Note: Descriptions are shown in the official language in which they were submitted.
1 31 9308
IR-891F HIGH ALKALINITY LIQUID AUTOMATIC
~ DTS~WAShER DETERGENT COMPOSITIONS
~be present invention relates to built aqueous liquid
automatic dishwasher detergent compositions with improved
cleaning performance and physical stability. More specifically
the invention relates to the use of higher alkalinity levels to
improve cleaning performance and rheological properties of long
chain fatty acid (and their metal salts) stabilized thickened
liquid automatic dishwasher detergent compositions.
The present invention specifically relates to automatic
dishwashing deteryent compositions having thixotropic properties,
lmproved chemical and physical stability, and with increased
apparent viscosity, and which are readily dispersible in the
washing medium to provide improved cleaning performance on
dishware, glassware, china and the like.
Commercially available hou~ehold-machine dishwasher
detergents provided in powder form have several disadvantage ,
e.g. non-uniform composition; costly operat1ons necessary in
their manufacture; tendency to cake in storage at high
humidities, resulting 1n the formation of lumps which are
difficult to disperse; dustiness, a source of particular
irritation to users who suffer allergles; and tendency to cake in
the dishwasher machine dispenser~ Liguid forms of such composi-
tions, however, generally cannot be used in automatic dish-
washers.
~ 131q308
¦ Recent research and development activity has focused on
¦the gel or "thixotropic" form of such compositions, e.g. scouring
¦cleansers and automatic-dishwa~her products characterized as
¦thixotropic pastes. Dishwasher products so provided are
¦ primarily objectionable in that they are insufficiently viscous
to remain "anchored" in the dispenser cup of the dishwasher.
Ideally, thixotropic cleansing compositions should be highly
viscous in a qulescent state, Bingham plastic in nature, and have
relatively high yield values. When subjected to shear stresses,
however, such as being shaken in a container or squeezed through
an orifice, they should quickly fluidize and, upon cessation of
the applied shear stress, guickly revert to the high viscosity/-
Bingham plastic state. Stability is likewise of primary
importance, i.e. there should be no significant evidence of phase
separation or leaking after long standing.
The provision of automatic-dishwa3her compositions in
gel orm haviny the aforedescribed properties has thus for proven
. problematical, particularly as regards compositions for use in
home dishwasher machines. For effective use, it is generally
recommended that the automatic dishwashing detergent, hereinafter
also designated ADD, contain (1) sodium tripolyphosphate (NaTPP)
to soften or tie up hard-water minerals and to emulsify and/or
peptize soil; (2) sodium silicate to supply the aIkalinity
necessary for effective detergency and to provide protection for
fine china glaze and pattern; (3~ sodium carbonate, generally
considered to be optional, to enhance alkalinity; (4) a chlorine-
releasing agent to aid in the elimination of soil specks which
lead to water spotting; and (5) defoamer/surfactant to reduce
foam, thereby enhancing machine efficiency and supplying
requisite detergency. See, for example, SDA ~etergents in Depth,
~ 1319308
"Formulations Aspects of Machine Dishwashing," Thomas Oberle
(1974). Cleansers approximating to the aforedescribed
_ compositions are mostly liquid~-or powders. Combining such
ingeedients in a gel form effective for home-machine use has
proved difficult. Generally, such compositions omit hypochlorite
bleach, since it tends to react with other chemically active
ingredients, particularly surfactant. Thus, U.S. Patent
4,115,308 discloses thixotropic au~omatic dishwasher pastes
containing a suspending agent, e.g. CMC, synthetic clays or the
like; inorganic salts including silicates, phosphates and '
polyphosphates; a small amount of surfactant and a suds
depressor. 81each is not disclosed. U.S. Patent 4,147,650 is
somewhat similar, optionally including Cl-(hypochlorite) bleach
but no or~anic surfactant or foam depressantO The product is
described, moreover, as a detergent slurry with no apparent
thixotropic prope~ties.
U.S. Patent 3,985,668 describes abrasive scouring
. cleaners of gel-like consistency containing (1) suspending agent,
preferably the Smectite and attapulgite types of clay; (2)
abrasive, e.g. silica sand or perlite; and (3) fil1er comprising
light density powdered polymers, expanded perlite and the like,
which has a buoyancy and thus stabilizing effect on the composi-
tion in addition to serving as a bulking agent, thereby
replacing water otherwise available for undesired supernatant
layer formation due to leaking and phase destabilization. The
foregoing are the essential ingredients. Optional ingredients
include hypochlorite bleach, bleach stable surfactant and buffer,
e.g. silicates, carbonates, and monophosphates. Builders, such
as NaTPP, can be included as further optional ingredients to
supply or supplement building function not provided by the
~ 1319308
buffer, the amount of such builder not exceeding 5% of the total
¦composition, according to the patent. ~aintenance of the desired
_ ¦ (greater than) p~ 10 levels i~-achieved by the buffer/builder
l components. High pH is said to minimize decomposition of
¦ chlorine bleach and undesired interaction between surfactant and
bleach~ When present, NaTPP is limited to S%, as stated. Foam
killer is not disclosed.
In U.K. Patent Application GB 2,116,199A and GB
2,140,450A, both o~ which are assigned to Colgate Palmolive,
liquid ADD compositions are disclosed which have properties
desirably characterizing thixotropic, gel-type structure and
which include each o the various ingredients necessary for
effective detergency within an automatic dishwasher. The
normally gel-liké aqueous automatic dishwasher detergent
lS composition having thixotropic properties includes the following
ingredients, on a weight basi3:
~a) S to 35~ alkali metal tripolyphosphate;
. (b) 2.5 to 20% sodium silicate;
tc) 0 to 9% alkali metal carbonate;
(d) 0.1 to 5% chlorine bleach stable, water dispersible
organic detergent active material;
(e) 0 to 5~ chlorine bleach stable foam depressant;
(f) chlorine bleach compound in an amount to provide
about 0.2 to 4~ of available chlorine;
(g) thlxotropic thickener in an amount sufficient to
provide the composition with thixotropy index of about 2.5 to 10;
(h) sodium hydroxide, as necessary, to adjust p~; and
(i) water, balance.
ADD compositions so formulated are low-foaming; are
readily soluble in the washing meclium and most effective at pH
131930~
62301-1564
values best conducive to lmproved cleaning performance, viz, pH
10.5-14. The compositions are normally of gel consistency,
i.e. a highly viscous, opaque jelly-like material having
Bingham plastic character and thus relatively high yield
values. ~ccordingly, a definite shear force is necessary to
initiate or increase flow. Under such conditions, the
composition is quickly fluidized and easily dispersed. When
the shear force is discontinued, the fluid composition quickly
reverts to a high viscosity, Bingham plastic state closely
approximating its prior consistency.
U.S. Patent 4,511,487, dated ~pril 16, 1985,
describes a low-foanling detergent paste for dishwashers. The
patented thixotropic cleaning agent has a viscosity of at least
30 Pa.s at 20C as determined with a ro~ational viseometer at a
spindle speed of 5 revolutions per minute. The composition is
based on a mixture of finely divided hydrated sodium
metasiliaate, an active chlorine compound and a thickeniny
agent whlch is a foliated slliaate of the hectorite type.
Small amount of nonionic tensides and alkali metal carbonates
and/or hydroxides may be used.
While these previously disclosed liquid ADD
formulations are not subject or are subject to a lesser degree
to one or more of ~he above-described deficiencies, it has been
found that in actual practice, still further improvements in
physical stability are required to increase the shelf-Iife of
the product and thereby enhance consu~er acaeptance.
In Canadian application Serial No. 546,1~1 filed
September 4, 1987 some of the present inventors described the
use of minor amounts o~ fatty acid metal salts, such as
aluminum stearate, as antisettling additives to improve
physical stability and rheological properties of clay based
`
1 31 9308
62301-1564
thixotropic aqueous li~uid ADD compositions.
Although this prior application dlsclosed alkalinity
levels to provide LADD compositions with pH's of at least 9.5,
preferably at least 12.5, in actual practice these composition
pH levels corresponded to pH levels in the aqueous wash bath
which were substantially lower, usually below pH 11. For
instance, the compositions exemplified in the examples o~
Serial No. ~03,924 included 2.2 weight percent or 3.1 weight
percent of a caustic soda solution (50~ NaOH), to provide
composition pH's of about 13. However, when added to the
aqueous wash bath at a typical concentration level of about 10
grams per liter, the wash bath had a pH of under 11, such as
1 0 . ~ .
While these prior compositions provide improved
physical stability ancl acceptable cleaning performance it was
desired to achieve stlll better cleaning performance. Toward
this end the present inventors decided to increase the
alkalinity level of the clay/fatty acid salt-containing liquid
ADD compositions as disclosed in the Canadian application
Serial No. 546,121.
Quite surprisingly, it was discovered that increasing
alkalinity not only provided the desired improvement in
cleaning performance, but unexpectedly also provided remarkable
improvement in stabilizing against change with time of the
rheological properties. It was also discovered, and this too
was totally unexpected, that at the hiyher alkalinity levels,
the decrease in availab~e chlorine, for chlorine bleach
containing compositions, was substantially reduced.
Accordingly, the invention seeks to provide liquid
ADD compositions having improved cleaning performance, ph~sical
stability and rheological properties.
' ~Q
.-,
1 31 ~308 62301-1564
The invention also seeks to provide chlorine bleach-
containing liquid ADD compositions in which loss of available
chlorine with time is reduced.
More specifically, this invention seeks to improve
the cleaning performance and physical stability of aqueous
liquid automatic dishwashex detergent pastes or gels containing
suspended particles (e.g. builder salts, bleach, etc.) clay
thickener and fatty acid metal salt stabili~er.
The invention will become more readily understood
from the following detailed description of the invention and
preferred embodiments thereof which are achieved by a highly
alkaline clay-khickened, built aqueous liquid automatic
dishwasher detergent composition comprising water, a clay
~hixotropic agent and also containing an amount of physical
stabilizer which is a long chain fatty acid metal salt
effeatively to increase the physical stability oE the
composition, and containing sufficient alkali metal or alkaline
earth metal components such tha~ when the compositior~ is added
to an aqueous wash bath, at a aonaentration of 10 grams per
liter, the wash b~th has a pH of at least 11.2. In a preferred
embodlment, the composition further includes a chlorine bleach
compound, whereby due to the high alkalinity levels is less
subject to loss of available chlorine during storage.
In accordance with an especially preferred
embodiment, the present invention provides a thickened aqueous
automatic dishwasher detergent composition which includes, on a
weight basis:
(a) 5 to 35% alkali metal tripolyphosphate;
(b) 2.5 to 30% alkali metal sillcate;
(c) 0 to 9~ alkali metal carbonate;
(d) 2 to 10% alkali metal hydroxide;
,~;, . ..
~,.
1 31 q308 62301-1564
(e) 0~1 to S~ chlorine bleach stable, water
dispersible organic detergent active material;
(f) 0 to 5~ chlorine bleach stable foam depressant;
(g) chlorine bleach compound in an amount to provide
about 0.2 to 4~ of available chlorine;
(h) 0/1 to 10% oi inorganic colloid-forming clay
(i) a metal salt of a long chain fatty acid in an
amount effectiYe to increase the physical stability o~ the
composition; and
(j) balance water;
the total amount of (b) alkali metal silicate such as sodium
silicate, (c) alkali metal carbonate and (d) alkali metal
hydroxide providing a pH sufficien~ly high such that when the
composition is diluted in an aqueous wash bath to provide a
concentration of 10 grams per liter the pH o~ the aqueous wash
bath becomes at least 11.2.
The invention also provides a method for cleaning
dishware in an automati~ dishwashing machine w:Lth an aqueous
wash bath containing an effective amount of the liquid
~0 automatic dishwasher detergent (LADD) composition as described
above. According to this aspect of the invention, the LADD
composition can be readily poured into the dispensing cup of
the automatic dishwashing machine and will be sufficiently
viscous to rema~n securely within the dispensing cup until
shear forces are again applied thereto, such as by the water
spray from the dishwashing machine.
It is known that LADD effecSiYeness is directly
related to (a) available chlorine levels; (b) alkalinity; (c)
solubility in washing medium; and (d) foam inhibition.
Therefore, it has been suggested that the pH of the LADD
composition be at least about 9.5, most preferably at least
1 31 9308 62301-1564
about 12.5. Amounts of from about 0.5 to 6 weight percent of
NaOH and about 2 to 9 weight percent of sodium carbonate in the
l.ADD composition are proposed in Canadian application Serial
No. 546,121.
In accordance with the present invention the types
and amounts of the alkaline components are chosen 50 that when
the composition is added to an aqueous wash bath to provide a
concentration of 10 grams of composition per liter of wash bath
the pH of the wash bath becomes at least 11.2, pre~erably at
least 11.5, such as from 11.5 to 13.5, preferably l1.5 to 12.5.
By operating at these higher than normal alkalinity levels the
cleaning per~ormance is improved and at the same time the
rheological properties, and particularly, physi~al stability,
are alæo improved. Furthermore, in the preferred embodiment in
which a chlorine bleach compound is inaluded in the LADD
composition, the additional beneflt o reduction of loss of
active chlorine is also obtained.
To achieve these high pH levels it is necessary to
increase the total concenkration o~ the alkaline components, as
compared to the levels actually used in the prior known LADD
compositions. Such a composition is shown as Example 4 in our
Canadian application Serial No. 5~6,121 as follows,
~,:
1 31 9308
Il Iredient Amount (~.I.) wt~
_ . _
_ Sodium silicate (47.5% sol!n 7.48
Na2O/SiO2=1/2.4)
Monostearyl phosphate 0.16
Dowfax 3B-2 0.36
10 Thermphos NW12.0
Thermphos N Hexa 12.0
15 Pluminum tristearate 0.1
Sodium carbonate, anhydrous 5.0
Caustic soda solution 3.1
(50% NaOH)
Pharmagel Euroclay 1.25
[Mg/Al silicate clay)
Sodium hypochlorite solution 1.0
~11%)
Water balance
pH 13 to 13.4.
In this Example 4, the quantity of sodium hydroxide was
increased from 2.2 weight percent (1.1 weight percent a.i.) to
6.2 weight percent ~3. weight percent a.i.) with a corresponding
decrease in the added water content, the sodium carbonate and
sodium metasilicate levels remaining unchanged at 5.0% and 15.74
(7.48% a.i.), respectively.
Tests for cleaning performance and rheological behavior
for the high alkalinity composition o~ Example 4 demonstrated
that these compositions were superlor to the control composition
(2.2 weight percent caustic soda solution). ~owever, when teseed
for available chlorine content, the control composition was
slightly superior to the Example 4 co~position~ In contrast,
when a high alkalinity formulation according to the invention wàs
prepared by increasing the caustic soda concentration at the
1~1e ~r~ 10
~ 1 31 9308
¦expense of sodium carbonate then not only cleaning performance
¦and rheological properties are improved, but loss of available
_ I chlorine content, as compared-~o the control, is substantially
reduced as well. Similarly, replacing Na2CO3 by additional
alkali metal silicate also reduces available chlorine loss while
improving cleaning performance and stabilizing rheolsgical
properties.
Therefore, in accordance with an especially preferred
embodiment of this invention, the high alkalinity is achieved in
a clay-thickened, fatty acid salt stabilized, chlorine-bleach
containing liquid automatic dishwasher detergent composition
wherein the alkaline compounds include, on an active hasis, based
on the total composition, from about 3 to 20 weight percent
alkali metal silicate, ~rom about 1.0 to 4.5 weight percent
alkali metal hydroxide, and from 0 to about 4 weight percent
alkali metal carbonate, with the proviso that the total amount of
alkali metal hydroxide and alkali metal carbonate is no more than
about 6.5 weight percent and the total amount of alkali metal
silicate and alkali metal carbonate is no more than about 20
weight percent, the p~ of the composition being at least 12.8,
and the pH of 1 liter of aqueous wash bath containing 10 grams of
the composition being at least 11.5.
Although the alkali metal of the alkaline compounds:
silica~e, carbonate a~d hydroxide, is preferably sodium, the
corresponding potassium compounds, or mixtures of sodium and
potassium compounds can also be used.
The sodium silicate, which provides alkalinity and
protection of hard surfaces~ such as fine china glaze and
pattern, is employed in an amount ranging from about 2.5 to 20
weight percent, preferably about 5 to 15 weight percent, in the
~ 131930~
composition. The sodium silicate is generally added in the form
l of an aqueous solution, preferably having Na20:SiO2 ratio of
-- I about 101.3 to 1:2.8, especiaLLy preferably 1:2.0 to 1:2.6. At
this point, it should be mentioned that most of the other
components of this composition, especially NaO~ and sodium
hypochlorite, are also often added in the form of a preliminary
prepared aqueous dispersion or solution.
The liquid automatic dishwasher detergent compositions
of this invention also generally include an alkali metal
phosphate detergency builder, such as sodium tripolyphosphate
(NaTPP), and this too will contribute to the pH of the
composition.
The preferred NaTPP is employed in the LADD composition
in a range of about 8 to 35 weight percent, preferably about 20
to 30 weight percent, and should preferably be free of heavy
metal which tends to decompose or inactivate the preferred sodium
hypochlorite and other chlorine bleach compounds. The NaTPP may
be anhydrous oe hydrated, including the stable hexahydrate with
a degree of hydration of 6 corresponding to about 10% by weight
of water or more. Especially preferred LADD compositions are
obtained, for example, when using a 0.5:1 to 2:1 weight ratio of
anhydrous to hexahydrated NaTPP, values of about 1:1 being
particularly preferred.
In addition to or in place of part or all of the NaTPP
detergency builder, other phosphorus or non-phosphorus inorganic
or organic detergency builder salts can also be used in the
composition. Examples of suitable detergency builders-
sequestrants include, for instance, trisodium nitrilotriacetate,
tetrasodiumethylenediamine tetraacetate, sodium citrate, and the
corresponding potassium salts. Tetrapotassium or tetrasodium
~ 12
~ 131~3C8
pyrophosphate can also be used. However, sodium tripolyphosphate
¦is highly preferred where phosphorus-containing detergents are
¦ permitted.
¦ Foam inhibition is important to increase dishwasher
machine efficiency and minimize destabilizing effects which
might occur due ~o the presence of excess foam within the washer
during use. Foam may be sufficiently reduced by suitable
selection of the type and/or amount Qf detergent active material,
the main foam-producing component. The degree of foam is also
somewhat dependent on the hardness of the wash water in the
machine whereby suitable adjustment of the proportions of NaTPP
which has a water softening effect may aid in providing the
desired degree o~ foam inhibition. However, it is generally
preferred to include a chlorine bleach stable foam depressant or
inhibitor. Particularly effective are the alkyl phosphonic acid
esters of the formula
O .
HO - P ~ R
and especially the alkyl acid phosphate esters of the formula
O
HO - P - OR
~OR
In the above formulas, one or both R groups in each type of ester
may ~epresent independently a C12-C20 alkyl group. The
ethoxylated derivatives of each type of ester r for example, the
condensation products of one mole of ester with from 1 to 10
moles, preferably 2 to 6 moles, more preferably 3 or 4 moles,
ethylene oxide can also be used. Some examples of the foregoing
are commercially available, such as the products SAP from Hooker
and LPKn-158 from Rnapsack. Mixtures of the two types, or any
l3l93b8
o~her chlorine bleach stable types, or mixtures of mono- and di-
esters of the same type, may be employed. Especially preferred
_ is a mixture of mono- and di-C~6-C1g alkyl acid phosphate esters
such as monostearyl/distearyl acid phosphates 1.2/1, and the 3 to
4 mole ethylene oxide condensates thereof. When employed,
proportions of 0.1 to 5 weight percent, preferably 0.1 to 0.5
weight percent, of foam depressant in the composition is typical,
the weight ratio of detergent active component (d) to foam
depressant (e) generally ranging from about 10:1 to 1:1 and
preferably about 5:1 to 1:1. Other defoamers which may be used
include, for example, the known silicones, such as available from
Dow Chemicals. In addition, it is an advantageous feature of
this invention that many of the stabilizing salts, such as the
stearate salts, for example, aluminum stearate, are also
ef~ective as oam killers.
Although any chlorine bleach compound may be employed
in the compositions of this invention, such as dichloro-
isocyanurate, dichloro-dimethyl handantoin, or chlorinated TSP,
alkali metal or alkaline earth metal, e.g. potassium, lithium,
magnesium and especially sodium, hypochlorite is preferred. The
composition should contain sufficient chlorine bleach compound to
provide about 0.2 to 4.0% by weight of available chlorine, as
determined, for example, by acidification of 100 parts of the
composition with excess hydrochloric acid. A solution containing
¦about 0.2 to 4.0% by weight of sodium hypochlorite contains or
¦provides roughly the same percentage of available chlorine.
¦About 0.8 to 1.6% by weight of available chlorine is especially
¦preferred. For example, sodium hypochlorite (NaOCl) solution of
from about 11 to about 13% available chlorine in amounts of about
3 to 20%, preferably about 7 to 12%, can be advantageou~ly used.
~ 131q308
¦ Detergent active material useful herein must be stable
¦in the presence of chlorine bleach, especially hypochlorite
_ ¦ bleach, and ~hose of the organic anionic, amine oxide, phosphine
l oxide, sulphoxide or betaine water dispersible surfactant types
¦ are preferred, the ~irst mentioned anionics being most preferred.
They are used in amounts ranging from about 0.1 to 5% preferably
about 0.3 to 2.0%. Particularly preferred surfactants herein are
the linear or branched alkali metal mono- and/or di-~Cg-C14)
alkyl diphenyl oxide mono- and/or disulphates, commercially
available for example as DOWFAX (registered trademark) 3B-2 and
DOWFAX 2A-l. In addition, the surfactant should be compatible
with the other ingredients of the composition. Other suitable
surfactants include the primary alkylsulphates, alkylsulphonates,
alkylarylsulphonates and sec.-alkylsulphates. Examples include
sodium Clo-Clg alkylsulphates such as sodium dodecylsulphate and
sodium tallow alcoholsulphate; sodium Clo-Clg alkanesulphonates
~uch as sodium hexadecyl-1-sulphonate and sodium C12-Clg
. alkylbenzenesulphonates such as sodium dodecylbenzenesulphonates.
The corresponding potassium salts may also be employed.
As other suitable surfactants or detergents, the amine
oxide surfactants are typically of the structure R2RlN~O, in
which each R represents a lower alkyl group, for instance,
methyl, and Rl represents a long chain alkyl group having from 8
to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or
cetyl group. Instead of an amine oxide, a corresponding
surfactant phosphine oxide R2RlPO or sulphoxide RRlSO can be
employed. Betaine surfactants are typically of the structure
R2RlN ~-R'1COO-, in which each R represents a lower alkylene group
having from 1 to 5 carbon atoms. Specific examples of these
surfactants include lauryl-dimethylamine oxide, myris~yl-
~ 131~318
¦dimethylamine oxide, the corresponding phosphine oxides and
¦sulphoxides, and the corresponding betaines, including
¦dodecyldimethylammonium aceta~e, tetradecyldiethylammonium
¦pentanoate, hexadecyldimethylammonium hexanoate and the like.
¦For biodegradability, the alkyl groups in these surfactants
¦should be linear, and such compounds are preferred.
¦ Surfactants of the foregoing type, all well known in
the art, are described, for example, in U.S. Patents 3,985,668
l and 4,271,030.
Thixotropic thickeners, i.e. thickeners for suspending
agents which provide an aqueous medium with thixotropic
properties, are known in the art and may be organic or inorganic
water soluble, water dispersible or colloid-formins, and
monomeric or polymeric, and should, of course, be stable in these
compositions, e.g~ stable to high alkalinity and chlorine bleach
compounds, such as sodium hypochlorite. Those especially
preferred generally comprise the inorganic, colloid-forming clays
. of smectite and/or attapulgite types. These materials are
generally used in amounts of about 0.1 to 10, preferably 1 to 5
weight percent, to confer the desired thixotropic properties and
Bingham plastic character. However, in the presence of the metal
salt fatty acid stabilizers the desired thixotropic properties
and Bingham plastic character can be obtained in the presence of
lesser amounts of the thixotropic ~hickeners. For example,
amounts of the inorganic colloid-forming clays of the smectite
and/or attapulgite types in the range of from 0.1 to 3%,
preferably 0.1 to 2.5~, especially 0.1 to 2%, are generally
sufficient to achieve the desired thixo~ropic properties and
Bingham plastic character when used in combination with the
physical stabilizer.
1 31 ~308
Smectite clays include montmorillonite (bentonite),
hectorite, smectite, saponite, and the like. Montmorillonite
_ clays are preferred and are available under the tradenames such
as Thixogel (registered trademark~ No. 1 and Gelwhite (registered
trademark) GP, 8, etc., from Georgia Kaolin Company; and ECCAGUM
(registered trademarkj GP, H, etc., from Luthern Clay Products~
Attapulgite clays include the materialR commercially available
under the tradename Attagel (registered trademark)l i.e. Attagel
40, Attagel 50 and Attagel 150 from Engelhard Minerals and
Chemicals Corporation. ~ixtures of smectite and attapulgite
types in weight ratios of 4:1 to 1:5 are also useful herein.
Abrasives or polishing agents should be avoided in the LADD
compositions as they may mar the surface of fine dishware,
crystal and the like.
The preferred long chain fatty acids are the higher
aliphatic ~atty acids having from about 8 to 22 carbon atoms,
more preferably from about 10 to 20 carbon atoms, and especially
. preferably from about 12 to 18 carbon atoms, inclusive of the
carbon atom of the carboxyl group of the fatty acid. The
aliphatic radical may be saturated or unsaturated and may be
straight or branched. Straight chain saturated fatty acids are
preferred. Mixtures of fatty acids may be used, such as those
derived from natural sources, such as tallow fatty acid, coco
atty acid, soya fatty acid, etc., or from synthetic sources
available from industrial manufacturing processes.
Thus, examples of the fatty acids from which the
polyvalent metal salt stabilizers can be formed include, for
example, decanoic acid, dodecanoic acid, palmitic acid, myristic
acid, stearic acid, oleic acid, eicosanoic acid, tallow ~atty
~ 1319308
acid, coco fatty acid, soya fatty acid, mixtures of these acids,
etc. Stearic acid and mixed fatty acids are preferred.
The pref erred metals~are the polyvalent metals of
l Groups IIA, IIB and IIIB, such as magnesium, calcium, aluminum
¦ and zinc, although other polyvalent metals, including those of
Groups IIIA, IVA, VA, IB, IVB, VB, VIB, VIIB and YIII of the
Periodic Table of the Elements can also be used. Specific
examples of such other polyvalent metals include Ti, Zr, V, Nb,
Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc. Generally, the metals may
be present in the divalent to pentavalent state. Preferably, the
metal salts are used i~ their higher oxidation states.
Naturally, for LA~D compositions, as well as any other appli-
cations where the invention composition will or may come into
contact with articles used for the handling, storage or serving
of food products or which otherwise may come into contact with or
be consumed by people or animals, the metal salt should be
selected by taking into consideration the toxicity of the metal.
. For this purpose, tbe calcium and magnesium salts are especially
higher preferred as generally safe food additives.
Many of these metal salts are commercially available.
For example, the aluminum salts are available in the triacid
form, e.~. aluminum stearate as aluminum tristearate, Al (C17-
H3sC00)3. The monoacid salts, e.g. aluminum monostearate and
diacid salts, e.g. aluminum distearate, and mixtures of two or
three of the mono-, di- and tri-acid salts can be used for those
metals, e.g. Al, with valences of +3,-and mixtures of the mono-
and di-acid salts can be used for those metals, e.g. ~n, with
valences of +2. It is most preferred that the diacids of the +2
valent metals and the triacids of the +3 valent metals, the
~ 131~3C8
¦tetraacids of the ~4 metals, and the pentacids of the +5 valent
¦metals, be used in predominant amounts.
_ ¦ The metal salts, as ~entioned above, are generally
l commercially available but can be easily produced by, for
¦ example, saponification of a fatty acid, e.g. animal fat,
followed by treatment with an hydroxide or oxide of the poly-
valent metal, for example, in the case of the aluminum salt,
with alum, alumina, etc., or by reaction of a soluble metal salt
with a soluble fatty acid salt.
Calcium stearate, i.e. calcium distearate, magnesium
stearate, i.e. magnesium distearate, aluminum stearate, i.e.
aluminum tristearate, and zinc stearate, i.e. zinc distearate,
are the preferred polyvalent fatty acid salt stabilizers. Mixed
fatty acid metal salts, such as the naturally occurring acids,
e.g. coco acid, as well as mixed fatty acids resulting from the
commercial manufacturing process are also advantageously used as
. an inexpensive but efective source of the long chain fatty acid.
The amount of the fatty acid salt stabilizer to achieve
the desired enhancement of physical stability will depend on such
factors as the nature of the fatty acid sa}t, th~ nature and
amount of the thixotropic agent, detergent active compound,
inorganic salts, especially NaTPP, other LADD ingredients, as
well as the anticipated storage and shipping conditions~
Generally, ~owever, amounts of the polyvalent metal
fatty acid salt stabilizing agents in the range of from about
0.02 to 1%, preferably from about 0.06 to 0.8%, e~pecially
preferably from about 0.08 tu 0.4%, provide a long term stability
and absence of phase separation upon standing or during
transport at both low and elevated temperatures as are required
for a commercially acceptable product~
- 1 31 ~308
¦ Depending on the amounts, proportions and t~pes of
l physical stabilizers and thixotropic agents, the addition of the
_ I fatty acid salt not only incre~ses physical stability but also
¦ provides a si~ultaneous increase in apparent viscosity. Ratios
¦ of fatty acid salt to thixotropic agent in the range of from
about 0.08-0.4 weight percent fatty acid salt and from about 1-
2.5 weight percent thixotropic agent are usually ~ufficient to
provlde these simultaneous benefits and, therefore, the use of
these ingredients in these ratios is most preferred.
The amount of water contained in these composition
should, of course, be neither so high as to produce unduly low
viscosity and Eluidity, nor so low as to produce unduly high
viscosity and low flowability, thixotropic properties in either
case being diminished or destroyed. Such amount is readily
lS determined by routine experimentation in any particular instance,
generally ranging from about 30 to 75 weight percent, preferably
about 35 to 65 weight percent. The water should also be
. preferably deionized or so~tened.
According to one preferred method of making these
compositions, one should dissolve or disperse first all the
inorganic salts, i.e. carbonate (when employed), silicate and
tripolyphosphate, in the aqueous medium. Thickening agent is
added last. The foam depressor (when employed) is preliminarily
provided as an aqueous dispersion, as is the thickening agent.
The foam depressant dispersion, caustic soda (when employed) and
inorganic salts are first mixed at elevated temperatures in
aqueous solution (deionized water) and, thexeafter, cooled, using
agitation throughout. Bleach, surfactant, fatty acid metal salt
stabilizer and thickener dispersion at room temperature are
¦ thereafter added to the cooled (25-35C) solution. Excluding the
1319308
chlorine bleach compound, total salt concentration (NaTPP, sodium
silicate and carbonate) is generally about 20 to 50 weight
_- percent, preferably about 30 t~ 40 weight percent in the compo-
sition.
Another highly preferred method for mixing the
ingredients of the LADD formulations involves first forming a
mixture of the water, foam suppressor, detergent, physical
stabilizer (fatty acid salt) atld thixotropic agent, e.g. clay.
These ingredients are mixed together under high shear conditions,
preferably staxting at room temperature, to form a uniform
dispersion. To this premixed portion, the remaining ingredient~
are introduced under low shear mixing conditions. For instance,
the required amount o the premix is introduced into a low shear
mixer and thereafter the remaining ingredients are added, with
mixing, eithex sequentially or simultaneously. Preferably, the
ingredients are added se~uentially, although it is not necessary
to complete the addition of all of one ingredient before
. beginning to add the next ingredient. Furthermore, one or more
of the ingredients can be divided into portions and added at
different times. Good results have been obtained by adding the
remaining ingredients in the following sequence: sodium
hydroxide, alkali metal carbonate, sodium silicate, alkali metal
tripolyphosphate (hydrated) r alkali metal tripolyphosphate
~anhydrous or up to 5~ water), bleach (preferably, sodium
hypochlorite) and sodium hydroxide.
Other conventional ingredients may be included in these
compositions in small amountsl generally less than about 3 weight
percent, such as perfume, hydrotropic agents such as the sodium
benzene, toluene, xylene and cumene sulphonates, preservatives,
dyestuffs and pigments and the like, all o~ course being stable
1 3 1 9 3 0 A
to chlorine bleach compound and high alkalinity (properties of
all the components). Especially preferred for coloring are the
_ chlorinated phthalocyanines an~ polysulphides of aluminosilicate
which provide, respectively, pleasing green and blue tints. Tio2
may be employed for whitening or neutralizing off-shades.
The liquid ADD compositions of this invention are
readily employed in known manner for washing dishes, other
kitchen utensils and the like in an automatic dishwasher,
l provided with a suitable detergent dispenser, in an aqueous wash
¦ bath containing an effective amount of the composition, generally
sufficient to fill or partially fill the automatic dispenser cup
of the particular machine being used.
The invention may be put into practice in various ways
and a number of specific embodiments will be described to
illustrate the invention with reference to the accompanying
examples.
All amounts of proportions referred to herein are by
. weight of the composition unless otherwise indicated.
Example 1
In order to demonstrate the effect of the alkalinity of
the fatty acid metal salt stabilized, clay thickened liquid ADD
~formulations, compositions as shown in Table I are prepared with
varylng amounts of alkaline compounds.
22
1 31 9308
I o ~o ~ ~ ~ ~o o o ~oou~ o
I z ~ ~ o o o ~ o
I ' P ~ o o o ~ o
I .; ,,
I .
o ~o I ~ro I o o o ~o ~ ou c~
o~ I ~ I o o o ~ ~ o
U~ .. . .... . .. ..
~ 00 0~ 0
o ~o o ~,, o o o ~oo o~ o
z ~`~ '- I t . . ~ o a~
_ ~ u~ o o o
~C
~ Z~ u~o o ~! o o ~ ,
_ ~ ~ o o o ~ o
~ .
~ ~ ~ ! ! . o ~ o
~1 ~ ~ oo o~ O
,,
o U~O o ~,, o o o ~o ou~ o
;~ ~ ~ o ~ o o ~ o
~ ooo,l0 j
O In O O ~r I I o o o ~o oo u~ o
. ~ 1`~ o r~ I I o o o ,~ o G~
o ,~ o o o _i o o
t~ ~1
I 1,~
â) a) o ~1 ~ v
. O O v ~ ~ C .C ~ O ,
u~ n v ~ ~ ,, ~ o m m
O O.C a~
C ~ ~ ~ P~
V
Z Z O O ~
o .c ~. ~ C
~ ~ ~o _~ o ~ ~ O a~ ~
N C C C ~ 1 C ~ ~ IU J J V
~ IJ S 11~ W
1~ 1 0 0 V V ~-1 ~ 3
0 ~ 3: o o o Q, ~ 0 ~ m
J- ~ O 0 0 U~ C
c a) u~ o L~m u ~ o
Q~ ~ æ o dP d~ dP v h V
.,, u ,~
P v X O ~ C (IJ
a ~ V o O ~1~ In ~ .C :I x ::1 ~ 0 ta r ~
)_1 C) u:~ U7 v O e~ Lrl ~ i O ~1 0 ~ O E~ ~
~: J~ ~o ~a ~ C ~ _ ~ 3 ~3 o tq ~
H ~3: v Z ZU~ a ~ P-
~ 1 31 9308
In preparing these formulations, the monostearyl
l phosphate foam depressant and Dowfax 3B-2 detergent active
_ I compound are added to the mixtuEe just before the Pharmagel H
l clay thickener; all of the NaOH is added after the clay.
The resulting liquid ADD formulations as shown in Table
I are measured or cleaning performance (Table II); and for
density, and physical stability (phase separation) on standing
and in a shipping test. The results are shown in Table III.
Table II
CLEANING PERFORMANCE
CompositionAVERAGE RATING ON AVERAGE RATING ~p
Run No. MIXED SOIL5 STARCHY SOILS
1 5.71 3.80
2 5.85 4.00
25 ' 6
CONTROL 5.12 3.50
PowDE~ 1) 6.11 4.61
~ 1) Commercially available powdery ADD, pH = 12.2
2) Dishes with rice and cuttery with rice and porridge
24
~ 1319308
I cn'-~
I C _ V ~
I Q~V a 3 ~
I ~ o Q~ ,. o o o~t o o
~ -_
I a~
I Q~
~1 ~1 o u
I 1
I
~ ~ ~J o~nOOOO U
e ~ ~ _ O ~ c~ O O O ~
H ¦ _ I r ~ o ~1 0 ~I O O
~ t, ~0
. ~ ~1 _ oo o o o O o
D W U V
. C~
U~ ~ ~
o ~ e
cl ~ ~o
I ' 131~3~-8
l~e~
¦ The control composition and the compositions of Run
_ ¦Nos. 3 and 5 were aged at 4Cj-room temperature (RT~, 35C or
¦43C and the viscosity of each sample was measured after storage
¦in a plastic bottle for 1, 4, 6 and 12 weeks with a Brookfield
LVT viscometer using a No. 54 spindle at 3 rpm. The results are
shown in Table IV.
Il
. Il 26
I 1 31 9308-
_ I : .
l ~
~1 .~,~ o ~ ~
~ 131930-~
1~
l The Control composition and the compositions of Run
_ ¦ Nos. 3 and 5 and a referentia~ ~xample in which the aluminum
l stearate of the control composition was omitted and the amount of
S ¦ clay increased to 2~ were ~ested to measure rheological
properties after standing at room temperature for 10 days, 6
weeks and 3 months. The results are shown in Table V.
28
~ 1 31 9308'
I OD ~ a~ ~r ~ ~r In ~ a~ co
I
...... I ~ I 00 0 1 0 OOQ O I O
-__
I O ~
I uI u~ u~ ~ l~ ~~9 a~ ~ ~D ~ ~
I .~ 0 I - I o - . ...
~ ~ ~1 0
~:
~ _I
1~ 1
Ul ~ ~ ~ 0 ~ ~
_ I ~ O
~1 I
O
I ~ 'In I o ~1 o~
O ~ I ~O ~D ~ I ~1--~ ~ ~D ~> ~1
r~
_.
E~
~1 ~
~ ~ ,~ . ~ O O O _1 ~1 ~1 0 0 0
0 0 0 0 0 0 00 0 0
E~ ~ p~ _, I oo o I o ooo ooo
SO ~1
~ o^ 00 0 1` t`~ U~ ~
.,1~ 0 .. . . ... ..
D~ ~ I ~
. ._ 1
_
. a~ oa~
. . - - . - -
~ E P- I c~ ,~ In I ~ ~I t--CD o .-1~
s a, - ~ '
3tY~
. ~
a~
P~ I . - . ~ ... ...
_ I ~D ~O W I U~
. U~ S U~ S
Ul ~C ~ ' 0 Y ~ Y J.~ U~ Y ~
~ ~ ~ w c ~ ~ c~ a) c
.,~ ~ ~ ~D O ' ~ ~ O ~ ~ O ~ W O
. ~ 3 E3 ~ 3 E3 ~ 3 E ~ 3 El
O U~ r~ O D ~ O ~D ~ O ~O
,~ ,
.~ q) f~
,i o ,~ .
u~ a) o o o
Q~ ~ Z Z
E ~ o :3 :~
~ 1 31 9308 '-
¦Example ~
¦ Using the control composition, and the compositions of
~: ¦Run Nos. 1, 3 and 5 the availa~le chlorine levels remaining after
storage at room temperature, 35C and 43C for 2, ~, 6 or 12
5 ¦ weeks was measured. The results are shown in Table VI. .
l . .
_ 30
1 31 9308
~1 ~ ~
Ul ~r ~n
l -~ ~ o ,. ,
a ~
O ~ D .
~1 ~
11 ~
~ ~ r
~D ~
P; ` P; ~
07 ,
Y
.
Z ~ Z
~; tX;
