Personal use soap bar compositions containing cationic polymers

A personal use soap bar composition containing alkali metal soaps of fatty acids having alkyl chain lengths of C.sub.8 -C.sub.22 which include an unhydrated cationic guar gum polymer as a skin feel and mildness additive. Prior to incorporating the polymer into the soap, it is mixed with an anhydrous polyglycol ether such as PEG-6 methyl ether. This eliminates the need to hydrate the cationic polymers to achieve uniform distribution of the polymer in the bar.

This invention relates to personal use soap bar compositions containing 
cationic polymers as skin benefiting agents. 
BACKGROUND OF THE INVENTION 
For a considerable number of years, polymers of various types have been 
incorporated into a variety of cleaning and personal use cleansing 
compositions for a variety of purposes. For example, polymers are used in 
powdered laundry detergents as production assistance, builder assistance, 
and anti-redeposition agents. In liquid laundry products, they are used as 
thickeners, and in automatic dishwasher liquids as builders and softeners 
and as thickeners; in dry dishwasher formulations as builders and 
softeners. 
In the field of personal use skin cleansing compositions, ideally such 
compositions should be both mild to the skin and give the user's skin a 
desirable smooth and slippery feel. It is known to incorporate cationic 
polymers into cleansing bar compositions to effect skin conditioning. In 
U.S. Pat. No. 5,064,555 and its related U.S. Pat. No. 4,820,447, there is 
disclosed skin cleansing soap bars comprising soap and a hydrated cationic 
guar-gum polymer, the addition of which is said to improve the mildness of 
the soap bar. According to the patents, the soap bars incorporate a 
hydrated cationic polymer having a molecular weight of from about 1000 to 
about 3,000,000 with it being preferred that such polymer be a cationic 
guar-gum polymer having a molecular weight in the range of 2500-350,000. 
The inventors state it is essential that the cationic polymer be hydrated 
to achieve uniform distribution of the polymer in the bar. It is further 
stated that the preferred cationic polymers are of the cationic guar-gum 
class, examples being JAGUAR C-14-S, C-15 and C-17 previously available 
from Celanese Corporation and now available from Rhone-Poulenc, inc. It is 
further disclosed that the polymers require a relatively large amount of 
water for their hydration. As an example, for JAGUAR C-15 the ratio of 
polymer to water is about 9 to 1; for JAGUAR C-14S, the ratio is about 19 
to 1. From a reading of the patents, it is clear that hydrating the 
cationic polymer is most important to a successful use of such polymer in 
a bar soap product. It is also clear that the need to hydrate the polymer 
is not only an extra step in the soap making process, but requires 
additional energy to dry the soap to its appropriate moisture level 
because of the incorporation of the additional water. 
It would therefore be a surprising advance in the soap-making art to 
provide a process for incorporating cationic polymers of the type 
disclosed in the aforementioned patents and particularly to incorporate 
cationic guar-gum polymers in soap compositions without the need to 
hydrate the polymer either prior to or during the soap-making process. It 
would also be an important advance that the incorporation of such 
so-called "dry" polymers be accomplished with very little or no gritty 
feeling to the bar compositions. In short, it would be an important 
advance to obtain the benefits of the use of cationic guar-gum polymers in 
bar products as disclosed in the aforementioned patents, without the need 
to hydrate the polymers. 
SUMMARY OF THE INVENTION 
It has been discovered that cationic guar-gum polymers can be incorporated 
into personal use soap bar compositions without the need to hydrate the 
polymer either prior to or during the preparation of the bar product. Such 
soap compositions can contain up to about 90% by weight of soap and from 
about 0.2% by weight to about 5% by weight of the unhydrated cationic 
guar-gum polymer, preferably about 0.5% by weight to about 2.0% by weight. 
Prior to incorporating the polymer into the soap, it is mixed with a 
polyethylene or polypropylene glycol linear polymer, preferably a 
polyglycol ether, such as PEG-6 methyl ether, and the anhydrous 
polymer/glycol mixture is then incorporated into the soap mass. PEG-6 
methyl ether is polyethylene glycol 6 methyl ether and is of the formula: 
CH.sub.3 OCH.sub.2 CH.sub.2).sub.6 OH. Any small amount of gritty feeling 
that may be present in the bar composition can be virtually eliminated by 
the addition of a superfatting agent, such as free fatty acid, to the soap 
mass, and, depending on the particular type of cationic guar-gum polymer 
used, by the further addition of polyhydric alcohol and/or milling of the 
soap mass. 
DETAILED DESCRIPTION OF THE INVENTION 
This discovery relates to personal use soap bar compositions which 
incorporate from about 0.2% by weight to bout 5.0% by weight of an 
unhydrated cationic guar-gum polymer as a skin feel and mildness additive. 
Prior to incorporating the polymer into the soap, it is mixed with an 
anhydrous polyethylene glycol linear polymer such as an anhydrous 
polyglycol ether, more specifically PEG-6 methyl ether. After mixing, the 
polymer/glycol mixture is then thoroughly mixed with the soap mass. To 
effect maximum smoothness of the bar, a minor amount of from about 1.0% by 
weight to about 10.0% by weight of a superfatting agent such as free fatty 
acid should be present in the soap. Preferably, about 2.0% by weight to 
about 5.0% by weight is used. Depending on the particular type of cationic 
guar-gum polymer employed, maximum smoothness of the bar and virtually no 
gritty feel may be obtained through the addition of a polyhydric alcohol 
and/or special milling of the soap. 
The soaps used are the well-known alkali metal soaps of fatty acids having 
alkyl chain lengths of C.sub.8 -C.sub.22, preferably C.sub.12 -C.sub.18. 
For example, sodium tallowate, sodium palm kernalate or sodium cocoate and 
mixtures thereof perform very well. The fatty acid soaps can be present in 
amounts up to about 90% by weight of the composition, more preferably in 
the range of 60-80% by weight and most preferably in the range of 65-70% 
by weight. A preferred soap is a mixture of sodium tallowate and sodium 
cocoate at a ratio of 80:20 or 70:30. 
Although a variety of cationic polymeric skin conditioning agents may be 
employed, we prefer the cationic guar-gums having molecular weights of 
from about 1 to about 1.7. Such polymers are available from Rhone-Poulenc, 
Inc. and designated as Jaguar C-14S, Jaguar C-15S and Jaguar C-17S, which 
are the single derivative (quaternized) polymers. We prefer to employ a 
polymer designated Jaguar C-162 and also available from Rhone-Poulenc. 
Jaguar C-162 also belongs to the family of quaternized guar-gums. Jaguar 
C-162 is distinguished from the other members of this family in that it 
has been "double derivatized". The guar backbone is first derivatized with 
propylene oxide to form hydroxypropyl groups. Then the polymer is 
quaternized which results in either formation of an ether linkage with a 
free hydroxy group on the guar backbone or an ether linkage with the free 
hydroxy group on the hydroxypropyl moiety. The purpose of the inclusion of 
the hydroxypropyl functionality is to increase polymer solubility in 
water. Polymers of this type typically contain insoluble impurities such 
as protein and lower chained galactose particles. Hydroxypropylation also 
derivatizes these impurities improving their solubility in water. Thus, 
Jaguar C-162 is a double derivative of guar containing both cationic 
groups and hydroxypropyl groups. The degree of substitution for the 
cationic group is approximately 0.1 which means there is 1 cationic group, 
on average, per 10 galactose/mannose sugar groups. The molecular 
substitution for the hydroxypropyl group is about 0.5 to about 0.6 
equivalent to, on average, 1 hydroxypropyl group per 2 galactose/mannose 
sugar groups. All the foregoing polymers are water soluble with Jaguar 
C-162 being about 2/3 the molecular weight of C-14S. As measured by 
viscosity: 
C-14S measures 3-4,000 cps for a 1% solution 
C-162 measures 300-100 cps for a 1% solution 
A preferred composition of this invention also contains from about 1.0% by 
weight to about 10.0% by weight of a superfatting agent such as a free 
fatty acid (alkyl C.sub.12 -C.sub.18) such as coconut fatty acid to 
improve the smoothness, reduce drag and give a grit free feel to the bar. 
It is also possible to employ oils such as coconut oil, palm kernel oil 
and basassu oil as the super fatting agent, either alone or in combination 
with the free fatty acids. 
We have also found that the addition of a polyhydric alcohol can improve 
the smoothness and grit free feel of the composition, particularly where 
Jaguar C-14S, C-15S or C-17S polymers are employed. Such polyhydric 
alcohols have 2 or more hydroxyl groups, preferably from 3 to 6 hydroxyl 
groups, and include such alcohols as glycerol, sorbitol, mannitol, 
erythritol, with sorbitol being preferred. The amount of such alcohol to 
be included ranges from about 1.0% by weight to about 12.0% by weight with 
about 4.0% by weight to about 10.0% by weight being preferred. When Jaguar 
C-16S polymer is employed, the polyhydric alcohol is not needed, although 
it certainly does not detract from the quality of the bar. 
Another surprising quality of this invention is that the unhydrated 
cationic guar-gum polymer can be incorporated into a translucent soap bar 
without adversely affecting the clarity of the bar. In this aspect of the 
invention, it is important that no free water be present during the mixing 
of the polymer with the polyglycol ether or even when the polyglycol 
ether/polymer mixture is added to the soap. The presence of water will 
tend to adversely effect the translucency of the bar. To aid in the 
translucency of the bar, we incorporate known translucency promoting 
agents such as glycerin in an amount of about 1.0% by weight to about 8.0% 
by weight of the composition. 
In preparing the personal cleansing bars of this invention, generally 
speaking, processes common to the production of conventional soap bars are 
employed with, of course, certain exceptions. The alkali metal soap is 
preferably used in pellet form and such soap pellets can consist, for 
example, of an 80/20 or 70/30 blend of sodium tallowate and sodium cocoate 
with the moisture level of the pellets ranging from about 10.5% by weight 
to about 18.0% by weight. About 12.0% by weight to 15.0% by weight of 
moisture is preferred. 
The unhydrated cationic polymer can be mixed with the polyethylene glycol 
ether using suitable mixing equipment to form a slurry. The ratio of 
cationic guar-gum to the glycol ether ranges from about 1 part of polymer 
to 1 part of said ether to about 1 part of polymer to about 4 parts of 
glycol ether with a ratio of about 1 to about 1.5 being preferred. The 
polymer/glycol ether slurry appears to be a colloidal suspension of the 
polymer in the glycol ether. After mixing is complete, the slurry and soap 
pellets are put into an amalgamator along with any fragrance, and, if not 
previously incorporated into the pellets, a suitable amount of super 
fatting agent. After thorough mixing in the amalgamator, the soap mass is 
sent to a multiple roll mill and then to a plodder where sorbitol, if 
used, can then be added. The soap can be plodded through a single screen 
or multiple screens, then extruded, formed into slugs and then stamped.

EXAMPLE I 
Antibacterial, translucent soap bars of the following composition were 
prepared: 
______________________________________ 
Ingredient Weight % 
______________________________________ 
Soap (sodium tallowate & sodium cocoate 70:30) 
67.0 
Water 
15.8 
Glycerin 7.1 
Free fatty acids 1.8 
PEG-6 methyl ether 1.50 
Fragrance 1.50 
Preservatives 0.30 
Jaguar C-162 1.0 
Sorbitol 1.1 
Triclocarbon 0.3 
Dyes/Colors 
______________________________________ 
0.001 
Soap pellets (70:30 ratio sodium tallowate/sodium cocoate) were prepared 
having about 2.0% by weight of superfatting agent (coconut oil), 7.6% 
glycerin and about 17.0% by weight of moisture. 
A slurry of about 35.7% of Jaguar C-162, 53% of PEG-6 methyl ether, 11.0% 
Triclocarban and dyes was prepared using suitable mixing equipment. 
Thereafter, the soap pellets and slurry were sent to an amalgamator along 
with fragrance and mixed for 2-3 minutes. 
Following mixing in the amalgamator, the soap mass was sent through a 
multiple roll mill and then to a multi-stage plodder with 10 mesh screens 
mounted on the end of each plodder. A portion of the sorbitol was added to 
the soap between plodders. Thereafter, the soap was sent to another 
multi-stage plodder with the remaining amount of sorbitol added to the 
soap prior to the final plodding step. Following plodding, the soap was 
extruded, cut and formed into bars. 
EXAMPLE II 
Soap bars prepared in accordance with EXAMPLE I were graded for bar feel 
according to the following scale: 
______________________________________ 
BAR FEEL GRADING SCALE 
DRAG GRIT 
______________________________________ 
10 Perfectly smooth and slippery 
no specks 
9 Practically smooth or 
one speck 
8 Barely detectable sandiness, roughness, draginess 
2-3 specks 
7 Slight sandiness, roughness, draginess 
4-5 specks 
6 Moderate overall sandiness, roughness, draginess 
6-10 specks 
5 Quite noticeable overall sandiness, roughness 
10-20 specks 
4 Pronounced overall sandiness or roughness 
&gt;20 specks 
3 Pronounced overall coarse sandiness or roughness 
-- 
2 Extreme overall course sandiness or roughness 
-- 
1 Extreme overall abrasive roughness 
-- 
______________________________________ 
A bar is graded according to the foregoing scale in which a grade of "10" 
indicates that the bar is perfectly smooth and slippery and has no specks 
of grit. 
A skilled operator runs the grading test. Water at 70.degree. F. is 
constantly run into a basin in a manner such that the water temperature is 
kept at a constant 70.degree. F. The operator takes the sample bar in 
his/her hands, and washes with the bar while keeping the bar submerged in 
the 70.degree. F. water. The bar is rotated in the operator's hands about 
60 to 70 times per minute. After about 15 seconds, the operator begins the 
grading, and this is continued for about one minute. A final grade is then 
given to the bar. 
The bars produced in accordance with Example I were grade "10" indicating 
that the bars were perfectly smooth and free of grit.