Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1995-09-01
2001-07-31
Sellers, Robert E. L. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C424S070110, C424S070130, C424S070150, C424S070160, C524S516000, C524S521000, C524S522000, C524S523000, C524S524000, C524S525000, C524S560000, C524S561000, C524S563000, C524S564000, C524S565000
Reexamination Certificate
active
06268431
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to shampoo compositions which provide hair cleaning and styling benefits. These are achieved by dispersing polymer latex particles in shampoo compositions, wherein the latex polymer has a selected low glass transition temperature (Tg).
BACKGROUND OF THE INVENTION
Many hair shampoo compositions provide acceptable cleaning but provide little or no styling benefits, e.g., body, hold, stiffness. To realize such benefits, separate cleaning and styling products are often applied to hair prior to, during or after shampooing.
Recently, hair shampoo compositions have been developed which can provide cleaning performance with some styling benefits, all from a single product. Many of these products contain styling polymers in a compatible shampoo base. To prepare such products, styling polymers can be dissolved in an organic solvent and then incorporated into the shampoo base. The organic solvent thereafter helps disperse the styling polymer in the shampoo composition, and also helps enhance deposition of the styling polymer onto hair. The use of these solvents, however, can sometimes contribute undesirable odors to the finished product, or otherwise present formulation problems, e.g. compatibility with other materials in the shampoo composition.
To minimize the use of these organic solvents, latex polymers rather than dissolved polymers have been employed as a means of incorporating styling polymers into a shampoo composition. Latex polymer systems are stable dispersions, typically colloidal dispersions, of water insoluble polymer particles in a continuous aqueous phase. As such, there is little or no organic solvent to contribute undesirable odors or to otherwise present incompatibilities with other materials in the shampoo composition. Without the organic solvent, however, deposition of the latex particles onto hair, which is essential for allowing the styling polymer to set and form a film onto the surface of hair, can be problematic. Historically, styling polymers (both latex and dissolved polymers) for use in shampoos have been selected so as to have higher Tg values. It was believed that higher Tg polymers would form stiffer films on hair, thus providing improved styling performance. Latex polymers, however, with the higher Tg values often have poor deposition profiles thus making it desirable to add latex deposition aids, e.g., cationic polymers, or to increase the concentration of the latex polymer in the styling shampoo composition.
The foregoing considerations involving styling shampoo compositions and latex polymer systems indicates that there is a continuing need to identify latex polymer shampoos with improved latex deposition profiles and styling performance. Accordingly, it is an object of the present invention to provide such compositions, and further to provide such compositions that do not necessarily require the use of latex deposition aids, and further to provide such compositions with reduced or minimal levels of polymer latex to achieve the desired latex deposition profile and styling performance.
SUMMARY OF THE INVENTION
The present invention is directed to hair shampoo compositions which provide excellent cleaning and styling performance. Compositions of this type comprise dispersed polymer latex particles, wherein the polymer latex particles have a glass transition temperature (Tg) of between about −20° C. and about 10° C. The shampoo compositions will generally be in the form of pourable liquids under ambient conditions and contain one or more compatible surfactants, an aqueous carrier, and one or more other optional materials.
DETAILED DESCRIPTION OF THE INVENTION
“Soluble” and “insoluble” used in reference to particular ingredients of the shampoo compositions refer to solubility or insolubility, respectively, of that ingredient in the shampoo composition of the present invention, unless otherwise specifically indicated. For example the terms “water soluble” and “water insoluble”, as used herein, refer to solubility of the particular ingredient in water, as opposed to solubility in the shampoo composition.
All percentages, parts and ratios are based on weight unless otherwise specified.
“Water soluble” refers to any material that is sufficiently soluble in water (distilled or equivalent) at 25° C. to form a substantially clear solution containing at least about 0.1% by weight of the material.
“Water insoluble” refers to any material that is not water soluble as defined herein.
“Ambient conditions” refers to air temperatures of about 25° C. under about 1 atm of pressure.
“Comprising” means various components can be conjointly employed in the shampoo composition of the present invention. “Consisting essentially of” and “consisting of” are embodied in the term “comprising.”
Polymer Latex Particles
The shampoo compositions of the present invention comprise dispersed polymer latex particles, wherein the latex polymer particles have a selected glass transition temperature (Tg) range within which the shampoo compositions have improved latex deposition profiles and styling performance.
The polymer latex particles for use in the shampoo composition of the present invention have a glass transition temperature (Tg) of between about −20° C. and about 10° C., preferably between about −15° C. and about 8° C., more preferably between about −10° C. and about 5° C.
The latex polymer systems for use in the shampoo compositions are dispersions, preferably colloidal dispersions, of water insoluble polymer particles in a continuous aqueous medium. Once incorporated into the shampoo compositions, the latex polymer particles may be maintained as dispersed particles primarily by surfactant, and to some extent (in the case of colloidal dispersions) by the inherent dispersion characteristics of colloidal particles in such compositions. The dispersed particles will generally have an average diameter of less than about 4 &mgr;m, preferably from about 0.005 &mgr;m to about 1 &mgr;m, more preferably from about 0.05 &mgr;m to about 0.51 &mgr;m.
Latex polymer particles for use in the shampoo compositions may be nonionic, anionic, cationic, zwitterionic or amphoteric. Latex polymer latex particles are well known in the polymer art, and for purposes of the present invention, may be obtained, prepared or synthesized by any means provided that the resulting polymer latex particles have the requisite Tg values described herein, and provided that such polymers are compatible with the essential components of the shampoo compositions, or do not otherwise unduly impair cleaning and/or styling performance of the composition.
Methods for preparing latex polymer systems with selected Tg values are well known in the polymer art. Such methods include, but are not limited to, selecting monomers or comonomers for polymerization or copolymerization reactions based on the inherent Tg value of the monomer or comonomer, and/or combining comonomers during copolymerization in weight ratios calculated to provide copolymers with the requisite Tg value. Such methods will typically be employed during emulsion polymerization in an aqueous medium, although other polymerization techniques such as solution polymerization may also be used.
Monomers suitable for use in the polymerization or copolymerization methods described briefly herein, include, styrene, butadiene, ethylene, acrylonitrile, chloroprene, vinylidene chloride, isoprene, isobutylene and vinyl chloride, and esters of acrylic, methacrylic, vinylacetic, maleic, crotonic and itaconic acids. These monomers may be used alone or in combination, or they may be mixed with one or more ionic monomers, e.g., acrylic acid, methacrylic acid, to form charged polymer latex systems. Many other monomers are known for use in making latex polymers, and can be used for purposes of preparing the latex polymers herein.
Specific latex polymers for use in the composition include, but are not limited to, the following available latex polymer systems grouped according to manufacturer or distributor:
1. Avai
Schwartz James Robert
Snyder Michael Albert
Peebles Brent M.
Sellers Robert E. L.
The Procter & Gamble & Company
Tucker Joan B.
Winter William J.
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