing protein-based stains that are commercially available include
those sold under the tradenames ALCALASE® and SAVINASE® by Novo Industries A/S (Denmark)
and MAXATASE® by International Bio-Synthetics, Inc. (The Netherlands). Other proteases
include Protease A (see European Patent Application 130,756, published January 9,
1985) and Protease B (see European Patent Application Serial No. 87303761.8, filed
April 28, 1987, and European Patent Application 130,756, Bott et al, published January
9, 1985).
[0052] An especially preferred protease, referred to as "Protease D" is a carbonyl hydrolase
variant having an amino acid sequence not found in nature, which is derived from a
precursor carbonyl hydrolase by substituting a different amino acid for a plurality
of amino acid residues at a position in said carbonyl hydrolase equivalent to position
+76, preferably also in combination with one or more amino acid residue positions
equivalent to those selected from the group consisting of +99, +101, +103, +104, +107,
+123, +27, +105, +109, +126, +128, +135, +156, +166, +195, +197, +204, +206, +210,
+216, +217, +218, +222, +260, +265, and/or +274 according to the numbering of
Bacillus amyloliquefaciens subtilisin, as described in the patent applications of A. Baeck, et al, entitled
"Protease-Containing Cleaning Compositions" having U.S. Serial No. 08/322,676, and
C. Ghosh, et al, "Bleaching Compositions Comprising Protease Enzymes" having U.S.
Serial No. 08/322,677, both filed October 13, 1994.
[0053] Amylases suitable herein include, for example, α-amylases described in British Patent
Specification No. 1,296,839 (Novo), RAPIDASE®, International Bio-Synthetics, Inc.
and TERMAMYL®, Novo Industries.
[0054] Engineering of enzymes (e.g., stability-enhanced amylase) for improved stability,
e.g., oxidative stability is known. See, for example J.Biological Chem., Vol. 260,
No. 11, June 1985, pp 6518-6521. "Reference amylase" refers to a conventional amylase
inside the scope of the amylase component of this invention. Further, stability-enhanced
amylases, also within the invention, are typically compared to these "reference amylases".
[0055] The present invention, in certain preferred embodiments, can makes use of amylases
having improved stability in detergents, especially improved oxidative stability.
A convenient absolute stability reference-point against which amylases used in these
preferred embodiments of the instant invention represent a measurable improvement
is the stability of TERMAMYL® in commercial use in 1993 and available from Novo Nordisk
A/S. This TERMAMYL® amylase is a "reference amylase", and is itself well-suited for
use in the ADD (Automatic Dishwashing Detergent) compositions of the invention, as
well as in inventive fabric laundering compositions herein. Even more preferred amylases
herein share the characteristic of being "stability-enhanced" amylases, characterized,
at a minimum, by a measurable improvement in one or more of: oxidative stability,
e.g., to hydrogen peroxide/tetraacetylethylenediamine in buffered solution at pH 9-10;
thermal stability, e.g., at common wash temperatures such as about 60
oC; or alkaline stability, e.g., at a pH from about 8 to about 11, all measured versus
the above-identified reference-amylase. Preferred amylases herein can demonstrate
further improvement versus more challenging reference amylases, the latter reference
amylases being illustrated by any of the precursor amylases of which preferred amylases
within the invention are variants. Such precursor amylases may themselves be natural
or be the product of genetic engineering. Stability can be measured using any of the
art-disclosed technical tests. See references disclosed in WO 94/02597, itself and
documents therein referred to being incorporated by reference.
[0056] In general, stability-enhanced amylases respecting the preferred embodiments of the
invention can be obtained from Novo Nordisk A/S, or from Genencor International.
[0057] Preferred amylases herein have the commonality of being derived using site-directed
mutagenesis from one or more of the
Baccillus amylases, especialy the
Bacillus alpha-amylases, regardless of whether one, two or multiple amylase strains are the
immediate precursors.
[0058] As noted, "oxidative stability-enhanced" amylases are preferred for use herein despite
the fact that the invention makes them "optional but preferred" materials rather than
essential. Such amylases are non-limitingly illustrated by the following:
(a) An amylase according to the hereinbefore incorporated WO/94/02597, Novo Nordisk
A/S, published Feb. 3, 1994, as further illustrated by a mutant in which substitution
is made, using alanine or threonine (preferably threonine), of the methionine residue
located in position 197 of the B.licheniformis alpha-amylase, known as TERMAMYL®, or the homologous position variation of a similar
parent amylase, such as B. amyloliquefaciens, B.subtilis, or B.stearothermophilus;
(b) Stability-enhanced amylases as described by Genencor International in a paper
entitled "Oxidatively Resistant alpha-Amylases" presented at the 207th American Chemical
Society National Meeting, March 13-17 1994, by C. Mitchinson. Therein it was noted
that bleaches in automatic dishwashing detergents inactivate alpha-amylases but that
improved oxidative stability amylases have been made by Genencor from B.licheniformis NCIB8061. Methionine (Met) was identified as the most likely residue to be modified.
Met was substituted, one at a time, in positions 8,15,197,256,304,366 and 438 leading
to specific mutants, particularly important being M197L and M197T with the M197T variant
being the most stable expressed variant. Stability was measured in CASCADE® and SUNLIGHT®;
(c) Particularly preferred herein are amylase variants having additional modification
in the immediate parent available from Novo Nordisk A/S. These amylases do not yet
have a tradename but are those referred to by the supplier as QL37+M197T.
[0059] Any other oxidative stability-enhanced amylase can be used, for example as derived
by site-directed mutagenesis from known chimeric, hybrid or simple mutant parent forms
of available amylases.
[0060] Cellulases usable in, but not preferred, for the present invention include both bacterial
or fungal cellulases. Preferably, they will have a pH optimum of between 5 and 9.5.
Suitable cellulases are disclosed in U.S. Patent 4,435,307, Barbesgoard et al, issued
March 6, 1984, which discloses fungal cellulase produced from
Humicola insolens and
Humicola strain DSM1800 or a cellulase 212-producing fungus belonging to the genus
Aeromonas, and cellulase extracted from the hepatopancreas of a marine mollusk (
Dolabella Auricula Solander). Suitable cellulases are also disclosed in GB-A-2.075.028; GB-A-2.095.275 and DE-OS-2.247.832.
CAREZYME® (Novo) is especially useful.
[0061] Suitable lipase enzymes for detergent use include those produced by microorganisms
of the
Pseudomonas group, such as
Pseudomonas stutzeri ATCC 19.154, as disclosed in British Patent 1,372,034. See also lipases in Japanese
Patent Application 53,20487, laid open to public inspection on February 24, 1978.
This lipase is available from Amano Pharmaceutical Co. Ltd., Nagoya, Japan, under
the trade name Lipase P "Amano," hereinafter referred to as "Amano-P." Other commercial
lipases include Amano-CES, lipases ex
Chromobacter viscosum, e.g.
Chromobacter viscosum var.
lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and further
Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and Disoynth Co., The Netherlands, and
lipases ex
Pseudomonas gladioli. The LIPOLASE® enzyme derived from
Humicola lanuginosa and commercially available from Novo (see also EPO 341,947) is a preferred lipase
for use herein. Another preferred lipase enzyme is the D96L variant of the native
Humicola lanuginosa lipase, as described in WO 92/05249 and Research Disclosure No.
35944, March 10, 1994, both published by Novo. In general, lipolytic enzymes are less
preferred than amylases and/or proteases for automatic dishwashing embodiments of
the present invention.
[0062] Peroxidase enzymes can be used in combination with oxygen sources, e.g., percarbonate,
perborate, persulfate, hydrogen peroxide, etc. They are typically used for "solution
bleaching," i.e. to prevent transfer of dyes or pigments removed from substrates during
wash operations to other substrates in the wash solution. Peroxidase enzymes are known
in the art, and include, for example, horseradish peroxidase, ligninase, and haloperoxidase
such as chloro- and bromo-peroxidase. Peroxidase-containing detergent compositions
are disclosed, for example, in PCT International Application WO 89/099813, published
October 19, 1989, by O. Kirk, assigned to Novo Industries A/S. The present invention
encompasses peroxidase-free automatic dishwashing composition embodiments.
[0063] A wide range of enzyme materials and means for their incorporation into synthetic
detergent compositions are also disclosed in U.S. Patent 3,553,139, issued January
5, 1971 to McCarty et al. Enzymes are further disclosed in U.S. Patent 4,101,457,
Place et al, issued July 18, 1978, and in U.S. Patent 4,507,219, Hughes, issued March
26, 1985. Enzymes for use in detergents can be stabilized by various techniques. Enzyme
stabilization techniques are disclosed and exemplified in U.S. Patent 3,600,319, issued
August 17, 1971 to Gedge, et al, and European Patent Application Publication No. 0
199 405, Application No. 86200586.5, published October 29, 1986, Venegas. Enzyme stabilization
systems are also described, for example, in U.S. Patent 3,519,570.
Coating Polymers
[0064] Preferred detergent compositions herein further include coating polymers, though
these may be omitted when the invention is practiced in a different mode, for example
as a method for dosing individual components into an automatic dishwasher. Suitable
polymers herein are selected so that, as incorporated into enzyme particle coatings,
they delay the disintegration or dissolution of the particle for specific time-periods.
Suitable polymers are, for example, the same as, or preferably, variants of, those
described in U.S. Patents 5,254,283 and 4,973,417; it should be appreciated that either
the thickness of the polymer coating, or its dispersing properties, can be modified
to accomodate the purposes of the invention. Polymer dispersing properties, to illustrate,
are strongly influenced by hydrophobicity and molecular weight, so that if, for example,
an acrylate polymer is too hydrophilic, it may be copolymerized to provide, say, an
ethacrylate or propacrylate rather than a methacrylate to increase hydrophobicity
to the desired extent.
[0065] In preferred detergent compositions herein, the coating polymer is at least partially
water-soluble at a pH in the range from about 5 to about 13.
[0066] In more detail, suitable coating polymers are selected from the group consisting
of: modified cellulose polymers; acrylates, methacrylates, ethacrylates and their
copolymers; polyethyleneglycols; film-forming polyesters; naturally derived gums;
and mixtures thereof.
[0067] Polymers further illustrative of those useful herein include the following:
Name |
Tradename |
Description |
Supplier |
Hydroxypropyl methylcellulose (HPMC) |
Methocel F50 Premium |
Water soluble polymers derived from cellulose |
Dow Chemicals |
|
|
|
|
HPMC, PEG, Titanium Dioxide, Polysorbate 80 |
Opadry |
A complete system for aqueous film coating |
Colorcon |
|
|
|
|
Ethylcellulose |
Aquacoat ECD-30 |
Ethylcellulose Aqueous dispersion |
FMC |
|
|
|
|
Methacrylic acid and ethyl acrylate |
Eudragit L 30D |
Anionic copolymer in aqueous dispersion (enteric coating) |
Rohm Pharma |
|
|
|
|
Polyethylene Glycols (PEG) |
same (except for Union Carbide name is Carbowax PEG) |
PEG-200 PEG-400 PEG-600 PEG-1000 PEG-1450 PEG-3350 PEG-8000 |
Sigma, Chemax, Union Carbide |
|
|
|
|
Carboxymethyl cellulose (CMC) |
Carbose D72 |
Chloracetic acid on alkali cellulose |
Penn Carbose |
|
|
|
|
Carrageenan |
NutricolGP 312 Konjac Powder |
Konjac gum blend with Carrageenan |
FMC |
|
|
|
|
PVA (polyvinyl alcohols) |
PVA 25 |
Polyvinyl Alcohol Based Product |
ABCO |
|
|
|
|
|
Binder K1 |
Polyvinyl Based Product |
ABCO |
|
|
|
|
[0068] Carrageenan and similar materials may be used with good results. In addition, certain
polyvinyl pyrrolidones and derivatives thereof may be used; such materials may also
provide dye transfer inhibition benefits when used in the compositions.
[0069] Polymers heretofore known as soil release polymers, such as those referred to in
U.S. Patent 4,721,580, issued January 26, 1988 to Gosselink, U.S. Patent 3,959,230
to Hays, issued May 25, 1976, and U.S. Patent 3,893,929 to Basadur issued July 8,
1975, may be useful herein as coating polymer. See also U.S. Patent 4,702,857, issued
October 27, 1987 to Gosselink. These soil release agents are described fully in U.S.
Patent 4,968,451, issued November 6, 1990 to J.J. Scheibel and E.P. Gosselink. Other
suitable polymeric soil release agents include the terephthalate polyesters of U.S.
Patent 4,711,730, issued December 8, 1987 to Gosselink et al, the anionic end-capped
oligomeric esters of U.S. Patent 4,721,580, issued January 26, 1988 to Gosselink,
and the block polyester oligomeric compounds of U.S. Patent 4,702,857, issued October
27, 1987 to Gosselink. Preferred polymeric soil release agents also include the soil
release agents of U.S. Patent 4,877,896, issued October 31, 1989 to Maldonado et al,
which discloses anionic, especially sulfoaroyl, end-capped terephthalate esters. In
general, Soil Release Polymers are preferred as coating materials herein when the
detergent composition is for use as a fabric laundering detergent.
[0070] In general, coating polymers herein may be used alone or in combination with any
other compatible ingredients used in enzyme particle manufacture, for example pigments,
provided that the level of such additives does not prevent the polymer from operating
nor cause a spotting/filming deficiency. The coating layer may, of course, be the
polymer alone, or at least consist essentially of said polymer without addition of
other materials.
[0071] Although in the simplest embodiments it suffices to have a single coating layer in
particles, multiple coatings, undercoatings, precoatings etc. are envisaged, provided
that the sum total of the coatings provides the desired dissolution profile.
[0072] Preferably, polymer coatings herein, especially those used for particles of a first
kind described in detail hereinafter, are applied by conventional Wurster fluidized
bed coating processes.
Detergent Compositions Comprising Coated Particles
[0073] Detergent composition herein include those wherein there exist a plurality of particles
of at least two distinct kinds. The term "plurality" of particles as used herein is
used to distinguish preferred embodiments of this invention from tablets, where typically
only one, two or a handful of large particles having sizes measured in millimeters
or even centimeters are used. Tablets are not preferred herein.
[0074] Particles of a first kind herein each comprise one or more detersive enzymes, one
or more bleach scavengers, surrounding or admixed with said detersive enzymes and
one or more coating layers comprising a coating polymer and at least partially separating
said detersive enzymes from at least a portion of said bleach scavengers.
[0075] The terms "surrounding or admixed with" are used to indicate that detersive enzyme
does not come into contact with water before bleach scavenger, which would occur,
for example, in the case of a two-sided tablet having bleach scavenger on one side
and enzyme on the other. In highly preferred embodiments of the invention, there is
always present at least some "surrounding" bleach scavenger or rapidly releasable
bleach scavenger contained in particles of a third kind as further described hereinafter.
[0076] Particles of a second kind herein each comprise at least one enzyme deactivating
bleach as described hereinbefore.
[0077] Additional particle types are also envisaged, especially particles of a third kind
which comprise bleach scavenger without enzymes. These particles may be coated, for
example to improve their mechanical handling characteristics, provided that the coating
does not significantly impair the dissolution profile of the detergent. In general,
from about 0.01 to about 1 weight fraction of said bleach scavenger may be incorporated
into said particles of said first kind and from about 0.01 to about 1 weight fraction
of said bleach scavenger is incorporated into said particles of said third kind.
[0078] Highly preferred detergent compositions for automatic dishwashing are those wherein
all of said particles are substantially free from plasticizers, fatty acids, soaps
and waxes having a measurable effect on spotting/filming.
[0079] In preferred detergent compositions herein, about 50% or more of said particles of
said first and second kinds have a maximum dimension of no greater than about 2,000
micron; more preferably, particles of the first kind are based upon coating relatively
small-sized enzyme cores, for example cores having a mean diameter of about 600 to
about 650 micron and a releatively narrow size distribution. There is accordingly
encompassed a detergent composition wherein about 50% or more, preferably about 80%
or more of said particles of said first kind have a mean particle size in the range
from about 400 micron to about 1000 micron.
[0080] Preferably, particles of said first kind have a disintegration rate of from about
1 (mg/(liter*min.)) to about 10 (mg/(liter*min.)) as measured at a pH of about 10
and a temperature of about 50 °C.
Fully-Formulated Detergent Composition
[0081] The present invention encompasses fully-formulated detergent compositions, including
those for use in automatic dishwashing. Such compositions are nonlimitingly illustrated
by those which comprise from about 0.1% to about 6%, preferably from about 0.2% to
about 4% of said detersive enzyme; from about 0.2% to about 10%, preferably from about
0.5% to about 8% of said bleach scavenger; from about 0.2% to about 10%, preferably
from about 0.5% to about 5% of said enzyme-deactivating bleach; and from about 0.01%
to about 8% , preferably from about 0.1% to about 6% of said coating polymer. Such
fully-formulated embodiments typically further comprise at least one low-foaming nonionic
surfactant, at least one builder, at least one chelant and at least one dispersant,
though additional or adjunct ingredients may be present.
Adjunct Ingredients
[0082] Even small quantities of greasy substances, including plasticizers, fatty acids soaps
and waxes, may have adverse effects on spotting/filming in an automatic dishwashing
operation, and may, moreover, carry insoluble or partially dissolved particles of
detergent ingredients onto the glassware. In addition to low tolerance for greasy
materials, there is typically, in automatic dishwashing, a rather low tolerance for
particulate insoluble materials. Accordingly, such materials are preferably minimized
when the present compositions are for automatic dishwashing use.
[0083] Detersive Surfactants --Surfactants are useful herein for their usual cleaning power and may be included
in embodiments of the instant detergent compositions at the usual detergent-useful
levels. In general, bleach-stable detersive surfactants are preferred.
[0084] Nonlimiting examples of surfactants useful herein include the conventional C
11-C
18 alkylbenzene sulfonates ("LAS") and primary, branched-chain and random C
10-C
20 alkyl sulfates ("AS"); the C
10-C
18 secondary alkyl sulfates of the formula CH
3(CH
2)
x(CHOSO
3-M
+)CH
3 and CH
3(CH
2)
y(CHOSO
3-M
+)CH
2CH
3 where x and (y + 1) are integers of at least about 7, preferably at least about 9,
and M is a water-solubilizing cation, especially sodium; unsaturated sulfates such
as oleyl sulfate; the C
10-C
18 alkyl alkoxy sulfates ("AE
xS") especially those wherein x is from 1 to about 7; C
10-C
18 alkyl alkoxy carboxylates (especially the EO 1-5 ethoxycarboxylates); the C
10-C
18 glycerol ethers; the C
10-C
18 alkyl polyglycosides and their corresponding sulfated polyglycosides; and C
12-C
18 alpha-sulfonated fatty acid esters. Detersive surfactants may be mixed in varying
proportions for improved surfactancy as is well-known in the art. If desired, the
conventional nonionic and amphoteric surfactants such as the C
12-C
18 alkyl ethoxylates ("AE") including the so-called narrow peaked alkyl ethoxylates
and C
6-C
12 alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxylate/propoxylates),
C
12-C
18 betaines and sulfobetaines ("sultaines"), C
10-C
18 amine oxides, and the like, can also be included in the cleaning compositions, The
C
10-C
18 N-alkyl polyhydroxy fatty acid amides can also be used. Typical examples include
the C
12-C
18 N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactants include the
N-alkoxy polyhydroxy fatty acid amides, such as C
10-C
18 N-(3-methoxypropyl) glucamide. The N-propyl through N-hexyl C
12-C
18 glucamides can be used for low sudsing. C
10-C
20 conventional soaps may also be employed. If high sudsing is desired, the branched-chain
C
10-C
16 soaps may be used. Mixtures of anionic and nonionic surfactants are especially useful.
Automatic dishwashing compositions typically employ low sudsing surfactants, such
as the mixed ethyleneoxy/propyleneoxy nonionics. Other conventional useful surfactants
are listed in standard texts.
[0085] Low-Foaming Nonionic Surfactant - ADD (Automatic Dishswashing Detergent) compositions of the present invention can
comprise low foaming nonionic surfactants (LFNIs). LFNI can be present in amounts
from 0 to about 10% by weight, preferably from about 0.25% to about 4%. LFNIs are
most typically used in ADDs on account of the improved water-sheeting action (especially
from glass) which they confer to the ADD product. They also encompass non-silicone,
nonphosphate polymeric materials further illustrated hereinafter which are known to
defoam food soils encountered in automatic dishwashing.
[0086] Preferred LFNIs include nonionic alkoxylated surfactants, especially ethoxylates
derived from primary alcohols, and blends thereof with more sophisticated surfactants,
such as the polyoxypropylene/polyoxyethylene/polyoxypropylene reverse block polymers.
The PO/EO/PO polymer-type surfactants are well-known to have foam suppressing or defoaming
action, especially in relation to common food soil ingredients such as egg.
[0087] The invention encompasses preferred embodiments wherein LFNI is present, and wherein
this component is solid at about 95
oF (35
oC), more preferably solid at about 77
oF (25
oC). For ease of manufacture, a preferred LFNI has a melting point between about 77
oF (25
oC) and about 140
oF (60
oC), more preferably between about 80
oF(26.6
oC) and 110
oF (43.3
oC).
[0088] In a preferred embodiment, the LFNI is an ethoxylated surfactant derived from the
reaction of a monohydroxy alcohol or alkylphenol containing from about 8 to about
20 carbon atoms, excluding cyclic carbon atoms, with from about 6 to about 15 moles
of ethylene oxide per mole of alcohol or alkyl phenol on an average basis.
[0089] A particularly preferred LFNI is derived from a straight chain fatty alcohol containing
from about 16 to about 20 carbon atoms (C
16-C
20 alcohol), preferably a C
18 alcohol, condensed with an average of from about 6 to about 15 moles, preferably
from about 7 to about 12 moles, and most preferably from about 7 to about 9 moles
of ethylene oxide per mole of alcohol. Preferably the ethoxylated nonionic surfactant
so derived has a narrow ethoxylate distribution relative to the average.
[0090] The LFNI can optionally contain propylene oxide in an amount up to about 15% by weight.
Other preferred LFNI surfactants can be prepared by the processes described in U.S.
Patent 4,223,163, issued September 16, 1980, Builloty, incorporated herein by reference.
[0091] Highly preferred ADDs herein wherein the LFNI is present make use of ethoxylated
monohydroxy alcohol or alkyl phenol and additionally comprise a polyoxyethylene, polyoxypropylene
block polymeric compound; the ethoxylated monohydroxy alcohol or alkyl phenol fraction
of the LFNI comprising from about 20% to about 80%, preferably from about 30% to about
70%, of the total LFNI.
[0092] Suitable block polyoxyethylene-polyoxypropylene polymeric compounds that meet the
requirements described hereinbefore include those based on ethylene glycol, propylene
glycol, glycerol, trimethylolpropane and ethylenediamine as initiator reactive hydrogen
compound. Polymeric compounds made from a sequential ethoxylation and propoxylation
of initiator compounds with a single reactive hydrogen atom, such as C
12-18 aliphatic alcohols, do not generally provide satisfactory suds control in the instant
ADDs. Certain of the block polymer surfactant compounds designated PLURONIC® and TETRONIC®
by the BASF-Wyandotte Corp., Wyandotte, Michigan, are suitable in ADD compositions
of the invention.
[0093] A particularly preferred LFNI contains from about 40% to about 70% of a polyoxypropylene/polyoxyethylene/polyoxypropylene
block polymer blend comprising about 75%, by weight of the blend, of a reverse block
co-polymer of polyoxyethylene and polyoxypropylene containing 17 moles of ethylene
oxide and 44 moles of propylene oxide; and about 25%, by weight of the blend, of a
block co-polymer of polyoxyethylene and polyoxypropylene initiated with trimethylolpropane
and containing 99 moles of propylene oxide and 24 moles of ethylene oxide per mole
of trimethylolpropane.
[0094] Suitable for use as LFNI in the ADD compositions are those LFNI having relatively
low cloud points and high hydrophilic-lipophilic balance (HLB). Cloud points of 1%
solutions in water are typically below about 32
oC and preferably lower, e.g., 0
oC, for optimum control of sudsing throughout a full range of water temperatures.
[0095] LFNIs which may also be used include a C
18 alcohol polyethoxylate, having a degree of ethoxylation of about 8, commercially
available as SLF18 from Olin Corp., and any biodegradable LFNI having the melting
point properties discussed hereinabove.
[0096] Builders - Detergent builders can optionally be included in the compositions herein to assist
in controlling mineral hardness. Inorganic as well as organic builders can be used.
Builders are typically used in automatic dishwashing and fabric laundering compositions,
for example to assist in the removal of particulate soils.
[0097] The level of builder can vary widely depending upon the end use of the composition
and its desired physical form. When present, the compositions will typically comprise
at least about 1% builder. High performance compositions typically comprise from about
10% to about 80%, more typically from about 15% to about 50% by weight, of the detergent
builder. Lower or higher levels of builder, however, are not excluded.
[0098] Inorganic or P-containing detergent builders include, but are not limited to, the
alkali metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by
the tripolyphosphates, pyrophosphates, and glassy polymeric meta-phosphates), phosphonates,
phytic acid, silicates, carbonates (including bicarbonates and sesquicarbonates),
sulfates, and aluminosilicates. However, non-phosphate builders are required in some
locales. Compositions herein function surprisingly well even in the presence of "weak"
builders (as compared with phosphates) such as citrate, or in the so-called "underbuilt"
situation that may occur with zeolite or layered silicate builders. See U.S. Pat.
4,605,509 for examples of preferred aluminosilicates.
[0099] Examples of silicate builders are the alkali metal silicates, particularly those
having a SiO
2:Na
2O ratio in the range 1.6:1 to 3.2:1 and layered silicates, such as the layered sodium
silicates described in U.S. Patent 4,664,839, issued May 12, 1987 to H. P. Rieck.
NaSKS-6® is a crystalline layered silicate marketed by Hoechst (commonly abbreviated
herein as "SKS-6"). Unlike zeolite builders, the Na SKS-6 silicate builder does not
contain aluminum. NaSKS-6 is the δ-Na
2SiO
5 form of layered silicate and can be prepared by methods such as those described in
German DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly preferred layered silicate
for use herein, but other such layered silicates, such as those having the general
formula NaMSi
xO
2x+1·yH
2O wherein M is sodium or hydrogen, x is a number from 1.9 to 4, preferably 2, and
y is a number from 0 to 20, preferably 0 can be used herein. Various other layered
silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11, as the α-, β- and γ-
forms. Other silicates may also be useful, such as for example magnesium silicate,
which can serve as a crispening agent in granular formulations, as a stabilizing agent
for oxygen bleaches, and as a component of suds control systems.
[0100] Silicates useful in automatic dishwashing (ADD) applications include granular hydrous
2-ratio silicates such as BRITESIL® H20 from PQ Corp., and the commonly sourced BRITESIL®
H24 though liquid grades of various silicates can be used when the ADD composition
has liquid form. Within safe limits, sodium metasilicate or sodium hydroxide alone
or in combination with other silicates may be used in an ADD context to boost wash
pH to a desired level.
[0101] Examples of carbonate builders are the alkaline earth and alkali metal carbonates
as disclosed in German Patent Application No. 2,321,001 published on November 15,
1973. Various grades and types of sodium carbonate and sodium sesquicarbonate may
be used, certain of which are particularly useful as carriers for other ingredients,
especially detersive surfactants.
[0102] Aluminosilicate builders may be used in the present compositions though are not preferred
for automatic dishwashing detergents. Aluminosilicate builders are of great importance
in most currently marketed heavy duty granular detergent compositions, and can also
be a significant builder ingredient in liquid detergent formulations. Aluminosilicate
builders include those having the empirical formula: [M
z(zAlO
2)
y]·xH
2O wherein z and y are integers of at least 6, the molar ratio of z to y is in the
range from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
[0103] Useful aluminosilicate ion exchange materials are commercially available. These aluminosilicates
can be crystalline or amorphous in structure and can be naturally-occurring aluminosilicates
or synthetically derived. A method for producing aluminosilicate ion exchange materials
is disclosed in U.S. Patent 3,985,669, Krummel, et al, issued October 12, 1976. Preferred
synthetic crystalline aluminosilicate ion exchange materials useful herein are available
under the designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. In an
especially preferred laundry embodiment, the crystalline aluminosilicate ion exchange
material has the formula: Na
12[(AlO
2)
12(SiO
2)
12]·xH
2O wherein x is from about 20 to about 30, especially about 27. This material is known
as Zeolite A. Dehydrated zeolites (x = 0 - 10) may also be used herein. Preferably,
the aluminosilicate has a particle size of about 0.1-10 microns in diameter. Individual
particles can desirably be even smaller than 0.1 micron to further assist kinetics
of exchange through maximization of surface area. High surface area also increases
utility of aluminosilicates as adsorbents for surfactants, especially in granular
compositions. Aggregates of silicate or aluminosilicate particles may be useful, a
single aggregate having dimensions tailored to minimie segregation in granular compositions,
while the aggregate particle remains dispersible to submicron individual particles
during the wash. As with other builders such as carbonates, it may be desirable to
use zeolites in any physical or morphological form adapted to promote surfactant carrier
function, and appropriate particle sizes may be freely selected by the formulator.
[0104] Organic detergent builders suitable for the purposes of the present invention include,
but are not restricted to, a wide variety of polycarboxylate compounds. As used herein,
"polycarboxylate" refers to compounds having a plurality of carboxylate groups, preferably
at least 3 carboxylates. Polycarboxylate builder can generally be added to the composition
in acid form, but can also be added in the form of a neutralized salt or "overbased".
When utilized in salt form, alkali metals, such as sodium, potassium, and lithium,
or alkanolammonium salts are preferred.
[0105] Included among the polycarboxylate builders are a variety of categories of useful
materials. One important category of polycarboxylate builders encompasses the ether
polycarboxylates, including oxydisuccinate, as disclosed in Berg, U.S. Patent 3,128,287,
issued April 7, 1964, and Lamberti et al, U.S. Patent 3,635,830, issued January 18,
1972. See also "TMS/TDS" builders of U.S. Patent 4,663,071, issued to Bush et al,
on May 5, 1987. Suitable ether polycarboxylates also include cyclic compounds, particularly
alicyclic compounds, such as those described in U.S. Patents 3,923,679; 3,835,163;
4,158,635; 4,120,874 and 4,102,903.
[0106] Other useful detergency builders include the ether hydroxypolycarboxylates, copolymers
of maleic anhydride with ethylene or vinyl methyl ether, 1, 3, 5-trihydroxy benzene-2,
4, 6-trisulphonic acid, and carboxymethyloxysuccinic acid, the various alkali metal,
ammonium and substituted ammonium salts of polyacetic acids such as ethylenediaminetetraacetic
acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid,
succinic acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid,
carboxymethyloxysuccinic acid, and soluble salts thereof.
[0107] Citrate builders, e.g., citric acid and soluble salts thereof (particularly sodium
salt), are polycarboxylate builders of particular importance for heavy duty laundry
detergent and automatic dishwashing formulations due to their availability from renewable
resources and their biodegradability. Citrates can also be used in combination with
zeolite, the aforementioned BRITESIL types, and/or layered silicate builders. Oxydisuccinates
are also useful in such compositions and combinations.
[0108] Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-1,6-hexanedioates
and the related compounds disclosed in U.S. Patent 4,566,984, Bush, issued January
28, 1986. Useful succinic acid builders include the C
5-C
20 alkyl and alkenyl succinic acids and salts thereof. A particularly preferred compound
of this type is dodecenylsuccinic acid. Specific examples of succinate builders include:
laurylsuccinate, myristylsuccinate, palmitylsuccinate, 2-dodecenylsuccinate (preferred),
2-pentadecenylsuccinate, and the like. Laurylsuccinates are the preferred builders
of this group, and are described in European Patent Application 86200690.5/0,200,263,
published November 5, 1986.
[0109] Other suitable polycarboxylates are disclosed in U.S. Patent 4,144,226, Crutchfield
et al, issued March 13, 1979 and in U.S. Patent 3,308,067, Diehl, issued March 7,
1967. See also U.S. Patent 3,723,322.
[0110] Fatty acids, e.g., C
12-C
18 monocarboxylic acids, can also be incorporated into the compositions alone, or in
combination with the aforesaid builders, especially citrate and/or the succinate builders,
to provide additional builder activity. Such use of fatty acids will generally result
in a diminution of sudsing in laundry compositions, which may need to be be taken
into account by the formulator. Fatty acids or their salts are undesirable in Automatic
Dishwashing (ADD) embodiments in situations wherein soap scums can form and be deposited
on dishware.
[0111] Where phosphorus-based builders can be used, the various alkali metal phosphates
such as the well-known sodium tripolyphosphates, sodium pyrophosphate and sodium orthophosphate
can be used. Phosphonate builders such as ethane-1-hydroxy-1,1-diphosphonate and other
known phosphonates (see, for example, U.S. Patents 3,159,581; 3,213,030; 3,422,021;
3,400,148 and 3,422,137) can also be used though such materials are more commonly
used in a low-level mode as chelants or stabilizers.
Chelating Agents
[0112] The compositions herein may also optionally contain one or more transition-metal
selective sequestrants or "chelating agents", e.g., iron and/or copper and/or manganese
chelating agents. Chelating agents suitable for use herein can be selected from the
group consisting of aminocarboxylates, phosphonates (especially the aminophosphonates),
polyfunctionally-substituted aromatic chelating agents, and mixtures thereof. Without
intending to be bound by theory, it is believed that the benefit of these materials
is due in part to their exceptional ability to control iron, copper and manganese
in washing solutions; other benefits include inorganic film prevention or scale inhibition.
Commercial chelating agents for use herein include the DEQUEST® series, and chelants
from Monsanto, DuPont, and Nalco, Inc.
[0113] Aminocarboxylates useful as optional chelating agents are further illustrated by
ethylenediaminetetracetates, N-hydroxyethylethylenediaminetriacetates, nitrilo-triacetates,
ethylenediamine tetraproprionates, triethylenetetraaminehexacetates, diethylenetriamine-pentaacetates,
and ethanoldiglycines, alkali metal, ammonium, and substituted ammonium salts thereof.
In general, chelant mixtures may be used for a combination of functions, such as multiple
transition-metal control, long-term product stbilization, and/or control of precipitated
transition metal oxides and/or hydroxides.
[0114] Polyfunctionally-substituted aromatic chelating agents are also useful in the compositions
herein. See U.S. Patent 3,812,044, issued May 21, 1974, to Connor et al. Preferred
compounds of this type in acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.
[0115] A highly preferred biodegradable chelator for use herein is ethylenediamine disuccinate
("EDDS"), especially (but not limited to) the [S,S] isomer as described in U.S. Patent
4,704,233, November 3, 1987, to Hartman and Perkins. The trisodium salt is preferred
though other forms, such as magnesium salts, may also be useful.
[0116] Aminophosphonates are also suitable for use as chelating agents in the compositions
of the invention when at least low levels of total phosphorus are permitted in detergent
compositions, and include the ethylenediaminetetrakis (methylenephosphonates) and
the diethylenetriaminepentakis (methylene phosphon ates). Preferably, these aminophosphonates
do not contain alkyl or alkenyl groups with more than about 6 carbon atoms.
[0117] If utilized, chelating agents or transition-metal-selective sequestrants will preferably
comprise from about 0.001% to about 10%, more preferably from about 0.05% to about
1% by weight of the compositions herein.
Optional Bleach Adjuncts
[0118] (a) Bleach catalysts - If desired, detergent compositions herein may additionally incorporate a catalyst
or accelerator to further improve bleaching. Any suitable bleach catalyst can be used.
Typical bleach catalysts comprise a transition-metal complex, often one wherein the
metal co-ordinating ligands are quite resistant to labilization. Such catalyst compounds
often have features of naturally occurring compounds but are principally provided
synthetically and include, for example, the manganese-based catalysts disclosed in
U.S. Pat. 5,246,621, U.S. Pat. 5,244,594; U.S. Pat. 5,194,416; U.S. Pat. 5,114,606;
and European Pat. App. Pub. Nos. 549,271A1, 549,272A1, 544,440A2, and 544,490A1; preferred
examples of these catalysts include Mn
IV2(u-O)
3(1,4,7-trimethyl-1,4,7-triazacyclononane)
2-(PF
6)
2, Mn
III2(u-O)
1(u-OAc)
2(1,4,7-trimethyl-1,4,7-triazacyclononane)
2(ClO
4)
2, Mn
IV4(u-O)
6(1,4,7-triazacyclononane)
4(ClO
4)
4, Mn
III-Mn
IV4-(u-O)
1(u-OAc)
2-(1,4,7-trimethyl- 1,4,7-triazacyclo-nonane)
2-(ClO
4)
3, Mn
IV-(1,4,7-trimethyl-1,4,7-triazacyclo-nonane)-(OCH
3)
3(PF
6), and mixtures thereof, though alternate metal-co-ordinating ligands as well as mononuclear
complexes are also possible and monometallic as well as di- and polymetallic complexes,
and complexes of alternate metals such as iron are all within the present scope. Other
metal-based bleach catalysts include those disclosed in U.S. Pat. 4,430,243 and U.S.
Pat. 5,114,611. The use of manganese with various complex ligands to enhance bleaching
is also reported in the following United States Patents: 4,728,455; 5,284,944; 5,246,612;
5,256,779; 5,280,117; 5,274,147; 5,153,161; and 5,227,084.
[0119] Said manganese can be precomplexed with ethylenediaminedisuccinate or separately
added, for example as a sulfate salt, with ethylenediaminedisuccinate. (See U.S. Application
Ser. No. 08/210,186, filed March 17, 1994.) Other preferred transition metals in said
transition-metal-containing bleach catalysts include iron or copper.
[0120] As a practical matter, and not by way of limitation, the bleaching compositions and
processes herein can be adjusted to provide on the order of at least one part per
ten million of the active bleach catalyst species in the aqueous washing liquor, and
will preferably provide from about 0.1 ppm to about 700 ppm, more preferably from
about 1 ppm to about 50 ppm, or less, of the catalyst species in the wash liquor.
[0121] (b) Bleach Activators - "Bleach activators" herein are optional materials herein, typified by TAED (tetra-acetyl
ethylenediamine). Numerous such activators are known. Various nonlimiting examples
of such activators are disclosed in U.S. Patent 4,915,854, issued April 10, 1990 to
Mao et al, and U.S. Patent 4,412,934. Nonanoyloxybenzene sulfonate (NOBS) or acyl
lactam activators may be used, and mixtures thereof with TAED can also be used. See
also U.S. 4,634,551 for other typical conventional bleach activators. Also known are
amido-derived bleach activators of the formulae: R
1N(R
5)C(O)R
2C(O)L or R
1C(O)N(R
5)R
2C(O)L wherein R
1 is an alkyl group containing from about 6 to about 12 carbon atoms, R
2 is an alkylene containing from 1 to about 6 carbon atoms, R
5 is H or alkyl, aryl, or alkaryl containing from about 1 to about 10 carbon atoms,
and L is any suitable leaving group other than an alpha-modified lactam. Further illustration
of bleach activators of the above formulae include (6-octanamidocaproyl)oxybenzenesulfonate,
(6-nonanamidocaproyl)oxybenzenesulfonate, (6-decanamido-caproyl)oxybenzenesulfonate,
and mixtures thereof as described in U.S. Patent 4,634,551. Another class of bleach
activators comprises the benzoxazin-type activators disclosed by Hodge et al in U.S.
Patent 4,966,723, issued October 30, 1990. Still another class of bleach activators
includes acyl lactam activators such as octanoyl caprolactam, 3,5,5-trimethylhexanoyl
caprolactam, nonanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam, octanoyl
valerolactam, decanoyl valerolactam, undecenoyl valerolactam, nonanoyl valerolactam,
3,5,5-trimethylhexanoyl valerolactam and mixtures thereof. The present compositions
can optionally comprise acyl benzoates, such as phenyl benzoate, or known quaternary
substituted bleach activators (QSBA). QSBA's are further illustrated in U.S. 4,539,130,
Sept. 3, 1985 and U.S. Pat. No. 4,283,301. British Pat. 1,382,594, published Feb.
5, 1975, discloses a class of QSBA's optionally suitable for use herein. U.S. 4,818,426
issued Apr. 4., 1989 discloses another class of QSBA's. Also see U.S. 5,093,022 issued
March 3, 1992 and U.S. 4,904,406, issued Feb. 27, 1990. Additionally, QSBA's are described
in EP 552,812 A1 published July 28, 1993, and in EP 540,090 A2, published May 5, 1993.
[0122] (c) Organic Peroxides, especially Diacyl Peroxides - These are extensively illustrated in Kirk Othmer, Encyclopedia of Chemical Technology,
Vol. 17, John Wiley and Sons, 1982 at pages 27-90 and especially at pages 63-72, all
incorporated herein by reference. Dibenzoyl peroxide is preferred.
Other Ingredients
[0123] Detersive ingredients or adjuncts optionally included in the instant compositions
can include one or more materials for assisting or enhancing cleaning performance,
treatment of the substrate to be cleaned, or designed to improve the aesthetics of
the compositions. Such materials are further illustrated in U.S. Pat. No. 3,936,537,
Baskerville et al. Adjuncts which can also be included in compositions of the present
invention, in their conventional art-established levels for use (generally from 0%
to about 20% of the detergent ingredients, preferably from about 0.5% to about 10%),
include other active ingredients such as dispersant polymers from BASF Corp. or Rohm
& Haas; color speckles, anti-tarnish and/or anti-corrosion agents, dyes, fillers,
optical brighteners, germicides, alkalinity sources, hydrotropes, anti-oxidants, enzyme
stabilizing agents, perfumes, solubilizing agents, clay soil removal/anti-redeposition
agents, carriers, processing aids, pigments, solvents for liquid formulations, fabric
softeners, static control agents, solid fillers for bar compositions, etc. Dye transfer
inhibiting agents, including polyamine N-oxides such as polyvinylpyridine N-oxide
can be used. Dye-transfer-inhibiting agents are further illustrated by polyvinylpyrrolidone
and copolymers of N-vinyl imidazole and N-vinyl pyrrolidone. If high sudsing is desired,
suds boosters such as the C
10-C
16 alkanolamides can be incorporated into the compositions, typically at 1%-10% levels.
The C
10-C
14 monoethanol and diethanol amides illustrate a typical class of such suds boosters.
Use of such suds boosters with high sudsing adjunct surfactants such as the amine
oxides, betaines and sultaines noted above is also advantageous. If desired, soluble
magnesium salts such as MgCl
2, MgSO
4, and the like, can be added at levels of, typically, 0.1%-2%, for example to provide
additional suds and to enhance grease removal performance.
Brightener
[0124] Any optical brighteners, fluorescent whitening agents or other brightening or whitening
agents known in the art can be incorporated in the instant compositions when they
are designed for fabric treatment or laundering, at levels typically from about 0.05%
to about 1.2%, by weight, of the detergent compositions herein.
pH and Buffering Variation
[0125] Many detergent compositions herein will be buffered, i.e., they are relatively resistant
to pH drop in the presence of acidic soils. However, other compositions herein may
have exceptionally low buffering capacity, or may be substantially unbuffered. Techniques
for controlling or varying pH at recommended usage levels more generally include the
use of not only buffers, but also additional alkalis, acids, pH-jump systems, dual
compartment containers, etc., and are well known to those skilled in the art. Detergent
compositions herein in granular form typically limit water content, for example to
less than about 7% free water, for best storage stability.
[0126] Storage stability of detergent compositions can be further enhanced by limiting the
content in the compositions of adventitious redox-active substances such as rust and
other traces of transition metals in undesirable form. Certain compositions may moreover
be limited in their total halide ion content, or may have any particular halide, e.g.,
bromide, substantially absent. Bleach stabilizers such as stannates can be added for
improved stability and formulations may be substantially nonaqueous if desired.
Methods
[0127] The present invention also encompasses a method for compatible staged release of
an enzyme-deactivating bleach followed by one or more detersive enzymes in an aqueous
washing process in a domestic washing appliance having at least one wash cycle of
finite total duration, comprising (a) a step of releasing, in a first period starting
at about 30 sec. into said cycle and finishing at a time which is not more than about
49% of said total duration, a stain removal effective amount of said enzyme-deactivating
bleach; followed by (b) a step of releasing, in a second period starting at about
1 minute into said cycle and continuing for from about 30 sec. to the end of said
cycle, at least one bleach scavenger capable of destroying said enzyme-deactivating
bleach or of reacting therewith to form an enzyme-compatible bleach; and followed
thereafter by (c) a step of releasing, in a third period starting at about 1 minute
into said cycle and continuing for from about 30 sec. to the end of said cycle, said
detersive enzyme, and wherein further said release of detersive enzyme is delayed
relative to the release of the bleach scavenger by a time sufficient to produce a
cleaning-effective amount of said detersive enzyme. While this method preferably utilizes
compositions according to the present invention, it is to be recognized that depending
on the features of the dishwashing machine used, multiple solid and/or liquid compositions
released by the machine according to a sequence of the present method may also be
employed.
[0128] Preferably in said method, said detersive enzyme release exceeds about 50% of the
total of said detersive enzyme no sooner than about 2 minutes into a wash cycle of
said appliance.
[0129] In more detail, said method can be carried out in aqueous solution wherein: said
domestic washing appliance is a U.S., European or Japanese automatic dishwasher; said
total duration is from about 3 minutes to about 3 hours; said wash cycle is isothermal
or temperature-varying, at temperatures of from about 5 °C to about 95 °C; a sum of
the maximum concentrations of all released ingredients is from about 200 ppm to about
10,000 ppm, expressed on the basis of a single water fill of said appliance; and said
release steps are further characterized in that, when the concentration of said detersive
enzyme in water first reaches about 10% of the total of said detersive enzyme released,
the unreacted concentration of said enzyme-deactivating bleach is less than about
0.2 ppm.
[0130] Highly preferred is a method wherein: said domestic washing appliance is a U.S. automatic
dishwasher; said total duration is from about 3 minutes to about 30 minutes; said
wash cycle is a warm-fill cycle attaining a maximum water temperature of no more than
about 70°C; a sum of the maximum concentrations of all released ingredients is from
about 800 ppm to about 4,000 ppm, and said release steps are further characterized
in that, when the concentration of said detersive enzyme in water first reaches about
10% of the total of said detersive enzyme released, the unreacted concentration of
said enzyme-deactivating bleach is less than about 0.05 ppm.
[0131] The aforementioned method may of course comprise additional steps, preceeding said
steps, of (1) charging said appliance with food-soiled dishware; (2) adding to a dispenser
cup of said appliance a formulated granular detergent product comprising each of said
enzyme-deactivating bleach, bleach scavenger and detersive enzyme ingredients together
with builders and alkali sufficent to bring the wash pH to within the range from about
9 to about 12; and (3) initiating a conventional wash cycle of said appliance. More
preferably still, said first period has a total duration of about 5 min. or less;
the total amount of said enzyme-deactivating bleach is sufficient to provide a concentration
in water of from about 20 ppm to about 250 ppm, said concentration being calculated
on the basis of no reaction with bleach scavenger; said second period starts at about
1 min. into, and ends about two minutes before the end of said wash cycle;said bleach
scavenger is released in an amount sufficient to equal at least 80% of the concentration
required for complete stoichiometric reaction of said bleach scavenger with said enzyme-deactivating
bleach; and said third period starts at about 2 min. into, and ends at about the end
of said wash cycle.
EXAMPLE 1
[0132] The following fully-formulated granular automatic dishwashing detergents are prepared
by mixing:
Example 1 |
A |
B |
INGREDIENTS |
wt % |
wt % |
Particles of Type 1 (Enzyme, Scavenger, Coating Polymer) |
6 |
6 |
Particles of Type 2 (Bleach, as Sodium Dichloroisocyanurate) |
6 |
7 |
Builder: Trisodium Citrate Dihydrate (anhydrous basis) |
10 |
20 |
Builder: Sodium Carbonate (anhydrous basis) |
20 |
10 |
Silicate: BRITESIL H2O®, PQ Corp. (as SiO2) |
12 |
8 |
Chelant: Diethylenetriaminepentaacetic Acid, Sodium Salt |
0 |
0.1 |
Chelant: Ethylenediamine Disuccinate, Trisodium Salt |
0.3 |
0 |
Chelant: Hydroxyethyldiphosphonate (HEDP), Sodium Salt |
0 |
0.5 |
Dispersant (See Note 1) |
6 |
8 |
Nonionic Surfactant (See Note 2)) |
2 |
2 |
Sodium Sulfate, water, minors |
Balance to 100% |
Balance to 100% |
Note 1: One or more of: Sokolan PA30®, BASF or Accusol 480N®, Rohm & Haas.
Note 2: SLF18®, Olin Corp. or LF404®, BASF. |
[0133] Particles of Type 1 for the above compositions are made as follows:
A Uni-Glatt laboratory fluidized bed spray coater (Wurster) is charged with about
300g of a simple co-granulate of Savinase® 12T and Termamyl® 60T, from Novo. The co-granulate
comprises 20% ammonium sulfate, by weight, and has an average diameter of about 650
µm. These particles are coated with about 75 g of a methacrylic acid copolymer (Eudragit
L30D®, Rohm Pharma GmbH, Darmstadt, Germany) by spraying with 500 g of the following
composition:
|
Parts by Weight |
Eudragit L30D |
1000 |
Propanediol |
30 |
Talc |
70 |
Antifoam emulsion |
2 |
Water |
898 |
Total Parts by Weight |

|
[0134] Spraying is at a rate of about 5 ml/min. at an inlet temperature of from about 40
°C to about 60 °C and an outlet temperature in the range from about 30 °C to about
40 °C.
[0135] Particles of Type 2 for the above compositions are particles of Sodium Dichloroisocyanurate, obtainable
from Olin Corp., having particle diameters of from about 400 to about 1000 µm.
EXAMPLE 2
[0136] The following fully-formulated granular automatic dishwashing detergents are prepared
by mixing:
Example 2 |
A |
B |
INGREDIENTS |
wt % |
wt % |
Particles of Type 1 (Enzyme, Scavenger, Coating Polymer) |
2 |
4 |
Particles of Type 2 (Bleach, as Sodium Dichloroisocyanurate) |
6 |
7 |
Particles of Type 3 (Additional Scavenger) |
0.5 |
2 |
Builder: Trisodium Citrate Dihydrate (anhydrous basis) |
10 |
20 |
Builder: Sodium Carbonate (anhydrous basis) |
20 |
10 |
Silicate: BRITESIL H2O®, PQ Corp. (as SiO2) |
12 |
8 |
Chelant: Diethylenetriaminepentaacetic Acid, Sodium Salt |
0 |
0.1 |
Chelant: Ethylenediamine Disuccinate, Trisodium Salt |
0.3 |
0 |
Chelant: Hydroxyethyldiphosphonate (HEDP), Sodium Salt |
0 |
0.5 |
Dispersant (See Note 1) |
6 |
8 |
Nonionic Surfactant (See Note 2)) |
2 |
2 |
Sodium Sulfate, water, minors |
Balance to 100% |
Balance to 100% |
Note 1: One or more of: Sokolan PA30®, BASF, Accusol 480N®, Rohm & Haas.
Note 2: SLF18®, Olin Corp. or LF404®, BASF. |
[0137] Particles of Type 1 for the above compositions are made as follows:
A Uni-Glatt laboratory fluidized bed spray coater (Wurster) is charged with about
300g of Protease D-loaded cores from Genencor further comprising 5% ammonium sulfate,
by weight added by the supplier, these cores having an average diameter of about 650
µm. These particles are coated with about 85 g of a methacrylic acid copolymer (Eudragit
L30D®, Rohm Pharma GmbH, Darmstadt, Germany) by spraying with 567 g of the following
composition:
|
Parts by Weight |
Eudragit L30D |
1000 |
Propanediol |
30 |
Talc |
70 |
Antifoam emulsion |
2 |
Water |
898 |
Total Parts by Weight |

|
[0138] Spraying is at a rate of about 5 ml/min. at an inlet temperature of from about 40
°C to about 60 °C and an outlet temperature in the range from about 30 °C to about
40 °C.
[0139] Particles of Type 2 for the above compositions are particles of Sodium Dichloroisocyanurate, obtainable
from Olin Corp., having particle diameters of from about 400 to about 1000 µm.
[0140] Particles of Type 3 for the above compositions are made as follows:
A Uni-Glatt laboratory fluidized bed spray coater (Wurster) is charged with about
300g of ammonium sulfate particles (about 60% by weight ammonium sulfate, 40% minors),
having an average diameter of about 650 µm. These particles are coated with about
75 g of a methacrylic acid copolymer (Eudragit L30D®, Rohm Pharma GmbH, Darmstadt,
Germany) by spraying with 567 g of the following composition:
|
Parts by Weight |
Eudragit L30D |
1000 |
Propanediol |
30 |
Talc |
70 |
Antifoam emulsion |
2 |
Water |
898 |
Total Parts by Weight |

|
Spraying is at a rate of about 5 ml/min. at an inlet temperature of from about 40
°C to about 60 °C and an outlet temperature in the range from about 30 °C to about
40 °C.
[0141] The above examples are of course illustrative, and are not intended to be limiting
of the invention. The present invention has additional ramifications and embodiments,
thus there is provided within the spririt and scope of the invention an improvement
in a method for washing domestic dishware in an automatic dishwashing applicance using
an enzyme and an enzyme-deactivating bleach. The improvement comprises releasing into
the water present in a cycle of said appliance first said enzyme-deactivating bleach,
followed by a bleach-compatibilizing amount or excess thereabove of a bleach scavenger,
followed by said detersive enzyme; provided that the total period for which said detersive
enzyme is present in said water exceeds the period for which said bleach is present
in enzyme-deactivating form. Achieving this method is in no way limited to the particular
granular embodiments shown. Thus, liquid forms of ingredients could be used and delivered,
for example, in an automatic dishwashing appliance employing a conventional timed
delivery mechanism to provide precisely the release profile indicated in Fig. 1. The
present invention accordingly provides numerous advantages to the consumer, such as
excellent removal of tea stains, starchy soil removal, excellent spotlessness and
lack of film on both glasses and dishware, excellent silvercare, and economy.