Note: Descriptions are shown in the official language in which they were submitted.
., WO 95/16019 PCT/US94/13653
2177677
STABILIZATION OF OXIDATION-SENSITIVE INGREDIENTS
IN PERCARBONATE DETERGENT COMPOSITIONS
TECHNICAL FIELD
The present invention relates to granular detergent compositions which
contain a percarbonate bleach and one or more oxidation-sensitive ingredients
such as fluorescent whitening agents, enzymes, perfumes, chelants, and the
like. The compositions are formulated not only to provide good detergency and
bleaching performance, but also to diminish or eliminate the oxidation of such
ingredients during storage of the compositions.
BACKGROUND OF THE INVENTION
The formulation of modern granular laundry detergents without the use of
phosphate builders and under various constraints with respect to fabric safety
and environmental effects is a substantial challenge. The formulator is faced
with the need to provide detergent compositions which remove a wide variety of
soils and stains from a wide variety of fabrics. Detergent compositions must
function effectively over a wide range of wash temperatures. They must be
storage-stable over a wide range of temperatures and humidities. Granular
detergents should desirably be free-flowing and easily dispensed in automatic
equipment. They must not suds too much nor too little. To be affordable, they
must be formulated using economical, yet safe and effective, ingredients.
Accordingly, there continues to be a substantial investment in the search for
new
and improved detergent compositions.
Inorganic bleaches such as percarbonate offer prospective advantages to
the detergent formulator due to their inherent cleaning ability. Moreover,
percarbonate bleaches offer prospective advantages over the commonly-used
perborate bleach, inasmuch as they do not disadvantageously interact with
important new surfactants such as the polyhydroxy fatty acid amides. In
addition,
there is now some indication that perborate bleach can sometimes undesirably
complex with, and stabilize, "polyol" stains, such as the polyphenolic
materials
found in chocolate. Percarbonates do not suffer from this disadvantage.
Moreover, if properly formulated, especially as disclosed herein, percarbonate
can
provide superior dispensing properties as compared with perborate.
WO 95/16019 PCT/US94/13653
2177677
-2-
Another type of ingredient which is often incorporated into granular laundry
detergents comprises the fluorescent whitening agents, more commonly referred
to
as "brighteners" or "optical bleaches". Such agents do not, themselves,
provide a
true "bleaching" and stain removal function, as does percarbonate. Rather,
such
agents are designed to deposit onto fabrics, especially white fabrics, to
subtly
adjust the overall visual perception from an undesirable "yellowish" shade to
a
"bluish" shade, which the consumer perceives as an improvement in the
whiteness
and brightness of the laundered fabric.
Unfortunately, it has now been found that granular detergents which contain
the desirable percarbonate bleach can undesirably cause yellowing of certain
oxidation-sensitive optical brighteners. It has now further been discovered
that
this undesirable yellowing effect is especially problematic with the
commercially
important class of stilbene brighteners.
Yet another type of ingredient which is often used in granular laundry
detergents comprises the various classes of detersive enzymes, including
proteases, amylases, lipases, cellulases and mixtures thereof. It has now been
determined that such enzymes can be wholly or partly inactivated in
percarbonate-
containing detergent compositions. Likewise, it has now further been
discovered
that other oxidation-sensitive detergent ingredients such as perfumes,
unsaturated
organics such as oleic acid, oleate soaps and oleyl sulfate, fatty amine
fabric
softeners and surfactants, amino chelants, and the like, are all susceptible
to
oxidative degradation on storage in the presence of percarbonate bleach.
While not intending to be limited by theory, it may now be hypothesized
that, even with so-called "stabilized" percarbonate, there is always some
leakage
of H202 from the percarbonate into the balance of the product on storage. This
peroxide leakage is exacerbated at the higher storage temperatures and
relative
humidities which may be experienced in warehouses. Moreover, it has now been
determined that if the presence of metal ions, e.g., copper and iron, is
minimized,
the "leaked" H202 may be relatively harmless to oxidation-sensitive
ingredients.
However, if uncontrolled metal ions are present, they appear to catalytically
decompose the leaked H202 into oxygen radicals which can decompose any
oxidation-sensitive ingredients.
WO 95/16019 21 l 7 6 7 7 PCT/US94/13653
-3-
By the present invention, it has been discovered that the inclusion of certain
silicate materials into percarbonate-containing laundry granules prepared as
disclosed herein minimizes the aforesaid degradation problems.
BACKGROUND ART
The use of brighteners for various purposes, including their use in laundry
detergents, is discussed in Encyclopedia of Chemical Technology, Kirk-Othmer,
Vol. 4, 3rd Ed., pages 213-226, John Wiley & Sons 1978. Problems associated
with stability are noted at pages 222-223. EP 451,893; U.S. 5,236,613;
Japanese
A-4-227,693; Japanese 63-62442 and Japanese KOKOKU 61-16319 relate to
percarbonate bleach. Detersive enzymes and/or enzyme stabilizers are described
in U.S. Patents 4,261,868, 3,600,619, 3,519,570 and European 0,199,405.
SUMMARY OF THE INVENTION
The present invention encompasses the use of a silicate material
(especially water-soluble silicate but also magnesium silicate colloids) to
diminish
or eliminate the oxidative degradation of oxidation-sensitive ingredients in
granular
detergent compositions, especially laundry detergents, which contain a
percarbonate bleach. Such oxidation-sensitive ingredients include optical
brighteners, perfumes, enzymes, chelants, fabric softeners, various
unsaturated
materials, and mixtures thereof, examples of which are disclosed hereinafter
or are
known to detergent formulators.
In a preferred mode the finished granular compositions afforded by this
invention comprise from 0.04% to about 15% by weight of one or more of the
aforesaid oxidation-sensitive ingredients in combination with a detergent
composition, characterized in that said detergent composition comprises:
(a) from 10% to 85% by weight of composition particles which
comprise:
(i) from 5% to 80% by weight of particle of a builder which is a
member selected from the group consisting of zeolite
builders, carbonate builders, or mixtures thereof;
(ii) from about 2% to about 15% by weight of a silicate, most
preferably a sodium silicate;
(iii) from 5% to 60% by weight of particle of a detersive
surfactant, or mixtures of detersive surfactants;
°
' WO 95/16019 ~ PCTIUS9.1/13653
-4-
(iv) from 0% to 70% by weight of particle of a water-soluble
inorganic sulfate salt, said sulfate salt being contaminated
with no more than 60 ppm iron and no more than 5 ppm
copper;
(v) when said water-soluble sulfate salt is present at a level of
1 % or greater in said particle, from 0.3% to 15% by weight of
a chelant;
(b) from 3% to 50% by weight of composition of percarbonate bleach
particles having an average particle size in the range from 500
micrometers to 1000 micrometers, not more than 10°~ by weight of
said percarbonate being particles smaller than 200 micrometers
and not more than 10% by weight of said particles being larger
than 1250 micrometers;
(c) from 5% to 35°~ by weight of composition of water-soluble sulfate
particles, said particles being dry-blended with particles (a) and (b),
said sulfate particles being contaminated with no more than 40
ppm ion and no more than 5 ppm copper, said sulfate particles
having an average particle size in the range from 250 micrometers
to 1400 micrometers, not more than 25°~ by weight of said sulfate
particles being larger than 1000 micrometers and not more than
2°~ of said particles being smaller than 250 micrometers; and
(d) optional adjunct ingredients.
In order to achieve optimal overall product stability, particle (a) should
have a moisture content not exceeding 13°~6, most preferably less than
10°h, by
weight. In order to achieve good flowability and dispensing in automatic
equipment, particle (a) should have a moisture content of at least 2°~,
by weight.
If particle (a) is prepared by spray-drying, it preferably should have a
moisture
content of at least about 7°~, by weight.
Preferred compositions herein are those wherein particle (a) comprises a
builder selected from the group consisting of zeolites A, P, MAP, X, Y or
mixtures
thereof, sodium carbonate builders, and mixtures thereof.
When particle (a) also comprises greater than 1 % of an optional water-
soluble sulfate component, it typically will also contain a chelant,
preferably
selected from the group consisting of phosphonate, amino carboxylate, and
polycarboxylate chelants, and mixtures thereof, usually at levels of from 0.3%
to
2171677
WO 95116019 PCT/US94113653
-5-
4.0% by weight in said particle.
For stability on storage, the particles of percarbonate bleach (b) may be
coated, e.g., with a member selected from the group consisting of water-
soluble
carbonate, water-soluble sulfate, water-soluble citrate, dehydrated or
partially
hydrated zeolite, water-soluble surfactants, or mixtures thereof. Whether or
not
stabilized by such means, the particles of percarbonate bleach preferably have
an average size in the range from 500 micrometers to 1,000 micrometers. For
stability purposes, it is also preferred that percarbonate particles (b) have
a
moisture content not greater than 1 %, more preferably not greater than 0.5%,
by
weight of said percarbonate particles.
When the product also contains dry blended sulfate, it is preferred in
order to provide further stability to the percarbonate that the particles of
sulfate
(c) contain less than 25 ppm, preferably less than 5 ppm, iron, and preferably
have an average particle size in the range of 450 micrometers to 800
micrometers.
In a preferred mode, the moisture content of the overall compositions
herein is not greater than 8% by weight.
All percentages, ratios and proportions herein are by weight, unless
otherwise specified. All documents cited are incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
The following describes the brightener component and typical
formulations and formulation components used herein, but is not limiting
thereof.
Percarbonate Bleach - The percarbonate bleach employed herein is the
conventional percarbonate material available from suppliers such as Solvay,
FMC, Tokai Denka and others. If desired, and to provide additional stability
on
storage, the particles of percarbonate can be coated or "dusted" with various
materials such as sodium citrate, sodium carbonate, sodium sulfate, water-
soluble surfactants, and mixtures thereof. Thus, a stabilized percarbonate
bleach can comprise 2.5% of a 2.5:1 sodium carbonate:sodium sulfate by
weight, or can comprise 5% citrate. A preferred percarbonate bleach is in the
form of particles having an average particle size in the range from 500
micrometers to 1,000 micrometers, not more than 10% by weight of said
percarbonate being particles smaller than 200 micrometers and not more than
10% by weight of said particles being larger than 1,200 micrometers. Typical
compositions will comprise from about 5% to about 25% by weight of
WO 95/16019 217 7 6 l 7 pCT~S94/13653
-6-
percarbonate bleach.
Silicate - The silicate stabilizer used herein especially includes the alkali
metal silicates having an Si02:Na20 ratio ("R") in the range of from about
1.6:1
to 3.2:1, although silicates outside this preferred range may be useful,
albeit
sub-optimal. The sodium form of the silicate is typically used, although the
inclusion of magnesium can further enhance stability of the overall
compositions,
as disclosed more fully hereinafter. It is also suitable to form in situ the
Mg
silicate form by adding in the same particle (for instance, in the same slurry
when
preparing spray dried particles) the sodium silicate and a magnesium salt
(magnesium sulfate or magnesium chloride, for instance). Suitable silicates
for
use herein include sodium silicate 1.6R solution, sodium silicate 2.OR solids
or
sodium silicate 3.2R solids, available from Hoechst or Akzo. The ratio of
silicate:oxidation-sensitive ingredient being stabilized is at least 1:1.
Brightener - Any optical brighteners known in the art which do not contain
copper or iron species can advantageously be incorporated into the detergent
compositions herein at levels typically from about 0.04% to about 1.2%, by
weight. Commercial optical brighteners which may be useful in the present
invention can be classified into subgroups which include, but are not
necessarily
limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic acid,
methinecyanines, dibenzothiphene-5,5-dioxide, azoles, 5- and 6-membered-ring
heterocycles, and other miscellaneous agents. Examples of such brighteners
are disclosed in 'The Production and Application of Fluorescent Brightening
Agents", M. Zahradnik, Published by John Wiley & Sons, New York (1982).
Specific examples of optical brighteners can be used in the present
compositions are those identified in U.S. Patent 4,790,856, issued to Wixon on
December 13, 1988. These brighteners include the PHORWHITE series of
brighteners from Verona. Other brighteners disclosed in this reference
include:
Tinopal UNPA, Tinopal CBS and Tinopal SBM; available from Ciba-Geigy; Arctic
White CC and Artic White CWD, available from Hilton-Davis, located in Italy;
the
2-(4-styryl-phenyl)-2H- naphthol[1,2-d]triazoles; 4,4'-bis- (1,2,3-triazol-2-
yl)-stil-
benes; 4,4'-bis(styryl)bisphenyls; and the aminocoumarins.~ Specific examples
of
these brighteners include 4-methyl-7-diethyl- amino coumarin;
1,2-bis(-benzimidazol-2-yl)ethylene; 1,3-diphenylphrazolines; 2,5-bis-
(benzoxazol-2-yl)thiophene; 2-styryl-naphth-(1,2-d]oxazole; and 2-(stil-
bene-4-yl)-2H-naphtho- [1,2-dJtriazole. See also U.S. Patent 3,646,015, issued
WO 95/16019 2 ~ ~ ~ s ~ ~ PCT/US9JI13653
February 29, 1972 to Hamilton.
It is to be understood that, while the present invention can be used with all
the aforesaid classes of brighteners and mixtures thereof, it is of special
importance for use with stilbene-type brighteners, due to their tendency to
yellow
in the presence of percarbonate bleach. The invention is especially useful
with
disodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2yl)aminojstilbene-
2,2'disulfonate available from Ciba-Geigy as Tinopal DMS and disodium 4,4'-
bis(4,6-di-anilino-1,3,5-triazin-2-yl)amino stilbene 2 disulfonate
brighteners.
Enzymes - Enzymes can be included in the formulations herein for a wide
variety of fabric laundering purposes, including removal of protein-based,
carbohydrate-based, or triglyceride-based stains, for example, and for the
prevention of refugee dye transfer, and for fabric restoration. The enzymes to
be
incorporated include proteases, amylases, lipases, cellulases, and
peroxidases,
as well as mixtures thereof. Other types of enzymes may also be included.
They may be of any suitable origin, such as vegetable, animal, bacterial,
fungal
and yeast origin. However, their choice is governed by several factors such as
pH-activity andlor stability optima, thermostability, stability versus active
detergents, builders and so on. In this respect bacterial or fungal enzymes
are
preferred, such as bacterial amylases and proteases, and fungal cellulases.
Enzymes are normally incorporated at levels sufficient to provide up to
about 5 mg by weight, more typically about 0.01 mg to about 3 mg, of active
enzyme per gram of the composition. Stated otherwise, the compositions herein
will typically comprise from about 0.001 °~ to about 5°~,
preferably 0.01 °~-1 %, by
weight of a commercial enzyme preparation. Protease enzymes are usually
present in such commercial preparations at levels sufficient to provide from
0.005 to 0.1 Anson units (AU) of activity per gram of composition.
Suitable examples of proteases are the subtilisins which are obtained
from particular strains of B.subtilis and B.licheniforms. Another suitable
protease
is obtained from a strain of Bacillus, having maximum activity throughout the
pH
range of 8-12, developed and sold by Novo Industries A/S under the registered
trade mark ESPERASE. The preparation of this enzyme and analogous
enzymes is described in British Patent Specification No. 1,243,784 of Novo.
Proteolytic enzymes suitable for removing protein-based stains that are
commercially available include those sold under the trademarks ALCALASE and
SAVINASE by Novo Industries AIS (Denmark) and MAXATASE by International
.~,", .
WO 95/16019 PCTNS9a/13653
21 776 77
_8_
Bio-Synthetics, Inc. (The Netherlands). Other proteases include Protease A
(see European Patent Application 130,756, published January 9, 1985) and
Protease B (see European Patent Application 251,446, published January 7,
1998, and European Patent Application 130,756, Bott et al, published January
9, 1985).
Amylases include, for example, a-amylases described in British Patent
Specification No. 1,296,839 (Novo), RAPIDASE, International Bio-Synthetics,
Inc. and TERMAMYL, Novo Industries.
The cellulases usable in the present invention include both bacterial or
fungal cellulase. Preferably, they wilt have a pH optimum of between 5 and
9.5.
Suitable cellulases are disclosed in U.S. Patent 4,435,307, Barbesgoard et al,
issued March 6, 1984, which discloses fungal cellulase produced from Humicola
insolens and Humicola strain DSM1800 or a cellulase 212-producing fungus
belonging to the genus Aeromonas, and cellulase extracted from the
hepatopancreas of a marine mollusk (Dolabella Auricula Solander). Suitable
cellulases are also disclosed in GB-A-2.075.028; GB-A-2.095.275 and
DE-OS-2.247.832.
Suitable lipase enzymes for detergent usage include those produced by
microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri
ATCC 19.154, as disclosed in British Patent 1,372,034. See also lipases in
Japanese Patent Application 53-20487, laid open to public inspection on
February 24, 1978. This lipase is available from Amano Phamnaceutical Co.
Ltd., Nagoya, Japan, under the trade mark Lipase P "Amano," hereinafter
referred to as "Amano-P." Other commercial lipases include Amano-CES,
lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var. lipolyticum
NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and
further Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and
Disoynth Co., The Netherlands, and lipases ex Pseudomonas gladioli. The
LIPOLASE enzyme derived from Humicola lanuginosa and commercially
available from Novo (see also EPO 341,947) is a preferred lipase for use
herein.
Peroxidase enzymes are used in combination with oxygen sources, e.g.,
percarbonate, perborate, persulfate, hydrogen peroxide, etc. They are used for
"solution bleaching," i.e. to prevent transfer of dyes or pigments removed
from
substrates during wash operations to other substrates in the wash solution.
Peroxidase enzymes are known in the art, and include, for example, horseradish
.
-~ WO 95116019 217 7 b 7 7 pCT~S94/13653
_g_
peroxidase, ligninase, and haloperoxidase such as chloro- and
bromo-peroxidase. Peroxidase-containing detergent compositions are
disclosed, for example, in PCT International Application WO 89/099813,
published October 19, 1989, by O. Kirk, assigned to Novo Industries A/S.
A wide range of enzyme materials and means for their incorporation into
synthetic detergent granules are also disclosed in U.S. Patent 3,553,139,
issued
January 5, 1971 to McCarty et al. Enzymes are further disclosed in U.S. Patent
4,101,457, Place et al, issued July 18, 1978, and in U.S. Patent 4,507,219,
Hughes, issued March 26, 1985, both. Enzyme materials useful for detergent
formulations are also disclosed in U.S. Patent 4,261,868, Hora et al, issued
April
14, 1981. The stability of SAVINASE, ENDO GLUCANASE A, cellulases,
amylases and lipases are all enhanced by the practice of the present
invention.
Chelatin4 Accents - The detergent compositions herein may also optionally
contain one or more iron and/or manganese chelating agents, especially when a
sulfate salt is present. Typically, the overall compositions may comprise from
about 0.1 % to about 10% by weight of such chelants. Such chelating agents can
be selected from the group consisting of amino carboxylates, amino
phosphonates, polyfunctionally-substituted aromatic chelating agents and
mixtures thereof, all as hereinafter defined. Without intending to be bound by
theory, it is believed that the benefit of these materials is due in part to
their
exceptional ability to remove iron and manganese ions from washing solutions
by formation of soluble chelates.
Amino carboxylates useful as optional chelating agents include ethylene=
diaminetetraacetates, N-hydroxyethylethylenediaminetriacetates,
nitrilotriacetates, ethylenediamine tetraproprionates, triethylenetetraamine-
hexaacetates, diethylenetriaminepentaacetates, and ethanoldiglycines, alkali
metal, ammonium, and substituted ammonium salts therein and mixtures therein.
WO 95/16019 217 7 6 7 7 PCT/US94113653
-10-
Amino phosphonates are also suitable for use as chelating agents in the
compositions of the invention when at least low levels of total phosphorus are
permitted in detergent compositions, and include ethylenediaminetetrakis
(methylenephosphonates), nitrilotris (methylenephosphonates) and
diethylenetriaminepentakis (methylenephosphonates) as DEQUEST ("DTPMP").
Preferably, these amino phosphonates do not contain alkyl or alkenyl groups
with more than about 6 carbon atoms. HEDP, 1,hydroxyethane diphosphonate,
is suitable and preferably combined with aminophosphonates or amino
carboxylates for use herein.
Polyfunctionally-substituted aromatic chelating agents are also useful in
the compositions herein. See U.S. Patent 3,812,044, issued May 21, 1974, to
Connor et al. Preferred compounds of this type in acid form are dihy-
droxydisulfobenzenes such as 1,2-dihydroxy -3,5-disulfobenzene.
A preferred biodegradable chelator for use herein is ethylenediamine
disuccinate ("EDDS"), especially the [S,S] form, as described in U.S. Patent
4,704,233, November 3, 1987, to Hartman and Perkins.
Perfumes - With respect to perfume stability, the compositions herein
exhibit improved stability with respect to perfume ingredients that are
sensitive to
oxidation, especially aldehydes and ketones. Thus, perfumery ingredients such
as the floral scents, the woody scents, the citrus scents and the musk scents,
and blends thereof, all of which comprise varying amounts of aldehyde and
ketone components, are advantageously employed herein. Importantly, the
common perfume "carriers" such as the phthalates, especially diethyl
phthalate,
are also stable in the present compositions. Perfumery ingredients and/or
carriers typically comprise from 0.01 % to 2% of the present compositions.
Additional Formulation Components
The following describes the formulation ingredients used in addition to
those above-disclosed.
Detergency Builders - The compositions also contain various conventional
builders, or, optionally, mixtures of builders, typically at levels from about
5% to
about 60%, by weight. Such builders assist in controlling mineral hardness in
wash liquors and to assist in the removal of particulate soils from fabrics.
-- WO 95116019 ~ ~ ~ ~ PCT/US94/13653
-11 -
Aluminosilicate (zeolite) builders are quite useful in particles (a) herein
and such builders are of great importance in most currently marketed heavy
duty
granular detergent compositions. Aluminosilicate builders include those having
the empirical formula:
Mz(zA102'ySi02)
wherein M is sodium, potassium, ammonium or substituted ammonium, z is from
about 0.5 to about 2; and y is 1; this material having a magnesium ion
exchange
capacity of at least about 50 milligram equivalents of CaC03 hardness per gram
of anhydrous aluminosilicate. Preferred aluminosilicates are zeolite builders
which have the formula:
Naz[(A102)z (Si02)y]'xH20
wherein z and y are integers of at least 6, the molar ratio of z to y is in
the range
from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
Useful aluminosilicate ion exchange materials are commercially available.
These aluminosilicates can be crystal'ine or amorphous in structure and can be
naturally-occurring aluminosilicates or synthetically derived. A method for
producing aluminosilicate ion exchange materials is disclosed in U.S. Patent
3,985,669, Krummel, et al, issued October 12, 1976. Preferred synthetic
crystalline aluminosilicate ion exchange materials useful herein are available
under the designations Zeolite A, Zeolite P (B), Zeolite X, Zeolite Y, and
Zeolite
MAP. In an especially preferred embodiment, the crystalline aluminosilicate
ion
exchange material has the formula:
Nal2[(A102)12(Si02)12]'xH20
wherein x is from about 20 to about 30, especially about 27. This material is
known as Zeolite A. Dehydrated (x = 0-10) Zeolite A can also be used.
Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in
diameter. Mixtures of zeolites with organic builders such as citrate are also
useful.
Examples of other silicate builders useful herein include the layered
sodium silicates described in U.S. Patent 4,664,839, issued May 12, 1987 to H.
P. Rieck. NaSKS-6 is the trademark for a crystalline layered silicate marketed
by Hoechst (commonly abbreviated herein as "SKS-6"). Unlike zeolite builders,
the Na SKS-6 silicate builder does not contain aluminum. NaSKS-6 has the
delta-Na2Si05 morphology form of layered silicate. It can be prepared by
methods such as those described in German DE-A-3,417,649 and
WO 95/16019 21 l 7 6 7 7 pCT~S9d/13653
-12-
DE-A-3,742,043. SKS-6 is a highly preferred layered silicate for use herein,
but
other such layered silicates, such as those having the general formula
NaMSix02x+1'yH20 wherein M is sodium or hydrogen, x is a number from 1.9 to
4, preferably 2, and y is a number from 0 to 20, preferably 0 can be used
herein.
Various other layered silicates from Hoechst include NaSKS-5, NaSKS-7 and
NaSKS-11, as the alpha, beta and gamma forms. As noted above, the
delta-Na2Si05 (NaSKS-6 form) is most preferred for use herein. Other silicates
may also be useful such as for example magnesium silicate, which can serve as
a crispening agent in granular formulations, as a stabilizing agent for oxygen
bleaches, and as a component of suds control systems. Mixtures of silicates,
especially layered silicates, with organic builders such as citrate are also
useful.
Examples of carbonate builders are the alkaline earth and alkali metal
carbonates as disclosed in German Patent Application No. 2,321,001 published
on November 15, 1973. Typical examples include calcite and sodium carbonate.
In addition to the foregoing zeolite, silicate or carbonate builders, the
finished compositions herein can optionally also comprise from 2% to 20% of
various organic detergent builders, including, but not restricted to, a wide
variety
of polycarboxylate compounds. Such builders can be dry-mixed with the overall
compositions, or, less preferably, can be incorporated into particle (a). As
used
herein, "polycarboxylate" refers to compounds having a plurality of
carboxylate
groups, preferably at least 3 carboxylates. Polycarboxylate builder can
generally
be added to the composition in acid form, but can also be added in the form of
a
neutralized salt. When utilized in salt form, alkali metals, such as sodium,
potassium, and lithium, or alkanolammonium salts are preferred.
Included among the polycarboxylate builders are a variety of categories of
useful materials. One important category of polycarboxylate builders
encompasses the ether polycarboxylates, including oxydisuccinate, as disclosed
in Berg, U.S. Patent 3,128,287, issued April 7, 1964, and Lamberti et al, U.S.
Patent 3,635,830, issued January 18, 1972. See also "TMSITDS" builders of
U.S. Patent 4,663,071, issued to Bush et al, on May 5, 1987. Suitable ether
polycarboxylates also include
WO 95116019 217 l b 7 7 pCT~S94/13653
-13-
cyclic compounds, particularly alicyclic compounds, such as those described in
U.S. Patents 3,923,679; 3,835,163; 4,158,635; 4,120,874 and 4,102,903.
Other useful detergency builders include the ether hydroxypolycar-
boxylates, copolymers of malefic anhydride with ethylene or vinyl methyl
ether, 1,
3, 5-trihydroxy benzene-2, 4, 6-trisulphonic acid, and
carboxymethyloxysuccinic
acid, the various alkali metal, ammonium and substituted ammonium salts of
polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic
acid, as well as polycarboxylates such as mellitic acid, succinic acid,
oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic acid,
carboxymethyloxysuccinic acid, and soluble salts thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly
sodium salt), are polycarboxylate builders of particular importance due to
their
availability from renewable resources and their biodegradability. Citrates are
often used in granular compositions in combination with zeolite and/or layered
silicate builders. Oxydisuccinates are also useful in such compositions and
combinations.
Also suitable in the detergent compositions of the present invention are
the 3,3-dicarboxy-4-oxa-1,6-hexanedioates and the related compounds
disclosed in U.S. Patent 4,566,984, Bush, issued January 28, 1986. Useful
succinic acid builders include the C5-C20 alkyl and alkenyl succinic acids and
salts thereof. A particularly preferred compound of this type is
dodecenylsuccinic acid. Specific examples of succinate builders include:
laurylsuccinate, myristylsuccinate, palmitylsuccinate, 2-dodecenylsuccinate
(pre-
ferred), 2-pentadecenylsuccinate, and the like. Laurylsuccinates are the
preferred builders of this group, and are described in European Patent
Application 86200690.5/0,200,263, published November 5, 1986.
Other suitable polycarboxylates are disclosed in U.S. Patent 4,144,226,
Crutchfield et al, issued March 13, 1979 and in U.S. Patent 3,308,067, Diehl,
issued March 7, 1967. See also Diehl U.S. Patent 3,723,322.
Fatty acids, e.g., C12-C1g monocarboxylic acids, can also be
incorporated into the compositions alone, or in combination with the aforesaid
builders, especially citrate and/or the succinate builders, to provide
additional
builder activity. Such use of fatty acids will generally result in a
diminution of
sudsing, which should be taken into account by the formulator.
While not preferred, in those situations where phosphorus-based builders
WO 95/16019 21 l l 6 7 7 pCT~S94/13653
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can be used, the various alkali metal phosphates such as the well-known sodium
tripolyphosphates, sodium pyrophosphate and sodium orthophosphate can be
used.
Detersive Surfactants - The compositions herein also contain various
anionic surfactants, or, optionally, mixtures of anionics with nonionic,
zwitterionic
or semipolar surfactants, typically at levels from about 5% to about 40%, by
weight.
Nonlimiting examples of surfactants useful herein include the
conventional C11-C1g alkyl benzene sulfonates ("LAS") and primary,
branched-chain and random C10-C20 alkyl sulfates ("AS"), the C1p-C1g
secondary (2,3) alkyl sulfates of the formula CH3(CH2)x(CHOS03-M+) CH3 and
CH3 (CH2)y(CHOS03 M+) CH2CH3 where x and (y + 1 ) are integers of at least
about 7, preferably at least about 9, and M is a water-solubilizing cation,
especially sodium, the C10-C1g alkyl alkoxy sulfates ("AEXS"; especially EO 1-
5
ethoxy sulfates), C10-C1g alkyl alkoxy carboxylates (especially the EO 1-5
ethoxycarboxylates), the C10-18 glycerol ethers, the C10-C1g alkyl
polyglycosides and their corresponding sulfated polyglycosides, and C12-C18
alpha-sulfonated fatty acid esters. If desired, the conventional nonionic and
amphoteric surfactants such as the C12-C1 g alkyl ethoxylates ("AE") including
the so-called narrow peaked alkyl ethoxylates and C6-C12 alkyl phenol
alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C12-C18
betaines and sulfobetaines ("sultaines"), C10-C1g amine oxides, and the like,
can also be included in the overall compositions. The C10-C1 g N-alkyl
polyhydroxy fatty acid amides can also be used. Typical examples include the
C12-C1g N-methylglucamides. Other conventional useful surfactants are listed
in standard texts.
Sulfate Salts - The compositions herein most preferably comprise a water-
soluble inorganic sulfate salt having the physical and chemical parameters
disclosed hereinabove. Typical examples of such salts include sodium sulfate,
magnesium sulfate and aluminum sulfate. The compositions typically comprise
from about 12% to about 25%, by weight, of sulfate.
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Adjunct Ingredients
The compositions herein can optionally include one or more other
detergent adjunct materials or other materials for assisting or enhancing
cleaning performance, treatment of the substrate to be cleaned, or to modify
the
aesthetics of the detergent composition (e.g., perfumes, colorants, dyes,
etc.).
The following are illustrative, but nonlimiting, examples of such materials.
Enzvme Stabilizers - The enzymes employed herein can be further
stabilized by the presence of water-soluble sources of calcium and/or
magnesium ions in the finished compositions which provide such ions to the
enzymes. Additional stability can be provided by the presence of various other
art-disclosed stabilizers, especially borate species: see Severson, U.S.
4,537,706, cited above. Typical detergents will comprise from about 1 to about
30, preferably from about 2 to about 20, more preferably from about 5 to about
15, and most preferably from about 8 to about 12, millimoles of calcium ion
per
kilo of finished composition. This can vary somewhat, depending on the amount
of enzyme present and its response to the calcium or magnesium ions. The
level of calcium or magnesium ions should be selected so that there is always
some minimum level available for the enzyme, after allowing for complexation
with builders, fatty acids, etc., in the composition. Any water-soluble
calcium or
magnesium salt can be used as the source of calcium or magnesium ions,
including, but not limited to, calcium chloride, calcium sulfate, calcium
malate,
calcium maleate, calcium hydroxide, calcium formats, and calcium acetate, and
the corresponding magnesium salts. A small amount of calcium ion, generally
from about 0.05 to about 0.4 millimoles per kilo, is often also present in the
composition due to calcium in the enzyme slurry and formula water. In granular
detergent compositions the formulation may include a sufficient quantity of a
water-soluble calcium ion source to provide such amounts in the laundry
liquor.
In the alternative, natural water hardness may suffice.
It is to be understood that the foregoing levels of calcium and/or
magnesium ions are sufficient to provide enzyme stability. More calcium and/or
magnesium ions can be added to the compositions to provide an additional
measure of grease removal performance. Accordingly, the compositions herein
may comprise from about 0.05% to about 2% by weight of a water-soluble
source of calcium or magnesium ions, or both. The amount can vary, of course,
with the amount and type of enzyme employed in the composition.
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The compositions herein may also optionally, but preterably, contain
various additional stabilizers, especially borate-type stabilizers. Typically,
such
stabilizers will be used at levels in the compositions from about 0.25% to
about
10%, preferably from about 0.5% to about 5%, more preferably from about
0.75% to about 3%, by weight of boric acid or other borate compound capable of
forming boric acid in the composition (calculated on the basis of boric acid).
Boric acid is preferred, although other compounds such as boric oxide, borax
and other alkali metal borates (e.g., sodium ortho-, meta- and pyroborate, and
sodium pentaborate) are suitable. Substituted boric acids (e.g., phenylboronic
acid, butane boronic acid, and p-bromo phenylboronic acid) can also be used in
place of boric acid.
Bleach Activators - The detergent compositions herein may optionally
contain bleaching agents or bleaching compositions containing a bleaching
agent and one or more bleach activators. If present, the amount of bleach
activators will typically be from about 0.1 % to about 60%, r yore typically
from
about 0.5% to about 40% of the bleaching compositic n comprising the
percarbonate bleaching agent-plus-bleach activator.
The percarbonates are preferably used in the presence of bleach
activators, which lead to the in situ production in aqueous solution (i.e.,
during
the washing process) of the peroxy acid corresponding to the bleach activator.
Various nonlimiting examples of activators are disclosed in U.S. Patent
4,915,854, issued April 10, 1990 to Mao et al, and U.S. Patent 4,412,934. The
nonanoyloxybenzene sulfonate (NOES) and tetraacetyl ethylene diamine
(TAED) activators are typical, and mixtures thereof can also be used. Benzoyl
caprolactam and benzoyloxybenzene sulfonate activators can also be used.
See also U.S. 4,634,551 for other typical bleaches and activators useful
herein.
Bleaching agents other than percarbonate bleaching agents are known in
the art and can optionally also be utilized herein. One type of non-oxygen
bleaching agent of particular interest includes photoactivated bleaching
agents
such as the sulfonated zinc and/or aluminum phthalocyanmes. See U.S. Patent
4,033,718, issued July 5, 1977 to Holcombe et al. If used, detergent
compositions will typically contain from about 0.025% to a~out 1.25%, by
weight,
of such photoactivated bleaches, especially sulfonated zinc phthalocyanine.
Polymeric Soil Release Aaent - Any polymeric soil release agent known to
those skilled in the art can optionally be employed in the compositions and
WO 95/16019 217 7 6 7 7 pCT~S94/13653
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processes of this invention. Polymeric soil release agents are characterized
by
having both hydrophilic segments, to hydrophilize the surface of hydrophobic
fibers, such as polyester and nylon, and hydrophobic segments, to deposit upon
hydrophobic fibers and remain adhered thereto through completion of washing
and rinsing cycles and, thus, serve as an anchor for the hydrophilic segments.
This can enable stains occurring subsequent to treatment with the soil release
agent to be more easily cleaned in later washing procedures.
The polymeric soil release agents useful herein especially include those
soil release agents having: (a) one or more nonionic hydrophile components
consisting essentially of (i) polyoxyethylene segments with a degree of
polymerization of at least 2, or (ii) oxypropylene or polyoxypropylene
segments
with a degree of polymerization of from 2 to 10, wherein said hydrophile
segment
does not encompass any oxypropylene unit unless it is bonded to adjacent
moieties at each end by ether linkages, or (iii) a mixture of oxyalkylene
units
comprising oxyethylene and from 1 to about 30 oxypropylene units wherein said
mixture contains a sufficient amount of oxyethylene units such that the
hydrophile component has hydrophilicity great enough to increase the
hydrophilicity of conventional polyester synthetic fiber surtaces upon deposit
of
the soil release agent on such surface, said hydrophile segments preferably
comprising at least about 25% oxyethylene units and more preferably,
especially
for such components having about 20 to 30 oxypropylene units, at least about
50% oxyethylene units; or (b) one or more hydrophobe components comprising
(i) C3 oxyalkylene terephthalate segments, wherein, if said hydrophobe
components also comprise oxyethylene terephthalate, the ratio of oxyethylene
terephthalate:C3 oxyalkylene terephthalate units is about 2:1 or lower, (ii)
C4-Cg
alkylene or oxy C4-Cg alkylene segments, or mixtures therein, (iii) poly
(vinyl
ester) segments, preferably polyvinyl acetate), having a degree of
polymerization of at least 2, or (iv) C1-C4 alkyl ether or C4 hydroxyalkyl
ether
substituents, or mixtures therein, wherein said substituents are present in
the
form of C1-C4 alkyl ether or C4 hydroxyalkyl ether cellulose derivatives, or
mixtures therein, and such cellulose derivatives are amphiphilic, whereby they
have a sufficient level of C1-C4 alkyl ether and/or C4 hydroxyalkyl ether
units to
deposit upon conventional polyester synthetic fiber surfaces and retain a
sufficient level of hydroxyls, once adhered to such conventional synthetic
fiber
surface, to increase fiber surface hydrophilicity, or a combination of (a) and
(b).
i
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Typically, the polyoxyethylene segments of (a)(i) will have a degree of
polymerization of from 2 to about 200, although higher levels can be used,
preferably from 3 to about 150, more preferably from 6 to about 100. Suitable
oxy C4-C6 alkylene hydrophobe segments include, but are not limited to,
end-caps of polymeric soil release agents such as M03S(CH2)nOCH2CH20-,
where M is sodium and n is an integer from 4-6, as disclosed in U.S. Patent
4,721,580, issued January 26, 1988 to Gosselink.
Polymeric soil release agents useful in the present invention also include
cellulosic derivatives such as hydroxyether cellulosic polymers, copolymeric
blocks of ethylene terephthalate or propylene terephthalate with polyethylene
oxide or polypropylene oxide terephthalate, and the like. Such agents are
commercially available and include hydroxyethers of cellulose such as
METHOCE~M(Dow). Cellulosic soil release agents for use herein also include
those selected from the group consisting of C1-C4 alkyl and C4 hydroxyalkyl
cellulose; see U.S. Patent 4,000,093, issued December 28, 1976 to Nicol, et
al.
Soil release agents characterized by polyvinyl ester) hydrophobe
segments include graft copolymers of polyvinyl ester), e.g., C1-C6 vinyl
esters,
preferably polyvinyl acetate) grafted onto polyalkylene oxide backbones, such
as polyethylene oxide backbones. See European Patent Application 0 219 048,
published April 22, 1987 by Kud, et al. Commercially available soil release
agents of this kind include the SOKALAN type of material, e.g., SOKALAN
. HP-22, available from BASF (West Germany).
One type of soil release agent is a copolymer having random blocks of
ethylene terephthalate and polyethylene oxide (PEO) terephthalate. The
molecular weight of this polymeric soil release agent is in the range of from
about 25,000 to about 55,000. See U.S. Patent 3,959,230 to Hays, issued May
25, 1976 and U.S. Patent 3,893,929 to Basadur issued July 8, 1975.
Another polymeric soil release agent is a polyester with repeat units of
ethylene terephthalate units containing 10-15°~ by weight of ethylene
terephthalate units together with 90-80°~ by weight of polyoxyethylene
terephthalate units, derived from a polyoxyethylene glycol of average
molecular
weight 300-5,000 Examples of this polymer include~the commercially available
material ZELCON 5126 (from Dupont) and MILEASE T (from ICI). See also U.S.
Patent 4,702,857, issued October 27, 1987 to Gosselink.
Another polymeric soil release agent is a sulfonated product of a
WO 95/16019 PCT/US94/13653
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_19_
substantially linear ester oligomer comprised of an oligomeric ester backbone
of
terephthaloyl and oxyalkyleneoxy repeat units and terminal moieties covalently
attached to the backbone. These soil release agents are described fully in
U.S.
Patent 4,968,451, issued November 6, 1990 to J. J. Scheibel and E. P.
Gosselink.
Other suitable polymeric soil release agents include the terephthalate
polyesters of U.S. Patent 4,711,730, issued December 8, 1987 to Gosselink et
al, the anionic end-capped oligomeric esters of U.S. Patent 4,721,580, issued
January 26, 1988 to Gosselink, and the block polyester oligomeric compounds of
U.S. Patent 4,702,857, issued October 27, 1987 to Gosselink.
Still other polymeric soil release agents also include the soil release
agents of U.S. Patent 4,877,896, issued October 31, 1989 to Maldonado et al,
which discloses anionic, especially sulfoaroyl, end-capped terephthalate
esters.
If utilized, soil release agents will generally comprise from about 0.01 % to
about 10.0%, by weight, of the detergent compositions herein, typically from
about 0.1 % to about 5%, preferably from about 0.2% to about 3.0%.
Clav Soil Removal/Antiredeposition Agents - The compositions of the
present invention can also optionally contain water-soluble ethoxylated amines
having clay soil removal and antiredeposition properties. Granular detergent
compositions which contain such agents typically contain from about 0.01 % to
about 10.0% by weight of the water-soluble ethoxylated amines.
The most preferred clay soil removal and anti-redeposition agent is
ethoxylated tetraethylenepentamine. Exemplary ethoxylated amines are further
described in U.S. Patent 4,597,898, VanderMeer, issued July 1, 1986. Another
group of preferred clay soil removal/antiredeposition agents are the cationic
compounds disclosed in European Patent Application 111,965, Oh and
Gosselink, published June 27, 1984. Other clay soil removallantiredeposition
agents which can be used include the ethoxylated amine polymers disclosed in
European Patent Application 111,984, Gosselink, published June 27, 1984; the
zwitterionic polymers disclosed in European Patent Application 112,592,
Gosselink, published July 4, 1984; and the amine oxides disclosed in U.S.
Patent 4,548,744, Connor, issued October 22, 1985. Other clay soil removal
and/or anti redeposition agents known in the art can also be utilized in the
compositions herein. Another type of preferred antiredeposition agent includes
the carboxy methyl cellulose (CMC) materials.. These materials are well known
WO 95/16019 2 l 7 7 6 7 7 pCT~S94/13G53
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in the art.
Polymeric Dispersin4 A4ents - Polymeric dispersing agents can
advantageously be utilized at levels from about 0.1 % to about 7%, by weight,
in
the compositions herein, especially in the presence of zeolite and/or layered
silicate builders. Suitable polymeric dispersing agents include polymeric
polycarboxylates and polyethylene glycols, although others known in the art
can
also be used. It is believed, though it is not intended to be limited by
theory, that
polymeric dispersing agents enhance overall detergent builder performance
when used in combination with other builders (including lower molecular weight
polycarboxylates) by crystal growth inhibition, particulate soil release
peptization, and anti-redeposition.
Polymeric polycarboxylate materials can be prepared by polymerizing or
copolymerizing suitable unsaturated monomers, preferably in their acid form.
Unsaturated monomeric acids that can be polymerized to form suitable polymeric
polycarboxylates include acrylic acid, malefic acid (or malefic anhydride),
fumaric
acid, itaconic acid, aconitic acid, mesaconic acid, citraconic acid and
methylenemalonic acid. The presence in the polymeric polycarboxylates herein
of monomeric segments, containing no carboxylate radicals such as vinylmethyl
ether, styrene, ethylene, etc. is suitable provided that such segments do not
constitute more than about 40% by weight.
Particularly suitable polymeric polycarboxylates can be derived from
acrylic acid. Such acrylic acid-based polymers which are useful herein are the
water-soluble salts of polymerized acrylic acid. The average molecular weight
of
such polymers in the acid form preferably ranges from about 2,000 to 10,000,
more preferably from about 4,000 to 7,000 and most preferably from about 4,000
to 5,000. Water-soluble salts of such acrylic acid polymers can include, for
example, the alkali metal, ammonium and substituted ammonium salts. Soluble
polymers of this type are known materials. Use of polyacrylates of this type
in
detergent compositions has been disclosed, for example, in Diehl, U.S. Patent
3,308,067, issued March 7, 1967.
AcryliGmaleic-based copolymers may also be used as a preferred
component of the dispersing/antiredeposition agent. Such materials include the
water-soluble salts of copolymers of acrylic acid and malefic acid. The
average
molecular weight of such copolymers in the acid form preferably ranges from
about 2,000 to 100,000, more preferably from about 5,000 to 75,000, most
_, WO 95/16019 217 7 6 7 7 PCT~S94/13653
-21 -
preferably from about 7,000 to 70,000. The ratio of acrylate to maleate
segments in such copolymers will generally range from about 30:1 to about 1:1,
more preferably from about 10:1 to 2:1. Water-soluble salts of such acrylic
acid/maleic acid copolymers can include, for example, the alkali metal,
ammonium and substituted ammonium salts. Soluble acrylate/maleate
copolymers of this type are known materials which are described in European
Patent Application No. 66915, published December 15, 1982.
Another polymeric material which can be included is polyethylene glycol
(PEG). PEG can exhibit dispersing agent performance as well as act as a clay
soil removal/antiredeposition agent. Typical molecular weight ranges for these
purposes range from about 500 to about 100,000, preferably from about 1,000 to
about 50,000, more preferably from about 1,500 to about 10,000.
Polyaspartate and polyglutamate dispersing agents (mol. wt. about
10,000) may also be used, especially in conjunction with zeolite builders.
It is to be understood that, while the present invention can be used with all
the aforesaid classes of brighteners and mixtures thereof, it is of special
importance for use with stilbene-type brighteners, especially distilbene
brighteners, due to their tendency to yellow in the presence of percarbonate.
Suds Suppressors - Compounds for reducing or suppressing the
formation of suds can be incorporated into the compositions of the present
invention. Suds suppression can be of particular importance under conditions
such as those found in European-style front loading laundry washing machines,
or in the concentrated detergency process of U.S. Patents 4,489,455 and
4,489,574, or when the detergent compositions herein optionally include a
relatively high sudsing adjunct surfactant.
A wide variety of materials may be used as suds suppressors, and suds
suppressors are well known to those skilled in the art. See, for example, Kirk
Othmer Encyclopedia of Chemical Technology, Third Edition, Volume 7, pages
430-447 (John Wiley & Sons, Inc., 1979). One category of suds suppressor of
particular interest encompasses monocarboxylic fatty acids and soluble sal'
therein. See U.S. Patent 2,954,347, issued September 27, 1960 to Wayne ~ ;.
John. The monocarboxylic fatty acids and salts thereof used as suds suppressor
typically have hydrocarbyl chains of 10 to about 24 carbon atoms, preferably
12
to 18 carbon atoms. Suitable salts include the alkali metal salts such as
sodiurn.
potassium, and lithium salts, and ammonium and alkanolammonium salts.
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The detergent compositions herein may also contain non-surfactant suds
suppressors. These include, for example: high molecular weight hydrocarbons
such as paraffin, fatty acid esters (e.g., fatty acid triglycerides), fatty
acid esters
of monovalent alcohols, aliphatic Cog-C4p ketones (e.g. stearone), etc. Other
suds inhibitors include N-alkylated amino triazines such as tri- to
hexa-alkylmelamines or di- to tetra-alkyldiamine chlortriazines formed as
products of cyanuric chloride with two or three moles of a primary or
secondary
amine containing 1 to 24 carbon atoms, propylene oxide, and monostearyl
phosphates such as monostearyl alcohol phosphate ester and monostearyl
di-alkali metal (e.g. K, Na, and Li) phosphates and phosphate esters. The
hydrocarbons such as paraffin and haloparaffin can be utilized in liquid form.
The liquid hydrocarbons will be liquid at room temperature and atmospheric
pressure, and will have a pour point in the range of about -40°C and
about 5°C,
and a minimum boiling point not less than about 110°C (atmospheric
pressure).
It is also known to utilize waxy hydrocarbons, preferrably having a melting
point
below about 100°C. The hydrocarbons constitute a preferred category of
suds
suppressor for detergent compositions. Hydrocarbon suds suppressors are
described, for example, in U.S. Patent 4,265,779, issued May 5, 1981 to
Gandolfo et al. The hydrocarbons, thus, include aliphatic, alicyclic,
aromatic,
and heterocyclic saturated or unsaturated hydrocarbons having from about 12 to
about 70 carbon atoms. The term "paraffin," as used in this suds suppressor
discussion, is intended to include mixtures of true paraffins and cyclic
hydrocarbons.
Another preferred category of non-surfactant suds suppressors comprises
silicone suds suppressors. This category includes the use of
polyorganosiloxane oils, such as polydimethylsiloxane, dispersions or
emulsions
of polyorganosiloxane oils or resins, and combinations of polyorganosiloxane
with silica particles wherein the polyorganosiloxane is chemisorbed of fused
onto
the silica. Silicone suds suppressors are well known in the art and are, for
example, disclosed in U.S. Patent 4,265,779, issued May 5, 1981 to Gandolfo et
al and European Patent Application No. 354016, published February 7,
1990, by Starch, M. S.
Other silicone suds suppressors are disclosed in U.S. Patent 3,455,839
which relates to compositions and processes for defoaming aqueous solutions
by incorporating therein small amounts of polydimethylsiloxane fluids.
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Mixtures of silicone and silanated silica are described, for instance, in
German Patent Application DOS 2,124,526. Silicone defoamers and suds
controlling agents in granular detergent compositions are disclosed in U.S.
Patent 3,933,672, Bartolotta et al, and in U.S. Patent 4,652,392, Baginski et
al,
issued March 24, 1987.
An exemplary silicone based suds suppresser for use herein is a suds
suppressing amount of a suds controlling agent consisting essentially of:
(i) polydimethylsiloxane fluid having a viscosity of from about 20 cs. to
about 1500 cs. at 25°C;
(ii) from about 5 to about 50 parts per 100 parts by weight of (i) of
siloxane resin composed of (CH3)3 Si01~2 units of Si02 units in a
ratio of from (CH3)3 Si01~2 units and to Si02 units of from about
0.6:1 to about 1.2:1; and
(iii) from about 1 to about 20 parts per 100 parts by weight of (i) of a
solid silica gel.
In the preferred silicone suds suppresser used herein, the solvent for a
continuous phase is made up of certain polyethylene glycols or polyethyl-
ene-polypropylene glycol copolymers or mixtures thereof (preferred), and not
polypropylene glycol. The primary silicone suds suppresser is
branched/crosslinked and not linear.
To illustrate this point further, typical laundry detergent compositions with
controlled suds will optionally comprise from about 0.001 to about 1,
preferably
from about 0.01 to about 0.7, most preferably from abut 0.05 to about 0.5,
weight
of said silicone suds suppresser, which cort~Nr ises (1 ) a nonaqueous
emulsion
of a primary antifoam agent which is a mixture of (a) a polyorganosiloxane,
(b) a
resinous siloxane or a silicone resin-producing silicone compound, (c) a
finely
divided filler material, and (d) a catalyst to promote the reaction of mixture
components (a), (b) and (c), to form silanolates; (2) at least one nonionic
silicone
surfactant; and (3) polyethylene glycol or a copolymer of
polyethylene-polypropylene glycol having a solubility in water at room
temperature of more than about 2 weight %; and without polypropylene glycol.
Similar amounts can be used in granular compositions, gels, etc. See also U.S.
Patents 4,978,471, Starch, issued December 18, 1990, and 4,983,316, Starch,
issued January 8, 1991, and U.S. Patents 4,639,489 and 4,749.740, Aizawa et al
at column 1, line 46 through column 4, line 35.
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The silicone suds suppressor herein preferably comprises polyethylene
glycol and a copolymer of polyethylene glycol/polypropylene glycol, all having
an
average molecular weight of less than about 1,000, preferably between about
100 and 800. The polyethylene glycol and polyethylene/polypropylene
copolymers herein have a solubility in water at room temperature of more than
about 2 weight °~, preferably more than about 5 weight °~.
The preferred solvent herein is polyethylene glycol having an average
molecular weight of less than about 1,000, more preferably between about 100
and 800, most preferably between 200 and 400, and a copolymer of
polyethylene glycol/polypropylene glycol, preferably PPG 200/PEG 300.
Preferred is a weight ratio of between about 1:1 and 1:10, most preferably
between 1:3 and 1:6, of polyethylene glycol:copolymer of
polyethylene-polypropylene glycol.
The preferred silicone suds suppressors used herein do not contain
polypropylene glycol, particularly of 4,000 molecular weight. They also
preferably do not conMain block copolymers of ethylene oxide and propylene
oxide, like PLURONIC L101.
Other suds suppressors useful herein comprise the secondary alcohols
(e.g., 2-alkyl alkanols) and mixtures of such alcohols with silicone oils,
such as
the silicones disclosed in U.S. 4,798,679, 4,075,118 and EP 150,872. The
secondary alcohols include the Cg-C16 alkyl alcohols having a C1-C16 chain. A
preferred alcohol is 2-butyl octanol, which is available from Condea under the
trademark ISOFOL 12. Mixtures of secondary alcohols are available under the
trademark ISALCHEM 123 from Enichem. Mixed suds suppressors typically
comprise mixtures of alcohol + silicone at a weight ratio of 1:5 to 5:1.
For any detergent compositions to be used in automatic laundry washing
machines, suds should not fomn to the extent that they overflow the washing
machine. Suds suppressors, when utilized, are preferably present in a "suds
suppressing ~ amount." By "suds suppressing amount" is meant that the
formulator of the composition can select an amount of this suds controlling
agent
that will sufficiently control the suds to result in a low-sudsing laundry
detergent
for use in automatic laundry washing machines. The compositions herein will
generally comprise from 0°~ to about 5% of suds suppressor. When
utilized as
suds suppressors, monocarboxylic fatty acids, and salts therein, will be
present
typically in amounts up to about 5%, by weight, of the detergent composition.
~.. WO 95116019 217 7 6 7 7 PCT/US94/13653
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Preferably, from about 0.5% to about 3% of fatty monocarboxylate suds
suppressor is utilized. Silicone suds suppressors are typically utilized in
amounts up to about 2.0%, by weight, of the detergent composition, although
higher amounts may be used. This upper limit is practical in nature, due
primarly
to concern with keeping costs minimized and effectiveness of lower amounts for
effectively controlling sudsing. Preferably from about 0.01 % to about 1 % of
silicone suds suppressor is used, more preferably from about 0.25% to about
0.5%. As used herein, these weight percentage values include any silica that
may be utilized in combination with polyorganosiloxane, as well as any adjunct
materials that may be utilized. Monostearyl phosphate suds suppressors are
generally utilized in amounts ranging from about 0.1 % to about 2%, by weight,
of
the composition. Hydrocarbon suds suppressors are typically utilized in
amounts ranging from about 0.01 % to about 5.0%, although higher levels can be
used. The alcohol suds suppressors are typically used at 0.2%-3% by weight of
the finished compositions.
In addition to the foregoing ingredients, the compositions herein can also
be used with a variety of other adjunct ingredients which provide still other
benefits in various compositions within the scope of this invention.
WO 95116019 PCTlUS9.1/13653
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The following illustrates a variety of such adjunct ingredients, but is not
intended
to be limiting therein.
Fabric Softeners - Various through-the-wash fabric softeners, especially
the impalpable smectite clays of U.S. Patent 4,062,647, Storm and Nirschl,
issued December 13, 1977, as well as other softener clays known in the art,
can
optionally be used typically at levels of from about 0.5% to about 10% by
weight
in the present compositions to provide fabric softener benefits concurrently
with
fabric cleaning. Clay softeners can be used in combination with amine and
cationic softeners, as disclosed, for example, in U.S. Patent 4,375,416, Crisp
et
al, March 1, 1983 and U.S. Patent 4,291,071, Harris et aIT ~ssued September
22,
1981. Mixtures of cellulase enzymes (e.g., CAREZYME, Novo) and clays are
also useful as high-performance fabric softeners. Various cationic materials
can
be added to enhance static control.
Other Ingredients - A wide variety of other ingredients useful in detergent
compositions can be included in the compositions herein, including other
active
ingredients, carriers, processing aids, dyes or pigments, etc. If high sudsing
is
desired, suds boosters such as the C10-C16 alkanolamides can be incorporated
into the compositions, typically at 1 %-10°~ levels. The C10-C 14
monoethanol
and diethanol amides illustrate a typical class of such suds boosters. Use of
such suds boosters with high sudsing adjunct surfactants such as the amine
oxides, betaines and sultaines noted above is also advantageous. If desired,
soluble magnesium salts such as MgCl2, MgS04, and the like, can be added at
levels of, typically, 0.1 °~6-2°~, to provide additional sudsing
andlor product
stability, as noted hereinafter.
Various detersive ingredients employed in the present compositions
optionally can be further stabilized by absorbing said ingredients onto a
porous
hydrophobic substrate, then coating said substrate with a hydrophobic coating.
Preferably, the detersive ingredient is admixed with a surfactant before being
absorbed into the porous substrate. In use, the detersive ingredient is
released
from the substrate into the aqueous washing liquor, where it performs its
intended detersive function.
To illustrate this technique in more detail, a porous hydrophobic silica
(trademark SIPERNAT D10, DeGussa) is admixed with a proteolytic enzyme
solution containing 3°~-5°~ of C13-15 ethoxylated alcohol EO(7)
nonionic
surfactant. Typically, the enzymelsurfactant solution is 2.5 X the weight of
silica.
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The resulting powder is dispersed with stirring in silicone oil (various
silicone oil
viscosities in the range of 500-12,500 can be used). The resulting silicone
oil
dispersion is emulsified or otherwise added to the final detergent matrix. By
this
means, ingredients such as the aforementioned enzymes, bleaches, bleach
activators, bleach catalysts, photoactivators, dyes, fluorescers, fabric
conditioners and hydrolyzable surfactants can be "protected" for use in
detergents, including liquid laundry detergent compositions.
Manufacturing Eguipment
As disclosed hereinabove, the granular compositions of this invention are
conveniently and preferably prepared using three types of particles,
designated
(a), (b) and (c) for convenience. The following illustrates the manufacture of
such preferred compositions. However, it is to be appreciated that other means
of combining the detersive ingredients may be employed without departing from
the spirit and scope of the invention.
Various means and equipment are available to prepare particle (a) for use
in granular detergent compositions according to the present invention.
(Particles
[b] and [c) can be prepared by conventional grinding or agglomerating
processes.) Current commercial practice in the field involves mixing the
various
ingredients in an aqueous medium (the so-called "crutcher mix") followed by
passage through a heated spray-drying tower to produce granular particles,
such
as (a), which often have a density less than about 550 g/l. If such low
density
particles are desired, spray-drying is an acceptable means for their
preparation.
If high density particles (above 550 g/I, preferably 650-900 g/I) are desired,
and
if spray-drying is used as part of the overall process herein, the resulting
spray-dried particles can be further densified such as by using the means and
equipment described hereinafter. In the alternative, the formulator can
eliminate
spray-drying by using mixing, densifying and granulating equipment that is
commercially available. The following is a nonlimiting description of such
equipment suitable for use herein.
High speed mixer/densifiers can be used in the present process to
prepare high density particles. For example, the device ~ marketed under the
trademark "Lodige CB30" Recycler comprises a static cylindrical mixing drum
having a central rotating shaft with mixing/cutting blades mounted thereon. In
use, the ingredients for the overall detergent composition are introduced into
the
drum and the shaft/blade assembly is rotated at speeds in the range of 100-
2500
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2177677
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rpm to provide thorough mixing/densification. Other such apparatus includes
the
devices marketed under the trademark "Shugi Granulator" and under the
trademark "Drais K-TTP 80).
Depending on the degree of densification and/or agglomeration desired, a
processing step involving further densification can be conducted. Equipment
such as that marketed under the trademark "Lodige KM600 Mixer", also known
as the "Lodige Ploughshare" can be used. Such equipment is typically operated
at 40-160 rpm. Other useful equipment includes the device which is available
under the trademark "Drais K-T 160". The Lodige CB or KM type equipment can
be used by itself or sequentially, e.g., by using the CB for paste dispersion
and
the KM for agglomeration. Batch or continuous feed can be employed.
In yet another mode, particle (a) of this invention can be prepared using a
fluidized bed mixer. In this method, the various ingredients are combined in
an
aqueous slurry and sprayed into a fluidized bed of particles comprising, for
example, particles of a zeolite or layered silicate or carbonate builder to
provide
the particles (a). In an alternate mode, the slurry can be sprayed into a
fluidized
bed of zeolite or layered silicate particles, plus particles of a surfactant.
In such
a process, the first step may optionally include mixing of the slurry using a
"Lodige CB30" or "Flexomix 160", available from Shugi. Fluidized bed or moving
beds of the type available under the trademark "Escher Wyss can be used in
such processes. Other types of granules manufacturing apparatus useful herein
include the apparatus disclosed in U.S. Patent 2,306,898, to G. L. Heller,
December 29, 1942.
Whatever the method employed, particles (a) are combined with
percarbonate particles (b) and sulfate particles (c), conveniently by dry-
blending.
Any adjunct agents, perfumes, etc., can be admixed or sprayed onto the mixture
of the three types of particles.
The final density of the particles and compositions herein can be
measured by a variety of simple techniques, which typically involve dispensing
a
quantity of the granular material into a container of known volume, measuring
the weight of material and reporting the density as grams/liter. Methods used
herein allow the material to flow into the measuring container under gravity,
and
without pressure or other compaction in the measuring container. The density
measurements should be run at room temperature. The granular material whose
density is being measured should be at least 24 hours old and should be held
at
T WO 95/16019 217 7 6 7 7 pCT~S94/13653
_29_
room temperature for 24 hours prior to testing. The relative humidity is not
particularly critical, but should not be so high that the particles stick
together. A
relative humidity of 50% or less is convenient. Of course, any clumps in the
material should be gently broken up prior to running the test. In one typical
method, the sample of material is allowed to flow through a funnel mounted on
a
filling hopper and stand (#150; Seedburo Equipment Company, Chicago, Illinois)
into an Ohaus cup of known volume and weight (#104; Seedburo). The top of
the cup is positioned about 50 mm from the bottom of the funnel, and the cup
is
filled to overflowing. A spatula or other straight edge is then scraped over
the
top of the cup, without vibration or tapping, to level the material, thereby
exactly
and entirely filling the cup. The weight of material in the cup is then
measured.
Density can be reported as g/l or ounces/cubic inch. Repeat runs are made and
reported as an average. Relative error is about 0.4%.
The detergent compositions herein will preferably be formulated such that,
during use in aqueous cleaning operations, the wash water will have a pH of
between about 6.5 and about 11, preferably between about 7.5 and about 10.5.
Techniques for controlling pH at recommended usage levels include the use of
buffers, alkalis, acids, etc., and are well known to those skilled in the art.
The following Examples A and B illustrate granular detergent
compositions according to this invention.
EXAMPLE I
Percent* Percent*
Formllnaredient A B
Spray -dried granule
Zeolite A (1-10 micrometer) 20.50 20.50
Silicate 1.6R 2.9 -
Silicate 3.2R - 2.9
DTPMP 0.3 0.3
Copolymer maleiGacrylic (mw 70,000)1.8 1.8
Magnesium sulfate 0.4 0.4
Sodium sulfate 7.7 8.6
LAS 5.9 0.0
C 16118AS 2.5 0.0
45AS 0.0 7.0
13/15AE3S 0.0 0.5
WO 95/16019 217 7 6 7 7 PCT~S94113653
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Moisturel 5.0 5.0
Dry blended
Sodium sulfate'"' 7.7 7.7
Percarbonate*"' 15.0 15.0
TAED 5.0 5.0
Na carbonate 12.7 12.7
Savinase (4.OKNPUIg) 0.9 0.9
Spray on
C14-15AE7 5.0 0.0
C 12-15AE3 0.0 4.0
Balance/moisture/misc. 100.0 100.0
* Percent by weight of final composition.
1 Corresponds to 10.6% moisture in the spray-dried granule component, said
component constituting 47% of the final composition.
"* Percarbonate coated with 2.5% of a carbonate/sulfate mixture (2.5:1 weight
ratio) having an activity of 13.25% (AvOx content), an average particle size
of
600um.
'"* Na sulfate with 3 ppm iron, 1 ppm copper, 1 % particles less than 250um,
10%
particles less than 425um, 60% particles less than 600um, 70% particles
below 850um, 90% particles less than 1000um.
The oxidation-sensitive ingredient, such as the brightener, can be added
to the product at any desired level in any convenient manner, such as by
incorporation into the spray-dry mixture, by addition to the product as a
powder,
or by spraying onto the product alone (e.g., the pertume) or in a nonionic
ethoxylated (AE) surfactant. With respect to brightener stability, the
measurement of brightener discoloration can be conducted by visual observation
of the stored, white granules (a distinct yellow color develops) or more
quantitatively by standard photometric means, e.g., Hunter Whiteness. As can
be seen from the following Results, brightener discoloration towards the
yellow is
substantially decreased by the compositions herein. The data show the
improved brightener color stability for granular Composition A of Example I,
vs.
various test products using Tinopal DMS brightener (disodium 4,4'-bis[(4-
anilino-
6-morpholino-1,3,5-triazin-2-yl)amino]stilbene-2,2'disulfonate). The following
Results are obtained with the brightener which is co-spray dried with zeolite,
silicate and surfactants.
WO 95/16019 PCT/US94113653
-31 -
Results (Hunter Color Measurement)
BIuelYellow Index
Test Composition (+ ve = yellow: -ve = blue
Fresh product -4.20
4 weeks' storage/90°F (32°C; 80°~ relative
humidity) closed carton
a) Product + percarbonate (includes crutched x.09
silicate)
TM
b) Commercial granular product (ARIEL) plus -0.75
percarbonate/no silicate
After 4 weeks' 40°C closed carton storage
c) Fresh product -4.20
d) Product with percarbonate (includes -3.92
crutched silicate)
e) Product with percarbonate (no crutched +1.67
silicate)
In a modification of the foregoing, the stabilization benefits of the silicate
are further improved by the addition of soluble magnesium salts such as Mg CI2
or Mg S04 to the spray-dried particles (a), conveniently in the cnrtcher mix.
While not intending to be limited by theory, it is hypothesized that the
Mglsilicate
colloids which form in the crutcher would strongly scavenge heavy metal
rations.
Magnesium saltailicate ratios as low as 0.2:3.0 are effective.
Moisture in the foregoing compositions can be measured by any
conventional means. In a preferred, simple method, moisture is measured as
moisture loss on heating. For example, a 2 gram sample of particles is loaded
onto the weighing pan of a PM400 Mettler balance fitted with an ~P16 infrared
heater. The sample is heated at 160°C for 20 minutes. The moisture
level is
displayed as a function of percent weight loss. The appropriate moisture level
contributes both to storage stability and, importantly, to the improved
dispensing
properties of the granules.
The improved dispensing properties which are also afforded by the
foregoing granules can be measured as follows. The detergent granules are
stored for 4 weeks in closed cartons at 90°F (32°C)/80°r6
relative humidity. After
storage, 150 g of the detergent granules are weighed into the main compartment
of a Hotpoint washing machine dispenser drawer. The drawer is preweighed.
WO 95/16019 217 7 6 7 7 pCT~S94/13653
- 32 -
Water (20°C) is flushed through the main compartment drawer at a
rate of 2
liters/min. for 2 minutes. The excess water in the compartment is drained off
and
the drawer is reweighed. This experiment is repeated 6 times. The percent
residue left in the drawer is expressed by the following formula. An
acceptable
level of residues is below 15%. The formulations according to this invention
pass this test.
residues = wei4ht drawer + product after flushin4 - wei4ht drawer
weight product added
The foregoing compositions also exhibit acceptable stability of the
percarbonate, i.e., typically less than about 15% decomposition, as measured
in
a simple storage test (28°C, sealed bottle, 6-weeks' storage).
The foregoing compositions according to this invention also exhibit
excellent enzyme stability on storage, as compared with nil-silicate
compositions
under the same storage test conditions.
The foregoing compositions according to this invention also exhibit
improved stability with respect to chelants, amine-based fabric softeners and
antistatic agents, perfume and oleyl sulfate surfactant, as compared with nil-
silicate compositions under the same storage test conditions.
While the foregoing Examples illustrate the practice of the technology
herein, it will be appreciated that simple modifications can be made without
departing from the spirit and scope of the invention.
