HIGH PERFORMING SILICONE MICROEMULSIONS FOR HAIR CARE

13.02.2019

Introduction

Today’s hair market is a highly competitive and segmented market place wherein formulators need to respond to a range of hair types, cultures, regions and ethnicities. A savvy youth market, emerging economies and an expanding group of sophisticated consumers need to be accommodated. To meet these requirements, the hair care industry must continuously develop creative solutions. Specialty silicone able to create hair care products that help to strengthen and protect hair from environmental stress, color fade, heat associated with hair grooming and even add volume or control hair frizziness. Silicone play a key role, whether in conditioners, shampoo, colorant or styling products.

Individualism in Hair Care

The concept of customized hair care products is gaining popularity as customers intend to portray their individuality and handle specific grooming challenges based on hair type and its desired style and condition. Specialty silicones can provide specific solutions for individual needs based on customer’s specific hair care requirements. For example, hair care products are extensively designed for fine, dry, kinky or curly hair, damaged or colored hair, and styles from long to short, voluminous to sleek. The range of conditioning levels is from intense to light with alternatives for heat and color protection as well as frizz control.

Specialty Silicone for Hair Moisturization

UV radiation, curling irons, and chemicals from colouring, perming and straightening – even frictional forces from daily combing and styling – all conspire to hair damage. In the case of coloured hair, regular washing can lead to discoloration. Aging along with the changes of hormone and sebum production can lead to dry, dull and grey hair. Hair moisturization is one of the most popular claims in hair care products nowadays. In fact, silicone does not provide moisturization to hair. But, when silicone is added to leave on or rinse off hair products, it gives the slippery texture that makes your hair feel is being moisturized. The definition of hair moisturization is different from skin moisturization. Hair moisturization is expressed by hair that is easy to comb when wet as well as dry, has healthy-looking shine, and fibres that align more easily to provide a sleek look. With the aid of specialty silicones, it is possible to formulate hair care products that can improve hair appearance. For example, incorporating specialty silicones in shampoos and conditioners can improve shine and help maintain the colour-treated hair.

Silicone Quaternium-17 in Microemulsion

High molecular weight silicones are well known for hair conditioning and protecting properties. But, high molecular weight silicones are difficult to formulate into hair care products due to their hydrophobic and high viscosity. However, when delivered as emulsion, small droplets of the high molecular weight of silicones can be easily mixed into hair care formulations. This is more convenient and saves on costs for manufacturing time (shorter) and manufacturing cost (energy and time saving) including productivity as well. The development of thermodynamically stable microemulsions with very fine silicone droplets is very beneficial to formulator. The droplets are smaller than the wavelength of visible light, therefore also transparent. This approach using fine droplets was used to developed a microemulsion based on high molecular weight Silicone Quaternium-17. The microemulsion BRB 5446 was then processed by emulsifying Silicone Quaternium-17 with emulsifier of Trideceth-7 and Trideceth-5. Therefore, this product does not contain polyether. The active silicones content in the microemulsion is approximately 15%. Meanwhile microemulsion BRB 5834 was developed with shine boosting Phenyl Trimethicone and cationic polymer Silicone Quaternium- 17 together with emulsifier of Laureth-4 and Laureth-23. It is a preservative and polyether free ingredient. The active silicones content in the microemulsion is approximately 17%. With its emulsion form, the new silicone microemulsion is easy to incorporate into hair care products, where it gives a moisturised feel along with superior conditioning, excellent wet and dry combing properties. It is Ideal for use in clear, leave-in and rinse-out products, for all hair types. Various tests were conducted to access the performance of microemulsion.

Performance Testing Combing Force Measurement

These studies show the significant benefits of silicone mircroemulsion BRB 5446 (INCI: Silicone Quaternium-17 (and) Trideceth-7 (and) Trideceth-5) and silicone microemulsion BRB 5834 (INCI: Phenyl Trimethicone (and) Laureth-4 (and) Silicone Quaternium-17 (and) Laureth-23) in conditioning performance based on ease of combing on wet and dry conditions. Combing force measurement was taken before and after application of shampoo and conditioner using MTT175 tensile tester (Dia- Stron). Test was conducted on virgin brown Caucasian hair tresses which has been pre-double bleached to make sure all chemicals substances has been removed from hair before measurements. Results of combing force measurements are shown in Figure 1. Both microemulsion BRB 5446 and microemulsion BRB 5834 significantly reduced combing force in wet and dry condition after shampoo and conditioner application compare to control. % Force reduction = TCW (untreated) – TCW (treated)/ TCW (untreated) TCW = Total Combing Work (in joules)

Figure 1. Ease of combing of wet & dry condition with Dia-Stron tensile tester

Thermal Protection

Thermal damage is the result of frequently use of hair dryer, straightening iron, curling and any other styling equipment which performed with heat. These heat treatments are conducted around 180- 230°C which thermally damage hair’s keratinous structure. If the use of hot styling tools is done improperly, the moisture will evaporate from hair, destroying all its natural oils and protein. All this leads to dull, brittle, dry and fragile hair. Therefore, thermal protection is essential in order to prevent heat damage. Specialty silicone can be used to protect hair from heat due to their film forming properties and low thermal conductivity. Virgin blonde Caucasian hair tresses has been pre-double bleached before performing test. Then, hair tresses treated with heat protecting spray formulated with silicone microemulsion BRB 5446 and followed by 50 cycles of flat iron at 230°C. Results shown in Figure 2. Figure 2 shows that less damage in hair tresses treated with silicone emulsion BRB 5446 compare to hair tresses without any treatment. Silicone Quaternium-17 helps to protect from heat damage, preventing cuticle to crack. Hair is easier to detangle, breaks less when combing and looks and feels healthier. A good result in thermal protection could also described good deposition of Silicone Quaternium- 17 from microemulsion on hair.

Figure 2. Thermal protection with flat iron test

Color Protection

Modern consumers often use hair dye with variable degree of longevity in order to change or enhance their natural hair colour. The permanent hair dyes, also referred to as oxidative dyes. The alkalising agent, hydrogen peroxide, swells the hair, enabling the dye precursors and a catalysing agent to reach the cortex. It is observed that hair treated with red hair dyes is particularly prone to fading after UV exposure and shampooing. Studies found that red coloured hair tresses lost color to a larger extent than other dye such as black, brown and blond. Thus, color fadeness of the hair dyes is not only a key performance characteristic of the dye formulation but could be also of high importance when formulating targeted rinse off or leave on products. The hair colour retention test was conducted on virgin blond Caucasian hair tresses. The tresses were treated with commercial red color dye. Then the tresses were washed with shampoo followed by rinse off conditioner. The tresses were washed in 15 cycles. Observation were taken at an interval of 5, 10, 15 washes. Hair Tresses I is untreated swatch, directly after dying, hair tresses II was treated 15 times with control shampoo and conditioner, hair tresses III was treated 15 times with shampoo and conditioner using silicone microemulsion BRB 5446 and hair tresses IV was treated times with shampoo and conditioner using non-silicone material. The results in Figure 3 show a clear improvement in color fading on hair tresses treated with silicone microemulsion BRB 5446 after 15 cycles of washing. Silicone microemulsion maintains colour vibrancy by forming a hydrophobic surface on hair.

Figure 3. Color Protection with Silicone Mircoemulsion

I: Color reference (not treated) II: Control (no silicone) III: Silicone Quaternium-17 (and) Trideceth-7 (and) Trideceth-5 IV: Non-silicone ingredients

Hair Shininess

Physical measurements show that phenyl groups attached to silicone increase shine on hair. In hair care, Phenyl Trimethicone is seen as the standard for delivering shine and consequently is used as a reference material for validation of test methods and claim substantiation. Benefits of Phenyl Trimethicone include improved organic compatibility, shine and gloss, spreadability and reduced tackiness. By adding Phenyl Trimethicone into silicone microemulsion BRB 5834, it means this microemulsion able to provide high shine to treated substrates such as hair. Virgin blonde Caucasian hair tresses has been pre-double bleached before performing test. Then, hair tresses treated with whipped cream formulated with silicone microemulsion BRB 5834. Hair tresses I treated with control whipped cream without any silicone microemulsion and hair tresses II treated with whipped cream formulated with 3% silicone mircroemulsion BRB 5834. The results in Figure 4 clearly indicated that hair tresses II treated with silicone microemulsion provide higher glossiness. The shine of the hair is a very highly appreciated attribute of healthy looking hair and a common claim of many hair care products.

Şekil 4. Improve Hair Shininess with Silicone Microemulsion

Application

The silicone microemulsion BRB 5446 and BRB 5834 is a low viscosity liquid and therefore is easy to incorporate into hair care formulation. It is soluble in water, cold processable and can be added into formulation at the end of process by gentle mixing. It is recommended to use in clear or opaque rinse off or leave-on hair care products.

Conclusion

Fast growing global cosmetic trends help create demand for high performance hair care products which required multifunctional materials such as silicone microemulsion. Silicone microemulsion is specially developed for hair treatment to respond to global need for customized hair treatments. Both silicone microemulsion BRB 5446 (INCI: Silicone Quaternium- 17 (and) Trideceth-7 (and) Trideceth-5) and silicone microemulsion BRB 5834 (INCI: Phenyl Trimethicone (and) Laureth-4 (and) Silicone Quaternium-17 (and) Laureth-23) are multifunctional hair conditioning agent. Both silicone microemulsion show efficient in providing soft look and feel on hair.