Composition

A personal cleansing composition comprising PA1 a. at least about one wt % of soap, and PA1 b. a sufficient amount of a compound to provide at least about 0.03 wt. % of a free fatty carboxylic acid, said compound of the formula ##STR1## wherein R is hydrogen or CH.sub.2 COOH, R.sub.a is hydrogen or carboxyl, and R.sub.b is hydrogen or methyl provided that when R is hydrogen, then R.sub.a is carboxyl and when R is CH.sub.2 COOH then R.sub.a is hydrogen.

This application claims benefit of Provisional Appln 60/003,992, filed Sep. 
19, 1995. 
BACKGROUND OF THE INVENTION 
Soaps have been used for hundreds of years to remove soil from skin. 
Continual efforts have been made to improve the actions of soaps while 
increasing mildness, shelf life, lather and the like. 
A new method has been discovered which can bring about a combination of 
increased lather, superfatting, and shelf life compared with previously 
modified compositions. This is accomplished by the presence in the solid 
or liquid formulation of a member of a specific family of compounds which 
has at least two of these effects. 
SUMMARY OF THE INVENTION 
In accordance with the invention, there is a personal cleansing composition 
comprising 
a. at least about 1 wt. % of soap, and 
b. a sufficient amount of a compound to provide at least about 0.03 wt. % 
of a free fatty carboxylic acid, said compound of the formula 
##STR2## 
wherein R is hydrogen, or CH.sub.2 COOH and R.sub.a is hydrogen or 
carboxyl, and R.sub.b is hydrogen or methyl provided that when R is 
hydrogen, R.sub.a is carboxy and when R is CH.sub.2 COOH then R.sub.a is 
hydrogen. 
DETAILED DESCRIPTION OF THE INVENTION 
The 2- phosphonobutane- 1,2,4-tricarboxylic acid compounds of FIG. 1 are 
known in the art as anti calculus agents in oral compositions. The typical 
excipients in oral compositions would be present in such oral care 
formulations, for example an oral flavoring agent, an abrasive, a 
fluoridating agent and the like. However, absent from such an oral 
composition would be a material which would bring about an unpleasant 
taste and which would be difficult if not impossible to mask by any 
reasonable level of flavorant. Examples of such materials would be 
ordinary soaps such as long chain alkyl or alkenyl, preferably normal, 
carboxylic acid salts such as sodium, potassium, ammonium or substituted 
ammonium. Since the compositions of this invention are not to be ingested, 
it is preferable that the flavoring agent be absent from this inventive 
composition or at most, a less than non soap masking quantity be present, 
assuming that such a masking level could be achieved. Additionally, it is 
preferred that neither a fluoridating agent nor an abrasive agent be 
present in the personal care, non-oral or ingested compositions of this 
invention. 
It has now been found that when a 2-phosphonobutane -1,2,4 tricarboxylic 
acid (PBCA) compound or 1-phosphonopropane-1,2,3-tricarboxylic acid (PPTC) 
compound, preferably PBCA of FIG. 1, is contacted with a soap in the 
presence of water, at lease three moles of free fatty acid are liberated 
from the soap for every mole of PBCA or PPTC present. The phosphonobutane 
becomes a salt and is highly effective as a preservative in the liquid or 
solid personal care cleansing composition. It is believed, although the 
applicants do not wish to be bound thereby, that PBCA and PPTC compounds 
function as a chelating agent for those small quantities of metals present 
that catalyze oxidation of long chain hydrocarbon containing compounds, 
particularly those having unsaturation. Therefore, the presence of the 
soap and the tricarboxylic acid brings about an excellent, in situ means 
of generating both a superfatting and a preservative effect for an 
ordinary soap containing personal care composition. 
The quantity of the Formula 1 compounds present in the personal cleansing 
composition is enough to generate at least about 0.03 wt. % of free fatty 
carboxylic acids in the composition after interaction with the soap 
present in the composition. Quantities of generated free fatty carboxylic 
acid minimums in like compositions can be at least about 0.1, 1.0, 2.0, 
5.0, 7.0 and 10.0 wt. % of the composition. Up to about 25 wt. % of the 
composition, preferably no more than about 20 wt. % of the composition are 
free fatty carboxylic acids. The free fatty carboxylic acid generated does 
not differ significantly in structure from the anionic portion of the soap 
present in the composition. The free fatty acid generated therefore, is 
substantially alkyl of about 10 to about 20 carbon atoms and normal as 
opposed to branched. Of course the total free fatty acid in the 
composition need not be generated solely from the interaction of the PBCA 
or PPTC but can be partially due to the addition of ordinary free fatty 
acids such as myristic, palmitic, and stearic or in-situ superfatting from 
citric acid. 
The quantity of soap, its structure previously identified as a long chain 
branched or normal carboxylic acid salt such as sodium, potassium, 
ammonium or substituted ammonium salt, present in the composition 
following the in situ generation of the free fatty carboxylic acid should 
be at a level wherein a surfactant effect, that is reduction of surface 
tension of water is achieved, when the composition is used to achieve 
removal of soil from skin. As used in this specification and claims, the 
numerical amounts of soap are those present after the formation of the in 
situ free fatty carboxylic acid. It is preferred to have at least about 1 
wt. % soap present in the composition, generally about 5 wt.% is employed. 
Common quantities of soap for a "syndet" bar are about 10 wt. to 30 wt. % 
and a "combar" is about 55 to about 80 wt. %. Soap levels as high as about 
90 to about 96 wt. % can be employed when a lower level of free fatty 
carboxyl acid is desired. 
Other surfactants can be present in the composition as well. Examples of 
such surfactants are the anionic, amphoteric, nonionic and cationic 
surfactants. Examples of anionic surfactant include but are not limited to 
alkyl sulfates, anionic acyl sarcosinates, methyl acyl taurates, N-acyl 
glutamates, acyl isethionates, alkyl sulfosuccinates, alkyl phosphate 
esters, ethoxylated alkyl phosphate esters, trideceth sulfates, protein 
condensates, mixtures of ethoxylated alkyl sulfates and the like. 
Alkyl chains for these surfactants are C.sub.8 -C.sub.22, preferably 
C.sub.10 -C.sub.18, more preferably C.sub.12 -C.sub.14. Alkyl glycosides 
and methyl glucose esters are preferred mild non-ionics which may be mixed 
with other mild anionic or amphoteric surfactants in the compositions of 
this invention. Alkyl polyglycoside detergents are useful lather 
enhancers. The alkyl group can vary from about 8 to about 22 and the 
glycoside units per molecule can vary from about 1.1 to about 5 to provide 
an appropriate balance between the hydrophilic and hydrophobic portions of 
the molecule. Combinations of C.sub.8 -C.sub.18, preferably C.sub.12 
-C.sub.16, alkyl polyglycosides with average degrees of glycosidation 
ranging from about 1.1 to about 2.7, preferably from about 1.2 to about 
2.5, are preferred. 
Anionic nonsoap surfactants can be exemplified by the alkali metal salts of 
sulfates and sulfonates having in their molecular structure an alkyl 
radical containing from about 8 to about 22 carbon atoms and a sulfonic 
acid or sulfuric acid ester radical (included in the term alkyl is the 
alkyl portion of higher acyl radicals). Preferred are the sodium, 
ammonium, potassium or triethanolamine alkyl sulfates, especially those 
obtained by sulfating the higher alcohols (C.sub.8 -C.sub.18 carbon 
atoms), sodium coconut oil fatty acid monoglyceride sulfates and 
sulfonates; sodium or potassium salts of sulfuric acid esters of the 
reaction product of 1 mole of a higher fatty alcohol (e.g., tallow or 
coconut oil alcohols) and 1 to 12 moles of ethylene oxide; sodium or 
potassium salts of alkyl phenol ethylene oxide ether sulfate with 1 to 10 
units of ethylene oxide per molecule and in which the alkyl radicals 
contain from 8 to 12 carbon atoms, sodium alkyl glyceryl ether sulfonates; 
the reaction product of fatty acids having from 10 to 22 carbon atoms 
esterified with isethionic acid and neutralized with sodium hydroxide; 
water soluble salts of condensation products of fatty acids with 
sarcosine; and others known in the art. 
Zwitterionic surfactants can be exemplified by those which can be broadly 
described as derivatives of alphatic quaternary ammonium, phosphonium, and 
sulfonium compounds, in which the aliphatic radicals can be straight chain 
or branched and wherein one of the aliphatic substituents contains from 
about 8 to 18 carbon atoms and one contains an anionic water-solubilizing 
group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A 
general formula for these compounds is: 
##STR3## 
wherein R.sup.2 contains an alkyl, alkenyl, or hydroxy alkyl radical of 
from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide 
moieties and from 0 to 1 glyceryl moiety; Y is selected from the group 
consisting of nitrogen, phosphorus, and sulfur atoms; R.sup.3 is an alkyl 
or monohydroxyalkyl group containing 1 to about 3 carbon atoms; X is 1 
when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus atom, 
R.sup.4 is an alkylene or hydroxyalkylene of from 0 to about 4 carbon 
atoms and Z is a radical selected from the group consisting of 
carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups. 
Examples include: 
4-N,N-di(2-hydroxyethyl)-N-octadecylammonio!-butane-l-carboxylate; 
5-S-3-hydroxypropyl-S-hexadecylsulfonio!-3 hydroxypentane-1-sulfate; 
3-P,P-P-diethyl-P 3,6,9 
trioxatetradexocyl-phosphonio!-2-hydroxypropane-1-phosphate; 
3-N,N-dipropyl-N-3 dodecoxy-2-hydroxypropylammonio!-propanel-phosphonate; 
3-(N,N-di-methyl-N-hexadecylammonio) propane-1-sulfonate; 
3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate; 
4(N,N-di(2-hydroxyethyl)-N-(2 hydroxydodecyl) 
ammonio!-butane-1-carboxylate; 
3-S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio!-propane-1-phosphate; 
3-(P,P-dimethyl-P-dodecylphosphonio)-propane-1-phosphonate; and 
5-N,N-di(3-hydroxypropyl)-N-hexadecylammonio!-2-hydroxy-pentane-1-sulfate 
. 
Examples of amphoteric surfactants which can be used in the compositions of 
the present invention are those which can be broadly described as 
derivatives of aliphatic secondary and tertiary amines in which the 
aliphatic radical can be straight chain or branched and wherein one of the 
aliphatic substituents contains from about 8 to about 18 carbon atoms and 
one contains an anionic water solubilizing group, e.g., carboxy, 
sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds 
falling within this definition are sodium 3-dodecylaminopropionate, sodium 
3-dodecylaminopropane sulfonate, N-alkyltaurines, such as the one prepared 
by reacting dodecylamine with sodium isethionate according to the teaching 
of U.S. Pat. No.2,658,072, N-higher alkyl aspartic acids, such as those 
produced according to the teaching of U.S. Pat. No.2,438,091, and the 
products sold under the trade name "Miranol" and described in U.S. Pat. 
No. 2,528,378. Other amphoterics such as betaines are also useful in the 
present composition. 
Examples of betaines useful herein include the high alkyl betaines such as 
coco dimethyl carboxymethyl betaine, lauryl dimethyl carboxy-methyl 
betaine, lauryl dimethyl alpha-carboxyethyl betaine, cetyl dimethyl 
carboxymethyl betaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, 
stearyl bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl dimethyl 
gamma-carboxypropyl betaine, lauryl bis-(2-hydro-xypropyl) 
alpha-carboxyethyl betaine, etc. The sulfobetaines may be represented by 
coco dimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, 
amido betaines, amidosulfobetaines, and the like. 
Many cationic surfactants are known to the art. By way of example, the 
following may be mentioned: 
stearyldimenthylbenzyl ammonium chloride; 
dodecyltrimethylammonium chloride; 
nonylbenzylethyldimethyl ammonium nitrate; 
tetradecylpyridinium bromide; 
laurylpyridinium chloride; 
cetylpyridinium chloride; 
laurylpyridinium chloride; 
laurylisoquinolium bromide; 
ditallow(Hydrogenated)dimethyl ammonium chloride; 
dilauryldimethyl ammonium chloride; and 
stearalkonium chloride. 
Additional cationic surfactants are disclosed in U.S. Pat. No. 4,303,543 
see column 4, lines 58 and column 5, lines 1-42, incorporated herein by 
reference. Also see CTFA Cosmetic Ingredient Dictionary, 4th Edition 1991, 
pages 509-514 for various long chain alkyl cationic surfactants; 
incorporated herein by references. 
Also present in the composition may be the standard agents found in these 
compositions such as fragrances, colorants, further preservatives, 
thickeners, electrolytes, pH adjusting agent and the like. 
The composition can take on the usual physical forms a personal care 
cleansing composition has, such as solid, gel or liquid. A solid material 
can have a minimum water content of about 2-3 wt. % or a substantially 
higher content for example, about 25 to 26 wt. %, or quantities in between 
these amounts such as about 7 to about 15 wt. %. The pH of such a 
composition can be from about 5 to about 11 as measured by pH meter of a 
1% solid product solution in water. The inventive compositions are 
chelating effective and temperature stable at alkaline pH. Such solid 
compositions generally take the form of a bar that is readily held in the 
hand. The bar is usually opaque but can be translucent or transparent. 
Liquid formulations are usually aqueous and have anywhere from about 10 to 
about 95 wt. % water. Compatible thickening agents can be added to the 
composition to obtain the desired viscosity. Gels can be made although 
usually an appropriate viscosity of a liquid soap is one that is readily 
hand pumpable from a container.

Below are examples of the invention, examples used for comparative purposes 
and preparation and test procedures. The indicated examples are not 
intended to narrow but merely exemplify the broad inventive concept. 
Soap samples were prepared by the following procedure: 
Sodium Soap (3978 gms, moisture=29.35%, the rest long chain alkyl with 70 
wt. % alkyl obtained from tallow/30 wt. % alkyl obtained from coconut oil) 
was melted (80.degree. C.) in a crutcher equipped with a stirrer. Ferric 
sulfate (10 ppm), copper sulfate (1 ppm) and t-butylhydroxytoluene (BHT) 
(200 ppm) were added to the soap followed by the in-situ fattening agent 
being studied--citric acid or PPTC or PBCA (23.73 gm). Sufficient amount 
of in situ fattening agent was added to fully neutralize free alkali 
present in soap (0.01-0.15 wt. percent sodium oxide) as well as to 
generate a certain quantity of free fatty acids. The contents in the 
crutcher were mixed for 30 minutes. The soap chips were then made by 
drying the soap to approximately 12-13% moisture. 
The soap chips were then mixed with perfume and titanium dioxide in an 
amalgamator at 25.degree.-30.degree. C., milled three times, plodded and 
pressed into soap bars. 
Extraction of Free Fatty Acids 
Soap chips prepared with PBCA, PPTC and citric acid were dried in a vacuum 
oven at 80.degree.-85.degree. C. and 25 inch Hg pressure. Fatty acids were 
extracted for 8-10 hours with dry acetone. The extracted fatty acids were 
dried to constant weight. The fatty acids were titrated with sodium 
hydroxide for % free fatty acids. The composition of fatty acids were 
determined by gas chromatography. All of the experiments were done in 
triplicate. Below are the results: 
IV. Composition of Fatty Acids Generated by In-Situ Superfatting Soap Base: 
wt. percent 
______________________________________ 
Acidulating Agent 
C-Chain Citric Acid PBCA PPTC 
______________________________________ 
C8 2.3 2.3 2.3 
C10 1.2 1.1 1.3 
C12 12.0 11.0 13.1 
C14 4.3 4.0 4.7 
C16 11.6 12.5 10.7 
C18 7.8 8.8 6.7 
C18:1 48.0 49.2 46.8 
:2 5.4 5.3 5.6 
:3 0.5 0.4 0.6 
Others 
MW 261 262 260 
Iodine Value (IV)* 
57 57 56 
______________________________________ 
*AOCS Official Methods Da 15-48 
These results show that the free fatty acid spectrum produced by citric 
acid, PPTC and PBCA are similar. 
Following the procedure above, soap samples were prepared with no in situ 
fatting agent (Example 1), citric acid in sufficient quantity to product 2 
wt. % of free fatty acid in the composition (Example 2), PPTC in 
sufficient quantity to produce 1 wt. % of free fatty acid in the 
composition (Example 3), and PBCA in sufficient quantities to produce 1.5 
wt. % of free fatty acid in the composition (Example 4). 
The induction time for the occurrence of oxidation of the soaps was 
measured by a rapid oxidative stability evaluation method. The samples 
were dried in a vacuum oven for approximately 2 hours at 170.degree. F. At 
the start, the vacuum oven was flushed with nitrogen. The final moisture 
content of the samples was adjusted to approximately 10%. 
A DuPont 9900 Thermal Analyzer with 912 (DSC) Module and Pressure Dual 
Sample Cell was used for all the samples. 
The soap chips were weighed (5-10 mg) in an open aluminum pan. The pan was 
then positioned on top of the "dimples" in the pressure cell. Two samples 
can be simultaneously tested in the dual cell. The pressure cell was 
assembled. The cell was purged with oxygen gas twice, and then pressurized 
to 200psi. The samples were heated to 135.degree. C. for 70/30 tallow 
alkyl/coco alkyl soap chips in the differential scanning calorimetry (DSC) 
cell. Induction times for the oxidation of the samples were measured 
isothermally. The onset of oxidation of the soap sample was indicated by a 
positive deviation from the baseline. The induction time of oxidation was 
determined by extrapolation of the base line and the leading slope of the 
peak. The longer the induction time the more stable the system. 
Below are the results 
______________________________________ 
Induction Time/ 
Example Minutes 
______________________________________ 
1 (no stabilizing agent) 
13.3 
2 (citric acid) 34.1 
3 (PPTC) 40.0 
4 (PBCA) 98.1 
______________________________________ 
Both the PPTC and PBCA provided greater oxidative stability to the system 
than citric acid. PBCA is preferred. The PPTC and PBCA were present in 
quantities which generated less free fatty acid than the citric acid. 
Clearly on a molar basis both the PPTC and PBCA were far more effective in 
stabilizing the system than citric acid.