Technical field
[0001] This invention relates to detergent compositions. In particular, it relates to granular
detergent compositions suitable for washing fabrics, clothes etc in automatic washing
machines with improved cleaning performance.
Background
[0002] Cationic surfactants have been frequently incorporated into detergent compositions
of various types. However, the inclusion of such cationic surfactants is generally
for the purpose of providing some adjunct fabric care benefit, and not for the purpose
of cleaning. For example, certain cationic surfactants have been included in detergent
compositions for the purpose of yielding a germicidal or sanitization benefit to washed
surfaces, as is disclosed in U.S Patent 2,742,434, Kopp, issued April 17,1956; U.S.
Patent 3,539,520, Cantor et al, issued November 10, 1970; and U.S. Patent 3,965,026,
Lancz, issued June 22, 1976. Other cationic surfactants such as ditallowdimethylammonium
chloride, have been included in detergent compositions for the purpose of yielding
a fabric-softening benefit, as disclosed in U.S. Patent 3,607,763, Salmon et al, issued
September 21, 1971; and U.S. Patent 3,644,203, Lamberti et al, issued February 22,
1972. Such components are also disclosed as being included in detergent compositions
for the purpose of controlling static, as well as softening laundered fabrics, in
U.S. Patent 3,951,879, Wixon, issued April 20, 1976; and U.S. Patent 3,959,157 Inamorato,
issued May 25, 1976.
[0003] Certain water-soluble cationic surfactants are also known to enhance cleaning performance,
especially on greasy and oily soils, when used in combination with nonionic or anionic
surfactants, see for instance European Patent Application, Publication No. 225. For
optimum grease detergency performance, however, these compositions require relatively
high levels of the cationic and nonionic surfactant components in relation to the
anionic surfactant level and this can result in a lack of "robustness", particularly
in the areas of clay soil detergency and whiteness maintenance, when the compositions
are used in multicycle wash-wear treatments in the presence of rinse-added cationic
fabric softener. Moreover, the compositions have their greatest effectiveness at medium
to high wash temperature (50°C and above); at low wash temperatures (up to about 40°C)
on the other hand, the rate of oil removal is greatly reduced and excessively long
wash times are required for optimum performance.
[0004] The Applicants have now discovered, however, that excellent grease/oil and lipid
soil removal performance can be secured simultaneously with good clay soil detergency
and whiteness maintenance, under realistic multicycle wash-wear conditions, including
low wash temperatures and carry-over of rinse-added softener, by using an anionic
surfactant together with a low level of an auxiliary surfactant system consisting
of a mixture of a water-soluble cationic surfactant and a semipolar amine-oxide surfactant.
[0005] The addition of amine-oxides to detergent compositions is not new of course. Thus
U.S. Patents 3,531,526, 4,133,779 and 3,202,714 all relate to detergent compositions
employing amine oxides at relatively high levels in a conventional detergent functionality.
However, there is apparently no appreciation in the art of the value of low levels
of mixed amine-oxide/cationic surfactant systems in improving low temperature cleaning
of greasy, oily and lipid soils under realistic multi-cycle wash-rinse-wear conditions.
[0006] The invention thus provides granular detergent compositions suitable for heavy duty
laundering purposes having improved cleaning performance especially on greasy, oily
and lipid soils without detriment to detergency performance on clay soils and without
detriment to the soil suspending or fabric whitening characteristics of the compositions,
across the range of wash temperatures and under realistic soil, fabric load and multi
wash-rinse-wear cycle conditions.
Summary of the invention
[0007] According to the present invention, there is provided a granular detergent composition
having a pH in 1% by weight aqueous dispersion of at least 7, comprising:
(a) from 2% to 60% by weight of surfactant selected from anionic surfactants and mixtures
thereof with nonionic, zwitterionic and ampholytic surfactants;
(b) from 0.5% to 6% by weight of cosurfactant comprising a 5:1 to 1:5 weight ratio
mixture of
(i) amine oxide having the general formula I:

wherein R is a linear or branched alkyl or alkenyl group having 10 to 14 carbon atoms,
each R1 is independently selected from methyl and ―(CnH2nO)mH where i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to 3,
the sum total of CnH2nO groups in a molecule being no more than 5, and
(ii) quaternary ammonium surfactant having the general formula II:

wherein R is a linear or branched alkyl, alkenyl or alkaryl group having 10 to 14
carbon atoms and each R3 is independently selected from methyl and ―(CnH2nO)m wherein i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to
3, the sum total of CnH2nO groups in a molecule being no more than 5, and wherein Z represents counteranion
in number to give electrical neutrality, wherein the weight ratio of surfactant:cosurfactant
is at least 1:1 and wherein the equivalent ratio of anionic surfactant:cationic surfactant
is also at least 1:1; and
(c) from 5% to 70% by weight of organic or inorganic detergent builder salt.
[0008] Detergent compositions of the invention contain a primary surfactant which is an
anionic surfactant or a mixture thereof with nonionic, zwiterionic or ampholytic surfactants,
and a cosurfactant which is a mixture of water-soluble quaternary ammonium surfactant
and amine-oxide. The primary surfactant constitutes from 2% to 60% of the detergent
compositions, preferably from 4% to 25%, and especially from 8% to 20%. The auxiliary
surfactant system is preferably from 1 % to 4% of the detergent composition with the
amine oxide and quaternary ammonium surfactants being present at a weight ratio of
from 3:1 to 1:3, with the individual cosurfactants each preferably constituting up
to 1.5% by weight of composition.
[0009] The weight ratio of surfactant:cosurfactant is at least 1:1, preferably from 2:1
to 50:1, more preferably from 3:1 to 20:1. Importantly, the anionic surfactant component
is present at an equivalent ratio with respect to the water-soluble quaternary ammonium
surfactant of at least 1:1. This is necessary for ensuring optimum grease and lipid
soil removal and good suspension of soil in the detergent wash liquor, and for achieving
excellent whiteness under multicycle wash-rinse-wear conditions.
[0010] Although as discussed above an anionic surfactant is an essential component of the
present compositions, preferred compositions contain as the primary surfactant a mixture
of anionic and alkoxylated nonionic surfactants in a weight ratio of from 20:1 to
1:5, more preferably from 6:1 to 1:3, especially from 5:1 to 1:1. Such compositions
are desirable from the point of view of providing optimum grease, lipid and particulate
detergency.
[0011] Optimum performance also depends sensitively on the choice of nonionic surfactant
and especially desirable from the viewpoint of grease detergency are biodegradable
nonionic surfactants have a lower consolute temperature in the range from about 25°C
to about 65°C, more preferably from about 30°C to about 50°C. Highly suitable nonionic
surfactants of this type have the general formula RO(CH
2CH
2O)
nH wherein R is primary or secondary branched or unbranched C
9-15alkyl or alkenyl and n (the average degree of ethoxylation) is from 2 to 9, especially
from 3 to 8. More hydrophilic detergents can be employed for providing particulate
detergency and anti-redeposition, however, for instance, nonionic detergents of the
general formula given above wherein R is primary or secondary, branched or unbranched
C
S-
24 alkyl or alkenyl and n is from 10 to 40. Combinations of the two classes of nonionic
surfactants can also be used with advantage of course.
[0012] The compositions of the invention are formulated to have a pH of at least 7 in the
laundry solution at conventional usage concentrations (about 1% by weight) in order
to optimize cleaning performance. Granular compositions herein preferably have a pH
of from 8.5 to 11.
[0013] The individual components of the present compositions will now be discussed in detail.
[0014] The anionic surfactant may be any one or more of the materials used conventionally
in laundry detergents. Suitable synthetic anionic surfactants are water-soluble salts
of alkyl benzene sulphonates, alkyl sulphates, alkyl polyethoxy ether sulphates, paraffin
sulphonates, alpha-olefin sulphonates, alpha- sulpho-carboxylates and their esters,
alkyl glyceryl ether sulphonates, fatty acid monoglyceride sulphates and sulphonates,
alkyl phenol polyethoxy ether sulphates, 2-acyloxy alkane-1-sulphonate, and beta-
alkyloxy alkane sulphonate.
[0015] A particularly suitable class of anionic surfactants includes water-soluble salts,
particularly the alkali metal, ammonium and alkanolammonium salts or organic sulphuric
reaction products having in their molecular structure an alkyl or alkaryl group containing
from about 8 to about 22, especially from about 10 to about 20 carbon atoms and a
sulphonic acid or sulphuric acid ester group. (Included in the term "alkyl" is the
alkyl portion of acyl groups). Examples of this group of synthetic detergents which
form part of the detergent compositions of the present invention are the sodium and
potassium alkyl sulphates, especially those obtained by sulphating the higher alcohols
(C
S-
1s) carbon atoms produced by reducing the glycerides of tallow or coconut oil and sodium
and potassium alkyl benzene sulphonates, in which the alkyl group contains from about
9 to about 15, especially about 11 to about 13, carbon atoms, in straight chain or
branched chain configuration, e.g. those of the type described in US-A-2,220,099 and
2,477,383 and those prepared from alkylbenzenes obtained by alkylation with straight
chain chloroparaffins (using' aluminium trichloride catalysis) or straight chain olefins
(using hydrogen fluoride catalysis). Especially valuable are linear straight chain
alkyl benzene sulphonates in which the average of the alkyl group is about 11.8 carbon
atoms, abbreviated as C11.S LAS.
[0016] Other anionic detergent compounds herein include the sodium C,
1-
18 alkyl glyceryl ether sulphonates, especially those ethers of higher alcohols derived
from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphonates
and sulphates; and sodium or potassium salts of alkyl phenol ethylene oxide ether
sulphate containing about 1 to about 10 units of ethylene oxide per molecule and wherein
the alkyl groups contain about 8 to about 12 carbon atoms.
[0017] Other useful anionic detergent compounds herein include the water-soluble salts or
esters of a-sulphonated fatty acids containing from about 6 to 20 carbon atoms in
the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble
salts of 2-acyloxy-alkane-1-sulphonic acids containing from about 2 to 9 carbon atoms
in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety;
alkyl ether sulphates containing from about 10 to 18, especially about 12 to 16, carbon
atoms in the alkyl group and from about 1 to 12, especially 1 to 6, more especially
1 to 4 moles of ethylene oxide; water-soluble salts of olefin sulphonates containing
from about 12 to 24, preferably about 14 to 16, carbon atoms, especially those made
by reaction with sulphur trioxide followed by neutralization under conditions such
that any sultones present are hydrolysed to the corresponding hydroxy alkane sulphonates;
water-soluble salts of paraffin sulphonates containing from about 8 to 24, especially
14 to 18 carbon atoms, and β-alkyloxy alkane sulphonates containing from about 1 to
3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane
moiety.
[0018] The alkane chains of the foregoing non-soap anionic surfactants can be derived from
natural sources such as coconut oil or tallow, or can be made synthetically as for
example using the Ziegler or Oxo processes. Water solubility can be achieved by using
alkali metal, ammonium or alkanolammonium cations; sodium is preferred. Suitable fatty
acid soaps can be selected from the ordinary alkali metal (sodium, potassium), ammonium,
and alkylolammonium salts of higher fatty acids containing from about 8 to about 24,
preferably from about 10 to about 22 and especially from about 16to about 22 carbon
atoms in the alkyl chain. Suitable fatty acids can be obtained from natural sources
such as, for instance, from oil, soybean oil, caster oil, tallow, whale and fish oils,
grease, lard and mixtures thereof). The fatty acids also can be synthetically prepared
(e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the
Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids
in tall oil. Naphthenic acids are also suitable. Sodium and potassium soaps can be
made by direct saponification of the fats and oils or by the neutralization of the
free fatty acids which are prepared in a separate manufacturing process. Particularly
useful are the sodium and potassium salts of the mixtures of fatty acids derived from
tallow and hydrogenated fish oil.
[0019] Nonionic surfactants which may be used in the present invention are condensates of
ethylene oxide with a hydrophobic moiety to provide a surfactant having an average
hydrophilic-lipophilic balance (HLB) in the range from about 8 to 17, preferably from
about 9.5 to 13.5, more preferably from about 10 to about 12.5. The hydrophobic 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.
[0020] Examples of suitable nonionic surfactants include:
1. The polyethylene oxide condensates of alkyl phenol, e.g. the condensation products
of alkyl phenols having an alkyl group containing from 6 to 12 carbon atoms in either
a straight chain or branched chain configuration, with ethylene oxide, the said ethylene
oxide being present in amounts equal to 3 to 30, preferably 5 to 14 moles of ethylene
oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived,
for example, from polymerised propylene, di-isobutylene, octene and nonene. Other
examples include dodecylphenol condensed with 9 moles of ethylene oxide per mole of
phenol; dinonylphenol condensed with 11 moles of ethylene oxide per mole of phenol;
nonylphenol and di- isooctylphenol condensed with 13 moles of ethylene oxide.
2. The condensation product of primary or secondary aliphatic alcohols having from
8 to 24 carbon atoms, in either straight chain or branched chain configuration, with
from 2 to about 40 moles, preferably 2 to about 9 moles of ethylene oxide per mole
of alcohol. Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms
and is ethoxylated with between 2 and 9, desirably between 3 and 8 moles of ethylene
oxide per mole of aliphatic alcohol. The preferred surfactants are prepared from primary
alcohols which are either linear (such as those derived from natural fats or, prepared
by the Ziegler process from ethylene, e.g. myristyl, cetyl, stearyl alcohols), or
partly branched such as the Lutensols, Dobanols and Neodols which have about 25% 2-methyl
branching (Lutensol® being a Trade Name of BASF, DobanolO and Neodolg being Trade Names of Shell), or Synperonics, which are understood to have about 50%
2-methyl branching (Synperonic® is a Trade Name of I.C.I.) or the primary alcohols having more than 50% branched
chain structure sold under the Trade Name Lial@ by Liquichimica. Specific examples of nonionic surfactants falling within the scope
of the invention Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-3, Dobanol 91-6,
Dobanol 91-8, Synperonic 6, Synperonic 14, the condensation products of coconut alcohol
with an average of between 5 and 12 moles of ethylene oxide per mole of alcohol, the
coconut alkyl portion having from 10 to 14 carbon atoms, and the condensation products
of tallow alcohol with an average of between 7 and 12 moles of ethylene oxide per
mole of alcohol, the tallow portion comprising essentially between 16 and 22 carbon
atoms. Secondary linear alkyl ethoxylates are also suitable in the present compositions,
especially those ethoxylates of the Tergitol series having from about 9 to 15 carbon
atoms in the alkyl group and up to about 11, especially from about 3 to 9, ethoxy
residues per molecule.
[0021] Also useful are the compounds formed by condensing ethylene oxide with a hydrophobic
base formed by the condensation of propylene oxide with propylene glycol. The molecular
weight of the hydrophobic portion generally falls in the range of about 1500 to 1800.
Such synthetic nonionic detergents are available on the market under the Trade Name
of "Pluronic" supplied by Wyandotte Chemicals Corporation.
[0022] Especially preferred nonionic surfactants for use herein are the C
9―C
15 primary alcohol ethoxylates containing 3-8 moles of ethylene oxide per mole of alcohol,
particularly the C
12―C
15 primary alcohols containing 6-8 moles of ethylene oxide per mole of alcohol.
[0023] A further essential component of the present compositions is an amine-oxide having
the general formula I

wherein R is a linear or branched alkyl or alkenyl group having from 10 to 14 carbon
atoms and each R
1 is independently selected from methyl and ―(C
nH
2nO)
mH wherein m is from 1 to 3 and the sum total of C
nH
2nO groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred
embodiment, j is 0 and each R
1 is methyl, and R is C
12-C
14 alkyl.
[0024] The quarternary ammonium surfactant component of the present composition is defined
by the general formula:

wherein R
2 is a linear or branched alkyl, alkenyl or alkaryl group having from 10 to 14 carbon
atoms and each R
3 is independently selected from methyl and (C
nH
2nO)
mH wherein m is from 1 to 3 and the sum total of C
nH
2nO groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred
embodiment j is 0, R
3 is selected from methyl, hydroxyethyl and hydroxypropyl and R is C
12-C
14 alkyl. Particularly preferred surfactants of this class include C
12 alkyl trimethylammonium salts, C
14 alkyltrimethylammonium salts, coconutalkyltrimethylammonium salts, coconutalkyldimethylhydroxyethyl-
ammonium salts, coconutalkyldimethylhydroxypropylammonium salts, and C
i2 alkyldihydroxyethyl- methylammonium salts.
[0025] Another group of useful cationic compounds are the diammonium salts of formula II
in which j is 1, R
2 is C
12-C
14 alkyl, each R
3 is methyl, hydroxyethyl or hydroxypropyl and i is 2 or 3. In a particularly preferred
surfactant of this type, R
2 is coconut alkyl, R
3 is methyl and i is 3.
[0026] The compositions of the invention also include at least one detergent organic or
inorganic builder salt which can be any one of the water soluble or water insoluble
salts conventionally used for this purpose. Suitable inorganic builder salts include
orthophosphates, pyrophosphates, tripolyphosphates and the higher polymeric glassy
phosphates, silicates, carbonates, and the water insoluble crystalline aluminosilicates
such as hydrated Zeolite A, X or P. Organic builder salts include the aminocarboxylates
such as the salts of nitrilotriacetic acid (NTA), ethylenediaminetetra acetic acid
(EDTA) and diethytenetriaminepenta acetic acid (DETPA) and the methylene phosphonate
analogues of these materials NTMP, EDTMP and DETPMP, as well as the salts of polycarboxylic
acids such as lactic acid, glycollic acid and ether derivatives thereof as disclosed
in Belgian Patents 821,368,821,369 and 821,370; succinic acid, malonic acid, (ethylene-
dioxy) diacetic acid, maleic acid, diglycollic acid, tartaric acid, tartronic acid
and fumaric acid; citric acid, aconitic acid, citraconic acid, carboxymethyloxysuccinic
acid, lactoxysuccinic acid, and 2-oxy-1,1,3-propane tri-carboxylic acid; oxydisuccinic
acid, 1,1,2,2-ethane tetracarboxylic acid, 1,1,3,3-propane tetracarboxylic acid and
1,1,2,3-propane tetracarboxylic acid; cyclo-pentane-cis, cis, cis-tetracarboxylic
acid; cyclopentadienide pentacarboxylic acid, 2,3,4,5-tetrahydrofuran-cis, cis, cis-tetracarboxylic
acid, 2,5-tetrahydrofuran-cis-dicarboxylic acid, 1,2,3,4,5,6-hexane-hexacarboxylic
acid, mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed
in British Patent 1,425,343.
[0027] The builder salts comprise from 5% to 70% by weight of the composition, preferably
from 10% to 50% by weight.
[0028] The compositions of the present invention can be supplemented by all manner of detergent
components. Soil suspending agents at about 0.1% to 10% by weight such as water-soluble
salts of carboxymethyl-cellulose, carboxyhydroxymethyl cellulose, and polyethylene
glycols having a molecular weight of about 400 to 10,000 are common components of
the present invention. Dyes, pigments, otpical brighteners, and perfumes can be added
in varying amounts as desired.
[0029] Other materials such as fluorescers, enzymes in minor amounts, anti-caking agents
such as sodium sulfosuccinate, and sodium benzoate can also be added. Enzymes suitable
for use herein include those discussed in U.S. patents 3,519,570 and 3,533,139 to
McCarty and McCarty et al issued July 7, 1970 and January 5, 1971 respectively.
[0030] Anionic fluorescent brightening agents are well-known materials, examples of which
are disodium 4,4'-bis-(2-diethanolamino-4-anilino-s-triazin-6-ylamino)stilbene-2:2'-disulphonate,
disodium 4,4'-bis-(2-morpholino-4-anilino-s-triazin-6-ylaminostillbene-2:2'-disulphonate
disodium 4'4-bis-(2,4-dianilino-s-triazin-6-ylamino)stilbene-2:2'-disulphonate, disodium
4,4-bis-(2-anilino-4-(N-methyl-N-2-hydroxyethyl- amino)-S-triazin-6-ylamino)stilbene-2,2'-disulphonate,
disodium 4,4'-bis-(4-phenyl-2,1,3-triazol-2yl)-stilbene-2,2'-disulphonate, disodium
4,4'-bis-(2-anilino-4-(1-methyl-2-hydroxyethylamino)-S-triazin-6-yl- amino)stilbene-2,2'-disulphonate
and sodium 2(stilbyl-4"-(naphtho-1',2':4,5)-1,2,3-triazole-2"-sulphonate.
[0031] An alkali metal, or alkaline earth metal, silicate can also be present. The alkali
metal silicate preferably is used in an amount from 0.5% to 10% preferably from 3%
to 8%. Suitable silicate solids have a molar ratio of SiOp/alkali metal
20 in the range from about 0.5 to about 4.0, but much more preferably from 1.0 to 1.8,
especially about 1.6. The alkali metal silicates suitable herein can be commercial
preparations of the combination of silicon dioxide and alkali metal oxide, fused together
in varying proportions.
[0032] The present compositions also contain suds regulating components in an amount of
from about 0.05% to about 3%. Preferred are microcrystalline waxes having a melting
point in the range from 35°C-115°C and saponification value of less than 100. The
microcrystalline waxes are substantially water-insoluble, but are water-dispersible
in the presence of organic surfactants. Preferred microcrystalline waxes having a
melting point from about 65°C to 100°C, a molecular weight in the range from 400-1000;
and a penetration value of at least 6, measured at 77°C by ASTM-D1321. Suitable examples
of the above waxes include micro- crystalline and oxidized micro-crystalline petrolatum
waxes; Fischer-Tropsch and oxidized Fischer-Tropsch waxes; ozokerite; ceresin; montan
wax; beeswax, candelilla; and carnauba wax.
[0033] U.S. Patent 3,933,672 issued January 20, 1976, to Bartollota et al., discloses silica
suds controlling agent suitable herein. The silicone material can be represented by
alkylated polysiloxane materials such as silica aerogens and xerogels and hydrophobic
silicas of various types. The silicone material can be described as siloxane having
the formula:

wherein X is from about 20 to 2,000 and R and R' are each alkyl or aryl groups, especially
methyl, ethyl, propyl, butyl and phenyl. The polydimethylsiloxanes (R and R' are methyl)
having a molecular weight within the range of from about 200 to about 2,000,000, and
higher, are all useful as suds controlling agents. Additional suitable silicone materials
wherein the side chain groups R and R' are alkyl, aryl, or mixed alkyl or aryl hydrocarbyl
groups exhibit useful suds controlling properties. Examples of the like ingredients
include diethyl-, dipropyl-, dibutyl-, methyl-, ethyl-, phenyl-, methylpolysiloxanes
and the like. Additional useful silicone suds controlling agents can be represented
by a mixture of an alkylated siloxane, as 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 trimethylsilanated) silica having a particle size in the range from
about 10 to 20 nm and a specific surface area above about 50 m
2/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 1:10. The silicone suds suppressing agent is advantageously
releasably incorporated in a water-soluble or water-dispersible, substantially non-surface-active
detergent-impermeable carrier.
[0034] Particularly useful suds suppressors are the self-emulsifying silicone suds suppressors,
described in DE-A-2,646,126 published April 28, 1977. An example of such a compound
is DB-544, commercially available from Dow Corning, which is a siloxane/glycol copolymer.
[0035] The granular detergent compositions herein can also advantageously contain a peroxy
bleaching component in an amount from 3% to 40% by weight, preferably from 8% to 33%
by weight. Examples of suitable peroxy bleach components for use herein include perborates
persulfates, persilicates, perphosphates, percarbonates, and more generally all inorganic
and organic peroxy bleaching agents which are known to be adapted for use in the subject
compositions. The composition can also advantageously include a bleach activator which
is normally an organic compound containing an N-acyl, or an O-acyl (preferably acetyl)
group. Preferred materials are N,N,N',N'-tetraacetyl ethylene diamine and N,N,N',N'-tetraacetylglycouril.
The bleach activator is preferably added at a level from 0.5% to 5% by weight of composition.
[0036] A further preferred ingredient of the instant compositions is from about 0.01 to
about 4%, especially from about 0.1 to about 1.0% by weight of a polyphosphonic acid
or salt thereof which is found to provide bleachable stain detergency benefits.
[0037] Especially preferred polyphosphonates have the formula-

wherein each R is CH
2P0
3H
2 or a water-soluble salt thereof and n is from 0 to 2. Examples of compounds within
this class are aminotri-(methylenephosphonic acid), ethylene diamine tetra(methylenephosphonic
acid) and diethylene triamine penta(methylene phosphonic acid). Of these, ethylenediamine
tetra-(methylene phosphonic acid) is particularly preferred.
[0038] A further optional component is from about 0.1 % to about 3%, especially from about
0.25% to about 1.5% of a polymeric material having a molecular weight of from 2000
to 2,000,000 and which is a copolymer of maleic acid anhydride and a polymerisable
monomer selected from C,-C
12-alkyl vinyl ethers, acrylic and methacrylic acid and C,-C
2o esters thereof, alkenes having from 2 to 12 carbon atoms, N-vinyl pyrrolidone and
styrene. Highly preferred examples of such carboxylates are 1:1 styrene/maleic acid
copolymer, di-isobutylene/maleic acid copolymers and methyl vinyl ether/maleic acid
copolymers. Other suitable polycarboxylates are poly-a-hydroxy acrylates and lactones
thereof as described in Belgian Patent 817,678 and GB-A-1,425,307.
[0039] Another suitable component of the present compositions is a water soluble magnesium
salt which is added at levels in the range from about 0.015% to about 0.2%, preferably
from about 0.03% to about 0.15% and more preferably from about 0.05% to about 0.12%
by weight of the compositions (based on weight of magnesium). Suitable magnesium salts
include magnesium sulfate, magnesium sulfate heptahydrate, magnesium chloride, magnesium
chloride hexahydrate, magnesium fluoride and magnesium acetate. Desirably, the magnesium
salt is added to granular compositions as part of the aqueous slurry crutcher mix
and is then converted to dry granular form for instance by spray drying.
[0040] Granular detergent compositions of the invention are preferably prepared by spray-drying
an aqueous slurry comprising the primary surfactant, cosurfactant and detergency builder.
The aqueous slurry is mixed at a temperature in the range 70―90°C and the water-content
of the slurry adjusted to a range of 25% to 45%, preferably 30%-38% by weight. Spray
drying is undertaken with drying gas inlet temperature of from about 250-350°C, preferably
275-330°C, providing a final moisture content in the range of from 8% to 14% by weight.
Nonionic surfactant, where present, can then be sprayed in fluid form onto the spraydried
detergent granules.
[0041] In the Examples which follow, the abbreviations used have the following designation:-

Examples I to IV
[0042] Built low-sudsing detergent compositions are prepared having the formulae given below.
To make the products a slurry is prepared containing all the components except the
nonionic surfactant, silicone prill, bleach and enzyme and the slurry is then spray
dried to form a granular intermediate. The bleach and enzyme are then dry-mixed with
the grnaular intermediate and the nonionic surfactant is finally sprayed onto the
granular mixture. All figures are given as % by weight.

[0043] The above products provide excellent grease/oil and lipid soil removal performance
simultaneously with good clay soil detergency and whiteness maintenance under realistic
multi-cycle wash-wear conditions, including low wash temperatures and carry-over of
rinse added softener.