FR2779440A1 - Anhydrous composition with low viscosity, especially for cosmetic use - Google Patents

Abstract

Anhydrous composition with a dynamic viscosity of no more than 10 Pa.s (measured at 25 deg C and a shear rate of 200 sec<-1>) comprises: (a) A partially crosslinked solid organopolysiloxane elastomer; and (b) a polydimethylsiloxane derivative with a kinematic viscosity of at least 300 \* 10<-6> m<2>/sec (measured at 25 deg C).

Description

The present invention relates to an anhydrous composition, in particular of

makeup, containing a partially crosslinked elastomeric organopolysiloxane and a polydimethylsiloxane derivative. This composition can be used in

cosmetic, dermatological, pharmaceutical and / or hygienic fields.

Anhydrous gels based on crosslinked elastomeric organosiloxane, as described in document US Pat. No. 4,987,169, are known to be products intended to be applied to the skin, exhibiting good cosmetic qualities such as

softness, dullness and a non-greasy feel.

To obtain uniform gels, the crosslinked elastomeric organosiloxane is generally combined with oils or solvents of a hydrocarbon or silicone nature. However, these gels often come in the form of powdery products or pasty in consistency. Thus, the viscosity of these products at the

temperature of 25 C is well above 100 10 'Pa.s.

However, more and more efforts are being made to produce fluid products which, on application, provide a feeling of freshness, which are easily spread over the skin (for example for sun products which must generally be applied to the whole body. ) and which can also be packaged in bottles

pumps for example for practical reasons.

For this, attempts have been made to increase the proportion of oil in these anhydrous gels relative to the proportion of crosslinked elastomeric organosiloxane. But we then encounter problems of instability and inhomogeneity of the gel over time. In fact, the mixture settles after a few days, or even immediately after its production, and the composition, in addition to the fact that it then presents an unaesthetic appearance, also loses in effectiveness as regards

concerns its cosmetic properties.

There therefore remains the need for anhydrous fluid products not subject to the phenomenon.

of demixing over time and which have good sensory qualities.

The subject of the invention is a composition, in particular a makeup composition, making it possible to remedy the drawbacks of the gels of the prior art. Surprisingly, the Applicant has found that the use of a polydimethylsiloxane derivative of particular kinematic viscosity made it possible to produce compositions based on crosslinked elastomeric organosiloxane which are stable while being fluid and while retaining good cosmetic properties, in particular the properties

of the sweetness and non-greasiness of classic pasty gels.

The invention applies not only to makeup products such as foundations, eye shadow, body makeup products, care products and / or lip treatment such as lipsticks or lip balms. but also to skin care and / or treatment products

human face and / or human body and / or scalp.

More precisely, the invention relates to an anhydrous composition characterized in that it comprises at least one solid elastomeric organopolysiloxane partially crosslinked and at least one polydimethylsiloxane derivative of kinematic viscosity, measured at a temperature of about 25 ° C. at least equal to 300 10-6 m2 / s, this composition having a dynamic viscosity, measured at a temperature of about 25 ° C. and at the rate of

shear of 200 s- ', at most equal to 100 10-'1 Pa.s.

All the dynamic viscosity measurements given in the present application were carried out at a temperature of about 25 ° C., at the rate of

shear 200 s-1, on a Rheomat RM 180 with Ms-r3 or Ms-r4 mobiles.

This composition can be a cosmetic, dermatological, pharmaceutical and / or hygienic composition. It can be used as is or be

incorporated into a more complex composition.

The compositions according to the invention are particularly comfortable on application, soft and non-sticky to the touch. They also exhibit excellent stability over time and to temperature variations. They are particularly easy to apply to the skin, even on large

surfaces, especially on the body.

Thus, the compositions according to the invention perfectly meet the following stability standards - resistance to the centrifugation test at 4000 rpm for 1 hour, and / or - resistance to aging at room temperature (25 ° C.) for 2 months at ambient temperature (25 C) and also at 45 C, and / or - resistance to 8 successive cycles of 8 hours each, including temperatures

range from -20 C to +20 C.

The term “elastomeric” is understood to mean a flexible, deformable material having viscoelastic properties and in particular having the consistency of a sponge.

or a flexible sphere.

The elastomeric organopolysiloxanes of the composition according to the invention are

in general partially or totally crosslinked and of three-dimensional structure.

Included in a fatty phase, they transform, depending on the level of fatty phase used, a product of spongy appearance when used in the presence of low fatty phase contents into a more or less homogeneous gel, in the presence of higher amounts of fatty phase. The gelation of the fatty phase by

these elastomers can be total or partial.

The elastomers of the composition of the invention can be conveyed in the form of a gel consisting of an elastomeric organopolysiloxane of three-dimensional structure, included in at least one hydrocarbon-based oil and / or one silicone oil. The elastomeric organopolysiloxanes of the composition according to the invention can be chosen from the crosslinked polymers described in application EP-A-0295886. According to this application, they are obtained by addition and crosslinking reaction, in the presence of a catalyst of platinum type, of at least: - (a) an organopolysiloxane having at least two C1-C6 alkenyl groups per molecule; and - (b) an organopolysiloxane having at least two hydrogen atoms bonded to a

silicon atom per molecule.

The elastomeric organopolysiloxanes of the composition according to the invention can also be chosen from those described in patent US Pat. No. 5,266,321. According to this patent, they are chosen in particular from: i) organopolysiloxanes comprising units R2SiO and RSiO5. and optionally R3SiO0.s and / or SiO2 units in which the radicals R, independently of one another, represent hydrogen, an alkyl such as methyl, ethyl or propyl, an aryl such as phenyl or tolyl, an unsaturated aliphatic group such as than vinyl, the ratio by weight of the R2SiO units to the RSiO1,5s units ranging from 1/1 to 30/1 - ii) the organopolysiloxanes insoluble and swellable in a silicone oil, obtained by adding an organohydrogenpolysiloxane (1) and of an organopolysiloxane (2) having unsaturated aliphatic groups such that the amount of hydrogen or unsaturated aliphatic groups in (1) and (2) respectively is between 1 and 20 mol% when the organopolysiloxane is not -cyclic and between 1 and 50 mol% when

the organopolysiloxane is cyclic.

The organopolysiloxanes which are the subject of the invention are for example those

marketed under the names KSG6 of Shin-Etsu, Trefil E-505C or Trefil E-

506C from Dow-Corning, Gransil from Grant Industries (SR-CYC, SR DMF10, SR-

DC556), or those marketed in the form of ready-made gels (KSG15, KSG17, KSG16, KSG18 from Shin-Etsu, Gransil SR 5CYC gel, Gransil SR DMF 10 gel, Gransil SR DC 556 gel, SF 1204 and JK 113 from General Electric . We can

also use a mixture of these commercial products.

Preferably, the organopolysiloxane (s) are present, as active material, at a concentration ranging from 0.1 to 80% by weight, by the contribution to the total weight of the composition and preferably from 0.5 to 20%, and of still preferably

from 2% to 15%.

A second essential component of the compositions according to the invention is a polydimethylsiloxane derivative of kinematic viscosity, measured at a temperature of about 25 ° C., at least equal to 300 10 'm2 / s. More preferably, these polydimethylsiloxane derivatives have a kinematic viscosity at least equal to 1000 106 m2 / s, and more preferably still at least equal to 100,000 10-6 m2 / s. These polydimethylsiloxane derivatives can also be in the solid state: they can then be used solubilized or dispersed in a solvent such as

for example a silicone oil of low kinematic viscosity.

These polydimethylsiloxane derivatives can be unsubstituted polydimethylsiloxanes or polydimethylsiloxanes substituted, for example by one or more hydroxyl, alkyl (for example ethyl, propyl or phenyl), alkoxy, ester and / or ether groups. These polydimethylsiloxane derivatives can optionally be substituted with one or more amino, sulfur,

vinyls, acrylics.

Preferably, the unsubstituted polydimethylsiloxanes in accordance with the invention have a degree of polymerization greater than or equal to 250 and a molecular weight

greater than or equal to 18,500.

Preferably, use is made in the compositions of the invention of polydimethylsiloxane derivatives substituted with one or more hydroxyl groups and / or

with one or more phenyl groups.

Mention may be made, as commercial products comprising polydimethylsiloxanes which are particularly suitable for the invention, the following products: - from "pure" polydimethylsiloxane: "Silicone SH-200" from TORAY with a viscosity of 1000 10-6 m2 / s, "Silicone BY.11.007 "from TORAY with a viscosity of 2000 to 5000 10- m2 / s," Silicone Viscasil 60 M "from General Electric; "Mirasil DM 500,000" from Rhodia-Chimie with viscosity 500,000 10-6 m2 / s and molecular weight 250,000, "Mirasil DM 500" from Rhodia-Chimie, "AK 300,000" from Wacker with viscosity 300,000 10- 6 m2 / s, "AK 500,000" from Wacker, "DC 200 Fluid" from Dow Corning with a viscosity of 60,000 10-6 m2 / s, "DC Fluid 200-350" from Dow Corning and viscosity 300 10-6 m2 / s, "Mirasil DM 300" from Rhodia Chimie with a viscosity of 300 106 m2 / s, - from polydimethysiloxanes associated with silicone or hydrocarbon oils of low molecular weight: "DC 1402" from Dow Corning (polydimethysiloxane in cyclotetramethicone and cyclopentamethicone), “Sil MK 88” from Shin-Etsu (12% polydimethysiloxane in C13-C16 isoparaffinic oil), “Silicone CF 1241” from General Electric (polydimethysiloxane with molecular weight 500,000 and viscosity 2,000,000 106 m2 / s at 33% in a fluid polydimethysiloxane of viscosity 1000 106 m2 / s), "XF-49601" from Toshiba (polydimethysiloxane of molecular weight 2000 000 at 15% in cyc lopentamethicone), - among the hydroxylated polydimethylsiloxanes: "DC 1403" from Dow Corning (a-co hydroxylated polydimethysiloxane of molecular weight 1,770,000 at 12% in a fluid silicone of viscosity 5 10 'm2 / s), "DC 1401" by Dow Corning (hydroxylated polydimethysiloxane of molecular weight 1,770,000 at 12% in cyclopentamethicone), "DC 9071" by Dow Corning (hydroxylated polydimethysiloxane of molecular weight 1,770,000 at 15% in cyclopentamethicone), "Abil OSW.13 "from Goldschmidt (13% hydroxylated polydimethysiloxane in cyclotetramethicone and cyclopentamethicone)," DC 1503 "from Dow Corning (15% hydroxylated polydimethysiloxane in a fluid silicone with a viscosity of 5 10-6 m2 / s), - among phenylated polydimethylsiloxanes: “Abil AV 1000” from Goldschmidt (polyphenylsiloxydimethylsiloxane with a viscosity of 1000 101 m2 / s), “Abil AV 350” from Goldschmidt (polyphenylsiloxydimethylsiloxane with a viscosity of 350 10 'm2 / s), “Mirasil DPDM-Chemhodia (polydiphenyldimethysiloxane), " Belsil PDM 1000 "from Wacker (polydimethyltrimethylsiloxydimethylsiloxane of molecular weight 9000 and viscosity 1000 10-6 m2 / s), - from phenylated polydimethylsiloxanes associated with an oil:" Mirasil C. DPDM "from Rhodia Chimie (polydiphenyldimethylsiloxane of molecular weight

600,000 and a viscosity of 1,000,000 10-6 m2 / s at 15% in cyclopentamethicone).

In a preferred embodiment of the invention, an a-w hydroxylated polydimethysiloxane is used, that is to say substituted with at least one OH group at each of the two ends of the silicone chain, of weight

molecular 1,770,000.

Preferably, the polydimethylsiloxane derivative (s) are present, as active material, at a concentration ranging from 1 to 99.5% by weight, relative to the total weight of the composition and preferably from 5% to 90%, and preferably

still from 7% to 80%.

The compositions according to the invention have a dynamic viscosity at most equal to 100 10 −1 Pa.s. They are fluid and spread easily on the skin. They

are thus particularly suitable for application to the whole body.

The compositions according to the invention can comprise, in addition to the organosiloxane

crosslinked and polydimethylsiloxane derivative, oils and / or solvents.

As oils which can be used in the invention, there may be mentioned in particular: - vegetable hydrocarbon oils such as liquid triglycerides of fatty acids, triglycerides of caprylic / capric acids such as those sold by the company Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by the company Dynamit Nobel or even wheat germ, corn, sunflower, shea, castor, sweet almond, macadamia, apricot, soy, cotton, alfalfa, poppy, pumpkin, sesame, squash, avocado, hazelnut, grape seed or blackcurrant, evening primrose, millet, barley, quinoa, olive, rye, safflower, bancoulier, passionflower, muscat rose; these vegetable oils have the particularity of being liquid at a temperature equal to or less than 25 C; - oils of formula RgCOOR10 in which R9 represents the residue of a higher fatty acid comprising from 7 to 19 carbon atoms and R10 represents a branched hydrocarbon chain containing from 3 to 20 carbon atoms such as for example Purcellin oil ( cetostearyl octanoate); - synthetic esters and ethers such as isopropyl myristate, octanoates, decanoates or ricinoleates of alcohols or polyalcohols; - fatty alcohols such as actyl dodecanol or oleic alcohol;

- their mixtures.

It is optionally possible to add to these oils silicone oils such as volatile or non-linear or cyclic polymethylsiloxanes, which are liquid or pasty at room temperature; linear or branched hydrocarbons of synthetic or mineral origin, such as volatile or non-volatile paraffin oils and their derivatives, petroleum jelly, polydecenes, hydrogenated polyisobutene such as parlam. These oils can be present in the compositions according to the invention in proportions which can range up to 90% by weight, relative to the total weight of the mixture.

composition, preferably ranging from 5 to 85%.

The compositions according to the invention can also comprise up to 10% by weight, relative to the total weight of the composition, of solvent as per

example ethanol.

Of course, a person skilled in the art will take care to choose these oils and / or solvents as well as their proportions so that they do not adversely affect the stability of the oils.

fluid compositions of the invention.

The composition according to the invention can also comprise a particulate phase which can comprise pigments and / or nacres and / or fillers usually used in cosmetic compositions. By pigments, it is necessary to understand white or colored particles, mineral or organic, insoluble in the medium, intended to color and / or opacify the composition. By fillers, it is necessary to understand colorless or white particles, mineral or synthetic, lamellar or non-lamellar, intended to give body or rigidity to the composition, and / or softness, dullness and uniformity to makeup. By nacres, we must understand iridescent particles that reflect

the light.

The pigments can be present in an amount of 0-20% by weight, relative to the total weight of the composition, and preferably in an amount of 215%. They can be white or colored, mineral and / or organic, of usual or nanometric size. Mention may be made, among inorganic pigments and nanopigments, of titanium, zirconium or cerium dioxides, as well as zinc, iron or chromium oxides, nanotitans, ferric blue. Among the organic pigments, mention may be made of carbon black, and the lacquers commonly used to give the lips and the skin a make-up effect, which are calcium, barium, aluminum or zirconium salts, dyes.

acids such as halo-acid, azo or anthraquinone dyes.

The nacres can be present in the composition in an amount of 0-20% by weight, preferably at a high level of the order of 2-15% by weight. Among the conceivable nacres, mention may be made of natural mother-of-pearl, mica coated with titanium oxide, iron oxide, natural pigment or bismuth oxychloride as well.

than colored titanium mica.

The fillers, which can be present in the composition in an amount of 0-20% by weight, relative to the total weight of the composition, preferably 2-10%, can be mineral or synthetic, lamellar or non-lamellar. Mention may be made of talc, mica, silica, kaolin, nylon and polyethylene powders, Teflon, starch, boron nitride, microspheres such as Expancel (Nobel Industrie), micro sponges such as than polytrap (Dow Corning) and

silicone resin microbeads (Tospearls from Toshiba, for example).

The composition of the invention can also comprise any additive usually used in the field concerned, such as fat-soluble dyes, coloring agents for the skin, antioxidants, essential oils, preservatives, neutralizers, surfactants, waxes, polymers compatible with the silicone medium, liposoluble polymers, in particular hydrocarbon-based polymers such as polyalkylenes, cosmetic or dermatological active agents such as, for example, emollients, moisturizers, vitamins, anti-wrinkle active agents, essential fatty acids, sun filters lipophilic. These additives can be present in the composition in an amount of 0 to

% of the total weight of the composition and better still from 0 to 10%.

Of course, a person skilled in the art will take care to choose the optional additional additives and / or their quantity in such a way that the advantageous properties of the composition according to the invention are not, or

substantially not, altered by the proposed addition.

The composition of the invention can be in the form of a colored make-up product for the skin, in particular the body, a foundation, a blush, a blush or eye shadow, or of lip makeup like a lipstick. It can also be in the form of a dermatological or skin care composition, or else in the form of a sun protection composition. It can then be in uncolored form, optionally containing cosmetic or dermatological active ingredients. It can also be used as a care base for the skin or the lips (lip balms,

protecting the lips from the cold and / or the sun and / or the wind).

Of course, the composition of the invention must be cosmetically or dermatologically acceptable, namely non-toxic and capable of being applied to the skin or mucous membranes (lips, inside of the eyelids) of human beings. The composition according to the invention can be manufactured by the known methods,

generally used in cosmetics or dermatology.

A subject of the invention is also a cosmetic process for making up or caring for the skin, in particular the body, or the mucous membranes (lips, interiors of the lower eyelids) of human beings, comprising application to the skin,

body or mucous membranes of the composition as defined above.

A subject of the invention is also the use of a polydimethylsiloxane derivative as defined above in an anhydrous composition comprising at least one solid elastomeric organopolysiloxane partially crosslinked to obtain a stable composition having a dynamic viscosity, measured at the temperature of 'about 25 C and at a shear rate of 200 s', at most equal to 100 10-' Pa.s. A subject of the invention is also the use of a polydimethylsiloxane derivative as defined above in a stable anhydrous composition comprising at least one solid elastomeric organopolysiloxane partially crosslinked and having a dynamic viscosity, measured at a temperature of about 25 C and at the rate of

shear of 200 s- ', at most equal to 100 10-'1 Pa.s.

The invention is illustrated in more detail in the following examples. The

percentages are given by weight, relative to the total weight of the composition.

EXAMPLE 1: (invention) Fluid foundation: - hydroxylated polydimethylsiloxane of molecular weight 1,770,000 at 15% in cyclopentamethicone sold under the trade name "DC 9071" by Dow Corning 40% cyclopentadimethicone 35% - pigments 8% - ethanol 5 % - crosslinked organosiloxane sold under the trade name “KSG 6” by Shin Etsu 10% This composition was prepared by simple mixing of the various constituents. It has a dynamic viscosity equal to 53 10- 'Pa.s. She may be

packaged in a pump bottle.

This composition also exhibits excellent stability, even after having been stored for 2 months at 45 ° C. It spreads easily on the skin and is soft on application.

EXAMPLE 2:

The Applicant has produced the following two compositions A and B: Composition A: (invention) - polydimethylsiloxane with a viscosity of 300 10 'm2 / s sold under the trade name "DC Fluid 200-350" by Dow Corning 90% - crosslinked organosiloxane sold under the trade name "KSG 6" by Shin Etsu 10% Composition B (comparative) polydimethylsiloxane of viscosity 100 10m-6 2 / s sold under the trade name "DC Fluid 200-100" by Dow Corning 90% - crosslinked organosiloxane sold under the trade name "KSG 6" by Shin Etsu 10%

These two compositions were produced by simple mixing of the constituents.

Composition A has a dynamic viscosity of 42 10- 'Pa.s. It spreads easily on the skin and is soft on application. It is homogeneous and stable,

even after several weeks.

Composition B, which comprises a polydimethylsiloxane not in accordance with the invention, shifts phase immediately after the preparation of the mixture. It happens

sedimentation: aggregates of particles form at the bottom of the container.

EXAMPLE 3: (invention) Body tinted fluid - polydimethylsiloxane with a viscosity of 300 10 'm2 / s sold under the trade name "DC Fluid 200-350" by Dow Corning 88.85% - crosslinked organosiloxane sold under the trade name "KSG 6" by Shin Etsu 10% - iron oxides 0.5% parlam oil 0.5% - polyhydrostearic acid stearate sold under the trade name "Solsperse 2100" by the company ZENECA 0.15% This composition was produced by simple mixture of the various constituents. She

has a dynamic viscosity of 42 10-'1 Pa.s.

This composition also exhibits excellent stability, even after having been stored for 2 months at 45 ° C. It spreads easily on the skin, is gentle on application and is particularly suitable for making up the entire body.

Claims (17)

1. Anhydrous composition characterized in that it comprises at least one partially crosslinked elastomeric solid organopolysiloxane and at least one polydimethylsiloxane derivative of kinematic viscosity, measured at a temperature of about 25 ° C., at least equal to 300 10'6 m2 / s, this composition having a dynamic viscosity, measured at a temperature of about 25 C and at shear rate of 200 s- ', at most equal to 100 10-1 Pa.s. 2. Composition according to Claim 1, characterized in that the polydimethylsiloxane derivative has a kinematic viscosity, measured at the temperature. of about 25 C, at least equal to 1000 10-6 m2 / s. 3. Composition according to claim 1 or 2, characterized in that the polydimethylsiloxane derivative has a kinematic viscosity, measured at temperature. of about 25 C, at least equal to 100,000 10'6m2 / s. 4. Composition according to any one of claims 1 to 3, characterized by the fact that the polydimethylsiloxane derivative is an unsubstituted polydimethylsiloxane whose degree of polymerization is greater than or equal to 250 and the weight molecular weight is greater than or equal to 18,500. 5. Composition according to any one of claims 1 to 3, characterized by the fact that the polydimethylsiloxane derivative is chosen from polydimethylsiloxane derivatives substituted with one or more hydroxyl groups and / or with one or more phenyl groups. 6. Composition according to Claim 5, characterized in that the polydimethylsiloxane derivative is a polydimethysiloxane hydroxylated in a-co by weight molecular 1,770,000. 7. Composition according to any one of the preceding claims, characterized in that the polydimethylsiloxane derivative (s) are present, as active material, at a concentration ranging from 1 to 99.5% by weight, relative to the total weight of the composition and preferably from 5% to 90%, and of more preferably from 7% to 80%. 8. Composition according to any one of the preceding claims, characterized in that the elastomeric organopolysiloxane is obtained by addition and crosslinking reaction, in the presence of a platinum-type catalyst, of at least: - (a) one organopolysiloxane having at least two C1- alkenyl groups C6 per molecule; and - (b) an organopolysiloxane having at least two hydrogen atoms bonded to a silicon atom per molecule. 9. Composition according to any one of the preceding claims, characterized in that the elastomeric organopolysiloxane is chosen from: - i) organopolysiloxanes comprising R2SiO and RSiO.5 units and optionally R3SiO0.s and / or SiO2 units in which the R radicals, independently of one another, represent a hydrogen, an alkyl such as methyl, ethyl or propyl, an aryl such as phenyl or tolyl, an unsaturated aliphatic group such as vinyl, the ratio by weight of the units R2SiO on the units RSiO1l5 ranging from 1/1 to 30/1 - ii) organopolysiloxanes insoluble and swellable in silicone oil, obtained by adding an organohydrogenpolysiloxane (1) and an organopolysiloxane (2) having unsaturated aliphatic groups such that the amount of hydrogen or unsaturated aliphatic groups in respectively (1) and (2) is between 1 and 20 mol% when the organopolysiloxane is non-cyclic and between 1 and 50 mol% when the organopolysiloxane is cyclic. 10. Composition according to any one of the preceding claims, characterized in that the elastomeric organopolysiloxane is present, as active material, at a concentration ranging from 0.1 to 80% by weight, relative to the total weight of the composition and preferably from 0.5 to 20%, and preferably still 2% to 15%. 11. Composition according to any one of the preceding claims, characterized in that it further comprises a particulate phase which can include pigments and / or nacres and / or fillers. 12. Composition according to any one of the preceding claims, characterized by the fact that it is stable. 13. Composition according to any one of the preceding claims, characterized by the fact that it is cosmetic. -14. Composition according to any one of the preceding claims, characterized in that it is in the form of a make-up product for the skin, in particular the body, a foundation, a blush, a blush or eye shadow or lip makeup, especially red lips. 15. Cosmetic process for making up or caring for the skin, body or mucous membranes of human beings, comprising application to the skin, body or skin. the mucous membranes of the composition according to any one of the claims previous ones. 16. Use of a polydimethylsiloxane derivative as defined in one any one of claims 1 to 6 in an anhydrous composition comprising at least one solid elastomeric organopolysiloxane partially crosslinked to obtain a stable composition having a dynamic viscosity, measured at a temperature of about 25 C and at a shear rate of 200 s- ', at most equal to 10-'1 Pa.s. 17. Use of a polydimethylsiloxane derivative as defined in one any one of claims 1 to 6 in a stable anhydrous composition comprising at least one partially crosslinked elastomeric solid organopolysiloxane and having a dynamic viscosity, measured at the temperature of about 25 C and at a shear rate of 200 s1, at most equal to 100 10 -Pa. S.