Depolymerization of silicone to obtain organochlorosilane

Abstract

The present application relates to a method for preparing organochorosilane CS by reacting at least one silicone S with a metal chloride or metalloid CM in the presence of at least one metal salt catalyst SM, wherein the metal chloride or metalloid CM is different from the metal salt SM.

Description

[0001] DESCRIPTION

[0002] Depolymerization of silicone to organochlorosilane

[0003] The present invention relates generally to the reuse of silicone polymers. More specifically, the process of the present invention relates to the depolymerization of silicone polymers to obtain organochlorosilanes. This process advantageously allows recycling of used or unused silicone polymers for the preparation of organochlorosilanes which can then be used in polymerization reactions.

[0004] Recycling industrial products and used silicone products is a current issue. Recycling silicone could reduce gas emissions (CO, CO2) from the silicone industry by 75% and silicone waste by 65%.

[0005] The depolymerization of organopolysiloxanes to fluorosilane is already known and described. Its reactions are favorable from a thermodynamic point of view since the Si-F bonds are very strong (about 135 kcal / mol) compared to the Si-O bonds of organopolysiloxanes (about 110 kcal / mol). However, these methods have certain disadvantages, notably the release of volatile products or the price of fluorine sources.

[0006] The Si-Cl bonds are, on the other hand, weaker (notably 90 Kcal / mol), the depolymerization of organopolysiloxanes into organochlorosilane is therefore not favorable.

[0007] It is known from Enthaler et al (J.Appl.Polym.Sci.2015) the depolymerization of polydimethylsiloxanes to produce chlorosilanes. The catalyst used is an iron salt. However, this process requires a large quantity of catalyst (7.5% by weight of catalyst relative to the weight of organopolysiloxane), a corrosive chlorine source such as acyl chloride and a high temperature of around 170-190°C.

[0008] There is therefore an interest in providing an alternative process for depolymerizing silicones into organochlorosilane. In particular, there is an interest in providing a catalytic system that allows this depolymerization to be carried out at lower temperatures, making it possible to limit the quantity of catalyst used and making it possible to use other sources of chloride.

[0009] An objective of the present application is therefore to propose a process for the depolymerization of silicones efficiently and making it possible to obtain a good yield of organochlorosilane. Another objective of the present application is to provide a catalytic system for implementing this process.

[0010] Another objective of the present application is to propose a simple and non-hazardous catalytic system compatible with industrialization of the process.

[0011] Still other objectives will appear upon reading the description of the invention which follows.

[0012] These objectives are fulfilled by the present application which relates to a process for preparing organochlorosilane CS by reacting at least one silicone S with a metal or metalloid chloride CM in the presence of at least one metal salt catalyst SM, the metal or metalloid chloride CM being different from the metal salt SM.

[0013] Silicones, otherwise known as organopolysiloxanes, are polymeric materials comprising alternating silicon and oxygen atoms with various organic radicals bonded to the silicon.

[0014] In the context of the present invention, silicone or silicone product or silicone polymer or organopolysiloxane means polymers comprising a siloxane backbone (Si-O-Si) having alternating silicon and oxygen atoms with various organic radicals bonded to the silicon. These silicone polymers can be liquid or solid, depending on the molecular weight and the degree of crosslinking.

[0015] The silicones S of the invention may be of any type, for example they may be linear organopolysiloxanes O such as oils or gums or branched organopolysiloxanes O such as resins.

[0016] The organopolysiloxane O may in particular be an oil or a gum, and preferably has a dynamic viscosity of between 50 and 600,000 mPa.s at 25°C or a consistency of between 200 and 2,000 expressed in tenths of millimeters at 25°C. All the viscosities referred to in the present disclosure correspond to a dynamic viscosity quantity at 25°C called “Newtonian”, that is to say the dynamic viscosity which is measured, in a manner known per se, with a Brookfield viscometer at a shear rate gradient sufficiently low so that the measured viscosity is independent of the rate gradient.

[0017] The term gum is used for organopolysiloxane compounds with viscosities typically greater than 600,000 mPa.s, which corresponds to a molecular weight greater than 260,000 g / mol. These organopolysiloxanes O may comprise one or more functional units such as:

[0018] - OH ;

[0019] - H ;

[0020] - alkenyl in particular comprising from 2 to 6 carbon atoms, preferably vinyl;

[0021] - O-Alk with Alk represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0022] - (O-Alk)x with Alk representing an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl, and x representing an integer between 2 and 200;

[0023] - a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1-C5)alkyl-CF3, the alkyl being linear or branched;

[0024] - amino group, in particular (Alk)-NH2 or (Alk)-NH-(Alk)-NH2, with Alk representing an alkyl comprising from 1 to 5 carbon atoms;

[0025] - cyclic amine for example -(CH2) z -O-piperidine in which z represents an integer from 1 to 5, preferably 3, and the piperidine may be substituted in particular by one or more alkyl groups comprising from 1 to 3 carbon atoms, preferably methyl, preferably the substituted piperidine is a group

[0026] Preferably, the functional patterns are chosen from:

[0027] - OH ;

[0028] - H ;

[0029] - alkenyl in particular comprising from 2 to 6 carbon atoms, preferably vinyl;

[0030] - a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1-C5)alkyl-CF3, the alkyl being linear or branched. Preferably, the organopolysiloxanes O may comprise one or more functional units such as H, OH, alkenyl (preferably vinyl), aryl, cyclic amine, as defined above.

[0031] The organopolysiloxanes O of the invention may be partially crosslinked.

[0032] The organopolysiloxanes O of the invention may in particular be used organopolysiloxanes, having served for example as heat transfer fluid, which should be recycled, the process of the invention thus making it possible to generate organochlorosilanes which can then be directly used in industrial processes. In the case of the use of used organopolysiloxanes O, the organopolysiloxane may then contain other elements such as additives, pigments, etc. The inventors have shown that the presence of these other elements does not disturb the depolymerization reaction and the formation of organochlorosilane CS.

[0033] According to one embodiment of the invention, the organopolysiloxane O of the invention comprises:

[0034] - at least 5 units, preferably at least 10 siloxyl units of formula R c SiO(4- C ) / 2 in which

[0035] R, identical or different, represents

[0036] • an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0037] • an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl; and c = 0, 1, 2 or 3; and

[0038] - possibly one or more motifs of formula R 1 d R e SiO(4-de) / 2 in which:

[0039] R is as defined above

[0040] R 1 , identical or different, represents:

[0041] • an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl;

[0042] • a hydroxyl group (OH);

[0043] • a group (O-Alk) with Alk representing an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably OCH3 or OC2H5, • a group (O-Alk) x with Alk represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl, and x represents an integer between 2 and 200,

[0044] • a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1 - C5)alkyl-CF3, the alkyl being linear or branched;

[0045] • an amino group chosen from (Alk)-NH2 or (Alk)-NH-(Alk)-NH2, with Alk representing an alkyl comprising from 1 to 5 carbon atoms;

[0046] • cyclic amine for example -(CH2) z -O-piperidine in which z represents an integer from 1 to 5, preferably 3, and the piperidine may be substituted in particular by one or more alkyl groups comprising from 1 to 3 carbon atoms, preferably methyl, preferably the substituted piperidine is a group a hydrogen; d=1, 2 or 3, preferably d=1 or 2, more preferably d=1; e=0, 1 or 2; and the sum d+e=1, 2 or 3.

[0047] It is understood in the above formulas that if more than one R group is present or if more than one R group 1 are present, they can be the same or different from each other.

[0048] Preferably, in the above formulas R 1 , identical or different, represents:

[0049] • an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl;

[0050] • a hydroxyl group (OH);

[0051] • a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1 - C5)alkyl-CF3, the alkyl being linear or branched;

[0052] • a hydrogen. In the present invention:

[0053] - a siloxyl unit “M” represents a siloxyl unit of formula YsSiOi / 2,

[0054] - a siloxyl unit “D” represents a siloxyl unit of formula YsSiOs / s,

[0055] - a siloxyl unit “T” represents a siloxyl unit of formula YSiOs / 2,

[0056] - a siloxyl unit “Q” represents a siloxyl unit of formula SiC>4 / 2, the symbols Y being R or R 1 .

[0057] The organopolysiloxane O may optionally comprise T and Q units.

[0058] According to a preferred embodiment, the organopolysiloxane O of the invention is preferably chosen from the compounds of formula (I):

[0059] R 1 aR(3-a)SiO-(SiR2O) n -(SiR 1 RO) m -SiR 1 aR(3-a) (I) in which:

[0060] R, identical or different, represents:

[0061] • an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0062] • an aryl group comprising from 6 to 10 carbon atoms, preferably phenyl;

[0063] R 1 , identical or different, represents:

[0064] • an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl;

[0065] • a hydroxyl group (OH);

[0066] • a group (O-Alk) with Alk representing an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably OCH3 or OC2H5,

[0067] • a group (O-Alk) x with Alk represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl, and x represents an integer between 2 and 200,

[0068] • a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1 - C5)alkyl-CF3, the alkyl being linear or branched; • an amino group chosen from (Alk)-NH2 or (Alk)-NH-(Alk)-NH2, with Alk representing an alkyl comprising from 1 to 5 carbon atoms;

[0069] • cyclic amine for example -(CH2) z -O-piperidine in which z represents an integer from 1 to 5, preferably 3, and the piperidine may be substituted in particular by one or more alkyl groups comprising from 1 to 3 carbon atoms, preferably methyl, preferably the substituted piperidine

[0070] M

[0071] < z NH r is a group;

[0072] • a hydrogen; a is an integer and represents 0, 1, 2 or 3, preferably 0, 1 or 2, more preferably 0 or 1; n represents an integer between 10 and 10,000, preferably between 10 and 5,000, preferably between 50 and 5,000, more preferably between 60 and 5,000, for example between 70 and 1,000; m represents an integer between 0 and 100, preferably between 0 and 50, more preferably between 0 and 30, preferably m=0.

[0073] Particularly preferably, the organopolysiloxane O of the invention is a compound of formula (I) in which R 1 , identical or different, represents:

[0074] • an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl;

[0075] • a hydroxyl group (OH);

[0076] • a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1 - C5)alkyl-CF3, the alkyl being linear or branched;

[0077] • a hydrogen.

[0078] Particularly preferably, the organopolysiloxane O of the invention is a compound of formula (I) in which R 1 , identical or different, represents CH3, vinyl, H, (C1-C5)alkyl- CF3OR OH. Particularly preferably, the organopolysiloxane O of the invention is a compound of formula (I) in which

[0079] R, identical or different, represents CH3 or phenyl, preferably CH3;

[0080] R 1 , identical or different, represents:

[0081] • an alkenyl group comprising from 2 to 6 carbon atoms, preferably vinyl;

[0082] • a hydroxyl group (OH);

[0083] • a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1 - C5)alkyl-CF3, the alkyl being linear or branched;

[0084] • a hydrogen.

[0085] Particularly preferably, the organopolysiloxane O of the invention is a compound of formula (I) in which

[0086] R, identical or different, represents CH3 or phenyl, preferably CH3;

[0087] R 1 , identical or different, represents CH3, vinyl, H, (C1-C5)alkyl-CF3 or OH.

[0088] The silicones S of the invention may also be of the crosslinked silicone material type such as, for example, gels or elastomers. The crosslinked silicone materials may be obtained by polycondensation, radical polymerization, thermal or UV-irradiated polyaddition, etc.

[0089] Silicone products have a multitude of applications. For example, they can be found in food applications (e.g., molds), medical applications, and the pharmaceutical sector, such as baby bottle nipples, catheters, implants, or medical tubing. In technical industrial applications, silicone is often used as a material for seals or membranes. In the automotive sector, it is used for hoses, cable sheathing or insulation, and as a damping material.

[0090] Silicone elastomers are crosslinked silicone materials containing fillers, such as silica, to achieve good mechanical properties.

[0091] By varying the silicone oils, fillers and additives as well as the crosslinking method, silicone elastomers exhibit different properties and colors. Silicone elastomers can be divided into three main groups well known to those skilled in the art. Hot vulcanizable elastomers (HTV or heat cured rubber (HCR)) are silicone elastomers obtained from silicone compositions with very high viscosity including silicone gums and fillers. They are vulcanized at high temperature, generally between 140 °C and 200 °C. Crosslinking is either radical catalyzed by peroxides or obtained by an addition reaction where platinum compounds are used as catalysts.

[0092] Liquid silicone rubber (LSR) is a silicone elastomer obtained from compositions comprising silicone oils and fillers. Crosslinking occurs by an addition reaction at temperatures similar to those of EVC, with crosslinking generally occurring much more quickly than those obtained by crosslinking two components that are mixed just before the start of crosslinking.

[0093] The third group is silicones obtained by crosslinking at room temperature silicone compositions from silicone oils and fillers crosslinking by polycondensation or polyaddition reactions. These elastomers are known in French as cold vulcanizable silicone elastomers (EVE, in English room temperature vulcanization (RTV)). These compositions are available in one- and two-component systems.

[0094] In the method of the present application, silicone S also means silicone-based materials, for example materials comprising at least 0.1% by weight of silicone relative to the total weight of silicone-based material. The silicone-based material may comprise up to 100% by weight of silicone, preferably up to 99.9% by weight of silicone relative to the total weight of silicone-based material. These silicone-based materials may also comprise additives or fillers such as colorants, silica, calcium carbonate, calcium oxide, celite, quartz, titanium oxide, cerium hydroxide, magnesium oxide, mica, etc.

[0095] In the process of the invention, the metal or metalloid chlorides CM include in particular metalloid chlorides, transition metal chlorides, alkaline earth metal chlorides, alone or as a mixture. Preferably, the metal or metalloid chloride CM is chosen from metal chlorides of formula M'Clz in which

[0096] M' represents B, Al, Ti, Zr, Mg, Zn, Ca, Sb, Ge, Si, or Cu, preferably B, Al, Ti, Zr, Mg, Ca, Zn, preferably B, Al, Mg, Zn, Ca, preferably B, Al; z represents an integer depending on the valence of the metal M', for example z represents 3, 4 or 5.

[0097] The metal chloride or metalloid CM is preferably chosen from BCh, AlCIs, TiCL, ZrCL, MgCh, ZnCh, CuCh, CaCh, SiCL, GeCL, SbCI5, alone or in a mixture, preferably BCh, AICI3, MgCh, ZnCh, CaCh, more preferably AICI3, BCI3, preferably BCI3.

[0098] The metal or metalloid chloride CM may be in solution in a solvent. This is particularly advantageous in the case of solid or gaseous metal or metalloid chloride in order to solubilize these chlorides in the reaction medium. The solvent may in particular be an organic solvent of the alkane, haloalkane, aromatic hydrocarbon type. Preferably, the solvent is chosen from dichloromethane, n-hexane, n-heptane, toluene, xylene, mesitylene.

[0099] Preferably, the quantity of metal chloride or metalloid CM used in the process of the invention is at least 50%, preferably between 50 and 800% by mole relative to the number of moles of Si-O, preferably between 50 and 300% by mole, for example between 50 and 200% by mole.

[0100] In the context of the present invention, the term “number of moles of Si-O” means the number of moles of Si-O bonds of the silicone S.

[0101] In the case where the starting silicone S is of unknown formula, in particular in the case of formulated commercial products, it is possible to estimate the number of moles of Si-O. Indeed, for formulated products, the person skilled in the art knows that the quantity of filler is between 20 and 40% by mass, thus, by estimating the quantity of filler at an average of 30% by mass, we have 70% by mass of silicone, which makes it possible to calculate the number of moles of Si-O bond from the average molar mass of the repeating unit.

[0102] The SM metal salt used as catalyst in the process of the invention is preferably chosen from salts of elements from group 13 of the periodic table and transition metals. The SM metal salts are preferably metal salts comprising at least one halogen atom, preferably Cl, Br, I, F, for example they are metal halides of formula MX m in which:

[0103] M represents Ga, Ge, Al, In or Fe, preferably Ga, Al, or Fe,

[0104] X represents Cl, Br, I, F, OTf, BF4, SbFe m represents an integer depending on the metal M, preferably m represents 2, 3 or 4.

[0105] Preferably, the metal salt SM is chosen from GaCh, FeCh, FeCh, InCh, AICI3, GeCL preferably FeCh, FeCh, AICI3, GaCh, InCh-

[0106] Depending on the nature of the metal salt, it is possible to solubilize it in a solvent. The solvent may in particular be an organic solvent such as an alkane, haloalkane, or aromatic hydrocarbon. Preferably, the solvent is chosen from dichloromethane, n-hexane, n-heptane, toluene, xylene, and mesitylene.

[0107] Preferably, the amount of metal salt SM used in the process of the invention is between 0.01 and 10% by weight relative to the weight of silicone S, preferably between 0.1 and 5% by weight, for example between 0.1 and 2% by weight.

[0108] Preferably, the quantity of SM metal salt used in the process of the invention is between 0.01 and 10 mol% relative to the number of moles of Si-O, preferably between 0.01 and 5 mol%, for example between 0.1 and 2 mol%.

[0109] Preferably, the Cl / Si-O molar ratio, the quantity of chlorine being that derived from the metallic or metalloid chloride CM and the number of moles of Si-O corresponding to the number of moles of Si-O bond in the silicone S, is between 1 and 3, preferably between 2 and 3, for example between 2 and 2.5, for example 2.

[0110] Advantageously and preferably, the reaction is carried out at a temperature between 0 and 200°C, preferably between 0 and 150°C, preferably between 20 and 130°C, more preferably between 30 and 110°C.

[0111] The reaction can last from a few minutes to a few hours.

[0112] A person skilled in the art will be able to adapt the temperature and duration of the reaction according to the reagents used and the reactors. The process of the invention advantageously makes it possible to obtain a mass yield of organochlorosilane SC greater than 80%, preferably greater than 90%, preferably greater than 95%.

[0113] In the context of the present invention, organochlorosilane means compounds of the following formula (A), (B) or (C):

[0114] R2SiCI2(A) RsSiCI (B) RSiCh (C) with R, identical or different, is chosen from:

[0115] - H,

[0116] - linear or branched alkyl comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0117] - aryl comprising from 6 to 10 carbon atoms, preferably phenyl

[0118] - OH ;

[0119] - alkenyl in particular comprising from 2 to 6 carbon atoms, preferably vinyl;

[0120] - a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1-C5)alkyl-CF3, the alkyl being linear or branched;

[0121] - O-Alk with Alk represents an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0122] - (O-Alk)x with Alk representing an alkyl group comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl, and x representing an integer between 2 and 200; amino group, in particular (Alk)-NH2 or (Alk)-NH-(Alk)-NH2, with Alk representing an alkyl comprising from 1 to 5 carbon atoms;

[0123] - cyclic amine for example -(CH2) z -O-piperidine in which z represents an integer from 1 to 5, preferably 3, and the piperidine may be substituted in particular by one or more alkyl groups comprising from 1 to 3 carbon atoms, preferably methyl, preferably the substituted piperidine is a group preferably the organochlorosilanes of the invention comprise at most one hydrogen atom.

[0124] Preferably, in formulas (A), (B) and (C), R, identical or different, is chosen from:

[0125] - H,

[0126] - linear or branched alkyl comprising from 1 to 15 carbon atoms, preferably from 1 to 12 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, preferably methyl;

[0127] - aryl comprising from 6 to 10 carbon atoms, preferably phenyl

[0128] - OH ;

[0129] - alkenyl in particular comprising from 2 to 6 carbon atoms, preferably vinyl;

[0130] - a linear or branched alkyl group comprising from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, substituted by at least one fluorine atom, for example 1 to 10 fluorine atoms, for example (C1-C5)alkyl-CF3, the alkyl being linear or branched; preferably the organochlorosilanes of the invention comprise at most one hydrogen atom.

[0131] Preferably, the preferred organochlorosilanes of the invention are those of formula (I) or (II).

[0132] Without wishing to be bound by any theory: the organopolysiloxanes of formula (I) are derived from the D units of silicone S, the R of formula (I) therefore depend on the D units of silicone S; the organopolysiloxanes of formula (II) are derived from the M units of silicone S, the R of formula (II) therefore depend on the M units of silicone S;

[0133] - the organopolysiloxanes of formula (III) are derived from the T units of silicone S, the R of formula (III) therefore depend on the T units of silicone S.

[0134] Particularly advantageously, the organochlorosilanes obtained by the process of the invention can be directly used in other industrial processes as a source of raw materials to then be hydrolyzed and condensed and produce new oils, resins or gums. The present application also relates to the use of the organochlorosilanes obtained by the process of the invention for the preparation of silicone, for example for the preparation of silicone oils, resins or gums.

[0135] The present application also relates to a process for preparing silicone, in particular oils, resins or gums, comprising the following steps:

[0136] 1) implementation of the process for preparing organochlorosilane according to the invention;

[0137] 2) preparation of silicone, in particular oils and resins or gums, from the organochlorosilanes obtained in step 1).

[0138] Step 2) can in particular be carried out by hydrolysis condensation.

[0139] This application will now be described with the help of the following examples.

[0140] Examples:

[0141] Silicones used in the examples:

[0142] In the following Me = methyl, Vi = vinyl

[0143] Silicone S1: n = 70 viscosity 100 mPa.s

[0144] S2 Silicone: n = 180, viscosity 1000 mPa.s

[0145] S3 Silicone: n = 70; viscosity 100 mPa.s

[0146] Silicone 278, viscosity 1500 mPa.sc

[0147] Silicone S5: n = 476, viscosity 10,000 mPa.s

[0148] Silicone n=46, viscosity 100 mPa.s

[0149] Silicone S7: n=656, viscosity 14000 mPa.s

[0150] Silicone 50, m= 10-15

[0151] Silicone S9: n=800-900, m=40-120, viscosity

[0152] 60,000 mPa.s

[0153] Silicone

[0154] Silicone S11: silicone rubber 0.6 to 100.10 6 g / mol

[0155] Silicone S12: silicone nipple pad (commercial product, composition unknown)

[0156] Silicone S13: silicone cake mold (commercial product, composition unknown)

[0157] Silicone S14: silicone sheet (commercial product, composition unknown)

[0158] Silicone S15: silicone tube (commercial product, composition unknown)

[0159] Silicone S16: EVC A

[0160] Silicone S17: EVC B

[0161] Silicone S18: RTV1

[0162] Silicone S19: RTV2 Silicone S20: Fluorinated silicone oil (Mn=14000) (CAS 63148-56-1)

[0163] Example 1: General protocol in discontinuous mode

[0164] In a flask (10 mL), a silicone S and a metal chloride CM are introduced. A metal salt SM or a metal salt solution is added and the reaction medium is heated (temperature 40°C) for 30 minutes. The reaction medium is cooled to room temperature (approximately 25°C) and mesitylene (240 mg) is introduced (mesitylene is an internal standard to detect the amount of organochlorosilane in the desired products). A sample is taken and analyzed by NMR- 1 H and NMR- 29 If. The yields in moles of compound of formula (I) and compound of formula (II) relative to the number of moles of D and M units of silicone S respectively are determined.

[0165] Example 2: Effect of the catalyst on the process of the invention

[0166] The protocol of Example 1 is carried out with silicone S1 (300 mg, 4 mmol MesSiO unit) and BCh in 1 M dichloromethane (3 mL, 9 mmol Cl', 350 mg BCh) as the metal chloride. The metal salt (MS), temperature and reaction time are mentioned in Table 1 below.

[0167] The process according to the invention can be carried out with different metal salts while giving good yields. Example 3: Effect of the chlorine source on the process of the invention

[0168] The protocol of Example 1 is implemented with silicone S1 (300 mg, 4 mmol SiMesO unit) and GaCh as metal salt (4 mg, 0.5 mol% relative to the number of mol Si- O). The metal chloride, temperature and reaction time are mentioned in Table 2 below.

[0169] The process of the invention can be carried out with different chlorine sources while giving good yields. Example 4: Effect of silicone on the process of the invention

[0170] The protocol of Example 1 is carried out with different silicones mentioned in Table 3 below, GaCh as metal salt (0.5 mol%, 4 mg), BCh as 1 M metal chloride in toluene or dichloromethane solvent (3 mL, except for S10: 6 mL). The process is carried out at 40°C. The silicone, temperature and reaction time are mentioned in Table 3 below. The results in Table 3 show that the process of the invention is versatile and can be used on all types of silicone including silicone mixtures and silicones including fillers or even used silicones.

Claims

DEMANDS 1. Method of preparing organochlorosilane CS by reaction of at least one silicone S with a metal chloride or metalloid CM in the presence of at least one metal salt catalyst SM, the metal chloride or metalloid CM being different from the metal salt SM.

2. Method according to claim 1, wherein the metal or metalloid chloride CM is selected from metalloid chlorides, transition metal chlorides, alkaline earth metal chlorides, alone or in mixture.

3. Method according to claim 1 or 2, wherein the metal chloride or metalloid CM is selected from metal chlorides of formula M'Clz in which M' represents B, Al, Ti, Zr, Mg, Zn, Ca, Sb, Ge, Si or Cu, preferably B, Al, Ti, Zr, Mg, Ca, Zn, preferably B, Al, Mg, Zn, Ca, preferably B, Al; z represents an integer depending on the valence of the metal M', for example z represents 3, 4 or 5.

4. Method according to any one of claims 1 to 3, wherein the metal chloride or metalloid CM is preferably selected from BCh, AlCls, TiCl, ZrCl, MgCls, ZnCh, CuCh, CaCh, GeCl, SiCl, SbCl5, alone or in mixture, preferably BCh, AlCl3, MgCh, ZnCh, CaCh, more preferably AlCl3, BCl3, preferably BCl3.

5. A method according to any one of claims 1 to 4, wherein the metal salt is selected from compounds of formula MX m in which: M represents Ga, Ge, Al, In or Fe, preferably Ga, Al, or Fe, X represents Cl, Br, I, F, OTf, BF4, SbFe, m represents an integer depending on the metal M, preferably m represents 2, 3 or 4.

6. Method according to any one of claims 1 to 5, wherein the metal salt is selected from GaCh, FeCh, FeCh, InCh, AlCl3, GeCl preferably FeCh, FeCh, AlCl3, GaCl3, InCl3.

7. A method according to any one of claims 1 to 6, wherein the quantity of metallic salt SM used in the process of the invention is included between 0.01 and 10% by mole relative to the number of moles of Si-O, preferably between 0.01 and 5% by mole, for example between 0.1 and 2% by mole.

8. Method according to any one of claims 1 to 7 wherein the reaction is carried out at a temperature between 0 and 200°C, preferably between 0 and 150°C, preferably between 20 and 130°C, more preferably between 30 and 110°C.

9. Method according to any one of claims 1 to 8, wherein the molar ratio CI / Si-0 is between 1 and 3, preferably between 2 and 3, for example between 2 and 2.5, for example 2.

10. Method according to any one of claims 1 to 9, wherein the amount of metal chloride or metalloid CM used in said method is at least 50%, preferably between 50 and 800% by mole relative to the number of moles of Si-O, preferably between 50 and 300% by mole, for example between 50 and 200% by mole.

11. Process for preparing silicone, in particular silicone oils, resins or gums, comprising the following steps: 1) implementation of the method for preparing organochlorosilane according to any one of claims 1 to 10; 2) preparation of silicone, in particular silicone oils, resins or gums, from the organochlorosilanes obtained in step 1).

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