Aqueous, bleach containing, liquid detergent compositions, which are stabilized against bleach decomposition due to contamination by transition metal traces are disclosed. The stabilizing effect is obtained by using specific diphosphonate compounds which are non-precipitating builders.

TECHNICAL FIELD 
The present invention relates to aqueous liquid detergent compositions 
containing a solid, water soluble peroxygen compound. 
Said peroxygen compounds are stabilized against decomposition due to 
contamination with transition metals, like iron and manganese. 
BACKGROUND 
It is only recently that it has become possible to formulate liquid 
detergent compositions containing solid, water soluble peroxygen bleaches. 
Such detergent compositions are described for instance in EP 0 294 904. 
Under normal circumstances, the chemical stability of said peroxygen 
compound in such liquid detergents is satisfying, thus providing the 
product with good storage stability characteristics. 
However, some products have shown a certain instability of the peroxygen 
compound, which creates a problem in terms of a sufficient storage 
stability for an adequate shelf life of these products. 
The cause for this peroxygen instability has now been identified as a 
contamination of the product by transition metal traces which catalyze the 
decomposition of the peroxygen compound in the composition. 
The contamination of the product by transition metal traces is an important 
problem which cannot be avoided in normal industrial practice; indeed, it 
has been discovered that some of the raw materials used for the 
manufacture of the product, are themselves carrying transition metals, at 
trace levels. 
Further, while manufacturing, shipping, handling or stocking the product, 
accidental contamination may occur because of corroded pipes or 
containers. 
A solution to this problem has been proposed in co-pending European patent 
application 90 20 0315, which describes aqueous liquid detergent 
composition containing a peroxygen bleach, wherein the peroxygen bleach is 
protected against decomposition due to transition metals by an efficient 
amount of hydroxyethylidene 1,1 disphosphonic acid (HEDP). In these 
compositions, the peroxygen compound is efficiently stabilized, but a new 
problem has been encountered in that HEDP tends to form large aggregates 
in the presence of calcium, which may precipitate. It is believed that 
this precipitation phenomenon may have somewhat of a detrimental effect on 
the whiteness maintenance of fabrics washed with HEDP-containing detergent 
compositions. 
Also newly encountered is the fact that the use of HEDP in liquid detergent 
compositions appears to interfere with the stability in the finished 
product of enzymes which can be used in detergent compositions. 
Of course, these problems can be overcome in an obvious way, e.g., by 
adding an enzyme stabilizing system and an anti-redeposition agent, or by 
compromising on the level of HEDP which is used. 
The object of the invention is, as an alternative, to provide for a liquid 
detergent compositions which contains a solid water-soluble peroxygen 
bleach, which further contains a compound protecting said bleaches from 
decomposition due to transition metals, wherein said compound is as 
efficient as HEDP in protecting the bleach, but wherein said compound does 
not involve any risk of precipitation in the presence of calcium. It is 
another object of the present invention to provide a liquid detergent 
composition wherein said compound does not interfere with the enzyme's 
stability in the finished product. 
SUMMARY OF THE INVENTION 
This invention provides aqueous liquid detergent compositions, which 
comprises a solid water soluble peroxygen compound and from 0.01% to 5.0% 
by weight preferably from 0.5% to 1.5% by weight of a compound selected 
from 
##STR1## 
wherein R is a C.sub.2 to C.sub.5 alkyl or alkenyl group and; 
##STR2## 
wherein R.sub.1 is H or CO.sub.2 H, and wherein x and y are integers, 
which refer to the mole proportions, and the mole ratio x:y is less than 
30:1 and; 
(iii) mixtures thereof. 
DETAILED DESCRIPTION 
The compounds which have been found to be useful for the protection of the 
water soluble peroxygen bleaches against decomposition due to transition 
metal traces, and yet do not precipitate are of the formula: 
##STR3## 
wherein R is a C.sub.2 to C.sub.5 alkyl or alkenyl group and; 
##STR4## 
wherein R.sub.1 is H or CO.sub.2 H, and wherein x and y are integers which 
refer to the mole proportions, and the mole ratio x:y is less than 30:1, 
preferably less than 20:1, most preferably 4:1. 
(iii) mixtures thereof. 
The ratio of x:y can be determined by phosphorous nuclear magnetic 
resonance spectroscopy techniques which are well known to those skilled in 
the art. 
Compounds according to formula (i) herein above can be prepared as 
described for instance in M. I. Kabachnik et Al., Russian Chemical Reviews 
43(9), p. 733-744 (1974). These chemical reactions involve the acylation 
of phosphorous acid or phosphorous trichloride by carboxylic acids, their 
anhydrides or halides: 
##STR5## 
with R being a C.sub.2 to C.sub.5 saturated or unsaturated linear or 
branched hydrocarbon chain. These reactions are well known from the man 
skilled in the art and will therefore not be further discussed here. 
Most preferred compound of formula (i) is 
##STR6## 
Compounds according to formula (ii) herein above, can have a molecular 
weight of from 1000 to 20000, preferably between 1000 and 5000, most 
preferably about 2000. The weight average molecular weight can be measured 
by the low angle scattering technique which is known to those skilled in 
the art (hereinafter referred to as LALLS). 
Compounds according to formula (ii) herein have been extensively described 
among others in U.S. Pat. No. 4,207,405 to the B. F. Goodrich Company. As 
described in this reference, the compounds of formula (ii) can be obtained 
by reacting phosphorous acid or a precursor of phosphorous acid which is 
capable of generating phosphorous acid in an aqueous solution, e.g. 
PCl.sub.3, in a polar organic solvent, with a water soluble carboxyl 
polymer. Starting materials and reaction conditions as well as proportion 
of the starting materials are discussed in more detail in the above 
reference which is available to those skilled in the art. 
The compounds of formula (i) or (ii) herein or mixtures thereof are 
incorporated in amounts ranging from 0.01% to 5% by weight of the total 
composition, preferably 0.05% to 1.5%. 
Synthetic anionic surfactants can be represented by the general formula 
R.sub.1 SO.sub.3 M wherein R.sub.1 represents a hydrocarbon group selected 
from the group consisting of straight or branched alkyl radicals 
containing from about 8 to about 24 carbon atoms and alkyl phenyl radicals 
containing from about 9 to about 15 carbon atoms in the alkyl group. M is 
a salt-forming cation which is typically selected from the group 
consisting of sodium, potassium, ammonium, and mixtures thereof. 
A preferred synthetic anionic surfactant is a watersoluble salt of an 
alkylbenzene sulfonic acid containing from 9 to 15 carbon atoms in the 
alkyl group. Another preferred synthetic anionic surfactant is a 
water-soluble salt of an alkyl sulfate or an alkyl polyethoxylate ether 
sulfate wherein the alkyl group contains from about 8 to about 24, 
preferably from about 10 to about 18 carbon atoms and there are from about 
1 to about 20, preferably from 1 to about 12 ethoxy groups. Other suitable 
anionic surfactants are disclosed in U.S. Pat. No. 4,170,565, Flesher et 
al., issued Oct. 9, 1979. 
The nonionic surfactants are conventionally produced by condensing ethylene 
oxide with a hydrocarbon having a reactive hydrogen atom, e.g. a hydroxyl, 
carboxyl, or amino group, in the presence of an acidic of basic catalyst, 
and include compounds having the general formula RA(CH.sub.2 CH.sub.2 
O).sub.n H wherein R represents the hydrophobic moiety, A represents the 
group carrying the reactive hydrogen atom and n represents the average 
number of ethylene oxide moieties. R typically contains from about 8 to 22 
carbon atoms. They can also be formed by the condensation of propylene 
oxide or copolymers of ethylene oxide and propylene oxide with a lower 
molecular weight compound. n usually varies from about 2 to about 24. 
The hydrophobic moiety of the nonionic compound is preferably a primary or 
secondary, straight or branched, aliphatic alcohol having from about 8 to 
24, preferably from about 12 to about 20 carbon atoms. A more complete 
disclosure of suitable nonionic surfactants can be found in U.S. Pat. No. 
4,111,855. Mixtures of nonionic surfactants can be desirable. 
Suitable cationic surfactants include quaternary ammonium compounds of the 
formula R.sub.1 R.sub.2 R.sub.3 R.sub.4 N.sup.+ where R.sub.1, R.sub.2, 
and R.sub.3 are methyl groups and R.sub.4 is a C.sub.12 -C.sub.15 alkyl 
group, or where R.sub.1 is an ethyl or hydroxy ethyl group, R.sub.2 and 
R.sub.3 are methyl groups and R.sub.4 is a C.sub.12 -C.sub.15 alkyl group. 
Zwitterionic surfactants include derivatives of aliphatic quaternary 
ammonium, phosphonium, and sulphonium compounds in which the aliphatic 
moiety can be a straight or branched chain and wherein one of the 
aliphatic substituents contains from about 8 to about 24 carbon atoms and 
another substituent contains, at least, an anionic water-solubilizing 
group. Particularly preferred zwitterionic materials are the ethoxylated 
ammonium sulfonates and sulfates disclosed in U.S. Pat. Nos. 3,925,262, 
Laughlin et al., issued Dec. 9, 1975 and 3,929,678, Laughlin et al., 
issued Dec. 30, 1975. 
Semi-polar nonionic surfactants include water-soluble amine oxides 
containing one alkyl or hydroxy alkyl moiety of from about 8 to about 28 
carbon atoms and two moieties selected from the group consisting of alkyl 
groups and hydroxy alkyl groups, containing from 1 to about 3 carbon atoms 
which can optionally be joined into ring structures. 
Suitable anionic synthetic surface-active salts are selected from the group 
of sulfonates and sulfates. The like anionic detergents are well-known in 
the detergent arts and have found wide-spread application in commercial 
detergents. Preferred anionic synthetic water-soluble sulfonate of sulfate 
salts have in their molecular structure an alkyl radical containing from 
about 8 to about 22 carbon atoms. 
Examples of such preferred anionic surfactant salts are the reaction 
products obtained by sulfating C.sub.8 -C.sub.18 fatty alcohols derived 
from tallow and coconut oil; alkylbenzene sulfonates wherein the alkyl 
group contains from about 9 to 15 carbon atoms; sodium alkylglyceryl ether 
sulfonates; ether sulfates of fatty alcohols derived from tallow and 
coconut oils; coconut fatty acid monoglyceride sulfates and sulfonates; 
and water-soluble salts of paraffin sulfonates having from about 8 to 
about 22 carbon atoms in the alkyl chain. Sulfonated olefin surfactants as 
more fully described in e.g. U.S. Pat. No. 3,332,880 can also be used. The 
neutralizing cation for the anionic synthetic sulfonates and/or sulfates 
is represented by conventional cations which are widely used in detergent 
technology such as sodium and potassium. 
A particularly preferred anionic synthetic surfactant component herein is 
represented by the water-soluble salts of an alkylbenzene sulfonic acid, 
preferably sodium alkylbenzene sulfonates having from about 10 to 13 
carbon atoms in the alkyl group. 
A preferred class of nonionic ethoxylates is represented by the 
condensation product of a fatty alcohol having from 12 to 15 carbon atoms 
and from about 2 to 10, preferably 3 to 7 moles of ethylene oxide per mole 
of fatty alcohol. Suitable species of this class of ethoxylates include: 
the condensation product of C.sub.12 -C.sub.15 oxo-alcohols and 7 moles of 
ethylene oxide per mole of alcohol; the condensation product of narrow cut 
C.sub.14 -C.sub.15 oxo-alcohols and 7 or 9 moles of ethylene oxide per 
mole of fatty(oxo)alcohol; the condensation product of a narrow cut 
C.sub.12 -C.sub.13 fatty(oxo)alcohol and 6,5 moles of ethylene oxide per 
mole of fatty alcohol; and the condensation products of a C.sub.10 
-C.sub.14 coconut fatty alcohol with a degree of ethoxylation (moles 
EO/mole fatty alcohol) in the range from 5 to 8. The fatty oxo alcohols 
while mainly linear can have, depending upon the processing conditions and 
raw material olefins, a certain degree of branching, particularly short 
chain such as methyl branching. 
A degree of branching in the range from 15% to 50% (weight %) is frequently 
found in commercial oxo alcohols. 
Preferred nonionic ethoxylated components can also be represented by a 
mixture of 2 separately ethoxylated nonionic surfactants having a 
different degree of ethoxylation. For example, the nonionic ethoxylate 
surfactant containing from 3 to 7 moles of ethylene oxide per mole of 
hydrophobic moiety and a second ethoxylated species having from 8 to 14 
moles of ethylene oxide per mole of hydrophobic moiety. A preferred 
nonionic ethoxylated mixture contains a lower ethoxylate which is the 
condensation product of a C.sub.12 -C.sub.15 oxo-alcohol, with up to 50% 
(wt) branching, and from about 3 to 7 moles of ethylene oxide per mole of 
fatty oxo-alcohol, and a higher ethoxylate which is the condensation 
product of a C.sub.16 -C.sub.19 oxo-alcohol with more than 50% (wt) 
branching and from about 8 to 14 moles of ethylene oxide per mole of 
branched oxo-alcohol. 
Suitable bleaches in the present compositions are solid, water-soluble 
peroxygen compounds. Preferred compounds include perborates, persulfates, 
peroxydisulfates, perphosphates and the crystalline peroxyhydrates formed 
by reacting hydrogen peroxyde with sodium carbonate or urea, preferably 
percarbonate. Preferred peroxygen bleach compounds are sodium perborate 
monohydrate and sodium perborate tetrahydrate, as well as sodium 
percarbonate. Perborate bleaches in the present composition are preferably 
in the form of small particles i.e. having a diameter of from 0,1 to 20 
micrometers, said particles having been formed by in situ crystallization 
of the perborate. The term "in situ crystallization" relates to processes 
whereby perborate particles are formed from larger particles or from 
solution, in the presence of the water/anionic surfactant/detergent 
builder matrix. This term therefore encompasses processes involving 
chemical reactions, as when sodium perborate is formed by reacting 
stoichiometric amounts of hydrogen peroxide and sodium metaborate or 
borax. It also encompasses processes involving dissolution and 
recrystallization, as in the dissolution of perborate monohydrate and 
subsequent formation of perborate tetrahydrate. Recrystallization may also 
take place by allowing perborate monohydrate to take up crystal water, 
whereby the monohydrate directly recrystallizes into the tetrahydrate, 
without dissolution step. 
For instance, a perborate compound, e.g., sodium perborate monohydrate, can 
be added to an aqueous liquid comprising the anionic surfactant and the 
detergent builder. The resulting slurry is stirred. During this stirring 
the perborate compound undergoes a process of 
dissolution/recrystallization. Due to the presence of the anionic 
surfactant and the detergent builder this dissolution/recrystallization 
process results in particles having the desired particle diameter. As the 
monohydrate is more susceptible to recrystallization, the monohydrate is 
preferred for this embodiment of the invention. For reasons of physical 
stability it is preferred that the particle size distribution is 
relatively narrow; i.e., it is preferred that less than 10% (wt) has a 
particle diameter greater than 10 micrometers. 
Otherwise, a perborate compound can be formed in situ by chemical reaction. 
For example, sodium metaborate can be added to an aqueous liquid 
comprising the anionic surfactant and the detergent builder. Then a 
stoichiometric amount of hydrogen peroxide is added while stirring. 
Stirring is continued until the reaction is complete. 
Instead of metaborate, other borate compounds, including e.g., borax and 
boric acid can be used. If borax is used as the boron compound, a 
stoichiometric amount of a base, e.g. sodium hydroxide, is added to ensure 
reaction of the borax to metaborate. The process then proceeds as 
described hereinabove for metaborate conversion. Instead of hydrogen 
peroxide, other peroxides may be used (e.g., sodium peroxide), as known in 
the art. 
Preferred liquid detergent compositions contain, in addition to water, a 
water-miscible organic solvent. The solvent reduces the solubility of the 
solid water-soluble peroxygen bleach in the liquid phase and thereby 
enhances the chemical stability of the composition. 
It is not necessary that the organic solvent be fully miscible with water, 
provided that enough of the solvent mixes with the water of the 
composition to affect the solubility of the solid water-soluble peroxygen 
bleach in the liquid phase. 
The water-miscible organic solvent must, of course be compatible with the 
solid water-soluble peroxygen compound at the pH that is used. 
Examples of suitable water-miscible organic solvents include the lower 
aliphatic monoalcohols, and ethers of diethylene glycol and lower 
monoaliphatic monoalcohols. Preferred solvents are ethanol, iso-propanol, 
1-methoxy, 2-propanol, ethyldiglycolether and butyldiglycolether. 
When sodium perborate is used, polyalcohols having vicinal hydroxy groups 
(e.g. 1,2-propanediol and glycerol) are less desirable, and the preferred 
solvent will then be ethanol. 
The compositions according to the present invention can also contain 
detergent enzymes; suitable enzymes include detergent proteases, amylases, 
lipases, cellulases and mixtures thereof. Preferred enzymes are high 
alkaline proteases e.g. Maxacal (R), Savinase (R) and Maxapem (R). 
Silicone-coated enzymes, as described in EP-A-0238216 can also be used. 
Preferred compositions herein optionally contain as a builder a fatty acid 
component. Preferably, however, the amount of fatty acid is less than 5% 
by weight of the composition, more preferably less than 4%. Preferred 
saturated fatty acids have from 10 to 16, more preferably 12 to 14 carbon 
atoms. Preferred unsaturated fatty acids are oleic acid and palmitoleic 
acid. 
Preferred compositions contain an inorganic or organic builder. Examples of 
inorganic builders include the phosphorous-based builders, e.g., sodium 
tripolyphosphate, sodium pyrophosphate, and aluminosilicates (zeolites). 
Examples of organic builders are represented by polyacids such as citric 
acid, nitrilotriacetic acid, and mixtures of tartrate monosuccinate with 
tartrate disuccinate. Preferred builders for use herein are citric acid 
and alk(en)yl-substituted succinic acid compounds, wherein alk(en)yl 
contains from 10 to 16 carbon atoms. An example of this group of compounds 
is dodecenyl succinic acid. Polymeric carboxylate builders inclusive of 
polyacrylates, polyhydroxy acrylates and polyacrylates/polymaleates 
copolymers can also be used. 
The compositions herein can contain a series of further optional 
ingredients which are mostly used in additive levels, usually below about 
5%. Examples of the like additives include: suds regulants, opacifiers, 
agents to improve the machine compatibility in relation to enamel-coated 
surfaces, bactericides, dyes, perfumes, brighteners and the like. 
In addition to the peroxygen stabilizing compounds, the preferred liquid 
compositions herein may further contain other chelants at a level from 
0,05% to 5%. 
These chelants include polyaminocarboxylates such as 
ethylenediaminotetracetic acid, diethylenetriaminopentacetic acid, 
ethylenediamino disuccinic acid or the water-soluble alkali metals 
thereof. Other additives include organo-phosphonic acids; particularly 
preferred are ethylenediamine tetra(methylenephosphonic acid), 
hexamethylenediamine tetra(methylenephosphonic acid), diethylenetriamine 
penta(methylenephosphonic acid) and aminetri(methylenephosphonic acid). 
Bleach stabilizers such as ascorbic acid, dipicolinic acid, sodium 
stannates and 8-hydroxyquinoline can also be included in these 
compositions, at levels from 0.01% to 1%. 
The beneficial utilization of the claimed compositions under various usage 
conditions can require the utilization of a suds regulant. While generally 
all detergent suds regulants can be utilized preferred for use herein are 
alkylated polysiloxanes such as dimethylpolysiloxane also frequently 
termed silicones. The silicones are frequently used in a level not 
exceeding 1.5%, most preferably from 0.05% to 1.0%. 
It can also be desirable to utilize opacifiers in as much as they 
contribute to create a uniform appearance of the concentrated liquid 
detergent compositions. Examples of suitable opacifiers include: 
polystyrene commercially known as LYTRON 621 manufactured by MONSANTO 
CHEMICAL CORPORATION. The opacifiers are frequently used in an amount from 
0.3% to 1.5%. 
The liquid detergent compositions of this invention can further comprise an 
agent to improve the washing machine compatibility, particularly in 
relation to enamel-coated surfaces. 
It can further be desirable to add from 0.1% to 5% of known 
antiredeposition and/or compatibilizing agents. Examples of the like 
additives include: sodium carboxymethylcellulose; hydroxy-C.sub.1-6 
-alkylcellulose; polycarboxylic homo- or copolymeric ingredients, such as: 
polymaleic acid; a copolymer of maleic anhydride and methylvinylether in a 
molar ratio of 2:1 to 1:2; and a copolymer of an ethylenically unsaturated 
monocarboxylic acid monomer, having not more than 5, preferably 3 or 4 
carbon atoms, for example (meth)-acrylic acid, and an ethylenically 
unsaturated dicarboxylic acid monomer having not more than 6, preferably 4 
carbon atoms, whereby the molar ratio of the monomers is in the range from 
1:4 to 4:1, said copolymer being described in more detail in European 
Patent Application 0 066 915, filed May 17, 1982. 
The compositions according to the invention have a pH at room temperature 
of at least 8.5, more preferably at least 9.0, most preferably at least 
9.5.