Note: Descriptions are shown in the official language in which they were submitted.
2~698~7
IR 4916A
NONAOUEOUS LIOUID 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
2~ activity at the operating temperature of the automatic
dishwasher. Chemical stability i3 the property whereby the
detergent composition containing enzymes does not undergo any
significant degradation during storage. This is also known as
shelf life. Activity is the property of maintaining enzyme
activity during usage. From 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 suitable environment, the
enzymes will suffer a degradation during storage which wlll
result in a product that will have a decreased initial
activity. When enzymes are a part of the detergent
composition, it has been found that the initial free water
content of the composition should be as low a level as
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?ossible, and this low water content must be maintained during
storage, since water will activate the enzymes. This
activation 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 prevent a significant decrease in this
activity is to start with an initial high activity of enzyme
and to use components in the dishwashing composition which
have a low hygroscopicity and a low alkalinity which will
minimize any losses in activity as the detergent is being
stored or used.
The stability of enzymes in a nonaqueous liquid detergent
can be improved by using an alkali metal silicate. In
addition, the individual components of the detergent
composition should each have an initial free water content
(unbounded water at 100C) of less than about 10 percent by
weight, more preferably less than 9 percent by weight, and
most preferably less than 8 percent by weight. During
manufacture the detergent composition may take-up moisture
2069847
Crom the atmosphere. As a result, the moisture content of the
detergent composition as it is being packaged may be greater
than 1 percent by weight, preferably less than 4 percent by
weight and most preferably less than 3 percent by weight.
Nonaqueous liquid dishwasher 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 less than 6 percent by weight, more preferably
less than 4 percent by weight and most preferably less than 3
percent by weight. A key aspect is to keep the free water
(non-chemically bonded water) in the detergent composition at
a minimum. It is critical that water not be added to the
composition. ~bsorbed and absorbed water are two types of
free water; and comprise the usual free water found in the
detergent composition. Free water will have the affect of
deactivating the enzyme. Furthermore, the pH of 1.0 weight ~
of an aqueous solution of a liquid detergent composition must
be less than 11.0 more preferably less than 10.6, and most
preferably less than 10.2. This low alkalinity of the
dishwashing detergent will also increase 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.
The free water content of the dishwashing detergent
compositions of the instant invention can be controlled to a
large extent by using components that have a low initial water
content and a low hygroscopicity. The individual components
of the instant composition should have a water content of less
than about 10 percent by weight, moxe preferably less than 9
20~847
~ercent by weight, and most preferably less than about 8
percent by weight. In addition, the organic components of the
dishwashing detergent composition should have low hydroxyl
group content to decrease the hydrogen bonding absorption of
water. In place of the carrier such as ethylene glycols or
glycerols, relatively low hydroxyl content-anhydrous organics
such as alcohol ethers and polyalkylene glycols can be used.
In place of polyacid suspending agents normally used in liquid
automatic dishwashing detergent compositions such as
polyacrylic acid or salts of polyacrylic acids, there should
be used polyacid/acid anhydride copolymers such as polyacrylic
acid/acid anhydride copolymers. Maleic anhydride is a
suitable acid anhydride. The net result is a decreased
hydroxyl group content which translates to a decreased
hygroscopicity of the detergent composition which helps
maintain the stability and the activity.
SUMMARY OF THE INVENTION
This invention is directed to producing a nonaqueous
liquid enzyme containing automatic dishwashing detergent
compositions which have an increased chemical stability and
essentially a constant activity at wash operating temperatures
of 100F to 140F. This is accomplished by controlling the
alkalinity and the hygroscopicity of the detergent composition
and using a novel mixture of enzymes. An alkali metal
silicate is used in the dishwashing detergent compositions
which may have a free water content of less than 6 percent by
weight, more preferably less than 4 percent by weight, and
most preferably less than 3 percent by weight throughout its
usage. The Na2O:SiO2 ratio can exceed 1:3.22 but should not be
2~69847
'ower than 1:2. In order to achieve this low free water
content, the wa~er content of each of the detergent components
should be less than 1 percent by weight, more preferably less
than 0.75 percent by weight, and most preferably less than 0.5
percent by weight. Furthermore, each of the organic
components should have a low hydroxyl group content in order
to decrease the potential amount of hydrogen bonded water in
the composition.
Conventional automatic dishwashing compositions usually
contain a low foaming surface-active agent, a carrier solvent
which is usually water, a chlorine bleach, alkallne 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 i9 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 Eormulate 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
2~6~7
depos1tion of troublesome protein and protein-grease complexes
on the hard dish surfaces. No surfactant system currently
known is capable of adequately performing this 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. US Patent 3,472,783
to Smille recognized that degradation 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 ln
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 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 enz~ne stabilizing compound. US Patent No.
3,799,879 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
2~69847
?roteolytic enzyme havlng a maximum activity at a pH of ~2 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
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
art disclosures are silent about how to formulate an effective
bleach-free automatic dishwashing compositions capable of
providing superior performance at low alkalinity levels during
conventional use.
US Patent Nos. 3,840,480; 4,568,476; 3,821,118 and
4,501,681 teach the use of enzymes in automatic dishwashing
detergents.
The aforementioned prior art fails to provide a liquid
automatic dishwashing detergent which 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 10.2 and the liquid automatic
dishwashing detergent has optimized cleaning performance in a
temperature range of 100F to 1~0F.
20S~7
It is an object of this invention to incorporate a unique
enzy~e mixture of proteolytic and amylolytic enzymes in
dishwasher detergent compositions which can be used in
automatic dishwashing operations capable of providing at Jeast
equal or better performance at operating temperatures of 100F
to 140F.
Both protein soils and carbohydrate soils are extremely
difficult to remove form dishware. The use of bleach in
automatic dishwashing compositions helps in the removal of
protein soils and high alkalinity of these automatic
dishwashing compositions helps in the removal of carbohydrate
soils, but even with bleach and high alkalinity these protein
and carbohydrate soils are not completely removed. The use of
a protease enzyme in the automatic dishwashing compositions
improves the removal of protein soils such as egg and milk
from dishware and the use of an amylase enzyme improves the
removal of carbohydrate soils such as starch from dishware.
Brief Description of the Drawings
Figure 1 illustrates a graph of a percent of egg removal at
various water and temperature conditions for Maxatase enzyme
versus wash temperature of cleaning at a pH of 9.1.
Figure 2 illustrates a graph of a percent of egg removal at
various water and temperature condition~ for Maxatase enzyme
versus wash temperature of cleaning at a pH of 8.8.
Flgure 3 illu3trates a graph of a percent of egg removal at
various water and temperature conditions for Maxacal enzyme
versus wash temperature of cleaning at a pH of 9.1.
DETAILED DESC~RIPTION
The present invention relates to a nonaqueous liquid
automatic dishwashing detergent compositions which comprise a
nonionic surfactant, a nonaqueous liquid carrier, sodium
silicate, a metal inorganic builder salt and a mixture of an
2 0 ~ 7
amylase enzyme and a protease enzyme and, optionally, a
detergent active material such as a nonlonic surfactant, a
foam depressant, and a lipase enzyme wherein the nonaqueous
liquid automatic dishwashing detergent composition has a pH of
less than 10.5 and the dishwashing detergent composition
exhibits maximum cleaning efficiency for both proteins and
starches at a wash temperature of 100F to 140F.
The liquid nonionic surfactants that can be, optionally,
used in the present nonaqueous liquid automatic dishwasher
detergent compositions are well known. A wide variety of the
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 propylene
oxide. Practically any hydrophobic compound having a
carboxyl, hydroxy and amido or amino group with a free
hydrogen attached to the nitrogen can be condensed with
ethylene oxide or with the polyhydration product thereof,
polyethylene glycol, to form a nonionic detergent. The length
of the hydrophilic or polyoxy ethylene/propylene chain can be
readily adjusted to achieve the desired balance between the
hydrophobic and hydrophilic groups. Typical suitable nonionic
surfactants are those disclosed in US Patent Nos. 4,316,812
and 3,630,929.
2~6~847
Preferably, the nonionic detergents that are used are the
low foaming poly-lower alkoxylated 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 S to 8 or 5 to
9 lower alkoxy grcups 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 minor (no
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 foaming
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 Cl3-CI5 fatty alcohol
condensed with 6 moles ethylene oxide and 3 moles propylene
oxide), Product B (a C~3-CI5 fatty alcohol condensed with 7 mole
propylene oxide and 4 mole ethylene oxide), and Product C (a
C13-CIs fatty alcohol condensed with 5 moles propylene oxide and
10 moles ethylene oxide). A particularly good surfactant is
Plurafac 132 which is a capped nonionic surfactant. Another
2~69847
group of low foam liquid nonionics are available from Shell
Chemical Company, Inc. under the Dobanol trademark: Dobanol
91-5 is an ethoxylated C9-cll fatty alcohol with an average of 5
moles ethylene oxide and Dobanol 25-7 is an ethoxylated Cl2-CI5
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 surfactant such as Synperonic LF D25
or LF RA 30 are especially preferred nonionic surfactants that
can be used in the nonaqueous liquid automatic dishwasher
detergent compositions of the instant invention. Other useful
nonionic surfactants are Synperonic RA 30, Synperonic RA 40
and Synperonic RA 340. The Synperonic surfactants are
especially preferred because they are biodegradable and low
foaming.
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, a water dispersible, having a
low cloud point ha~l 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 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
20~9~47
.egistered trademarks), both of which are linear secondary
alcohol ethoxylates made by Unlon 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. Another useful surfactant is Tergitol
MDS-42 a mixed ethoxylation product of 13-15 cations alcohols
with 10 moles of EO and 5 moles of PO.
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 11. Such
produc~s 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 alkyl polysaccharides surfactants, which are used
alone in conjunction with the aforementioned surfactant and
have a hydrophobic group containing from 8 to 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 10, preferably from
1.5 to 4, most preferably from 1.6 to 2.7 saccharide units
~0~9847
~e.g., galactoslde, glucoside, fructoside, glucosyl,
fructosyl; and/or galactosyl units). Mixtures of saccharide
moieties may be used in the alkyl polysaccharide surfactants.
The number x indicates the number of saccharide units in a
particular alkyl polysaccharide surfactant. For a particular
alkyl polysaccharide molecule x can only assume integral
values. In any physical sample of alkyl polysaccharide
surfactants there will be in general molecules having
different x values. The 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 l-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,
galactoside, fructosides, etc., is preferred. In the
preferred product the additional saccharide units are
predominately attached ~o 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 13
carbon atoms. Preferably, the alkyl group is a straight chain
saturated alkyl group. The alkyl group can contain up to 3
13
20698~
ydroxy 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-,
tetra-, penta- and hexaglucosides, galactosides, lactosides,
fructosides, fructosyls, lactosyls, glucosyls and/or
galactosyls and mixtures thereof.
The alkylmonosaccharides 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
R2O(CnH2nO)r(Z)~
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 8, preferably
from 1.5 to 4, 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
2069847
esired glucoside. Alternatively the alkyl polyglucosides 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
the alkyl polyglucosides can be prepared by a two step
procedure in which a short chain alcohol (Cl6) 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 (~20H) 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 amount of unreacted alcohol (the free fatty alcohol
content) in the desired alkyl polysaccharide surfactant is
preferably less than 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 10~.
The used herein, "alkyl polysaccharide surfactant" is
intended to represent both the preferred glucose and galacto~e
derived surfactants and the less preferred alkyl
polysaccharide surfactants. Throughout this specification,
"alkyl polyglucoside" is used to include alkyl polyglycosides
because the stereochemistry 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
20S~47
~ler, PA. APG 25 is a nonlonic alkyl polyglycoside
characterized by the formula:
CnH2n+lo~c6Hloo5)~H
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 25C of 1.1 g/ml; a density at 25C of 9.1
lbs/gallon; a calculated HLB of 12.1 and a ~rookfield
~iscosity 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 nonaqueous liquid nonionic surfactant has dispersed
therein fine par~icles or organic and/or inorganic detergent
builders. A preferred solid builder salt is an alkali metal
polyphosphate such as sodium tripolyphosphate ("TPP" ) . In
place of all or part of the alkali metal polyphosphate one or
more other detergent builder salts can be used. Suitable
other builder salts are alkali metal carbonates, borates,
phosphates, bicarbonates, silicates, lower polycarboxylic acid
salts, and polyacrylates, polymaleic anhydrides and copolymers
of polyacrylates and polymaleic anhydrides and polyacetal
carboxylates.
Specific examples of such builders 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
16
2~69847
~tassium 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.
A preferred builder salt is sodium tripolyphosphate
(TPP). The TPP is a blend of anhydrous TPP and a small amount
of TPP hexahydrate such that the chemically bound water
content which corresponds to about one H2O 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
par'icles size of the Thermphos NW TPP, as supplied, is
usually averages about 200 microns with the largest particles
being 400 microns.
The alkali metal silicates are useful builder salts which
also function to make the composition anti-corrosive so that
damage to eating utensils and to automatic dishwashing machine
parts is minimized. Sodium silicates of Na2O/SiO2 ratios of
from 1:1 to 1:2.4 especially 1:2 to 1:3 are preferred.
Potassium silicates of the same ratios can also be used. The
preferred alkali metal silicates are sodium disilicate and
sodium metasilicate.
Another class of builders useful herein are the water
insoluble aluminosilicates, both of the crystalline and
amorphous type. Various crystalline zeolites (i.e~ alumino-
17
2~6~8~7
llicates) 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 userul herein can
be found in Belgium Patent No. 835,351. The zeolites
generally have the formula
(M20) ~ (Al203) y (si2) ~ WH20
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 i9 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 200 millie~uivalents per
gram or greater, e.g. 400 meq/g.
In conjunction with the builder salt are optionally used
a low molecular weight polyacrylates which have 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 weight polyacrylate is
Acrysol~ 45ND manufactured by Rohm and ~aas and having a
molecular weight of 4,500. A suitable suspending and anti-
redepositing agent consists of a copolymer of a polyacid and
an acid anhydride. Such a material should have a water
absorption at 38C and 78 percent relative humidity of less
than about 40 percent and preferably less than 30 percent.
The builder is commercially available under the tradename of
Sokalan CP 45. This is a partially neutralized copolymer of
acrylic acid and maleic acid sodium salt. This suspending and
anti-deposition agent also serves to inhibit encrustation,
18
2069~7
.e. inhibits the formulation and precipitation of dicalcium
phosphate. Thls suspending agent has a low hygroscopicity as
a result of a decreased hydroxyl group content. 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.
AcusolTM 640 ND provided by Rohm & Haas is another useful
suspending agent. Other builder salts which can be mixed with
the sodium carbonate are gluconates and nitriloacetic acid
salts.
The stability against settling properties can be improved
by the addition to the composition of a small effective amount
of phosphoric ester and the viscosity and anti-gel propertie~
of the composition can be improved by adding to the
composition an effective amount of an alkylene glycol
monoalkyl ether.
In accordance with an embodiment of the present invention
the stability of the suspension is increased by including in
the composition an acidic organic phosphorus compound having
an acidic-POH group. The use of organic phosphoric acid
esters as stabilizing additives to nonionic laundry detergent
compositions containing polyphosphate builders is well known.
I'he acidic organic phosphorus compound may be, for
instance, a partial ester of phosphoric acid and an alcohol
such as an alkanol which has a lipophilic character, having,
for instance, more than 5 carbon atoms, e.g. 8 to 20 carbon
atoms. A specific example is a partial ester of phosphoric
acid and a C~6 to Cl8 alkanol (Empiphos 5632 from Marchon); it
is made up of 35~ monoester and 65~ diester. The inclusion of
19
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lite small amounts of the acidic organic phosphorus compound
makes the suspension significantly more stable against
settling on standing but remains pourable and decreases its
plastic viscosity. It is believed that the use of the acidic
phosphorus compound may result in the formation of a high
energy physical bond between the -POH portion of the molecule
and the surfaces of the inorganic polyphosphate builder so
that these surfaces take on an organic character and become
more compatible with the nonionic surfactant.
The thickening agents that can be used are those that
will swell and develop thixotropic properties in a nonaqueous
environment. These include organic polymeric materials and
inorganic and organic modified clays. Essentially, any clay
can be used as long as it will swell in a nonaqueous medium
and develop thixotropic properties. A preferred clay is
bentonite organoclay. A swelling agent i9 used with the
bentonite clay. The preferred swelling agent is a combination
of propylene carbonate and Maxatasetripropylene glycol methyl
ether. However, any other substance that will cause bentonite
to swell in a nonaqueous environment and thus develop
thixotropic properties can be used.
Suitable polymeric thickening agents are polycarboxylate
polymers such as Carbopol polymers manufactured by B.F'.
Goodrich. Carbopol 614 and Carbopol 617 are especially
preferred polymeric thickening agents. Another class of
suitable thickening agents are silicas such as Cab-O-Sil which
are useful at a concentration of 0.1 to 3.0 weight percent.
Another class of thickening agents are polyacrylates having a
molecular weight of 1,000 to 50,000. An especially preferred
20~8~7
lyacrylate is Sokalan CP 45, manufactured by BASF and
Acrysol~ 4sND manufactured by Rohm Haas. These polyacrylates
are used at a concentration level of 0.1 to 10 weight percent.
Other polymeric thickening agents are low molecular
weight associative thickeners such as Dapral~) T210 and T212
from AKZO chemicals. Dapral T210 and T212 are low molecular
weight dialkyl polyglycol ethers with an average molecular
weight of 8000. They are liquids and soluble and compatible
in non-aqueous media. Specially preferred is Dapral T210 in
1-5~ and in combination with other thickening agents such as
colloidal silica.
Essentially, any compatible anti-foaming agent can be
used. Preferred anti-foaming agents are silicone anti-foaming
agents. TheRe are alkylated polysiloxanes and include
polydimethyl siloxanes, polydiethyl siloxanes, polydibutyl
siloxanes, phenyl methyl siloxanes, dimethyl silanated silica,
trimethysilanated silica and triethylsilanated silica.
Suitable anti-foam agents are Silicone L7604 and DB-100.
Other suitable anti-foaming agents are Selecore DB 700 used at
0.2 to 1.0 weight ~, sodium stearate used at a concentration
and of 0.5 to 1.0 weight ~. Another class of suitable foam
depressants used at concentration levels of 0 to 1.5 weight ~,
more preferably 0.2 to 1.0 weight ~. are the alkyl phosphoric
acid esters of the formula
O
H--OP--R
OR
available from BASF-Wyandotte and the alkyl phosphate esters
of the formula
20~9~7
HO--P--R
lR
available from Hooker (SAP) and Knapsack (LPKn-158) in which
one or both R groups in each type of ester may be represented
independently by a Cl220 alkyl or ethoxylated alkyl group.
The perfumes that can be used include lemon perfume and
other natural scents. Essentially, any opacifier pigment that
is compatible with the remaining components of the detergent
formulation can be used. A useful and preferred opacifier is
titanium dioxide.
The nonaqueous carrier materials that can be used for the
liquid automatic dishwashing detergen~ compositions are
contained in the composition at a concentration level of at
least 40 wt.~ to 65 wt.~, more preferably at least 45 wt.~ to
60 wt.~, are those that have a low hydroscopicity. These
include the higher glycols, polyglycols, polyoxides and glycol
ethers. Suitable substances are propylene glycol,
polyethylene glycol, polypropylene glycol, diethylene glycol
monoethyl ether, diethylene glycol monopropyl ether,
diethylene glycol monobutyl ether, tripropylene glycol methyl
ether, propylene glycol methyl ether (DM), dipropylene glycol
methyl ether (DPMI), propylene glycol methyl acetate (PMA),
dipropylene glycol methyl ether acetate (DPMA), ethylene
glycol n-butyl ether and ethylene glycol dipropyl ether. A
preferred nonaqueous carrier of the instant invention is
polyethylene glycol 200 or polyethylene glycol 300.
Other useful solvents are ethylene oxide/propylene oxide,
propylene oxide liquid random copolymer such as Synalox
2~6~47
olvent series from Dow Chemical (Synalox 50-50B). Other
suitable solvents are propylene glycol ethers such as PnB,
DPnB and TPnB (propylene glycol mono n-butyl ether,
dipropylene glycol and tripropylene glycol mono n-butyl ether,
dipropylene glycol and tripropylene glycol mono n-butyl ethers
sold by Dow Chemical under the tradename Dowanol. Also
tripropylene glycol mono methyl ether "TPM Dowanol" from Dow
Chemlcal is suitable. Another useful series of solvents are
supplied by CCA biochem b.u. of Holland such as Plurasolv RML,
Plurasolv REL(S), Plurasolv REL, Plurasolv RIPL and Plurasolv
RBL .
Mixtures of PEG solvent with Synalox or PnB, DPnB, TPnB
and TPM solvents are also useful. Preferred mixtures are PEG
300/Synalox 50-50~ and PEG 300/TPnB in weight ratios of 95:5
to 50:50. EP/PO capped nonionic surfactants can be used as a
liquid solvent carrier and an example of such a nonionic
surfactant is Plurafac LF 132 sold by BASF.
The stabiliziny system of the instant compositions
comprise a finely divided silica such as Cab-O-Sil M5, PTG or
Aerosil 200 which are used at a concentration level o~ O to
4.0 weight percent, more preferably 0.5 to 3.0 weight ~. Al90
employed as a stabilizing system are mixtures of finely
divided silica such as Cab-O-Sil, and nonionic associative
thickeners such as Dapral T210, T212 (Akzo) which are low
molecular weisht dialkyl polyglycol ethers with a dumbbell-
like structure or Pluracol TH 916 a~d TH 92~ (BASF)
associative thickeners having star-like structure with a
hydrophilic core and hydrophobic tail. These thickeners are
used at concentration levels of O to 5.0 weight percent
20~98~7
ogether with 0 to 2.0 weight percent of finely divided
silica. Other useful stabilizing systems are blends of
organoclay and hydroxypropyl cellulose polymer (HPC). A
suitable organoclay is Bentone NL27 gel sold by NL Chemical.
A suitable cellulose polymer is Klucel M Cellulose having a
molecular weight of about 1,000,000 and is sold by Aqualon
Company. Bentone gel contains 9% Bentone NL 27 powder (100
percent active), 88 percent TPM solvent (tripropylene glycol
mono methyl ether) and 3 percent propylene carbonate (polar
additive). The organic modified clay thickeners are used at
concentration levels of about 0 weight percent to about 15
weight percent in conjunction with Klucel M at concentration
levels of about 0 to about 0.5 weight percent, more
preferably about 0.2 weight percent to about 0.4 weight
percent. Another useful thickening agent is a high molecular
weight long chain fatty alcohol (C20-C40) such as UnilinTM 425
sold by Petrolite chemicals.
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 of the present invention can
possibly include a peroxygen bleaching agent at a
concentration level of 2 to 15 wt.%. The oxygen bleaching
agents that can be used are alkali metal perborate,
perphthalic acid, percarbonate and perphosphates, and
potassium monopersulfate. A preferred compound is sodium
24
2~69847
erborate monohydrate. The peroxygen bleaching compound is
preferably used in admixture with an activator thereof.
Suitable activators are those disclosed in U.S. Patent No.
~,264,466 or in column 1 of U.S. Patent No. 4,430,244.
Polyacylated compounds are preferred activators. Suitable
preferred activators are tetraacetyl ethylene diamine
("TAED"), pentaacetyl glucose, and ethyledine benzoate
acetate.
The activator which is present at a concentration level
of 0.5 to 5.0 wt.~ usually interacts with the peroxygen
compound to form a peroxyacid bleaching agent in the wash
water. It is preferred to include a sequestering agent of
high complexing power to inhibit any undesired reaction
between such peroxyaci.d and hydrogen peroxide in the wash
solution in the presence of metal ions. Suitable sequestering
agents include the sodium salts of nitrilotriacetic acid
(NTA), ethylene diamine tetraacetic acid (EDTA), diethylene
triamine pentaacetic acid (DETPA), diethylene triamine
pentamethylene phosphoric acid (DTPMP) sold under the
tradename D~QUEST 2066 and ethylene diamine tetramethylene
phosphoric acid (EDITEMPA). The sequestering agents can be
used alone or in an admixture.
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 liquid automatic dishwasher
detergent composition. Proteolytic enzymes remove protein
residues, lipolytic enzymes fat residues and amylolytic
2~6~8~
nzymes remove starches. Proteolytic enzymes include the
protease enzymes subtilisn, bromelin, papain, trypsin and
pepsin. Amylolytic enzymes include alpha-amylase enzymes.
Lipolytic enzymes include the lipase enzymes. The preferred
amylase enzyme is available under the name Maxamyl, derived
from Bachillus liceniformis and is available from Gist-
Brocades of the Netherlands in the form of a nonaqueous slurry
(18 wt.~ of enzyme) having an activity of 40,000 TAU/g. The
preferred protease enzyme is available under the name MaxataseR
and is available from Gist-Brocades of the Netherlands and is
derived from a novel Bacillus strain designated "PB 92"
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. Preferred enzyme activities
per wash are Maxatase 250-800 KDU per wash and Maxamyl 4,000-
10,000 TAU per wash.
Maxatase protease enzyme, 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). Maxamyl amylase enzyme, a thermostable B.
licheniformis alpha-amylase (39,500 TAU/g) which is supplied
in a nonaqueous slurry (18 weight percent) by International
BioSynthetics (Glst Brocades). At a concentration level of 8
of Maxatase and 1.0~ of Maxamyl in the instant automatic
dishwashing compositions, a 25 gram dose of automatic
dishwashing composition per wash delivers 9,875 TAU of Maxamyl
amylase and 780,000 DU of Maxatase protease.
~6
2~S9~7
The weight ratio of the Protease enzyme to the amylolytic
enzyme in the nonaqueous liquid automatic dishwasher detergent
compositions is 9:1 to 1.1:1 more preferably 8:1 to 1.1:1.
The detergent composition can have a fairly wide ranging
composition. The surfactant can comprise 0 to 15 percent by
weight of the composition, more preferably 2 to 15 percent by
weight, and most preferably 4 to 12 percent by weight. The
soil suspending agent which is preferably a copolymeri~ed
polyacrylic acid will be present in an amount of 0 to 20
percent by weight, more preferably 1 to 10 percent by weight
and most preferably 3 to 8 percent by weight. The anti-
foaming agent will be present in an amount of 0 to 2.5 percent
by weight, more preferably 0.1 to 2.0 percent by weight and
most preferably 0.2 to 1.5 percent by weight. The builder,
which is preferably sodium tripolyphosphate, is present in an
amount of 10 to 40 percent by weight, more preferably 20 to 38
percent by weight and most preferably 20 to 35 percent by
weight.
The thickener, which is preferably a bentonite clay gel,
is a mixture of propylene carbonate and tri-propylene glycol
methyl ether (TPM) and Bentone NL 27 i9 preferred, it is
present in an amount of 0 to 15 percent by weight, more
preferably 5 to 10 percent by weight.
Other useful thickeners are fatty acid and metal fatty
acid salts as described in U.S. Patents 4,752,409 and
4,836,946, are also useful thickeners used at a concentrate
level of 0.02 to 5 weight percent, more preferably 0.02 to 3
weight percent, and most preferably 0.05 to 3.0 weight
percent. Other useful thickeners are polycarboxylate polymers
2 0 ~
,uch as Carbopol polymers manufactured by B.F. Goodrich at
concentration levels of 0.1 to 5.0 weight percent and more
preferably 0.1 to 3.0 weight percent. Low molecular weight
polyacrylate polymers such as Sokolan~ CP45, Acusol~ 460ND,
and Acrysol'm 45ND are useful as thickeners at concentration
levels of 0.1 to 10.0 weight percent, and more preferably at
0.1 to 5.0 weight percent.
The alkali silicate, of which sodium silicate is
preferred, will be present in an amount of 0 to 15 percent by
weight, more preferably 6 to 12 percent by weight and most
preferably 3 to 9 percent by weight. The opacifier pigment
will be present in an amount of 0.0 to 1.0 percent by weight,
more preferably 0.1 to 1.0 percent by weight and most
preferably 0.5 percent by weight.
The enzymes will be present in slurry form (18~ enzyme in
polyethylene glycol 400) in an amount of 0.8 to 16.0 percent
by weight, more preferably 0.9 to 14.0 percent by weight, and
most preferably 1.0 to 12.0 percent by weight. The Maxatase
protease in the automatic dishwashing composition enzyme will
comprise 0.5 to 12.0 percent by weight, more preferably 0.7 to
10.0 weight percent and most preferably 0.8 to 9.0 percent by
weight. The amylase enzyme will comprise 0.3 to 6.0 percent by
weight, more preferably 0.4 to 3.0 weight percent and most
preferably 0.5 to 2.0 weight percent. The lipase enzyme will
comprise 0.00 to 8.0 percent by weight of the detergent
composition. Other components such as color and perfumes will
be comprised of 0.1 to 1.0 percent by weight of the detergent
composition. Another suitable lipase is ~ipolas 30T from Novo
206~847
'orporation. Another useful lipase enzyme is Pntanu PS lipase
provided by Amunco International Enzyme Co, Inc. The llpase
enzymes are especially beneficial in reducing grease residues
and related filming problems on glasses and dishware. The
remainder of the detergent composition will be comprised of
the nonaqueous carrier. This will range from 15 ~o 65 weight
percent, more preferably 25 to 57 weight percent, and most
preferably 40 to 55 weight percent.
The detergent formulation is produced by combining the
liquid components consisting of the carrier, surfactant and
anti-foam agent and then adding the builder salt (TPP), the
anti-redeposition agent (copolymerized polyacrylic acid) and
alkali metal silicate. This mixture is then ground in a ball
mill (Attritor or Netzsch) to a particle size of less than
about 40 microns, and preferably to a size of about 4 to 5
microns. The enzyme mixture is then added. The enzymes
preferably will be in a polyethylene glycol slurry. This
enzyme mixture is mixed into the ground slurry. Then the
thickener, thickener swelling agents, opacifiers, brighteners,
stabilizing agents and perfumes are added. After a thorough
mixing, the detergent composition is packaged.
The concentrated nonaqueous liquid 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 measu-ed
capacity for 80cc or 90 grams o~ detergent. In normal use,
for example, ~or a full load of dirty dishes 60 grams of
powdered detergent are normally used.
29
2~8~7
In accordance with the present invention only about 20cc
to about 35 cc or 40 grams or less of the concentrated liquid
nonionic detergent composition is needed, and more preferably
20cc or 25 grams of concentrated liquid is used per dispenser
cup. The normal operation of an automatic dishwashing machine
can involve the following steps or cycles: washing, rinse
cycles with hot wa~er. The entire wash and rinse cycles
require about 120 minutes. The temperature of the wash water
is 100F to 140F and the temperature of the rinse water is
100F to 140F. The wash and rinse cycles use 8 to 12 liters
of water for the wash cycle and 8 to 12 liters of water of the
rinse cycle.
The highly concentrated nonaqueous liquid automatic
dishwashing detergent compositions exhibit excellent cleaning
properties of proteinaceous soils such as egg and starchy
carbohydrates such as oatmeal and minimizes the formation of
spots and films on the dishware and glasses. In an
embodiment of the invention the stability of the builder salts
in the composition during storage and the dispersibility of
the composition in water is improved by grinding and reducing
the particle size of the solid builders to less than 100
microns, preferably less than 40 microns and more preferably
to less than 10 microns. The solid builders are generally
supplied in particle sizes of 100, 200 or 400 microns. The
nonionic liquid gurfactant phase can be possibly mixed with
the solid builders prior to carrying out the grinding
operation.
In the grinding operation it is preferred that the
proportion of solid ingredients be high enough (e.g. at least
2069847
0~, such as about 50~) that the solid particles are in
contact with each other and are not substantially shielded
from one another by the nonionic surfactant liquid. After the
grinding step any remaining liquid nonionic surfactant can be
added to the ground formulation. Mills which employ grinding
balls (ball mills) or similar mobile grinding elements give
very good results. For larger scale work a continuously
operating mill in which there are 1 mm. or 1.5 mm diameter
grinding balls working in a very small gap between a stator
and a rotor operating at a relatively high speed e.g. a CoBall
mill or a Netzsch ball mill may be employed; when using such a
mill, it is desirable to pass the blend of nonionic surfactant
and solids first through a mill which does not effect such
fine grinding (e.g. to 40 microns) prior to the step of
grinding to an average particle diameter below 10 microns in
the continuous ball mill.
It is also contemplated within the scope of this
invention to form compositions without grinding, wherein he
particle size has a distribution of 60-120 microns. In a
preferred embodiment the detergent builder particles have a
particle size distribution such that no more than 10~ by
weight of said particles have a particle size of more than 10
microns.
31
2~698~7
ESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
The concentraced nonaqueous liquid dishwasher detergent
compositions were formulated from the following ingredients ln
the amounts specified.
Ingredients Comparison
Maxatase Maxatase Maxacal
Composition(a) Composition(b~
Composltion ~c ),
Polyethylene Glycol 300Q.S. Q.S. Q.S.
Synperonic ~FD 25
Surfactant 8.00 8.00 8.00
Sodium Silicate
(Na2O:SiO2/1:2) 9.00 8.00 g.oo
Sodium Tripolyphosphate
Anhy. 33-00 30-00 30.00
Sokalan CP 45 Polymer 5.00 5.00 5.00
Maxamyl Amylase Enzyme Slurry
(activity: 42,800 TAU/g) 1.00 1.00 1.00
Maxacal Protease Enzyme Slurry
(activity: 890,509 ADU/g) --- --- 3.50
Maxatase Protease Enzyme Slurry
(activity: 604,000 DU/g) 3.50 3.50 ---
pH (1~ solution) 9.10 8.80 9.10
2~69847
L_ oratory Cleaning Performance
Laboratory performance of the compositions of Example were
carried out using multi-soils at various temperatures and water
hardness conditions. This i5 done to show differences between the
prototype formulations. Egg soil was prepared by mixing egg yolk
with an equal amount of 2.5 N calcium chloride solution. 0.4
grams of this mixture was applied as thin cross-wise film to the
usable surface of 7.5 inch china plates. The plates were aged in
50~ relative humidity overnight. Oatmeal soil was prepared by
boiling 24 grams of Quaker Oats in 400 ml of tap water for ten
minutes. 3 grams of this mixture was spread as thin film onto a
7.5 inch china plate. The plates were aged for 2 hours at 80C
(176F). They were then stored overnight at room temperature. Two
plates of each egg and oatmeal were used per wash. The plates
were placed in the same positions in the dishwasher. 25 grams of
the detergent was used as a single dose per wash. All plates were
scored by measuring the percent area cleaned. The multi-soil
cleaning test results are reported below. The results tabulated
were average of at least 2 runs. Average results reflect the
average performance results obtained in three different water
conditions in given temperatures and the overall average showed
the average results obtained in five temperature in three
different water conditions and these results were also shown
graphically in Figures 1-3. The performance rating shows a
2~ normalized results with Maxacal Protease Enzyme and oatmeal
cleaning was not considered in calculations. Maxacal (Composition
C) is the worst performer and is not suitable for such high 135-
140F temperature wash conditions. The optimum wate temperature
recommended by Autodish manu~acturers for US is 140F. By
2~98~7
r ~cing alkalinity of the formulation, the performance of
Maxatase was further improved (composition b). Maxatase
(compositions a and b) outperformed Maxacal protease.
34
20~9~7
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