Patent Application
20080139765
The present invention relates generally to improvements of wear resistant cosmetic compositions. Specifically, this invention relates to a cosmetic composition containing particular copolymers with glass transition temperatures greater than 70° Celsius that demonstrate enhanced wear in combination with a smooth, non-tacky feel. Since most carrier solvents formulated into cosmetics are weak solvents with high boiling points and slow evaporation rates the cosmetic films stay wet and tacky thus yielding an inferior product poor in cosmetic performance. The polymers of the present invention overcomes this deficiency due to the high Tg associate with the polymer which yields an apparent faster dry time in the applied coating thus improving the cosmetic's film integrity. A material's glass transition temperature, Tg, is the temperature below which molecules have little relative mobility. Tg is usually applicable to wholly or partially amorphous phases such as glasses and plastics. For inorganic or mineral glasses, such as common silicon dioxide (SiO2) glass, it is the mid-point of a temperature range in which they gradually become more viscous and change from being liquid to solid. Thermoplastic (non-crosslinked) polymers are more complex because, in addition to a melting temperature, Tm, above which all their crystalline structure disappears, such plastics have a second, lower Tg below which they become rigid and brittle, and can crack and shatter under stress. Small molecular weight pure substances such as water have just one such condensed-phase temperature, below which they are solid crystals (or amorphous ice if cooled below Tg fast enough) and above which they are liquids. Above Tg, the secondary, non-covalent bonds between the polymer chains become weak in comparison to thermal motion, and the polymer becomes rubbery and capable of elastic or plastic deformation without fracture. This behavior is one of the things which make most plastics useful. But such behavior is not exhibited by crosslinked thermosetting plastics which, once cured, are set for life and will shatter rather than deform, never becoming plastic again when heated, nor melting.
Cosmetic coatings formulated with various organic waxes, solvents, polymers, additives and film formers that are known in the art to impart uniform films protective barriers can be compounded for the skin, hair and lips. The deleterious effects caused by the slow evaporation rate of the solvents typically utilized in cosmetic formulations result in slow dry time, poor adhesion and tend to delaminate off the surface to which they are applied. The tack and poor adhesion lead to product transfer which requires the consumer to reapply the product more frequently
Current products that reduce the dry time also have limitations. The key limitations are an objectionable tacky feel to the skin, lips or lashes on application and a tendency to pull against the skin when applied.
Accordingly, there is a need to develop a wear resistant product that can be applied to the hair, skin, lips or nails that will balance the dry time of the cosmetic while not compromising the film properties.
U.S. Pat. No. 6,083,516 issued Jul. 4, 2000 to Curtis, et al entitled Wear resistant cosmetics teaches that wear-resistant cosmetic products can be formulated in cosmetically acceptable carriers using polymers from about 0.1 weight percent to about 15 weight percent that incorporate an alkyl cycloalkylacrylate constituent incorporated on the polymer, preferably from about 0.1 weight percent to about 15 weight percent.
Since cosmetic products are not permanent coatings the solvents act more like a plasticizers than solvents. By increasing the glass transition temperature (Tg) or hardness of the polymer the apparent dry time is much faster. The quick “dry to touch” yields a tack free, durable temporary film. However, as the solvent continues to evaporate the coating will become more brittle and eventually fail. The failure should not be observed by the end user due to the short time for expected use.
We have surprisingly found that using aliphatic acrylates and methacrylates specifically t-butyl methacrylate in combination with other monomers typically used in vinyl polymerization, polymers with Tg's greater then 70 degrees Celsius can be formulated for solubility and performance for use in the personal care products. Polymers that have been heretofore unavailable can be made. Such polymers are extremely soluble in weak solvents with low solubility constants or low Kb values. By varying the isomers, adjusting the carbon length and molecular weight it is possible to offer polymers that are soluble in cosmetic carriers, with fast dry time that do not have the limitations stated previously.
Against the foregoing background, it is a primary object of the present invention to provide a cosmetic composition having superior wear resistance.
Another object of the present invention to provide cosmetic compositions that produce quick drying protective films on the skin, hair or lips.
It is yet another object of the present invention to provide a wear resistant cosmetic composition that is neither tacky, dry nor drags against the skin, hair or lips upon application.
To the accomplishment of the foregoing objects and advantages, we have surprisingly found that the present invention directed to wear-resistant cosmetic composition must include tertiary butyl methacryaltes and C18-C22 acrylates and methacrylates. Multiple polymers were synthesized with various dry times, glass transition temperatures, flexibility and functionalities for improved performance.
The present invention is drawn to a process for making a compound conforming to the following structure:
wherein;
The present invention is also drawn to a polymer prepared by reacting:
In a preferred embodiment the present invention is also drawn to a polymer prepared by reacting: a first monomer conforming to the following structure CH2═CH—C(O)—O—C(CH3)3 with a second monomer conforming to the following structure CH2═CH—C(O)—OR1 to be soluble in characteristic cosmetic solvents and having a Tg greater than 70° Celsius;
wherein;
wherein said reaction is a free radical reaction conducted in the presence of a free radical initiator selected from the group consisting of t-amyl peroctoate, benzoyl peroxide, azobisisobutrylnitrile and mixtures thereof.
The present invention provides a wear-resistant cosmetic such as, for example, a lipstick, a makeup, a sunscreen, blush or mascara. It has surprisingly been found that a polymer of the present invention provides superior wear resistance to such cosmetic compositions or formulas, both alone and preferably in combination with an alkyl cycloalkylacrylate copolymer. Moreover, it has surprisingly been found that cosmetic formulas containing the compounds of the present invention are non-tacky and have a pleasant feel when applied to the skin. These compositions are easy to apply, have improved skin and lip adherence (transfer resistance), and provide enhanced wear and longevity.
Most preferably, the wear-resistant cosmetic composition according to the present invention includes a polymer of the present invention in a cosmetically acceptable carrier. In a preferred embodiment the ratio of the first monomer to the second monomer ranges from 1:10 to 1:1. In a more preferred embodiment the ratio of the first monomer to the second monomer ranges from 1:10 to 1:2.
The reaction is a free radical reaction conducted in the presence of a free radical initiator selected from the group consisting of t-amyl peroctoate, benzoyl peroxide, azobisisobutrylnitrile and mixtures thereof.
Polymers of the Present Invention
The polymers of the present invention are prepared by reacting acrylate monomers, one having an alkyl group C18-C22, and the other having a tertiary butyl carbon arrangement. This is very important for the properties of the product. Additionally a cosmetically acceptable solvent is used. By cosmetically acceptable is meant the solvent has no mal odor. Finally a free radical initiator is added. Free radical imitators are well known in the art. Preferred initiators are selected from the group consisting of t-amyl peroctoate, benzoyl peroxide, azobisisobutrylnitrile and mixtures thereof.
Procedure:
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The compounds of the present invention provide cosmetic compositions that demonstrate enhanced wear in combination with a smooth, non-tacky feel. Since most carrier solvents formulated into cosmetics are high boiling, slow evaporating solvents, the resulting films remain wet and tacky resulting in poor cosmetic performance. The polymers of the present invention overcome this deficiency by making use of polymers with high glass transition temperature to compensate for the long evaporation time of the solvent.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth hereinabove but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains.
This application claims priority to and benefit of U.S. Provisional Application No. 60/873,076, filed Dec. 7, 2006, the disclosure of each of which are incorporated herein for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 60873076 | Dec 2006 | US |
