Note: Descriptions are shown in the official language in which they were submitted.
CA 02221169 1997-11-14
W096/36687 PCT~P96102130
A~TOMATIC DISH~ ~TNG COMPOSITIONS
CONTAINING AL~MIN~M SA~TS
FIELD OF T~E lN v~llON
This invention relates to automatic dishwashing
detergent compositions containing an aluminum species which
inhibits corrosion o~ fine tableware.
BACRGRO~N~ OF TRE lN V~N 1 lON
It is well known in the art that automatic dishwashers
corrode glassware particularly when cleaned with highly
15 alkaline detergent compositions. See Newton, R. G., The
Durability of Glass-A Review, Glass Technology Vol. 26 No. 1,
February 1985, pp. 21-38 and US 4,933,101 (Cilley et al.).
The visible for-m~s of glassware corrosion are generally caused
by hydrolysis and therefore dissolution of the glassware's
20 silicate network. This dissolution is known to be very low at
pH values below 9.5 and increases with increasing pH (see
Kruger, A. A., The Role of the Surface on Bulk Physical
Properties of Glasses, in Surface and Near-Surface Chemistry
of Oxide Materials, eds. Nowotny, J., and Dufour, L.-C., pp.
25 413-448). Thus detergent compositions having an alkalinity
of less than about pH 10 were conventionally believed to
exert very low corrosivity towards glassware.
Cleaning restrictions forced prior art formulators to
30 seek solutions to tableware corrosion while maintaining high
alkalinity in detergent products. The art teaches that
silicate in combination with fast dissolving al~lm;n~lm salts
avoids high alkalinity corrosion of glassware. See US
~ = :
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WO 96/366X7 PCT/EP96/02130
3,350,318, issued on October 31, 1967 to Green and US
3,255,117 issued June 7, 1966 to Knapp et al.
As detergent compositions have increasingly become based
5 on enzymes allowing the products to be milder and more
environmentally friendly, it was believed that glassware
corrosion would not be a problem especially at pH values of
less than about 10.
It has now been discovered that detergent formulations
having neutral pH or low alkalinity signi~icantly corrode
fine tableware, particularly lead crystal glassware. It is
believed that the lead and boron minerals of the tableware
take part in the ~ormation of the silicate network. When
15 such minerals are extracted the silicate network falls apart
readily. This corrosion is especially pronounced in the
absence o~ silicate which is not always incorporated in low
alkalinity or neutral pH products. It has further been
observed that detergent compositions incorporating alllm;nllm
20 salts to inhibit corrosion compromise cleaning and leave
significant stains on washed tableware.
It has been surprisingly discovered that by utilizing
certain slow dissolving al--m;n~lm salts in automatic
25 dishwashing compositions that tableware corrosion can be
inhibited and that cleaning efficiency can be improved.
It has also been surprisingly discovered that by
utilizing certain sequestrants in combination with any water
30 soluble aluminum salt that both tableware corrosion and the
negative impact on cleaning efficiency can be m;n;m;zed.
It is thus an object o~ the present invention to provide
improved pH-neutral to mildly alkaline automatic dishwashing
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detergent compositions which not only protect against
tableware corrosion but also provide good cleaning
performance in removing stains from tableware.
Another object o~ the invention is to provide a process
for incorporating alllmlnllm salts in automatic dishwashing
detergent compositions to provide e~fective cleaning
performance without tableware corrosion. Although the
preparation of the compositions containing the slow
l0 dissolving aluminum salts may be by any conventional method,
a premix of aluminum-sequestrant complexes must be prepared
before the r~m~;ning components are added to ~orm the
alllm;nllm-sequestrant compositions.
S~MM~Y OF TEE lN V ~'N-l'lON
= The compositions of the invention are automatic
dishwashing detergent compositions which substantially
inhibit lead corrosion of fine tableware, comprising:
a) 0.0l to 25 wt. ~, pre~erably l to 15, o~ an alllm;nllm
salt which dissolves at a rate to deliver less than 0.56 mM
all~mlnllm(III) per minute at 42~C to a wash liquor ;
b) l to 20 wt. ~ of a bleaching agent selected from a
peroxygen agent, hypohalite agent, corresponding salts and
mixtures thereof;
c) l to 75 wt. ~ of a builder, and
d) 0 to 40 wt. ~ of a surfactant,
CA 02221169 1997-11-14
.
C 6294 (V)
a 1~ aqueous solution o~ the detergent composition
having a pH of from neutral to less ~ 10 and having up to 5wt% of
added silicates.
5 In view o~ its low rate of dissolution, the aluminum salt o~
the invention is characterised by controlled release o~
aluminum(III) ions ~rom the product to the sur~ace o~ the
tableware. The aluminum salt may be part o~ an aluminum-
sequestrant complex in which the aluminum is ~ound by a
t~ 10 sequestrant, said complex preventing ~or at least one hour,
~ the precipitation o~ any aluminum compound ~rom an aqueous
solution having a pH in the range o~ ~ro~ 7 to 10.
The compositions o~ the invention may be in any variety
15 o~ physical ~orms, namely, liquid, powder or gel.
DETAILFD DESCRIPTIO~ OF TEE PREFERRED EMsoDIM~NTs
The compositions o~ the invention are e~ective cleaners
20 which do not corrode tableware, particularly tableware ~or
entertainment or decorative purposes. Such glassware
generally has a high re~ractive index which gives the classic
"spar~le" when cut into decorative shapes. For purposes o~
this invention, the lead content o~ such tableware is more
25 than about 20~ by weight.
Slow Dissolvinq Al--~;nl-m Salts
The term "slow dissolving aluminum salt" re~ers to an
30 aluminum salt that dissolves at a rate to yield less than
0.56 mM aluminum(III) per minute at 42~C.
Slow dissolving aluminum salts within the scope o~ the
invention include: aluminum stearate, aluminum tartrate,
AA~NDED S11EET
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WO 96/36687 PCT/EP96/02130
~ aluminum acetate, aluminum acetotartrate, alnm;nllm
salicylate, alllm;nllm bis(acetylsalicylate), alllm;nllm ~ormate,
aluminum octoate, all~minllm borate, all~m1nllm oleate, aluminum
palmitate, aluminum acetylacetonate, alllm;nllm phosphate and
!, mixtures thereof. Preferred aluminum salts include alllm;nllm
acetate, aluminum acetylacetonate, alllminllm octoate and
aluminum phosphate. Most preferred all~m;nllm salts include
aluminum acetate, all~mlnllm acetylacetonate and alllm;nllm
octoate.
11~
The aluminum salt should be incorporated in the
detergent composition in an amount to deliver O.l mM to lO
mM, pre~erably O.5 mM to 5 mM, most pre~erably 1 mM to 2 mM
Al~III) in the wash.
l!~
Aluminum-Sequestrant Complexes
The term 'lalllm;nllm-sequestrant complex" refers to a
system containing an alnm;nllm salt and a sequestrant which,
when prepared properly, results in a reduced release rate of
20 Al(III) ions.
Aluminum salts useful to form the alnm;nllm-sequestrant
complexes within the scope of the invention include: alnm;nllm
sulfate, sodium aluminate, alllm;nnm acetate, alllm;nllm
2.5 acetylacetonate, alllm;nllm formate, alllm;nllm borate, alllm;nllm
octoate, alllm;nllm oleate,.aluminum palmitate, aluminum
tartrate, alllm;nllm acetotartrate, and mixtures thereof.
Preferred alnm;nllm salts include: alllm;nnm sulfate, sodium
aluminate, alllm;nllm acetate, alnm;nllm acetylacetonate, and
30 alllm;nllm borate. Most preferred alllm;nllm salts include:
- , alllm;nnm sulfate, sodium aluminate, and alllm;nllm
acetylacetonate.
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Sequestrants within the scope of the invention include
the following acids and their alkali metal salts: EDTA,
oxalic acid, citric acid, cyanuric acid, NTA, sodium
orthophosphoric acid, malonic acid, succinic acid, tartaric
5 acid, aspartic acid, glutamic acid, phosphonic acid, and
polyphosphoric acid. Preferred sequestrants include: EDTA,
oxalic acid, sodium citrate, and cyanuric acid. Most
preferred sequestrants include: sodium citrate, oxalic acid,
and cyanuric acid.
The aluminum-sequestrant complex is prepared as follows:
with stirring, the desired amount of the selected sequestrant
is added to water. During dissolution of the sequestrant,
the pH of the solution is adjusted with an inorganic acid, or
15 an inorganic base, preferably NaOH or H2SO4 to a pH of not
less than one pH unit above the pKa of at least one of the
ionizable groups on the sequestrant. This mixture is allowed
to stir until the sequestrant is completely dissolved. The
aluminum salt is dosed into the solution of the sequestrant
20 and allowed to dissolve. During the dissolution of the
aluminum salt, the pH of the system is adjusted to the same
pH as during the initial dissolution of the sequestrant with
NaOH or H2S04, as necessary. After the al-lm;nllm salt is
completely dissolved, the complex is ready for use.
Alkalini tY
The alkalinity of a 1~ aqueous solution of the
compositions of the invention should be neutral to low
30 alkalinity, being less than a pH of 10, more preferably 7 to
9. Maintenance of the composition's pH within the desired
range provides stain removal while inhibiting corrosion of
fine tableware.
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WO 96/36687 PCT/EP96/02130
The alllminllm salts can interact with tea stains so that
the incorporation of slow dissolving alllm;nllm salts in the
compositions allows effective bleaching before substantial
levels of Al(III) are released into the wash water.
'5
In the aluminum-sequestrant complexes, on the other
hand, the aluminum is bound to the sequestrant strongly
enough to delay interaction of Al(III) with tea stains.
llD
Any number of conventional buffer agents may be used to
maintain the desired pH range. Such materials can include,
for example, various water soluble inorganic salts such as
the carbonates, bicarbonates, sesquicarbonates, silicates,
15 pyrophosphates, phosphates, tetraborates and mixtures
thereof.
The buffering agents should be present in the
compositions in a amount of from about 2 to about 30 wt. ~,
20 preferably from 5 to about 25~ by wt. of the total
composition.
Deterqent Builder Materials
The compositions of this invention can further contain
all manner of detergent builders commonly taught for use in
automatic dishwashing of compositions to increase the
effectiveness of the detergent by in part, binding calcium
salts to act as a softener. The builders can include any of
30 the conventional inorganic and organic water-soluble builder
salts, or mixtures thereof and may comprise 1 to 75~, and
preferably, from about 5 to about 70~ by weight of the
cleaning composition.
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Typical examples o~ phosphorus-containing inorganic
builders, when present, include the water-soluble salts,
especially alkali metal pyrophosphates, orthophosphates and
polyphosphates. Specific examples of inorganic phosphate
5 builders include sodium and potassium tripolyphosphates,
phosphates, pyrophosphates and hexametaphosphates.
Suitable examples of non-phosphorus-containing inorganic
builders, when present, include water-soluble alkali metal
10 carbonates, bicarbonates, sesquicarbonates, borates,
silicates, metasilicates, and crystalline and amorphous
aluminosilicates. Speci~ic examples include sodium carbonate
(with or without calcite seeds), potassium carbonate, sodium
and potassium bicarbonates, silicates and zeolites.
Particularly pre~erred inorganic builders can be
selected from the group consisting o~ sodium
tripolyphosphate, potassium pyrophosphate, sodium carbonate,
potassium carbonate, sodium bicarbonate, sodium silicate and
20 mixtures thereof. When present in these compositions, sodium
tripolyphosphate concentrations will range ~rom about 2~ to
about 40~; pre~erably ~rom about 5~ to about 30~. Sodium
carbonate and bicarbonate when present can range from about
5~ to about 50~; pre~erably from about 10~ to about 30~ by
25 weight of the cleaning compositions. Sodium tripolyphosphate
and potassium pyrophosphate are pre~erred builders in gel
formulations, where they may be used at ~rom about 3 to about
30~, preferably ~rom about 10 to about 20~.
Organic detergent builders can also be used in the
present invention. Examples of organic builders include
alkali metal citrates, succinates, malonates, ~atty acid
sul~onates, ~atty acid carboxylates, nitrilotriacetates,
phytates, phosphonates, alkanehydroxyphosphonates,
-
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wos6l36687 PCT~P96/02130
oxydisuccinates, alkyl and alkenyl disuccinates,
oxydiacetates, carboxymethyloxy succinates, ethylenediamine
tetraacetates, tartrate monosuccinates, tartrate
disuccinates, tartrate monoacetates, tartrate diacetates,
', oxidized starches, oxidized heteropolymeric polysaccharides,
polyhydroxysulfonates, polycarboxylates such as
polyacrylates, polymaleates, polyacetates,
polyhydroxyacrylates, polyacrylate/polymaleate and
polyacrylate/ polymethacrylate copolymers,
10 aminopolycarboxylates and polyacetal carboxylates such as
those described in U.S. Paten~ Nos. 4,144,226 and 4,146,495.
Alkali metal citrates, oxydisuccinates, polyphosphates
and acrylate/maleate copolymers are especially preferred
15 organic builders. When present they are preferably available
from about 1~ to about 35~ of the total weight of the
detergent compositions.
The foregoing detergent builders are meant to illustrate
20 but not limit the types of builders that can be employed in
the present invention.
Surfactants
2!~ Useful surfactants include anionic, nonionic, cationic,
amphoteric, zwitteronic types and mixtures of these surface
active agents. Such surfactants are well known in the
detergent art and are described at length in "Surface Active
Agents and Detergents", Vol. II, by Schwartz, Perry & Birch,
30 Interscience Publishers, Inc. 1959, herein incorporated by
reference.
Anionic synthetic detergents can be broadly described as
surface active compounds with one or more negatively charged
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WO 96/36687 PCT/EP96/02130
functional groups. Soaps are included withln this category.
A soap is a C8-C22 alkyl fatty acid salt of an alkali metal,
alkaline earth metal, ammonium, alkyl substituted ammonium or
alkanolammonium salt. Sodium salts of tallow and coconut
5 fatty acids and mixtures thereof are most common. Another
important class of anionic compounds are the water-soluble
salts, particularly the alkali metal salts, of organic sulfur
reaction products having in their molecular structure an
alkyl radical containing from about 8 to 22 carbon atoms and
10 a radical selected from the group consisting of sulfonic and
sulfuric acid ester radicals. Organic sulfur based anionic
surfactants include the salts of Cl0-CI6 alkylbenzene
sulfonates, C,0-C22 alkane sulfonates, Cl0-C22 alkyl ether
sulfates, Cl0-C22 alkyl sulfates, C4 - Clo dialkylsulfosuccinates,
15 Cl0-C22 acyl isothionates, alkyl diphenyloxide sulfonates,
alkyl napthalene sulfonates, and 2-acetamido hexadecane
sulfonates. Organic phosphate based anionic surfactants
include organic phosphate esters such as complex mono- or
diester phosphates of hydroxyl-terminated alkoxide
20 condensates, or salts thereof. Included in the organic
phosphate esters are phosphate ester derivatives of
polyoxyalkylated alkylaryl phosphate esters, of ethoxylated
linear alcohols and ethoxylates of phenol. Also included are
nonionic alkoxylates having a sodium alkylenecarboxylate
25 moiety linked to a terminal hydroxyl group of the nonionic
through an ether bond. Counterions to the salts of all the
foregoing may be those of alkali metal, alkaline earth metal,
ammonium, alkanolammonium and alkylammonium types.
Nonionic surfactants can be broadly defined as surface
active compounds with one or more uncharged hydrophilic
substituents. A major class o~ nonionic surfactants are
those compounds produced by the condensation of alkylene
oxide groups with an organic hydrophobic material which may
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WO 96/36687 PCT/EP96/02130
~ be aliphatic or alkyl aromatic in nature. The length of the
hydrophilic or polyoxyalkylene radical which is condensed
with any particular hydrophobic group can be readily adjusted
to yield a water-soluble compound having the desired degree
5 of balance between hydrophilic and hydrophobic elements.
Illustrative, but not limiting examples, of various suitable
nonionic surfactant types are:
(a) polyoxyethylene or polyoxypropylene condensates of
10 aliphatic carboxylic acids, whether linear- or branched-chain
and unsaturated or saturated, containing ~rom about 8 to
about 18 carbon atoms i.n the aliphatic chain and
incorporating from about 2 to about 50 ethylene oxide and/or
propylene oxide units. Suitable carboxylic acids include
15 "coconut" fatty acids (derived from coconut oil) which
contain an average o~ about 12 carbon atoms, "tallow" fatty
acids (derived from tallow-class fats) which contain an
average of about 18 carbon atoms, palmitic acid, myristic
acid, stearic acid and lauric acid,
(b) polyoxyethylene or polyoxypropylene
condensates of aliphatic alcohols, whether linear- or
branched-chain and unsaturated or saturated, containing from
about 6 to about 24 carbon atoms and incorporating from about
25 2 to about 50 ethylene oxide and/or propylene oxide units.
Suitable alcohols include "coconut" fatty alcohol, "tallow"
fatty alcohol, lauryl alcohol, myristyl alcohol and oleyl
alcohol. Particularly preferred nonionic surfactant
= compounds in this cateyory are the "Neodol" type products, a
30 registered trademark of the Shell Chemical Company.
Also included within this category are nonionic
sur~actants having a formula:
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n (CH2CH~)X(CH2CH20)y~CH2CH~H (I~
Rl R2
wherein R is a linear
5 alkyl hydrocarbon radical having an average of 6 to 18 carbon
atoms, Rl and R2 are each linear alkyl hydrocarbons of about 1
to about 4 carbon atoms, x is an integer o~ ~rom 1 to 6, y is
an integer of ~rom 4 to 20 and z is an integer ~rom 4 to 25.
One pre~erred nonionic sur~actant o~ ~ormula I is
Poly-Tergent SLF-18 a registered tr~m~rk of the Olin
Corporation, New Haven, Conn. having a composition o~ the
abo~e ~ormula where R is a C6-C,0 linear alkyl mixture, Rl and
15 R2 are methyl, x averages 3, y averages 12 and z averages 16.
A180 suitable are alkylated nonionics as are described in
U.S. Patent 4,877,544 (Gabriel et al.), incorporated herein
by reference.
Another nonionic sur~actant included within this category
are compounds of formula:
R3 (CH2CH20)qH (II)
25 wherein R3 is C6-C~ linear or branched alkyl hydrocarbon
radical and q is a number from 2 to 50; more pre~erably R3 is
a C8-C~8 linear alkyl mixture and q is a number from 2 to 15.
(c) polyoxyethylene or polyoxypropylene condensates o~
30 alkyl phenols, whether linear- or branched-chain and
unsaturated or saturated,cont~; n; ng ~rom about 6 to 12 carbon
atoms and incorporating ~rom about 2 to about 25 moles of
ethylene oxide and/or propylene oxide.
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(d) polyoxyethylene derivatives o~ sorbitan mono-, di-,
and tri-fatty acid esters wherein the fatty acid component
has between 12 and 24 carbon atoms. The pre~erred
polyoxyethylene derivatives are of sorbitan monolaurate,
'; sorbitan trilaurate, sorbitan monopalmitate, sorbitan
tripalmitate, sorbitan monostearate, sorbitan
monoisostearate, sorbitan tripalmitate, sorbitan
monostearate, sorbitan monoisostearate, sorbital tristearate,
sorbitan monooleate, and sorbitan trioleate. The
10 polyoxyethylene ch~;n~ may contain between about 4 and 30
ethylene oxide units, preferably about 20. The sorbitan
ester derivatives contain 1, 2 or 3 polyoxyethylene ch~ i n~
dependent upon whether they are mono-, di- or tri-acid
esters.
1 _i
(e) polyoxyethylene-polyoxypropylene block copolymers
having formula:
HO(CH2CH2O)~(CH(CH3)CH2O) b (CH2CH2O)cH (III)~C~
or
HO(CH(CH3)CH2O) d (CH2CH2O)C(CHCH3CH2O)~ (IV)
wherein a, b, c, d, e and f are integers from 1 to 350
reflecting the respective polyethylene oxide and
polypropylene oxide blocks of said polymer. The
polyoxyethylene component of the block polymer constitutes at
least about 10~ of the block polymer. The material
30 preferably has a molecular weight of between about 1,000 and
15,000, more preferably from about 1,500 to about 6,000.
These materials are well-known in the art. They are
available under the trademark "Pluronic" and ~Pluronic R", a
product of BASF Corporation.
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(~) Alkyl glycosides having ~ormula:
R40(R50) (zl) (V)
5 wherein R4 is a monovalent organic radical (e.g., a
monovalent saturated aliphatic, unsaturated aliphatic or
aromatic radical such as alkyl, hydroxyalkyl, alkenyl,
hydroxyalkenyl, aryl, alkylaryl, hydroxyalkylaryl, arylalkyl,
alkenylaryl, arylalkenyl, etc.) containing ~rom about 6 to
10 about 30 (pre~erably ~rom about 8 to 18 and more pre~erably
from about 9 to about 13) carbon atoms; Rs is a divalent
hydrocarbon radical cont~;n;ng ~rom 2 to about 4 carbon atoms
such as ethylene, propylene or butylene (most pre~erably the
unit (RsO) n represents repeating units o~ ethylene oxide,
15 propylene oxide and/or random or block combinations thereof);
n is a number having an average value of ~rom 0 to about 12;
zl represents a moiety derived ~rom a reducing saccharide
containing 5 or 6 carbon atoms (most pre~erably a glucose
unit); and p is a number having an average value of ~rom 0.5
20 to about 10 pre~erably ~rom about 0.5 to about 5
Within the compositions of the present claim, alkyl
polyglycosides will be present in amounts ranging from about
0.01 to about 20~ by weight, pre~erably ~rom about 0.5 to
25 about 10~, optimally between about 1 and 5~.
Examples of commercially available materials ~rom Henkel
~nmm~n~lltgesellscha~t Aktien o~ Dusseldor~, Germany include
APG 300, 325 and 350 with R4 being Cg-Cll, n is 0 and p is
30 1.3, 1.6 and 1.8-2.2 respectively; APG 500 and 550 with R4 is
C~2-C,3, n is 0 and p is 1.3 and 1.8-2.2, respectively; and
APG 600 with R4 being Cl2-C~4, n is 0 and p is 1.3.
Particularly pre~erred is APG 600.
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(g) Amine oxides having formula:
5R~7N=o (VI)
wherein R5, R6 and R7 are saturated aliphatic radicals or
substituted saturated aliphatic radicals. Preferable amine
oxides are those wherein Rs is an alkyl chain of about 10 to
about 20 carbon atoms and R6 and R7 are methyl or ethyl groups
or both R5 and R6 are alkyl ch~1 n~ of about 6 to about 14
10 carbon atoms and R7 is a methyl or ethyl group.
Amphoteric synthetic detergents can be broadly described
as derivatives of aliphatic and tertiary amines, in which the
aliphatic radical may be straight chain or branched and
15 wherein one of the aliphatic substituents contain from about
8 to about 18 carbons and one contains an anionic
water-solubilizing group, i.e., carboxy, sulpho, sulphato,
phosphato or phosphono. Examples of compounds falling within
this definition are sodium 3-dodecylamino propionate and
20 sodium 2-dodecylamino propane sulfonate.
Zwitterionic synthetic detergents can be broadly described
as derivatives of aliphatic quaternary ~mmon1um~ phosphonium
and sulphonium compounds in which the aliphatic radical may
25 be straight chained or branched, and wherein one of the
aliphatic substituents contains from about 8 to about 18
carbon atoms and one contains an anionic water-solubilizing
group, e.g., carboxy, sulpho, sulphato, phosphato or
phosphono. These compounds are frequently referred to as
30 betaines. Besides alkyl betaines, alkyl amino and alkyl
amido betaines are encompassed within this invention.
Silicates
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If silicates are present in the compositions of the
invention, they should be in an amount to provide neutral or
low alkalinity (less than pH 10) of the composition.
Preferred amounts of silicates present should be from about 1
5 to about 5~. Especially preferred is sodium silicate in a
ratio of SiO2:Na2O up ~rom about 1.0 to about 3.3, pre~erably
from about 2 to about 3.2.
Filler
An inert particulate filler material which is
water-soluble may also be present in cleaning compositions in
powder form. This material should not precipitate calcium or
magnesium ions at the filler use level. Suitable for this
15 purpose are organic or inorganic compounds. Organic fillers
include sucrose esters and urea. Representative inorganic
fillers include sodium sulfate, sodium chloride and potassium
chloride. A preferred filler is sodium sulfate. Its
concentration may range from 0~ to 60~, preferably from about
20 10~ to about 30~ by weight of the cleaning composition.
Thickeners and Stabi1izers
Thickeners are often desirable for liquid cleaning
25 compositions. Thixotropic thickeners such as smectite clays
including montmorillonite (bentonite), hectorite, saponite,
and the like may be used to impart viscosity to liquid
cleaning compositions. Silica, silica gel, and
aluminosilicate may also be used as thickeners. Salts of
30 polyacrylic acid (of molecular weight of from about 300,000
up to 6 million and higher), including polymers which are
cross-linked may also be used alone or in combination with
other thickeners. Use of clay thickeners for automatic
dishwashing compositions is disclosed for example in U.S.
CA 0222ll69 l997-ll-l4
W096/36687 PCT~P96102130
17
Patent Nos. 4,431,559; 4,511,487; 4,740,327; 4,752,409.
Commercially available synthetic smectite clays include
Laponite supplied by Laporte Industries. Commercially
available bentonite clays include Korthix H and VWH ex
'i Combustion Engineering, Inc.i Polargel T ex American Colloid
Co.; and Gelwhite clays (particularly Gelwhite GP and H) ex
English China Clay Co. Polargel T is preferred as imparting a
more intense white appearance to the composition than other
clays. The amount o~ clay thickener employed in the
10 compositions is ~rom 0.1 to about 10~, preferably 0.5 to 5~.
Use o~ salts of polymeric carboxylic acids is disclosed ~or
example in UK Patent Application GB 2,164,350A, U.S.
4,859,358 and U.S. 4,836,948.
For liquid formulations with a ~Igel" appearance and
rheology, particularly if a clear gel is desired, a chlorine
stable polymeric thickener is particularly useful. U.S.
Patent No. 4,260,528 discloses natural gums and resins for
use in clear autodish detergents, which are not chlorine
20 stable. Acrylic acid polymers that are cross-linked
manu~actured by, for example, B.F. Goodrich and sold under
the trade name "Carbopol~ have been found to be effective for
production of clear gels, and Carbopol 940 and 617, having a
molecular weight of about 4,000,000 is particularly preferred
_ 2S for maint~tn;ng high viscosity with excellent chlorine
stability over extended periods. Further suitable
chlorine-stable polymeric thickeners are described in U.S.
Patent No. 4,867,896 incorporated by reference herein.
The amount of thickener employed in the compositions is
from 0 to 5~, preferably 0.5-3~.
Stabilizers and/or co-structurants such as long chain
calcium and sodium soaps and C~2 to C~ sulfates are detailed
CA 0222ll69 l997-ll-l4
W096/36687 PCT~P96/02130
18
in U.S. Patent Nos. 3,956,158 and 4,271,030 and the use of
other metal salts of long chain soaps is detailed in U.S.
Patent No. 4,752,409. Other co-structurants include Laponite
and metal oxides and their salts as described in U.S.
5 4,933,101, herein incorporated by reference. The amount of
stabilizer which may be used in the li~uid cleaning
compositions is from about 0.01 to about 5~ by weight of the
composition, pre~erably 0.01-2~. Such stabilizers are
optional in gel formulations. Co-structurants which are
10 found especially suitable for gels include trivalent metal
ions at 0.01-4~ of the compositions, Laponite and/or
water-soluble structuring chelants at 1-60~. These
co-structurants are more fully described in the co-pending
U.S. Patent 5,141,664 by Corring et al., filed December 30,
15 1987, which application is hereby incorporated by reference.
Defoamer
The formulations of the cleaning composition comprising
surfactant may further include a de~oamer. Suitable
20 defoamers include mono- and distearyl acid phosphate,
silicone oil and mineral oil. Even i~ the cleaning
composition has only defoaming surfactant, the defoamer
assists to ml n;m~ ze foam which food soils can generate. The
compositions may include 0.02 to 2~ by weight of defoamer, or
25 preferably 0.05-1.0~.
Minor amounts of various other components may be present
in the cleaning composition. These include bleach scavengers
including but not limited to sodium bisulfite, sodium
30 perborate, reducing sugars, and short chain alcohols;
solvents and hydrotropes such as ethanol, isopropanol and
xylene sulfonates; flow control agents (in granular ~orms);
enzyme stabilizing agents; soil suspending agents;
antiredeposition agents; anti-tarnish agents; anti-corrosion
-
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WO 96136687 PCT/EP96/02130
19
agents; colorants; other functional additives; and perfume.
The pH of the cleaning composition may be adjusted by
addition o~ strong acid or base. Such alkalinity or
buffering agents include sodium carbonate and sodium borate.
Enzymes
Enzymes capable of facilitating the removal of soils from
a substrate may also be present in the invention in an amount
of from 0 to 10 weight percent, preferably 1 to 5 weight
10 percent Such enzymes include proteases (e.g., Alcalase-,
Savinase and Esperase ~rom Novo Industries A/S), amylases
(e.g., Termamyl from Novo Industries), and lipases (e.g..
Lipolase ~rom Novo Industries).
15 Bleachin~ A~ent
A wide variety of halogen and peroxygen bleach sources may
be used in the present invention. Examples of such halogen
and peroxygen bleaches are described in US Patent No.
5,200,236 issued to Lang et al., herein incorporated by
20 reference.
Among suitable reactive chlorine or bromine oxidizing
materials are heterocyclic N-bromo and N-chloro imides such
as trichloroisocyanuric, tribromoisocyanuric,
,'5 dibromoisocyanuric and dichloroisocyanuric acids, and salts
thereof with water-solubilizing cations such as potassium and
sodium. Hydantoin compounds such as 1,3-dichloro-5,5-
dimethylhydantoin are also quite suitable.
Dry, particular, water-soluble anhydrous inorganic salts
are likewise suitable for use herein such as lithium, sodium
or calcium hypochlorite and hypobromite. Chlorinated
trisodium phosphate is another core material.
Chloroisocyanurates are, however, the preferred bleaching
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agents. Potassium dichloroisocyanurate is said by Monsanto
Company as ACL-59 . Sodium dichloroisocyanurates are also
available from Monsanto as AC8-60, and in the dihydrate
form, from the Olin Corporation as Clearon CDB-56, available
5 in powder form (particle diameter of less than 150 microns);
medium particle size (about 50 to 400 microns); and coarse
particle size (150-850 microns). Very large particles (850-
1700 microns) are also found to be suitable for
encapsulation.
Peroxy 81eachinq A~ent
The oxygen bleaching agents of the compositions include
organic peroxy acids and diacylperoxides. Typical monoperoxy
15 acids useful herein include alkyl peroxy acids and aryl
peroxy acids such as:
(i) peroxybenzoic acid and ring-substituted
peroxybenzoic acids, e.g., peroxy-alpha-naphthoic acid, and
20 magnesium monoperphthalate
(ii) aliphatic and substituted aliphatic monoperoxy
acids, e.g., peroxylauric acid, peroxystearic acid,
epsilon-phthalimido peroxyhexanoic acid and o-
25 carboxyben~m;do peroxyhexanoic acid, N-nonenyl-
amidoperadipic acid and N-nonenylamidopersuccinic acid.
Typical diperoxy acids use~ul herein include alkyl
diperoxy acids and aryldiperoxy acids, such as:
~ 2-diperoxydodecanedioic acid
(iv) 1,9-diperoxyazelaic acid
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(v) diperoxybrassylic acid; diperoxysebacic acid and
diperoxy-isophthalic acid
(vi) 2-decyldiperoxybutane-l,4-dioic acid
(vii)N,N'-terephthaloyl-di(6-aminOperCaproic acid).
A typical diacylperoxide useful herein includes
dibenzoylperoxide.
Inorganic peroxygen compounds are also suitable ~or the
present invention. Examples of these materials useful in the
invention are salts of monopersulfate, perborate monohydrate,
perborate tetrahydrate, and percarbonate.
Pre~erred oxygen bleaching agents include epsilon-
phthalimido-peroxyhexanoic acid, o-
carboxybenzamidoperoxyhexanoic acid, and mixtures thereof.
The oxygen bleaching agent is present in the composition
in an amount from about of l to 20 weight percent, preferably
l to 15 weight percent, most preferably 2 to lO weight
percent.
The oxygen bleaching a~ent may be incorporated directly
into the formulation or may be encapsulated by any number of
encapsulation techniques known in the art to produce stable
capsules in alkaline liquid formulations.
A pre~erred encapsulation method is described in U.S.
5,200,236 issued to Lang et al., herein incorporated by
reference. In the patented method, the bleaching agent is
encapsulated as a core in a paraffin wax material having a
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melting point ~rom about 40~C to about 50~C The wax coating
has a thickness of ~rom 100 to 1500 microns.
Bleach Precursors
Suitable peroxygen peracid precursors ~or peroxy bleach
compounds have been amply described in the literature,
including GB Nos. 836,988; 855,735; 907,356i 907,358;
907,950; 1,003,310 and 1,246,339; U.S. Pat. Nos. 3,332,882
10 and 4,128,494.
Typical examples o~ precursors are polyacylated alkylene
diamines, such as N,N,N',N'-tetraacetylethylene diamine
(TAED) and N,N,N',N'-tetraacetylmethylene ~;~;ne (TAMD);
15 acylated glycolurils, such as tetraacetylglycoluril (TAGU);
triacetylcyanurate, sodium sulphophyl ethyl carbonic acid
ester, sodium acetyloxybenene sul~onate (S~3S), sodium
nonanoyloxy benzene sulfonate (SNOBS) and choline
sul~ophenyl carbonate. Peroxybenzoic acid precursors are
20 known in the art, e.g., as described in GB-A-836,988.
Examples o~ suitable precursors are phenylbenzoate; phenyl p-
nitrobenzoate; o-nitrophenyl benzoate; o-carboxyphenyl
benzoate; p-bromo-phenylbenzoate; sodium or potassium
benzoyloxy benzene-sul~onate; and benzoic anhydride.
Preferred peroxygen bleach precursors are sodium
p-benzoyloxybenzene sulfonate, N,N,N',N'-tetraacetylethylene
~;~m;ne~ sodium nonanoyloxybenzene sul~onate and choline
sul~ophenyl carbonate.
Process
The compositions cont~;n;ng the slow dissolving aluminum
salts as de~ined herein may be prepared in any conventional
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manner known in the art to form any variety of physical forms
of the compositions.
For the compositions cont~;ning the al~lminllm-sequestrant
5 complex, it is essential that a premix of the sequestrant
material and the alllminllm salt be prepared prior to the
incorporation of other components of the compositions of the
invention. Once the premix is prepared, it may be processed
with other detergent components in any conventional manner to
1l~ form any variety of physical forms of automatic dishwashing
detergent compositions, such as liquid, tablet, powder, gel.
To prepare the premix, the selected sequestrant should
be completely dissolved in water to form a solution with a pH
1~ at least one pH unit greater than the p~a of at least one of
the ionizable groups of the sequestrant. The pH must be
maintained at this level during the entire dissolution step
and the alkalinity of the solution may be adjusted by the
= addition of either an inorganic acid or an inorganic base,
2l~ such as NaOH or H2SO4.
While maintaining the solution at a pH as described
above, the selected alnm;nllm salt is added to the solution
and the pH is again adjusted to as close to the same pH as
during the initial dissolution of the sequestrant as
2!, possible. Once the alnm;nllm salt is dissolved into the
sequestrant solution, the premix can be incorporated with
other components to form the composition.
The following examples will serve to distinguish this
3l3 invention from the prior art and illustrate its embodiments
more fully. Unless otherwise indicated, all parts,
percentages and proportions referred to are by weight.
Example 1
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24
It was surprisingly observed that at low and neutral pH
levels (less than about pH l0) lead mineral ~rom lead
containing glassware was more substantially extracted than at
higher pH. Speci~ically, lead containing glass tiles
5 obtained from Q-Glass, Inc. o~ Towaco, NJ and having a 50
lead content were soaked for 24 hours at 65~C in one liter
soft water containing 6.8 grams of an automatic dishwashing
composition having the ~ollowing ~ormula:
Ingredient % of Acti~e
CDB capsules' 4.3
Potassium tripolyphosphate 34
Polymer2
Bu~ering agents 9
15 Non-ionic sur~actant 2
Potassium hydroxide (45~ l
soln.)
Enzymes 0.8
Water
to balance
The pH's o~ the ~our solutions were adjusted to 7.5,
8.6, 9.5, and l0.5 with NaOH and H2SO4. A~ter soaking, the
lead containing glass tiles and an aliquot o~ each detergent
25 1Chlorine supplied as CDB-56, which is 56% available chlorine, and encapsulated according to US 5,200,236
issued to Lang et al. The resulting capsules are 50% CDB 56 and 50% wax coating.
2Carbopol 627, a high ~ r polymer having a n.c' ' ~ weight of about one miliion supplied by B.F.
Goodrich Company.
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WO 96/36687 PCT/EP96102130
solution were withdrawn. The lead tiles were weighed to
determine weight loss. The aliquots were analyzed for
metals using Inductively Coupled Plasma (ICP) spectrometry.
The results of each analysis are presented in Table 1 below:
Table 1
pH Value Weight 1088 Lead Extracted (ppm)
(%)
7 5 0, 3 0 170
10 8.6 0.30 155
9.5 0.20 go
10 . 5 0 . 07 30
Thus, as the alkalinity of the detergent compositions
15 increased above about 10, the amount of lead extracted from
the lead articles significantly decreased.
Exam~le 2
It was observed that the addition of selected aluminum
salts to the automatic dishwashing composition of Example 1
significantly reduced the lead extracted from the lead
cont~;ning glass tiles after soaking in a detergent solution.
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Detergent solutions according to Example 1 and further
containing various aluminum salts to deliver 2.2 millimoles
Al(III) per liter were prepared. Lead containing glass tiles
were soaked in the detergent solutions under the conditions
5 described in Example l except that the pH's of the detergent
solutions were maintained at 8.6. After soaking, aliquots of
the solutions were analyzed using ICP to determine the amount
of lead extracted into the detergent solution. The results
of the experiment are presented in Table 2 below:
Table 2
Detergent Compo~itionsExtracted Lead in ppm
Control (No aluminum salt) 155
15 Aluminum stearate 35
Aluminum acetate 35
Aluminum acetylacetonate 65
Aluminum phosphate 70
It was thus observed that the addition of aluminum salts
to the low alkalinity detergent solutions significantly
reduced the amount of lead extracted from the lead containing
articles.
25 Example 3
To observe the effect of the presence of aluminum salts
in an automatic dishwashing detergent composition, lead
containing articles of having decors of various colors were
30 washed in a dishwasher and the fading of the decor of the
articles was scored.
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27
Compositions according to Example 1 were prepared using
various aluminum salts to deliver Al(III) in an amount of 2.2
millimoles Al(III) per liter in the dishwasher. A 1~
solution of each of the compositions had a pH of 8.6. The
5 following articles were washed in a Bauknecht dishwasher for
15 washes in soft water: 1 yellow plate, 1 red plate, 1 blue
glass, 1 tweety glass and 1 orange glass. After the 15
washes, the articles were removed and scored for fading of
decor from 0 (no fading) to 6 (substantially faded). The
10 scored results are exhibited in Table 3 below:
Table 3
Composit Yellow Red Blue Tweety Orange
ion Plate Plate Glass Glass Glass
15 Control 5 5 5 5 5
(No
aluminum
salt)
Aluminum 1 1.5 1.5 1.5 1.5
sulfate
Aluminum O 0.5 1.5 0.5 2
acetate
Aluminum 0.5 1.5 1 1.5 0.5
acetylac
e-tonate
Aluminum 1 1.5 1.5 3 3.5
ocotate
Aluminum 4.5 3.5 4 5 5
phosphat
- It was observed that all the aluminum salt containing
35 compositions exhibited less decor fading than those
compositions which did not contain aluminum salts.
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Example 4
It has been surprisingly found that the presence of an
aluminum salt can negatively impact the removal of stains,
5 particularly tea stain, under the conditions obtained by
using these detergent compositions. This is most likely
caused by a direct interaction between aluminum and the
stain. It has been also surprisingly found that controlling
the release of aluminum can minimize this negative impact.
To observe the effect of the presence of aluminum salts in an
automatic dishwashing detergent composition on tea stain
removal, tea stained cups and saucers were washed in the
dishwasher and scored with regard to stain removal.
Compositions according to Example 3 were prepared using
various aluminum salts to deliver Al(III) in an amount of 2.2
millimoles Al(III) per liter in the dishwasher. A 1~
solution of each of the compositions had a pH of 8.6. For
20 each experiment, eight cups and eight saucers were stained in
a tea liquor and allowed to dry. Four cups and four saucers
of the original eight were stained an additional three times,
yielding four cups and saucers stained once, and four cups
and saucers stained four times. These articles were washed
25 one (1) time in water containing 250 ppm permanent / 320 ppm
temporary hardness with the compositions described above.
The scored results are exhibited in Table 4 below:
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29
Table 4
Composit4X cup 4X lX cup lX
-' ion saucer saucer
Control 0 0 0 o
5 (No
aluminum
salt)
Aluminum 5 5 5 5
sulfate
Aluminum 1 0 0 0
acetate
Aluminum 3 0 1 0.75
acetylac
15 e-tonate
Aluminum0.25 0 0 0
octoate
Aluminum0.5 0 0 0
~hosphat
20 e
From the above, it was observed that using slow-
dissolving aluminum salts (i.e. aluminum acetate, aluminum
25 octoate and aluminum phosphate) in the wash results in the
bleaching of tea stains from stained articles significantly
better than using fast-dissolving aluminum salts.
Exam~le 5
Another option to control the release of aluminum is by
binding the aluminum to a sequestrant. Surprisingly, it has
been found that this way aluminum can be prevented to
interact with the stain, while still delivering its benefit
35 of preventing lead leaching of decorated tableware.
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For this option, the order of processing detergent
compositions incorporating aluminum salts is critical in
order to provide compositions which both effectively remove
stains from articles and which inhibit extraction of
5 minerals. To demonstrate the criticality of processing,
selected cups and saucers were stained in tea, the most
difficult stain to remove from tableware. Twelve cups and
saucers were stained in a concentrated tea liquor, allowed to
dry and then stained three additional times for a total of
l0 four tea stainings. For each of the detergent compositions
described below, four cups and saucers were placed in a
Bauknecht dishwasher and washed one (l) time:
Composition l was prepared by adding aluminum sulfate to
15 deliver Al(III) in an amount to deliver of 0.8 millimoles
Al(III) per liter in the dishwasher to the composition
described in Example l.
Composition 2 was not prepared according to the
20 invention. Sodium citrate having PKa values of pK1=3.l,
pK2=4.8 and pK3=6 . 4 was selected as the sequestrant. Aluminum
sulfate, in an amount to deliver 0.8 mM Al(III) in the wash
was dosed into deionized water; during dosing, the pH of the
solution was maintained at 9.5. After dosing the aluminum
25 salt, sodium citrate to deliver 0.8 mM in the wash was added
to the system. The pH of the resulting system was adjusted
to 8.9 to form the premix. This premix was added to the
composition described in Example l to generate Composition 2.
Composition 3 was prepared according to the invention.
Sodium citrate in an amount to deliver 0.8 mM in the wash was
completely dissolved in water; during dissolution, the pH of
the solution was maintained at 9.5. Once the sequestrant
completely dissolved, aluminum sulfate to deliver 0.8 mM
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WO 96/36687 PCT/EP9610213Q
Al(III) in the wash was added to the solution. The pH of the
resulting solution was adjusted to 8.9 to form the premix.
This premix was added to the composition described in Example
1 to generate Composition 3.
The stained articles were evaluated for residual tea
stain. A score of 0 indicated that no tea stains were
observed while a score of 5 indicated that a large amount of
residual tea stain on the washed articles was observed. The
10 results are presented in Table 5 below:
Table 5
Composition ReRidual Tea Stain
lS Composition 1-no sequestrant 5
Composition 2-incorrect premix 4
process
Composition 3-correct premix 0
process
It was thus observed that incorrect processing of the
aluminum salt and sequestrant components produces an inactive
premix which interferes with the removal of tea stain from
washed articles.
Example 6
Various sequestrant materials were combined with
all~m;~llm sulfate to form a premix according to the invention
30 and the effect of the premix on tea stain removal was
observed.
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32
Cups and saucers were stained as described in Example 5
above. Four samples of premix formulations were prepared to
deliver l.2 millimoles per liter of various sequestrant
materials and 0.4 millimoles per liter of aluminum sulfate.
5 The stained articles were washed in a Bauknecht dishwasher
according to Example 5 above and the washed articles were
rated for residual tea stain with 0 being no stain remaining
and 5 being significantly stained. The results are presented
in Table 6 as follows:
Table 6
Composition Cup8 SaUCer8
No 5 4
sequestrant/aluminum
salt
Succinic acid/aluminum 3 o
salt
Malonic acid/aluminum 2 o
20 salt
Cyanuric acid/aluminum l o
salt
It was thus observed that a premix of various
25 sequestrant materials and the aluminum sulfate significantly
reduced tea stain on washed articles when compared to
articles washed with aluminum sulfate alone.
ExamPle 7
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Various sequestrant materials were combined with sodium
aluminate to form a premix according to the invention and the
effect of the premix on tea stain removal was observed.
Cups and saucers were stained as described in Example 5
above. Four samples of premix formulations were prepared to
deliver l.2 millimoles per liter o-f various sequestrant
materials and 0.4 millimoles per liter of sodium aluminate.
The stained articles were washed in a Bauknecht dishwasher
lO according to Example 5 above and the
washed articles were rated for residual tea stain with 0
being no stain remaining and 5 being significantly stained.
The results are presented in Table 7 as follows:
Table 7
Composition Cup8 Saucers
no sequestrant 5 4
20 EDTA 0 0
Sodium orthophosphate l o
It was thus observed that the use of a premix of
= 25 sequestrants with different aluminum salts according to the
invention significantly reduces residual tea stain relative
to the use of the aluminum salts alone.
Example 8
CA 02221169 1997-11-14
C 629~ (V)
Benzoic acid was combined with aluminum sulfate at
differing ratios to form a premix according to the invention.
The effect o~ these premixes on tea stain removal was observed.
Cups were stained as described in Example 5. Five
samples o~ premix ~ormulations were prepared to deliver 0.4
millimoles per liter of aluminum sulfate at differing ratios
to benzoic acid. The stained articles were washed in a
Bauknecht dishwasher according to Example 5. The washed
10 articles were rated for residual tea stain
with 0 being no stain remaining and 5 being significantly
stained. The results are presented in Table 8 as ~ollows:
Table 8
Ratio o~ be~zoic acid C~p8
to Al(III)
1 : 2 1.25
1: 1 1.0
201.5 : 1 0
~'
3 : 1 0
It was thus observed that as the ratio of benzoic acid
25 to aluminum is increased, the tea stain removal performance
of the resulting premix improves.
A~AEN~:)E~ S11~ET
