Note: Descriptions are shown in the official language in which they were submitted.
~ Wo 94/24247 PCT/US94103739
2~9983
CONCENTRATED LIQUID DETERGENT CONTAINING SUSPENDED PEROXYGEN
BLEACH, ORGANIC SOLVENT AND 5-20% WATER
Technical Field
The invention relates to concentrated liquid detergent
compositions which contain a suspending solid peroxygen
compound.
Backqround
Answering the long-felt need for aqueous liquid detergent
compositions containing a peroxygen bleach, which would be
stable and efficient at the same time, EP-A-293 040
and EP-A-294 904 have described aqueous detergent
compositions having a pH above 8 containing an anionic
surfactant at conventional levels, i.e. above 5% by weight,
typically from 15% to 40% by weight, and a solid water
soluble peroxygen bleach, suspended in a specific
water/solvent medium.
In such compositions, particular attention had to be
given to the physical stability of suspended particles in the
liquid medium. One option is represented by EP-A-0 430 330,
describing liquid detergent compositions in which solid
W094~7 2 1 5 9 9 8 3 PCT~S94/03739 0
particles, in particular particles of a peroxygen compound,
are suspended by means of a structured phase (surfactant
"neat phase").
Surfactant structured (neat) phases are known as means to
suspend solid particles such as zeolites in liquid detergent
compositions, see in particular EP-A-79 646, EP-A- 170 091
and EP-A-295 021.
In bleach-containing liquid detergent compositions,
chemical stability also represents an important concern, and
high level of organic solvents should in principle be
necessary, in order to achieve an optimal chemical stability.
However, organic solvents at high levels have been found to
have a detrimental effect on the formulation of surfactant
neat phases, so that a good compromise between chemical and
physical stability when using structured phases to suspend a
peroxygen bleach compound was not easy to obtain.
The problem is especially acute in the case of
percarbonate, which is more difficult to stabilize chemically
than perborate.
The present invention provides concentrated liquid
detergent compositions formulated as a neat phase in which
solid suspended peroxygen compounds, such as perborate or
percarbonate, in particular percarbonate, can be stabilized
chemically and physically. Indeed, the present invention
provides liquid detergent bleach-containing compositions
which exhibit a very good chemical stability, and are in the
form of a perfectly stable structured phase.
Summary of the invention
The present invention relates to a liquid detergent
composition containing a surface-active agent, water, an
~ W094/~7 2 ~ 5 9 9 8 3 PCT~S94/03739
organic solvent, and a solid peroxygen compound in the form
of suspended particles. Said composition comprises at least
10% by weight of the total composition of a compound of the
~ formula
J RO(CH2CH2O)yH
wherein :
- R is a Cn alkyl, alkenyl, aryl or alkyl aryl group
- and n is an integer of from 4 to 22
- and y = 0 to 4
- and n/y ~ 2 if y f o
In the composition according to the present invention the
level of water is from 5% to 20~ by weight of the total
composition, and the weight ratio of organic solvent to water
is of at least 0.8.
Detailed Descri~tion
The structured ~hase
In the following, the e~pression "structured phase"
refers to an essentially lamella-structured or spherulitic
composition in which aqueous layers are separated by double
layers of hydrophobic materials. Such a lamellar structure
can be identified by observing the product through an optical
microscope, between crossed Nichol prisms. The structured
phases are characterized by specific textures which are
described for instance by F.B. Rosevear, Journal of the
American Oil Chemists Society, vol. 3, page 628, 1954.
Importantly, the compositions herein compulsory contain a
surface-active agent and an organic solvent. Said
compositions herein can be formulated as a structured phase
W094/~7 21~ 9 9 8 3 PCT~S94/03739
--
by incorporation of at least lO~ by weight of a compound of
the formula
Ro(cH2cH2o)yH
wherein
- R is a Cn alkyl, alkenyl, alkynyl, aryl or alkyl
aryl group
- n is an integer of from 4 to 22
_ y = o to 4
- and n/y >~ 2 if y ~ O
or mixtures thereof.
Preferred compounds according to this definition are
nonionic surfactants consisting of condensation products of
ethylene oxide with a fatty alcohol in the presence of an
acidic or basic catalyst. Fatty alcohols having from 13 to
15 carbon atoms are preferably used to make such condensation
products.
Also preferred compounds according to the above
definition are such solvents as butanol, butoxyethanol,
benzylalcohol, hexyl diglycol ether, butyl diglycolether, and
mixtures thereof.
The preferred compositions herein therefore contain at
least one of the organic solvents above, or a nonionic
surfactant as defined above, or both types of compounds.
Most preferably, the organic solvents described above
should be used in combination with another solvent such as
described hereinafter. Similarly, the nonionic surfactants
described above are preferably used in combination with an
anionic surfactant, and/or other types of surfactants,
including other nonionic surfactants, described hereinafter.
~ W094/~7 2 1 5 9 9 8 3 PCT~S94/03739
The water level and the water to orqanic solvent ratio
Two critical features of the present compositions are
represented by the water level and the organic solvent to
water weight ratio.
The water level is of 5% to 20~ by weight of the present
composition, i.e., the present compositions are relatively
concentrated.
The organic solvent to water weight ratio is at least
0.8, preferably at least 1Ø
It is the combination of these two features which allows
to achieve both a good chemical and physical stability in the
present liquid detergent compositions, in particular when the
suspended peroxygen compound is percarbonate.
The solid peroxyqen compound
Suitable solid peroxygen compounds include the
perborates, persulfates, peroxydisulfates, perphosphates and
the crystalline peroxyhydrates formed by reacting hydrogen
peroxide with sodium carbonate (forming percarbonate) or
urea. Preferred peroxygen bleach compounds are perborates
and percarbonates. Percarbonates, known to be difficult to
stabilize, have been found to be perfectly stabilized in the
present composition, and are therefore the most preferred
species for use herein.
The weight-average particle diameter of the peroxygen
compounds herein must be in the range from 0.1 to 350
micrometers, preferably from 0.5 to 20 micrometers.
The required small particle size can be achieved by
physical techniques, such as grinding, or any suitable
W094/~7 -2 1 ~ 9 9 8 3 PCT~S94/03739 ~
chemical technique such as in-situ crystallization,
especially for perborate, as it is described in detail in EP-
A-294 904.
The peroxygen compounds are present in the compositions
herein at levels of from 5% to 40%, preferably from 10% to
30%, most preferably from 15% to 25%, by weight of the
composition.
The orqanic solvent
The organic solvent preferably contains at least one
solvent corresponding to the formula RO(CH2CH20)yH as
described above, for the structured phase formation; butyl
diglycol ether and hexyl diglycol ether being preferred;
other organic solvents which may be used preferably in
combination with such required solvents, can be selected from
the group of : polyalcohols having vicinal hydroxy groups
(e.g. 1,2-propanediol and glycerol); lower monoaliphatic
monoalcohols; specifically ethanol, n-propanol; iso-propanol;
polyethylene glycol (e.g., PEG 150, 200, 300, 400);
dipropylene glycol; ethoxymethanol; methoxyethanol;
ethoxyethanol; ethyldiglycolether; benzylalcohol;
butoxypropanol; butoxypropoxypropanol; and mixtures hereof.
Preferred are ethanol, propanediol, and mixtures thereof,
when the peroxygen bleach compound is percarbonate, and
ethanol when the peroxygen bleach compound is perborate.
The present liquid bleach compositions exhibit a pH (1%
solution in distilled water) of at least 8, preferably of at
least 9, more preferably of at least 9.5. The alkaline pH
allows to get a good bleaching action of the peroxygen
compound, particularly when the peroxygen is a percarbonate
or perborate.
~ WOg4/~7 2 1 5 9 9 8 3 PCT~S94/03739
The surface active aqent
The compositions of the invention contain a surface
active agent selected from anionic, nonionic, zwitterionic or
cationic surface-active agents, and mixtures thereof.
Preferably the compositions herein contain an anionic,
synthetic or natural surfactant.
Synthetic anionic surfactants can be represented by the
general formula R1So3M wherein R1 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 typically is selected from the group
consisting of sodium, potassium, ammonium, and mixtures
thereof.
Preferred among anionic synthetic surfactants are the
water-soluble salts of alkylbenzene sulfonic acid, preferably
sodium alkylbenzene sulfonates having from about 10 to 13
carbon atoms in the alkyl group.
Other suitable anionic surfactants can be represented by
the water-soluble salts 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
20 carbon atoms, and preferably from about 1 to about 12
ethoxy groups for the alkyl polyethoxylate ether sulfates.
Particularly preferred are alkyl sulfates containing from
12 to 15 carbon atoms in the alkyl chain. Natural coconut or
palm kernel alkyl sulfate are especially preferred.
W094124247 2 1 5 9 9 8 3 ~uss~3~s ~
Other suitable anionic surfactants are disclosed in
U.S. Patent 4,170,565, Flesher et al., issued October 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 amido
group, in the presence of an acidic or basic catalyst, and
include compounds having the general formula RA(CH2CH20)nH
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. n varies from
about 4 to about 24.
R is an alkyl, alkenyl, aryl or alkyl aryl having from
about 8 to about 24, preferably from about 12 to about 20
carbon atoms.
A more complete disclosure of suitable nonionic
surfactants can be found in U.S. Patent 4,111,855. Mixtures
of nonionic surfactants can be desirable.
Zwitterionic surfactants include derivatives of aliphatic
quaternary ammonium, phosphonium, and sulphonium compounds in
which the aliphatic moiety can be 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.
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.
~ WOg4t~7 2 1 S 9 9 8 3 PCT~S94/03739
Examples of suitable cationic surfactants include
quaternary ammonium compounds of the formula R1R2R3R4N+X-,
wherein Rl is C12-C20 alkyl or hydroxyalkyl; R2 is C1-C4
alkyl or C12-C20 alkyl or hydroxyalkyl or C1-C4 hydroxyalkyl,
R3 and R4 are each C1-C4 alkyl or hydroxyalkyl, or C6-C8 aryl
or alkylaryl; and X~ is halogen. Preferred are mono-long
chain quaternary ammonium compounds (i.e., compounds of the
above formula wherein R2 is Cl-C4 alkyl or hydroxyalkyl).
The total amount of surfactant in the compositions is of
from 5% to 60%, preferably 15% to 40% by weight of the total
composition.
Optional inqredients
The compositions of the invention may also contain a
builder. Preferred are C1o-C16 alk(en~yl substituted
succinic acids, typically present at levels of from 5% to 30%
by weight of the total composition. The preferred builder
for use herein is a mixture of dodecenyl substituted succinic
acid and tetradecenyl substituted succinic acid.
Examples of other suitable organic builders for use
herein are represented by polyacids such as citric acid,
nitrilotriacetic acid, and mixtures of tartrate monosuccinate
with tartrate disuccinate. Polymeric carboxylate builders
inclusive of polyacrylates, polydydroxy acrylates and
polyacrylates/polymaleates copolymers can also be used.
It is preferred, however, that those of the above
builders which are water-soluble, be used at levels not
exceeding 1% by weight of the total composition.
Other optionals include detergent enzymes. Suitable
enzymes include the detergent proteases, amylases, lipases
W094/~7 2 1 5 9 9 8 3 PCT~S94103739 ~
and cellulases. Enzymatic stabilizing agents for use in
aqueous liquid detergents can also be used herein.
It is preferred, however, that salts of formic acid such
as sodium formate, which is a typical enzyme stabilizing
agent, be used at levels not exceeding 0.5% by weight of the
total composition.
The compositions of the invention may also contain
chelants, especially chelants for transition metal ions,
since such ions can have a detrimental effect on the chemical
stability of the compositions, the peroxygen bleaching agents
being sensitive to these ions. Such chelants include
ethylenediaminotetracetic acid, diethylenetriaminopentacetic
acid, ethylenediamino disuccinic acid or the water-soluble
alkali metals thereof. Other chelants include organo-
phosphonic acids; particularly preferred are ethylenediamino
tetramethylenephosphonic acid, hexamethylenediamino
tetramethylenephosphonic acid, diethylenetriamino
pentamethylenephosphonic acid, aminotrimethylenephosphonic
acid and hydroxyethylidene 1,1 diphosphonic acid.
In the present context however, the very good chemical
stability of the compositions makes it possible to include
only very small levels of such chelants, typically 0.2%.
The compositions herein can contain 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.
The beneficial utilization of the claimed compositions
under various usage conditions can require the utilization of
~ WOg4/~7 21~ ~ 9 8 3 PCT~S94103739
Il
a suds regulant like polysiloxanes such as
dimethylpolysiloxane, also frequently used in a level not
exceeding 1.5%, most preferably between 0.1% and 1.0%
In selecting optional ingredients, it is also preferred
that the level of electrolytes in the compositions herein is
kept to a minimum. For instance, preferred compositions
according to the present invention contain no more than 0.5%
by weight of the total composition of added electrolytes such
as sodium or potassium salts of bromide, chloride, iodide,
nitrate and C1-4 alkyl carboxylates. Accordingly, the liquid
detergent formulations of the present invention are
substantially free of electrolytes.
Use of the comPositions
The present concentrated compositions are designed to be
used as is and are not diluted before use.
ExamPle
Ingredients Composition wt%
Linear alkyl benzene sulfonate lO
C13-C15 alcohol ethoxylated (EO3) lO
Dodecenyl/Tetradecenyl succinic
acids* 19
Diethylenetriaminepentamethylene
phosphonic acid 0.2
Propanediol 5
Ethanol 6
Butyl diglycol ether 5
Sodium Percarbonate 21
Protease 0.5
wog4~4247 215998~
PCT~S94/03739
I .
Opacifier 0.6
Dye (1%) 0.4
Perfume 0.5
Water Up to lO0
Water content 13.9
Solvent content 16.5
Solvent/Water content 1.18
*75% dodecenyl succinic acid, 25% tetradecenyl succinic acid
