CA1242950A - Liquid cleansing compositions - Google Patents

Abstract

LIQUID CLEANSING COMPOSITIONS

ABSTRACT
Liquid cleansing compositions which are cosmetically attractive, stable and which also have excellent performance properties. The compositions contain a water-soluble cellulose polymer, a solvent, a synthetic surfactant, and water as essential components and have a neat viscosity (100%) of 2,000 to 12,000 cps and a dilute viscosity (50%) of 15 to 95 cps. The compo-sitions also contain a very low level of electrolytes.

Description

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Robert J. Maile, Jr.
TECHNICAL FIELD
The present invention is related to liquid cleansing products, especially bath/shower compositions which contain a cellulose polymer as a thickening/skin feel aid and a solvent for viscosity control and phase stability.
BACKGROUND ART
The use of thickeners in liquid personal cleansing compo-sitions is well known. U.S. Pat. Nos. disclosing such compo-sitions are 3,697,644, Ortober 10, 1972 to Laiderman; 3,932,610, January 13, 1976 to Rudy et al.; 4,031,306, June 21, 1977 to DeMartino et al.; and 4,061,602, December 6, 1977 to Oberstar et al .
It is also known that liquid personal cleansing products can be thickened by:
a. Using polymeric additives that hydrate, swell or moiecularly associate to provide body ~e.g., hydroxy-propyl guar gum is used as a thickening aid in shampoo compositions~. *
b. Using a combination of tarbopol (an acrylic acid poly-mer~ and guar gum derivatives (e.g., using combina-tions of ~arbopol and Jaguar HP-60 gum/guar gum derivatives to provide thickening and soft silky skin feel, as well as shelf stability).
c. Adding electrolytes, such as using NaCI to swell mi-celles to provide body.
While it is known to use thickeners in liquid cleansing corn-positions, there is no teaching or suggestion of certain problems 30 encountered with cellulose polymers in making stable, good per-forming liquid cleansing bath/shower compositions, or solutions thereto .
Specifically, there are no suggestiuns ~r incorporating the soivents used in this invention into such compositions to obtain 35 satisfactory stable products.
It is, therefore, an object of the present invention to * Trad~nark ** Trademark 35~) provide cellulose polymers containing liquid cleansing bath/shower compositions which are phase stable and cosmetically attractive.
It is a further ~bject of the present invention to provide liquid cleansing compositions which are clear as well as stable.
It is still a further object of the present invention to provide liquid cleansing compositions which deliv~r satisfactory skin feel and rinse properties.
These and other objects of the present invention will become obvious from the detailed description which follows.
BRIEF DESCRIPTION OF THE FIGURE
The Figure shows four viscosity curves for five products vs. product concentration. Curve 1 represents Example A;
Curve 2 represents Example l l; Curve 3 represents Examples I (same as Example B) and lll; and Curve 4 Example C. The five product formulations are found in the examples.
Curve 1 represents a product which has a high degree of slipperiness but is difficult to rinse. Curves 2 and 3 represent products which have the desired degree of slipperiness and ease of rinsing. Curve 4 represents a product which has a low degree of slipperiness, bu~ which is easy to rinse.
SUMMARY OF THE INVENTION
me present invention relates to liquld personal cleansing compositions consisting essentially of fram about 0.1% to about 1.5% of a water-soluble cellulose polymer consisting of nonionic and anionic cellulosic polymer such as hydroxymethyl-, hydroxyethyl-, hydroxypropyl-, hydroxybutyl methyl-, carboxymethyl cellulose, and the like, and mixtures thereof, fram about 0.5% to about 20% of a solvent consisting of ethylene glycol or propylene glycol (the moncmers) or polyoxyethylene glycol or polyoxypropylene glycol (considered as polymeric forms of ethylene glycol and propylene glycol, respectively) or the mixed block copolymers of polyoxyethylene glycol and polyoxypropylene glycol and muxtures thereof, from about 10% to about 50% of a synthetic surfactant, and frQm about 50% to about 80% of water. The liquid cleansing composition has a neat (100%) viscosity of 2,000-12,000 cps and a dilute (50%) viscosity of 15-95 cps. The compositions must contain less than 1% electrolyte.

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26~:35~

DETAILED DESCRIPTI()N OF THE INVENTION
An important attribute of a personal cleansing product is the feel of the product in use. This feel can be described as soft, silky and slippery. Another important attribute is the ease of 5 rinsing of the product while in use. A poor rinsing product can be described as one in which there is a prolonged feeling of slipperiness and slickness during the rinsing process.
It has been discovered that the slipperiness and ease of rinsing of a product can be related in part to the viscosity of the 10 solution of the product in water as it is diluted. This can be -~ used to help describe products which have the desired level of skin feel and ease of rinsing characteristics for certain end uses.
The desired product must then be ~ormulated to provide the desired ditute viscosity curve which controls skin feel and rinsing 15 in use, the desired neat viscosity, the desired amount of lather in use and a stable product that does not separate or change in neat viscosity while stored.
It has been found that products with high dilution viscosity curves are desirable to most women and disliked by most men 20 because the product imparts a high degree of slipperiness and silkiness, i.e., suitable for feminine use but not by both sexes.
In addition, these produc~s are difficult to rinse for the same reasons. On the other hand, products that have low dilution viscosity curves provicle insufficient silky, slippery feel for both 25 men and women, but are very easy to rinse.
This invention relates to shelf stable products with desirable neat viscosity, using selected thickeners, e.g., hydroxyethyl cellulose, and selected solvents, e.g., polyoxyethylene or propy-lene glycol. The products are stable and provide a desirable 30 level of skin feel for both men and women by controlling the viscosity upon dilution relationships.
It is known to use "Jaguar HP-60" polymer ~hydroxypropyl guar gum, rnolar substitution = 0.6) in a personal cleansing product. This provides a high dilu~ion viscosity curve desirable ~5 to most women and undesirable to most men. It is also known to use a combination of "Carbopol"and"Jaguar HP-60" and other guar * Trademark ~2~2~5~

gum derivatives which provide so~ silky skin feel that are shelf stable. These formulations though do not provide the desired dilute viscosity and control of skin feel achieved in this development.
The terms "Neat Viscosity" and "I)ilute Viscosity" as used herein are defined according to the method taught herein, unless otherwise indicated.
Cellulosic Th:ckeners The cellulosic thickeners in this inventlon are categorized as nonionic or anionic and are selected to provide the desired viscosities. Suitable cellulosic thickeners are listed in the Glossary and Chapters 3, 4, 12 and 13 of the Handbook of Water-Soluble Gums and Resins, Robert L. Davidson, McGraw-Hill Book Co ., New York, N . Y ., 1980, The nonionic cellulosic thickeners include, but are not limited to, the following polymers:
1. hydroxyethyl cellulose;

2. hydroxymethyl cellulose;

3. hydroxypropyi cellulose; and

4. hydroxybutyl methyl ce~ ose~
The anionic cellulosic thickener includes carboxymethyl cellulose and the I ike .
The preferred thickener i5 hydroxyethyl cellulose, which is made by treating cellulose with sodium hydroxide and reacting 25 with ethylene oxide. Hydroxyethyl groups ~molar substitution 1.5 to 3, preferably 2 to 3) are introduced to yield a hydroxyethyl ether. The reaction product is purified and ground to a fine white powder.
The amount of cellulosic thickener found useful in the pres-30 ent compositions is about 0 .1% to about 1 . 5%, preferably fromabout 0.1% to about 1.0%. The thickeners are used in combination with the solvent to produce the neat and dilute viscosities of 2,000 ~o 12,000 cps and 15 to 95 cps, respectively, preferably 4,00û to lû,000 cps and 20 to 60 cps, respectiveiy.
35 Solvent A second essential component of the present compositions is a ~L2~2~35~

solvent consisting of ethylene glycol or propylene glycol (the monomers) or polyoxyethylene glycol or polyoxypropylene glycol (considered as a polymeric form of ethylene glycol or propylene glycol) or the mixed block copolymers of polyoxyethylene glycol

5 and polyoxypropylene glycol and mixtures thereof. The polymeric forms of solvent have àn average molecular weight in the range of from about 200 to about 10,000, preferably 400 to 800. The solvent is present a~ a level of from about 0 . 5g6 to about 20%, preferably from about 1% to about 10% in the present 10 compositions.
Surfactant The third essential component of the present compositions is a surfactant. The surfactant, which may be selected from any of a wide variety of anionic (nonsoap), amphoteric, zwitterionic, 15 nonionic and, in certain instances, cationic surfactants, is pres-0nt at a level of from about 1096 to about 50%, preferably from about 10% to about 30~.
Anionic nonsoap surfactants can be exemplified by the alkali metal salts of organic sulfuric reaction products having in their ~0 molecular struc~ure an alkyl radical containing from 8 to 22 car-bon atoms and a sulfonic acid or sulfuric acid es~er radical (included in the term alkyl is the alkyl portion of higher acyl radicals). Preferred are ~he sodium, ammonium, potassium or triethanolamine alkyl sulfates, especially those obtained by sul-25 fating the higher alcohols (C8-C18 carbon a~oms~, sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulf~ric acid esters of the reaction product of 1 mole of a higher ~atty alcohol (e.g., tallow or coconut oil alcohols) and 1 to 12 moles of ethylene oxide; sodium or potassium 30 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 neu-35 tralized with sodium hydroxide; water soluble salts of conden-sation products of fatty acids with sarcosine; and others known in the art.

Nonionic surfactants can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydro-philic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. Examples of pre-ferred classes of nonionic surfactants are:
1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of aikyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 60 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.
2. Those derived from the condensation of ethylene oxide with the product resulting from the reaction of pro-pylene oxide and ethylene diamine products which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 40% to about 80% polyoxyethylene by weight and having 3 molecular weight of from about 5,000 to about 1 1,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess pro-pylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.
3. The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration with ethylene oxide, e.g., a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms. Other ethylene oxide condensation products are ethoxylated fatty acid esters of polyhydric ~2~2~

alcohols (e.g., ITween 20-polyoxyethylene 120) sorbitan monolaurate) .
4. Long chain tertiary amine oxides corresponding to the following general formula:
R1 R2R3N ~ O
wherein R1 contains an alkyl, alkenyl or monohydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide rnoieties, and from 0 to 1 glyceryl moiety, and R2 and R3 contain from 1 to about 3 carbon atoms and from 0 ~o about 1 hydroxy ~-- group, e.g., methyl, ethyl, propyl, hydroxy ethyl, or hydroxy propyl radicals. The arrow in the ~ormula is a conventional representation of a semipolar bond. Ex-amp1es of amine oxides suitable for use in this invention include dimethyldodecylamine oxide, oie~rldi(2-hydroxy-ethyl~ amine oxide, dimethyloctylamine oxide, dimethyl-decylamine oxide, dimethyltetradecylamine oxide, 3,6,9-trioxa heptadecy ld iethy lami ne ox ide, d i ( 2-hyd roxyethy l 1-tetradecylamine oxide, 2-dodecoxyethyldimethylamine oxide, 3-dodecoxy-2-hydroxypropyldi (3-hydroxypropyl)-amine oxide, dimethylhexadecylamine oxide.
5. Long chain tertiary phosphine oxides corresponding to the following general formula:
RR' R" P ~ O
wherein R contains an alkyl, alkenyl or monohydroxy-alkyl radical ranging from 8 to 18 carbon atoms in chain length, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and R' and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a con-ventional representation of a semipolar bond. Examples of suitable phosphine oxides are: dodecyldimethylphos-phine oxide, tetradecylmethylethylphosphine oxide, 3,6,9-trioxaoctadecyldimethylphosphine oxide, cetyl-dimethylphosphine oxide, 3-dodecoxy-2-hydroxypropyl-di~2-hydroxyethyl) phosphine oxide stearyldimethyl-phosphine oxide, cetylethylpropylphosphine oxide, * Trad~[nark ., , .

.9S~

oleyldiethyiphosphina oxide, dodecyldiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipro-pyl phosphine oxide, dodecy Id i ( hydroxymethyl ) phosph ine oxide, dodecyldi(2-hydroxyethyl)phosphine oxide, tetra-decylmethyl-2-hydroxypropylphosphine oxide, oleyldi-methylphosphine oxide, 2-hydroxydodecyldimethylphos-phine oxide.

6. Long chain dialkyl sulfoxides containing one short chain alkyl or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually methyl) and one long hydrophobic chain which contain alkyl, alkenyl, hydroxy alkyl, or keto alkyl radicals containing from about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryi moiety. Exampies include: octadecyl methyl sulfoxide, 2-ketotridecyl methyl sulfoxide, 3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide, dodecyl methyl sulfoxide, oleyl 3-hydroxy-propyl sulfoxide, tetradecyl methyl sulfoxide, 3-methoxytridecyl methyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl sulfoxide .
Zwitterionic surfactants can be exemplified by those which can be broadly described as derivatives of aliphatic 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 phos-phonate. A general formula for these compounds is:
(R3) R - Y ( ) - CH 2 ~ R4 - Z ( ~ ) wher~in R contains an alkyl, alkenyl, or hydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethyl-35 ene oxide moie~ies ancJ from 0 to 1 glyceryl moiety; Y is selectedfrom the group consisting of nitrogen, phosphorus, and sulfur atoms; R is an alkyl or monohydroxyalkyl group containing 1 to 35~

about 3 carbon atoms; X is 1 when Y is a sulfur atom and 2 when Y ss a nitrogen or phosphorus atom; R is an alkylene or hy-droxyalkylene of from 1 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sul-fonate, sulfate, phosphonate, and phosphate groups.
Examples include: 4-[N,N-di(2-hydroxyethyl)-N-octadecyl-ammonio ] -butane- 1 -ca rboxy I ate; 5- [ S-3-hyd roxypropyl -S-hexade-cy I su I fon io ] -3 -hyd roxypenta ne- 1 ~su I fate; 3- [ P, P- P-d iethy I - P-3, 6, 9-trioxatetradexocylphosphonio]-2-hydroxypropane-1 -phosphate;
3- [ N, N-di propyl-N-3-dodecoxy-2-hydroxypropy lammonio ] -propane-_ 1 -phosphonate; 3- ( N, N -d imethy 1- N -hexadecy lammon io ) propane- 1-sulfonate; 3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypro-pane-1-sulfonate; 4-[N,N-di(2-hydroxyethyl)-N-(2-hydroxydode-cyl)ammonio]-butane-1-carboxylate; 3-lS-ethyl-S-~3-dodecoxy-2-1 5 hyd roxyp ropyl ) su I fon io ] -propane- 1 -phosphate; 3- ( P, P-d imethy I -P-dodecy Iphosphonio) -propane-1 -phosphonate; and 5- [ N, N-d i ~ 3-hy-droxypropyl )-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 ter-tiary amines in which the aiiphatic 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-dodecylarninopropionate, sodiurn sodium 3-dodecylaminopropane suifonate, 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 trad~nark "Miranol" and described in U.S. Pat.
No. 2,528,378. Other amphoterics such as betaines are also useful in the present composition.
Exarnples of betaines useful herein include the high alkyl betaines such as coco dimethyl carboxymethyl betaine, lauryl ~ZI .~ d dimethyl carboxymethyl betaine, lauryl dimethyl alpha-carboxy-ethyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, stearyl bis-[2-hydroxy-propyl) carboxymethyl betaine, oleyl dimethyl gamma-carboxy-5 propyl betaine, lauryl bis-(2-hydroxypropyl) alpha-carboxyethyl betaine, etc. The sulfo-betaines may be represented by coco dimethyl sulfopropyl betaine, stearyl dimethyl sulfopropyl betaine, lauryl bis-(2-hydroxyethyl) sulfopropyl betaine, amido betaines amidosulfobetaines, and the like.
Many cationic surfactants are knc~wn to the art. By way of example, the following may be mentioned:
stearyldimethyl~en~yl ammonium chloride;
dodecyltrirnethylammonium chloride;
nonylbenzylethyldimethyl ammonium nitrate;
tetradecylpyridinium bromide;
laurylpyridinium chloride;
cetylpyridinium chloride;
laurylpyridinium chloride;
laurylisoquinoiium bromide;
ditallow~hydrogenated)dimethyl ammonium chloride;
dilauryldimethyl ammonium ch'oride; and stearalkonium chloride.
Many additional nonsoap surfactants are described in McCUTCHEON'S, DETFRGENTS AND EMULSIFIERS, 1979 ANNUAL, 25 published by Allured Publishing Corporation~

The above-mentioned surfactants can be used in the liquid cleansing bath/shower compositions of the present invention. The anionic surfactants, particularly the alkyl sulfates, the ethoxy-30 lated alkyl sulfates and mixtures thereof are preferred. Morepreferred are anionic surfac~ants selected from the group con-sisting of sodium alkyl glycerol ether sulfonate, sodium lauroyi sarcosina~e, sodium alkyl sulfate, sodium ethoxy (3) alkyl sulfate, and mixtures thereof.

5~

Electrolyte An additional requirement of the present compositions i5 that they contain a low level of electrolyte. Electrolytes include inorganic salts le.g., sodium chloride~ as well as organic salts 5 (e.g., sodium citrate). The amount of electrolyte varies with the ~ype of sur~actant but should not be present in finished product at a level greater than 1. 0%, preferably as little as possible and less than 0 . 5% . I n addition to the above-mentioned chloride and citrate salts, other salts include phosphates, sulfates and other 10 nalogen ion salts. The counter ions of such salts can be sodium or other monovalent cations as well as di- and trivalen~ cations.
It is recognized that these salts may cause instability if present a$ greater than 1 . 0% levels .
Aqueous Carrier .

The liquid cleansing bath/shower compositions herein are in the form of liquids in which water is the principal diluent. The level of water in the compositions is typically from about 50% to about 80%.
t)ptional Components The liquid cleansing bath/shower compositions can contain a variety of nonessential optional ingredients suitable for rendering such compositions more desirable. Such conventional optional ingredients are well known to those skilled in the art, e.g., preservatives such as benzyl alcohol, me~hyl paraben, propyl paraban and imidazolidinyl urea; other thickeners and viscosity modifiers such as C~-C1 ~ e~hanolamide (e.g ., coconut ethanol-amide) and polyvinyl alcohol; skin moisturizers such as glycerine;
pH adjusting agents such as citric acid, succinic acid, phosphoric acid , sodium hydroxide , etc.; suspending agents such as magnesium/aluminum silicate; perfumes; dyes; and sequestering agents such as disodium ethylenediamune tetraacetate.
One preferred form of the present compositions is a clear product. However, if desired, a pearlescer such as ethylene glycol distearate may be used to give the product a pearlescen$
3~ effect.

A preferred liquid cleansing product contains from about 1~6 to about 5~ of an alkanolamide of a fatty acid having from about 8 to about 18 carbon atoms.
If present, the optional components individuaily generally comprise from about 0,001% to 10.0~ by weight of the composition.
The pH of the liquid cleansing bath/shower compositions herein is generally from about 3 to about 9, preferably from about 5 to about 8.
Method of Manufacture 1 n The liquid cleansing compositions of the present invention may be made using techniques well known in the art. A suitable method is shown in Fxample 1.
Industrial Applicability The liquid cleansing compositions are useful as a cleansing aid for the entire body. The basic invention of a cellulose poly-mer thickener and solvent may also be applicable in other li~uid type products such as liquid hand soaps and light duty dish-washing liquids that require a certain degree of skin feel.
Method I - Neat Viscosity (100% Product) Operation: (Brookfield LVF-Type Viscometer) Pour approximately 140g of the finished product into a 150 ml beaker taking care to avoid trapping air bubbles. Check the product temperature with the thermometer - the temperaturP
should be between 7'1.5-75.5F. If not, a warm water or a cold water bath must be used to adjust the temperature. A common galvanized laboratory tray (depth of approximately 2~ inches) may be used. Temperatures of the baths should be 60-65F for the cold and 85-90F for the warm water. Place the beaker in the bath and stir sample gently with the thermometer, taking care to avoid generation of air bubbles. The sample is ready for analysis when a uniform temperature of 74 . 5-75 . 5F exists throughout the sample. Attach spindle #4 to the viscometer. While the tempera-ture of the sample is within the limits, carefully lower viscometer spindle #4 into the beaker. The spindle guard should not be attached. (~iote: It is important that the spindle temperature is equilibrated to room temperature before inserting into the sample;

r3n allow at least 15 minutes for temperature equilibration after washing spindle. ) Do not lower the spindle below the depth notch. If this occurs, raise the spindle and carefully wipe the shaft above the notch, then reins~rt the spindle into the sample.
Center the spindle in the beaker with the surface of the sample in the center of the spinclle depth notch. Start the viscometer motor, set at 30 rpm's, wait 15 seconds, then take a meter reading. Take two additional readings. Refer to the Brookfield viscometer manual for proper operation.
Calculations:
Calculate the viscosity of the sample as follows:
Viscosity = A x 200 A = Average of the three meter readings.
200 = Conversion factor found in the Brookfield manual for spindle #4 @ 30 rpm's.

NVTE: When reporting the viscosity of the solution, always include the temperature 74.5-75.5F (23.S-24.2C).
Method 11 - Dilute Viscosity (50g~ Product/50s~ Water~
Operation: (Brookfield LVF-Type Viscometer~
Pour 175g of finished product and 1 75g of distilled water into a 400 ml beaker. Mix by hand with stirring rod taking care to avoid air bubbles. Check the solution temperature with the thermometer - the temperature should be between 74.5-75.5F. If not, a warm water or a cold water bath must be used to adjust the temperature. A common galvanized laboratory tray (depth of approximately 2~ inches) may be used. Temperatures of the baths should be 60-65F for the coid and 85-90F for the warm water. Place the beaker in the bath and stir sample gently with the thermometer, taking care to avoid generation of air bubbles.
The sample is ready for analysis when a uniform temperature of 74.5-75. 5F exists throughout the sample. Attach spindle #I to the viscometer. While the temperature of the sample is within the ~s limits, car~Fully lower viscometer spindle #l in the beaker. The spindle guard should not be attached. ( Note: It is important 5~3 that the spindle temperature is equilibrated to room temperature before inserting into the sample; allow at least 15 minutes for temperature equilibration after washing spindle. ) Do not lower the spindle below the depth notch. If this occurs, raise the spindle and carefully wipe the shaft above the notch, then re-insert the spindle into the sample. Center the spindle in the beaker with the surface of the sample in the center of the spindle depth notch. Start the viscometer motor, set at 30 rpm's, wait 15 seconds, then take a meter reading. Take two additional readings. Refer to the Brookfield viscometer manual for proper -~ operation.
Calculations:
Calculate the viscosity of the sample as follows:
Viscosity = A x 2 A = Average of the three meter raadings 2 = Conversion factor found in the Brookfield manual for spindle #1 @ 30 rpm's.

NOTE: When reporting the viscosity of the solution, always include the temperature, 74.5-75.5F (23.6-24.2C3.
EXAMPLES
The following examples further describe and demonstrate the preferred embodiments within the scope of the present invention.
The Examples are given solely for the purpose of iliustration and are not to be construed as limitations of the present invention as many variations thereof are possible without departing from its spirit and scope. Unless otherwise indicated, all percentages and ratios herein are by weight.
In addition to the examples is a Skin Feel Test Procedure and the results thereof (Tables 1 and 2) that demonstrate the differences in both in-use slipperiness and ease of rinsing for HEC-thickened products vs. "Jaguar" and salt-thickened products.
Skin Feel Test ~Forearms) Procedu re:
Pre-~i~lasi1. Paneiists were asked to first wash both ~orearms using CAMA~ toilet bar soap. After rinsing, while the arms * Trademark ~2~

were still wet, an initial skin friction reading ~using a Skin Friction Meter, Ser. No. 595108, made by the Department of Engineering, University of Newcastle, Newcastle, England) was made on both forearrns. Two syringes were then filled with 1.û
ml of two of the three products to be tested.
In-Use Slipperiness. With arms still wet, the first product was delivered to the palm of the right hand. The product was then rubbed on the underside of the left forearm for 10 strokes (1 stroke is clefined as rubbing the forearm from the wrist to the inside crease of the elbow and back to the wrist). The second product was immediately delivered to the left palm and rubbed on the underside of the right arm for 10 strokes. At this point, a skin friction reading was taken with the products still on the arms. Results are shown in Table 1.
Ease of Rinsing. Panelists were then asked to rinse each arm separately, counting the number of bare hand strokes needed to completely rinse the product off their forearms. Results are shown in Table 2.
TAB LE
2a Skin Friction Meter Results ( In-Use Siipperiness) Skin friction data of product on skin correlate with expected in-use slipperiness based on the skin feel agents used in the following products. Examples A, B and C listed below describe the three formulas used in this test.

5~

Component A B C
Sodium Lauryl Ethoxy l3) Sulfate Solution (28.5% solution) 39,3~ 38.5% 21.5%
Sodium Lauryl Sulfate Solution (28,5% solution) 32.2 31.6 N/A
Coconut Monoethanolamide 4.0 4.0 N/A
Coconut Diethanolamide - - 2 . 2 Perfume 3,0 2.0 N/A
Ethylene Glycol Distearate 1.0 1.0 NtA
Ethylene Diamine Tetraacetic Acid 0.1 0 1 N/A
Preservatives 0.25 0.25 N/A
Color Solution 0 . 8 1 .1 N /A
Citric Acid 0.25 0.12 N/A
Sodium Chloride 0 1 0.1 0.5 "Jaguar HP-60"* 0.55 - N/A
"Natrosol 250 "* - 0. 2 N/A
Propylene Glycol 9 0 3, 0 3 . 5 Distilled Water Balance Balance Balance .
100 . 00%100 . 0096 100 . 00%
1Commercially available FA Bath Foam made by Henkel Co.
N/A = Data not available.

The Neat and Dilute Viscosities of the above liquid cleansers, Examples A, B and C, are shown in the Figure as 25 Curves 1, 3 and 4, respectively. The skin friction reduction results are as follows:
% Reduction of Skin Product Friction__h Product A - with Jaguar gum 70%
B - with HEC 62%
C - without skin feel agent (salt thickened) 54%

NOTE: Above results are based on a comple~e round robin paired comparison test using a base panel of 22-23 for each pair tested.

* Trad~mark 95~

The confidence levels of significant differences (using the Student T test) between the three products are as foilows:
Product Comparison % Confidence "Jaguar" gum vs . no skin feel 5agent (salt thickened) 99.5%
-Jaguar gum vs. HEC 96.0%
HEC vs. no skin feel agent (salt thickened) 95.0 Panelist Pcinsing Results (Ease of Rinsing~
Panelist product rinsing results correlate with expected ease of rinsing. The results are as follows:
l S Avg . No. of Strokes Req'd to Compietely Product Rinse Product A - with Saguar gum 12.2 B - w;th HEC 10.8 20C - without skin feel agent (salt thickened) 9.7 NOTE: Above results are based on a complete round robin paired comparison test using a base panel of 22-23 for 25each pair tested.

The confidence levels of significant differences between the three products are as follows:
Product Comparison % Confidence 30aguar gum vs. no skin feel agent (salt thickened) 99+%
Jaguar' gum vs. HEC 88%
HEC vs. no skin feel agent 15alt thickened) 87%

95!n EXAMPLE I
A full product formula was made with 0.2% hydroxyethyl cellulose (HEC) and 3% propylene glycol. The base formulation used in this variation contained the following ingredients:
Component Wt. Composition Sodium Lauryl Ethoxy (3) Sulfate Solution ( 28.5% solution )38 . 5%
Sodium Lauryl Sulfate Solution ~2a.5~ solution) 31.6 Coconut Monoethanolamide 4.0 - - Perfume 2, 0 Ethylene Glycol Distearate 1.0 Ethylene Diamine Tetraacetic Acid 0.1 Preservatives 0. 25 Color Solution 1.1 Citric Acid 0.12 Hydroxyethyl Cellulose (HFC) 0.2 Propylene Glycol 3 . o Distilled Water Balance 100.00%
Product Neat Viscosity = 5000 cps;
Product Dilute Viscosity = 20 cps; see Curve 3 of Figure.
'Natrosol 250 ''~egree of hydroxyethyl molar substitution =
2 . 5, supplied by Hercules I ncorporated .
The above composition was prepared in the following manner:
- A cold ( room temperature) mix was prepared by adding ingredients in the following order: 50% of the added dis-tilled water, hydroxyethyl cellulose, sodium lauryl ethoxy (3) sulfate solution and 50% of the sodium lauryl sulfate solution .
- A hot (60-71.1C, 140-160F) mix was prepared by adding ingredients in the following order: 50~ of the added distilled water, 50% of the sodium lauryl sulfate solution, ethylene diamine tetraacetic acid, preservatives, coconut ~2~

monoethanolamide, propylene glycol and ethylene glycol distearate .
- The hot mix was poured into the cold mix, with agitation .
- The remaining ingredients were mixed in the following order: color solution, citric acid and perfume.
EXAMPLE I I
A second full product formula was made with 0.5% hydroxy-ethyl cellulose (HEC) and 5% propylene glycol. The base formu-lation used in this variation contained the following ingredients:
_-- Component Wt. Composition Sodium Lauryl Ethoxy (3) Sulfate Sol ution ( 2 8, 5~ sol ution ) 3 8 . 5%
Sodium Lauryl Sulfate Solution (28.5% solution) 31.6 Coconut Monoethanolamide 4.0 Perfume 3 .
Ethylene Glycol Distearate 1 . 0 Ethylene Diamine Tetraacetic Acid 0.1 20 Preservatives 0 . 25 Color Solution 0 . 39 Citric Acid 0.29 Hyd roxyethyl Cel I u i ose ~ H EC ) O . 5 Propylene Glycol 5.0 25 Distilled Water Balance 1 00. 00%

Product Neat Viscosity = 5000 cps:
Product Dilute Viscosity = 30 cps; see Curve 2 of Figure.
30 1 Natrosol 250,TMsupplied by Hercules Incorporated.

The above composition of the present invention was prepared in a manner similar to that described in Example 1.

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A third full product formula was made with 0. 2~ hydroxy-ethyl csllulose (HEC) and 2% polyoxyethylene glycol (PEG 600), The base formula used in this variation contained the following ingredients:
Component Wt. ComposEtion Sodium Lauryl Ethoxy ~3) Sulfate Solution (28.5% solution) 38.5%
Sodium Lauryl Sulfate Solution (28.5~ solution ) 31.6 _- Coconut Monoethanolamide 4.0 Perfume 3.0 Ethylene Glycol Distearate 1.0 Ethylene Diamine Tetraacetic Acid0.1 15 Preservatives 0 . 25 Color Solution 0.39 A~ Citric Acid 0 . 29 Hydroxyethyl Cellulose (HEC)1 0.2 Polyoxyethylene Glycol2 2.0 2û Distilled Water Balance 1 ~0 . 00%
Product Neat Viscosity = 5000 cps;
Product Dilute Viscosity = 20 cps; see Curve 3 of Figure.
-1 Natrosol 250'*supplied by Hercules Incorporated.
"2Carbowax PEG 600, *s*upplied by Union Carbide, having about 13 EO units.

The above composition of the present invention was prepared in a manner similar to that described in Example 1.
Examples l-lll demonstrated the following regarding in-use skin feel slipperiness and rinsing characteristics using the Skin Feel Test:
1. No difference in slip or ea~e of rinsing between the three HEC formulas of Examples 1-111.
35 2. Less slip and easier to rinse than a similar formula, Example A, which has 0.55% iaguar HP-60 gum.

* Trademark ** Trademark s~

3. More slip and harder to rinse than ~ormula thickened with electrolyte ( NaCI ), Example C .
The Figure shows plots of viscosity vs. dilute concentration curves with noted product skin feel attributes. As can be seen, 5 the three HEC formula dilution curves are similar and fall in between the highly slick/slippery formula thickened with Jaguar gum Example A and the less slick/slippery competitive formula thickened with electrolyte Example C . Çurve 1 represents a product, Example A, which has a high degree of siipperiness but 10 is difficult to rinse. Curves 2 and 3 represent products, Ex-amples ll and l/lll, respectively, which have the desired degree of slipperiness and ease of rinsing. Curve 4 represents a prod-uct, Example C, which has a low degree of slipperiness, but which is easy to rinse. See Methods I and l l for neat and dilute 15 viscosity procedures.
EXAMPEES IV ~ V
These examples illustrate the need for a solvent, in this case propylene glycol, to achieve phase stability. Two full product formulations were prepared, one ( IV) with 0% propylene glycol 20 and the other ~V) with 3% propylene glycol. The base formula-tion used in these variations contained the following in~redients:
Component Wt. Composition Sodium Lauryl Ethoxy (3) Sulfate Solution (28.5% solution)38.5%
Sodium Lauryl Sulfate Solution ( 28 . 5% solution ) 31 . 6 Coconut monoethanolamide 4.0 Perfume 2, 0 Ethyiene Glycol Distearate 1 . 0 Ethylene Diamine Tetraace~ic Acid 0.1 Preservatives 0 ~ 25 Color Solution 1.1 Citric Acid 0.12 Hydroxyethyl Cellulose ~HEC)1 0.2 Propylene Glycol 0 or 3 Distilled Water Balance 100.00%

~2~

Product Neat Viscosity (with propylene glycol) = 4750 cps Product Neat Viscosity (without propylene glycol~ = 8000 cps 1 Natrosol 250, supplied by Hercules Incorporated.

The above compositions of the present invention were pre-pared in a manner similar to that described in Example 1.
Results showed the non-propylene glycol-containing formula ( IV) had phase separation after only a few days; whereas the propylene glycol formula (V) of this invention remained phase 10 stable for several months.
,~

* Trademark `::

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Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A liquid personal cleansing product consisting essentially of:
A. from about 0.1% to about 1.5% of a water-soluble cellu-losic thickener selected from the group consisting of nonionic and anionic cellulosic polymers and mixtures thereof:
B. from about 0.5% to about 20% of a solvent consisting of ethylene glycol, propylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, mixed block copolymers of polyoxyethylene glycol and polyoxypropylene glycol, and mixtures thereof;
C. from about 10% to about 50% of a synthetic surfactant;
D. from about 0.001% to about 1.0% of an electrolyte;
E. from about 50% to about 80% water; and wherein said polymeric solvents of B. have a molecular weight of from about 200 to about 10,000; and wherein said product has a neat product viscosity (100%) of from about 2,000 cps to about 12,000 cps, and a dilute product vis-oosity (50%) of from about 15 cps to about 95 cps; wherein said liquid personal cleansing product is substantially a single phase product.

2. A liquid cleansing product according to Claim 1 wherein said water-soluble cellulosic polymer is a nonionic cellulosic material selected from the group consisting of hydroxymethyl, hydroxy-ethyl, hydroxypropyl and hydroxybutyl methyl cellulose and the like, and mixtures thereof.

3. A liquid cleansing product according to Claim 2 wherein said hydroxyethyl cellulose has a molar substitution of from about 1.5 to about 3Ø

4. A liquid cleansing product according to Claim 3 wherein the hydroxyethyl cellulose is present at a level of from about 0.1% to about 1.0% and has a molar substitution of from about 2.0 to about 3Ø

5. A liquid cleansing product according to Claim 1 wherein said water-soluble cellulosic polymer is a anionic polymer selected from the group consisting of carboxymethyl cellulose and its derivatives.

6. A liquid cleansing product according to Claim 5 wherein said anionic polymer has a molar substitution of from about 0.4 to about 4.5.

7. A liquid cleansing product according to Claim 1 wherein the solvent is present at a level of from about 1% to about 10%.

8. A liquid cleansing product according to Claim 1 wherein the surfactant is present at a level of from about 10% to about 30%.

9. A liquid cleansing product according to Claim 8 wherein the surfactant is an anionic surfactant.

10. A liquid cleansing product according to Claim 9 wherein the anionic surfactant is selected from the group consisting of sodium alkyl glycerol ether sulfonate, sodium lauroyl sarcosinate, sodium alkyl sulfate, sodium ethoxy (1-12) alkyl sulfate and mixtures thereof.

11. A liquid cleansing product according to Claim 1 wherein said product has a neat viscosity (100%) of from about 4,000 cps to about 10,000 cps and a dilute product viscosity (50%) of from about 20 cps to about 60 cps.

12. A liquid cleansing product according to Claim 11 wherein said product contains from about 1% to about 5% of an alkanola-mide of a fatty acid having from about 8 to about 18 carbon atoms.

13. A liquid cleansing product according to Claim 11 wherein said product contains from about 0.1% to about 10% of an opacifier selected from the group consisting of ethylene glycol distearate, talc and mixtures thereof.

14. The liquid cleansing product according to Claim 1 wherein said polymeric solvents of B. have molecular weights of from about 400 to about 800.