Mild personal cleansing bar composition with balanced surfactants, fatty acids, and paraffin wax

This invention is an improved mild personal cleansing syndet bar comprising: long chain synthetic surfactant having essentially saturated C.sub.15 -C.sub.22, preferably C.sub.16 -C.sub.18, alkyl or acyl chains, more preferably cetearyl sulfate; a high lathering, mild synthetic surfactant, preferably C.sub.12 -C.sub.14 acyl isethionate; soap; fatty acids; sodium isethionate; and paraffin wax, preferably a high melting point paraffin wax. The bar has improved processability, good smears, and good in-use properties without meaningful lather negatives.

TECHNICAL FIELD 
This invention relates to personal cleansing bars based on synthetic 
surfactants and to processes of making them. 
BACKGROUND OF THE INVENTION 
"Soap, since its appearance in history, has helped safeguard two of our 
greatest treasures: our health and our children. Health is directly 
related to cleanliness. Data proves that the higher the consumption of 
soap in a country, the lower will be the infant mortality rate. 
"In industralized countries, soap is the most-taken-for-granted and readily 
available personal care product used on our body daily. Soap is also the 
most inexpensive product we use in relation to its per use cost. In many 
less fortunate countries both laundry and toilet soaps are still scarce, 
expensive essentials . . . . 
"Soap is most probably the oldest of toiletries, and, in spite of being 
readily available in most parts of the world, it is still scarce in many 
countries. The oldest literary reference to soap relates to the washing of 
wool and is found in clay Sumarian tablets dating about 2500 B.C.E. 
Sumerian was a language spoken in the area of the Tigris and Euphrates 
Rivers, now Southern Iraq. The patriarch Abraham and his family came from 
Sumer. Another Sumerian tablet, dating 2200 B.C.E. gives the formula 
consisting of water, alkali and cassia oil. 
"Cleanliness is essential to our well being. A clean body, clean bath, 
clean home, and clean environment are the norm today." (Soap Technology 
for the 1990's, L. Spitz et al., American Oil Chemists' Society, 
Champaign, Ill., pp. 1-2) This reference discusses syndet and combo bars, 
particularly on pp. 209-229. 
Synthetic surfactant-based personal cleansing bars have attracted much 
interest recently because they can be selected to be milder to the skin 
than soap-based products. This mildness, however, comes with negatives to 
both the manufacturer and the consumer. The bar soap manufacturer 
experiences difficult processability due to the sticky nature of such 
products, as well as high raw material costs. The consumer experiences the 
negative performance properties of poor lather, messy smear, bar softness, 
and consequently, high wear rates. 
U.S. Pat. No. 2,988,511, Mills and Korpi, issued Jun. 13, 1961, 
incorporated herein by reference, discloses a milled detergent bar with at 
least 75% by weight of: (1) 15%-55% of anionic sulfuric reaction products 
which do not hydrolyze unduly, said salts being selected from sodium and 
potassium salts, and said anionic organic sulfuric reaction products 
containing at least 50% alkyl glyceryl ether sulfonates, 10%-30% of which 
are alkyl diglyceryl ether sulfonates, the alkyl radicals containing 10-20 
carbon atoms; (2) 5%-50% soap; and (3) 20%-70% of a binder material 
selected from freshly precipitated calcium soaps of fatty acids having 
10-18 carbon atoms, freshly precipitated magnesium soap, starch, normally 
solid waxy materials which will become plastic under conditions 
encountered in the milling of soap. Paraffin is not mentioned in Mills et 
al. '511. 
Commonly assigned U.S. Pat. No. 4,673,525, Small et al., issued Jun. 16, 
1987, discloses mild personal cleansing bars based on selected mild 
surfactant; moisturizer; 0%-5% polymeric skin mildness aid; and some soap. 
This patent goes a long way in providing a practical mild personal 
cleansing bar; but some processing problems have been experienced due to 
the sticky nature of some of the preferred ingredients. 
The use of paraffin wax in synthetic surfactant-based bars, per se, is 
known. However, the known bars suffer from a combination of harshness 
and/or lather deficiencies. E.g., U.S. Pat. No. 2,653,913, van Dijck et 
al., issued Sep. 29, 1953, discloses bars comprising 80% synthetic anionic 
surfactant (selected from sodium secondary or primary alkyl sulfates or 
sodium dodecylbenzene sulfonate), 18% paraffin, melting point (M.P.) 
140.degree.-150.degree. F., and 2% sodium alginate. The surfactants 
employed are non-mild surfactants. 
U.S. Pat. No. 2,734,870, Lewis, issued Feb. 14, 1956, discloses bars 
comprising 40-60% paraffin (M.P.&gt;125.degree. F.), 2-5% fatty acid, and 
60-40% sodium alkyl aryl sulfonate. The high level of paraffin in these 
bars results in unacceptably low lather. 
U.S. Pat. No. 3,129,187, Meehan, issued Apr. 14, 1964, discloses bars 
comprising 50-75% sodium alkylbenzene sulfonate, 5-35% stearyl alcohol, 
1-25% paraffin (M.P. 125.degree.-170.degree. F.), and 2-25% stearyl MEA. 
The harsh surfactants employed would result in harsh products. 
U.S. Pat. No. 4,151,105, O'Roark, issued Apr. 24, 1979, discloses bars 
comprising 20-40% synthetic anionic surfactant (composed of sodium cocoyl 
isethionate and/or sodium lauryl sulfoacetate), 10-30% paraffin (M.P. 
130.degree.-140.degree. F.), 5-15% powdered starch, 10-30% dextrin and 5% 
fatty acid. The low melting point of the wax employed would cause a 
substantial soil load on the lather potential and result in poor lather 
volumes. The synbars of the present invention are preferably free of 
dextrin and powdered starch. 
U.S. Pat. No. 4,335,025, Barker et al., issued Jun. 15, 1982, discloses a 
process for making syndet bars containing a "waxy extender." 
OBJECTS OF THE INVENTION 
One object of this invention is to provide a personal cleansing syndet bar 
composition which exhibits improved processability of the syndet bar while 
not sacrificing lather or bar messiness. 
SUMMARY OF THE INVENTION 
This invention relates to an improved processable, mild personal cleansing 
syndet bar comprising: long chain C.sub.15 -C.sub.22 alkyl or acyl 
synthetic surfactant having essentially saturated, preferably C.sub.16 
-C.sub.18, alkyl chains, soap, free fatty acid, a lathering mild 
surfactant comprising C.sub.12 -C.sub.14 alkyl (cocoyl) isethionate, and a 
selected paraffin wax. The bar has improved procssability without a 
meaningful bar messiness or lather negative. More specifically the 
composition comprises: 
A. from about 4% to about 32% of essentially saturated long chain (C.sub.15 
-C.sub.22 alkyl) synthetic surfactant selected from the group consisting 
of: alkyl sulfate, acyl isethionate, alkyl sarcosinate, alkyl glyceryl 
ether sulfonate, and mixtures thereof; 
B. from about 4% to about 30% of paraffin wax having a melting point of 
from about 130.degree. F./54.degree. C. to about 180.degree. F./82.degree. 
C; 
C. from about 20% to about 70% lathering mild synthetic surfactant; and 
wherein said lathering mild synthetic surfactant is selected from C.sub.12 
-C.sub.14 acyl isethionate, C.sub.12 -C.sub.14 alkyl glyceryl ether 
sulfonate, C.sub.12 -C.sub.14 sodium acyl sarcosinate, and mixtures 
thereof; and wherein at least about 10% of said bar is said mild lathering 
C.sub.12 -C.sub.14 alkyl isethionate; 
D. from about 2% to about 30% free fatty acid; 
E. from 0% to about 15%, preferably from about 2% to about 10%, soap; 
F. from about 2% to about 8% sodium isethionate; 
G. from 0% to about 2% sodium chloride; and 
H. from about 1.5% to about 10% water; 
wherein said bar has a pH of from about 4.0 to about 9.0. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 40% to 
about 70% by weight of the bar, the ratio of said stearic acid to said 
lauric acid is from about 5:1 to about 10:1. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 30% to 
about 45%, the ratio of said stearic acid to said lauric acid is from 
about 2:1 to about 6:1. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 20% to 
about 35%, the ratio of said stearic acid to said lauric acid is from 
about 0.1 to about 2:1. 
DETAILED DESCRIPTION OF THE INVENTION 
A mild synthetic surfactant-based (syndet) bar with improved 
processability, good lather and/or reduced messiness (smear) is indeed an 
advance in this art. The present invention provides such an improved 
syndet bar comprising: (1) from about 4% to about 32%, preferably from 
about 5% to about 30%, of C.sub.15 -C.sub.22, preferably C.sub.16 
-C.sub.18, essentially saturated long chain alkyl sulfates; acyl 
isethionate, alkyl sarcosinate, alkyl glyceryl ether sulfonate, and 
mixtures thereof; (2) from about 20% to about 70%, preferably from about 
30% to about 60% by weight of said bar, of mild, high lathering, synthetic 
surfactants with at least about 10% by weight of the bar being C.sub.12 
-C.sub.14 alkyl isethionate; (3) from about 2% to about 30%, preferably 
from about 3% to about 20%, of C.sub.10 -C.sub.22, preferably C.sub.12 
-C.sub.18, essentially saturated fatty acids; (4) from 0% to about 15%, 
preferably from about 2% to about 10%, C.sub.10 -C.sub.22, preferably 
C.sub.12 -C.sub.18, alkali metal soaps, preferably sodium or potassium 
soaps; (5) from about 4% to about 30%, preferably from about 5% to about 
28%, paraffin wax with an average melting point of from about 130.degree. 
F. to about 180.degree. F., preferably from about 140.degree. F. to about 
165.degree. F., more preferably from about 142.degree. F. to about 
160.degree. F.; (6) from 0% to about 10% auxiliary plastic binders such as 
polyethylene glycols and/or monoglyceride; (7) from about 1.5% to about 
10%, preferably from about 2% to about 8%, more preferably from about 3% 
to about 6%, water; (8) from 0% to about 2% sodium chloride; and (9) from 
about 2% to about 8% sodium isethionate; and the pH of the bar is from 4 
to 9, preferably from 5 to 8. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 40% to 
about 70% by weight of the bar, the ratio of said stearic acid to said 
lauric acid is from about 5:1 to about 10:1. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 30% to 
about 45%, the ratio of said stearic acid to said lauric acid is from 
about 2:1 to about 6:1. 
When the level of C.sub.12 -C.sub.14 mild surfactant is from about 20% to 
about 35%, the ratio of said stearic acid to said lauric acid is from 
about 0:1 to about 2:1. 
While not being bound to any theory, it is advantageous to think of a 
synbar as comprising two separate components: the matrix and the actives. 
The matrix provides the physical characteristics (processability and bar 
messiness) while the actives provide lathering and mild properties. The 
matrix, if not chosen correctly, can impede lather generation, cause poor 
bar feel, increase or decrease wear rate beyond an acceptable level, 
and/or reduce product mildness. Likewise, the actives must be chosen so as 
to provide acceptable levels of lathering without negatively impacting 
mildness, a trade-off in formulations. 
Bars with improved processability comprising long chain alkyl sulfate and 
selected binders are described in commonly assigned, copending U.S. patent 
applications: Ser. No. 07/605,614, J. R. Schwartz, W. E. Eccard, T. A. 
Bakken, and L. A. Gilbert, filed Oct. 30, 1990; Ser. No. 07/647,030, J. R. 
Schwartz, W. E. Eccard, T. A. Bakken, and L. A. Gilbert, filed Jan. 28, 
1991; and Ser. No. 07/703,212, W. E. Eccard, J. R. Schwartz, T. A. Bakken, 
and L. A. Gilbert, filed May 20, 1991, all of said patent applications 
incorporated herein by reference. The present compositions yield bars 
having even better processability than those specifically exemplified in 
those patent applications. 
The formulation of synthetic detergent-based (syndet) bars is a delicate 
balancing act. There are numerous bar use properties to take into 
consideration: lather, messiness, economy, product pH, bar firmness, etc. 
There are also numerous manufacturing aspects to balance: product 
stickiness, softness, ability to weld, and be transferred and stored 
conveniently. The present invention is of a personal cleansing bar which 
performs exceptionally well in all attributes (especially bar messiness) 
while having no negative processing issues. 
It will be appreciated that the development of an appropriate bar matrix is 
a delicate balancing act between plasticity and brittleness while not 
comprising lather performance. Typical bar matrix plasticizer materials 
such as triglycerides, fatty alcohols, etc., which tend to form a 
sufficiently plastic matrix, but also tend to depress lather potential. 
Other commonly used additive matrix materials such as salts, 
polysaccharides, etc., tend to make an overly brittle and water-soluble 
matrix that induces poor bar messiness performance. 
The terms "synthetic bar," also "syndet bar," as used herein mean that the 
"bar" has more synthetic surfactant than soap unless otherwise specified. 
The term "AS syndet bar" means a syndet bar containing alkyl sulfate 
surfactant or its equivalent, unless otherwise specified. The term "long 
chain" means C.sub.15 and C.sub.22, preferably C.sub.16 -C.sub.20, and 
mixtures thereof. The terms "C.sub.12 -C.sub.14 alkyl" and cocoyl" as used 
herein are synonymous. 
The percentages, ratios, and parts herein are on a total composition weight 
basis, unless otherwise specified. All levels and ranges herein are 
approximations, unless otherwise specified. Levels of ingredients are 
expressed herein on a "solids" basis, incorporating all non-water 
components together, unless otherwise specified. 
An essential element of the present invention is the surfactant system. The 
long chain alkyl sulfate (hereinafter including its long chain equivalent 
synthetic surfactants) is key and is defined herein, as comprising 
C.sub.16 -C.sub.18 alkyl chains at a level of at least about 90%, 
preferably about 93%, and more preferably about 97%. The long chain alkyl 
sulfate (and its equivalents) is derived from corresponding saturated 
straight chain alcohols. The preferred alkyl sulfate has a ratio of 
C.sub.16 -C.sub.18 alkyl chains in the range of from about 100% C.sub.16 
to about 100% C.sub.18 by weight. A commercially available C.sub.16 
-C.sub.18 alkyl sulfate is SIPON.RTM. EC-111 (formerly SIPEX.RTM. EC-111), 
sodium cetearyl sulfate, which is approximately 60% C.sub.16 and 36% 
C.sub.18. SIPON.RTM. EC-111 is sold by Alcolac Company, Baltimore, Md. 
21226. Another source is Henkel Corp., Ambler, Pa. 19002. Henkel's sodium 
cetearyl sulfate, LANETTE E, is an estimated 50-50% C.sub.16 -C.sub.18 
alkyl sulfate sold as an emulsifier. 
Other long chain surfactants which are equivalents to the long chain alkyl 
sulfate (mostly insoluble) could serve as either full or partial 
replacements for the long chain alkyl sulfate. Examples includes long 
chain isethionates, sarcosinates, glyceryl ether sulfonates, etc. The acyl 
esters of isethionic acid salts, with esters of C.sub.16 -C.sub.18 acyl 
isethionates and no more than 25% or lower C.sub.14 acyl groups are also 
useful. Preferred is stearoyl isethionate with C.sub.14 3%; C.sub.16 50%; 
and C.sub.18 47%. Some preferred compositions include from about 3% to 
about 20% of stearoyl isethionate. 
It is noted that surfactant mildness can be measured by a skin barrier 
destruction test which is used to access the irritancy potential of 
surfactants. In this test the milder the surfactant, the lesser the skin 
barrier is destroyed. Skin barrier destruction is measured by the relative 
amount of radio-labeled water (.sup.3 H--H.sub.2 O) which passes from the 
test solution through the skin epidermis into the physiological buffer 
contained in the diffusate chamber. This test is described by T. J. Franz 
in the J. Invest. Dermatol., 1975, 64, pp. 190-195; and in U.S. Pat. No. 
4,673,525, Small et al., issued Jun. 16, 1987, incorporated herein by 
reference, and which disclose a mild alkyl glyceryl ether sulfonate (AGS) 
surfactant based synbar comprising a "standard" alkyl glyceryl ether 
sulfonate mixture. Barrier destruction testing surprisingly shows that the 
long chain alkyl sulfates are milder than standard AGS. The long chain 
alkyl sulfate preferably comprises 5-25% by weight of the bars of this 
invention. 
The present invention contains a mild lathering surfactant at a level of 
from about 20% to about 70%, preferably from about 30% to about 60%. 
Examples of a high lathering or lather enhancing surfactant, especially 
milder ones, are: alkyl isethionate; sodium acyl sarcosinate, alkyl 
glyceryl ether sulfonate. 
The isethionates, sarcosinates, and glyceryl ether sulfonates may be pure 
chain length variants or those derived from commercial oils such as 
coconut. The lauryl chain length should account for at least 20% to as 
much as 100% of the weight of the given mild surfactant. 
A "high lathering surfactant" as defined herein, is one which lathers 
better than the long chain C.sub.16 -C.sub.18 alkyl sulfate. 
A "mild surfactant" as defined herein is one that is milder than sodium 
dodecyl sulfate. 
Numerous examples of surfactants in general are disclosed in the patents 
incorporated herein by reference. They include limited amounts of 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 alkyl amine oxides, betaines, sultaines, 
and mixtures thereof. Included in the surfactants are the alkyl ether 
sulfates with 1 to 12 ethoxy groups, especially ammonium and sodium lauryl 
ether sulfates. Alkyl chains for these other surfactants are C.sub.8 
-C.sub.22, preferably C.sub.10 -C.sub.18. Alkyl glycosides and methyl 
glucose esters are preferred mild nonionics which may be mixed with other 
mild anionic or amphoteric surfactants in the compositions of this 
invention. 
The bars of this invention can have up to about 10% of high lathering, 
non-mild surfactants and still maintain the mildness requirement of the 
bar. Examples of these surfactants include linear alkylbenzene sulfonates 
and shorter chain or traditional (coconut) alkyl sulfates. 
A preferred syndet bar contains a mixture of C.sub.12 -C.sub.14 alkyl 
isethionate (SCI) and sodium linear alkylbenzene sulfonate in a ratio of 
from about 35:1 to about 15:1, preferably from about 30:1 to about 30:1. 
The primary basic binders of the present invention are: (1) free fatty acid 
and (2) paraffin wax. 
The fatty acid material which is desirably incorporated into the present 
invention includes material ranging in hydrocarbon chain length of from 
abut 10 to about 22, essentially saturated. These fatty acids may be 
highly purified individual chain lengths and/or crude mixtures such as 
those derived from fats and oils. 
The preferred ratio of stearic to lauric acids is dependent upon the level 
of mild synthetic surfactant(s), e.g., C.sub.12 -C.sub.14 acyl 
isethionate, in the bar. Products that have higher levels of acyl 
isethionate require a larger ratio of stearic to lauric acid. The ratio is 
critical to the overall acceptability of a given product since it impacts 
product lather and smear, as well as processability. For high levels of 
acyl isethionate (&gt;40%), the preferred ratio of stearic: lauric is from 
about 5:1 to about 10:1, more preferably from about 6:1 to about 9:1; 
moderate levels of acyl isethionate (between 45% and 30%), the preferred 
ratio of stearic:lauric is from about 2:1 to about 6:1, more preferably 
from about 3:1 to about 5:1; for low levels of acyl isethionate (&lt;35%), 
the preferred ratio of stearic:lauric is from 0:1 (all stearic) to about 
2:1, more preferably from 0:1 (all stearic) to about 0.5:1. 
The composition may include soaps derived from hydrocarbon chain lengths of 
from about 10 to about 22, essentially saturated. It is preferred that the 
soap be the sodium salt, but other soluble soap can be used. Potassium, 
ammonium, triethanolammonium, and mixtures thereof, are deemed acceptable. 
The soaps are preferably prepared by the in situ saponification of the 
corresponding fatty acids, but they may also be introduced as preformed 
soaps. 
"Insoluble" soaps, e.g., magnesium and zinc soaps, are not included in the 
2-15% level of "soap" in the composition definition. However, insoluble 
soaps can be used as non-lathering, non-soil-load diluents. 
An important component of this invention is a wax having a melting point 
(M.P.) of from about 130.degree. F. to about 180.degree. F. 
(54.degree.-82.degree. C.), preferably from about 140.degree. F. to about 
165.degree. F. (60.degree.-74.degree. C.), and most preferably from about 
142.degree. F. to about 160.degree. F. (61.degree.-71.degree. C.). A 
preferred paraffin wax is a fully refined petroleum wax which is odorless 
and tasteless and meets FDA requirements for use as coatings for food and 
food packages. Such paraffins are readily available commercially. A very 
suitable paraffin can be obtained, for example, from The National Wax Co. 
under the trade name 6975, 
The paraffin preferably is present in the bar in an amount ranging from 
about 4% to about 30% by weight. The paraffin ingredient is used in the 
product to impart skin mildness,, plasticity, firmness, and 
processability. It also provides a glossy look and smooth feet to the bar. 
The paraffin ingredient is optionally supplemented by a microcrystalline 
wax. A suitable microcrystalline wax has a melting point ranging, for 
example, from about 140.degree. F. (60.degree. C.) to about 185.degree. F. 
(85.degree. C.), preferably from about 145.degree. F. (62.degree. C.) to 
about 175.degree. F. (79.degree. C.). The wax preferably should meet the 
FDA requirements for food grade microcrystalline waxes. A very suitable 
microcrystalline wax is obtained from Witco Chemical Company under the 
trade name Multiwax X-145A. The microcrystalline wax preferably is present 
in the bar in an amount ranging from about 0.5% to about 5% by weight. The 
microcrystalline wax ingredient imparts pliability to the bar at room 
temperatures. 
Auxiliary plastic binders may be incorporated into the bar at levels of 
from 0% to about 10%. These binders may be selected from monoglycerides, 
polyethylene glycols, fatty alcohols, sugars, tallow alcohol ethoxylates, 
and mixtures thereof. Other plastic binders are identified in the 
published literature, such as J. Amer. Oil Chem. Soc. 1982, 59, 442. The 
binder system can contain several plasticizers. 
The syndet bar of this invention may comprise 0% to about 5%, preferably 
from about 0.5% to about 3%, of a suitably fast hydrating cationic 
polymer. The polymers have molecular weights of from about 1000 to about 
3,000,000. 
The cationic polymer (skin conditioning agent) is selected from the group 
consisting of: 
(I) cationic polysaccharides; 
(II) cationic copolymers of saccharides and synthetic cationic monomers, 
and 
(III) synthetic polymers selected from the group consisting of: 
(A) cationic polyalkylene imines 
(B) cationic ethoxy polyalkylene imines, and 
(C) cationic poly[N-[-3-(dimethylammonio)propyl]-N'-[3-(ethyleneoxyethylene 
dimethylammonio)propyl]urea dichloride]. 
Specific examples of members of the cationic polysaccharide class include 
the cationic hydroxyethyl cellulose JR 400 made by Union Carbide 
Corporation; the cationic starches Stalok.RTM. 100, 200, 300 and 400 made 
by Staley, Inc.; the cationic galactomannans based on guar gum of the 
Galactasol 800 series by Henkel, Inc., and the Jaguar series by Celanese 
Corporation. 
Examples of members of the class of copolymers of saccharides and synthetic 
cationic monomers include those composed of cellulose derivatives (e.g., 
hydroxyethyl cellulose) and N,N-diallyl,N-N-dialkyl ammonium chloride 
available from National Starch Corporation under the trade name Celquat. 
The cationic synthetic polymers useful in the present invention are 
cationic polyalkylene imines, ethoxypolyalkylene imines, and 
poly[N-[-3-(dimethylammonio)propyl]-N'-[3-(ethyleneoxyethylene 
dimethylammonio)propyl]urea dichloride] the latter of which is available 
from Miranol Chemical Company, Inc., under the trademark of Miranol A-15, 
CAS Reg. No. 68555-36-2. 
Preferred cationic polymeric skin conditioning agents of the present 
invention are those cationic polysaccharides of the cationic guar gum 
class with molecular weights of 1,000 to 3,000,000. More preferred 
molecular weights are from 2,500 to 350,000. These polymers have a 
polysaccharide backbone comprised of galactomannan units and a degree of 
cationic substitution ranging from about 0.04 per anhydroglucose unit to 
about 0.80 per anhydroglucose unit with the substituent cationic group 
being the adduct of 2,3-epoxypropyltrimethyl ammonium chloride to the 
natural polysaccharide backbone. Examples are JAGUAR C-14-S, C-15 and C-17 
sold by Celanese Corporation. In order to achieve the benefits described 
in this invention, the polymer must have characteristics, either 
structural or physical which allow it to be suitably and fully hydrated 
and subsequently well incorporated into the soap matrix. 
Other ingredients of the present invention are selected for the various 
applications. E.g., perfumes can be used in formulating the skin cleansing 
products, generally at a level of from about 0.1% to about 1.5% of the 
composition. Alcohols, hydrotropes, colorants, and fillers such as talc, 
clay, calcium carbonate and dextrin can also be used. Cetearyl alcohol is 
a mixture of cetyl and stearyl alcohols. Preservatives, e.g., sodium 
ethylenediaminetetraacetate (EDTA), generally at a level of less than 1% 
of the composition, can be incorporated in the cleansing products to 
prevent color and odor degradation. Anti-bacterials can also be 
incorporated, usually at levels up to 1.5%. Salts, both organic and 
inorganic, can be incorporated. Examples include sodium chloride, sodium 
isethionate, sodium sulfate, and their equivalents. The following patents 
disclose or refer to such ingredients and formulations which can be used 
in the soap/synbars of this invention, and are incorporated herein by 
reference: 
______________________________________ 
Pat. No. Issue Date Inventor(s) 
______________________________________ 
4,234,464 11/1980 Morshauser 
4,061,602 12/1977 Oberstar et al. 
4,472,297 9/1984 Bolich et al. 
4,491,539 1/1985 Hoskins et al. 
4,540,507 9/1985 Grollier 
4,673,525 6/1987 Small et al. 
4,704,224 11/1987 Saud 
4,812,253 3/1989 Small et al. 
4,820,447 4/1989 Medcalf et al. 
4,954,282 9/1990 Rys et al. 
______________________________________ 
The syndet bars of this invention have a pH of from 4 to 9 in a 1% aqueous 
solution. The preferred pH is from 5 to 8, more preferably about 6.5 to 
7.5. 
Laboratory Assessment of Bar 
The following test procedures are used to evaluate the critical bar 
performance attributes of mildness and bar processability. 
Smear Test Procedure 
Equipment: 
1. #2-202C Fisher Brand Hexagonal Polystyrene weighing dishes 
(4".times.3"). 
2. #14-366A Fisher Brand Spatula. 
3. Balance capable of weighing to two decimal points. 
4. 120.degree. F. temperature Room. 
5. Timer. 
Test Method 
The bar is placed in 30 mls of 100.degree. F. (.about.38.degree. C.) water 
for two hours. The wet surface is scraped and the weight of this material 
is called the "wet" smear grade. The wet smear is dried, as is the liquid 
soak material, the weights of these combined is the "dry" smear grade. 
Bar Soap Handwash Lather Volume Test 
The handwash lather test is used to provide in-use lather volume 
measurements for the lather performance of skin cleansing bars. The test 
measures both the ultimate lather volume generated and the volume which is 
generated after a very short lathering period (to reflect lathering ease). 
The lather volumes are generated under soil-loaded conditions. 
Synthetic soil is used for the soil-loaded lather volume test reported 
herein. Its formula and procedure for making it are set out below. 
TABLE 1 
______________________________________ 
Synthetic Soil 
Ingredients Wt. % 
______________________________________ 
Hyfac 430.sup.a 1.87 
Lauric Acid.sup.b 
1.42 
Neo-fat 14.sup.c 5.68 
Neo-fat 16.sup.d 11.16 
Neo-fat 18.sup.e 5.40 
Neo-fat 90-04.sup.f 
9.81 
Industrene 226.sup.g 
1.26 
Paraffin Wax 7.30 
Squalane.sup.h 3.70 
Lanolin Anhydrous 
19.40 
Coconut Oil 3.30 
Tallow 29.70 
100.00% 
______________________________________ 
.sup.a Emery Industries, Inc., Cincinnati, Ohio 
.sup.b Emery Industries, Inc., Cincinnati, Ohio 
.sup.c Armour Industrial Chemical Co., Chicago, Illinois 
.sup.d Armour Industrial Chemical Co., Chicago, Illinois 
.sup.e Armour Industrial Chemical Co., Chicago, Illinois 
.sup.f Armour Industrial Chemical Co., Chicago, Illinois 
.sup.g Humko Products, Memphis, Tennessee 
.sup.h Robeco Chemicals, Inc., New York, New York 
Procedure 
1. Heat above materials together continuously between 
160.degree.-175.degree. F. 
2. Mix 25 parts of above formula with 25 parts of a 5% to 80% tallow/20% 
coconut soap solution and 50 parts of distilled water at 150.degree. F. 
3. Cool mixture to room temperature while stirring constantly. 
4. Store in covered glass container. 
Equipment 
The following equipment is used: 
1. Water source and sink with temperature control. The water source should 
be medium hardness (6-9 grain/gallon) for most testing, although water of 
lower and higher hardness can be used for special purposes. 
2. Synthetic soil (see Table 1). 
3. Paper towels. 
4. Test bars. 
5. Control bars. 
Procedure 
The following procedure is used: 
1. Set temperature at 95.degree.-100.degree. F. 
2. Rub 0.22 cc of soil on hands. 
3. Wet hands. 
4. Rotate bar 3 times in both hands. 
5. Add a little water, rub both hands 5 times. 
6. Rotate hands 3 times (without soap), grade for flash volume. 
7. Rotate 7 more times, grade for ultimate volume. 
8. Collect lather and deposit on sink top. 
9. Compare volume with standard bar target volume and assign grade. 
Grading Scale 
Soil Loaded 
7--Exceptional 
6--Very much higher than target 
5--Higher than target 
4--Target volume 
3--Slightly lower than target 
2--Lower than target 
In Vitro Skin Barrier Penetration Test (Mildness) 
This test was performed according to the procedure described in U.S. Pat. 
No. 4,812,253, Small et al., issued Mar. 14, 1989, said patent 
incorporated herein by reference. 
Frequently, materials which tends to improve processability also tend to 
have other negatives, particularly in terms of product mildness. Referring 
to Table 2, using the barrier destruction method to assess product 
mildness, individual raw materials sodium cetearyl sulfate is shown to be 
surprisingly more mild than the ultra mild sodium cocoglycerylether 
sulfonate, as well as a shorter chained AS, sodium dodecyl sulfate. The 
lower the number in Table 2 the milder the product. 
TABLE 2 
______________________________________ 
Mg .sup.3 H.sub.2 O Transported 
______________________________________ 
Water 0.137 
Sodium Cetearyl Sulfate 
0.302 
Sodium Cocoglycerylether Sulfonate 
0.458 
Sodium Dodecyl Sulfate 
1.289 
Sodium Laurate 1.805 
______________________________________ 
Assessment of Processability: The Mill Test 
Mill Test Procedure 
1. A standard three-roll mill is employed with the take-up roll set at 
120.degree. F. (48.degree. C.), the transfer roll at 110.degree. F. 
(43.degree. C.) and the discharge roll at 80.degree. F. (26.degree. C.). 
2. Final flake thickness is about 0.010 inches. 
3. After the third mill pass, the material is evaluated as described below. 
Assessment 
______________________________________ 
Grade Product Appearance 
______________________________________ 
10 Soap-like. 
9 Non-sticky; less than four compaction layers; 
no build-up. 
8 Non-sticky; less than four compaction layers; 
0.010" build-up. 
7 Slightly sticky; about eight compaction layers; 
0.010"-0.016" build-up. 
6 Slightly sticky; large chunks; bridging; 
&gt;0.016" build-up. 
5 More sticky; sheeting; &gt;0.016" build-up. 
______________________________________ 
Crutching 
1. Add melted sodium cetearyl sulfate to the crutcher. 
2. Add predetermined quantity of Hamposyl L-30 solution to the crutcher 
mix. 
3. Add the predetermined quantity of AGS paste to the water in the 
crutcher. The AGS paste can be at ambient temperature or preheated to 
150.degree. F. (65.degree. C.). 
4. Turn on the agitator and recirculation pump and maintain temperature in 
crutcher at 130.degree.-150.degree. F. (54.degree.-65.degree. C.) by 
adjusting steam and water valves. 
5. Allow contents in crutcher mix to return to 130.degree.-150.degree. F. 
(54.degree.-65.degree. C.) prior to adding predetermined quantity of 
stearic acid. 
6. Add to heated crutcher mix predetermined quantity of soap or NaOH to 
form in-situ soap. 
7. Allow the contents in the crutcher to mix and/or react for about 15 
minutes while maintaining the temperature at 130.degree.-150.degree. F. 
(54.degree.-65.degree. C.). 
8. Add sodium chloride plasticizer and titanium dioxide to the heated 
crutcher mix. 
9. Add lauric and/or coconut fatty acids to crutcher mix and allow contents 
of crutcher to mix for about 15 minutes while maintaining temperature at 
130.degree.-150.degree. F. (54.degree.-65.degree. C.). 
10. Add paraffin wax in a molten form and allow crutcher to mix 
approximately 1/2 hour until uniform. 
Drying 
The crutcher mix is dried and cooled using a combination flash chamber and 
chill roll or chill belt. The crutcher mix is first heated to 
approximately 300.degree. F. (149.degree. C.) by a heat exchanger and then 
flash dried in a chamber above the chill roll or chill belt. From the 
flash chamber the hot, dried mix is extruded onto the chill roll or chill 
belt. The chill belt or chill roll provides a uniform, thin, cool 
(85.degree.-95.degree. F., 29.degree.-35.degree. C.) product in flake or 
chip form. Typical moisture for the flake is 1-10%, preferably about 
2-4.5%. The ways to regulate the moisture, in the order of preference, are 
(1) increasing or decreasing steam pressure on the heat exchanger; (2) 
increasing or decreasing crutcher mix rate to the heat exchanger; and (3) 
increasing or decreasing crutcher mix temperature to the heat exchanger. 
Amalgamating 
The flakes are weighed and mixed in a batch amalgamator to obtain uniform 
flake size. Preweighed perfume is added to the flakes and mixed in the 
amalgamator to obtain the desired finished product perfume level. The 
perfumed flakes are transferred to the mix hopper or directly to the 
plodder. 
Milling 
The 3-roll soap mills are set up with the first roll at 120.degree. F. 
(49.degree. C.) and the other two mills at about 44.degree. F. (7.degree. 
C.). The material is passed through the mills several times to provide a 
homogeneous mixture of perfume and dried flakes. 
Plodding and Stamping 
The plodder is set up with the barrel temperature at about 115.degree. F. 
(46.degree. F.) and the nose temperature at 114.degree.-122.degree. F. 
(45.degree.-50.degree. C.). The ideal plodder is a dual stage plodder that 
allows use of a vacuum of about 15-25 inches (38-64 cm) of Hg. The plugs 
could be cut in 5-inch (13 cm) sections and stamped with a cold die block 
using die liquor such as alcohol, if appropriate.

EXAMPLES AND FORMULAS 
The following formulas and examples are illustrative and are not intended 
to limit the scope of the invention(s). The methods of making milled bars 
are well known. All levels and ranges, temperatures, results etc., used 
herein are approximations unless otherwise specified. The bars of this 
invention in the Formulas and Examples all have a pH of about 6.5 to about 
7.5. 
The level of the water in the above syndet bars stabilizes upon storage 
from about 6% to about 3%. 
COMATIVE BAR 
Comparative Bar is DOVE.RTM., a currently marketed product based on sodium 
cocoyl isethionate. The ingredients of DOVE.RTM. are: sodium cocoyl 
isethionate, stearic acid, sodium tallowate, water, sodium isethionate, 
coconut acid, sodium stearate, sodium dodecylbenzenesulfonate, sodium 
cocoate, fragrance, sodium chloride, and titanium dioxide. Performance 
properties show DOVE.RTM. to be deficient in both lather, as well as 
smear, when compared with Examples 2 and 9 of the present invention. Since 
the exact composition of the product is not known, mill grade is not 
reported. Examples 1, and 3-8 have either improved smear or improved 
lather when compared with DOVE.RTM.. 
EXAMPLES 1-2 
Examples 1 and 2 contain a high level of sodium cocoyl isethionate. In 
these cases, a relatively high ratio of stearic acid to lauric acid is 
required to achieve the correct balance of lather, smear and 
processability. The ratio must be carefully chosen, however. Example 1 
demonstrates that when the stearic:lauric ratio gets too large (12.2:1), 
the soil lather becomes less desirable; notice that the smear is 
relatively poor as well. Example 2, with a somewhat lower stearic:lauric 
ratio (6.8:1 has improved soil lather and smear with no detriment to 
processability. 
EXAMPLES 3-6 
Examples 3 through 6 contain a moderate level of sodium cocoyl isethionate. 
This level of isethionate requires a lower stearic:lauric ratio than 
Examples 1 and 2, but, again, the ratio must be carefully chosen. As with 
Example 1, Example 3 has a stearic:lauric ratio (18.2:1) that is too high 
and results in poor lather performance. Example 4 has a stearic:lauric 
ratio that is too low (2:1) and the result is better lather but poor bar 
messiness, as well as decreased processability. Examples 5 and 6 have 
better balanced stearic:lauric ratios (4.1:1 and 5:1, respectively) and 
the result is the appropriate balance between lather, smear and 
processability. 
EXAMPLES 7-9 
Examples 7 through 9 represent products with lower levels of sodium cocoyl 
isethionate. As can be seen, all products contain substantially lower 
ratios of stearic:lauric acids. As Example 9 demonstrates, a well 
performing and processing product results when no stearic acid is added 
(ratio of stearic:lauric to zero). 
Examples 2, 6 and 9 are highly preferred personal cleansing bars of the 
present invention which have very good lathers and smears with improved 
processability over bars of the current state of the art. 
TABLE 3 
______________________________________ 
Comp. Bar Ex. 1 Ex. 2 Ex. 3 
Ingredient (Wt. %) (Wt. %) (Wt. %) 
(Wt. %) 
______________________________________ 
Sodium Cocoyl 
* 51.80 50.90 40.60 
Isethionate 
Sodium Linear 
* 2.00 1.90 1.60 
Alkylbenzene 
Sulfonate 
Sodium Cetearyl 
* -- 11.20 11.20 
Sulfate 
Paraffin * 9.90 9.70 9.70 
Sodium Soap * 8.30 4.60 9.30 
(in situ) 
Lauric Acid * 1.20 1.20 0.90 
Stearic Acid 
* 14.60 8.20 16.40 
Sodium Chloride 
* 0.50 0.50 0.01 
Sodium Isethionate 
* 5.90 5.80 4.60 
Titanium Dioxide 
* 0.25 0.25 0.25 
Perfume * 1.20 1.20 1.20 
Water * 4.50 4.50 4.50 
Ratio of Stearic: 
Lauric Acids 
* 12.2:1 6.8:1 18.2:1 
Performance Data: 
Avg. Soil Lather 
3.0 2.75 3.75 1.25 
Smear, Wet 3.8 4.5 2.4 2.5 
Smear, Dry 1.6 2.7 1.7 1.5 
Processability 
Mill Grade -- 9.00 9.00 9.00 
______________________________________ 
*Not known. 
Example 2 has a mill grade of 9 which is as good as an all-soap bar. 
Example 2 has a superior Average Soil Lather of 3.75 vs. 3.0 for the 
Comparative Bar. Example 2 has a superior wet smear of 2.4 vs. 3.8 for the 
Comparative Bar. Example 2 has a Dry Smear of 1.7 which is comparable to 
the 1.6 Dry Smear of the Comparative Bar. 
TABLE 4 
______________________________________ 
Ex. 4 Ex. 5 Ex. 6 
Ingredient (Wt. %) (Wt. %) (Wt. %) 
______________________________________ 
Sodium Cocoyl Isethionate 
40.60 40.60 39.00 
Sodium Linear Alkylbenzene 
1.60 1.60 1.60 
Sulfonate 
Sodium Cetearyl Sulfate 
11.20 11.20 9.53 
Paraffin 9.70 9.70 14.10 
Sodium Soap (in situ) 
9.30 9.30 8.90 
Lauric Acid 5.80 3.40 2.80 
Stearic Acid 11.60 14.00 13.90 
Sodium Chloride 0.01 0.01 0.01 
Sodium Isethionate 
4.60 4.60 4.50 
Titanium Dioxide 
0.25 0.25 0.25 
Perfume 1.20 1.20 1.20 
Water 4.50 4.50 4.50 
Ratio of 2:1 4.1:1 5:1 
Stearic:Lauric Acids 
Performance Data: 
Avg. Soil Lather 
4.25 3.75 2.75 
Smear, Wet 4.3 3.5 2.3 
Smear, Dry 2.3 1.9 1.3 
Processability 
Mill Grade 7.50 8.00 9.00 
______________________________________ 
TABLE 5 
______________________________________ 
Ex. 7 Ex. 8 Ex. 9 
Ingredient (Wt. %) (Wt. %) (Wt. %) 
______________________________________ 
Sodium Cocoyl Isethionate 
31.10 31.10 33.20 
Sodium Lauroyl Sarcosinate 
5.90 5.90 5.90 
Sodium Cetearyl Sulfate 
15.73 15.73 27.99 
Paraffin 27.60 27.60 16.40 
Sodium Soap (in situ) 
3.00 3.00 3.00 
Lauric Acid 4.60 1.60 4.40 
Stearic Acid -- 3.00 -- 
Sodium Chloride 0.80 0.80 0.80 
Sodium Sulfate 0.89 0.89 0.42 
Sodium Isethionate 
4.70 4.70 4.60 
Titanium Dioxide 
0.25 0.25 0.25 
Perfume 1.20 1.20 1.20 
Water 4.50 4.50 4.50 
Ratio of 0:1 1.9:1 0:1 
Stearic:Lauric Acids 
Performance Data: 
Avg. Soil Lather 
3.75 1.50 3.00 
Smear, Wet 2.5 2.8 3.4 
Smear, Dry 2.0 1.8 2.3 
Processability 
Mill Grade 7.50 6.50 8.00 
______________________________________ 
Referring to the Performance Data in Tables 3 and 5, note that Example 9 
has a good Mill Grade of 8. Example 9 has comparable lather vs. that of 
the Comparative Bar. Example 9 has a Wet Smear that is better, but its Dry 
Smear is slightly worse than that of the Comparative Bar.