A new standard for fixative performance: Noveon researchers have developed a unique polymer for hair styling products. The benefits of this new fixative polymer are detailed.

THE GLOBAL HAIR STYLING market is a lively and rapidly growing market. New product forms continually enter the market, driven by an increasingly diverse consumer population, more active lifestyles, changing demo- and psychographics, fast-moving hair and fashion trends and ongoing pressure from the regulatory environment. The convergence of these trends has led to the increased use of products that provide a strong foundation for styles, such as gels, mousses, conditioning stylers, pastes, cremes and lotions and other forms. Often, they are used without a second finishing step such as hair spray.

Ultimately, consumers want styling solutions, not just product forms. Loyalty is built on products that meet individual needs while delivering superior end benefits. For some, the desired result is volumizing and lift, while others want soft, springy, long-lasting curls or a defined curl pattern without frizz. Still others want sleek, straight styles or volume reduction and control of wavy hair. In the ethnic market, desirable benefits are a smooth, moisturized feel with a healthy-looking sheen. Today's younger consumers are experimenters, seeking products that enable creativity and styling "fun" with tactile appeal, beyond functional benefits.

Gone are the days when a good initial style with an hour or two of hold was enough. Regardless of the profile of the target consumer, today's products must provide longer-lasting style retention than ever before, enable versatility in the styling technique employed or in the appearance and feel of the finished style and allow for easy reshaping and restylability, without the necessity of shampooing and reapplication.

This has opened the door for a new standard in styling polymer technology that overcomes the deficiencies of traditional polymers, such as poor humidity resistance, excessive flaking, a stiff and/or raspy, rough feel on hair, tackiness and stickiness, style droop and poor efficiency in use.

New Fixate G-100 polymer (INCI: AMP-Acrylates/Allyl Methacrylate Copolymer) is a patented acrylic styling polymer that delivers dramatically better styling results, superior aesthetics and an enhanced feel on the hair, while meeting the formulator's need for efficiency, cost control and ease in manufacturing.

This new copolymer is from Noveon (formerly BF Goodrich), the makers of Carbopol polymers, a company with extensive experience in polymer technology and with strong applications expertise in the hair styling segment.

Structural Properties

The theoretical structure of Fixate G-100 polymer shows a highly branched, blocky copolymer with distinct hydrophilic and hydrophobic domains (Fig. 1). This yields a product that provides an optimal balance of humidity resistance and hold, without stickiness, flaking or buildup. Within the polymer design, the functionality of individual monomers contributes to the unique properties of the copolymer. In the hard, hydrophilic portion, methacrylic acid functionality provides firm hold, good wet combing and excellent solubility. In the softer, hydrophobic portion, polyacrylate functionality contributes to a clear, uniform film, enhanced humidity resistance, excellent adhesion and a soft, smooth finished feel on hair.

[FIGURE 1 OMITTED]

Application

Fixate G-100 polymer offers formulating versatility, from soft, touchable hold to a firm, crisp finish. It is suitable for use in aqueous, hydro-alcoholic, dispersion and emulsion formulas, (1) in products that range from water-thin to medium viscosity (35,000 mPa*s), (2) or in higher viscosity applications where clarity is less critical or where other ingredients are used to boost viscosity, as in cremes or pastes.

Fixate G-100 polymer is a liquid dispersion polymer, supplied as 26% solids in water. Therefore, unlike polymers supplied in solvents, the product presents no flammability hazard and requires no special handling, although care should be used to prevent freezing. For ease in use, the product is supplied pre-neutralized, at pH 6.0.

Superior Product Performance

High humidity curl retention is a key performance measure for styling products. Products formulated with Fixate G-100 polymer show exceptional performance in style retention and humidity resistance. This performance is demonstrated through quantitative tests which measure the percent curl retention of hair tresses, in 90% relative humidity at 25[degrees]C, over a period of eight hours. Tests were conducted using a starting gel formulation at pH 6.0, containing 1.0% fixative polymer solids and 1.0% Carbopol polymer solids.

In this test, nine clean tresses were treated, then wrapped on rollers mad allowed to dry overnight. Treated tresses were then carefully removed from rollers and hung in a high humidity chamber. Measurements were taken at regular time intervals to determine the effect of humidity on curl retention. A curled tress is said to have "failed" at the time when it displays less than 70% retention of its original curl. The 70% level is designated by the red line (Fig 2).

[FIGURE 2 OMITTED]

Tests showed that traditional fixative polymers (PVP, PVP/VA) lost their holding power in just an hour under test conditions, while Polymer X, a VP/acrylates/lauryl methacrylate copolymer, failed within two hours (Fig. 3). The gel formulated with Fixate G-100 polymer retained greater than 80% of initial curl after a full eight hours. Additional applications work has yielded formulas which enable 24 hours curl retention without failure (Fig. 4).

[FIGURES 3 & 4 OMITTED]

Efficiency in Use

Fixate G-100 polymer offers superior efficacy, even at lower use levels, as demonstrated by this formula containing just 0.7% fixative solids and 0.9% Carbopol 980 polymer.

Properties                                     Economy Styling Gel

Appearance                                       Crystal clear gel
pH                                                         5.6-6.0
Viscosity, initial (mPa*s)                           18,000-26,000
Clarity (%T)                                                 85-95
Stability                      Passed three months at 45[degrees]C
                                   Passed three cycles freeze/thaw
High Humidity Curl Retention            82% of original curl after
                                                           8 hours
                               80% of original curl after 24 hours
Fixate G-100 Polymer Solids                               0.70% wt.

Viscosity measured with a Brookfield RVT@20rpm, 25[degrees]C, #6 spindle. Clarity measured with Brinkmann PC920 colorimeter, 420nm. Humidity: 90% relative humidity at 25[degrees]C.

This economical, high clarity gel has superior aesthetic properties, is easy to apply and disperse through hair and provides excellent style support with long-lasting hold.

The photos at left (Fig. 5) demonstrate the curl retention results. After eight hours, tresses retained an average of 82% of initial curl, and after 24 hours, tresses still retained fully 80% of initial curl. In a repeat test with the same base formula, but with Fixate G-100 polymer at just 0.5% fixative solids, tresses still retained 80% of initial curl after eight hours, as well as after 24 hours, though this formula provided a less crisp feel on the hair.

[FIGURE 5 OMITTED]

Salon Evaluation vs. Traditional Fixatives

Salon tests were conducted to determine the effect of movement and "real life" wear conditions on style retention. Differences are clearly visible, even under test conditions of about 50% relative humidity, Importantly, the hygroscopic nature of traditional polymers suggests that results would have been even more dramatic at higher levels of humidity.

In one evaluation, spray gel formulas were compared in a half-head test (Fig. 6). One side featured PVP/VA 73W at 4.0% fixative solids with Carbopol 980 polymer at 0.3%, while the other side featured Fixate G-100 polymer at 1.0% fixative solids with 0.7% Carbopol 980 polymer to balance viscosity properties. Equal amounts of product were applied to each side and worked through hair. The hair was dried using a blowdryer, heat-styled with a curling iron, brushed through and finger-styled. Results were evaluated for initial style, style after brush-through and then style retention after three hours. The lines shown help to align features on the model for easier comparison, while the arrows designate the level of curl in each style. By comparing the location of arrows left to right in the top set of photographs, the significant style droop observed on the side that featured PVP/VA 73W is quickly evident. In contrast, the lower set of photographs demonstrates nearly complete style retention on the side that featured Fixate G-100 polymer, even with 75% less fixative polymer in the spray gel formula.

[FIGURE 6 OMITTED]

Superiority of curl formation is further demonstrated in the photo at left (Fig. 7). In this test, equal levels of polymer solids were compared, with 1.0% of Fixate G-100 polymer vs. 1.0% of PVP/VA 73W. The side styled with Fixate G-100 polymer shows significantly better lift, as well as better curl formation, even on this model with baby fine hair.

[FIGURE 7 OMITTED]

Consumers today are likely to have hair that has been damaged by one or more of the following factors: mechanical means such as combing, brushing and styling; thermal styling; environmental exposure; reactive chemistry used in coloring, lightening, texturizing or straightening. These consumers, especially, respond favorably to products which diminish the perception of damage and which enhance the feel, body and appearance of their hair, the sensory cues of "healthy hair."

Unlike traditional polymers that can provide spotty deposition or a rough texture on the hail, Fixate G-100 polymer provides a smooth, continuous flow over the hair (Fig. 8). This gives a unique leveling effect on hair which promotes better adhesion and cohesion and increases light refraction, leading to improved styling performance and hair that is left with a healthier, shinier appearance and an unsurpassed smooth feel.

[FIGURE 8 OMITTED]

Another critical success factor in styling is that the product shows no flaking or buildup. This is particularly important for consumers with dark hair, as in the Hispanic or Asian market segments, or when styling practices promote repeat application between infrequent shampoos, as in the ethnic market. Traditional PVP fixatives form a strong, but very brittle film that tends to be easily fractured and then flakes or dusts, visible at just 350X magnification (Fig. 9). Modification of the polymer with vinyl acetate (PVP/VA) minimizes flaking, but compromises film strength and hold properties. The exceptional film forming properties of Fixate G-100 polymer yields effective holding power, with virtually no flaking.

[FIGURE 9 OMITTED]

The carefully balanced hydrophilic and hydrophobic segments within the polymer structure, as well as its pH, also contribute to superior washability.

Formulation and Processing

Recommended use levels range from 1.9-11.5% as supplied (0.5-3.0% total solids), depending on application and desired properties. Fixate G-100 polymer is compatible with a wide variety of rheology modifiers, including Carbopol polymers (980, ETD 2020, Ultrez 21), cellulosics and other synthetic thickeners. Recommended Carbopol polymer use level is 0.7-1.0%, adjusted as needed to achieve the desired viscosity. AMP-95 is recommended for Carbopol polymer neutralization.

For gels, recommended use levels range between 0.5% and 1.0% (total solids), with optimal clarity achieved between pH 5.8 and 6.3. In cremes and lotions, use levels of 1.0-2.0% provide excellent results, and in pump sprays for scrunching or finishing, 3.0% or more, depending on hold and crispness desired/ In pump sprays, for best humidity resistance, 0.2% Carbopol 1980 polymer is recommended, providing a viscosity in the range of 300 mPa*s. The product is compatible with other commonly used fixative agents, which can be mixed to modify styling product properties. Importantly, it should be noted that the inclusion of hygroscopic fixative polymers, such as PVP or PVP/VA, may result in decreased humidity resistance when compared to the use of Fixate G-100 polymer as the sole fixative ingredient.

Fixate G-100 polymer provides flexibility in order of addition. The polymer may be added to formulation before or after neutralization of the Carbopol polymer, depending on the formulation and production requirements.

Compatibility

As shown in Fig. 10, Fixate G-100 polymer demonstrates good compatibility with many ingredients commonly used to condition, "soften" hold, or to modify other properties, without sacrificing hold or humidity resistance properties. Gels in this study, contained 1.0% fixative solids, 1.0% Carbopol ETD 2020 polymer solids, and 1.0% of the additive noted.

[FIGURE 10 OMITTED]

Cationic tolerance depends on the nature, charge density, and concentration of the cationic ingredient used. Because Fixate G-100 polymer is anionic, there may be a tendency for incompatibility with some cationic ingredients, or with cationics at high use levels.

In conclusion, new Fixate G-100 polymer clearly overcomes the deficiencies of traditional fixative polymers. Its patented structure and unique properties correlate with improved product flow over hair, superior humidity resistance and style retention, more elastic films with virtually no flaking, and an unsurpassed feel on the hair. With Fixate G-100 polymer, a whole new world of styling product possibilities awaits you.

For more information, visit www.carbopol.com or www.personalcare.noveoninc.com. Carbopol, Fixate and Ultrasil are trademarks or registered trademarks of Noveon IP Holdings Corp. AMP-95 is a registered trademark of The Dew Chemical Company.

Notes

(1.) Polymer has not been tested for use in hair spray applications. Noveon has conducted toxicology studies on experimental acrylate copolymers that are similar to Fixate G-100 polymer. These studies indicate that Fixate G-100 polymer has a low potential to cause skin irritation, eye irritation and skin sensitization when used in hair fixative formulations. Although Noveon has not conducted any inhalation toxicity testing on Fixate G-100 polymer, the inhalation toxicity of acrylate copolymers is described in the Final Report on the Safety Assessment of Acrylates Copolymer and 33 Related Cosmetic Ingredients, International Journal of Toxicology, 21 (Suppl.3): 1-50, 2002. EPA has noted that water soluble polymers are not the type of polymer that pose a high concern with respect to lung toxicity. However, Noveon recommends that formulators minimize the potential for exposure to the lower lung and avoid dispensing methods that create small particles (<10 microns), which can penetrate into the lower lung. This product is not designed or intended for use in applications that target the lower lung.

(2.) Viscosity measure Brookfield RVT spindle #6@20 rpm, 25[degrees]C.

By Julie Shlepr with Ramiro Galleguillos, Dan Hasman, Nancy Marchant, Julie-Schmucker-Castner, Francine Shuster, Catherine Smith, Dave Weaver and Joe Zellia.

Noveon, Inc. Cleveland, OH