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Description  |
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FIELD OF THE INVENTION
This invention relates to an improved phosphate-containing powdered automatic dishwashing detergent for dishwashing machines. More particularly, this invention relates to a concentrated powdered dishwashing composition which contains enzymes
that can function at a low alkalinity and high operating temperatures.
BACKGROUND OF THE INVENTION
It has been found to be very useful to have enzymes in dishwashing detergent compositions because enzymes are very effective in removing food soils from the surface of glasses, dishes, pots, pans and eating utensils. The enzymes attack these
materials while other components of the detergent will effect other aspects of the cleaning action. However, in order for the enzymes to be highly effective, the composition must be chemically stable, and it must maintain an effective activity at the
operating temperature of the automatic dishwasher. Chemical stability, such as to bleach agents, is the property whereby the detergent composition containing enzymes does not undergo any significant degradation during storage. Activity is the property
of maintaining enzyme activity during usage. Front the time that a detergent is packaged until it is used by the customer, it must remain stable. Furthermore, during customer usage of the dishwashing detergent, it must retain its activity. Unless the
enzymes in the detergent are maintained in a minimum exposure to moisture and water, the enzymes will suffer a degradation during storage which will result in a product that will have a decreased activity. When enzymes are a part of the detergent
composition, it has been found that the initial water content of the components of the composition should be as low a level as possible, and this low water content must be maintained during storage, since water in the alkaline product will deactivate the
enzymes. This deactivation will cause a decrease in the initial activity of the detergent composition.
After the detergent container is opened, the detergent will be exposed to the environment which contains moisture. During each instance that the detergent is exposed to the environment it could possibly absorb some moisture. This absorption
occurs by components of the detergent composition absorbing moisture, when in contact with the atmosphere. This effect is increased as the container is emptied, since there will be a greater volume of air in contact with the detergent, and thus more
available moisture to be absorbed by the detergent composition. This will usually accelerate the decrease in the activity of the detergent composition. The most efficient way to keep a high activity is to start with an initial high activity of enzyme
and to use components in the dishwashing composition which do not interact with the enzyme or have a low water affinity which will minimize any losses in activity as the detergent is being stored or used.
Powdered detergent compositions which contain enzymes can be made more stable and to have a high activity, if the initial free water content of the detergent composition is less than about 10 percent by weight, more preferably less than about 9
percent by weight and most preferably less than about 8 percent by weight. Furthermore, the pH of a 1.0 wt % aqueous solution of the powdered detergent composition should be less than about 11.0 more preferably less than about 10.6, and most preferably
less than about 10.3. This low alkalinity of the dishwashing detergent should maintain the stability of the detergent composition which contains a mixture of enzymes, thereby providing a higher initial activity of the mixture of the enzymes and the
maintenance of this initial high activity.
A major concern in the use of automatic dishwashing compositions is the formulation of automatic dishwashing compositions which have a low alkalinity and can operate at a high temperature while maintaining superior cleaning performance and dish
care. The present invention teaches the preparation and use of powdered automatic dishwashing compositions which are phosphate containing and have superior cleaning performance and dish care and are used at operating temperatures of 100.degree. F. to
140.degree. F.
SUMMARY OF THE INVENTION
This invention is directed to producing powdered phosphate enzyme-containing automatic dishwashing detergent compositions that have an increased chemical and enzyme stability as evidenced by retained enzyme activity during storage and essentially
a higher enzyme activity at wash operating temperatures of about 40.degree. C. to 65.degree. C. (about 104.degree. F. to 150.degree. F.), wherein the composition also can be used as a laundry pre-soaking agent. This is accomplished by controlling
the alkalinity of the detergent composition and using a unique mixture of enzymes. An alkali metal silicate is used in the powdered dishwashing detergent compositions. The preferred builder system of the instant compositions comprises at least one
phosphate builder salt which can be used in conjunction with a polymeric builder salts and non-phosphate containing builder salts.
It is to be understood that the term powder in this invention includes within its definition tablets, soluble capsules and soluble sachet. It is also possible to use the instant compositions as a laundry presoaking powder.
Conventional powdered automatic dishwashing compositions can also contain a low foaming surface-active agent, a chlorine bleach, alkaline builder materials, and usually minor ingredients and additives. The incorporation of chlorine bleaches
requires special processing and storage precautions to protect composition components which are subject to deterioration upon direct contact with the active chlorine. The stability of the chlorine bleach is also critical and raises additional processing
and storage difficulties. In addition, it is known that automatic dishwasher detergent compositions may tarnish silverware and damage metal trim on china as a result of the presence of a chlorine-containing bleach therein. Accordingly, there is a
standing desire to formulate detergent compositions for use in automatic dishwashing operations which are free of active chlorine and which are capable of providing overall hard surface cleaning and appearance benefits comparable to or better than active
chlorine-containing detergent compositions. This reformulation is particularly delicate in the context of automatic dishwashing operations, since during those operations, the active chlorine prevents the formation and/or deposition of troublesome
protein and protein-grease complexes on the hard dish surfaces and no surfactant system currently known is capable of adequately performing that function.
Various attempts have been made to formulate bleach-free low foaming detergent compositions for automatic dishwashing machines, containing particular low foaming nonionics, builders, filler materials and enzymes. U.S. Pat. No. 3,472,783 to
Smille recognized that degradation of the enzyme can occur, when an enzyme is added to a highly alkaline automatic dishwashing detergent.
French Patent No. 2,102,851 to Colgate-Palmolive, pertains to rinsing and washing compositions for use in automatic dishwashers. The compositions disclosed have a pH of about 6 to 7 and contain an amylolytic and, if desired, a proteolytic
enzyme, which have been prepared in a special manner from animal pancreas and which exhibit a desirable activity at a pH in the range of about 6 to 7. German Patent No. 2,038,103 to Henkel & Co. relates to aqueous liquid or pasty cleaning compositions
containing phosphate salts, enzymes and an enzyme stabilizing compound. U.S. Pat. No. 3,799,879 to Francke et at, teaches a detergent composition for cleaning dishes, with a pH of from 7 to 9 containing an amylolytic enzyme, and in addition,
optionally a proteolytic enzyme.
U.S. Pat. No. 4,101,457, to Place et at., teaches the use of a proteolytic enzyme having a maximum activity at a pH of 12 in an automatic dishwashing detergent.
U.S. Pat. No. 4,162,987, to Maguire et at., teaches a granular or liquid automatic dishwashing detergent which uses a proteolytic enzyme having a maximum activity at a pH of 12 as well as an amylolytic enzyme having a maximum activity at a pH
of 8.
U.S. Pat. No. 3,827,938, to Aunstrup et at., discloses specific proteolytic enzymes which exhibit high enzymatic activities in highly alkaline systems. Similar disclosures are found in British Patent Specification No. 1,361,386, to Novo
Terapeutisk Laboratorium A/S, British Patent Specification No. 1,296,839, to Novo Terapeutisk Laboratorium A/S, discloses specific amylolytic enzymes which exhibit a high degree of enzymatic activity in alkaline systems.
Thus, while the prior art clearly recognizes the disadvantages of using aggressive chlorine bleaches in automatic dishwashing operations and also suggests bleach-free compositions made by leaving out the bleach component, said an disclosures are
silent about how to formulate an effective bleach-free powdered automatic dishwashing compositions capable of providing superior performance during conventional use.
U.S. Pat. Nos. 3,821,118 and 3,840,480; 4,568,476, 4,501,681 and 4,692,260 teach the use of enzymes in automatic dishwashing detergents, as well as Belgian Patent 895,459; French Patents 2,544,393 and 1,600,256; European Patents 256,679;
266,904; 271,155; 139,329; and 135,226; and Great Britain Patent 2,186,884.
The aforementioned prior art fails to provide a stable powdered automatic dishwashing detergent which is phosphate-containing and contains a mixture of enzymes as well as optionally, a peroxygen compound with an activator for the simultaneous
degradation of both proteins and starches, wherein the combination of anylase and protease enzymes have a maximum activity at a pH of less than 11.0 and the powdered automatic dishwashing detergent has high cleaning performance in a temperature range of
about 40.degree. C. to about 65.degree. C. (about 100.degree. F. to 150.degree. F.) as well as having improved enzyme stability during storage. It is an object of this invention to incorporate a novel enzyme mixture in a phosphate-containing,
powdered automatic dishwasher detergent composition for use in automatic dishwashing operations capable of providing at least equal or better performance to conventional automatic dishwashing compositions at operating temperatures of about 40.degree. C.
to about 65.degree. C.
DETAILED DESCRIPTION
The present invention relates to a powdered automatic dishwashing detergent compositions which comprise a nonionic surfactant, alkali metal silicate, a phosphate-containing builder system, optionally, a peroxygen compound with an activator as a
bleaching agent and a mixture of an amylase enzyme and a protease enzyme, wherein the powdered automatic dishwashing detergent composition has a pH of less than 11.0 and the powdered dishwashing detergent composition exhibits high cleaning efficiency for
both proteins and starches at a wash temperature of about 40.degree. C. to about 65.degree. C. (about 100.degree. F. to about 150.degree. F.).
The composition of the present invention comprise approximately by weight;
(a) 10 to 65%, more preferably 15 to 65% of at least one alkali metal phosphate builder salt;
(b) 0 to 30%, more preferably 1 to 25% of at least one alkali metal phosphate free builder salt;
(c) 0 to 20%, more preferably 1 to 20% of at least one low molecular weight non-cross-linked polyacrylate polymer;
(d) 0 to 30%, more preferably 3.0 to 30% of an alkali metal silicate;
(e) 0 to 15%, more preferably 0.5 to 10.0% of a liquid nonionic surfactant;
(f) 0 to 1.5%, more preferably 0. 1 to 1.5% of an anti-foaming agent;
(g) 0.5 to 15%, more preferably 1.0 to 12% of at least one protease enzyme;
(h) 0.3 to 8%, more preferably 0.5 to 6.0% of an amylase enzyme;
(i) 0 to 20%, more preferably 1.0 to 17% of a peroxygen bleaching agent;
(j) 0 to 7%, more preferably 1 to 5% of a peroxygen bleach activator;
(k) 0 to 8.0%, more preferably 0 to 6% of a lipase enzyme; and
(l) 30 to 30% of a filler or extender such as an alkali metal sulfate.
The nonionic surfactants that can be used in the present powdered automatic dishwasher detergent compositions are well known. A wide variety of these surfactants can be used.
The nonionic synthetic organic detergents are generally described as ethoxylated propoxylated fatty alcohols which are low-foaming surfactants and may be possibly capped, characterized by the presence of an organic hydrophobic group and an
organic hydrophilic group and are typically produced by the condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene oxide and/or propyleneoxide (hydrophilic in nature). Practically any hydrophobic compound having a
carboxy, hydroxy, amide or amino group with a free hydrogen attached to the oxygen or the nitrogen can be condensed with ethylene oxide or propylene oxide or with the polyhydration product thereof, polyethylene glycol, to form a nonionic detergent. The
length of the hydrophilic or polyoxyethylene chain can be readily adjusted to achieve the desired balance between the hydrophobic and hydrophilic groups. Typical suitable nonionic surfactants are those disclosed in U.S. Pat. Nos. 4,316,812 and
3,630,929.
Preferably, the nonionic detergents that are used are the low-foaming polyalkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilic poly-lower alkoxy group to a lipophilic moiety. A
preferred class of the nonionic detergent employed is the poly-lower alkoxylated higher alkanol wherein the alkanol is of 9 to 18 carbon atoms and wherein the number of moles of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 15. Of such
materials it is preferred to employ those wherein the higher alkanol is a high fatty alcohol of 9 to 11 or 12 to 15 carbon atoms and which contain from 5 to 15 or 5 to 16 lower alkoxy groups per mole. Preferably, the lower alkoxy is ethoxy but in some
instances, it may be desirably mixed with propoxy, the latter, if present, usually being major (more than 50%) portion. Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups
per mole.
Useful nonionics are represented by the low foam Plurafac series from BASF Chemical Company which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain of ethylene oxide and
propylene oxide, terminated by a hydroxyl group. Examples include Product A (a C.sub.13 -C.sub.15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide). Product B (a C.sub.13 -C.sub.15 fatty alcohol condensed with 7 mole
propylene oxide and 4 mole ethylene oxide), and Product C (a C.sub.13 -C.sub.15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide). Another group of liquid nonionics are available from Shell Chemical Company, Inc. under
the Dobanol trademark: Dobanol 91-5 is a low foam ethoxylated C.sub.9 -C.sub.11 fatty alcohol with an average of 5 moles ethylene oxide and Dobanol 25-7 is an ethoxylated C.sub.12 -C.sub.15 fatty alcohol with an average of 7 moles ethylene oxide.
Another liquid nonionic surfactant that can be used is sold under the tradename Lutensol SC 9713.
Synperonic nonionic surfactants from ICI such as Synperonic LF/D25 LF/RA30 are especially preferred nonionic surfactants that can be used in the powdered automatic dishwasher detergent compositions of the instant invention.
Poly-Tergent nonionic surfactants from Olin Organic Chemicals such as Poly-Tergent SLF-18, a biodegradable, low-foaming surfactant is specially preferred for the powdered automatic dishwasher detergent compositions of this instant invention.
Poly-Tergent SLF-18 which is alkoxylated linear alcohol and water dispersible and has a low cloud point and lower surface tension and lower foaming is very suitable for automatic dishwasher detergent.
Other useful surfactants are Neodol 25-7 and Neodol 23-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 13 carbon atoms and the number
of ethylene oxide groups present averages about 6.5. The higher alcohols are primary alkanols. Other examples of such detergents include Tergitol 15-S-7 and Tergitol 15-S-9 (registered trademarks), both of which are linear secondary alcohol ethoxylates
made by Union Carbide Corp. The former is mixed ethoxylation product of 11 to 15 carbon atoms linear secondary alkanol with seven moles of ethylene oxide and the latter is a similar product but with nine moles of ethylene oxide being reacted.
Also useful in the present compositions as a component of the nonionic detergent are higher molecular weight nonionics, such as Neodol 45-11, which are similar ethylene oxide condensation products of higher fatty alcohols, with the higher fatty
alcohol being of 14 to 15 carbon atoms and the number of ethylene oxide groups per mole being about 11. Such products are also made by Shell Chemical Company.
In the preferred poly-lower alkoxylated higher alkanols, to obtain the best balance of hydrophilic and lipophilic moieties the number of lower alkoxies will usually be from 40% to 100% of the number of carbon atoms in the higher alcohol,
preferably 40 to 60% thereof and the nonionic detergent will preferably contain at least 50% of such preferred poly-lower alkoxy higher alkanol.
The alkylpolysaccharides are surfactants which are also useful alone or in conjunction with the aforementioned surfactants and those having a hydrophobic group containing from about 8 to about 20 carbon atoms, preferably from about 10 to about 16
carbon atoms, most preferably from 12 to 14 carbon atoms, and polysaccharide hydrophilic group containing from 1.5 to about 10, preferably from about 1.5 to 4, and most preferably from 1.6 to 2.7 saccharide units (e.g., galactoside, glucoside,
fructoside, glucosyl, fructosyl, and/or galactosyl units). Mixtures of saccharide moieties may be used in the alkyl polysaccharide surfactants. The letter x indicates the number of saccharide units shown later in a particular alkylpolysaccharide
surfactant formula. For a particular alkylpolysaccharide molecule x can only assume integral values. In any physical sample can be characterized by the average value of x and this average value can assume non-integral values. In this specification the
values of x are to be understood to be average values. The hydrophobic group (R) can be attached at the 2-, 3-, or 4- positions rather than at the 1-position, (thus giving e.g. a glucosyl or galactosyl as opposed to a glucoside or galactoside).
However, attachment through the 1-position, i.e., glucosides, galactosides, fructosides, etc., is preferred. In the preferred product the additional saccharide units are predominately attached to the previous saccharide unit's 2-position. Attachment
through the 3-, 4-, and 6-positions can also occur. Optionally and less desirably there can be a polyalkoxide chain joining the hydrophobic moiety (R) and the polysaccharide chain. The preferred alkoxide moiety is ethoxide.
Typical hydrophobic groups include alkyl groups, either saturated or unsaturated, branched or unbranched containing from about 8 to about 20, preferably from about 10 to about 16 carbon atoms. Preferably, the alkyl group is a straight chain
saturated alkyl group. The alkyl group can contain up to 3 hydroxy groups and/Or the polyalkoxide chain can contain up to about 30, preferably less than 10, alkoxide moieties.
Suitable alkyl polysaccharides are decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, and octadecyl, di-, tri-, tetra-, penta-, and hexaglucosides, galactosides, lactosides, fructosides, fructosyls, lactosyls, glucosyls and/or galactosyls and
mixtures thereof.
The alkyl monosaccharides are relatively less soluble in water than the higher alkyl polysaccharides. When used in admixture with alkyl polysaccharides, the alkyl monosaccharides are solubilized to some extent. The use of alkyl monosaccharides
in admixture with alkyl polysaccharides is a preferred mode of carrying out the invention. Suitable mixtures include coconut alkyl, di-, tri-, tetra-, and pentaglucosides and tallow alkyl tetra-, penta-, and hexaglucosides.
The preferred alkyl polysaccharides are alkyl polyglucosides having the formula:
wherein Z is derived from glucose, R is a hydrophobic group selected from the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, and mixtures thereof in which said alkyl groups contain from about 10 to about 18, preferably from 12 to 14
carbon atoms; n is 2 or 3 preferably 2, r is from 0 to about 10, preferable 0; and x is from 1.5 to about 8, preferably from 1.5 to 4, most preferably from 1.6 to 2.7. To prepare these compounds a long chain alcohol (R.sub.2 OH) can be reacted with
glucose, in the presence of an acid catalyst to form the desired glucoside. Alternatively the alkyl polyglucosides can be prepared by a two step procedure in which a short chain alcohol (R.sub.1 OH) an be reacted with glucose, in the presence of an acid
catalyst to form the desired glucoside. Alternatively the alkyl polyglucosides can be prepared by a two step procedure in which a short chain alcohol (C.sub.1-6) is reacted with glucose or a polyglucoside (x=2 to 4) to yield a short chain alkyl
glucoside (x=1 to 4) which can in turn be reacted with a longer chain alcohol (R.sub.2 OH) to displace the short chain alcohol and obtain the desired alkyl polyglucoside. If this two step procedure is used, the short chain alkylglucoside content of the
final alkyl polyglucoside material should be less than 50%, preferably less than 10%, more preferably less than 5%, most preferably 0% of the alkyl polyglucoside.
The mount of unreacted alcohol (the free fatty alcohol content) in the desired alkyl polysaccharide surfactant is preferably less than about 2%, more preferably less than about 0.5% by weight of the total of the alkyl polysaccharide. For some
uses it is desirable to have the alkyl monosaccharide content less than about 10%.
The used herein, "alkyl polysaccharide surfactant" is intended to represent both the preferred glucose and galactose derived surfactants and the less preferred alkyl polysaccharide surfactants. Throughout this specification, "alkyl
polyglucoside" is used to include alkyl polyglycosides because the stereo chemistry of the saccharide moiety is changed during the preparation reaction.
An especially preferred APG glycoside surfactant is APG 625 glycoside manufactured by the Henkel Corporation of Ambler, Pa. APG 25 is a nonionic alkyl polyglycoside characterized by the formula:
wherein n=10(2%); n=12(65%); n=14(21-28%); n=16(4-8%) and n=18(0.5%) and x(degree of polymerization)=1.6. APG 625 has: a pH of 6-8(10% of APG 625 in distilled water); a specific gravity at 25.degree. F. of 1.1 grams/ml; a density at 25.degree.
F. of 9.1 kgs/gallons; a calculated HLB of about 12.1 and a Brookfield viscosity at 35.degree. C., 21 spindle, 5-10 RPM of about 3,000 to about 7,000 cps. Mixtures of two or more of the liquid nonionic surfactants can be used and in some cases
advantages can be obtained by the use of such mixtures.
The liquid nonaqueous nonionic surfactant is absorbed on a builder system which comprises a phosphate-containing particles which is a builder salt and optionally a low molecular weight polyacrylate type polymer such as a polyacrylate, organic
and/or inorganic detergent builders as well as phosphate free builder salts such as an alkali carbonate such as sodium carbonate or sodium citrate or a mixture of sodium carbonate and sodium citrate. The nonaqueous liquid nonionic surfactant has
dispersed therein free particles or organic and/or inorganic detergent builders. Preferred solid builder salts are an alkali metal polyphosphate such as sodium tripolyphosphate ("TPP"), potassium tripolyphosphate or potassium pyrophosphates and mixtures
thereof. The TPP is a blend of anhydrous TPP and a small amount of TPP hexahydrate such that the chemically bound water content is about 1%, which corresponds to about one H.sub.2 O per pentasodium tripolyphosphate molecule. Such TPP may be produced by
treating anhydrous TPP with a limited amount of water. The presence of the hexahydrate slows down the rapid rate of solution of the TPP in the wash bath and inhibits caking. One suitable TPP is sold under the name Thermphos NW. The particles size of
the Thermphos NW TPP, as supplied usually averages about 200 microns with the largest particles being about 400 microns. In place of all or part of the alkali metal polyphosphate one or more non phosphate detergent builder salts can be used. Suitable
non phosphate builder salts are alkali metal carbonates, borates, bicarbonates, citrates, lower polycarboxylic acid salts, and polyacrylates, polymaleic anhydrides and copolymers of polyacrylates and polymaleic anhydrides and polyacetal carboxylates.
Specific examples of builder salts useful in the instant composition are sodium carbonate, potassium carbonate, sodium tetraborate, sodium pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, potassium pyrophosphate, sodium
bicarbonate, sodium hexametaphosphate, sodium sesquicarbonate, sodium mono and diorthophosphate, and potassium bicarbonate. The builder salts can be used alone with the nonionic surfactant or in an admixture with other builders. Typical builders also
include those disclosed in U.S. Pat Nos. 4,316,812, 4,264,466, and 3,630,929 and those disclosed in U.S. Patent Nos. 4,144,226, 4,135,092 and 4,146,495, all of which are herein incorporated by reference.
Other phosphate-free builder salts which can be mixed with the phosphate containing builder salts are alkali metal carbonates, citrates, gluconates, phosphonates and nitriloacetic acid salts. In conjunction with the builder salts are optionally
used a low molecular weight non-crosslinked polyacrylates having a molecular weight of about 1,000 to about 100,000, more preferably about 2,000 to about 80,000. A preferred low molecular weight polyacrylate is Sokalan.TM.CP45 or Sokalan.TM.CP5
manufactured by BASF and having a molecular weight of about 70,000. Another preferred low molecular weight polyacrylate is Acrysol.TM.LMW45ND manufactured by Rohm and Haas and having a molecular weight of about 4,500. Noroso.TM.WL2 comprises 26% LMV
45ND sprayed on 74% sodium carbonate.
Sokalan.TM.CP45 or CP5 is a copolymer of an acrylic acid and a maleic acid anhydride. Such a material should have a water absorption at 38.degree. C. and 78 percent relative humidity of less than about 40 percent and preferably less than about
30 percent. The builder is commercially available under the tradename of Sokalan.TM.CP45. This is a partially neutralized copolymer of acrylic acid and maleic anhydride sodium salt. Sokalan.TM.CP45 is classified as a suspending and anti-deposition
agent. This suspending agent has a low hygroscopicity. Another builder salt is Sokalan.TM.CP5 having a molecular weight of 70,000 which is a completely neutralized version of CP45. An objective is to use suspending and anti-redeposition agents that
have a low hygroscopicity. Copolymerized polyacids have this property, and particularly when partially neutralized. Acusol.TM.64ND provided by Rohm Haas is another useful suspending agent.
Another class of builders useful herein are the aluminosilicates, both of the crystalline and amorphous type. Various crystalline zeolites (i.e. alumino-silicates) are described in British Patent No. 1,504,168, U.S. Patent No. 4,409,136 and
Canadian Patent Nos. 1,072,835 and 1,087,477. An example of amorphous zeolites useful herein can be found in Belgium Patent No. 835,351. The zeolites generally have the formula
wherein x is 1, y is from 0.8 to 1.2 and preferably 1, z is from 1.5 to 3.5 or higher and preferably 2 to 3 and w is from 0 to 9, preferably 2.5 to 6 and M is preferably sodium. A typical zeolite is type A or similar structure, with type 4A
particularly preferred. The preferred aluminosilicates have calcium ion exchange capacities of about 200 milliequivalents per gram or greater, e.g. 400 meq/g.
The alkali metal silicates are useful anti-corrosion agents which function to make the composition anti-corrosive to eating utensils and to automatic dishwashing machine parts. Sodium silicates of Na.sub.2 O:SiO.sub.2 ratios of from 1:1 to
1:2.4. Potassium silicates of the same ratios can also be used. The preferred silicates are sodium disilicate and sodium metasilicate.
Essentially, any compatible anti-foaming agent can be used. Preferred anti-foaming agents are silicone anti-foaming agents. These are alkylated polysiloxanes and include polydimethyl siloxanes, polydiethyl siloxanes, polydibutyl siloxanes,
phenyl methyl siloxanes, trimethysilanated silica and triethylsilanated silica. A suitable anti-foaming agent is Silicone TP-201 from Union Carbide. Other suitable anti-foaming agents are Silicone DB700, DB100 used at about 0.2 to about 1.0 percent by
weight, sodium stearate used at a concentration level of about 0.5 to 1.0 weight percent and 1.0 weight percent, and LPKn 158 (phosphoric ester) sold by Hoechst used at a concentration level of about 0 to about 1.5 weight percent, more preferably about
0.1 to about 1.0 weight percent. The perfumes that can be used include lemon perfume and other natural scents. Essentially, any opacifier that is compatible with the remaining components of the detergent formulation can be used. A useful and preferred
opacifier is titanium dioxide at a concentration level of about 0 to about 1.0 weight percent.
A key aspect is to keep the free water (non-chemically bounded water) in the detergent composition at a minimum. Absorbed and adsorbed water are two types of free water, and comprise the usual free water found in a detergent composition. Free
water will have the affect of deactivating the enzymes.
The detergent composition can include a filler or extender such as an alkali metal sulfate (sodium sulfate) at a concentration of 0 to about 30.0 wt. percent, more preferably about 1 to about 25.0 wt. percent.
The detergent composition of the present invention can include a peroxygen bleaching agent at a concentration level of about 0 to about 20 weight percent, more preferably about 0.5 to about 17 weight percent and most preferably at about 1.0 to
about 14 weight percent. The oxygen bleaching agents that can be used are alkali metal perborate, percarbonate, perphthalic acid, perphosphates, and potassium monopersulfate. A preferred compound is sodium perborate monohydrate and dihydrate. The
peroxygen bleaching compound is preferably used in admixture with an activator at a concentration of about 1 to about 5 weight percent. Suitable activators are those disclosed in U.S. Pat. No. 4,264,466 or in column 1 of U.S. Pat. No. 4,430,244,
both of which are herein incorporated by reference. Polyacetylated compounds are preferred activators. Suitable preferred activators are tetraacetyl ethylene diamine ("TAED"), pentaacetyl glucose and ethylidenebenzoate acitate.
The activator usually interacts with the peroxygen compound to form a peroxyacid bleaching agent in the wash water.
The detergent formulation also contains a mixture of a protease enzyme and an amylase enzyme and, optionally, a lipase enzyme that serve to attack and remove organic residues on glasses, plates, pots, pans and eating utensils. Lipolytic enzymes
can also be used in the powdered automatic dishwasher detergent composition. Proteolytic enzymes attack protein residues, lipolytic enzymes fat residues and amylolytic enzymes starches. Proteolytic enzymes include the protease enzymes subtilisn,
bromelin, papain, trypsin and pepsin. Amylolytic enzymes include amylase enzymes. Lipolytic enzymes include the lipase enzymes. The preferred amylase enzyme is available under the name Maxamyl, derived from Bacillus licheniformis and is available from
Gist-brocades of the Netherlands in a prill form (Maxamyl CXT) (activity of about 5,000 TAU/g). One preferred protease enzyme is available under the name Maxatase, and is derived from a novel Bacillus strain designated "PB92" wherein a culture of the
Bacillus is deposited with the Laboratory for Microbiology of the Technical University of Delft and has the number OR-60. Maxatase protease enzyme is a low alkaline B. licheniformis protease 600,000 DU/g which is supplied in a nonaqueous slurry (18
weight percent) by International BioSynthetics (Gist-Brocades). One of the preferred protease enzyme is available under the name Protein Engineered Maxacal or Maxapem 15 or Maxapem 42 (PEM 42) and is derived from Bacillus alcalophylus which is a high
alkaline mutant proteolytic enzyme and is available from Gist-Brocades, of the Netherlands. Maxapem 42 is supplied in a nonaqueous slurry (18 wt. % of enzyme/activity of 900,000 AD u/g). Preferred enzyme activities per wash are Maxapem 42 per wash and
Maxamyl 4,000-10,000 TAU per wash. Maxapem 15 is supplied in a nonaqueous slurry (5.55% wt. of enzyme with activity 40,000 ADU/g and preferred enzyme activity of Maxapem 15 is 400-900 KADU per wash. Maxatase and Maxapem can be used together. Maxapem
42 protease enzyme is supplied in a nonaqueous slurry (18 weight percent) by International BioSynthetics (Gist-Brocades). Maxamyl amylase enzyme is a thermostable B. licheniformis alpha-amylase (39,500 TAU/g) whic | | |