FIELD OF THE INVENTION This invention relates to a cosmetic film forming composition which is especially useful as a nail coating composition which upon drying forms a film which will adhere to keratin of a nail. More particularly, the present invention relates to cosmetic film forming compositions which consist of aqueous emulsion (A) which comprises a sulfopolyester and a copolymer of vinyl acetate and dialkyl maleate, and aqueous emulsion (B) which comprises an aqueous emulsion of acetoacetoxyethyl alkylacrylate or the reaction product of acetoacetoxyethyl alkylacrylate with a vinylfunctional monomer. These cosmetic film forming compositions are fast drying, have good adhesive properties and are environmentally compatible.

BACKGROUND OF THE INVENTION Many types of cosmetic film forming compositions including nail coating formulations are available. The majority of such nail coatings are lacquers which consist of a nitrocellulose, aryl sulfonamide formaldehyde resin, plasticizer and organic solvent mixture together with a small proportion of colorant and other ingredients. These nail lacquers have the disadvantages of poor adhesion to the nail (keratin) , poor moisture vapor transmission, discoloration of the nail, and require a long drying time. In addition, the nail lacquers contain volatile organic solvents which cause safety, toxicological and environmental concerns.

Film forming compositions have been disclosed in U.S. Pat. Nos. 4,939,233, 4,946,932 and 4,158,053. U.S. Pat. No. 4,939,233 discloses film forming compositions that contain a polyester having repeat units from at

least one difunctional sulfomonomer containing at least one metal sulfonate group attached to an aromatic nucleus wherein the functional groups are carboxyl or hydroxyl, and an addition polymer having a majority of repeat units from vinyl acetate, wherein the later polymer is formed from monomers polymerized in an aqueous dispersion of said polyesters. The use of such compositions in nail polishes, produce films that exhibit poor adhesion, poor durability and poor water resistance.

U.S. Patent 4,946,932 discloses film forming compositions that contain an aqueous dispersion of a sulfonate group—containing polyester or polyesteramide and a polymer comprising repeat units from one or more α, β—unsaturated monomers. The use of such compositions in nail polishes, produce films that exhibit poor adhesion, poor durability and poor water resistance. U.S. Pat. No. 4,158,053 discloses aqueous nail coating formulations which are prepared by an aqueous emulsion polymerization of two or more monomers selected from alkyl acrylates, alkyl methacrylates and styrene compounds. The use of such formulations on nails, produce slow drying films that exhibit poor adhesion and poor durability. Thus, it would be highly desirable if a new cosmetic film forming composition could be developed that would provide better adhesive properties, water resistance, durability, vapor transmission, hold out, less odor, and faster drying times while maintaining high gloss without the presence of volatile organic compounds.

SUMMARY OF THE INVENTION Accordingly, it is one object of the present invention to provide a cosmetic film forming composition having improvements in one or more of the above desirable features.

Another object of this invention is to provide a cosmetic film forming composition which has little or no volatile organic content.

These and other objects are accomplished herein by a cosmetic film forming composition comprising:

(A) 30 to 85 weight percent of an aqueous emulsion comprising

(1) a sulfopolyester consisting essentially of repeat units from (a) a dicarboxylic acid selected from the group consisting of aromatic dicarboxylic acids, saturated aliphatic dicarboxylic acids, cycloaliphatic dicarboxylic acids, and combinations thereof; (b) a diol; and

(c) a difunctional sulfomonomer containing at least one sulfonate group attached to an aromatic nucleus wherein the functional groups are hydroxy, carboxy or amino, provided the difunctional sulfomonomer is present in an amount from 4 to 25 mole percent based on 100 mole percent dicarboxylic acid and 100 mole percent diol; and

(2) a copolymer having repeat units from 50 to 90 weight percent vinyl acetate and 10 to 50 weight percent of a dialkyl maleate having the formula

RO-C-HC=CH—C—OR which is polymerized in an aqueous dispersion of the sulfopolyester; and

(B) 15 to 70 weight percent of an aqueous emulsion containing acetoacetoxyethyl alkylacrylate having the formula:

or a reaction product of acetoacetoxyethyl alkylacrylate with a vinylfunctional monomer selected from the group consisting of CH _j =CH — COOR ² (I)

CH ₂ — G — CH ₃ (II) COOR ²

and mixtures thereof; provided that the total solids in the film forming composition is from 30 to 65 weight percent; wherein: R is a monovalent alkyl radical having 1 to 12 carbon atoms, R ¹ is a monovalent alkyl radical having 1 to 4 carbon atoms, R ² is selected from the group consisting of an alkyl radical having 1 to 20 carbon atoms, a substituted alkyl radical having 1 to 20 carbon atoms, phenyl, substituted phenyl, cycloalkyl, furfuryl, and tetrahydrofurfural, and R ³ is independently selected from the group consisting of hydrogen and an alkyl radical having 1 to 4 carbon atoms.

DESCRIPTION OF THE INVENTION Aqueous emulsion (A) contains a sulfopolyester and a copolymer. The sulfopolyester, component (1) , contains repeat units from a dicarboxylic acid, a diol and a difunctional sulfomonomer. Dicarboxylic acids useful in the present invention include aromatic dicarboxylic acids preferably having 8 to 14 carbon atoms, saturated aliphatic dicarboxylic acids preferably having 4 to 12 carbon atoms, and cycloaliphatic dicarboxylic acids preferably having 8 to 12 carbon atoms. Specific examples of dicarboxylic acids are: terephthalic acid, phthalic acid, isophthalic acid, naphthalene—2,6—dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl—4,4'—dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and the like. The polyester may be prepared from two or more of the above dicarboxylic acids.

It should be understood that use of the corresponding acid anhydrides, esters, and acid chlorides of these acids is included in the term "dicarboxylic acid".

The diol component of the polyester includes cycloaliphatic diols preferably having 6 to 20 carbon atoms or aliphatic diols preferably having 3 to 20 carbon atoms. Examples of such diols are: ethylene glycol, diethylene glycol, triethylene glycol, 1,4—eye1ohexanedimethano1, propane—1,3-dio1, butane—1,4—diol, pentane—1,5-diol, hexane—1,6—diol , 3-methylpentanediol—(2,4) , 2—methylpentanediol—(1,4) , 2,2,4—trimethylpentane—diol—(1,3),

2—ethylhexanediol—(1,3), 2 ,2-diethylpropane—diol—(1,3) , hexanediol—(1,3), 1,4—di—(hydroxyethoxy)—benzene, 2,2—bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-l,1,3,3—tetramethyl—cyclobutane,

2,2—bis-(3—hydroxyethoxypheny1)—propane, and 2,2-bis—(4-hydroxypropoxypheny1)-propane. The polyester may be prepared from two or more of the above diols. The difunctional sulfomonomer component of the polyester may be a dicarboxylic acid or an ester thereof containing a sulfonate group (—S0 ₃ ^~ ) , a diol containing a sulfonate group, or a hydroxy acid containing a sulfonate group. The cation of the sulfonate salt may be Na+, Li+, K+, NH ₄ +, and substituted ammonium. The term "substituted ammonium" refers to ammonium substituted with an alkyl or hydroxy alkyl radical having 1 to 4 carbon atoms. The difunctional sulfomonomer contains at least one sulfonate group attached to an aromatic nucleus wherein the functional groups are hydroxy, carboxy or amino. Advantageous difunctional sulfomonomer components are those wherein the sulfonate salt group is attached to an aromatic acid nucleus such as benzene, naphthalene, diphenyl, oxydiphenyl, sulfonyldiphenyl or methylenediphenyl nucleus. Preferred results are obtained through the use of sulfophthalic acid, sulfoterephthalic acid, sulfoisophthalic acid,

4—sulfonaphthalene—2,7—dicarboxylic acid, and their esters. The sulfomonomer is present in an amount from 4 to 25 mole percent based on 100 mole percent dicarboxylic acid and 100 mole percent diol. Preferred results are achieved when the difunctional sulfomonomer component is 5—sodiodiosulfoisophthalic acid or its esters, and the diol is a mixture of ethylene glycol or

1,4-cyclohexanedimethanol with diethylene glycol.

Component (2) is a copolymer having repeat units from 50 to 90 weight percent vinyl acetate and 10 to 50 weight percent of a dialkyl maleate or fumerate. The dialkyl maleate or fumerate has the general formula:

RO C—HC=CH—C OR

wherein R is a monovalent alkyl radical having 1 to 12 carbon atoms. The vinyl acetate and dialkyl maleate are polymerized in an aqueous dispersion containing the sulfopolyester (1) , to form a copolymer (2) . Preferably, the dialkyl maleate is dibutyl maleate. It is important to note that ethylene may be substituted for the dialkyl maleate or fumerate under certain processing conditions to achieve a satisfactory cosmetic film forming composition. It is preferred that the copolymer (2) be comprised of units derived from vinyl acetate present at levels at 80 weight percent and units derived from a dialkyl maleate present at levels of 20 weight percent. It is also preferred that aqueous emulsion (A) consist of from 5 to 20 weight percent of sulfopolyester (1) and from 80 to 95 weight percent of copolymer (2) .

Component (B) of the present invention is an aqueous emulsion containing acetoacetoxyethyl alkylacrylate having the formula:

wherein R ¹ is a monovalent alkyl radical having 1 to 4 carbon atoms. Preferably, the acetoacetoxyethyl alkylacrylate is acetoacetoxyethyl methacrylate. Component (B) may also be a reaction product of

acetoacetoxyethyl alkylacrylate with a vinylfunctional monomer of formulae I—III: CH ₂ =CH—COOR ² (I)

CH ₂ =C-CH ₃ (II) COOR ² R ³ -C=CHR ³ (III)

* \

%= .

In formulas I—III, above, R ² is selected from an alkyl radical having 1 to 20 carbon atoms, a substituted alkyl radical having 1 to 20 carbon atoms, phenyl, substituted phenyl, cycloalkyl, furfuryl, and tetrahydrofurfural. R ³ is independently selected from hydrogen and an alkyl radical having 1 to 4 carbon atoms. The term "substituted alkyl" refers to an alkyl radical substituted with phenyl, substituted phenyl, cycloalkyl, hydroxy, epoxy, C _λ to C ₄ alkoxy, or —N(R ⁴ )R ⁵ group. R ⁴ and R ⁵ are independently selected from hydrogen, Cj to C _g alkyl, and C, to C _g hydroxy alkyl. Examples of substituted alkyl groups are 2—hydroxyethyl, 2—ethoxyethyl, benzyl, 2—phenylethyl, 2,3-epoxy-l-propyl, cyclohexylmethyl, 2—cyclohexylethyl , 2,3—dihydroxypropy1, 2—dimethylaminoethy1 , 3—diethylaminopropyl, and 2—[ (N,N—di—2—hydroxyethyl)a ino]ethyl.

The term "substituted phenyl" refers to a phenyl radical substituted with one or more groups selected from C _j to C ₄ alkyl, Cj to C ₄ alkoxy, and halogen. Examples of substituted phenyl groups are 4—methylphenyl, 3,4-dimethylphenyl, 3—methylphenyl, 2—chlorophenyl, 4—chlorophenyl, 2,5—dichlorophenyl, 4—ethoxyphenyl, 4—n—butylphenyl, 3—isopropoxyphenyl, 4—t—butyloxyphenyl , 2—ethoxy—5—methylphenyl and

2,5-diethoxyphenyl. The term "cycloalkyl" refers to a C ₃ to C _g cycloaliphatic monovalent radical such as cyclopentyl and cyclohexyl.

Mixtures of such vinylfunctional monomers may also be reacted with acetoacetoxyethyl methacrylate and used as aqueous emulsion (B) . Aqueous emulsion (B) is present in an amount of from 15 to 70 weight percent, preferably 15 to 25 weight percent based on the total weight of components (A) and (B) . Examples of suitable acrylate esters, formula I, are methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, 2—ethylhexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, 2,3—epoxy—1—propyl acrylate,

2-dimethylaminoethyl acrylate, and lauryl acrylate.

Examples of methacrylate esters, formula II, are methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, phenyl methacrylate, benzyl methacrylate, propyleneglycol monomethacrylate, stearyl methacrylate, tetrahydrofurfuryl methacrylate, furfuryl methacrylate, 2—diethylaminoethyl methacrylate and hydroxyethyl methacrylate.

Examples of suitable aromatic vinylfunctional monomers, formula III, are styrene, 4—vinyItoluene,

2—vinyItoluene, a—methylstyrene, 4—isopropylstyrene, and diisopropenyl benzene.

In addition to the above three classes of vinylfunctional monomers, formulas I, II and III, additional optional vinylfunctional monomers may be reacted with acetoacetoxyethyl alkylacrylate; however, the total amount of any of the optional vinylfunctional monomers should not exceed 10 percent by weight of the vinylfunctional monomers of formulae I—III, and should preferably be less than 5 percent by weight. The

specific nature of the optional vinylfunctional monomer is not critical so long as the amount of any optional vinylfunctional monomer does not deleteriously effect the film forming properties of the formulations. The combination of aqueous emulsions (A) and (B) to be used in nail coating formulations have a total solids content from 30 to 65 percent, with a preferred range of from 45 to 55 percent. The total solids content of the aqueous emulsions (A) and (B) is controlled by the relative amounts of polymers which are used in the polymerization reactions and by the amount of water added during the polymerizations. The total solids content can be lower than 30 percent, but too low a solids content increases drying time and is not economical. To obtain the optimum thickness of a coating, the higher solids content is preferred. If the total solids content goes above 65 percent, viscosity increases rapidly and the viscosity will be too high to result in a suitable product. It has been discovered that the adhesion and durability of the nail coating formulations utilizing the film forming compositions of the present invention can be improved by incorporating a fixing or crosεlinking agent into the compositions of the present invention. The fixing or crosslinking agent is preferably applied directly to the nails (keratin) before the application of the nail coating formulation. Alternatively, the fixing or crosslinking agent may be incorporated into the nail coating formulation prior to applying the nail coating formulation to the nails. The fixing or crosslinking agents may be dissolved in water, acetone or a mixture of water and acetone at levels of 1 to 10 weight percent. Preferred are solutions containing 1% ZnCl ₂ , 4% water and 95% acetone, percentages by weight, or a solution containing 90 to 95

weight percent acetone and 5 to 10 weight percent of a triamine.

Useful fixing or crosslinking agents include divalent metals, trivalent metals, aldehydes, amino acids, diamines and triamines. Specific examples include zinc chloride, zinc acetate, formaldehyde, alanine and cystine. Preferred amines contain a polymeric portion consisting of poly(oxyalkylene) , such as JEFFAMINE 600 and 2000, available from Texaco Chemical Company. Formaldehyde has been found to be especially effective as a fixing agent in the case where a fixing agent is incorporated into a nail coating formulation, which contains the compositions of the present invention, prior to applying the nail coating formulation to the nails.

Many other ingredients can be added to the compositions of the present invention to enhance the performance properties of the nail polish. For example, preservatives, colorants, dispersing agents, wetting agents, thickeners, coalescing agents, antifoams, buffers, chelating agents and ultraviolet light absorbing agents, stabilizers, fillers, and the like, can be included herein. All of these additives and the use thereof are well known in the art. Any of these compounds can be used so long as they do not hinder the present invention from accomplishing its objects.

Components (A) and (B) of the present invention are prepared as aqueous emulsion polymers. In the case of aqueous emulsion (A) , the vinyl acetate and dialkyl maleate are added to an aqueous dispersion of the water—dispersible sulfopolyester and polymerized by free radical initiation in conventional emulsion or suspension polymerization processes. The polymerization can be initiated by a water—soluble free radical initiator known in the art such as sodium persulfate or

by an oil—soluble initiator such as benzoyl peroxide. Other useful initiators include non—redox initiators, such as persulfate salts, hydrogen peroxide, and organic peroxides; redox initiators, such as sodium persulfate, sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium thiosulfate, and sodium formaldehyde sulfoxylate. Redox initiators require an activator, such as ferrous sulfate heptahydrate, and ferrous ammonium sulfate. The preferred initiators are persulfate salts, sodium formaldehyde sulfoxylate, and ferrous sulfate heptahydrate.

The sulfopolyesters which are used in the present invention typically become very viscous at concentrations above 30 percent solids. Thus, the reaction typically is begun with a polyester dispersion that is 30 percent total solids or less. However, the water—dispersible polyester dispersions which are prepared by the process of the present invention can be prepared at final total solids levels up to 65 percent. The increase in solids level is achieved during polymerization by controlling the amount of water, if any, which is added along with the vinyl acetate and dialkyl maleate. By decreasing the amount of water added during the polymerization, increasing total solids contents up to 65 percent is possible.

In a preferred embodiment, the sulfopolyester is prepared by melt polymerization, and an aqueous dispersion containing 5—35 weight percent, preferably from 10 percent to 30 percent total solids, is prepared from the sulfopolyester directly. A mixture of the vinyl acetate, dialkyl maleate and the polymerization initiators are then added to the aqueous dispersion of the sulfopolyester and polymerization initiated to produce an aqueous dispersion. The aqueous dispersion

so produced can be prepared with total solids contents from 10 percent to 65 percent.

In the case of aqueous emulsion (B) , the acetoacetoxyethyl methacrylate alone or in combination with a vinylfunctional monomer of Formulae I—III, is combined with water, initiator and surfactant, and polymerized by free radical initiation in conventional emulsion or suspension polymerization processes. The polymerization can be initiated by a water—soluble free radical initiator known in the art such as sodium persulfate or by an oil—soluble initiator such as benzoyl peroxide. Other useful initiators include non—redox initiators, such as persulfate salts, hydrogen peroxide, and organic peroxides; redox initiators, such as sodium persulfate, sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium thiosulfate, and sodium formaldehyde sulfoxylate. Redox initiators require an activator, such as ferrous sulfate heptahydrate, and ferrous ammonium sulfate. The preferred initiators are persulfate salts, sodium formaldehyde sulfoxylate, and ferrous sulfate heptahydrate.

More than one surfactant may be used, and a combination of anionic and non—anionic surfactants are possible. Cationic surfactants are rarely used. The anionic and non—anionic surfactants are preferred. Examples of suitable non—ionic surfactants are alcohol— ethylene oxide condensates, fatty acid—ethylene oxide condensates, phenol—ethylene oxide condensates, modified alkyl resins, and sorbitol—fatty acid adducts.

Preferred non—ionic surfactants are phenol—ethylene oxide condensates and modified alkyl resins. Examples of suitable anionic surfactants are polyether sulfonates, dialkyl sulfosuccinateε, alkyl and alkaryl sulfonates, dialkyl sulfosuccinamides, alkyl sulfates.

and phosphate esters. Preferred anionic surfactants are polyether sulfonates and alkyl sulfonates.

The aqueous emulsions prepared in this manner are suitable for cosmetics where film forming properties are desired. The compositions of the present invention are especially useful in nail coating formulations. To obtain the most effective utilization of the compositions of this invention as nail coatings, it is recommended that the nails be cleaned prior to applying the nail coating composition. Useful cleaning compounds include ethyl acetate, acetone, toluene, xylene and the like.

The invention will be further illustrated by a consideration of the following examples, which are intended to be exemplary of the invention. All parts and percentages in the examples are on a weight basis unless otherwise stated.

EXAMPLE 1 Sulfopolyester (1) was prepared by the following procedure.

A mixture containing 73.66 grams isophthalic acid (0.44375 moles), 15.08 grams of 5—sodiosulfoisophthalic acid (0.05625 moles), 68.1 grams of diethylene glycol (0.6425 moles), 15.48 grams of 1,4—cyclohexanedimethanol (0.1075 moles), 0.19 grams of titanium isopropoxide, and 0.847 grams of sodium acetate tetrahydrate, was prepared. The mixture was placed in a 500 mL round bottom flask under a nitrogen atmosphere. The flask was immersed in a Belmont bath. The mixture was heated with stirring to 200°C. After two hours, the temperature was increased to 280°C. and maintained for one hour under reduced pressure of 0.5 to 0.1 mm of Hg. The flask was allowed to cool to room temperature and the copolyester was removed from the flask. The polymer had an I.V. of

0.45 and a glass transition temperature of 30°C. as measured using a differential scanning calorimeter (DSC) . The polymer which was transparent and amorphous was extruded and pelletized.

EXAMPLE 2 Aqueous emulsion (A) was prepared by the following procedure.

A mixture containing 856.0 grams of the sulfo—polyester prepared in Example 1, 1384.0 grams of deionized water, and 6.0 grams of ammonium persulfate, was prepared. The mixture was heated to 70°C. and 1400.0 grams of vinyl acetate and 360.0 grams of dibutyl maleate were added over a period of three hours while the mixture underwent agitation. The temperature and agitation were maintained for four additional hours before cooling the mixture to room temperature.

The pH of the aqueous emulsion was adjusted to 5.0—5.5 by the addition of concentrated ammonium hydroxide and the emulsion was filtered through a 53μm nylon mesh filter. The emulsion had a weight average molecular weight of 58,998 and a number average molecular weight of 8,095 as measured by gel permeation chromatography (GPC) . Content of solids was 50% by weight.

The polymer composition consisted of 12% by weight of sulfo—polyester, 88% by weight of copolymers of vinyl acetate and dibutyl maleate, with the vinyl acetate derived units making up 70% by weight and the dibutyl maleate derived units making up 18% by weight of the total polymer composition.

EXAMPLE 3 Aqueous emulsion (B) was prepared by the following procedure.

A mixture containing 1372.9 grams of deionized water, 43.1 grams of Alipal CO—436, and grams of anionic surfactant, was prepared. The mixture was placed in a three liter jacketed flask equipped with an agitator, nitrogen sparge and a temperature probe. The mixture was heated to 70°C. under a surface nitrogen sparge. A monomer blend containing 150 grams of acetoacetoxyethyl methacrylate, 324 grams of butyl acrylate and 526 grams of methyl methacrylate, was prepared. Ammonium persulfate, 4.0 grams was dissolved in 152.4 grams of water. A portion of the monomer blend, 100 grams, was added to the flask while dropwise addition of the ammonium persulfate initiator solution was begun, and agitation was continued. Following an exotherm, the remaining monomer blend was added under the surface with a simultaneous dropwise addition of the ammonium persulfate initiator solution over a period of three hours. The temperature was maintained at 70°C. throughout the addition of monomers and for an additional twenty minutes while the remainder of the ammonium persulfate initiator solution was added. After cooling to room temperature, the emulsion which had a solids content of 40% by weight was filtered through a medium paint filter to remove any large particles. Particle size determination showed an effective particle size of 63 nm. By GPC analysis, a weight average molecular weight of 480,422 and a number average molecular weight of 83,930 were determined.

EXAMPLE 4 Nail coating compositions were prepared by the following procedure.

A mixture containing 80.0 grams of the aqueous emulsion of Example 2 and 20.0 grams of the polymer composition of Example 3, was prepared. The mixture was applied to fingernails which had been cleaned with either Solution A, B, C or D:

Solution A was prepared by dissolving 1.0 gram of ZnCl ₂ in a mixture containing 95.0 grams of acetone and 4.0 grams of deionized water.

Solution B was prepared by dissolving 5.6 grams of JEFFAMINE 600, which is available from Texaco Chemical Company, in 94.4 grams of acetone.

Solution C was prepared by dissolving 2.0 grams of aluminum ammonium sulfate in a mixture containing 60.0 grams of acetone and 38.0 grams of deionized water. Solution D was HYDROTRITICUM 2000 which is a hydrolyzed whole wheat protein available from Croda, Inc.

In each case the nail polish dried in less than one minute and exhibited a glossy finish, good vapor transmission, excellent adhesion and durability. In addition, no chipping was observed after four days of wear.

EXAMPLE 5 Nail coating compositions were prepared by the following procedure.

A mixture containing 10.0 grams of the aqueous emulsion prepared in Example 3 was blended with 1.14 grams of a 37% formaldehyde solution in deionized water. The mixture, 2.0 grams was blended with 8.0 grams of the aqueous emulsion of Example 2 and 1.1 grams of finely divided red pigment (D. & C. Red 17) .

The nail polish was applied to fingernails which had been cleaned with acetone. The nail polish dried in less than one minute and exhibited a glossy finish, good

vapor transmission, excellent adhesion and durability. In addition, no chipping was observed after three days of wear.

Many variations will suggest themselves to those skilled in this art in light of the above detailed description. All such obvious modifications are within the full intended scope of the appended claims.