FR2832616A1 - Sebum-absorbing paper, useful for refreshing the skin, is coated with microcapsules containing a crystalline compound with a defined enthalpy of fusion - Google Patents

Abstract

Sebum-absorbing paper is coated on at least one side with microcapsules containing a crystalline compound with an enthalpy of fusion of 75-330 kJ/kg. An Independent claim is also included for production of the sebum-absorbing paper by coating paper with a composition containing encapsulated crystalline compounds.

Description

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Anti-sebum paper containing thermostabilizing microcapsules
The present application relates to the field of sebum absorbing papers. More particularly, it relates to a sebum-absorbing paper comprising on at least one of its faces, preferably on only one of its faces, microcapsules containing a phase change material, the present application also relates to a process for the preparation of such sebum absorbing paper.

 The sebum absorbing papers are known in the prior art to eliminate the sebum present on the surface of the face, especially the forehead, the nose, the cheeks, the eyelids, and thus help to keep the skin clean and facilitate the application of care and make-up products.

 They are mainly used when it is hot and the production of sebum on the surface of the face is important, giving the face a shiny and unattractive fatty appearance.

 Generally, these anti-sebum papers are made from natural fibers. Patent applications JP 81008606, JP 10001900 and JP 63196664 describe such anti-sebum papers.

 More recently, there has been proposed in patent application WO 99/29220 an anti-sebum paper comprising a porous stretch film made from a plastic material.

 In patent application JP 5337009, it has been proposed to reduce the gloss of the skin by using a paper on which mattifying powders have been deposited.

 The main problem posed on the basis of the present application is obtaining a paper capable of absorbing sebum and of imparting a feeling of freshness to the skin.

 Indeed, the products of the prior art absorb the sebum by simple pressure on the skin without the need to rub the face.

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 However, these papers of the prior art, even if they are intended to be used when it is hot, do not bring any freshness to the skin.

 Patent application EP 1 066 826 relates to a sheet intended for cleaning the skin comprising an area capable of absorbing sebum and a second area containing an aqueous cleansing liquid, the freshness being provided by a solution, preferably alcoholic or containing a surfactant , which is deposited on the skin.

 Surprisingly and advantageously, the Applicant has found an anti-sebum paper which also makes it possible to provide a refreshing effect to the skin to which it is applied, this paper not having the drawbacks of the papers of the prior art.

 The subject of the present application relates to a sebum absorbing paper comprising, on at least one of its faces and preferably on only one of its faces, microcapsules containing at least one encapsulated crystalline compound having an enthalpy of fusion (AHf ), measured by differential enthalpy analysis, between 75 and 330 kJ / kg.

 The present invention also relates to a process for preparing said sebum absorbing paper according to the invention and the use of a sebum absorbing paper to impart a prolonged freshness to the skin.

 The sebum absorbing paper is preferably made from a single layer of paper, it is therefore a monolayer support which is much easier to produce than the multilayer supports proposed in the prior art. However, it could also be possible to prepare sebum absorbing papers according to the invention comprising several superimposed papers (multilayer support).

 The thermostabilizing microcapsules present in the sebum absorbing paper have improved heat absorption and restitution capacities, thus another advantage of these microcapsules is that they make it possible to significantly improve the

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 thermal stability of the sebum absorbing papers which contain them.

 The microcapsules used in the present invention contain, in a sealed and impermeable envelope, at least one crystalline compound in the molten state. These are partially or completely crystalline compounds which, when brought to a temperature close to their melting temperature, absorb a large amount of heat, called latent heat of fusion. The absorption of this latent heat of fusion results in a stability of the temperature of the compound despite the addition of thermal energy. This effect is similar to a "buffer" effect and makes it possible to thermostate, for a certain time and in a temperature range close to the melting temperature of the compound, the direct environment of the microcapsules despite a variation in the outside temperature.

 At user level, the absorption of this latent heat of fusion results in a feeling of freshness. This sensation of heat will last during the whole period during which the compounds encapsulated in the microcapsules are still at least partly in the crystalline state (they have not yet become completely amorphous), that is to say during the whole period. during which the "buffer" effect described above occurs.

 The microcapsules capable of absorbing heat and capable of stabilizing the temperature of their immediate environment will hereinafter be called "thermostabilizing microcapsules".

 Another advantage of the present application is that it makes it possible, if this is desired, to dispense with the use of an alcohol in the sebum-absorbing paper.

 In fact, we have seen that in the prior art, it was proposed to impart freshness to the skin by means of a composition preferably containing an alcohol.

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 However, alcohols are known to dry out the skin and cause tightness, in particular in the case of dry and fragile skin.

 In addition, since alcohol is a good solvent, alcohol-containing compositions can help remove makeup from the skin.

 This drawback becomes unacceptable when users of sebum absorbing paper do not simultaneously wish to remove make-up.

 The anti-sebum paper used within the meaning of the present application is a material in the form of sheets made up of discrete fibers, of small size linked together. Generally, these fibers are of cellulose nature and are held together by hydrogen bonds.

 Generally, sebum absorbing papers are obtained from discrete fibers of small size. The fibers are arranged in the form of a sheet on a fine grid from a dilute aqueous suspension which is then dehydrated.

 Traditional papers use fibers from 1 to 4 mm. These papers generally used in the cosmetic field are, as such, capable of absorbing sebum.

 All papers capable of absorbing sebum can be used in the context of the invention. Preferably, the papers which can be used to prepare the absorbent paper according to the invention are papers based on vegetable fibers such as cellulose, hemp or also papers based on synthetic fibers such as polypropylene. These fibers are bonded together by means of a binder and can be coated with silica, talc or another suitable inorganic powder. Conventionally, within the meaning of the present invention, papers based on vegetable fibers and microporous papers made of plastic material can be used interchangeably.

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 This anti-sebum paper is intended for topical application, that is to say an external application on keratin materials, such as the skin, scalp, eyelashes, eyebrows, nails and mucous membranes.

 The term "crystalline compound" as used in the present application encompasses partially or fully crystalline compounds. The degree of crystallinity of the compounds used is not decisive insofar as the compound exhibits the enthalpy of crystalline fusion required for use to refresh the skin.

 The thermal absorption capacity of the microcapsules used is directly proportional to the enthalpy of fusion of the encapsulated crystalline compound. This enthalpy of fusion is measured by differential enthalpy analysis (in English: Differential Scanning Calorimetry).

 The enthalpy of fusion of a compound is the amount of energy required to transform a partially or totally crystalline sample into a completely amorphous sample. The thermogram ACp = f (T), in which ACp represents the difference in thermal capacity of the sample compared to a reference sample undergoing no thermal transition in the field studied, therefore presents an endothermic signal whose area is proportional at the enthalpy of fusion (AHf) of the sample.

As indicated, the microcapsules used in the sebum absorbing papers of the present invention contain crystalline compounds having an enthalpy of fusion of between 75 and 330 kJ / kg. This enthalpy of fusion is preferably between 100 and 300 kJ / kg, and ideally between 150 and 280 kJ / kg.

 In addition to the thermal capacity of the crystalline compounds enclosed in the thermostabilizing microcapsules of sebum-absorbing papers, the melting point of these compounds is an essential parameter determining the mode of action, the field of application and the effectiveness of said papers.

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 To bring a feeling of freshness to the skin, the melting temperature of the encapsulated crystalline compound should be slightly lower than the temperature of human skin. By slightly lower is meant 5 C lower, preferably 3 C.

 The temperature of human skin is around 32 C, depending on the outside temperature, it can increase by a few degrees.

 Preferably, an encapsulated crystalline compound is used, the melting of which takes place at a temperature between approximately 25 ° C. and 40 °.

 Thus, at the storage temperature of these sebum absorbing papers, the crystalline compound encapsulated in the microcapsules is in the crystalline state. After application to the skin, it will melt by drawing from the immediate skin environment the heat necessary for this fusion, thereby creating a local feeling of freshness for the user.

 The microcapsules provide a fresh effect from the start of the application of the paper to the skin. The effect felt by the user will be an immediate sensation of freshness.

 It is also interesting to mention that the sebum absorbing function of the paper is not diminished in the presence of the microcapsules.

 The feeling of freshness obtained when using sebum absorbing papers according to the invention is obtained without the need to rub the sebum absorbing paper on the skin.

 Indeed, such friction would necessarily result in causing the makeup present on the skin.

 The application of sebum absorbing papers to the skin by simple affixing, allows in a few seconds to absorb the excess sebum and to give the skin a freshness effect.

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 The parts of the absorbent paper which have effectively absorbed sebum have a transparent appearance which contrasts with the opaque parts of the unsoiled paper.

 This freshness effect is comparable to that of menthol, but unlike the latter, the use of crystalline compounds encapsulated in accordance with the invention, insofar as there is no direct contact between the crystalline compounds encapsulated and the skin, excludes any risk of irritation. In general, it is entirely possible to dispense with the use of alcohols to prepare the sebum absorbent paper according to the present application.

 The "thermostated" sebum absorbing papers according to the present invention will be useful in all applications where it is a question of providing or locally removing heat or locally stabilizing the temperature of surfaces (face, body, etc.). on which they are applied.

 The crystalline compounds are preferably encapsulated in a sealed envelope. This encapsulation is an essential condition for the reversibility of the fusion / crystallization processes.

Indeed, the encapsulated molten compound will not be able to diffuse in the absorbent paper and will crystallize again when the outside temperature becomes below its melting point.

température de fusion comprise entre 25 C et 40 C choisi parmi : les hydrocarbures aliphatiques en Ciao-40, c'est-à-dire contenant de 10 à 40 atomes de carbone, - les hydrocarbures aromatiques, - les acides gras en Cs-4o tels que l'acide stéarique et l'acide laurique, - les alcools gras en Ci 40 tels que l'alcool stéarylique et l'alcool laurylique, As examples of encapsulated crystalline compounds suitable for the present invention, there may be mentioned the compounds of

melting temperature between 25 C and 40 C chosen from: Ciao-40 aliphatic hydrocarbons, that is to say containing from 10 to 40 carbon atoms, - aromatic hydrocarbons, - Cs-4o fatty acids such as stearic acid and lauric acid, - Ci 40 fatty alcohols such as stearyl alcohol and lauryl alcohol,

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 - the esters of CIO-40 fatty acids such as methyl stearate and methyl cinnamate, - mineral salts containing a large fraction of water of crystallization, such as calcium chloride hexahydrate, sulphate decahydrate sodium, sodium hydrogen phosphate dodecahydrate, sodium thiosulfate pentahydrate and nickel nitrate hexahydrate, - fatty acid triglycerides in C1O-40, - silicone waxes such as polydimethylsiloxanes with end groups behenoxy or stearoxy (INCI behenoxydimethicone and stearoxydimethicone), polymethylstearyloxy-dimethylsiloxanes (INCI: stearic ester dimethicone), polymethylstearyl-dimethylsiloxanes (INCI stearyldimethicone), copolymers containing methacrylethyl stearyl dimethylethyl stearyl methacrylate stearyl dimethyl esters C) alkyldimethicone), the fatty chains of all these compounds being preferably linear and / or saturated.

 Mention may also be made of at least partially crystalline hot-melt polymers having a crystalline melting point in the temperature zone indicated above.

 Such polymers are, for example, olefinic homopolymers and copolymers, including polyolefinic waxes, such as ethylene homopolymers, ethylene and propylene copolymers, ethylene and octene copolymers, ethylene copolymers and butene and the copolymers of ethylene and vinyl acetate.

 Mention may also be made of poly (alkylene oxide), alkyl polyesters, poly (e-caprolactones), polyamides, in particular those resulting from the polycondensation of dimer of fatty acids, as well as copolymers of fluorinated olefins .

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 Another group of usable crystalline polymers is formed by the polymers with crystallizable side chains described in J. Polymer Sci. : Macromol. Rev. 8: 117-253 (1974). These are vinyl and / or acrylic polymers or copolymers containing a large fraction, generally at least equal to 50% by weight, of copolymerized units comprising long crystallizable linear aliphatic side chains, or crystallizable fluorinated or perfluorinated side chains. US Patent 5,156,911 describes the use of such polymers with crystallizable side chains in adhesive assemblies whose adhesive properties vary as a function of temperature.

 These compounds can be used alone or as a mixture of two or more of them.

 The preferred encapsulated crystalline compounds for the present invention are straight chain aliphatic hydrocarbons containing from 10 to 40, preferably from 13 to 28 and more preferably from 16 to 23 carbon atoms. Indeed, the melting temperature of the compounds of this series of homologous hydrocarbons increases in a perfectly predictable manner with the number of carbon atoms (-5.5 C for n-tridecane (C13) to 61.4 C for n-octacosane (C28)) in the temperature range concerned by the cosmetic applications described above. We can cite for example octadecane with a melting point of 28 C.

 The crystalline compounds having an enthalpy of fusion (AHf) of between 75 and 330 kJ / kg are preferably encapsulated in a sealed envelope.

 The material forming the wall of the microcapsules can be chosen from all the materials conventionally used in the field of microencapsulation.

 This material can be amorphous, crystalline or semi-crystalline.

When it is crystalline or semi-crystalline, it must have a higher melting point than that of the encapsulated crystalline compounds. Furthermore, this material must be sufficiently elastic to resist variations in the volume of the crystalline compound during the transition from

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 phase and to resist shear forces when applying the composition containing them. In addition, it must be inert vis-à-vis the encapsulated substances and the compounds of the cosmetic formulation with which it will be in contact.

 Depending on the method chosen, it will be possible to use, as the material forming the envelope of the microcapsules, polymers such as polyamides, polyurethanes, polyureas, polyesters, polycyanoacrylates, urea-formaldehyde or melamine formaldehyde resins, and gelatin / gum systems. arabic, and silica.

 The microcapsules can be prepared according to well known methods described for example in the work entitled "Microencapsulation, Methods and Industrial Applications", Director of publication S. Benita, Marcel Dekker (1996). By way of example, mention may be made of interfacial polymerization or polycondensation, coacervation, atomization, centrifugal extrusion or microencapsulation on rotary discs.

 The thermostabilizing microcapsules are known and marketed for example under the name Thermasorb by the company Frisby Technologies Inc. or under the references 9850K and 9850Q by the company 3M.

 These microcapsules are in the form of a fine, fluid and non-film-forming powder. Their use is known, for example, in the field of insulated clothing and shoes, in microelectronic cooling systems and in the field of packaging.

 It is also possible to use, as compound constituting the wall of the microparticles, a non-polymeric material. One can use for example microcapsules based on precipitated silica, amorphous, hydrated or hydrophobic, proposed by the company PHASE CHANGE LABORATORIES under the name AcuTemp.

 The larger size of the microcapsules is preferably limited, for obvious reasons of visibility, to a few tens or hundreds of micrometers. We generally prefer to use

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 microcapsules having an average diameter between 0.01 and 100 micrometers, better still between 0.05 and 50 micrometers.

 The sebum absorbing papers used in the present invention generally contain from 0.1% to 60% by weight, and preferably from 0.5% to 50% by weight of microcapsules, based on the final sebum absorbing paper.

 The sebum absorbing papers according to the present invention may also contain cosmetic active ingredients and / or adjuvants suitable for bringing freshness to the skin. These active cosmetic ingredients and adjuvants can be introduced onto the absorbent paper directly or in encapsulated form.

The adjuvants which can be used are conventionally chosen from the group formed by solvents, pH regulating agents, preserving agents, fillers, emollients, anti-foaming agents.
All the cosmetic active ingredients and / or adjuvants are preferably present in the sebum absorbing papers of the present invention in an amount of between 0 and 60% by weight, preferably between 0.5 and 50% by weight relative to the weight of the final sebum absorbent paper.

 The fillers used in the sebum absorbing papers according to the invention are chosen from the group formed by silica, alumina, talc, kaolin, mica, micaceous titanium, zeolite, ultramarine, oxides of zinc or iron oxides, organic powders of polymers such as nylon, vinyl polymers, crosslinked elastomers containing dimethylsilicone units, polymethylated methacrylates or methacrylatesmethacrylates-dimethyl-alkylene copolymers.

 The active can for example be an anti-aging active and / or an anti-seborrheic active. The term “anti-aging active agent” is understood here to mean any active agent capable of treating or preventing any sign of aging of the skin including the scalp, the hair or the mucous membranes (lips), that is to say any agent capable in particular of treating and / or prevent wrinkles and fine lines on the skin, give a clear complexion and smooth the skin, prevent and / or treat

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 loss of firmness and / or elasticity of the skin and / or treatment of blemishes.

 In general, the active agents can be chosen, for example, from hydrating agents, anti-free radical agents, keratolytic agents, anti-seborrheic agents, vitamins, anti-elastase and anti-collagenase agents, proteins, derivatives of fatty acids, steroids, trace elements, whitening agents, extracts of plant origin and also of algae and plankton, filters, enzymes and co-enzymes, flavonoids, ceramides, and their mixtures.

 As hydrating agents, mention may in particular be made of sodium lactate; polyols, and in particular glycerin, sorbitol, polyethylene glycols; mannitol; amino acids; hyaluronic acid; lanolin; urea and mixtures containing urea, such as NMF (Natural Moisturizing Factor); petroleum jelly; lysine pidolate (lysine salt of pyrrolidone carboxylic acid or PCA lysine); ammonium lactate; and their mixtures.

 Mention may in particular be made, as anti-free radical agents, of derivatives of phosphonic acid; ethylenediamine tetracetic acid and its salts such as the sodium salt; guanosine; superoxydismutase; tocopherol (vitamin E) and its derivatives (acetate); ethoxyquin; lactoferrin; lactoperoxidase, and nitroxide derivatives; superoxide dismutases; glutathione peroxidase; plant extracts with anti-free radical activity such as the aqueous extract of wheat germ marketed by the company Silab under the reference Detoxiline; and their mixtures.

l'acide n-dodécanoyl-5 salicylique et leurs sels ; les a-céto-acides comme l'acide ascorbique ou vitamine C et ses dérivés ; les ss-cétoacides ; les rétinoïdes comme le rétinol (vitamine A) et ses esters, le As keratolytic agents, there may be mentioned, for example, ahydroxy acids, in particular acids derived from fruits, such as glycolic, lactic, malic, citric, tartaric, mandelic acids, their derivatives and mixtures; P-hydroxy acids such as salicylic acid and its derivatives such as n-octanoyl-5-salicylic acid or

n-dodecanoyl-5 salicylic acid and their salts; a-keto acids such as ascorbic acid or vitamin C and its derivatives; ss-keto acids; retinoids such as retinol (vitamin A) and its esters,

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 retinal, retinoic acid and its derivatives, as well as the retinoids described in documents FR-A-2,570, 377, EP-A-199,636, EP-A-325,540, EP-A-402,072, and mixtures thereof .

 As anti-seborrhoeic agents, zinc salts and in particular zinc gluconate, vitamins B3 (niacinamide) and B5 (panthenol), zinc oxide and its derivatives, triclosan, triclocarban, can also be used. C8G lipid sold by the company SEPPIC or capryloylglycine, clove extract, octopirox, hexamidine, azelaic acid, and any suitable anti-comedolitic agent.

 As vitamins, in addition to vitamins A, E, C, B3 and B5 indicated above, there may be mentioned in particular the derivatives and precursors of these vitamins, such as lycopenes or carotenes precursors of vitamin A, and their mixtures.

 As anti-elastase agents, there may be mentioned in particular peptide derivatives, and in particular peptides from legume seeds such as those marketed by the Serobiological Laboratories of Nancy under the reference Parelastyl; the derivatives of N-acylamino-amides described in application FR 2 810 033, such as for example {2- [acetyl- (3-trifluoromethyl-phenyl) -amino] -3-methyl-butyrylamino} ethyl acetate and l {2- [acetyl- (3-trifluoromethylphenyl) -amino] -3-methyl-butyryl-amino} acetic acid, and mixtures thereof.

As anti-collagenase agents, mention may be made of metalloprotease inhibitors, such as ethylenediamine acid (EDTA), cysteine, and their mixtures.

 As proteins, mention may be made, for example, of proteins (of wheat or of soybeans), their hydrolysates, such as those sold by the company Silab under the reference Tensine, and their mixtures.

 As fatty acid derivatives, mention may in particular be made of polyunsaturated phospholipids, including the essential fatty acid phospholipids of octopus, and their mixtures.

 As steroids, there may be mentioned for example DHEA or dehydroepi-androsterone, its biological precursors, its metabolites, and their mixtures. By "biological precursors" of DHEA, we mean

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 means in particular A5-pregnenolone, 17a-hydroxy pregnenolone and 17a-hydroxy pregnenolone sulfate. By DHEA derivatives is meant both its metabolic derivatives and its chemical derivatives. As metabolic derivatives, there may be mentioned in particular A5-androstene-3, 17-diol and in particular 5-androstene 3ss, 17ss-diol, A4-androstene-3, 17-dione, 7 hydroxy DHEA (7a-hydroxy DHEA or 7ss-hydroxy-DHEA) and 7-keto-DHEA which is itself a metabolite of 7ss-hydroxy DHEA.

 As trace elements, one can for example copper, zinc, selenium, iron, magnesium, manganese, and their mixtures.

 As bleaching agents, any compound can be used to treat or prevent age spots, that is to say any depigmenting compound which acts directly on the vitality of epidermal melanocytes where melanogenesis takes place and / or which interferes with one of the steps in the biosynthesis of melanin either by inhibiting one of the enzymes involved in melanogenesis or by intercalating as a structural analogue of one of the chemical compounds in the melanin synthesis chain, a chain which can thus be blocked and ensure depigmentation. Mention may be made, for example, as a whitening active agent, of kojic acid and its derivatives, hydroquinone and its derivatives such as arbutin and its esters; ellagic acid and its derivatives; plant extracts, especially licorice, mulberry or skullcap; glutathione and its precursors; cysteine and its precursors; compounds derived from aminophenol described in document WO-A-99/10318, such as in particular N-ethyloxycarbonyl-4-amino-phenol, N-ethyloxycarbonyl-O- ethyloxycarbonyl-4-amino-phenol, N-cholesteryloxycarbonyl -4aminophenol, N-ethylamino-carbonyl-4-aminophenol; and mixtures of these compounds.

 As algae extracts, there may be mentioned extracts of red or brown algae, and for example the extract of brown algae from the Laminaria family, such as the extracts of the species Laminaria digitata, and more particularly that sold by CODIF under the name Phycosaccharides, which is a solution

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 concentrate of an oligosaccharide obtained by controlled enzymatic depolymerization of membrane polysaccharides of a brown alga. It includes the chain of two uric acids: mannuronic acid and guluronic acid.

 As plankton extracts, mention may be made of plankton in aqueous dispersion (CTFA name: Vitreoscilla Ferment) sold under the name MEXORYL SAH by the company Chimex.

 As filters, there may be used in the composition according to the invention all UVA and UVB chemical sun filters or physical filters usually usable in the cosmetic field.

 As UVB filters, there may be mentioned, for example: (1) salicylic acid derivatives, in particular homomenthyl salicylate and octyl salicylate; (2) cinnamic acid derivatives, in particular 2-ethylhexyl pmethoxycinnamate, sold by the company Givaudan under the name Parsol MCX; (3) derivatives of liquid ss, ss'-diphenylacrylate, in particular α-cyano-a. 2-ethylhexyl diphenylacrylate or octocrylene, sold by the company BASF under the name UVINUL N539; (4) p-aminobenzoic acid derivatives; (5) 4-methyl benzylidene camphor sold by the company Merck under the name EUSOLEX 6300; (6) 2-phenylbenzimidazole 5-sulfonic acid sold under the name EUSOLEX 232 by the company Merck; (7) derivatives of 1,3, 5-triazine, in particular: - 2,4,6-tris [p- (2'-ethylhexyl-l'-oxycarbonyl) anilino] -1, 3,5triazine marketed by BASF under the name UVINUL T150, and - dioctyl butamido triazone sold by the company Sigma 3V under the name UVASORB HEB; (8) mixtures of these filters.

 Examples of UVA filters include:

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(1) dibenzoylmethane derivatives, in particular 4- (ter.- butyl) 4'-methoxy dibenzoylmethane sold by the company Givaudan under the name PARSOL 1789; (2) 1,4-benzene acid [di (3-methylidenecampho-10-sulfonic acid)] optionally in partially or totally neutralized form, sold under the name MEXORYL SX by the company Chimex.

(3) benzophenone derivatives, for example: - 2,4-dihydroxybenzophenone (benzophenone-1); - 2,2 ', 4,4'-tetra-hydroxybenzophenone (benzophenone-2); - 2-hydroxy-4-methoxy-benzophenone (benzophenone-3), sold under the name UVINUL M40 by the company BASF; - 2-hydroxy-4-methoxy-benzophenone-5-sulfonic acid (benzophenone-4) as well as its sulfonate form (benzophenone-5), sold by the company BASF under the name UVINUL MS40; - 2, 2'-dihydroxy-4, 4'-dimethoxy-benzophenone (benzophenone-6); - 5-chloro-2-hydroxybenzophenone (benzophenone-7); - 2, 2'-dihydroxy-4-methoxy-benzophenone (benzophenone-8); - the disodium salt of the 2, 2'-dihydroxy-4, 4'-dimethoxybenzophenone-5, 5'-disulfonic acid (benzophenone-9); - 2-hydroxy-4-methoxy-4'-methyl-benzophenone (benzophenone-10); - benzophenone-11; - 2-hydroxy-4- (octyloxy) benzophenone (benzophenone-12). (4) silane derivatives or polyorganosiloxanes containing a benzophenone group; (5) anthranilates, in particular menthyl anthranilate sold by the company Haarman & Reiner under the name NEO HELIOPAN MA;

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- le 6-méthoxy-1, l'-bis- (3-triméthylsilanyl-propyl)-1 H, 1'H- [2, 2'] bibenzimidazolyl-benzoxazole ; - le 2- [1- (3-trimethylsilanyl-propyl)-lH-benzimidazol-2-yl]benzothiazole ; qui sont décrits dans la demande de brevet EP-A-1 028 120 ; (8) les dérivés de triazine, et en particulier la 2,4-bis { [4- (2- éthyl-hexyloxy)-2-hydroxy]-phényl}-6- (4-méthoxy-phényl)-1, 3,5triazine commercialisé par la société Ciba Geigy sous la dénomination TINOSORB S, et le 2, 2'-méthylènebis- [6- (2H benzotriazol-2-yl) 4- (1, 1, 3,3-tétraméthylbutyl) phénol] commercialisé par la société Ciba Geigy sous la dénomination TINOSORB M ; (9) leurs mélanges. (6) compounds comprising per molecule at least two benzoazolyl groups or at least one benzodiazolyl group, in particular 1, 4-bis-benzimidazolyl-phenylen-3, 3 ', 5,5'tetrasulfonic acid as well as its marketed salts by Haarman &Reimer; (7) silicon derivatives of N-substituted benzimidazolyl-benzazoles or of benzofuranyl-benzazoles, and in particular: - 2- [1- [3- [1, 3,3, 3-tetramethyl-1- [(trimethylsilyl) oxy] disiloxanyl] propyl] -1 H-benzimidazol-2-yl] -benzoxazole; - 2- [1- [3 - [1, 3, 3, 3-tetramethyl-l- [(trimethylsilyl) oxy] disiloxanyl] propyl] -1 H-benzimidazol-2-yl] - benzothiazole; - 2- [1- (3-trimethylsilanyl-propyl) -1 H-benzimidazol-2-yl] - benzoxazol;

- 6-methoxy-1, l'-bis- (3-trimethylsilanyl-propyl) -1 H, 1'H- [2, 2 '] bibenzimidazolyl-benzoxazole; - 2- [1- (3-trimethylsilanyl-propyl) -1H-benzimidazol-2-yl] benzothiazole; which are described in patent application EP-A-1 028 120; (8) triazine derivatives, and in particular 2,4-bis {[4- (2-ethyl-hexyloxy) -2-hydroxy] -phenyl} -6- (4-methoxy-phenyl) -1, 3 , 5triazine marketed by the company Ciba Geigy under the name TINOSORB S, and the 2, 2'-methylenebis- [6- (2H benzotriazol-2-yl) 4- (1, 1, 3,3-tetramethylbutyl) phenol] marketed by the company Ciba Geigy under the name TINOSORB M; (9) their mixtures.

 It is also possible to use a mixture of several of these filters and a mixture of UVB filters and UVA filters and also mixtures with physical filters.

 As physical filters, mention may be made of titanium oxides (amorphous or crystallized titanium dioxide in rutile form and / or anatase), of zinc, of iron, of zirconium, of cerium or their mixtures. These metal oxides can be in the form of particles having a micrometric or nanometric size (nano-pigments). Under

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 form of nanopigments, the average particle sizes range, for example, from 5 to 100 nm. Preferably nanopigments are used.

 As enzymes, it is possible to use any enzyme of animal, microbiological (bacterial, fungal or viral) or synthetic (obtained by chemical or biotechnological synthesis) origin, in pure crystalline form or in a form diluted in an inert diluent.

Mention may be made, for example, from lipases, proteases, phospholipases, cellulases, peroxidases, in particular lactoperoxidases, catalases, superoxide dimutases, or from plant extracts containing the abovementioned enzymes, and their mixtures.

 As co-enzymes, ubiquinone or coenzyme Q 10 which belongs to the family of benzoquinones with an alkylene chain can be used.

 As flavonoids, mention may be made, for example, of isoflavonoids which constitute a subclass of flavonoids, formed of a 3-phenyl chroman skeleton which may include various substituents and different levels of oxidation. The term isoflavonoid groups together several classes of compounds among which mention may be made of isoflavones, isoflavanones, rotenoids, pterocarpans, isoflavanes, isoflavanes-3-enes, 3-arylcoumarins, 3-aryl-4hydroxycoumarins, coumestanes, coumaronochromones, (X-methyldeoxybenzoines, 2-arylbenzofurans, and mixtures thereof. In this regard, reference is advantageously made to a complete review of isoflavonoids, their methods of analysis and their sources, in Chapter 5, "Isoflavonoids", written by PM Dewick, in The Flavonoïds, Harbone editor, pp. 125-157 (1988).

 Isoflavonoids can be of natural or synthetic origin. By "natural origin" is meant the isoflavonoid in the pure state or in solution at different concentrations, obtained by different extraction processes from an element, generally a plant, of natural origin. By "synthetic origin" is meant the isoflavonoid in the pure state or in solution at different concentrations, obtained by chemical synthesis.

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 We prefer to use isoflavonoids of natural origin. Among these, there may be mentioned: daidzine, genistin, daidzein, formononetin, cuneatin, genistein, isoprunetin and prunetin, cajanin, orobol, pratensinin, sandalwood, junipegenin A , glycitein, afrormosine, retusin, tectorigenin, irisolidone, jamaicin, and their analogs and metabolites.

 As ceramides, any type of ceramide, of natural or synthetic origin, for example of type II, of type III, of type IV, of type V or of type VI, and their mixtures, can be used.

 Mention may be made, for example, of ceramides, N-oleoyldihydrosphingosine, N-stearoyl phytosphingosine, N-hydroxybéhénoyl-dihydro sphingo sine, N - hydroxypalmitoyl-dihydrosphingosine, N-linoleoyldihydrosphingosine, Npalmitoyinihydroyldihydrin Nbéhénoyldihydrosphingosine, and their mixtures.

 Mention may also be made of the product consisting of a mixture of glycoceramides, sold under the trade name GLYCOCER by the company WAITAKI INTERNATIONAL BIOSCIENCES; the compounds described in documents EP-A-0227994 and WO-A- 94/07844, such as for example QUESTAMIDE H (bis- (Nhydroxyethyl N-ketyl) malonamide) sold by the company QUEST, N- (2-hydroxyethyl ) -N- (3-ketyloxy-2-hydroxypropyl) cetyl acid amide; N-docosanoyl N-methyl-D-glucamine described in patent application WO-A-92/05764.

 Mixtures of these ceramides can also be used.

 The process for preparing sebum absorbent paper is also an object of the present invention.

This process essentially comprises two stages:
A) the preparation of the composition containing the encapsulated crystalline compounds
B) coating this composition in paper.

 The composition containing the microcapsules (encapsulated crystalline compounds) is obtained by mixing the microcapsules

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 with possibly a binder and possibly a cosmetic active principle such as those mentioned above, this active principle will then not be found in encapsulated form.

 This composition will advantageously comprise from 1 to 100% by weight of microcapsules, from 0 to 5% of binders, the complement to 100% consisting of one or more active cosmetic compounds and adjuvants as indicated above.

 In addition, this composition will be dissolved in an aqueous or hydroalcoholic, dispersing and volatile liquid medium.

 As hydroalcoholic medium is meant a medium containing water and 30 to 95% of an alcohol containing from 1 to 8 carbon atoms such as ethanol, isopropanol and n-propanol.

 The binders which can be used to fix the microcapsules and any active cosmetic ingredients on the absorbent paper will preferably be chosen from polyvinyl alcohol, starch, carboxymethylcellulose, sodium alginate or hydroxypropycellulose.

 The absorbency of the final sebum absorbent paper will be 3 to 25g of sebum per m2 of sebum absorbent paper.

 This composition is then coated on a paper such that, in the end, this paper contains from 0.5 to 40 g / m2, preferably 2 to 20 g / m2 and even better from 5 to 15 g / m2 of the microcapsule mixture. + binders + cosmetic active ingredients + adjuvants.

 To carry out this step, all the methods allowing to realize a dry coating could be used, it will be for example an impregnation followed by a drying on roller, a hot calendering, or a drying under current hot air.

 The anti-sebum paper obtained is essentially free of water, that is to say that it contains less than 10% by weight and preferably less than 5% by weight of water relative to the weight of the assembly. paper + coating composition.

 The examples which follow illustrate the invention without limiting its scope.

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Examples of composition
Example 1 - kaolin 27.00% - preservatives (parabens) 0.4% - carboxy methyl sodium cellulose 6.00% - heat-stabilizing microcapsules 66.6% with octadecane at 77% by weight
Example 2 - talc 50.00% - magnesium stearate 2.90% - preservatives (parabens) 0.45% - hydroxypropyl cellulose 6.00% - heat stabilizing microcapsules 40.65% with octadecane at 77% by weight
The powders are dispersed in water using standard stirring techniques. The deposition of the powders on one side of the anti-sebum paper is carried out using conventional coating techniques used for example in the paper industry. The quantity of powders coated on the paper is between 0.5 g / m and 5 g / m2, after wringing between two hot cylinders, and drying under a current of hot air.

Claims (16)

1. Sebum-absorbing paper comprising, on at least one of its faces, microcapsules containing at least one encapsulated crystalline compound having an enthalpy of fusion (AHf), measured by differential enthalpy analysis, between 75 and 330 kJ / kg .  2. Sebum absorbing paper according to claim 1 such that it comprises microcapsules on only one of its faces.  3. Sebum absorbing paper according to claim 1 or 2 such that the enthalpy of fusion of the crystalline compound is between 100 and 300 kJ / kg, preferably 150 and 280 kJ / kg.  4. Sebum absorbing paper according to one of the preceding claims such that the melting point of the crystalline compound is between 250C and 40 C.  5. Sebum absorbing paper according to one of the preceding claims, such that the encapsulated crystalline compound has a melting temperature between 25 ° C. and 400 ° C. and is chosen from: - aliphatic hydrocarbons in Ciao-40, - aromatic hydrocarbons, - fatty acids in CS-40, - fatty alcohols in Cl-40, - esters of fatty acids in CIO-40, - mineral salts containing a large fraction of water of crystallization, - fatty acid triglycerides in CI0-40, - silicone waxes, - hot-melt polymers at least partially crystalline alone or in the form of a mixture of two or more of them. <Desc / Clms Page number 23>  6. Sebum absorbing paper according to the preceding claim such that the crystalline compound is an aliphatic hydrocarbon with a linear and saturated chain containing from 10 to 40 carbon atoms, preferably from 13 to 28 carbon atoms, and better still from 16 to 23 carbon atoms.  7. Sebum absorbing paper according to one of the preceding claims such that the material forming the envelope of the microcapsules is chosen from polyamides, polyurethanes, polyureas, polyesters, polycyanoacrylates, urea-formaldehyde or melamine-formaldehyde resins , and the gelatin / gum arabic and silica systems.  8. Sebum absorbing paper according to one of the preceding claims, such that the microcapsules have an average diameter of between 0.01 and 100 micrometers, better still between 0.05 and 50 micrometers.  9. Sebum absorbing paper according to one of the preceding claims such that the microcapsules represent from 0.1 to 60% by weight, preferably from 0.5 to 50% by weight relative to the total weight of the final sebum absorbing paper .  10. Sebum absorbing paper according to one of the preceding claims as it contains a filler included in the group formed by silica, alumina, talc, kaolin, mica, micaceous titanium, zeolite, l ultramarine, zinc oxides or iron oxides, organic powders of polymers such as nylon, vinyl polymers, crosslinked elastomers containing dimethylsilicone units, polymethylated methacrylates or methacrylate-methacrylate-dimethyl-alkylene copolymers.  11. Sebum absorbing paper according to one of the preceding claims as it contains at least one cosmetic active principle chosen from the group formed by anti-aging agents, hydrating agents, anti-free radical agents, keratolytic agents , anti-seborrheic agents, vitamins, anti-elastase and anti-collagenase agents, proteins, acid derivatives <Desc / Clms Page number 24>  fats, steroids, trace elements, whitening agents, extracts of plant origin and also of algae and plankton, filters, enzymes and co-enzymes, flavonoids, ceramides, and mixtures thereof.  12. Sebum absorbing paper according to one of the preceding claims as it contains at least one adjuvant chosen from the group formed by solvents, pH regulating agents, preserving agents, fillers, emollients, anti agents -foam.  13. Sebum absorbing paper according to one of claims II or 12 as it contains at least one cosmetic active principle and / or at least one adjuvant, introduced into the sebum absorbing paper directly or in encapsulated form.  14. Sebum absorbing paper according to one of claims 10 to 13 such that all of the active cosmetic ingredients and adjuvants are present in an amount between 0 and 60% by weight, and preferably between 0.5 and 50% by weight relative to the weight of the final sebum absorbent paper.  15. Method for preparing a sebum-absorbing paper according to one of the preceding claims, characterized in that the following steps are carried out: A) preparation of a composition containing encapsulated crystalline compounds, B) coating the composition on a paper.  16. Use of a sebum absorbing paper according to one of claims 1 to 14 to give the skin a prolonged supply of freshness.