Field of the Invention

The present invention relates to novel, quick drying creme pig ented nail enamel compositions which dry in less than three minutes. The compositions of the present invention preferably dry in a period of time no greater than about two minutes and most preferably dry in a period no greater than about 90 seconds. Compositions drying in a period less than 60 seconds are especially preferred and are also described.

The compositions of the present invention have accep¬ table static viscosities ranging from about 300 to about 1200 centipoises and may accommodate numerous pigments to produce nail enamel compositions exhibiting favorable characteristics, including acceptable durability and gloss.

The compositions of the present invention comprise aprimary film-forming polymer, a secondary film-forming polymer, for example, a resin which functions to strengthen the primary film-forming polymer and improve the adhesion and gloss of the nail enamel, a traditional plasticizer, guanine in an amount ranging from about .125% to .50% and preferably about .25% by weight, an organoclay thixotropic agent and a solvent system containing a ketone volatile in an amount no less than about 4.5% and preferably no less than about 13% by weight of the composition and further including a wetting solvent and a diluent. In the particular preferred composi¬ tions accordingto the present invention, ketone comprise about 15% to about 25% of the total weight of the composition and guanine from .125% to .50% by weight of the total solu¬ tion. In a particularly preferred embodiment of the nail enamel compositions according to the present invention, ketones comprise about 15% to about 25% of the total weight of the composition and guanine comprises from about .125% to .50% by weight of the total solution.

Preferably, the nail enamel compositions of the present invention also contain a pigment for coloring the nail coat¬ ing, in addition to other additives such as preservatives, stabilizers and fragrances.

Background of the Invention

A large number of methods and compositions for beautify¬ ing and strengthening the nails of humans are well known. Prior art methods include coating the nail of an animal, including humans with a composition including a film-forming polymer and additional ingredients such as pigment, plasticizer and solvents or alternatively, attaching preformed artificial nails to human nails with adhesives. Additional- methods include adding crosslinkable polymers to nail coating compositions to mend, strengthen and elongate natural nails and repairing nails with a fabric patch.

Most nail enamel compositions presently on the market or disclosed in the prior art dry in five minutes or longer. Even those nail enamels that claim to be quick-dry, i.e., dry in about five minutes are often not truly dry but rather are only dry to the touch. When a purportedly "dry" nail enamel of the prior art brushes up against a hard surface, the nail enamel often smudges, leaving substantial amounts of tack.

A nail polish which can be used to coat a natural orsynthetic nail which dries in less than three minutes without requiring an additional application of a base coat or top coat as is disclosed in the prior art would be very desirable.

Nail polishes which dry in a period of less than about 150 seconds would be even more desirable, as would polishes that dry inperiods less than about 90 seconds. A nail polish composition which would dry in a period of no greater than about 60 seconds would be especially useful in situa¬ tions where "drying" time is important.

Working women need to have a product which can be easily applied and which dries in the shortest amount of time to avoid a situation where they are simply wasting precious time waiting for their nail polish to dry. Further, fast drying reduces the chance that the manicure can be damaged or marred as wet polish can be easily abraded or scraped. In the manicure and pedicure industries, a pigmented nail polish- composition which can dry in a period less than three minutes would provide a significant advantage over the prior art compositions.

Solvent mixtures for nail enamels of the prior art have covered a wide range of compositions and have included as many

as six or seven solvents to control flow, viscosity, evaporation rate and drying time of the enamel. In general, due to the wide differences in evaporation rates of the sol¬ vents which are included in the prior art compositions, these compositions undergo many changes during the drying of the film. For example, during the course of evaporation of the solvent from the nail enamel on the nail, differential evaporation of the solvents within the composition may result in the presence of higher concentrations of certain solvents during drying, which in turn creates precipitation of the film-forming polymer, resin and/or plasticizer, thereby destroying the integrity of the film and the appearance of the enamel. If the solvent becomes too lean to maintain the solubility of the resin in solution, the resin will precipitate, also resulting in unacceptable results.

The complicated character of the nail enamel mixtures of the prior art and the many possible combinations of volatile and non-volatile components had, until the unexpected discov¬ ery of the present invention, made the determination of a proper solvent balance from the perspective of viscosity, solubility of the individual components and the acceptability of the deposited enamel (gloss) in combination with a drying- time of less than three minutes, virtually impossible. Until the discovery of the present invention, the identification of the evaporation rates of the individual solvents under various conditions had not removed the uncertainty involved in determining a suitable solvent balance incorporating quick drying characteristics. Although the desirability of a quick drying nail enamel has been a long-felt need, the rate of drying of the nail enamels of the prior art has been limited by the aforementioned considerations. Thus, before the dis¬ covery of the present invention, simply incorporating low boiling solvents did not increase the likelihood that an acceptable solvent system for nail enamels would be found or that one could obtain a nail enamel composition which dried in under three minutes. Further, when low boiling (below 80° C) solvents including ketones are used in creme nail enamel which include a broad shade range, films evidencing non-optimal durability and brittleness may occur. Adding additional traditional plasticizer to overcome this problem, may increase

the drying time. In the present invention, the use of ketones in certain weight percentages of the composition and guanine in certain weight percentages, in combination with numeroussolvents which provide acceptable viscosity, creates a consistent quick-drying solvent system which provides the nail enamel with favorable characteristics of drying time, viscosity, gloss, flexibility and durability.

Acetone, also known as 2-propanone, dimethylketone and beta-ketopropane is a volatile solvent which has a boiling point of 56.5° C and methylethyl ketone has a boiling point of 79.6° C. Both acetone and methylethyl ketone are miscible with an extremely large number of solvents including water, alcohol, dimethylformamide, chloroform, methylene chloride, toluene, esters, including methylacetate and ethylacetate, benzene and toluene, ethers and numerous oils and hydrocarbons, among others. The uniqueness of these ketones for use in the present invention resides in the fact that acetone or methylethyl ketone will interact with solvents used in nail enamels to produce a solvent system which evaporates in under three minutes and instills acceptable characteristics which are desired in nail enamels.

It has surprisingly been discovered that the inclusion of specific weight percentages of these ketones in combination with additional liquid components including wetting agents and diluents in compositions for coating natural and synthetic nails produces a nail coating composition which dries in a period of time less than three minutes and produces a coating on a nail which is hard, flexible and has good wear- characteristics including durability and high gloss. Moreover, the use of acetone or methylethyl ketone in the volatile component of nail enamel compositions of the present invention within specific weight percentages and the use of guanine within specific weight percentage provides a consistent basis upon which one of ordinary skill in the art may modify nail enamel compositions according to the present invention without dramatically adversely affecting the drying time of the nail enamel and without dramatically adversely affecting other characteristics which are required for commercially competitive nail enamels.

Creme-pigmented nail enamels ("Cremes") are highly

colored non-pearlescent colors of nail enamel as understood in the industry for commercial scaleup. Non-pearlescent colors are any straight colored shade yielding a range of colors from white through the pastels, including dark colors and earth tones. The pigments used to produce these non pearles- cent shades are titanium dioxide, the iron oxides, Drug & Cos¬ metic colors and lakes thereof. Lakes are metallic salts of one of the Drug & Cosmetic Colors. Typically the lakes are used since the dyes tend to stain fingernails. All this is well known in the art.

When a full range of colors were developed using quick-drying technology using an absence of guanine in com¬ bination with acetone and/or methylethyl ketone, certain prob¬ lems were identified which limited the number of colors of creme nail enamel that could be offered commercially. Certain colors could be included which yielded a satisfactory wearing nail enamel. When the range of colors was broadened, fast drying properties were maintained, but less than ideal wear was experienced. The films for the shades that were com¬ mercially unsatisfactory, were brittle and chipped from the finger nail to a degree to be of relatively little commercial value. It was also found that merely increasing the level of suspended solids caused enamel polishes to become brittle.

An obvious solution to this problem would have been to increase the traditional plasticizer component to compensate for brittleness. This was attempted. When the traditional plasticizer was increased to relatively high levels, flexible films did result as expected, but unexpectantly a pronounced increase in drying time occurred.

Objects of the Present Invention

It is therefore an object of the present invention to provide a creme pigmented nail polish composition with satis¬ factory wear characteristics which can be applied tonatural and synthetic nails and will dry in a period less than 3 minutes, preferably less than two minutes, most preferably less than 90 seconds and especially less than 60 seconds.

It is still a further object of the present invention to provide a novel method for coating nails with a pigmented nail

polish composition containing an organoclay thixotropic agent which dries in a period less than three minutes, preferably- less than two minutes, most preferably less than 90 second- sand especially less than 60 seconds.

It is yet an additional object of the present invention to provide a broad range of shades of creme nail enamel with good wear properties which dry in a period less than three minutes, preferably less than two minutes, most preferably less than 90 seconds and less especially less than 60 seconds. These and other objects of the present invention may be readily gleaned from the detailed description of the invention which is set forth herein.

Brief Description of the Invention

In accordance with the objects of the present invention there is provided a creme pigmented nail enamel preparation comprising a fluid mixture adapted for drying and hardening to form a coating on a nail. The fluid mixture comprises, in part, a plurality of solvents, which include acetone, methylethyl ketone or combinations thereof, the others being- primarily in the form of a wetting agent and/or a diluent. In nail enamel compositions according to the present invention, the ketone blend comprises about 4.5% to about 35% by weight. Also, an oil free plasticizing agent is included in amounts from about .125% to about .50% on a dry basis. It has sur¬ prisingly been discovered that either acetone or methylethyl ketone at specific concentrations will interact with a large number of solvents within a nail coating composition to pro¬ duce a composition which will dry within a period of time sig¬ nificantly shorter than would be expected from the evaporation rates of the individual solvents. It is particularly surpris¬ ing that the nail enamel compositions according to the present invention dry in such short periods of time and pro¬ vide favorable viscosity and wear characteristics including gloss and durability.

Summary of the Invention

The present invention therefore relates to novel composi-

tions for coating natural and synthetic nails which dry to a hard, flexible coating exhibiting favorable characteristics of durability and high gloss comprising: a) a primary film-forming polymer; b) a secondary film-forming polymer; c) at least one plasticizer; d) at least one organoclay thixotropic agent; e) at least one pigment; f) an oil free plasticizing component; and g) a solvent system comprising an amount of a ketone having a boiling point of less than 80° C ranging from about 4.5% to about 35% by weight of said com¬ position said solvent system combination possessing solubility characteristics to dissolve said primary and secondary film-forming polymers and said plasticizer and to produce a gel with said organoclay thixotropic agent to produce a stable composition having a static viscosity ranging from about 300-400 to about 1200 centipoises, said composition drying on a natural or synthetic nail surface within a period of time less than three minutes. In addition to the components set forth above, the compositions of the present invention may further comprise additional agents, for example, fragrances and preservatives, among others.

It is a surprising result that the nail enamel com¬ positions embraced by the present invention which include sig¬ nificant quantities of solvents which include acetone or methylethyl ketone and which have a static viscosity of about 300 to about 1200 centipoises, optimally, about 800 centipoises, consistently dry in less than three minutes. It is particularly surprising that the inclusion of certain- weight percentages of acetone or methylethyl ketone (in most instances, higher amounts of methylethyl ketone compared to acetone) in combination with numerous solvents which do not otherwise dry within a period less than three minutes will produce nailenamel compositions which will dry in a period of time less than three minutes, for example, two and a half minutes, 90 seconds or even less than 1 minute. Inclusion of

T

guanine as an oil free plasticizing component allows develop¬ ment of a broader range of creme colors which wear well in use. The amount of guanine used in the present invention is substantially below the levels generally used in frosted enamel polishes. Frosted nail enamel uses guanine as a pearl producing pigment often in ranges from .75% to 1.25% by weight to produce the required "frosted" look.

It is also surprising that the solvent systems which are used in the compositions of the present invention dry in such a short period of time in a uniform fashion without streaking or precipitation of the solid material. The result¬ ing enamel coat is uniform, hard and flexible and exhibits favorable durability and high gloss.

Description of the Preferred Embodiment of the Invention

In accordance with the present invention, the creme pigmented nail enamel compositions of the present invention include an effective amount of a primary film- forming polymer to provide durability, hardness, gloss and adhesion to the nail enamel after it dries on a nail or other flexible surface. The primary film-forming polymer is used as the base material for the nail enamel to give the nail enamel compositions their basic properties. In the present invention numerous film-forming polymers may be used as the primary film-forming polymer alone or in combination including cel¬ lulose acetate, cellulose acetate-butyrate, ethylcellulose, numerous vinyl polymers as well as a number of methacrylate and acrylate type polymers. Additional primary film-forming polymers include, for example, nitro-starch and polyvinyl acetate, methacrylate and nitrocellulose, polyvinylacetate and nitrocellulose, polyurethanes, polyamides, alkyl vinyl ether- maleic anhydride copolymer, polyvinyl butyral, siloxanylalkyl ester-(meth)acrylate copolymers, polyacrylic and polyethyleneimine/polyepoxide copolymers, among others. Preferably, nitrocellulose is used as the film-forming polymer in the present invention.

In addition to the primary film-forming polymer, the compositions of the present invention also include an amount of a secondary film-forming polymer effective to strengthen

the primary film-forming polymer and also provide the enamel- coating with acceptable gloss and adhesion characteristics in combination with the primary film-forming polymer. Exemplary secondary film-forming polymers or resins which may be used in the present invention include, for example, drying and- nondrying alkyd resin, polyvinyl resins, for example polyvinyl acetate, polyester resins, acrylate and methacrylate resins, alkyd resins, melamine resins, polyamides, ester gums, rosinand polyesters and polytetrahydrofuran and arylsul- fonamide formaldehyde resins, for example toluene sulfonamide formaldehyde resin, among others. These secondary film-forming polymers are added to the primary film-forming polymers of the present invention to strengthen and add acceptable wear char¬ acteristics in combination with the primary film-forming polymer. Toluene sulfonamide-formaldehyde resin, a condensa¬ tion product of formaldehyde and toluene sulfonamide is espe¬ cially preferred for use as a secondary film-formingpolymer in the present invention.

In addition to the primary and secondary film-forming polymers the compositions according to the present invention also comprise at least one traditional plasticizer, preferably for example, dibutyl phthalate and most preferably a mixture of dibutyl phthalate and camphor to add characteristics offlexibility to the nail coating. Certain secondary film forming polymers, for example, toluene sulfonamide/epoxy resin and toluene sulfonamide/epoxy resin butyl acetate, available from Telechemische, Newburgh, New York, which have acceptable plasticization characteristics may be used in certain embodi¬ ments of the present invention without the need to include a separate plasticizer.

In addition to the above-described components, the compositions of the present invention may additionally com¬ prise an organoclay thixotropic agent, for example, stearalkonium hectorite, such as the Bentones ^tm , available from NL Industries, New Jersey, USA as suspension agents for the nail polish and in addition a coloring substance or pig¬ ment to give the preparation a cosmetically acceptable shade and to opacify the film.

In addition to the components set forth above, the com¬ positions of the present invention may also include further

additives including stabilizers, preservatives, fragrances and anti-oxidants.

To provide acceptable static viscosities within the range of about 400 to about 1200 centipoises, the nail enamel com¬ positions of the present invention generally comprise about 50% to about 75% by weight solvent, preferably about 60% to about 70% by weight solvent, and most preferably about 64% to about 68% by weight solvent.

In addition to the disclosed weight percentages of ketones which are used in the present invention as sol¬ vents,other exemplary solvents include esters of acetic acid such as ethyl acetate, methyl acetate, n-butyl acetate and amylacetate. In addition, the liquid components may contain a variety of diluents for suspending the solids and forviscosity control. Suitable diluents include for example, methanol, ethanol, isopropanol, n-butanol, methyl- chloroform, methylene chloride, toluene, xylene, addi¬ tional aromatic (containing phenyl groups) solvents and mix¬ tures thereof, numerous ethers, and alkanes including pentane, cyclopentane, hexane, and cyclohexane, among others, in varying weight percentages. In addition to the above- named diluents, other diluents include, for example, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, among others. High boiling solvents, for example, cellosolve, butyl cel- losolve acetate, cellosolve acetate, methyl cellosolve acetate, butylcellosolve, ethyl cellosolve and phenylated sol¬ vents including xylene may also be used. Of course, these high-boiling liquids, because of their tendency to increase drying times are included in weight percentages in composi¬ tions of the present invention in amounts consistent with producing a nail composition which dries in less than three minutes. One of ordinary skill in the art will know to vary the weight percentages of acetone and methylethyl ketone and the other liquids used in compositions of the pres¬ ent invention within the teachings of the present invention to produce a large number of acceptable liquid or solvent combinations for use in nail enamel compositions which dry in a period of less than three minutes. In certain aspects of the present invention it has been found advantageous that the solvent system used in the creme pigmented nail enamel com-

positions according to the present invention include, in addition to an effective amount of acetone or methylethyl ketone to reduce the drying time of the nail enamel to below three minutes, a liquid diluent is included to provide favorable interaction with the nitrocellulose film-forming polymer.

In the present invention, it has been found advantageous to include acetone or methylethyl ketone in amounts ranging- from about 4.5% to about 35% (preferably above about 7% for acetone within this range and preferably above about 10-12% for methylethyl ketone within this range) , more preferably about 13% to about 30% and most preferably about 15% to about 25% by weight acetone or methylethyl ketone. In the present invention plates or needles of guanine are used in amounts ranging from about .125% to .50% by weight. In certain embodiments of the present invention in which pigment and the thixotropic agent Bentone RSNC^m _S included, about 12-18% by weight acetone or methylethyl ketone has been found to be quite advantageous.

The compositions of the present invention also generally include at least one additional solvent other than acetone or methylethyl ketone, and a liquid diluent. This additional solvent may be any solvent which is compatible with acetone and methylethyl ketone and provides solubility characteristics of the solvent system which are consistent with dissolving the primary film-forming polymer, the secondary film-forming polymer and the plasticizer and with forming a gel with the organoclay thixotropic agents which are used in the present invention. Exemplary additional solvents for purposes of the present invention include esters, preferably an ester of acetic acid such as methyl acetate, ethyl acetate, propylacetate, n-butyl acetate, amyl acetate and mixtures of theseesters in amounts ranging up to about 50% or more by weight of the nail enamel compositions, and preferably about 20% to about 30% by weight of the nail enamel compositions.

Liquid diluents which may not be not true solvents for the primary or secondary film-formers for use in the present invention include the aromatic diluents, for example, toluene, xylene and certain naphtha derivatives. Because of the regulatory implications of using certain of these diluents, a

number of substitutes for toluene may be included in composi¬ tions of the present invention. Substitutes for toluene include, for example, the previously mentioned esters of acetic acid such as methyl acetate, ethyl acetate propyylacetate and n-butyl acetate and also include certain chlorinated hydrocarbons, for example, methylene chloride, methylchloroform, various ketones other than acetone or methylethyl ketone and various hydrocarbons including hexane, heptane, cyclohexane and pentane and certain ethers, for example petroleum ether and higher boiling ethers, among others.

It is an especially surprising and unexpected result that acetone or methylethyl ketone in an amount ranging from about 4.5% to about 35% by weight of the final composition in combination with a solvent system which otherwise does not dry or evaporate within a period of three minutes on a human or artificial nail will dry in a time period less than three minutes. The solvents which are included with acetone or methylethyl ketone in the present invention are chosen for their ability, in combination with acetone and methylethylketone, to dissolve the primary film-forming polymer, the secondary film-forming polymer and the plasticizer and for their ability to provide a final static viscosity in combination with the solids of the compositions of the present invention including pigment and thixotropic agent in the range of about 300-400 to about 1200 centipoises, preferably about 800 centipoises. Solvents are chosen for their ability to provide adequate gel formation of the thixotropic agent(s) as well as for the previously described characteristics of dissolving the solid components of the nail enamel.

Solvent mixtures are particularly adapted for use in com¬ bination with pigmented polymer bases for use in nail enamel compositions. In this aspect of the present invention, a solvent mixture comprises acetone and methylethyl ketone in an amount equal to about 6% to about 70% by weight of the solvent mixture and at least one additional solvent to produce a solvent mixture which, in combination with a polymer base containing an organoclay thixotropic agent adapted for use in pigmented nail enamel preparations, provides a nail enamel

preparation comprising at least about 4.5% to about 35% by weight acetone and/or methylethyl ketone in combination with a diluent and guanine comprising from .125% to .50% by weight, said nail enamel composition having a static vis¬ cosity ranging from about 300-400 to about 1200 centipoises and drying in a period less than three minutes, the nail enamel providing a hard, flexible pigmented surface having acceptable wear characteristics including durability and high gloss.

The present invention includes a process for making the creme pigmented nail enamel compositions of the present inven¬ tion. Creme pigmented nail enamel compositions of the present invention are formulated by first mixing a solvent combina¬ tion (Solvent Blend A) including an amount of acetone and methylethyl ketone equal to about 6% to about 70% by weight of the solvent mixture in combination with an additional sol¬ vent and liquid diluent to produce a solvent mixture. An example of such Solvent Blend A is as follows:

Acetone 6.7%

Methylethyl ketone 23.6%

Ethyl Acetate 39.9%

Toluene 28.8%

N Butyl Acetate 1.0%.

Thereafter a solution of primary film-forming polymer is made by combining 50% by weight of the Solvent Blend A with 50% by weight of dry Nitrocellulose 1/2 second R.S. available from a number of manufacturers including Hercules of Philadelphia, Pennsylvania, to form a working solution. Since the above described nitrocellulose is wetted by the manufac¬ turer with 30% isopropyl alcohol, the formula is as shown in the following table as Example I.

TABLE - EXAMPLE I

Nitrocellulose Solution 35% Solid

Nitrocellulose R.S.

Grade Hercules 35%

Isopropyl Alcohol

(included in commercial nitrocellulose by manufacturer) 15%

Solvent Blend A 50%

Pigments for use in the present invention include for example, red pigments, including for example, D & C red Nos. 10, 11, 12 and 13, D & C red No. 7, TOB-BON maroon (D & C red No. 34) . Other pigments which may be used in compositions according to the present invention include the Lake pigments, for example, D & C yellow No. 5 Lake, D & C Red No. 2 Lake, and Ext. D & C Red No.2 Lake. In addition to the above-named pigments, additional pigments can include cosmetic-grade or purified titanium dioxide (white) , yellow and red iron oxides, iron blue, iron black, ultramarine blue, chromide oxidegreens, carbon black or lampblack (generally, in minute quantities) , among others. The above named colors areavailable in dispersed chip form. These chips are from the Penn Color Company, Doylestown, Pennsylvania.

A Solvent Blend B is prepared by mixing the following: Ethyl Acetate 44.0%

N Butyl Acetate 13.0%

Toluene 43.0%.

An organoclay thixotropic (pigment suspending) paste is produced by combining 10% by weight Bentone 27 (stearalkonium hectorite) with 90% by weight Solvent Blend B. The thixotropic paste elements are combined by blending using a very high shear explosion proof Waring blender or an equiv¬ alent high shear mixer as desired, such as sand mills, attritors or colloid mills, for five minutes until a thick particle free paste results.

Separate color solution are prepared for each color desired. For example, a color combination of the color D & c Red 7 with a white base titanium dioxide, combine 10% by weight D & C Red 7 chips with 5.0% by weight titanium dioxide chips with 85% by weight Solvent Blend B by mixing them together at a high speed with a laboratory or production cowles dissolver for ten minutes or until a smooth particle free color solution results.

Separate colors are prepared in exactly the same way. For example, a white color is produced by combining in thesa e way 10% by weight titanium dioxide chip with 90%

byweight Solvent Blend B. The color chips are commercially available from Penn Color, Inc., Doylestown, Pennsylvania. The final composition produced by the method according to the present invention obtains a final static viscosity ranging from about 300-400 to about 1200 centipoises.

A sample of red fast drying nail enamel was prepared from the previously described components produced according to the method of the present invention results in a working composition comprising the following: Nitrocellulose Solution 35% solids (primary film-forming polymer) 51.45%

Bentone 27 Paste (thixotropic paste) 10.0% Camphor 3.09%

Dibutyl Phthlate 6.77%

Color Solution

(or any of the previously described color solutions) 15.00%

Toluene Sulfonamide Resin 5.20%

Ketone Blend A 8.49%

Ketone Blend A is formed by mixing the following: Ketone Blend A (by weight)

Acetone 16.6%

Methylethyl ketone 83.4%

When the above working composition is broken down into its individual ingredients, it consists of the following:

Nitrocellulose 1/2 second R.S. 18.01%

Isopropyl Alcohol 7.72%

Acetone 3.12%

Methylethyl ketone 13.15%

N Butyl Acetate 3.08%

Toluene 16.76%

Ethyl Acetate 19.84%

Dibutyl Phthlate 6.77%

Camphor 3.09%

Bentone 27 1.00%

Titanium Dioxide chip .75%

D.C. Red chip 1.50%

Toluene Sulfonamide Resin 5.20%

After the above is formulated, .25% by weight guanine is added to unexpectably improve the film properties of the for¬ mulation while maintaining the desired drying time.

The above process and formula yielded a very attractive red nail enamel with good gloss. It had a very fast drying time of 60 seconds using the previously described method. Ten panelists were chosen to wear the formula and they found it to be a very satisfactory product with an exceptionally fast drying time.

While it is possible to produce the compositions of the present invention following the general procedures of the method aspect of the present invention, it is clearly preferred that all mixing of the nail enamel compositions and especially those containing an organoclay thixotropic agent, preferably stearalkonium hectorite, and pigment, be performed under high shear speed. Therefore, one of the more important aspects of the method of the present invention includes the use of vigorous stirring at high shear speed, for example using a Hoffmeyer industrial mixer for a period of time suf¬ ficient to produce a thixotropic gel, generally at least about one hour and preferably at least about two hours. There are four Solvent Blends which can be used where the combination can be varied to arrive at the same result. These are shown in the following mixtures for Solvent Blends C, D, E and F.

TABLE FOR VARIOUS SOLVENT BLENDS

Nitrocellulose solutions were made using the Solvent Blends C, D, E and F. According to the following tables:

Nitrocellulose Solution C

Nitrocellulose 1/2 sec. dry R.S. 35?

Isopropyl alcohol 15%

Solvent Blend C 50%

Nitrocellulose Solution 35% D Nitrocellulose 1/2 sec. dry R.S. 35%

Isopropyl alcohol 15%

Solvent Blend D 50%

Nitrocellulose Solution 35% E

Nitrocellulose 1/2 sec. dry R.S. 35%

Isopropyl Alcohol 15%

Solvent Blend E 50%

Nitrocellulose Solution 35% F

Nitrocellulose 1/2 sec. dry R.S. 35%

Isopropyl Alcohol 15%

Solvent Blend F 50%

Further, color solutions were prepared using chips supplied by Penn color according to the formulas. Solvent Blend A can be mixed with Solvent Blend C, D, E or F to arrive at the same result.

Solvent Blend B is used to make color solutions and thethixotropic paste.

To make color solutions, Solvent Blend B is mixed- pursuant to the Color Table to arrive at the colors B, C, D,E, F and G.

COLOR TABLE Color Solvent Blend B

B D & C Yellow 5 chip 15% 85%

C D & C Red 6 Chip 15% 85%

D D & C Red 34 chip 15% 85%

E Cosmetic inon blue chip 15% 85% F Cosmetic russet chip 15% 85%

G Titanium dioxide chip 15% 85%

The above chips and solvent were combined and mixed with a cowels laboratory disperser until smooth.

Additional nail polish formulas were made using the above colors and nitrocellulose solutions according to the following

SUBSTITUTES ET

formulas.

EXAMPLE II

Nitrocellulose Solution C 51.45%

Bentone27 paste 10.00%

Camphor 3.09%

Dibutyl phthlate 6.77%

Color Solution (G) White 5.00%

Color Solution (B) Yellow 2.50%

Color Solution (E) Blue 2.50%

Color Solution (D) Red 34 5.00%

Toluene Sulfonamide resin 5.20%

Methylethyl Ketone 8.49%

When the above mauve polish is broken down into its individual components, the amounts of each ingredient is as follows:

EXAMPLE II DETAIL (in % by weight)

Nitrocellulose 1/2 sec. R.S. 18.01

Isopropyl alcohol 7.72

Methylethyl ketone 16.28

N butyl acetate 3.09

Toluene 16.76

Ethyl acetate 19.83

Dibutyl phthlate 6.77

Camphor 3.09

Titanium dioxide chip 0.75

Yellow chip 0.375

Inon blue chip 0.375

Toluene sulfonamide resin 5.20

Bentone 27 1.00

The above formula yielded a mauve shade of creme nail enamel which was somewhat brittle on drying. The subjects wore polish for three days and it was found to be unsatisfac¬ tory because it chipped excessively from the nail .25% guanine was added to the formula and it was retested for wear. The problem of chipping was eliminated by guanine addi-

tion.

Example III describes a different shade combining colors D, F and G and nitrocellulose solution (from Solvent Blend- Table) when mixed according to the invention, will produce Example III as shown below.

EXAMPLE III

Nitrocellulose Solution D 51.45%

Bentone 27 paste 10.00%

Camphor 3.09%

Dibutyl phthlate 6.77%

Color Solution G 2.50%

Color Solution D 10.00%

Color Solution F 2.50%

Toluene Sulfonamide resin 5.20%

Acetone 8.49%

When the above is broken down into individual components, the amounts of each ingredient is as follows:

EXAMPLE III, IV and V DETAIL (in % by weight)

Again the examples were brittle, but useable. The brittleness was corrected by addition of guanine. It dried

faster than 1 minute as shown in Example III.

Examples IV & V were prepared using same colors as Exam¬ ple III, but with nitrocellulose solutions E & F.

EXAMPLE IV - V (in % by weight)

IV V

Nitrocellulose Solution E 51.45

Nitrocellulose Solution F

Bentone27 paste 10.00

Camphor 3.09

Dibutyl Phthlate 6.77

Color Solution G 2.50

Color Solution D 10.00

Color Solution F 2.50

Toluene Sulfonamide 5.20

Acetone 8.49

The various other components are shown in Column 3 and 4 of Example III, IV AND V Detail. Both examples IV and V dried in under one minute, both were brittle.

Example IV was treated with MPA 60, a polyethylene waxdispensed in toluene (a product of Rheox, Inc., P.O. Box 700, Hightstown, N. J. 08520) as a replacement for guanine. The product was added to the batch and mixed with a cowels dissolver until temperature rose to 60"C. The batch was allowed to cool. Example V was treated with .25% guanine. Both polishes were flexible after their respective treatments.

Compositions of the present invention for coating a natural or synthetic nail comprise the following ingredients: a) a primary film-forming polymer; b) a secondary film-forming polymer; c) at least one traditional plasticizer; d) at least one organoclay thixotropic agent; e) at least one pigment; f) an oil free plasticizer; and g) a solvent system comprising an amount of methylethyl ketone or acetone ranging from about 4.5% to about 35% by weight of said composition with said solvent system dis solving said primary and secondary film-forming

polymers and said plasticizer thixotropic agent to produce a composition having a static viscosity ranging from about 300-400 to about 1200 centipoises, said composition drying on a natural or synthetic nail within a period of less than three minutes.

In addition to the above components, the compositions according to the present invention may further comprise one or more additional agents, for example, stabilizers, fragrances, anti-oxidants and preservatives.

The compositions of the present invention contain a primary film-forming polymer for example, cellulose acetate, cellulose acetate-butyrate, ethyl cellulose, numerous vinyl- polymers as well as a number of methacrylate and acrylate type polymers and combinations of these polymers and related film- forming polymers as described herein. The preferred primary film-former for use in the present invention is nitrocel¬ lulose.

Nitrocellulose for nail enamel compositions of the present invention is of two standard types designated respec¬ tively, RS and SS, also designated European Type E and M, respectively. Another type of nitrocellulose, AS nitrocel¬ lulose, is generally not used in nail enamels. RS nitrocel¬ lulose, available from a number of manufacturers including S.N.P.E. of Bergerac, France (as the equivalent Bergerac type) and Hercules Inc., of Philadelphia, Pennsylvania, USA, the preferred nitrocellulose for use in nail enamels, is available in a wide range of viscosities.

Although a number of different nitrocellulose film- formers may be used in compositions of the present invention including RS 18-25 cp, RS 1/4 sec. and RS 5-6 sec. , European Standard 33, 28 and 11, Bergerac E19, E20, E27 and E80, it is preferred that nitrocellulose RS 1/2 second, available from Hercules, be used in the compositions of the present inven¬ tion. European Standard 22 and Bergerac E35 nitrocellulose may also be used in the present invention and in many aspects these nitrocellulose types may be substituted for nitrocellulose RS 1/2 second from Hercules. One of ordinary skill in the art will recognize that in formulating nail polish compositions according to the present invention, dif-

ferent viscosities of nitrocellulose may be used, depending upon the viscosity and other characteristics of the final com¬ position desired.

In general, the primary film-forming polymer is included in compositions of the present invention in amounts effective to provide toughness, hardness, resistance to abrasion, solvent release and a film thickness, in combina¬ tion with secondary film-forming polymers and traditional plasticizers. In general, the amount and type of primary film-formingpolymer is chosen so that the nail enamel, after drying on a natural or synthetic nail will have a thickness of about 2.5 mil to 6 mil, preferably about 3 mil after only one coat. While it is to be recognized that more than one coat of nail enamel may be used to coat nails according to the present invention, preferred compositions according to the present invention are compositions that provide acceptable character¬ istics including film thickness after one coat.

In general, the amount of primary film-forming polymer comprises about 5% to about 25% by weight of the com¬ positions, preferably about 9.0% to about 25% by weight of the compositions and most preferably about 14% to about 20% by weight of the composition.

In addition to the primary film-forming polymer, the com¬ positions of the present invention also include a secondary film-forming polymer which is added to the primary filmforming polymer for its ability to provide strength, gloss and adhe¬ sion. Exemplary secondary film-forming polymers which may be used in the present invention include alkyd resins (both drying and nondrying) , polyvinyl resins, for example, polyvinyl acetate, polyester resins, acrylic and methacrylic resins and arylsulfonamide-formaldehyde resins.

Toluenesulfonamide-formaldehyde resin, a condensation product of formaldehyde and toluene sulfonamide is especially preferred for use as a secondary film-forming polymer in the present invention. In general, the amount of secondary film¬ forming polymer used is that amount effective to strengthen the primary film-forming polymer and provide an effective gloss and adhesion. One of ordinary skill in the art will be able to determine the amount of secondary film-forming polymer which may be added to the compositions of the present

invention to produce the desired effect without engaging in undue experimentation. However, in general, the amount of secondary film-forming polymer to be used in the present invention ranges from about 3.0% to about 13% by weight of the composition, preferably about 4.0% to about 8% by weight and most preferably about 5.0% by weight of the composition. In addition to primary and secondary film-forming polymers, the compositions according to the present invention also include at least one traditional plasticizer. Traditional plasticizers for use in the present invention are added to soften and plasticize the primary film-forming polymer. The choice of plasticizer for a nail enamel composition may vary as a function of the color, odor, effect on viscosity of the enamel, effect on the drying rate, the amount needed to meet flexibility requirements, the volatility of the plasticizer and compatibility with the other components of the compositions. Traditional plasticizers for use in the present invention include tricresyl phosphate, diamylphthalate, dioctylphthalate, diphenylphthaiate, dibutoxyphthalate, dibutyl phthalate, diethyl phthalate, dibutyl tartrate, benzyl benzoate, tributyl phosphate, butylacetyl ricinoleate, butyl glycolate, butyl stearate, triphenyl phosphate, triethyl citrate, camphor, castor oil and dibutoxy ethylphthalate, among others. Preferred tradi¬ tional plasticizers for use in the present invention include dibutyl phthalate, camphor and especially mixtures of dibutyl phthalate and camphor. Care must be used to determine the level of traditional plasticizer used in commer¬ cial scale up to avoid brittleness of the primary film-forming polymer since the composition may become quite brittle when used with a full range of colors.

Traditional plasticizers are used to impart flexibility to primary film-forming polymer. Unexpectably, it has surprisingly been found that guanine crystals, in plate or needle form, which is an oil free material, has the ability to cooperate with or completely plasticize the primary film- forming polymer without any negative effect on the drying time. To the best of applicant's understanding, guanine has never been used as a traditional plasticizer or used in a creme pigmented nail polish as a plasticizing component.

SUBSTITUTE SHEET

Other alkaloids or compounds in the same general class as guanine, such as xanthine may perform as well as guanine.

Guanine is normally used as a pearlescent pigment in frosted type nail enamel in ranges from .75% to 1.25% by weight. Natural pearlescent (guanine) are crystals which are obtained from the scales of fish and give them their pearly lustrous appearance. There are two main categories of guanine: broad surfaced crystals called plates; and thin elongated crystals called needles. The main physical- properties of guanine are:

Refractive Index 1.85

Specific Gravity 1.6 gram/cc

Dimensions; plates 30x6 microns; needles 30x1 micro .

Guanine is commercially available from the Mearl Cor¬ poration, New York, New York. Because guanine is relatively expensive, only a small amount is used for this purpose and is used in conjunction with a traditional plasticizer. The com¬ bination is chosen to yield a flexible film which dries faster than three minutes and preferably less than one minute. By acceptable flexibility, we mean that the composition will evi¬ dence a substantial absence of cracking when a 6 mil film which has been dried on an aluminum strip surface for at least two hours is bent around a 0.25" mandrel (available from Gardner Corporation,Florida, USA) . In general, the amount of traditional plasticizer for use in the compositions of the present invention ranges from about 2.0% to about 7.5%, preferablyabout 3.0 to about 6.0% and most preferably about 3.5 to about 5.5% by weight. In cases where the primary film-forming polymer or secondary film-forming polymer is instilled with traditional plasticizer-like characteristics or with an absence of these characteristics, the amount of traditional plasticizer may vary below and above these ratios. In addition to the primary and secondary film-forming polymers and plasticizer, the compositions according to the present invention also include a solvent mixture containing acetone or methylethyl ketone and a liquid diluent in an amount ranging from about 6.0% to about 70% of the totalweight of the salvent. Because the total amount of solvent ranges from about 50% to about 75% by weight of the nail enamel

compositions of the present invention, the ketone mixture therefore comprises about 4.5% to about 35% by weight of the total weight of the nail enamel compositions. The amount of ketone included in the compositions is selected to create an interaction with the other solvents that are used in the compositions. It has surprisingly been found that acetone or methylethyl ketone used in combination with the additional solvents of the solvent combination will result in a nail enamel composition which will dry in less than three minutes. We note that the amount of methylethyl ketone which will be used to produce the favorable interaction will generally be significantly greater than is the amount of acetone which will produce the favorable drying interaction and drying times significantly less than three minutes. By "dry" we mean that the nail enamel compositions will evidence a substantial absence of tack with a cotton swab (Q-tip ^tm , available from Chesebrough-Pond's, Greenwich, Connecticut, USA) when drawndown on to a 3 mil thick layer on lineta cards (Lineta Company, Hohokus, New Jersey) at room temperature and a relative humidity of about 50 to 55%. Of course, the drying time of a nail enamel formulation will vary as a function ofthe temperature and relative humidity of the ambient atmos¬ phere.

In addition to acetone and methylethyl ketone, the inclusion of methylchloroform in compositions of the present invention in certain cases may have a beneficial effect on the drying time. However, the effect of methylchloroform is not nearly as great as that produced by the disclosed weight per¬ centages of acetone and methylethyl ketone.

While not being limited by way of theory, it is believed that acetone and/or methylethyl ketone are responsible for creating an interaction with the other solvents utilized in the present invention to substantially reduce the drying times of nail compositions to below three minutes. Such interaction may be due to the universality of solvency that acetone and methylethyl ketone display with almost any solvent or may be due to the formation of an azeotropic mixture having a boiling point lower than the individual components. As noted, acetone and methylethyl ketone are miscible with a very large number of different solvents which vary dramatically in solubility

characteristics. It is quite surprising that a combination of solvents which, in combination with the non-volatile com¬ ponents of the present invention, normally do not dry within a period even close to three minutes, dries in a period under three minutes with the inclusion of the disclosed amounts of acetone. Even more surprising is the fact that the inclusion of at least about 16% by weight acetone or methylethyl ketone in combination with other solvents will produce a pigmented nail enamel composition which will dry in about 60 seconds and in certain cases, in even less time.

The amount of acetone and methylethyl ketone included within the compositions according to the present invention varies between about 4.5% and about 35%. This range represents a guideline for inclusion of acetone and methylethyl ketone in compositions according to the present invention to produce a nail enamel composition which dries in less than three minutes. The lower limit of this range represents the least amount of acetone and methylethyl ketone that is used to pro¬ duce a nail enamel which dries in less than about three minutes. We note that in general, the amount of methylethyl ketone which is included to produce the three minute drying time is usually at least about 10-12% by weight. The upper limit of this range represents the amount of acetone above which begins to produce an unacceptable streaking effect on the enamel during coating. In addition, compositions con¬ taining more than about 35% acetone and methylethyl ketone tend to fall below acceptable viscosities. Compositions according to the present invention include an amount of acetone generally falling within this range, the amount of acetone to be included being determined by the desired drying time and the additional solvents which are added to produce the desired viscosity and flow characteristics.

In many of the commercial nail enamel preparations on the market, toluene, xylene or other aromatic solvent is included in varying amounts as a diluent. The use of toluene as diluent is to provide acceptable viscosities and other character¬ istics. In an additional aspect, the present invention also relates to quick-drying compositions which have acceptable characteristics and which exclude toluene and other aromatic solvents which may not be acceptable for inclusion in cosmetic

formulations by regulatory agencies. In this aspect of the present invention, toluene or other aromatic solvents are replaced with another solvents, especially one of the esters of acetic acid such as ethyl acetate or methyl acetate, among others. In fact, through choice of solvents, it ispossible to produce a nail enamel composition in which the solvent system is comprised of innocuous solvents. In addition, certain chlorinated hydrocarbons for example, methylchloroform, methylene chloride, chloroform and other solvents, for example, hexane, cyclohexane, pentane and- heptane, as well as numerous additional solvents may be usedto replace toluene and related aromatic solvents.

In creme compositions of the present invention which contain a pigment and an organoclay thixotropic agent, the choice of solvents which may substitute for the toluene or other aromatic diluent is limited. In these compositions, care must be taken to substitute a solvent which in combination with the diluent solvent produces a solvent combination which dissolves the primary film-forming polymer, secondary film-forming polymer and plasticizer and produces a gel in combination with the organoclay thixotropic agent. Care must be taken especially when choosing the amount and- type of diluent solvent(s) to be used. In certain cases, the use of very large quantities of non-polar solvents, for example, hydrocarbons such as hexane, heptane and pentane as well as other non-polar solvents, without the inclusion of sufficient amounts of more polar solvents, may affect the ability of the organoclay thixotropic agent to form a gel, which is preferably a colloidal gel. In addition, the inclusion of large percentages of highly polar solvents, for example, methanol, ethanol and isopropanol in certain com¬ positions may adversely affect the ability of the thixotropic agent to form a gel, preferably a colloidal gel and compositions to maintain storage stability for any com¬ mercially viable period of time. Therefore, as a guideline and general rule for formulating compositions of the present invention, polar substitutes for toluene as the liquid diluent in this aspect of the present invention should be limited to no greater than about 25% by weight of the total weight of the composition and preferably no greater than about 18% by weight

SUBSTITUTESHEET

of the composition. Preferably, substitutes for toluene in this aspect of the present invention include esters of acetic acid, for example methyl acetate, ethyl acetate and n- butylacetate, chlorinated hydrocarbons, for example, methylenechloride, chloroform and methylchloroform as well as other liquid diluents of similar polarity to toluene. Less polar diluents than those set forth above may also be used, but care should be taken to choose the amount and type of diluent(s)based upon the amount of acetone and wetting agent (both of which tend to be polar solvents) to be included in the compositions of the present invention.

Although the amount of pigment in compositions of the present invention will vary as a function of the type of pig¬ ment and other components included in the compositions, in general, pigments are included in an amount ranging from about 0.025 to about 4.0% by weight and preferably in an amount ranging from about 0.5 to about 1% by weight of the composi¬ tion. To provide a wide range of shades, it is necessary to include guanine in amounts from .125% to .50%, and preferably .25% as an oil free plasticizer. This range of guanine is generally below the amount required to produce a commercially viable pearlescent nail enamel. Applicant does not believe that the guanine used, pursuant to the present invention, dis¬ solves in the solvent blends, but could be providing the plasticizing effect by acting more like a reinforcing rod rather than a lubricating oil. Since pigments are included in compositions according to the present invention, it is useful to include an organoclay thixotropic agent for enhancing the suspension of pigment in the other components of the com¬ position. A number of organoclay thixotropic agents used in the nail enamel art may be used to produce compositions according to the present invention, including for example, bentonite, generally sodium bentonite and calcium bentonite, montmorillonite clay, which is generally a key component of bentonite, hectorites, which are trioctahedral hydrated sili¬ cate of magnesium and lithium of the montmorillonite group of clays having the general formula (Mg,Li)3Si4010(0H)2 and smectite, which are dioctahedral and trioctahedral clay minerals (montmorillonite and saponite) and their chemical varieties which are preferably modified with quaternary

ammonium compounds, for example as described in Remz, Cos¬ metics & Toiletries. 103, 70 (December, 1988). Preferred organoclay thixotropic agents for use in the present inven¬ tion include the hectorite clays modified with quaternary ammonium compounds as described above, especially stearalkonium hectorites.

Particularly preferred hectorites for use in the present invention include the Bentones ^tπι , available from NL Industries, New Jersey, USA. An especially preferred stearalkonium hectorite thixotropic agent for use in the present invention is Bentone RSNC^ ^m , available from PennColor, Doylestown, Pennsylvania USA. Bentone RSNCtm _ls a composition containing about 25% by weight stearalkonium hectorite milled to about 5 microns in nitrocellulose and plasticizer (camphor) . In particular, preferred compositions according to the present invention, thixotropic agent is included in an amount sufficient to pro¬ duce a gel, preferably a colloidal gel. In general, the thixotropic agent is included in the compositions of the present invention in amounts sufficient to produce a colloidal gel, usually from about .5% to about 3% by weight of the com¬ position, preferably about .75% to about 1.25% and most preferably about 1% by weight of the composition.

The use of a preferred thixotropic agent stearalkonium hectorite, and especially Bentone RSNC ^tm in compositions according to the present invention results in a gel which serves to suspend the pigment and maintain the pigment in suspension for extended periods of storage. The thixotropic agents which are used in the present invention are generally combined with pigment and a sufficiently polar solvent mixture containing sufficient quantities of acetone, a wetting agent and a diluent solvent(s) and mixed under shearing force (Hoffmeyer industrial mixer generally for a period of at least one hour, preferably two hours) . In this aspect of the pres¬ ent nvention, certain highly preferred compositions according to the present invention which include Bentone RSNC ^tm in suf¬ ficient quantity to produce a gel are storage stable, i.e., they maintain their viscosity, consistency and pigment in suspension without the need for significant shaking even after extended periods of storage.

It is important to note that the ketone-containing solvent mixtures chosen for use in compositions according to the present invention which contain this thixotropic agent should be of sufficient polarity to favorably interact with the stearalkonium hectorite to produce a gel upon standing. The gel which is produced in preferred embodiments of the present invention results in a suspension of pigment which will not settle to the same extent as nail enamel compositions which do not contain such a gel suspension. The compositions of the present invention which utilize stearalkonium hectorite thixotropic agents are therefore storage stable and may be applied to the nail even after periods of long storage by a simple shaking of the container before application. In many cases there is no need to include for example, a steel ball to enable a vigorous shaking of the composition before applica¬ tion as is required by many of the compositions of the prior art.

In addition to the above-described components, the com¬ positions of the present invention may also include additional additives including stabilizers, preservatives, anti-oxidants and fragrances and other additives including UV absorbers leveling agents and other additives, depending upon the desired result. These components are well known in the art and may be included in amounts well within the teachings of the art.

The nail enamel compositions of the present invention have characteristics of quick-drying, flexibility, durability, adequate viscosity and high gloss. The pigmented compositions of the present invention dry in a period of less than about three minutes. By "dry" we mean that the compositions will evidence a substantial absence of tack (absence of smudging) after a three minute drying period at room temperature and a relative humidity of about 50-55%. Compositions of the present invention are also flexible, i.e., the composi¬ tion will evidence a substantial absence of cracking when a 6 mil film which has been dried on an aluminum strip surface for at least about two hours is bent around a 0.25" mandrel (available from Gardner Corporation,Florida, USA). Composi¬ tions of the present invention are also durable and do not appreciably chip or crack for a period of at least about

three days of wearing on a human or synthetic nail.

The viscosities of compositions of the present invention are commercially acceptable. In general, as previously indi¬ cated, the static viscosities of the compositions of the present invention fall within the range of about 300-400 to about 1200 centipoises, preferably about 800 centipoises. For purposes of defining the present invention, static vis¬ cosities are determined on a Brookfield RVF viscometer after at least 24 hours of incubation at 25 C using a spindle #3 at 25°C and 20 RPM. In addition to static viscosities, shaken viscosities of the compositions according to the present invention are also generally commercially acceptable. Shaken viscosities differ from static viscosities and are determined in the following two ways. First, shaken viscosities are determined using a Brookfield LVF viscometer, spindle #3 at 60 RPM after the compositions are shaken for a brief period. The compositions of the present invention exhibit a shaken viscosity under these conditions generally ranging from about 250 to about 500 centipoises, with an optimum of about 400 centipoises. Additional shaken viscosities are determined at 6 RPM on a Brookfield LVF viscometer, spindle #3 at 25°C. Viscosities of the compositions of the present invention under these conditions generally range from about 800 to about 1200 centipoises, with an optimum of about 1000 centipoises.

Compositions of the present invention generally exhibit an acceptable gloss ranging from about 70 to about 95% reflection of light as determined by a Glossguard Meter (6 mil thick coating on an aluminum surface) . Preferably, the compositions of the present invention exhibit a gloss ranging from about 85 to about 95% reflection of light as determined by a Glossguard Meter.

In still another aspect of the present invention, sol¬ vent mixtures particularly adapted for use in combination with pigmented polymer bases for use in nail enamel composi¬ tions are also disclosed. In this aspect of the present invention, a solvent mixture comprises acetone or methylethyl ketone in an amount equal to about 6% to about 70% by weight of the solvent mixture and at least one additional solvent having a polarity sufficient to produce a solvent mixture which, in combination with a polymer base adapted for use in

nail enamel preparations comprising a primary, film-forming polymer, a secondary film-forming polymer, at least one plasticizer, an organoclay thixotropic agent and pigment, pro¬ vides a gelled nail enamel preparation containing at least about 4.5% to about 35% by weight acetone or methylethyl ketone having a static viscosity ranging from about 300-400 to about 1200 centipoises and drying in a period less than three minutes to a hard, flexible pigmented surface having acceptable wear characteristics including durability and high gloss.

To determine static viscosities, compositions were allowed to stand for at least 24 hours in a con¬ stant temperature bath at 25 C. Static viscosity tests were performed using a Brookfield LVF, spindle #3 at 12 RPM and 25 C. To determine static viscosity the dial reading was multiplied by a factor to determine approximate viscosity (e.g., 16 X 100 = 800 cps) . It should be noted that the static viscosities were determined in the following experi¬ ments with a Brookfield LVF, spindle #3, but are defined in the general invention using a Brookfield RVF, spindle #3 as those of ordinary skill in the art would define them. Because access to a Brookfield RVF was not available, the static viscosities in the following invention are presented using the available Brookfield LVF instrumentation. The compositions of the present invention have acceptable viscosities. Shaken viscosities were determined on a Brookfield LVF using Spindle #3 at 25 C: a) at 60 RPM. To determine viscosity the dial reading was multiplied by a factor to determine approximate viscosity (e.g., 20 X = 400 cps). b) at 6 RPM. To determine viscosity dial reading was multiplied by a factor to determine approxi¬ mately (e.g. , 5 X 200 = lOOOcps) .

Because of the nature of the viscosity determination, and may depend upon the amount of shaking done (variable) , shaken viscosities are believed to be less reliable than are the static viscosities.

This invention has been described in terms of thespecific embodiment set forth in detail herein, but it should be understood that these are by way of illustration

and the invention is not necessarily limited thereto. Modifications and variations will be apparent from the dis¬ closure and may be resorted to without department from the spirit of the inventions those of skill in the art will readily understand. Accordingly, such variations and modifications are considered to be within the purview and scope of the invention and the following claims.