WO2012052439A1

WO2012052439A1 - Process for preparing a silicone resin and cosmetic use of the resin

Info

Publication number: WO2012052439A1
Application number: PCT/EP2011/068192
Authority: WO
Inventors: Malgorzata Kujawa
Original assignee: L'oreal
Priority date: 2010-10-18
Filing date: 2011-10-18
Publication date: 2012-04-26
Also published as: FR2966156A1; FR2966156B1

Abstract

The invention relates to a process for preparing an MQ-T propyl resin, comprising: the reaction by condensation of an MQ resin and of a T-propyl resin, the resins comprising free hydroxyl groups, in the presence of a first organic solvent chosen from aromatic hydrocarbon-based solvents; and of a catalyst, followed by the addition and reaction of a silane terminating agent; and then the addition of a second organic solvent chosen from non-aromatic oils and the removal of the first organic solvent. Cosmetic use of the product obtained according to the preparation process.

Description

Process for preparing a silicone resin and cosmetic use of the resin

The present invention relates to a process for preparing an MQ-T propyl silicone resin and to the use of the said resin in cosmetics.

MQ-T propyl resins, which may be used in cosmetic compositions, especially makeup compositions, are known from patent application WO 2005/075 542.

These resins are generally prepared by condensation reaction of a first MQ resin and of a second T-propyl resin in the presence of an aromatic organic solvent such as xylene, which is necessary firstly to dissolve the two starting resins and secondly to perform the condensation reaction. However, such an aromatic organic solvent is not cosmetically acceptable, and it is thus necessary, after obtaining the resin derived from the reaction carried out, to perform a solvent exchange that consists in adding a cosmetically accept- able non-aromatic organic solvent, such as isododecane, and to eliminate the aromatic organic solvent by evaporation or distillation. Now, it has been observed that when the first MQ resins and/or second T-propyl resin used from the start of the synthetic process contain(s) residual hydroxyl groups (-OH), the MQ-T propyl resin obtained from such resins generates problems during the solvent exchange step: the presence of the residual hydroxyl groups gives rise to additional condensation reactions, which modifies the chemical constitution of the MQ-T propyl resin and gives rise to a change in the molecular weight of the resin and a change in the rheological properties of the resin, inducing an increase in viscosity and gelation of the organic solvent medium conveying the resin. These rheological defects also create difficulties in fully removing the aromatic organic solvent during the solvent exchange and in dissolving or dispersing the MQ-T propyl resin in the non-aromatic organic solvent. It has also been found that such a resin conveyed in the non-aromatic organic solvent leads to a mixture that does not show good stability over time, especially after storage for one month at room temperature (25°C) and 45°C: specifically, a change in the viscosity of the organic solvent medium and a variation of the molecular weight of the resin are observed.

The resin therefore does not conserve its initial properties, thus causing a nuisance for its use in cosmetic products.

Furthermore, when the resin is formulated in a cosmetic composition, the residual hy- droxyl groups present in the MQ-T propyl resin interact with the associated ingredients (especially salts or ingredients of ionic nature such as surfactants or ionic polymers) present in the composition or with the materials forming the packaging in which the composition is conditioned (especially glass). The aim of the present invention is thus to provide a process for synthesizing MQ-T propyl resin that makes it possible to obtain a resin that is stable on storage when it is conveyed in a non-aromatic organic solvent medium, especially in isododecane, and rela- tively inert with respect to the solvent exchange step (no post-condensation inducing gelation).

The Applicant has discovered that the stability of the resin can be improved by performing, during the process for synthesizing the said resin, a termination step using a particu- lar silane after the step of reaction of the starting resins and before the step of solvent exchange. This process allows total removal of the aromatic synthetic solvent and conveys the final resin obtained in a solvent medium that is suitable for cosmetic uses.

Patent application WO 2005/075 542 describes the possibility of using a starting MQ resin containing residual hydroxyl groups modified with end groups of M type (R₃Si-0- unit), but such an MQ resin disrupts the condensation reaction, which does not take place correctly and is thus detrimental to the formation of the expected MQ-T propyl resin. Thus, the invention relates to a process for preparing an MQ-T propyl resin, comprising at least:

(i) in a first step:

- the reaction by condensation of:

A) an MQ resin (resin A) comprising at least 80 mol% of units (R¹ ₃SiOi_/2)_a and

R¹ representing an alkyl group containing from 1 to 8 carbon atoms, a C₆-Ci₆ aryl group, a carbinol group or an amino group,

a and d being greater than zero,

the ratio a/d being between 0.5 and 1.5;

and

B) a T-propyl resin (resin B) comprising at least 80 mol% of units (R³Si0_3/2)_c,

R³ representing an alkyl group containing from 1 to 8 carbon atoms, a C₆-Ci₆ aryl group, a carbinol group or an amino group,

c being greater than zero,

on condition that at least 40 mol% of the groups R³ are propyl groups, in which the mass ratio resin A/resin B is between 15:85 and 95:5,

resins A and B comprising free hydroxyl groups, in the presence of a first organic solvent chosen from aromatic hydrocarbon-based solvents, and of a catalyst, and then

(ii) in a second step:

- the addition and reaction of a silane terminating agent;

(iii) in a third step:

- the addition of a second organic solvent chosen from non-aromatic oils and the removal of the first organic solvent.

The first step may optionally include the addition of an additional polyorganosiloxane (known as component C) comprising units R² ₂Si0₂/2 or R³Si0_3/2. The radicals R¹ , R² and R³ of the MQ and T-propyl resins and optionally of the additional polyorganosiloxane used in the process according to the invention independently represent an alkyl group containing from 1 to 8 carbon atoms, a C6"Ci6 aryl group, a carbinol group or an amino group.

The alkyl groups may be chosen especially from methyl, ethyl, propyl, butyl, pentyl, hexyl and octyl groups. Preferably, the alkyl group is a methyl group or a propyl group.

The C6"Ci6 aryl groups may be chosen from phenyl, naphthyl, benzyl, tolyl, xylyl, xenyl, methylphenyl, 2-phenylethyl, 2-phenyl-2-methylethyl, chlorophenyl, bromophenyl and fluorophenyl groups, the C6"Ci6 aryl group preferentially being a phenyl group.

In the present invention, the term "carbinol group" means any group containing at least one hydroxyl radical bonded to a carbon (COH). The carbinol groups may thus contain more than one COH radical, for instance

If the carbinol group is free of aryl groups, it comprises at least 3 carbon atoms. If the carbinol group comprises at least one aryl group, it comprises at least 6 carbon atoms. As examples of carbinol groups free of aryl groups and comprising at least 3 carbon atoms, mention may be made of the groups of formula R⁴OH in which R⁴ represents a divalent hydrocarbon-based radical comprising at least 3 carbon atoms or a divalent hy- drocarbonoxy radical comprising at least 3 carbon atoms. As examples of groups R⁴, mention may be made of alkylene radicals such as -(CH₂)_X-, the value of x being between 3 and 10, -CH₂CH(CH₃)-, -CH₂CH(CH₃)CH₂-, -CH₂CH₂CH(CH₂CH₃)CH₂CH₂CH₂- and - OCH(CH₃)(CH₂)x-, the value of x being between 1 and 10. As examples of carbinol groups comprising aryl groups containing at least 6 carbon atoms, mention may be made of R⁵OH in which R⁵ represents an arylene radical such as - (CH₂)xC₆H₄-, x having a value between 0 and 10, -CH₂CH(CH₃)(CH₂)_XC₆H₄-, x having a value between 0 and 10, -(CH₂)xC₆H₄(CH₂)_x-, x having a value between 1 and 10. The carbinol groups comprising aryl groups generally comprise from 6 to 14 atoms.

According to the invention, the term "amino group" especially means groups of formula - R⁶NH₂ or -R⁶NHR⁷NH₂, R⁶ representing a divalent hydrocarbon-based radical containing at least 2 carbon atoms and R⁷ representing a divalent hydrocarbon-based radical containing at least 2 carbon atoms. The group R⁶ generally represents an alkylene radical containing from 2 to 20 carbon atoms. Examples of groups R⁶ that may be mentioned include ethylene, propylene, -CH₂CHCH₃-, butylene, -CH₂CH(CH₃)CH₂-, pentamethylene, hexamethylene, 3-ethylhexamethylene, octamethylene and decamethylene groups.

The group R⁷ generally represents an alkylene radical containing from 2 to 20 carbon atoms. Examples of groups R⁷ that may be mentioned include ethylene, propylene, - CH₂CHCH₃-, butylene, -CH₂CH(CH₃)CH₂-, pentamethylene, hexamethylene, 3- ethylhexamethylene, octamethylene and decamethylene groups.

The amino groups are generally -CH₂CH₂CH₂NH₂ and -CH₂(CH₃)CHCH₂(H)NCH₃, -CH₂CH₂NHCH₂CH₂NH₂, -CH₂CH₂NH₂, -CH₂CH₂NHCH₃, -CH₂CH₂CH₂CH₂NH₂, -(CH₂CH₂NH)₃H and -CH₂CH₂NHCH₂CH₂NHC₄H₉.

Preferably:

R¹ represents a methyl group.

R² represents a methyl group or a phenyl group. Preferably, R² represents a methyl group.

R³ represents a propyl group.

Preferably, the MQ and T-propyl resins used in the process according to the invention are free of units D, R¹ represents a methyl group and R³ represents a propyl group.

The first step: Resin A is an MQ resin comprising at least 80 mol% of units (R¹ ₃SiOi_/2)_a and (Si0_4/2)_d (units M and Q, respectively) in which R¹ is as defined above, i.e. it represents an alkyl group containing from 1 to 8 carbon atoms, a C6"Ci₆ aryl group, a carbinol group or an amino group, a and d being greater than zero, and the ratio a/d being between 0.5 and 1.5. a and d represent the mole fraction of the total number of moles of all the units M and Q, respectively, present in resin A. Thus, resin A comprises at least 80 mol% of units M and Q, these units M and Q being present in a mole fraction respectively equal to a and d as described previously. This especially means that a + d≥ 0.8.

The MQ resins that may be used as resin A, and the method for preparing them, are known in the prior art. For example, patent US 2 814 601 , belonging to Currie et al., dated 26 November 1957, describes a process for manufacturing MQ resins by transformation of a water-soluble silicate into a silicic acid monomer or a silicic acid oligomer using an acid. Once the appropriate polymerization has been performed, trimethylchloro- silane end groups are introduced to obtain the MQ resin. Another process for preparing MQ resins is described in patent US 2 857 356 belonging to Goodwin, dated 21 October 1958. Goodwin describes a process for manufacturing an MQ resin by cohydrolysis of a mixture of an alkyl silicate and of a water-hydrolysable trialkylsilane organopolysiloxane. The MQ resins that are suitable for use as component A) in the present invention may contain units D and T, on condition that at least 80 mol% or even 90 mol% of the total siloxane units are units M and Q. The MQ resin contains hydroxyl groups. The MQ resin may thus comprise hydroxyl groups in a total amount of between 2% and 10% by weight relative to the total weight of the MQ resin. Preferably, the MQ resin used in the process according to the invention comprises hydroxyl groups in a total amount of between 2% and 5% by weight relative to the total weight of the MQ resin.

The amount of hydroxyl groups present in resin A may be measured, for example, according to the method described in the article Smith & Kellum, Anal. Chem. 39 (1967) 339. Resin B is a T-propyl resin comprising at least 80 mol% of units (R³Si0₃/2)_c, R³ being as defined above, i.e. representing an alkyl group containing from 1 to 8 carbon atoms, a C₆-Ci6 aryl group, a carbinol group or an amino group, c being greater than 0, on condition that at least 40 mol% of the groups R³ are propyl groups. Thus, resin B comprises at least 80 mol% of units R³Si0_3/2 as described previously, these units being present in a mole fraction equal to c. This especially means that c≥ 0.8.

Preferably, the T-propyl resin according to the invention is a silsesquioxane resin. Silses- quioxane resins are well known in the prior art and are generally obtained by hydrolysis of an organosilane comprising three hydrolysable groups, such as halogen or alkoxy groups, present in the molecule. Component B) may thus be obtained by hydrolysis of propyltrimethoxysilane, propyltriethoxysilane or propyltripropoxysilane, or by cohydrolysis of the abovementioned propylalkoxysilanes with various alkoxysilanes. Examples of these alkoxysilanes that may be mentioned include methyltrimethoxysilane, methyltrieth- oxysilane, methyltriisopropoxysilane, dimethyldimethoxysilane and phenyltrimethoxysi- lane. Propyltrichlorosilane may also be hydrolysed alone, or in the presence of alcohol. In this case, the cohydrolysis may be performed by adding methyltrichlorosilane, di- methyldichlorosilane, phenyltrichlorosilane or similar chlorosilanes and methyltrimethox- ysilane, methyltriethoxysilane, methyltriisopropoxysilane or similar methylalkoxysilanes. As alcohols that are suitable for this purpose, mention may be made of methanol, etha- nol, n-propyl alcohol, isopropyl alcohol, butanol, methoxyethanol, ethoxyethanol or similar alcohols. As examples of solvents of hydrocarbon type that may be used, mention may be made of toluene, xylene or similar aromatic hydrocarbons; hexane, heptane, isooctane or similar linear or partially branched saturated hydrocarbons; and also cyclo- hexane or similar aliphatic hydrocarbons.

The T-propyl resin (resin B) used in the process according to the invention may contain units M, D and Q, on condition that at least 80 mol% or even 90 mol% of the total silox- ane units are units T. The T-propyl resin may also contain hydroxyl groups.

The T-propyl resin may thus comprise hydroxyl groups in a total amount of between 3% and 8% by weight of hydroxyl groups relative to the total weight of the T-propyl resin.

Advantageously, the mass ratio resin A/resin B is between 20:80 and 95:5. Preferably, the mass ratio resin A/resin B is between 20:80 and 90: 10.

For example, the mass ratio resin A/resin B may be 85: 15 or 50:50 or 30:70, or 95:5. Preferably, the mass ratio resin A/resin B is equal to 30:70.

The amount of component C) may vary, but on condition that it results in a content of less than 30 mol% of additional units D or T, relative to the total molar amount of silox- ane units in the reaction mixture. According to one embodiment of the process according to the invention, the first step may optionally include the addition of an additional polyorganosiloxane (known as component C) comprising units R² ₂Si0₂/2 or R³Si0_3/2.

The polyorganosiloxane (component C) used according to the invention comprises units R² ₂Si0₂/2 (units D) and/or R³Si0_3/2 (units T). The additional polyorganosiloxane may be added in order to introduce various units D and T into the MQ-T propyl resins, so as to modify the properties of the resulting resins. The structure or the formula of the polyor- ganosiloxane is not limiting, on condition that the said polyorganosiloxane comprises a measurable amount of units R² ₂Si0_2/2 or R³Si0_3/2, and that the total amount of polyorganosiloxane added to the reaction between A) and B) does not amount to more than 50 mol% of units D or T in the reaction mixture.

The polyorganosiloxane may also comprise combinations of units M, D, T and Q, pro- vided that at least the units D or T are present. Thus, the polyorganosiloxane may be chosen from fluid silicones, gums or resins known in the prior art and comprising units D or T, or mixtures thereof. The units D typically comprise methyl or phenyl groups or mixtures thereof as groups R². The units T typically comprise methyl or phenyl groups or mixtures thereof as groups R³. The additional polyorganosiloxane may be a linear fluid polydiorganosiloxane with a viscosity of between 10 and 1000 cS (mm²/s). The fluid polydiorganosiloxane may be a polydimethylsiloxane or a polymethylphenylsiloxane. The polyorganosiloxane may also be an organosilsesquioxane resin. The organosilsesquiox- ane resin is typically a methylsilsesquioxane resin or a phenylsilsesquioxane resin. Components A), B) and optionally C) described previously may react via any method known in the prior art for acting on the units M, D, T and Q. Preferably, however, components A), B) and optionally C) react via a condensation reaction in the presence of a catalyst. The first organic solvent is chosen from aromatic hydrocarbon-based solvents, such as xylene or toluene.

Condensation reaction catalysts that may be used are especially metal hydroxides such as potassium hydroxide or sodium hydroxide; metal salts such as silanolates, carboxy- lates and carbonates; aqueous ammonia; amines; titanates such as tetrabutyl titanate; and mixtures thereof. The catalyst is preferably potassium hydroxide. Typically, the reaction between components A), B) and optionally C) may be performed by heating the reaction mixture to temperatures ranging from 50 to 140°C. Preferably, this reaction temperature may range from 100 to 140°C. The reaction may be performed as a semi-continuous or continuous process or in batch mode.

The first step of the process according to the invention produces an MQ-T propyl resin comprising units:

(iii) (R³Si0_3/2)_c and

and which correspond, respectively, to the units M, D, T and Q.

The amount of each unit present in the MQ-T propyl resin may be expressed as a mole fraction (i.e. a, b, c or d) of the total number of moles of all the units M, D, T and Q pre- sent in the MQ-T propyl resin. This especially means that a + b + c + d = 1.

The value of a (mole fraction of units M) is between 0.05 and 0.5, or alternatively between 0.15 and 0.4.

The value of b (mole fraction of units D) is between 0 and 0.3, alternatively between 0 and 0.1 , or alternatively between 0 and 0.05. Thus, the MQ-T propyl resin according to the invention may be free of units D, or alternatively may comprise up to 0.3 mole fraction of units D.

Preferably, the MQ-T propyl resin obtained according to the process of the invention is free of units D.

The value of c (mole fraction of units T) is greater than 0, alternatively between 0.05 and 0.65, or alternatively between 0.4 and 0.65.

The value of d (mole fraction of Q units) is between 0.05 and 0.6, alternatively between 0.2 and 0.6, or alternatively between 0.2 and 0.55.

The MQ-T propyl resin obtained according to the process according to the invention is characterized in that at least 40 mol%, preferably at least 50 mol% and preferably at least 90 mol% of alkyl groups R₃ of the units T are propyl groups.

The MQ-T propyl resin obtained after the first step of the process according to the invention, and especially the siloxane units D, T or Q of this resin, comprise hydroxyl groups (- OH) and/or alkoxy groups.

These hydroxyl groups typically result from the reaction of a hydrolysable group on the siloxane unit with water; the alkoxy groups result from an incomplete hydrolysis when alkoxysilane precursors are used or result from the exchange of alcohol with hydroly- sable groups.

Preferably, the total amount by weight of -OH groups present in the MQ-T propyl resin is about 3%, preferably 2% and preferably 1.5%. Preferably, the total amount by weight of alkoxy groups present in the MQ-T propyl resin is less than or equal to 20% by weight and preferably less than or equal to 10% by weight.

The MQ-T propyl resin obtained may have a number-average molecular mass (M_N) of between 3000 and 10 000 g/mol. Preferably, this number-average molecular mass (M_N) may be between 5000 and 8000 g/mol.

As examples of MQ-T propyl resins obtained according to the first step of the process according to the invention, mention may be made of: MQ-T propyl resins comprising the following units:

(R³Si0₃/₂)_c in which R³

MQ-T propyl resins comprising the following units:

(R³Si0₃/₂)_c in which R³

(Si0_4/2)_d;

MQ-T propyl resins comprising the following units:

((CH₃)₃Si0_1/2)_a

((CH₃)₂Si0_2/2)_b, ((CH₃)(C₆H₅)Si0_2/2)_b.

(R³Si0_3/2)_c in which R³ = CH₃CH₂CH₂

(Si0_4/2)_d;

MQ-T propyl resins comprising the following units:

((CH₃)₃Si0_1/2)_a

((CH₃)₂Si0_2/2)_b

(R³Si0_{3 2})c in which R³ = CH₃CH₂CH₂-, and (C₆H₅Si0₃/₂)c

MQ-T propyl resins comprising the following units:

((CH₃)₂Si02/2)b, ((CH3)(C₆H₅)Si02/2)b'

(R³Si0₃/₂)_c in which R³ = CH₃CH₂CH₂-, and (C_eH₅SiOa/2)c

(Si0_4/2)_d;

in which a has a total value in the resin of between 0.05 and 0.5, the sum b+b' has a total value in the resin of between 0 and 0.3, c has a total value in the resin of between 0.05 and 0.65 and d has a total value in the resin of between 0.05 and 0.6.

After the first step, the catalyst may be neutralized by adding a standard neutralizer. For example, acetic acid may be used, especially when the catalyst is a base such as potassium hydroxide.

The second step:

The second step of the process according to the invention comprises the addition of a silane terminating agent.

Preferably, the silane terminating agent is a monofunctional organosilane.

As examples of monofunctional organosilanes, mention may be made of diorganosilanes and triorganosilanes, in particular halodiorganosilanes, alkoxydiorganosilanes, carboxy- diorganosilanes, halotriorganosilanes, alkoxytriorganosilanes and carboxytriorganosi- lanes.

As examples of monofunctional organosilanes, mention may be made of chlorodimethyl- silane, chlorotrimethylsilane, chlorodiphenylsilane, chlorotriphenylsilane, isopropoxydi- methylsilane, isopropoxytriphenylsilane, acetoxydimethylsilane, acetoxytrimethylsilane, acetoxydiphenylsilane and acetoxytriphenylsilane, the silanes of formula R'-| R'2 R'3 SiCI or R'-| R'2 R'3 Si (OAlk) or R'-| R'₂ R'3 Si (OCOAlk) in which R'-| , R'₂ and R'₃, which may be identical or different, denote hydrogen or an organic group, with the proviso that at least two of the groups R'-| R'2 and R'3 are an organic group. Preferably, the groups R'-| R'2 and R'3 are, independently of each other, a methyl or phenyl group. Mixtures of silane terminating agents may also be used.

Preferably, the silane terminating agent is chlorotrimethylsilane. The silane terminating agent is preferably added in an amount ranging from 0.0005% to 0.06% by weight and preferably ranging from 0.005% to 0.02% by weight relative to the total weight of the resins (A and B). The addition and the reaction of the silane terminating agent are preferably performed at a temperature of between 20°C and 150°C and preferably between 80°C and 120°C.

After the addition of the silane terminating agent, the reaction mixture is preferably maintained at a temperature of between 60°C and 150°C, especially for 5 to 120 minutes and preferably for 30 to 60 minutes.

The third step:

The third step of the process according to the invention comprises the addition of a sec- ond non-aromatic solvent chosen from non-aromatic oils,

and the removal of the first aromatic organic solvent.

The third step may be performed according to the known techniques of solvent exchange in organic synthesis. The first aromatic organic solvent may be removed via well-known evaporation or distillation techniques.

The second non-aromatic solvent may be a non-aromatic oil chosen especially from non- aromatic hydrocarbon-based oils and non-aromatic silicone oils. Advantageously, the non-aromatic oil is a volatile oil.

For the purposes of the invention, the term "volatile oil" means an oil that is capable of evaporating on contact with keratin materials in less than one hour, at room temperature and atmospheric pressure (760 mmHg). The volatile oils that may be used according to the invention are volatile cosmetic oils, which are liquid at room temperature, having a non-zero vapour pressure, at room temperature and atmospheric pressure, ranging in particular from 0.13 Pa to 40 000 Pa (10^"3 to 300 mmHg), in particular ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mmHg) and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mmHg). Conversely, a non-volatile oil has a vapour pressure of less than 1.33 Pa (0.01 mmHg). The non-aromatic hydrocarbon-based oil may be chosen from:

- hydrocarbon-based oils containing from 8 to 16 carbon atoms, and especially C₈-Ci₆ branched alkanes such as C₈-Ci₆ isoalkanes of petroleum origin (also known as isoparaf- fins), for instance isododecane (also known as 2,2,4,4,6-pentamethylheptane), iso- decane and isohexadecane, and, for example, the oils sold under the trade names Isopar® and Permethyl®; linear alkanes, for instance n-dodecane (C12) and n- tetradecane (C14) sold by Sasol under the respective references Parafol 12-97 and Parafol 14-97, and also mixtures thereof, the undecane-tridecane mixture, and mixtures of n-undecane (C1 1) and of n-tridecane (C13) obtained in Examples 1 and 2 of patent application WO2008/155 059 from the company Cognis, and mixtures thereof;

- linear or branched hydrocarbons of mineral or synthetic origin, such as petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parleam®, squalane and liquid paraffins, and mixtures thereof; - synthetic esters such as oils of formula F^COOR^ in which R represents a linear or branched fatty acid residue containing from 1 to 40 carbon atoms and R'₂ represents an in particular branched hydrocarbon-based chain containing from 1 to 40 carbon atoms, on condition that R + R'₂ > 10_, for instance purcellin oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, C12 to Ci₅ alkyl benzoate, hexyl laurate, diisopropyl adi- pate, isononyl isononanoate, 2-ethylhexyl palmitate, isostearyl isostearate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate, alkyl or polyalkyl heptanoates, octanoates, decanoates or ricinoleates such as propylene glycol dioctanoate; hydroxy- lated esters such as isostearyl lactate, diisostearyl malate and 2-octyldodecyl lactate; polyol esters and pentaerythritol esters;

- fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain containing from 12 to 26 carbon atoms, for instance octyldodecanol, isostearyl alcohol, oleyl alcohol, 2-hexyldecanol, 2-butyloctanol and 2- undecylpentadecanol;

- higher fatty acids such as oleic acid, linoleic acid or linolenic acid, and mixtures thereof; and

- hydrocarbon-based oils of plant origin such as triglycerides consisting of fatty acid es- ters of glycerol, the fatty acids of which may have chain lengths varying from C₄ to C₂₄, these chains possibly being linear or branched, and saturated or unsaturated; these oils are especially heptanoic or octanoic acid triglycerides, or alternatively wheatgerm oil, sunflower oil, grapeseed oil, sesame seed oil, corn oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cottonseed oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, poppy oil, pumpkin oil, marrow oil, blackcurrant oil, evening primrose oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passion flower oil and musk rose oil; shea butter; or else caprylic/capric acid triglycerides, for instance those sold by the company Stearineries Dubois or those sold under the names Miglyol 810®, 812® and 818® by the company Dynamit Nobel.

The non-aromatic silicone oil may be chosen from:

volatile linear or cyclic silicone oils, especially those with a viscosity < 5 centistokes (5 x 10^"6 m²/s), and especially containing from 2 to 10 silicon atoms and in particular from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups containing from 1 to 10 carbon atoms. As volatile silicone oils that may be used in the invention, mention may be made especially of octamethylcyclotetrasiloxane, decamethylcyclopen- tasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethy- loctyltrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane and dodecamethylpentasiloxane, and mixtures thereof.

Preferably, the non-aromatic oil is chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms. Preferentially, the non-aromatic oil is isododecane.

The final product obtained from the synthetic process according to the invention thus comprises the MQ-T propyl resin as a mixture with the non-aromatic oil. Such a mixture may be used in cosmetic applications.

Another subject of the invention is a product that may be obtained according to the process described previously.

Another subject of the invention is a composition comprising, in a physiologically accept- able medium, a mixture of an MQ-T propyl resin and of a non-aromatic oil, which may be obtained according to the preparation process described previously.

Another subject of the invention is a non-therapeutic cosmetic process for treating keratin materials, comprising the application to the keratin materials of a composition as de- fined previously.

Another subject of the invention is a composition comprising, in a physiologically acceptable medium, a mixture of an MQ-T propyl resin and of a non-aromatic oil, which may be obtained according to the preparation process described previously, and a dermatologi- cal active agent, for treating skin diseases.

The composition described previously comprises a physiologically acceptable medium, i.e. a medium that is compatible with keratin materials, such as facial or bodily skin, the lips, the hair, the eyelashes, the eyebrows and the nails.

The composition described previously may comprise a cosmetic ingredient chosen from thickeners, emulsifiers, surfactants, gelling agents, cosmetic active agents, fragrances, fillers, dyestuffs, moisturizers, vitamins, polymers, oils and waxes.

The invention will now be illustrated with the aid of the non-limiting examples that follow. Example 1 :

The following resins are used:

MQ resin = an MQ resin of formula M0.43Q0.57 and of M_n = 3230 dissolved in xylene to a proportion of 70.8% by weight of solids. The MQ resin was manufactured according to the techniques described by Daudt in patent US 2 676 182. T-Propyl resin = a propyl silsesquioxane resin at 74.8% by weight in toluene. The propyl silsesquioxane resin was obtained by hydrolysis of propyltrichlorosilane.

Preparation of the MQ-T^ resins An MQ resin, a T-propyl resin, xylene and 1 M KOH in water in the proportions presented in Table 1 are introduced into a 3-necked flask equipped with a stirrer, a temperature probe and Dean-Stark apparatus mounted with a condenser. Xylene is pre-introduced into the Dean-Stark apparatus so as to ensure maintenance of a level of solids of 50% in the reactor. The mixture in the reactor is refluxed (between 100 and 140°C) for at least 3 hours. Any water formed in the reaction mixture is continuously removed and trapped in the form of an azeotrope in the Dean-Stark apparatus. After refluxing for 3 hours, the water is removed from the apparatus and heating is continued for a further 30 minutes. After cooling the mixture, an excess of acetic acid is added to neutralize the KOH in the mixture. The mixture is then filtered to remove the salts formed, by passing it through a filter under pressure. An intermediate resin having the characteristics described in Table 2 below is obtained (the structures of the resulting siloxane resins are characterized by ²⁹Si NMR spectroscopy and GPC).

0.005% to 0.02% by weight, relative to the weight of MQ and T resins used, of trimethyl- chlorosilane (terminating agent) is then added, and the mixture is left to react for 1 hour at 90°C.

Solvent exchange is performed by heating the mixture in a rotary evaporator under vacuum. After removing the majority of the xylene, decamethylcyclopentasiloxane (or isodo- decane) is added while continuing to remove any residual aromatic solvent.

Table 1 ExamMass Weight% Weight% of Weight% of Weight% of Weight% of ple ratio of of MQ T-propyl xylene 1 M KOH acetic acid

MQ/T^Pr resin resin

resins

added

1-a (85: 15) 59.4 10.5 29.1 0.9 0.2

1-b (50:50) 34.9 34.8 29.1 0.9 0.2

1-c (30:70) 20.9 48.8 29.2 0.9 0.2

1-d (95:5) 67.1 3.5 28.3 0.9 0.2

Table 2

The solutions of resin obtained in isododecane are stable on storage for 1 month at room temperature (25°C) and 45°C, without observing any gelation of the solutions (no variation in viscosity) or any change in the molecular weight of the resins obtained.

Example 2: MQ-T propyl/phenyl resin prepared according to the following sequences:

MQ T-propyl T-phenyl resins are prepared according to the procedure described in Example 1 with the ingredients described in Table 3 below. In this series, a phenyl silses- quioxane resin is added during the first step to introduce additional T-phenyl units into the final siloxane resin. The intermediate resins obtained at the end of the first step are described in Table 4 below.

Table 3

Table 4

Example 3:

A liquid lipstick was prepared, having the following composition:

Formula Weight percentage %

MQ-T propyl resin in isodo- 84.0

decane, as prepared in Example 1-c above 5.0

Isononyl isononanoate

Red 7 (Unipure Red LC 3079 1.0

OR from LCW (Sensient))

isododecane qsf

Total: 100

The composition obtained is stable on storage. After application to the lips, a glossy deposit is obtained.

Claims

1. Process for preparing an MQ-T propyl resin, comprising at least:

(i) in a first step:

- the reaction by condensation of:

a and d being greater than zero,

the ratio a/d being between 0.5 and 1.5;

and

c being greater than zero,

(ii) in a second step:

- the addition and reaction of a silane terminating agent;

(iii) in a third step:

2. Process according to the preceding claim, characterized in that the first step comprises the addition of an additional polyorganosiloxane (known as component C) comprising units R² ₂Si0₂/2 or R³Si0_3/2, R² representing an alkyl group containing from 1 to 8 carbon atoms, a C₆-Ci₆ aryl group, a carbinol group or an amino group.

3. Process according to either of the preceding claims, characterized in that the radicals R¹ and R³ of the MQ and T-propyl resins and optionally the radicals R² and R³ of the additional polyorganosiloxane independently represent an alkyl group containing from 1 to 8 carbon atoms, a C₆-Ci₆ aryl group, a carbinol group or an amino group.

4. Process according to any one of the preceding claims, characterized in that R¹ represents a methyl group and R³ represents a propyl group.

5. Process according to any one of Claims 2 to 4, characterized in that R² represents a methyl group or a phenyl group.

6. Process according to any one of the preceding claims, characterized in that the MQ resin comprises hydroxyl groups in a total amount of between 2% and 10% by weight relative to the weight of the MQ resin.

7. Process according to any one of the preceding claims, characterized in that the T- propyl resin comprises hydroxyl groups in a total amount of between 3% and 8% by weight of hydroxyl groups, relative to the weight of the T-propyl resin.

8. Process according to any one of the preceding claims, characterized in that the first organic solvent is chosen from xylene and toluene.

9. Process according to any one of the preceding claims, characterized in that the catalyst is chosen from metal hydroxides, silanolates, carboxylates, carbonates; aqueous ammonia; amines; and mixtures thereof.

10. Process according to any one of the preceding claims, characterized in that the si- lane terminating agent is chosen from chlorodimethylsilane, chlorotrimethylsilane, chlorodiphenylsilane, chlorotriphenylsilane, isopropoxydimethylsilane, isopropoxytriphen- ylsilane, acetoxydimethylsilane, acetoxytrimethylsilane, acetoxydiphenylsilane and ace- toxytriphenylsilane.

1 1. Process according to any one of the preceding claims, characterized in that the si- lane terminating agent is chlorotrimethylsilane.

12. Process according to any one of the preceding claims, characterized in that the si- lane terminating agent is added in an amount ranging from 0.0005% to 0.06% by weight and preferably ranging from 0.005% to 0.02% by weight relative to the total weight of the resins (A and B).

13. Process according to any one of the preceding claims, characterized in that the non- aromatic oil is chosen from:

- hydrocarbon-based oils containing from 8 to 16 carbon atoms;

- petroleum jelly, polydecenes, polyisobutene, squalane and liquid paraffins, and mixtures thereof;

- oils of formula F^COOR^ in which R represents a linear or branched fatty acid residue comprising from 1 to 40 carbon atoms and R'₂ represents a hydrocarbon-based chain that is especially branched, containing from 1 to 40 carbon atoms provided that R + R'₂ > 10;

- fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain containing from 12 to 26 carbon atoms;

- higher fatty acids chosen from oleic acid, linoleic acid and linolenic acid, and mixtures thereof;

- hydrocarbon-based oils of plant origin;

- volatile linear or cyclic silicone oils.

14. Process according to any one of the preceding claims, characterized in that the non- aromatic oil is isododecane.

15. Product that may be obtained according to the process according to any one of the preceding claims.

16. Composition comprising, in a physiologically acceptable medium, a mixture of an MQ-T propyl resin and of a non-aromatic oil, which may be obtained according to the preparation process according to any one of Claims 1 to 14.

17. Non-therapeutic cosmetic process for treating keratin materials, comprising the application to the keratin materials of a composition according to the preceding claim.

18. Composition comprising, in a physiologically acceptable medium, a mixture of an MQ-T propyl resin and of a non-aromatic oil, which may be obtained according to the preparation process according to any one of Claims 1 to 14, and a dermatological active agent, for treating skin diseases.