j. Soc. Cosmet. Chem., 48, 1-21 (January/February 1997) OrDanofunctionalized silicone resins for personal care applications M.D. BERTHIAUME and A.D. BAUM, GE Silicones, 260 Hudson River Road, Waterford, NY 12188. Accepted for publication February 28, 1997. Presented at the Society of Cosmetic Chemists' Annual Seminar, Boston, May 10, 1996. Synopsis Synthesis of a number of organomodified silicone resins is described herein, along with their subsequent evaluation in various personal care applications. Alkyl-modified siloxysilicates were found to impart volu- mizing benefits to hair conditioners without increasing combing forces. The extent of the volume enhance- ment was dependent upon alkyl chain length. Maximum tress diameter was found to increase with increas- ing alkyl chain length above %6- Resins modified with olefins having chain lengths of %0 or less did not function as volumizing agents. Styryl-functional siloxysilicates increased apparent luster or shine of hair, while polyether-modified silicone resins were found to offer set retention benefits for hair and to function as oil-in-water emulsifiers. It is anticipated that these materials may be designed to act as water-in-oil, or water-in-silicone emulsifiers by altering the polyether moiety and degree of polyether substitution. Several ester-functional siloxysilicates were evaluated for substantivity and found to resist water wash-off, suggest- ing use in skin care and color cosmetic applications. The ester materials were also found to provide a mild conditioning benefit to hair. INTRODUCTION Several decades ago, formulating chemists wishing to work with silicone materials were limited to dimethicone polymers and cyclomethicone fluids only. The low surface ten- sion and lubricious nature characteristic of silicone fluids rendered these materials ex- cellent additives in personal care products to reduce drag and impart a velvety soft feel to hair and skin. Cyclomethicones are typically utilized as part of the carrier or delivery system for antiperspirants and deodorants, to act as fugitive emollients in skin care products, and to improve rub-in characteristics of sunscreens, liquid foundations, and anti-cellulite creams. In addition to imparting a lubricating effect, dimethicones reduce whitening that may occur during the rub-in process of creams and lotions. These materials also provide a breathable barrier on the surface of the skin, and fluids ranging from 20-12,500 cst in viscosity are currently recognized as skin-protectant drugs under the FDA monograph when incorporated into the formulation at levels of 1-30% active (1-3). The first use of polydimethylsiloxane or dimethicone in a protective skin care lotion actually dates back to the late 1940s when Revlon launched a product known as Silicare (4).

2 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Incorporation of silicones into hair care products followed shortly thereafter, dating back to the early 1950s, when Lanolin Plus introduced a spray lotion called Sudden Date (5), and in 1958 the first patent incorporating dimethicone into conditioning shampoos was issued to the Simonize Co. (6). The unique properties and benefits afforded by silicones in personal care products became increasingly evident, but their usage remained quite limited for many years due to their inherent solubility and incompatibility problems. With the advent of new polymeric thickeners and suspending agents, silicone emulsi- fiers, and organomodification of the silicone polymers themselves, the use of silicones in personal care products has dramatically increased in recent years, to the point that approximately half of all new personal care products introduced into the marketplace in 1994 contained at least one type of silicone in the formulation (7). Today there is a wide variety of silicone products available that provide numerous benefits in personal care formulations (8-9). Dimethicones are still used to provide an anti-whitening effect and a breathable barrier on the skin, and for their conditioning benefits in hair care products. Dimethicone copolyols, or silicone glycol copolymers, are primarily used as resin plasticizers in hair-fixative products. They are also utilized in shampoo systems as co-solubilizers and for their ability to reduce irritation to skin and mucous membranes by primary surfactants in these formulations (10). They may addi- tionally provide light conditioning benefits and are widely utilized as emulsifiers in skin care compositions, particularly in antiperspirants and sunscreens. Aminofunctional si- loxanes provide conditioning benefits and impart softness to hair, while phenylmodified silicones are used as luster-enhancing additives in hair products and ernollients for the skin. Alkyl-modified silicone polymers provide an occlusive barrier in skin products, reducing the amount of transepidermal water loss to levels similar to those observed with petrolatum (11). Also available are specialty materials containing a wide range of func- tionalities grafted onto the silicone chain, including protein moieties, quats, fatty acids, amphoteric surfactants, amino acids, and fragrance oils (12-15). Silicone resins are also used as additives in personal care formulations, providing im- proved deposition characteristics and substantivity to hair and skin (16-22). There are two types of silicone resins known as silsesquioxane or "T" resins (SIO3/2) and siloxy- silicates or "Q" resins (SIO4/2). Silsesquioxanes are best known for their ability to provide "slip" in color cosmetics and reduce agglomeration in powders. Siloxysilicates are most often used in sunscreens and color cosmetics to form a protective film on the surface of the skin, holding actives (or pigments) in place, and in hair care products to increase deposition of other silicones and to impart stiffness (21-24). The use of silicone resins, however, is still somewhat limited due to their inherent solubility limitations and instability in oil-based systems. It was the authors' intent to prepare a series of resins with a greater organic character to lessen these formulation restrictions. This paper describes the synthesis of several siloxysilicate resins with pendant groups consisting of organic esters, alkyls, polyethers, and phenethyl moieties, and their subsequent evalu- ations in personal care applications. EXPERIMENTAL SYNTHESIS The organomodified siloxysilicate resins used in these experiments were prepared in-