Light duty liquid cleaning composition comprising an ethoxylated methyl ester

A light duty liquid detergent with desirable cleansing properties and mildness to the human skin comprising: a C.sub.8-18 ethoxylated alkyl ether sulfate anionic surfactant, a sulfonate anionic surfactant, a water insoluble organic compound, a cosurfactant, an ethoxylated methyl ester and water.

BACKGROUND OF THE INVENTION 
The present invention relates to novel light duty liquid detergent 
compositions with high foaming properties and improved cleaning 
performance, containing an anionic surfactant, cosurfactant, urea, water 
insoluble organic compound, ethoxylated methyl ester and water. 
Nonionic surfactants are in general chemically inert and stable toward pH 
change and are therefore well suited for mixing and formulation with other 
materials. The superior performance of nonionic surfactants on the removal 
of oily soil is well recognized. Nonionic surfactants are also known to be 
mild to human skin. However, as a class, nonionic surfactants are known to 
be low or moderate foamers. Consequently, for detergents which require 
copious and stable foam, the application of nonionic surfactants is 
limited. 
The prior art is replete with light duty liquid detergent compositions 
containing nonionic surfactants in combination with anionic and/or betaine 
surfactants wherein the nonionic detergent is not the major active 
surfactant, as shown in U.S. Pat. No. 3,658,985 wherein an anionic based 
shampoo contains a minor amount of a fatty acid alkanolamide. U.S. Pat. 
No. 3,769,398 discloses a betaine-based shampoo containing minor amounts 
of nonionic surfactants. This patent states that the low foaming 
properties of nonionic detergents renders its use in shampoo compositions 
non-preferred. U.S. Pat. No. 4,329,335 also discloses a shampoo containing 
a betaine surfactant as the major ingredient and minor amounts of a 
nonionic surfactant and of a fatty acid mono- or di-ethanolamide. U.S. 
Pat. No. 4,259,204 discloses a shampoo comprising 0.8-20% by weight of an 
anionic phosphoric acid ester and one additional surfactant which may be 
either anionic, amphoteric, or nonionic. U.S. Pat. No. 4,329,334 discloses 
an anionic-amphoteric based shampoo containing a major amount of anionic 
surfactant and lesser amounts of a betaine and nonionic surfactants. 
U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition based on 
the alkali metal silicate content and containing five basic ingredients, 
namely, urea, glycerin, triethanolamine, an anionic detergent and a 
nonionic detergent. The silicate content determines the amount of anionic 
and/or nonionic detergent in the liquid cleaning composition. However, the 
foaming property of these detergent compositions is not discussed therein. 
U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent for 
laundering fabrics comprising a mixture of substantially equal amounts of 
anionic and nonionic surfactants, alkanolamines and magnesium salts, and, 
optionally, zwitterionic surfactants as suds modifiers. 
U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition for 
laundering socks or stockings comprising a specific group of nonionic 
detergents, namely, an ethylene oxide of a secondary alcohol, a specific 
group of anionic detergents, namely, a sulfuric ester salt of an ethylene 
oxide adduct of a secondary alcohol, and an amphoteric surfactant which 
may be a betaine, wherein either the anionic or nonionic surfactant may be 
the major ingredient. 
The prior art also discloses detergent compositions containing all nonionic 
surfactants as shown in U.S. Pat. Nos. 4,154,706 and 4,329,336 wherein the 
shampoo compositions contain a plurality of particular nonionic 
surfactants in order to effect desirable foaming and detersive properties 
despite the fact that nonionic surfactants are usually deficient in such 
properties. 
U.S. Pat. No. 4,013,787 discloses a piperazine based polymer in 
conditioning and shampoo compositions which may contain all nonionic 
surfactant or all anionic surfactant. 
U.S. Pat. No. 4,671,895 teaches a liquid detergent composition containing 
an alcohol sulfate surfactant, a nonionic surfactant, a paraffin sulfonate 
surfactant, an alkyl ether sulfate surfactant and water but fails to 
disclose an alkyl polysaccharide surfactant. 
U.S. Pat. No. 4,450,091 discloses high viscosity shampoo compositions 
containing a blend of an amphoteric betaine surfactant, a polyoxybutylene 
polyoxyethylene nonionic detergent, an anionic surfactant, a fatty acid 
alkanolamide and a polyoxyalkylene glycol fatty ester. But, none of the 
exemplified compositions contains an active ingredient mixture wherein the 
nonionic detergent is present in major proportion, probably due to the low 
foaming properties of the polyoxybutylene polyoxyethylene nonionic 
detergent. 
U.S. Pat. No. 4,595,526 describes a composition comprising a nonionic 
surfactant, a betaine surfactant, an anionic surfactant and a C.sub.12 
-C.sub.14 fatty acid monoethanolamide foam stabilizer. 
SUMMARY OF THE INVENTION 
This invention relates to a high foaming liquid cleaning composition 
containing an anionic surfactant, cosurfactant, methyl ethoxylated ester, 
a water insoluble organic compound and water. 
Another object of this invention is to provide a novel, light duty liquid 
composition with desirable high foaming and cleaning properties which is 
mild to the human skin. 
Additional objects, advantages and novel features of the invention will be 
set forth in part in the description which follows, and in part will 
become apparent to those skilled in the art upon examination of the 
following or may be learned by practice of the invention. The objects and 
advantages of the invention may be realized and attained by means of the 
instrumentalities and combinations particularly pointed out in the 
appended claims. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to a light duty liquid composition which can 
be in the form of a microemulsion comprises approximately by weight: 
(a) 15% to 35%, more preferably 20% to 30% of an anionic sulfonate 
surfactant; 
(b) 1% to 14%, more preferably 4% to 10% of an ethoxylated alkyl ether 
sulfate surfactant and/or alkyl sulfate surfactant; 
(c) 1% to 10%, more preferably 3% to 9% of a cosurfactant; 
(d) 1% to 10%, more preferably 3% to 9% of an ethoxylated methyl ester; 
(e) 0 to 10%, more preferably 1% to 7% of a zwitterionic surfactant; 
(f) 0 to 3%, more preferably 0.5% to 2.5% of an inorganic magnesium salt; 
(g) 0.05 to 3%, more preferably 0.1% to 2.5% of a water insoluble organic 
compound such as a water insoluble hydrocarbon, perfume or essential oil; 
(h) 0 to 8%, more preferably 0.5% to 5% of a low temperature stability 
agent which prevents phase separation of the composition at 4C, wherein 
the preferred low temperature stability agent is urea; 
(i) the balance being water, wherein the composition does not contain an 
ethoxylated nonionic surfactant, ethoxylated/propoxylated nonionic 
surfactant, amine oxide surfactant or an alkyl polyglucoside surfactant. 
Other suitable water-soluble nonionic detergents are marketed under the 
trade name "Pluronics." The compounds are formed by condensing ethylene 
oxide with a hydrophobic base formed by the condensation of propylene 
oxide with propylene glycol. The molecular weight of the hydrophobic 
portion of the molecule is of the order of 950 to 4000 and preferably 200 
to 2,500. The addition of polyoxyethylene radicals to the hydrophobic 
portion tends to increase the solubility of the molecule as a whole so as 
to make the surfactant water-soluble. The molecular weight of the block 
polymers varies from 1,000 to 15,000 and the polyethylene oxide content 
may comprise 20% to 80% by weight. Preferably, these surfactants will be 
in liquid form and satisfactory surfactants are available as grades L 62 
and L 64. 
The anionic sulfonate surfactants which may be used in the composition of 
this invention are water soluble and include the sodium, potassium, 
ammonium and ethanolammonium salts of linear C.sub.8 -C.sub.16 alkyl 
benzene sulfonates; C.sub.10 -C.sub.20 paraffin sulfonates, alpha olefin 
sulfonates containing about 10-24 carbon atoms, C.sub.8 -C.sub.18 alkyl 
sulfates and C.sub.8 -C.sub.18 ethoxylated alkyl ether sulfates. The 
preferred anionic sulfonate surfactant is a C.sub.12-18 paraffin sulfonate 
present in the composition at a concentration of about 14% to 24 wt. %, 
more preferably 15% to 22%. 
The paraffin sulfonates may be monosulfonates or di-sulfonates and usually 
are mixtures thereof, obtained by sulfonating paraffins of 10 to 20 carbon 
atoms. Preferred paraffin sulfonates are those of C.sub.12-18 carbon atoms 
chains, and more preferably they are of C.sub.14-17 chains. Paraffin 
sulfonates that have the sulfonate group(s) distributed along the paraffin 
chain are described in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; and 
3,372,188; and also in German Patent 735,096. Such compounds may be made 
to specifications and desirably the content of paraffin sulfonates outside 
the C.sub.14-17 range will be minor and will be minimized, as will be any 
contents of di- or poly-sulfonates. 
Examples of suitable other sulfonated anionic detergents are the well known 
higher alkyl mononuclear aromatic sulfonates, such as the higher 
alkylbenzene sulfonates containing 9 to 18 or preferably 9 to 16 carbon 
atoms in the higher alkyl group in a straight or branched chain, or 
C.sub.8-15 alkyl toluene sulfonates. A preferred alkylbenzene sulfonate is 
a linear alkylbenzene sulfonate having a higher content of 3-phenyl (or 
higher) isomers and a correspondingly lower content (well below 50%) of 
2-phenyl (or lower) isomers, such as those sulfonates wherein the benzene 
ring is attached mostly at the 3 or higher (for example 4, 5, 6 or 7) 
position of the alkyl group and the content of the isomers in which the 
benzene ring is attached in the 2 or 1 position is correspondingly low. 
Preferred materials are set forth in U.S. Pat. No. 3,320,174, especially 
those in which the alkyls are of 10 to 13 carbon atoms. 
The C.sub.8-18 alkyl ether sulfate surfactants have the structure 
EQU R--(OCHCH.sub.2).sub.n OSO.sub.3.sup.- M.sup.+ 
wherein n is about 1 to about 22 more preferably 1 to 3 and R is an alkyl 
group having about 8 to about 18 carbon atoms, more preferably 12 to 15 
and natural cuts, for example, C.sub.12-14 or C.sub.12-16 and M is an 
ammonium cation or a metal cation, most preferably sodium. The ethoxylated 
alkyl ether sulfate is present in the composition at a concentration of 
about 2.0 to about 5.0 wt. %, more preferably about 2.5% to 4.5 wt. %. 
The alkyl ether sulfate may be made by sulfating the condensation product 
of ethylene oxide and C.sub.8-10 alkanol, and neutralizing the resultant 
product. The ethoxylated alkyl ether sulfates differ from one another in 
the number of carbon atoms in the alcohols and in the number of moles of 
ethylene oxide reacted with one mole of such alcohol. Preferred 
ethoxylated alkyl ether polyethenoxy sulfates contain 12 to 15 carbon 
atoms in the alcohols and in the alkyl groups thereof, e.g., sodium 
myristyl (3 EO) sulfate. 
Ethoxylated C.sub.8-18 alkylphenyl ether sulfates containing from 2 to 6 
moles of ethylene oxide in the molecule are also suitable for use in the 
invention compositions. These surfactants can be prepared by reacting an 
alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and 
neutralizing the resultant ethoxylated alkylphenol. The concentration of 
the ethoxylated alkyl ether sulfate surfactant is about 1 to about 8 wt. 
%. 
The water-soluble zwitterionic surfactant (betaine), which can be used in 
the light duty liquid detergent composition, provides good foaming 
properties and mildness to the present nonionic based liquid detergent. 
The zwitterionic surfactant is a water soluble betaine having the general 
formula: 
##STR1## 
wherein X.sup.- is selected from the group consisting of SO.sub.3.sup.- 
and CO.sub.2.sup.- and R.sub.1 is an alkyl group having 10 to about 20 
carbon atoms, preferably 12 to 16 carbon atoms, or the amido radical: 
##STR2## 
wherein R is an alkyl group having about 9 to 19 carbon atoms and a is the 
integer 1 to 4; R.sub.2 and R.sub.3 are each alkyl groups having 1 to 3 
carbons and preferably 1 carbon; R.sub.4 is an alkylene or hydroxyalkylene 
group having from 1 to 4 carbon atoms and, optionally, one hydroxyl group. 
Typical alkyldimethyl betaines include decyl dimethyl betaine or 
2-(N-decyl-N, N-dimethyl-ammonia) acetate, coco dimethyl betaine or 
2-(N-coco N, N-dimethylammonia) acetate, myristyl dimethyl betaine, 
palmityl dimethyl betaine, lauryl dimethyl betaine, cetyl dimethyl 
betaine, stearyl dimethyl betaine, etc. The amidobetaines similarly 
include cocoamidoethylbetaine, cocoamidopropyl betaine and the like. A 
preferred betaine is coco (C.sub.8 -C.sub.18) amidopropyl dimethyl 
betaine. 
The water insoluble organic compound which is a water insoluble saturated 
or unsaturated organic compounds contain 4 to 20 carbon atoms and up to 4 
different or identical functional groups and is used at a concentration of 
about 1.0 wt. % to about 8 wt. %, more preferably about 2.0 wt. % to about 
7 wt. %. Examples of acceptable water insoluble saturated or unsaturated 
organic compound include (but are not limited to) water insoluble 
hydrocarbons containing 0 to 4 different or identical functional groups, 
water insoluble aromatic hydrocarbons containing 0 to 4 different or 
identical functional groups, water insoluble hetero cyclic compounds 
containing 0 to 4 different or identical functional groups, water 
insoluble ethers containing 0 to 3 different or identical functional 
groups, water insoluble alcohols containing 0 to 3 different or identical 
functional groups, water insoluble amines containing 0 to 3 different or 
identical functional groups, water insoluble esters containing 0 to 3 
different or identical functional groups, water insoluble carboxylic acids 
containing 0 to 3 different or identical functional groups, water 
insoluble amides containing 0 to 3 different or identical functional 
groups, water insoluble nitrides containing 0 to 3 different or identical 
functional group, water insoluble aldehydes containing 0 to 3 different or 
identical functional groups, water insoluble ketones containing 0 to 3 
different or identical functional groups, water insoluble phenols 
containing 0 to 3 different or identical functional groups, water 
insoluble nitro compounds containing 0 to 3 different or identical 
functional groups, water insoluble halogens containing 0 to 3 different or 
identical functional groups, water insoluble sulfates or sulfonates 
containing 0 to 3 different or identical functional groups, limonene, 
dipentene, terpineol, essential oils, perfumes, water insoluble organic 
compounds containing up to 4 different or identical functional groups such 
as an alkyl cyclohexane having both three hydroxys and one ester group and 
mixture thereof. 
Typical heterocyclic compounds are 
2,5-dimethylhydrofuran,2-methyl-1,3-dioxolane, 2-ethyl 2-methyl 1,3 
dioxolane, 3-ethyl 4-propyl tetrahydropyran, 3-morpholino-1,2-propanediol 
and N-isopropyl morpholine A typical amine is alphamethyl 
benzyldimethylamine. Typical halogens are 4-bromotoluene, butyl chloroform 
and methyl perchloropropane. Typical hydrocarbons are 
1,3-dimethylcyclohexane, cyclohexyl-1decane, methyl-3 cyclohexyl-9 nonane, 
methyl-3 cyclohexyl-6 nonane, dimethyl cycloheptane, trimethyl 
cyclopentane, ethyl-2 isopropyl-4 cyclohexane. Typical aromatic 
hydrocarbons are bromotoluene, diethyl benzene, cyclohexyl bromoxylene, 
ethyl-3 pentyl-4 toluene, tetrahydronaphthalene, nitrobenzene and methyl 
naphthalene. Typical water insoluble esters are benzyl acetate, 
dicyclopentadienylacetate, isononyl acetate, isobornyl acetate and 
isobutyl isobutyrate. Typical water insoluble ethers are di(alphamethyl 
benzyl) ether and diphenyl ether. Typical alcohols are phenoxyethanol and 
3-morpholino-1,2-propanediol. Typical water insoluble nitro derivatives 
are nitro butane and nitrobenzene. 
Suitable essential oils are selected from the group consisting of: Anethole 
20/21 natural, Aniseed oil china star, Aniseed oil globe brand, Balsam 
(Peru), Basil oil (India), Black pepper oil, Black pepper oleoresin 40/20, 
Bois de Rose (Brazil) FOB, Borneol Flakes (China), Camphor oil, White, 
Camphor powder synthetic technical, Cananga oil (Java), Cardamom oil, 
Cassia oil (China), Cedarwood oil (China) BP, Cinnamon bark oil, Cinnamon 
leaf oil, Citronella oil, Clove bud oil, Clove leaf, Coriander (Russia), 
Coumarin 69.degree. C. (China), Cyclamen Aldehyde, Diphenyl oxide, Ethyl 
vanilin, Eucalyptol, Eucalyptus oil, Eucalyptus citriodora, Fennel oil, 
Geranium oil, Ginger oil, Ginger oleoresin (India), White grapefruit oil, 
Guaiacwood oil, Gurjun balsam, Heliotropin, Isobornyl acetate, 
Isolongifolene, Juniper berry oil, L-methyl acetate, Lavender oil, Lemon 
oil, Lemongrass oil, Lime oil distilled, Litsea Cubeba oil, Longifolene, 
Menthol crystals, Methyl cedryl ketone, Methyl chavicol, Methyl 
salicylate, Musk ambrette, Musk ketone, Musk xylol, Nutmeg oil, Orange 
oil, Patchouli oil, Peppermint oil, Phenyl ethyl alcohol, Pimento berry 
oil, Pimento leaf oil, Rosalin, Sandalwood oil, Sandenol, Sage oil, Clary 
sage, Sassafras oil, Spearmint oil, Spike lavender, Tagetes, Tea tree oil, 
Vanilin, Vetyver oil (Java), Wintergreen, Allocimene, Arbanex.TM., 
Arbanol.RTM., Bergamot oils, Camphene, Alpha-Campholenic aldehyde, 
I-Carvone, Cineoles, Citral, Citronellol Terpenes, Alpha-Citronellol, 
Citronellyl Acetate, Citronellyl Nitrile, Para-Cymene, Dihydroanethole, 
Dihydrocarveol, d-Dihydrocarvone, Dihydrolinalool, Dihydromyrcene, 
Dihydromyrcenol, Dihydromyrcenyl Acetate, Dihydroterpineol, 
Dimethyloctanal, Dimethyloctanol, Dimethyloctanyl Acetate, Estragole, 
Ethyl-2 Methylbutyrate, Fenchol, Fernlol.TM., Florilys.TM., Geraniol, 
Geranyl Acetate, Geranyl Nitrile, Glidmint.TM. Mint oils, Glidox.TM., 
Grapefruit oils, trans-2-Hexenal, trans-2-Hexenol, cis-3-Hexenyl 
Isovalerate, cis-3-Hexanyl-2-methylbutyrate, Hexyl Isovalerate, 
Hexyl-2-methylbutyrate, Hydroxycitronellal, lonone, Isobornyl Methylether, 
Linalool, Linalool Oxide, Linalyl Acetate, Menthane Hydroperoxide, 
I-Methyl Acetate, Methyl Hexyl Ether, Methyl-2-methylbutyrate, 
2-Methylbutyl Isovalerate, Myrcene, Nerol, Neryl Acetate, 3-Octanol, 
3-Octyl Acetate, Phenyl Ethyl-2-methylbutyrate, Petitgrain oil, 
cis-Pinane, Pinane Hydroperoxide, Pinanol, Pine Ester, Pine Needle oils, 
Pine oil, alpha-Pinene, beta-Pinene, alpha-Pinene Oxide, Plinol, Plinyl 
Acetate, Pseudo lonone, Rhodinol, Rhodinyl Acetate, Spice oils, 
alpha-Terpinene, gamma-Terpinene, Terpinene-4-OL, Terpineol, Terpinolene, 
Terpinyl Acetate, Tetrahydrolinalool, Tetrahydrolinalyl Acetate, 
Tetrahydromyrcenol, Tetralol.RTM.), Tomato oils, Vitalizair, Zestoral.TM.. 
As used herein and in the appended claims one of the organic chemicals is a 
perfume which is used in its ordinary sense to refer to and include any 
non-water soluble fragrant substance or mixture of substances including 
natural (i.e., obtained by extraction of flower, herb, blossom or plant), 
artificial (i.e., mixture of natural oils or oil constituents) and 
synthetically produced substance) odoriferous substances. Typically, 
perfumes are complex mixtures of blends of various organic compounds such 
as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of 
essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% 
to 70% by weight. The essential oils themselves are volatile odoriferous 
compounds and also serve to dissolve the other components of the perfume. 
The cosurfactant may play an essential role in the formation of the dilute 
o/w microemulsion and the concentrated microemulsion compositions. Very 
briefly, in the absence of the cosurfactant the water, detergent(s) and 
hydrocarbon (e.g., perfume) will, when mixed in appropriate proportions 
form either a micellar solution (low concentration) or form an 
oil-in-water emulsion in the first aspect of the invention. With the 
cosurfactant added to this system, the interfacial tension at the 
interface between the emulsion droplets and aqueous phase is reduced to a 
very low value. This reduction of the interfacial tension results in 
spontaneous break-up of the emulsion droplets to consecutively smaller 
aggregates until the state of a transparent colloidal sized emulsion. 
e.g., a microemulsion, is formed. In the state of a microemulsion, 
thermodynamic factors come into balance with varying degrees of stability 
related to the total free energy of the microemulsion. Some of the 
thermodynamic factors involved in determining the total free energy of the 
system are (1) particle-particle potential; (2) interfacial tension or 
free energy (stretching and bending); (3) droplet dispersion entropy; and 
(4) chemical potential changes upon formation. A thermodynamically stable 
system is achieved when (2) interfacial tension or free energy is 
minimized and (3) droplet dispersion entropy is maximized. 
Thus, the role of cosurfactant in formation of a stable o/w microemulsion 
is to (a) decrease interfacial tension (2); and (b) modify the 
microemulsion structure and increase the number of possible configurations 
(3). Also, the cosurfactant will (c) decrease the rigidity. Generally, an 
increase in cosurfactant concentration results in a wider temperature 
range of the stability of the product. 
The major class of compounds found to provide highly suitable cosurfactants 
for the microemulsion over temperature ranges extending from 5.degree. C. 
to 43.degree. C. for instance are water-soluble polyethylene glycols 
having a molecular weight of 150 to 1000, polypropylene glycol of the 
formula HO(CH.sub.3 CHCH.sub.2 O).sub.n H wherein n is a number from 2 to 
18, mixtures of polyethylene glycol and polypropylene glycol (Synalox) and 
mono and di C.sub.1 -C.sub.6 alkyl ethers and esters of ethylene glycol 
and propylene glycol having the structural formulas R(X).sub.n OH, R.sub.1 
(X).sub.n OH, R(X).sub.n OR and R.sub.1 (X).sub.n OR.sub.1 wherein R is 
C.sub.1 -C.sub.6 alkyl group, R.sub.1 is C.sub.2 -C.sub.4 acyl group, X is 
(OCH.sub.2 CH.sub.2) or (OCH.sub.2 (CH.sub.3)CH) and n is a number from 1 
to 4, diethylene glycol, triethylene glycol, an alkyl lactate, wherein the 
alkyl group has 1 to 6 carbon atoms, 1 methoxy-2-propanol, 
1methoxy-3-propanol, and 1methoxy 2-, 3- or 4-butanol. 
Representative members of the polypropylene glycol include dipropylene 
glycol and polypropylene glycol having a molecular weight of 150 to 1000, 
e.g., polypropylene glycol 400. Other satisfactory glycol ethers are 
ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol 
monobutyl ether (butyl carbitol), triethylene glycol monobutyl ether, 
mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol 
monobutyl ether, mono, di, tripropylene glycol monomethyl ether, propylene 
glycol monomethyl ether, ethylene glycol monohexyl ether, diethylene 
glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene 
glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol 
monopropyl ether, ethylene glycol monopentyl ether, diethylene glycol 
monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol 
monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol 
monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol 
monopropyl ether, triethylene glycol monopentyl ether, triethylene glycol 
monohexyl ether, mono, di, tripropylene glycol monoethyl ether, mono, di 
tripropylene glycol monopropyl ether, mono, di, tripropylene glycol 
monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di, 
tributylene glycol mono methyl ether, mono, di, tributylene glycol 
monoethyl ether, mono, di, tributylene glycol monopropyl ether, mono, di, 
tributylene glycol monobutyl ether, mono, di, tributylene glycol 
monopentyl ether and mono, di, tributylene glycol monohexyl ether, 
ethylene glycol monoacetate and dipropylene glycol propionate. When these 
glycol type cosurfactants are at a concentration of about 1.0 to about 14 
weight %, more preferably about 2.0 weight % to about 10 weight % in 
combination with a water insoluble hydrocarbon which is at a concentration 
of at least 0.5 weight %, more preferably 1.5 weight % one can form a 
microemulsion composition. 
While all of the aforementioned glycol ether compounds provide the 
described stability, the most preferred cosurfactant compounds of each 
type, on the basis of cost and cosmetic appearance (particularly odor), 
are dipropylene glycol monomethyl ether and diethylene glycol monobutyl 
ether. Other suitable water soluble cosurfactants are water soluble esters 
such as ethyl lactate and water soluble carbohydrates such as butyl 
glycosides. 
The amount of cosurfactant required to stabilize the microemulsion 
compositions will, of course, depend on such factors as the surface 
tension characteristics of the cosurfactant, the type and amounts of the 
primary surfactants and water insoluble hydrocarbon, and the type and 
amounts of any other additional ingredients which may be present in the 
composition and which have an influence on the thermodynamic factors 
enumerated above. 
The ethoxylated methyl esters used in the instant compositions are depicted 
by the formula: 
##STR3## 
wherein x is a number from 6 to 12 and n is a number from 2 to 12. 
The ability to formulate mild, acid or neutral products without builders 
which have grease removal capacities is a feature of the present invention 
because the prior art o/w microemulsion formulations most usually are 
highly alkaline or highly built or both. 
The instant microemulsion formulas explicitly exclude alkali metal 
silicates and alkali metal builders such as alkali metal polyphosphates, 
alkali metal carbonates, alkali metal phosphonates and alkali metal 
citrates because these materials, if used in the instant composition, 
would cause the composition to have a high pH as well as leaving residue 
on the surface being cleaned. 
The instant compositions can optionally contain a Lewis base, neutral 
polymer which is selected from the group consisting of an ethoxylated 
polyhydric alcohol, a polyvinyl pyrrolidone polymer and a polyethylene 
glycol. The Lewis base neutral polymer is used at a concentration of 0 to 
10 wt. %, more preferably 0.5 to 8 wt. %. 
One Lewis base is an ethoxylated polyhydric alcohol which is depicted by 
the following formula: 
##STR4## 
wherein w equals one to four and x, y and z have a value between 0 and 60, 
more preferably 0 to 40, provided that (x+y+z) equals about 2 to about 
100, preferably about 4 to about 24 and most preferably about 4 to about 
19, and wherein R' is either hydrogen atom or methyl group. A preferred 
ethoxylated polyhydric alcohol is glycerol 6EO. 
Another Lewis base is a polyvinyl pyrrolidone polymer which is depicted by 
the formula: 
##STR5## 
wherein m is about 20 to about 350 more preferably about 70 to about 110. 
Another Lewis base is a polyethylene glycol which is depicted by the formul 
a 
EQU HO--(CH.sub.2 --CH.sub.2 O--).sub.n H 
wherein n is about 8 to about 225, more preferably about 10 to about 
100,000, wherein PEG1000 is preferred which is a polyethylene glycol 
having a molecular weight of about 1000. 
In addition to the above-described essential ingredients required for the 
formation of the cleaning compositions, the compositions of this invention 
may often and preferably do contain one or more additional ingredients 
which serve to improve overall product performance. 
One such ingredient is an inorganic or organic salt of oxide of a 
multivalent metal cation, particularly Mg.sup.++. The metal salt or oxide 
provides several benefits including improved cleaning performance in 
dilute usage, particularly in soft water areas, and minimized amounts of 
perfume required to obtain the microemulsion state. Magnesium sulfate, 
either anhydrous or hydrated (e.g., heptahydrate), is especially preferred 
as the magnesium salt. Good results also have been obtained with magnesium 
oxide, magnesium chloride, magnesium acetate, magnesium propionate and 
magnesium hydroxide. These magnesium salts can be used with formulations 
at neutral or acidic pH since magnesium hydroxide will not precipitate at 
these pH levels. 
Although magnesium is the preferred multivalent metal from which the salts 
(inclusive of the oxide and hydroxide) are formed, other polyvalent metal 
ions also can be used provided that their salts are nontoxic and are 
soluble in the aqueous phase of the system at the desired pH level. 
Thus, depending on such factors as the pH of the system, the nature of the 
anionic surfactant and cosurfactant, as well as the availability and cost 
factors, other suitable polyvalent metal ions include aluminum, copper, 
nickel, iron, calcium, etc. It should be noted, for example, that with the 
preferred paraffin sulfonate anionic detergent calcium salts will 
precipitate and should not be used. It has also been found that the 
aluminum salts work best at pH below 5 or when a low level, for example 1 
weight percent, of citric acid is added to the composition which is 
designed to have a neutral pH. Alternatively, the aluminum salt can be 
directly added as the citrate in such case. As the salt, the same general 
classes of anions as mentioned for the magnesium salts can be used, such 
as halide (e.g., bromide, chloride), sulfate, nitrate, hydroxide, oxide, 
acetate, propionate, etc. 
The liquid cleaning compositions of this invention may, if desired, also 
contain other components either to provide additional effect or to make 
the product more attractive to the consumer. The following are mentioned 
by way of example: Colors or dyes in amounts up to 0.5% by weight; 
bactericides in amounts up to 1% by weight; preservatives or antioxidizing 
agents, such as formalin, 5-chloro-2-methyl-4-isothaliazolin-3-one, 
2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight; and pH 
adjusting agents, such as sulfuric acid or sodium hydroxide, as needed. 
Furthermore, if opaque compositions are desired, up to 4% by weight of an 
opacities may be added. 
The instant composition can contain 0 to 10 wt. %, more preferably 0.1 to 8 
wt. % of an antibacterial agent which is selected from the group 
consisting 2,4,4'-trichloro-2-hydroxy diphenyl ether, essential oils, 
3,4,4'-trichloro carbanilide, benzoic esters and parachloro metal xylenol 
and mixtures thereof. 
The instant compositions contain about 0 to about 10 wt. %, more preferably 
0.1 to 8 wt. % of a disinfectant agent selected from the group consisting 
of C.sub.8 -C.sub.16 alkyl amines, C.sub.8 -C.sub.16 alkyl benzyl dimethyl 
ammonium chlorides, C.sub.8 -C.sub.16 dialkyl dimethyl ammonium chlories, 
C.sub.8 -C.sub.16 alkyl, C.sub.8 -C.sub.14 alkyl dimethyl ammonium 
chloride and chlorhexidine and mixtures thereof. Some typical disinfectant 
agent useful in the instant compositions are manufactured by Lonza, S.A. 
They are: Bardac 2180 (or 2170) which is N-decyl-N-isonoxyl-N, N-dimethyl 
ammonium chloride; Bardac 22 which is didecyl dimethyl ammonium chloride; 
Bardac LF which is N,Ndioctyl-N, N-dimethyl ammonium chloride; Bardac 114 
which is a mixture in a ratio of 1:1:1 of N-alkyl-N, N-didecyl-N, 
N-dimethyl ammonium chloride/N-alkyl-N, N-dimethyl-N-ethyl ammonium 
chloride; and Barquat MB-50 which is N-alkyl-N, N-dimethyl-N-benzyl 
ammonium chloride. 
##STR6## 
Another disinfecting agent is dimethyl benzyl alkonium chloride (BASF). 
The instant compositions can contain a booster agent for the disinfecting 
agent which improves the bacterial activity of the disinfecting agent 
thereby increasing the bacterial kill. The booster agent is selected from 
the group consisting of hydroxy containing organic acids such as citric 
acid and latic acid and mixtures thereof and chelatants such as methyl 
glycine triacetate, imino disuccinate and glutamic N,N-diacetate and 
mixtures thereof. The booster agent is used at a concentration of 0 to 
about 5 wt. %, preferably about 0.1 wt. % to about 3 wt. %. 
The final essential ingredient in the inventive microemulsion compositions 
having improved interfacial tension properties is water. The proportion of 
water in the microemulsion compositions generally is in the range of 30% 
to 82%, preferably 40% to 70% by weight of the usual diluted o/w 
microemulsion composition. 
In final form, the instant compositions exhibit stability at reduced and 
increased temperatures. More specifically, such compositions remain clear 
and stable in the range of 5.degree. C. to 50.degree. C., especially 
10.degree. C. to 43.degree. C. Such compositions exhibit a pH of 5 to 8. 
The liquid microemulsion compositions are readily pourable and exhibit a 
viscosity in the range of 6 to 300 milliPascal . second (mPas.) as 
measured at 25.degree. C. with a Brookfield RVT Viscometer using a #1 
spindle rotating at 20 RPM. Preferably, the viscosity is maintained in the 
range of 10 to 200 mpas.