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Description  |
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FIELD OF THE INVENTION
The present invention relates to laundry detergents and bleaching systems
which comprise acyl valerolactam bleach activators.
BACKGROUND OF THE INVENTION
It has long been known that peroxygen bleaches are effective for stain
and/or soil removal from fabrics, but that such bleaches are temperature
dependent. At a laundry liquor temperature of 60.degree. C., peroxygen
bleaches are only partially effective. As the laundry liquor temperature
is lowered below 60.degree. C., peroxygen bleaches become relatively
ineffective. As a consequence, there has been a substantial amount of
industrial research to develop bleaching systems which contain an
activator that renders peroxygen bleaches effective at laundry liquor
temperatures below 60.degree. C.
Numerous substances have been disclosed in the art as effective bleach
activators. One widely-used bleach activator is tetraacetyl ethylene
diamine (TAED). TAED provides effective hydrophilic cleaning especially on
beverage stains, but has limited performance on dingy stains and body
soils. Another type of activator, such as nonanoyloxybenzenesulfonate
(NOBS) and other activators which generally comprise long chain alkyl
moieties, is hydrophobic in nature and provides excellent performance on
dingy stains. However, many of the hydrophobic activators developed thus
far can promote damage to natural rubber parts used in certain washing
machines and to natural rubber articles exposed to the activators. Because
of these negative effects on natural rubber machine parts and articles,
the selection of such detergent-added bleaching systems has been limited.
It has now been determined that in conventional bleaching systems,
particularly those comprising a hydrophobic bleach activator and a source
of hydrogen peroxide, the bleach activator undergoes perhydrolysis to form
a peroxyacid bleaching agent. A by-product of the perhydrolysis reaction
between such bleach activators and hydrogen peroxide is a diacylperoxide
(DAP) species. It has now further been discovered that the DAP's derived
from hydrophobic activators tend to be insoluble, poorly dispersible, oily
materials which form a residue which can deposit on the natural rubber
machine parts that are exposed to the laundry liquor. The oily DAP residue
can form a film on the natural rubber parts and promote free radical and
peroxide damage to the rubber, which eventually leads to failure of the
part. This is particularly true of rubber parts which have prolonged
exposure to the laundry liquor, such as sump hoses.
By the present invention, is has now been discovered that the class of
bleach activators derived from acyl valerolactams forms peroxyacids upon
perhydrolysis without the production of oily, harmful DAP's. Without
intending to be limited by theory, it is believed that the bleach
activators employed herein provide good cleaning performance with safety
to natural rubber, since they do not expose the natural rubber machine
parts or articles to DAP oxidation. Whatever the reason, natural rubber
parts and articles remain substantially undamaged by the bleaching systems
of the present invention.
By the present invention, it has also now been discovered the bleach
activators of this invention provide dingy soil clean-up and enhanced
nucleophilic and body soil removal. Furthermore, the bleaching systems and
activators herein are effective at low concentration levels and at
temperatures below 60.degree. C. when used in the manner provided by this
invention. In addition, the activators herein have better perhydrolysis
speed and yield when compared to other lactam bleach activators, such as
acyl caprolactam activators.
Accordingly, the present invention presents an effective, color-safe
bleaching system which does not promote damage to natural rubber parts in
washing machines or damage to natural rubber articles.
SUMMARY OF THE INVENTION
The present invention relates to acyl valerolactam bleach activators and
their use in bleaching systems and laundry detergents. The valerolactams
are selected from the group consisting of:
a)
##STR1##
wherein R.sup.1 is a substituted or unsubstituted, including saturated or
unsaturated, alkyl or alkoxy group containing from about 1 to about 18
carbon atoms wherein the longest linear alkyl or alkoxy chain extending
from and including the carbonyl carbon contains from about 2 to about 12
carbon atoms;
b)
##STR2##
i.e., substituted and unsubstituted benzoyl valerolactams wherein
substituents R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are members
selected from the group consisting of H, halogen, alkyl, alkoxy,
alkoxyaryl, alkaryl, and alkaryloxy moieties having from about 1 to about
12 carbon atoms, preferably from about 3 to about 12 carbon atoms, and
substituents having the structure:
##STR3##
wherein R.sup.7 is selected from the group consisting of H, alkyl,
alkaryl, alkoxy, alkoxyaryl, alkaryloxy, and aminoalkyl; X is O, NH, or
NR.sup.9, wherein R.sup.9 is H or a C.sub.1 -C.sub.4 alkyl group; R.sup.8
is an alkyl, cycloalkyl, or aryl group containing from 3 to 11 carbon
atoms; and c) mixtures of a) and b).
In a preferred embodiment of structure a), R.sup.1 is selected from the
group consisting of alkyl or alkoxy units having from about 7 to about 11
carbon atoms, including heptyl, octyl, nonyl, decyl, undecyl, decenyl,
2,4,4-trimethylpentyl, 1-ethylpentyl, and mixtures thereof.
In a preferred embodiment of structure b), R.sup.2, R.sup.3, R.sup.4, and
R.sup.5 are H and R.sup.6 is selected from the group consisting of H,
methyl, methoxy, ethyl, ethoxy, propyl, propoxy, isopropyl, isopropoxy,
butyl, tert-butyl, butoxy, tert-butoxy, pentyl, pentoxy, hexyl, hexoxy,
Cl, and NO.sub.2. In still another preferred embodiment, R.sup.2, R.sup.3,
R.sup.4 are H, and R.sup.5 and R.sup.6 are members selected from the group
consisting of methyl, methoxy, and Cl.
The invention also relates to bleaching systems and laundry detergents
comprising the bleach activators. Said bleaching system comprises:
A) at least about 0.1%, preferably from about 1% to about 75%, by weight of
bleaching system, of a peroxygen bleaching compound capable of yielding
hydrogen peroxide in an aqueous solution;
B) at least about 0.1%, preferably from about 0.1% to about 50%, by weight,
of one or more acyl valerolactam bleach activators selected from the group
consisting of:
a)
##STR4##
wherein R.sup.1 is as defined above; b)
##STR5##
wherein R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are as defined
above; and
c) mixtures of a) and b).
The peroxygen bleaching compound can be any peroxide source, and is
preferably a member selected from the group consisting of sodium perborate
monohydrate, sodium perborate tetrahydrate, sodium pyrophosphate
peroxyhydrate, urea peroxyhydrate, sodium percarbonate, sodium peroxide
and mixtures thereof. Highly preferred peroxygen bleaching compounds are
selected from the group consisting of sodium perborate monohydrate, sodium
perborate tetrahydrate, sodium percarbonate and mixtures thereof. The most
highly preferred peroxygen bleaching compound is sodium percarbonate.
The invention also encompasses laundry compositions in granular, paste,
liquid, or bar form which comprise at least about 0.1% of the aforesaid
bleaching system together with at least about 1% of conventional detergent
ingredients which are present in the composition at the levels indicated
hereinafter.
The acyl valerolactams herein can also be used in combination with other
bleach activators, such as N-acyl caprolactams, tetraacetyl ethylene
diamine, alkanoxybenzenesulfonates, including nonanoyloxybenzenesulfonate,
benzoxazin-type bleach activators, and peroxyacid agents and activators
having amide moieties. Preferably, if using an automatic washing machine
equipped with natural rubber parts or if washing articles comprising
natural rubber, the amount of alkanoxybenezenesulfonates used in
combination with the activators of this invention should be kept at a
minimum.
The bleaching method herein is preferably conducted with agitation of the
fabrics with an aqueous liquor containing the aforesaid bleaching system
at levels from about 50 ppm to about 27,500 ppm. The method can be carried
out at any desired washing temperature, even at temperatures below about
60.degree. C., and is readily conducted at temperatures in the range of
from about 5.degree. C. to about 45.degree. C. The method can be conducted
conveniently using a composition which is in bar form, but can also be
conducted using granules, flakes, powders, pastes, liquids and the like.
The aqueous laundry liquor typically comprises at least about 300 ppm of
conventional detergent ingredients, as well as at least about 25 ppm of
the bleaching compound and at least about 25 ppm of the bleach activator.
Preferably, the liquor comprises from about 900 ppm to about 20,000 ppm of
conventional detergent ingredients, from about 100 ppm to about 25,000 ppm
of the bleaching compound and from about 100 ppm to about 2,500 ppm of the
bleach activator. The conventional detergent ingredients and bleaching
system will typically be combined into a detergent composition such as a
granular laundry detergent or laundry detergent bar.
The conventional detergent ingredients employed in said method and in the
compositions herein comprise from about 1% to about 99.8%, preferably from
about 5% to about 80%, of a detersive surfactant. Optionally, the
detergent ingredients comprise from about 5% to about 80% of a detergent
builder. Other optional detersive adjuncts can also be included in such
compositions at conventional usage levels.
All percentages, ratios, and proportions herein are by weight, unless
otherwise specified. All documents cited are incorporated herein by
reference.
DETAILED DESCRIPTION OF THE INVENTION
The bleaching system employed in the present invention provides effective
and efficient surface bleaching of fabrics which thereby removes stains
and/or soils from the fabrics. The bleaching system is particularly
efficient at cleaning concentrated soil loads, especially mixtures of
hydrophobic and hydrophilic soils. Hydrophobic soils are generally
associated with nucleophilic, lipid and protein-based soils and stains,
such as body soils, blood, etc., but are also effective on so-called
"dingy soils". Dingy soils are those that build up on textiles after
numerous cycles of usage and washing, and result in a gray or yellow tint
on white fabrics. Hydrophilic soils include food and beverage stains.
Further, the bleaching system is safe to natural rubber machine pans and
articles.
The bleaching mechanism and, in particular, the surface bleaching mechanism
are not completely understood. However, it is generally believed that the
bleach activator undergoes nucleophilic attack by a perhydroxide anion,
which is generated from the hydrogen peroxide evolved by the peroxygen
bleaching compound, to form a peroxycarboxylic acid. This reaction is
commonly referred to as perhydrolysis. It is also believed, that the
bleach activators within this invention can render peroxygen bleaches more
efficient even at laundry liquor temperatures wherein bleach activators
are not necessary to activate the bleach, i.e., above about 60.degree. C.
Therefore, with bleach systems of the invention, less peroxygen bleach is
required to achieve the same level of surface bleaching performance as is
obtained with the peroxygen bleach alone.
The components of the bleaching system herein comprise the bleach activator
and the peroxide source, as described hereinafter.
Bleach Activators
Methods of making acyl valerolactams are illustrated by laboratory
syntheses included in Examples I and II.
Preferred valerolactams of structure a) include those wherein the R.sup.1
moiety is selected from alkyl and alkoxy groups containing from about 7 to
about 11 carbon atoms. Examples of preferred valerolactams include
octanoyl valerolactam, nonanoyl valerolactam, decanoyl valerolactam,
undecenoyl valerolactam, 3,5,5-trimethylhexanoyl valerolactam,
2-ethylhexanoyl valerolactam, isononanoyl valerolactam and mixtures
thereof. Highly preferred valerolactams of structure a) include nonanoyl
valerolactam, isononanoyl valerolactam, and 2-ethyhexanoyl valerolactam.
Preferred valerolactams of structure b) include benzoyl valerolactam,
substituted benzoyl valerolactam, including alkaryl and alkoxyaryl
valerolactams wherein the alkaryl or alkoxyaryl moiety contains from about
3 to about 12 carbon atoms, terephthaloyl divalerolactam, and mixtures
thereof. Examples of substituted benzoyl valerolactams include
methylbenzoyl valerolactam, ethylbenzoyl valerolactam, ethoxybenzoyl
valerolactam, propylbenzoyl valerolactam, propoxybenzoyl valerolactam,
isopropylbenzoyl valerolactam, isopropoxybenzoyl valerolactam,
butylbenzoyl valerolactam, butoxybenzoyl valerolactam, tertbutylbenzoyl
valerolactam, tertbutoxybenzoyl valerolactam, pentylbenzoyl valerolactam,
pentoxybenzoyl valerolactam, hexylbenzoyl valerolactam, hexoxybenzoyl
valerolactam, 2,4,6-trichlorobenzoyl valerolactam, pentafluorobenzoyl
valerolactam, dichlorobenzoyl valerolactam, dimethoxybenzoyl valerolactam,
4-nitrobenzoyl valerolactam, 3-chlorobenzoyl valerolactam, 4-chlorobenzoyl
valerolactam, 2,4-dichlorobenzoyl valerolactam, terephthaloyl
divalerolactam, and mixtures thereof. Highly preferred valerolactams of
structure b) include benzoyl valerolactam, 3-chlorobenzoyl valerolactam,
and 4- nitrobenzoyl valerolactam.
The bleaching system comprises at least about 0.1%, preferably from about
0.1% to about 50%, more preferably from about 1% to about 30%, most
preferably from about 3% to about 25%, by weight, of one or more acyl
valerolactam bleach activators. In highly preferred embodiments, the
bleaching system comprises percarbonate and a bleach activator selected
from the group consisting of benzoyl valerolactam, nonanoyl valerolactam,
isononanoyl valerolactam, 2-ethylhexanoyl valerolactam, 3-chlorobenzoyl
valerolactam, and 4-nitrobenzoyl valerolactam.
When the activators are used, optimum surface bleaching performance is
obtained with washing solutions wherein the pH of such solution is between
about 7 and 10.5, preferably between about 8.5 and 10.5, most preferably
about 9.5 to about 10.5, in order to facilitate the perhydrolysis
reaction. Such pH can be obtained with substances commonly known as
buffering agents, which are optional components of the bleaching systems
herein.
The Peroxygen Bleaching Compound
The peroxygen bleaching compounds useful herein are those capable of
yielding hydrogen peroxide in an aqueous liquor. These compounds are well
known in the art and include hydrogen peroxide and the alkali metal
peroxides, organic peroxide bleaching compounds such as urea peroxide, and
inorganic persalt bleaching compounds, such as the alkali metal
perborates, percarbonates, perphosphates, and the like. Mixtures of two or
more such bleaching compounds can also be used, if desired.
Preferred peroxygen bleaching compounds include sodium perborate,
commercially available in the form of mono-, tri-, and tetra-hydrate,
sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, sodium peroxide,
and sodium percarbonate. Particularly preferred are sodium perborate
tetrahydrate, sodium perborate monohydrate and sodium percarbonate. Sodium
percarbonate is especially preferred because it is very stable during
storage and yet still dissolves very quickly in the bleaching liquor. It
is believed that such rapid dissolution results in the formation of higher
levels of percarboxylic acid and, thus, enhanced surface bleaching
performance.
Highly preferred percarbonate can be in uncoated or coated form. The
average particle size of uncoated percarbonate ranges from about 400 to
about 1200 microns, most preferably from about 400 to about 600 microns.
If coated percarbonate is used, the preferred coating materials include
mixtures of carbonate and sulphate, silicate, borosilicate, or fatty
carboxylic acids.
The bleaching system comprises at least about 0.1%, preferably from about
1% to about 75%, more preferably from about 3% to about 40%, most
preferably from about 3% to about 25%, by weight, of said peroxygen
bleaching compound capable of yielding hydrogen peroxide in an aqueous
solution.
The weight ratio of bleach activator to peroxygen bleaching compound in the
bleaching system typically ranges from about 2:1 to 1:5. In preferred
embodiments, the ratio ranges from about 1:1 to about 1:3.
The bleach activator/bleaching compound systems herein are useful per se as
bleaches. However, such bleaching systems are especially useful in
compositions which can comprise various detersive adjuncts such as
surfactants, builders, enzymes, and the like as disclosed hereinafter.
Such laundry detergent compositions comprise at least about 0.1%,
preferably from about 1% to about 50%, of the bleaching system and at
least about 1%, preferably from about 50% to about 99.9%, of conventional
detergent ingredients.
Detersive Surfactant
The amount of detersive surfactant included in the fully formulated
detergent compositions afforded by the present invention can vary from
about 1% to about 99.8%, by weight of the detergent ingredients, depending
upon the particular surfactants used and the effects desired. Preferably,
the detersive surfactants comprise from about 5% to about 80%, by weight
of the detergent ingredients.
The detersive surfactant can be nonionic, anionic, ampholytic,
zwitterionic, or cationic. Mixtures of these surfactants can also be used.
Preferred detergent compositions comprise anionic detersive surfactants or
mixtures of anionic surfactants with other surfactants, especially
nonionic surfactants.
Nonlimiting examples of surfactants useful herein include the conventional
C.sub.11 -C.sub.18 alkyl benzene sulfonates and primary, secondary, and
random alkyl sulfates, the C.sub.10 -C.sub.18 alkyl alkoxy sulfates, the
C.sub.10 -C.sub.18 alkyl polyglycosides and their corresponding sulfated
polyglycosides, C.sub.12 -C.sub.18 alpha-sulfonated fatty acid esters,
C.sub.12 -C.sub.18 alkyl and alkyl phenol alkoxylates (especially
ethoxylates and mixed ethoxy/propoxy), C.sub.12 -C.sub.18 betaines and
sulfobetaines ("sultaines"), C.sub.10 -C.sub.18 amine oxides, and the
like. Other conventional useful surfactants are listed in standard texts.
One particular class of adjunct nonionic surfactants especially useful
herein comprises the polyhydroxy fatty acid amides of the formula:
##STR6##
wherein: R.sup.1 is H, C.sub.1 14 C.sub.8 hydrocarbyl, 2-hydroxyethyl,
2-hydroxypropyl, or a mixture thereof, preferably C.sub.1 -C.sub.4 alkyl,
more preferably C.sub.1 or C.sub.2 alkyl, most preferably C.sub.1 alkyl
(i.e., methyl); and R.sup.2 is a C.sub.5 -C.sub.32 hydrocarbyl moiety,
preferably straight chain C.sub.7 -C.sub.19 alkyl or alkenyl, more
preferably straight chain C.sub.9 -C.sub.17 alkyl or alkenyl, most
preferably straight chain C.sub.11 -C.sub.19 alkyl or alkenyl, or mixture
thereof, and Z is a polyhydroxyhydrocarbyl moiety having a linear
hydrocarbyl chain with at least 2 (in the case of glyceraldehyde) or at
least 3 hydroxyls (in the case of other reducing sugars) directly
connected to the chain, or an alkoxylated derivative (preferably
ethoxylated or propoxylated) thereof. Z preferably will be derived from a
reducing sugar in a reductive amination reaction; more preferably Z is a
glycityl moiety. Suitable reducing sugars include glucose, fructose,
maltose, lactose, galactose, mannose, and xylose, as well as
glyceraldehyde. As raw materials, high dextrose corn syrup, high fructose
corn syrup, and high maltose corn syrup can be utilized as well as the
individual sugars listed above. These corn syrups may yield a mix of sugar
components for Z. It should be understood that it is by no means intended
to exclude other suitable raw materials. Z preferably will be selected
from the group consisting of --CH.sub.2 --(CHOH).sub.n --CH.sub.2 OH,
--CH(CH.sub.2 OH)--(CHOH).sub.n-1 --CH.sub.20 H, --CH.sub.2 --(CHOH).sub.2
(CHOR')(CHOH)--CH.sub.2 OH, where n is an integer from 1 to 5, inclusive,
and R' is H or a cyclic mono- or poly-saccharide, and alkoxylated
derivatives thereof. Most preferred are glycityls wherein n is 4,
particularly --CH.sub.2 --(CHOH).sub.4 --CH.sub.2 OH.
In Formula (I), R.sup.1 can be, for example, N-methyl, N-ethyl, N-propyl,
N-isopropyl, N-butyl, N-isobutyl, N-2-hydroxy ethyl, or N-2-hydroxy
propyl. For highest sudsing, R.sup.1 is preferably methyl or hydroxyalkyl.
If lower sudsing is desired, R.sup.1 is preferably C.sub.2 -C.sub.8 alkyl,
especially n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl and
2-ethyl hexyl.
R.sup.2 --CO--N< can be, for example, cocamide, stearamide, oleamide,
lauramide, myristamide, capricamide, palmitamide, tallowamide, etc.
Detergent Builders
Optional detergent ingredients employed in the present invention contain
inorganic and/or organic detergent builders to assist in mineral hardness
control. If used, these builders comprise from about 5% to about 80% by
weight of the detergent compositions.
Inorganic detergent builders include, but are not limited to, the alkali
metal, ammonium and alkanolammonium salts of polyphosphates (exemplified
by the tripolyphosphates, pyrophosphates, and glassy polymeric
meta-phosphates), phosphonates, phytic acid, silicates, carbonates
(including bicarbonates and sesquicarbonates), sulphates, and
aluminosilicates. However, non-phosphate builders are required in some
locales.
Examples of silicate builders are the alkali metal silicates, particularly
those having a SiO.sub.2 :Na.sub.2 O ratio in the range 1.6:1 to 3.2:1 and
layered silicates, such as the layered sodium silicates described in U.S.
Pat. No. 4,664,839, issued May 12, 1987 to H. P. Rieck, available from
Hoechst under the trademark "SKS"; SKS-6 is an especially preferred
layered silicate builder.
Carbonate builders, especially a finely ground calcium carbonate with
surface area greater than 10 m.sup.2 /g, are preferred builders that can
be used in granular compositions. The density of such alkali metal
carbonate built detergents can be in the range of 450-850 g/l with the
moisture content preferably below 4%. Examples of carbonate builders are
the alkaline earth and alkali metal carbonates as disclosed in German
Patent Application No. 2,321,001 published on Nov. 15, 1973.
Aluminosilicate builders are especially useful in the present invention.
Preferred aluminosilicates are zeolite builders which have the formula:
Na.sub.z [(AlO.sub.2).sub.z (SiO.sub.2).sub.y ].xH.sub.2 O
wherein z and y are integers of at least 6, the molar ratio of z to y is in
the range from 1.0 to about 0.5, and x is an integer from about 15 to
about 264.
Useful aluminosilicate ion exchange materials are commercially available.
These aluminosilicates can be crystalline or amorphous in structure and
can be naturally-occurring aluminosilicates or synthetically derived. A
method for producing aluminosilicate ion exchange materials is disclosed
in U.S. Pat. No. 3,985,669, Krummel, et al, issued Oct. 12, 1976.
Preferred synthetic crystalline aluminosilicate ion exchange materials
useful herein are available under the designations Zeolite A, Zeolite P
(B), and Zeolite X. Preferably, the aluminosilicate has a particle size of
about 0.1-10 microns in diameter.
Organic detergent builders suitable for the purposes of the present
invention include, but are not restricted to, a wide variety of
polycarboxylate compounds, such as ether polycarboxylates, including
oxydisuccinate, as disclosed in Berg, U.S. Pat. No. 3,128,287, issued Apr.
7, 1964, and Lamberti et al, U.S. Pat. No. 3,635,830, issued Jan. 18,
1972. See also "TMS/TDS" builders of U.S. Pat. No. 4,663,071, issued to
Bush et al, on May 5, 1987.
Other useful detergent builders include the ether hydroxypolycarboxylates,
copolymers of maleic anhydride with ethylene or vinyl methyl ether,
1,3,5-trihydroxy benzene-2,4,6-trisulphonic acid, and
carboxymethyloxysuccinic acid, the various alkali metal, ammonium and
substituted ammonium salts of polyacetic acids such as ethylenediamine
tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates
such as mellitic acid, suetinit acid, oxydisuccinic acid, polymaleic acid,
benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and
soluble salts thereof.
Citrate builders, e.g., citric acid and soluble salts thereof (particularly
sodium salt), are preferred polycarboxylate builders that can also be used
in granular compositions, especially in combination with zeolite and/or
layered silicate builders.
Also suitable in the detergent compositions of the present invention are
the 3,3-dicarboxy-4-oxa-1,6-hexanedioates and the related compounds
disclosed in U.S. Pat. No. 4,566,984, Bush, issued Jan. 28, 1986.
In situations where phosphorus-based builders can be used, and especially
in the formulation of bars used for hand-laundering operations, the
various alkali metal phosphates such as the well-known sodium
tripolyphosphates, sodium pyrophosphate and sodium orthophosphate can be
used. Phosphonate builders such as ethane-1-hydroxy-1,1-diphosphonate and
other known phosphonates (see, for example, U.S. Pat. Nos. 3,159,581;
3,213,030; 3,422,021; 3,400,148 and 3,422,137) can also be used.
Optional Detersive Adjuncts
As a preferred embodiment, the conventional detergent ingredients employed
herein can be selected from typical detergent composition components such
as detersive surfactants and detergent builders. Optionally, the detergent
ingredients can include one or more other detersive adjuncts or other
materials for assisting or enhancing cleaning performance, treatment of
the substrate to be cleaned, or to modify the aesthetics of the detergent
composition. Usual detersive adjuncts of detergent compositions include
the ingredients set forth in U.S. Pat. No. 3,936,537, Baskerville et al.
Adjuncts which can also be included in detergent compositions employed in
the present invention, in their conventional an-established levels for use
(generally from 0% to about 20% of the detergent ingredients, preferably
from about 0.5% to about 10%), include enzymes, especially proteases,
lipases and cellulases, color speckles, suds boosters, suds suppressors,
antitarnish and/or anticorrosion agents, soil-suspending agents, soil
release agents, dyes, fillers, optical brighteners, germicides, alkalinity
sources, hydrotropes, antioxidants, enzyme stabilizing agents, perfumes,
solvents, solubilizing agents, clay soil removal/anti-redeposition agents,
polymeric dispersing agents, processing aids, fabric softening components
such as smectite clays, static control agents, etc.
Bleach systems optionally, but preferably, will also comprise a chelant
which not only enhances bleach stability by scavenging heavy metal ions
which tend to decompose bleaches, but also assists in the removal of
polyphenolic stains such as tea stains, and the like. Various chelants,
including the aminophosphonates, available as DEQUEST from Monsanto, the
nitrilotri acetates, the hydroxyethyl-ethyl enedi amine triacetates, and
the like, are known for such use. Preferred biodegradable, non-phosphorus
chelants include ethylenediamine disuccinate ("EDDS"; see U.S. Pat. No.
4,704,233, Hartman and Perkins), ethylenediamine-N,N'-diglutamate (EDDG)
and 2-hydroxypropylenediamine-N,N'-disuccinate (HPDDS) compounds. Such
chelants can be used in their alkali or alkaline earth metal salts,
typically at levels from about 0.1% to about 10% of the present
compositions.
Optionally, the detergent compositions employed herein can comprise, in
addition to the bleaching system of the present invention, one or more
other conventional bleaching agents, activators, or stabilizers. In
general, the formulator will ensure that the bleach compounds used are
compatible with the detergent formulation. Conventional tests, such as
tests of bleach activity on storage in the presence of the separate or
fully-formulated ingredients, can be used for this purpose.
Specific examples of optional bleach activators for incorporation in this
invention include tetraacetyl ethylene diamine (TAED), N-acyl
caprolactams, alkanoyloxybenzenesulfonates, including
nonanoyloxybenzenesulfonate and benzoyloxybenzenesulfonate, the
benzoxazin-type bleaching activators disclosed in U.S. Pat. No. 4,966,723,
Hodge et at, issued Oct. 30, 1990, and the peroxyacid agents and
activators having amide moieties disclosed in U.S. Pat. No. 4,634,551,
Burns et at, issued Jan. 6, 1987. Such bleaching compounds and agents can
be optionally included in detergent compositions in their conventional
art-established levels of use, generally from 0% to about 15%, by weight
of detergent composition.
Bleaching activators of the invention are especially useful in conventional
laundry detergent compositions such as those typically found in granular
detergents or laundry bars. U.S. Pat. No. 3,178,370, Okenfuss, issued Apr.
13, 1965, describes laundry detergent bars and processes for making them.
Philippine Patent 13,778, Anderson, issued Sep. 23, 1980, describes
synthetic detergent laundry bars. Methods for making laundry detergent
bars by various extrusion methods are well known in the art.
Perhydrolysis Speed and Yield
The activators herein have better perhydrolysis speed and yield when
compared to other lactam derived bleach activators. For example, after
approximately five minutes, a solution of nonanoyl valerolactam generates
approximately 95% of the theoretical yield of peracid. In comparison,
after approximately five minutes, an identical solution of nonanoyl
caprolactam generates approximately 35% of the theoretical yield of
peracid. After 15 minutes, the nonanoyl caprolactam solution generates
approximately 68% of the theoretical yield of peracid. Accordingly, the
user can expect better bleaching performance at shorter wash times with
the valerolactam activators.
The comparison is made using standard peracid titration procedures. The
activator is dispersed in a detergent solution. At specific time
intervals, samples of the solution are taken and added to a mixture of
acetic acid, water, and ice to quench the perhydrolysis reaction. A
quantity of potassium iodide is added to the sample giving the sample a
brown color. The resulting solution is titrated with thiosulphate until
the color is removed. From the known quantity of thiosulphate used in the
titration, the amount of peracid can be determined.
Liquid Bleaches
The bleach activators of this invention are also useful in liquid bleach
compositions. Therefore, in accordance with one aspect of the invention, a
stable aqueous liquid bleach is provided. In a preferred embodiment, the
liquid bleaches comprise a liquid valerolactam such as decanoyl
valerolactam or nonanoyl valerolactam which is most preferably emulsified
in the peroxide liquid composition. Such liquid bleaches comprise:
A) from about 1% to about 25%, more preferably from about 3% to about 12%,
most preferably from about 5% to about 10%, by weight, of a (solid or,
preferably, liquid) valerolactam bleach activator selected from the group
consisting of:
a)
##STR7##
wherein R.sub.1 is as defined above; b)
##STR8##
wherein R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are as defined
above; and
c) mixtures of a) and b);
B) from about 0.1% to about 10%, more preferably from about 0.3% to about
7%, most preferably from about 0.5% to about 5%, by weight, of a peroxygen
bleaching compound comprising hydrogen peroxide or which is capable of
yielding hydrogen peroxide in an aqueous solution.
Optionally, the liquid bleach composition can further comprise from about
1% to about 20%, preferably from about 5% to about 15%, by weight, of a
phase stabilizer and from about 0.001% to about 2%, preferably from about
0.05% to about 1%, by weight, of a chelating agent. The balance of the
liquid bleach composition is water.
The liquid peroxide-containing bleach is formulated in the acid pH range
for stability. In-use in a laundering operation, the bleach is added to a
laundry liquor which typically has a pH in the base range, i.e., 9.5-13,
which then destabilizes the peroxide to perform its bleaching function.
Nonionic Surfactant
The liquid bleach compositions of the invention, optionally, but
preferably, include a nonionic surfactant as a phase stabilizer to
facilitate maintenance of its continuous isotropic state. To this end,
several nonionic surfactants are particularly useful. Suitable nonionic
surfactants include the polyethylene oxide condensates of alkyl phenols,
e.g., the condensation products of alkyl phenols having an alkyl group
containing from about 6 to 15 carbon atoms, in either a straight chain or
branched chain configuration, with from about 3 to 20 moles of ethylene
oxide per mole of alkyl phenol.
Other nonionic surfactants which function as suitable phase stabilizers are
the water-soluble and water-dispersible condensation products of aliphatic
alcohols containing from 8 to 22 carbon atoms, in either straight chain or
branched configuration, with from 3 to 20 moles of ethylene oxide per mole
of alcohol. Still other nonionic surfactants include semi-polar nonionic
surfactants such as water-soluble amine oxides containing one alkyl moiety
of from about 10 to 18 carbon atoms and two moieties selected from about 1
to about 3 carbon atoms; water-soluble phosphine oxides containing one
alkyl moiety of about 10 to 18 carbon atoms and two moieties selected from
the group consisting of alkyl groups and hydroxyalkyl groups containing
from about 1 to 3 carbon atoms; and water-soluble sulfoxides containing
only alkyl moiety of from about 10 to 18 carbon atoms and a moiety
selected from the group consisting of alkyl and hydroxyalkyl moieties of
from about 1 to 3 carbon atoms.
Preferred nonionic surfactants are of the formula R.sup.1 (OC.sub.2
H.sub.4).sub.n OH, wherein R.sup.1 is a C.sub.8 -C.sub.16 alkyl group of
C.sub.8 -C.sub.12 alkyl phenyl group, and n is from 3 to about 20.
Particularly preferred are condensation products of C.sub.9 -C.sub.15
alcohols with from about 5 to about 20 moles of ethylene oxide per mole of
alcohol. The most preferred nonionic of this type is an alkyl ethoxylate
having from about 9 to 11 carbon atoms and an average degree of
ethoxylation of about 10 which is available from Shell Oil Co. under the
product name of NEODOL 91-10.
The liquid bleach composition will generally comprise from about 1% to
about 20%, preferably from about 5% to about 15%, by weight, of the
nonionic surfactant phase stabilizer.
With the aforementioned chelating agent and phase stabilizer, i.e. nonionic
surfactant, the stable aqueous liquid bleach composition in accordance
with the invention can be produced. The resulting liquid bleach
composition has a relatively low viscosity which renders it more pourable
and therefore, more convenient for users especially when the composition
is used as an additive. The viscosity of the present liquid bleach is
preferably in a range from about 10 to about 500 cps, more preferably from
about 10 to about 300 cps, and most preferably from about 10 to 100 cps.
pH Adjusting Agent
It has been found that optimum stability of the liquid peroxygen bleaches
is achieved when the aqueous liquid bleach has a pH in range from about 2
to about 7, more preferably from about 3 to about 5, and most preferably
from about 3.5 to about 4.5. For purposes of achieving such pH's in the
present stable aqueous liquid bleach composition, a pH adjusting agent may
optionally be included. It is a well known technique to use pH adjusting
agents to alter aqueous solutions such as the present liquid bleach, to
the desired pH.
Typical pH adjusting agents can be either of the acid type or of the base
type. Acidic pH adjusting agents are designed to compensate for the
presence of other highly alkaline materials land include organic and
inorganic acids, acid mixtures and acid salts. Non-limiting examples of
such acidic pH adjusting agents include citric acid, glycolic acid,
phosphoric acid, lauric acid and mixtures thereof. Representative examples
of alkaline pH adjusting agents include but not limited to sodium
hydroxide, salts of phosphates, citrates and mixtures thereof.
In addition to the materials described above, the liquid bleach may also
include perfumes colorants, brighteners, viscosity adjusters such as
thickeners, and other conventional components typically used in detergent
compositions, if compatible.
The liquid bleach of the invention can be produced by a wide variety of
processes. While not intending to be limiting, the most economical and
easiest manner in which the liquid bleach can be produced is to simply
disperse all of the preferred components in water. As those skilled in the
art will appreciate, it may be desirable to disperse certain components in
water before others. This offers an inexpensive way to produce the present
liquid bleach composition.
In accordance with another aspect of the invention, a method of bleaching
fabrics comprises the step of contacting fabrics with a diluted aqueous
solution of the liquid composition of the invention. Another method
contemplated by the invention involves laund | | |
