WO1992000723A1

WO1992000723A1 - Skin moisturizing composition and process of using

Info

Publication number: WO1992000723A1
Application number: PCT/US1991/004747
Authority: WO
Inventors: Harry A. Smith
Original assignee: DowBrands Inc
Current assignee: DowBrands Inc
Priority date: 1990-07-05
Filing date: 1991-07-03
Publication date: 1992-01-23
Anticipated expiration: 1993-01-05

Abstract

Disclosed is a moisturizing composition comprising a matrix copolymer of from 10 to 60 weight percent of carboxylic acid monomeric units with the balance being non-acidic monomeric units copolymerizable with the carboxylic acid monomeric units, and isopropanolamine or an isobutanolamine as a neutralizing agent, one or more chelating agents for preferentially chelating calcium of the skin of a user, and a vehicle for the matrix copolymer, neutralizing agent and chelating agent. Further disclosed is a process for moisturizing the skin by applying the above composition to the surface of the skin.

Description

SKIN MOISTURIZING COMPOSITION AND PROCESS OF USING

This invention relates generally to skin moisturizing compositions.

Skin moisturizing compositions enhance the ability of the skin to retain moisture, and further provide a soft, smooth, and supple feel to the skin.

Such compositions typically contain an emollient, a humectant, and surfactants. The emollient is an oily material that forms an oily layer on the skin's surface to hold in moisture, generally by forming a physical barrier against escaping moisture. The humectant is typically a hydrophilic substance that binds up such water by chamical means at the surface of the skin.

Moisturizing compositions are typically emulsions with the surfactants maintaining dispersion of the emollient in an aqueous phase.

A problem with prior art moisturizing compositions is the lack of moisturizing longevity provided thereby. Longevity refers to the length of time enhanced levels of moisture are maintained in the skin after application of the composition. Prior art moisturizing compositions typically moisturize for only about 2 to 6 hours after application. Since moisturizing compositions are very often applied by the consumer only once or twice a day, it would be desirable to have a composition that would moisturize for from 12 to 20 hours. Further, it would be desirable to have a composition that provides such longevity while providing a desirable degree of moisturizing and desirable skin feel properties, particularly in the interval of time just after application of the composition to a user's skin. The degree of moisturizing refers to the difference in the level of moisture in the skin before and any given point in time after the application of the composition to the skin.

The present invention provids a skin moisturizing composition comprising which meets these needs. The skin moisturizing composition of the present invention comprises (a) a matrix copolymer of 10 to 60 weight percent of one or more monoethylenically unsaturated carboxylic acid monomeric units and 90 to 40 weight percent of one or more non-acidic monoethylenically unsaturated monomeric units copolymerizable with the carboxylic acid monomeric units and (b) an isopropanolamine or an isobutanolamine. A process of moisturizing skin comprises applying to the surface of the skin the above-described composition.

The matrix copolymer of the present moisturizing compositions may comprise from 10 to 60, preferably more than 15 to 60, more preferably more than 15 to 40, and most preferably from 20 to 30 weight percent of one or more monoethylenically unsaturated carboxylic acid monomeric units, with the balance of ..he copolymer being one or more non-acidic monoethylenically unsaturated monomeric units copolymerizable with the acid monomeric units.

Suitable carboxylic acid monomeric units for the matrix copolymer of the present compositions include monoethylenically unsaturated carboxylated vinyl monomers such as acrylic acid, methacrylic acid, itaconic acid, aconitic acid, cinnamic acid, crotonic acid, citraconic acid, mesaconic acid, maleic acid, fumaric acid, and the like. A most preferred carboxylic acid is methacrylic acid.

Suitable non-acidic monomeric units of the matrix copolymer of the present compositions may include monoethylenically unsaturated monomeric units copolymerizable with the aforementioned acidic monomeric units such as alkyl and hydroxyalkyl acrylate and methacrylate esters, vinyl chloride, vinylidene chloride, conjugated dienes such as butadiene, isoprene, neoprene and the like, nitrile monomers such as acrylonitrile and methacrylonitrile, alkenyl aromatics such as styrene, α-methylstyrene, vinyl toluene and the like, vinyl esters such as vinyl acetate and the like, amide monomers such as acrylamide, methacrylamide, diacetone acrylamide, methylolacrylamide and methylolmethacrylamide, and esters of the above- mentioned carboxylic acids. Preferred monoethylenically unsaturated monomeric units are alkyl methacrylates having 1 to 4 carbons in the alkyl group and alkyl acrylates having from 1 to 18 and more preferably from 1 to 12 carbon atoms in the alkyl group. Suitable non- acidic monomeric units include alkyl and hydroxyalkyl acrylate and methacrylate esters such as methylacrylate, methylmethacrylate, ethylacrylate, ethylhexyl- methacrylate, 2-hydroxyethylacrylate, 2- hydroxyethylmethacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, hydroxypropylacrylates and methacrylates, tetraethylene glycol monomethacrylate, pentaethylene glycol monomethacrylate, dipropylene glycol monomethacrylate and dipropylene glycol monoacrylate. Most preferred non-acidic monomeric units comprise methylmethacrylate, ethylacrylate, butylacrylate and ethylhexylacrylate.

The matrix copolymer may be prepared by various 0 processes known to the art such as by emulsion polymerization, suspension polymerization, bulk polymerization, and the like. Preferably, the matrix copolymer is prepared by emulsion polymerization, and is -- further preferably incorporated in the present compositions in the form of a latex. Alternately, the matrix copolymer may be prepared under nonaqueous conditions such as by bulk polymerization, and subsequently combined with water. 0

The matrix copolymer provides a matrix or base within the composition to enhance uniform dispersion of the other components in the composition.

_c The term "matrix" utilized in describing the copolymer is employed for purposes of identification in view of other types of polymers described herein; the term is not a limitation directed to the structure or form of the copolymer. 0

The matrix copolymer of the present compositions is preferably substantially uncrosslinked, but may possess the limited degree of crosslinking occurring naturally without the inclusion of an artificial free radical or ionic crosslinking agent. Matrix copolymers useful in the present compositions preferably have a glass transition temperature of between 30 and 95°C. More preferably, the matrix copolymers have glass transition temperatures between 40 and 70°C and most preferably between 45 and 60°C. The glass transition temperature of the matrix copolymer can be above normal skin temperatures (30 to 37°C) since water in the present compositions generally plasticizes the matrix copolymer to an extent that its

10 effective glass transition temperature is less than normal skin temperature.

The matrix copolymer or mixture of copolymers useful in the present compositions preferably comprise * - from 0.2 to 8.0 percent and more preferably 0.75 to 3-0 by weight of the composition.

An important aspect of the compositions of the present invention is the presence therein of a certain _Q neutralizing agent or agents. Preferred neutralizing agents of the present compositions are the isopropanolamines and the isobutanolamines. Suitable isopropanolamines include monoisopropanolamine, diisopropanolamine, and triisopropanolamine. Suitable 5 isobutanolamines include monoisobutanolamine, diisobutanolamine and triisobutanolamine. The more preferred neutralizing agents are the isopropanolamines. The most preferred isopropanolamine is triisopropanolamine due to its lower tendency to form 0 nitrosamines.

The neutralizing agent or agents are employed in the present compositions in an amount sufficient to partially neutralize the carboxyl groups of the acidic monomeric units of the matrix copolymer as well as other carboxyl groups which may be present in other components of the compositions, such as the carboxyvinyl polymers and fatty acid emulsifying agents mentioned below as additional preferred ingredients of the compositions. Preferably 18 or more, more preferably from 20 to 50, and most preferably from 25 to 35 percent of the carboxyl groups of the acidic monomeric units of the matrix copolymer are neutralized. The same proportions apply to carboxyl groups present in other components of

10 the compositions.

Numerous organic and inorganic agents having basic moieties, including various alkanolamines, have been utilized as neutralizing agents generally. The m - isobutanolamines and the isopropanolamines, however, and particularly monoisopropanolamine and triisopropanolamine provide the present compositions with superior moisturizing longevity compared to prior art compounds utilizing other alkanolamines. 0

It has also been found that the degree of moisturization of the present long-lived compositions, at least in the first several hours after application, can be enhanced by the presence or addition of certain 5 chelating agents.

Moisturizing lotions are frequently applied in response to a dry feeling on the skin of a consumer, so that these first several hours after application of a 0 lotion to the skin of a consumer are of considerable significance. Given a generally equivalent longevity between two compositions, it is for this reason considered that compositions which can provide greater moisturization in the hours immediately following application to the skin of a user will generally be preferred, even if other compositions would ultimately provide a greater degree of moisturization.

Where the moisturizing longevities and initial degrees of moisturization (i.e., over the first several hours of use) of two compositions both differ significantly from one another, as where one composition provides a much longer lived moisturization but a lesser initial degree of moisturization compared to a second composition, these differences will normally be weighed

10 to determine which composition is to be preferred under the circumstances. An ideal moisturizing composition would provide at least 12 to 20 hours of moisturization, with a peak, high degree of moisturization coming in the m m initial three hours or so following application to the skin of a user.

The improved moisturization associated with the aforementioned chelating agents appears to be related 0 directly to the chelation of calcium on the skin, and accordingly those chelating agents and amounts thereof which preferentially tie up calcium on the skin of a user as opposed to magnesium are preferred. Chelating agents found useful for providing an increased degree of 5 moisturization in the first several hours after application include H4EDTA, NasDTPA, the sodium, potassium and amine salts of EDTA, and analogous materials where a phosphonate group replaces the carboxyl group of these materials, with Na₃HEDTA being a 0 preferred material.

Preferred amounts of these materials for achieving a high degree of initial moisturization and suitable longevities can be expected to vary from material to material, but for Na2EDTA it appears that a content of from 0.30 to 0.35 percent by weight of the composition is best, while for Na3HEDTA it appears that from 0.4 to 0.6 percent by weight is best. The best chelating agents and amounts thereof can be determined with further investigation, however, using the criteria described above and the guidance provided by the examples below.

The present compositions may have an aqueous and/or oily vehicle to provide body and consistency.

10 The vehicle may take different forms such as a lotion, cream, or an ointment. Suitable oily vehicles include emollients. Aqueous vehicles are preferred, and may comprise water or more preferably a latex or emulsion of m m an oily phase in water.

As for other ingredients, the present compositions preferably also contain one or more surfactants as emulsifying agents. The emulsifying ₀ agents comprise from 1 to 10 weight percent of the composition. The emulsifying agents may be anionic, cationic or nonionic.

Suitable emulsifying agents should be _*y- compatible with other components of the composition and cosmetically suitable i.e., aesthetic, nontoxic, nonirritating, render a desirable skin feel, and lack odors, colors, etc. that are unpleasant or difficult to mask.

30

Though cationic surfactants may be used as emulsifying agents, anionic and nonionic surfactants are preferred. Typical cationic surfactants include cetyl pyridinium chloride and alkyl dimethylbenzoammonium chloride. Suitable nonionic surfactants include fatty alcohols, fatty acid amides, fatty acid esters of polyols, and ethylene oxide adducts of the preceeding species. Also suitable are ethylene oxide adducts of alkyl phenols and fatty acids. Suitable ethylene oxide adducts of fatty alcohols include those of stearyl alcohol, cetyl alcohol, lauryl alcohol, and the like. Suitable ethylene oxide adducts of fatty acids include those of stearic acid, lauric acid, palmitic acid, and the like. Suitable ethylene oxide adducts of fatty acid esters of polyols include those of glycerol monostearate, ethylene glycol monostearate, sorbitol monostearates and the like. Preferred nonionic surfactants are fatty acid esters of polyols and ethylene oxide adducts of fatty alcohols. Most preferred nonionic surfactants include glycerol monostearate and cetyl alcohol.

Suitable anionic surfactants include, but are not limited to, amine or alkali metal acid salts of fatty acids, linear alkylbenzene sulfonates, alkylether sulfates, alkyl sulfosuccinates, and sulfonate derivatives of nonionic surfactants. Preferred anionic surfactants are ammonium stearates and palmitates.

The present compositions further preferably comprise a thickening agent to provide body and viscosity. The thickening agent may be any material which increases the viscosity of the composition and which is compatible with the other components of the composition. Preferably, the thickening agent is a carboxyvinyl polymer or a cellulosic polymer. More preferably, the thickening agent is a carboxyvinyl polymer. The carboxyvinyl polymer preferably is comprised primarily of a monoethylenically unsaturated acidic monomeric unit and a small amount, from 1 to 5 weight percent, of a polyethylenically unsaturated non- acidic monomeric unit copolymerizable therewith as a crosslinker. Suitable acidic monomeric units may be the same as those described above for the matrix copolymer. Suitable polyethylenically unsaturated non-acidic monomeric units include divinylbenzene and vinyl esters of polyols with two or more unsaturated ester groups. Preferably, the non-acidic monomeric unit provides a limited degree of crosslinking between the segments of the carboxyvinyl polymer. Preferred carboxyvinyl polymers comprise polycarboxylic acids wherein there is present a small amount of non-acidic monomeric units to provide a limited degree of crosslinking. The Carbopol 934, 940, 941, 980, 981, and 984 polycarboxylic acids (marketed by B.F. Goodrich) are preferred.

Polycarboxylic acids may be activated as thickening agents upon partial neutralization by a neutralizing agent as described above.

The present compositions further preferably comprise a humectant to enhance retention of water in the skin. Suitable humectants include glycerine, propylene glycol, and sorbitol. A most preferred humectant is glycerine due to its efficacy and economy.

The present compositions provide enhanced moisturizing longevity while providing a desirable degree of moisturizing and desirable skin feel properties compared to prior art moisturizing compositions. In prior art compositions, moisturizing longevity of greater than 6-7 hours was not possible. Preferred present compositions moisturize for a period of up' to about 70 hours. Preferred present compositions moisturize from 12 to 20 hours. A moisturizing longevity of from 12 to 20 hours is desirable because consumers often apply moisturizing compositions only once or twice per day.

A process of moisturizing skin according to the present invention comprises applying to the surface of the skin a composition of the present invention as described above.

EXAMPLES

Preparation of the Latex Copolymer

A matrix copolymer in latex form was prepared by a standard emulsion polymerization technique. A charge of 40 grams of mixed monomers of 35 parts methyl acrylate, 20 parts ethyl acrylate, 20 parts methyl methacrylate, and 25 parts of methacrylic acid by weight was added to 775 g. of water and 7.8 g. of 30.8 percent Conco Sulfate WAQ brand of sodium lauryl sulfate (marketed by Continental Chemical Co.) in a 2 liter flask equipped with a nitrogen purge, a reflux condenser, and a stirrer. The resulting mixture was heated to 70°C, at which point a solution containing 4 g of Na2S₂U8 in 25 ml. of H₂O was added thereto, and the heat was removed. The temperature of the resulting mixture increased to 75°C and then subsided. An additional 360 grams of the mixed monomers was then pumped into the flask at the rate of 90 g. per hour while maintaining a temperature of 70°C. After all the monomer had been added, the mixture was heated for an additional hour at 70°C and then heated at 90-95°C for 2 hours to remove traces of monomer. The resulting latex was cooled and filtered. The final latex contained about 33 weight percent of vinyl polymer solids. Example 1

A skin care composition according to the present invention was prepared as follows:

-. Oil Phase: These materials were weighed out in the following order:

1.5 g Lanolin

5.0 g Isopropyl Palmitate ₁₀ 2.5 g PEG-400 Distearate (Stepan Chemical, a distearate ester of a polyethylene glycol with a molecular weight of about 400)

2.5 g Glycerol Monostearate

1.0 g Cetyl Alcohol 15 0.5 g Stearyl Alcohol

1.0 g Stearic Acid

0.07 g Methyl Paraben

0.03 g Propyl Paraben

0 The mixture was stirred and heated to 75-80°C.

Water Phase: Weighed out these materials

2.5 g Glycerine ₅ 25.0 g O.856 Carbopol 940 polycarboxylic acid

(marketed by B.F. Goodrich) in water 50.1 g Deionized water.

Stirred and heated to 75-80°C. 0 The oil phase was added to the water phase at the indicated temperature slowly while stirring, and then removed from the heat and allowed to cool. At 50-55°C, 6.1 g (5.6 ml) of the latex of the matrix copolymer (24.6? solids) prepared above was mixed in.

At 40-45°C, 0.15 g Dowicil 200 (1(3- 5 chloroallyl)-3.5,7-triaza-1-azonia-adamantane chloride) (marketed by The Dow Chemical Company) was added.

A solution of 0.51 g triisopropanolamine and 2.0 g water was then mixed in to form the final 10 composition at less than 40° C, preferably at 35 to 38° C.

Example 2

m m Another composition according to the present invention was prepared in the same manner as the composition of Example 1 except that the lanolin was replaced in the same proportions with cetyl palmitate, the isopropyl palmitate was replaced with Finsolv P 0 (marketed by Fintex) brand of a PPG-15 stearyl ether benzoate, and PEG-400 distearate was replaced in the same proportions with PEG 1000 monostearate (Stepan Chemical, a monostearate of a polyethylene glycol with molecular weight of 1000). 5

In the following examples, moisturizing compositions were tested for moisturizing longevity and degree of moisturizing by applying 0.20 ml of a given composition to the back of the hand and the inside of 0 the arm (smooth, hairless area of forearm) (about 4 square inches) and then testing for skin moisture content where the lotion had been applied.

The test for determining skin moisture was an infrared determination using a Wilkes Skin Analyzer to compare absorbance peaks at 6.1 microns and at 6.6 microns. The reference baseline (R o) was measured before application of the compositions, wherein Rw equals the absorbance at 6.1 microns divided by the absorbance at 6.6 microns. After the compositions are applied to the skin, R_w increases due to the increase in level of moisture in the skin. The time required for R_w to return to its initial value Rwo is the moisturizing longevity. References for the methodology are: N. A. Puttnam, J. Soc. Cosmet. Chem. 23, 209-226 (1972); A. Triebskorn, M. Gloor, F. Greiner, Dermatologica 167, 64- 69 (1983); and R. 0. Potts, Cosmetics & Toiletries 100, 27-31 (1985).

Example 3

The moisturization longevity of several compositions of the present invention was evaluated. Compositions were prepared as in Example 2 except that the triisopropanolamine (TIPA) content was varied.

Moisturizing longevity for each of the compositions was measured as a function of equivalents of TIPA to total equivalents of carboxyl groups in the composition contributed by the matrix copolymer, the Carbopol 940 polycarboxylic acid, and the stearic acid. The results are set forth in Table I:

TABLE I Longevity vs TIPA Content

equivalents of TIPA A/C= Total equivalents of C00H in composition

Example 4

The degrees of moisturizing of two compositions of the present invention were evaluated. The compositions were prepared and formulated as in Example 2 except that the TIPA content was varied. The compositions, referred to as Sample #1 and Sample #2 in Table 2 below, each have an A/C ratio of 0.5 and 0.75 respectively (A/C ratio being defined in Table I). The results are set forth in Table II:

10

15

20

25

Degree of

Moisturization = R_wt - Rwo

Rwt = Rw at time t

Rwo = w at time zero (reference baseline ^ determined prior to application of compositions) Example 5

Another composition according to the present invention was prepared in the same manner as the composition of Example 2 except that TIPA was replaced by 0.32 g of monoisopropananolamine. The composition exhibited a moisturizing longevity of 17 hours.

₁₀ Example 6

Oil Phase: These materials were weighed out in the m m following order:

1.0 g Cetyl Palmitate

0.5 g Velsan D8P3 emollient (Sandoz Chemical,

Isopropyl PPG-2-Isodoceth-7 Carboxylate) ₀ 2.0 g Isopropyl Palmitate

1.5 g Cetiol LC emollient (Henkel Chemical, cococaprate/caprylate mixture)

0.63 g PEG-1000 Monostearate

0.37 g Glycerol Monostearate 5 0.25 g Stearic acid

0.66 g Cetyl Alcohol

0.34 g Stearyl Alcohol

0.07 g Methyl Paraben

0.03 g Propyl Paraben 0 0.5 g Dimethylsiloxane

The mixture was stirred and heated to 75-80°C.

Water Phase: These materials were weighed out: 4.0 g Glycerine

25.0 g of a slurry containing 0.8 Carbopol 940 polycarboxylic acid (marketed by B.F. Goodrich) in water

58.04 g Deionized water.

The materials were then stirred and heated to

75-80°C.

The oil phase was added to the water phase at the indicated temperature slowly while stirring, and then the heat removed and the whole allowed to cool.

At 50-55°C, 4.5 g of the latex of the matrix copolymer (24.6 solids) prepared above was mixed in.

At 40-45°C, 0.15 g Dowicil 200 (1(3- chlorolallyl)-3_>5,7-triaza-1-azonia-adamantane chloride) (marketed by The Dow Chemical Company) was added.

At less than 40°C, 0.46 grams of a solution of 85 percent by weight of triisopropanolamine in water (15 percent by weight) was then mixed in to form the final composition.

. The composition was applied and tested for moisturization in the manner of Example 2 over a period of three hours after application, with the average degree of moisturization being 0.15 over these three hours.

Example 7

In this example, a skin care composition was made and tested in the manner of Example 6, except that 0.2 g of Na2EDTA was added in place of 0.2 g of water in the water phase materials. The average degree of moisturization over the first three hours after application was 0.30, or double the average initial degree of moisturization seen in the same composition in ς the absence of Na2EDTA.

Examples 8 and 9

Two compositions of the present invention were 10 made using the same materials as in Example 6, but employing 1.0 and 1.5 g, respectively, of the Velsan D8P3 emollient and 1.0 and 0.5 g, respectively, of the Cetiol LC emollient rather than the 0.5 and 1.5 g of these ingredients employed in Example 6. The average

15 degrees of moisturization measured for these compositions for the three hours following their application were 0.14 and 0.14.

Examples 10 and 11 0

The compositions of examples 8 and 9 were prepared except that in the water phase of each 0.2 g of Na2EDTA was again substituted for 0.2 g of water. The average degrees of moisturization provided by these 5 compositions over the first three hours following application were 0.21 and 0.23, or about 1.5 and 1.6 times the average degrees of moisturization measured for the same compositions in examples 8 and 9 absent the 0 Na2EDTA.

Example 12

For this example a series of skin care compositions was prepared as follows, with differing amounts of Na2EDTA being employed in each composition of the series:

Oil Phase: These materials were weighed out for each composition in the following order:

0.8 g Cetyl Palmitate

2.0 g Velsan D8P3 (Sandoz Chemical, Isopropyl

PPG-2-Isodoceth-7 Carboxylate) emollient

3.0 g Finsolv P PPG-15 stearyl ether benzoate (Fintex)

1.0 g Cetiol LC emollient (Henkel Chemiical, cococaprate/caprylate mixture)

0.63 g PEG-1000 Monostearate

0.37 g Glycerol Monostearate

0.25 g Stearic acid

0.66 g Cetyl Alcohol

0.34 g Stearyl Alcohol

0.07 g Methyl Paraben

0.03 g Propyl Paraben

0.5 g Dimethylsiloxane

The mixture was stirred and heated to 75-8θ°C.

Water Phase: These materials were weighed out in the indicated amounts:

8.0 g Glycerine

46.0 g of a slurry containing 0.8 Carbopol 940 polycarboxylic acid (marketed by B.F. Goodrich) in water

0.125 (Composition #1), 0.2 (#2) , 0.3 (#3), 0.4 (#4), 0.5 (#5), or 0.75 grams of Na2EDTA (Composition #6). 30.97 (Composition #1), 30.89 (#2), 30.79 (#3), 30.69 (#4), 30.59 (#5), or 30.47 g of Deionized water (Composition #6).

The materials were then stirred and heated to

75-80°C.

The oil phase was added to the water phase at the indicated temperature slowly while stirring, and 0 then the heat removed and the whole allowed to cool.

At 50-55°C, 4.5 g of the latex of the matrix copolymer (24.6% solids) prepared above was mixed in.

₅ At 40-45°C, 0.15 g Dowicil 200 (1(3- chloroallyl)-3.5,7-triaza-1-azonia-adamantane chloride) (marketed by The Dow Chemical Company) was added.

At less than 40°C, 0.61 grams of a solution of ₀ triisopropanolamine in water (85 percent by weight triisopropanolamine with 15 percent by weight of water) was then mixed in to form a final composition at a given level of Na2EDTA.

_c The compositions were applied and tested for average degree of moisturization in the first three hours after their application. The results of the degree of moisturization tests for these compositions are reported in Table III below. 0

Examples 13-32

For these examples a number of skin care compositions were prepared as in example 12, except that a variety of chelating agents were tried, usually in several amounts. The materials other than water were the same and were used in the same amounts as in example 12, and the amount of water employed was changed in the various compositions to accommodate the different amounts of chelating agents.

The compositions were applied and tested for average degree of moisturization over the first three hours after application and for moisturization longevity, with the results for various chelating agent additives and amounts of such additives being reported below in Table IV. Several compositions were reapplied and retested for purposes of assessing the reproducibility of the measured degrees of moisturization.

0

Claims

WHAT IS CLAIMED IS:

1. A moisturizing composition comprising a) a matrix copolymer of from 10 to 60 weight percent of one or more monoethylenically unsaturated carboxylic acid monomeric units and from 90 to 40 weight percent of one or more non-acidic monoethylenically unsaturated monomeric units copolymerizable with the carboxylic acid monomeric units; and b) a neutralizing agent selected from the group consisting of an isopropanolamine and an isobutanolamine.

2. The composition of Claim 1, wherein the acidic monomeric unit comprises more than 15 to 60 percent by weight of the matrix copolymer.

3. The composition of Claim 1, wherein the acidic monomeric unit comprises more than 15 to 40 percent by weight of the matrix copolymer.

4. The composition of Claim 1, wherein the acidic monomeric unit comprises from 20 to 30 percent by weight of the matrix copolymer.

5. The composition of Claim 1, wherein the composition further comprises a material for preferentially chelating calcium on the skin of a user of the composition.

6. The composition of Claim 5, wherein the calcium-chelating material is selected from the group consisting of H4EDTA, NasDTPA, the sodium, potassium and amine salts of EDTA, and phosphonated analogues of these materials.

7. The composition of Claim 6, wherein the calcium-chelating material is Na₃HEDTA.

8. The composition of Claim 1, wherein the composition further comprises a carboxyvinyl polymer,

9. The composition of Claim 1, wherein the neutralizing agent is an isopropanolamine.

10. The composition of Claim 9_> wherein the isopropanolamine is tri-isopropanolamine.

11. The composition of Claim 9_> wherein the isopropanolamine is monoisopropanolamine.

12. The composition of Claim 1, wherein the matrix copolymer is in the form of a latex.

13. The composition of Claim 1, wherein the matrix copolymer is substantially uncrosslinked.

14. The composition of Claim 1, wherein the acidic monomeric unit is methacrylic acid.

15. The composition of Claim 1, wherein the non-acidic monomeric unit is selected from the group consisting of ethylacrylate, methylacrylate, methyl methacrylate, butylacrylate and ethylhexylacrylate.

16. A method of moisturizing skin, comprising: applying to the surface of the skin the composition of any of Claims 1-15.