Note: Descriptions are shown in the official language in which they were submitted.
r WO 95/02676 O PCT/US94/07823
1
BTAHILISED HLEAC8INf3 COMP08ITIONB
This invention relates to bleaching compositions
comprising alkali metal percarbonate as an oxygen-releasing
compound and alkali metal carbonate or bicarbonate
particles. These bleaching compositions are useful as
components of laundry detergent compositions, machine
dishwashing compositions and bleach booster compositions,
in particular laundry detergent compositions.
Bleaching compositions containing alkali metal
percarbonate are known in the art. Percarbonate is an
attractive perhydrate bleaching agent for use in bleaching
compositions because it dissolves readily in water and is
weight efficient. In laundry detergent compositions it is
particularly useful because after giving up its available
oxygen it provides a useful source of carbonate ions for
detergency purposes and does not provide undesirable by-
products.
The inclusion of percarbonate salts in bleaching
compositions has been restricted hitherto by the relative
instability of the bleach. In particular, percarbonate
salts decompose rapidly when stored in a moist and/or warm
atmosphere.
Bleaching compositions containing percarbonate as a
bleaching component usually also contain carbonate such as
sodium carbonate. This acts to neutralise acidity released
when the composition is added to water. Such acidity
inhibits the performance of the percarbonate and may
inhibit the performance of other components of the
bleaching composition, for instance enzymes in the case of
laundry detergent compositions. In the case of granular
zeolite-built detergent compositions the carbonate acts
also to facilitate processing of the zeolite-containing
composition into granules.
However, the presence of carbonate particles can
contribute to reduced storage stability of the
percarbonate. During storage, in particular storage under
CA 02167160 2000-09-20
2
cool conditions, carbonate particles can absorb moisture, which
is released during storage in warm conditions, for instance at
above 30°C. In the resulting warm, moist atmosphere the
storage stability of the percarbonate is reduced.
It has been attempted to solve this problem by coating the
carbonate particles. However this is a complex and expensive
process and may reduce the ability of the carbonate to absorb
moisture; this moisture-absorption ability is an advantageous
one, therefore to reduce it is not preferred.
According to the invention there is provided a particulate
composition comprising:
(a) an alkali metal percarbonate salt selected from
either sodium percarbonate or potassium
percarbonate; and
(b) particles of alkali metal carbonate or bicarbonate,
said particles having a mean particle size of 250~un
or greater.
It has been found that the use of particles of carbonate
with the defined size results in greater storage stability of
the particulate compositions of the invention whilst retaining
the fast release of alkalinity in cold water necessary for
good product performance.
The alkali metal carbonate or bicarbonate is preferably
selected from sodium carbonate, potassium carbonate, sodium
bicarbonate and potassium bicarbonate mixtures thereof.
Particularly preferred mixtures include mixtures of sodium
carbonate with sodium bicarbonate, sodium carbonate with
potassium carbonate and sodium carbonate with sodium
bicarbonate and potassium carbonate.
The particles of carbonate and bicarbonate have a mean
particle size of 250um or greater, preferably 300um or
greater, more preferably 400 to 800um. It is preferred that
fewer than 200 of the particles have a particle size below
250Nm and that fewer than 5o have a particle size below
150um; more preferably fewer than loo have a particle size
below 250um. It is also preferred that fewer than 200
WO 95/02676 PCT/US94/07823
2167160
3
of the carbonate or bicarbonate particles have a particle
size greater than 1,OOO;Cm.
The mean particle size of the particles of carbonate
and bicarbonate herein is determined by reference to a
method involving choice of varied sizes of sieve through
which the sample is attempted to be passed. The mean
particle size of a sample is given by the diameter of sieve
through which half of the mass of the sample will pass, and
accordingly through which half of the sample will not pass.
It will be appreciated by a person skilled in the art that
a suitably large size of sample should be employed in any
determination to give a statistically meaningful result.
It will also be appreciated that for any large bulk sample,
a number of representative smaller samples made at sampling
points throughout the extent of the bulk sample should be
made, as are sufficient to give a statistically meaningful
result. Another (equivalent) way of expressing the mean
particle size herein is that it is the particle size at
which a line drawn vertically such as to bisect the area
under the differential particle size distribution curve
would result in an equal dissection of that area into two
equal parts.
The alkali metal percarbonate used may preferably be
sodium percarbonate or potassium percarbonate, more
preferably sodium percarbonate. The percarbonate is
generally in particulate form. The percarbonate particles
generally have a mean particle diameter of 150-1200~m,
preferably 300-900~m. The particles of percarbonate may be
coated or uncoated. If the percarbonate particles are
coated this is preferably with a water-soluble coating.
Suitable coating materials include the alkali and alkaline
earth metal carbonates; the alkali or alkaline earth metal
sulphates; the mixed salts of alkali or alkaline earth
metal sulphates and carbonates; the mixed salts of alkali
or alkaline earth metal chlorides and carbonates; the mixed
salts of alkali or alkaline earth metal nitrates and
carbonates.
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It is preferable that both the carbonate or
bicarbonate and the percarbonate particles are introduced
into the composition by dry mixing, since this facilitates
achieving rapid dissolution of both when the composition is
added to water.
The particulate composition of the invention may take
various forms. It may be a machine dishwashing composition
of otherwise conventional composition and so may also
comprise alkaline material selected from sodium silicate
and sodium hydroxide. The carbonate or bicarbonate is
preferably present in an amount of 5 to 50% by weight of
total composition. It may be a bleach booster composition
of otherwise conventional composition for addition to a
laundry wash.
Preferably it is a laundry detergent composition.
This is preferably phosphate-free and is preferably zeolite
built. It may also comprise surfactant typically in an
amount of 3 to 35% by weight of total composition, said
surfactant being selected from anionic, cationic, non-
ionic, ampholytic and zwitterionic surfactants and mixtures
thereof .
When the composition of the invention is a laundry
detergent composition it may preferably contain carbonate
or bicarbonate in an amount of 5 to 25%, more preferably 5
to 20%, by weight of total composition; percarbonate is
preferably present in an amount of up to 40% by weight of
total composition.
Where the bleaching processes utilizing the bleaching
compositions of the invention are carried out at least in
part at temperatures lower than about 60°C the bleaching
compositions of the invention will also preferably contain
additional bleaching agents more suited to low temperature
bleaching. These will include, for example peroxyacid
bleach precursors (bleach activators) and preformed organic
peracids.
The peroxyacid bleach precursors probably contain one
or more N- or O- acyl groups, which precursors can be
WO 95/02676 216 l j ~ O PCT~S94/07823
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 GH-A-1586789. The
5 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,N',N' tetra acetylated compounds of formula
O O
r a
CH3-C \ iC-CH3
N- ( CH2 ) x-N /~~
CH3-~ n-CH3
O O
wherein x can be O or an integer between 1 & 6.
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 GH-A-907356.
The most preferred peroxyacid bleach precursor is TAED.
Another preferred class of peroxyacid bleach activator
compounds are the amide substituted compounds of the
following general formulae:
R' - C - N-R2 - C - L or R' - N - C-R2 - C - L
~O R5 ,0 R5 0
wherein R' is an aryl or alkaryl group with from about 1 to
about 14 carbon atoms, R2 is an alkylene, arylene, and
alkarylene group containing from about 1 to 14 carbon
atoms, and R5 is H or an alkyl, aryl, or alkaryl group
containing 1 to 10 carbon atoms and L can be essentially
any leaving group. R' preferably contains from about 6 to
12 carbon atoms. R2 preferably contains from about 4 to
8 carbon atoms. R' may be straight chain or branched
alkyl, substituted aryl or alkylaryl containing branching,
substitution, or both and may be sourced from either
WO 95/02676
216 716 0 PCT~S94/07823
6
synthetic sources or natural sources including for example,
tallow fat. Analogous structural variations are
permissible for RZ. The substitution can include alkyl,
aryl, halogen, nitrogen, sulphur and other typical
substituent groups or organic compounds. RS is preferably
H or methyl. R' and RS should not contain more than 18
carbon atoms total. Amide substituted bleach activator
compounds of this type are described in EP-A-0170386.
Other peroxyacid bleach precursor compounds include
sodium nonanoyloxy benzene sulfonate, sodium trimethyl
hexanoyloxy benzene sulfonate, sodium acetoxy benzene
sulfonate and sodium benzoyloxy benzene sulfonate as
disclosed in, for example, EP-A-0341947.
The compositions of the invention may contain as the
peroxy compound organic peroxyacids of which a particularly
preferred class are the amide substituted peroxyacids of
general formulae:
R' - C - N-RZ - C - OOH or R~ - N - C-R2 - C - OOH
2 0 O ~5 ~ RS
where R', R2 and R5 are as defined previously for the
corresponding amide substituted peroxyacid bleach activator
compounds.
Other organic peroxyacids include the diacyl peroxides
and dialkyl peroxides. Suitable are diperoxy dodecanedioic
acid, diperoxy tetra decanedioic acid,
diperoxyhexadecanedioc acid, mono- and diperazelaic acid,
mono- and diperbrassylic acid, monoperoxy phthalic acid,
perbenzoic acid, and their salts as disclosed in, for
example, EP-A-0341 947.
The bleaching compositions of the invention are useful
in the bleaching of cellulosic~fibrous material. The term
cellulosic fibrous material as used herein has reference to
wood, cotton, linen, jute and other materials of a
cellulosic nature, and also includes individual fibres, for
example wood pulp or cotton fibre, as well as yarns, tows,
WO 95/02676 216 716 0 pCT/US94/07823
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webs, fabrics (woven or non-woven) and other aggregates of
such fibres. The bleaching compositions of the invention
are also useful in the belaching of synthetic textiles
including polyamides, viscose, rayon, and polyesters.
The bleaching compositions of the invention are also
useful in cleaning compositions. These cleaning
compositions may be used in essentially any washing,
laundering or cleaning processes in which bleaching is
required. Thus, the cleaning compositions may be used in
home or industrial laundering or automatic dishwashing
processes, as laundry additive compositions, stain pretreat
compositions, carpet and upholstery cleaners, and in any
process involving the cleaning of hard surfaces such as
bottle washing, dairy cleaning and kitchen and bathroom
cleaning processes, including for example toilet bowl
cleaning.
In processes for the bleaching of cellulosic fibre or
synthetic textiles the bleaching compositions of the
invention are used in an aqueous solution. The most
preferred peroxy compound for use in such processes is
hydrogen peroxide. The pH of the aqueous peroxy solution
is often adjusted with inorganic alkali metal basic
materials, such as sodium hydroxide, sodium carbonate,
sodium silicate and mixtures thereof. The optimum pH lies
somewhere between 7.5 to 12.5. Usually, if. the pH is
higher than about 12.5 the peroxy-compounds rapidly
decompose so that it is difficult to control a proper
bleaching rate without undue damage to the fibres. At pH
values lower than about 7.5 the rate of bleaching in most
cases is slow to the extent of being uneconomical for
bleaching.
Whilst amorphous silicates, especially sodium silicate
may be used to provide alkalinity in the peroxy solutions
for use in the bleaching of cellulosic fibres its tendency
to form as deposits on the fibres being bleached means that
its use is preferably kept to a minimum. Crystalline
layered silicates when co-agglomerated with acid materials
WO 95/02676
PCT/US94/07823
8
such as citric acid are preferred since they do not deposit
on fabrics. Most preferably, the peroxy solutions for use
in the bleaching of cellulosic fibres and synthetic
textiles using the bleaching compositions of the invention
contain no or little (less than 5%) sodium silicate.
The methods for bleaching using the peroxy solutions
containing the bleaching compositions of the present
invention vary widely, as for example, from using the
peroxy solutions at temperatures of from about 70'C to
about 100'C for periods of time from about 30 minutes to
about 6-8 hours, as well as continuous bleaching methods
which entail the use of the peroxy solutions at normal
temperatures, ie., about 25'C and contacting the cellulose
material by saturation, removing the excess moisture and
exposing the cellulose material to saturated steam at
temperatures form about 100' C to about 135' C, for period of
time from a few seconds (about 20) to about 1 hour and
even longer in some cases. U.S. Patents 2,839,353,
2,960,383, and 2,983,568 are illustrative of being
representative of continuous peroxy bleaching methods.
The bleaching compositions of the invention may also
be incorporated into compositions for use in essentially
any laundering, washing or cleaning processes. Laundry
compositions incorporating the bleaching compositions of
the invention can be formulated as granular compositions
and heavy duty liquid compositions.
The compositions may in addition comprise in general
terms those ingredients commonly found in detergent
products which may include organic surfactants, detergent
builders, anti-redeposition and soil supsension agents,
suds suppressors, enzymes, optical brighteners,
photoactivated bleaches, perfumes, filler salts, anti-
corrosion agents and colours.
Laundry detergent compositions may also comprise
fabric softening and antistatic agents.
A wide range of surfactants can be used in the
detergent compositions. A typical listing of anionic,
WO 95/02676 216 716 0 PCT~S94/07823
9
nonionic, ampholytic and zwitterionic classes, and species
of these surfactants, is given in U.S.P. 3,929,678 issued
to Laughlin and Heuring on December, 30, 1975. A list of
suitable cationic surfactants is given in U.S.P. 4,259,217
issued to Murphy on March 31, 1981.
Mixtures of anionic surfactants are suitable herein,
particularly blends of sulphate, sulphonate and/or
carboxylate surfactants. Mixtures of sulphonate and
sulphate surfactants are normally employed in a sulphonate
to sulphate weight ratio of from 5:1 to 1:2, preferably
from 3:1 to 2:3, more preferably from 3:1 to 1:1.
Preferred sulphonates include alkyl benzene sulphonates
having from 9 to 15, especially 11 to 13 carbon atoms in
the alkyl radical, and alpha-sulphonated methyl fatty acid
esters in which the fatty acid is derived from a C~
fatty source, preferably from a C~6-C~a fatty source. In
each instance the cation is an alkali metal, preferably
sodium. Preferred sulphate surfactants in such sulphonate
sulphate mixtures are alkyl sulphates having from 12 to 22,
preferably 16 to 18 carbon atoms in the alkyl radical.
Another useful surfactant system comprises a mixture
of two alkyl sulphate materials whose respective mean chain
lengths differ from each other. One such system comprises
a mixture of C~~-C~5 alkyl sulphate and C~6 C~a alkyl sulphate
in a weight ratio of C~'-CAS: C~6-C~a of from 3:1 to 1:1. The
alkyl sulphates may also be combined with alkyl ethoxy
sulphates having from 10 to 20, preferably 10 to 16 carbon
atoms in the alkyl radical and an average degree of
ethoxylation of 1 to 6. The cation in each instance is
again an alkali metal, preferably sodium.
Another highly preferred anionic surfactant system
comprises a mixture of a C~2-CZO alkyl sulfate salt with a
water soluble C».C~e alkyl ethoxysulfate salt containing an
average of from 1 to 7 ethoxy groups per mole wherein the
weight ratio of alkyl sulfate to alkyl ethoxysulfate salt
lies in the range from 2 . 1 to 19 : 1, more preferably
CA 02167160 2000-09-20
from 3 . 1 to 12 . 1 and most preferably from 3.5 . 1 to 10 .
1.
The alkyl sulfate salts may be derived from natural or
synthetic hydrocarbon sources. Preferred examples of such
5 salts include the substantially branched C19-Cls alkyl sulfate
salts, that is where the degree of branching of the C14-Cis
alkyl chain is greater than about 20°s. Such substantially
branched C19-Cls alkyl sulfate salts are usually derived from
synthetic sources. Also preferred are C16-CZo alkyl sulfate
10 salts which are usually derived from natural sources such as
tallow fat and marine oils.
The C11-Cie alkyl ethoxysulfate salt comprises a primary
alkyl ethoxysulfate which is derived from the condensation
product of a C11-Cis alcohol condensed with an average of from
one to seven ethylene oxide groups, per mole. Preferred are
the C12-Cis alkyl ethoxysulfate salts with an average of from
one to five ethoxy groups per mole, and most preferably with
an average of from one to three ethoxy groups per mole.
The C11-Cie alcohol itself can be obtained from natural or
synthetic sources. Thus, C11-Cia alcohols, derived from natural
fats, or Ziegler olefin build-up, or OXO synthesis can form
suitable sources for the alkyl group. Examples of
synthetically derived materials include Dobanol'~' 25 (RTM) sold
by Shell Chemicals (UK) Ltd which is a blend of C12-Cis
alcohols, Ethyl'' 24 sold by the Ethyl Corporation, a blend of
Cis-Cis alcohols in the ratio 67 o C13, 33% Cls sold under the
trade marks Lutensol by BASF GmbH and Synperonic (RTM) by ICI
Ltd., and Lial 125 sold by Liquichimica Italiana. Examples of
naturally occurring materials from which the alcohols can be
derived are coconut oil and palm kernel oil and the
corresponding fatty acids. The level of C11-Cie alkyl
ethoxysulfate is preferably from 0.5o to 10% more preferably
from 0.5% to 5o and most preferably from 1o to 3o by weight of
the composition.
Other anionic surfactants suitable for the purposes of the
invention are the alkali metal sarcosinates of formula
WO 95/02676 216 716 0 PCTILTS94/07823
11
R-CON ( R~ ) CH2 COOM
wherein R is a CS-CST linear or branched alkyl or alkenyl
group, R' is a C~-C~ alkyl group and M is an alkali metal
ion. Preferred examples are the lauroyl, Cocoyl (C~Z-C~4),
myristyl and oleyl methyl sarcosinates in the form of their
sodium salts.
One class of nonionic surfactants useful in the
present invention comprises condensates of ethylene oxide
with a hydrophobic moiety, providing surfactants having an
l0 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
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 C9-C~5 primary alcohol ethoxylates containing an
average of from 3-8 moles of ethylene oxide per mole of
alcohol, particularly the C~4-C~5 primary alcohols
containing an average of from 6-8 moles of ethylene oxide
per mole of alcohol and the C~2-C~5 primary alcohols
containing an average of from 3-5 moles of ethylene oxide
per mole of alcohol.
Another class of nonionic surfactants comprises alkyl
polyglucoside compounds of general formula
RO (C~H~O) tZx
wherein Z is a moiety derived from glucose; R is a
saturated hydrophobic alkyl group that contains from 6 to
18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is
from 1.1 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.
CA 02167160 2000-09-20
12
Another preferred nonionic surfactant is a polyhydroxy
fatty acid amide surfactant compound having the structural
formula:
O R1 ~I~
i
RZ - C - N - Z
wherein: R1 is H, C1-C4 hydrocarbyl, 2-hydroxy ethyl, 2-hydroxy
propyl, or a mixture thereof, preferably C1-C4 alkyl, more
preferably C1 or Cz alkyl, most preferably C1 alkyl (i.e.,
methyl); and RZ is a CS-C31 hydrocarbyl, preferably straight
chain C~-C19 alkyl or alkenyl, more preferably straight chain
C9-C1~ alkyl or alkenyl, most preferably straight chain C11-C1~
alkyl or alkenyl, or mixture thereof: and Z is a
polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with
at least 3 hydroxyls directly connected to the chain, or an
alkoxlylated derivative (preferably ethoxylated or
propoxylated) thereof. Z preferably will be derived from a
reducing sugar in a reductive amination reaction; more
preferably Z is a glycityl. Suitable reducing sugars include
glucose, fructose, maltose, lactose, galactose, mannose, and
xylose. As raw materials, high dextrose corn syrup, high
fructose corn syrup, and high maltose corn syrup can be
utilized as well as the individual sugars listed above. These
corn syrups may yield a mix of sugar components for Z. It
should be understood that it is by no means intended to
exclude other suitable raw materials. Z preferably will be
selected from the group consisting of -CHZ- (CHOH) n-CHZOH,
2 5 -CH ( CHZOH ) - ( CHOH ) n_1-CHZOH, -CHZ- ( CHOH ) Z ( CHOR' ) ( CHOH ) -
CHZOH,
where n is an integer from 3 to 5, inclusive, and R' is H or a
cyclic or aliphatic monosaccharide, and alkoxylated
derivatives thereof. Most preferred are glycityls wherein n
is 4, particularly -CHZ- (CHOH) 4-CHzOH.
In Formula (I), R1 can be, for example, N-methyl, N-ethyl,
N-propyl, N-isopropyl, N-butyl, N-2-hydroxy ethyl, or N-2-
hydroxy propyl.
WO 95/02676 216 716 0 PCT/US94/07823
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R2-CO-N< can be, for example, cocamide, stearamide,
oleamide, lauramide, myristamide, capricamide, palmitamide,
tallowamide, etc.
Z can be 1-deoxyglucityl, 2-deoxyfructityl, 1-
deoxymaltityl,
1-deoxylactityl, 1-deoxygalactityl, 1-deoxymannityl, 1-
deoxymalto-triotityl, etc. Preferred compound are N-methyl
N-ideoxyglucityl C~'-C~8 fatty acid amides.
A further class of surfactants are the semi-polar
surfactants such as amine oxides. Suitable amine oxides
are selected from mono C6C2o, preferably Coo-C~4 N-alkyl or
alkenyl amine oxides and propylene-1,3-diamine dioxides
wherein the remaining N positions are substituted by
methyl, hydroxyethyl or hydroxpropyl groups.
Cationic surfactants can also be used in the detergent
compositions herein and suitable quaternary ammonium
surfactants are selected from mono Ca C~6, preferably C~o-C~~
N-alkyl or alkenyl ammonium surfactants wherein remaining
N positions are substituted by methyl, hydroxyethyl or
hydroxypropyl groups.
Laundry detergent compositions incorporating the
bleaching compositions of the invention comprise from 3% to
35% of surfactant but more usually comprise from 5% to 25%,
more preferably from 10% to 25% surfactant by weight of the
compositions.
Machine dishwashing detergent compositions
incorporating the bleaching compositions of the invention
comprise from 0% to 10% by weight, preferably from 0.5% to
10% by weight, most preferably from 1% to 5% of surfactant
by weight of the compositions. The surfactants may be
selected from anionic, cationic, nonionic, amphotonic or
zwitterionic surfactants. Most preferably the surfactants
are low-foaming. A typical listing of surfactants for
inclusion in automatic dishwashing detergent compositions
is given in EP-A-0414 549. Most preferred are low-foaming
nonionic surfactants, especially the water soluble
ethoxylated C6-C~6 fatty alcohols and C6 C~6 mixed
WO 95/02676 6 ~ PCT/LIS94/07823
14
ethoxylated/propoxylated fatty alcohols and mixtures
thereof. Preferably, the ethoxylated fatty alcohols are
the Coo-C~6 ethoxylated fatty alcohols with a degree of
ethoxylation of from 5 to 50, most preferably these are
the C~Z-C~6 ethoxylated fatty alcohols with a degree of
ethoxylation from 8 to 40. Preferably the mixed
ethoxylated/propoxylated fatty alcohols have an alkyl chain
length of from 10 to 16 carbon atoms, a degree of
ethoxylation of from 3 to 30 and a degree of propoxylation
of from 1 to 10.
Combinations of surfactant types are preferred, more
especially anionic-nonionic and also anionic-nonionic-
cationic blends. Particularly preferred combinations are
described in GB-A-2040987 and EP-A-0087914. Although the
surfactants can be incorporated into the compositions as
mixtures, it is preferable to control the point of addition
of each surfactant in order to optimise the physical
characteristics of the composition and avoid processing
problems.
Preferred modes and orders of surfactant addition are
described hereinafter.
Another highly preferred component of the detergent
compositions of the invention is a detergent builder system
comprising one or more other non-phosphate detergent
builders. These can include, but are not restricted to,
crystalline layered sodium silicates, carbonates borates,
alkali metal aluminosilicates, monomeric polycarboxylates,
homo or copolymeric polycarboxylic acids or their salts in
which the polycarboxylic acid comprises at least two
carboxylic radicals separated from each other by not more
than two carbon atoms, carbonates, silicates and mixtures
of any of the foregoing.
Preferred non-phosphate builder salts are the
crystalline layered sodium silicates of the general formula
3 5 NaMS f x0~,~ . 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
WO 95/02676 216 716 0 PCT~S94107823
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,
5 3 or 4 and is preferably 2. More preferably M is sodium
and y is 0 and preferred examples of this formula comprise
the a -, 8 -, 7 - and d - forms of Na2Si205. These
materials are available from Hoechst AG FRG as respectively
NaSKS-5, NaSKS-7, NaSKS-il and NaSKS-6. The most
10 preferred material is d -Na2Si205, NaSKS-6.
These materials are processed into free flowing solids
with a particle size of from 150 to 1000 micrometers and a
bulk density of at least 800 g/litre preferably
approximately 900 g/litre. However, as made, the crystals
15 are fragile and break down easily into particles of size
less than 100 micrometers.
The laundry detergent compositions incorporating the
bleaching compositions of the present invention preferably
comprise crystalline layered sodium silicate at a level of
from 1% to 80% by weight of the composition, more
preferably from 5% to 40% and most preferably from 5% to
20% by weight.
The crystalline layered sodium silicate material is
preferably present as a particulate in intimate admixture
with a solid, water-soluble ionisable material. The solid,
water-soluble ionisable material is selected from organic
acids, organic and inorganic acid salts and mixtures
thereof. The primary requirement is that the material
should contain at least one functional acidic group of
which the pKa should be less than 9, providing a capability
for at least partial neutralisation of the hydroxyl ions
released by the crystalline layered silicate.
Surprisingly, it has been found for the purposes of the
present invention, that the ionisable material need not
have a pH <7 in solution, or be present in an amount
capable of providing hydrogen ions in stoichiometric parity
with the hydroxyl ions produced by dissolution of the
WO 95/02676 216 716 0 pCT~S94/07823
16
crystalline silicate. In fact neutralisation of the
ionisable material during storage of the particulate,
whilst causing a loss in fabric damage benefit, does not
eliminate it.
The ionisable material should also have a mean
particle size not greater than 300 micrometers and
preferably not greater than 100 micrometers. This
facilitates uniform distribution of the ionisable material
and the crystalline silicate and is believed to enhance
localised pH reduction when the particulate dissolves in
the wash liquor.
Suitable organic acids include ascorbic, citric,
glutaric, gluconic, glycolic, malic, malefic, malonic,
oxalic, succinic and tartaric acids, 1 hydroxy ethane 1,1-
diphosphonic acid (EHDP), amino poly methylene phosphonic
acids such as NTMP, EDTMP & DETPMP, and mixtures of any of
the foregoing. Suitable acid salts include sodium
hydrogen carbonate, sodium hydrogen oxalate, sodium
hydrogen sulphate, sodium acid pyrophosphate, sodium acid
orthophosphate, sodium hydrogen tartrate or mixtures of any
of the foregoing.
The particulate mixture of crystalline layered
silicate and solid water soluble ionisable material will
have a pH of at least 10 (as measured on a 1% solution in
20' C distilled water) and more usually will have a pH of at
least 11, normally at least 11.5.
The incorporation of other ingredients additional to
the crystalline layered silicate and ionisable water
soluble compound can be advantageous particularly in the
processing of the particulate and also in enhancing the
stability of detergent compositions in which the
particulates are included. In particular, certain types of
agglomerates may require the addition of one or more binder
agents in order to assist in binding the silicate and
ionisable water soluble material so as to produce
particulates with acceptable physical characteristics.
The binder agents may be present at a level of from 0% to
WO 95/02676 216 716 0 ~T~S94107823
17
20% by weight of the composition. Preferably, the binder
agents will be in intimate admixture with the silicate and
ionisable water soluble material. Preferred binder agents
have a melting point between 30'C-70'C. The binder agents
are preferably present in amounts from 1-l0% by weight of
the composition and most preferably from 2-5% by weight of
the composition.
Preferred binder agents include the Cio-CZO alcohol
ethoxylates containing from 5-100 moles of ethylene oxide
l0 per mole of alcohol and more preferably the CAS-C2o primary
alcohol ethoxylates containing from 20-100 moles of
ethylene oxide per mole of alcohol.
Other preferred binder agents include certain
polymeric materials. Polyvinylpyrrolidones with an average
molecular weight of from 12, 000 to 700, 000 and polyethylene
glycols with an average weight of from 600 to 10,000 are
examples of such polymeric materials. Copolymers of malefic
anhydride with ethylene, methylvinyl ether or methacrylic
acid, the malefic anhydride constituting at least 20 mole
percent of the polymer are further examples of polymeric
materials useful as binder agents. These polymeric
materials may be used as such or in combination with
solvents such as water, propylene glycol and the above
mentioned Coo-C2oalcohol ethoxylates containing from 5-100
moles of ethylene oxide per mole. Further examples of
binder agents in accord with the invention include the Coo -
CZO mono- and diglycerol ethers and also the Coo-C~ fatty
acids. Solutions of certain inorganic salts including
sodium silicate are also of use for this purpose.
Cellulose derivatives such as methylcellulose,
carboxymethylcellulose and hydroxyethylcellulose, and homo-
or co-polymeric polycarboxylic acid or their salts are
other examples of binder agents in accord with the
invention.
The particulate can also include other components that
are conventional in detergent compositions, provided that
these are not incompatible per se and do not interfere with
CA 02167160 2000-09-20
18
the building function of the crystalline layered silicate.
Thus the particulate can include up to 50% by weight of the
particulate of an anionic, nonionic, ampholytic or
zwitterionic surfactant or a mixture of any of these and
certain preferred particulate embodiments incorporate
surfactants. Examples of such surfactants are described more
fully hereinafter. However it is important that any
surfactant material that is incorporated into the particulate
does not introduce a level of free (unbound) moisture that can
even partially dissolve the crystalline layered silicate. For
this purpose, the surfactant should be solid and should
preferably contain no more than about 5$ free (unbound)
moisture, preferably no more than 2°s free moisture and most
preferably less than 1~ free moisture.
Other ingredients can also be incorporated in a total
amount of up to 50o by weight of the particulate, subject to
the same conditions set out above for the inclusion of
surfactants. Thus such optional ingredients should preferably
be solid at normal (ambient) temperatures, and should contain
no more that 5o by weight of free (unbound) moisture,
preferably less than 1~.
Non-aqueous liquid components can be incorporated in
amounts of up to 20s by weight of the particulate provided
that the crystalline layered silicate does not have an
appreciable solubility in such components. This also
applies to normally solid components applied in a molten
form to serve as agglomeration/coating agents for the
particulate.
The particulates can take a variety of physical forms
such as extrudates, marumes, agglomerates, flakes or compacted
granules. A preferred process for preparing compacted
granules comprising crystalline layered silicate and a
solid, water-soluble ionisable material has been disclosed
in WO 92/18594, published October 29, 1992.
w_,.. W~ 95/02676 216 7 ~ ~ ~ PCT/LTS94107823
19
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 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 28%, more
l0 preferably from 18% 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 CaCO3/litre/minute/ (gram/litre) [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
WO 95/02676 216 716 0 PCT~S94/07823
of CaCO3/litre/ minute/ (gram/litre) [4
grains/gallon/minute/(gram/gallon)].
Aluminosilicate ion exchange materials useful in the
practice of this invention are commercially available and
5 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
10 available under the designations Zeolite A, Zeolite B,
Zeolite P, Zeolite X, Zeolite HS, Zeolite MAP, Zeolite Y
and mixtures thereof. In an especially preferred
embodiment, the crystalline aluminosilicate ion exchange
material is Zeolite A and has the formula
15 Na ~Z [ (AlOZ ) ~Z (Si02) ~2 ] . xHZ o
wherein x is from 20 to 30, especially 27. Zeolite X of
formula Nay [ (AlOZ)~(SiOz) ~~] . 276 H20 is also suitable, as
well as Zeolite HS of formula Nab [ (A102)6(SiOZ) 6] 7.5 HZ O) .
Suitable water-soluble monomeric or oligomeric
20 carboxylate builders can be selected from a wide range of
compounds but such compounds preferably have a first
carboxyl logarithmic acidity/constant (pK~) of less than 9,
preferably of between 2 and 8.5, more preferably of between
4 and 7.5.
The logarithmic acidity constant is defined by
reference to the equilibrium
H~ + A ~ HA
where A is the fully ionized carboxylate anion of the
builder salt.
The equilibrium constant for dilute solutions is
therefore given by the expression
IxA]
IH'] fA-l
and pK~ = log~oR.
PCT/LTS94/07823
,_, WO 95/02676 216 716 0
21
For the purposes of this specification, acidity
constants are defined at 25'C and at zero ionic strength.
Literature values are taken where possible (see Stability
Constants of Metal-Ion Complexes, Special Publication No.
25, The Chemical Society, London): where doubt arises they
are determined by potentiometric titration using a glass
electrode.
The carboxylate or polycarboxylate builder can be
momomeric or oligomeric in type although monomeric
l0 polycarboxylates are generally preferred for reasons of
cost and performance.
Monomeric and oligomeric builders can be selected from
acyclic, alicyclic, heterocyclic and aromatic carboxylates
having the general formulae
(a)
Y
Ri X ~ m ~
(b)
Y
X C
Z
n
or
Yp O ZQ
wherein R~ represents H,C~_3o alkyl or alkenyl optionally
substituted by hydroxy, carboxy, sulfo or phosphono groups
or attached to a polyethylenoxy moiety containing up to 20
ethyleneoxy groups; RZ represents H,C~_~ alkyl, alkenyl or
hydroxy alkyl, or alkaryl, sulfo, or phosphono groups;
X represents a single bond; 0'; S; SO; S02; or NR~;
Y represents H; carboxy;hydroxy; carboxymethyloxy; or
C~_3o alkyl or alkenyl optionally substituted by hydroxy or
carboxy groups;
Z represents H; or carboxy;
m is an integer from 1 to 10;
CA 02167160 2000-09-20
22
n is an integer from 3 to 6;
p, q are integers from 0 to 6, p + q being from 1 to 6;
and wherein, X, Y, and Z each have the same or different
representations when repeated in a given molecular formula,
and wherein at least one Y or Z in a molecule contain a
carboxyl group.
Suitable carboxylates containing one carboxy group
include the water soluble salts of 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, (ethylenededioxy)
diacetic acid, malefic acid, diglycolic acid, tartaric acid,
tartronic acid and fumaric acid, as well as the ether
carboxylates described in German Offenlegenschrift
2, 446, 686, and 2, 446, 687 and U. S. Patent No. 3, 935, 257 and
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, issued September 2, 1975, 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.
WO 95/02676 216 716 0 PCT/US94/07823
23
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
2o 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
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. These
materials are normally used at levels of from 0.5% to 10%
by weight more preferably from 0.75% to 8%, most preferably
from 1% to 6% by weight of the composition.
The detergent compositions incorporating the bleaching
compositions of the present invention will comprise non
phosphate detergent builder compounds at a level of from 1%
to 80% by weight of the compositions, more preferably from
CA 02167160 2000-09-20
24
10% to 60% by weight and most preferably from 20% to 50% by
weight.
Within the preferred laundry detergent compositions,
sodium aluminosilicate such as Zeolite A will comprise from 20%
to 60% by weight of the total amount of builder, a monomeric or
oligomeric carboxylate will comprise from 5% to 30% by weight
of the total amount of builder and the crystalline layered
silicate will comprise from 10 % to 65 % by weight of the total
amount of builder. In such compositions the builder system
preferably also incorporates a combination of auxiliary
inorganic and organic builders such as sodium carbonate and
malefic anhydride/acrylic acid copolymers in amounts of up to
35% by weight of the total builder.
The detergent compositions may contain optional chelant
ingredients. Such optional chelants may include the organic
phosphonates, including amino alkylene poly (alkylene
phosphonate), alkali metal ethane 1-hydroxy diphosphonates,
nitrilo trimethylene phosphonates, ethylene diamine tetra
methylene phosphonates and diethylene triamine penta methylene
phosphonates. The phosphonate compounds may be present either
in their acid form or as a complex of either an alkali or
alkaline metal ion, the molar ratio of said metal ion to said
phosphonate compound being at least 1 . 1. Such complexes are
described in US-A-4,259,200. Preferably, the organic
phosphonate compounds where present are in the form of their
magnesium salt. The level of phosphorus containing chelants in
the compositions of the invention is preferably minimised, with
their complete exclusion from the compositions being most
preferred.
Silicates are useful components of automatic dishwashing
detergent compositions incorporating the bleaching
compositions of the present invention. Suitable silicates
include the water soluble sodium silicates with an
Si02 . Na20 ratio of from 1.0 to 2.8. The silicates may be
in the form of either the anhydrous salt or a hydrated
r WO 95/02676 PCT/US94/07823
salt. Sodium silicate with an Si02 . Na20 ratio of 2.0 is
most preferred. Silicates are present in the machine
dishwashing detergent compositions at a level of from 5% to
50% by weight of the composition, more preferably from 10%
5 to 40% by weight.
Whilst soluble silicates serve a variety of purposes
in conventional laundry detergent formulations, their
presence may be unnecessary in detergent compositions
incorporating crystalline layered silicate material.
10 However as the crystalline layered silicate, which forms
part of the builder system of the detergent composition,
must be added as a dry mix ingredient, soluble silicates
may still be useful as structurants in the spray dried
granules that normally form part of a laundry detergent
15 composition. This is particularly desirable if the spray
dried granule does not incorporate an aluminosilicate
builder and would otherwise comprise only organic
materials. Suitable silicates are those having an Sio2:Na2o
ratio in the range from 1.6 to 3.4, ratios from 2.0 to 2.8
20 being preferred.
The detergent compositions incorporating the bleaching
compositions of the present invention will generally
include an inorganic perhydrate salt, normally in the form
of the sodium salt. Suitable inorganic perhydrate salts
25 have been described herein before. The bleaching
composition will usually be incorporated to give a
perhydrate level of from 3% to 40% by weight, more
preferably from 5% to 30% by weight and most preferably
from 10% to 25% by weight of the detergent composition.
The detergent compositions incorporating the bleaching
compositions of the present invention will also generally
include peroxyacid bleach precursors (bleach activators).
Suitable peroxyacid bleach precursors have been described
hereinbefore. The peroxyacid bleach precursors are normally
incorporated at a level of from 1% to 20%, more preferably
from 1% to 15%, most preferably from 3% to 10% by weight of
the compositions.
CA 02167160 2000-09-20
26
The detergent compositions may also contain organic
peroxyacids at a level of from to to 15% by weight, more
preferably from 1% to 10% by weight of the composition.
Detergent compositions in which solid peroxybleach
precursors are protected via an acid coating to minimize
fabric colour damage are disclosed in the Applicant's
copending British Application No. 9102507.2 filed February 6,
1991.
Anti-redeposition and soil-suspension agents suitable
herein include cellulose derivatives such as methylcellulose,
carboxymethylcellulose and hydroxyethycellulose, homo- or co-
polymeric polycarboxylic acids or their salts and polyamino
compounds. Polymers of this type include the polyacrlyates
and copolymers of malefic anhydride with ethylene, methylvinyl
ether or methacrylic acid the malefic anhydride constituting at
least 20 mole percent of the copolymer disclosed in detail in
EP-A-137669. Polyamino compounds such as those derived from
aspartic acid are disclosed in EP-A-305282, EP-A-305283 and
EP-A-351629. These materials are normally used at levels of
from 0.5°s to 10°s by weight, more preferably from 0.750 to
8s,
most preferably from la 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 2.5o by weight. These polymers and the
previously mentioned homo- or co-polymeric polycarboxylate
salts are valuable for improving whiteness maintenance, fabric
ash deposition, and cleaning performance on clay,
proteinaceous and oxidizable soils in the presence of
transition metal impurities.
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-
WO 95/02676 216 716 0 PCT/US94/07823
27
anilino-2-triazin-6-ylaminostilbene-2:2'-di
sulphonate,disodium 4, 4'-bis-(2,4-dianilino-s-triazin-6-
ylamino)st ilbene-2:2' - disulphonate, monosodium 4~'4~~-
bis-(2,4-dianilino-s-triazin-6-ylam ino)stilbene-2-
sulphonate, disodium 4,4~-bis-(2-anilino-4-(N-methyl-N-2-
hydroxye thylamino)-2-triazin-6-ylamino)stilbene-2,2' -
disulphonate, disodium 4,4'-bis-(4-phenyl-2,1,3-triazol-2-
yl)stilbene-2,2' disulphonate, disodium 4,4~bis(2-anilino-4-
(1-methyl-2-hydroxyethyl amino)-s-triazin-6-
ylamino) stilbene-2, 2~disulp honate and sodium 2 (stilbyl-4~~-
(naphtho-1~,2~:4,5)-1,2,3 - triazole-2~~- sulphonate.
Soil-release agents useful in detergent compositions
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 ) ~3 ) o.TS ( POH ) o.ZS C T-PO ) y.a ( T-PEG ) o.' J T ( PO-
H ) 0. 25 ( ( PEG ) '3CH3 ) 0. 75
where PEG is - (OCZH4) 0-, PO is (OC'H60) and T is (pC OC6H4C0) .
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 generally 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-
WO 95/02676 21 b 716 0 PCT~S94/07823
28
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
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 manometers to 20
manometers and a specific surface area above 50 mz/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 0.001% to 5% by weight of the
composition, preferably from 0.1% to 3% 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
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 Czo-Cz4 fatty acids,
microcrystalline waxes and high MWt copolymers of ethylene
21 671 60
29
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 detergent
compositions is one or more enzymes. These may be
incorporated at a level of from O.lt to 10~, more
preferably 0.5~ to 5~ by weight of the detergent
to composition.
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.
Preferred commercially available protease enzymes
include those sold under the trademarks Alcalase and
Savinase by Novo Industries A/S (Denmark) and Maxatase by
International Bio-Synthetics, Inc. (The Netherlands).
Preferred amylases include, for example, -amylases
obtained from a special strain o! 8 lichenitorms, described
in more detail in GH-1,269,839 (Novo). Preferred
commercially available amylases include for example,
Rapidase, sold by Int~rnational Bio-Synthetics Inc, and
Termamyl, sold by Novo Industries A/S.
An especially preferred lipase enzyme is manufactured
and sold by Novo Industries A/S (Denmark) under the trade
mark Lipolase (Biotechnology Newswatch, 7 March 1988, page
6) and mentioned along with 'other suitable lipases in EP-A
0258068 (Novo).
A further optional ingredient useful in detergent
compostions is a corrosion inhibitor C»-C~ fatty acids are
preferred examples of such corrosion inhibitors.
Fabric softening agents can also be incorporated into
laundry detergent compositions. These agents may be
inorganic or organic in type. Inorganic softening agents
are exemplified by the smectite clays disclosed in GH-A
WO 95/02676 216 716 0 pCT~S94107823
1,400,898. Other suitable inorganic softening systems
comprising smectite clays, including hectorite and
montmorillonite, are also disclosed in EP-A-0522206.
Organic fabric softening agents include the water insoluble
5 tertiary amines as disclosed in GH-A-1514276 and EP-B-
0011340.
Their combination with mono C~2-C~4 quaternary ammonium
salts is disclosed in EP-B-0026527 & 528. Other useful
organic fabric softening agents are the dilong chain amides
10 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
15 5% to 15%, more preferably from 8% 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
20 from 0.5% to 5% 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 0.1% to 2%, normally from 0.15% to
1.5% by weight. Where a portion of the composition is
25 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.
30 In general detergent compositions can be made via a
variety of methods including dry mixing, spray drying,
agglomeration and granulation and preferred methods involve
combinations of these techniques. A preferred method of
making the granular laundry detergent compositions involves
a combination of spray drying, agglomeration in a high
speed mixer and dry mixing.
~18~ 160
31
The bulk density of the granular detergent
compositions incorporating the bleaching compositons of the
present invention may be in the range of about 450 to 600
g/litre as is typical for conventional laundry detergent
compositions. Alternatively, the granular detergent
compositions may be concentrated granular detergent
compositions that are characterised by a relatively high
density in comparison with conventional detergent
compositions. Such high density compositions have a bulk
l0 density of at least 650 g/litre, more usually at least 700
g/litre and more preferably from 800 g/litre to 1100
g/litre.
Bulk density is measured by means o! a simple funnel
and cup device consisting o!-a conical funnel moulded
rigidly on a base and provided with a flap valve at its
lower extremity to allow the contents of the funnel to ba
emptied into an axially aligned cylindrical cup disposed
below the funnel. The funnel is 130 mm and 40 mm at its
respective upper and lower extremities. It is mounted so
that the lower extremity is 140 mm above the upper surface
o! the base. The cup has an overall height o! 90 mm, an
internal height o! 87 mm and an internal diameter of 84 mm.
Its nominal volume is 50o ml.
To carry out a measurement, the funnel is tilled with
powder by hand pouring, the flap valve is opened and powder
allowed to overfill the cup. The tilled cup is removed
from the frame and excess powder removed from the cup by
pawing a straight edged implement e.g. a knife, across its
upper edge. The filled cup~is then weighed and the value
obtained for tha weight of powder doubled to provide the
bulk density in g/litre. Replicate measurements are made as
required.
Concentrated laundry detergent compositions also
normally incorporate at least one mufti-ingredient
component i.e. they do not comprise compositions formed
merely by dry-mixing individual ingredients. Compositions
in which each individual ingredient is dry-mixed are
WO 95/02676 216 716 0 PCT/US94107823
32
generally dusty, slow to dissolve and also tend to cake and
develop poor particle flow characteristics in storage.
Preferably the carbonate and percarbonate are dry mixed
with the other ingredients, some or all of which may be
spray dried or agglomerated ~in a multi-component mix.
Preferred laundry detergent compositions comprise at
least two particulate multi-ingredient components. The
first component comprises at least 15%, conventionally from
25% to 50%, but more preferably no more than 35% by weight
of the composition and the second component from 1% to 50%,
more preferably 10% to 40% by weight of the composition.
The first component comprises a particulate
incorporating an anionic surfactant in an amount of from
0.75% to 40% by weight of the powder and one or more
inorganic and/or organic salts in an amount of from 99.25%
to 60% by weight of the powder. The particulate can have
any suitable form such as granules, flakes, prills, marumes
or noodles but is preferably granular. The granules
themselves may be agglomerates formed by pan or drum
agglomeration or by in-line mixers but are customarily
spray dried particles produced by atomising an aqueous
slurry of the ingredients in a hot air stream which removes
most of the water. The spray dried granules are then
subjected to densification steps, e.g. by high speed cutter
mixers and/or compacting mills, to increase density before
being reagglomerated. For illustrative purposes, the first
component is described hereinafter as a spray dried powder.
Suitable anionic surfactants for the purposes of the
first component have been found to be slowly dissolving
linear alkyl sulfate salts in which the alkyl group has an
average of from 16 to 22 carbon atoms, and linear alkyl
carboxylate salts in which the alkyl group has an average
of from 16 to 24 carbon atoms. The alkyl groups for both
types of surfactant are preferably derived from natural
sources such as tallow fat and marine oils.
The level of anionic surfactant in the spray dried
powder forming the first component is from 0.75% to 40% by
WO 95/02676 21 b 716 0 ~T~S94/07823
33
weight, more usually 2.5% to 25% preferably from 3% to 20%
and most preferably from 5% to 15% by weight. Water-
soluble surfactants such as linear alkyl benzene
sulphonates or C~'-C~5 alkyl sulphates can be included or
alternatively may be applied subsequently to the spray
dried powder by spray on.
The other major ingredient of the spray dried powder
is one or more inorganic or organic salts that provide the
crystalline structure for the granules. The inorganic
and/or organic salts may be water-soluble or water-
insoluble, the latter type being comprised by the, or the
major part of the, water-insoluble builders where these
form part of the builder ingredient. Suitable water
soluble inorganic salts include the alkali metal carbonates
and bicarbonates. Amorphous alkali metal silicates may
also be used to provide structure to the spray dried
granule provided that aluminosilicate does not form part
of the spray dried component.
However, in concentrated detergent compositions it is
preferred that no sodium sulphate is added as a separate
ingredient and its incorporation as a by-product e.g. with
sulph(on)ated surfactants, should be minimised.
Where an aluminosilicate zeolite forms the, or part of
the, builder ingredient, it is preferred that it is not
added directly by dry-mixing to the other components, but
is incorporated into the multi-ingredient component(s).
The first component can also include up to 15% by
weight of miscellaneous ingredients such as brighteners,
anti-redeposition agents, photoactivated bleaches (such as
tetrasulfonated zinc phthalocyanine) and chelants. Where
the first component is a spray dried powder it will
normally be dried to a moisture content of from 7% to 11%
by weight, more preferably from 8% to 10% by weight of the
spray dried powder. Moisture contents of powders produced
by other processes such as agglomeration may be lower and
can be in the range 1-10% by weight.
WO 95/02676
216 716 0 pCT~S94/07823
34
The particle size of the first component is
conventional and preferably not more than 5% by weight
should be above l.4mm, while not more than 10% by weight
should be less than 0.15 mm in maximum dimension.
Preferably at least 60%, and most preferably at least 80%,
by weight of the powder lies between 0.7 mm and 0.25 mm in
size. For spray dried powders, the bulk density of the
particles from the spray drying tower is conventionally in
the range from 540 to 600 g/litre and this is then enhanced
by further processing steps such as size reduction in a
high speed cutter/mixer followed by compaction.
Alternatively, processes other than spray drying may be
used to form a high density particulate directly.
A second component of a preferred detergent
composition is another multi-ingredient particulate
containing a water soluble surfactant.
This may be anionic, nonionic, cationic or semipolar
in type or a mixture of any of these. Suitable surfactants
are listed hereinbefore but preferred surfactants are 04-
C~5 alkyl sulphates, linear C~~- CAS alkyl benzene
sulphonates and fatty C~4-C~8 methyl ester sulphonates.
The second component may have any suitable physical
form, i. e. it may take the form of flakes, prills, marumes,
noodles, ribbons, or granules which may be spray-dried or
non spray-dried agglomerates. Although the second
component could in theory comprise the water soluble
surfactant on its own, in practice at least one organic or
inorganic salt is included to facilitate processing. This
provides a degree of crystallinity, and hence acceptable
flow characteristics, to the particulate and may be any
one or more of the organic or inorganic salts present in
the first component.
The particle size range of the second component should
be such as to obviate segregation from the particles of the
first component when blended therewith. Thus not more than
5% by weight should be above 1.4 mm while not more than 10%
should be less than 0.15 mm in maximum dimension.
WO 95/02676 PCTILTS94107823
A- 2167160
The bulk density of the second component will be a
function of its mode of preparation. However, the
preferred form of the second component is a mechanically
mixed agglomerate which may be made
5 by adding the ingredients dry or with an agglomerating
agent to a pan agglomerator, 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 MaschinenbanGmbH, D-4790
10 Paderborn 1, Elsenerstrasse 7-9, Postfach 2050 F.R.G. By
this means the second component can be given a bulk density
in the range from 650 g/litre to 1190 g/litre more
preferably from 750 g/litre to 850 g/litre.
Preferred laundry detergent compositions include a
15 level of alkali metal carbonate in the second component
corresponding to an amount of from 3% to 15% by weight of
the composition, more preferably from 5% to 12% by weight.
This will provide a level of carbonate in the second
component of from 20% to 40% by weight.
20 A highly preferred ingredient of the second component
is also a hydrated water insoluble aluminosilicate ion
exchange material of the synthetic zeolite type, described
hereinbefore, present at from 10% to 35% by weight of the
second component. The amount of water insoluble
25 aluminosilicate material incorporated in this way is from
1% to 10% by weight of the composition, more preferably
from 2% to 8% by weight.
In one process for preparing the second component, the
surfactant salt is formed in situ in an inline mixer. The
30 liquid acid fona of the surfactant is added to a mixture of
particulate anhydrous sodium carbonate and hydrated sodium
aluminosilicate in a continuous high speed blender, such as
a Lodige C6 mixer, and neutralised to form the surfactant
salt whilst maintaining the particulate nature of the
35 mixture. The resultant agglomerated mixture forms the
second component which is then added to other components of
the product. In a variant of this process, the surfactant
WO 95/02676
216 716 0 PCT~S94/07823
36
salt is pre-neutralised and added as a viscous paste to the
mixture of the other ingredients. In the variant, the
mixer serves merely to agglomerate the ingredients to form
the second component.
In a particularly preferred process for making the
granular laundry detergent compositions, part of the spray
dried product comprising the first granular component is
diverted and subjected to a low level of nonionic
surfactant spray on before being reblended with the
remainder. The second granular component is made using the
preferred process described above. The first and second
components together with a crystalline layered silicate
particulate composition, the perhydrate bleach and any
peroxy acid bleach precursor particles, other dry mix .
ingredients such as any carboxylate chelating agent, soil-
release polymer and enzyme are then fed to a conveyor belt,
from which they are transferred to a horizontally rotating
drum in which perfume and silicone suds suppressor are
sprayed on to the product. In highly preferred
compositions, a further drum mixing step is employed in
which a low (approx. 2% by weight) level of finely divided
crystalline material is introduced to increase density and
improve granular flow characteristics.
In preferred concentrated detergent products
incorporating an alkali metal percarbonate as the
perhydrate salt it has been found necessary to control
several aspects of the product such as its heavy metal ion
content and its equilibrium relative humidity.
Laundry detergent compositions in accordance with the
invention can also benefit from delivery systems that
provide transient localised high concentrations of product
in the drum of an automatic washing machine at the start of
the wash cycle, thereby also avoiding problems associated
with loss of product in the pipework or sump of the .
machine.
Delivery to the drum can most easily be achieved by
incorporation of the composition in a bag or container from
WO 95/02676
216 716 0 PCT~S94/07823
37
which it is rapidly releasable at the start of the wash
cycle in response to agitation, a rise in temperature or
immersion in the wash water in the drum. Alternatively the
washing machine itself may be adapted to permit direct
addition of the composition to the drum e.g. by a
dispensing arrangement in the access door.
Products comprising a laundry detergent composition
enclosed in a bag or container are usually designed in such
a way that container integrity is maintained in the dry
state to prevent egress of the contents when dry, but are
adapted for release of the container contents on exposure
to a washing environment, normally on immersion in an
aqueous solution.
Usually the container will be flexible, such as a bag
or pouch. The bag may be of fibrous construction coated
with a water impermeable protective material so as to
retain the contents, such as is disclosed in European
published Patent Application No. 0018678. Alternatively it
may be formed of a water-insoluble synthetic polymeric
material provided with an edge seal or closure designed to
rupture in aqueous media as disclosed in European published
Patent Application Nos. 0011500, 0011501, 0011502, and
0011968. A convenient form of water frangible closure
comprises a water soluble adhesive disposed along and
sealing one edge of a pouch formed of a water impermeable
polymeric film such as polyethylene or polypropylene.
In a variant of the bag or container form, laminated sheet
products can be employed in which a central flexible layer
is impregnated and/or coated with a composition and then
one or more outer layers are applied to produce a fabric-
like aesthetic effect. The layers may be sealed together
so as to remain attached during use, or may separate on
contact with water to facilitate the release of the coated
or impregnated material.
An alternative laminate form comprises one layer
embossed or deformed to provide a series of pouch-like
containers into each of which the detergent components are
WO 95/02676
216 716 0 PCT/LTS94/07823
38
deposited in measured amounts, with a second layer
overlying the first layer and sealed thereto in those areas
between the pouch-like containers where the two layers are
in contact. The components may be deposited in
particulate, paste or molten form and the laminate layers
should prevent egress of the contents of the pouch-like
containers prior to their addition to water. The layers
may separate or may remain attached together on contact
with water, the only requirement being that the structure
should permit rapid release of the contents of the pouch-
like containers into solution. The number of pouch-like
containers per unit area of substrate is a matter of choice
but will normally vary between 500 and 25,000 per square
metre.
Suitable materials which can be used for the flexible
laminate layers in this aspect of the invention include,
among others, sponges, paper and woven and non-woven
fabrics.
However the preferred means of carrying a laundry
process is to introduce the composition into the liquid
surrounding the fabrics that are in the drum via a reusable
dispensing device having walls that are permeable to liquid
but impermeable to the solid composition.
Devices of this kind are disclosed in European Patent
Application Publication Nos. 0343069 & 0343070. The latter
Application discloses a device comprising a flexible sheath
in the form of a bag extending from a support ring defining
an orifice, the orifice being adapted to admit to the bag
sufficent product for one washing cycle. A portion of the
washing medium flows through the orifice into the bag,
dissolves the product, and the solution then passes
outwardly through the orif ice into the washing medium. The
support ring is provided with a masking arrangement to
prevent egress of wetted, undissolved, product, this
arrangement typically comprising radially extending walls
extending from a central boss in a spoked wheel
WO 95/02676 216 716 0 pCT~S94/07823
39
configuration, or a similar structure in which the walls
have a helical form.
An article by J. Bland published in Manufacturing
Chemist, November 1989, pages 41-46 also describes
especially preferred dispensing devices for use with
granular laundry detergent products which are of a type
commonly known as the "granulette".
A laundry detergent composition according to the
invention is illustrated in the following non limiting
to example in which all percentages are on a weight basis
unless otherwise stated.
In the detergent compositions, the abbreviated
component identifications have the following meanings
Z,AS . Sodium linear C~Z alkyl benzene
sulphonate
C~6 - ~8 AS . Sodium C~6 - C~a alkyl sulphate.
C~4 - ~5 AE7 . A C~4 CAS primary alcohol
condensed with an average of 7
moles of ethylene oxide per mole.
TAED : Tetraacetyl ethylene diamine
Silicate : Amorphous Sodium Silicate
(SiOZ:Na20 ratio normally follows)
CMC . Sodium carboxymethyl cellulose
Zeolite 4A . Hydrated Sodium Aluminosilicate
of formula Na~2 (AlO2Si02) 12 27H20
having a primary particle size in
the range from 1 to 10
micrometers
Citrate : Tri-sodium citrate dihydrate
MA/AA : Copolymer of 1:4 maleic/acrylic
acid, average molecular weight
about 70, 000, available from BASF
under the trade name Sokalan CP5
DTPMP : Diethylene triamine penta
(Methylene phosphoric acid),
marketed by Monsanto under the
Trade name bequest 2060
216 716 p PCT/US94/07523
WO 95/02676
Suds . A mixture of hydrophobic silica
and silicone oil
Percarbonate : Anhydrous sodium percarbonate
bleach of empirical formula
5 2Na2C03. 3H202.
Savinase : Proteolyic enzyme sold by Novo
Industries A/S.
Lipase . Lipolytic enzyme sold by Novo
Industries A/S.
10
LAS ~$
C16-18 AS 2$
C14-15 AE7 4$
Silicate 2.Or 4$
15 Copolymer AA/MA 4$
Zeolite 4A 20%
Citrate 5%
Phosphonate - DTPMP 0.4%
TAED 5%
20 CMC 0.5%
Suds Suppressor 1%
Savinase (4.0 KNPU/g) 1.5%
Lipolase (100,000 LU/g 0.4%
Sodium Carbonate (anhydrous) 15%
25 Percarbonate 20%
Balance Moisture Miscellaneous look
Sodium Carbonate Particle Size > 2360 ~Cm 0%
> 850 ~m 18.5%
> 425 ~m 60$
> 250 ~1m 91%
< 150 ~m 2.5%
