METAL COMPLEXES OF B-DIKETONES AND/OR POLYPHENOLS BY GREEN CHEMISTRY, PREPARATION METHOD THEREOF, SUNSCREEN THEREOF, SKIN OR HAIR TONE CONCEALER THEREOF, HAIR DYEING THEREOF AND OTHER USES THEREOF

Abstract

The present invention relates to a method to synthesize with high yield a colored metal complex of β-diketones and/or polyphenols by mechanochemistry without using aqueous or organic solvents and covers new complexes obtained therefrom. In an embodiment, only the reactants, a metal alkoxide and a β-diketone and/or a polyphenol, are present and react at different molar ratios to form a metal complex in the form of a homogeneous colored material (i.e. powder) with high yield. If curcumin is used, the color of the final metal complex dye depends on several factors such as the curcuminoids, the metal, the type of alkoxide used, the stoichiometric molar ratio of both reactants and the additives used. If titanium alkoxide and any additive is used, a red or violet colored titanium curcumin complex in powder form is produced. The production process of the metal complex in powder form is characterized by facility of scale up. The entire product is ready to be used in several applications. If polyphenols such as ferulic acid, quercetin, ellagic acid or lignin are used instead of curcumin, other colored complexes are obtained using mechanochemistry. In addition, the product comprising metal complexes of β-diketones and/or polyphenols is characterized by green chemistry manufacture. Besides, these metal complexes of β-diketones and/or polyphenols in several formulations are characterized by improved stability under storage conditions and improved sun protection against UV rays for human skin and human hair. The product is ready to be used alone or in combination with other additives or active ingredients in different formulations. The invention also covers the use of these metal β-diketones/polyphenol complexes in food, cosmetics, the pharmaceutical field and in the creativity field, as sunscreen, skin and hair concealer or foundation in powder form or cream, keratinous dye, textile dye, food dye, dye emulsions, miniemulsions, polymer colloids and catalysts.

The production process of these novel metal-complex dyes is also characterized by rapid production of colored compounds without using solvents and, thus, ecofriendliness. The process of the production of metal β-diketone and/or polyphenol complexes is characterized by the non-formation of toxic by-products and high yield.

In addition, the present invention comprises a hair dyeing molecule or formulation and procedure combining excellent dyeing properties with reduced risk of development cancer or allergies, while being ecological and of the natural origin.

Claims

1. A metal complex in powder or colloidal form comprising the product of the reaction of (a) at least one β-diketone and/or at least one polyphenol with (b) at least one metal alkoxide obtainable by mechanochemistry without the addition of organic or aqueous solvent.

2. A metal complex according to claim 1 further comprising (c) at least one additive.

3. A metal complex according to claim 1 wherein: (a) the at least one β-diketone compound or its tautomers is selected from: synthetic β-diketones either with modification of the methylene group or with the introduction of nitrogen or sulfur groups into the keto-enol moiety such as: acetylacetone (pentane-2,4-dione), 3-Y-pentane-2,4-dione (wherein Y=Cl, Br, Me), benzoylacetone, dibenzoylmethane, diisobutyrylmethane, 2,2-dimethylheptane-3,5-dione, 2,2,6-trimethylheptane-3,5-dione, dipivaloylmethane, trifluoreacetylacetone, hexafluoroacetylacetone, benzoyltrifluoroacetone, pivaloyltrifluoroacetone, heptafluorodimethyloctanedione, octafluoropentane-2,3-dione, 4H,4H-decafluoroheptan-3,5-dione, 2-thenoyltrifluoroacetone, 2-furoyltrifluoroacetone, 2-thenoylacetone, 2-furoylacetone, cycloheptane-1,3-dione, diferuloylmethane, thio-β-diketone, chiral β-diketones, fluorinated 1,3-diketones and synthetic derivatives of 1,7-bisphenyl heptane-3,5-dione, synthetic curcuminoids or curcumin derivatives, curcumin conjugates, tetrahydrocurcumin and mixtures thereof. naturally occurring β-diketones such as: curcumin and its derivatives such as curcumin species (Zingiberaceae): from turmeric rhizome; curcumin, demethoxycurcumin, bisdemethoxycurcumin or mixtures thereof; green turmeric, dried turmeric, turmeric oleoresin; curcumin metabolites such as tetrahydrocurcumin, curcumin glucuronide; other curcuminoids such as cyclocurcumin, cassumunin A, cassamunin B, casamunin C and mixtures thereof; formulations containing curcumin including nanoparticles, liposomal encapsulation, phospholipid complexes, emulsions, capsules, tablets, and powders, either used alone or in combination with other compounds such as medicines, polyphenols, alkaloids (piperine), carbohydrates (monosaccharides, oligosaccharides and polysaccharides), proteins, amonoacids; herbal preparations such as extracts or tincture containing the keto-enol tautomers β-hydroxychalcones and β-ketodihydrochalcones. (b) the at least one polyphenol either synthetic or natural is selected from Simple aglycone or glycone phenols e.g. arbutin; Phenolic acids, e.g. vanillic acid and syringic acid; Phenolic aldehydes, e.g. vanillin and syringaldehyde; Phenylethanoids (phenylacetic acids, acetophenones, phenethyl alcohol derivatives), e.g. tyrosol; Phenylpropanoids (hydroxycinnamic acids and derivatives, cinnamic aldehydes, monolignols, phenyl propenes, coumarins, isocoumarins, chromones), e.g. ferulic acid, p-coumaryl alcohol, cafeic acid and rosmarinic acid; Stilbenoids, e.g. resveratrol; Anthraquinones and anthrones, e.g. aloe emodin, alizarin, purpurin, carminic acid; Xanthonoids, e.g. mangiferin; Naphthoquinones, e.g, lawsone, alkannin and juglone; Raspberry ketone; Open bridge flavonoids (chalcones, dihydrochalcones, and the keto-enol tautomers β-hydroxychalcones and β-ketodihydrochalcones), e.g. 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione isolated from the root bark of Pongamia pinnata or the stem bark of Millettia ovalifolia; Closed bridge flavonoids (aurones, auronols, flavans, flavan-3-ols, flavans-4-ols, flavan-3,4-diols, flavones, flavonols, flavanones, anthocyanidins, flavanonols, isoflavones and neoflavonoids), e.g. quercetin, chrysin, rutin, naringin, hesperidin; Diarylheptanoids, e.g. curcumin; Phenolic dimers and condensation oligomeric products such as ellagic acid, lignans, biscoumarins, dimers and trimers of ferulic acid, cafeic acid oligomers, bis-xanthones and xantholignoids, dimeric or oligomeric stilbenoids, bisantraquinones, dianthrones, di and oligomeric stilbenes; Polymeric phenols (tannins and lignins), e.g. gallotannins, elligatannins, proanthocyanidines, phlorotannins, thearubigins, kraft lignin, lignosulfonates; Hybrid phenolic (phenolic terpenes and phenolic lipids), e.g. carvacrol, thymol, THC, CBG, carnosic acid, carnosol, cardanol, bilobol, gingerols, shogaols, ginkgolic acids; Aqueous or organic extract or tinctures of polyphenols or mixtures of polyphenols; and wherein the optional additive is either added to one or both reactants, or simultaneously with the reactants or subsequently after the complex is recently initiated or after the final complex is formed whereby the amount of additive compound is between 0.01 wt % and 50 wt % of the mixture of compound(s) (a) and compound(s) (b), preferably 5-30 wt %.

4. A metal complex according to claim 1, wherein the at least one metal alkoxide (b) is a compound of formula M(OR).sub.x or [M(OR.sub.x)].sub.n or heterometalic alkoxide such as mixed halide-alkoxides or a bimetallic alkoxide (double alkoxide), or polymeric metal alkoxide or metal-oxo-alkoxides or metal aryloxide wherein, (a) M is one or more elements from the elemental periodic table, preferably titanium, zirconium, hafnium, vanadium, aluminium, germanium, silicon, niobium, lithium, tantalum, zinc, magnesium, antimony, indium, gallium, copper, holmium, tin, lanthanum, erbium, terbium, barium, gadolinium, yttrium, tantalum, dysprosium, cobalt, tellurium, lead, bismuth, calcium, cerium, iron, strontium, molybdenum, tungsten, neodymium, nickel, samarium, europium, holmium, osmium, praseodymium, boron, sodium, potassium, thallium, copper, scandium, nickel, chromium, manganese, platinum, ruthenium, gold, silver, beryllium, cadmium, mercury, thorium, selenium, or mixtures thereof, (b) R is an organic radical such as methoxide, ethoxide, propoxide (n- and iso), butoxide (n-, iso-, sec-, and tert-), amiloxide (n-, sec-, tert-) and neopentyloxide, aryloxide and (c) x corresponds to the valency of the metal M (d) n corresponds to the degree of molecular association.

5. A metal complex according to claim 1, characterized by a metal alkoxide to β-diketone molar ratio of 100:1 to 1:100 and a metal alkoxide to polyphenol molar ratio of 100:1 to 1:100.

6. A metal complex according to claim 1, wherein the β-diketone is a naturally or synthetically occurring β-diketone, preferably curcumin and/or the polyphenols are a natural or synthetically flavonoid preferably quercetin and/or a natural or synthetic phenylpropanoid preferably ferulic acid or a natural or synthetic phenolic dimer preferably ellagic acid and a natural or modified polymeric phenol preferably lignin.

7. A metal complex according to claim 1, wherein the metal is titanium, zinc, cerium, iron, aluminium, zirconium, silicon, silver, erbium, terbium, barium, gadolinium, yttrium, cobalt, bismuth, calcium, strontium, molybdenum, europium, holmium, boron, sodium, potassium, chromium, manganese, platinum, gold, silver, gallium, holmium, tin, lanthanum, copper, tantalum, magnesium, lithium, antimony, indium, vanadium, tungsten or germanium and mixtures thereof.

8. A process for the fabrication of a metal β-diketone and/or a metal polyphenol complex in powder form according to claim 1, comprising in any order, simultaneously or sequentially: (a) mixing (or adding) the at least one metal alkoxide compound (b) with (into) the at least one β-diketone compound and/or polyphenol (a) in a container (or a substrate such as keratinosous fibre or other material); (b) optionally macerating by mechanochemistry or by hand the reactants until a homogeneous powder (or tone) is obtained and (c) optionally letting rest the powder (coloring matter).

9. A process according to claim 8 wherein the mechanochemistry includes the use of a mechanical mortar and pestle, high speed milling, ball milling, attrition milling and planetary milling and/or wherein the container is a hand or mechanical mortar or pestle or a hand or comb and a substrate such as keratinous material whereby, an optional moderate increase of the temperature is applied.

10. A process according to claim 8 further comprising adding at least one additive compound (c) to at least one β-diketone and/or at least one polyphenol (a) and at least one metal alkoxide (b) simultaneously, or to every reactant (a) or (b), or after the reactants are put into contact or after the final complex is formed, wherein the metal from the metal alkoxide compound is selected from titanium, zinc, cerium, iron, aluminium, zirconium, silicon, silver, erbium, terbium, barium, gadolinium, yttrium, cobalt, bismuth, calcium, strontium, molybdenum, europium, holmium, boron, sodium, potassium, chromium, manganese, platinum, gold, silver, gallium, holmium, tin, lanthanum, copper, tantalum, magnesium, lithium, antimony, indium, vanadium, tungsten or germanium and mixtures thereof, and said additive compound (c) is selected from: the group of further β-diketones, further polyphenols, further metal β-diketones, further metal polyphenols, solvents, fatty oils, phenolic acids, fatty alcohols, organic acids, vitamins, aminoacids, lipids, proteins, carboxylic acids, synthetic or natural colorants, wetting agents, swelling agents, penetrants, pH regulators, surfactants, perfumes, thickeners, milling adjuvants, salts, oxides, water, whereby the amount of additive compound is between 0.01 wt % and 50 wt % of the mixtures of compound(s) (a) and compound(s) (b), preferably 5-30 wt %.

11. A process according to claim 8, comprising (a) adding the metal alkoxide compound (b) to a curcumin and/or quercetin and/or ferulic acid and/or ellagic acid and/or lignin compound (a) and consecutively adding the compound (c) in a hand or mechanical mortar; (b) macerating the reactants until a homogeneous powder is obtained; (c) letting rest whereby the powder obtained is a colored material with colors such as red, yellow, orange, violet, pink, green or brown.

12. A metal complex obtained by the process of claim 8.

13. A composition in the form of an emulsion (water in oil or oil in water), miniemulsion, microemulsion, suspension or dispersion comprising a metal complex according to claim 1, preferably wherein the metal complex is encapsulated in a polymer matrix.

14. A cosmetic, sunscreen, pharmaceutical (to be used as a further medical treatment for treating and preventing a skin or hair condition), food, staining, painting or coating composition comprising a metal complex according to claim 1.

15. A process for the fabrication of a sunscreen product with tone concealer, to prevent premature aging of the keratinous material and to prevent skin or hair disorders, comprising the following steps: (a) a metal complex according to claim 1 is mixed with a vehicle in such a way that the desired sun protection factor is obtained, whereby said vehicle is selected from: a cream base for preparing skin or hair creams without active ingredients, without perfumes, without parabens such as cetomacrogol crème commercially available, comprising water, decyl oleate, cetaryl alcohol, cetearth-20, sorbitol, sorbic acid, or any cetomacrogol crème; a pasty fatty substance such as waxes, gum or mixtures thereof, an oil, a fatty alcohol, a surfactant, a gel, a powder, a UV filter and/or UV absorber, a skin or hair protecting, an emollient, an humectant, an emulsifyer, an skin or hair conditioning, a refatting agent, a masking agent, an emulsion stabilizer, a cleansing agent, an antioxidant, an opacifying agent, a solvent, a viscosity controller, a bulking agent, an abrasive, an anticaking agent, a preservative, a parfum, a buffer agent, an antimicrobial, a salt, water or mixtures thereof or any other cosmetically or pharmaceutically acceptable vehicle; (b) optionally adjusting the desired sun protection factor by the addition of further synthetic or natural filters such as those listed in the EU Cosmetic Ingredient Database.

16. A method of coloring a material according to claim 1, which comprises applying to the material being colored or letting the material being colored into contact with, in any order, successively or simultaneously, (a) at least one β-diketone and/or at least one polyphenol (b) at least one metal alkoxide (c) and optionally at least one additive under conditions that the material being colored is absorbed or adsorbed with the compound (a) and left under conditions that no lateral reactions take place or lateral reactions are minimized, and then the compound (b), the metal alkoxide, is provided; wherein the at least one additive (c) can be added to at least one compound (a) or at least one metal alkoxide whereby if an additive such as an aqueous or organic solvent is used to enhance the diffusion of compound (a) or (b), it is preferably let evaporating or drying in the substrate before the next compound is added and if an aqueous or organic herbal extract or tincture is used, the solvent is let to dry in the substrate before the next component is added.

17. A metal complex (or mixture thereof) according to claim 1 which is present as a component of a textile dye, keratinous dye, wood dye, food dye, pharmaceutical dye in powder form or as colloids, catalyst for reactions and polymerization either alone or in combination with other dyes or catalysts such as zeolites, as additives in semiconductors, conductors or superconductors or DNA binding agent coating technique.

18. A method for forming a metal complex, said method comprising the step of reacting at least one β-diketone and/or at least one polyphenol with at least one metal alkoxide without the addition of organic or aqueous solvent.

19. The method of claim 18 wherein the metal complex comprises a metal β-diketonate or a metal polyphenol.

20. A composition comprising a dye, which composition comprises the metal complex of claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0091] This invention covers a process for the synthesis of metal β-diketonates from at least one β-diketone and at least one metal alkoxide by mechanochemistry. Similarly, this invention covers a process for the synthesis of metal polyphenol complexes from at least one polyphenol and at least one metal alkoxide by mechanochemistry. Similarly, this invention covers a solvent-free mechanochemical synthesis of a stable metal complex by reacting with at least one β-diketone and/or at least one polyphenol. In particular, the present invention deals with the mechanochemical synthesis of metal complexes by using e.g. curcumin and/or quercetin and/or ferulic acid and/or lignin and/or ellagic acid and at least one metal alkoxide as starting materials.

β-Diketones and Polyphenols

[0092] A β-diketone is a diketone in which the two keto groups are separated by a single carbon atom. In this view, a β-ketoester, a thio β-diketone and a β-ketoamine (Shiff base) behave similar to a β-diketone since they contain a reactive hydroxyl group which is prone to react readily with metal alkoxide.

[0093] The β-diketonate ligand has the ability to coordinate with most elements which is a feature that distinguishing it from other organic ligands.

[0094] β-diketones undergo keto-enol tautomerism. Tautomerism implies the presence of the ketone and the enol forms in equilibrium. Pentane-2,4-dione (more informally acetylacetone) is the β-diketone that has been most studied. The feature of β-diketonate chemistry, in particular of acetylacetone, is the tendency to form inert (at least for catalyst) tri or tetramer complexes with a metal for most transition and main group elements.

[0095] The β-diketone compound to prepare the metal β-diketonate complexes of the present invention may be selected from: [0096] 1. synthetic β-diketones either with modification of the methylene group or with the introduction of nitrogen or sulfur groups into the keto-enol moiety such as: pentane-2,4-dione (acetylacetone), 3-Y-pentane-2,4-dione (wherein Y=Cl, Br, Me), benzoylacetone, benzoylacetone, dibenzoylmethane, diisobutyrylmethane, 2,2-dimethylheptane-3,5-dione, 2,2,6-trimethylheptane-3,5-dione, dipivaloylmethane, trifluoreacetylacetone, hexafluoroacetylacetone, benzoyltrifluoroacetone, pivaloyltrifluoroacetone, heptafluorodimethyloctanedione, octafluoropentane-2,3-dione, 4H,4H-decafluoroheptan-3,5-dione, 2-thenoyltrifluoroacetone, 2-furoyltrifluoroacetone, 2-thenoylacetone, 2-furoylacetone, cycloheptane-1,3-dione, thio-β-diketones, chiral β-diketones, and mixtures thereof. [0097] 2. naturally occurring β-diketones such as: [0098] (a) curcumin and its derivatives such as from curcumin species (Zingiberaceae): curcumin from turmeric rhizome; curcumin, demethoxycurcumin, bisdemethoxycurcumin or mixtures thereof; curcumin metabolites such as tetrahydrocurcumin, curcumin glucuronide; synthetized curcumin and mixtures thereof; other curcuminoids such as cyclocurcumin, cassumunin A, cassamunin B, cassamunin C. [0099] (b) β-diketones derived from leaf wax of Festuca ovina, from epicuticular waxes of barley or from epicuticular waxes of vanilla bean species. [0100] (c) Pongamol from pangamia glabra fruits, (+)-usnic acid from Usnea dasypoga, clusianone and 7-epi-clusianone from Guttiferae (Clusiaceae) [0101] (d) Any other compound able to form keto-enol tautomerism

[0102] Pettinari O..sup.18 et al. reviewed the syntheses of β-diketones and metal β-diketonates. β-diketones may also be obtained by in situ synthesis prior or during the complexation of the present invention.

[0103] Curcumin, a β-diketone with sterically bulky functional groups, can provide an alternative route, for instance, for catalysis chemistry by its complexation with metals. The diarylheptanoid moiety of curcumin comprises both aryl groups tethered by a linear seven carbon chain having substituents. Both β-diketone substituent and the diarylheptanoid with the double bonds make curcumin one of the most ubiquitous compounds for several uses such as pharmaceuticals, cosmetics, foods, coatings, catalyst, reagents for film deposition.

[0104] Since curcumin is both a β-diketone and a diarylheptanoid, other diarylheptanoids having β-diketone substituents to produce the metal β-diketonate complexes may be selected from naturally occurring diarylheptanoids such as those isolated from Zingiberaceae, Centrolobium Sclerophyllum, Betulaceae, Myricaceae, Juglandaceae, Aceraceae or synthetic diarylheptanoids.

[0105] Phenolic compounds or polyphenols comprise a wide variety of molecules that have several hydroxyl groups on aromatic rings such as lignins but also molecules with one phenol ring such as phenolic acid and phenolic alcohols.

[0106] The term polymeric phenols is preferred to polyphenols because otherwise lignin would be excluded according with the strict definition of polyphenols. Polyphenols in line with WBSSH definition exclude many compounds purely based on the solubility or molecular weight. Quideau et al.sup.19 (2011) proposed the definition of polyphenol as plant secondary metabolites derived exclusively from the shikimate-derived phenylpropanoid and/or the polyketide pathway(s) featuring more than one phenolic ring and being devoid of any nitrogen-based functional group in the most basic structural expression. In a recently book edited by Watson R. R.,.sup.20 Tsimogiannis D. and Oreopoulou V. in chapter 16 Classification of phenolic compounds in plants revised the classification of polyphenols according to Harborne..sup.21 Thus, the synthetic or naturally occurring polyphenol compound from plants or animals (e.g., insects and crustaceans) to prepare the metal polyphenol complexes of the present invention may be selected from:

Simple aglycone or glycone phenols e.g. arbutin;
Phenolic acids, e.g. vanillic acid and syringic acid;
Phenolic aldehydes, e.g. vanillin and syringaldehyde;
Phenylethanoids (phenylacetic acids, acetophenones, phenethyl alcohol derivatives), e.g. tyrosol;
Phenylpropanoids (hydroxycinnamic acids and derivatives, cinnamic aldehydes, monolignols, phenyl propenes, coumarins, isocoumarins, chromones), e.g. ferulic acid, p-coumaryl alcohol, cafeic acid and rosmarinic acid;
Stilbenoids, e.g. resveratrol;
Anthraquinones and anthrones, e.g. aloe emodin, alizarin, purpurin, carminic acid;
Xanthonoids, e.g. mangiferin;
Naphthoquinones, e.g, lawsone, alkannin and juglone;
Raspberry ketone;
Open bridge flavonoids (chalcones, dihydrochalcones, and the keto-enol tautomers β-hydroxychalcones and β-ketodihydrochalcones), e.g. 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione isolated from the root bark of Pongamia pinnata or the stem bark of Millettia ovalifolia;
Closed bridge flavonoids (aurones, auronols, flavans, flavan-3-ols, flavans-4-ols, flavan-3,4-diols, flavones, flavonols, flavanones, anthocyanidins, flavanonols, isoflavones and neoflavonoids), e.g. cathechin, epicatechin, epigallocatechin gallate, quercetin, chrysin, rutin, naringin, hesperidin;
Diarylheptanoids, e.g. curcumin;
Phenolic dimers and condensation oligomeric products such as ellagic acid, lignans, biscoumarins, dimers and trimers of ferulic acid, cafeic acid oligomers, bis-xanthones and xantholignoids, dimeric or oligomeric stilbenoids, bisantraquinones, dianthrones, di and oligomeric stilbenes;
Polymeric phenols (tannins and lignins), e.g. gallotannins, elligatannins, proanthocyanidines, phlorotannins, thearubigins, kraft lignin, lignosulfonates;
Hybrid phenolic (phenolic terpenes and phenolic lipids), e.g. carvacrol, thymol, THC, CBG, carnosic acid, carnosol, cardanol, bilobol, gingerols, shogaols, ginkgolic acids;
Aqueous or organic extracts or tinctures or powders of polyphenols are commonly composed of a mixture of several polyphenols as occurs in nature, e.g. extracts or powders from plants of genera: Curcuma, Lawsonia, lndigofera, Genipa, Oenothera, Lespedeza, Passiflora, Hamamelis, Theobroma, Coffea, Chamaemelum, Quercus, Zingiber, Capsicum, Malva, Bixa, Tagetes, Cynara, Glycine, Asperula, Angelica, Hieracium, Ammi, melilotus, Aesculus, Lithospermum, Solidago, Origanum, Camellia, Schisandra, Hibiscus, Rosa, Ribes, Acacia, Bactris, Rhus, Gingko, Juglans, Hibiscus.

[0107] The chemical composition of polyphenols in nature commonly is a mixture of several polyphenols or is conjugated with sugar and organic acids.

[0108] Some of these polyphenols such as lignin may be selected from the milled wood lignin (from milling wood or chips), or the by-product of the treatment of the lignocellulose material in the paper industry. Chemical agents such as caustic alkalis, ammonia, chlorite, sulfur dioxide, diluted and concentrated acids and solvents are commonly used to produce pulp and paper. These agents commonly modify the lignin and should be eliminated from the end product, but they are not entirely eliminated and then reduce the application potential of lignin. Ligninsulfonates are obtained from the (acidic) sulfite process; kraft lignins are the product of sulfate pulping process; soda lignins are sulfur free; and organosolv lignins are extracted by solvents and are of high purity.

[0109] Therefore, in the present invention, the term polyphenols refers also to extracts of materials containing polyphenols which have been subjected to the complexation procedure of the present invention. In addition, the polyphenol compounds of the present invention include polyphenols that are subjected, prior to the complexation of the present invention, to another kind of chemical, biochemical, enzymatic, or physical procedure or complexation. As further presented in this invention, the encapsulation of polyphenols is a strategy to enhance the properties of polyphenols. Thus, polyphenols which are modified or protected are also used as a source of polyphenol in the present invention. Similarly, β-diketones which are protected (e.g. as enol ethers or enamines) or manipulated may also be used as a source of β-diketones compound in the present invention.

[0110] Lignin may be selected from a native lignin, an enzymatic lignin, an alkaline lignin, a lignosulfonate (as a sodium-, calcium-, magnesium-, or ammonium salts) or a kraft lignin or an organosolv lignin.

[0111] Polyphenols have several health benefits for humans and animals due to several properties, including antioxidant, anti-inflammatory, cardioprotective and neuroprotective functions. Besides, polyphenols are anti-bacterial, anti-viral and anti-fungal. These capabilities of polyphenols are key to their use for treatment of several diseases, in food-processing and for anti-aging purposes in various cosmetic and pharmaceutical formulations. However, polyphenols are sensitive to several environmental factors such as light and heat and may degrade rapidly under water, air or storage conditions. The present invention provides a new synthetic approach to stabilize polyphenols and/or β-diketones by complexation with metal alkoxides with an excellent stability e.g. to environmental and storage conditions. These novel metal complexes can be further encapsulated, e.g., by miniemulsion polymerization for further applications.

Metal Alkoxides

[0112] According to IUPAC,.sup.22 the term alcoholates is synonymous of alkoxides. Alcoholates should not be used for solvates derivate from an alcohol such as CaCl.sub.2.nH.sub.2O, for the ending -ate often occurs in names for anions.

[0113] Metal alkoxides.sup.23 or metal alcoholates have the formula M(OR).sub.x where M is the metal (or non-metal or other cationic species), R is an organic radical and x corresponds to the valency of the metal M. The metal alkoxide can be either in solid or liquid form. They are produced from almost any metal of the periodic table of the elements. Both metal and radical confer properties of the alkoxide. The metal provides the electronegativity, whereas the radical provides the acidity and the ramification. Thus, metal alkoxides are so versatile and diverse that they can be either water-soluble or water-sensitive. One of the advantages of alkoxides is that they only form their parental alcohol as a by-product. The health hazard of metal alkoxides depend on the metal they contain and the alcohol they produce after hydrolysis. The chelates with which the metal alkoxides are formed, e.g., β-diketones, β-ketoesters are generally more stable than the alkoxides themselves.

[0114] M(OR).sub.x or [M(OR.sub.x)].sub.n is a metal alkoxide or heterometallic alkoxide such as mixed alkoxide mixed halide-alkoxides or bimetallic alkoxide (double alkoxide), or polymeric metal alkoxide or oxo metal alkoxides metal aryloxide or bi-, tri-, and tetrametallic alkoxides or adducts with neutral ligands where [0115] (a) M is one or more elements from the elemental periodic table, preferably titanium, zirconium, hafnium, vanadium, aluminium, germanium, silicon, niobium, lithium, tantalum, zinc, magnesium, antimony, indium, gallium, copper, holmium, tin, lanthanum, erbium, barium, gadolinium, yttrium, tantalum, dysprosium, cobalt, tellurium, lead, bismuth, calcium, cerium, iron, strontium, molybdenum, tungsten, neodymium, nickel, samarium, europium, osmium praseodymium, boron, sodium, potassium, thallium, copper, scandium, nickel, chromium, manganese or mixtures thereof; [0116] (b) R is an organic radical such as methoxide, ethoxide, propoxides (n- and iso-), butoxides (n-, iso-, sec-, and tert-), amyloxides (n-, sec-, tert-) and neopentyloxides, aryloxides; [0117] (c) x corresponds to the valency of the metal M and [0118] (d) n corresponds to the degree of molecular association

[0119] The term heterometal alkoxide with bi-, tri-, and tetrametallic alkoxides (as explained in the corresponding chapter in Alkoxo and Ariloxo Derivatives of Metals by Bradley D. C. et al) such as bimetallic alkoxides M.sub.n M.sub.m′ (OR).sub.p is adopted here since their structure and physicochemical properties belong to the same types as those of homometallic ones. A metal alkoxide or a heterometal alkoxide is not a salt since they do not proceed from the reaction of an acid and a base neutralizing each other.

[0120] Polymeric metal alkoxides [M(OR).sub.x].sub.n are the product of partial hydrolysis or thermolysis of M(OR).sub.x where n is corresponds to the degree of molecular association.

[0121] Adducts of metal alkoxides with ligands such as M(OR).sub.x.mL where m is the composition of the solvates. Optionally, the metal alkoxide used in the present invention can be prepared in situ by reaction of alcohols with metals, with metal hydroxides, with metal halides, with metal amides or metal alkoxide of other alcohols or mixed halides alkoxides or by alcoholysis and transesterification reaction and others methods (alkoxides, metal in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed. vol 2).

[0122] The metal β-diketonate complex synthetized in the present invention is the product of the oxygen-bonded β-diketonate complexation between a β-diketone and a metal alkoxide promoted by mechanochemical synthesis to assure homogeneity of the final product

[0123] The metal polyphenol complex synthetized in the presence invention is the product of the reaction of a polyphenol with a metal alkoxide.

[0124] Both β-diketonate and polyphenol may be mixed before the reaction with the metal alkoxide. In this way, even more different complexes and colors are obtained.

[0125] In the present invention, the mechanical grinding is preferably achieved by a simple hand mortar and pestle. Various mechanical deformation methods, well known in the prior art, can be used such as mechanical mortar and pestle, high speed milling, ball milling, attrition milling and planetary milling.

[0126] The process of the invention may comprise the following steps: [0127] 1. At least one metal alkoxide is added to the β-diketone and/or polyphenol (or vice versa) in the desired stoichiometric ratio metal alkoxide to β-diketone and/or metal alkoxide to polyphenol, such as between 1/100 to 100/1 or vice versa. Both reactants are homogeneously mixed before the following step 2. In some cases where the molecular weight is not exact known, e.g in the case of lignin, weight ratio metal alkoxide to β-diketone and/or polyphenol between 1/100 to 100/1 may be used. [0128] a. Optionally, depending of the further use of the metal β-diketone or polyphenol complex as a sunscreen, dye or colloids, an amount of additive between 0.01 wt. % and 50 wt. % of the total weight of both reactants is added. The additive compound is selected from the following either as a single compound or a combination of two or more compounds selected from the group of further β-diketones, further polyphenols, further metal β-diketones, further metal polyphenols, solvents, fatty oils, fatty alcohols, organic acids, vitamins, aminoacids, lipids, proteins, carboxylic acids, synthetic or natural colorants, wetting agents, swelling agents, penetrants, pH regulators, surfactants, perfumes, thickeners, milling adjuvants, salts, oxides, water. [0129] b. Optionally, the additive is added to the reactants taking account of the compatibilities. [0130] c. Optionally the additive is added simultaneously with the reactants. [0131] 2. The abovementioned mixture may be ground by hand or mechanically, so that the mechanochemical reaction occurs between the two reactants. Several mechanochemistry methods can be used, such as hand and mechanical mortar and pestle, ball milling, attrition milling, planetary milling. The mechanochemical reaction gives a colored homogeneously and finely dispersed powder material. The color in the final powder depends of the metal used and the radical of the metal alkoxide as well as the β-diketonate and the polyphenolic ligand. [0132] 3. Optionally the additive is added after the complex is formed. [0133] 4. The abovementioned mixture may be let to rest (such as for 1 hour). [0134] 5. The resulting, finely dispersed and colored powder is ready to be used in food, cosmetics, pharmaceuticals, paints, and other applications.

[0135] The β-diketones (and 3-ketoesters) and/or the polyphenols and the metal alkoxide act as reactive compounds prone to react in a well-known synthetic route. The mechanochemical synthesis enhances and promotes the reaction of both reactive compounds and provides the desired colored product or product precursor for further uses such as sunscreens. All reactive compounds used for the process of the present invention can be either in solid or liquid forms under the conditions used for the mechanochemical synthesis. In addition, one or more reactive compounds for the process of the present invention can be used in gaseous state under the conditions used in the mechanochemical synthesis, as long as at least one other compound is either solid or liquid under the conditions used in the mechanochemical process.

[0136] The mechanochemical route of synthesis is a direct synthesis that uses either manual or mechanical milling or grinding to initiate or facilitate the process in solid state or solid-liquid state. Either solid-solid synthesis without solvent or with minimal amounts of solvent or solid-liquid synthesis is used to promote mechanochemical reactions. The most important advantage of mechanochemistry is the solvent-free synthesis or near solvent-free synthesis with only small amounts of solvents (i.e. less than 10 wt % based on the total of weight of the reaction mixture), the so-called liquid-assisted grinding. According to Tanaka,.sup.24 the solvent-free term refers to the stoichiometric application of solid or liquid reagents with less than a 10% excess of a liquid or soluble reagent and/or less than 10% of a liquid or soluble catalyst. Minimal amount of solvent implies that no solvent is a priori and deliberately added to the reaction that could require solvent-consuming purification steps after the reaction.

[0137] Solvent-free organic synthesis is eco-friendly and obviates the necessity of further steps of solvent evaporation and recycling of the solvent. In addition, the amount of hazardous by-products that can interact with the solvent is decreased. In contrast to mechanochemistry, the traditional production of metal β-diketonate complexes by solution-based methods uses substantial amounts of solvents, generally organic such as toluene or benzene in order to remove the alcohol produced during the reaction and to complete the reaction. Consequently, the solvent has to be removed by different methods such as distillation, distillation under reduced pressure or vacuum extraction. This process is tedious and involves careful handling of toxic compounds. In the present invention, since both the metal alkoxide and the β-diketone and polyphenols are sensitive to solvents, it is beneficial to let react only by mechanochemistry.

[0138] Mechanochemistry can promote reactions quickly and in large quantities. The effectiveness of the mechanochemical reactions depends on the chemical and the mechanical properties of the agents or reactants. Mechanochemical phenomena may lead to the activation of strong covalent chemical bonds by the presence of an external mechanical force. However, more labile non-covalent bonds may be also activated e.g. supramolecular materials.

[0139] Although the theory of the mechanochemical reactions is still in its infancy and, so far, there is not a general theory for mechanochemical reactions, some possible phenomena may involve:

formation of active surface radicals; modification of physicochemical properties; enhancement of reactivity due to stable changes in the structure; enhancement of effectivity in the solid phase than in the liquid phase..sup.24, 25

[0140] The mechanochemical reactions of the process of the present invention can be made by various methods.

[0141] Prior to starting the mechanochemical process, a detailed control of the form of the reactive compound should be effected. If both reactive compounds are grove solids, they can be ground separately before the mechanochemical process begins. Optionally, if possible, a slight increase of the temperature for allowing to produce the homogeneous mixture would be convenient. The starting materials are combined at slow speed and then ground together at higher speed. The grinding can be done under dry or wet conditions. A dry grinding is preferred. However, in case wet grinding is required, inert grinding aids that do not react with either the reactant compound or the final product are preferred.

[0142] The energy of the grinding process can be varied within wide ranges. Low energy ball-milling, attrition milling, vibratory milling and similar low energy grinding processes known in the art of grinding are preferred over high energy milling processes, since the use of a grinding medium at high energy can produce wear and, thereby, contaminate the reactant and the product obtained. However, when high energy milling is needed, high energy ball milling, high energy planetary milling and similar can be used. Grinding media that do not react with the reactant compound and product are preferred and can be agate or similar materials. To increase the reactivity of the reactant compounds or to induce melting of one or more reactants if need be, the milling process can be carried out at high temperatures or the reactive compounds can be pre-heated prior of the start of the milling process.

[0143] Additives such as cutting, milling and grinding aids, lubricants, surfactants, polymers and antistatic agents may be used to prevent agglomeration of the particles and, thus, improve the grinding efficiency. These additives can be in the form of a liquid, a solid, a semisolid, a waxy substance, flakes and micronized beads. A great variety of substances can be used to enhance the milling process. A careful selection with regard to the impact on the quality of the final product as well as environmental issues must be considered. These additives may be selected from the group consisting of ethoxylated alkyl phenol (such as Dodoxynol-5, 6, 7, 9, 12 and Nonoxynol-9, 30), fatty alcohol ethoxylated (such as emulan OG or emulan TO 40), sodium dodecylbenzenesulphonate, sodium dodecyl sulphate, maltodextrin, lecithin (such as phosphatidylcholine, hydroxylated lecithines), fatty acids (such as stearic acid, oleic acid), polysorbates and similar. These additives may be used in a concentration between 0.01 and 10 wt % based on the total weight of the reactive mixture.

[0144] Depending on the reactivity of the milled materials and the intensity of the milling process, the milling time can vary between 1 minute and 1 hour.

[0145] Mechanical grinding device which controls parameters such as mortar and pestle speed is more appropriate for the synthesis due to the ease of standardization and reproduction of results. For small quantities or at laboratory scale, a micro mill where the speed of both mortar and pestle can be controlled is preferred. In addition, the mortar and pestle could be covered with a transparent cover for safety. A simple hand mortar and pestle, preferably from agate to avoid contamination, is sufficient for small quantities of sample.

[0146] The process of the present invention enables the preparation of metal β-diketonate complexes and/or metal polyphenol complexes with high yields and under ecofriendly conditions as well as the immediate synthesis of a ready sample for further analysis such as powder X-ray diffraction (XRD) studies. The process of the present invention obviates the troublesome processes to purify the product in solution-based methods or in mechanochemical methods using large amounts of additives. The metal complex in powder form is ready to be characterized by several analytical techniques such as XRD or spectrophotometric measurements.

[0147] For XRD studies of the metal complexes of the present invention, a drying process may optionally be carried out at the boiling point of the parental alcohol or at reduced pressure, among others. In this way, the water or parental alcohol, that might be produced in the reaction, is eliminated. However, the direct characterization of the metal complex after the mechanochemical reaction without removal of the volatile by-products or without dissolution or recrystallization in other solvents is preferred.

[0148] In fact, the product of the present invention, the metal β-diketonate/polyphenol complex in powder form, can be crystalline, semicrystalline or amorphous depending on the selection of the reactants and the molar ratio of the reactants used. If two different metal β-diketonate/polyphenol complexes—with the same or different metal atom—obtained separately by mechanochemistry and by redistribution reaction, are allowed to react by mechanochemistry, cocrystalline complexes can be obtained.

[0149] For further applications of the metal β-diketonate/polyphenol complex produced in this invention, such as precursors for film formation techniques or metal oxides with a treated surface such as those to be used in sunscreen or ceramic production, partial or total elimination of the organic material can be conducted. Since the final metal β-diketonates/polyphenol complexes contain mainly carbon, oxygen and hydrogen and the metal or mixture of metals (such as those from curcumin and metal alkoxide), the calcination or pyrolysis of the organic material proceed straightforward. The temperature used for the decomposition of the product prepared by the mechanochemistry method is preferably above 300° C. for three hours, more preferably about 600° C. for three hours, and most preferably about 900° C. for 3 hours. Depending on the film deposition technique to be used, subsequent thermal treatments and dwell times can be optionally adjusted. Thus, if more crystallinity is desired or required, the final metal β-diketonate/polyphenol complexes can be sintered.

Mechanochemical Reaction of Titanium Alkoxide with Curcumin

[0150] Mechanochemical synthesis of the sole reactants titanium n-butoxide and curcumin in a molar ratio titanium n-butoxide to curcumin of 1:1 in a mechanical agate mortar and pestle led at the beginning to an orange reddish paste which turned red after three minutes of constant milling. The orange reddish paste was easily milled to a fine red-colored titanium-curcumin complex. The complexation does not need any additional catalyst. Titanium n-butoxide acts as a catalyst and as a metal precursor. No separation of phases occurred.

[0151] The titanium-curcumin complex produced in the present invention is red-colored, whereby the red coloration is not due to external influences such as acids, bases, solvents or catalysts. Only the two reactants—curcumin and a metal alkoxide—are the starting materials.

Use of the Metal Complexes for Sunscreens with Concealer Effect

[0152] Many people are reluctant to use sunscreens that leave a whitish color or chalky look on the skin. Most natural sunscreens in the market have this disadvantage. The problem is compounded if high amounts of pigments or dyes are added to the sunscreen (to produce the so-called foundation) since it often generates aggregation or irregularities in the sunscreen itself or in the skin and the masking effect is lost. Thus, the desired final naturally looking texture of the sunscreen is not achieved.

[0153] Curcuminoids have been used as skin protectant in cosmetic formulations. For instance, Vicco Turmeric Cream used curcumin or turmeric in formulations. These formulations are yellow colored and perhaps undesirable in cosmetic preparations because yellowing is usually associated with spoilage. Efforts have been made to change the color of curcumin by synthetic treatment. Thus, as mentioned previously, tetrahydrocurcumin or tetrahydrocurcuminoids has been used also as skin lightening taking advantage of its colorlessness or off-white color.

[0154] As previously explained, curcumin changes color with the change of the pH. However, this change is not stable and curcumin degradation begins quickly.

[0155] Traditionally in many countries, curcumin is mixed with a base, such as calcium hydroxide, to produce a red colored paste to be used as a colorant for bindi. However, this mixture is very unstable as it is only a product of acidity or basicity of the medium or the physical impregnation and people add different red colored matter such as toxic colorants in order to produce red color.

[0156] There is no evidence of red colored curcuminoid in the market by chemical or biochemical procedures with outstanding stability in different media and that could be used with less risks around the world.

[0157] One of the objects of the present invention is to use the metal β-diketonate/polyphenol complexes, in particular metal curcumin and/or ferulic acid and/or quercetin and/or ellagic acid and/or lignin complexes, having metals such as titanium, zinc, cerium, iron, aluminium, zirconium, silicon, or germanium and mixtures thereof as a sunscreen. The use of this product as a sunscreen is characterized by beautiful purple or red coloration (or their shades) that is distributed homogeneously on the skin. In addition, the use of the metal β-diketonate/polyphenol complexes of the present invention as a sunscreen shows excellent stability in the vehicle without forming precipitates or aggregates in an homogeneous composition. With little changes in the composition of the reactants of the complexes and in the conditions of the reaction and the vehicle of the formulation used, a wide range of skin tones are achieved in line with guides used in the cosmetics to match the color of the skin.

[0158] The product of this invention to be used as a sunscreen is further formed by the mechanochemical reaction of β-diketone and/or polyphenol (e.g., curcumin, quercetin, ferulic acid, ellagic acid, and lignin) and metal alkoxide. Optionally, between 0.01 and 50 wt % of the mixture of the β-diketone and/or polyphenol and metal alkoxide of an additive such as perfume (e.g. pentane-2,3-dione), solvent (e.g. pentane-2,4-dione), acids (e.g. ascorbic acid, tartaric acid, citric acid, acetic acid), fatty alcohol (e.g. cetyl alcohol), natural oils or extracts (e.g. plukenetia volubilis seed) can be added to the prior mixture to impart different colors to the final product. The additive or mixtures of additives can be added conveniently to the metal alkoxide or to the β-diketonate and/or the polyphenol. Additives may be preferentially inert but it is not restrictive. A controlled reaction with the additives may be advantageous to generate other properties, if desired.

[0159] The metal β-diketone/polyphenol complexes having the additive are then mixed with a vehicle or carrier to produce a sunscreen, a foundation, or a hair dye. The vehicle or carrier can be any appropriate material such as any base cream, oil, gel or powder.

[0160] The vehicle substance or base can be selected from: [0161] a cream base for preparing skin or hair creams without active ingredients, without perfumes, without parabens such as cetomacrogol crème commercially available, comprising water, decyl oleate, cetaryl alcohol, cetearth-20, sorbitol, sorbic acid, or any cetomacrogol crème; [0162] a pasty fatty substance such as waxes, gum or mixtures thereof; an oil, a fatty alcohol, a surfactant, a gel, a powder, a UV filter and/or UV absorber, a skin or hair protecting, an emollient, an humectant, an emulsifier, a skin or hair conditioning, a refatting agent, a masking agent, an emulsion stabilizer, a cleansing agent, an antioxidant, an opacifying agent, a solvent, a viscosity controller, a bulking agent, an abrasive, an anticaking agent, a preservative, a parfum, a buffer agent, an antimicrobial, a salt, water or mixtures thereof or any other cosmetically or pharmaceutically acceptable vehicle;

[0163] In addition, the desired sun protection factor can be optionally adjusted by the addition of further synthetic or natural filters such as those listed in the EU Cosmetic Ingredient Database.

[0164] The weight ratio of the metal complex to the vehicle can be between 1:100 to 100:1. Preferably, weight percentage of the metal complex is a range between 0.01 to 30 wt % depending of the solar protection factor that is desired.

[0165] The active ingredient for the sunscreen is the titanium complex, or zinc complex or zinc-titanium complex or mixtures thereof. Optionally, another metal or mixture of metals can be used.

[0166] If niobium n-butoxide instead of titanium n-butoxide, and curcumin is used, an almost instantaneous red paste that solidifies into a dark red bordering black powder is achieved.

[0167] This invention covers a mechanochemical process for the synthesis of metal complexes from a β-diketone and/or polyphenol and a metal alkoxide. The present invention of metal complexes of β-diketone and/or polyphenol is characterized by a solvent-free synthesis or near solvent-free synthesis with only small amounts of additives. This solvent-free organic synthesis is ecofriendly and avoids the necessity of further steps of solvent evaporation and recycling of the solvent. In addition, the amounts of hazardous by-products diminish. Thus, the entire process for the production of metal complexes of β-diketones and/or metal complexes of polyphenols in powder or colloidal form of my present invention fulfills the conditions to be considered green chemistry.

[0168] The simplicity, high yield, low cost and ease of scale up makes the process of the present invention to produce metal 3-diketonate complexes and metal polyphenol complexes and their use as sunscreen with concealer very attractive for industrial applications.

[0169] A major advantage of the process of the present invention to produce metal complexes by mechanochemistry over conventional methods to produce organic-inorganic hybrid materials is the rapid completion of the reaction within a few minutes of grinding, the low polydispersity of the finely ground powder and the high stability and homogeneity of the complex obtained. In addition, the process of the present invention provides novel nanostructures similar to those obtained by solution-state methods for instance after pyrolysis. Since the use of solvent in the present invention is reduced to a minimum or the process is entirely solvent-free, no additional steps are necessary to remove it. In this way, the high yield process of the present invention to produce metal β-diketonate complexes and metal polyphenol complexes, in particular, metal curcumin complexes and metal quercetin complexes and metal ferulic acid complexes, metal ellagic acid and metal lignin complexes is cost effective.

[0170] Other advantage of the present invention is the production of metal complexes with a pleasant odor that does not resemble the original odor of the reactants,

Semipermanent and Temporary Hair Dyes

[0171] The urge of solving problems regarding use of less amount of primary intermediates and couplers without detriment to the performance of hair dye with healthier properties such as protecting the hair from the sun and balancing durability and safety of the dye should be the goal of hair dyeing production.

[0172] Natural colorants with synthetic procedures to boost in the lab the already known properties of natural constituents or to find new products or processes thereof has been my goal in the present aspect of my invention on hair dyes and other cosmetic products.

[0173] With light deviations of the formula, the composition of the present invention can be oxidative or non-oxidative. The total or partial diminution of potential allergens or carcinogens such as those containing amine, e.g. p-phenylenediamine, is achieved without detriment to the desired final color.

[0174] Hair dying compositions containing these new complexes and methods of application are also disclosed: Cosmetic dyeing compositions containing, in an appropriate medium and by functionalization of the surface, a complex formed by the reaction of a β-diketone and/or a polyphenol with a metal alkoxide.

[0175] The dying formulation of the present invention containing β-diketones and/or polyphenols and a metal alkoxide as active ingredient forms a stable colour without the use of amines or sulfur containing compounds or salts or oxides commonly used in oxidative hair dyeing. However, the use of these compounds is not restricted and they can be added, if desired, to add additional properties to the final product.

[0176] The dyeing product and dyeing process disclosed in the present invention covers all types of hair such as brown, blond, black, gray or damaged hair. The process and product of the present invention covers in particular curly and gray hair well-known to be very challenging to be colored. Curly and gray hair is covered with an environmentally friendly product and process yielding a durable and stable colored product.

[0177] The cosmetic dyeing composition of the present invention provides a strong wash fastness, and water repellency that makes the hair dye stable to weather or sporting such as surfing, swimming with resistance to washing out in salty or chlorinated water without detriment to the stability or colored dripping.

[0178] The process of the present invention can be used for all kind of keratinous materials such as eyelashes, eyebrows, skin, and nails.

[0179] In the case of curcumin and/or quercetin and metal alkoxide, the color is only formed by these two/three reactants. There are no amine-containing compounds, no-sulfur containing compounds, no salts, no mordants present in the present dye composition to produce color. However, these non-essential compounds may be used if desired. The composition of dyeing hair further consists of at least one coupler and at least one developer conventionally used in oxidative hair dying. Optionally, a coupler or a developer is appropriately mixed either with the β-diketone, the polyphenol or the metal alkoxide. Hence, an oxidating agent may be also used. Moreover, combining at least one basing agent with at least one oxidating agent, as in the standard practice, may be used, if desired.

Process for Dying in One Step

[0180] One aspect of the present invention is a process of dyeing keratinous material by one step for instance by applying to the keratinous materials one of more cosmetic formulations containing the prepared product. Several products of the present invention may be applied taken together or separately.

[0181] Additives can be added before, during or at the end of the hair dyeing.

[0182] At least one complex formed in the present invention can be applied directly to the hair in wet (after the reactants are mixed and before the final powder is formed) or dried form (powdered form after mechanosynthesis with or without additives) or by using a suitable solvent once the complex is formed with or without surface functionalization. Optionally, the product of the present invention may be functionalized before applied to the hair in several forms such as paste, cream or colloids or the like as disclosed for the sunscreen formulation. Optionally the product of the present invention can be applied using an appropriate functionalization of the surface and a suitable solvent.

[0183] The present invention also provides a dyeing composition containing the hair dye comprising the complex produced by the reaction of at least one β-diketone and/or at least one polyphenol with at least one metal alkoxide, at least on additive selected from the group consisting of a wetting agent, a swelling agent, a penetrant, a pH regulator, a surfactant, a perfume, a synthetic or natural colorant, a thickener, water, etc.

Process for Dyeing in More than One Steps, in Loco Complexation Hair Dyeing (ILCHD)

[0184] During the process call hereinafter in loco complexation hair dyeing, ILCHD, a β diketone and/or a polyphenol is applied or put in contact with the substrate such as keratinous material to allow the penetration in the cortex of the hair. Once in the fibre, a metal alkoxide is added to the substrate, a complexation is clearly formed and proven by the formation of color. Presumably, a small increase of the temperature—since the process is exothermic, at least for the complexation of β-diketone with metal alkoxide—enhances the diffusion into the hair cortex and the complex is formed in loco. Thus, the β-diketone and the polyphenol are derivatised or complexed in loco and it is confined into the hair. Once the complex is entrapped in the hair, it is not removed unless rinsing with shampoo.

[0185] The β-diketone and/or polyphenol is diffused into the hair by the addition of a solvent in sufficient amount to solubilize them (preferably warm water or warm alcohol). After the solvent is evaporated, the metal alkoxide is added. Some solvents or additives are allowed to stay in the keratinous material but preferably in a minimal amount.

[0186] Since the complexes formed are UV-VIS absorbing materials may be detected instantaneously. However, some gentle massage with the hands or comb, to stimulate a triboeffect as in mechanosynthesis, can be advantageous. ILCHD process is advantageous in comparison with conventional hair dyeing:

No amine-containing compound or amino-phenol compound is needed to form color; However, their use is not restricted to ILCHD;
The formation of color or change of color is instantaneous. Less time consuming process or shorter leave-on times than in natural or oxidative hair dyeing;
Minimal or no damage to the hair;
Several surprising properties to the hair such as manageability of curly hair and relaxing of the hair.

[0187] Combination of different colors and shades combination can be formed only by subtle changes in the radicals of the β-diketones, the polyphenol, and the metal alkoxide used.

[0188] Some additives can be added to the reactants to generate diverse colors, shades, textures.

[0189] A semipermanent hair dye is achieved that does not wash out with water and lasts for more than six washings with or without shampoo. However to be more permanent hair dye, conventional hair dye procedures as known since the beginning of the 20.sup.th century can be applied.

[0190] Due to the use of metals such as titanium or zinc and β-diketones and/or polyphenols the hair is protected against radiation such as ultraviolet. Additionally more benefits are added to increase the health of the keratinous material coming from the ingredients themselves or by combination effects such as antioxidant, antimicrobials, anti-dandruff, anti-acne, non-comedogenic properties.

[0191] The process of application of the hair dye is gentle and pleasing and can be done easily.

[0192] Gray hair is dyed to red, orange, brown and other color and shades.

[0193] The ILCHD is carried out at room temperature. However, the temperature can be varied to increase or decrease the rate of diffusion of the reactants or the complexes formed.

[0194] Optionally, as in oxidative hair dye, a pH modifier and an oxidizer can be used to increase or decrease the rate of diffusion of the reactants or the complexes formed.

[0195] For the color to develop, there is no reason to include amine-containing compounds in the formulation. However, they may be added in the β-diketonate compound or in the alkyl or aryl moieties of the metal alkoxides. Moreover, conventional base intermediates and couplers can be used as conventional hair dyeing strategies, and even the product of the present invention can be blended with a conventional hair dye or hair dyeing process to produce a permanent dye.

Process of Dyeing Keratinous Material with Curcumin and Quercetin and the Metal Alkoxide

[0196] One aspect of the present invention is a process of dyeing keratinous material by one or more steps, by applying to the keratinous materials a curcuminoid such as curcumin extract freshly prepared or commercially obtained and/or a polyphenol such as ferulic acid, quercetin, ellagic acid, and lignin.

[0197] The turmeric fresh or boiled roots are triturated and passed by a sieve. The curcumin extract is then used for further ILCHD. In addition, other β-diketone/polyphenol extract, tincture or powders can be used for ILCHD.

[0198] The hair may be or may not be washed beforehand. The curcuminoid and/or polyphenol extract is applied extensively in the hair and let to dry. Preferably the excess of curcumin and/or polyphenol that is adhered to the hair by no absorbed can be rinsed with water, if desired. The same procedure can be repeated several times, preferably twice. Thus, the hair has not only absorbed but adsorbed curcumin and/or polyphenol. Speculatively, the β-diketonate moieties may react with the disulfide bonds of the hair and absorbed into the hair shaft. Similarly, phenol moieties may react with the amine or sulfur groups of the aminoacids of the hair.

[0199] A metal alkoxide, e. g. titanium ethoxide, is then applied as either as delivered or in combination with an additive added in the hair by using e.g. a plastic pipette or a dropper bottle or a bottle with orifice reducing dropper. Preferably the alkoxide should not be diluted because the solvent used may also solubilize the curcumin and bleed from the hair. The hair turns immediately red or violet after the application. After carefully massaging with the hands, simulating a pestle, the hair is pleasingly dyed. A leave-in time is set between 0.5 and 60 min, preferably between 5 and 30 min and more preferably 10-15 min. As some free alkoxide may be found, optionally more curcumin or polyphenol can be added to the hair. Finally, the hair is washed with or without shampoo and let to dry.

[0200] In this method of application of the hair dye system, there is not addition of alkali; no acid is used for developing color. Even more, not oxidating agent is used. However, it is not restrictive. Thus, the hair dye composition can further contain an oxidative dye, an alkaline agent and an oxidizer.

[0201] Because curcuminoids, i.e. polyphenols stands up well to heat processing, the temperature may be lightly increased to form different colors. However, the process is preferably performed at room temperature.

[0202] This is a semipermanent hair dye because it is a product that lasts for at least six washings with or without shampoo and does not use hydrogen peroxide to develop the hair color.

[0203] The compound produced in the present invention is a novel substance, firstly synthesize by the inventor with several advantages and with several fields of application.

[0204] In the present invention, the color in the complex is determined by the initial compounds, a β-diketone and/or polyphenol and metal alkoxide. A great variety of colors are produced without the use of primary intermediaries or couplers such as amine derivatives, peroxides or ammonia. Thus, the hair dye containing a least one β-diketone and at least one polyphenol may be safer and healthier for the user. Since the amount of ingredients present in the present invention is small, the reproducibility of the final color is higher and the risk of having collateral reactions that can cause damage to the hair and produce toxic intermediates and by-products is minimal. Hence, the use of a hair dye with fewer ingredients such as those based on the present invention helps to reduce damage to the hair.

Other Uses

[0205] The present invention, comprising the synthesis of a metal complex in powder or colloidal form to be used as a catalyst for several reactions or polymerization, is characterized by the one-step production of an ecofriendly catalyst for reactions of polymerization and eco-friendliness. Transition metal β-diketonates may be used to substitute the toxic mercury or tin catalysts for the polyurethane formation such as titanium, copper. [0206] Use of metal complexes in all types of catalysis. [0207] Several uses in decorative design in the skin use in different tribes around the world. such as mehndi or sindoor. [0208] Oxidative hair dyeing. [0209] By using lanthanide complexes a broad variety of materials that can be applied in magnetic resonance imaging. [0210] Precursor for superconducting. [0211] Chelating agent of intermediate for other reactions. [0212] Dye or stain for several substrates such as paper, textile, leather, stone, wood, natural or synthetic polymers or fibres. [0213] Applications related with the optical properties in solar cells, nonlinear optics, display devices, optical data storage [0214] medicinal and biomedical applications including both imaging and therapy

Example 1: Titanium Complexes of Curcumin

Materials

[0215] Either curcumin for synthesis (Merck) or curcumin, 95% (total curcuminoid content) from Turmeric rhizome (Alfa Aesar) Titanium(IV) n-butoxide, 99% (Acros Organics)

X-ray diffraction (XRD)

[0216] Diffractograms were obtained in a Xpert PANalytical Empyrean Serie II-alpha1, model 2012 with a K-alpha1 wavelength of 1.5405980 and K-Alpha2 wavelength of 1.5444260 (Cu) from 2θ range from 5° to 50° with a scan step size of 0.026.

Synthesis

[0217] Titanium n-butoxide (0.3410 g, 1 mmol) was mixed with curcumin (0.3686, 1 mmol) in a agate mortar and immediately milled using a hand agate mortar and pestle. The reaction started with an orange-reddish paste that turned, after five minutes of grinding, into a red colored homogeneous powder. The reaction yielded a fine red powder with a yield of 88%. The complete yield is only diminished by the difficulty to remove the powder from the mortar. The product of the reaction is let to rest for one hour.

[0218] For X-ray diffraction analysis, the titanium-curcumin complex in powder form is dried at 124° C. for 12 hour in order to remove water or n-butanol included in the composite.

Discussion

[0219] Small differences in the comparison between the diffraction patterns of the crystalline curcumin and the titanium-curcumin complexes such as at 2θ≈13.5° reveal a new crystalline material that is different from the curcumin crystal structure.

Example 2: Sunscreen with Concealer Effect

Materials

[0220] Either curcumin for synthesis (Merck) or curcumin, 95% (total curcuminoid content) from Turmeric rhizome (Alfa Aesar)

Titanium(IV) n-butoxide, 99% (Acros Organics)

2-4-Pentanedione, 99+% (Acros Organics)

Synthesis

[0221] Titanium n-butoxide (0.3678 g, 1 mmol) was mixed with curcumin (0.3362 g, 1 mmol), and to this mixture 2-4-Pentanedione (0.0747 g, 0.75 mmol) was added in a agate mortar and immediately milled using a hand agate mortar and pestle. The reaction started with an orange-reddish paste that turned, after five minutes of grinding, into a red colored homogeneous powder. The reaction yielded a fine red powder with a yield of 85%. The complete yield is only diminished by the difficulty to remove the powder from the mortar.

Discussion

[0222] The titanium-curcumin complex was added to the cetomacrogol and mixed by using a mechanical stirrer or a mortar. Only 1% weight of the previously prepared titanium curcumin complex in cetomacrogol crème provided a beautiful and stable purple color in the cream. The purple sunscreen with concealer effect form a tender and natural texture on the skin while masking without pasting. Although redundant, it is not white, therefore, does not have a chalky appearance.

[0223] Different hues of red color can be produced varying the amount of additive or replacing it for another one. The sun protection factor can be adjusted either by varying the amount of metal curcumin complexes or by the addition of other natural or synthetic filters.

Example 3: Niobium-Curcumin Complexes

Materials

[0224] Either curcumin for synthesis (Merck) or curcumin, 95% (total curcuminoid content) from Turmeric rhizome (Alfa Aesar) Niobium n-butoxide, 99% (metals basis) (Alfa Aesar)

X-Ray Diffraction (XRD)

[0225] Diffractograms were obtained in a Xpert PANalytical Empyrean Serie II-alpha1, model 2012 with a K-alpha1 wavelength of 1.5405980 and K-Alpha2 wavelength of 1.5444260 (Cu) from 2θ range from 5° to 50° with a scan step size of 0.026.

Synthesis

[0226] Niobium n-butoxide (0.2539 g, 0.55 mmol) was mixed with curcumin (0.1844 g, 0.5 mmol) in a ceramic mortar and immediately milled using a hand agate mortar and pestle. The reaction started with a dark red sticky paste that turned, after two minutes of grinding, into a homogeneous powder of red color bordering black. The complete yield is only diminished by the difficulty to remove the sticky material from the mortar.

[0227] No additional treatment was carried out in the final niobium-curcumin complex for the XRD analysis.

Discussion

[0228] The diffraction pattern showed a semi-crystalline material, although there was no additional treatment to remove the possible water or n-butanol present by inclusion in the complex.

[0229] Although the embodiments of the present invention have been described and illustrated in detail, it will be understood that the present invention is not limited to the above-described embodiments, and various modifications in design may be made without departing from the spirit and scope of the invention defined in the claims.

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