Silicone Quaternium-22: New Silicone
Transcription
Silicone Quaternium-22: New Silicone
6-2009 English Edition International Journal for Applied Science • Personal Care • Detergents • Specialties S. Herrwerth, I. Ulrich-Brehm, U. Kortemeier, P. Winter, M. Ferenz, B. Grüning: Silicone Quaternium-22: New Silicone Technology for Premium Hair Conditioning with Additional Benefits CO S M ET I C S HAIR CARE S. Herrwerth**, I. Ulrich-Brehm*, U. Kortemeier*, P. Winter*, M. Ferenz*, B. Grüning* Silicone Quaternium-22: New Silicone Technology for Premium Hair Conditioning with Additional Benefits Material Conditioning agents must adsorb to the surface of hair in order to perform effectively. The surface of the hair contains protein structures forming anionic centers. In instances of chemical damage, e.g. by bleaching, dying or perming, the number of anionic groups is even higher due to the generation of oxidized protein groups such as cysteic acid. Therefore cationic molecules are a preferred class of conditioning agents providing the required affinity towards hair. Cationic conditioners ensure a pronounced conditioning effect, especially on damaged areas. The currently available cationic modified polydimethylsiloxanes (Fig. 1) are composed either of unmodified linear siloxane backbones with quaternary groups at each end or comb-like siloxane chains with quaternary groups attached to the silicone chain. The undisturbed silicone backbone of the linear siloxanes provides a good conditioning effect, but each molecule possesses only two cationic groups at the sides which can cling to the hair’s surface. In the comb-like cationic siloxanes as well as in the often used amodimethicone derivatives, the silicone chains are disturbed by organic modifications and thus do not provide a conditioning effect that is as good as the linear structures. On the other hand, more than two cationic anchor groups can be incorporated into the molecules leading to an improved substantivity. The new patent protected technology of Silicone Quaternium-22 represents a clear SOFW-Journal | 135 | 6-2009 Abstract ilicone Quaternium-22 (Trade name: ABIL® T Quat 60) represents a major step ahead in silicone conditioning technology. Verified by Confocal Laser Scanning Microscopy, ABIL® T Quat 60 shows excellent substantivity to hair due to its unique triple cationic charge. In addition to the outstanding conditioning profile, Silicone Quaternium-22 offers impressive heat protection properties, an improved color wash-fastness of dyed hair, a superior skin feel and enhanced foam properties. The excellent processability of Silicone Quaternium-22 ultimately turns it into a premium and at the same time easy to use conditioning agent. S improvement over the traditional structure. The T-shaped silicone backbone carries three quaternary groups, while at the same time the silicone domain is expanded in another dimension (Fig. 2). The length of the uninterrupted silicone chain is a decisive factor contributing to the exceptional properties of silicone. Correspondingly, the T-shape further improves the already excellent characteristics of silicone conditioners while at the same time the increase in cationic centers enhances the adherence to hair and other protein surfaces. Fig. 1 Current cationic modified siloxane technology 1 CO S M ET I C S HAIR CARE The composition of the new Silicone Quaternium-22 is 65% active Silicone Quat and 35% PPG-3 Myristyl Ether. The substantivity of Silicone Quaternium-22 on hair via delivery out of a conditioner rinse was confirmed by Confocal Laser Scanning Microscopy (CLSM) (1). For this trial a special derivative of Silicone Quaternium-22 was prepared and labeled with fluorescein, a fluorescent marker (Fig. 3). The covalent bond between fluorescein and the silicone ensures a true labeling without significantly changing the molecular structure and surface interaction. The modified Silicone Quaternium-22 was incorporated into a conventional conditioner rinse formulation (Table 1). After application and rinsing of this test formulation, single hair fibers were examined with CLSM (Fig. 4). The reflection mode (a) shows the topography of the hair fiber. The image in fluorescence mode (b) shows the localization of the labeled material on the same fiber area. This demonstrates that due to its unique triple cationic charge, Silicone Quaternium-22 is highly substantive to hair out of a conditioner rinse application. Conversely, untreated hair used as a control, did not display any fluorescence. Performance Tests The multiple performance benefits of Silicone Quaternium-22 can be demonstrated in various tests. The prototypical conditioning profile was scored by sensory assessments. To examine the additional benefit of heat protection the thermal stability of hair fibers was examined using Differential Scanning Calorimetry (DSC). Employing the use of a spectrophotometer, the efficiency of Silicone Quaternium-22 in improving color wash fastness was established by the measurement of color values. Subsequently skin feel and foam quality were evaluated through hand washing trials. Conditioning Profile via Sensory Assessment Two types of cosmetic hair treatments have been applied as model systems: a standard shampoo (Table 2) and condi- 2 Fig. 2 T-shaped cationic modified siloxane technology of Silicone Quaternium-22 Fig. 3 Structure of the covalently Fluorescein labeled Silicone Quaternium-22 Test material VARISOFT® 300 TEGINACID® C TEGO® Alkanol 16 Citric acid Water Silicone Quaternium-22 with fluorescein marker Cetrimonium Chloride (CTAC) Ceteareth-25 Cetyl Alcohol 1.5% 1.0% active 0.5% 5.0% to pH 4 ad. 100.0% Table 1 Test formulation 1: Conditioner rinse Fig. 4 Substantivity of Silicone Quaternium-22 was proven by Confocal Laser Scanning Microscopy with covalently Fluorescein labelded Silicone Quaternium-22 SOFW-Journal | 135 | 6-2009 CO S M ET I C S HAIR CARE tioner rinse (Table 3). The test compound Silicone Quaternium-22 has been incorporated into these base formulations in a standardized procedure. The evaluation was carried out using bundled European hair (length = 18 cm, weight = 4 g, supplier: Kerling International Haarfabrik GmbH, Germany). The hair was predamaged by an intensive standardized bleaching process, which simulates typical damage by products commonly found in the market. The conditioning performance was assessed in a sensory hair swatch test by a panel of 10 experts using a standardized scale of 1–5, with »1« representing poor performance and »5« characterizing excellent performance. The findings of the sensory assessment for Detangling, Wet Comb and Wet Feel as the most important sensory parameters are shown in Fig. 5 for a conditioner rinse with various amounts of Silicone Quaternium-22 and in Fig. 6 for a shampoo formulation with 0.8% weight percent Silicone Quaternium-22. The conditioner rinse formulation was based on Ceteareth-25 and Cetyl Alcohol, using Cetrimonium Chloride (CTAC) as the organic standard conditioning agent (Table 3). It is common in the Personal Care industry to use silicone derivatives in combination with organic quats because of their known synergistic effects. Therefore the test material Silicone Quaternium-22 was examined in a base formulation containing CTAC. As can be seen in Fig. 5 the well known, sound conditioning properties of CTAC can be improved significantly by the addition of Silicone Quaternium-22 in low concentrations. The shampoo formulation was based on a combination of Sodium Laureth Sulfate and Cocamidopropyl Betaine with Cationic Guar as the standard conditioner (Table 2). Due to the pronounced substantivity of this cationic modified, hydrophilic polymer, Cationic Guar is applied as a so-called »deposition polymer« in shampoo formulations. In this function it supports the activity of silicone based conditioning agents and increases the amount of the silicone based conditioning agents that are adsorbed onto the substrate. SOFW-Journal | 135 | 6-2009 ABIL® T Quat 60 Silicone Quaternium-22 Texapon NSO (28% a.m.) TEGO® Betain F 50 (38% a.m.) Jaguar C 162 Sodium Laureth Sulfate NaCl ANTIL® 171 Oleate/Cocoate Citric Acid Water Cocamidopropyl Betaine Hydroxypropyl Guar Hydroxypropyltrimonium Chloride 0.8% versus 0% in control formulation 24.0% 6.0% 0.2% 1.2% PEG-18 Glyceryl 2.5% to pH 5.5 ad. 100.0% Table 2 Test formulation 2: Shampoo ABIL® T Quat 60 VARISOFT® 300 Silicone Quaternium-22 Cetrimonium Chloride (CTAC) TEGINACID® C TEGO® Alkanol 16 Citric acid Water Ceteareth-25 Cetyl Alcohol various % active 1.0% active versus 0% in control formulation 0.5% 5.0% to pH 4 ad. 100.0% Table 3 Test formulation 3: Conditioner rinse Fig. 6 illustrates the explicit improvement in score for the combination of Cationic Guar and Silicone Quaternium-22. The sensory assessment shows that Silicone Quaternium-22 exhibits outstand- ing conditioning properties on hair from conditioner rinse and shampoo formulations. It significantly improves the combability of the hair and leads to excellent manageability. uFig. 5 Sensory Assessment of hair tresses. Various % Silicone Quaternium-22 in conditioner rinse formulation. Low concentration of Silicone Quaternium-22 provides outstanding conditioning performance in combination with organic quats 3 CO S M ET I C S HAIR CARE uFig. 6 Sensory assessment of hair tresses. 0.8% Silicone Quaternium-22 in a shampoo formulation. Silicone Quaternium-22 boosts the conditioning performance significantly Heat Protection Hair is subjected to thermal stress by the application of high temperature styling devices, commonly used for curling or straightening. But already the thermal stress caused by blow-drying results in thermal damages of the keratinous structure. Specialty silicones enable formulators to create products that help protect hair. This protective effect can be explained by the low thermal conductivity of silicone derivatives, resulting in reduced heat flow from the heat source to the hair fiber. The method of choice in this study to determine a compound’s effectiveness in protecting hair fibers against heat is the analysis of the fiber’s keratin structure via Differential Scanning Calorimetry (DSC) (2). The denaturation temperature delivered by DSC is a significant parameter in determining the degree of damage to the fiber’s keratin structure. The protective effect provided by Silicone Quaternium-22 when delivered in the form of a conditioner rinse was tested on damaged bleached hair as well as on undamaged brown hair. In the test setup flat tresses (European human hair, single bleached) of 0.5 cm width were used and the hair tresses underwent 4 treatment cycles, consisting of shampooing (0.5 g / tress for 1 min, 1 min at rest, 1 min rinsing) followed by conditioning (0.5 g / tress for 1 min, 1 min at rest, 1 min rinsing with a standard conditioner rinse formulation or a conditioner rinse formulation with 1.5% Silicone Quaternium-22 (Table 3). After drying at room temperature and a defined humidity the uFig. 7 Thermal damaging of undamaged brown hair tresses. 1% Silicone Quaternium-22 in conditioner application provides about 40% heat protection 4 tresses were treated three times for 10 seconds each application with a hair straightener at approx. 180 °C. Subsequently the contact area of the hair tresses with the straightener was prepared for the DSC measurement. The tresses that were not thermally damaged and treated with CTAC only were used as the control. The chart in Fig. 7 depicts the results for undamaged brown hair. The decrease in denaturation temperature induced by thermal damage is strongest with CTAC treated tresses. The incorporation of Silicone Quaternium22 makes the hair less susceptible to thermal damage. As can be seen in Fig. 7 an improvement in heat protection of approximately 40% is achieved on the brown undamaged hair, clearly indicating how radical damaging effects of thermal styling tools are reduced. Similarly, by incorporating Silicone Quaternium-22 in the test formulation an approximately 40% increase in heat protection was observed in experiments using damaged bleached hair tresses. Silicone Quaternium-22 effectively provides defense against the intense heat that is generated by modern appliances for different hair types. Color Protection / Improved Color Wash Fastness Hair coloring became very popular in the last decade and therefore one of the key areas in the hair care market is color protection. It is no surprise that most manufacturers are developing products that are tailored for the hair color market. No single source causes hair color fading. However, the application of shampoo inevitably leads to the continual fading of color and a diminished brilliance of the hair. This effect is one of the reasons why it is highly desirable for shampoo formulations to contain ingredients which counteract this phenomenon and effectively improve the color wash fastness. The measurement of the color wash fastness can be done by using a spectrophotometer. For this study a CIE-L*a*b* Colorimeter (Comission Internationale d’Eclarage, international committee of illumination) was used (CIE-L*a*b* Colorimeter, Dr. SOFW-Journal | 135 | 6-2009 CO S M ET I C S HAIR CARE Lange, Duesseldorf, Germany). In the operating procedure flat glued tresses of single bleached European human hair, 4 g weight, 16 cm length and 2 cm width, were used. A demipermanent hair dye (»L’Oreal Garnier Movida Nr. 27 Granatrot«) was applied according to the operating guidelines delivered with the product. After drying a minimum of 24 h, the initial color value was determined by 12 single measurements of the CIEL*a*b* color values. The tresses were treated with the shampoo test formulations (Table 2) according to a defined washing procedure of fifteen cycles. After standardized drying, the color values were measured after one, ten and 15 washing cycles and the »delta-E-values« (∆E) were calculated as described in the literature (3). The lower the difference in the color values before and after the shampoo treatments, the better the wash fastness property of the tested formulation. The color variations are expressed as the integral difference ∆E, based on changes of brightness (L*), red-green (a*) and blueyellow (b*) shift. A concentration of 0.8% Silicone Quaternium-22 was used in the test shampoo formulation (Table 2) and 0% Silicone Quaternium-22 in the control formulation. The efficiency of Silicone Quaternium-22 for color protection is demonstrated in Fig. 8, where the ∆E values after a single shampoo treatment, as well as after 10 and 15 shampoo treatments are represented. Immediately after one single washing the color protection afforded by Silicone Quaternium-22 becomes apparent. With each subsequent washing cycle the shielding effect of the new T-shaped Silicone Quaternium-22 conditioning agent becomes more pronounced. This demonstrated color protection for dyed hair is decidedly attractive as it is a consumer perceivable property. More and more, consumers now prefer their hair care products to provide a color protection benefit. Approximately 20% of the hair care products now on the market claim color protection and about 13% heat protection (4). Using Silicone Quaternium-22 enables the formulator to differentiate hair care products in an attractive way, namely with the proven SOFW-Journal | 135 | 6-2009 claim for longer lasting color retention and heat protection. Skin Feel and Foam Consumers will value heat protection in the long term and color retention in the short term, but definitely will desire certain sensorial benefits immediately. From the consumer’s perspective, the foam properties as well as skin and hair conditioning are aspects of particular importance which are observed immediately. In particular sensory methods are useful in determining the influence of a certain ingredient on skin feel and foam properties. When performed by trained personnel, sensory use data will closely parallel consumer preferences. The impressive skin conditioning benefits of Silicone Quaternium-22 are demonstrated in a sensory hand wash test conducted by a trained group of 10 panelists in a standardized washing procedure. The effect of the incorporation of 0.5% Silicone Quaternium-22 was evaluated and has been represented graphically in Fig. 9. In skin cleansing formulations Silicone Quaternium-22 is able to provide a remarkable improvement of wet and dry skin feel. Both during and after-use, the skin feels soft and smooth with a pleasant perception of moisturization. Furthermore the foam properties are enhanced providing the formulator a more rich and denser foam with better stability. The results of the sensory hand wash test ∆ Fig. 8 Color Fading – 0.8% Silicone Quaternium-22 provides improved color wash fastness in a shampoo formulation (Table 2) Fig. 9 Sensory hand wash test results judging foam and skin feel ba a scale (1-5; 5 = best) 5 CO S M ET I C S HAIR CARE confirm the striking improvements in foam properties as well as in skin feel facilitated by the addition of Silicone Quaternium-22 to the formulation. The formulation of the sensory hand wash test is described in Table 4. Advantages in Processing Silicone Quaternium-22 can be used versatile in various rinse-off applications e.g. conditioning shampoos, hair rinses, balms, styling products, body washes and leave-in formulations. Silicone Quaternium-22 is soluble in surfactant systems and ethanol and therefore highly suitable for clear formulations. At room temperature Silicone Quaternium-22 is a clear and easy to process liquid. The lactate based counter ion chemistry makes it also applicable at low pH without the associated odor problems. In general a decrease in viscosity of surfactant formulations is commonly associated with the use of silicone derivatives. This phenomenon is typically counteracted by increasing the amount of thickener in order to maintain the desired viscosity. Since this new technology shows a much less pronounced influence on viscosity, when using Silicone Quaternium-22 the amount of thickener in a formulation can be reduced significantly. This in turn leads to substantial cost savings for the formulator. Fig. 10 shows an example of a shampoo formulation containing 9% SLES, 3% CAPB, 0.3% HP Guar HP Chloride and 0.7% NaCl. At the active matter content of 0.5% cationic modified siloxane, the formulation with Silicone Quaternium22 requires 28% less hydrophilic thickener (ANTIL® 171, PEG-18 Glyceryl Oleate/ Cocoate) to achieve the desired viscosity of 4000 mPas compared to the formula with a linear cationic modified siloxane. ABIL® T Quat 60 Silicone Quaternium-22 Texapon NSO (28% a.m.) TEGO® Betain F 50 (38% a.m.) NaCl Water Sodium Laureth Sulfate Silicone Quaternium-22 represents a major step forward in silicone conditioning technology. Due to the unique triple cationic charge it shows excellent sub- 6 Cocoamidopropyl Betaine 8.0% 2.0% ad. 100.0% Table 4 Test formulation 4: Sensory hand wash test Fig. 10 Required thickener concentration (ANTIL® 171, PEG-18 Glyceryl Oleate/ Cocoate) for a viscosity of 4000 mPas in a shampoo formulation Guidelines Formulations Ingredient INCI Sodium Laureth Sulfate, 28% VARISOFT® PATC* ANTIL® 200* ABIL® T Quat 60* Perfume Water Polymer JR 400** TEGO® Betain F 50* Preservative * Conclusion 0.5% versus 0% in control formulation 32.0% Evonik Goldschmidt Palmitamidopropyltrimonium Chloride PEG-200 Hydrogenated Glyceryl Palmate; PEG-7 Glyceryl Cocoate Silicone Quaternium-22 Polyquaternium-10 Cocamidopropyl Betaine ** % 32.0 1.5 1.9 1.5 0.25 56.05 0.3 6.5 q.s. Amerchol Manufacture: Dissolve the Polyquaternium-10 in water and let it swell. Dissolve the ingredients in the given order in SLES. Then add water/PQ-10 and the Betain. Formulation 1 Conditioning shampoo for coarse and damaged hair with color protecting properties SOFW-Journal | 135 | 6-2009 CO S M ET I C S HAIR CARE Ingredient INCI Water VARISOFT® EQ 65* VARISOFT® BT 85 Pellets* ABIL® T Quat 60* TEGO® Alkanol 1618* Preservative, Perfume * Distearyl Dimonium Chloride, Cetearyl Alcohol Behentrimonium Chloride Silicone Quaternium-22 Cetearyl Alcohol % 90.2 2.0 2.0 0.8 5.0 q.s. Evonik Goldschmidt Manufacture: Add all ingredients to water and heat to 75 °C with adequate mixing. Homogenize at 75 °C and cool down while stirring. Add perfume and preservative at a temperature below 40 °C. Homogenize a second time at room temperature. Formulation 2 Conditioning hair rinse with heat protecting properties Ingredient INCI * ABIL® Quat 60 TAGAT® CH 40* Perfume TEGO® Betain 810* Water TEGO® Cosmo C 100* TEGOCEL® HPM 50* VARISOFT® 300* LACTIL®* Citric Acid, 30% Preservative * Silicone Quaternium-22 PEG-40 Hydrogenated Castor Oil Capryl/Capramidopropyl Betain Creatine Hydroxypropyl Methylcellulose Cetrimonium Chloride Sodium Lactate; Sodium PCA, Glycine; Fructose; Urea; Niacinamide; Inositol; Sodium Benzoate; Lactic Acid stantivity to hair as confirmed by CLSM. In addition to the outstanding conditioning profile, Silicone Quaternium-22 offers impressive heat protection properties, improved color protection for dyed hair, superior skin feel and enhanced foam properties. Because of a less pronounced thinning effect in surfactant formulations cost savings can be realized. Highly suitable for clear formulations Silicone Quaternium-22 can be incorporated into shampoo and conditioner rinse applications likewise. The lactate based counter ion chemistry makes it also applicable at low pH without the associated odor problems. The excellent processability of Silicone Quaternium-22 ultimately makes it into a premium and at the same time easy to use conditioning agent. % 0.5 0.5 0.3 2.0 940 0.5 0.3 1.3 0.5 0.1 q.s. Evonik Goldschmidt Manufacture: Dissolve TEGO® Cosmo C 100 in water, then the Cellulose and let it swell with agitation. Mix the ingredients in the given order. Adjust the pH value to approximately 4.5. Formulation 3 Clear leave-in conditioning foam with heat protecting properties References (1) M. Minsky, Scanning 10, 128-138 (1988) (2) F.-J. Wortmann, C. Springob, G. Sendelbach, J. Cosmet. Sci., 53, 219-228 (July/August 2002) (3) S. Herrwerth, H. Leidreiter, U. Kortemeier, C. Hartung, B. Grüning, Cosmetics & Toiletries, 123, 101-110, 2008 (4) S. Marchioretto, S. van Doorn, Happi, 54-58, February 2009 * Author’s address: Dr. Sascha Herrwerth Dr. Isabella Ulrich-Brehm Uta Kortemeier Patrick Winter Dr. Michael Ferenz Dr. Burghard Grüning Evonik Goldschmidt GmbH Goldschmidtstrasse 100 45127 Essen Germany ** Corresponding author: Email: sascha.herrwerth@evonik.com SOFW-Journal | 135 | 6-2009 7