Liquid detergent composition

Novel liquid detergent compositions are provided which contain a high purity amphoteric surfactant, one or more anionic surfactants and a nonionic foam boosting compound.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present disclosure relates to novel liquid detergent compositions. More 
specifically, this disclosure relates to detergent compositions wherein 
certain types of surfactants are combined with water and other optional 
additives to produce a final liquid which can be used as a manual 
dishwashing detergent having improved foam stability and grease cutting 
ability. 
2. Technology Description 
Liquid cleaning preparations generally consist of aqueous solutions of 
surfactants and additives. They are used in particular for cleaning hard 
surfaces, for example, glass, ceramic materials, plastics, painted and 
polished surfaces. One important application for liquid cleaning 
preparations is liquid cleaning compositions for manual washing of dishes, 
e.g., plates, utensils, crockery, pots and pans. Manual dishwashing is 
normally carried out at moderately elevated temperatures of from about 
35.degree. to 45.degree. C. in highly dilute cleaning solutions. The 
detergent power of a cleaning preparation is generally judged by the user 
to be better, the longer the suds or foam remains. Grease cutting ability 
is another basis for evaluating the efficacy of a liquid cleaning 
preparation. Because the hands remain in contact with the washing suds for 
a prolonged period, the compatibility of the detergent with the skin is a 
particularly important factor in manual dishwashing. For these reasons, 
the artisan will be guided in the choice of the components and composition 
of a manual dishwashing detergent by other considerations than for liquid 
cleaning preparations for other hard surfaces. 
Ongoing research toward developing improved liquid detergent compositions 
suitable for manual dishwashing has led to compositions containing a 
variety of materials intended to impart or enhance one or more desirable 
property of the detergent composition. Examples of materials included in 
liquid dishwashing detergents include, for example: various amounts of 
magnesium ions or other divalent ions (See, e.g., U.S. Pat. Nos. 
4,316,824; 4,435,317; 4,823,635; 5,096,622; and 5,269,974); a combination 
of a water-soluble paraffin monosulfonate salt and a corresponding 
water-soluble salt of a disulfonate (See, e.g., U.S. Pat. No. 4,102,826); 
sulfonate dialkyl tetraline (See, e.g., U.S. Pat. No. 4,235,758); dialkyl 
ester of sulfosuccinic acid (See, e.g., U.S. Pat. Nos. 4,596,672 and 
4,680,143); certain betaines (See, e.g., U.S. Pat. No. 4,671,894 and 
4,681,704); fatty alkylmonoglucoside (See, e.g., U.S. Pat. No. 4,732,704); 
a combination of a 20 cationic surfactant and a water soluble C.sub.21 
dicarboxylic salt (See, e.g., U.S. Pat. No. 4,853,147); amine oxide or 
amidoamine oxide (See, e.g., U.S. Pat. Nos. 5,238,609 and 5,298,195); and 
a combination of three different types of amphoteric compounds (See, e.g., 
U.S. Pat. No. 5,340,502). 
There exists a need for a liquid detergent suitable for manual dishwashing 
which is easy and inexpensive to manufacture, is stable, has superior 
grease cutting ability, provides long-lasting suds, is environmentally 
safe and is mild for human skin contact. 
SUMMARY OF THE INVENTION 
The novel detergent compositions in accordance with this disclosure 
include: (i) one or more anionic surfactants at least one of which is an 
ether sulfate, and (ii) a high purity amphoteric compounds of the formula: 
EQU R--C(O)--N(H)--CH.sub.2 CH.sub.2 --N--((CH.sub.2).sub.y 
X)--(CH.sub.2).sub.z COOM 
wherein R represents aliphatic radicals containing from about 5 to about 19 
inclusive carbon atoms, Y is an number of from 2 to 4 inclusive, Z is 1, X 
is OH or NH.sub.2 and M is a metal, said composition containing less than 
about 4.5% unalkylated amide, a glycolic acid content of less than about 
5.5% and an alkali metal salt content of less than about 27%, each 
percentage being by weight based on the active weight of the amphoteric 
surfactant. 
Optionally the present compositions include a nonionic foam boosting 
surfactant. In preferred embodiments, the nonionic foam boosting 
surfactant is an alkyl amide of the formula: 
##STR1## 
wherein R is a fatty alkyl group and R' and R" are the same or different 
and are individually selected from the group consisting of --H, --CH.sub.2 
CH(CH.sub.3)OH, --(CH.sub.2 CH.sub.2 O).sub.x H, and 
##STR2## 
wherein X is a number from 1 to 20 and R" is a fatty alkyl group. In other 
preferred embodiments, the detergent compositions contain at least two 
different anionic surfactants, with at least one of the anionic detergents 
being in the form of an ammonium salt and another of the anionic 
detergents being an alkali metal salt. 
In a particularly useful embodiment, the present disclosure relates to a 
detergent composition suitable for hand or manual dishwashing comprising 
an aqueous solution containing a combination of surfactants comprising: a) 
at least one salt of an aromatic anionic compound; b) at least one metal 
salt of an alkyl anionic compound; c) at least one ammonium salt of an 
ethoxylated and sulfated alcohol; d) a high purity amphoteric compound as 
defined herein; and e) a nonionic foam boosting alkylamide compound. 
Preferably, the liquid detergent compositions comprise a mixture of 
surfactants, comprising: 
(i) between 1 and 20 active weight percent of one or more of the high 
purity amphoteric surfactants; 
(ii) between 1 and 60 active weight percent of one or more of the anionic 
surfactants; and 
(iii) up to 25 active weight percent of one or more of the nonionic foam 
boosting surfactants; 
the active percent being from 20 to 95 percent of the total surfactant load 
or the total surfactant in the composition. 
In yet another aspect, the present invention relates to a novel process for 
preparing a liquid detergent composition by a) preparing a concentrated 
aqueous solution containing a mixture of surfactants as defined herein; 
and b) diluting the concentrated aqueous solution at a temperature not 
substantially greater than room temperature to provide a homogeneous, 
clear, shelf-stable liquid detergent composition. 
Also, the compositions of the present disclosure are sufficiently mild that 
lower chain length anionic surfactant known to have irritating qualities 
can be effectively used in a mild formulation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In describing the preferred embodiments, certain terminology will be 
utilized for the sake of clarity. Such terminology is intended to 
encompass the recited embodiment, as well as all technical equivalents 
which operate in a similar manner for a similar purpose to achieve a 
similar result. 
The present invention utilizes amphoteric surfactant(s) of defined purity 
and anionic surfactant(s) in an aqueous liquid to produce a liquid 
detergent composition which has excellent foaming and grease cutting 
properties. In the preferred embodiment, the amount of combined surfactant 
is between 20 and 95 active percent of the total surfactant load. The 20 
to 95 active weight percent of the formulation includes between about 1 
and about 20 parts active amphoteric surfactant as defined herein, between 
about 1 and about 60 parts active anionic surfactant and between about 1 
and about 25 parts active nonionic foam boosting surfactant. 
The present liquid detergent compositions include one or more primary 
surfactants to provide foaming and grease cutting and a foam stabilizing 
amount of one or more amphoteric and, optionally nonionic surfactants. 
In particularly useful embodiments, one or more anionic surfactant wherein 
at least one is an ether sulfate is chosen to serve as the primary 
surfactant. The anionic surfactant(s) chosen with the exception of the 
ether sulfate is not critical and may be any of the known anionic 
surfactants and is chosen on the basis of compatibility, effectiveness and 
economy. These anionic surfactants include any of the known hydrophobes 
attached to a carboxylate, sulfonate, sulfate or phosphate polar, 
solubilizing group including salts. Salts may be the sodium, potassium, 
ammonium and amine salts of such surfactants. 
Examples of such anionic surfactants include water soluble salts of alkyl 
benzene sulfonates having between 6 and 22 carbon atoms in the alkyl 
group, alkyl and aryl ether sulfates having between 6 and 22 carbon atoms 
in the alkyl or aryl group, alkali metal, ammonium and alkanolammonium 
salts or organic sulfuric reaction products having in their molecular 
structure an alkyl or alkaryl group containing from 6 to 22 carbon atoms 
and a sulfonic or sulfuric acid ester group. 
Particularly preferred are linear alkali metal, e.g., sodium, and ammonium 
alkyl ether sulfates that are synthesized by sulfating a higher alcohol 
having between 6 and 18 carbon atoms and ethoxylated with 2 to 9 moles of 
ethylene oxide. Another preferred anionic surfactant is alkyl benzene 
sulfonate, in which the alkyl group contains between about 9 to about 15, 
and even more preferably, between about 11 to about 13 carbon atoms in a 
straight chain or branched chain configuration and even most preferred a 
linear straight chain having an average alkyl group of about 11 carbon 
atoms. As used herein, alkyl is intended to include fatty alkyl groups 
from natural sources generally containing a wide range of chain lengths 
and those ranges are intended to be substantially included in any carbon 
chain range. 
In particularly preferred embodiments, mixtures of anionic surfactants are 
utilized, with mixtures of alkyl ether sulfate and alkylaryl sulfonates 
being especially preferred. Such embodiments comprise a mixture of alkali 
metal salts, preferably sodium salts, of alkyl benzene sulfonates having 
from about 9 to 15, and more preferred between 11 and 13 carbon atoms with 
an alkali metal salt, preferably sodium, of an alkyl sulfate and alkyl 
ethoxy sulfate having 10 to 20 and preferably 12 to 18 carbon atoms and an 
average ethoxylation of 7 to 11. 
In another particularly preferred embodiment, three different anionic 
surfactants are employed as the primary surfactant, namely: i) an 
alkylaryl sulfonate; ii) an alkali metal salt of an C.sub.6 -C.sub.20 
alkylethoxy sulfate having an average ethoxylation of 7 to 11; and iii) an 
ammonium salt of a C.sub.6 -C.sub.20 alkyl ethoxy sulfate having an 
average ethoxylation of 1 to 4. 
Specific anionic surfactants which may be selected as the linear alkyl 
benzene sulfonates can be illustrated by dodecylbenzene sulfonate, 
decylbenzene sulfonate, undecylbenzene sulfonate, tridecylbenzene 
sulfonate, nonylbenzene sulfonate and the sodium, potassium, ammonium, 
triethanolammonium and isopropylammonium salts thereof. A particularly 
preferred sulfonate salt is sodium dodecylbenzene sulfonate. Such 
chemicals are sold under the trade name Biosoft 100 by Stepan Chemicals of 
Northfield, Ill. Other anionic surfactants include polyethoxylated alcohol 
sulfates, such as those sold under the trade name Neodol 25-3S by Shell 
Chemical Company. Examples of other anionic surfactants are provided in 
U.S. Pat. No. 3,976,586, the disclosure of which is incorporated by 
reference. 
In practice, the anionic portion comprises between 1 and 60 active parts of 
the liquid composition. In particularly preferred embodiments, the amount 
is between 15 and 45 active parts. 
Detergent compositions in accordance with this disclosure also include a 
foam stabilizing amount of a high purity amphoteric surfactant alone or in 
combination with minor amounts of other amphoteric surfactants. 
The particularly useful amphoteric surfactants for the invention include 
both mono and dicarboxylates, although the amount of dicarboxylates is 
less than 15% and preferably less than 10% by weight based on the weight 
of the mono and dicarboxylate. The mono-carboxylate can be represented by 
the formula: 
##STR3## 
wherein R is an alkyl group of 6-20 carbon atoms, x is 1 or 2 and M is 
hydrogen or sodium. 
The most preferred amphoteric surfactants are highly purity substituted 
imidazoline-derived amphoacetate surfactant compositions containing as the 
main component a compound of the formula: 
EQU R--C(O)--N(H)--CH.sub.2 CH.sub.2 --N--((CH.sub.2).sub.y 
X)--(CH.sub.2).sub.z COOM 
wherein R represents aliphatic radicals containing from about 5 to about 19 
inclusive carbon atoms, Y is an number of from 2 to 4 inclusive, Z is 1, X 
is OH or NH.sub.2 and M is a metal, said composition containing less than 
about 4.5% unalkylated amide, a glycolic acid content of less than about 
5.5% and a alkali metal salt content of less than about 27%, each 
percentage being by weight based on the active weight of the amphoteric 
surfactant. Such high purity surfactants are commercially available under 
the tradenames MIRANOL ULTRA C-32 and MIRAPON EXCEL 825, both available 
from Rhone-Poulenc, Inc. Cranbury, N.J. 
To prepare the preferred high purity amphoteric surfactants, an imidazoline 
is heated with a salt of a monohaloacetate. The haloacetate salt is 
preferably in aqueous solution prior to admixture with the imidazoline. A 
convenient method for accomplishing that is to prepare the salt from the 
acid just prior to the reaction. An advantage to this procedure is that 
the salt can be prepared with an excess of base to provide neutralization 
for the hydrohalic acid formed during the reaction of the imidazoline with 
the haloacetate salt. The excess pH preferably ranges from about 8 to 
about 10. Of course, haloacetate salt can be purchased or prepared 
elsewhere, dissolved in water and used as such or preferably with an added 
amount of base corresponding to the excess discussed above. 
The mole ratio of the monohaloacetic acid or its salt form to the 
imidazoline or amine is preferably greater than one. At amounts of less 
than one, insufficient monohaloacetic acid salts are present to effect 
complete alkylation leaving the product contaminated with the amido amine 
which has no surface activity. If too high a ratio is used, the product 
will contain excess glycolic acid since the monohaloacetate salt will 
react with the base to convert that reactant to glycolic acid. 
Surprisingly, the ratio can be kept as low as possible with only a slight 
excess needed to drive the reaction to completion while still achieving 
substantially full alkylation. It is possible to keep the ratio as low as 
1.05:1. Preferably the ratio ranges from about 1.05:1 to about 1.5:1, more 
preferably 1.05:1 to about 1.4:1 and most preferably 1.05:1 to abut 1.2:1. 
The reaction is generally conducted at a temperature conducive to the 
reaction as is well known in the industry. Reaction temperatures for the 
main reaction can range as high as 95.degree. C., preferably between abut 
50.degree. C. and about 95.degree. C. Preferably, the temperature ranges 
from about 75.degree. to about 85.degree. C. The reaction can be heated 
after the main reaction is considered complete to insure completeness of 
reaction. Temperatures during this portion of the reaction can range as 
high at 100.degree. C. 
The reaction times are sufficient to accomplish each desired reaction step 
and can be easily determined by a skilled artisan. 
In general, the monohaloacetic acid or salt is blended with the imidazoline 
at a rate as fast as possible and practical to admix the reactants 
completely. Because pH control is essential the reactants, especially the 
base, are added at such a rate as to prevent pH rises above about pH 10. 
Care is taken to avoid localized "hot spots" during the addition of base. 
The base is added incrementally to avoid any pH surge. 
The careful pH and temperature control during the reaction allows the 
reaction to proceed with less sodium monohaloacetate salt resulting in a 
higher purity product (less by-product unalkylated amide, glycolic acid, 
NaCl and residue haloacetate salt). The compositions are characterized by 
levels of unalkylated amide of less than about 4.5%, preferably less than 
about 2.0% and more preferably less than about 0.5% unalkylated amide on 
an actives basis. The compositions are also characterized by levels of 
glycolic acid of less than about 5.5%, preferably less than about 3.5% and 
more preferably less than about 2.5% glycolic acid on an actives basis. 
The compositions are further characterized by levels of alkali metal salt, 
e.g., sodium chloride, of less than about 27%, preferably less than about 
23% and more preferably less than about 20% salt on an actives basis. A 
particularly preferred high purity amphoteric surfactant composition has 
an unalkylated amide content ranging from about 4.5% to about 1%, a 
glycolate content ranging from about 5.5% to about 1.5%, and a salt 
content ranging from about 27% to about 15%. 
In practice, the amphoteric surfactant comprises between 1 and 20 active 
parts of the liquid composition. In particularly preferred embodiments, 
the amount is between 5 and 15 active parts, and in even more preferred 
embodiments, the amount ranges between about 8 and about 13 active parts. 
Other amphoteric surfactants which may be present in minor amounts can be 
illustrated by the alkali metal, alkaline earth metal, ammonium or 
substituted ammonium salts of alkyl amphocarboxy glycinates and alkyl 
amphocarboxypropionates, alkyl amphodipropionates, alkyl amphodiacetates, 
alkyl amphoglycinates and alkyl amphopropionates wherein alkyl represents 
an alkyl group having 6 to 20 carbon atoms. Other suitable amphoteric 
surfactants include alkyliminopropionates, alkyl iminodipropionates and 
alkyl amphopropylsulfonates having between 12 and 18 carbon atoms, 
alkylbetaines and amidopropylbetaines and alkylsultaines and 
alkylamidopropylhydroxy sultaines wherein alkyl represents an alkyl group 
having 6 to 20 carbon atoms. Each of these types of amphoteric surfactants 
are known to those skilled in the art and are commercially available from 
a variety of sources. With respect to the additional amphoteric 
surfactant, the term "minor amount" is intended to mean 10% on an active 
basis based on the total actives in the composition. 
As used herein, the term "ampho" such as part of the compound 
"amphodiacetate" is intended to designate a structure of the formula 
##STR4## 
A non-ionic surfactant may be used in combination with the amphoteric 
surfactant to provide foam stabilization. The particular nonionic 
surfactant(s) selected is not critical and may be any of the known 
nonionic surfactants and is selected on the basis of compatibility, 
effectiveness and economy, though alkanolamides are most preferred. 
Examples of useful nonionic surfactants include condensates of ethylene 
oxide with a hydrophobic moiety which has an average hydrophilic 
lipophilic balance (HLB) between about 8 to about 16, and more preferably, 
between about 10 and about 12.5. These surfactants include the 
condensation products of primary or secondary aliphatic alcohols having 
from about 8 to about 24 carbon atoms, in either straight or branched 
chain configuration, with from about 2 to about 40, and preferably between 
about 2 and about 9 moles of ethylene oxide per mole of alcohol. Such 
materials are commercially sold under the trade name Neodol 25-9, Neodol 
25-6.5 and Neodol 25-7 sold by Shell Chemical Company. 
Other suitable nonionic surfactants include the condensation products of 
about 6 to about 12 carbon atom alkyl phenols with about 3 to about 30, 
and preferably between about 5 and about 14 moles of ethylene oxide. 
Examples of such surfactants are sold under the tradenames Igepal CO 530, 
Igepal CO 630, Igepal CO 720 and Igepal CO 730 by Rhone-Poulenc Inc. Still 
other suitable nonionic surfactants are described in U.S. Pat. No. 
3,976,586, the disclosure of which is incorporated herein by reference. 
Particularly preferred nonionic surfactants are non-ionic amides including 
alkanolamides, ethoxylated alkanolamides, and ethylene bisamides with 
alkanolamides being most preferred. Alkanolamides have the general 
formula: 
##STR5## 
wherein R is a fatty alkyl group and R' and R" are the same or different 
and are individually selected from the group consisting of --H,--CH2CH2OH 
and --CH2CH(CH3)OH. Alkanol amides having C.sub.8 -C.sub.18 fatty alkyl 
groups are preferred such as, for example coco-, lauric, myristic, 
linoleic or stearic groups. Cocodiethanolamide is the most preferred 
nonionic surfactant to be employed in compositions in accordance with this 
invention. 
In practice, the nonionic portion comprises between 1 and 25 active parts 
based on the total surfactant load in the composition. In particularly 
preferred embodiments, the amount is between 5 and 20 active parts, and in 
even more preferred embodiments, the amount ranges between about 6 and 
about 12 active parts. 
The present liquid detergent compositions preferably contains anionic 
surfactant(s), a high purity amphoteric surfactant composition and a 
nonionic foam boosting surfactant where the ratio of anionic primary 
surfactant to high purity amphoteric surfactant to nonionic foam boosting 
surfactant ranges from about 3:1:1 to about 9:1:1 and more preferably from 
about 4:1:1 to 7:1:2. 
The described liquid detergent compositions are essentially unbuilt 
liquids, i.e., do not contain proportions of organic or inorganic builder 
salt in the detergent building proportions, and, therefore, are 
particularly suitable for use as liquid, hand dishwashing detergents, 
though a small amount of builder could be added for metal ion sensitivity. 
Thus, the present compositions can contain any of the usual adjuvants 
found in those compositions provided that they do not interfere with the 
performance properties of the inventive liquids. For example, liquid 
detergent compositions generally need to contain one or more hydrotropes. 
These are materials present in a formulation to control solubility, 
viscosity, clarity and stability, but which themselves make no active 
contribution to the performance of the product. Examples of hydrotropes 
include one or more lower aliphatic alcohols, such as C.sub.1 -C.sub.3 
lower alkyl alcohols, especially ethanol, as well as fatty alcohols such 
as C.sub.8 to C.sub.20 ; and particularly mixtures of lower aliphatic 
alcohols, e.g., C.sub.1 -C.sub.3 lower alkyl alcohols, and fatty alcohols; 
urea; lower alkylbenzene sulphonates such as sodium toluene or xylene 
sulphonates; and combinations of these. Hydrotropes should be used in the 
minimum possible quantities consistent with good formulation properties 
over a wide temperature range. Other additional ingredients include minor 
proportions of perfumes and colors for aesthetic purpose, opacifiers such 
as ethylene glycol distearate or polystyrene, thickening agents such as 
natural gums or hydroxypropyl methyl cellulose, sequestering agents such 
as citrate or ethylene diamine tetraacetate, preservatives such as 
formaldehyde or Dowicil.RTM. 200 or monomethyloldimethyl hydantoin, 
non-tarnishing agents, spot prevention agents, odor absorbing ingredients 
such as sodium bicarbonate, antimicrobial agents, and inert salts such as 
sodium sulfate or sodium chloride. The total concentration of added 
ingredients usually will be less than 5%, preferably less than 3%, by 
weight of the total composition. 
Generally, the viscosity of the liquid compositions will be within the 
range of about 20 centipoises (cps) to 2000 cps., and preferably from 75 
cps. to 1500 cps. Viscosity is measured using a Brookfield Viscometer, 
Model RV, with a #3 spindle rotating at 100 r.p.m. The most preferred 
viscosity range is 150 cps. to 1200 cps. based upon current consumer 
preferences. However, it will be recognized by one skilled in the art that 
liquids of even higher viscosity can be achieved by including up to 2% by 
weight of a known thickening agent in the compositions. 
Generally, these liquid compositions are prepared by admixing the 
individual detergent ingredients with the formula weight of water with 
agitation at a temperature in the range of about 20.degree. C. to 
65.degree. C. Usually, the individual detergents are added in the form of 
aqueous solutions or dispersions of the anionic detergent salts. 
Typically, the amphoteric surfactant is added in liquid form as one of the 
last ingredients. Additionally, it is desirable to add any solubilizing 
agent to the formula weight of water prior to the additional of the 
essential anionic detergent ingredients in order to avoid formation of 
gels. Any additional ingredients, such as color and perfume usually are 
added with agitation after the surfactants while cooling the mixture to a 
temperature of 20.degree. C. to 32.degree. C. The pH is usually adjusted, 
if necessary, to a pH in the range of 5-8, preferably 6.5-7.5, for 
dishwashing products by addition, for example, of either sulfuric acid or 
citric acid or sodium hydroxide, potassium hydroxide or triethanolamine. 
Further, any adjustment of viscosity may be achieved by adding additional 
amounts of the appropriate solubilizers or thickening agents. 
It is a surprising and unexpected advantage of the particularly preferred 
compositions disclosed herein that they can be combined to form a 
concentrate at temperatures not substantially exceeding room temperature 
and further that the concentrates can be let down, i.e., diluted, with 
instant solubility at room temperature to finished consumer products which 
are clear, homogeneous and shelf-stable at temperatures not substantially 
exceeding room temperature. By the phrase "temperatures not substantially 
exceeding room temperatures", it is meant temperatures below about 
27.degree. C. This constitutes a significant processing advantage over 
prior detergent compositions which frequently require elevated 
temperatures during processing, particularly during let down. 
The invention is described in greater detail by the following non-limiting 
examples. 
EXAMPLE 1 
This example illustrates the process of preparing a preferred high purity 
amphoteric surfactant composition used in the present detergent 
compositions. 
To a reaction vessel is added 20.57 parts water, 0.07 parts 
ethylenediaminetetraacetic acid, 11.92 parts monochloroacetic acid (99+%) 
and 20.93 parts of ice. To the reactor is then slowly added with cooling 
12.5 parts of 50% sodium hydroxide solution. The temperature is maintained 
at from 35.degree. C. to 40.degree. C. during the caustic addition. 
Coco imidazoline (equivalent weight of about 270) which has been premelted 
at a temperature of from 65.degree. to 70.degree. C. in an amount of 28.78 
parts is added to the reaction vessel as fast as possible. The temperature 
is kept below 50.degree. C. during the addition which is completed in 20 
minutes. The reaction mixture goes through a gel phase before becoming a 
clear liquid. Reaction temperature is maintained at 50.degree. C. for 2 
hours after coco imidazoline addition is complete. The temperature is then 
raised to 75.degree. C. and caustic is added in three steps. 
Specifically, 1.93 parts of a 50% sodium hydroxide solution is charged and 
the reaction mixture held for 15 minutes at 75.degree. C. An additional 
1.93 is charged and held for 15 minutes at 75.degree. C. and then 1.43 
parts of 50% sodium hydroxide are charged. The pH after these additions 
was 9.3. The reaction mixture is held at 75.degree. C. for an additional 3 
hours. During this time, the reaction pH is determined every 30 minutes. 
If the pH is less than 8.5, additional sodium hydroxide is added to 
elevate the pH to 9.5. After 3 hours, the chloride level is determined, 
i.e., inorganic chloride divided by the amount of chloride present in the 
reactants. The ratio is determined by measuring the chloride content in a 
sample followed by boiling the sample in caustic to liberate any 
organically bound chloride, thus determining the total chlorine present in 
the sample. If the chloride ratio is 0.99, or above, the reaction is 
considered completed and the mixture is additionally heated to 90.degree. 
to 95.degree. C. for 2 hours. After rechecking the chloride ratio, the 
product is cooled to 60.degree. C. and sufficient water is charged to a 
solids content of 44% to 45%. 
In the examples that follow, the grease cutting and foam stability of the 
detergent formulations were tested using the methodology set forth in ASTM 
D4009-81. In summary, a soil prepared from flour, shortening and oleic 
acid is applied in a standard manner to a stack of twenty plates. A 0.1% 
solution of formulation to be tested is prepared in a basin and the dishes 
are washed one at a time following a predetermined procedure. Foam 
stability is determined by the number of plates washed before half of the 
water surface is no longer covered with suds. Grease cutting ability is 
determined by the number of plates which can be cleaned of the soil to the 
extent that the dish squeaks when a finger is run over its clean surface. 
EXAMPLE 2 
To show the superior effects provided by the surfactant combinations 
disclosed herein, a series of experiments were conducted using simplified 
surfactant systems. In each simplified system, the test formulation 
included 30% actives with set ratios for the ingredients. The ingredients 
used to prepare the test formulations included one or more of: 
AMPHOTERIC SURFACTANT 
A--high purity cocoamphoacetate 
ANIONIC SURFACTANTS 
B--sodium salt of a linear ether sulfate 
C--ammonium salt of a linear ether sulfate 
D--sodium salt of an aromatic ether sulfate 
E--ammonium salt of an aromatic ether sulfate 
NONIONIC SURFACTANT 
F--cocodialkanolamide 
The ratio of anionic surfactant to amphoteric surfactant in each test 
formulation which includes those ingredients is 7:1 and the ratio of 
anionic surfactant to nonionic surfactant in each test formulation which 
includes those ingredients is 7:1.6. Where all three types of materials 
are included in the test formulation the ratio of anionic surfactant to 
amphoteric surfactant to nonionic surfactant is 7:1:1.6. Where two anionic 
surfactants were included in the test formulation, equal parts of each 
anionic surfactant were used. The results of the tests for grease cutting 
ability and foam stability are reported in Table 1 as #plates/#plates with 
the first number reflecting grease cutting and the second number 
reflecting foam stability. 
TABLE 1 
______________________________________ 
ANIONIC AMPHOTERIC 
SURFACT- 
AMPHOTERIC NONIONIC NONIONIC 
ANT(S) ANIONIC ANIONIC ANIONIC 
ALONE SURFACTANTS SURFACTANTS SURFACTANTS 
______________________________________ 
B: 5/5 A + B: 7/7 F + B: 6/6 A + F + B: 8/8 
C: 5/5 A + C: 7/7 F + C: 6/6 A + F + C: 8/8 
D: 4/4 A + D: 5/5 F + D: 5/5 A + F + D: 7/9 
E: 4/4 A + E: 5/5 F + E: 6/6 A + F + E: 8/8 
B + C: 4/4 
A + B + C: 6/6 
F + B + C: 6/6 
A + F + B + C: 8/8 
B + D: 1/2 
A + B + D: 6/6 
F + B + D: 5/5 
A + F + B + D: 6/6 
B + E: 2/2 
A + B + E: 6/6 
F + B + E: 5/5 
A + F + B + E: 6/6 
C + D: 2/2 
A + C + D: 5/5 
F + C + D: 6/6 
A + F + C + D: 6/6 
C + E: 2/3 
A + C + E: 6/6 
F + C + E: 6/6 
A + F + C + E: 6/6 
D + E: 2/2 
A + D + E: 4/4 
-- A + F + D + E: 5/5 
______________________________________ 
As the data in Table 1 show, the addition of either a nonionic or 
amphoteric surfactant improved the effectiveness of the anionic 
surfactant(s). The improvement as most dramatic where a combination of 
alkyl ether sulfate and aromatic ether sulfate anionic surfactants was 
employed. In another aspect, the effectiveness of the anionic surfactants 
as surprisingly improved where a combination of amphoteric and nonionic 
surfactants were used together with one or more anionic surfactants. 
The amphoteric and nonionic components of a liquid dishwashing detergent 
are generally the most costly surfactant ingredients in the formulation. 
When tested alone, the high purity amphoteric and the nonionic surfactants 
each achieved a 7/7 score. Thus, the present detergent compositions are 
extremely advantageous from an economical perspective since only a small 
amount of the amphoteric and/or nonionic surfactant need be combined with 
the primary surfactant to achieve excellent foam stability and grease 
cutting. 
EXAMPLE 3 
A liquid detergent is prepared having the following formulation: 
______________________________________ 
Ingredient W/W % 
______________________________________ 
Sodium Cocoamphoacetate (See Example 1) 
13.50 
Ammonium Salt of Nonylphenol 
16.20 
Ether Sulfate 
Cocamide DEA/DEA 8.00 
Sodium Lauryl Ether Sulfate 
28.37 
(9 moles EO) 
Sodium C.sub.8 -C.sub.10 Alkyl Ether Sulfate 
24.28 
Sodium Xylene sulfonate 5.00 
Ethanol-190 Proof 3.80 
Citric Acid 0.85 
______________________________________ 
The above formulation is prepared as follows: Into a clean mixing vessel is 
first added to the amphoteric surfactant. The following ingredients are 
then added sequentially to the vessel with mixing: sodium C.sub.8 
-C.sub.10 alkyl ether sulfate; the ammonium aromatic ether sulfate; the 
amide; the xylene sulfonate; the non-ionic surfactant and ethanol. Mixing 
is continued until a clear, homogenous solution is obtained. Citric acid 
is then added to the vessel. The mixture is sampled and pH of the mixture 
is adjusted to 6.9-7.2 by the addition of either citric acid or a 30% 
solution of ammonium hydroxide. The remaining anionic surfactant is then 
charged to the vessel and mixing is continued to produce a homogenous 
clear yellow liquid. 
The foam stability of the formulation of Example 3 at 35% solids let down 
as tested using the above-described ASTM method is 16 plates and the 
grease cutting ability is 16 plates. For comparison purposes, the foam 
stability and grease cutting ability of a commercially available 
dishwashing detergent (DAWN) is determined to be 13 and 10 plates, 
respectively, using the same technique. 
EXAMPLE 4 
A liquid detergent is prepared having the following formulations: 
______________________________________ 
Ingredient W/W % 
______________________________________ 
Deionized Water 6.30 
Sodium Hydroxide 3.50 
Dodecyl benzene sulfonic acid 
9.54 
Sodium Xylene Sulfonate 7.50 
Ethanol 190 proof 3.80 
C.sub.12 -C.sub.15 Alcohol Alkylether sulfate 
30.43 
Lauryl fatty alcohol 1.68 
Cocamide DEA/DEA 8.00 
Ammonium salt of ethoxylated 
15.75 
and sulfated C.sub.8 -C.sub.10 alcohol 
Sodium Cocamphoacetate (See Example 1) 
13.50 
______________________________________ 
The above formulation is prepared as follows: The water is added to a 
previously cleaned mixing vessel. Sodium hydroxide solution is added to 
the vessel, and while agitating the dodecyl benzene sulfonic acid is 
slowly added to the vessel. The temperature of the mixture is then lowered 
to about 20.degree. C. and the sodium xylene sulfonate is charged to the 
vessel. Ethanol is then added to the vessel while maintaining the 
temperature of the vessel at around 20.degree. C. While mixing, the 
following materials are sequentially added to the vessel: sodium alkyl 
ether sulfate; lauryl alcohol; alkanolamide; the ammonium alkylether 
sulfate and the amphoteric surfactant. Mixing is continued until a 
homogeneous mixture is obtained. The mixture is sampled and the pH of the 
mixture is adjusted to 6.9-7.3 by the addition of either sulfuric acid or 
sodium hydroxide with mixing. The resulting product is a clear pale yellow 
liquid. 
The foam stability of the formulation of Example 3 at 30% solids let down 
as tested using the above described ASTM method is 20+ plates and the 
grease cutting ability is 17 plates. 
Various additives can be added during let down of the formulation of 
Example 4 including, but not limited to, perfume, dye, thickener (e.g., a 
guar derivative in an appropriate acidic aqueous solution) and functional 
ingredients (e.g., antimicrobial). The composition of Example 4 also 
provides the advantage that a consumer product can be attained by let down 
at ambient temperatures. 
Having described the invention in detail and by reference to the preferred 
embodiments thereof, it will be apparent that modifications and variations 
are possible without departing from the scope of the appended claims.