Note: Descriptions are shown in the official language in which they were submitted.
2~98~4
F 1136A
POWDERED AUTOMATIC DISHWASHING COMPOSITION
CONTAINING ENZYMES
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 i9 the property of maintaining enzyme
activity during usage. From the time that a detergent is
packaged until it i5 used by the customer, it must remain
stable. Furthermore, during customer usage of the dishwashiny
detergent, it must retain its activity. Unless the enzymes in
the detergent are maintained in a minimum e~posure to moisture
or 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
~0~98~4
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 will deactivate the enzymes. This
deactivation will cause a decrease in the initial activity of
~he 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 i9 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 which 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 10 percent by weight, more preferably less than 9
percent by weight and most preferably less than 8 percent by
weight. Furthermore, the pH of a 1.0 wt~ aqueous solution of
the powdered detergent composition should be less than ahout
2~6985~
11.5 more preferably less than 11.0, and most preferably less
than 10.5. This low alkalinity of the dishwashing detergent
should maintaln 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 phosphate-free compositions
which are safe to the environment while maintaining superior
cleaning performance and dish care. The present invention
teaches the preparation and use of powdered automatic
dishwashing compositions which are phosphate-free and have
superior cleaning performance and dish care.
SUMMARY OF THE INVENTION
This invention is directed to producing powdered
phosphate-free enzyme-containing automatic dishwa3hing
detergent compositions that have an increased chemical
stability and essentially high at wash operating temperatures
of 40C to 65C, 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 a mixture of sodium carbonate and/or sodium citrate
and a low molecular weight polyacrylic polymer.
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
usually contain a low foaming surface-active agent, a chlorine
~leach, alkaline builder materials, and usually minor
ingredients and additives. The incorporation of chlorine
bleach 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 i8 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
~nown is capable of adequately performing that function.
Various attempts have been made to formulate bleach-free
low foaming detergent compositions for automatic dishwashing
2~S~8J
machines, containing particular low foaming nonionics,
builders, filler materials and enzymes. US Patent 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 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 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. US Patent No. 3,79g,879 to Francke et al, 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.
US Patent 4,101,457, to Place et al., teaches the use of a
proteolytic enzyme having a maximum activity at a pH of 12 in
an automatic dishwashing detergent.
US Patent 4,162,987, to Maguire et al., 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.
US Patent No 3,827,938, to Aunstrup et al., discloses
specific proteolytic enzymes which exhibit high enzymatic
2 0 ~
actlvities in highly alkaline systems. Similar disclosures
are found in British Patent Specificatlon ~To. 1,361,386, to
Novo Terapeutisk Laboratorium A/S. British Patent
Specification No. 1,296,839, to Novo Terapeutisk La~oratorium
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
art disclosures are silent about how to formulate an effective
bleach-free powdered automatic dishwashing compositions
capable of providing superior performance during conventional
use.
US Patent 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 powdered
automatic dishwashing detergent which is phosphate-free and
contains a mixture of enzymes for the simultaneous degradation
of both proteins and starches, wherein the combination of
enzymes have a maximum activity at a pH of less than 11 to 12
as measured b~ Anson method and the powdered automatic
dishwashing detergent has optimized cleaning performance in a
temperature range of 4~C to 65~C.
2 ~ 6 ~ ~ 5 L~l
It is an object of this inventlon to incorporate an enzyme
mixture in a phosphate-free, 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 40C to 65C.
DETAILED DESCRIPTION
The present invention relates to a powdered automatic
dishwashing detergent compositions which comprise a nonionic
surfactant, alkali metal silicate, a phosphate-free builder
system, a peroxygen compound with 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 11.5 in the washing liquor
at a concentration of 10 grams per liter of water and the
powdered dishwashing detergent composition exhibits high
cleaning efficiency for both proteins and starches at a wash
temperature of 40C to 65C.
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 are 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
2 ~ ~ r~ 8 5 l~
(hydrophilic in nature). Practically any hydrophobic compound
having a carboxy, hydroxy, amido 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 hvdrophilic or polyoxy
ethylene chain can be readily adjusted to achieve the desired
balance between the hydrophobic and hydrophilic groups.
fflical suitable nonionic surfactants are those disclosed in
US Patent 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 an
hydrophilic poly-lower alkoxy group to a lipophilic moiety. A
preferred class of the nonionic detergent employed is the
poly-lower alkoxylated higher alkanol whexein 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. Pxeferably, the lower alkoxy i5
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.
20~8~4
Useful nonionics are represented by the low foam Plurafac
series from BASF Chemical Conpany which are the reaction
product of a higher llnear 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~3-CIs fatty alcohol condensed
with 6 moles ethylene oxide and 3 moles propylene oxide).
Product B (a C~3-C~s fatty alcohol condensed with 7 mole
propylene oxide and 4 mole ethylene oxide), and Product C (a
0 C~3- C15 fatty alcohol condensed with 5 moles propylene oxide and
10 moles ethylene oxide). Particularly good surfactants are
Plurafac LF132 and LF 231 which are capped nonionic
surfactants. ~nother liquid nonionic surfactant that can be
used is sold under the tradename Lutensol SC 9713.
Synperonic nonionic surfactant from ICI such as Synperonic
LF/D25 are especially preferred nonionic surfactants that can
be used in the powdered automatic dishwasher detergent
compositions of the instant invention.
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 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
20~8~
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
~he 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
u~eful alone or in conjunction with the aforementioned
surfactants and have those having a hydrophobic group
containing from 8 to 20 carbon atoms, preferably from 10 to
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). ~ixtures of saccharide moieties may be used in the
alkyl polysaccharide surfactants. The number x indicates the
2 0 ~
number of saccharide units in a particular alkylpolysaccharide
surfactant. For a particular alkylpolysaccharide molecule x
can only assume integral values. In any physical sample can
be characterized by the average value o~ 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 l-position, (thus giving e.g. a
glucosyl or galactosyl as opposed to a glucoside or
galactoside). However, attachment through the l-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 i9
ethoxide.
Typical hydrophobic groups include alkyl groups, either
saturated or unsaturated, branched or unbranched containing
from about 8 to about 20, preferably from 10 to 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
30, preferably less than 10, most preferably 0, alkoxide
moieties.
Suitable alkyl polysaccharides are decyl, dodecyl,
tetradecyl, pentadecyl, hexadecyl, and octadecyl, di-, tri-,
20~85~
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 alkylpolysaccharides. When used in
admixture with alkylpolysaccharides, the alkyl monosaccharides
are solubilized to some extent. The use of alkyl
monosaccharides in admixture with alkylpolysaccharides 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:
R2O(CnH2nO)r(Z)~
wherein Z is derived from glucose, R i~ a hydrophobic group
selected from the group consisting of alkyl, alkylphenyl,
hydroxyalkylphenyl, and mixtures thereof in which said alkyl
groups contain from 10 to 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 8, preferably from 1.5 to
~, most preferably from 1.6 to 2.7. To prepare these
compounds a long chain alcohol (R2OH) can be reacted with
glucose, in the presence of an acid catalyst to form the
desired glucoside. Alternatively the alkylpolyglucosides can
be prepared by a two step procedure in which a short chain
alcohol (R~OH) an be reacted with glucose, in the presence of
an acid catalyst to form the desired glucoside. Alternatively
12
2~8~4
the alkylpolyglucosides can be prepared by a two step
procedure in which a short chain alcohol (C~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
~onger chain alcohol (R2OH) to displace the short chain alcohol
and obtain the desired alkylpolyglucoside. If this two step
procedure is used, the shcrt chain alkylglucoside content of
the final alkylpolyglucoside material should be less ~han 50~,
preferably less than 10~, more preferably less than 5~, most
preferably 0% of the alkylpolyglucoside.
The amount of unreacted alcohol (the free fatty alcohol
content) in the desired alkylpolysaccharide surfactant is
preferably less than about 2~, more preferably less than 0.5%
by weight of the total of the alkylpolysaccharide. For some
uses it is desirable to have the alkyl monosaccharide content
less than 10~.
The used herein, "alkyl polysaccharide surfactant" i9
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 625 i9 a nonionic alkyl polyglycoside
characterized by the formula:
CnH2n+lO(C6H~O5)~H
2~3~
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 o~ 6-8(10~ of APG 625 in distilled water); a
specific gravity at 25C of 1.1 grams/ml; a density at 25C of
~.1 kgs/gallons; a calculated HLB of 12.1 and a Brookfield
viscosity at 35C, 21 spindle, 5-10 RPM of 3,000 to 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 mixture of phosphate-free
particles which is a builder salt and a low molecular weight
polyacrylate type polymer such as a polyacrylate organic
and/or inorganic detergent builders. A preferred solid builder
15 salt is an alkali carbonate such as sodium carbonate or an
alkali metal citrate such as sodium citrate or a mixture of
sodium carbonate and sodium citrate. When a mixture of sodium
carbonate and sodium citrate is used, a weight ratio of sodium
citrate to sodium carbonate is 9:1 to 1:9, more preferably 3:1
20 to 1:3.
Other builder salts which can be mixed with the sodium
carbonate and/or sodium citrate are gluconates phosphonates
and nitriloacetic acid salts. In conjunction with the builder
salts are optionally used low molecular weight polyacrylates
25 having a molecular weight of 1,000 to 100,000, more preferably
2,000 to 80,000. A preferred low molecular weight
polyacrylate is Sokalan~CP45 manufactured by BASF and having a
molecular weight of 70,000. Another preferred low molecular
14
20S~
;
weight polyacrylate is Acrysol~nLMW45ND manufactured by Rohrn
and Haas and having a molecular welght of 4,500. Norasol~WL2
comprises 26~ BMW45ND sprayed on 74% soda ash.
Sokalan~CP45 is a copolymer of an acrylic acid and an acid
anhydride. Such a material should have a water absorption at
38C and 78 percent relative humidity of less than 40 percent
and preferably less than 30 percent. The builder is
commercially available under the tradename of Sokalan~CP45.
This is a partially neutralized copolymer of metacrylic acid
and maleic anhydride sodium salt. Sokalan~CP45 is classified
as a suspending and anti-deposition agent. This suspending
agent has a low hygroscopicity. Another builder salt is
Sokalan~CP5 having a molecular weight of 70lO00. An objective
is to u~e suspending and anti-redeposition agents that have a
low hygroscopicity. Copolymerized polyacids have this
property, and particularly when partially neutralized.
Acusol~640ND provicled by Rohm Haas is another useful
suspending and anti-redepositing agent.
Another cla~s of builders useful herein are the
aluminosilicates, both oE the crystalline and arnorphous type.
Various crystalline zeolites (i.e. alumino-silicates) are
described in British Patent No. 1,504,168l U.S. Patent No.
4l409l136 and Canadian Patent Nos. 1l072l835 and 1l087l477.
An example of amorphous zeolites useful herein can be found in
Belgium Patent No. 835,351. The zeolites generally have the
formula
(M20) ~ (Al203) y (si2) ~ Wl~20
2~8~
wherein x is 1, y is from 0.8 to 1.2 and preferably 1, z is
from 1.5 to ~.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 Na20/SiO2 ratios of from 1:1 to 1:3.4, more
preferably 1:1 to 1:2.8. Potassium silicates of the same
ratios can also be used. The preferred silicates are sodium
disilicate (anhydrous), sodium disilicate (hydrated) and
sodium metasilicate and mixtures thereof, wherein the
preferred silicate is hydrated disilicate.
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, dimethyl silinated silica,
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 used at 0.2 to 1.0 percent by weight, sodium stearate
used at a concentration level of 0.5 to 1.0 weight percent,
and LPKN 158 (phosphoric ester) sold by Hoechst used at a
concentration level of 0 to 1.5 weight percent, more
16
2~8~
preferably 0.1 ~o 1.0 weight percen~. 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 0 to 1.0 weight percent.
A key aspect is to keep the free water (non-chemically
bonded 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 of the present invention
includes a peroxygen bleaching agent at a concentration level
of about 0 to about 20 weight percent, more preferably 0.5 to
17 weight percent and most preferably at 1.0 to 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. The peroxygen
bleaching compound is preferably used in admixture with an
activator at a concentration level of 1-5 wt. percent.
Suitable activator~ are those disclosed in U.S. Patent No.
4,264,466 or in column 1 of U.S. Patent No. 4,430,244.
Polyacetylated compounds are preferred activators. Suitable
preferred activators are tetraacetyl ethylene diamine
("TAED"), pentaacetyl glucose and ethylidenebenzoate acetate.
2Q6~854
The activator usually i~teracts with the peroxygen
compound to form a peroxyacid bleaching agent in the wash
water.
The detergent formulation also contains a mixture of a
proteolytic enzyme and an amylotytic enzyme and, optionally, a
lipolytic enzyme that serve to attack and remove organic
residues on glasses, plates, pots, pans and eating utensils.
Proteolytic enzymes attack protein residues, lipolytic enzymes
fat residues and amylolytic enzymes starches. Proteolytic
enzymes include the protease enzymes subtilism, 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 available in
the form of a prill having an activity of about 6,000 TAU/g.
One of the preferred protease enzyme is available under the
name Maxacal derived from Bacillus alcalophilus, and is
supplied by Gist-brocades, of the Netherlands in a prill form
(activity of about 329KADU/g.). Preferred enzyme activates
per wash are Maxacal-300-700 KADU per wash and Maxamyl-2,000
to 4,000 TAU per wash.
Another preferred protease enzyme is available under
the name Maxatase derived from a novel Bacillus strain
designated "PB92" wherein a culture of the Bacillus i3
deposited with the ~aboratory for Microbiology of the
Technical University of Del~t and has a number OR-60, and is
supplied by from Gist-Brocades, of the Netherlands in a prill
2~8~
form (activity o~ about 40,000 DU/g.). Preferred enzyme
activates per wash are Maxatase 250-600 KDU per wash.
The alkali silicate, which is a corrosion inhibitor,
wherein sodium disilicate is preferred, will be present in an
amount of about 0 to 30 percent by weight, more preferably
about 3 to about 30 percent by weight and most preferably
about 4 to about 28 percent by weight.
` The opacifier will be present in an amount of about 0 to
about 1.0 percent by weight, more preferably about 0.1 to
about 7 percent by weight and most preferably about 0.4
percent by weight.
The enzymes will be present in an arnount in a prill form
as supplied by Gist-Brocades at a concentration of about 0.8
to 22.0 percent by weight, more preferably about 0.9 to 20.0
percent by weight, and most preferably about 1.0 to about 18.0
percent by weight. The protease enzyme prills in the
automatic dishwashing composition will comprise about 0.5 to
about 15.00 percent by weight, more preferably about 0.7 to
about 13.0 weight percent and most preferably about 0.8 to
about 11.0 percent by weight. The amylase enzyme prills will
comprise about 0.3 to about 8.0 percent by weight, more
preferably about 0.4 percent to about 7.0 weight percent and
most preferably about 0.5 to about 6.0 weight percent. The
lipase enzyme will comprise about 0.00 to about 8.0 percent by
weight of the detergent composition. A typical lipase enzyme
is Lipolase 100 T from Novo Corporation. The lipase enzymes
are especially beneficial in reducing srease residues and
related filming problems on glasses and dishware. Another
19
2~8~
useful lipase enzyme i9 Amano PS lipase provided by Amano
International Enzyme Co., Inc.
Other components such as perfumes will comprise about 0.1
to about 5.0 percent by weight of the detergent composition.
One method o~ producing the powder detergent formulation
having a bulk density of about 0.8 is to spray dry by any
conventional means the nonionic surfactant and defoamer onto
the perborate bleach compound and the builder salt. This
spray dry materials can be used immediately, but it is
preferred to age it for 24 hours. The spray dried materials
are dry blended in any suitable conventional blender such as a
tumble blender at about room temperature with the other
ingredients of the composition until a homogenous blend is
obtained.
The weight ratio of the proteolytic enzyme to the
amylolytic enzyme in prill form the powdered automatic
dishwasher detergent compositions is 6:1 to 1:1, and more
preferably 4.5:1 to 1.1:1.
The detergent composition can have a fairly wi.de ranging
composition. The surfactant can comprise 0 to 15 percent by
weight of the composition, more preferably 0.1 to 15 percent
by weight, and most preferably about 1 to 12 percent by
weight. The anti-foaming agent will be present in an amount
of about 0 to about 1.5 percent by weight, more preferably
about 0.1 to about 1.2 percent by weight and most preferably
about 0.1 to about 1 percent by weight. The builder system,
which is preferably sodium carbonate and/or sodium citrate, is
present in an amount of 2 to 40 percent by weight, more
206~8~4
preferably 4 to 40 percent by weight and most preferably 5 to
30 percent by weight. The builder system also preferably
contains the low molecular weight polyacrylate type polymer at
a concentration level of about 0 to 20 weight percent, more
preferably 1.0 to 17 weight percent and most preferably a to
17 weight percent. The composition also includes the
peroxygen bleaching agent at a concentration of about 0 to 20
wt. percent and the activator at a concentration of about 1 to
5 wt. percent.
The alkali silicate, which is a corrosion inhibitor,
wherein sodium disilicate is preferred, will be present in an
amount of 0 to 40 percent by weight, more preferably 3 to 40
percent by weight and most preferably 4 to 40 percent by
weight.
The opacifier will be present in an amount of 0 to 1.0
percent by weight, more preferably 0.1 to 0.7 percent by
weight and most preferably about 0.4 percent by weight.
The enzymes will be present in an amount in a prill form
as supplied by Gist-Brocades at a concentration of 0.8 to 22.0
percent by weight, more preferably 0.9 to 20.0 percent by
weight, and most preferably 1.0 to 18.0 percent by weight.
The protease enzyme prills in the automatic dishwashing
composition will comprise 0.5 to 15.00 percent by weight, more
preferably 0.7 to 13.0 weight percent and most preferably 0.8
to 11.0 percent by weight. The amylase enzyme prills will
comprise 0.3 to 8.0 percent by weight, more preferably 0.4
percent to 7.0 weight percent and most preferably 0.5 to 6.0
welght percent. The lipase enzyme prills will comprise 0.00
2~98.5~
to ~.0 percent by weight of the detergent composition. A
;; typical lipase enzy~e is Lipolase 100T from Novo Corporation.
The lipase enzymes are especially beneficial in reducing
grease residues and related filming problems on glasses and
dishware. Another useful lipase en~yme is Amano PS lipase
provided by Amano International Enzyme Co., Inc.
Other components such as perfumes will comprise 0.1 to 5.0
percent by weight of the detergent composition.
One method of producing the powder detergent formulation
having a bulk density of 0.8 is to spray dry by any
conventional means the nonionic surfactant and defoamer onto
the perborate bleach compound and the builder salt. This
spray dry materials can be used immediately, but it is
preferred to age it for 24 hours. The spray dried materials
are dry blended in any suitable conventional blender such as a
tumble blender at about room temperature with the other
ingredients of the composition until a homogenous blend is
obtained.
The instant compositions also can be produced as low
density powders according to the procedure as set forth in
U.S. Patent 4,931,203, wherein these powders have a bulk
density less than the bulk density of the bulk density of the
standard powders which have a bulk density of about 0.8
kg/liter.
The concentrated powdered nonionic automatic dishwashing
detergent compositions of the present invention disperses
readily in the water in the dishwashing machine. The
presently used home dishwashing machines have a measured
2~3~
capacity for 80 cc or 90 grams of detergent. In normal use,
for example, for a full load of dirty dishes 60 grams of
powdered detergent are normally used.
In accordance with the present invention only about 19 cc
or about 15 grams of the concentrated powdered detergent
composition is needed. The normal operation of an automatic
dlshwashing machine can involve the following steps or cycles:
washing, rinse cycles with cold water and rin~e cycles with
hot water. The entire wash and rinse cycles require about 60
minutes. The temperature of the wash water is 40C to 65C
and the temperature of the rinse water is 55C to 65C. The
wash and rinse cycle~ use 4 to 7.5 liters of water for the
wash cycle and 4 to 7.5 liters of water for the hot rinse
cycle.
The highly concentrated powdered automatic dishwashing
detergent compositions exhibit excellent cleaning properties
and because of the high concentration of the detergent in the
composition, the detergent is not totally consumed during the
wash cycle or totally eliminated during the rinse cycle such
that there is a sufficient amount of detergent remaining
during the rinse cycle to substantially improve the rinsing.
The washed and dried dishes are free of undesirable traces,
deposits or film due to the use of hot water in the rinse
cycle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example~1
2 ~ 6 ~
The concentrated powdered nonionic ~urfactant detergent
composition was formulated from the following ingredients in
the amounts specified according to the previously defined and
described dry blending process.
20~8~
H _ ~ ~ ~ -- = 'I
~ ~a 1~ ~h~ ~
I ~ I al ~ l l ~D l l
o
--o _
~ ~ _~ l l ,
_~ __ __~
a _ ~ 9 ~ , ~ a a 2 a ~c a 9 ~ a q ~ a a ~-
In o u~ o u,
2~8~
.. _ -- Ln Ln I
Ln o . . o I
Ln l ~ ~ ~D ~ O O ~ l l l
o o 1 n Ln o I
Ln l ~ ~ ~I l o o ~ l l I
._ I
Ln Ln I
o o ~ . o I
Ln l ~ ~1 ~ ~ o o ~1 l l I
O N _ Ln Ln O
~1 ~ l l o ~ ~1 a~ l I ~`I
_..... ... ..... .... __ _
~ I
o d~ Ln ~n o I
o ~ ,~ l l I
o ~r _ n Ln o _ ~
l l ,1 ~ l l o ~ ,~ l l I
. _ ---I
oi l
o ~r Ln Ln o
' l o - rl, ' .__ l o ~, o l ~
l l ~ ~ l l o ~ ~ l l I
- -- ~ - - -
o Ln Ln o
o ~ ,i l l I
~_ _ __ __~ ~ _ ___ ~1
O ~ rd
-I
X O O\o ~ ~ ~ al td Cq ~ I
L) ~) L) O h ~ L) O ~ ~I h a) 01
O :~ O O o t:n ~ ';S! ~ v h O h h ~ 11~ ~;
~ k O Q, O ~ ~ J~ ~ ~ ~ a O o O Ln ~ O
C~ X C~ X ~ t~l a) 1~ - h ~ ~1 rl o ~ ~ ~1 ~h ~ ::~ O E~
P3 ~ (n ~ rd ~ ~ O Ln r~ O O -rJ a) ~¢ rl ~ :~4 O a) o ~ r~ O
p~ ~ Ln ~ cn ~ 3 m v~ u~ ~ ~ E~ cn ~ u~ ~ cn ~ ~ ~ ~ ~
_ --......... ~=_ _ .__ _ _ ._ = _
Ln o Ln o Ln
~ ~ (~1 r`'3
2~g54
Example II
Formulas (~-I) of Example 1 were tested in a European
style Philips 664 Dishwasher working at 55C with a charge of
15.0 grams per wash of the Formulas (A-I) and 3 ml./per wash
of commercial Galaxy rinse aid sold by Colgate-Palmolive Co.
; The load of items placed in the dishwasher consisted of 6
plates soiled with 3.0 grams of a mixture of 12.0 grams of
porridge oats with 188 grams of water and 3 plates soiled with
0.4 grams of calcium chloride denaturated egg yolk and three
plates soiled with 5 grams of a microwave oven baked mixture
of 177 grams of egg yolk with 50 grams of margarine and 3 CUp9
soiled with tea after overglaze removal wherein all the plates
and cups were dried prior to being placed in the dishwasher.
The pH of the washing bath and the formulation were measured.
The hardness of the rin~e water was 38 (C~C03) ppm. Each
formulation was evaluated for spotting and filming. The
results were evaluated on a scale of 1 to 10 with the higher
number being the better result.
2~8~
TABLE II
. _ _. - '
TEST CLEANING PERFORMANCE EVA~UATIONS (AT 55C)
~ ~_ __ __ _ __~ __ r---r--
SOIL A B C D E ¦ F G H I
REMOVAL
_ _ .._ ~ .. _ __ . ..-= . ---
I OATMEAL 7 7.5 8.5 10 10 10 10 10 10
_
MICROEGGS 5 7.5 9 5 7.5 9 8.8 8.2 9.0
CALCIUM 2 9 9.5 2 9.3 9 9.7 9.7 10
l 11
l FILMING 7.6 7.5 7.3 7.6 7.5
11
SPOTTING 6.0 7.5 6.3 8.2 7.5
_ __
GLASS 8.3 9.2 8.7
DAYLIGHT
TEA STAIN 10 6 10
. ._ .
GREASY 9 5 9 7 8
BUILD-UP
STRAINER
_ _ _ i
GREASY
BUILD-UP
_ 11
SPOTTING 8.5 7.2 8.2 ll
l FILMING 7.7 7.5 7.3
. .__ 11
GLASS 8.5 8.5 9.8
DAYLIGHT
. . _ ll
GREASY 9.0 9.0 9.0
BUILD-UP
STRAINER
=
The above described examples of illustrative compositions
of the invention were evaluated for performance according to
the following laboratory test methods.
All cleaning performance were carried out under European
washing conditions in automatic dishwashers with a built-in
heater and water softening ion-exchange resin, at a
temperature range of about 50C to about 65C with 3ml of a
rinse aid (Galaxy Rinse Aid) used in the later stages of the
cycle (automatically dispersed by a built-in closing device
28
2~6~
during the last rinse cycle). Fifteen ~rams of the
illustrative compositions were used as a simple dose per wash.
In the so-called soil cleaning test, 3 cups and 2 sets of
plates were identically soiled with food (tea stain, oatmeal
soil, hardened egg soil and microwave oven-cooked egg soil).
The cup staining was obtained by using 3 cups previously
filled with a 5~ fluorhydric acid solution during 15 minutes
in order to remove the protection. The cups were washed and
dried just before staining. The tea stain was prepared by
adding 90 ml boiling water to one 2g dose of LIPTON yellow
label tea and leaving the system at test for 20 minutes.
After emptying, the cups were then allowed to dry for 12
hours.
Oatmeal soil was prepared by boiling 24 grams of Quaker
oats in 400 ml of tap water for ten minutes and then
homogenized with a high shearing device (Ultrawax). Three
grams of this mixture was spread as thin film onto 7.5 inch
china plates. The plates were aged for 2 hours at 80C, and
then stored overnight at room temperature. Hardened egg 90il
was prepared by mixing egg yolk with an equal amount of 2.5N
calcium chloride solution. 0.4 grams of this mixture was
applied as a thin crosswise film to the usable surface of 7.5
inch china plates. Microwave-egg 90il was prepared by mixing
hot egg yolk and cooked margarine with a homogenizer
(Ultraturax device). Five grams of this mixture were spread
as thin film onto 7.5 inch china plates, and the soiled plates
were baked afterwards for one minute in a microwave oven. The
two type of egg soils were stored overnight at room
29
~ ~ ~7~8
temperature. Six plates of oatmeal, 3 cups soiled with tea,
and three plates of each egg were used per wash, together with
six clean glasses. The twelve soiled plates, the three soiled
cups, and the six glasses were always placed in the same
positions in the dishwasher at each run. In each test four
different compositions were assessed using a series of four
dishwashers.
A11 washed plates were scored each run by determining the
percent area cleaned (percentage of soil removal) with the aid
of a reference scale of gradually cleaned plates. Average
percentages of soil removal for each type of soil after four
runs were converted in a 0 to lQ scale, 0 being for no soil
removal and 10 for perfect cleaning. Glasses were rated in a
viewing box for filming and spotting and under natural
lighting for evaluation. They were rated according to a
scale ranging from 0 (bad performance) to 10 (perfectly clean
glasses) with the aid of reference glasses.
In the multisoil cleaning test different dishware/soil
combinations were used. The dishwasher load included each run
six plates of oatmeal, three cup~ soiled with tea, one dish of
white sauce, one dish of rice, four glasses soiled with tomato
juice, four glasses soiled with cocoa, and four soiled with
milk. Pieces of cutlery (forks, knives and spoons, six each)
were also included and soiled with porridge soil, rice and
rice with cheese soils.
Same Latin Square procedure was used as for soil cleaning
test. Percentages of soil removal on all the dishware and
glasses were converted in 0 to 10 scale, 0 being for no soil
20~8~4
removal and 10 for perfect cleaning. Glasses were also scored
for ~ilming, spotting redeposition of soils and global
evaluation according to a 0 (bad performance) to 10 (very good
performance) scale with the aid of reference glasses. A
different scale was used to distinguish the data from soil
removal performance. Results tabulated were average of four
runs.
In the greasy residue build-up test, the dishwasher load
included six clean plates in the lower basket and six clean
glasses in the upper basket. The soil load was consisting of
100 grams of a greasy soil mixture prepared by mixing mustard
(42 weight ~) white vinegar (33 wt. %), corn oil (15 wt. ~),
and lard (10 wt. ~) altogether.
In each test, four different compositions were assessed
according to a Rubin Square procedure by using a series of
four dishwashers during at the same time. 50 grams of greasy
soil mixture were poured each run in the wash bath together
with fifteen grams of the detergent composition used as a
single dose per wash. After each run, the upper basket
containing the six glasses, the cutlery basket with the
plastic tiles as well as the dishwasher filter elements were
moved from one dishwasher to the following one, before
conducting the next run. Such a procedure was used to assess
the performance of compositions on glasses and on plastic
dishware surfaces under conditions of repeated washer in the
presence of said greasy soil mixture.
After each cycle, glasses were scored in a viewing box for
filming and spotting and under natural lighting for 966d
31
2 ~ 4
aspect according to the same O (bad performance) to 10
(perfectly clean glasses) scale as for the so-called soil
cleaning test with the aid of reference glasses.
The same procedure was repeated three times using the same
set of glasses so as to calculate average performance results
for each composition after 4 cycles. The dishwashers filter
parts were also inspected after each cycle to evidence greasy
deposit build up differences between compositions.
Example 3
The concentrated powdered nonionic surfactant detergent
composition was formulated from the following ingredients in
the amounts specified according to the pre~iously defined and
described dry blending process.
2 ~1 ~ e~ 8 ~i ~
TABLE III
~ . ~
: ¦RAW MATERIALS FORMULA CO~POSITIONS (IN
I PARTSJ
I A IB C D E F G
/ ,
Anhydrous 23 23 23 23
¦Sodium
IMetasilicate
I
Sodium 23 23 23
Disilicate (at
122~ water)
_ _ ....
Nonionic 8.0 16.0
coated Maxcal
at 330 KADU/g
Nonionic 6.9 6.9 11
coated Maxamyl
at 5800 TAU/g
-- --11
cNoatediC 10.9 10.9 7
Maxatase at
440 KDU/g
_ ....... _ _
PEG coated
Maxacal at 350
KADU/g _
._ .
206~8~
PEG coated .
Maxamyl at
5900 TAU/g
.. _ .. _
PEG coated
Maxapem CX30
~at 600 KADU/g
SOKALAN CP45 10 10 10 10 10 10 10
at 60~ water
from BASE'
SODA ASH 34.2 34.2 34.2 34.2 34.2 29.2 29
._ .. __
Sodium Citrate
Dihydrated
TAED
SILICONE DB100 0.5 0.5 0.5 0.5 0.5 0.5 0.5
SYNPERONIC 4.5 4.5 4.5 4.5 4.5 4.5 4.5
SODIUM 10 10 10 10 10 10 10
PERBRATE
MONOHYDRATED
CAUSTIC SODA 5 5
I
LIPOLASE 100T _ = _ = ~ =
34
205~5~
.
RAW MATERIALS FORMULA COMPOSITIONS (IN
PARTS)
_ ~ r--~ ~--_~ __
H I J K L M N
:~ __ _ .
Anhydrous
Sodium
¦Metasilicate
¦Sodium 23 23 23 23 23 26.1 25.1 ¦
¦Disilicate (at
l22% water)
I I
¦Nonionic coated
¦Maxcal at 330
KADU/g
I 11
Nonionic coated 5 5 3 3 3 5 5
Maxamyl at 5 a o o
TAU/g
Nonionic coated 13 13 15 15 15 13 13
Maxatase at 440
KDU/g _
PEG coated
Maxcal at 350
KADU/g
PEG coated
TAU/g
.. _ _ __ ._
PEG coated
Maxapen CX 30
at 600 KADU/g _ _ ~
SOKALAN CP 45 10 10 10 10 5 10 10
at 60~ water
from BASF
_ _ __
l SODA ASH 29 26 20.2 252.7 31 26 26
_ ._ .__
SODIUM CITRATE
DIHYDRATED
__ _
TAED 3 3 3 3 3 3
... ... __
SILICONE DB100 0.5 0.5 0.25 0.75 0.5 0.5 0.5
SYNPERONIC 4.5 4.5 2.5 7.5 4.5 4.5 4.5
LFD25
SODIUM PERBRATE 10 10 10 10 10 10 10
MONOHYDRATED
_
CAUSTIC SODA 5 5 5 5 5 1 9 1.9
. _
2Q~9~
¦¦ LIPOLASE 100T
. ( NOVO )
__ . . _ .
'
36
2~3~
Example IV
Formulas (A-N) of Example II1 were tested in a European
style Philips 664 Dishwasher working at 55C with a charge of
15.0 grams per wash of the Formulas (A-N) and 3 ml./per wash
of commercial Galaxy rinse aid sold by Colgate-Palmolive Co.
The load of items placed in the dishwasher consisted of 6
plates soiled with 3.0 grams of a mixture of 12.0 grams of
porridge oats with 188 grams of water and 3 plates soiled with
0.4 grams of calcium chloride denaturated egg yolk and three
plates soiled with 5 grams of a microwave oven baked mixture
of 177 grams of egg yolk with 50 grams of margarine and 3 cups
soiled with tea after overglaze removal wherein all the plates
and cups were dried prior to being placed in the dishwasher.
The pH of the washing bath and the formulation were measured.
The hardness of the rinse water was 38 (C2C03) ppm. Each
formulation was evaluated for spotting and filming. The
results were evaluated on a scale of 1 to 10 with the higher
number being the better result.
2~$~54
~ TABBE IV
I
~EST CLEANING PERFORMANCE EVALUATIONS (AT 55~) 1
r~
SOIL REMOVAL A ¦B C D E ¦F G
_ _ _ _= _ :1
: OATMEAL 7 7.5 8.5 10 10 10 10
11
MICROEGGS 5 7.5 9 5 7.0 7.4 7.2
CALCIUM EGGS 2 9 9.5 2 8.8 9.1 fl.9
_
FILMING 7.5 7.6 7.8
GLASS
DAYLIGHT
I
TEA STAIN
_ . __ .. __ 11
GREASY
BUILD-UP ON
STRAINER
. .. -- _ ._ 'I
GREASY
BUILD-UP
SPOTTING
FILMING _ _ _
DAYLIGHT
GREASY
BUILD-UP ON
STRAINER
.
38
2 ~ 5 ~
TABLE IV (Cont.)
__ ,___
¦TEST CLEANING PERFORMANCE EVALUATIONS (AT
¦SOIL REMOVAL H II I J IK IL M IN
~ _= . _ ,. _
~OATMEAL 10 10 10 101 10 10 10
MICROEGGS 7.5 7 7.8 7.8 1 7.8 6.2 6.8
CALCIUM EGGS 10 10 10 10 lo 10 9.8
.
FILMING 7.8 7.7 6.7 7.8 1 6.5 7.4 8.2
SPOTTING 7.7 7.8 6.3 8.2 7.3 7.8 9.0
GLASS DAYLIGHT - 8.8 9.7 ¦
TEA STAIN 5 9
GREASY BUILD-UP 9 5
ON STRAINER
_ . _ ._ - =
GREASY BUILD-UP
SPOTTING I I 7.1 8.3
FILMING_ ~ 7.4 1 7.7
GLASS DAYLIGHT 8.1 9.3
i GREASY BUILD-UP 8.0 1.3
ON STRAINER
_ . _ ._ _. _
The above described examples of illustrative compositions
of the invention were evaluated for performance according to
the following laboratory test methods.
All cleaning performance were carried out under European
washing conditions in automatic dishwashers with a built-in
heater and water softening ion-exchange resin, at a
temperature range of about 50C to about 65C with 3ml of a
rinse aid (Galaxy Rinse Aid) used in the later stages of the
cycle (automatically dispersed by a built-in closing device
during the last rinse cycle). Fifteen grams of the
illustrative compositions were used as a simple dose per wash.
39
20~854
In the so-called soil cleaning test, 3 cups and 2 sets of
plates were identically soiled with food (tea stain, oatmeal
soil, hardened egg soil and microwave oven-cooked egg soil).
The cup staining was obtained by using 3 cups previously
filled with a 5~ fluorhydric acid solution during 15 minutes
in order to remove the protection. The cups were washed and
dried just before staining. The tea stain was prepared by
adding 90 ml boiling water to one 2g dose of LIPTON yellow
label tea and leaving the system at test for 20 minutes.
After emptying, the cups were then allowed to dry for 12
hours.
Oatmeal soil was prepared by boiling 24 grams of Quaker
oats in 400 ml of tap water for ten minutes and then
homogenized with a high shearing device (Ultrawax). Three
grams of this mixture was spread as thin film onto 7.5 inch
china plates. The plates were aged for 2 hours at 80C, and
then stored overnight at room temperature. Hardened egg soil
was prepared by mixing egg yolk with an equal amount of 2.5N
calcium chloride solution. 0.4 grams of this mixture was
applied as a thin crosswise film to the usable surface of 7.5
inch china plates. Microwave-egg 90il was prepared by mixing
hot egg yolk and cooked margarine with a homogenizer
(Ultraturax device). Five grams of this mixture were spread
as thin film onto 7.5 inch china plates, and the soiled plates
were baked afterwards for one minute in a microwave oven. The
two type of egg soils were stored overnight at room
temperature. Six plates of oatmeal, 3 cups soiled with tea,
and three plates of each egg were used per wash, together with
20~8~
six clean glasses. The twelve soiled plates, the three soiled
cups, and the six glasses were always placed in the same
positions in the dishwasher at each run. In each test four
different compositions were assessed using a series of four
~ishwashers.
All washed plates were scored each run by determining the
percent area cleaned (percentage of soil removal) with the aid
of a reference scale of gradually cleaned plates. Average
percentages of soil removal for each type of soil after four
runs were converted in a 0 to 10 scale, 0 heing for no soil
removal and 10 for perfect cleaning. Glasses were rated in a
viewing box for filming and spotting and under natural
lighting for evaluation. They were rated according ~o a scale
ranging from 0 (bad performance) to 10 (perfectly clean
glasses) with the aid of reference glasses.
In the multisoil cleaning test different dishware/soil
combinations were used. The dishwasher load included each run
six plates of oatmeal, three cups soiled with tea, one dish of
white sauce, one dish of rice, four glasses soiled with tomato
juice, four glasses soiled with cocoa, and four soiled with
milk. Pieces of cutlery (forks, knives and spoons, 9iX each)
were also included and soiled with porridge soil, rice and
rice with cheese soils.
Same Latin Square procedure was used as for soil cleaning
test. Percentages of soil removal on all the dishware and
glasses were converted in 0 to 10 scale, 0 being for no soil
removal and 10 for perfect cleaning. Glasses were also scored
for filming, spotting redeposition of soils and global
41
~9~
evaluation according to a o (bad performance) to 10 (very good
performance) scale with the aid of reference glasses. A
different scale was used to distinguish the data from soil
removal performance. Results tabulated were average of four
runs.
In the greasy residue build-up test, the dishwasher load
included six clean plates in the lower basket and six clean
glasses in the upper basket. The soil load was consisting or
100 grams of a greasy soil mixture prepared by mixing mustard
(42 weight ~) white ~inegar (33 wt. ~), corn oil (15 wt. ~),
and lard (10 wt. ~) altogether.
In each test, four different compositions were assessed
according to a Rubin Square procedure by using a series of
four dishwashers during at the same time. 50 grams of yreasy
soil mixture were poured each run in the wash bath together
with fifteen grams of the detergent composition used as a
single dose per wash. After each run, the upper basket
containing the six glasses, the cutlery basket with the
plastic tiles as well as the dishwasher filter elements were
moved from one dishwasher to the following one, before
conducting the next run. Such a procedure was used to assess
the performance of compositions on glasses and on plastic
dishware surfaces under conditions of repeated washer in the
presence of said greasy soil mixture.
After each cycle, glasses were scored in a viewing box for
filming and spotting and under natural lighting for 966d
aspect according to the same O (bad performance) to 10
42
20S~8~4
(perfectly clean glasses) scale as for the so-called soil
cleaning test wlth the aid of reference glasses.
The same procedure was repeated three times using the same
set of glasses so as to calculate average performance results
for each composition after 4 cycles. The dishwashers filter
parts were also inspected after each cycle to evidence greasy
deposit build up differences between compositions.
43
