Note: Descriptions are shown in the official language in which they were submitted.
WO 95/13344 PCT/US94/11511
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GRANULAR DETERGENT COMPOSITION COMPRISING A LOW BULK DENSITY
COMPONENT.
The invention concerns a granular detergent component
having a bulk density of less than 400 g/1 which comprises
an anionic surfactant, zeolite, and, optionally, a co-
filler. The invention also concerns a granular laundry
detergent composition comprising the low bulk density
component and, additionally, high density granular
components, preferably including percarbonate.
In conventional processes for preparing granular laundry
detergents, spray drying of an aqueous slurry has been used
to prepare granular components having a rather wide range
of bulk densities depending on factors such as choice and
level of ingredients used in the slurry, and processing
conditions in the spray drying tower. However spray dried
products on their own do not have high enough bulk density
for todays granular detergents.
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Recent trends in granular laundry detergents have seen
increases in the bulk density of the finished products.
Such high bulk densities offer greater convenience to the
consumer, and environmental benefits due to, for example,
reduced packaging requirements. These densities have been
achieved by preparing and combining individual detergent
components having high bulk densities.
Combinations of spray dried powders with other granular
components are known in the prior art, some examples of
which are cited below.
EPA289312, published 2nd November 1988 discloses a process
for the spray-drying of an aqueous slurry which contains
carbonate and a crystal growth modifier. Optional post-
treatments include spraying on of nonionic surfactant and
mixing with other components including bleach, bleach
activator, enzymes, etc. Such components require the
presence of relatively high levels of organic materials, in
particular anionic surfactants (in this application
surfactants are present at a level of at least 5$ by
weight).
W09303131, published on 18th February 1993 discloses a
spray dried component which comprises alkyl sulphate,
aluminosilicate and silicate. Certain ratios of the
components as well as processing conditions are specified.
The spray dried component is then mixed with bleach, bleach
activator, foam inhibitor, enzymes etc. The application
WO 95/13344 PCT/US94/11511
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3
considers the problem of replacing linear alkyl benzene
sulponate (LAS) by the more biodegradable alkyl sulphates.
Such components are difficult to spray dry and require the
introduction of specific process parameters such as low
temperature spray drying.
High bulk density components which are desirable in todays
granular detergents, such as carbonate, percarbonate and
silicate, do not offer the detergent formulator much
flexibility in terms of finished product bulk density. A
low bulk density spray-dried component, however, which
could be blended with the high bulk density components
would offer greatly increased flexibility in terms of
achieving the desired final product density. Such
flexibility arises from the possibility to vary parameters
such as the composition of the aqueous slurry prior to
spray drying, the parameters of the spray drying process
and the ratio of the low bulk density component to the high
bulk density components which may be used.
It is the aim of the present invention to provide a spray-
dried component having a bulk density of less than 400 g/1
which contains a low level of organic material. The organic
material facilitates the production of spray dried
components having good physical properties, and which can
be made at a low bulk density without loss of quality. The
organic material chosen for use in the present invention is
WO 95/13344 ~ ~ PCT/tJS94111511
4
low levels of surfactant, preferably anionic surfactant at
a level of from 0.050 to 2~ by weight, which has a Krafft
point of at least 30°C.
A second aspect of the present invention is to provide a
finished composition which comprises the low bulk density
spray-dried component, together with additional higher bulk
density components.
A third aspect of the present invention is to provide
spray-dried components which are low in moisture content,
and which have a high capacity for moisture uptake. Such
components, when combined with granular percarbonate offer
improved storage stability of the percarbonate, especially
in humid conditions.
Detailed Description of the Invention
In its first aspect the present invention is concerned with
a granular detergent component having a bulk density of
less than 400 g/1 comprising from 20$ to 50$ by weight of
aluminosilicate, and optionally up to 50$ by weight of a
co-filler. The granular components of the invention further
comprise from 0.050 to 2o by weight of anionic surfactant.
The anionic surfactant may be used alone, or it may be
combined with non-anionic surfactants. The anionic
surfactant, or mixture of anionic and non-anionic
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surfactants (when present), has a Krafft Point greater than
30°C. Preferably the anionic surfactant is present at a
level of from 1~ to 1.8o, and is C14-C20 alkyl sulphate.
Preferably the co-filler is a hydratable inorganic salt
selected from the group of salts consisting of carbonate,
bicarbonate, sesquicarbonate, sulphate, citrate or mixtures
of these, and is present at a level of from 10 to 30~ by
weight of the low bulk density component.
In its second aspect, the low bulk density component is
mixed with other components. Such granular components
preferably include those selected from the group consisting
of silicate, layered silicate, carbonate, bicarbonate,
sesquicarbonate, sulphate, citrate or mixtures of these. It
is preferred that the spray-dried component is present in
the composition at a level of from 10$ to 60~ by weight,
and that the granular components which individually have a
bulk density of greater than 800 g/1 are present, when
mixed together in the composition at a level of up to 50$
by weight, preferably from 10 to 40~.
In its third aspect the composition further comprises
granular percarbonate having a bulk density of at least 800
g/1. Where present the perearbonate is preferably at a
level of greater than 3~ by weight of the finished
composition, and more preferably from 5$ to 50$ by weight
of the finished composition. In such a percarbonate
WO 95/13344 PCT/US94/11511
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containing composition, the spray dried component is
processed so that therein the ratio of total water to
aluminosilicate does not exceed 1:3, preferably does not
exceed 1:5.
The various detergent ingredients are defined in more
detail below.
Surfactants
The surfactants which are useful as components of the low
bulk density component of the present invention are those
having a Krafft Point greater than 30°C.
Water-soluble salts of the higher fatty acids, i.e.,
"soaps", are useful anionic surfactants in the compositions
herein. This includes alkali metal soaps such as the
sodium, potassium, ammonium, and alkylammonium salts of
higher fatty acids containing from about 8 to about 24
carbon atoms, and preferably from about 12 to about 18
carbon atoms. Soaps can be made by direct saponification
of fats and oils or by the neutralization of free fatty
acids. Particularly useful are the sodium and potassium
salts of the mixtures of fatty acids derived from coconut
oil and tallow, i.e., sodium or potassium tallow and
coconut soap. Those soaps having a chain length of at least
12 carbon atoms are especially useful in the present
WO 95/13344 PCT/US94/11511
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invention because they have Krafft points in the required
range.
. Useful anionic surfactants also include the water-soluble
salts, preferably the alkali metal, ammonium and
alkylolammonium salts, of organic sulfuric reaction
products having in their molecular structure an alkyl group
containing from about 10 to about 20 carbon atoms and a
sulfonic acid or sulfuric acid ester group. Examples of
this group of synthetic surfactants are the sodium and
potassium alkyl sulfates, especially those obtained by
sulfating the higher alcohols (Cg-Clg carbon atoms) such as
those produced by reducing the glycerides of tallow or
coconut oil. Those alkyl sulphates having a chain length of
at least 14 carbon atoms are especially useful in the
present invention because they have Krafft points in the
required range.
Other useful anionic surfactants herein include the water-
soluble salts of esters of alpha-sulfonated fatty acids
containing from about 6 to 20 carbon atoms in the fatty
acid group and from about 1 to 10 carbon atoms in the ester
group; and alkyl ether sulfates containing from about 10 to
20, especially 16 to 20, carbon atoms in the alkyl group
and from about 1 to 30 moles of ethylene oxide.
Also useful are the sulphonation products of fatty acid
methyl esters containing a alkyl group with from 10 to 20
WO 95113344 PCT/US94/11511
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8
carbon atoms. Preferred are the C16-18 methyl ester
sulphonates (MES).
Particularly preferred surfactants herein include; primary
and secondary alkyl sulfates; coconutalkyl glyceryl ether
suifonates; alkyl ether sulfates wherein the alkyl moiety
contains from about 16 to 18 carbon atoms and wherein the
average degree of ethoxylation is from about 1 to 4; olefin
or paraffin sulfonates containing from about 16 carbon
atoms; and methyl ester sulphonates.
Preferred nonionics are the water-soluble condensation
products of aliphatic alcohols containing from 8 to 22
carbon atoms, in either straight chain or branched
configuration, with from 4 to 25 moles of ethylene oxide
per more of alcohol. Particularly preferred are the
condensation products of alcohols having an alkyl group
containing from about 9 to 15 carbon atoms with from about
4 to 25 moles of ethylene oxide per mole of alcohol; and
condensation products of propylene glycol with ethylene
oxide.
Another class of nonionic surfactants comprises alkyl
polyglucoside compounds of general formula
RO (CnH2n0)tZx
wherein Z is a moiety derived from glucose; R is a
saturated hydrophobic alkyl group that contains from 12 to
WO 95113344 PCT/US94/11511
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18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is
from 1.3 to 4, the compounds including less than 10$
unreacted fatty alcohol and less than 50~ short chain
alkyl polyglucosides. Compounds of this type and their
use in detergent compositions are disclosed in EP-B
0070074, 0070077, 0075996 and 0094118.
Still another class of nonionic surfactants comprises
polyhydroxy fatty acid amides which may be produced by
reacting a fatty acid ester and an N-alkyl polyhydroxy
amine. A preferred amine is N-(R1)-CH2(CH20H)4-CH2-OH and
the preferred ester is a C12-C20 fatty acid methyl ester.
Most preferred is the reaction product of N-methyl
glucamine with C12-C20 fatty acid methyl ester.
Methods of manufacturing polyhydroxy fatty acid amides
have been described in WO 92 6073, published on 16th
April, 1992. This application describes the preparation of
polyhydroxy fatty acid amides in the presence of solvents.
In a highly preferred embodiment of the invention N-methyl
glucamine is reacted with a C12-C20 methyl ester.
One class of nonionic surfactants useful in the present
invention comprises condensates of ethylene oxide with a
hydrophobic moiety, providing surfactants having an
average hydrophilic-lipophilic balance (HLB) in the range
from 8 to 17, preferably from 9.5 to 13.5, more preferably
from 10 to 12.5. The hydrophobic (lipophilic) moiety may
WO 95113344 ' PCT/US94/11511
be aliphatic or aromatic in nature and the length of the
polyoxyethylene group which is condensed with any
particular hydrophobic group can be readily adjusted to
yield a water-soluble compound having the desired degree
of balance between hydrophilic and hydrophobic elements.
Especially preferred nonionic surfactants of this type are
the Cg-C15 primary alcohol ethoxylates containing 3-9
moles of ethylene oxide per mole of alcohol, particular~y
the C13-C15 primary alcohols containing 6-9 moles of
ethylene oxide per mole of alcohol and the C11-C15 Primary
alcohols containing 3-5 moles of ethylene oxide per mole
of alcohol.
Surfactants which have a Krafft Point of less than 30°C are
not excluded from the present invention, but they should be
used in combination with high Krafft Point surfactants in
surfactant systems at levels whereby the total surfactant
system has a Krafft Point in excess of 30°C.
Anionic surfactant having a lower Krafft Point which may be
used in this way include sodium and potassium alkyl benzene
sulfonates in which the alkyl group contains from about 9
to about 15 carbon atoms, in straight or branched chain
configuration, e.g., those of the type described in U.S.
Pat. Nos. 2,220,099 and 2,477,383. Especially valuable are
linear straight chain alkyl benzene sulfonates in which the
WO 95/13344 PCT/US94I11511
" 2174721
average number of carbon atoms in the alkyl group is from
about 11 to 13, abbreviated as C11-C13 ~S~
Other classes of surfactants include the following:
Useful cationic surfactants include water-soluble
quaternary ammonium compounds of the form R4R5RgR~N+X-,
wherein R4 is alkyl having from 10 to 20, preferably from
12-18 carbon atoms, and R5, R6 and R~ are each C1 to C~
alkyl preferably methyl; X- is an anion, e.g. chloride.
Examples of such trimethyl ammonium compounds include C12-
14 alkyl trimethyl ammonium chloride and cocalkyl trimethyl
ammonium methosulfate.
Semi-polar nonionic surfactants include water-soluble amine
oxides containing one alkyl moiety of from about 10 to 18
carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups
containing from 1 to about 3 carbon atoms; water-soluble
phosphine oxides containing one alkyl moiety of about 10 to
18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups
containing from about 1 to 3 carbon atoms; and water-
soluble sulfoxides containing one alkyl moiety of from
about 10 to 18 carbon atoms and a moiety selected from the
group consisting of alkyl and hydroxyalkyl moieties of from
about 1 to 3 carbon atoms.
WO 95113344 PCT/US94/11511
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Ampholytic surfactants include derivatives of aliphatic or
aliphatic derivatives of heterocyclic secondary and
tertiary amines in which the aliphatic moiety can be either
straight or branched chain and wherein one of the aliphatic
substituents contains from about 8 to 18 carbon atoms and
at least one aliphatic substituent contains an anionic
water-solubilizing group.
Zwitterionic surfactants include derivatives of aliphatic
quaternary ammonium phosphonium, and sulfonium compounds in
which one of the aliphatic substituents contains from about
8 to 18 carbon atoms.
The low bulk density component of the present invention
comprises other detergent ingredients selected from a wide
range of possible ingredients which are commonly used in
laundry detergents. The particles will contain from 20 to
50~ by weight of aluminosilicate and up to 50~ by weight of
co-filler, and optionally other components; preferred
components being described below.
Whilst a range of aluminosilicate ion exchange materials
can be used, preferred sodium aluminosilicate zeolites
have the unit cell formula
Naz [ (A102 ) z (Si02 ) y ) xH 20
wherein z and y are at least 6; the molar ratio of z to y
is from 1.0 to 0.5 and x is at least 5, preferably from
WO 95/13344 PCT/US94/11511
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7.5 to 276, more preferably from 10 to 264. The
aluminosilicate materials are in hydrated form and are
preferably crystalline, containing from 10~ to 280, more
preferably from 16o to 22~ water in bound form.
The above aluminosilicate ion exchange materials are
further characterised by a particle size diameter of from
0.1 to 10 micrometers, preferably from 0.2 to 4
micrometers. The term "particle size diameter" herein
represents the average particle size diameter of a given
ion exchange material as determined by conventional
analytical techniques such as, for example, microscopic
determination utilizing a scanning electron microscope or
by means of a laser granulometer. The aluminosilicate ion
exchange materials are further characterised by their
calcium ion exchange capacity, which, is at least 200 mg
equivalent of CaC03 water hardness/g of aluminosilicate,
calculated on an anhydrous basis, and which generally is
in the range of from 300 mg eq./g to 352 mg eq./g. The
aluminosilicate ion exchange materials herein are still
further characterised by their calcium ion exchange rate
which is at least 130 mg equivalent of
CaC03/litre/minute/(g/litre) [2 grains Ca++/
gallon/minute/gram/gallon)] of aluminosilicate (anhydrous
basis), and which generally lies within the range of from
130 mg equivalent of CaC03/litre/minute/(gram/litre) [2
grains/gallon/minute/ (gram/gallon)] to 390 mg equivalent
of CaC03/litre/minute/ (gram/litre)
WO 95113344 ~ ~ ' PCT/US94/11511
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[6 grains/gallon/minute/(gram/gallon)], based on calcium
ion hardness.
Optimum aluminosilicates for builder purposes exhibit a
calcium ion exchange rate of at least 260 mg equivalent of
CaC03/litre/ minute/ (gram/litre) [4
grains/gallon/minute/(gram/gallon)].
Aluminosilicate ion exchange materials useful in the
practice of .his invention are commercially available and
can be naturally occurring materials, but are preferably
synthetically derived. A method for producing
aluminosilicate ion exchange materials is discussed in US
Patent No. 3,985,669. Preferred synthetic crystalline
aluminosilicate ion exchange materials useful herein are
available under the designations Zeolite A, Zeolite B,
Zeolite X, Zeolite HS, Zeolite MAP and mixtures thereof.
In an especially preferred embodiment, the crystalline
aluminosilicate ion exchange material is Zeolite A and has
the formula
Na 12 [(A102 ) 12 (Si02)12 ]. xH2 0
wherein x is from 20 to 30, especially 27. Zeolite X of
formula Nag6 ((A102)g6(Si02)106]~ 276 H20 is also
suitable, as well as Zeolite HS of formula Nag
[(A102)6(Si02)6] 7.5 H2 0.
Suitable co-fillers can include, but are not restricted
to, alkali metal carbonates, bicarbonates,
.... PCTIUS94/11511
W O 95113344
15 21 7 4 7 2 1
sesquicarbonates, sulphates, monomeric polycarboxylates,
salts of homo or copolymeric polycarboxylic acids in which
the polycarboxylic acid comprises at least two carboxylic
radicals separated from each other by not more than two
carbon atoms, organic phosphonates and aminoalkylene poly
(alkylene phosphonates) and mixtures of any of the
foregoing.
By the term "hydratable salt" it is meant that the salt is
in a state in which it may absorb additional water by
hydration. That is to say that the salt is present either
in its anhydrous form, or in a partially hydrated form.
Preferred builder systems are free of boron compounds and
any polymeric organic materials are preferably
biodegradable.
Suitable water-soluble monomeric or oligomeric carboxylate
builders include lactic acid, glycolic acid and ether
derivatives thereof as disclosed in Belgian Patent Nos.
831,368, 821,369 and 821,370. Polycarboxylates containing
two carboxy groups include the water-soluble salts of
succinic acid, malonic acid, (ethylenedioxy) diacetic
acid, malefic acid, diglycolic acid, tartaric acid,
tartronic acid and fumaric acid, as well as the ether
carboxylates described in German Offenlegenschrift
~,y46,686, and 2,446,687 and U.S. Patent No. 3,935,257 and
16 21 747 21
the sulfinyl carboxylates described in Belgian Patent No.
840,623. Polycarboxylates containing three carboxy groups
include, in particular, water-soluble citrates, aconitrates
and citraconates as well as succinate derivatives such as
the carboxymethyloxysuccinates described in British Patent
No. 1,379,241, lactoxysuccinates described in British
Patent No. 1,389,732, and aminosuccinates described in
Canadian Patent No. 973,771, and the oxypolycarboxylate
materials such as 2-oxa-1,1,3-propane tricarboxylates
described in British Patent No. 1,387,447.
Polycarboxylates containing four carboxy groups include
oxydisuccinates disclosed in British Patent No. 1,261,829,
1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane
tetracarboxylates and 1,1,2,3-propane tetracarboxylates.
Polycarboxylates containing sulfo substituents include the
sulfosuccinate derivatives disclosed in British Patent Nos.
1,398,421 and 1,398,422 and in U.S. Patent No. 3,936,448,
and the sulfonated pyrolysed citrates described in British
Patent No. 1,439,000.
Another preferred polycarboxylate builder is
ethylenediamine-N, N'-disuccinic acid (EDDS) or the alkali
metal, alkaline earth metal, ammonium, or substituted
ammonium salts thereof, or mixtures thereof.
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Alicyclic and heterocyclic polycarboxylates include
cyclopentane-cis,cis,cis-tetracarboxylates,
cyclopentadienide pentacarboxylates, 2,3,4,5-
tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5-
tetrahydrofuran - cis - dicarboxylates, 2,2,5,5-
tetrahydrofuran - tetracarboxylates, 1,2,3,4,5,6-hexane -
hexacarboxylates and carboxymethyl derivatives of
polyhydric alcohols such as sorbitol, mannitol and
xylitol. Aromatic polycarboxylates include mellitic acid,
pyromellitic acid and the phthalic acid derivatives
disclosed in British Patent No. 1,425,343.
Of the above, the preferred polycarboxylates are
hydroxycarboxylates containing up to three carboxy groups
per molecule, more particularly citrates.
The parent acids of the monomeric or oligomeric
polycarboxylate chelating agents or mixtures thereof with
their salts, e.g. citric acid or citrate/citric acid
mixtures are also contemplated as components of builder
systems of detergent compositions in accordance with the
present invention.
Other suitable water soluble organic salts are the homo-
or co-polymeric polycarboxylic acids or their salts in
which the polycarboxylic acid comprises at least two
carboxyl radicals separated from each other by not more
than two carbon atoms. Polymers of the latter type are
disclosed in GB-A-1,596,756. Examples of such salts are
WO 95113344 PCT/US94/11511
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polyacrylates of MWt 2000-5000 and their copolymers with
malefic anhydride, such copolymers having a molecular
weight of from 20,000 to 70,000, especially about 40,000.
Such builder polymeric materials may be identical to the
polymeric materials as binder materials and coating
materials, as described hereinabove. These materials are
normally used at levels of from 0.5$ to 10~ by weight more
preferably from 0.75° to 80, most preferably from to to 6~
by weight of the composition.
Organic phosphonates and amino alkylene poly (alkylene
phosphonates) include alkali metal ethane 1-hydroxy
diphosphonates, nitrilo trimethylene phosphonates, ethylene
diamine tetra methylene phosphonates and diethylene
triamine penta methylene phosphonates, although these
materials are less preferred where the minimisation of
phosphorus compounds in the compositions is desired.
The primary component of the present invention has a bulk
density of less than 400 g/1 and is preferably prepared by
spray drying, although other techniques of preparing low
density flowable powders may be used. Following the spray
drying route, an aqueous slurry is prepared comprising the
solids. The slurry is then pumped at high pressure through
atomising nozzles into a drying tower where excess water is
driven off, producing a flowable powder. The resulting
powder may then be oversprayed with liquid ingredients,
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,9
especially nonionic surfactants for which the powder has a
high adsorption capacity before it loses its good flow
characteristics.
Examples of other components which may be used in laundry
detergents, and which may be incorporated into the low bulk
density component are described below under "Other Optional
Ingredients"
Percarbonate bleach
In a preferred embodiment of the present invention,
compositions will include a percarbonate bleach, normally
in the form of the sodium salt, as the source of alkaline
hydrogen peroxide in the wash liquor. This percarbonate is
normally incorporated at a level of from 3$ to 50~ by
weight, more preferably from 5$ to 30~ by weight and most
preferably from 8~ to 25~ by weight of the total
composition.
Sodium percarbonate is an addition compound having a
formula corresponding to 2Na2C03.3H202, and is available
commercially as a crystalline solid. Most commercially
available material includes a low level of a heavy metal
sequestrant such as EDTA, 1-hydroxyethylidene 1, 1-
diphosphonic acid (HEDP) or an amino-phosphonate, that is
WO 95/13344 PCT/US94/11511
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incorporated during the manufacturing process. For the
purposes of the detergent composition aspect of the
present invention, the percarbonate can be incorporated
into detergent compositions without additional protection,
but preferred executions of such compositions utilise a
coated form of the material. The preferred coating is a
mixed salt of an alkali metal sulphate and carbonate.
Such coatings together with coating processes have
previously been described in GB-1,466,799, granted to
Interox on 9th March 1977. The weight ratio of the mixed
salt coating material to percarbonate lies in the range
from 1:200 to 1:4, more preferably from 1:99 to 1:9, and
most preferably from 1:49 to 1:19. Preferably, the mixed
salt is of sodium sulphate and sodium carbonate which has
the general formula Na2SO4.n.Na2C03 wherein n is from 0.1
to 3, preferably n is from 0.3 to 1.0 and most preferably
n is from 0.2 to 0.5. Another preferred coating material
is citrate, or mixtures of citrate with sulphate or
carbonate. Water soluble surfactants may also be used as
coating materials.
An alternative, although less preferred coating material
is sodium silicate of Si02:Na20 ratio from 1.6:1 to 3.4:1,
preferably 2.8:1, applied as an aqueous solution to give a
level of from 2 o to 10'0, (normally from 3 o to 5n ) of
silicate solids by weight of the percarbonate. Magnesium
silicate can also be included in the coating. However
silicate should not be the major coating agent in order to
WO 95/13344 PCT/US94/11511
21 7~7 21
maintain good dispensing properties. If present, the
silicate level in the coating should be less than 3$ by
weight of the percarbonate.
The particle size range of the crystalline percarbonate is
from 150 micrometers to 1500 micrometers, preferably from
250 micrometers to 1000 micrometers with a mean particle
size of from 500 micrometers to 700 micrometers.
Whilst heavy metals present in the sodium carbonate used to
manufacture the percarbonate can be controlled by the
inclusion of sequestrants in the reaction mixture, the
percarbonate still requires protection from heavy metals
present as impurities in other ingredients of the product.
Granular Sodium Silicate
Suitable silicates are those having an Si02:Na20 ratio in
the range from 1.6 to 3.4, the so-called amorphous
silicates of Si02 . Na20 ratios from 2.0 to 2.8 being
preferred. These materials can be added at various points
of the manufacturing process, such as in the form of an
aqueous solution serving as an agglomerating agent for
other solid components, or, where the silicates are
themselves in particulate form, as solids to the other
particulate components of the composition.
WO 95113344 PCT/US94111511
22
Within the silicate class, highly preferred materials are
crystalline layered sodium silicates of general formula
NaMSix02x+1~YH20
wherein M is sodium or hydrogen, x is a number from 1.9 to
4 and y is a number from 0 to 20. Crystalline layered
sodium silicates of this type are disclosed in EP-A-
0164514 and methods for their preparation are disclosed in
DE-A-3417649 and DE-A-3742043. For the purposes of the
present invention, x in the general formula above has a
value of 2, 3 or 4 and is preferably 2. More preferably M
is sodium and y is 0 and preferred examples of this
formula comprise the~,~,~ and ~ forms of Na2Si205. These
materials are available from Hoechst AG FRG as
respectively NaSKS-11 and NaSKS-6. The most preferred
material is r~ -Na2Si205, (NaSKS-6). Crystalline
layered silicates are incorporated either as dry mixed
solids, or as solid components of agglomerates with other
components.
Other ingredients which may be dry added into the
composition in their granular form include carbonate,
bicarbonate, sesquicarbonate, sulphate, citrate or mixtures
of these all of which have been described above.
Furthermore some components may be added in the granular
form of the acid, for example citric acid. It will be
understood that such granulates may consist solely of one
2174721
23
component, or may be co-granulates of two of more
components.
Additional Surfactant-Comprising Components
Granular components which also comprise substantial amounts
of surfactants may also be dry added into the finished
composition. Such surfactant particles of the present
invention may take the form of flakes, prills, marumes,
noodles, ribbons, but preferably take the form of granules.
A preferred way to process the particles is by
agglomerating powders (such as those described hereinabove
e.g. aluminosilicate, carbonate) with high active
surfactant pastes and to control the particle size of the
resultant agglomerates within specified limits. Such a
process involves mixing an effective amount of powder with
a high active surfactant paste in one or more agglomerators
such as a pan agglomerator, a Z-blade mixer or more
preferably an in-line mixer such as those manufactured by
Schugi (Holland) BV, 29 Chroomstraat 8211 AS, Lelystad,
Netherlands, and Gebruder Lodige Maschinenbau GmbH, D-4790
Paderborn 1, Elsenerstrasse 7-9, Postfach 2050, Germany.
Most preferably a high shear mixer is used, such as a
Lodige CB (Trade Mark).
A high active surfactant paste comprising from 50% by
weight to 100% by weight, preferably 70% by weight to 850
by weight of surfactant is used. The surfactant system may
comprise any of the groups of anionic, nonionic, cationic,
WO 95/13344 PCT/US94/11511
2174-X21
24
amphoteric, and zwitterionic surfactants, or mixtures of
these. The paste may be pumped into the agglomerator at a
temperature high enough to maintain a pumpable viscosity,
but low enough to avoid degradation of the anionic
surfactants used. An operating temperature of the paste of
50°C to 80°C is typical.
A particularly suitable process of making surfactant
particles from high active surfactant pastes is more fully
described in EP 510 746, published on 28th October, 1992.
The term mean particle size as defined herein is calculated
by sieving a sample of the composition into a number of
fractions (typically 5 fractions) on a series of Tyler
sieves. The weight fractions thereby obtained are plotted
against the aperture size of the sieves. The mean particle
size is taken to be the aperture size through which 50~ by
weight of the sample would pass. For the purposes of the
present invention the surfactant containing granules should
have a mean partle size of less than 480 micrometers,
preferably less than 400 micrometers, and most preferably
less than 350 micrometers.
Other Optional Ingredients
Detergent compositions of the present invention may,
optionally, include anti-redeposition and soil suspension
agents, bleach activators, optical brighteners, soil
release agents, suds suppressors, enzymes, fabric softening
WO 95/13344 PCT/US94/11511
agents, perfumes and colours, as well as other ingredients
known to be useful in laundry detergents.
Anti-redeposition and soil-suspension agents suitable
herein include cellulose derivatives such as
methylcellulose, carboxymethylcellulose and
hydroxyethycellulose, and homo-or co-polymeric
polycarboxylic acids or their salts. Polymers of this
type include copolymers of malefic anhydride with ethylene,
methylvinyl ether or methacrylic acid, the malefic
anhydride constituting at least 20 mole percent of the
copolymer. These materials are normally used at levels of
from 0.5o to 10~ by weight, more preferably from 0.75$ to
80, most preferably from 1~ to 6$ by weight of the
composition.
Other useful polymeric materials are the polyethylene
glycols, particularly those of molecular weight 1000-
10000, more particularly 2000 to 8000 and most preferably
about 4000. These are used at levels of from 0.20$ to 5$
more preferably from 0.25 to 2.5~ by weight. These
polymers and t~:~ previously mentioned homo- or co-
polymeric poly~~~~~boxylate salts are valuable for improving
whiteness maintenance, fabric ash depositi .~, and cleaning
performance on clay, proteinaceous and oxidizable soils in
the presence of transition metal impurities.
WO 95/13344 PCT/US94/11511
26
In a preferred embodiment of the present invention, the
composition comprises peroxyacid bleach precursor. The
solid peroxyacid bleach precursors of the present invention
comprise precursors containing one or more N- or 0- acyl
groups, which precursors can be selected from a wide range
of classes.
Suitable classes include anhydrides, esters, imides and
acylated derivatives of imidazoles and oximes, and
examples of useful materials within these classes are
disclosed in GB-A-1586789. The most preferred classes are
esters such as are disclosed in GB-A-836988, 864,798,
1147871 and 2143231 and imides such as are disclosed in
GB-A-855735 & 1246338.
Particularly preferred precursor compounds are the N-
,N,N1N1 tetra acetylated compounds of formula
0 0
II II
CH3 - C ~ ~ C - CH3
N - (CH2) x N'
CH3 - C \ C - CH3
(I II
0 0
wherein x can be 0 or an integer between 1 & 6.
WO 95/13344 PCT/US94/11511
27
Examples include tetra acetyl methylene diamine (TAMD) in
which x=1, tetra acetyl ethylene diamine (TAED) in which
x=2 and tetraacetyl hexylene diamine (TAHD) in which x=6.
These and analogous compounds are described in GB-A-
907356. The most preferred peroxyacid bleach precursor is
TAED.
Other activators are perbenzoic acid precursors such as
benzoyloxybenzene sulphonate (BOBS) and benzoyl
caprolactam.
Is is most preferred that a peroxyacid bleach precursor is
present at a level of at least 0.5~ by weight of the
composition. The particles of peroxyacid bleach precursor
preferably have a particle size of from 100 micrometers to
1500 micrometers.
These peroxyacid bleach precursors can be partially
replaced by preformed peracids such as N,N
phthaloylaminoperoxy acid (PAP), nonyl amide of
peroxyadipic acid (NAPAA), 1,2 diperoxydodecanedioic acid
(DPDA) and trimethyl ammonium propenyl imidoperoxy
mellitic acid (TAPIMA). Other bleach precursors include
glycolate esters (described in EP 507475); 4h-3,1 -
benzoxazin - 4 ones: cationic precursors (described in EP
458396 and EP 464880); ester carbonate activators
(described in EP 475511), NOBS, iso-NOBS.
WO 95/13344 ~ PCT/US94111511
28
Preferred optical brighteners are anionic in character,
examples of which are disodium 4,41-bis-(2-diethanolamino-
4-anilino -s- triazin-6- ylamino)stilbene-2:21
disulphonate, disodium 4,41-bis-(2-morpholino -4-anilino-
2-triazin-6-ylaminostilbene-2:21-disulphonate,disodium 4,
41-bis-(2,4-dianilino-s-triazin-6-ylamino)stilbene-2:21 -
disulphonate, monosodium 41 411-bis-(2,4-dianilino-s-
triazin-6 ylamino)stilbene-2- sulphonate, disodium 4,41-
bis-(2-anilino-4-(N-methyl-N-2-hydroxyethylamino)-2-
triazin-6-ylamino)stilbene-2,21 - disulphonate, disodium
4,41-bis-(4-phenyl-2,1,3-triazol-2-yl)stilbene-2,21
disulphonate, disodium 4,41bis(2-anilino-4-(1-methyl-2-
hydroxyethylamino)-s-triazin-6-ylamino)stilbene-
2,21disulphonate and sodium 2(stilbyl-411-(naphtho-
11,21:4,5)-1,2,3 - triazole-211- sulphonate.
Soil-release agents useful in compositions of the present
invention are conventionally copolymers or terpolymers of
terephthalic acid with ethylene glycol and/or propylene
glycol units in various arrangements. Examples of such
polymers are disclosed in the commonly assigned US Patent
Nos. 4116885 and 4711730 and European Published Patent
Application No. 0272033. A particular preferred polymer
in accordance with EP-A-0272033 has the formula
(CH3(PEG)43)0.75(POH)0.25(T-PO)2.8(T-PEG)0.41T(PO-
H) 0.25 ( (PEG) 43CH3) 0.75
WO 95/13344 PCT/US94/11511
~y74'~21
29
where PEG is -(OC2Hq)0-, PO is (OC3H60) and T is
(pCOC6HqC0) .
Certain polymeric materials such as polyvinyl pyrrolidones
typically of MWt 5000-20000, preferably 10000-15000, also
form useful agents in preventing the transfer of labile
dyestuffs between fabrics during the washing process.
Another optional detergent composition ingredient is a
suds suppressor, exemplified by silicones, and silica-
silicone mixtures. Silicones can be genera~;ly represented
by alkylated polysiloxane materials while silica is
normally used in finely divided forms, exemplified by
silica aerogels and xerogels and hydrophobic silicas of
various types. These materials can be incorporated as
particulates in which the suds suppressor is
advantageously releasably incorporated in a water-soluble
or water-dispersible, substantially non-surface-active
detergent-impermeable carrier. Alternatively the suds
suppressor can be dissolved or dispersed in a liquid
carrier and applied by spraying on to one or more of the
other components.
As mentioned above, useful silicone suds controlling
agents can comprise a mixture of an alkylated siloxane, of
the type referred to hereinbefore, and solid silica.
Such mixtures are prepared by affixing the silicone to the
WO 95113344 PCT/US94111511
surface of the solid silica. A preferred silicone suds
controlling agent is represented by a hydrophobic
silanated (most preferably trimethyl-silanated) silica
having a particle size in the range from 10 nanometers to
20 nanometers and a specific surface area above 50 m2/g,
intimately admixed with dimethyl silicone fluid having a
molecular weight in the range from about 500 to about
200,000 at a weight ratio of silicone to silanated silica
of from about 1:1 to about 1:2.
A preferred silicone suds controlling agent is disclosed
in Bartollota et al. US Patent 3,933,672. Other
particularly useful suds suppressors are the self-
emulsifying silicone suds suppressors, described in German
Patent Application DTOS 2,646,126 published April 28,
1977. An example of such a compound is DC0544,
commercially available from Dow Corning, which is a
siloxane/glycol copolymer.
The suds suppressors described above are normally employed
at levels of from O.OOlo to 0.5$ by weight of the
composition, preferably from 0.01$ to 0.1$ by weight.
The preferred methods of incorporation comprise either
application of the suds suppressors in liquid form by
spray-on to one or more of the major components of the
composition or alternatively the formation of the suds
suppressors into separate particulates that can then be
WO 95/13344 PCT/US94/11511
31
mixed with the other solid components of the composition.
The incorporation of the suds modifiers as separate
particulates also permits the inclusion therein of other
suds controlling materials such as C20-C24 fatty acids,
microcrystalline waxes and high MWt copolymers of
ethylene oxide and propylene oxide which would otherwise
adversely affect the dispersibility of the matrix.
Techniques for forming such suds modifying particulates
are disclosed in the previously mentioned Bartolotta et al
US Patent No. 3,933,672.
Another optional ingredient useful in the present
invention is one or more enzymes.
Preferred enzymatic materials include the commercially
available amylases, neutral and alkaline proteases,
lipases, esterases and cellulases conventionally
incorporated into detergent compositions. Suitable enzymes
are discussed in US Patents 3,519,570 and 3,533,139.
Fabric softening agents can also be incorporated into
detergent compositions in accordance with the present
invention. These agents may be inorganic or organic in
type. Inorganic softening agents are examplified by the
smectite clays disclosed in GB-A-1,400,898. Organic
fabric softening agents include the water insoluble
tertiary amines as disclosed in GB-A-1514276 and EP-B-
0011340.
WO 95/13344 PCT/US94/11511
32
Their combination with mono C12-C14 quaternary ammonium
salts is disclosed in EP-B-0026527 & 528. Other useful
organic fabric softening agents are the dilong chain
amides as disclosed in EP-B-0242919. Additional organic
ingredients of fabric softening systems include high
molecular weight polyethylene oxide materials as disclosed
in EP-A-0299575 and 0313146.
Levels of smectite clay are normally in the range from 50
to 150, more preferably from 8o to 12$ by weight, with the
material being added as a dry mixed component to the
remainder of the formulation. Organic fabric softening
agents such as the water-insoluble tertiary amines or
dilong chain amide materials are incorporated at levels of
from 0.5o to 5o by weight, normally from 1$ to 3~ by
weight, whilst the high molecular weight polyethylene oxide
materials and the water soluble cationic materials are
added at levels of from O.lo to 2~, normally from 0.15 to
1.5~ by weight. Where a portion of the composition is
spray dried, these materials can be added to the aqueous
slurry fed to the spray drying tower, although in some
instances it may be more convenient to add them as a dry
mixed particulate, or spray them as a molten liquid on to
other solid components of the composition.
WO 95113344 PCT/US94/11511
~17~ ~~~
33
Examples
All percentages in these examples are weight percentages:
Example 1 Example 2
C16/18 alkyl sulphate 1.9 1.6
Zeolite A (anhydrous basis) 40.0 29.5
Acrylic-Malefic co-polymer 10.0 8.5
Sodium Carbonate 31.0 46.8
DTPMP 3.0 2.5
Optical Brightener 0.7 0.6
Miscellaneous 5.3 4.5
Water (bound to zeolite) 8.0 5.9
Water (free) 0.1 0.1
(DTPMP - diethylene triamine penta methylene phosphonate)
WO 95/13344 PCT/US94/11511
34
Example 3 Example 4 Example
5
Spray dried powder 25.9 - 26.3
(from Example 1)
Spray dried powder - 30.9 -
(from Example 2)
Sodium Percarbonate 17.5 13.0 16.3
*
Enzyme Granulate 1.9 0.7 1.0
*
Layered Silicate 12.4 8.0 8.8
(SKS-6~p~ ex hoechst)
*
Bleach Activator 6.0 2.7 2.8
(TAED)
Granulate
Sodium Bicarbonate 9.5 5.8 4.0
*
Anionic Surfactant 25.0 20.7 23.4
Granulate 1
Suds Suppressor 0.9 0.8 0.8
Granulate
Zeolite A 1.3 3.0 3.0
Nonionic Surfactant 4.6 4.6 4.6
(sprayed on)
Sodium Sulphate * - 9.8 9.0
The granular components marked withan asterisk (*) in
examples 3 to 5 havea bulk density of greater than 800
g/1.
WO 95/13344 PCT/US94/11511
35 21 747 21
The anionic surfactant granulate (indicated as 1) in
examples 3 to 5 comprises 35$ by weight anionic surfactant,
26o by weight zeolite A, 28$ sodium carbonate, 5~
carboxymethyl cellulose, the balance being water.
