Recent Patent Applications for the Use of Polymers for Hair Care

One of the endeavors of the Institute for Formulation Science at the School of Polymer & High Performance Materials at the University of South Mississippi is to closely monitor patents. Here is a look at selected advances in polymers in hair care that have been reported in recently published US Patent Applications.

New Conditioners, Safer Conditioners
Conditioning can be achieved by treating the hair with silicones in leave-in and rinse-off applications. Henkel researchers have proposed an improvement in such hair treatment from a product containing PEG-10 dimethicone and cyclopentasiloxane.¹ It is interesting that the method of evaluation was differential thermal analysis of the hair. It is reported that the treatment raised peak temperature from 150° to 153° and this was postulated to show a more stable hair structure after treatment. This transition probably corresponds to the melting of the alpha helical protein structure of the hair keratin. In this context it is interesting that it has been claimed that individuals can be identified by the differential scanning calorimetry curves of their hair.²

Hair colorants are increasingly featuring mild ingredients.

Polymersomes are giant vesicles that are made from amphipathic block copolymers.³ The molecular weight of the block copolymers is much greater than phospholipids and this confers greater stability on polymersomes than phospholipid vesicles. Shiseido researchers have taken advantage of this vesicular stability by incorporating cationic surfactant conditioners into poly(oxybutylene-oxyethylene) polymersomes to enhance the skin safety of topical application of the cationic surfactants.⁴

Permanent waving is also known to damage the hair. Homogeneity of permanent waving and natural feel of the hair can be imparted by including the zwitterionic polyurethane-39 (for example Merquat 3330) in the reducing part of the perming composition.⁵

A variation of this theme has been accomplished by Shih-Ruey Chen and Kevin Frederick.⁶ It is notable that Shih-Ruey Chen was co-inventor of the amphoteric terpolymers that became polyquaternium-39. Chen and Frederick’s new adaptation involves polymerizing anionic monomers in the presence of alkylamines to form the anionic polymer/cationic “surfactant”complex in situ.

The complex is included in shampoo and conditioner compositions to confer feel and conditioning benefits to hair. For example, acrylic acid, sodium acrylamidopropane sulfonate, and acryloylethoxyethyl trimethylammonium chloride were polymerized in the presence of soyamidopropyl dimethylamine, in aqueous solution, to synthesize the desired complex. It is notable that the claimed composition is one that is formed by [batch] polymerizing the aforementioned monomer mixture; the difference in reactivity ratios of these monomers would be expected to produce a “gemische” of various polymer compositions rather than a single terpolymer.

Cationic Biocidal Conditioning Polymers
Cationic polymers are useful as hair conditioners but they also can show efficacy as biocides. The advantage of such polymers is that they can act as preservatives during product storage, and as germicides on surfaces but they are too large to penetrate the skin barrier on topical application. This provides a perception of safe use on human substrates. BASF has a long history of producing cationic imidazolium polymers and the company recently demonstrated that such polymers are effective microbiocides in shampoo and conditioner formulations. These imidazolium polymers are effective against microorganisms for long time periods. Moreover, they can be used in human hygiene biocidal products, health area disinfectants, food area disinfectants and even as drinking water disinfectants. These compounds promise to be useful in our continual battle to control pathogens while maintaining human health.

Benefits of Hydroxypropylation
Conventional conditioning shampoos contain cationic polymers that form complex coacervates with anionic surfactants. Most commonly the cationic polymers are polyquaternium-10 or guar hydroxypropyltrimonium chloride. A recent application divulges that these conventional cationic polymers tend to leave the hair sticky and it is revealed that cationic hydroxypropylcellulose confers both good feel and good manageability to the hair.⁸

In a continuation of the trend toward sustainable materials, hydroxypropyl starch has been shown to be an effective fixative for temporary styling of hair even in a high humidity environment^9,10 especially if nonionic or anionic fixative resins, such as PVP/VA copolymer, or chitosan, are included in the formulation.^11,12 Hydroxypropyl starch phosphate (Structure XL from Akzo Nobel) enhances the viscosity and stability of formulations thickened with conventional associative thickeners.¹³ Starch compounds have a tendency to clog aerosol valves. Clogging may be averted by the inclusion of specific stearates in the formulation.¹⁴

Hydrophobic Modification Enhancements
A recent application from L’Oréal claims shampoo compositions containing a liquid C10-30 alcohol and a nonionic associative thickener.¹⁵ The alcohols are in the formulation to impart conditioning benefits and the role of the associative thickener is to provide a stable viscous composition that can be metered into the hand with the added benefit of providing improved lathering. The patent application acknowledges that natural polymers such as cellulosics have been used for this purpose but it charges that these natural polymers give unstable or inhomogeneous compositions. A long list of nonionic associative thickeners are disclosed but the only thickener that is exemplified is Rheolate FX 100 (from Elementis).

A hydrophobically-modifed polymethacrylate (acrylates/beheneth-25 methacrylate – Novethix L10 polymer from Lubrizol) finds use in difficult-to-thicken zwitterionic surfactant systems.¹⁶ Shampoo systems are often thickened by the addition of salt. The salt causes a change in micelle structure to worm-like micelles with enormous effective molecular weights. The worm-like micelles effectively behave like polymers in solution to enhance the viscosity of the shampoos. However, zwitterionic surfactants tend to phase separate and do not thicken upon the addition of salt. Moreover, conventional high molecular weight polymeric thickeners confer undesirable mucus type of rheology and micellar associative thickeners thin on hot days. The acrylates/beheneth-25 methacrylate, when blended with a zwitterionic surfactant, overcomes these problems and confers thickening with desirable rheological characteristics.

Hair bleaching compositions usually comprise a mixture of an aqueous hydrogen peroxide with a water-free powder containing a peroxide salt. The mixture is applied to hair for a specified time and bleaching is achieved. However, bleaching compositions cause hair damage. This damage can be mollified by the addition of cationic polymers to the bleaching composition. These polymers do not usually enhance the bleaching performance, but Kao researchers have discovered that a special cationic polymer, polyquaternium-67, does enhance the performance and also leaves hair in good condition with respect to combing, grip, elasticity, shine manageability, body and volume.¹⁷

Polyquaternium-67 (SoftCAT SK conditioning polymers from Dow Chemical) is just like the classic cationic hydroxyethylcellulose polyquaternium-10 (Polymer JR) except that polyquaternium-67 has dodecyl groups substituted on some of the quaternary amines. It is interesting that the researchers found that the enhanced performance was not realized when polyquaternium-10 was used.
Another hydrophobically-modified polymeric quaternium salt of hydroxyethylcellulose is polyquaternium-72 (Mirustyle CP from Croda). Polyquaternium-72 is the polymeric quaternary ammonium salt of hydroxethylcellulose reacted with a coco-alkyl dimethyl ammonium substituted epoxide and its primary feature is its ability to fix hair tresses with curl memory. That is, the curls can be stretched or deformed many times but every time they return to the style in which they were originally set. Henkel researchers prescribe the use of polyquaternium-72 in hair rinses and conditioners to impart bounce and velvety feel to the treated hair.¹⁸

Hydrophobically-modified sugars have been brought forward as a way to impart durable semi-permanent shape to the hair by L’Oréal researchers.¹⁹ The use of sugars in hair care is not new. For example, Hollenberg introduced glucose to improve the tactile and elastic properties²⁰ and to repair damaged hair.²¹ However, the L’Oréal researchers used hydrophobically-modified saccharides to achieve their goal of semi-permanent styling. The ingredient used was cetearyl wheat straw glycosides (Xyliance from Soliance), which, interestingly, is supplied as an emulsifier rather than a hair styling aid.
Hair fixatives that allow the hair to be restyled continue to be sought. One way to achieve restylability is to essentially plasticize the hair fixative resin and, in this context, some hairspray polymers can be plasticized by sugar alcohols.²² This approach also offers the prospect of water-based products that offer good styling properties with low viscosity and no stickiness even in high humidity environments.^23,24 In this case the fixative reins can be well-known fixatives and the sugar alcohols are selected from maltitol , soribitol, mannitol, arabitol, galactitol, xylitol, erythritol, inositol or derivatives such as polyoxypropylene sorbitol (Uniol HS-1600D). The preferred sugar alcohol plasticizers confer styles that can be reshaped at will.²⁵

Reshaping can also be achieved by applying a fixative that can be molded when hot but sets when cold. For example N-propionylethyleneimine/dimethylsiloxane copolymer applied to the hair allows the hair to conform to a desired style that can be re-shaped by heating the hair to about 50°C with a hair dryer.²⁶ Moreover, this polymer provides good feel characteristics to the styled hair.

Frizzy hair can be controlled by polyamides that are made from dimer acids, alkyldiamines and polyether diamines.^27,28

Latex Reemerges in New Forms
Latex polymers based upon ethyl acrylate and methacrylic acid are well-known thickeners. When copolymerized with other alkyl(meth)acrylates, the polymers are useful hair fixatives. In an extension of this technology, Dow Chemical researchers have found that inclusion of styrene as a co-monomer raises the refractive index and confers shine to the hair, and the inclusion of hydroxyethyl methacrylate enhances the polymer solubility, giving rise to clear fixative solutions that enhance the shine even more.²⁹ In another variant on this theme, detangling with good removal from the hair is attributed to comb copolymers prepared from methacrylic acid, ethyl acrylate and a macromer having a chain comprising polyoxyethylene and polyoxypropylene.³⁰ Similar polymers with hydrophobic main chains (for example by including styrene in the monomer mix) function as thickeners for aqueous formulations.³¹

Another multifunctional thickening latex polymer, with thickening and film-forming properties, is polyacrylate-1 crosspolymer. Commercial variants of polyacrylate-1 contain dimethylaminoethylmethacrylate (DMEAMA) as a co-monomer. However, dimethylaminoethyl methacrylate is unstable in aqueous formulations due to hydrolysis of the DMEAMA, which is initiated by “backbiting” of the lone pair on the nitrogen on the electron deficient carbonyl group.

The hydrolytic character of these polymers is reported to be improved by the use of dimethylaminopropyl methacrylate and substantially improved by the use dimethylaminodimethylpropylmethacrylate.³² These monomers resist the backbiting hydrolysis because they are less likely to form the cyclic intermediate. Polymers with the latter monomer show good long term stability with respect to viscosity, yield stress and turbidity.

Polymers in latex form offer the advantages of high solids ingredients in water as carrier. However, the aqueous phase must be preserved. This aspect is a negative quality in a European market that is driving toward “preservative-free” products. Preservative-free lattices can be produced by drying the latex but that leads to an undesirable dustiness. One way to overcome this drawback is to prepare the polymer as beads by suspension polymerization rather than emulsion polymerization. However, it is difficult to remove residual monomer from beads obtained from the polymerization of methacrylic acid, ethyl acrylate and n-butyl methacrylate.

DSM researchers have discovered that removal of residual monomer is facilitated by including ethyl methacrylate as a monomer in the polymerization mixture.^33,34 The result is a polymer produced as non-dusty beads with low residual monomer content. The polymer (with an INCI name of acrylates copolymer and a tradename of Tilamar Fix A1000 from DSM Nutritional Products) is soluble in water and ethanol when neutralized with 2-amino-2-methylpropanol and it confers excellent curl retention even at 90% relative humidity.

Mousse continues to be a viable product category and Kao researchers have, interestingly, described foams comprising any cationic polymer and any aqueous thickening polymer in combination with volatile and non-volatile silicones and fixative polymers give good foam, good cracking sound when the foam collapses and good hold properties on the hair.³⁵

From Lips to Hair
In cosmetic formulation it is not uncommon for innovation to occur by transferring an ingredient from one product category to another. One case in point is the recent re-deployment of a lip moisturizer to become an ingredient in the hair colorant category.³⁶

Hair colorants tend to increase the porosity of hair and this makes it easier for the color to be leached from the hair by shampoo. The color fading that results is a disadvantage to the consumers and it is especially prevalent among the red tones that are in vogue.

An Avon researcher has discovered that color retention can be improved by treatment of the newly colored hair by the film-former triisostearyl trilineolate (Schercemol TIST Ester from Lubrizol). This ester, which is commonly used as a moisturizer for lip care formulations, is believed to form a water resistant film on the hair. The color-retentive properties are improved further by the inclusion of the silicone polyurethane bis hydroxypropyl dimethicone/(SMDI) copolymer and perfluorononyl dimethicone (Pecosil from Pheonix Chemical).

References

1. Knappe, Thorsten; Richters, Bernd; Unencumbering hair treatment product, United States Patent Application 20120201773, August 9, 2012, assigned to Henkel AG.
2. E. Y. Ionashiro1; T. S. R. Hewer1; F. L. Fertonani; E. T. de Almeida; M. Ionashiro; Application of differential scanning calorimetry in hair samples as a possible tool in Forensic Science, Ecletica Quimico, 29, (2004), 53-56.
3. Discher, B.M.; Won, Y-Y.; Ege, D.S.; Lee, James C-M.; Bates, F.S.; Discher, D.E.; Hammer, D.A.; Polymersomes: Tough vesicles from diblock copolymers, Science, 284, (1999), 1143.
4. Sugiyama; Yuki; Ohmori; Takashi; Koga; Nobuyoshi; Polymersomes and production method thereof, US Patent Application 20120231055, September 13, 2012, assigned to Shiseido Company.
5. Wood, Jonathan; Hullmann, Alexandra; Schneider, Jorg; Process for permanent shaping of human hair, US Patent Application20120255573, October 11, 2012, assigned to Kao Germany.
6. Chen; Shih-Ruey T.; Frederick Kevin W. Water soluble polymer complexes with surfactants, US Patent Application 20120251475, October 4, 2012, assigned to WSP Chemicals & Technology.
7. Konradi, Rupert; Siemer, Michael; Sobotka, Bettina; Koltzenburg, Sebastian; Haberecht, Monika; Compositions containing polymeric, ionic compounds comprising imidazolium groups, US Patent Application 20120244095, September 27, 2012, assigned to BASF SE.
8. Doi, Yasuhiro; Terazaki, Hiroyuki; Takai, Masanori; Mizushima, Hiromoto; Hasebe, Yoshihiro; Hair cosmetic, US Patent Application 20120230934, September 13, 2012, assigned to Kao Corporation.
9. Schweinsberg, Matthias; Knappe, Thorsten; Roenisch, Ralf; Schriefers, Mathias; Dogan, Carine, Composition for Shaping Keratin Fibres Containing Starches Modified with Propylene Oxide, US Patent Application 20120201774, August 9, 2012.
10. Schweinsberg, Matthias; Roenisch, Ralf; Schriefers, Mathias; Dogan, Carine, Compositions for Shaping Keratin Fibres Containing Starches Modified with Propylene Oxide, US Patent Application 20120207695, August 16, 2012.
11. Mueller, Burkhard; Kaftan, Pamela; Bayersdoerfer, Rolf; Schweinsberg, Matthias; Roenisch, Ralf; Schriefers, Mathias; Dogan, Carine; Knappe, Thorsten; Reineking, Miriam; Agent for treating keratin-containing fibers, containing a non-ionic starch modified by propylene oxide and an additional film-forming and/or stabilizing nonionic polymer, US Patent Applications 20120207692, 20120207693, and 20120207694, August 16, 2012.
12. Mueller, Burkhard; Kaftan, Pamela; Bayersdoerfer, Rolf; Schweinsberg, Matthias; Roenisch, Ralf; Schriefers, Mathias; Dogan, Carine; Knappe, Thorsten; Agent for temporarily styling keratin-containing fibers, containing a non-ionic starch modified by propylene oxide and a chitosan, US Patent Application 20120213724, August 23, 2012.
13. Hashimoto Tomohiro; Aqueous composition for cosmetics and cosmetic including the same, US Patent Application 20120237462, September 20, 2012, assigned to Akzo Nobel N.V.
14. Mueller, Burkhard; Heinsohu, Ulrike; Aerosol comprising a starch compound and a (c8 to c20) monocarboxylic acid compound, US Patent Application 20120258052, October 11, 2012.
15. Mathonneau; Estelle, “Cosmetic composition comprising a surfactant, a liquid fatty alcohol and a nonionic associative polymer, and cosmetic treatment method”, US Patent Application 20120247498, October 4, 2012, Assigned to L’Oreal.
16. Galleguillos, Ramiro; Mullee, James E.; Purohit, Pinky G.; “Surfactant-Polymer Blends”, US Patent Application 20120213725, August 23, 2012, Assigned to Lubrizol Advanced Materials.
17. Schafer, Sabine; Hullmann, Alexandra; Bleaching composition, US Patent Application 20120251604, October 4, 2012, Assigned to Kao Germany GMBH.
18. Krueger; Marcus; Delowsky; Jens; Hair treatment agents comprising polyquaternium-72, US Patent Application 20120204895, August 16, 2012, assigned to Henkel AG.
19. Nguyen, Nghi; Cannell; David W., Heat activated durable styling compositions comprising saccharide type compounds and film forming agents, US Patent Application 20120213723, August 23, 2012.
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21. Hollenberg and Matzik, Seifen, Oele, Fette, Wachase 117(1) (1991)
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24. Kurashima, Takumi; Shimizu, Hideki; Toyoda, Tomonori; Fujiyama, Taizo; Hair Styling Cosmetic Composition, US Patent Application 20120251472, October 4, 2012, assigned to Shiseido company
25. Schweinsberg, Matthias; Kuhnert, Oliver; Marchese, Luca; Method of creating hairstyles that can be remodelled, US Patent Application20120199155, August 9, 2012.
26. Fukuhara, Kazuhisa; Tada, Kiyotake; Kodate, Takashi; Kobaru, Shuichiro; Hair styling method, US Patent Application 20120216823, August 30, 2012, assigned to KAO Corporation.
27. Schweinsberg, Matthias; Kuhnert, Oliver; Marchese, Luca, Cosmetic product for controlling frizzy and unmanageable hair, US Patent Application20120199154, August 9, 2012.
28. Schweinsberg,; Matthias; Marchese, Luca; Dogan, Carine; Bayersdoerfer, Rolf; Polyamides of fatty acid dimers and diamines for fixing a hairstyle, US Patent Application 20120204896, August 16, 2012,
29. Collin; Jennifer Reichl; Hallden-Abberton, Michael Paul; Falcone, Beth Ann; Wang, Miao; Zeng; Fanwen; Hair styling composition, US Patent Application 20120240953, Sept. 27, 2012.
30. Suau, Jean-Marc; Guerret, Olivier; Comb polymers for the hair, US Patent Application 20120251474, October 4, 2012, assigned to Coatex S.A.S.
31. Souzy, Renaud; Suau, Jean-Marc; Kensicher, Yves; Guerret; Olivier; Cosmetic formulation containing a non water-soluble amphiphilic copolymer as thickening agent, US Patent Application 20120230920, September 13, 2012, assigned to Coatex A.S.
32. Tamareselvy, Krishnan; Filla, Deborah S.; Purohit, Pinky G.; Hydrolytically Stable Multi-Purpose Polymer, US Patent Application 20120237465, September 20, 2012, assigned to Lubrizol Advanced Materials
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