Note: Descriptions are shown in the official language in which they were submitted.
2012172
.
LIGHT-DUTY LIQUID DISHWASHING DETERGENT COMPOSITION
CONTAINING AN ALKYL ETHOXY CARBOXYLATE SURFACTANT
Technical Field
The present invention relates to light-duty liquid
dishwashing detergent compositions containing alkyl ethoxy
carboxylate surfactants (alternatively labeled alkyl polyethoxy
carboxy methylates, alkyl polyethoxy acetates, alkyl polyether
carboxylates, etc.) of the type disclosed in U.S. Pat. Nos.
2,183,853; 2,653,972; 3,003,954; 3,038,862; 3,741,911; and
3,941,710; British Pat. Nos. 456,517 and 1,169,496; Canadian Pat.
No. 912,395; French Pat. Nos. 2,014,084 and 2,042,793; Netherland
Patent Application Nos. 7,201,735-Q and 7,406,336; and Japanese
Patent Application Nos. 96,579/71 and 99,331/71.
Backqround Art
There has been considerable demand for light-duty liquid
dishwashing detergents capable of providing good grease removal.
These compositions are well known in the art and are described,
for example, in U.S. Pat. Nos. 4,316,824 (Pancheri), 4,681,704
(Bernardino et al.), and 4,133,779 (Hellyer et al.). These
compositions, although being good grease and soil cleaners, can be
harsh to the skin under certain conditions, particularly when used
during the dry winter months.
Likewise, the art is replete with detergent compositions that
are mild to the skin. These mild compositions often contain
sulfates of highly ethoxylated alcohols. See, for example, U.S.
Pat. No. 3,743,233, Rose and Thiele. Betaines have also been
suggested for use in improving mildness of a liquid dishwashing
composition. See, for example, U.S. Pat. No. 4,555,360 (Bissett
et al). Alkyl ethoxy carboxylates are also known as mild
surfactants for use in liquid detergent compositions. See
Japanese Patent Applications 48-60706 and 48-64102.
These alkyl ethoxy carboxylate surfactants, however, have been
described as being poor in their grease cutting ability and
require the use of other surfactants to achieve the desired
cleaning.
2012172
_ 2
Rarely have these two important features of mildness and
grease cutting ability been incorporated in one product. It is
generally thought that one must be sacrificed for the benefit of
the other. It is therefore an object of this invention to provide
a detergent composition that exhibits good grease removal while
manifesting mildness to the skin.
SummarY of the Invention
The present invention relates to a light-duty liquid
dishwashing detergent composition comprising from about 5% to 50%
of a surfactant mixture comprising:
(a) from about 80% to 100% of alkyl ethoxy carboxylates of
the formula:
RO(CH2CH20)xCH2COO-M+
wherein R is a C12 to C16 alkyl group, x ranges from 0 to
about 10 and the ethoxylate distribution is such that, on a
weight basis, the amount of material where x is 0 is less
than about 20% and the amount of material where x is greater
than 7 is less than about 25%, the average x is from about 2
to 4 when the average R is C13 or less, and the average x is
from about 3 to 6 when the average R is greater than C13, and
M is a cation;
(b) from 0% to about 10% of alcohol ethoxylates of the
formula:
RO(CH2CH20)XH
wherein R is a C12 to C16 alkyl group and x ranges from 0 to
about 10 and the average x is less than about 6; and
(c) from 0% to about 10% of soaps of the formula:
RC00-M+
wherein R is a Cll to Cls alkyl group and M is a cation;
said composition having a pH from about 7 to 11.
2012172
3 -
Detailed OescriDtion of the Invention
The light-duty liquid dishwashing detergent compositions of
the present invention contain a surfactant mixture comprising a
major amount of an alkyl ethoxy carboxylate surfactant and little
or no alcohol ethoxylate and soap by-product contaminants. These
and other complementary optional ingredients typically found in
liquid dishwashing compositions are set forth below.
AlkYl EthoxY CarboxYlate-Containing Surfactant Mixture
The composition of this invention contains from about 5% to
50% by weight, preferably from about 10% to 40%, most preferably
from about 12% to 30%, of a surfactant mixture restricted in the
levels of contaminants.
The surfactant mixture contains from about 80X to 100%,
preferably from about 857. to 95%, most preferably from about 90%
to 95%, of alkyl ethoxy carboxylates of the generic formula
RO(CH2CH20)xCH2COO-M+ wherein R is a C12 to C16 alkyl group, x
ranges from O to about 10, and the ethoxylate distribution is such
that, on a weight basis, the amount of material where x is O is
less than about 20%, preferably less than about 15%, most
preferably less than about 10%, and the amount of material where x
is greater than 7 is less than about 25X, preferably less than
about 15%, most preferably less than about 107" the average x is
from about 2 to 4 when the average R is C13 or less, and the
average x is from about 3 to 6 when the average R is greater than
C13, and M is a cation, preferably chosen from alkali metal,
alkaline earth metal, ammonium, mono-, di-, and tri-ethanol-
ammonium, most preferably from sodium, potassium, ammonium, and
mixtures thereof with magnesium ions. The preferred alkyl ethoxy
carboxylates are those where R is a C12 to C14 alkyl group.
Suitable alcohol precursors of the alkyl ethoxy carboxylates
of this invention are primary aliphatic alcohols containing from
about 12 to about 16 carbon atoms. Other suitable primary
aliphatic alcohols are the linear primary alcohols obtained from
the hydrogenation of vegetable or animal fatty acids such as
coconut, palm kernel, and tallow fatty acids or by ethylene build
- 4 ~ 201 21 72
up reactions and subsequent hydrolysis as in the Ziegler type
processes. Preferred alcohols are n-octyl, n-nonyl, n-decyl,
u-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, and
n-hexadecyl. Other suitable alcohol precursors include primary
alcohols having a proportion of branching on the beta or 2-carbon
atoms wherein the alkyl branch contains from 1 to 4 carbon atoms.
In such alcohols at least 30% of the alcohol of each specific
chain length is desirably linear and the branching preferably
comprises about 50% of methyl groups with smaller amounts of
ethyl, propyl and butyl groups. These alcohols are conveniently
produced by reaction of linear olefins having from about 11 to 17
carbon atoms with carbon monoxide and hydrogen. Both linear and
branched chain alcohols are formed by these processes and the
mixtures can either be used as such or can be separated into
individual components and then recombined to give the desired
blend.
Typical processes for producing "Oxo" halides which are then
used to prepare alcohols are disclosed in U.S. Patent Nos.
2,564,456 and 2,587,858 and the direct bydroformylation of olefins
to give alcohols is disclosed in U.S. Patent Nos. 2,504,682 and
1,581,988.
The equivalent secondary alcohols can also be used. It will
be apparent that by using a single chain length olefin as starting
material, a corresponding single chain length alcohol will result,
but it is generally more economical to utilize mixtures of olefins
having a spread of carbon chain length around the desired mean.
This will, of course, provide a mixture of alcohols having the
sime distribution of chain lengths around the mean.
Primary aliphatic alcohols derived from vegetable oils and
fats and from other petroleum feed stocks having alkyl or alkylene
groups as part of their structure will also contain a range of
chain lengths. Since the range of chain lengths is Cg-C20 and
beyond, it is therefore normal practice to separate the product
from such feed stocks into different chain length ranges which are
chosen with reference to their ultimate use.
- 201 21 72
_ - 5 -
The desired average ethoxy chain length on the alcohol
ethoxylate can be obtained by using a catalyzed ethoxylation
process, wherein the molar amount of ethylene oxide reacted with
each equivalent of fatty alcohol will correspond to the average
number of ethoxy groups on the alcohol ethoxylated. The addition
of ethylene oxide to alkanols is known to be promoted by a
catalyst, most conventionally a catalyst of either strongly acidic
or strongly basic character. Suitable basic catalysts are the
basic salts of the alkali metals of Group I of the Periodic Table,
e.g., sodium, potassium, rubidium, and cesium, and the basic salts
of certain of the alkaline earth metals of Group II of the
Periodic Table, e.g., calcium, strontium, barium, and in some
cases magnesium. Suitable acidic catalysts include, broadly, the
Lewis acid of Friedel-Crafts catalysts. Specific examples of
these catalysts are the fluorides, chlorides, and bromides of
boron, antimony, tungsten, iron, nickel, zinc, tin, aluminum,
titanium, and molybdenum. The use of complexes of such halides
with, for example, alcohols, ethers, carboxylic acids, and amines
have also been reported. Still other examples of known acidic
alkoxylation catalysts are sulfuric and phosphoric acids;
perchloric acid and the perchlorates of magnesium, calcium,
manganese, nickel, and zinc; metals oxalates, sulfates,
phosphates, carboxylates, and acetates; alkali metal
fluoroborates, zinc titanate; and metal salts of benzene sulfonic
acid. The type of catalyst used will determine the distribution
of the range of ethoxy groups. Stronger catalysts will result in
a very tight or narrow distribution of the ethoxy groups around
the mean. Weaker catalysts will result in a wider distribution.
The surfactant mixture also contains from 0% to about 10X,
preferably less than about 8%, most preferably less than about 5%,
of alcohol ethoxylates of the formula RO(CH2CH20)xH wherein R is a
C12 to C16 alkyl group and x ranges from 0 to about 10 and the
average x is less than 6. The surfactant mixture also contains 0%
to about 10%, preferably less than about 8%, most preferably less
than about 5%, of soaps of the formula RC00-M+ wherein R is a C
to C1s alkyl group and M is a cation as described above.
201 21 72
The uncarboxylated alcohol ethoxylates noted above are a
detriment to the alkyl ethoxy carboxylate surfactant mixture.
Therefore, it is critical that the alkyl ethoxy carboxylate-con-
taining surfactant mixture used in this invention contain less
than about 10% by weight of the alcohol ethoxylates they are
derived from. Although commercially available alkyl ethoxy
carboxylates contain 10% or more of alcohol ethoxylates, there are
known routes to obtain the desired high purity alkyl ethoxy
carboxylates. For example, unreacted alcohol ethoxylates can be
removed by steam distillation, U.S. Pat. No. 4,098,818 (Example
I), or by recrystallization of the alkyl ethoxy carboxylate,
British Pat. No. 1,027,481 (Example 1). Other routes to the
desired carboxylates are the reaction of sodium hydroxide or
sodium metal and monochloracetic acetic, or its salt, with alcohol
ethoxylates under special pressure and temperature combinations,
as described in U.S. Pat. Nos. 3,992,443 and 4,098,818; and
Japanese Patent Application No. 50-24215.
Alternatively, a hindered base, such as potassium
tert-butoxide can replace the sodium hydroxide in the above cited
patents, thus yielding high purity alkyl ethoxy carboxylates with
less stringent temperature and pressure requirements.
Specifically, a hindered base of the formula RO-M+, constituting
generally an alkyl group, a reactive oxygen center, and a cation
is used. The structure of this hindered base is secondary or
tertiary and contains a non-linear alkyl group with at least one
site of branching within 3 carbon atoms of the reactive center,
the oxygen atom, and an alkali metal or alkaline earth metal
cation. The process comprises reacting the alcohol ethoxylates
with the hindered base described above and either anhydrous
chloroacetic acid, at a molar ratio of the hindered base to the
anhydrous chloroacetic acid of 2:1, or an alkali metal salt or
alkaline earth metal salt of anhydrous chloroacetic acid, at a
molar ratio of the hindered base to the alkali metal salt or
alkaline earth metal salt of chloroacetic acid of 1:1, wherein the
molar ratio of the ethoxylated fatty alcohol to the anhydrous
, ~. .
201 2~ 72
- 7 -
.
chloroacetic acid or the alkali metar salt or arkaline earth metal
salt thereof is from about 1:0.7 to about 1:1.25, the temperature
is from about 20 to 140C, and the pressure is from about 1 to 760
mm Hg.
Other routes to high purity alkyl ethoxy carboxylates are the
reaction of alcohol ethoxylate wi~h oxygen in the presence of
platinum, palladium, or other noble metals, as disclosed in U.S.
Pat. No. 4,223,460 (Example 1-7); U.S. Pat. No. 4,214,101 (Example
1); U.S. Pat. No. 4,348,509; German Patent No. 3,446,561; and
Japanese Patent Application No. 62,198,641. One of the
by-products of such reactions is soap, which should be limited, as
described above, to avoid adversely affecting the cleaning and
mildness advantages provided by the present compositions. This
can be accomplished by using alcohol ethoxylate feedstock
containing low levels of unethoxylated fatty alcohol and by
selecting catalysts that preferentially oxidize the terminal
methylene in the alcohol ethoxylate, at least about 90% of the
time, preferably at least about 95% of the time. Oxidation of
non-terminal methylene groups in the alcohol ethoxylate will
generate soap from ethoxylated fatty alcohol components.
The compositions of this invention have a pH from about 7 to
11, determined as the pH of the undiluted composition with a pH
meter. The preferred detergent composition has a pH from about 8
to 10.5 and most preferably from about 8.5 to 10. Traditionally,
liquid dishwashing compositions have a pH of about 7. It has been
found for detergent compositions of this invention that a more
alkaline pH of about 9 greatly improves the grease cleaning as
compared to a product with a pH of 7. This cleaning benefit
appears to be unique to compositions containing the present alkyl
ethoxy carboxylates. Surprisingly, the compositions of this
invention are still very mild to hands at an alkaline pH.
If a composition with a pH greater than 7 is to be most
effective in improving performance, it should contain a buffering
agent capable of maintaining the alkaline pH in the composition
and in dilute solutions of the composition. This buffering agent
may be an active detergent in its own right, or it may be a low
- 2012172
molecular weight, organic or inorganic material that is used in
this composition solely for maintaining an alkaline pH. Preferred
buffering agents for compositions of this invention are
nitrogen-containing materials. Some examples are glycine or other
amino acids or lower alcohol amines like mono-, di-, and
tri-ethanolamine. These buffering agents are typically present at
a level of from about 0.1% to 10% by weight, preferably from about
1% to 77O~ most preferably from about 1.5X to 5%.
The cations for the alkyl ethoxy carboxylates herein can be
alkali metals, alkaline earth metals, ammonium, and lower alkanol
ammonium ions. It has been found that for the present alkyl
ethoxy carboxylates the presence of divalent cations greatly
improves the cleaning of greasy soils. This is especially true
when the compositions are used in softened water that contains few
divalent ions. Dishwashing liquid compositions that contain alkyl
ethoxy carboxylates that do not conform to the narrow definition
of this invention will be less benefited by the addition of
divalent ions and, in many cases, will actually exhibit reduced
cleaning performance upon the addition of divalent cations. It is
believed that divalent ions increase the packing of the present
alkyl ethoxy carboxylates at the oil/water interface, thereby
reducing interfacial tension and improving grease cleaning.
Preferably, the divalent ions are added as a chloride or
sulfate salt to compositions containing an alkali metal or
ammonium salt of the alkyl ethoxy carboxylate, most preferably the
sodium sa~t, after the composition has been neutralized with a
strong base. The level of divalent ion in the composition is from
0% to about 1.5%, preferably from about 0.2% to 1%, most
preferably from about 0.3% to 0.8%, by weight. Particularly
preferred divalent ions are magnesium ions.
When both divalent ions and alkaline pH are combined with the
surfactant mixture of this invention, grease cleaning is achieved
that is superior to that obtained by either alkaline pH or
divalent ions alone. Preferably, the divalent ion is magnesium,
present in the composition at a level of from about 0.17. to 17.,
most preferably from about 0.3% to 0.8%, by weight, while the pH
9 201 21 72
is preferably from about 8 to 9.5 and most preferably from about
8.5 to 9.5. Compositions that contain higher levels of magnesium
and have a pH much above about 9.5 are not preferred due to a
tendency to form precipitates.
Co-Surfactants
The compositions of this invention preferably contain certain
co-surfactants to aid in the foaming, detergency, and/or mildness.
Included in this category are several anionic surfactants
commonly used in liquid dishwashing detergents. The cations
associated with these anionic surfactants can be the same as the
cations described previously for the alkyl ethoxy carboxylates.
Examples of anionic co-surfactants that are useful in the present
invention are the following classes:
(1) Alkyl benzene sulfonates in which the alkyl group
contains from 9 to 15 carbon atoms, preferably 11 to 14 carbon
atoms in straight chain or branched chain configuration. An
especially preferred linear alkyl benzene sulfonate contains about
12 carbon atoms. U.S. Pat. Nos. 2,220,099 and 2,477,383 describe
these surfactants in detail.
(2) Alkyl sulfates obtained by sulfating an alcohol having 8
to 22 carbon atoms, preferably 12 to 16 carbon atoms. The alkyl
sulfates have the formula ROSO3-M+ where R is the Cg 22 alkyl
group and M is a mono- and/or divalant cation.
(3) Paraffin sulfonates having 8 to 22 carbon atoms,
preferably 12 to 16 carbon atoms, in the alkyl moiety. These
surfactants are commercially available as Hostapur SAS from ~~~~
Hoechst Celanese.
(4) Olefin sulfonates having 8 to 22 carbon atoms,
prefera~ly 12 to 16 carbon atoms. U.S. Pat. No. 3,332,880
contains a description of suitable olefin sulfonates.
(5) Alkyl ether sulfates derived from ethoxylating an
alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon
atoms, less than 30, preferably less than 12, moles of ethylene
oxide. The alkyl ether sulfates having the formula:
RO(C2H4O)XSO3-M+
, ~
-` 2 0 1 2 1 7 2
- 10 -
- where R is the Cg 22 alkyl group, x is 1-30, and M is a mono- or
divalent cation.
(6) Alkyl glyceryl ether sulfonates having 8 to 22 carbon
atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety.
(7) Dialkyl sulfosuccinates of the formula:
CH2 - CH - SO3-M+
COOR1 COOR2
where each of R1 and R2, which may be the same or different,
represents a straight chain or branched chain alkyl group having
from about 4 to 10 carbon atoms and more preferably from about 6
to 8 carbon atoms, and M+ represents a mono-or divalent cation. A
more complete description of suitable dialkyl sulfosuccinates can
be found in GB 2,105,325 and GB 2,104,913.
(8) Fatty acid ester sulfonates of the formula:
R1 - CH(SO3-M+)C02R2
wherein R1 is straight or branched alkyl from about Cg to C1g,
preferably C12 to C16, and R2 is straight or branched alkyl from
about C1 to C6, preferably primarily C1, and M+ represents a mono-
or divalent cation.
(9) Mixtures thereof.
The above described anionic surfactants are all available
commercially. It should be noted that although both dialkyl
sulfosuccinates and fatty acid ester sulfonates will function well
at neutral to slightly alkaline pH, they will not be chemically
stable in a composition with pH much greater than about 8.5.
Other useful co-surfactants for use in the compositions are
the nonionic fatty alkylpolyglucosides. These surfactants contain
straight chain or branched chain C8 to C1s, preferably from about
C12 to C14, alkyl groups and have an average of from about 1 to 5
glucose units, with an average of 1 to 2 glucose units being most
preferred. U.S. Pat. Nos. 4,393,203 and 4,732,704, describe
these surfactants
The co-surfactants for the compositions of this invention can
also contain mixtures of anionic surfactants with alkyl
polyglucosides. The co-surfactants are present in the composition
~,~
- -11- 2012172
- at a level of from 0% to about 35% by weight, preferably from
about 5% to 25%, and most preferably from about 7% to 20%.
Suds Booster
Another component which may be included in the composition of
this invention is a suds stabilizing surfactant (suds booster) at
a level of less than about 15%, preferably from about 0.5% to 12%,
more preferably from about 1% to 10%. Optional suds stabilizing
surfactants operable in the instant composition are of five basic
types -- betaines, ethylene oxide condensates, fatty acid amides,
amine oxide semi-polar nonionics, and cationic surfactants.
The compositon of this invention can contain betaine
detergent surfactants having the general formula:
R - N(R1)2 - R2COO
wherein R is a hydrophobic group selected from the group
consisting of alkyl groups containing from about 10 to about 22
carbon atoms, preferably from about 12 to about 18 carbon atoms,
alkyl aryl and aryl alkyl groups containing a similar number of
carbon atoms with a benzene ring being treated as equivalent to
about 2 carbon atoms, and similar structures interrupted by amido
or ether linkages; each Rl is an alkyl group containing from 1 to
about 3 carbon atoms; and R2 is an alkylene group containing from
1 to about 6 carbon atoms.
Examples of preferred betaines are dodecyl dimethyl betaine,
cetyl dimethyl betaine, dodecyl amidopropyldimethyl betaine,
tetradecyldimethyl betaine, tetradecylamidopropyldimethyl betaine,
and dodecyldimethylammonium hexanoate.
Other suitable amidoalkylbetaines are disclosed in U.S. Pat.
Nos. 3,~50,417; 4,137,191; and 4,375,421; and British Patent GB
No. 2,103,236.
It will be recognized that the alkyl (and acyl) groups for
the above betaine surfactants can be derived from either natural
or synthetic sources, e,g., they can be derived from naturally
occurring fatty acids; olefins such as those prepared by Ziegler,
- 2 0 1 2 1 72
- 12 -
_ .
or Oxo processes; or from olefins separated from petroleum either
with or without "cracking".
The ethylene oxide condensates are broadly defined as
compounds produced by the condensation of ethylene oxide groups
(hydrophilic in nature) with an organic hydrophobic compound,
which can be aliphatic or alkyl aromatic in nature. The length of
the hydrophilic or polyoxyalkylene radical which is condensed with
any particular hydrophobic group can be readily adjusted to yield
a water-soluble compound having the desired balance between
hydrophilic and hydrophobic elements.
Examples of such ethylene oxide condensates suitable as suds
stabilizers are the condensation products of aliphatic alcohols
with ethylene oxide. The alkyl chain of the aliphatic alcohol can
either be straight or branched and generally contains from about 8
to about 18, preferably from about 8 to about 14, carbon atoms for
best performance as suds stabilizers, the ethylene oxide being
present in amounts of from about 8 moles to about 30, preferably
from about 8 to about 14 moles of ethylene oxide per mole of
alcohol.
Examples of the amide surfactants useful herein include the
ammonia, monoethanol, and diethanol amides of fatty acids having
an acyl moiety containing from about 8 to about 18 carbon atoms
and represented by the general formula:
Rl - C0 - N(H)m - l(R2oH)3 - m
wherein R is a saturated or unsaturated, aliphatic hydrocarbon
radical having from about 7 to 21, preferably from about 11 to 17
carbon atoms; R2 represents a methylene or ethylene group; and m
is 1, 2, or 3, preferably 1. Specific examples of said amides are
mono-ethanol amine coconut fatty acid amide and diethanol amine
dodecyl-fatty acid amide. These acyl moieties may be derived from
naturally occurring glycerides, e.g., coconut oil, palm oil,
soybean oil, and tallow, but can be derived synthetically, e.g.,
by the oxidation of petroleum or by hydrogenation of carbon
monoxide by the Fischer-Tropsch process. The monoethanol amides
and diethanolamides of C12 14 fatty acids are preferred.
- 13 - 2012172
Amine oxide semi-polar nonionic surfactants comprise
compounds and mixtures of compounds having the formula
R2
I
Rl (C2H40) nN '~
I
R3
wherein Rl is an alkyl, 2-hydroxyalkyl, 3-hydroxyalkyl, or
3-alkoxy-2-hydroxypropyl radical in which the alkyl and alkoxy,
respectively, contain from about 8 to about 18 carbon atoms, R2
and R3 are each methyl, ethyl, propyl, isopropyl, 2-hydroxyethyl,
2-hydroxypropyl, or 3-hydroxypropyl, and n is from 0 to about 10.
Particularly preferred are amine oxides of the formula:
R2
Rl - N ~ 0
I
R3
wherein Rl is a C12 16 alkyl and R2 and R3 are methyl or ethyl.
The above ethylene oxide condensates, amides, and amine oxides are
more fully described in U.S. Pat. No. 4,316,824 (Pancheri).
The composition of this invention can also contain certain
cationic quarternary ammonium surfactants of the formula:
[Rl(OR2)y] [R3(oR2)y]2R4N+X~
or amine surfactants of the formula:
[Rl(oR2)y][R3(0R2)y]R4N
wherein Rl is an alkyl or alkyl benzyl group having from about 6
to about 16 carbon atoms in the alkyl chain; each R2 is selected
from the group consisting of -CH2CH2-, -CH2CH(CH3)-, -CH2CH(CH20H)-,
-CH2CH2CH2-, and mixtures thereof; each R3 is selected from the group
consisting of Cl-C4 alkyl, Cl-C4 hydroxyalkyl, benzyl, and hydrogen
when y is not 0; R4 is the same as R3 or is an alkyl chain wherein
the total number of carbon atoms of Rl plus R4 is from about 8 to
A'''
201 21 72
- 14 -
about 16; each y is from 0 to about 10, and the sum of the y values
is from 0 to about 15; and X is any compatible anion.
Preferred of the above are the alkyl quaternary ammonium
surfactants, especially the mono-long chain alkyl surfactants
described in the above formula when R4 is selected from the same
groups as R3. The most preferred quaternary ammonium surfactants are
the chloride, bromide, and methylsulfate Cg 16 alkyl
trimethylammonium salts, Cg 16 alkyl di(hydroxyethyl)methylammonium
salts, the Cg 16 alkyl hydroxyethyldimethylammonium salts, Cg 16
alkyloxypropyl trimethylammonium salts, and the Cg 16 alkyloxypropyl
dihydroxyethylmethylammonium salts. Of the above, the C10 14 alkyl
trimethylammonium salts are preferred, e.g., decyl trimethylammonium
methylsulfate, lauryl trimethylammonium chloride, myristyl
trimethylammonium bromide and coconut trimethylammonium chloride, and
methylsulfate.
The suds boosters used in the composition of this invention can
contain any one or mixture of the suds boosters listed above.
Additional OPtional Inqredients
In addition to the ingredients described hereinbefore, the
compositions can contain other conventional ingredients suitable for
use in liquid dishwashing compositions.
Optional ingredients include drainage promoting ethoxylated
nonionic surfactants of the type disclosed in U.S. Pat. No.
4,316,824, Pancheri (February 23, 1982).
Others include detergency builders, either of the organic or
inorganic type. Examples of water-soluble inorganic builders which
can be used, alone or in admixture with themselves or with organic
alkalin~ sequestrant builder salts, are alkali metal carbonates,
phosphates, polyphosphates, and silicates. Specific examples of such
salts are sodium tripolyphosphate, sodium carbonate, potassium
carbonate, sodium pyrophosphate, potassium pyrophosphate, potassium
tripolyphosphate, and sodium hexametaphosphate. Examples of organic
builder salts which can be used alone, or in admixture with each
other or with the preceding inorganic alkaline builder salts, are
- 15 201 21 72
alkali metal polycarboxylates, e.g., water-soluble citrates such as
sodium and potassium citrate, sodium and potassium tartrate, sodium
and potassium ethylenediaminetetraacetate, sodium and potassium
N-(2-hydroxyethyl)-ethylene diamine triacetates, sodium and potassium
nitrilo triacetates (NTA), sodium and potassium
N-(2-hydroxyethyl)-nitrilo diacetates, sodium and potassium
oxydisuccinates, and sodium and potassium tartrate mono- and
di-succinates, such as described in U.S. Pat. No. 4,663,071 (Bush et
al., issued May 5, 1987). Other
organic detergency builders such as water-soluble phosphonates can
find use in the compositions of the invention. In general, however,
detergency builders have limited value in dishwashing detergent
compositions, and use at levels above about 10% can restrict
formulation flexibility in the liquid compositions herein because of
solubility and phase stability considerations.
Alcohols, such as ethyl alcohol and propylene glycol, and
hydrotropes, such as sodium and potassium toluene sulfonate, sodium
and potassium xylene sulfonate, trisodium sulfosuccinate, and related
compounds (as disclosed in U.S. Pat. No. 3,915,gO3,
and urea, can be utilized in the interests or
achieving a desired product phase stability and viscosity. Alcohols
such as ethyl alcohol and propylene glycol at a level of from 0% to
about 15%~ potassium or sodium toluene, xylene, or cumene sulfonate
at a level of from 0% to about 10% and urea at a level of from 0% to
about 10Z are particularly useful in the compositions of the
invention.
Other desirable ingredients include diluents and solvents.
Diluents can be inorganic salts, such as sodium sulfate, ammonium
chloride, sodium chloride, sodium bicarbonate, etc., and the solvents
include~ water, lower molecular weight alcohols, such as ethyl
alcohol, isopropyl alcohol, etc. Compositions herein will typically
contain up to about 80%, preferably from about 30% to about 70%, most
preferably from about 40% to about 65%, of water.
A'~''
20 1 2 1 72
Examole I
The following three compositions of the present invention are
prepared according to the descriptions set forth below.
Formulation A is made by adding ethanol, sodium chloride, and
sodium xylene sulfonate to the alkyl ethoxy carboxylate-containing
surfactant mixture.. The remaining surfactants are then added and
mixed in. Glycine is then added and the pH is adjusted to about 10
with sodium hydroxide. Finally, the magnesium chloride is added,
which reduces the pH to about 9.5. Final viscosity and pH
adjustments can be made at this time, followed by the addition of
perfume and dye. The balance is water.
Formulation B is made by adding ethanol, sodium chloride, and
sodium xylene sulfonate to the sodium alkyl ethoxy carboxylate. The
remaining formula components are added in the order given in the
table.
Formulation C is made by adding ethanol, sodium chloride, and
sodium xylene sulfonate to the sodium salt of alkyl ethoxy
carboxylate. The alkyl glucoside is mixed in and the temperature of
the mixture raised to about 40C. The coconut monoethanolamine amide
is warmed to about 65C and mixed in. Minor pH and viscosity
adjustments are made at this time, followed by the addition of dye
and perfume and water to bring the formulation to 100%.
% BY Weight
Formulation Formulation Formulation
Components A B C
Sodium C12 13 alkyl ethoxy 15 15 15
(2.8 ave.) carboxylate*
C12-l3 alkyl ethoxy 0.97 0.97 0.97
(2.8 ave.) alcohol*
Sodium C12 13 alkyl ethoxy 15
(0.8 ave.) sulfate
Sodium C12 14 fatty acid - 15
~-sulfonate methyl ester
C(2l-l3 alky)l polyglucoside - 15
C12 14 alkyl dimethyl betaine 4.0
C12-14-16 alkyl dimethyl 4 0
amine oxide
~01 21 72
_ - 17 -
C12 14 fatty acid mono- - - 4.0
ethanolamine amide
Magnesium ion 0.76 0.76
(added as M9cl2.6H2o)
Glycine 4.0
Sodium xylene sulfonate 2.0 2.2 2.0
Ethanol 7.5 7 o 7 o
Sodium chloride 1.5 <1 2.25
Product pH 9.5 7.55 7.05
Perfume and dye 0.15 0.15 0.15
Water Balance Balance Balance
*The surfactant mixture containing sodium alkyl ethoxy carboxylate
and alkyl ethoxy alcohol is prepared according to the process
outlined below:
1. A C12 13 alkyl ethoxy (3.0 ave.) alcohol is reacted with
potassium t-butoxide and sodium chloroacetate in the ratio of
1:1.1:1.1 by first mixing the alkyl ethoxylate with the
potassium t-butoxide at about 60C and about 20 mm Hg
pressure for about 1 hour. Hereinafter, t-butanol is
continuously removed from the reaction mixture by
distillation. Thereafter, the vacuum is broken and sodium
chloroacetate is added with mixing. The pressure is
reestablished at about 18-20 mm Hg, and the reaction is
allowed to continue for about 3 hours. Afterwards, the
reaction pressure is brought to atmospheric level with
nitrogen, and the steam heating coils are turned off. The
reaction is left in this state overnight. The next day the
reaction mixture temperature is increased and the pressure
reduced to remove more t-butanol from the system. The
reaction mixture is then added to an aqueous solution of
hydrochloric acid containing 105% of the theoretical amount
needed to neutralize the potassium t-butoxide initially
added. The acid aqueous reaction product is heated to force
phase separation of the organic and aqueous materials. The
organic phase is collected.
2. Step 1 above is repeated using a C12 13 alkyl ethoxy (2.7
201 21 72
- 18 -
ave.) alcohol and a ratio of this ethoxy alcohol to potassium
t-butoxide and sodium chloroacetate of 1:1.3:1.3. The
potassium t-butoxide is added to the alkyl ethoxylate, which
is at a temperature of about 32.2C, and the reaction mixture
is then increased to about 76.7C. The vacuum pump is then
turned on to achieve reduced pressure. The reaction
temperature is increased to about 104.4C, and the t-butanol
is pulled off and collected over about a 30 minute period.
The sodium chloroacetate is then added to the reaction
mixture, which has been cooled slightly to about 66C. The
reaction is mixed for about 1.5 hours, cooled, and added to
an aqueous solution of sufficient hydrochloric acid to
achieve a pH of 3.4. Water is added to increase the volume
of the reaction mixture by about 50%, and the mixture is then
heated to about 49C. The top organic layer is collected,
and the washing process is repeated.
3. The surfactant mixtures produced in Steps 1 and 2 above are
mixed at a ratio of 40.4 to 59.6. A portion of this larger
combined surfactant mixture is neutralized with 50% sodium
hydroxide to a pH of about 8 and diluted by about 50% with a
25/75 by volume mixture of water and ethanol. The resulting
solution is continuousiy extracted at room temperature with
hexanes for about four days. The lower aqueous phase is
collected, and some ethanol and water is removed by heating
to yield a paste containing the alkyl ethoxy carboxylate
containing surfactant mixture described below.
In the above, the surfactant portion of the above mixture
contains about 93.97O alkyl ethoxy carboxylates of the formula
RO(CH2CH20)xCH2COO~Na+ where R is a C12 13 alkyl averaging 12.5; x .
ranges from 0 to about 10, and the ethoxylate distribution is such
that the amount of material where x is 0 is about 2.8% and the
amount of material where x is greater than 7 is less than about 2%
by weight of the alkyl ethoxy carboxylates. The average x in the
distribution is 2.8. The surfactant mixture also contains about
6.1% of alcohol ethoxylates of the formula R0(CH2CH20)XH with R
being a C12 13 alkyl averaging 12.5 and the average x - 2.8. The
20 1 2 1 72
. - 19 -
surfactant mixture contains 0% soap materials.
The above formulations provide an excellent combination of
grease cleaning and mildness benefits. Using the alkyl ethoxy
carboxylate containing surfactant mixture as a building block, a
range of good grease cleaning is achieved with the rank order
being Formulation A > Formulation B > Formulation C. These same
formulations provide a range of mildness benefits with the rank
order being Formulation C > Formulation B > Formulation A.
Example II
The formulations in Example I can also be successfully made
by replacing the alkyl ethoxy carboxylate-containing surfactant
mixture with a surfactant mixture (described below) prepared via
an oxidation process wherein alcohol ethoxylates are reacted witb
oxygen in the presence of a noble metal catalyst as is disclosed
15 generally in U.S. Pat. Nos. 4,223,460; 4,214,101; and 4,348,509;
and German Pat. No. 3,446,561; and Japanese Patent Application No.
62,198,641. The surfactant mixture comprises
92.4% alkyl ethoxy carboxylates of the formula RO(CH2CH20)xCH2COO~Na+
wherein R is a C12 14 alkyl averaging 12.7 with x ranging from 0
20 to about 12. In the ethoxylate distribution, the weight YO of the
component x = 0 is about 10%, and the amount of the materials with
x greater than 7 is less than about 3% by weight. The average x
in the distribution is 2.5. The surfactant mixture also contains
about 6.4% of alcohol ethoxylates of the formula RO(CH2CH20)xH
25 with R being a C12-l4 alkyl averaging 12.7 and the average x is
about 3.7. ln addition, the surfactant mixture contains about
1.2% by weight of soaps of the formula RCOO~Na+ wherein R is
C11-13 averaging C11.7 This formulation would contain 15X by
weight of the alkyl ethoxy carboxylates, 1.04X by weight of
alcohol ethoxylates, and 0.20% by weight of soaps. The other
components in the formulations are identical. Minor modifications
in the ethanol and the sodium xylene sulfonate levels may be made
to adjust the viscosity and stability of the formulation to match
the formulations of Example I.
20 1 2 1 7~
- 20 -
These formulations give approximately the same grease
cleaning and mildness benefits as seen in Example I.
Examole III
The following formulation containing the surfactant mixture
used in Example I comprising the same alkyl ethoxy carboxylates
provides exceptional grease cleaning and hand mildness, with
sudsing somewhat less than Formulations A, B, and C.
Formulation D
ComDonents (Wt. %)
Sodium C12 13 alkyl ethoxy (2.8 ave.) carboxylate 28
- C12 13 alkyl ethoxy (2.8 ave.) alcohol 1.8
Magnesium ion (added as MgCl2.6H20) 0.6
Glycine 4.0
Sodium xylene sulfonate 2.0
Ethanol 7 5
Sodium chloride 1.5
Product pH 9.0
Perfume and dye 0.15
Water Balance
