Note: Descriptions are shown in the official language in which they were submitted.
WO 94/~251 2 1 5 5 ~ ~ ~ PCT~4/01115
-
P~lo~TR BLEU~NG OR CL~llNG Oo~ ONS ~X~A~nN~ A lM~ILICATES
5 TECHNI CAL F I ELD
The present invention relates to particulate detergent,
bleaching or cleaning compositions containing crystalline
aluminosilicates (zeolites), and also containing ingredients
sensitive to moisture, especially bleach ingredients, for
example, inorganic persalts such as sodium percarbonate,
organic or inorganic peroxyacids, bleach precursors, or bleach
catalysts.
BACKGROUND AND PRIOR ART
The ability of crystalline aluminosilicates ~zeolites) to
sequester calcium ions from aqueous solution by an ion-
exchange mechanism has led to their becoming a well-known
replacement for phosphates as detergency builder. Many
particulate detergent compositions currently sold commercially
in Europe, Japan and the USA contain zeolite.
Although many crystal forms of zeolite are known, the
preferred zeolite for detergents use has always been zeolite
A, used in sodium form.
Examples of prior art documents disclosing detergent
compositions containing zeolites are EP 456 515A (Procter &
Gamble), EP 38 591A and EP 21 491A (Procter & Gamble),
EP 87 035A (Union Carbide), US 4 604 224 and CA 1 072 853
(Colgate). The use of zeolites A, X, B ( P) and Y is
disclosed, and general formulae with a range of possible
cations given, but sodium is always the highly preferred
cation and all specific disclosure relates to zeolites in
sodium form.
W094l~251 PCT~4/01115
21 5~ 2 2
Sodium percarbonate is a well-known bleaching ingredient
in bleaching and detergent compositions and is widely
disclosed in the literature, although in recent years its use
in commercial products has been abandoned in favour of sodium
perborate. Sodium percarbonate is less stable than sodium
perborate in the presence of moisture, and its stabilisation
in detergent powders has long been recognised as a problem.
This problem becomes especially acute if sodium percarbonate
is to be included in a detergent powder with a high mobile
water content, when it tends to become deactivated in storage.
This situation applies in particular to powders containing
zeolites, because those materials contain a large amount of
relatively mobile water.
This problem is addressed in GB 2 013 259A (Kao), which
suggests as one solution the use of a zeolite in which the
sodium cations have been partially exchanged for calcium or
magnesium ions. This measure improves the stability of
sodium percarbonate, but at the cost of reduced building
(calcium and magnesium ion-exchanging) efficacy.
An alternative approach to the problem of percarbonate
stability in particulate zeolite-containing detergent
compositions is disclosed in EP 522 726A (Unilever), according
to which conventional zeolite A is replaced by maximum
aluminium zeolite P (zeolite MAP), a material described and
claimed in EP 384 070A (Unilever). Use of this zeolite gives
substantially improved sodium percarbonate storage stability.
Similar improvements have been observed in the storage
stability of sodium perborate monohydrate, as disclosed in
EP 552 053A (Unilever); bleach precursors, as disclosed in
EP 552 054A (Unilever); peroxyacids, as disclosed in our
copending International Patent Application No. EP/93/03369
filed on 29 November 1993; and certain manganese bleach
catalysts, as disclosed in our copending British Patent
Application No. 93 05599.4 filed on 18 March 1993.
~- - 3 -
The p~esent inven~ion is based on the discovery that
further significant improvements in the storage sta~ility of
sodium percarbo~ate and ~her moi~ture-sensitive ingredients
in particulate zeolite-containing detergent and cle~ g
compositions can be achieved by the use of zeolites in which
the sodium ions have been wholly or partially exc~anged for
other cations. This is surprising because the ion-exchanged
forms do not, in general, have lower moisture content~ than
their ~odium counterparts and, in the present in~ention, they
are used in fully hydrated fonm in environments where there is
no control of mobile water content. Improvements are observed
both with zeolite A and with zeolite MAP.
EP 364 184A (Unilever) discloses non-aqueous cleaning
compositions containing dispersed aluminosilicate particles
which have been deactivated ~y treatment with an ammonium or
substituted ammonium compound and thereafter heated to reduce
the water content below 24 wt~. The treatment reduces the
aluminosilicate-catalysed decomposition of bleach precursors
such as tetraacetylethylenedia~ine in the liquid product.
Unlike the present in~ention, EP 364 184A is concerned with an
environment (a non-aqueous liquid) in whic~ the water conten~
is strictly limited and controlled, and with aluminosilicates
which ~ust be partially dehydrated.
DE~INITl:ON OF TH~ INVENTION
The present invention provides a particulate detergent,
bleaching or clP~ni n~ composltion comprising:
(a) from 2 to 60 wt% of one or more organic detergent
surfac~ants,
(b) from lo to 80 wt~ o~ a build~r system comprising a
crystalline alu~inosilicate ~aving ex~hAngeable cations,
'~ ~
- 4 - ~ ~ 5~-5~
(c) from 5 to 40 wt% o~ a bleach system ~omprising a
bleach ingredient sensitive to moisture,
(d) optionally other ingredie~ts to 100 wt~,
wherein at least 5~ of the exchangeable cations of the
aluminosilicate (b) include ~mmonium, lithium or hydrogen ions
or combinations thereof.
The invention further provides, as a novel m--a~erial~
zeolite P having a silicon to alumini~m ratio not exceeding
1.33, preferably not exceeding 1.15 and more preferably not
exceeding 1.07, ha~ing exchangeable cations wherein the
exchangeable cations include ~m.o~ium, lithium or hydrogen
ions or combinations thereof.
DETAILED DESCRIPTION OF' THE INV~TION
The composition of the invention ha~ two essential
ingredien~s: the aluminosilica~e, and the moisture-sensitive
~ingredient.
The io~-~Yr~n~ed zeolite
The compositions of the in~e~tion require as an e~sential
ingredien~ a crystalline aluminosilicate (zeoli~e~ in which
the exchangeable cations consist at least in part of cations
derived from a wea~ monoacidic base, namely, ~mmon;um, lithium
or hydrogen ions or comb~nations thereof.
21558S2
W094/~251 PCT~4/01115
._ 5
.,,, ' .
Such a zeolite may readily be prepared by ion exchange
from a sodium zeolite, and for convenience will be referred to
as an ion-exchanged zeolite, although in principle the
invention would also encompass the use of directly synthesised
wholly non-sodium zeolites not prepared by ion-exchange, to
the extent that such materials can be prepared.
Zeolites capable of ion exchange are représented by the
following general formula:
M~(SiO )j(AlO2)~ . z H~O
where M is a monovalent cation. The ratio of silicon to
aluminium (y:x) can vary, as can the amount of water of
hydration.
A partially exchanged zeolite may be represented as:
MlX.M2(X - X ~ (SiO~)y (Alo2)x ~ Z H20
wherein Ml and M2 are two different exchangeable monovalent
cations.
The (molar) percentage extent of exchange quoted
hereafter can then be defined, for cation Ml, as
x' x 100
x
The values of x and x' can be determined by conventional
analytical methods, for example, atomic absorption
spectroscopy.
- 6 -
The cations Ml for the zeolites used in the present
invention are ~mo~;um, lithium and hydro~en. Zeolites in
hydrogen and ammonium form are preferred, and zeolites in
hydrogen form are especially preferred. Potas~ium ions,
derived from a ~trong ba~e, ha~e been found to have the
opposite effect, potassium zeolites giving worse stability of
moisture-sensitive ingredie~ts than the cor~esponding sodium
zeolites.
The preferred cation M~ is ~odium.
Where Ml is the hydrogen ion, the value of x' is best
determuned by difference between ~he aluminium content tx~ and
the second cation (M2) content.
The zeolite may be of any crystal form suitable for
detergents use. As indicated previously, zeolite A is the
most popular detergent zeolite. The art also discloses the
possible use of zeolites X, Y and P(B) although in practice
those have not found favour be~ause their calcium ion exchange
is either inadequate or too slow.
Zeolite A has ~he advantage of being a "maximum
aluminium~ struc~ure containing the maxim~m possible
25 proportion of alumlnium to silicon (or the minimllm possible
Si:Al ratio of 1.0) so that its capacity for taking up calcium
ions from aqueous solution is intrinsically greater than those
of zeolite X, Y and P which generally contain a lower
proportion o~ aluminium (ox have a higher Si :Al ratio) .
Accordingly, in one preferred embodiment of the invention
~he partially or wholly ion-exchanged zeolite is zeolite A.
Alternatively, and most preferably, the partially or
wholly ion-exchanged zeolite may be zeolite M~P as described
and claimed in EP 384 070B (Unilever) as discu~~ed above.
.,L ~
WO94/~1 2 1 ~ ~ 8 5 2 PCT~4/0111
_ 7
'.=,...
This is maximum aluminium zeolite P, that is to say, zeolite P
having a Si:Al ratio not greated than 1.33, preferably not
greater than 1.15 and more preferably not greater than 1.07.
Zeolite MAP has various advantages over zeolite A, one of
which is that, even in sodium form, it improves the stability
of sodium percarbonate and various other bleach ingredients
stability as discussed previously.
Ion-exchanged zeolites are described in the literature,
for example, by D W Breck and E M Flanagan, "Molecular
Sieves", Soc Chem Ind (London), 1968, pages 47-61;
US 4 346 067 (Exxon Corporation) describes ammonium-exchanged
zeolites, and EP 223 396A (Mobil Oil Corporation) describes
hydrogen-exchanged zeolites, both useful as catalysts in
hydrocarbon conversion reactions.
However, zeolite MAP in ion-exchanged form is believed to
be a novel material and is claimed as part of the present
invention.
Extent of exchanqe
It appears that the zeolites should desirably be in the
ion-exchanged form to an extent of at least 5%, preferably at
least 10% and more preferably at least 20 wt%, in order for
the benefit of improved moisture-sensitive ingredient
stability to be fully realised. Greater extents of ion-
exchange do not appear to give further improvements, but
neither does the benefit fall again.
Accordingly, the zeolites used in accordance with the
present invention should preferably be in ion-exchanged form
to an extent of at least 5%, more preferably at least 10% and
most preferably at least 20%.
WO 94124251 8 PCT~P94/0l115
2 1 5 ~ 8 ~ ~
Zeolite A has been found to give good results when in 10-
50% ion-exchanged form, more especially 20-50% ion-exchanged
form, while zeolite MAP has been found to give good results
when in 10-90% ion-exchanged form, more especially 20-90% ion-
exchanged form.
The lower limits quoted here are specifically applicable
to ammonium-exchanged zeolites. The corresponding limit for
other cations may not necessarily be identical but could
readily be determined by one skilled in the art by the methods
described in the Examples herein.
Pre~aration of the ion-exchan~ed zeolite
The ion-exchanged zeolite may conveniently be prepared by
immersing the corresponding sodium zeolite in an aqueous
solution of a salt of the desired cation, for example, an
ammonium or lithium salt.
Hydrogen-exchanged zeolites may be prepared similarly, by
immersion in a aqueous solution of a strong acid, for example,
hydrochloric acid.
The percentage extent of exchange can be controlled by
varying the concentration of the salt or acid, and the amount
of zeolite added, as described in more detail by D W Breck et
al in JACS 78 5963 et seq (1956).
Com~ositions of the invention
The detergent, bleaching or cleaning compositions of the
invention containing a builder system based on crystalline
aluminosilicate (zeolite), and also contain at least one
moisture-sensitive ingredient. While the invention is
W094/~251 215 ~ ~ J 2 PCT~4/01115
,", 9
believed to be applicable to any moisture-sensitive
ingredient, initial work has been concentrated on moisture-
sensitive bleach ingredients.
Moisture-sensitive bleach in~redients
Examples of moisture-sensitive bleach ingredients include
peroxy bleach compounds, for example, inorganic or organic
persalts and peroxyacids, bleach activators (bleach
precursors), and bleach catalysts.
Inorqanic persalts
Inorganic persalts include the alkali metal perborates,
percarbonates, perphosphates, persilicates and persulphates.
Inorganic persalts susceptible to moisture, to which the
present invention is especially applicable, include sodium
perborate monohydrate, and, more especially, sodium
percarbonate.
Inorganic persalts may advantageously be used in
conjunction with a bleach precursor or bleach activator.
Bleach precursors may themselves be susceptible to moisture
and their stability therefore improved by means of the present
invention.
A bleach stabiliser (heavy metal sequestrant) may also be
present. Suitable bleach stabilisers include ethylenediamine
tetraacetate (EDTA) and the polyphosphonates such as Dequest
(Trade Mark), EDTMP.
- 35
W094/24~1 PCT~4/01115
2155852 1 o
Bleach ~recursors
Preferred bleach precursors are peroxycarboxylic acid
precursors, more especially peracetic acid precursors and
peroxybenzoic acid precursors; and peroxycarbonic acid
precursors.
Examples of peroxyacid bleach precursors suitable for use
in the present invention include:~0
N,N,N~,N'-tetracetyl ethylenediamine (TAED);
2-(N,N,N-trimethylammonium) ethyl sodium-4-
sulphophenyl carbonate chloride (SPCC), also known as
cholyl-p-sulphophenyl carbonate (CSPC);
sodium nonanoyloxybenzene sulphonate (SNOBS);
sodium 4-benzoyloxybenzene sulphonate (SBOBS);~0
sodium 3,5,5-trimethylhexanoyloxybenzene sulphonate
(STHOBS);
and glucose pentaacetate (GPA).
Peroxvacids
Peroxyacids to which the invention is applicable
may be organic or inorganic.
Organic peroxyacids normally have the general formula:
HOOC - C - R - Y
WO94~4251 1 ~ 21~ 2 PCT~410111
wherein R is an alkylene or substituted alkylene group
containing from 1 to 20 carbon atoms, optionally having an
internal amide linkage; or a phenylene or substituted
phenylene group; and Y is hydrogen, halogen, alkyl, aryl, an
imido-aromatic or non-aromatic group, a carboxylic acid or
percarboxylic acid group, or a quaternary ammonium group.
Typical monoperoxy acids useful in the compositions of
the invention include, for example:
(i) peroxybenzoic acid and ring-substituted
peroxybenzoic acids, eg peroxy-alpha-naphthoic acid;
(ii) aliphatic, substituted aliphatic and arylalkyl
monoperoxyacids, eg peroxylauric acid, peroxystearic
acid and N,N'-phthaloylaminoperoxy caproic acid
(PAP);
(iii) 6-octylamino-6-oxoperoxyhexanoic acid.
Typical diperoxyacids useful in the compositions of the
invention include, for example:
(iv) 1,12-diperoxydodecanedioic acid (DPDA);
(v) 1,9-diperoxyazelaic acid;
(vi) diperoxybrassilic acid, diperoxysebacic acid and
diperoxyisophthalic acid;
(vii) 2-decyldiperoxybutane-1,4-dioic acid; and
(viii) 4,4'-sulphonylbisperoxybenzoic acid.
WO941~1: PCT~4/01115
215 ~ 1 2
(ix)N,N'-terephthaloyl-di(6-aminoperoxycaproic
acid), also known as N,N'-di(5-percarboxypentyl)
terephthalamide (TPCAP).
Bleach catalvsts
A class of bleach catalysts to which the present invention is
applicable is described and claimed in EP 458 397A and
EP 458 398A (Unilever).
The bleach catalyst is defined as comprising a source of
Mn and/or Fe ions and a ligand which is a macrocyclic organic
compound of formula I:~5
r [NR-'-(CR'(R2)U)t]s ~ (I)
wherein t is an integer from 2 to 3; s is an integer from 3
to 4, u is zero or one; and R1, R2 and R3 are each
independently selected from H, alkyl and aryl, both optionally
substituted.
Examples of preferred ligands are:
l,4,7-triazacyclononane (TACN);
l,4,7-trimethyl-l,4,7-triazacyclononane (l,4,7-Me3TACN);
2-methyl-l,4,7-triazacyclononane (2-MeTACN);
l,2,4,7-tetramethyl-l,4,7-triazacyclononane
(l,2,4,7-Me4TACN);
l,2,2,4,7-pentamethyl-l,4,7-triazacyclononane (l,2,2,4,7-
MesTACN);
l,4,7-trimethyl-2-benzyl-l,4,7-triazacyclononane; and
l,4,7-trimethyl-2-decyl-l,4,7-triazacyclononane.
Especially preferred is l,4,7-trimethyl-l,4,7-
triazacyclononane (l,4,7-Me-TACN).
WO94/~251 ~15 5 8 3 2 PCT~4/01i15
1 3
The aforementioned ligands may be synthesised by the
methods des~ribed in K. Wieghardt et al., Inorganic Chemistry
1982, 21, page 3086.
The source of iron and/or manganese ions and ligand may
be added separately or in the form of a mono-, di- or
tetranuclear manganese or iron complex. When added
separately, the ligand may be in the form of an acid salt such
as l,4,7-Me3TACN hydrochloride. The source of iron and
manganese ions may be a water soluble salt such as iron or
manganese nitrate, chloride, sulphate or acetate or a
coordination complex such as manganese acetylacetonate. The
source or iron and/or manganese ions should be such that the
ions are not too tightly bound, ie all those sources from
' which the ligand of formula (I), as hereinbefore defined, may
extract the Fe and Mn in a wash liquor.
Preferred mononuclear complexes have the formula
(a) [LMn1V(OR)~]Y
wherein Mn is manganese in the +4 oxidation state;
R is a C,-C,0 radical selected from the group alkyl,
cycloalkyl, aryl, benzyl and radical combinations
thereof;
at least two R radicals may also be connected to one
another so as to form a bridging unit between two
oxygens that coordinate with the manganese;
L is a ligand of formula (I) as hereinbefore defined;
and Y is an oxidatively-stable counterion;
or the formula
- 35
WO94/~251 PCT~4/01115
1 4 '~
2155852
(b) [~LMnXp]ZYq
wherein Mn can be either in the II, III or IV
oxidation state;
each X independently represents a coordinating species
with the exception of RO-, such as Cl-, Br~, I-, F-, NCS-
N3-, I3-, NH3, RCOO-, RSO3-, RS04- in which R is alkyl or
aryl, both optionally substituted, OH-, o22-, HOO-, H20,
SH, CN-, OCN-, S42- and mixtures thereof;
p is an integer from 1-3;
z denotes the charge of the complex and is an integer
which can be positive, zero or negative;
Y is a counterion the type of which is dependent upon the
charge z of the complex;
q = z/[charge Y];
and L is a ligand as hereinbefore defined.
Such mononuclear complexes are further described in our
copending European Patent Application EP 549 272A, filed on 18
September 1992 and published on 30 June 1993.
Preferred dinuclear complexes have the formula
~ X = z
L Mn ~ X ~ MnL Yq
wherein Mn is manganese which can independently be in the
III or IV oxidation state;
C3515PCl
'~ - 15 - 21558a2
.~,
X is independently a coordinating or bridging species
selected from the group consisting of H2O, o22-, OH-, HO2-,
SH-, S2-, >SO, Cl-, SCN-, N3-, RSO3-, RCOO-, NH2- and NR3,
with R being H, alkyl, aryl, both optionally substituted,
and RiCOO, where Rl is an alkyl or aryl radical, both
optionally substituted;
L is a ligand of formula (I) as hereinbefore defined;
z denotes the charge of the complex and is an integer
which can be positive or negative, or is zero;
Y is a monovalent or multivalent counterion, leading to
charge neutrality, which is dependent upon the charge z
ofthe complex; and
q = z / [charge Y].
Such dinuclear complexes of this type are further
described in EP 458 397A and EP 458 398A (Unilever).
The bleach catalyst is advantageously in the form of
granules as described and claimed in our International Patent
Application No. PCT/GB94/01904 filed on 2 September 1994.
These granules comprise:
(i) from 0.5 to 20 wt%, preferably from 1 to 15 wt%, of
the catalyst itself,
(ii) from 5 to 90 wt% of a soluble core material,
preferably selected from sodium bicarbonate, magnesium
and potassium nitrates, and magnesium sulphate,
(iii) from 5 to 91 wt% of a binding agent selected from
silicone oils, fatty acids, fatty esters, tri-, di- and
monoglycerides, waxes and solid hydrocarbons.
A4E~'DSHE~
2155~S~
WO941~251 PCT~4/01ll5
1 6
.,~
An especially preferred binding agent is cetostearyl
stearate.
Preferably, these granules will also comprise an inert
solid. Preferred inert materials include silicas such as
Gasil, Aerosil and Sorbosil (Trade Marks); clays such as
kaolin; alumina; and titanium dioxide.
Other preferred granules are described and claimed in our
British Patent Application No. 93 18295.4 filed on 3 September
1993.
Alternatively, the bleach catalyst may be in the form of
granules as described and claimed in our copending application
EP 544 440A filed on 18 November 1992 and published on 2 June
1993. These granules comprise:
(i) from 0.5 to 8 wt% of the catalyst itself,
(ii) optionally from 0 to 90 wt~ of a inert salt selected
from chlorides, carbonates and mixtures thereof, and
(iii) from 5 to 91 wt% of a binding agent selected from
water-soluble non-oxidisable polymers, alkali metal
silicates, saturated fatty acid soap mixtures, and
combinations of these.
A preferred binding agent is sodium silicate, and a
preferred inert salt is sodium carbonate.
Preferred granules include catalyst/sodium
stearate/lauric acid granules, and catalyst/sodium
carbonate/sodium silicate/zeolite granules.
Preferably, the manganese catalyst within the granules is
of an a~erage particle size as small as possible, preferably
below 250 micrometres for proper distribution and to ensure
WO 94/~2S1 1 7 215 S ~ 5 2 PCT~4/Ollls
,_
_
fast delivery to the wash, although particles which are too
small may cause handling problems during the granulation
process. A preferred and optimum manganese catalyst particle
size is within a range of from 50 to 150 micrometres.
.
Bleachina com~ositions
The composition of the invention may, for example, be a
detergent additive wholly or predominantly constituted by
aluminosilicate builder and one or more moisture-sensitive
bleach ingredients.
An additive of this type may be used in conjunction with
a conventional product under conditions where high water-
hardness and/or a heavily soiled load re~uire extra building
and/or extra bleaching capacity.
Such an additive may also form part of a Baukasten
(building block) system, for example, as described in
EP 419 036A (Unilever), where it may be used together with an
underbuilt and/or non-bleaching main wash powder.
Deter~ent com~ositions
The composition of the invention may alternatively be a
particulate detergent composition, which may suitably contain
the following ingredients:
(a) one of more organic detergent surfactants,
(b) a builder system comprising a crystalline
aluminosilicate as defined above,
WO94/24251 1 8 PCT~P94/01115
215585 '7
(c) one or more ingredients sensitive to moisture,
(d) optionally other detergent ingredients.
Detergent compositions of the invention containing
moisture-sensitive bleach ingredients may suitably contain the
following ingredients:
(a) one of more organic detergent surfactants,
(b) a builder system comprising a crystalline
aluminosilicate as defined above,
(c) a bleach system comprising one or more ingredients
sensitive to moisture,
(d) optionally other detergent ingredients.
Preferred detergent compositions according to the
invention may contain the following ingredients in the
following proportions:
(a) from 2 to 60 wt% of one or more detergent
surfactants,
(b) from 10 to 80 wt% of one or more detergency
builders, including zeolite in partially or wholly
ion-exchanged form,
(c) from 5 to 40 wt% of a bleach system comprising a
bleach ingredient sensitive to moisture, and
(d) optionally other detergent ingredients to 100 wt%.
wo g4/~25, 1 9 2 1 ~ 5 ~ ~ 2 PCT~4tO111s
The bleach ingredient sensitive to moisture may be, as
previously indicated, a persalt, a bleach precursor, a
peroxyacid or a bleach catalyst; more particularly, sodium
percarbonate, a peroxyacid, or a bleach catalyst as defined
above.
Deter~ent surfactants
The detergent compositions of the invention will contain,
as essential ingredients, one or more detergent-active
compounds (surfactants) which may be chosen from soap and non-
soap anionic, cationic, nonionic, amphoteric and zwitterionic
detergent-active compounds, and mixtures thereof. Many
suitable detergent-active compounds are available and are
fully described in the literature, for example, in "Surface-
Active Agents and Detergents", Volumes I and II, by Schwartz,
Perry and Berch.
The preferred detergent-active compounds that can be used
are soaps and synthetic non-soap anionic and nonionic
compounds.
Anionic surfactants are well-known to those skilled in
the art. Examples include alkylbenzene sulphonates,
particularly linear alkylbenzene sulphonates having an alkyl
chain length of C~-C15; primary and secondary alkyl sulphates,
particularly C,-,-Cl~ primary alkyl sulphates; alkyl ether
sulphates; olefin sulphonates; alkyl xylene sulphonates;
dialkyl sulphosuccinates; and fatty acid ester sulphonates.
Sodium salts are generally preferred.
Nonionic surfactants that may be used include the primary
and secondary alcohol ethoxylates, especially the C8-C20
primary and secondary aliphatic alcohols ethoxylated with an
average of from l to 20 moles of ethylene oxide per mole of
WO94/2~1 2 o PCT~4/01115
21~5~52
alcohol, and more especially the Cg-Clc primary aliphatic
alcohols ethoxylated with an average of from 1 to 10 moles of
ethylene oxide per mole of alcohol.
Also of interest are non-ethoxylated nonionic
surfactants, for example, alkylpolyglycosides; O-alkanoyl
glucosides as described in EP 423 968A (Unilever); and
polyhydroxyamides.
The choice of detergent-active compound (surfactant), and
the amount present, will depend on the intended use of the
detergent composition: different surfactant systems may be
chosen, as is well known to the skilled formulator, for
handwashing products and for products intended for use in
different types of washing machine.
The total amount of surfactant present will also depend
on the intended end use, but may generally range from 2 to
60 wt%, preferably from 5 to 40 wt~.
Detergent compositions suitable for use in most automatic
fabric washing machines generally contain anionic non-soap
surfactant, or nonionic surfactant, or combinations of the two
in any ratio, optionally together with soap.
The deterqencv builder sYstem
The detergent compositions of the invention also contains
one or more detergency builders. The total amount of
detergency builder in the compositions will suitably range
from 10 to 80 wt%.
The detergency builder system of the compositions of the
invention is based on zeolite, optionally in conjunction with
one or more supplementary builders.
WO94/~251 2 1 215 ~ ~ ~ 2 PCT~4/01115
...._
The amount of zeolite present may suitably range from 5
to 60 wt%, more preferably from 15 to 40 wt%, calculated on an
anhydrous basis (equivalent to from 6 to 75 wt%, preferably
from 19 to 50 wt%, calculated on a hydrated basis).
The zeolite may, if desired, be used in conjunction with
other inorganic or organic builders. Inorganic builders that
may be present include sodium carbonate, if desired in
combination with a crystallisation seed for calcium carbonate,
as disclosed in GB 1 437 950 (Unilever). Organic builders
that may be present include polycarboxylate polymers such as
polyacrylates, acrylic/maleic copolymers, and acrylic
phosphinates; monomeric polycarboxylates such as citrates,
gluconates, oxydisuccinates, glycerol mono-, di- and
trisuccinates, carboxymethyloxysuccinates,
carboxymethyloxymalonates, dipicolinates,
hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and
succinates; and sulphonated fatty acid salts. This list is
not intended to be exhaustive.
Preferred supplementary builders for use in conjunction
with zeolite include citric acid salts, more especially sodium
citrate, suitably used in amounts of from 3 to 20 wt%, more
preferably from 5 to 15 wt%. The combination of zeolite MAP
with citrate as a detergency builder system is described and
claimed in EP 448 297A (Unilever).
Also preferred are polycarboxylate polymers, more
especially acrylic/maleic copolymers, suitably used in amounts
of from 0.5 to 15 wt%, especially from 1 to 10 wt%, of the
detergent composition; the combination of zeolite MAP with
polymeric builders is described and claimed in EP 502 675A
(Unilever).
WOs4/~1 PCT~4/011l5
2155 8~ 2 2 2 _
The bleach svstem
As previously indicated, the detergent compositions of
the invention may contain a bleach system which includes at
least one moisture-sensitive ingredient. The bleach system
may generally comprise a peroxy bleach compound, for example,
an inorganic or organic persalt, optionally in conjunction
with a bleach activator (bleach precursor) to improve
bleaching action at low wash temperatures; or an inorganic or
organic peroxyacid. A bleach stabiliser (heavy metal
sequestrant) may also be present. According to a preferred
embodiment of the invention, a bleach catalyst as previously
defined may also be present.
Preferred inorganic persalts are sodium perborate
monohydrate and sodium percarbonate. As indicated above,
sodium percarbonate is especially sensitive to moisture and
benefits particularly from the present invention.
In detergent compositions according to the invention,
sodium percarbonate or other persalts may suitably be present
in an amount of from 5 to 30 wt%, preferably from 10 to
25 wt%, based on the whole composition.
Bleach precursors are suitably used in amounts of from 1
to 8 wt%, preferably from 2 to 5 wt%.
Organic or inorganic peroxyacids are normally used in an
amount within the range of from 2 to 10 wt%, preferably from 4
to 8 wt%.
The amount of the bleach catalyst described above present
in the detergent compositions of the invention is suitably
from 0.02 to 0.08 wt%.
WO g4/~2~1 2 3 2 1 5 ~ 8 a 2 pCT~4/01115
~,_
Other inaredients
Other materials that may be present in detergent
compositions of the invention include sodium silicate;
antiredeposition agents such as cellulosic polymers;
fluorescers; inorganic salts such as sodium sulphate; lather
control agents or lather boosters as appropriate; pigments;
and perfumes. This list is not intended to be exhaustive.
~re~aration of the deterqent com~ositions
The particulate detergent compositions of the invention
may be prepared by any suitable method.
One suitable method comprises spray-drying a slurry of
compatible heat-insensitive ingredients, including the
zeolite, any other builders, and at least part of the
detergent-active compounds, and then spraying on or postdosing
those ingredients unsuitable for processing via the slurry,
including sodium percarbonate and any other bleach
ingredients. The skilled detergent formulator will have no
difficulty in deciding which ingredients should be included in
the slurry and which should not.
The compositions of the invention may also be prepared by
wholly non-tower procedures, for example, dry-mixing and
granulation, or by so-called "part-part" processes involving a
combination of tower and non-tower processing steps.
The benefits of the present invention are observed in
powders of high bulk density, for example, of 700 g/l or
above. Such powders may be prepared either by post-tower
densification of spray-dried powder, or by wholly non-tower
methods such as dry mixing and granulation; in both cases a
high-speed mixer/granulator may advantageously be used.
WO 94124251 2 4 PCT~4/01115
21~5~52
Processes using high-speed mixer/granulators are disclosed,
for example, in EP 340 013A, EP 367 339A, EP 390 251A and
EP 420 317A (Unilever).
EXAMPLES
The invention is further illustrated by the following
Examples, in which parts and percentages are by weight unless
otherwise indicated. Examples identified by numbers are in
accordance with the invention, while those identified by
letters are comparative.
WO94/~251 2 5 215 5 8 5 2 PCT~W4/01115
EXAMPLES 1 to 14, COMPARATIVE EXAMPLES A and B
Pre~aration of ion-exchanaed zeolites
Exam~le 1
Pre~aration of ammonium-exchan~ed zeolite A
Sodium zeolite 4A powder (Wessalith (Trade Mark) P ex
Degussa) was converted to a partially ammonium-exchanged form
as follows.
150 g of hydrated sodium zeolite 4A were slurried with
1 litre of 0.2 molar ammonium sulphate solution (adjusted to
pH 9 with ammonium hydroxide) for 1 hour at 60~C. The slurry
was then filtered, and the filter cake re-slurried in a
further 1 litre of fresh ammonium sulphate solution. This
procedure was repeated to give a total of 3 exchange steps.
The zeolite was finally filtered and washed with demineralised
water then oven dried at 100~C. The dried zeolite was ground
in a pestle and mortar and stored under ambient conditions for
several days to fully rehydrate.
The calculated ammonium (NH4) content for full exchange
of zeolite A is 10.0 wt% NHg. The material prepared as
described above had an ammonium (NH4) content of 5.04 wt~,
corresponding to 50.4~ exchange.
WO94/2U51 PCT~4/011l5
2 ~ 2 6
Exam~le 2
Pre~aration of ammonium-exchanqed zeolite MAP
Ammonium-exchanged zeolite MAP was prepared, by the
method described in Example 1, from sodium zeolite MAP
prepared by a method similar to that described in Examples 1
to 3 of EP 384 070A (Unilever). The starting zeolite MAP had
a silicon to aluminium ratio of 1Ø
The calculated ammonium content for full exchange of
zeolite MAP i5 10 . 4 wt%. The exchanged material had an
ammonium (NH~) content of 7.95 wt%, corresponding to 76.4%
exchange.
Exam~le 3
Pre~aration of lithium-exchanaed zeolite A
Sodium zeolite 4A was converted to (partially) lithium-
exchanged form by a method similar to that used in Example 1,
using 0.2 molar lithium chloride solution instead of ammonium
sulphate solution.
Exam~le 4
Pre~aration of lithium-exchanaed zeolite MAP
Lithium zeolite MAP was prepared from the sodium zeolite
MAP used in Example 2, by the method described in Example 3.
WO g4t~251 ~ 7 2 1 5 5 8 ~ 2 PCT~4/01115
Exam~le 5
Pre~aration of hvdroaen-exchan~ed zeolite A
150 g of hydrated sodium zeolite 4A were slurried in 3
litres of demineralised water. The pH of the slurry was
monitored using a pH electrode, and the pH adjusted to a value
of 8.0 by the slow addition of 0.1 molar hydrochloric acid.
Following addition of the acid, the zeolite was filtered,
washed with demineralised water, and oven dried at 100~C.
The dried zeolite was ground in a pestle and mortar and stored
under ambient conditions for several days to rehydrate fully.
Exam~le 6
Pre~aration of hYdro~en-exchanqed zeolite MAP
Partially hydrogen-exchanged zeolite MAP was prepared
from the sodium zeolite MAP used in Example 2 by the method
described in Example 5.
Com~arative Exam~le A
Pre~aration of ~otassium-exchan~ed zeolite A
Partially potassium-exchanged zeolite A was prepared from
the sodium zeolite A used in Example 1 by the method described
in Example 3, except that the lithium chloride solution was
replaced by 0.2 molar potassium chloride solution.
WO 9412~251 PCI'/EP94/01115
215S8S2 28
Com~arati~e Exam~le B
Pre~aration of ~otassium-exchanqed zeolite MAP
Partially potassium-exchanged zeolite MAP was prepared
from the sodium zeolite MAP used in Example 2 by the method
described in Example 4, except that the lithium chloride
solution was replaced by 0.2 molar potassium chloride
solution.
wo 94l242sl 2 9 2 1 ~ ~ 8 ~ Epg4/Ollls
Exam~les 7 to 10
Pre~aration of a ranae of ~artiallY exchanaed sodium/ammonillm
zeolite 4A sam~les
150 g samples of hydrated sodium zeolite were slurried
with ammonium sulphate solutions (1 litre) having different
concentrations, at pH 9 for 1 hour at 40~C. The zeolites
were then filtered, washed with water, and dried in an oven at
100~C. The dried zeolite samples were then ground in a
pestle and mortar and allowed to hydrate fully under ambient
conditions for several days. The resulting products were
analysed to determine the actual level of ammonium exchange
achieved.
Exam~le Ammonium Ammonium Extent of
sul~hate content exchanae
concentration
(molar) (wt %) (%)
7 0.10 1.31 13
8 0.21 2.35 23
9 0.41 3.60 35
0.82 4.74 46
WO94/24251 3 o PCT~P94/01115
21S~8~2
Exam~les 11 to 13
Pre~aration of ~ ran~e of ~artiallY exchan~ed sodium/ammonium
zeolite MAP sam~les
Four samples of partially exchanged sodium/ammonium
zeolite MAP were prepared by the method described in Examples
7 to 10. Preparative and analytical details were as follows:
Exam~le Ammonium Ammonium Extent of
sul~hate content exchan~e
concentration
(molar) (wt %) (%)
11 0.11 1.13 11
12 0.21 2.47 24
13 0.42 5.89 57.5
14 0.84 8.74 85
WO94/~2~1 3 1 2 1 5 5 ~ 5 ~ PCT~4/01115
'_
EXAMPLES 15 to 30 COMPARATIVE EXAMPLES C to K
Sodium ~ercarbonate stabilitv
Fxam~les 15 to 17, Com~arative Exam~les C and D
Sodium ~ercarbonate stabilitv of zeolite A/~ercarbon~te
mixtures
Test samples were prepared by mixing 3.75 g of each of
the following zeolites with 1.25 g of sodium percarbonate (the
500-710 micrometre sieve fraction of Oxyper (Trade Mark) ex
Interox), to give mixtures consisting of 75 wt% zeolite and
25 wt% percarbonate.
Exam~le Zeolite tv~e
C Sodium zeolite A (Wessalith P)
Ammonium-exchanged zeolite A (Example 1)
16 Lithium-exchanged zeolite A (Example 3)
25 17 Hydrogen-exchanged zeolite A (Example 5)
D Potassium-exchanged zeolite A (Comparative
Example A)
Storage stability was assessed by means of the following
accelerated storage test under extremely severe conditions
which is designed to show up differences in a shorter period
of time than would be possible in a test using more realistic
conditions and normal product packaging.
wo 94/24251 3 2 PCTlEPg4lolllS
i 8 5 2
The samples were stored in open-topped glass bottles at
37~C and 70% relative humidity. Bottles were removed from
storage at regular intervals and the powder mixtures analysed
for remaining available oxygen (AvO). The results were as
follows:
~xam~le AvO after time (days)
Q 3 6 lQ 14
C 100 62.7 47.7 33.4 16.6
15 1 100 92.3 86.4 78.0 68.6
16 100 85.0 75.7 60.9 55.7
17 100 85.0 67.0 50.0 36.6
D 100 54.0 34.5 19.5 12.3
It will be noted that the ammonium-exchanged, lithium-
exchanged and hydrogen-exchanged zeolites all greatly improved
the storage stability of the sodium percarbonate, the
ammonium-exchanged material giving the largest benefit; while
the potassium-exchanged material gave rather worse results
than the all-sodium zeolite.
WO94/~251 3 3 21 5 ~ PCT~W4/01115
.... ..
_
Exam~les 18 to 20 Com~arative ~xam~les E and F
Sodium ~ercarbonate stabilitv of zeolite MAP/~ercarbonate
mixtures
Test samples were prepared as described in Examples 15 to
17, each containing 3.75 g (75 wt%) of zeolite and 1.25 g
(25 wt~) of sodium percarbonate:
Exam~le Zeolite tv~e
E Sodium zeolite MAP (starting material for
Examples 2 and 4)
18 Ammonium-exchanged zeolite MAP (Example 2)
19 Lithium-exchanged zeolite MAP (Example 4)
20 20 Hydrogen-exchanged zeolite MAP (Example 6)
F Potassium-exchanged zeolite MAP
(Comparative Example B).
Storage stability at 37'C and 70% relative humidity in
open-topped glass bottles was measured as described in
Examples 15 to 17. The results were as follows:
WO 94/24251 PCr/EP94/01115
2155P~2 34
Exam~le AvO after time (days)
Q 3 6 10 14
E 100 73.7 59.1 37.7 27.3
18 100 94.3 91.4 90.2 90.9
19 100 92.1 90.9 83.0 73.6
100 93.4 84.0 73.3 62.1
F 100 61.5 40.9 24.5 14.1
Comparison of these results with those of Examples 15 to
17 shows how the stability improvement achieved by replacement
of zeolite A by zeolite MAP can be taken further by means of
the present invention.
It will be noted that use of ammonium zeolite MAP
(Example 18) resulted in virtually no percarbonate loss even
after 14 days' open storage in very unfavourable conditions.
As with zeolite A, the potassium-exchanged material gave
worse results than the sodium zeolite.
WO 94/24251 3 5 2 ~ 5 ~ PCT/EP94/0111~
,~,.,
Exam~les 21 to 24 Com~arative Exam~le G
Sodium ~ercarbonate stability in mixtures with differentlY
exchanaed sodium/ammonium zeolite A sam~les
The procedure of Examples 15 to 17 was repeated using the
partially exchanged sodium/ammonium zeolites of Examples 7 to
10. The storage stability results were as follows,
Comparative Example G being the starting all-sodium zeolite A.
Exam~le AvO after time (days)
3 5 10 17
G 68.2 54.6 29.8 12.7
21 (7) 94.6 89.8 73.9 56.g
22 (8) 94.1 90.5 83.0 69.8
23 (9) 90.9 90.5 82.5 66.4
24 (10) 97.3 93.6 87.0 74.5
It will be seen that a very significant benefit is
achieved even at only 11% exchange (Example 21).
WO94~1 PCT~4/01115
Z155g5~ 36
Exam~les 25 to 28 Com~arative Exam~le H
Sodium ~ercarbonate stabilitv in mixtures with differentlv
exchan~ed sodium/ammonium zeolite MAP sam~les
The procedure of Examples 21 to 24 was repeated using the
partially exchanged sodium/ammonium zeolite MAP of Examples 11
to 14. The storage stability results were as follows,
Comparative Example H being the starting all-sodium zeolite
10 MAP.
Exam~le AvO after time (days)
~ 5 10 17
H 74.6 61.4 38.4 26.8
25 (11) 95.5 91.6 81.8 77.7
26 (12) 93.2 91.6 88.6 80.9
27 (13) 96.8 90.2 82.3 73.6
28 (14) 95.2 90.0 80.5 72.7
The pattern is similar to that observed with the
partially exchanged zeolite A, with the maximum benefit
apparently being achieved when the extent of ammonium exchange
is 23% or more (Examples 26, 27 and 28).
WO94/~251 3 7 21~5~ ~ ~ PCT~4/01115
_
Exam~les 29 and 30 Com~arative Exam~les J and K
Sodium ~ercarbonate stabilitY in deterqent aranules
Detergent granules were prepared by granulating zeolite
with nonionic surfactant in a laboratory-scale granulator,
using in each case just sufficient nonionic surfactant to
achieve granulation. The nonionic surfactant used was
Synperonic (Trade Mark) A7 ex ICI, a C12-Cls primary alcohol
ethoxylated with an average of 7 moles of ethylene oxide per
mole of alcohol.
The zeolites used were the ammonium-exchanged zeolites of
Examples 1 and 2, and the corresponding sodium zeolites (the
starting materials used in Examples 1 and 2). The
compositions of the granules were as follows:
Exam~le Zeolite Nonionic surfactant
Tv~e (a/200c zeolite)
J Na A 61.5
29 NH4 A (Ex 1) 64.8
25 K Na MAP 75.3
NHt MAP (Ex 2) 82.0
The granules were sieved, and the 250-700 micrometre
fraction was used in the test described below to determine
percarbonate storage stability.
wog4n4~ 3 8 PCT~4/01115
2'155~52 '~
Each test sample was prepared by mixing detergent
granules (8.75 g) with sodium percarbonate (1.25 g).
The percentage compositions of the test samples were therefore
as follows:
~xam~le Com~osition (wt%)
Zeolite Nonionic Percarbonate
J 66.9 20.6 12.5
29 66.1 21.4 12.5
~; 63.6 23.9 12.5
62.1 25.4 12.5
As in previous Examples, the samples were stored in open-
topped glass bottles at 37{C and 70% relative humidity. The
results were as follows:
Exam~le AvO after time (days)
Q 6 9 14
J 100 30.2 20.5 4.1
29 100 83.9 77.7 51.6
K 100 50.0 42.0 10.5
100 90.0 90.9 79.5
WOg4/~251 215 5 8 5 2 PCT~4/01115
~._
Exam~les 31 to 35, Com~arative Examples L to O
Bleach catalvst stabilitY
Exam~le 31, Com~arative Exam~le L
Detergent base powders were prepared by mixing zeolite A,
in sodium or ion-exchanged form, with a liquid surfactant
blend - coconut alcohol sulphate (cocoPAS), coconut alcohol
3EO nonionic surfactant, coconut alcohol 7EO nonionic
surfactant and water - in a laboratory-scale granulator.
The zeolites were as used in previous Examples: the ammonium
zeolite A was that of Example 1, and the sodium zeolite the
raw material of Example 1. The differences in formulation
reflect the different carrying capacities of the two zeolites.
The base powders were mixed with manganese catalyst
granules to give powders having the following formulations:
Exam~le L Exam~le 31
Zeolite A (Na)* 65.5
Zeolite A (NH~)* (Ex 1) - 68.6
CocoPAS 7.5 6.7
Coco 7EO 7.5 6.7
Coco 3EO 9.6 8.5
Soap 2.9 2.6
Water 2.0 1.8
Total base powder 95.0 95.0
Catalyst granules 5.0 5.0
_____ _____
100 . O 100 . O
* hydrated basis
WO94/~U51 4 0 PCT~4/01115
2 L55 ~ a 2
The catalyst granules had the following formulation:
Catalyst (Mn 1,4,7-Me3TACN) 1.8
Zeolite MAP 46.6
5 Soap/fatty acid* 20.5
Citric acid 22.2
Titanium dioxide 8.9
100 . O
*30% neutralised mixture of Cl~-C,~ saturated fatty acids
(about 60% Cl, 17% Cl~, 20% Cl~, 3% Cl5+ C19).
Samples of each powder were stored in open-topped glass
jars at 37-C and 70% relative humidity. After a period of 28
days, the samples were removed from storage, and pairs of
samples of Powders 31 and L were compared visually by a panel
of eight assessors, to assess relative discoloration. The
results were as follows:
Panellists showing a preference for Powder 31 8
Panellists showing a preference for Powder L 0
The powder of Example 31 showed slight discoloration,
while the powder of Comparative Example L was quite badly
discoloured. On an arbitrary scale of 0 to 10, panellists
allocated the following discoloration scores:
Powder 31 3
Powder L 6
W094/~251 4 1 2 1 ~ S ~ 5 ~ PCT~4/01115
Exam~le 32, Com~arative Exam~le M
Detergent base powders were prepared by mixing zeolite
MAP, in sodium or ion-exchanged form, with the liquid
surfactant blend used in Examples 31 and L, in a laboratory-
scale granulator. The ammonium-exchanged zeolite MAP was
that of Example 2, and the sodium zeolite MAP the raw material
of Example 2. Again, the differences between the
formulations reflect the different carrying capacities of the
two zeolites.
The base powders were mixed with manganese catalyst
granules to give powders having the following formulations:
Exam~le M Exam~le 32
Zeolite MAP (Na)* 58.9
Zeolite MAP (NH~)* (Ex 2) - 63.6
20 CocoPAS 9.2 8.0
Coco 7EO 9.2 8.0
Coco 3EO 11.7 10.1
Soap 3.5 3.1
~~?ater 2.5 2.2
Total base powder 95.0 95.0
Catalyst granules 5.0 5.0
100.0 100.0
* hydrated basis
Storage tests and assessment of discoloration were
carried out as described in Examples 31 and L. The results
were as follows:
WO94/2L~1 4 2 PCT~4/01115
21~5~52
Panellists showing a preference for Powder 32 6
Panellists showing a preference for Powder M 2
The powder of Comparative Example M (containing sodium
zeolite MAP) was significantly less discoloured that the
powder of Comparative Example L (containing sodium zeolite A),
the discoloration score being 2.
Exam~le 33, Com~arative Exam~le N
The procedure of Examples 31 and L was repeated using
different catalyst granules, having the following composition:
Catalyst (Mn 1,4,7-Me TACN) 2.0
Cetocetylstearate 31.0
Silica* 26.4
Sodium bicarbonate 39.6
20 Titanium dioxide 1.0
100. 0
*Gasil (Trade Mark) 200TP ex Crosfield.
Example 33 contained 95 wt% of the base powder of Example
31 (ammonium-exchanged zeolite A), and Comparative Example N
contained 95 wt% of the base powder of Comparative Example A
(sodium zeolite A). Each powder also contained 5 wt% of the
catalyst granules. Storage tests were carried out as in
earlier Examples, and the panel assessment results were as
follows:
Panellists showing a preference for Powder 33 8
35 Panellists showing a preference for Powder N 0
wo g4n42sl 4 3 2 1 5 5 8 5 ~ ~/EP94/01115
The discoloration scores were as follows:
Powder 3_ o
Powder N 8
Exam~le 34 Com~arative Exam~le P
The procedure of Examples 33 and N was repeated using
ammonium-exchanged zeolite MAP (Example 34) and sodium zeolite
MAP (Example P).
Example 34 contained 95 wt% of the base powder of Example
32 (ammonium-exchanged zeolite MAP), and Comparative Example P
contained 95 wt% of the base powder of Comparative Example M
(sodium zeolite MAP). Each powder also contained 5 wt% of
the catalyst granules. Storage tests were carried out as in
earlier Examples, and the panel assessment results were as
follows:
Panellists showing a preference for Powder 34 7
Panellists showing a preference for Powder P
The discoloration scores were as follows:
Powder 34 0
Powder P 3
W094n4~1 4 4 PCT~4/01115
2,15~2 .. _
Exam~le 35. Com~arative Exam~le O
This Example describes an accelerated storage test to
show the effect of zeolite type on the decomposition of the
manganese catalyst Mn 1,4,7-Me3TACN. In this test, the
catalyst, not in granular form, was in direct contact with
zeolitic base powder.
Crystalline catalyst (0.26 g) was granulated with 7EO
nonionic surfactant (3 g) and zeolite (10 g) to give the
following compositions:
Example Q 35
Catalyst 1.96 1.96
Zeolite A (Na)* 75.42
Zeolite A (NH4,)* (Ex 1) - 75.42
Nonionic 7EO** 22.62 22.62
-_____ ______
100.00 100.00
*hydrated basis
**C,2lsoxo alcohol, 7EO: Synperonic (Trade Mark) A7 ex ICI.
The granules were stored at 37'C and 70% relative
humidity and their colour assessed visually at regular time
intervals.
The granules of Comparative Example Q showed significant
levels of brown discoloration after 24 hours' storage. The
granules of Example 35, however, showed no discoloration even
after 7 daysl storage.
* * *
