Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
WO 94/03572 2 1 4 1 6 1 0 PCr/US93/06876
,~
DETERGENT COMPOSITIONS
This invention relates to detergent compositions cont~ining
crystalline layered silicates and ethylene~ mine-N, N'-disuccinic
acid or salts thereof.
Detergent compositions incorporating layered sodium silicates are
known in the art, being disclosed in, for example, DE-A-3742043
and EP-A-0337219. These disclosures teach that the layered
cryst~lline forms of sodium silicate display superior mineral hardness
sequestration ability relative to the corresponding silicate salts in
amorphous form and are thus advantageous as detergent builder
materials.
Laundry detergent compositions cont~inin~ the nil-phosphorus,
chelant, ethylene~i~mine-N, N'-disuccinic acid (EDDS) are also
known in the art, being disclosed in, for example, EP-A-0267 653.
This disclosure teaches that EDDS when incorporated in such
laundry compositions assists in the removal of food, beverage and
certain other organic stains from fabrics during the laundry process.
It also teaches that EDDS may be used as a replacement for all or
part of the phosphonate chelants currently used in many existing
laundry products.
A known problem associated with laundry washing processes is the
deposition and build up of insoluble inorganic salt encrustations on
the surface of the fabrics during the wash process. These
encrustations may remain largely intact on the fabric surface at the
end of the wash process. Over a number of wash cycles further
build up of such insoluble inorganic salt deposits may occur giving
21~1611~
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the fabrics a dingy, discoloured appearance. The inorganic salts are
largely calcium or m~gne~ium salts or salts of heavy metal ions such
as zinc, iron, manganese and copper.
The Applicant has established that it is the build up of insoluble
heavy mehl ion salts which principally contributes to the
aforementioned dingy and discoloured fabric appearance. The
Applicant has also established that the encrustation of such heavy
metal ion salts on the surface of the fabrics may contribute to
loc~lice~ fabric ~m~E~e when the &bric is washed using a de~ergc-lt
composition cont~inin~ a peroxygen bleach. This effect arises due to
the action of the heavy metal ion salt which cahlytically activates the
peroxygen bleach at the fabric surface, thus c~nsin~ fabric tl~m~e.
The Applicant has now found that the above mentioned problem of
build up on fabrics of insoluble inorganic salts, and particularly
heavy metal ion salts, over a number of wash cycles, can be
miti~t~l by the use of laundry detergent compositions cont~ining
cryst~lline layered sodium silicates and EDDS in combination.
Surprisingly, the action of EDDS and cryst~lline layered silicates in
combination is significantly better that that of compositions
con~inin only one of these colllpon~nts.
It is therefore an object of the present invention to provide detergent
compositions cont~inin~ cryst~lline layered silicate in combination
with EDDS which reduce the level of deposition of inorganic salt
encrustations on the surface of fabrics during a laundry washing
process, and in particular to reduce the multi-cycle build up of such
encrustations.
It is a further object of the present invention to provide detergent
compositions which reduce the level of deposition of heavy metal ion
cont~ining inorganic salt encrustations on the surface of fabrics
during a laundry washing process thus providing improved whiteness
m~intenance of the white fabrics, and reducing the colour ~l~m~e of
the coloured fabrics washed in such a process.
Whilst the problem of the surface the surface encrustation of heavy
metal ion cont~ining inorganic salts during a washing process is of
particular importance to laundry processes, the problem of salt
encrustation may also be encountered in essentially any washing or
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WO 94/03572 PCI-/US93/06876
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cleaning processes. Thus it is anticipated that the detergent
compostions of the invention will also be of use in mitigating salt
encrustation in, for example, automatic dishwashing processes, and
~ in any process involving the cleaning of hard surfaces.
According to the present invention there is provided a detergent
composition comprising
(a) from 1% to 80% by weight of a crystalline layered silicate
builder material of formula LMSiXO2x~ 1 yH2O wherein L is
an alkali metal, and M is sodium or hydrogen, x is a number
from 1.9 to 4 and y is a number from 0 to 20;
(b) from 0.05% to 10~ by weight of ethylene di~mine-N,N'-
disuccinic acid, or alkali metal, ~Ik~line earth, ammonium or
substit~te~ ammonium salts thereof, or mixtures thereof;
(c) from 0% to 30% by weight of a detergent surfactant selected
from anionic surfactants, nonionic surfactants, zwitteronic
surfachnts, ampholytic surfactants, cationic surfactants and
mixtures thereof; and
(d) from 0% to 50% by weight of additional non-phosphate
detergent builder compounds.
The detergent compositions of the invention comprise two essential
components, viz. the crystalline layered silicate and the
ethylenediamine-N,N'- disuccinic acid or salt thereof.
The detergent compositions of the invention may have essentially any
physical form. Preferred executions include granular compositions,
especially concentrated granular laundry compositions, and heavy
duty liquid compositions.
The crystalline layered silicate material has the general formula
LMSiX02x+ I-YH20
wherein L is an alkali metal, preferably Na, and M is sodium or
hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to
20. Crystalline layered sodium silicates of this type are disclosed in
EP-A-0164514 and methods for their preparation are disclosed in
~14151~
W O 94/03572 PC~r/US93/0687-
,_
DE-A-3417649 and DE-A-3742043. For the purposes of the
present invention, x in the general formula above has a value of 2, 3
or 4 and is preferably 2. More preferably M is sodium and y is 0
and preferred examples of this formula comprise the o(-, n -, ~- and
~- forms of Na2Si2Os. These materials are available from Hoechst
AG FRG as respectively NaSKS-5, NaSKS-7, NaSKS-l 1 and
NaSKS-6. The most preferred material is -Na2Si2Os, 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 are fragile and break down easily into particles of
size less than 100 micrometers.
In the detergent compositions of the present invention, the crystalline
layered silicate builder material comprises from 1% to 80% by
weight of the composition, more preferably from 5% to 40% and
most ~lerelably from 7% to 20% by weight.
The crys~ e layered sodium silicate material is preferably present
in granular d~tergent compositions in accord with the invention as a
particulate in intim~te 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 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 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
W O 94/03572 2 I ~1610 PC~r/US93/068~
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."~
material and the crystalline silicate and is believed to enh~nce
localised pH reduction when the particulate dissolves in the wash
llquor.
Suitable organic acids include ascorbic, citric, glutaric, gluconic,
glycolic, malic, maleic, malonic, oxalic, succinic and tartaric acids,
1 hydroxy ethane I, l-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
foregomg.
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 20% by weight of the particulate. 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 1-10% by weight of the particulate and most
preferably from 2-5% by weight of the particulate.
Preferred binder agents include the Clo-C20 alcohol ethoxylates
cont~ining from 5-100 moles of ethylene oxide per mole of alcohol
2 l94~l365~1~ Pcr/uss3/06s7
6 w
and more preferably the Cls-C20 primary alcohol ethoxylates
con~ining from 20-100 moles of ethylene oxide per mole of alcohol.
Other preferred binder agents include cerhin 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 maleic anhydride with ethylene, methylvinyl ether or meth~crylic
acid, the maleic anhydride con.ctit~ltin~ 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 Clo-C20 alcohol ethoxylates cont~inin~ from 5-100
moles of ethylene oxide per mole. Further examples of binder agents
include the Clo -C20 mono- and diglycerol ethers and also the Clo-C20
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 suitable binder agents.
The particulate can also include other components that are
conventional in detergent compositions, provided that these are not
incompatible Der se and do not interfere with 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% free moisture and
most preferably less than 1% free moisture.
wo s4/03s72 2 1~ 1 6 1 0 Pcr/uss3/06876
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Other ingredients can also be incorporated in a total amount of up to
~0~ 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 than 5 % by weight of free
(unbound) moisture, preferably less than l ~o.
Non-aqueous liquid components can be incorporated in amounts of
up to 20% 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
extrlldates, 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 the commonly assigned PCT
Application No.WO 92/06163.
The compositions of the invention contain, as an e~senti~l component
from 0.05% to 10% by weight of the composition, preferably from
0.05% to 1% by weight, most preferably from 0.1% to 0.5% by
weight of ethyleneAi~mine-N,N'~isuccinic acid (EDDS) or the alkali
metal, alkaline earth metal, ammonium, or substituted ammonium
salts thereof, or mixtures thereof. Preferred EDDS compounds for
inclusion in the granular detergent compositions are the free acid
form and the sodium or m~gnesium salt thereof. Examples of such
preferred sodium salts of EDDS include Mg EDDS and Mg2 EDDS.
The magnesium complexes are the most preferred for inclusion in
granular compostions in accord with the invention. These complexes
may be added to the compositions as such, or they may be formed
during the process for making the composition by the reaction of an
inert magnesium salt such as MgC12 or Mg SO4 with an EDDS
compound added as either the acid, or as a salt or complex. Where
the EDDS compound is added in the making process, together with
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WO 94/03572 PCI /US93/0687
the inert magnesium salt, it is preferred that the molar ratio of
magnesium to EDDS should be greater than 1:1, preferably greater
than 3:1, to ensure formation of the desired magnesium complexes.
The structure of the acid form of EDDS is as follows.
H-N-CH -CH -N-H
2 2 1
C~12 CH a~ CH
1 2
COOH COOH COOH COOH
EDDS can be synthesised, for example, from readily available,
inexpensive starting materials such as maleic anhydride and
ethylene~i~mine as follows.
2 O=C C=O + NH2 -CH2 -CH2 -NH2 ~ Na~OH ) EDt~S
CH--CH
A more complete disclosure of methods for synthesising EDDS from
commercially available starting materials can be found in US Patent
3,158,635, Kezerian and Ramsay, issued November 24, 1964.
The synthesis of EDDS from maleic anhydride and ethylene diamine
yields a mixture of three optical isomers, [R,R], [S,S], and [S,R],
due to the two asymmetric carbon atoms. The biodegradation of
EDDS is optical isomer-specific, with the [S,S] isomer degrading
most rapidly and extensively, and for this reason the [S,S] isomer is
most preferred for inclusion in the compositions of the invention.
The [S,S] isomer of EDDS can be synthesised from L-aspartic acid
and 1,2-dibromoethane, as follows.
WO 94/03572 2 1 ~ i 6 1 0 PCr/U593/06876
._ 9
NaOH
2 C~2 ~H_ NH2 ~ Br-CH2-CH2_EIr ~ S SlEDDs
~OOH ~H
A more complete disclosure of the reaction of L-aspartic acid with
1,2-dibromoethane to form the [S,S] isomer of EDDS can be found
in Neal and Rose, Stereospecific Ligands and Their Complexes of
Ethylene~i~mine-discuccinic Acid, Inorp~nic Chemistry, Vol. 7
(1968), pp. 2405-2412.
Detergent compositions in accordance with the invention also
comprise in general items those ingredients commonly found in
detergent products which may include organic surfactants, additional
detergent builders, oxygen bleach systems and ancillary materials
such as anti-redeposition and soil suspension agents, suds
suppressors, additional heavy metal ion chelating agents, enzymes,
optical briPhteners, photoactivated bleaches, perfumes and colours.
Some products also include fabric softening and ~ntist~tic agents.
A wide range of surf~ct~nts can be used in the detergent
compositions. A typical listing of anionic, 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 surf~ct~n~s 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: I to I :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 12-C 18 fatty source, preferably from a C 16-C 18
fatty source. In each instance the cation is an alkali metal,
preferably sodium. Preferred sulphate surfactants in such sulphonate
'_ lo 2 ~
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 C14-C~5 alkyl sulphate and C~6-CI8 alkyl sulphate in a
weight ratio of C,4-C,5:C,6-C,8of 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-C20
alkyl sulfate salt with a water-soluble C~-C~9 alkyl ethoxysulfate salt containing an
average of from 1 to 7 ethoxy groups per mole wherein the weight ratio of alkyl
sulfate to alkyl ethyoxysulfate salt lies in the range from 2:1 to 19:1, more
preferably 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 salts include the substantially branched Cl4-CI5
alkyl sulfate salts, that is where the degree of branching of the Cl4-C~5 alkyl chain is
greater than about 20%. Such substantially branched C,4-C,5 alkyl sulfate salts are
usually derived from synthetic sources. Also preferred are C,6-C20 alkyl sulfate salts
which are usually derived from natural sources such as tallow fat and marine oils.
The C,~-CI9 alkyl ethoxysulfate salt comprises a primary alkyl ethoxylsulfate which
is derived from the condensation product of a Cll-C~9 alcohol condensed with an
average of from one to seven ethylene oxide groups, per mole. Preferred are the
C,2-CI5 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 groupsper mole.
~2
The C~-C~9 alcohol itself can be obtained from natural or synthetic sources. Thus,
C~-C~9 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 C,2-C,5 alcohols, Ethyl 24 sold by the Ethyl Corporation, a
blend of C~3-C~5 alcohols in the ratio 67% C~3, 33% C~5 sold under the trade name
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 C"-C,8 alkyl ethoxysulfate is preferably from 0.5% to
10% more preferably from 0.5% to 5% and most preferably from 1% to 3% by
weight of the composition.
Other anionic surfactants suitable for the purposes of the invention are the alkali
metal sarcosinate of formula
R-CON (R') CH2 COOM
wherein R is a C5-C~7 linear or branched alkyl or alkenyl group, R~ is a C,-C4 alkyl
group and M is an alkali metal ion. Preferred examples are the lauroyl, Cocoyl
(C12-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 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 aromatic in nature and the length of the
polyoxyethylene group which is condensed with any particular hydrophobic group
can be readily adjusted to yield a water-soluble compound having the desired degree
of balance between hydrophilic and hydrophobic elements.
Especially preferred nonionic surfactants of this type are the Cg-C15 primary alcohol
ethoxylates containing on average of from 3-8 moles
.
2 1 ~ 1 6 1 ~ ~
WO 94/03572 ~ ~ ~ PCI'/US93/0687
of ethylene oxide per mole of alcohol, particularly the C14-Cls
primary alcohols cont~ining an average of from 6-8 moles of
ethylene oxide per mole of alcohol and the C12-Cls primary
alcohols cont~ininP on 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 (CnH2nO)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~o
short chain alkyl polyglucosides. Compounds of this type and their
use in detergent compositions are disclosed in EP-B 0070074,
0070077, 0075996 and 0094118.
Another preferred nonionic surf~ct~nt is a polyhydroxy fatty acid
amide surfactant compound having the structural formula:
O Rl
Il I
R2 - C - N - Z
wherein: Rl is H, Cl-C4 hydrocarbyl, 2-hydroxy ethyl, 2-hydroxy
propyl, or a mixture thereof, preferably Cl-C4 alkyl, more
preferably Cl or C2 alkyl, most preferably Cl alkyl (i.e., methyl);
and R2 is a Cs-C31 hydrocarbyl, preferably straight chain C7-Clg
alkyl or alkenyl, more preferably straight chain Cg-C17 alkyl or
alkenyl, most preferably straight chain C I l-C 17 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
WO 94/03572 ~ 1 1 1 6 1 0 PCI/US93/06876
. 13
,~_,.,
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 intenr~ed to exclude
other suitable raw materials. Z preferably will be selected from the
group consisting of -CH2-(CHOH)n-CH20H, -CH(CH20H)-
(CHOH)nI-CH20H,-CH2-(CHOH)2(CHOR')(CHOH)-CH20H,
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 -CH2-
(CHOH)4-CH20H.
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.
R2-CO-N ~ can be, for example, cocamide, stearamide, ole~mi~le~
lauramide, myri~t~mi-le, capric~micle, palmitamide, tallowamide,
etc.
Z can be 1-deoxyglucityl, 2-deoxyfructityl, l-deoxymaltityl,
1-deoxylactityl, l-deoxygalactityl, l-deoxymannityl, l-deoxymalto-
triotityl, etc. Preferred compound are N-methyl N-ldeoxyglucityl
C14-Clg fatty acid amides.
A further class of surfactants are the semi-polar surfactants such as
amine oxides. Suitable amine oxides are selected from mono
C8-C20~ preferably Clo-C14 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 C8-C16, preferably Clo-C14 N-alkyl or alkenyl
WO 94/03572 2 i 4 1 6 1 0~ - PCI'/US93/0687f
._
14 _
ammonium surfactants wherein rem~ining N positions are substituted
by methyl, hydroxyethyl or hydroxypropyl groups.
The detergent compositions comprise from 0% to 30% by weight of
surfactant. Laundry detergent compositions more usually comprise
from 5% to 20% by weight of surf~ct~nt, more preferably from 75
to 15~ by weight of the compositions.
Machine dishwashing detergent compositions more usually 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-fo~ming. A typical listing of
surfactants for inclusion in automatic dishwashing detergent
compositions is given in EP-A-0414 549. Most preferred are low-
fo~ming nonionic surf~ct~nts, especially the water soluble
ethoxylated C6-C16 fatty alcohols and C6-C16 mixed
ethoxylated/propoxylated fatty alcohols and mixtures thereof.
P~efer~bly, the ethoxylated fatty alcohols are the Clo-C16
ethoxylated fatty alcohols with a degree of ethoxylation of from 5 to
50, most preferably these are the C12-C16 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.
2'1~1S10 i~i
wo s4/03s72 Pcr/uss3/06876
.~ ,....
",_ 15
Highly preferred components of the detergent compositions of the
invention are other non-phosphate detergent builders, hereinafter
referred to as additional non-phosphate detergent builders. These
can include, but are not restricted to, 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.
Whilst a range of aluminosilicate ion exchange materials can be
used, preferred sodium aluminosilicate zeolites have the unit cell
formula
Naz [(A102 ) z (SiO2 )y ] xH 2~
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, cont~ining from 10% to 28%, more
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 sc~nnin& 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/
WO94/c3~1 41610 PCI/US93/0687f
16
(gram/gallon)] to 390 mg equivalent of CaC03/litre/minute/
(gram/litre) 16 grains/gallon/minute/(gram/gallon)], based on calcium
ion hardness.
Optimum aluminosilicates for builder~rposes exhibit a calcium ion
exchange rate of at least 260 mg equ~alent of CaC03/litre/ mimlte/
(gram/litre) [4 grains/gallon/minute/(gram/gallon)].
Aluminosilicate ion exchange materials useful in the practice of this
invention are commercially available and can be naturally occurring
materials, but are preferably synthetically derived. A method for
producing aluminosilicate ion exchange materials is discussed in US
Patent No. 3,985,669. Preferred synthetic crystalline aluminosilicate
ion exchange materials useful herein are available under the
designations Zeolite A, Zeolite B, Zeolite P, Zeolite X, Zeolite HS,
Zeolite MAP, Zeolite MAB and mixtures thereof. In an especially
preferred embodiment, the crystalline aluminosilicate ion exchange
material is Zeolite A and has the formula
Na 12 [(AlO2 ) 12 (SiO2)l2 ]- xH2 0
wherein x is from 20 to 30, especially 27. Zeolite X of formula
Na86 [(Al~2)86(sio2)lo6]. 276 H20 is also suitable, as well as
Zeolite HS of formula Na6 [(Alo2)6(sio2)6] 7-5 H2 ~)-
Suitable water-soluble monomeric or oligomeric carboxylate builders
can be selected from a wide range of compounds but such
compounds preferably have a first carboxyl logarithmic
acidity/constant (pKl) 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.
21gl61~ ' :
WO 94/03572 ; PCI/USiY3/06876
17
.~",.
The equilibrium constant for dilute solutions is therefore given by the
expression
K 1 = rHA]
- [H + ] [A-]
and pK 1 = log 1 oK -
For the purposes of this specification, acidity con~t~ntc 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 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
(~) Y
al ~C c ~2
Z ~o
~b) Y
X f
or
~c) Y~ ~ ~q
2141610
W O 94/03572 PC~r/US93/0687
18
wherein Rl represents H,CI 30 alkyl or alkenyl optionally
substituted by hydroxy, carboxy, sulfo or phosphono groups or
attached to a polyethylenoxy moiety cont~inin~ up to 20 ethyleneoxy
groups; R2 represents H,C1 4 alkyl, alkenyl o~ hydroxy alkyl, or
alkaryl, sulfo, or phosphono groups;
X represents a single bond; O; S; SO; S(~2; or NRl;
Y represents H; carboxy;hydroxy; carboxymethyloxy; or
Cl 30 alkyl or alkenyl optionally substituted by hydroxy or carboxy
groups;
Z represents H; or carboxy;
m is an integer from l to 10;
n is an integer from 3 to 6;
p, q are integers from 0 to 6, p + q being from l 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 Containin~ 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 cont~inin& two carboxy groups include the water-
soluble salts of succinic acid, malonic acid, (ethylenedioxy) ~i~cetic
acid, maleic 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.
3,93~,257 and the sulfinyl carboxylates described in Belgian Patent
No. 840,623. Polycarboxylates Cont~inin~ 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.
l,379,241, lactoxysuccinates described in British Patent No.
l,389,732, and aminosuccinates described in Netherlands
Application 7205873, and the oxypolycarboxylate materials such as
2-oxa-1,1,3-propane tricarboxylates described in British Patent No.
l ,387,447.
Polycarboxylates containing four carboxy groups include
oxydisuccinates disclosed in British Patent No. l,261,829, 1,1,2,2-
W O 94/03572 2 1 1 6 PC~r/US93/06876
19
. ,._
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.
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 cont~ining Up to three carboxy groups per
molecule, more particularly citrates.
The parent acids of the monomeric or oligomeric polycarboxylate
chel~tin~ agents or mixtures thereof with their salts, e.g. citric acid
or citrate/citric acid mixtures are also contemplated as components
of builder systems of detergent compositions in accordance with the
present invention.
Other suitable water soluble organic salts are the homo- or co-
polymeric polycarboxylic acids or their salts in which the
polycarboxylic acid comprises at least two carboxyl radicals
separated from each other by not more than two carbon atoms.
Polymers of the latter type are disclosed in GB-A-1,596,756.
Examples of such salts are polyacrylates of MWt 2000-5000 and
their copolymers with maleic 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~Zo, most preferably from
1 % to 6% by weight of the composition.
2141610
W O 94/03572 P(~r/US93/06876
-
The compositions of the invention may contain Qptional chelant
ingredients. Such optional chelants may include;the organic
phosphonates, including amino alkylene poly~alkylene phosphonate),
alkali metal ethane l-hydroxy diphospho~es,'nitrilo tremethylene
phosphonates, ethylene ~i~mine tetra methylene phosphonates and
diethylene tri~mine penta methylene phosphonates. The phosphonate
compounds may be present either in their acid form or as a complex
of either an alkali or ~ line 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 ~,259,200. Preferably, the
organic phosphonate compounds where present are in the form of
their m~,~nesium salt. The level of phosphorus cont~ining chelants in
the compositions of the invention is preferably minimi~ed, with their
complete exclusion from the compositions being most preferred.
Whilst soluble silicates serve a variety of purposes in conventional
formulations, their presence is llnnecess~ry in compositions in
accordance with the present invention. 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 detergent 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 being
preferred.
For the purposes of detergent compositions incorporating the
crystalline layered silicates as part of the builder system, the
additional non-phosphate builders will comprise from 0% to 50% by
weight of the compositions, more preferably from 10% to 40% by
weight. Within the preferred 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~Zo by weight of the total
amount of builder and the crystalline layered silicate will comprise
WO94/03572 214~16~1~ PCI'/US93/06876
21
." ._
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 maleic anhydride/acrylic acid copolymers in
amounts of up to 35% by weight of the total builder.
The detergent compositions of the present invention will generally
include an inorganic perhydrate bleach, normally in the form of the
sodium salt. The perhydrate is usually incorporated at a 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
composltlon.
The perhydrate may be any of the inorganic salts such as perborate,
percarbonate, perphosphate and persilicate salts but is conventionally
an alkali metal normally sodium, perborate or percarbonate. Sodium
perborate can be in the form of the monohydrate of nominal formula
NaBO2H2O2 or the tetrahydrate NaBO2H2O2.3H2O.
Sodium percarbonate, which is the preferred perhydrate, is an
addition compound having a formula corresponding to
2Na2CO3.3H2O2 and is available commercially as a crystalline
solid. Alt}~ough the percarbonate can be incorporated into detergent
compositions without additional protection, preferred executions of
such compositions utilise a coated form of the material. The most
preferred coating material comprises salt of an alkali metal sulphate
and carbonate. Such coatings together with coating processes have
previously been described in GB-1,466,799, granted to Interox on
9th March 1977. The weight ratio of the mixed salt coating material
to percarbonate lies in the range from 1:200 to 1:4, more preferably
from 1:99 to 1:9, and most preferably from I :49 to I :19.
Preferably, the mixed salt is of sodium sulphate and sodium
carbonate which has the general formula Na2SO4.n.Na2CO3
wherein n is form 0.1 to 3, preferably n is from 0.3 to 1.0 and most
preferably n is from 0.2 to 0.5.
Another suitable coating material is sodium silicate of SiO2:Na2O
ratio from 1.6:1 to 3.4:1, preferably 2.8:1, applied as an aqueous
WO 94/03572 PCI'/US93/0687
22
solution to give a level of from 2% to 10%, (normally from 3% to
5%) of silicate solids by weight of the percarbonate. Magnesium
silicate can also be included in the coating. Other suitable coating
materials include the alkali and alkaline earth metal sulphates and
carbonates.
Whilst heavy metals present in the sodium carbonate used to
m~nllf~cture the percarbonate can be controlled by the inclusion of
ch~l~nts in the reaction mixture, the percarbonate still requires
protection from heavy metals present as impurities in other
ingredients of the product. Accordingly, in detergent compositions
~ilising percarbonate as the perhydrate salt, the total level of Iron,
Copper and M3n~nese ions in the product should not exceed
25 ppm and preferably should be less than 20 ppm in order to avoid
an lJn~cceptably adverse effect on percarbonate stability. Detergent
compositions in which alkali metal percarbonate bleach has enhanced
stability are disclosed in the Applicant's copending PCT Application
No. WO 92/06163
Bleach systems incorporated into detergent compositions of the
present invention preferably include solid peroxyacid bleach
precursors (bleach activators). The solid peroxyacid bleach
precursors are normally incorporated at a level of from 1 % to 20%,
more preferably from I % to 15~, most preferably from 1 % to 10%
by weight of the composition.
These precursors probably contain one or more N- or O- acyl
groups, which precursors can be selected from a wide range of
classes. Suitable classes include anhydrides, esters, imides and
acylated derivatives of imidazoles and oximes, and examples of
useful materials within these classes are disclosed in GB-A-1586789.
The most preferred classes are esters such as are disclosed in
GB-A-836988, 864,798, 1147871 and 2143231 and imides such as
are disclosed in GB-A-855735 & 1246338.
Particularly preferred precursor compounds are the N,N,NINl tetra
acetylated compounds of formula
WO 94/03572 2 1 1~1 6 1 0 PCT/US93/06876
~__' 23
'.~_
O O
CH3 - C \ / C - CH3
~ N - (CH2)X - N \
CH3 C C - CH3
O O
wherein x can be O or an integer between 1 & 6.
Examples include tetra acetyl methylene di~minto. (TAMD) in which
x= 1, tetra acetyl ethylene diamine (TAED) in which x=2 and
tetraacetyl hexylene di~mine (TAHD) in which x=6. These and
analogous compounds are described in GB-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:
R1 - C - N-R2 - C - L or R1 - N - C-R2 - C - L
d R5 ~ ~5 (~ O
wherein R1 is an aryl or alkaryl group with from about 1 to about 14
carbon atoms, R2 is an alkylene, arylene, and alkarylene group
cont~ining from about 1 to 14 carbon atoms, and R5 is H or an alkyl,
aryl, or alkaryl group cont~ining 1 to 10 carbon atoms and L can be
essenti~lly any leaving group. R1 preferably contains from about 6
to 12 carbon atoms. R2 preferably contains from about 4 to 8
carbon atoms. Rl may be straight chain or branched alkyl,
substituted aryl or alkylaryl cont~ining branching, substitution, or
both and may be sourced from either synthetic sources or natural
sources including for example, tallow fat. Analogous structural
variations are permissible for R2. The substitution can include alkyl,
aryl, halogen, nitrogen, sulphur and other typical substituent groups
or organic compounds. RS is preferably H or methyl. Rl and R5
should not contain more than 18 carbon atoms total. Amide
WO 94/03~;72 2 1 ~ 1 6 1 0 PCI/US93/0687~
24 ~,"
substituted bleach activator compounds of this type are described in
EP-A-0 170386 .
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 also contain organic
peroxyacids at a level of from 1 ~Zo to 15% by weight, more
preferably from 1~ to 10% by weight of the composition . A
particularly preferred class are the amide substituted peroxyacids of
general formulae:
Rl - C - N-R2 - C - OOH or Rl - N - C-R2 C - OOH
O ~5 O R5 O
where R1, R2 and R5 are as defined previously for the
corresponding amide substituted peroxyacid bleach activator
compounds.
Other organic peroxyacids include diperoxy dodecanedioc acid,
diperoxy tetra decanedioc 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.
Detergent compositions in which solid peroxybleach precursors are
protected via an acid coating to minimise 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, carboxymethylceliulose
and hydroxyethycellulose, homo-or co-polymeric polycarboxylic
acids or their salts and ployamino compounds. Polymers of this type
W094/03572 2141610 PCr/US93/06876
.,,~_
include the polyacrylates and copolymers of maleic anhydride with
ethylene, methylvinyl ether or methacrylic acid, the maleic
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~Zo to 10% by weight, more preferably from 0.755Zo
to 8%, most preferably from l ~ to 6~o by weight of the
composltlon.
Other useful polymeric materials are the polyethylene glycols,
particularly those of molecular weight 1000-10000, more particularly
2000 to 8000 and most preferably about 4000. These are used at
levels of from 0.20% to 5% more preferably from 0.25% to 2.5~
by weight. These polymers and the previously mentioned homo- or
co-polymeric polycarboxylate salts are valuable for improving
whiteness m~intenance, 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-diethanolamino4-anilino -s- triazin-
6- ylamino)stilbene-2:21 disulphonate, disodium 4,41 -bis-(2-
morpholino ~-anilino-2-triazin-6-ylaminostilbene-2 :21 -
disulphonate,disodium 4, 4l-bis-(2,4-dianilino-s-triazin-6-
ylamino)stilbene-2:21 - disulphonate, monosodium 41,411 -bis-(2,4-
dianilino-s-triazin-6-ylamino)stilbene-2- sulphonate, disodium 4,41-
bis-(2-anilino-4-(N-methyl-N-2-hydroxyethylamino)-2-triazin-6-
ylamino)stilbene-2,2l - disulphonate, disodium 4,41-bis-(4-phenyl-
2,1,3-triazol-2-yl)stilbene-2,21 disulphonate, disodium 4,41 bis(2-
anilino-4-( l -methyl-2-hydroxyethylamino)-s-triazin-6-
ylamino)stilbene-2,21 disulphonate and sodium 2(stilbyl-411 -
(naphtho- 11,21 :4,5)- 1,2,3 - triazole-211 - sulphonate.
Soil-release agents useful in compositions of the present invention
are conventionally copolymers or terpolymers of terephthalic acid
21~1610
W 0 94/03572 i PC~r/US93/0687
26 _
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
3 ~3 O.~S )0.2StS ~o)2~S-P W )o ~lS~-0--)o ~P~C) CH )
~h-~- P~C 1~ -~oc~)o-,ro ~ (OC3-60) ~~ s 1~ (~COC6~co).
Cerhin 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 particul~tes
in which the suds suppressor is advanhgeously releasably
incorporated in a water-soluble or water~ispersible, substantially
non-surface-active detergent-i,l,petl,leable 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
sil~n~te~ (most preferably trimethyl-silanated) silica having a particle
size in the range from 10 nanometers to 20 nanometers and a specific
surface area above 50 m2/g, intimately admixed with dimethyl
silicone fluid having a molecular weight in the range from about 500
to about 200,000 at a weight ratio of silicone to silanated silica of
from about 1: 1 to about 1 :2.
214161û
W O 94/03572 PC~r/US93/06876
27
, i, .
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 silico 1e suds suppressors,
described in German Patent Application I~TOS 2,646,126 published
April 28, 1977. An example of such a co~npound is DC0544,
commercially available from Dow Cornin~, which is a
siloxanetglycol 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 C20-C24 fatty acids, microcrystalline waxes and high MWt
copolymers of ethylene oxide and propylene oxide which would
other~vise adversely affect the dispersibility of the matrix.
Techniques for forming such suds modifying particulates are
disclosed in the previously mentioned Bartolotta et al US Patent No.
3,933,672.
Another optional ingredient useful in the present invention is one or
more enzymes.
Preferred enzymatic materials include the commercially available
amylases, neutral and alkaline proteases, lipases, esterases and
cellulases conventionally incorporated into detergent compositions.
Suitable enzymes are discussed in US Patents 3,519,570 and
3,533,139.
Preferred commercially available protease enzymes include those
sold under the tradenames Alcalase and Savinase by Novo Industries
21~1610
WO 94/03~72 PCI'/US93/06876
28
A/S (Denmark) and Maxatase by International Bio-Synthetics, Inc.
(The Netherlands).
Preferred amylases include, for example, -amylases obtained from
a special strain of B licheniforms, des~r~ed in more detail in GB-
1,269,839 (Novo). Preferred commerclally available amylases
include for example, Rapidase, sold by International Bio-Synthetics
Inc, and Termamyl, sold by Novo Industries A/S.
An especially preferred lipase enzyme is m~nl~factured and sold by
Novo Industries A/S (Denmark) under the trade name Lipolase
(Biotechnology Newswatch, 7 March 1988, page 6) and mentioned
along with other suitable lipases in EP-A-0258068 (Novo).
Fabric softening agents can also be incorporated into detergent
compositions in accordance with the present invention. These agents
may be inorganic or organic in type. Inorganic softening agents are
examplified by the smectite clays disclosed in GB-A-1,40~,898.
Organic fabric soRening agents include the water insoluble tertiary
amines as disclosed in GB-A-1514276 and EP-B-0011340.
Their combination with mono C12-C14 quaternary ammonium salts
is disclosed in EP-B-0026527 & 528. Other useful organic fabric
softening agents are the dilong chain amides as disclosed in EP-B-
0242919. Additional organic ingredients of fabric softening systems
include high molecular weight polyethylene oxide materials as
disclosed in EP-A-0299575 and 0313146.
Levels of smectite clay are normally in the range from 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 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 spray dried, these
WO 94/03572 2 1 4 1 6 1 0 PCI/US93/06876
.. ,._
29
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.
In general granular detergent compositions in accordance with the
present invention can be made via a variety of methods including dry
mixing, spray drying, agglomeration and gr~nlJl~tion and preferred
methods involve combinations of these techniques. A preferred
method of m~lcin,~ the compositions involves a combination of spray
drying, agglomeration in a high speed mixer and dry mixing.
The bulk density of the granular detergent compositions of the
present invention may be in the range of about 400 to 600 g/litre as
is typical for conventional laundry delergent compositions.
Alternatively, the granular detergent compositions may be
concentrated granular detergent compositions that are characterised
by a relatively high density in comparison with conventional laundry
detergent compositions. Such high density compositions have a bulk
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 of a simple funnel and cup device
consictin~ of 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 be emptied into an axially aligned cylindricl 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 of the base. The cup
has an overall height of 90 mm, an internal height of 87 mm and an
internal diameter of 84 mm. Its nominal volume is 500 ml.
To carry out a measurement, the funnel is filled with powder by
hand pouring, the flap valve is opened and powder allowed to
overfill the cup. The filled cup is removed from the frame and
excess powder removed from the cup by passing a straight edged
implement e.g. a knife, across its upper edge. The filled cup is then
weighed and the value obtained for the weight of powder doubled to
W O 94/03572 2 1 4 1 6 1 Q - ' PC~r/US93/0687~
provide the bulk density in g/litre. Replicate measurements are made
as required.
Concentrated detergent compositions also nor~lly incorporate at
least one multi-ingredient component i.e. th~g~do not comprise
compositions formed merely by dry-mixi~individual ingredients.
Compositions in which each individual ingredient is dry-mixed are
generally dusty, slow to dissolve and also tend to cake and develop
poor particle flow characteristics in storage.
Preferred granular detergent compositions in accordance with the
invention comprise at lease 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 prefe~ably 10% to 40% by weight of the
composition.
The first component comprises a particulate incorporating an anionic
surfact~nt 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
atomisin~ 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
WO 94/03572 2 1 4 1 6 1 0 PCI/US93/06876
31
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 weight, more usually
2.5% to 25% preferab!y from 3% to 20% and most preferably from
5% to 15% by weight. Water-soluble surf~c~ntc such as linear alkyl
benzene sulphonates or C14-Cls 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 crys~ ne 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 aluminosilic~te 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
wo 94~03572 2 1 4 1 6 1 0 ' i Pcr/uss3/0687~
32
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.
The particle size of the first comp~nënt is conventional and
preferably not more than 5 % by weight should be above 1 .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 composition in accordance with
the invention is another multi-ingredient particulate cont~ining 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 C14-CIs alkyl sulphates, linear Cl 1-
Cls alkyl benzene sulphonates and fatty C14-CIg 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
21~I61,n,
WO 94/03~72 PCl'/US93/06876
,~_
~_ 33
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.
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
by adding the ingredients dry or with an agglomerating agent to a
pan agglomerator, Z blade mixer or more l~ref~rdbly an in-line mixer
such as those manufactured by Schugi (Holland) BV, 29
Chroomstraat 8211 AS, Lelystad, Netherlands and Gebruder Lodige
MaschinenbanGmbH, D4790 Paderborn 1, Flce~erstrasse 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 compositions include a 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.
A highly preferred ingredient of the second component is also a
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 aniount of water insoluble
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 liquid acid form 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
mixture. The resultant agglomerated mixture forms the second
component which is then added to other components of the product.
W O 94/03572 2 1 ~ 1 6 1 0 : PC~r/US93/0687~
34
In a variant of this process, the surfactant 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 aggl~merate the ingredients
to form the second component.
In a particularly preferred process f~r m~king the granular detergent
compositions of the invention, part of the spray dried product
comprising the first granular component is diverted and subjected to
a low level of nonionic surfachnt spray on before being reblended
with the rem~in~er. The second granular component is made using
the preferred process described above. The first and second
components together with the cryshlline layered silicate particulate
compositions, 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
horizonhlly rotating drum in which perfume and silicone suds
sllp~ressor 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 cryst~lline
material is introduced to increase density and improve granular flow
characteristics .
In preferred concentrated detergent products incorporating an alkali
mehl percarbonate as the perhydrate salt it has been found necessary
to control several aspects of the product such as its heavy mehl ion
content and its equilibrium relative humidity. Sodium percarbonate-
conhining compositions of this type having enhanced stability are
disclosed in the commonly assigned PCT Application No. WO
92/061 63.
Laundry 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.
WO 94/03~72 2 1 4 1 B 1 ~ P~/US93/06876
Delivery to the~ drum can most easily be achieved by incorporation of
the composition in a bag or container from~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 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 constNction 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, l~min~te~ 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 deposited in measured amounts,
with a second layer overlying the first layer and sealed thereto in
2l4l6la
W O 94/03572 ~ PC~r/US93/0687
36
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 l~min~te layers~s~ould prevent egress
of the contents of the pouch-like containers ~ri'or to their addition to
water. The layers may separate or may.rëmain 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 l~lnin~te layers
in this aspect of the invention include, among others, sponges, paper
and woven and non-woven fabrics.
However the preferred means of carrying out a laundry process is to
introduce the composition into the liquid surro!~n~ing the fabrics that
are in the drum via a reusable dispen~in~ device having walls that
are permeable to liquid but in.per,..eable 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 orifice into the washing medium. The support ring is
provided with a m~ing arrangement to prevent egress of wetted,
undissolved, product, this arrangement typically comprising radially
extending walls extending from a central boss in a spoked wheel
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 products which are of a type
commonly known as the "granulette".
WO 94/03~72 2 1 ~ 1 6 1 0 PCr/US93/06876
' .................................. 37
The invention is illustrated in the following non limiting Examples,
in which all percentages are on a weight basis unless otherwise
stated.
,
2141610
WO 94/03572 PCI'/US93/0687~'
38
In the detergent compositions, the abbreviated component
identifications have the following meanings:
LAS : Sodium linear C12 alky~-~benzene
sulphonate
TAS : Sodium tallow alkyl~sulphate
TAEn : Tallow alcohol ethoxylated with n moles of
ethylene oxide per mole of alcohol
2~EY : A C12 1s predomin~ntly linear primary
alcohol con~lel~serl with an average of Y
moles of ethylene oxide
TAED : Tetraacetyl ethylene ~ mine
Silicate : Amorphous Sodium Silicate (SiO2:Na2O
ratio normally follows)
NaSKS-6 : Crystalline layered silicate of formula
~ -Na2Si2os
Carbonate : Anhydrous sodium carbonate
CMC : Sodium carboxymethyl cellulose
Zeolite A : Hydrated Sodium Aluminosilicate of
formula Nal2(A 1 ~2SiO2) 1 2. 27H20
having a primary particle size in the range
from I to 10 micrometers
Polyacrylate : Homopolymer of acrylic acid of MWt 4000
Citrate : Tri-sodium citrate dihydrate
MA/AA : Copolymer of 1:4 maleic/acrylic acid,
average molecular weight about 80,000.
WO 94/03572 2 1 ~ 1 6 1 0 PCI~/US93/06876
. 39
,~_
Perborate : Anhydrous sodium perborate monohydrate
bleach, empirical formula NaBO2.H2O2
Enzyme : Mixed proteolytic and amylolytic
enzyme sold by Novo Industries AS.
DETPMP : Diethylene tri~mine penta (methylene
phosphonic acid), marketed by Monsanto
under the Trade name Dequest 2060
Suds : 25% paraffin wax Mpt 50~C, 17%
Suppressor hydrophobic silica, 58% paraffin oil.
EDDS Ethylenediamine -N, N - disuccinic acid,
[S,S] isomer in the form of its sodium salt.
wo 94/03s72 2 1 4 1 6 1 0 Pcr/US93/06876
Example I
The following detergent compo'sitions were prepared (parts by
weight). Compositions A-D are prior art at compositions and
composition E is in accordance with the invention.
A B C D E
LAS 7-7 7-7 7-7 7-7 7-7
TAS 2.4 2.4 2.4 2.4 2.4
TAE11 l.l 1.1 1.1 l.l 1.1
25E3 3 3 3 3 3 3 3 3 3 3
Zeolite A l9.5 19.5 19.5 13.0 13.0
Citrate 6.5 6.5 6.5
MA/AA 4.3 4.3 4.3 4 3 4 3
NaSKS-6* - - - 10.0 10.0
Citric Acid* - - - 2.7 2.7
TAE50* - - - 0.3 0.3
Carbonate 1t.1 11.1 11.1 9.8 9.8
Perborate 16.0 16.0 16.0 16.0 16.0
TAED 5.0 5.0 5 0 5 0 5 0
EDDS - - 0.2 - 0.2
CMC 0.5 0.5 0.5 0.5 0.5
Suds Suppressor 0.5 0.5 0.5 0.5 0.5
Enzyme 1.4 1.4 1.4 1.4 1.4
Silicate (2.0 ratio) 4.4 4.4 4.4
MgSO4 0.4 0.4 0.4 0.4 0.4
DETPMP - 0.4 - - -
Water minors and miscellaneous to balance
* Present as components of crystalline layered silicate particulates
W O 94/03572 2 ~ 4 1 fi 1 0 ' ; PC~r/US93/06876
~_ 41
The performance of the three compositions was compared in full
scale twenty-five cycle washing machine tests using Miele 701
washing machines. Each full wash-cycle comprised a pre-wash and
main-wash cycle. The boilwash setting (temperature = 95~C) was
selected for each wash cycle 'and water of 25~ German Hardness
(Ca: Mg = 3: l) was employed. Each laundry load comprised four
15 cm x 30 cm pieces of each of clean white terry towel, knitted
cotton and cotton fabrics. Before the comm~-~cement of the first full
wash cycle the laundry load together with 20 g of artificial soil and a
dispe~ing device of the "granulette" type con~inin~ 100 g of the
detergent product was placed in the drum of the washing machine.
For each of the subsequent twenty four full wash cycles the same
amount of detergent product and artificial soil was used. The
artificial soil comprised; Sg of palmitic acid, Sg of stearic acid, 4g of
sieved clay, 3g of glycerol/trioleate and 3g of dirty motor oil. At the
end of the twenty fifth full wash cycle the laundry load was removed
from the m~chine, dried and then an ~ssesslnent of the
whiteness/dinginess and heavy metal ion content of each of the four
pieces of the three types of fabric was made.
Whiteness In~inter~nce.
The whiteness/-lingine~s of each piece of fabric was assessed by an
expert panel using a five point Scheffe scale. The combined
averaged results of each of the three sets of comparisons are as set
out below, with prior art composition A which contains no
crystalline layered silicate or chelant being used as the common
reference.
B/A C/A D/A E/A
0.89 0.04 0.39 1.75 s
s = statistically significant at the 95% confidence level.
The comparison B/A shows the advantage obtained for the inclusion
of a phosphonate chelant in the composition A. The comparison C/A
shows the very minor advantage obtained when EDDS is similarly
added to the composition A (NB: 0.2~Zo by weight EDDS is
W O 94/03572 2 1 4 1 6 1 0 PC~r/US93/0687'
42
approximately an equimolar amount to 0.4% by weight DETPMP).
The comparison D/A shows the small advantage obtained when a
proportion of the Zeolite A, and all of the citrate and silicate of
composition A is replaced by crystalline layeréd silicate particulates
cont~ining SKS-6, citric acid and TAE50. .~he comparison E/A
shows the significant advantage obtained ~or the use of composition
E in accordance with the invention.
Heavy metal ion content
The heavy metal ion content of the inorganic salt encrustations
adhered to each of the fabrics was measured using the following
procedure. A sample of at least 2 grams in weight was cut out from
each piece of fabric obtained from the hereinbefore described twenty
five cycle test procedure. The sample was then placed in a clean
porcelain crucible and heated in a fume hood using a bunsen burner
until the fabric caught fire and was burnt out completely, to leave
any inorganic salt residues in the crucible. The inorganic salt
resi~ es were weighed using an accurate chemical balance and then
dissolved in a known volume of lM sulphuric acid solution. The
iron, copper, zinc and m~n~nese ion content of this solution was
then determined using atomic absorption spectroscopy and thus the
iron, copper, zinc and manganese content of the inorganic residues
was obtained.
The total average iron, copper, zinc and manganese content of the
inorganic residues obtained for the fabrics tested using compositions
C,D and E are as set out below.
C D E
2400 ppm 950 ppm 690 ppm
