Title of Invention	ORGANOSILICONE DERIVATIVES OF AMINO HYDROXBENZOPHENONES AND THEIR USE AS UV-A FILTERS IN COSMETIC PREPARATIONS
Abstract	The present invention relates to organosilicone derivatives of amino hydroxybenzophenones, a process for their preparation thereof, a cosmetic compositions comprising the organosilicone derivative and the use thereof for protecting hair and/or skin from damage caused by UV-A irradiation.

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ORGANOSILICONE DERIVATIVES OF AMINO HYDROZYBENZOPHENONES AND THEIR USE AS UV-A FILTERS IN COSMETIC PREPARATIONS The present invention relates to organosilicone derivatives of amino hydroxybenzo-phenones, to a process for their preparation, compositions comprising these derivatives and the use thereof. More particularly, the invention relates to organosilicone compounds comprising a unit of formula I wherein b is 0, 1, 2, 3; and R" is hydrogen, a saturated or unsaturated C1-C10hydrocarbon group or a trimethylsilyloxy group. Suitable organosilicone compounds are polymeric materials which maybe homopolymers consisting only of such units of formula I, or they may be copolymers containing both units having either the general formula I or II. The units of formula I maybe distributed randomly in an organosiloxane polymer, they may be the end blocking units of the polymer or they maybe located at the end of the polymer and pending in a chain of the polymer at the same time. The organosilicone compounds may vary from freely flowing liquids to highly viscous gum-like materials or resinous soiids. If a is 2 the two substitutents Rl may be identical or different. If b is 2 or 3 the two or three substituents R2 may be identical or different. If the polymer contains more than one unit of formula I the substituents Rl maybe identical or different from unit to unit. If the polymer contains more than one unit of formula II the substituents R~ maybe identical or different from unit to unit Examples for a saturated or unsaturated C1-C30hydrocarbon group include C1-C30alky! such as methyl, ethyl, propyl and butyl; C2-C30alkenyl such as vinyl and allyl and unsub-stituted or substituted aryl such as phenyl, alkaryl and alkoxyphenyl. The hydrocarbon group is unsubstituted or substituted by, e.g. halogen, e.g. a halogenated C1-C18hydro-carbon group. Examples for cycloalkyl and cycloalkenyl include cyclopropyl, 2-methyl-cycIopropyl, cyclobutyl, cydopentyl, cyclohexyl, cyciopropenyl, cyclobutenyl, cydopentenyl, (3-methyl)-cyclopenta-2,4-dienyl and 11-cyclododecenyl. The terms "divalent C3-C12alkylene chain" and "divalent C3-C12alkenylene chain" mean linker groups, in particular linker groups which link the UV absorbing chromophoric residue to the silane, oligosiloxane or polysiloxane moiety. Examples for C3-C12alkylene include straight chain or branched saturated hydrocarbon residues such as 3-propylene, 2-propylene, 2-methyl-3-propylene, 3-butylene, 4-butylene, 4-pentylene, 5-pentyIene, 6-hexylene, and the like. Examples for CrCnalkenylene include unsaturated hydrocarbon residues containing at least one double bond, such as for example, 2-propen-2-ylene, 2-propen-3-ylene, 3-buten-3-ylene, 3-buten-4-ylene, 4-penten-4-ylene, 4-penten-5-ylene, In the organosilicone compounds of the invention die following preferences apply independently, collectively or in any combination or sub-combination: (a) organosilicone compounds wherein the number of units of formula I is limited to a maximum of 50%, more preferably of 10 to 40 %, most preferably 30 to 40% of the total number of siloxane units in the molecule; . (b) liquid substantially linear organosiloxane homopolymers and copolymers, for example those having a viscosity from 50-20000 mVs; (d2) b is 2; (d3) R2 is methyl in 80 %, preferably 100 % of units of formula II. When a = land b = 2 the organosilicone compound is a substantially linear or cyclic di-organo-siloxane polymer. However, if the diorgar.osiloxane is a substantially linear polymer at least two endblocking units must be present, thus requiring either the presence of two units in which a has a value of 2 or two units in which b is 3. A preferred linear diorgano-siloxane polymer (hereinafter: COMPOUND) is a polymer comprising one structural unit of formula IVa and one structural unit of. formula IVb SiH derivatives are well known in the silicone industry and are commercially available. They are described, for example, in the following patents: US 3,220,972, US 3,697,474 and US 4,340,709. The hydrosilylation may be carried out by reacting the SiH derivative in the presence of a transition metal catalyst, e.g. platinum on charcoal or a platinum complex catalyst, such as e.g. di vinyl-tetramethyl disiloxane platinum complex with a compound of formula VII in which R3, R4 and X are as defined for formula III and Y' has the same definition as Y in formula III, but is terminated either with a double or a triple bond. The addition may proceed at both positions of the unsaturated carbon-carbon bond, leading to isomeric mixtures of organosilicone products e.g. containing exo and endo double bonds. The hydrosilylation maybe performed in a suitable reaction solvent, e.g. in isopropanol or toluene. The reactants may be present in about equal molar amounts. The reaction may be run at an elevated temperature, e.g. in a range of from 40°C to 150°C, preferably from 50°C to 100°C, e.g., at about 80°C. Compounds of formula VII are generally known and maybe prepared, e.g., according to the procedure described in EP 1,046,391 by acylation of the corresponding amino substituted phenols followed by reaction with the respective alcohol or amine such as propinol, allyl alcohol, vinyl alcohol, prop-2-ynyl amine or vinyl amine. Exemplary amino The compounds of the present invention have adsorption maxima in the UV-A region and are effective in absorbing ultra violet radiation in the UV-A range (320-400nm) which makes them particularly suitable for use in cosmetic sunscreen preparations where absorption in the UV-A range is particularly desirable. Thus, the present invention also relates to compositions comprising the novel organosilicone compounds, formulated into a suitable support or substrate. Typically, the compositions of the invention are adopted for protecting a material that is sensitive to ultraviolet radiation, in particular solar radiation, such as skin and/ or hair and comprises an effective photoprotective amount of an organosilicone compound of the invention. For the preparation of light screening agents, especially of preparations for dermatological and/or cosmetic use, such as skin protection and sunscreen formulations for everyday cosmetics a compound of this invention may be incorporated in auxiliary agents, e.g. a cosmetic base, which are conventionally used for such formulations. Where convenient, other conventional UV-A and/or UV-B screening agents may also be added. The combination of UV filters may show a synergistic effect. The preparation of said light screening agents is well known to the skilled artisan in this field. The concentration of UV filters is not critical. For example, the amount of compounds of the present invention and optionally an additional hydrophilic and/or lipophilic UV-A or UV-B screening agent other than the compounds described in this invention maybe in the range of from 0.5 to 12% by weight of the total composition. These additional screening agents are advantageously selected from the compounds listed below without being limited thereto: Examples of UV B screening agents, i.e. substances having absorption maxima between about 290 and 320 nm, which come into consideration for combination with the compounds of the present invention are for example the following organic and inorganic com- anedioic acid diethyl ester as described in EP 895,776; organosiloxane compounds containing benzmaionate groups as described in EP 358,584, EP 538,431 and EP 709,080; biometrizole trisiloxane (MEXORYL XL); pigments such as microparticulated TiO2, and he like, wherein the term "microparticulated" refers to a particle size from about 5 nm to bout 200 nm, particularly from about 15 nm to about 100 nm, and which T1O2 particles nay be coated by metal oxides such as e.g. aluminum or zirconium oxides or by organic coatings such as e.g. polyols, methicone, aluminum stearate, alkyl silane; imidazole derivatives such as e.g. 2-phenyl benzimidazole sulfonic acid and its salts (PARSOL®HS). Salts of 2-phenyl benzimidazole sulfonic acid are e.g. alkali salts such as sodium- or potassium salts, ammonium salts, morpholine salts, salts of primary, sec. and tert amines like mono-thanolamine salts, diethanolamine salts and the like; salicylate derivatives such as iso-propylbenzyl salicylate, benzyl salicylate, butyl salicylate, octyl salicylate (NEO HELIOPAN DS), isooctyl salicylate or homomenthyl salicylate (homosalate, HELIOPAN) and the like; xiazine derivatives such as octyl triazone (UV1NULT-150), dioctyl butamido triazone UVASORB HEB), bis ethoxyphenoi methoxyphenyl triazine (TINOSORB S) and the like; polysiloxane containing a UV-B chromophor like e.g. Polysilicone 15 (Dimethicodiethyl-benzalmalonate or Parsol SLX). Examples of UV A screening agents i.e. substances having absorption maxima between about 320 and 400 nm, which come into consideration for combination with the compounds of the present invention are for example the following organic and inorganic compounds: dibenzoylmethane derivatives such as 4-tert. butyl-4'-methoxydibenzoyl-methane (PARSOL® 1789), dimethoxydibenzoylmethane, isopropyldibenzoylmethane and "microparticulated" refers to a particle size from about 5 nm to about 200 nm, particularly from about 15 nm to about 100 nm, and which ZnO particles maybe coated by metal oxides such as e.g. aluminum or zirconium oxides or by organic coatings such as e.g. polyols, methicone, aluminum stearate, alkyl silane. As dibenzoylmethane derivatives have limited phostability it may be desirable to photo-stabilize these UV-A screening agents. Thus, the term "conventional UV-A screening agent" also refers to dibenzoylmethane derivatives such as e.g. PARSOL® 1789 stabilized by, e.g., 3,3-diphenylacrylate derivatives as described in EP 514,491 and EP 780,119; benzylidene camphor derivatives as described in US 5,605,680; organosiloxanes containing benzmatonate groups as described in EP 358,584, EP 538,431 and EP 709,080. The compositions of the invention may also contain usual cosmetic adjuvants and additives, such as preservatives/ antioxidants, fatty substances/ oils, water, organic solvents, silicones, thickeners, softeners, emulsifiers, additional sunscreens, antifoaming agents, moisturizers, fragrances, surfactants, fillers, sequestering agents, anionic, cationic, nonionic or amphoteric polymers or mixtures thereof, propellants, acidifying or basifying agents, dyes, colorants, pigments or nanopigments, in particular those suited for providing an additional photoprotective effect by physically blocking out ultraviolet radiation, or any other ingredients usually formulated into cosmetics, in particular for the production of sunscreen/ antisun compositions. The necessary amounts of the cosmetic and dermatological adjuvants and additives may, based on the desired product, easily be chosen by a skilled artisan in this field and will be illustrated in the examples, without being limited hereto. An additional amount of antioxidants/ preservatives is generally preferred. All known antioxidants usually formulated into cosmetics may be used. Especially preferred are antioxidants chosen from the group consisting of amino acids (e.g. glycine, histidine, tyrosine, tryptophane) and their derivatives, imidazole (e.g urocanic acid) and derivatives, peptides such as D,L-carnosine, D-carnosine, L-carnosine and derivatives (e.g. anserine), carotin- compounds (such as buthionine sulfoximine, homocysteine sulfoximine, buthionine sulfone, penta-, hexa-, heptathionine sulfoximine) in very low compatible doses (e.g. pmol/kg to µmol/kg), additionally (metal)-chelators (such asα-hydroxyfatty acids, palmic-, phytinic acid, lactoferrin),α-hydroxyacids (such as citric acid, lactic acid, malic acid), huminic acid, gallic acid, gallic extracts, bilirubin, biliverdin, EDTA, EGTA and its derivatives, unsaturated fatty acids and their derivatives (such as γ-linoleic acid, linolic acid, oleic acid), folic acid and its derivatives, ubiquinone and ubiquinol and their derivatives, vitamine C and derivatives (such as ascorbyl palmitate and ascorbyl tetraisopalmitate, Mg-ascorbyl phosphate, Na- ascorbyl phosphate, ascorbyl acetate), tocopherol and derivates (such as vitamin-E-acetate, nat. vitamin E and mixtures thereof), The lipid phase may advantageously be chosen from: mineral oils and mineral waxes; oils such as triglycerides of caprinic acid or caprylic acid, preferably castor oil; oils or waxes and other natural or synthetic oils, in a preferred embodiment esters of fatty acids with alcohols e.g. isopropanol, propyleneglycol, glycerin or esters of fatty alcohols with lower carboxylic acids or fatty acids; alkylbenzoates; silicone oils such as dimethylpolysiloxane, diethylpolysiloxane, diphenylpolysiloxane, cyciomethicone and mixtures thereof. Exemplary fatty substances which maybe incorporated into the oil phase of the emulsion, microemulsion, oleo gel, hydrodispersion or lipodispersion of the present invention are advantageously chosen from esters of saturated and/or unsaturated, linear or branched alkyl carboxylic acids with 3 to 30 carbon atoms, and saturated and/or unsaturated, linear and/or branched alcohols with 3 to 30 carbon atoms as well as esters of aromatic carboxylic acids and of saturated and/or unsaturated, linear or branched alcohols of 3-30 carbon atoms. Such esters may advantageously be selected from octylpalmitate, octyl-cocoate, octylisostearate, octyldodeceylmyristate, cetearylisononanoate, isopropylmyristate, isopropylpalmitate, isopropylstearate, isopropyloleate, n-butylstearate, n-hexyllaureate, n-decyloleat, isooctylstearate, isononylstearate, isononylisononanoate, 2-ethyl hexylpalmitate, 2-ethylhexyllaurate, 2-hexyldecyistearate, 2-octyldodecylpalmitate, stearylheptanoate, oleyloleate, oleylerucate, erucyloleate, erucylerucate, tridecylstearate, tridecyltrimellitate, and synthetic, half-synthetic or natural mixtures of such esters e.g. jojoba oil. Still other fatty components which may advantageously be incorporated into formulations of the present invention include isoeikosane; neopentylglycol diheptanoate; propylene- . The oily phase of the formulation of the present invention may also contain natural vegetable or animal waxes such as bee wax, china wax, bumblebee wax and other waxes of insects as well as shea butter and cocoa butter. A moisturizing agent may be incorporated into a composition of the present invention to maintain hydration or rehydrate the skin. Moisturizers that prevent water from evaporating from the skin by providing a protective coating are called emollients". Additionally an emollient provides a softening or soothing effect on the skin surface and is generally considered safe for topical use. Preferred emollients include mineral oils, lanolin, petrolatum, capric, caprylic triglyceraldehydes, cholesterol, silicones such as dimethicone, cyclomethi-cone, almond oil, jojoba oil, avocado oil, castor oil, sesame oil, sunflower oil, coconut oil and grape seed oil, cocoa butter, olive oil aloe extracts, fatty acids such as oleic and stearic, fatty alcohols such as cetyl and hexadecylalcohol, diisopropyl adipate, hydroxybenzoate esters, benzoic acid esters of C9-15-alcohols, isononyl iso-nonanoate, ethers such as poly-oxypropylene butyl ethers and polyoxypropylene cetyl ethers, and C12-15-alkyl benzoates, and mixtures thereof The most preferred emollients are hydroxybenzoate esters, aloe vera, C12-15 -alkyl benzoates, and mixtures thereof. An emollient may be present in an amount of about 1 wt.% to about 20 wt.% of the total weight of the composition. The preferred amount of emollient may be about 2 wt.% to about 15 wt.%, and most preferably about 4 wt.% to about 10 wt.%. Moisturizers that bind water, thereby retaining it on the skin surface are called humectants. Suitable humectants may be incorporated into a composition of the present invention such as glycerin, polypropylene glycol, polyethylene glycol, lactic acid, pyrrolidon carboxylic acid, urea, phopho'.ipids, collagen, elastin, ceramides, lecithin sorbitol, PEG-4, and mixtures thereof. Additional suitable moisturizers are polymeric moisturizers of the family of water soluble and/ or swellable/ and/ or with water gelating polysaccarides such as hyaluronic acid, chitosan and/or a fucose rich polysaccharide which is e.g. available as Fucogel* 1000 (CAS-Nr. 178463-23-5) by SOLABIA S. One or more humectants are optionally present at about 0.5 wt.% to about 8 wt.% in a composition of the present invention, preferably about 1 wt.% to about 5 wt.%. The aqueous phase of the compositions of the present invention may contain usual cosmetic additives such as alcohols, especially lower alcohols, preferably ethanoi and/ or iso-propanol, low diols oder polyols and their ethers, preferably propylenglycols, glycerin, ethyleneglycol, ethyleneglycol monoethyl- or monobutyl-ether, propylene glycol-mono-methyl-, monoethyl- or monobutyl ether, diethylene glycol-monomethyl-or monoethyi-ether and analogue products, polymers, foam stabilisators; electrolytes and especially one or more thickeners. Thickeners that may be used in formulations of the present invention neutralizing agents which may be included in the composition of the present invention to neutralize components such as e.g. an emulsifier or a foam builder/stabilizer include but are not limited to alkali hydroxides such as a sodium and potassium hydroxide; organic bases such as diethanolamine (DEA), triethanolamine (TEA), aminomethyl propanol, and mixtures thereof; amino acids such as arginine and lysine and any combination of any foregoing. The neutralizing agent may be present in an amount of about 0.01 wt.% to about 8 wt.% in the composition of the present invention, preferably, 1 wt.% to about 5 wt.%. The addition of electrolytes into the composition of the present invention maybe necessary to change the behavior of a hydrophobic emulsifier. Thus the emulsions/ microemulsions of this invention may preferably contain electrolytes of one or several salts including anions such as a chloride, a sulfate, a carbonate, a borate or an aluminate, without being limited thereto. Other suitable electrolytes may be on the bases of organic anions such as, but not limited to, lactate, acetate, benzoate, propionate, tartrate and citrate- As cations preferably ammonia, alkylammonia, alkali- or alkaline earth metals, magnesium-, iron- or zinc-ions are selected. Especially preferred salts are potassium and sodium chloride, magnesium sulfate, zinc sulfate and mixtures thereof. Electrolytes are present in an amount of about 0.01 wt.% to about 8 wt.% in the composition of the present invention. The cosmetic compositions of the invention are useful as compositions for photoprotect-ing the human epidermis or hair against the damaging effect of ultraviolet irradiation, as antisun/ sunscreen composition or as makeup product. Such compositions can, in particular, be provided in the form of a lotion, a thickened lotion, a gel, a cream, a milk, an ointment, a powder or a solid tube stick and may optionally be packaged as an aerosol and maybe provided in the form of a mousse, foam or a spray. When the cosmetic composition according to the invention is provided for protecting the human epidermis against UV radiation or as antisun/ sunscreen composition, it may be in the form of a suspension or dispersion in solvents or fatty substances, or alternatively in the form of an emulsion or When the cosmetic composition according to the invention is used for protecting the hair, it may be in the form of a shampoo, a lotion, a gel or a rinse out composition, to be applied before or after shampooing, before or after dyeing or bleaching, before, during or after permanent-waving or hair straightening operation, a styling or treatment lotion or a gel, a blow-drying or hairsetting lotion or gel, a hair lacquer, or a composition for permanent-waving, straightening, dyeing or bleaching the hair. When the cosmetic composition according to the invention is used as makeup product for eyelashes, the eyebrows, the skin or the hair, such as an epidermal treatment cream, a foundation, a tube of lipstick, an eyeshadow, a face powder, an eyeliner, a mascara or a coloring gel, it may be solid or pasty, anhydrous or in aqueous form, such as O/W or W/O emulsion, suspension or gel. The present invention also features formulating the organosilicone compounds according to the invention as an agent for screening out UV radiation, in particular for controlling the color of human skin. The organosilicone compounds according to this invention show an excellent liposolubility and can thus be incorporated in high concentrations into cosmetic formulations which leads to high protection factor of the final compositions. Additionally they are homogeneously distributed in the cosmetic formulation containing at least a fatty phase and an cosmetically accepted organic solvent which leads, applied on the skin/ or hair, to the formation of a protective film which protects effectively the skin and/ or hair against the deleterious effects of UV-radiation. Thus, it is another object of the present invention to use the compounds of the invention for protecting the skin and/ or hair against ultraviolet radiation, in particular solar radiation, comprising topically applying an effective amount of a cosmetic composition containing the organosilicone compounds according to the invention. Finally, this invention also features non-therapeutic regime/ regimen for controlling the variation of the color of the skin caused by ultraviolet radiation, comprising topically applying onto the skin an effective amount of a cosmetic composition containing organosilicone compounds according to the invention. According to another embodiment of the invention, a organosilicone compound of this invention can be used as protecting agent against UV radiation for plastics. The organosilicone derivatives of the invention are also photostable. In accordance with the foregoing the invention provides (1) An organosilicone compound for use as a UVA filter, e.g. for use in a cosmetic composition; (2) A cosmetic composition comprising an organosilicone compound as under (1) as active ingredient together with cosmetically accepted adjuvants and additives, in particular a composition further comprising a screening agent selected from the group consisting of UV-A screening agents, UV-B screening agents, and mixtures thereof, e.g. a complementary anorganic UV screening agent, such as a coated or uncoated pigment or nanopigment of a metaloxide selected from the oxides of titanium, zinc, iron, zirconium and cerium; (3) A cosmetic composition comprising an organosilicone compound as under (1) as active ingredient together with cosmetically accepted adjuvants and additives for protecting human hair and/or skin against damage in which UVA irradiation plays a role or is implicated; (4) A method to the protection of human hair and/or skin against damage in which UVA irradiation plays a role or is implicated which comprises topically applying an effective amount of an organosilicone compound as under (1); (5) Use of an organosilicone compound as under (1) for protecting human hair and/or skin against damage in which UVA irradiation plays a role or is implicated. The following examples are provided to further illustrate the processes and compositions of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way. In the Examples, FC. means Flash chromatography; HV means high vacuum (0.1 Pa or below); [NCI means International Nomenclature Cosmetic Ingredients. All structures were unambiguously identified via H-NMR (300MHZ, CDCl3). The photostability of the products were measured according to Berset et. al; Internat. J. Cosmetic Science 18:167-177 (1996). A solution of 1.75 mmol of 2-(4-diethyIamino-2-hydroxybenzoyl)benzoicacid prop-2-ynyl ester and 1.75 mmol eq. SiH of a COMPOUND wherein B, B', R1 and R3 are methyl, Z is H, r is in its statistical mean 14 and s is in its statistical mean 4 (MW ~ 1500) in 3 mi toluene under an inert atmosphere is heated to 53°C. A catalytic amount of platinum carbon 5% is added and the reaction is kept at 55°C for 20h. The product solution is washed with a mixture of water/methanol = 1:10, dried (Na2SO4), and concentrated. After the residue is dissolved in 3 ml toluene, active charcoal is added and the mixture is stirred for 2d at RT. After filtration over Celite the solvent is evaporated to yield a yellow oil (two isomers). UV (EtOH): 354 nm (E= 477), having unlimited solubility in Cetiol LC and Crodamol DA and excellent photostability qualities in film. 0.5 g of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid prop-2-ynyI ester, 2 g of polysiloxane AE-151 of Wacker-Chemie GmbH, and a catalytic amount of platinum carbon 5% in 10 ml of xylene are placed in a three-necked reaction flask under an inert atmosphere and heated for 2h at 70°C. The product solution is filtered through Celite, washed with a mixture of water/methanol = 1:10 and concentrated to yield a brownish oil (two isomers). UV 354 nm (E=147), having unlimited solubility in Cetiol LC and Crodamol DA and excellent photostability qualities in film. A solution of 1.4 mmol of 2-(4-ciethyIamino-2-hydroxyben2oyl)-propargylicbenzamide and 1.2 mmol of heptamethyltrisiloxane of formula IV wherein B, B', R and R2 are methyl, Z is hydrogen, r is 0 and s is 1, in 10 ml of toluene under an inert atmosphere is heated to 55°C. A catalytic amount of platinum-divinyl-tetramethyl-disiloxane complex is added and the reaction is kept at 80 to 35°C for 36 hours and at 100°C for four hours. 0.3 g of additional heptamethyltrisiloxane and a small amount of catalyst are added. After heating for another 18 hours at reflux, the product solution is concentrated and chromatographed twice (CH2Cl2/MeOH) to yield the product (two isomers). UV (EtOH): 358 nm (E= 227). Example C1: Preparation of a broad spectrum sunscreen lotion containing 2% of a organosilicone compound of the invention addition of KOH, cooling and degassing of the emulsion. Example C2: Preparation of a broad spectrum sunscreen lotion containing 4% of a organosilicone compound of the invention Example C3: Preparation of abroad spectrum sunscreen cream containing 4% of a polysiloxane compound of the invention 8000 t/minutes. When homogeneous. Part B is pre-heated to 75°C and added to Part A. The mixture is cooled to 40°C and Part C is added. The water loss is compensated and stirring is continued while cooling to ambient temperature. Then the mixture is mixed for 30 seconds with a turbine at 8000 t/minute. The cream has a low skin penetration quality. WHAT IS CLAIMED IS: 1. An organosilicone compound comprising a unit of formula I group. 2. A linear diorgano-siloxane polymer comprising one structural unit of formula IVa and one structural unit of formula IVb wherein Z is as defined in claim 1; R1, R6, R7, R8, R9, R10 and R11 independently are as defined in claim 1 for R2; B and B' independently are a group Z or a group R"; r is an integer from 0 to 200; and s is an integer from 0 to 50, wherein at least B or B' is Z when s is 0. 3. A process for the preparation of an organosilicone compound according to claim 1 comprising reacting (hydrosilylating) an organosilicone compound comprising a unit of formula VI (VI) wherein a is 0,1 or 2; and Rl is hydrogen, a saturated or unsaturated C1-C30 hydrocarbon group or a trimethylsilyloxy group; and, optionally, a unit of formula II according to claim 1, with a compound of formula VII in which R3 , R4 and X are as defined in claim 1 and Y' has the same definition as Y in claim 1, but is terminated either with a double or a triple bond. 4. A cosmetic composition comprising an organcsilicone compound as in claim 1 together with cosmetically accepted adjuvants and additives. 5. A cosmetic composition comprising an organcsilicone compound as in claim 1 for protecting human hair and/or skin against damage in which UVA irradiation plays a role or is implicated. 6. A method to the protection of human hair and/or skin against damage in which UVA irradiation plays a role or is implicated which comprises topically applying an effective amount of an organosilicone compound as in claim 1. 7. Use of an organosilicone compound as in claim 1 for protecting human hair and/or skin against damage in which UVA irradiation plays a role or is implicated. 8. The invention substantially as described hereinbefore, especially with reference to the Examples. 9. An organosilicone compound comprising a unit of formula substantially as herein described and exemplified.

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