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Description  |
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FIELD OF THE INVENTION
This invention pertains to personal cleansing compositions for personal
washing, which compositions comprise quaternary amine polymers.
BACKGROUND OF THE INVENTION
Liquid and solid bar compositions based on soap and/or synthetic
surfactants are commonly used for cleansing the human body. A wide variety
of additives have been suggested for inclusion in said compositions. Some
enhance the physical properties, e.g., bar hardness, wear rate, resistance
to water. Others enhance the in-use properties such as lather
characteristics and some impact on the impression the composition has on
the skin both during washing (bar feel) and afterwards.
It has been discovered that the addition of certain polymeric materials to
such liquids and bars can have a beneficial skin mildness effect for the
user without deleteriously affecting other product properties. In general,
the useful polymers should be soluble or dispersible in water to a level
of at least 1% by weight, preferably at least 5% by weight at 25.degree.
C. Suitable polymers are high molecular weight materials (mass-average
molecular weight determined, for instance, by light scattering, being
generally from about 20,000 to about 5,000,000, preferably from about
50,000 to about 4,000,000, and more preferably from about 500,000 to about
3,000,000) and preferably have a thickening ability such that a 1%
dispersion of the polymer in water at 20.degree. C. exceeds about 1 PaS(1O
poise) at a shear rate of 10.sup.-2 sec.sup.-1 Useful polymers are the
cationic, nonionic, amphoteric, and anionic polymers useful in the
cosmetic field. Preferred are cationic and nonionic resins and mixtures
thereof. Highly preferred are the cationic resins.
To date the preferred cationic polymers include cationic guar gums such as
hydroxyproxyltrimethylammonium guar gum.
However, it has been discovered that there is an odor problem with using
such "cationic trimethylamine quaternized polymers" in compositions having
a pH of 7.5 or above. They break down and release odoriferous labile
amines.
Odoriferous labile amines are detectable at levels as low as 2 ppb.
Personal cleansing products containing odoriferous quaternary amine
polymers are disclosed in one or more of the following patents:
______________________________________
Pat. No. Date Inventor(s)
______________________________________
US 3,761,418 9/1973 Parran, Jr.;
US 4,234,464 11/1980 Morshauser;
US 4,061,602 12/1977 Oberstar et al.;
US 4,472,297 9/1984 Bolich et al.;
US 4,491,539 1/1985 Hoskins et al.;
US 4,540,507 9/1985 Grollier;
US 4,673,525 6/1987 Small et al.;
US 4,704,224 11/1987 Saud; and
Jap. J57105 6/30/82 Pola.
______________________________________
All of the above patents are hereby incorporated herein by reference,
especially their for basic personal cleansing product and quat polymer
disclosures.
SUMMARY OF THE INVENTION
The present invention relates to a personal cleansing product made with a
selected quaternized cationic polymer wherein each quaternary ammonium
moiety is derived from a bulky amine. The preferred product is a toilet
bar.
OBJECTS OF THE INVENTION
An object of the present invention is to provide an improved toilet bar,
preferably a soap bar, comprising a cationic polymeric skin conditioning
agent which does not comprise a potential odoriferous amine moiety.
Other objects will become apparent from the detailed description below.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises basic personal cleansing compositions
comprising from about 0.2% to about 5% by weight selected cationic polymer
wherein each cationic group is derived from a "bulky" amine. Compared to
personal cleansing compositions which are prepared with cationic polymers
which comprise a potential labile amine moiety, e.g., trimethylamine-based
cationic polymers, the compositions of this invention consistently exhibit
superior odor stability due to the selected "bulky amine" cationic
polymers. The term "basic personal cleansing compositions" as used herein
means that the composition has a pH of at least about 7.5, preferably at
least about 8.5.
While not being bound to any theory, illustrations A and B show the
theoretical degradation of labile amine containing cationic polymers in a
basic environment. Generic degradation:
Polymer-CHR--CH.sub.2 --N.sup.+ (CH.sub.3).sub.3
.fwdarw.polymer--CR.dbd.CH.sub.2 +N(CH.sub.3).sub.3 (A)
where R can be meant to represent any group (e.g., H, OH, alkyl chain);
e.g.,
Guar-CH.sub.2 --O--CH.sub.2 --C--H(OH)--CH.sub.2 --N.sup.+ (CH.sub.3).sub.3
.fwdarw.Guar-CH.sub.2 --O--CH.sub.2 C(OH).dbd.CH.sub.2 +N(CH.sub.3).sub.3
(B)
The extent of this degradation and the effect of it on product odor were
not appreciated heretofore. The level of hydration required to cause a
problem is very low and therefore it is extremely difficult to detect and
identify the offending material.
The Bulky Amine Cationic Polymers
Bulky amine polymers are defined herein as POLYMERS with the following
non-labile cationic functional group:
(I) (POLYMER)--CR.sup.1 H--CR.sup.2 R.sup.3 --NR.sup.4 R.sup.5 R.sup.6
wherein R.sup.1 -R.sup.3 is H or any other substituent and R.sup.4,
R.sup.5 and R.sup.6 combine with N to form a pendant amine which when free
has less odor impact than trimethylamine, preferably at least one of
R.sup.4, R.sup.5 and R.sup.6 is alkyl having a chain length of from about
2 to about 24 carbon atoms, or an alkoxy alkyl group containing from about
2 to about 12 carbon atoms.
Some examples of preferred bulky amine polymers are cationic guar gums
having the following structures;
##STR1##
An example of a bulky amine hydroxyethyl cellulose (HEC) polymer is:
##STR2##
These "bulky amine" groups add additional complexity to the preparation of
the polymer and the finished compositions. They would not be used, except
for the existence of the odor problem with the trimethylamine derived
polymer. They may also have improved skin conditioning benefits.
The composition of this invention preferably comprises from about 0.2% to
about 5%, preferably from about 0.5% to about 2%, of the cationic polymer.
The average molecular weight of the preferred cationic guar gum is from
about 50,000 to about 1,000,000, preferably from about 100,000 to about
500,000, and more preferably from about 250,000 to about 400,000 and the
degree of substitution is from about 0.5 to about 4, preferably from about
1 to about 2.5. Some preferred cationic guars (galactomannans) are
disclosed in U.S. Pat. No. 4,758,282, Stober et al., issued Jul. 19, 1988,
incorporated herein by reference. The cationic guar gum polymers disclosed
in commonly assigned U.S. patent application Ser. No. 07/266,039, J. R.
Knochel and P. E. Vest, filed Nov. 2, 1988, would be suitable when the
cationic groups are substituted with bulky amine groups.
Other bulky amine cationic polymeric skin conditioning agents useful in the
present invention have molecular weights of from 1,000 to 3,000,000.
Useful polymers are 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 any other
synthetic polymer containing pendant quaternary amine groups, e.g.,
quaternized silicones and quaternized methacrylates.
Specific examples of members of the bulky amine cationic polysaccharide
class include the cationic hdyroxyethyl cellulose, e.g., LM-200 made by
Union Carbide Corporation.
The cationic copolymers of saccharides and synthetic cationic monomers
useful in the present invention encompass those containing the following
saccharides: glucose, galactose, mannose, arabinose, xylose, fucose,
fructose, glucosamine, galactosamine, glucuronic acid, galacturonic acid,
and 5 or 6 membered ring polyalcohols. Also included are hydroxymethyl,
hydroxyethyl and hydroxypropyl derivatives of the above sugars.
The boiling points of some exemplary substituted amines are set out in
Table 1.
TABLE 1
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Eliminated Amine Boiling Point/.degree.C.
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Labile Amine
Trimethylamine 3
Bulky Amine
Dimethylethylamine
36
Methyldiethylamine
63
Triethylamine 89
Dimethyloctylamine
195
Dimethylcyclohexylamine
158
Dimethylbenzylamine
183
Dimethylethanolamine
133
Diethylethanolamne
161
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For a homologous series of compounds (e.g., tri-substituted amines),
volatility decreases with increasing molecular weight. Volatility is
dependent, among other things on the boiling point of the neat component.
Odor impact also has a strong dependence on the amount of volatilized
material that reaches the nose. Table 1 demonstrates the significant
effect which adding "bulky" groups has on volatility and, hence, odor
impact of amines. For pure hydrocarbon substitution, the larger the alkyl
chains (or the larger than degree of long chain substitution) the lower
the odor impact. Thus, bulky amines have boiling points of greater than
ambient temperature, and preferably at least about 30.degree. C., more
preferably more than about 80.degree. C.
The Surfactant Component
The surfactant component of the present compositions comprises alkali metal
soap or synthetic surfactant or mixtures thereof.
Alkali metal soaps can be made by direct saponification of the fats and
oils or by the neutralization of the free fatty acids which are prepared
in a separate manufacturing process. Particularly useful are the sodium
and potassium salts of the mixtures of fatty acids derived from coconut
oil and tallow, i.e., sodium and potassium tallow and coconut soaps.
The term "tallow" is used herein in connection with fatty acid mixtures
which typically have an approximate carbon chain length distribution of
2.5% C.sub.14, 29% C.sub.16, 23% C.sub.18, 2% palmitoleic, 41.5% oleic and
3% linoleic. (The first three fatty acids listed are saturated.) Other
mixtures with similar distribution, such as the fatty acids derived from
various animal tallows. The tallow can also be hardened (i.e.,
hydrogenated) to convert part or all of the unsaturated fatty acid
moieties to saturated fatty acid moieties.
When the terms "coconut oil" and "coconut fatty acid" (CNFA) are used
herein, they refer to fatty acid mixtures which typically have an
approximate carbon chain length distribution of about 8% C.sub.7, 7%
C.sub.10, 48% C.sub.12, 17% C.sub.14, 9% C.sub.16, 2% C.sub.18, 7% oleic,
and 2% linoleic. (The first six fatty acids listed are saturated.) Other
sources having similar carbon chain length distribution such as palm
kernel oil and babassu kernel oil are included with the terms coconut oil
and coconut fatty acid.
A preferred soap bar of this invention comprises soap as its primary or
sole surfactant It also contains as an essential ingredient a skin
conditioning amount of a hydrated, cationic guar gum provided by a
cationic guar gum polymer. This polymer is uniformly distributed in the
soap bar matrix without affecting the smooth feel of the dry or wet bar.
Another preferred toilet bar is based on mild synthetic surfactants as
disclosed in commonly assigned U.S. Pat. No. 4,673,525, Small et al.,
issued Jun. 16, 1987, incorporated herein by reference.
Synthetic detergents can also be present in compositions herein. Preferred
types of synthetic detergents are of the anionic or nonionic type.
Examples of anionic synthetic detergents are the salts of organic sulfuric
reaction products such as
alkyl sulfates having the formula R.sub.24 OSO.sub.3 M;
alkyl sulfonates having the formula R.sub.24 SO.sub.3 M;
alkyl ether sulfates having the formula R.sub.24 (OC.sub.2 H.sub.4).sub.x
OSO.sub.3 M;
alkyl mono glyceride sulfonates having the formula
##STR3##
and alkyl benzene sulfonates having the formula
##STR4##
In the above formulae, R.sub.24 is a straight or branched chain alkyl of
from about 8 to about 24 carbon atoms; M is an alkali metal or ammonium
ion; x is a number of from 1 to about 10; y is a number of from 1 to 4;
and X is selected from the group consisting of chlorine, hydroxyl, and
-SO.sub.3 M, at least one X in each molecule being -SO.sub.3 M. Examples
of nonionic synthetic detergents are ethoxylated fatty alcohols (e.g., the
reaction product of one mole of coconut fatty alcohol with from about 3 to
about 30 moles of ethylene oxide) and fatty acid amides such as coconut
fatty acid monoethanolamide and stearic acid diethanolamide. Although it
may be desirable in some instances to incorporate synthetic detergents
into the compositions of the present invention, the compositions herein
can be free of synthetic detergents. Preferred are the mild synthetic
surfactants disclosed in U.S. Pat. No. 4,673,525, Small et al., issued
Jun. 16, 1987, incorporated herein by reference.
Insoluble Alkaline Earth Metal Soaps
Insoluble alkaline earth metal soaps such as calcium stearate and magnesium
stearate can also be incorporated into compositions of the present
invention at levels up to about 30%. These materials are particularly
useful in toilet bars in which synthetic detergents are present in that
they tend to reduce the relatively high solubility which such bars
normally have. These alkaline earth metal soaps are not included within
the term "soap" as otherwise used in this specification. The term "soap"
as used herein refers to the alkali metal soaps.
Optional Components
The compositions of the present invention can contain optional components
such as those conventionally found in personal cleansing products.
Conventional antibacterial agents can be included in the present
compositions at levels of from about 0.5% to about 4%. Typical
antibacterial agents which are suitable for use herein are 3,4-di and
3,4',5-tribromosalicyla-anildes;
4,4'-dichloro-3-(trifluoromethyl)carbanilide; 3,4,4'-trichlorocarbanilide
and mixtures of these materials. Conventional nonionic emollients can be
included as additional skin conditioning agents in the compositions of the
present invention at levels up to about 40%, preferably at levels of from
about 1% to about 25%. Such materials include, for example, mineral oils,
paraffin wax having a melting point of from about 100.degree. F., fatty
sorbitan esters (see U.S. Pat. No. 3,988,255, Seiden, issued Oct. 26,
1976, incorporated by reference herein), lanolin and lanolin derivatives,
esters such as isopropyl myristate and triglycerides such as coconut oil
or hydrogenated tallow.
Free fatty acid such as coconut fatty acid can be added to the compositions
herein to improve the volume and quality (creaminess) of the lather
produced by the compositions herein.
Conventional perfumes, dyes and pigments can also be incorporated into
compositions of the invention at levels up to about 5%. Perfumes are
preferably used at levels of from about 0.5% to 3% and dyes and pigments
are preferably used at levels of from about 0.001% to about 0.5%.
Bar Preparation
Toilet bars of the present invention can be prepared in any conventional
manner. E.g., the bulky amine cationic polymer can be added to noodles of
the base soap mixture containing from about 10% to about 22% moisture in
an amalgamator. Any optional ingredients such as perfumes, dyes, etc., are
also added to the amalgamator. The mixture is processed in the amalgamator
and milled in the conventional manner under conventional conditions. It is
then extruded (plodded) into logs for cutting and stamping into toilet
bars.
In a method of making the bar of the present invention, the bulky amine
cationic polymer is added to soap noodle and mixed in the soap mixing
steps of the soap bar making process.
The soap bars of this invention preferably contain up to 20% of a synthetic
surfactant. If a synthetic surfactant is included, a mild one is
preferred. A mild synthetic surfactant is defined herein as one which does
relatively little damage to the barrier function of the stratum corneum.
The mild surfactant is preferably used at a level of 0-20%, preferably
about 2-15%. The fatty acid soap and mild surfactant mixture preferably
has a ratio of 2.5:1 to 37:1, preferably from 2.5:1 to 14:1, and most
preferably from 6.5:1 to 14:1, soap:synthetic.
A preferred soap bar of this invention also contains from about 2% to about
17% moisturizer, preferably one selected from glycerin and free fatty acid
or mixtures thereof. The more preferred bar of this invention contains at
least 4% moisturizer.
Some preferred mild synthetic surfactants useful in this invention include
alkyl glyceryl ether sulfonate (AGS), anionic acyl sarcosinates, methyl
acyl taurates, N-acyl glutamates, alkyl glucosides, acyl isethionates,
alkyl sulfosuccinate, alkyl phosphate esters, ethoxylated alkyl phosphate
esters, alkyl ether sulfates, methyl glucose esters, protein condensates,
mixtures of alkyl ether 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 chain lengths for these surfactants are
C.sub.8 -C.sub.22, preferably C.sub.10 -C.sub.18. The most preferred mild
surfactant is sodium CN AGS.
The following examples are presented by way of illustration only.
EXAMPLES 1 AND 2
Toilet bars made using the ingredients set out in Table 2.
TABLE 2
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Ex. 1 Ex. 2
Ingredient Parts Parts
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Sodium Tallowate.sup.(1)
32.90 32.90
Sodium Cocoate.sup.(1)
32.90 32.90
Water 9.50 9.50
Sodium Cocoglyceryl Ether
8.80 8.80
Sulfonate (AGS)
Glycerin 4.00 4.00
Coconut Fatty Acid 3.80 3.80
Triclocarban 1.50 1.50
Sodium Chloride 1.20 1.20
Fragrance 1.20 1.20
Polyquaternium-7.sup.(2)
1.00 1.00
LM-200.sup.(3) 1.00 --
Guar-HPTC.sup.(4) -- 1.00
Titanium Dioxide 0.35 0.35
Tetrasodium EDTA 0.06 0.06
BTH.sup.(5) 0.02 0.02
Miscellaneous.sup.(6)
* *
Totals 100.00 100.00
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.sup.(1) The values stated for sodium tallowate and sodium cocoate includ
a low level (>0.1%) of unsaponifiable material.
.sup.(2) The trade name for Polyquaternium7 is Meraquat 500.
.sup.(3) LM200 is a cationic cellulosic polymer comprising a bulky cocoyl
amine.
.sup.(4) Guar HPTC is guar hydroxypropyltriammonium chloride is Jaguar C1
(HiTek). Molecular weight is about 200,000 .+-. 75,000.
.sup.(5) BHT is included in the respective perfume formulas to impart
preservative/antioxidant properties both to the perfume and to the
finished bar formula.
.sup.(6) "Miscellaneous" includes a low level of sodium sulfate and
unsulfonated alcohol which come in, e.g., as a byproduct of the AGS
stream.
In general, making procedures common to those used for conventional toilet
soap bar making are employed.
Mixing/Milling Steps
Polymer Addition Step
Plodded soap noodles are conveyed to a continuous mixer (CM) where
approximately 1.0 part of cationic polymer is introduced, mixed, and
plodded with the soap noodles. Uniform distribution during this addition
and mixing step is important for acceptable bar feel performance. The
polymer/soap noodles (generic noodles) are conveyed to milling.
Generic Milling Step
Two four-roll soap mills (feed, stationary, middle, and top rolls) are used
in this step. This is a split milling (two set of mills are used in
parallel) process to obtain a homogeneous mix. Efficient milling is needed
in this intimate mixing step.
Dry Mixing Step
The generic noodles are conveyed to a second process system continuous
mixer (CM) for the addition and mixing of other minors. This mix is
plodded and conveyed to the third process CM.
Wet Mixing Step
The perfume and NaCl/sodium ethylene diamine tetra acetate (EDTA) solution
are added and mixed in this wet mixing (CM) step. This finished soap
formula is then plodded into soap noodles and conveyed via a transport
plodder to a final milling step.
The mixture is milled using a four-roll mill, plodded, and then stamped
into toilet bars of any convenient size and shape. The resulting bars are
tested for odor. The bars have a pH of 9.5 in a 1% aqueous solution.
Odor Test Procedure
Polymer Cleaning
Stock samples of polymer are cleaned by swelling the polymer with water
followed by extensive aeration. These "cleaned" polymers are fairly amine
odor-free. After long storage times, some of these polymers exhibited a
slight, but recognizable amine odor. Bulky modified polymers required
little, if any, cleansing prior to testing/evaluating.
Effects Testing Procedures
The general procedure followed in evaluating the effects of pH on polymer
or final product odor was to place about 200 mg of the clean polymer (or a
finished product) in a screw-top vial (8 dram) and then add the test
solution (buffers at pH values of 7, 10, or 14). The vials are capped and
the odor allowed to build up for a short amount of time. Odor is evaluated
via olfactory sensing by a panel of experts.
The pH buffers are commercially available buffers:
pH 7--KH.sub.2 PO.sub.4 --NaOH
pH 10--H.sub.3 BO.sub.3 --KOH
pH 14--1N NaOH.
TABLE 3
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Odor Evaluation of Polymers and Products Under
Induced Alkaline Conditions (pH.about.10-14)
Polymer/Product Odor Evaluation
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JR-400 Strong amine odor
Jaguar C-15 Strong amine odor
LM-200 No amine odor
Product of Ex. 1 No amine odor
Product of Ex. 2 Strong amine odor
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Note:
Ex. 1 product produced with LM200
Ex. 2 product produced with Jaguar
JR-400 made by Union Carbide Corporation and JAGUAR C-15 made by Hi-Tek
Polymers, Inc., are outside the selected polymers of this invention.
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Description |
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